Book of AbstractsBook of AbstractsK. Petrova, Z. Prouza
National Institute of Public Health, Radiation Hygiene Centre, Czech Republic
The authors present and discuss in their paper reasons for the creation of
central registries of exposure to ionizing radiation and inform on recent
status in this field world-wide and in the Czech Republic. The
creation of the Central Registry of Occupational Radiation Exposure (CR ORE)
has been prepared in the Czech Republic since 1993 , when the detailed
analyse of status in this area in our country was done.
The actions leading to the creation of the CR ORE were opened in 1994 under the financial
participation of the Ministry of Industry and Trade. Following steps have been already done: the choose
of the company for software covering of the system, the enter into the co-operation with the Central
Service of Personal Dosimetry and dosimetric services operating in NPP and uranium industry, the
effort on a methodology unification of a dosimetric evaluation of the occupational exposure. The contact
with the International System on Occupational Exposure was also opened up in 1994 and the created
national system of ORE registration is built in the harmony with the recommendations and demands of
this international system. The paper gives more detailed information on the structure of creating
program and discuss some actual arising problems.
The preparation of the Central Registry of Medical Radiation Exposure ( CR MRE) in the CR is recently
in the stage of analyse of present status and approaches to the solution of this problem both world-wide
and in the Czech Republic. New approach to the evaluation of medical exposures that can be recently
observe in the world is taken in apart in a preparation of CR MRE in the CR. The attention is paid to
the determination of the age and sex dose distributions for individual examinations. The authors show
conclusions of UNSCEAR Report 1993 concerning to observation of medical exposures and discuss
some specific problems conducting with the evaluation of radiation burden arising from medical
exposures. The co-operation with some medical utilities , Institute of Health Information Systems of
Ministry of Health and General Health Insurance Company was done to obtain necessary data on
medical exposures in CR. The methodology of data collection and special database system for input and
transfer of data is recently created. This system allows to distribute data according to demanded
parameters. Presented are some partial results following from obtained data
as yet.
P. Ragni, R. Horn-Orni
Istituto di Chimica Nucleare del C.N.R., Area della Ricerca Monterotondo
Scato (RM), Italia
Ufficio di Sicurezza e Prevenzione del C.N.R., Via di Pietralata 190, Roma, Italia
It is foreseen the installation of a 40 MeV Scanditronix cyclotron with a PET facility in the new C.N.R.
Research Area at Tor Vergata, about 20 km far from Rome.
It will be the first medium size cyclotron for chemical and medical research in Italy and in the area of
Mediterranean Countries and it is foreseen the start of research activities open to international
cooperations and the production of PET and SPECT short-live radioisotope for medical purposes, also
in order to supply some hospitals needs.
In the present work is reported the final building project and are briefly stressed the studies carried out
to assure radiation protection requirements for the dangerous areas (shielding protections, duct holes,
doors), also taking in account the new law prescriptions that are going to
be approved.
Then are reported the main radiation protection criteria and procedures for PET and SPECT
radioisotopes production, for liquid waste disposal and for airborne
radioactivity.
N. Vana, W. Schöner, M. Fugger, Y. Akatov *
Atominstitute of the Austrian Universities, Schüttelstrasse 115, A-1020
Vienna, Austria
* Institute for Biomedical Problems (IMBP), Choroshovskoje shosse 76 A,
123 007 Moscow, Russia
For determination of the absorbed dose and the dose equivalent in complex mixed radiation fields, new
methods were developed in the frame of the Austrian-Soviet space mission AUSTROMIR in October
1991. The method utilizes the changes of peak height ratios in thermoluminescence glowcurves. Peak
height ratios depend on the linear energy transfer (LET) of absorbed radiation. This effect was calibrated
in different radiation fields (alpha-, beta-, gamma-, neutron fields and heavy charged particle beams).
The method was approached for dose measurements during several space programmes (DOSIMIR,
BION-10, PHOTON-8).
During the Russian long term flight RLF six dosemeter packets were exposed in three different periods.
Two places with different shielding (the working area and the cabin of the board engineer) were chosen
for exposition of the dosemeters during each period in order to measure the variation of absorbed dose
as well as the variation of average LET of absorbed radiation within the habitable part of space station
MIR. These results will be compared with the results during two former periods of measurements on
space station MIR (AUSTROMIR/DOSIMIR) and results obtained inside of biosatellite BION-10 and
the space shuttle mission STS-60.
Work supported by the Austrian Society for Aerospace Medicine, ASM
B. Vekic 1, S. Kovacevic 1, M. Ranogajec-Komor 1, N. Duvnjak 2, P. Marusic 2, P. Anic 3, P. Dolencic 3
1 Rudzer Boskovic Institute, Zagreb, Croatia
2 New Hospital, Zagreb, Croatia
3 University Hospital "Merkur", Zagreb, Croatia
Computed tomography (CT) has become a major source of the population exposure to diagnostic
X-rays, and the knowledge of the doses delivered by the CT equipment has become very important.
Considerable efforts should be made to keep these doses to a reasonable minimum, without sacrificing
the image quality. The conditions of exposure in CT are quite different from those in conventional
X-ray imaging. This has required the development of specific techniques for assessing patient dose
from CT. The aims of this work were to determine the doses delivered to various organs of patients
undergoing computed tomography of abdomen and thorax as measured on the surface of the body and
to estimate the risk to the patients.
Dosimetric measurements were performed at two different CT scanners (Siemens SOMATOM DR-H,
ver. HC-l and Shimadzu SCT-4500TE). The doses absorbed by different organs (gonads, chest, thyroid
and eye lens) and by the examined part of the body of 44 patients of various sex and age were measured
with TLD-700.
The doses absorbed by different organs during the diagnostic CT examination of the body depended on
the technical parameters, such as the number of scans, mAs, the thickness of scans, scanning times, tube
voltage and other characteristics, some of which depended on the type and severity of illness, Clinical
parameters, such as patient size and composition and patient cooperation with regard to control and
motion, also influence the dose and the image quality. The highest dose measured in this study (89.19
mGy) was delivered to kidney during CT examination of this organ.
S. Ramboiu
Medical Center and Health Services and Management, Cluj-Napoca, Romania
Workers in uranium nine are subjected to the risk of internal contamination
by Radon-222 and Radon-222 short-lived progeny inhalation.
The paper presents some methods to improve radioprotection of workers in "Avram Iancu" uranium
mine, on the basis of simultaneous measurements of Radon-222 and its progeny concentrations in the
underground air.
Kuznetz's and Rock's methods were used to measure Radon-222 and Radon-222 short-lived progeny
concentrations in air, respectively.
Internal contamination of workers in "Avram Iancu" uranium mine is indirectly evaluated by
multiplying the weakly measured Radon-222 concentrations in air by a constant value of the equilibrium
factor between Radon-222 and progeny, of 30%.
As a consequence of an insufficient flow rate of air, the concomitant determinations of Radon-222 and
its progeny reveal that the equilibrium factors ranged between 20% and 80% . So, the utilisation of the
equilibrium factor of 30 % had to an under evaluation of internal doses.
The method proposed in the aim to improve the estimation of the individual internal doses consist in
a monthly determinations of equilibrium factors in all working places.
The methods to improve the underground ventilations are also presented.
B. Vokal, J. Burger, T. Mohar, M. Franko and I. Kobal
Jozef Stefan Institute, Jamova 39, Ljubljana, Slovenia
One of the most important radionuclides released to the environment from nuclear power plants is
carbon-14. It is produced in light water reactors by neutron activation of oxides and by the reaction of
impurities, such as nitrogen, in the fuel, moderator and coolant. C-14 is mainly released to the
environment in stack gas. However, uncontrolled releases of C-14 can also occur during maintenance
and various repair work inside the nuclear power plant.
For this reason it was the objective of this work to monitor C-14 inside
the Krsko Nuclear Power Plant.
Air was continuously taken at several locations inside the plant by a CO2/CH4 sampler for two week
periods. CO2 was absorbed in a potassium hydroxide trap and then the hydrocarbons were converted
into CO2 by a Pd catalyst kept at 600 C and removed in a second potassium hydroxide trap. Sample
activities were measured by liquid scintillation counting (LSC) after precipitation of carbonate with
BaCl2 in the form of BaCO3.
Variations in radioactive CO2 and hydrocarbon concentrations in air at various locations in the plant will
be reported.
K. Sentija, V. Kasuba
Institute for Medical Research and Occupational Health, Ksaverska cesta 2, 41000 Zagreb, Croatia
Cytogenetic monitoring for long term exposure to low-level ionizing radiation was evaluated.
Peripheral blood samples from 21 subjects working in a department of urology were collected and
cultivated for standard chromosome aberration method. All chromosome-type aberrations i.e.
isochromatid breaks, dicentrics and rearrangements were considered and compared to control. The
medical personnel consisted of physicians, nurses and technicians professionally exposed to low-level
ionizing radiation for 17.3 years in average. Among them, a subgroup of 12 subjects performed
urological diagnostic and therapeutical ultrasound procedures for the last 7.1 years. A higher percentage
of total aberrations, and a significant increase of chromosome breaks, rings, dicentric chromosomes and
acentric fragments was observed in the exposed group compared to control. Comparing the ultrasound
subgroup with the rest of the exposed personnel, a significant increase of chromatid breaks and rings
was noted. Correlating duration of exposure to ultrasound and chromosome aberrations, a positive
correlation for chromosome breaks, acentrics and dicentrics was found. Apart from confirming ionizing
radiation as a radiomimetic agent, our results point out ultrasound as a potentially additional
contributing factor in chromosome damage.
V. Brumen, I. Prlic, Z. Radalj, D. Horvat and H. Cerovac
Institute for Medical Research and Occupational Health Zagreb, 2 Ksaverska street, POB 291, Zagreb, Croatia
The aim of this work is to present the complete results of periodical health surveillance of medical
personnel occupationally exposed to ionizing radiation sources, conducted according to established law
regulations in Croatia. The report comprises a total of 21 examinees
(11 female, 10 male), mean age
43,19 +- 9,85 years, originating from different professional groups
and working in a radiation zone l4,7 +- 8,27 years on the average. Within the framework of this study, the results of their biomonitoring,
including haematological parameters (whole blood count), ophthalmological findings (fundus oculi),
cytogenetic test (conventional structural chromosomal aberration analysis) and peripheral blood flow
survey (capillaroscopy and dermothermometry) will be presented. Filmdosimetric data for the referred
period will also be reported.
M. Bayer *, N. Muntean *, T. Fiat **, L.Daraban **
* Medical Center and Health Services and Management, Cluj, Romania
** Babes Bolyai University, Faculty of Physics, Cluj-Napoca, Romania
The paper presents the Iod-131 contamination of the atmosphere within some nuclear medicine centers
unit in Cluj-Napoca and Baia Mare towns. The air samples were collected in different workrooms e.g.
laboratories for the first dilution and administrative and measuring offices.
The used working method was based on filtering a definite air volume through an active coal filter who
is impregnated with AgNO3 solution. The I-131 retained was measured with the well-type NaI(Tl)
crystal scintillation counter connected to an impulse meter with an efficiency to 20 % to 40 % the
efficiency of filtration was 90 % and the minimum detectable activity
was 1.11 Bq/m.c.
In 1991 the filtering cartridge was replaced by a SLF-2I-50 special
filter for radio iodine.
The registered values ranging between 1.11 Bq/m.c. and 29.63 Bq/m.c. are situated below the
admissible levels of the occupational exposure norms.
Accordingly, the studied nuclear medicine centers do present safe work
conditions.
C. Fulea, S. Ramboiu
Medical Center and Health Services and Management, Cluj-Napoca, Romania
The protection of reproductive organs in children during the pelvis radiography doses exert a direct
effect in reducing the possible associated genetic risk. The heavy exposure of children undergoing pelvis
X-ray examination require a practical method for diminishing the irradiation at the level off the gonad
area because at least 1% of the cases with ship dysplasia cannot be clinically diagnosed within the first
months of life.
Our paper presents the design a hip mask for children (0-1 years) gonad protection during the pelvis
radiography.
The doses absorbed by the radiosensitive organs were evaluated by the Monte Carlo calculation
technique on the bases of the measurements effectuated by LIF thermoluminescent dosimeters in a
group of 60 children.
Out of the total number of the basin radiography 86.4 % has been yearly applied in children within the
first year of life to detect the hip congenital dysplasia.
M. Neznal, M. Neznal, J. Smarda
RADON v.o.s. corporation, Za koncem 1380, 289 22 Lysa nad Labem, Czech Republic
The uniform method for radon risk classification of foundation soils used in the Czech Republic is based
on the soil-gas radon concentration measurement and on the determination of soil permeability. The first
proposal was given in 1990. Three categories of risk were defined - low, medium and high risk of radon
infiltration from the ground. A four years experience has resulted in some modifications of the origin
classification method. The modifications were recommended in 1994. RADON v.o.s. corporation
participated in solving several research projects that concerned further
improvement of the method.
As for practical applicability of radon survey results, it seems useful to define a single parameter (radon
availability) for characterizing the radon potential of soils. Different ways how to define this parameter
will be presented and discussed.
X. Myteberi 1, P. DeFelice 2
1 Institute Of Nuclear Physics, Tirana, Albania
2 National Institute Of Radiation Metrology, ENEA,CRE Casaccia, Rome, Italy
One important requirement for accurate monitoring of Radon in working environment and/or dwellings
is to ensure the necessary reliability and traceability.
A Rn-222 Reference Measurement System recently developed in the same way at ENEA and INP is
presented. It is based on a Radon transfer counting system calibrated by some Ra-226 standard liquid
solution traceable to the international system. Reference counting instruments are cylindrical
electrostatic cells equipped with Si detectors. It is used for the detection of the electrostatically collected
Po-118 and Po-214 ions produced in the decay of Rn-222. The activity of Rn-222 gas in a spherical
glass bulb can be measured by the Reference System, by a particular procedure that does not requires
the calculation of any volume ratio of any assumption of total radon removal from the liquid Ra-226
solution. The overall uncertainty estimated for the calibration of Rn-222 sources is about 1% at the 68%
confidence level.
The measurement systems and operational procedures adopted for Radon metrology are described. The
paper also reports the participation of ENEA in the 2nd EUROMET intercomparison of the Rn-222
measurement systems of a number of European labs, and the efforts performed to stabilize the
traceability of INP to ENEA.
The possibilities of calibration for some passive detectors by the above
system are discussed.
References:
J. Fietz
Research Center Rossendorf (FZR), Germany
Uranium ore mining and processing leads to the release of natural radionuclides into the biosphere and
so enhances their natural concentrations in the near-site environment. Radionuclides of the uranium
progeny are concentrated mainly in the processing residues (tailings), but also in lean ore and rock heap
dumps, in deep and in surface waters and in the atmosphere. The additional exposure of the residents
to these pollutants has to be restricted by an ecologically orientated production as well as by thorough
remediation after closing-down of the site.
According to the classification of the ICRP, site contamination by natural radionuclides represents a
"pre-existing" situation, that can only be influenced by intervention. The dose limits do not apply in
this case and are replaced by recommended levels, which depend on the specific situation. Concerning
the remediation of uranium production sites, an effective dose equivalent of 1 mSv/a above the natural
level has been introduced as a primary criterion in most countries. From this criterion secondary
quantities are derived for activity concentrations in different environmental media and for radon
exhalation rates.
In the former Eastern Bloc countries about 700 000 t uranium were produced from 1945 - 1993. This
production mainly followed military-industrial demands, ecological aspects were largely subordinated
to it. Therefore, site remediation for many of the recently closed-down installations will prove a very
expensive process both under technical and financial aspects.
Following a review of uranium production in Eastern Europe and in the Asian CIS-countries, the
radiological situation for selected sites is analyzed, and basic demands for remediation programs are
discussed.
R. Ilic, M. Krizman, J. Skvarc, Z. Jeran
Jozef Stefan Institute, Jamova 39, Ljubljana, Slovenia
In the period December 1993 - February 1994 long term concentrations of indoor radon were measured
in 892 randomly selected dwellings in Slovenia with a passive radon dosemeter, utilizing CR-39 etched
track detector. The latent track images were transformed to visible tracks by the electrochemical etching
technique; the numbers of tracks were evaluated by the TRACOS automatic
image analysis system.
The measured data cover the whole territory of Slovenia quite uniformly. Compared to the total number
of buildings (463.000 houses), approximately every 500th house was examined. Results were
statistically evaluated and modified for seasonal corrections. Maps of indoor radon concentrations in
Slovenia were constructed in different formats, including those of grid squares (5 km x 5 km, 10 km x
10 km) and one with concentration isolines. Average annual concentrations in all communities were also
determined and are presented on a separate map. The approximate median annual average concentration
was found to be 54 Bq/m3, the arithmetic mean concentration was 87 Bq/m3, and the geometric mean
59 Bq/m3.
The main conclusions derived from this work are the following:
Based on the methodology of dose assessment following ICRP 50 recommendations, the average annual
effective dose equivalent due to inhalation of indoor radon was estimated. The value obtained of 2 mSv
per year is nearly the same as found in neighbouring countries.
The intervention level for indoor radon, based on a statistical analysis of the results of indoor radon
concentrations and the criterion for high radon areas according to ICRP 65 recommendations, was
derived. Remedial action should be taken when radon levels exceed the recommended action level of
400 Bq/m3; for new dwellings radon in future should not be greater than
200 Bq/m3.
As a result of this work Slovenia may be categorized in the group of countries with a well defined status
of natural radioactivity: there will no longer be a blank area on the
radiological map of Europe.
P. DeFelice, Xh. Myteberi *
Instituto Nazionale di Metrologia delle Radiazioni Ionizzati, ENEA Dip. Ambiente, Centro Ricerche
CASSACIA, Roma, Italy
* Institute of Nuclear Physics, Tirana, Albania
A 222Rn Transfer Measurement System was recently developed at ENEA, the Italian Primary Standard
Institute for Ionising Radiation Quantities. This system is based on a NaI(Tl) well type detector calibrated
by a set of standard radon gas sources in glass bulbs traceable to the ENEA 222Rn Reference Measurement
System. The Transfer Measurement System has been characterized in terms of several additional
parameters such as the operating range, the linearity and reproducibility of the system response, the
short-term and long-term stability. The Transfer Measurement System is now
used, at ENEA, for the non-destructively calibration of 222Rn gas sources in
glass bulbs, with a combined uncertainty of about 1%
(1 sigma).These sources are then used for production of standard radon atmospheres in the two ENEA radon
chambers. The paper describes the Transfer Measurement System, the procedure adopted for its calibration
and the results of other characterization tests. The paper also reports the participation of ENEA in a
EUROMET intercomparison of the 222Rn measurement systems of a number of European laboratories
carried out in 1994. A short outline is finally given of the other calibration facilities developed at ENEA
for radon metrology.
T. Peic, G. Dinca, I. C. Dutu, R. Peic, G. N. Sandor
Research and Design Institute for Rare and Radioactive Metals-Research Laboratory for Radiation Protection, Working Conditions and Ecology- Petru Groza Town, Romania
The polluting potential with radium 226 of formation waters from oil and natural gas fields was reported
in 1983 by the Research Laboratory for Radiological protection from Petru Groza-Bihor. From 574
samples of formation waters arising from wells from different parts of country, 318 (55%) had a radium
226 content exceeding the MPC for drinking water, ranging from 0.16 Bq/L to 60.74 Bq/L. The fact
that these waters are not injected in all situation, being discharged into watercourses or on agricultural
lands, imposed further investigations. So, 40 oil treating stations and 8 natural gas ones were
investigated. The results confirmed the pollution by radium of certain watercourses as well as of soil
and vegetation. The radioactive crusts from tubing or other devices can contribute to the internal
contamination of the workers.
The presence of over 15.000 wells and of over 50.000 hectares polluted by oil products underlines the
necessity of approaching the problems related to polluting formation waters due to their high radium
226 content.
G. Marx, E. Toth
Dept. of Atomic Physics, Eötv&oul;s University, Budapest, Hungary Lauder School, Budapest, Hungary
In 1992 an enhanced radon exhalation was discovered in the bedrooms of the village of Mtraderecske,
reaching several thousand Bq/m3 in some living houses in yearly average. The mean radon activity
concentration of the village is above 200 Bq/m3 in yearly average. The phenomenon is surprising
because the rock is not especially rich in uranium. The radon exhalation is highly variable in time (year
by year) and in space (within a few meters). The interest of the population made the survey practically
in each house necessary in four seasons. The people have been informed and positive examples of radon
migration have been realized. The origin of the radon has complex geophysical-geochemical reasons,
that was studied by observing changes in time (in correlation with seismic activity and precipitation),
by measuring radon in soil, rock, and well water. In this way a model for the origin of radon can be built
up. The survey has been made able by the responsible unselfish cooperation of the teachers of the
Lauder School and the school in Matraderecske, together with their students. it helped to increase the
level of nuclear literacy among people. The survey has been supported by the
OMFB and by the OTKA-T7603 project for buying instruments and detectors.
T. Heistracher 1, W. Hofmann 1 and I. Balashazy 1,2
1 Institute of Physics and Biophysics, University of Salzburg, Austria
2 KFKI Atomic Energy Research Institute, Budapest, Hungary
The local distribution of radon decay products deposited within bronchial bifurcations, particularly the
formation of hot spots, may be more relevant for the determination of cellular doses in bronchial tissue
than the commonly computed deposition efficiency, which is conceptually equivalent to the assumption
of a uniform nuclide distribution.
Particle deposition patterns within three-dimensional models of asymmetric bronchial airway
bifurcations are simulated by a numerical fluid dynamics and particle trajectory model: (I) Airflow is
computed by solving the Navier-Stokes equations with a finite volume method, (ii) trajectories of
particles entrained in the airstream are simulated by Monte Carlo techniques, and, (iii) particle
deposition patterns are determined by the intersection of the particle trajectories with the surrounding
surfaces.
Inspiratory deposition patterns of 1 nm (unattached fraction) and 0.2
um (attached fraction) particles
illustrate the formation of enhanced deposition sites at the carinal ridge, which is consistent with the
action of strong local secondary flows. Such highly localized accumulations of radon decay products
may produce high local cellular doses, which may significantly exceed dose estimates based on uniform
nuclide distributions.
A. Mohamed 1, W. Hofmann 1 and I. Balashazy 1,2
1 Institute of Physics and Biophysics, University of Salzburg, Austria
2 KFKI Atomic Energy Research Institute, Budapest, Hungary
Inhaled radon progeny are deposited in different regions of the human bronchial tree as functions of
particle size and flow rate. This initial deposition pattern is subsequently modified by radioactive decay,
mucociliary clearance and transport through epithelial tissue into blood. Thus, sensitive bronchial basal
and secretory cells are irradiated by two different alpha particle sources: (I) radon progeny in the sol
and/or gel phase of the mucus layer, and (ii) radon progeny within the
bronchial epithelium.
An analytical method has been used to compute the local energy deposition of Po-218 and Po-214 alpha
particles in 1 m spheres located at different depths in bronchial epithelium. In order to reach the target,
alpha particles travel either through tissue alone ( near wall" dose) or through air and tissue ( far wall"
dose). While the depth-dose distributions for nuclides uniformly distributed within the epithelium are
practically constant with depth, they decrease in an almost linear fashion with increasing depth for
nuclides on the airway surface.
Histological studies have shown that the locations and relative frequencies of basal and secretory cell
nuclei vary within a given bronchial airway generation and among different airway generations. Thus,
different assumptions about cell-specific depths and their frequency distributions appreciably affect the
related dose estimates.
E. Kunz, L. Tomasek 1, V. Placek 1, T. Müller 2
1 National Institute of Public Health, Prague, Czech Republic
2 Institute of Occupational Hygiene in Uranium Industry, Kamenna,
Czech Republic
Long term exposure to radon and its progeny is one of the most important health problems.
Epidemiological studies have demonstrated that exposure of miners to radon in a mine
atmosphere can cause lung cancer.
The presentation issues from data of the oldest Czechoslovak cohort study (N=4320), which belongs
among the largest ones with the longest follow-up. By the end of 1990, a total of 700 lung cancers
were observed. Individual exposures have been revised, particularly the recent working history of the
miners.
The most recent analysis has shown that (similarly as in other cohorts of radon exposed miners) the
excess relative risk of lung cancer per unit exposure is modified by time since exposure and
exposure rate.
In addition in revising the data it has been found that the exposure revision had a great impact on the
risk coefficient. This is also the main reason why the ERR/WLM coefficients reported during
1993-4 for this study were different. Observed findings are being verified from the point of
view of histological types, which is available for about 67% of cases.
G. N. Sandor, G. Dinca, T. Peic
Research and Design Institute for Rare and Radioactive Metals-Research Laboratory for Radiation Protection, Working Conditions and Ecology- Petru Groza Town, Romania
Between 1970-1993 were investigated 285 mining and exploration non-uranium units, at
114(40%)being exceeded the maximum permissible equilibrium equivalent concentration(MPC)of
radon 222 for public (111Bq/m3) and at 15 (5,3%) the MPC for occupational exposure (1110Bq/m3),
so being necessary the recommendation of limiting measures.
The causes of appearance and accumulation of radon have been clarified,the main source being the
presence of natural radioactive elements in barren rocks and minerals and the cause of accumulation the
inefficiency of ventilation.
The rock, mineral and water samples were analysed for their natural uranium and thorium and radium
226 content. On a PC were worked out the data regarding 2327 mineral samples, 5924 barren rock, 475
water ones, 3898 gamma dose rate measurements, and radon and radon daughters measurements from
3023 underground workplaces.
The mean individual annual effective doses for each type of useful mineral were assessed, these ranging
from 0,77 mSv/year (salt mines) to 60,21 mSv/year (barytine mines).
S. Oberstedt, H. Vanmarcke
Studiecentrum voor Kernenergie SCK.CEN, Boeretang 200, B - 2400 Mol, Belgium
Since some decades it is known, that most of the radiation dose to the lung is due to the inhalation of
the short-lived decay products of 222Rn. Their deposition in the respiratory tract strongly depends on
the attachment rate to aerosol-particles present in the indoor air and their plate-out rate to the surfaces.
Instead of measuring the activity size distribution of the airborne decay products, knowledge on the
respiratory tract retention has been incorporated in the design of a measurement system, called
bronchial dosemeter, to assess the lung dose directly. The simulation of the deposition characteristics
of the short-lived radon daughters in the nasal cavity and the bronchial tree is based on the comparison
of the model of the respiratory tract with results from screen penetration theory. A bronchial dosemeter
consisting of three sampling heads has been built and calibrated. Additionally, an outline of future
activities will be given.
T.Vaida 1, V.Pacurar 1, Fl.Maghiar 1, C.Cosma 2, D.Ristoiu 2, S. Ramboiu 2, A.Poffijn 3
1 Faculty of Medicine and Oncologic Centre Oradea, Romania
2 Faculty of Physics and Hygienic and Health Institute, Cluj-Napoca,
Romania
3 Radon Research Group, University of Gent, Belgium
The best estimation of risk to which everyone is exposed from natural radon in buildings is now
obtained by extrapolation from observation of men exposed to radon in mines. In the last years there
are also some epidemiological studies which try to find out a direct connection between the lung cancer
risk and the indoor radon concentration in buildings.
Our study follows the estimation of the rate of the primary broncho-pulmonary cancer in a period of two
years (1993-1994) at the population in the Bihor district exposed probably at the increasing
concentration of radon, heaving age between 15-80 years.
In these two years there are founded 471 cases of primary broncho-pulmonary cancer: 398 men (84.4%)
and 73 women (15.6%). In 1993 were diagnosticated 234 new cases (190 men and 44 women) and in
1994 were founded 237 cases (208 men and 29 women).
For the epidemiological study were selected those ill persons who had the age between 40-75 years, in
the moment of study's and those who leaved or leave more than 25 years in the
Bihor district.
I. Csige 1, I. Hunyadi 1, G. Geczy 2, J. Hakl 1
We have estimated radon exposures from inhaled radon and its decay products (according to the
proposals of the ICRP 65) for participants in speleotherapy in different Hungarian karstic caves. We
have found, that about 5-10% of patients receive more than 5 mSv of effective dose equivalent during
their cures, which value is a suggested annual limit of exposure of general population from natural
background. Therefore, we propose to evaluate and show the radon doses of the patients in their
medical records in the future. We have also estimated the annual effective dose equivalent from radon
and its decay products for the staff members of speleotherapeutic treatments and found that it is
probably in the range between 15 and 40 mSv/year. We suggest continuous monitoring of their doses
(preferably with personal radon dose meters) making possible to prevent them from receiving higher
doses than reasonably acceptable.
G. Marovic, J. Sencar
Institute for Medical Research and Occupational Health, Zagreb
Department of Radiation Protection, HR-41001 Zagreb, Ksaverska cesta 2,
P.O.Box 291, Croatia
The presence of 226Ra in drinking water may directly affect human health, due to its exceptional
radiotoxicity. The paper describes the study of 226Ra content in drinking water of Croatia: tap water
from the public supply system of several towns in Croatia and bottled mineral water from two mineral
water springs. In the samples of tap and mineral water collected over several years 226Ra was
determined by alpha-spectrometric measurement after radiochemical separation.
R. Burkhardt, N. Muntean, I. Mocsy
Medical Center and Health Services and Management, Cluj-Napoca, Romania
The biological effects made by the natural irradiation are difficult to define because of the
environmental factors acting upon the people. Radon is a natural radionuclide with a wide spread in the
environment and it has an important role among the cancer risk factors. It enters the body by the
ingestion of drinking water, food and by the inhalation of the air. The radon from the air comes from
the water and it is soluble in the fluids and the grease of the body so it is a potential risk factor for the
people.
A.A. Cigna
Societa Speleologica-Italiana, Fraz. Tuffo, I-14123 Cocconato, Asti, Italy
The problem of radon has drawn the attention of many scientists all over the world particularly in the
last decade. Obviously the main object of the researches carried out on this argument was the
evaluation of the indoor radon concentration because this is, in general, the most relevant source of
irradiation from radon for the population. Nevertheless also the caves were considered because the
radon concentration in caves may rich sometimes values rather high.
R. Winkler, W. Hofmann and R. Rolle
Institut für Physik und Biophysik, Universität Salzburg, Austria
The radiation doses delivered to the bronchial epithelium upon inhalation of radon and its short-lived
decay products are caused primarily by the alpha-emitting radon daughters Po-218 and Po-214. Thus
the reliability of any dose estimate for risk assessment purposes depends on the accuracy with which
these concentrations can be determined in ambient air.
I. Balashazy 1,2 , W. Hofmann 1 and T. Heistracher 1
1 Institute of Physics and Biophysics, University of Salzburg, Austria The validity of extrapolating rat inhalation data to human conditions depends on the similarities and
differences of their nuclide deposition patterns. Statistical analyses of human and rat tracheobronchial
morphometry data have revealed distinct asymmetric features of their airway branching patterns,
particularly for the monopodial branching structure of the rat lung. Our predictions of particle deposition
patterns within asymmetric bronchial bifurcations in human and rat lungs are based on a numerical
model for the calculation of airflow and particle trajectories in three-dimensional asymmetric bifurcation
models: (I) the Navier-Stokes equations for the air velocity field are solved by a finite difference
method, and (ii) trajectories of aerosol particles entrained in the airstream are simulated by Monte Carlo
techniques.
M. Andjelov 1, J. Cloute-Cazalaa 2, M. Janot 2, P. Jovanovic 3,
I. Kobal 4, J.f. Pineau 2, P. Zettwoog 5
1 Institute of Geology, Geotechnology and Geophysics, 61000 Ljubljana,
Dimiceva 14, Slovenia The method is based on differential gamma spectroscopy with a collimated
GeHP gamma detector.
N. Lokobauer, Z. Franic, J. Sencar, G. Marovic
Institute for Medical Research and Occupational Health, Zagreb,
Department of Radiation Protection The paper deals with the investigation of indoor radon activity concentrations in the following spas in
the Republic of Croatia: Bizovacke Toplice, Stubicke Toplice, Tuheljske
Toplice, Krapinske Toplice, Varazdinske Toplice and Istarske Toplice.
V. Cuculeanu and A. Lupu
National Institute of Meteorology and Hydrology, Bucharest, Romania
Assuming steady-state diffusion equation within both vegetation and open atmosphere, the radon/thoron
and daughter profiles were deduced using the Green's function method. This analytical approach has
the advantage of providing a unique solution for the diffusion equation, thus eliminating the errors
introduced by the usual numerical methods.
M. Korun, R. Martincic, B. Pucelj, M. Ravnik
Jozef Stefan Institute, Jamova 39, Ljubljana, Slovenia
The fluxes of thermal and fast neutrons were measured by a high-resolution -ray spectrometer. Capture
-rays from absorption of neutrons in boron were detected. For the measurement of the flux density of
thermal neutrons the sensitive volume of the detector was surrounded by a thin converter (~ 0.2 g cm-2)
of boric acid. Fast neutrons were slowed down and absorbed by a thick converter (~ 3 g cm-2) of borated
paraffin. The measured flux density of thermal neutrons 1.7 +- 0.8 10-3 cm-2 s-1 agrees well with the
published values [1,2], whereas the flux density of fast neutrons 16 +- 3 cm-2 s-1 agrees with the data
from [2] and exceeds the value from [3] for a factor of two.
A. Varhegyi, I. Barany, I. Vados
Mecsekuran Ore Mining Ltd., H-7614 Pecs, P.O.B. 65., Hungary
The uranium mining activity has been started in 1956. in Hungary (in Mecsek mountains, Southern part
of the country). Since that time, about 20 million m3 rock has been removed, enormous tailings hills
and tailings ponds has been produced and the depth of mining exceeded 1000 m. The mining and
milling has a significant impact both on the natural and the human environment. To study and manage
that impact, a monitoring system has been established and continuously developed on the influenced
area.
D. Ristoiu 1, C.Cosma 1, T. Ristoiu 2
1 University Babes-Bolyai, Cluj-Napoca, Romania Radon is produced in soil by Radium decay, being an Uranium daughter. Radon mitigation from soil
to atmospheric air is due to pressure, concentration and temperature gradients existing between soil and
air.
E. Toth
Lauder School, Budapest, Hungary
In the year 1994/95 over 3000 country houses were measured in Hungary (ground floor, bedroom,
pillow level, several seasons) with the help of CR39 track detectors. The distribution shows a lognormal
character with high confidence level, indicating several factors influencing the radon concentration
indoor. In this way regions with enhanced radon activity concentration could be found. The overall
number of houses above international action limits (above 400 Bq/m3, or above 800 Bq/m3 respectively)
can be estimated. The survey has been made able by the responsible cooperation of physics teachers and
their students countrywide. It has been supported by the OMFB and by the OTKA-T7603 project for
buying instruments and detectors.
A. Vasarhelyi, I. Csige, J. Hakl, I. Hunyadi
Institute of Nuclear Research of the Hungarian Academy of Sciences, H-4001
Debrecen, POB 51, Hungary
We have studied the effect of atmospheric pressure variation on radon entry rate into houses by
measuring the radon activity concentration and the air pressure as a function of time in two dwellings.
The houses were studied under normal living conditions. From the measured time series, we have
selected time intervals, in which the doors and windows of the houses were kept closed continuously.
For each of these periods we analyzed the build up of the radon activity concentration, and determined
the radon production rate [Bqm-3s-1], and the natural ventilation rate [h-1] of the room. For both houses
we assumed that the main source of radon is the underlying soil. According to this, we have estimated
the average exhalation rates by dividing the radon production rate by the
surface of the floors.
M. Caresana, V. Cattaneo
Dipartimento di Ingegneria Nucleare, Politecnico di Milano, Milano, Italy
The purpose of this work is to illustrate the calibration of an ionization chamber to be used for
calibrating dosimeters based on the cellulose nitrate film LR115, produced
by Kodak.
R. Bodnar, Z. Lendvai, C. Nemeth, J. Somlai
University of Veszprem, Dept. of Physics, Veszprem, Hungary
The natural radioactivity 238U and its daughter elements in rocks - as in coal resources too - of the
Transdanubian region can reach ten to twentyfold of the world average.
G. Dinca, T. Peic
Research and Design Institute for Rare and Radioactive Metals-Research Laboratory for Radiation Protection,
Working Conditions and Ecology- Petru Groza Town, Romania
Natural uranium, radium 226 and radon 222 content of thermal waters springing from 67 wells from
Satu Mare, Bihor, Arad and Tim districts and the radiological impact of these due to utilization were
investigated, over 1700 radiochemical and radiometric measurement being performed. The mean
contents are comparable to those of ground waters, varying only with respect to the area: natural
uranium from 0.003 to 0.013 mg/L, radium from 0.02 to 0.10 Bq/L, and
radon 222 to 9.5 Bq/L.
I. Mocsy, N. Muntean
Medical Center and Health Services and Management, Cluj-Napoca, Romania
We studied Rn-222 concentration from indoor air in two types of dwellings: block of flat district
(concrete made) and a detached-houses zone (red brick made). These dwellings are different by the
building materials, by the type of heating, by their level from
the soil and by the surface of the rooms.
G. Salvadori 1, S.P. Ratti 1, G. Belli 1, I. Kobal 2, J. Vaupotic 2
1 University of Pavia, Department of Nuclear and Theoretical Physics,
Via A. Bassi, 6 - 27100 Pavia, Italy In this paper we show an original application of the theory of fractals and stochastic multifractals to the
analysis of the spatial distribution of 222Rn "indoor" in Slovenia. The data consist of about 1300
measurements collected in schools, in buildings made of wood or concrete.
J. Rode #, J. Vaupotic *, K. Draslar v, I. Kobal *
# Institute of Biology, Ljubljana, Slovenia In two preliminary experiments, laboratory rats were exposed in a small chamber (0,25 m3) to radon-rich
air. In both experiments the exposure was about 0.9 WLM. In the first run two rats were exposed for
14 days and in second one three rats for 6 days. In the throat and trachea of the rats the effects of radon
decay products were followed by scanning electron microscopy.
J. Vaupotic, I. Kobal
Jozef Stefan Institute, Jamova 39, 61111 Ljubljana, POB 100, Slovenia
In the radon survey programme in kindergartens in Slovenia, instantaneous indoor air radon
concentrations were obtained under closed conditions in all 730 such buildings using alpha scintillations
cells. At each place one room was selected for inspection. In all these rooms the gamma dose rate was
also recorded with a portable scintillation instrument. In 50 places in the city of Ljubljana with radon
concentrations more than 200 Bqm3, track etch detectors and thermoluminescent dosimeters were
exposed for three months in winter time in order to obtain average indoor radon concentrations and
gamma dose rates, respectively. An average ratio of the average concentrations versus instantaneous
ones was obtained, even though this ratio differed substantially from place to place. On the basis of this
ratio, radiation doses due to radon and its progeny were estimated for children and personnel in all the
kindergartens. Gamma doses were also evaluated.
B. Michalik, S. Chalupnik, J. Skowronek, J. Lebecka
Central Mining Institute, Katowice, Poland
In Polish coal mines there are some waste materials of high radioactivity. Enhanced natural radioactivity
of these wastes is caused by saline waters which often contain radium isotopes and barium ions. From
such waters radium and barium are coprecipitated out by sulphates in underground workings or on the
surface. Radioactive deposits sometimes cause radiation hazard for underground crews, serious technical
problem in exploitation of pumps and pipelines and radioactive contamination on the surface, mainly
in the vicinity of settlement ponds and alongside the river banks. Deposit of RaSO4 + BaSO4, in which
concentration of 226Ra may reach even 400000 Bq/kg, sometimes are a source of radiation hazard for
mining crews. Elevated radiation doses may be obtained mainly during cleaning of gritters, settlement
tanks and storage of radioactive deposits.
A. Mielnikow, B. Michalik, S. Chalupnik, J. Lebecka
Central Mining Institute, Katowice, Poland
On basis of guidelines for development of QUALITY SYSTEM for a testing laboratory (European
Norm Series EN 45000) a quality assurance system was implemented in gamma spectroscopy
laboratory, where routine measurements of natural (mainly Ra-226, Ra-228, Ra-224, K-40) and artificial
(mainly Cs-137 and Cs-134) isotopes are performed. We measure a variety of samples, but mainly coals,
rocks, ashes, deposits, vegetation and air filters.
N. Vana and P. Hofmann
Atomic Institute of the Austrian Universities, Schüttelstrae 115,
A-1020 Wien, Austria
The equipment for nuclear track evaluation consists of a microscope, a video camera and a PC. With
the software of the video-digitizer track dimensions and their mean grey value can be measured on the
monitor with a resolution about 0.27 um.
A. Kovac, B. Breznik
Nuklearna Elektrarna Krsko, 68270 Krsko, Slovenia
Krsko Nuclear Power Plant Ecological Information System (EIS) was developed for two main functions.
F. Campi, C. Mascherpa, S. Terrani
Nuclear Engineering Dept., Polytechnic of Milan, Italy
For civilian purposes Tritium is presently used in quantities of tens of PBq (MCi) in laboratories for the
studies of technology involving Tritium, at the JET plant as fuel for the process of nuclear fusion and
in the manufacture of radio-luminescent items.
L. Conte, G. Pedroli *, M. Monciardini, R. Novario, A. Beretta
Servizio di Fisica Sanitaria dell'Ospedale di Circolo di Varese, Italy Radioactive waste is an inevitable result of the use of unsealed radionuclides in Nuclear Medicine.
There are three types of waste: liquid, solid and gaseous. Solid waste usually consist of used generators,
contaminate glassware, syringes, cleaning material, bench cover and so on. Material which cannot be
disposed of immediately shall be stored for decay level which permit disposal with ordinary refuse.
Solid waste, such as contaminated paper, glassware, swabs and similar material may be immediately
disposed of with an appropriate volume of ordinary refuse.
G. Salvadori, S.P. Ratti, G. Belli, E. Quinto
Universita degli Studi di Pavia, Dipartimento di Fisica Nucleare a Teorica,
Via A. Bassi 6, I-27100 Pavia, Italy
This work deals with the 137Cs cumulative soil deposition in several European Countries. The
measurements, collected after the Chernobyl nuclear accident, come from the REM data bank and
amount to a few hundred samples. We study both the geographical and the statistical distribution of the
measurements, showing the existence of an (asymptotic) hyperbolic behaviour as well as the presence
of multifractal features. Based on such analyses, we introduce a multifractial model to describe the
overall distribution of the radioactive pollutant, even in sites where no data are available. Our working
hypothesis is that the fallout is strongly influenced by complex meteorological factors, which are known
to feature fractal properties.
Z. Prouza
Centre of Radiation Hygiene NIPH, Prague, Czech Republic
The principles of emergency planning in the Czech Republic are based on the same philosophy as the
ICRP Publication 40 and the IAEA Safety Series No. 55 and 72, and include already the post Chernobyl
experiences. The Czech Republic legislation, in connection with political and economical changes in
the country, experiences an extensive reconstruction and proposals of the Law on "Peaceful Use of
Nuclear Energy and Ionizing Radiation" ("Atomic Act") and Act on "Prevention and Liquidation
Industrial Accidents and Natural Catastrophes" already being elaborated. These Acts and related laws
should solve our legislative problems on field of emergency planning and preparedness. The structure,
philosophy and principles of the proposal of the "Atomic Act" will be built on new International Basic
Safety Standards.
I. Winkelmann, H. Buchröder, M. Thomas
Bundesamt für Strahlenschutz, Waldowallee117, 10318 Berlin, Germany
Nuclide specific aerial measurements of surface soil contamination were performed after the Chernobyl
reactor accident in the southern part of Germany. For these measurements, a helicopter equipped with
a gamma ray spectrometer system including a HPGe detector (50 % relative efficiency) and 3
NaI(Tl)-detectors (volume 12 l) was used. The paper describes the complete measuring system in detail
which can be used for nuclide specific measurements of soil contamination as well as for the detection
of sources of gamma radioactivity. At an altitude of 100 m, a soil contamination of several kBq/m2 for
134Cs and 137Cs can be measured with a HPGe-detector by a measuring time of 60 s (helicopter speed
100 km/h). For the detection of gamma rays emitting point sources, the 12 l NaI(Tl)-detector is used.
Assuming line spacing of 300 m and a speed of 100 km/h, an area of about 30 km2 can be surveyed per
hour. Thus 60Co-sources of some GBq activity can be detected. The system was practically applied the
first time by measuring the deposition of artificial radionuclides in the southern part of Germany after
the Chernobyl reactor accident. The aerial measuring system was also tested in the former USSR, in a
region north of Chernobyl, with nuclide deposition values of up to 2MBq/m2. The results of aerial
measurements in selected areas are presented.
G. Graziani
Environment Institute, JRC Ispra, 21020 Ispra, Italy
This paper presents some of the recent improvements introduced in the regulatory dispersion models.
In particular, the classical Pasquil-Goffered parameterization of atmospheric turbulence is abandoned,
as it has been warmly suggested by the scientific community during the three Workshops on this
argument that were held over the last two years in Europe (Risoe, Denmark, May 1992; Manno,
Switzerland, August 1993; Mol, Belgium, November 1994). The alternative is the use of similarity
theory with the definition of physical quantities, such as the Monin Obukhov length and the friction
velocity, that vary with continuity. These quantities can be determined from a few meteorological
measurements that are usually available at the foreseeable release sites of conventional pollutants. The
dependence from these quantities of the turbulent parameters, like dispersion coefficients and mixing
layer depth is also reported.
M. Nösterer 1 , W. Hofmann 1 and S.G. Andreev 2
1 Institute of Physcis and Biophysics, University of Salzburg, Austria Between 1930 and 1950, an estimated 10,000 to 20,000 patients received Thorostrast injections in
Germany. About 59% of the intravascularly injected Thorotrast was retained by the liver. Based on a
mean injected volume of 25 ml and an average exposure time of about 40 years, Thorotrast patients
received a mean liver dose of about 9 Gy. As a consequence, 35% of German Thorotrast patients died
of liver tumors; in contrast, no case of primary liver tumors was
observed in the control group.
D. Nikodemova, M. Vladar, I. Gomola
Institute of Preventive and Clinical Medicine, Bratislava, Slovakia
The aim of the work was to determine the average effective dose to the Slovak population from
external radiation and radon daughter inhalation. This estimation has been done by experimental
procedures.
P. Szerbin and E. Koblinger-Bokori
"Frederic Joliot-Curie" National Research Institute for Radiobiology and Radiohygiene,
POB 101, Budapest, 1775, Hungary
110mAg contamination of the environment may occur as a result of atmospheric release during normal
operation of nuclear power plants (NPP). There is some data, according which the 110mAg release of
NPPs, equipped with soviet-type WWER reactors, such as the NPP Paks, Hungary, increase in the early
periods of operation. Besides, considerable amount of 110mAg was released to the atmosphere during
the Chernobyl reactor accident.
S. Salagean, C. Fulea, I. Mocsy, I. Uray, N. Muntean
Medical Center and Health Services and Management, Cluj-Napoca, Romania
During the period between 1987-1991 there were prelevated water, seston and sediment samples from
two dam lakes - Gilau (Cluj county) and Virsolt (Salaj county) and from the river Somes - representing
the drinking water sources of the riverside population.
M. Stepisnik, O. Jarh, I. Mele
Agency for Radwaste Management, Hajdrihova 2, Ljubljana, Slovenia
Radioactive waste in Slovenia comes not only from nuclear power plant
Krsko but also from industry,
hospitals and research. These wastes can potentially present risks to health and environment if they are
not managed adequately. The Agency for Radwaste Management is responsible for providing the final
disposal of radioactive wastes in Republic of Slovenia. Since most of the waste is categorized as low
and intermediate level - short lived waste (according to IAEA classification) the work is oriented
towards the construction of LILW repository. It must guarantee complete isolation of radionuclides for
a period of 300 years. By this time the activity of radionuclides will decay to a level comparable to
natural radioactivity of environment.
C. Schmitzer
Austrian Research Centre Seibersdorf, Austria
Jointly initiated by NATO Partnership for Peace and UN Department for Humanitarian Affairs, the
EXERCISE '95 took place on the Kola peninsula near Murmansk, Russia. Organised by the Russian
ministry for disaster management, the trigger incident was supposed to be an explosion in a nuclear
power plant, similar to the Chernobyl incident.
H. Rabitsch *, E. Pichl *, J. Pletz **, G. Kahr *
* Abteilung für Strahlenphysik, Institut für Theoretische Physik,
Technische Universität Graz, Petersgasse 16, A-8010 Graz, Austria In comparison to single exposures it is of particular interest to study the distribution of radionuclides
in the body of domestic animals after continuous ingestion of radionuclides. We performed a study to
determine the activity concentrations of Cs-137 and of the naturally occuring K 40 throughout the
gastro-intestinal tract of a cow.
G. Salvadori, S.P. Ratti, G. Belli, E. Quinto
Universita degli Studi di Pavia, Dipartimento di Fisica Nucleare e
Teorica, Pavia, Italy
This paper deals with the 137Cs concentration in air/air dust after the Chernobyl nuclear accident in
Northern Italy. Measurements from the REM data bank provide the experimental starting point; we
exploit here the empirical parametrization of the temporal trend of the radioactive pollution in a few
Provinces we calculated in other works. Since the fallout was strongly influenced by complex
meteorological phenomena featuring fractal properties, the high space-time variability of the radioactive
concentration is modelled by means of fractals, which may also take into account the geographical
sparseness of pollution. Here we present an original fractal approach to the overall description of the
radioactive pollution, even in sites where no data are available. The model is based on the Fractal Sum
of Pulses theory involving additive stochastic processes. The results are interesting, since realistic
scenarios of environmental pollution are produced and the quantitative comparisons with the available
data are always acceptable for all the sites considered and for the
whole time period of interest.
D. Drabova, I. Malatova, Z. Prouza, I. Bucina
Centre of Radiation Hygiene, National Institute of Public Health,
Prague, Czech Republic
Radiation Monitoring Network of the Czech Republic (RMN) was established after the Chernobyl
accident. It consists of laboratories and monitoring groups of hygienic service, nuclear power plants,
hydrometeorological service, research institutes and other institutions.
R. Bergmann 1 , W. Hofmann 1 and L. Koblinger 1,2
1 Institute of Physics and Biophysics, University of Salzburg, Austria The linear dimensions of present lung models are based on morphometric measurements on fully
inflated lungs. To simulate deposition of inhaled radionuclides in human lungs under normal breathing
conditions, airway diameters and lengths have to be scaled down to the smaller dimensions at functional
residual capacity. Two scaling procedures have been applied here: (I) all linear dimensions vary with
the cube root of the total lung volume, and (ii) the airway lengths remain invariant with total lung
volume, while the relative changes of airway diameters increase with progression through the airway
system.
G. Pausch 1, W. Hofman 1, F. Steger 2 and R. Türk 3
1 Institut für Physik und Biophysik, Universität Salzburg,
Austria In the years following a fallout event, the initial contamination pattern will be modified by
environmental/biological factors and by human activities. A peat-bog, however, is a special example
of an ecosystem, which is generally not disturbed by human activities and in which the soil structure
is not affected by animal activities. In addition, lichens, mushrooms and mosses, which typically can
be found in a peat-bog, are known to accumulate radioactive fallout nuclides very efficiently and may,
therefore, be used as biological indicators of the radioactive contamination.
F. D Alberti, L. Risposi
Dept. of Physics, University of Milan, Italy
The aim of this work is to study the behaviour of plutonium (Pu-238, Pu-239, Pu-240) in the
environment around the Joint Research Centre of Ispra site.
M. Gastberger 1 , W. Hofmann 1 and R. Türk 2
1 Institut für Physik und Biophysik, Universität Salzburg,
Austria Previous studies have demonstrated that lichens are suitable and inexpensive biological detectors of the
local nuclear fallout pattern. Particularly in mountainous regions, the deposited radionuclide activities
may vary considerably from site to site due to specific local meteorological conditions, which may also
affect the growth of lichens and their uptake of radionuclides. Thus the goal of this study was to find
out, whether lichens are still suitable biological detectors of the local radioactive contamination pattern
several years after the initial deposition event.
C.Cosma, I.Pop, C.Micu and I. Cosmuta
Faculty of Physics, University Babes-Bolyai, Cluj-Napoca, Romania
After the Chernobyl accident there is a large diversity of 137Cs deposits in different countries. In
Romania the greatest deposits are on the NE-SW direction, some of these presenting over 20 kBq.m-2
for 137Cs [1].
A. Feher 1, P. Zagyvai 1, L. Nemes 1, H. Bitt 2, K. Kautny 2,
S. Vinkovics 2
1 Technical University of Budapest, Institute of Nuclear Techniques,
Hungary The AMS-01 air monitoring system has been designed for field applications. It operates with two
subsequent static filters for airborne particulate and iodine species in order to deliver an early warning
if the appearance of artificial radioactivity in the air is confirmed. Gamma counts of contaminating
radionuclides are evaluated upon unfolding the contribution of natural radioactivity. This task is rather
sophisticated since the quantity of natural radionuclides shows regular seasonal and diurnal fluctuations
and rapid occasional changes due to local meteorological effects. The sensitivity of the system is
primarily determined by the ratio and the absolute amounts of radon and thoron descendants. Analytical
equations describing their build-up and sorption equilibrium on the surface of the particle filter are
introduced as they are applied in the evaluation algorithm of AMS-01. Practical solutions are presented
which provide an optimal operation with sufficient sensitivity (< 50 mBq/m for 137Cs and 131I) and
exemption from false warnings at the same time. Operational experiences as well as methods for testing
and calibration are summarised.
C. Dumitru, M.A. Puscalau
Institute of Atomic Physics, Institute for Physics and Nuclear Engineering ( LAB.7 ),
Bucharest-Magurele, P.O.BOX MG-6, Romania
Following the Chernobyl nuclear reactor accident on 26 April 1986, the deposition densities, in
Bucharest area, were 47 kBq/m2 for I-131, 4.3kBq/m2 for Cs-134 and 9.0 kBq/m2 for Cs-137.
Iodine-131 was measured in human thyroid since 12 May 1986 till 17 June 1986, for 390 adults residing
in Bucharest. Cs-134 and Cs-137 body contamination was measured in 2883 adults (1656 males and
1227 females) from July 1986 and December 1989.
K. Kosutic, Z. Grahek, S. Lulic
"Rudzer Boskovic" Institute, Center of Marine Research, Bijenicka
54, Zagreb, Croatia
The presence of inactive and radioactive strontium in the effluents and their possible interactions in
environment are of a special radiological interest. The physicochemical state in which particular
radionuclides are found is important for the uptake of radioactive substances into organisms. The
parameter of the circulation of strontium in a biological chain is the "concentration factor" which
indicates the possibility of accumulation radioactive strontium in
particular biological species.
Z. Franic, M. Maracic
Institute for Medical Research and Occupational Health, Department for Radiation Protection
Ksaverska cesta 2, HR-41001 Zagreb, P.O. Box 291, Croatia
Due to chemical and metabolic similarity to calcium, bone is the critical organ for radioactive isotopes
of strontium.
B. Pucelj, M. Korun, R. Martincic, M. Ravnikar
Jozef Stefan Institute, Jamova 39, Ljubljana, Slovenia
Mobile radiological laboratory was founded in early eighties when the first nuclear power plant in Slovenia
was commissioned. The main aim was to provide skilled manpower and equipment for independent field
measurements in case of nuclear or radiological emergency. The main equipment nowadays consists of:
a germanium detector mounted in the van for measuring different kinds of samples, in-situ germanium
detector, portable monitors for measurement of external radiation, surface contamination with beta and
gamma emitters, continuous measuring system for external radiation based on GM tubes which is
operational during the voyage, pressurised ionizing chamber coupled with a GPS system to correlate dose-rate measurements with the position of the van, samplers for aerosols and different forms of iodine,
sampling and sample preparation equipment, meteorological station and personal protective equipment.
G. Volent, I. Barnabas and E. Viragh
Radiation Protection Department, Paks NPP, 7031 Paks, P.O.B. 71, Hungary
The Paks Nuclear Power Plant runs with four Soviet-designed VVER-440 type reactors, each of 440
MWe capacity. The first unit went into operation in 1983, the fourth reactor unit in 1987. Like many
industrial activities, the operation of nuclear power plants entails the production of effluents which are
released into the environment.
E. Gjeci, Xh. Myteberi
Institute of Nuclear Physics, Tirana, Albania
A modest activity of environmental radioactivity monitoring started at INP nearby 1980. Especially,
during and immediately after the Chernobyl accident some efforts on
gross alpha - beta contamination of air,
fallout, milk, vegetables, soil and waters, as well as emitters determination were performed. Taking
into account the fact Sr-90 is one of the more hazardous fission products, two different radiochemical
separation methods are used for some samples like soil, fresh and powder milk as well as sediments. Sr-90 activity concentration is determined by LSC of the dissolved precipitate,also by gross beta low-level
counting method. The results and dynamics of Sr-90 in milk during 1986-1987 are presented. Some
nowadays measurements are given, too.
A. Andrasi 1, H. Lettner 2, E. Lovranich 3, F. Steger 3, J. Urban 1,
E. Urbanich 3 and P. Zombori 1
1 KFKI Atomic Energy Research Institute, Budapest, Hungary Connecting to an international intercomparison exercise of mobile laboratories organized in Gera (FRG)
in 1993 a satellite action was organized by the three teams to investigate the radiological situation in
some high altitude Alpine regions of Salzburg province. The places were selected for the high natural
(Ra) and artificial fallout (Cs-137) activity concentration detected earlier in this region. In situ gamma
spectrometric and dose rate measurements were performed in three places of different site
characteristics: (a) on an undisturbed grassy meadow in Salzburg, on Alpine meadows (b) near
Badgastein (Nassfeld) and (c) in Obertauern. These measurements were the basis for the site selection
of a larger scale international intercomparison exercise in 1994.
T. Anovski 1, L. Cvetanovska-Nastevska 2, N. Jovanovski 2
1 Faculty of Technology and Metalurgy, Skopje, Macedonia Distribution of 137Cs, as one of the most important anthropogenic radioactive pollutant on the
environment, in various samples within the Vardar river catchment area
has been determined.
M.Krizman, B.Pucelj, M.Korun, D.Konda, J.Smrke
Jozef Stefan Institute, Jamova 39, SI-61111 Ljubljana, Slovenia
Soon after World War II it was recognized that brown coals from Lower Carniola (coal mines in
Kocevje, Kanizarica, Vremski Britof) contain quite high amounts of uranium, up to ten times more than
other coals in Slovenia. Enterprises were obliged to collect coal ash; it was intended for further
processing and yellow cake production, but due to an insufficient content of uranium these plans were
never realized. In Kocevje, the coal mine was in operation from 1803 and ceased production in 1972.
Huge amounts of coal mining wastes and coal ash were freely disposed of on an area (1.25 km2)
between the town of Kocevje and the nearby village of Salka vas. Excavated underground shafts
collapsed and a lake with an area of 0.25 km2 appeared in the vicinity
of the town.
D.Kroutilikova, Z.Prouza, L.Hobzova
Centre of Radiation Hygiene, National Institute of Public Health,
Prague, Czech Republic
The territorial network of the thermoluminescence dosimeters (TLD) is one of the most important
components of the Czech Radiation Monitoring Network (CRMN). Recently, a modernization of the
instrument equipment and the dosimetry has been realizing. From 1996 the CRMN will use the TLD
system HARSHAW 4000 along with the type 8807 environmental dosimeter. The poster summarizes
both the hitherto experiences of the use of the TLD in CRMN and results obtained at a testing of the
new system and the new dosimeters.
A. Komosa
Department of Radiochemistry and Colloid Chemistry, Maria Curie-Sklodowska
University, Pl.M.C.Sk odowskiej 3, 20-031 Lublin, Poland
Up till now the region of Lublin (eastern part of Poland) have not been studied as concerns a
contamination with the alpha-emitting transuranium isotopes. This is why we have undertaken a study
in this field. We have developed the methods for plutonium and americium separation from
environmental matrices and the alpha spectrometry measurements as a result of a cooperation with
J.Stefan Institute in Ljubljana (Slovenia).
S. Chibowski, J. Szczypa, J. Zygmunt
Department of Radiochemistry and Colloid Chemistry, Faculty of Chemistry,
Maria Curie Sk odowska University, 20-031 Lublin, Poland
The results of the measurements of the radioactivity level of soil and grass samples of Eastern Poland
as well as of the ground layer of the atmosphere are presented. Natural and artificial gamma emitters
are distinguished in the presentation. The total activity of soil samples ranges from 200 to 1200 Bq/kg
with 55-70% contribution of potassium 40. The rest is due to the presence of the following natural: Ra-226, Bi-214, Pb-214, Th-234, Ac-228, Bi-212, Pb-212, Ra-224 and Th-228 and artificial: Cs-137 and
Cs-134 radionuclides.
Z. Jeran 1, R. Jacimovic 1, Franc Batic 2, A. Prosenc 1
1 Jozef Stefan Institute, Jamova 39, 61111 Ljubljana, Slovenia Epiphytic lichens, symbiotic organisms composed of an algae and fungus, are efficient accumulators
of many elements, particularly heavy metals and radionuclides that are released into the atmosphere
because of natural or human activities. In 1992 a national biomonitoring programme was initiated
covering the whole territory of Slovenia to measure the levels of some natural (210Pb, 40K, U, Th) and
artificial (137Cs, 134Cs) radionuclides in the epiphytic lichen Hypogymnia physodes L. (Nyl.) as to obtain
information on their levels in our environment.
M.Krizman * and L.Mljac **
* Jozef Stefan Institute, Jamova 39, Ljubljana, Slovenia The o tanj coal-fired power plant (750 MWel) has been in operation for more than 20 years and
currently produces almost a million tonnes of coal ash per year. Fly ash with a U content of 25 mg/kg
is transported as a slurry and disposed firstly into lake water and later into wet ponds. The whole area
including the disposal site lies on sinking terrain due to coal mining and excavation, and several lakes
were created after flooding of the land. The largest of them is located just on the edge of the fly ash
deposit, so water has direct contact with the deposited ash. The size of the landfill area is about 50 ha,
including the wet ponds and dry part of the disposal site, partly covered with a soil layer and
recultivated.
S. Arh
Slovenian Nuclear Safety Administration, Slovenia
The primary task of the system is to detect any incidents involving radioactivity as fast as possible, to
initiate appropriate measures, and to give warning to the population immediately.
D. Barisic, S. Lulic, A. Vertacnik, N. Vdovic, M. Jurasic
1 Center of Marine Research - Department Zagreb, "Rudzer Boskovic"
Institute, Bijenicka 54, Zagreb, Croatia The activity of 137Cs in shallow northern Adriatic sediments was obtained on the basis of the
measurement results from 21 sediment box cores, sampled during the ASCOP 16 cruise in the summer
1990. 137Cs was determined in surface sediments (0 to 3 cm) and 12 to 15 cm deep sediment. It was
found that the lowest caesium concentrations correspond to sands which are spread along the Croatian
coast. Parallel to the Italian coast, 137Cs concentrations in pelites are the highest. It seems that the
influence of Po River is significant for 137Cs activities in recent marine sediments along Italian coast
south of Po River delta. Significantly higher 137Cs activities in 0 to 3 cm sediment layer can be
attributed to the deposition caused by Chernobyl accident.
P. Spezzano, S. Bortoluzzi, R. Giacomelli, L. Massironi
ENEA - Dipartimento Ambiente, AMB-ICR-TER, CR Saluggia, Italy
Concentrations of 137Cs in water were monitored after the Chernobyl accident from January 1987 to
December 1991 in the Dora Baltea river (northwest Italy), a river characterized by a catchment area
located in the Italian Alpine region. The Dora Baltea river (160 km in length and average flow rate of
110 m3/s) originates from the massif of Mont Blanc (4810 m of altitude) and flows in the Po river. Its
basin, of 4322 km2, collects most of the waters from the western alpine mountains in a region which is
the most intensely covered with glaciers (about 190 km2) of the Italian side of the Alps.
M. Ranogajec-Komor, S. Miljanic, M. Osvay *, S. Ferek, I. Dvornik
Rudzer Boskovic Institute, 41000 Zagreb, P.O.B. 1016, Croatia Detailed measurements of sensitivity, linearity, supralinearity and fading of the TLD-100, TLD-700,
CaF2:Mn and Al2O3:Mg, Y detectors with various encapsulations were carried out to asses the
suitability of these detectors for measuring total gamma dose in a mixed n+gamma irradiation field
during the International Intercomparison of the Criticality Dosimetry Systems organized by the
Commission of European Communities at SILENE Reactor in Valduc, 1993.
R. Rolle, H. Lettner, W. Hofmann, R. Winkler
Institute of Physics and BIophysics, University of Salzburg, Austria
Alpha measuring instruments for ambient radon progeny are usually calibrated by comparison
measurements in an official radon chamber. An alternative, or additional way of calibration, is the
calculation of the efficiency from specifications of the measuring geometry.
J. Hakl 1, I. Hunyadi 1, I. Csige 1, J. Somlai 2, G. Faludi 2,
K. Varga 3
1 Institute of Nuclear Research of the Hungarian Academy of
Sciences, H-4001 Debrecen, POB 51, Hungary We have developed a method to determine dissolved radon and radium content of water samples using
track etch type radon monitors. In two measurements the radon exposures in a freshly sealed and in a
degassed water sample are determined. From the measured exposures the radon and radium content of
fresh water is calculated. The method can be applied as well for in situ integrating measurement of total
radon content of natural waters. The results of theoretical and experimental calibrations will be
presented together with some results of field test studies.
G. Uchrin
Institute of Isotopes of the Hungarian Academy of Sciences, H-1525
Budapest, P.O.Box 77, Hungary
LiF:M,C,P detectors are highly sensitive to their heat
treatment, annealing above 240 deg C usually destroys
their thermoluminescence, TL, properties. Thermally stimulated exoelectron emission, TSEE, glow
curve exhibits peaks much higher than the main TL dosimetric peak. It was revealed that the TSEE glow
curve did not change significantly when the detectors were red out up to 500 deg
C and this readout was repeated more than ten times. LiF:M,C,P detectors from Poland, Krakow, INF type MCPN-S and from
China, Model GR-200, have been investigated using a multi-needle type GM detector based TSEE
reader, developed at Fontenay-aux-Roses, France. The main TSEE parameters of these detectors such
as glow curve, sensitivity, dose response, fading, minimum detectable dose, energy dependence of beta
dose measurement, etc. are given and compared with other LiF,Mg,Ti detectors.
M.Noll, W.Schöner *, M.Fugger *, N.Vana *, H. Brandl **
Institute for Space Dosimetry, A-1190 Vienna, Döblinger
Hauptstrae 7, Austria For dose measurements in unknown mixed (n, )-fields in aircrafts thermoluminescence dosemeters were
used embedded in poystyrol or polyethylen of varying thickness (25 cm diameter spheres, 2 cm
polystyrol, 2 mm polystyrol). Beside the determination of the absorbed dose the evaluation of the linear
energy transfer (LET) with the method of the peak height ratio was determined. Furthermore the peak
height ratio makes the determination of the different fractions induced by gammas, thermal neutrons or
other high-LET radiation depending on the poystyrol thickness possible.
* I. Gresits, * S. Tölgyesi, * J. Solymosi, * L. Gy. Nagy,
** T. Past, ** L. Szabo, *** P. Ormai
* Technical University Budapest, Department of Physical Chemistry, H-1521,
Budapest, Hungary New analytical procedures on the alpha-emitting isotopes of evaporating tailings and proposed purified
water discharges were developed. During sample treatment of the evaporating tailings the samples were
decomposed by oxidation after removing of the big bulk of boric acid. Samples of the purified water
discharges were concentrated by an unusual process based on a microwave technology.
J. Simon, E. Erdos, J. Soos, T. Pinter *, P. Zagyvai **, A. Gujgiczer,
R. Chobola, J. Solymosi, L. Gy. Nagy
Technical University Budapest, Department of Physical Chemistry, H-1521,
Budapest, Hungary Continuous analysis of radioiodines in pressurised water type nuclear power plant primary coolant
produces information about the state of the fuel element cladding. An immediate detection of cladding
failure is important in reactor safety.
Z. Illes, A. Gujgiczer, L. Simoncsics, O. Zsille, G. Plachtovics,
J. Solymosi
Technical University Budapest, Department of Physical Chemistry, H-1521, Budapest, Hungary
This small device makes the nowadays just wide-spread personal computers (IBM PC/AT compatible)
suitable to measuring gamma-spectrum by using most of the NaI(Tl) scintillation probes.
A. Vincze *, G. Volent **, J. Solymosi
* Technical University Budapest, Department of Physical Chemistry, H-1521,
Budapest, Hungary The retention properties of the charcoal based radioactive gas adsorber systems are key parameters as
far as the continuous release of fission product gases at NPP Paks is concerned. The retention of the
radioactive noble gases takes place on the charcoal adsorber by dynamic adsorption, meanwhile their
activity decrease according to their half-life-times.
F. Steger 1, H. Lettner 2, A. Andrasi 3 and E. Lovranich 1
1 Austrian Research Center Seibersdorf, Department Radiation Protection,
Austria In-situ gammaspectromety has become a useful method to assess the nuclide concentration of artificial
and natural gamma-emitters in the soil. For the quality assurance of the measurements periodically
intercomparison exercises are essential. To meet this requirement exercises were organized in different
European countries since 1989. The last exercise in September 1994 was organized in Salzburg /
Austria. The participation of approx. 30 measurement teams from all over Europe emphasizes the
importance of the intercomparison. Salzburg was selected because the Province of Salzburg / Austria
was among the heaviest contaminated region outside the former USSR by the Chernobyl fallout. Two
different typical sites were selected for the measurements: Site 1 was inside the urban area of Salzburg
on intensively used agricultural land which had not been disturbed since the fallout. This site is
representative for intensively used agricultural regions in the Province of Salzburg. Site 2 was in the
mountainous region of the Tauern on elevated altitude of approx. 1700 m. This site represents the soil
and contamination conditions of the Alpine region. Both sites differ significantly in terms of different
soil distribution that is crucial for the evaluation of the gamma spectra. The participants use different
approaches for the evaluation of the gamma spectra in terms of consideration the depth distribution. The
results are presented.
G. Greifeneder 1, H. Aiginger 1, F. Steger 2, J. Flores 3
1 Atominstitute of the Austrian Universities, A-1020 Vienna, Austria A widely used method to investigate thyroid carcinomas, but also disorders of the thyroid function is
the measurement of the 131J-retention using a whole body counter. Normally just the retention of oral
administered radioiodine is controlled. We developed a method to analyze the distribution of 131J beside
the retention in the human body which provides much better information on human metabolism.
I.Malatova, D.Drabova
Centre of Radiation Hygiene, National Institute of Public Health,
Prague, Czech Republic
Centre of Radiation Hygiene of NIPH is in charge of running Radiation Monitoring Network of Czech
Republic (RMN). One from main task of the RMN is to follow activity of artificial radionuclides in
different components of environment, in food chain and in biological samples from which internal
contamination of people could be estimated. Results from whole-body counting are included, too.
Altogether 12 laboratories, equipped by semiconductor gamma spectrometry regularly supply the
measured data about the radionuclide activity concentration in different samples.
H. Russold, Hj. Müller, H. Rabitsch, W. Ninaus
Abteilung für Strahlenphysik, Institut für Theoretische Physik,
Technische Universität Graz, Petersgasse 16, A-8010 Graz, Austia
Measuring smallest activities as required in environmental monitoring demands high efficiencies and
large sample volumes. Both are well accomplished by a Marinelli-beaker-geometry but they are affected
by the self-absorption.
E. Blahak 1, K. Erdelyi 2, S. Pellet 1, L. Szobonya 3
1 "Frederic Joliot Curie" National Research Center for Radiobiology and
Radiohygene, H-1775 Budapest, Pf 101., Hungary The survey of nuclear radiation exposure of the population showed that about 70-90% of the total dose
is originated from the medical diagnostic examination. This high ratio led to the conclusion that
optimising the exposure condition plays a very important role in reducing the total radiation dose of the
population.
K. Erdelyi, I. Szendro
MicroVacuum Ltd., H- 1 147 Budapest, Kerekgyarto u. 10, Hungary
Understanding of the basic nature of nuclear radiation plays an important role in education of population
for nuclear radiation protection. The developed G-MES computer aided nuclear radiation measurement
and educational system is a multipurpose device for education of nuclear physics in secondary and high
schools.
I. Winkelmann, H. Buchröder, Ch. Brummer, M. Thomas
Bundesamt für Strahlenschutz, Waldowallee117, 10318 Berlin, Germany
The method of in-situ gamma ray spectrometry for measurements of environmental radioactivity is
described. Results of measurements of natural radionuclides in surface soil by means of in-situ gamma
ray spectrometry on some selected characteristic sites in the vicinity of uranium mine facilities in
Thuringia and Saxony are presented and compared to those from soil sample analysis. The selected
areas mainly heaps and tailings ponds from uranium processing facilities represent different nuclide
composition and activity levels. Specific activities of radionuclides of the U-Ra series of up to 2200
Bq/kg have been measured.
S. Deme, I. Apathy, I. Feher
KFKI Atomic Energy Research Institute, H-1525, Budapest, Hungary
A new, microprocessor based thermoluminescent dosemeter (TLD) reader Pille'95 has been developed
for environmental and space dosimetry. The new reader uses the same type of bulb dosemeter (TLB-2
based on CaSO4:Dy) as the earlier version of the Pille reader developed in period 1978-84.
J. Paradiz, B. Druskovic and J. Skrk *
National Institute of Biology Ljubljana, Karlovska 19, POB 141,
61000 Ljubljana, Slovenia Possible applicability of cytogenetic analyses of irradiated plant cells for biological dosimetry of
environmental ionizing radiations was studied. The dose-effect relationships for chromosomal damages
in onion meristematic cells were established after plants were irradiated and then grown in laboratory
and field conditions.
E. Lovranich, F. Steger, L. Riedlmayer
Austrian Research Center Seibersdorf, Department Radiation Protection,
Austria
At the Austrian Research Centre Seibersdorf a Whole-Body-Counter with semiconductor detectors was
designed and installed. The measurement geometry is the 'Scan-Geometry'. Two high-purity germanium
detectors (each 30% rel. eff.) are scanning across the person, one below and the other above the person.
Both detectors are shielded with a lead-shield. The wall-thickness is between 2 and 4 cm. It is also
possible to use additional lead-collimators in different shapes. Physical characteristics as longitudinal,
transversal and vertical variations of efficiencies were measured. Calibration measurements were done
with the BGA-Phantom in different sizes and lower limits of detection were calculated. This Whole-Body-Counter is very convenient for radiation protection measurements, although the shielded room
where it is situated has not extremely good low-level conditions.
H. Lettner, A.K. Hubmer, R. Rolle, R. Winkler, F. Steinhäusler
Institute for Physics and Biophysics, University of Salzburg, Austria
Long-term continuous measurement of the atmospheric outdoor alpha-activity concentration have been
performed by using a newly developed aerosol-monitor, roof-mounted 15 m above ground. The
alpha-activity concentration was identified to be predominantly attributed to radon progeny. The total
alpha-activity covers a range of two orders of magnitude.
I. Kasa, J. Solymosi, A. Molnar
Technical University Budapest, Department of Physical Chemistry, H-1521,
Budapest, Hungary
Calcium sulphate doped with dysprosium or thulium (CaSO4:Dy, CaSO4:Tm) has excellent dosimetric
properties.
G. Dajko
Institute of Nuclear Research of the Hungarian Academy of Science, H-4001 Debrecen, Pf. 51., Hungary
Different etching solutions which are suitable for an effective chemical etching at room temperature
were tested.
Z. Radalj, Z. Cerovac *, I. Prlic, H. Cerovac
Institute for Medical Research and Occupational Health Zagreb
2 Ksaverska street, POB 291, Zagreb, Croatia Key words: radiation protection, film dosimetry, TLD, pocket dosemeter
I. C. Dutu, G. N. Sandor, T. Peic, G. Dinca
Research and Design Institute for Rare and Radioactive Metals- Research Laboratory for Radiation
Protection, Working Conditions and Ecology- Petru Groza Town, Romania
The research has been done on laboratory level by using native natural zeolites in sorbtion columns.
The zeolite were of clinoptilolyte type, and waste waters used have been: mine drainage waters, waste
waters from radiometric sorting of ore, and tailings pond waters from a uranium processing plant.
L.Daraban *, T. Fiat *, M.D.Croitoru *, Marta Bayer **
* Babes Bolyai University, Faculty of Physics, Cluj-Napoca, Romania We registered the neutrons spectrum emitted by a Am-241 - Be-9 source having the flux value of about
106 n/s, using a spectrometer with a 30*20 mm stilben crystal scintillator and a pulse shape
discriminator device, by the charge comparison method.
T. Streil, G. Holfeld, V. Oeser, Ch. Feddersen, K. Schönefeld
and R. Klinke *
SARAD GmbH , Cunnersdorfer Str. 12, D-01705 Freital, Germany The knowledge of equilibrium factor F between the radon gas and its short-lived progeny and the
change of the unattached / attached ratio is important for the risk assessment. The continuous
measurement of this parameters is very difficult.
P. Jachs 1, F. J. Maringer 1, M. Tschurlovits 2
1 BFPZ Arsenal, Geotechnisches Institut, Vienna, Austria A new method to obtain the efficiency of a Ge-coaxial-detector in dependence of the gamma-ray energy
and of the relative source-to-detector position is presented. Because of the geometry (detector and
sample are of cylindrical shape) ring-shaped sources of various radii were used. For that purpose
standard solutions in the energy region of 80 to 2000 keV were prepared. The spectra of these sources
were measured at different positions by using detector-insets with adjustable height.
Xh. Myteberi 1, A. Hoxha 2 and A. Simeqi 2
1 Institute of Nuclear Physics, Tirana, Albania In the frame of a QA/QC national program, some methods of absolute measurement of radioactivity are
carried-out. Starting more than 15 years ago, over 15 radioisotopes are standardized by 4 , LSC,
4 (PC)- and sum-peak coincidences methods. The most important methods are presented. One-dimensional extrapolation of efficiency for I-131 and Au-198, two-dimensional extrapolation of
efficiency for Cs-134 and tracing by Cs-134 for Cs-137 methods of standardization are briefly
described. The estimated overall uncertainty for the above radionuclides was better than 0.3% at 99.7
confidence level. The deviations of our results from those of solutions certified by DAMRI-Saclay have
been less than 0.2%.
J. Buysse, A. Poffijn, G. Meesen
I.N.W. Nuclear Physics Lab, Proeftuinstraat 86, B-9000 Gent, Belgium
It is a well known fact that radon is the most important factor in the natural radiation background. For
large scale radon measurements, different types of integrating devices, mainly based on nuclear track
detectors such as polycarbonate, cellulose nitrate or CR-39 can be used. For high exposures the problem
of track saturation occurs. This is especially true for electrochemically etched detectors which have large
track diameters.
H. Stadtmann 1, L. Breitenhuber 2, P. Kindl 2
1 Austrian Research Centre Seibersdorf, Austria The use of electret ionisation chambers for the measurement of gamma dose and radon exposure was
increasing rapidly in the last years. In contrast to conventional ion chambers, the electric field in these
detectors is not constant during the exposure time. Both field-strength and direction are changing due
to inhomogeneous discharge of the electret surface charges.
C. Dumitru, M.A. Puscalau
Institute of Atomic Physics, Institute for Physics and Nuclear Engineering (Lab 7)
Bucharest-Magurele, P.O.BOX MG-6, Romania
A lung counter installation was constructed and calibrated for the determination of small amounts of
X or gamma ray photon emitters, in the energy range from 10 keV to 200 keV, which could
contaminate, through inhalation, the human lungs.
H. Doerfel
Karlsruhe Research Center - Technology and the Environment, Karlsruhe, Germany
The conventional procedures for in vivo monitoring of gamma-emitting radionuclides involve the
determination of body or organ burdens using whole body counting techniques and the subsequent
estimation of intake and committed dose equivalent. For these procedures extensive information is
required, such as time and pathway of intake, physical and chemical form of incorporated materials,
metabolism etc. By means of routine monitoring these information become hardly available, thus
resulting in significant uncertainties for the estimation of intake and committed dose equivalent.
G. Greifeneder 1, H. Aiginger 1, F. Steger 2, E. Unfried 1,
L. Riedlmayer 2, H. Havlik 3, H. Bergmann 3
1 Atominstitute of the Austrian Universities, A-1020 Vienna, Austria The detector system of the high sensitive whole body counter consists of four 8"x4"-NaJ(Tl) crystals
with multi-slit focused collimators inside a massive shielding chamber. Two of these linear scanning
detectors are placed above and two below the bed. They can be arranged independently in three
dimensions. A pressedwood phantom was constructed to simulate different point source positions in the
human body.
P. Beck, K. Duftschmid, St. Kerschbaumer, Ch. Schmitzer,
Ch. Strachotinsky
Austrian Research Centre Seibersdorf, Austria
Because of new recommendations of the International Commission on Radiation Protection ICRP60 the
natural exposure in civil aviation should be take into account. An update of the quality factors for
neutron radiation increases the quota for the neutron component of the equivalent dose of about 60%
compared to values of ICRP60. Numerous exposure measurements at civil airlines in Sweden, USA,
Russia and Germany show a radiation exposure in the range of 5 - 10 mSv/year. This is clearly more
than the average annual dose of occupational radiation workers (in Austria about 1.5 mSv/year).
M. Montalto, R. Giacomelli, M. Nocente, S. Bortoluzzi, P. Spezzano
ENEA, Dipartimento Ambiente, AMB-ICR-TER CR Saluggia, Italy
This paper describes the design criteria, which were used for the realization of an automatic system for
the real time monitoring of the artificial radioactivity in the air.
R.A.Tawil 1, K.J.Velbeck 1, J.Fellinger 2, R.Plompen 2, M.Majewski 2
1 Harshaw/Bicron Radiation Measurement Products, 6801 Cochran Road,
Solon, OH 44139, USA This paper describes and reports the performance of a new manual TLD system that reads all forms of
TL materials for a wide variety of applications. The system is composed of a two-PMT Model 4500
TLD reader, advanced dosimeters, automatic QC Glow Curve Analysis, and Neural Network dose
algorithm.
A.A. Russo
Italian National Research Council, Dept. of Prevention and Work Safety, Rome, Italy
In the 1995 the European Prestandard CENELEC ENV. 50166 was approved and promulgated. This
technical standard is oriented to establish the methodology for the protection of the workers and the
general public against the risks, due to the exposure to electromagnetic fields in the range of frequency
from O Hz up to 300 GHz. The prestandard is divided in two different parts; the first one regards the
low frequency range from 0 Hz up to 10 kHz and the second one the high frequency range from 10 kHz
up to 300 GHz. This is a prospective standard for provisional application so gain experience in its use.
In this prestandard the following main arguments are considered: the exposure limits, both for the
workers and the general public, the methods of measurements, the rationale for the setting the limits.
The scope of the standard is the prevention of the adverse short-time effects on the human beings from
the exposure to electromagnetic fields, with particular regard to the methodology for their evaluation
from protection point of view. In the present paper the author want to show the principles of the
prestandard and to make a possible evaluation of the potential impact, due to its application, on the
research, industrial and medical fields both from technical and economical point of view.
C. Petrini, A. Polichetti, P. Vecchia
Physics Laboratory, National Institute of Health, Rome, Italy
New regulations have recently been proposed in Italy, both at national and regional level, aimed at
preventing possible long-term health effects of magnetic fields from power lines. Based on some
indications from the epidemiological literature, the proposed standards require the exposure limits to
be reduced to values that are three orders of magnitude lower than recommended by IRPA/INIRC
guidelines. Such drastic action obviously involves high economic and social costs, and a careful
cost/benefit analysis is therefore required prior to the enforcement of new standards. As a basic input
for such analysis, a quantitative estimate of health risks has been performed, based on detailed data on
the distribution of population around power lines. This kind of data are generally not found in the
literature and are now available in Italy as the result of an extensive survey performed by the national
electrical utility, ENEL. Estimates of excess cancer are presented, which are based on risk factors given
by the most recent and large epidemiological studies.
S. Tofani, G. d Amore, G. Fiandino, M. Tasso
Servizio di Fisica Sanitaria, Azienda USL 9, Ivrea, Italy
Results of narrow- and broad-band measurements of the Magnetic Flux Density (MFD) inside and
outside houses located close to a 380 KV double circuit power line are reported together with the
correspondent calculated values. The survey lasted 3 months with week-long continuous MFD
measurements. The monitoring of the current flowing in the line was also provided. The agreement
between calculated and measured MFD values is within 10%. The MFD assessment accuracy was
within 8% either by taking the metre maximum reading (or by measuring the three orthogonal
components). The maximum harmonic component has been always below 1.3% the fundamental. The
front door MFD measurement can give a good estimate of the exposure inside the house depending on
the house position in respect to the line. The time and seasonal variation of the exposure was estimated
about 25%.
V. Lepori 1, A. Polichelli 2, P. Vecchia 2
1 PMIP Dept. of Physics and Environment Protection - USSL 5, Como, Italy Experimental surveys performed by a number of health authorities in Italy have shown that in several
cases electromagnetic fields radiated by antennas for radio and TV broadcasting exceed exposure limits
recommended by international organizations such as IRPA/INIRC, or set by regional standards in some
Italian regions. As a basic tool for a nationwide control of the health and environment impact of such
plants, a national archive of broadcaster in Italy has been designed and developed.
G. Keck, G. Schauberger, A. Cabaj
Institut für Medizinische Physik, Veterinärmedizinische
Universität Wien, Austria
For the application of solaria at present the following international recommendations on limits of
exposure exist, which differ strongly:
K. Schulmeister, C. Schmitzer
Austrian Research Centre Seibersdorf, Austria
With laser materials processing, direct exposure to the laser beam is usually not the main hazard. The
high power laser beam is enclosed up to the surface of the workpiece and is usually directed towards
the ground. Errant beams can be caused by uncontrolled reflections off the workpiece surface, however
this happens rarely and protection is generally afforded by shields around the workstation.
K. Skornik
International Atomic Energy Agency, Division of Nuclear Safety
The paper presents the main policy directions and programme for education and training in radiation
protection and nuclear safety, as part of the IAEA s long standing commitment to promotion of
occupational health and safety through manpower development in Member States. Radiation protection
and nuclear safety are primarily a national responsibility. Many developing Member States still find it
difficult, however, to set up and/or implement manpower development programmes, due to budgetary
constraints, shortage of qualified teachers and other deficiencies in infrastructure. There is a persistent need
for assistance in many areas of radiation protection and nuclear safety given the fact that nuclear methods
which lead to electricity generation and improvements in food production, health care, industry and
hydrology, are increasing in number and are often competitive with other methods. The aim of the
Agency s assistance is to strengthen the relevant part of national infrastructures. Manpower training
receives much attention in this strategy with the objective of achieving national self-sufficiency.
A.A. Cigna
Fraz. Tuffo, I-14123 Cocconato (Asti), Italy
The starting and the development of the Radiation Protection Programme within the European
Community are here described. Such a programme undervent an evolution as a consequence of the
results achieved and the needs arising. Some data describing such an evolution are here reported.
L. Frittelli, R. Mezzanotte
National Agency for Environmental Protection - ANPA, Roma, Italy
Recently, in March 95, a new "Legislative Decree" was adopted, for the implementation of six UE
Directives, about radiation protection of the population, of workers and of the environment.
R. Martincic 1, U. Miklavzic 1, M. Kanduc 2, S. Lulic 3, J. Kovac 4
1 Jozef Stefan Institute, Jamova 39, Ljubljana, Slovenia The off-site monitoring system is briefly described and some illustrative results concerning
pollution of the river Sava, drinking water, foodstuffs and external radiation are presented.
Conservatively estimated dose burdens received by a member of the reference population group
as a result of NPP emissions amount to values of "the committed effective dose equivalent"
smaller than 10 uSv per each year of operation. This value represents less than 0.5% of the
annual dose received on average from natural and artificial sources by a member of the general
public in the "normal" environment. The dose estimates concerning NPP have been performed
since 1982 on the basis of emission data as well as off-site environmental measurements.
B. Breznik
Nuklearna Elektrarna Krsko, 68270 Krsko, Slovenia
Krsko NPP, a Westinghouse two-loop PWR of 632 MWe power, is in commercial operation since 1982.
Reduction of radioactive releases to the environment and the reduction of doses to workers is basic goal
in the plant radiological protection. The radiation protection program is established to ensure that the
radiation exposures to workers and members of the public are minimized according to the As Low As
Reasonably Achievable approach and controlled in accordance with international safety standards and
Slovenian regulations.
B. Pucelj
Jozef Stefan Institute, Jamova 39, Ljubljana, Slovenia
Reactor centre Podgorica, belonging to J. Stefan Institute, is located about ten kilometres from
Ljubljana. The main facilities, concerning sources of radiation, are: experimental reactor TRIGA Mark
II, radiochemical laboratories and the temporary storage facility for low and intermediate radioactive
waste. The radiological influence of the centre on the environment is estimated by measurements
according to a special monitoring programme. The backbone of the programme are two kinds of
measurements: the control of emissions and immissions. The control of releases of radioactive aerosols
and gases to the atmosphere is performed by continuous measurements of the releases from the stack
of the reactor. Liquid releases from radiochemical laboratories to the river Sava are controlled by taking
samples and measuring the isotopic concentrations prior to the release. Several measurements and
controls are done to evaluate the immissions to the environs. It is estimated that the highest dose to the
nearby population is lower then about one Sv for atmospheric and liquid releases.
R. Martincic, M. Korun, B. Pucelj, B. Usenicnik *
Jozef Stefan Institute, Jamova 39, Ljubljana, Slovenia Historically, accidents have occurred during the production, transport and use of the radioactive
materials. Experience has shown that advance emergency planning is essential in order to mitigate the
consequences of accidents.
M. Fabretto, S. Colonnello, V. Barbina
CRAD, Centro di Ricerca Applicata e Documentazione, Udine, Italy
Radioactive sources accidentally mixed in scrap material and then melted in the steel process caused
numerous incidents in the last years, resulting in significant levels of contamination of the steel making
plants and posing serious safety problems for employees and the general public. In order to prevent this
risk several companies developed radiation detection systems specially designed to detect the presence
of gamma-emitting radioactive sources buried in scrap carried by railcars or lorries.
F. Dobici, S. Piermattei, A. Susanna
National Agency for Environment Protection, ANPA, Roma, Italy
For years there have been sporadic reports of incidents from trafficking of scrap metals radioactively
contaminated or containing radioactive sources. However recently there have been an increase of
events indicating that this problem is so growing as to generate possible consequences, from a radiation
protection standpoint, to workers and to the public.
B. Pucelj, M. Korun, D. Kavsek, Z. M. Rosman, T. Sutej 1
Jozef Stefan Institute, Jamova 39, Ljubljana, Slovenia Significantly elevated dose rate was measured locally outdoors in a metal producing facility. Further
measurements by in-situ gamma spectrometry revealed that it was due to radiation from 137Cs with the
activity of the order of tens of GBq, most probably from an unaccounted radiographic source buried in
the soil about 10 to 20 cm deep. Since the source was located at a place where it did not present any
immediate health threat to the population or to the workers of the plant its removal was carefully
planned to minimize the dose to the team involved. The source was successfully recovered and safely
stored in the temporary storage facility for low and intermediate radioactive waste of Slovenia in Reactor
centre near Ljubljana. Although the capsule was partly corroded no soil contamination was detected.
The highest dose to a member of recovery team was 50 uSv.
R. Delia, A. Moccaldi, G. Barone Adesi
Ministry of Health, ISPESL (National Institute of Prevention and Work Safety), Rome, Italy
The risk connected with metallic scraps is a relevant problem from the radioprotection point of view,
as the presence of detected contamination and radioactivity on stocks of these materials imported from
European Eastern Countries has shown.
M.Tschurlovits *)
Atominstitute of Austrian Universities, Vienna, Austria
Usually, figures are set by authorities to control doses from controlled sources (normal operation ) or
from sources not under control ( in emergency cases ). Such figures might be called reference levels,
action levels, limits etc. and are conceptually expressed in terms of effective dose. For practical reasons,
some derived quantities as activity concentration in a given substance, e.g. in foodstuffs are used,
obviously assuming a given model.
A. Dalheimer 1, K. Henrichs 2
1 Institut für Strahlenhygiene, Bundesamt für Strahlenschutz,
D-85764 Oberschleiheim, Germany In Germany, the working group "Incorporation Monitoring" of the Radiation Protection Association
defined a new standard for the monitoring of workers occupationally exposed to radioactive material.
During the last two years this draft has been accepted by the German government in the form of three
guidelines.
C. Hone
Radiological Protection Institute of Ireland, Dublin, Ireland
Since 1997 Ireland has operated a licensing system to regulate the use of ionising radiation in medicine,
industry and education/research. The system extends to all sources from irradiators containing
petabecquerels of cobalt-60 to veterinary x-ray units.
The paper should have particular relevance for other small countries, particularly those without nuclear
power or very limited nuclear programmes, which are in the process of developing or reviewing their
arrangements for the monitoring and surveillance of sources of ionising radiation.
M.Beno
Institute of Preventive and Clinical Medicine, Limbova 14, 83301 Bratislava, Slovakia
The adaptive response after low dose irradiation attracted much attention in the last decade. It was
already used as an example in advertising the "hormetic" effects of low dose irradiation (Luckey,T.D
: Radiation Hormesis, p.85, C.R.C. Press Inc., 1991, 306 p). The work reported aimed at gaining
information about the frequency of observation of the adaptive response in a human population sample.
D. Sacco, R. Delia, G. Bindi, A. Bonanni, S.Casciardi, Loppa, F. Marena, P. Rossi,
F. Ruggeri, L. Venturini
ISPESL, Via di Fontana Candida N01, Monteporzio Catone, Roma, Italy
The steel scrap recycling by iron and steel industry is increasing mouved by profits and by the purpose
of protection of environmental resources. Besides the use of radioactive sources in several fields
(medical, industrial and in scientific researches) on one hand, and the disposal of made radioactive
materials from nuclear reactors on the other hand, makes the likelihood no more negligible that some
radionuclides could be found, accidentally or fraudulently, in steel recycling scrap. Radiation protection
problems for surveillance both of employees in the production cycle and of people and environment in
general arose.
S. Renier
EDF, Industrial Safety, Radioprotection and Environment Department, Environment Group
One of the operator's fundamental missions is to evaluate the maximum potential volume of
radioactivity which may be released, estimate the environmental impact, very rapidly carry out initial
measurements at the site and outside the site, taking into account the wind factors, and transmit the
results of all these evaluations to the local authorities.
EDF specialists apply this method in accordance with a guide entitled "the Health Physics Control
Center work tool", which details the three components in the evaluation process.
M.Tschurlovits
Atominstitute of Austrian Universities, Vienna, Austria
The international development of the field "radioecology" in the last decade is presented. The
development can be separated into two groups: measuring programs dealing with the assessment of
activity concentration in environmental compartment on the one hand and modelling activities on the
other hand. Model validation exercises are going on. Programs dealing with retrospective dose
assessment are discussed. Experience gained in participation in the IAEA VAMP program , river
subgroup are discussed.
S. Pellet, L. Ballay
National Research Institute for Radiobiology and Radiohygiene, Budapest, Hungary
Illicit trafficking of various nuclear material has been arisen in Europe as well as in Hungary in the past
few years as a curiosity. This unexpected phenomenon stressed the radiation protection authorities to
overview the regulations and operational guidance for radiological health actions relating to found or
seized nuclear and/or radioactive materials by security organizations. The main radiological health
features of Hungarian incidence will be introduced also the actions were taken in National Institute for
Radiobiology and Radiohygiene and in National Radiological Health Emergency Service. Also the
frame of the coming new regulation relating to radiological health responsibilities in case of found or,
seized nuclear materials.
M.Tschurlovits
Atominstitute of Austrian Universities, Vienna, Austria
Radiation protection standards define clearly figures limiting the radiation exposure of groups, e.g
occupationally exposed persons, in terms of the quantity E (effective dose), being a quantity defined
by ICRP for risk estimation, is used.
V. Klener
Centre of Radiation Hygiene, National Institute of Public Health, Prague, Czech Republic
The field of Radiation Protection has been developing in the Czech Republic since the early nineteen-
fifties as a specific branch of Occupational Medicine. Later its scope increased to cover environmental
problems and Radiation Protection became an autonomous field in Public Health. The executive
framework was structured on the lines of Soviet Hygiene Service. After the fundamental political
changes of 1989 the Hygiene Service has undergone substantial transformation and Radiation
Protection is no longer considered a typical branch of Public Health. Accordingly the then Atomic
Energy Commission of the Czech Republic has redefined its role and become a State Office of Nuclear
Safety. Following the current tendency of International Governmental Organizations to bring closer the
protection of health and the safety of radiation sources - as expressed in the International Basic Safety
Standards (1994) - both these activities have been entrusted to a single Governmental Authority. The
first Atomic Law in the Czech Republic is now prepared for approval by Parliament and will legally
fulfill the rearrangement and establish an Office of Nuclear Safety and Radiation Protection.
B. Kanyar, N. Fulop, N. Glavatszkih, A. Nemeth
National Research Institute for Radiobiology and Radiohygiene, Budapest, Hungary
In Hungary the organisation of the nationwide environmental radiation monitoring is rather complex
with several ministries, authorities and different types of laboratories involved. Therefore the Hungarian
Atomic Energy Commission initiated some centralisation in the monitoring programme as a whole and
data collection together with data analysis, dose assessments, decision support procedures etc. The
National Research Institute for Radiobiology and Radiohygiene has had charged to direct the operative
work and establish a central data bank, mainly for laboratory- type of data, in close cooperation with the
different authorities and laboratories.
R. Martincic, P. Strohal *
Jozef Stefan Institute, Jamova 39, Ljubljana, Slovenia In view of the particular character of the radiation risks a system of radiation protection and safety has
developed over many decades as the effects of ionizing radiation have been better and better understood.
2 Eötvös Lordnt Univ. Dept. of Phys. Geog. H- 1 083
Budapest, Ludovika tdr 2, Hungary
CONTENT OF 226Ra IN TAP AND MINERAL WATERS OF THE REPUBLIC OF
CROATIA AND POSSIBLE HEALTH EFFECTS
The study showed that 226Ra content for investigated categories of waters are below the levels at which
any unacceptable dose due to ingestion would arise. The dose from consumption of bottled mineral
water has been estimated and compared to the dose received from public
system tap water over the year.
THE RADON-222 CONCENTRATION IN THE DRINKING WATER
AND THE CANCER HUMAN RISK
Here we try to put into evidence the relation between Rn in drinking water and the incidence of cancer
mortality in a community of people from the town of Miercurea Ciuc in
Harghita county.
Thus we determinate the Rn-concentration from the drinking water of the town. We estimated the
gastric internal dose by the "Kahbs" method and we carried out a retrospective epidemiological study
out the gastric cancer.
With the results obtained we try to estimate the implication of Rn-222 from the drinking water in the
human cancerogeneses.
RADON CONCENTRATION IN ITALIAN CAVES:
SOME ASPECTS OF RADIATION PROTECTION
In Italy a number of measurements have been carried out in caves and here the radon concentration
recorded for each cave are reported. These are listed beginning from North to South Italy. Also the
cave file number is given with the cave name.
Some conclusions on the meaning of these data are also included, in particular with an evaluation of the
doses involved by exposure to radon in the caves studied.
METHODOLOGY OF AMBIENT RADON DAUGHTER MEASUREMENTS
In the present study, four different measurement techniques will be compared: (I) gross alpha quasi-continuous sampling measurements with a Pylon WL-meter, with varying time intervals between
sampling and measurement; (ii) gross alpha grab sampling measurements with a Pylon WL-meter, using
a new filter for each sampling period; (iii) spectrometric alpha grab sampling measurements with a filter
device and subsequent analysis of the alpha spectra; and, (iv) spectrometric alpha and beta
measurements with the Rolle"-meter. This methodological study has indicated that the standard
deviations of the radon daughter concentrations are smallest for the
spectrometric methods.
In a preliminary study in selected working and living environments, the following parameters were also
measured: unattached fractions, activity and mass size distributions, number concentrations, humidity
and temperature. Only a complete on-site determination of these physical and environmental factors will
permit a reliable dose and risk assessment for inhaled radon daughters.
DEPOSITION OF INHALED RADIONUCLIDES IN BRONCHIAL AIRWAYS:
IMPLICATIONS FOR EXTRAPOLATION MODELING
2 KFKI Atomic Energy Research Institute, Budapest, Hungary
The effects of interspecies differences in radionuclide deposition patterns are explored for two typical
bifurcation geometries in segmental bronchi (generations 4-5) and terminal bronchioles (generations 15-16) of the human and rat lungs, for inspiration as well as expiration. The observed interspecies
differences in localized deposition patterns and related deposition efficiencies demonstrate that the
respective asymmetries in airway branching affect the local distributions of deposited radionuclides in
bronchial airway bifurcations and, consequently, the applicability of
extrapolating carcinogenic risk.
A NEW METHOD FOR RAPID MAPPING OF THE RADON EMANATION
POTENTIAL OF THE SOIL OVER LARGE AREAS
2 ALGADE - BP 46 - 87250 BESSINES, France
3 Institute of Occupational Safety of the Republic of Slovenia,
61105 Ljubljana, p.p. 27, Bohoriceva 22a, Slovenia
4 Jozef Stefan Institute, Jamova 39, POB 100, 61111 Ljubljana, Slovenia
5 CERTAC, S.A., France
By studying the differential absorption of different gamma lines of the U decay chain, it is possible to
obtain the radon profile in the soil under investigation.
The first experiments, conducted in France and in Slovenia, show interesting results, even with a small
volume detector.
Further development of this method will be implemented, to allow it to be used on board a truck or an
airborne platform.
RADON IN THE SPAS IN THE REPUBLIC OF CROATIA
HR-41001 Zagreb, Ksaverska cesta 2, P.O.Box 291, Croatia
Radon activity concentrations were measured by means of solid state nuclear track detectors (Kodak
LR-115 films). The investigations include indoor measurements around the swimming pools at the
levels of 2m and 0.5m above the water surface.
Elevated radon activity concentrations were detected in the spa of Istarske Toplice, which are known
as "sulphur radioactive spa". In this spa the average radon activity concentrations measured around the
swimming pools at the levels of about 2m and 0.5m above the water surface were 872 Bqm-3 and 926
Bqm-3, respectively.
DIFFUSION CHARACTERISTICS OF ATTACHED AND UNATTACHED
RADON PROGENY OVER A VEGETATED SOIL
Gravitational settling has been taken into account using different sedimentation velocities for the
attached and free daughters. At the ground level the boundary condition consists in equating the flux
due to the concentration gradient and gravitational settling with the
deposition rate.
The turbulent diffusion coefficient within vegetation was quantified in accordance with the existing
experimental data deduced from the concentration gradients.
The equilibrium factor and the unattached fraction were studied for different turbulence intensities,
vegetation types and aerosol concentrations.
The predicted values of concentration, equilibrium factor and unattached fraction were compared with
experimental values and a reasonable agreement was noted.
MEASUREMENT OF THE AMBIENT NEUTRON BACKGROUND WITH A
HIGH-RESOLUTION -RAY SPECTROMETER
References:
ENVIRONMENTAL-RADIOLOGICAL MONITORING SYSTEM
AT MECSEKUR N LTD (MECSEK MOUNTAINS, HUNGARY)
Air, aerosol, fall-out, water, plant and soil samples are regularly collected for detailed radiological
analysis. The natural radioactive nuclide content of samples are analysed both qualitatively and
quantitatively with high resolution gamma spectroscopy. The radiological contamination of uranium
mining district is controlled by systematic in situ gamma-ray dose, radon concentration and radon
exhalation measurements. The surfacial, mine and groundwaters are monitored by regular sampling and
subsequent radiochemical analysis (for U, Ra and Rn content). Automatic radon monitoring devices are
operated in the dosemetrically most critical points of the mines and mill. The annual activity escape
from the mines and mill into the environment is also monitored.
RADON MITIGATION IN SOILS
2 Technical University, Cluj-Napoca, Romania
The pressure-induced flow (advection) prevails in fractured soils
with crack radius r>0.001mm. The
concentration gradients determine radon diffusion from soil to air. Diffusion prevails in porous soils
with pore radius r<1um, while in compact soils with a fine granulation,
r<0.01um, radon mitigation
takes place by Knudsen diffusion. Generally Knudsen diffusion has a small contribution, while
advection and diffusion are the main mechanisms of radon mitigation in soils. The existence of
temperature gradients is favouring the termodiffusion which appears
especially around soil surface.
Radon transport from soil to air is determined by soil parameters as: porosity, granulation, moisture, and
it is influenced by meteorological conditions such as: atmospheric temperature and pressure, winds and
precipitations.
We developed a theoretical model for simulation of radon mitigation in soil and its dependence of these
parameters. We also made an experimental device for verifying the
theoretical model.
SURVEY OF RADON ACTIVITY AT GROUND LEVEL
IN VILLAGE HOUSES OF HUNGARY
EFFECT OF ATMOSPHERIC PRESSURE ON RADON ENTRY RATE INTO
HOUSES
Investigating the average exhalation rates as a function of the atmospheric pressure we have found an
anticorrelation between them. We have also observed a hysteresis in the average exhalation rate -
pressure curve. Modelling radon entry rate into houses from porous media under varying atmospheric
pressure condition we found agreement between theoretical and experimental
results.
CALIBRATION OF A DOSIMETER FOR DETECTION OF RADON ACTIVITY IN
AIR
The chamber is filled with a radon concentration obtained from a source of few Ci of salts of Ra-226,
contained in a cruet; the value of this radon concentration is obtained by drawing a known volume of
radon-air blend in a vial and by measuring the activity with a Ge-Li counter, intercalibrated with the
Italian Primary Metrological Center. The drawing of gas is made using two different methods, in order
to avoid systematic errors due to the radon-air blend movimentation.
The calibration factor of the ionization chamber, namely ratio between the equilibrium current and the
radon concentration, is 3,77 1016 Bq/m3/A.
Concerning the dosimeters calibration, is our experience a good exposure time, within the calibrated
chamber, of about one or two days.
The calibration factor of the dosimeters in resulted to be
4,7 10-4 tr/cm2/Bq*h/m3.
DOSE AND RADON MEASUREMENTS INSIDE HOUSES CONTAINING ASH AS
BUILDING MATERIAL
After coal processing the derivatives (slag, ash, waste) become enriched in those decay elements even
40-80 times of the world average.
Unfortunately these materials were built in houses - sometimes in offices or schools - as backfill or
insulation.
In these buildings partly the dose caused by outer gamma-radiation is rising (on the floors and roofs of
these buildings 500-900 nSv/h dose can be detected). On the other hand, the radon concentration
depending on the emanation factor of these materials and the way of
life is found to be very high (600-2000 Bq/m3), thus the inner radiation
dose deriving from that is also significant.
At those places, that have high radon concentration together large dose rate, the achieved dose can only
be reduced by costly architectural intervention.
RADIOLOGICAL IMPACT OF SOME UTILIZATIONS OF THERMAL
WATERS FROM THE WESTERN PLAIN
At the wells in the perimeter of Oradea city, the thermal water has an uranium content comparable to
that of ground water, but the radon content is 4 to 8 times higher and radium reaches to 2.5 Bq/L, the
mean value for the 5 wells being 1.4 Bq/L. These thermal waters are used in the swimming-pools from
Oradea and also as warm water over the last 10 years period, in about 1400
flats.
It was not proved a radiation risk for public or a pollution of the environment at B ile Felix, B ile 1Mai
and Moneasa spas or at the swimming-pools from Carei, Marghita, Satu Mare or at the usage of thermal
water as heat source or at flax and hump retting.
The possibility of existing high radium content thermal water sources, enforces the medical licensing
for any future utilization.
RADON-222 CONCENTRATION IN DIFFERENT DWELLINGS
FROM CLUJ-ROMANIA
Radon concentration was determined in all the rooms under normal living conditions in the period of
Sept.-Nov. 1994. The "SI-5S Prassi" apparatus was used for this. The values of Rn-222 from the air in
the blocks were between 30-80 Bq/m.c., the maximum values being over 100 Bq/m.c. in the case of
non-ventilation within 12 hours.
In the detached-houses under the same conditions, maximum values, higher than 500 Bq/m.c. were
found in non-ventilated rooms having no cellars (140-150 Bq/m.c.) as against those with cellar. No
significant differences were found either related to the building materials or to the type of heating
(central heating and natural gas).
We found of special importance the increased Rn-222 concentrations in the air of the bathrooms after
water use.
From the analysis of the results follows that the most important
contribution to the accumulation of Rn-222 in the indoor spaces is related
to the type of foundation and the soil under the houses.
THE SPATIAL DISTRIBUTION OF 222RN "INDOOR" IN SLOVENIA
AS A STOCHASTIC MULTIFRACTAL PROCESS
2 Jozef Stefan Institute, 61111 Ljubljana, Jamova 39, P.O.Box 100, Slovenia
The dangerousness of Radon may depend upon its in situ concentration, however, the presence of "hot
spot" may not be detected due to averaging procedures or to insufficient spatial and/or (fractal)
dimensional resolution of the sampling network.
The geometry of the network show fractal features which, in turn, gives a sparse (inhomogeneous)
sampling of the phenomenon: this means that some of its components (especially the most intense ones)
are almost surely missed in the gaps of the networks themselves. The values of radioactive concentration
show an (asymptotic) hyperbolic distribution (a fingerprint of multifractality), revealing the presence
of a high variability and of strong local fluctuations.
The application of both the P.D.M.S. and D.T.M. techniques show the presence of (stochastic)
multifractal structures; the estimate of the relevant parameters indicates that the spatial distribution of
Radon can be classified as a "conditionally soft/hard" multifractal process.
Overall, this research shows that fractals and multifractals represent a powerful tool to characterize the
Radon pollution of the environment by means of a single statistical law, from the smallest up to the
largest spatial scales, without introducing arbitrary data regularization.
SCANNING ELECTRON MICROSCOPY OF RAT THROAT AND TRACHEA
FOLLOWING THE EFFECTS OF RADON DECAY PRODUCTS
* Jozef Stefan Institute, Jamova 39, Ljubljana, Slovenia
v Department of Biology, Faculty of Biotechnology, Ljubljana, Slovenia
RADIATION DOSE ESTIMATES IN SLOVENIAN KINDERGARTENS
APPLYING SOLID STATE DETECTORS
GUIDLINES FOR TREATMENT OF SOLID WASTES WITH ENHANCED
NATURAL RADIOACTIVITY IN POLISH COAL INDUSTRY
Radioactive wastes cause also contamination of the natural environment. Radium and barium sulphates
are sometimes precipitated in settlement pond and rivers. Moreover, from radium-bearing waters which
do not contain barium ions, radium can be removed from water by adsorption on bottom sediments in
rivers. Concentration of 226Ra in such sediments is usually lower than 1000 Bq/kg, but enhanced
radium concentrations were found many kilometres from the discharge points.
It was necessary to prepare guidelines for treatment of materials with enhanced natural radioactivity.
Such guidelines have been worked out during past few years and applied in all coal mining industry.
On the other hand, it is a common practise in Poland, that ashes from power plants are stored
underground and such guidelines are also very useful for this purpose.
QUALITY ASSURANCE SYSTEM IN GAMMA SPECTROMETRY LABORATORY
Laboratory of gamma spectroscopy in Central Mining Institute has three HPGe detectors. There is one
coaxial detector with 45% relative efficiency, one detector for low energy region and one detector with
extended range). We have also two Ge(Li) detectors from former Czechoslovakia. Shielding is made
of steel - with thickness 40 cm. The electronics and software (Genie-PC) was bought at "Canberra" and
"Silena".
The paper describes not only the system of quality assurance but also main problems met by its
implementation and results of intercomparison measurements. The QAS has been introduced in 1992.
In 1993 the Accreditation Certificate of Testing Laboratory for our Laboratory has been obtained from
the Polish Bureau of Research and Certification as a fifth
laboratory in Poland.
EQUIPMENT FOR THE OPTICAL EVALUATION OF NUCLEAR TRACK DETECTORS
This equipment has been used to evaluate MAKROFOL and CR-39 detectors which were exposed in
space on the MIR-space station for several months.
This equipment was also used for thermal neutron-dosimetry with a lower
limit of 0,5 mSv/cm2, alpha particle measurement and measurement of the
fluence of 12C ion beams in the Dubna synchrophasotron.
SESSION III:
RADIATION PROTECTION AND ENVIRONMENT
KRSKO NPP ECOLOGICAL INFORMATION SYSTEM
The first function is to collect data from different measuring points, proceed the data and distribute them
to some places at power plant and to some outside institutions. EIS collects data from three automatic
meteorological stations, hydrological station on Sava river, some continuous dose rate measuring devices
located in the vicinity and from Radiation Monitoring System.
The second function of EIS is dose calculation in case of emergency. Dose calculating programme is
important part of EIS and with its calculations and graphical displays offers tool and support for dose
assessment.
TRITIUM MEASUREMENT BY GAS SCINTILLATION
Given the extreme mobility of Tritium in most materials, it is necessary to use systems for double
containment, such as glove boxes or spaces between primary and secondary container, in which inert
gas like argon or nitrogen flows. With these systems it is possible to recover Tritium that escapes from
the primary containment. Presently the gas flow is monitored continuously by means of ionization
chambers which may present problems in particular applications ("memory effect" with high activity,
strong dependence of the response on the presence of impurity, etc.).
The aim of the work presented is to determine the prospects for realizing a new type of monitor
principally dedicated to measuring the gas activity in the isolation spaces of the containing systems of
the high activity Tritium plants. This monitor should have sufficient sensitivity, quick response and
should be easily decontaminated.
As detection technique we chose the scintillation produced in the inert gas by radioactive decay. With
the first prototype, designed in cylindrical form, it was possible to observe gaseous scintillation events
in mixture of Tritium and argon or nitrogen. Following that, a spherical prototype was designed of
which we studied the performances and the dependence of the response varying the pressure, the
concentration of Tritium, the percentage of the impurity and the gas flux.
The results are satisfactory and suggest that the monitor could be used in glove boxes and double
containment systems. In the future we plan to test the monitor using large quantities of Tritium and to
study the dependence of the response on the size and shape of the
monitor chamber.
EVULATION OF LOW-LEVEL SOLID RADIOACTIVE WASTE GENERATED
BY A LARGE HOSPITAL AND DISPOSED OF WITH ORDINARY REFUSE
* Servizio di Fisica sanitaria dell'Ospedale S. Gerardo di Monza, Italy
The activity of these low-level solid radioactive waste was monitored to estimate the fraction of the
employed activity of the solid low-level waste generated in different practices which concern the use
of unsealed radioactive substances in therapy, diagnosis "in vivo"
and "in vitro".
MODELLING THE CHERNOBYL RADIOACTIVE FALLOUT IN EUROPE: A
MULTIFRACTAL APPROACH
OFF-SITE EMERGENCY PLANNING IN CZECH REPUBLIC
At the present time our regulations are based on an assumption that the protection measures (PM) are
introduced in the cases where it is to assume that intervention levels (IL) will be exceeded. When
exceeding the upper limit of the IL interval for given PM, the implementation of that PM is regarded
as necessary, when the lower limit of the IL interval is exceeded, the optimization is provided with
respect to the extent, feasibility and price of the given PM.
Principles of protective measures implementation in the case of an occurring or suspect radiation
accident (several PM are carried in Emergency Planning Zone after warning and without waiting for
result of monitoring the actual radiation situation and without waiting for a decision of District
Emergency commission, the others are implemented in agreement with results of monitoring, actual
course of accident and on the decision of District Emergency Commission) are explained. Present the
emergency planning structure in Czech Republic is demonstrated.
RAPID DETERMINATION OF SOIL CONTAMINATION
BY HELICOPTER GAMMA RAY SPECTROMETRY
RECENT DEVELOPMENTS IN THE ATMOSPHERIC DISPERSION MODELS
TO BE USED FOR REGULATORY PURPOSES AND IN RISK EVALUATION
As a further improvement, a recent solution of the dispersion equation is also given that takes explicitly
into account the finite emission duration.
BIOPHYSICAL MODEL FOR THOROTRAST-INDUCED LIVER CANCERS
2 Institute of Chemical Physics, Russian Academy of Sciences, Moscow, Russia
A biophysical model for Thorotrast-induced liver carcinogenesis has been developed, which is based
on experimentally observable in-vitro cellular radiation effects, such as cell killing, oncogenic
transformation, stimulated mitosis, removal from contact inhibition and adaptive response. In this
initiation-promotion model, we assume 7 transitions in the development of a cell from the initial
unirradiated level (state 0) to a fully transformed cell,
eventually leading to a frank tumor (state 7).
Consistent with the epidemiological evidence provided by the German Thorotrast study, our biophysical
model predicts that (I) the cumulative incidence rises steeply with increasing cumulative exposure after
a mean latency period of about 20 years, and (ii) a higher dose rate leads to a higher cumulative
incidence at the same cumulative exposure time, but to a lower incidence at the same cumulative dose
( inverse dose-rate effect").
MONITORING OF NATURAL RADIOACTIVITY IN SLOVAKIA
The effective dose after external irradiation summarizes contributions of cosmic and terestial
components of natural radiation. The territorial net of thermoluminescent detectors and monitoring net
IRIS were used for this purpose.
Screening of the equilibrium equivalent radon concentration (EER) in randomly chosen dwellings of
Slovakia was used as a basis for the estimation of the population effective dose due to radon inhalation.
For EER estimation an integral method using the solid state track
detectors was applied.
EFFECT OF DIFFERENT TREATMENTS ON 110mAg PLANT UPTAKE IN VARIOUS SOIL
TYPES
Stable silver generally is not an important pollutant, therefore very few references are available on plant
uptake of silver, the same is true for the radiosilver studies.
In the presented study plant (yellow leguminous bean) uptake of 110mAg from different types of soil was
investigated. Most typical Hungarian soils (leached Ramann brown forest soil, alluvial soil, chernozem-light sandy soil, calcareous chernozem soil) were selected for the experiments carried out under
laboratory conditions. Results are presented in relation to major soil characteristics and, in addition,
effects of two different treatments: phosphate and organic matter
fertilization on plant uptake are given.
The highest uptake was found in bean grown on leached Ramann brown forest soil, whereas the lowest
value was measured in the plant grown in calcareous chernozem soil. Organic fertilization reduced
significantly the uptake of radiosilver in all investigated types of soil. The largest factor of reduction was
found to be as high as 5. Phosphate fertilization was less effective.
Our study clearly demonstrates that carefully selected post-accident treatment (e.g. organic fertilization
following silver contamination) can significantly reduce the environmental consequences of radioactive
release. Methods to be developed on the basis of such studies, could be used for remedial actions of
agricultural lands, polluted with radioactive substances.
A FIVE YEAR , POST CHERNOBYL ACCIDENT, SURVEY OF CS-137 LEVEL
IN SOME ROMANIAN FRESHWATER BASINS
The Cs-137 content from water was determinated radiochemical with Ammonium Phosphomolybdate,
and for the seston and sediment samples there were made gamma-spectrometric analyses with a
multichannel analyzer.
The presence of Cs-137 was still detected in all the investigated samples and in all the stages of
prevelation, five years after the Chernobyl nuclear accident.
The distribution of Cs-137 was as follows: 92.61 % to 99.60% in sediment, 0.32 % to 7.33 % in seston
and under 1% in water. This demonstrates a massive accumulation in sediment, with values of the K.D.
(distribution coefficient) up to thousands. At the same time a concentration occurred on the level of the
physical and biological supports from water, which was proven by the high values (between 5 and 180)
of the F.C. (concentration factor) of Cs-137 in seston. This accumulation has a special importance,
because "the stocking" of the radionuclide from water-diminishes the environment and population's
contamination risk.
RADIOACTIVE WASTE REPOSITORY AND RADIATION PROTECTION
The site selection criteria has been established but the decision about the location for final repository
in Slovenia is not yet made due to strong public opposition. Environmental studies and research work
on environmental impact of different disposal types as well as the survey of international practice were
carried out. We are strongly aware of extreme importance of radiation protection at future repository
site in Slovenia. The preparation of the program of initial state measurements is in the final phase and
will provide the reference data for future environmental monitoring at the time of operation of the
repository. The preliminary study of acceptance criteria for low and intermediate level radioactive
wastes deals with criteria that radwaste should meet in order to minimize the public exposure, to
enhance environmental protection and to optimize the economy of waste management. Future studies
must prove full safety of repository in compliance with our legislation.
NUCLEAR DISASTER MANAGEMENT THE MURMANSK EXERCISE
Different international teams participated in an effort to determine the extent and implications of the
incident, gauge radiation levels in the environment, study relief and evacuation procedures, and estimate
the applicability of recommended protection measures.
The exercise was organised in three time scenarios, starting with the third day after the accident up to
one month after the accident.
The system developed by the Research Centre and employed by the Austrian NBC defence group
encompasses a scenario analysis tool based on three-dimensional dispersion calculations and forecasting
capability, GPS-based acquisition of radiation data by mobile teams, and permanent site monitoring
instrumentation. Additionally, a robust NaI food stuff probe ensures local consumption to be free of
contamination.
Information on the general exercise and procedures is given and the Austrian system and its application
throughout the exercise is discussed.
ACTIVITY LEVELS OF CS-137 AND K-40 IN THE GASTRO-INTESTINAL TRACT OF
A COW
** Fachabteilung fr Veterinärwesen der Steiermärkischen
Landesregierung, Graz, Austria
As a consequence of the fallout following the Chernobyl accident the cow ingested chronically heavily
contaminated forage during four years. The cow was slaughtered in November 1992 and samples of the
whole gastro-intestinal tract were taken. The activities of the contents from the forstomachs and the guts
were determined immediately after sampling. Other samples of tissues and organs from the tongue along
to the rectum had to be deep-frozen and were thawed and prepared
before measuring.
Activities of Cs-137 and K-40 were determined simultaneously by gamma counting with the help of
semiconductor-detectors.
The activity concentrations of Cs-137 are in general higher than the corresponding concentrations of
K-40. High values of the Cs-137/K-40-ratio were obtained for the mucosa of the reticulum, the tongue
and the wall of the rumen. Low ratios were found for the
activities of the contents in the rumen.
MODELLING THE CHERNOBYL RADIOACTIVE FALLOUT IN NORTHERN ITALY:
A MONOFRACTAL APPROACH
RADIATION MONITORING NETWORK OF THE CZECH REPUBLIC
The radiation situation is controlled in principle by three subnetworks in which some or all above
mentioned components of RMN participate:
THE EFFECT OF MORPHOMETRIC SCALING ON DEPOSITION
AND CLEARANCE OF INHALED RADIONUCLIDES
2 KFKI Atomic Energy Research Institute, Budapest, Hungary
Deposition and mucociliary clearance of inhaled particles in a stochastic morphometric model of the
human lung are simulated by the Monte Carlo code IDEAL-4. The effects of different scaling
procedures on total, regional and local deposition of inhaled radionuclides have been investigated for
different particle sizes and breathing patterns. The corresponding effects on the retention patterns of
inhaled radionuclides in bronchial airways are illustrated here for two radionuclides: Tc-99m (half-life
of 8 days), and J-131 (half-life of 0.25 days).
In general, the various scaling procedures (I) increase total, bronchial and acinar (only for intermediate
particle sizes), and (ii) increase retention in bronchial airways, relative to the corresponding simulations
based on the original morphometric data.
RADIOACTIVE FALLOUT NUCLIDES IN A PEAT-BOG ECOSYSTEM
2 Institut für Strahlenschutz, Forschungszentrum Seibersdorf, Austria
3 Institut für Pflanzenphysiologie, Universität Salzburg, Austria
In the present study, Cs-137 activities from the Chernobyl fallout were measured in the different
components of a peat-bog ecosystem in Koppl near Salzburg, together with soil parameters, such as
humidity, density and pH-value. The measured samples displayed a wide range of Cs-137 activities (in
kBq per kg dry weight): 1.2-11.3 (lichens), 2.4-6.2 (mosses), 1.9-99.8 (mushrooms), 0.8-5.3 (berries),
0.3-11.1 (higher plants), and 0.2-1.5 (bark). From the measured Cs-137 activities in different soil layers
(the Cs-137 activity decreases in a linear fashion with increasing depth), surface contaminations in the
range of 16.7-28.7 kBq/m2 could be derived. These values compare favourably with the soil
contaminations obtained from in-situ gamma spectrometry, based on the measured activity-depth
distributions.
MEASURES OF PLUTONIUM IN ENVIRONMENTAL SAMPLES
After the International Moratorium in 1963 no release of plutonium in the environment had happened
but the burn up of satellite Snap 9A in April 1964, therefore the plutonium concentration in air and in
fallout samples has continuously been decreasing, so it was necessary to carry out techniques for the
optimisation of instrumentation in order to obtain a better sensibility.
Due to the low activity in the environmental samples, long time measurements are necessary. For this
reason solid state detectors were used instead of ionization chambers, because the former gives more
stability. By this device sensibilities of the order of 10-5 Bq.m-2 in fallout, of 10-6 Bq.g-1 in soil and of
10-8 Bq.m-3 in air, were obtained. In this work correlations between atmospheric parameters and
concentration of plutonium in the samples were considered.
THE APPLICABILITY OF LICHENS AS RETROSPECTIVE BIOMONITORS OF
THE RADIOACTIVE CONTAMINATION IN A MOUNTAIN ECOSYSTEM
2 Institut f¨r Pflanzenphysiologie, Universität Salzburg, Austria
In this study, soil and lichen samples were collected from the Stubnerkogel in the Gastein valley, in the
south of the Province of Salzburg, Austria. The samples were taken in the summer of 1993, i.e. more
than 7 years after the Chernobyl nuclear accident. The measured lichen and soil samples had Cs-137
activities between 400 and 5000 Bq per kg dry weight.
The results of our study suggest that lichens can be used as retrospective biomonitors of the radioactive
contamination even a few years after the fallout event. However, the initial contamination pattern of
lichens may be modified by several biological factors in the years following the radioactive fallout.
Hence, only lichens from sites with similar growth conditions should
be considered.
SOME ASPECTS OF CESIUM DEPOSITION IN TRANSILVANIA (ROMANIA)
Our measurements were made using a NP 424 type of four channels gamma analyzer coupled with a
large NaI(Tl) scintillator (76x45 mm). The calibration of this installation was made in two different
ways: a) by simulation of a volumetric sample using a 137Cs punctual source and b) using romanian
standard samples prepared in the frame of the Environmental Radioactivity
seminar.
The measurements made using undisturbed soil samples give values between 4-60 kBq.m-2 and show
an accumulation of cesium at the base of the slopes.
Following a determination of 137Cs from a roof deposit sample of Cluj-Napoca city also using the
gamma spectra obtained immediately after Chernobyl disaster we estimated the other deposit as: 95Nb,
103Ru, 125Sb, 144Ce, 131I, 140Ba, 129Te. For the total contribution in this region we obtained 1.130
kBq.m-2 much larger than the average in Romania.
Reference:
[1] C.Cosma et al.,Studia Universitates Babes-Bolyai, Physica,33(2),65(1988).
ANALYSIS OF RESPONSES FROM AN ENVIRONMENTAL AIR MONITORING
SYSTEM
2 Bitt Technology, Spillern, Austria
INTERNAL CONTAMINATION FOLLOWING
THE CHERNOBYL NUCLEAR REACTOR ACCIDENT
Both measurements were made using a Whole Body Counter, equipped with a NaI(Tl) thyroid detector
and a NaI(Tl) body detector.
From the activity, experimentally determined, we calculated the beta and gamma equivalent dose in
thyroid, using the 364 key peak-area of the Iodine- 131. For the measurement
period, this was 1635 uSv, compared with 2800 uSv thyroid equivalent doses
reported for Romania to the United Nations of
Scientific Committee (1988) Fig.XVI.
For Cs-134 and Cs-137, we calculated the effective doses, separately. In the period from May 1986 till
December 1989, the total effective dose accumulated from intake of Cs-134 and
Cs-137 was 352.3 uSv, from which 150.6 uSv was the contribution of Cs-134
and 201.7 uSv was the contribution of Cs-137,
values which are in accordance with effective doses values reported for Romania ( Bucharest area ) to
the United Nation Scientific Committee (1988) Table 20.
The correlation between body burden with these radionuclides and food
consumption is also described.
THE CONCENTRATION OF RADIOACTIVE STRONTIUM
AND TOTAL STRONTIUM IN SOME SAVA RIVER SAMPLES
The objective of this paper is determineted radioactive strontium (90Sr), total calcium and total strontium
in the samples of the Sava river (water, sediment and some species of fishes), to calculate the values of
"concentration factor" parameter.
RADIOACTIVE CONTAMINATION OF ANIMAL BONES BY 90Sr
Long term-data on 90Sr activities in bones of some domestic animals (cows, pigs and lambs) are
presented. As a refractory component of the radioactive debris originating in the Chernobyl nuclear
accident, strontium was not subjected to global dispersion processes, being mainly deposited around the
accident site. Therefore, in Croatia the Chernobyl nuclear accident caused only slight increase in the
lamb bones, while bones of cows and pigs remained practically unaffected.
Using simple mathematical model, turnover rates and corresponding mean residence times of 90Sr in
bones for respective species were estimated.
MOBILE RADIOLOGICAL LABORATORY -
REGULAR EXERCISES AND INTERCOMPARISON MEASUREMENTS
There is a negligible possibility that equipment and teams will operate properly in an emergency without
regular training of teams and working with equipment. For these reasons it has been a practice from the
very beginning to have several field exercises each year. As a part of the emergency programme the team
visits three times a year the nuclear power plant and its surrounding. Several field intercomparison
measurements of liquid and atmospheric samples are made with the stationary and mobile laboratory of
the nuclear power plant. The team visits fixed sampling points around the power plant that are used for a
regular monitoring programme and are also planned to present the backbone of the offsite emergency
control system. All the equipment is tested in field conditions.
Besides there are other occasions to get more experience - the team has regularly participated in
intercomparison field exercises in neighbouring countries and has also been involved in field
measurements in suspected and true cases of radiological emergencies.
MONITORING OF RADIOACTIVE RELEASES
AND ENVIRONMENTAL IMPACT OF PAKS NPP
The health authority has limited the maximum radioactivity discharges to the environment in such a
way, that no one of the surrounding population could accumulate more than 250 uSv/y effective dose
equivalent relating to 1 GWe capacity. The corresponding limits for airborne and liquid effluents are
167 uSv/y and 83 uSv/y effective dose equivalent, respectively. According to these regulations derived
limits are established for gaseous and liquid discharges.
At Paks NPP the monitoring of radioactive releases and environmental presence of radioactive material
are performed by telemetric systems and analysis samples taken from emissions and environment. The
sensitivity requirements of these measuring methods need to be met the derived limits and potential
activity concentration in different environmental media.
The introduction of above mentioned monitoring programme and of the recent results are the subject
of our poster paper.
DETERMINATION OF RADIOSTRONTIUM AND ACTINIDES IN SOME ENVIRONMENTAL
SAMPLES OF ALBANIA
Regarding actinides determination in Albanian soil and sediments, several radiochemical manipulation
were necessary. The choice of a particular method was the object of some criteria, like its selectivity and
separation efficiency. A brief description of the necessary steps for actinides separation method is given,
including the dissolution of ashed sample with mineral acids, the selective anion exchange
chromatography method for Pu, Am, U, Th separation from Am of U by liquid-liquid extraction with
conc. TBP and finally the preparation of thin sources by rare earth fluoride cooprecipitation using
membrane filters.
The measurements of actinides by a Canberra alpha-spectrometric system supplied with a solid state (PIPS)
detector are presented. The results of our lab. and that of IAEA
(Seibersdorf) are reported.
References:
FIELD MEASUREMENTS ON HIGH ALTITUDE ALPINE AREAS OF AUSTRIA
2 University of Salzburg, Austria
3 Austrian Research Centre Seibersdorf, Austria
The measurements confirmed the high fallout radionuclide concentration of Chernobyl origin and gave
an indication of very different depth distribution characteristics in the soil. A new method of in situ
gamma spectrometry with collimated detector arrangement was tested and compared to the traditional
uncollimated wide area monitoring method. In the course of the exercise the recently established on-route monitoring system was used. With this investigation interesting fluctuations in the environmental
radiation level due to natural radioactivity was detected.
The results of the measurements obtained during the field exercise will be
presented in the paper.
ENVIRONMENTAL MONITORING OF 137CS IN
THE VARDAR RIVER CATCHMENT AREA
2 Center for Application of Radioisotopes in Science and Industry,
P.O.Box 274, 91000 Skopje, Macedonia
By application of radioecological. model on effective dose equivalent for different transfer media and
exposure pathways as a contribution of 137Cs to the total exposure
of a man were calculated.
ENVIRONMENTAL RADIOACTIVITY AROUND THE FORMER COAL MINE
A pilot research study was performed recently concerning the levels of radioactivity in the mine
environment to acertain the possible impact of the former mining activities on the surroundings. A
comprehensive programme of sampling and radiation measurements covered the following items:
gamma dose-rate measurements on the coal and ash tailings deposit and outside the area, analysis of
deposited materials, radon and radon daughter measurements outdoors and indoors, and radioactivity
of the lake water.
Results showed that coal samples and mixtures with ash, coal and soil contain high quantities of
uranium and radium. Great variations in contents of natural radionuclides (U-nat, 226Ra) were found,
mainly in the range of 400-1200 Bq/kg, but in some places even more than 4000 Bq/kg. Radioactivity
in the disposal terrain is not uniformly distributed; in some parts of the depository gamma dose-rates
up to 0.3-0.4 uGy/h were measured. Mainly, values of 0.20-0.25 uGy/h were found over the total area.
Radon in dwellings was also measured: winter daily radon concentrations in houses, built on or near the
affected area, reach up to 2600 Bq/m3 with an average of 200 Bq/m3 in living rooms, while in cellars
concentrations in one case reached 3150 Bq/m3. Most of these houses are made of local clay bricks, so
indoor gamma dose rates were expected to be enhanced; we found values mostly around 0.15 Gy/h.
Due to leaching of excavated materials by precipitation, the radioactivity of lake water (and also seepage
water) is evidently higher than in other surface waters, i.e. at minimum by an order of magnitude: 226Ra
30 Bq/m3, 238U 160 Bq/m3. Some measurements are still in progress.
The town of Kocevje is situated in a totally closed circular valley. In the period of strong temperature
inversions we measured relative high radon and radon daughter concentrations: for radon a daily
average about 80 Bq/m3 with early morning maxima even up to 150 Bq/m3. These are surprisingly high
figures when compared to simultaneously measured values in the region of the uranium mine area
around the Zirovski vrh. In spite of a large U mine waste deposits and tailings pile, which represent high
emission sources of radon, the concentrations of outdoor radon in the nearby surroundings of the
uranium mine never reach these values. Uranium contents in soil in the Kocevje region far exceed the
national average level. This feature, together with millions of tonnes of waste coal tailings and ash, are
obviously the reason for the highest occurrence of outdoor radon. The map of indoor radon in Slovenia
also confirms this finding: the Kocevje community is categorized among radon prone areas with an
average annual indoor concentration of radon being 160 Bq/m3.
TERRITORIAL NETWORK OF TLD IN CZECH REPUBLIC
STUDY ON DETERMINATION OF PLUTONIUM ISOTOPES IN SOILS
FROM LUBLIN REGION (POLAND)
The analytical quality of the method of plutonium isotopes determination was verified by analyzing the
IAEA reference material: Soil-6. Using a Students's t-test we found that
a difference between Pu-239,240 contents obtained and a certified value
is statistically insignificant.
For plutonium radiation measurements we use the Canberra's alpha spectrometer equipped with partially
depleted PIPS detector of 20 keV FWHM resolution, and efficiency of 46.5%.
We determined the plutonium isotopes contents in the samples of upper layers of different soils
collected in Lublin region. It was found that the amount of Pu-239,240 in all samples ranged from 0.074
to 0.337 Bq per kg dry weight of soil, and Pu-238 from MDA to 0.026 Bq/kg.
The ratio of Pu-238/Pu-239,240 suggested rather a fallout origination of
plutonium isotopes determined.
The minimum detectable amount (MDA) of plutonium was calculated to
be 2 - 15 mBq/kg of soil
depending on radiochemical yield (as found with Pu-242 tracer) and a
time of measurement.
STUDIES OF THE PRESENCE OF GAMMA EMITTERS IN THE NATURAL
ENVIRONMENT OF EASTERN POLAND
From the ratio of activities of Cs-134 and Cs-137 just after the Chernobyl accident, the contribution of
after-Chernobyl Cs-137 and that from the global fall out to the total Cs-137 activity can be calculated
in particular segments of soil profiles. These data may be used to calculate the vertical migration rates
in various types of soil. In 1994 the after-Chernobyl radiocesium was found in the uppermost soil layer
down to about 10 cm. Its average contribution to the total contamination of the uppermost 5 cm layer
with cesium averaged 77%.
The total activity of grass in the studied area ranged from 15 to 1375 Bq/kg of dry matter. The activity
of radiocesium in grass in the studied area ranged from 1 to 172 Bq/kg of dry matter and it depends on
the type of soil and on the contents of potassium in the soil. The calculated transfer factors (TF) of Cs-137 from soil to grass range from 0.03 to 21 and in most cases they decrease when TF of K-40
increases.
The radioactivity of the ground layer of the atmosphere was as low
as 1.2 to 3.4 mBq/m3.
The present results suggest that there was no substantial radioactive fallout in Central-Eastern Poland
over the last year.
NATURAL AND ARTIFICIAL RADIONUCLIDES IN LICHENS
AS AIR POLLUTION MONITORS
2 Biotechnical Faculty, Department of Agronomy, Jamnikarjeva 101,
61111 Ljubljana, Slovenia
The epiphytic lichen Hypogymnia physodes L. (Nyl.) was collected at 86 sampling points of the 16 x
16 km bioindication grid of Slovenia and the levels of 210Pb, 40K, 134,137Cs were determined by direct
counting of dry samples using gamma spectrometry. U and Th levels were determined by the k0-standardisation method of Instrumental neutron activation analysis.
The results are presented as geographical isocontours of radionuclide activity on a national scale. The
geographical distribution of radionuclides obtained from lichen data were divided into 7 classes
according to percentile values (10, 30, 50, 70, 90 and 95 %) and were mapped using the Surfer
programme.
Each of the radionuclides analysed has its own geographical distribution pattern as a consequence of
its origin. 210Pb is the long lived radionuclide produced in the atmosphere by radioactive decay of its
gaseous parent 222Rn, 40K, U and Th are natural radionuclides contained in the lithosphere, but
137+134Cs were released to the atmosphere during the Chernobyl accident and in atmospheric nuclear
tests.
The mean value of 210Pb was about 600 mBq g-1, with the highest activity levels up to 1900 mBq g-1
in lichens collected in the southern - Dinaric region of Slovenia.
40K levels were in the range between 65 - 290 mBq g-1. Elevated levels were found in NW and W parts
and at some locations in the east of Slovenia. Also the U and Th levels in lichens were low as expected,
with mean value of 0.12 and 0.29 g g-1, respectively. The highest activity of both Cs-isotopes was
found in samples from the north and north-west parts of Slovenia, which are known to have received
the highest amounts of precipitation during the period following the Chernobyl accident.
ENVIRONMENTAL RADIOACTIVITY DUE TO FLY-ASH DISPOSAL -
RESULTS OF A MONITORING PROGRAMME
** ERICo, Velenje, Slovenia
Radioactive materials released into the environment are dispersed and transferred through various
environmental pathways, leading to external and internal radiation exposure. A short term surveillance
programme was conducted to investigate these routes.
Results showed enhanced gamma radiation: dose-rate levels are significantly higher mainly within the
area of the uncovered deposited material. Airborne radioactivity also originates from dry uncovered
surfaces: the important pathways are inhalation of dust particles with long-lived radioactivity, and
inhalation of radon with its short-lived progeny. Periodic high concentrations of air particulates due to
wind erosion of bare areas, were observed even at moderately distant locations. Superficial radioactive
contamination of vegetables and grass was also taken into account and measurements are still in
progress. Surprisingly, the average concentrations of radon and its daughters over the landfill were in
very similar to those in its nearby vicinity. The attention at this point is now focused on short term
measurements, preferably in very stable weather conditions.
Leaching of radionuclides with lake and rain water and pile drainage water are the main sources of
radioactive contamination of the lake, its outflowing waters and sediments.
The high alkalinity of lake water due to the presence of fly ash (the pH is nearly 11) strongly influences
the solubility and therefore the radionuclide concentrations: a very low concentration of uranium was
measured while radium (226Ra) is present in concentrations an order of magnitude higher than in other
uncontaminated waters. River sediments also showed increased river bed radioactivity even at longer
distances from the discharge points.
As far as we know, a similar surveillance programme on fly-ash disposal has not been performed
elsewhere; the main conclusion of some previous investigations, covering only some of the pathways,
was the absence of any radiological impact. Based on our results, an extended programme will be
carried out next year to ensure a more complex evaluation of the environmental impact. The programme
will also include radioactivity measurements of local precipitation, continuous measurements of radon
and its daughters, and extended measurements of radon exhalation rates from various materials. It will
ensure the present state of radioactive contamination on the site and its surrounding is precisely defined
and later, to assess possible positive effects of remediation measures and restoration of the site.
RADIATION WARNING SYSTEM IN SLOVENIA (ROSS)
The system will consist of 30 gamma dose rate stations and 2 alpha and beta aerosol monitors connected
to the central computer. Meteorological data will be also collected.
A radiological network of four stations around NPP Krsko already works. In 1995 it will be
supplemented with 9 new gamma monitors on different places. Data are collected automatically on
every half an hour.
10 independent gamma monitors already work on meteorological stations. Data are manually collected
once a day by phone call to the sites. Automatic connection to the centre is planned via the public
switched telephone network. Gamma monitors are MFM-202, made in Slovenia by
Institute "Jozef Stefan". Alnor Area Radiation monitoring System AAM-95 is also tested.
137Cs IN NORTHEREN ADRIATIC SEDIMENTS
2 Department of Geology, Faculty of Natural Sciences, University of
Zagreb, Croatia
A LONG-TERM STUDY OF CAESIUM TRANSPORT IN A RIVER OF THE
ITALIAN ALPINE REGION AFTER THE CHERNOBYL RELEASE
A strong seasonal variation of water 137Cs concentrations was observed, with elevated concentrations
in summer and lower concentrations during all the other seasons. Increased water concentrations in
summer were attributed to caesium deposition and accumulation on snow-covered surfaces in winter
and then released in summer during ice and snow melting as a consequence of the seasonal increase of
temperature. An attempt of relating the observed cyclical variations with estimated transfer rates from
the catchment has also been performed.
SESSION IV:
NUCLEAR INSTRUMENTATION AND DOSIMETRY
CHARACTERIZATION OF TL DOSIMETERS FOR DETERMINATION OF THE
GAMMA COMPONENT IN A MIXED n+ RADIATION FIELD
* Institute for Isotopes, 1526 Budapest, P.O.B. 77, Hungary
After mixed field irradiation, some detectors were read at Valduc, others at the Ru er Bo kovi Institute
(RBI). The readings have shown the agreement between the Valduc and RBI gamma field calibrations.
After readout the recalibration of the response to gamma rays and accurate determination of fading
kinetics was performed. No change of sensitivity after neutron irradiation could be observed with TLD-700 and CaF2:Mn detectors. The reproducibility of Al2O3:Mg, Y detectors deteriorated somewhat, with
no systematic change of sensitivity. The sensitivity of TLD-100 detectors changed after neutron
irradiation.
CALCULATED ALPHA COUNTING EFFICIENCY OF A SAMPLE/DETECTOR
GEOMETRY FOR AMBIENT RADON PROGENY MEASUREMENT
The alpha detection efficiency is determined by the effective solid angle and by the alpha energy
absorption in the various sections of the sample/detector geometry. For most commercial instruments,
with concentric sample and detector, absorption along the longest path, i.e. diagonally across the
measuring geometry, is sufficiently low for an alpha particle still to produce a detector signal above a
threshold. In that case only the effective solid angle needs to be calculated for the gross alpha counting
efficiency. For point sources the solid angle subtended by the detector can be calculated, and the
effective solid angle is obtained by averaging for source elements over the whole source. In the more
general case of spectrometric efficiency the effective solid angle needs to be evaluated for specific
intervals of residual energy of alpha particles that reach the detector.
In a preliminary study using a certified alpha source, calculated and measured efficiencies showed good
agreement under varied measuring geometries. The use of the calculation method of calibration could
complement, or even to some extent replace the more costly radon chamber calibration of radon progeny
instruments and should assist in better quality assurance in the assessment of public radiation exposure.
MEASUREMENT OF DISSOLVED RADON AND RADIUM CONTENT OF
WATER SAMPLES BY TRACK ETCH TECHNIQUE
2 Department of Radiochemistry, University of Veszprem, H-8200 Veszprem,
Egyetem ut 10, Hungary
3 Bessenyei György Teacher's Training College,
H-4401 Nyiregyhaza, POB 166, Hungary
We found that the method allows a cheap and simultaneous examination of a large number of samples.
TSEE CHARACTERISTICS OF LiF:M,C,P DETECTORS
EQUIVALENT DOSE MEASUREMENTS IN AIRCRAFTS WITH TLD S UNDER
CONSIDERATION OF THE PEAK HEIGHT RATIO
* Atominstitute of the Austrian Universities, A-1020 Vienna,
Schüttelstrae 115, Austria
** Institute of the German Airforce, D-82242 Fürstenfeldbruck, Germany
For evaluation of the fraction of thermalized neutrons and fast neutrons (including protons and other
charged particles) of the equivalent dose the neutron energy dependence of the TL-response was
calibrated using TLDs embedded in polyethylen spheres (diameter 25 cm) in a special arrangement. The
calibration was performed with several neutron sources (thermal, Pu-Be, Am-Be and 14 MeV neutrons).
The results show that with the applied method information of the fraction of the different kind of
radiation depending on the geometry can be obtained. Additional measurements with active systems
were performed and the results compared.
QUANTITATIVE DETERMINATION OF THE TRANSURAN ISOTOPES FROM
EVAPORATING RESIDUE AND PURIFIED WATER DISCHARGES OF NUCLEAR POWER PLANT
PAKS
** Ist Dept. of Medicine, Medical University of Pecs H-7643 Pecs,
P.O. Box: 99, Hungary
*** NPP Paks, 7031, Paks, Pf.71., Hungary
Thin sample layer for the alpha spectroscopy was prepared on a new way in a cathode potential
regulated electrodeposition cell to increase selectivity. The activity-concentration values were calculated
in a usual way know from the literature. The usefulness of process are demonstrated on authentic sample
spectra.
SELECTIVE INSTRUMENTAL MONITORING OF RADIOIODINES IN NPP PRIMARY
COOLANT
** Technical University Budapest, Institute of Nuclear Technics, H-1521,
Budapest, Hungary
* NPP Paks, 7031, Paks, Pf.71, Hungary
Direct measurement of the coolant is disturbed by it's high matrix activity, therefore radioiodines have
to be separated.
A method has been developed to select radioiodines by chemical separation. Iodine selectivity of the
method was determined and proved. Neither ionic or non-ionic nor gaseous components were found in
the selected sample.
On the basis of this method a computerised apparatus has been built and tested at the Hungarian power
plant at Paks city. Radioactive concentration of all of the five radioiodine isotopes are continuously
monitored selectively and results are produced in every 15 minutes.
Characteristics of the apparatus:
- high selectivity of radioiodine analysis
- for gamma-spectrometry a simple NaI(Tl) scintillation detector is applied
- simple and not expensive accessories and materials are used
- there is no radioactivity accumulation in the system during a long
period of operation
- automatic operation without the need of human control for several weeks
- apparatus as an industrial equipment can be placed on line
primary coolant sampling.
Apparatus is advised to be placed in pressurised water type nuclear power plants especially in Eastern
Europe, Russia, Ukraine etc.
INTELLIGENT NUCLEAR SPECTROMETER
The main purpose of the development was making a low-cost device, that employs the existing old-type
scintillation probes in multichannel analyzer, taking out the simple
multiscalers.
The device based on an 8-bit microcontroller. This one deals with the data collection and the
communication towards the PC. The signals coming from the scintillation probe are received by a 256-channel Wilkinson-type A/D converter (programmable amplification). The also programmable output
high voltage to the photomultiplier has an excellent dc stability
( 800-1200 V +- 0.1%).
The communication towards the PC is through the very popular RS-232C interface.
The device can run on battery or on ac power supply, suitable on in-situ measurement too.
The handling program is running on the PC under the Microsoft Windows v3.1 environment. Using the
possibilities of the operation system (Dynamic Data Exchange = DDE) the measured data can also be
processed with other popular software (e.g.: MS-Excel, Lotus 1-2-3 etc.).
The base-software contains:
- setting the amplify and the high voltage
- count rate monitoring
- calibration: energy, efficiency, FWHM
- peak search
- smoothing (5, 7, 9 points)
- documentation
- some built-in standard measuring method
A PROCEDURE FOR THE CONTINUOUS CONTROL OF THE RETENTION
PROPERTIES OF GAS ADSORBER SYSTEMS
** NPP Paks, 7031, Paks, Pf.71, Hungary
For the optimal operation of the adsorber units the on-line control and analysis of the retention
properties would be required. Therefore a procedure has been developed for the determination of the
retention times and the dynamic adsorption coefficients for the specific noble gas isotopes. The method
is based on the continuous analysis of the in- and out-flow of the adsorber system by gamma- ray
spectroscopy using semiconductor detectors.
After the successful laboratory test, the procedure was installed and the retention properties of a charcoal
based radioactive gas adsorber system were determined.
For the evaluation of the data, a theoretical model was developed, which was used for the calculation
of the dynamic retention coefficients of the noble gas isotopes.
The brief introduction of the procedure and some relevant results are the subject of the presentation.
IN-SITU GAMMASPECTROMETRY INTERCOMPARISON EXERCISE
IN SALZBURG / AUSTRIA
2 Institute of Physics and Biophysics, University of Salzburg, Austria
3 Health Physics Department, KFKI Budapest, Hungary
THE IMPORTANCE OF LOCALISATION WITHIN 131J-RETENTION
MEASUREMENTS
2 Austrian Research Center Seibersdorf, A-2444 Seibersdorf, Austria
3 Department of Nuclear Medicine, University of Vienna, A-1090 Vienna, Austria
To demonstrate the power of this high sensitive method we investigated patients with total thyroid
ectomie. To ensure the absence of new metastasis oral dosis with 20 uCi has been provided. One hour
and 72 hours later profile scan measurements with a whole body counter using a special detector
configuration have been done. Looking just at the retention values the possible presence of thyroid
tissue cannot be excluded of certainty but regarding the spatial resolution in addition a decision between
localisation and dislocalisation is possible. Therefore it can be decided about the physiological or
pathological meaning of these retention values.
QUALITY ASSURANCE OF ACTIVITY MEASUREMENT IN RADIATION
MONITORING NETWORK OF CZECH REPUBLIC
To ensure compliance of the measurement from all laboratories, interlaboratory comparisons are
organized by the Centre of Radiation Hygiene NIPH at least once in a year. For the aim of the
intercomparison exercises, different reference material with unknown mixture of radionuclides is usually
supplied to individual laboratories of RMN. As one of their important task is to determine radionuclide
activity in the case of any radiation accident as quick as possible, intercomparison exercise was aimed
a.o. on the quick response and on the determination of radionuclides activity in sample of non-standard
measuring geometry. Laboratory of gamma-spectrometry of the CRH NIPH, who organizes these
intercomparisons, participates regularly in international intercomparisons, including intercomparisons
of whole body counting.
DETERMINATION OF THE SELF-ABSORPTION IN ENVIROMENTAL
SAMPLES OF MARINELLI-GEOMETRY AND HPGE-DETECTORS USING
MONTE-CARLO-SIMULATIONS
In gamma-spectroscopy the self-absorption-coefficients are very important if the mean free paths of the
photons are different in calibration- and sample-materials due to other chemical compositions or/and
different densities.
It is the purpose of this study to find an analytical term for self-absorption for Marinelli-geometry by
fitting results of Monte-Carlo-calculations. This term is required to cover the desired energy range as
well as arbitrary chemical compositions and densities.
The numerical simulations of self-absorption-coefficients for Marinelli-geometry make use of the
Monte-Carlo-transport-code EGS4 for photons and electrons. Calculations are made for photon energies
in the range from 20 keV up to 2 MeV for HPGe-coaxial-detectors. We consider environmental samples
with densities between 0.1 g/ccm and 2.0 g/ccm. Self-absorption-coefficients are calculated (a) by
means of attenuated photon flux and (b) the energy depositions by photons in the detector. Results of
both methods are compared with experimental data.
There is a good agreement between the simulated and experimental results.
CHARACTERISTICS OF X-TEST INSTRUMENT FOR MEDICAL DIAGNOSTIC X-RAY
MACHINES
2 MicroVacuum Ltd., H- 1 147 Budapest, Kerekgyarto u. 10, Hungary
3 SFW Software Anstalt, H- 1 13 3 Budapest, Kapat u. 44, Hungary
The X-TEST instrument provides a very simple and low cost tool for every-day quality test of the X-ray
machines allowing the comparison of the measured dose value to the reference dose levels.
The main characteristics of the X-TEST instrument are small size, portable, rechargeable-accu operated,
using Si(Li) detector, automatic reset after exposure. An 8 character LCD display presents the output
readings for dose, dose-rate, exposure time and homogeneity factor. The applied small current
integrated circuits, microcontroller assure very reliable operation. In addition to the detailed technical
characteristics, the results of intercomparison measurements are also going to be demonstrated.
COMPUTER AIDED NUCLEAR RADIATION MEASUREMENT AND EDUCATIONAL
SYSTEM
In our presentation we will demonstrate the main application fields:
Examination of the statistical nature of the nuclear decay
Examination of the distance dependence of the radiation field
Absorption of the nuclear radiation in different materials
Continuous monitoring of background radiation with alarm
The G-MES system consists of a nuclear radiation monitor, a computer interface, an IBM compatible
PC with WINDOWS operation background and the G-MES software.
The G-MES system software utilises all the benefits supplied by the WINDOWS operation. The
software can be easily controlled from the MENU items. The measured data are continuously
demonstrated in graphics on the display and can be saved and printed. Theoretical and practical
information are implemented in HELP file and can be reached without interrupting the measurement.
The G-MES system is available in English, German and Hungarian language.
IN-SITU GAMMA RAY SPECTROMETRY FOR MEASUREMENTS OF
ENVIRONMENTAL RADIOACTIVITY
ENVIRONMENTAL DOSE MEASUREMENT WITH MICROPROCESSOR
BASED PORTABLE TLD READER
Due to application of new electronic circuits the reader read out
precision equal to 0.1 uGy, the
background stability is about +-1 uGy. Each bulb is combined with a memory chip containing the
individual identification number of the dosemeter. This number is automatically registered during read
out process as well as the time of measurement and the temperature inside the reader. The
microprocessor calculates the corrected dose and writes all date on a memory card together with the 100
channel glow curve up to 4000 measurements. The rechargeable battery operated reader weights about
2 kg.
Using the mentioned TLD system the usual environmental gamma-radiation doses can be measured with
time period 2-3 days without any transport dose. As the measuring range of the system covers more that
six orders of magnitude both the normal and accidental environmental doses can be measured. The
portable reader significantly accelerates the availability of accidental doses.
The space version of the reader shall be used by ESA astronaut on the board of the Mir space station
in second half of 1995.
ONION ROOT TIP CELL SYSTEM FOR BIODOSIMETRY?
* Institute of Oncology, Department of Radiobiology, Zaloska 2,
61000 Ljubljana, Slovenia
Irradiations were performed on onion ( Allium cepa L.) with 60 Co gamma rays in two series of
experimental plants. In the first one, 2-3 cm long roots in tap water were irradiated with single doses
of 1, 3, 5 and 8 Gy at the dose rate of 1.6 Gy/min and samples for cytogenetic analysis were taken 6,
12, 24, 30, 48, 54, 72 and 78 hours after each irradiation and the control. In the second series dormant
onion bulbs were irradiated with 10, 20 and 30 Gy at the dose rate of 1.8 Gy/min and samples for
cytogenetic analyses were taken 6, 8, 11, 15 and 20 days after irradiated and control bulbs were planted
and grown in field conditions. Squash-slides of onion root tips were prepared for cytogenetic analyses
by standard methods, and the mitotic indices (MI), frequency of chromosomally aberrant cells (AC) as
well as frequency of interphase cells having micronuclei (MN) were determined for each sampling time,
radiation dose and the control.
The results of cytogenetic analyses in onion cells of both experimental series reveal the dose dependent
relationships of MI, AC and MN but, they are statistically not significant enough to be used as biological
dosimeter of absorbed radiation dose in plants from natural environments.
A WHOLEBODY COUNTER WITH SEMICONDUCTOR DETECTORS FOR
RADIATION PROTECTION MEASUREMENTS
DAILY AND SEASONAL VARIATIONS OF OUTDOOR ALPHA-ACTIVITY
CONCENTRATION IN SALZBURG CITY/AUSTRIA
Three different components of variations could be identified with regard to temporal variations:
Short-term diurnal component (daily variation), mid-term component (days to weeks) and long-term
component (seasonal variation). Large diurnal variations could be observed reaching up to one order
of magnitude, depending on the prevailing meteorological conditions.
Variations in that time range of days to weeks are caused by to the local weather situation. Abrupt
changes in the time-dependent activity concentrations reflect fast changes in the weather situation,
which are characteristic for this geographical position at the northern slope of the Alps. The third
component with a period of months is due to long-term seasonal variations. The diurnal component is
most the pronounced, exceeding both the mid-term component due to the prevailing weather conditions
and the seasonal component. The results of continuous measurements of the outdoor alpha-activity
concentration over a time span of 1,5 years are presented in the paper.
PREPARATION AND INVESTICATION OF THERMOLUMINESCENCE
PROPERTIES OF CaSo4:Dy,Cu
Nowadays they are among the most sensitive thermoluminescent dosimeter (TLD) materials, thus
application to measuring of small dose are wide ranging. The dosimetric characteristics of CaSO4:Dy
is in the dose range of 10-6-1 Gy linear, and above 1 Gy it is supralinear.
The glow curve of CaSO4:Dy has peak(s) in three temperature range: at 80- 120 C low temperature
peak(s) (LTP); at 220-250 C dosimetric peak (DP); and about 350 C high temperature peak(s)
(HTP). Generally the LTP in responsable for fadding, while HTP accounts for supralinearity.
Reducement of LTP can be achieved by special purification of the starting materials [1], while that of
HTP is carried out by application of copper coactivator [2].
The effect of copper on the HTP of the glow curve was investigated in the concentration range of 0-0,3
mol % copper, at different Dy concentrations.
The CaSO4:Dy,Cu has been prepared - according to our method [3] - by crystallization from hot sulfuric
acid containing a small amount of hydrogen peroxide.
According to the data of measurements, the HTP (the deep traps) decreased significantly and the upper
limit of the linearity is increased more than one order of magnitude. Thus the application of
CaSO4:Dy,Cu may be extended to the field of the accident dosimetry as well.
The results of our investigations will be discussed in detail in the presentation.
References:
ELECTROCHEMICAL ETCHING OF CR-39 DETECTORS AT ROOM TEMPERATURE
It was found that the so called PEW solutions seemed suitable for the electrochemical etching at room
temperature without any chemical preetching of detectors.
The background obtained with electrochemical etching was determined at different electrical
parameters.
The sensitivity of CR-39 detectors was investigated for AmBe neutrons at different etching conditions.
IMPROVEMENT OF PERSONAL DOSIMETRY - POCKET DOSEMETER
* ALARA INSTRUMENTS, d.o.o.
Film and TLD dosimetry both have a certain delay in dose reporting, since the reports on occupational
doses are usually available to the users within 40 days after the actual exposure. This is particularly
important when the dose is received within the short-time interval or when the radiation source has some
technical failures. For that reason, the additional monitoring is recommendable. An electronic pocket
dosemeter is a device which serves as an on-line exposure monitor in daily routine, making dose report
promptly available to the user. The importance of this opportunity raises when significant exposure is
to be expected due to the nature of work or exceptional circumstances. Such dosemeters are already
available on the market , but we have developed one covering 8 main parameters such as exposure time,
dose rate, dose, total dose, dose limit etc. Pocket dosemeter is to be considered the addition to the
regular state dosimetry, able to complete the information on radiation exposure. In cases of any
irregularities, the information is promptly reported to the health officer in charge, so that the cause can
be eliminated as soon as possible. Therefore, personal film and TLD dosimetry carried out in our
Laboratory has been recently improved by pocket dosemeter usage.
REMOVAL OF Ra 226 FROM WASTE WATERS ORIGINATING IN MINING
AND PROCESSING OF URANIUM ORES,USING NATURAL ZEOLITES
The waste waters having contents of more than 3.7 Bq 226 Ra/liter, have been passed through simple
and double columns at different flow rates and geometres of columns (height/diameter).
On the basis of the experimental results,the parameters of the procedure have been established, which
enable us to obtain a radium removal efficiency of more than 95% at the passage of above 2000 BEV
waste waters.
Some elution tests of radium have been effectuated, too, which have proved that natural zeolite can be
used, if it is useful, in several sorbtion cycle, the efficiency of removal remaining at high values.
The analytical control of processes has been achieved by radium 226 determination (indirectly by
measurement of its daughter-radon 222).
FAST NEUTRON SPECTROMETRY WITH THE STYLBEN CRYSTAL
SCINTILLATOR AND PULSE SHAPE DISCRIMINATION
**Medical Center and Health Services and Management Cluj, Romania
This device, we build, is able to saturate the pulses generated by the gamma photons depending on their
energy. So by cutting off the 4.43 MeV gamma photons the utilisation of a Cob-60 source is enough.
The value of the discrimination efficiency was 5*10-4 (gamma = impulse number which get into the
neutronic spectrum / number of all incident gamma photons) for a discrimination threshold get at En
*= 1 MeV. The standardisation of the recoil protons spectrum was made by using the Compton
electrons, generated by sources with known energies (actually we standardised with Emax = from
Compton edge). This energies are turned by the luminosity function into equivalent proton energy which
produce the same number of photons in the scintillator. This formula was checked with D - D and D -
T neutrons.
We calculated also the efficiency of the scintillator depending on the neutrons energy and we introduced
a correction factor that stands for he secondary effects which affect the recoil proton spectrum. The
neutronic spectrum was extracted from the recoil protons spectrum by using a unfolding programme.
The energetic groups that we established for the Am - 241 - Be - 9 source spectrum are in agreement
with the reference material.
SARAD EQF 3020 A NEW MICROSYSTEM BASED MONITORING SYSTEM
FOR THE CONTINUOUSE MEASUREMENT OF RADON AND THE
ATTACHED AND UNATTACHED FRACTION OF THE RADON PROGENY
*Fraunhofer-Institute of Microelectronic Circuits and Systems, Finkenstr. 61,
D-47057 Duisburg, Germany
Therefore we developed a monitorsystem using separated measurement heads for the single components
of the radon progeny which are in connection with an aerosol ( attached fraction ) and which are not (
unattached fraction ) by means of a filter combination consisting of screen ( mesh grid ) and glass fiber
filter.
The air to be measured passes the screen and the aerosol filter in an open geometry. The filtered air goes
to a measuring chamber where decay products from the radon present in the chamber volume are
deposited by an electrostatic field onto the third sensor. The air is pumped every 2h for 6min. After the
pump interval by automatically swivelling of the screen and one detector head start the decay detection
of the on the filters collected radon progeny. The A/D converters contained in the microsystems [ Streil,
et al. 1994 ] allow for a discrimination of radon, thoron and radon and thoron daughters. The monitor
SARAD EQF 3020 is optional also available with three conventional 2 cm2 PIN-diodes for the alpha
detection. The decay of the individual components is followed for 2h after pumping for the three sensors
to calculate radon and progeny concentrations.
With this protocol we get a detection limit of about 1 Bq/m3. At 100 Bq/m3 the statistical error is below
10% ( 1s ). Dead time losses of the sensor are below 10 % for up to 106 alpha particles per second and
cm2. Therefore concentrations of up to 10 MBq/m3 can be measured.
The efficiency of the radon-and progeny monitoring systems was proved in various applications like the
quality control of mitigation actions .
Dresden and Freital are placed in a high radon risk area with radon concentration in buildings up to 100
000 Bq/m3. In more than 50 new and old buildings radon mitigation action are tested.
Reference:
Streil, T., R. Klinke, A. Erlebach, P. Hübler, W. Kluge,
H. Kück and G. Zimmer; Sensors and Actuators A, 41-42 (1994) 85-87.
LOW-LEVEL GAMMASPECTROMETRY WITH GERMANIUM-DETECTORS:
EXPERIENCE WITH A NEW CALIBRATION METHOD
2 Atominstitute of Austrian Universities, Vienna, Austria
The peak- and the total-efficiency in dependence of the energy and the source-to-detector distance was
obtained by numerous measurements. In order to get a mathematical expression computer aided
parameter fitting was carried out.
A function of 27 parameters was found to describe the depencies of the peak-efficiency. An analogous
function (25 parameters) describes the total-efficiency-dependencies. Both approaches agree reasonably
well with the measured data.
The formula for the peak-efficiency epsilon is:
epsilon=a1*E**a2 * (1-exp(a3*E**a4))
where:
E - gamma-ray energy,
ai = ai (E, r, h, tan theta, s) - parameter functions
s = k0 + k1*E + k2*E2 - distance virtual point detector" - end cap
d - distance virtual point detector" - source
theta - angle between detector axis and d
These functions represent the measured efficiency data with an accuracy of only 3 % in the energy range
100-2000 keV.
This new method offers the advantage that the functions for efficiency-calibration can be generalized
to any other coaxial-detector of similar measuring geometry; for fitting the parameters only a few
measurements with calibration sources will be necessary.
SUM-PEAK AND 4 (PC)-GAMMA COINCIDENCES METHODS FOR RADIOACTIVITY
METROLOGY AT INP OF TIRANA
2 University of Shkodra, Albania
Thin pure Au and Mn-Cu alloy detectors are used for the absolute measurement of thermal neutron
fluency at different points of activation geometry of an Am-Be source by 4 - method. The
comparable respective values are given.
Due to the wide use in nuclear medicine and veterinary and the great interest of I-125 accurate
measurements, the sum-peak method is recently applied. The same solutions are standardized both by
our lab. and by Italian primary institute (INMRI/ENEA). Our values of their activity concentration
deviated less than -0.5% from those found by Italian institute. The procedures and the corrections
performed by INP are reported. Taking into account the total deviation range of 3.6% for 18 participants
of I-125 intercomparison, organized by BIPM (1988) and the Italian result there (+1.2% from mean
value), our bilateral comparison indirectly confirmed the correctness of our procedures and methods.
References:
SATURATION EFFECT ON ELECTROCHEMICALLY
ETCHED POLYCARBONATE DETECTORS
The saturation effect of electrochemically etched polycarbonate detectors (Makrofol) has been
investigated in laboratory and field conditions. Track densities of
up to 4000 tracks/cm2 have been used.
The tracks were counted manually on prints made with a microfiche reader. The results of these tests
show a non-linear response between radonexposure and trackdensity. By correcting for this non-linearity, we showed that electrochemically etched Makrofol detectors can be used for trackdensities
up to 4000 tracks/cm2.
To investigate the error on a radon measurement induced by the uncertainties on exposure time,
variations in etching conditions and manual track counting, a theoretical analysis has been conducted.
This analysis shows that the minimal error (1 sigma) we can expect for a radon measurement is in the
order of 20 % for track densities above 400 tracks/cm2. Under 100 tracks/cm2, the uncertainty raises
steeply.
CALCULATION OF THE ELECTRIC FIELD INSIDE ELECTRET IONISATION
CHAMBERS - INFLUENCE ON THE RESPONSE FUNCTION
2 Technical University Graz, Austria
Data of numerical field calculations inside cylindrical electret ionisation chambers are given. The
change of the field-strength distribution with respect to electret discharge is described. The influence
on the response function is discussed and experimentally verified.
The results lead to a good overview of the dynamics of the electret discharge inside ion chambers.
Possibilities for optimisation of these detectors are derived.
THE LUNG COUNTER FOR "IN-VIVO" ASSESSMENT OF
LOW ENERGY PHOTON EMITTERS IN LUNGS
The counting system consist of one phoswich detector, suitable to detect low level, low energy radiation
in the presence of high background.
The scintillation sandwich is composed by a NaI(Tl) crystal, diameter 127 mm and thickness 5mm,
optically coupled to a CsI(Tl) crystal, diameter 127 mm and thickness 50 mm, installed inside a steel
monitoring shield.
An additional "graded Z" lining consisting of 5 mm lead and I mm copper has been added.
The phoswich detector is connected to a pulse shape discrimination electronic chain for energy selection
and background reduction.
The whole system was calibrated using a male thorax phantom whose lungs were filled with standard
natural uranium pellets, simulating an even distribution. The activities of the lungs were 203.350 Bq
for the right and 141.624 Bq for the left. The obtained efficiency factors for the right and left lungs
were 5.14310-2 imp/Bqs and, respectively, 3.49310-2 imp/Bqs.
This paper will discuss the results of background reduction and the calibration of the lung counter.
A NEW DETECTOR SYSTEM FOR DIRECT ASSESSMENT OF DOSE
EQUIVALENT RATE DUE TO INCORPORATION OF GAMMA-EMITTING RADIONUCLIDES
In order to meet these difficulties, at Karlsruhe Research Center a new method for direct internal
dosimetry has recently been developed. The method is based on the measurement of the integral photon
flux emitted from the body using a special detector system, which has been optimized in such a way that
the system sensitivity matches the respective dose factors for a maximum number of radionuclides and
deposition sites in the body.
The detector system consists of four plastic scintillation detectors, which are positioned at the thyroid,
at the lungs, under the gastro-intestinal tract and over the thighs of the seated person. The detector
system is very easy to handle. The measurement can be performed by anybody without special training
and the results in terms of dose equivalent rate are available after a very short measuring time (20 s).
When performing one routine measurement per week, the lower detection limit is less than 0.1 mSv/a
and the mean detection uncertainty is about 20 % for known radionuclide mixtures, and about 60 % for
unknown radionuclide mixtures.
A METHOD FOR CALCULATING THE SPATIAL DISTRIBUTION OF
RADIOACTIVITY MEASURED BY A WHOLE BODY COUNTER
2 Austrian Research Center Seibersdorf, A-2444 Seibersdorf, Austria
3 Department of Biomedical Engineering and Physiks, University of Vienna, A-1090 Vienna, Austria
To achieve spatial resolution a special detector configuration was chosen. Using different point source
positions linear profile scans were measured systematically for various radionuclides (133Ba, 131J, 22Na,
137Cs, 60Co) over a wide energy range. Based on these data a model was developed. This model allows
to determine an unknown position of a point source in the pressedwood phantom and can be easily
extend to medical applications.
ACREM: THE AIR CREW RADIATION EXPOSURE MEASURING SYSTEM
An economical and simple method to record the radiation exposure is realised by a combination of
measurements with a reliable gamma dose rate instrument (SSM-1, Radiation Measurement System of
Seibersdorf) and using a software algorithm. Operating a GPS (global position system) in addition the
energy spectrum of the cosmic radiation, depending of the geographical position and altitude and from
this the total radiation exposure of the air crew is achieved. Uncertainties because of statistical events
of solar flares or the changing of altitude and route of the airline can be excluded compared to
calculation models only of radiation exposure determination.
AUTOMATIC SYSTEM FOR CONTINUOUS MONITORING OF GAMMA
ACTIVITIES IN ATMOSFERIC PARTICULATE
The air monitoring system includes:
- air sampler;
- spectra acquisition system;
- computer and various peripheral units.
The air sampler is formed by a filter holder and a suction unit.
The filter holder is directly mounted on the high-purity germanium detector, and was designed so as to
optimize both the flow rates of filtered air and the detection geometry of the radiations emitted by the
radionuclides eventually present.
Special attention was paid to minimize particulate losses along device ducts. Particulate losses showed
to be lower than 10%.
The designed automatic monitoring system allows to carry out the monitoring of air radioactivity
complying with the same operating parameters, which are used in the traditional manual procedure. The
minimum detectable activities and the particulate-collection showed, in every respect, to be equivalent
to the traditional system.
In addition, it allows to reduce, even to few minutes, the time intervals between different measurements
and, therefore, a continuous alarm system is available.
MANUAL TLD SYSTEM FOR MULTIPLE DOSIMETER FORMS AND
APPLICATIONS
2 Bicron Technologies Vertriebs-GmbH, Viktoriastrae 5, 42929 Wermelskirchen, Germany
The TLD reader incorporates independent dual hot gas and single planchet heating methods integrated
into one drawer. This supports the reader's use in such diverse applications as external whole body and
extremity personnel dosimetry, medical physics, environmental monitoring, spice and food irradiations,
archeological and high dose dosimetry. The various dosimeters include card-mounted chips in
symmetric and non-symmetric holders, high sensitivity LiF:Mg,Cu,P material, rods, microcubes, and
powder.
Application software to perform data acquisition and storage, Calibration, Quality Assurance and
Control, automatic glow curve analysis with identification of irregularities and neural network-based
algorithms is layered on the system to provide building blocks for increased capability.
Test data presented in this paper include sensitivity, linearity, minimum delectability, repeatability,
residual effects, ambient light sensitivity, glow curve analysis and algorithm performance.
SESSION V:
NON-IONIZING RADIATION
THE NEW EUROPEAN TEHNICAL STANDARDS ON THE HUMAN EXPOSURE
TO ELECTROMAGNETIC FIELDS
HIGH VOLTAGE POWER LINES IN ITALY:
QUANTITATION OF EXPOSURE AND HEALTH RISK EVALUATION
ASSESSMENT OF MAGNETIC FIELDS EXPOSURE FROM AC POWER LINES
IN AN ITALIAN RESIDENTIAL AREA
THE ITALIAN NATIONAL ARCHIVE OF RADIO AND TV BROADCASTERS:
PRELIMINARY EVALUATIONS OF HEALTH AND ENVIRONMENTAL IMPACT
2 Physics Laboratory, National Institute of Health, Rome, Italy
From the main archive, installed on PC, regional subsets may be extracted, which are managed by the
same application program, developed both for MS DOS and Macintosh. The data refer to 27,332 radio
and 28,769 TV broadcasters, for a total of 56,101 plants, a number probably higher than in any other
country. Preliminary analyses of data provide important information on the distribution, both
geographical and for class of power, of emitters. A detailed comparison of distribution of antennas and
population has been made, limited for the moment to the region Lombardy. Similar analyses are being
performed in other Regions, which are likely to be involved in the same kind of problems.
EVALUATION OF RECOMMENDATIONS ON LIMITS OF EXPOSURE TO
ULTRAVIOLET ON THE BASIS OF DATA FROM THE AUSTRIAN POPULATION
1. IRPA/INIRC (1991): 30 MED/a;
2. IEC 335-2-27 (1978, 1989): 25 kJ/m2/a for each region of the body, that is 100 MED/a.
On the basis of our data from the Austrian population (1) we can give an evaluation of the
recommendations for a whole population.
For the Austrian population older than 16 years we found for 1990 a mean UV-exposure of 53 MED
(22 MED for work outdoors, 29 MED leisure time and holidays, 1.5 MED solaria). A demographic
analysis shows, that the mean UV-exposure of more than of the Austrians is below 38 MED/a. Highly
exposed groups are outdoor workers (>4 h/d) with 125 MED/a, persons exercising summersports
outdoors and spending their holidays at the Mediterrian (84 MED/a) and the user of solaria (79 MED/a).
Only 9.8 % of the Austrian population use solaria. A frequency distribution of skin dose shows, that 80
% of them do not reach 30 MED/a, less than 1 % exceed 100 MED/a. The recommendation of the IEC
therefore is much too high, it seduces rather to use solaria than to restrict their application. We
recommend to adapt the international standard IEC 335-2-27 to the IRPA/INIRC
recommendations, so that irradiation schedules on the basis of an annual dose of 7.5 kJ/m2 and
skin area (that is 30 MED/a) should be drawn up.
Reference:
(1) Keck Gertrud, Cabaj A., Schauberger G. (1992): UV-Exposition der
Österreichischen Bevölkerung durch solare Strahlung in Beruf,
Freizeit und Urlaub sowie durch die Nutzung von Solarien, Hrsg. vom
Gesundheitsministerium für Gesundheit, Sport und Konsumentenschutz.
SECONDARY HAZARDS OF HIGH POWER LASER BEAM WELDING
Secondary hazards such as UV-radiation, ozone and fume produced by the laser-workpiece interaction
are more serious due to the every-day, long term exposure of the worker.
In this paper, an overview will be given of the secondary hazards associated with C02 laser welding.
The UV-radiation emitted by the high temperature plasma above the welding-keyhole and the ozone and
NOx production due to UV-induced photodissociation of oxygen and high temperature gas-phase
reactions will be discussed. Spectral measurements of the plasma emission showed that the allowed
dose for UV-radiation and blue light exposure per work day can be exceeded in as short as a few
seconds. Similarly, measurements and models of the ozone and NOx concentration showed that the
maximum workplace concentrations might be reached quickly if no appropriate exhaust and filter
system is installed.
SESSION VI:
RADIATION PROTECTION AND THE SOCIETY
IAEA POLICY AND PROGRAMME FOR EDUCATION AND TRAINING IN RADIATION
PROTECTION
The guidelines for planning Agency activities in this respect are based on systematic analyses of Member
State needs, and comprise concentration and standardization of efforts to assure both the highest possible
standard and cost-effectiveness of the programme delivered. The programme reflects the differences
amongst Member States in their radiation safety infrastructures and commitments to nuclear technologies.
For education and training activities, it is structured at three geographical levels (interregional, regional
or national). The modalities include:
- Post-graduate educational courses in radiation protection (in Arabic, English, French, Russian and
Spanish)
- Post-graduate educational courses in nuclear safety (in Russian and Spanish)
- Specialized training courses/workshops on selected aspects of radiation protection/nuclear safety
(interregional/regional/national).
Other mechanisms comprise: fellowships, scientific visits, seminars and educational/training material.
THE RADIATION PROTECTION PROGRAMME OF THE EUROPEAN UNION
AND THE ROLE OF UIR (INTERNATIONAL UNION OF RADIOECOLOGY)
The main features of the 4th Framework Programme 1994-1998 concerning the Radiation Protraction
are also considered.
The role played by the International Union of Radioecology (UIR). which was founded in 1978, both
in the past and in the present situation is acknowledged and the results obtained by the cooperation
among different groups of scientists and other institutions are emphasized.
THE NEW ITALIAN REGULATIONS IN MATTER OF RADIOPROTECTION
In the paper the general outline of Decree will be presented, and some particular aspects of the Italian
regulation will be discussed.
MONITORING PROGRAMME ARROUND NUCLEAR POWER PLANT KRSKO
2 Institute of Occupational Safety, Bohoriceva 22a, Ljubljana, Slovenia
3 "Rudzer Boskovic" Institute, Center of Marine Research, Bijenicka 54,
Zagreb, Croatia
4 Institute for Medical Research and Occupational Health, Ksaverska cesta 2,
41000 Zagreb, Croatia
RADIOLOGICAL PROTECTION PROGRAM AT KRSKO NPP
The basis for the operational and technical measures is provided by the Radiation Protection Manual and
ALARA Manual. The effluent control is based on the Standard Radioactive Effluent Technical
Specifications, and environmental surveillance is established according to the program defined by the
regulations. The dose constraints and performance indicators are used to assure the effectiveness of the
radiation protection program and provide a convenient follow-up tool.
The monitoring program results of each year show that there is no measurable dose to the public due to
radioactive releases. The commitment to the dose burden of any member of a critical group is assessed
to be below the dose constraint. Individual and collective doses of the workers are within a range typical
for the PWR's of a similar type.
ENVIRONMENTAL RADIOLOGICAL MONITORING AROUND TRIGA REACTOR
EMERGENCY PREPAREDNESS IN SLOVENIA
* Administration for Civil Protection and Disaster Relief, Ljubljana, Slovenia
The paper presents the general philosophy applied in Slovenia to the problem of emergency response;
background information on the Slovene nuclear power plant and nuclear energy programme;
experiences in the light of the recommendations provided by the international bodies; and finally legal,
organizational, planning and reviewing aspects of the Civil Protection Organization applying to
radiological emergencies.
EFFECTIVENESS TESTS OF RADIATION DETECTION SYSTEMS
FOR VEHICLES CARRYING SCRAP METAL
These systems generally consist in two or more detector assemblies located on the two sides of the
railcars or lorries approach. The detectors are connected to a computer-controlled alarm system which
usually includes special diagnostic and sensitivity controls. However the overall effectiveness of the
system, in terms of high sensitivity-i.e. high detection probability of low activity sources - and low false
alarm rate, depend on a strict initial test procedure and subsequent correct routine checks. In this
connection different acceptance protocols based on a number of sensitivity tests and false alarm
rejection checks have been proposed, e.g. by the American Institute of Scrap Recycling Industries and,
most recently, by the Italian Health Ministry.
CRAD, being charged of the installation and management of a radiation detection system for vehicles
carrying scrap metal on behalf of a steel industry in North-East Italy, is gaining a sound experience in
applying the acceptance protocols and assessing the error probability figures vs. minimum detectable
activity and vehicle speed, which is presented in this work.
RADIOMETRIC CONTROLS OF CONTAMINATED SCRAP METALS
IMPORTED IN ITALY, TECHNICAL AND REGULATORY FEATURES
Following several detections of contaminated scrap metals in some recycling industries and in some
consignments entering the italian boundaries, the competent Authorities laid down rules to put under
control the problem.
In this paper technical and regulatory features are discussed.
A CASE OF A FOUND RADIOGRAPHIC SOURCE
1 Health Inspectorate of Republic Slovenia, Ljubljana, Slovenia
THE RADIOMETRIC CONTROLS ON METALLIC SCRAPS
Consequently many controls have been carried out on the imported metallic scraps at the boundaries.
These radiometric surveys have shown the possibility of presence of contaminated material in the
imported stocks. The measurements have been carried out both on every road and railway load, coming
from extra-European Community Countries, for fifteen months. The detected values of the radioactivity
outside of the scrap containers resulted greater than the radioactivity background value, with a variable
frequency between 0.1% and 1% of the surveyed loads. The presence of the radioactivity in the scraps
gives born so to an health radiological problems both for the workers and for the population. In fact
during the recycling processes of the scraps the worker can be exposed to undue radiation levels, greater
than the background level and the population can be exposed to the same levels in the utilization of the
products obtained by the recycling processes. In the present paper the author shows the obtained results
in the carried out survey and the Italian promulgated legislative safety measures, in reason to prevent
the possible risks connected with this kind of work. These measures are charged to the utilizing person
of the scraps, to the Central and regional Authorities.
CAN COMPLIANCE WITH A LIMIT BE ASSURED BY MEASUREMENTS?
In any case, an apparently very precise figure is established and compliance has to be achieved by
measurements whether or not the considered figure is consistent with the limit.
Two figures with different properties have to be compared: a constant number on the one hand and an
estimated value with a confidence interval on the other hand
The most frequent case is to check the question whether an activity in the sample is less than or equal
to a preselected limit.
It is proposed to consider a sample in compliance with the limit when the following condition is
fulfilled:
A+N*sigma <= L
where:
A...activity concentration determined by measurement
n..number of standard deviations, chosen as 1
s....standard deviation of the measurements
L.. limit
The concept is discussed in more detail in the paper.
*) The concept presented here was developed and discussed in the subgroup "Low Level measurements" of
the Austrian Standards Institute (NORM,) Radiation protection branch.
Members of the Working Group are: H.Friedmann, E.Henrich, P.Kindl, A.Leitner, F.J.Maringer, F.Steger,
M.Tschurlovits (chairman), E. Unfried, G.Winkler
THE REGULATORY SYSTEM OF MONITORING WORKERS IN GERMANY
FOR INTAKES OF RADIOACTIVITY WITH SPECIAL REFERENCE TO THORIUM
2 Zentrales Referat Strahlenschutz, Siemens AG, D-81730 München, Germany
The purpose of the approach was the installation of a system:
- defining clear criteria for the necessity
of regular and special monitoring programs,
- giving guidelines for monitoring programs ensuring that dose assessments are reliable as
necessary with the lowest possible expenses,
- standardizing as far as possible the procedures of dose assessments, and
- guaranteeing the necessary of quality standards.
The most important features of these regulations will be discussed in this contribution and their
application will be exemplified for the specially difficult monitoring of thorium intakes.
RADIOLOGICAL PROTECTION IN A NON-NUCLEAR COUNTRY
Licences in respect of radioactive materials and irradiating apparatus are issued by the Radiological
Protection Institute of Ireland which is the national competent authority for matters relating to
radiological protection. The licences include conditions which must be upheld by the licensee. These
conditions place an obligation on the licensee too, among other things, maintain and service licensed
items, calibrate dose measuring equipment, investigate and report to the institute all doses in excess of
prescribed action levels (which are always lower than statutory limits). They, also specify limits for
radioactive waste disposal. The institute carries out inspections of licensees to ensure compliance with
these conditions and other regulations pertaining to ionising radiation. This paper will discuss the
experience gained in operating the licensing system. In particular it
will address the following issues
COMBINED LOW- AND HIGH-DOSE IRRADIATION AND ITS
INTERPRETATION FROM THE POINT OF VIEW OF RADIATION PROTECTION
In our experiments we counted chromosomal aberrations and micronuclei in human lymphocytes after
a combination of low-dose irradiation with tritium and high-dose irradiation with gamma rays from a
60Co source. Three types of response could be revealed by biometric testing: additive, adaptive and
synergic. The testing leads us to suppose a normal distribution of the clastogenic effect in samples of
lymphocytes taken from a healthy adult population, the most lymphocyte samples responding additively
and the adaptive and synergic types of response being at the extreme ends of the distribution. The
occurrence of these extreme types of response depends upon the magnitude of the first, low dose and
their expression may be limited to a narrow dosage-interval. A high interindividual variability prevented
to estimate an "optimal" low dose which would allow in future to assess one of the extreme types of
response in every individual.
From the point of view of radiation protection it is important to take into account the possibility of a
synergic response after combination of two (or more) doses of radiation, especially in the low-dose
region. This needs further attention to pay as the contemporary limits are accepted under the premise
of additive effects of repeated doses, but, the question arises if the limits include an acceptable safety
margin for individuals whose tissues may react synergically.
RADIOACTIVITY IN THE SCRAP RECYCLING PROCESS: RADIATION
PROTECTION ASPECTS AND EXPERIMENTAL MONITORING PROBLEMS
First of all, we characterize different kind of radioactive materials that can found in scraps, pointing
out the potential hazards from exposure of workers and people and from environmental contamination,
related to physical, chemical and geometrical specifications of the involved radionuclides.
The suitable monitoring systems for scrap recycling facilities are presented considering the different
phases of production cycle (transport, storage, manipulation, melting ... ).
At least, experimental data, taken in some periods of the monitoring campaign made at the Italian border
on imported scraps, are presented. In particular, we point out the comparison on experimental data
taken with different portable detector of different technical specifications.
EVALUATING THE SHORT-TERM RADIOLOGICAL
CONSEQUENCES OF RELEASES IN ACCIDENT SITUATIONS
1. METHODS USED BY EDF'S TECHNICAL TEAMS
The radiological consequences of an accident are evaluated using
a three-pronged method:
A computer program has been developed to help the Health Physics Control Center teams in their
work. The package is known as GEEE (Gestion des Effluents et de l'Environnement), or
management of effluents and the environment.
2. GEEE SOFTWARE PACKAGE
The GEEE program is a value-added tool, ensuring.
RECENT DEVELOPMENTS IN RADIOECOLOGY
Both assessment and modelling are going to become more developed. Examples of these activities are
presented. The present developments lead to the conclusion the existing problems can be solved only
by cooperation of measurement and modelling groups. This collaboration is important for not to leave
the field to groups, directed by politicians seeking for short term gain, in order to give retrospective
justification in a specious manner of decisions not be based on objective analysis.
ILLICIT TRAFIKING OF NUCLEAR MATERIAL IN HUNGARY,
REGULATORY AND OPERATIONAL ACTIONS IN THE FIELD OF RADIOLOGICAL HEALTH
CONSIDERATION OF INHOMOGENEOUS RADIATION FIELDS FOR
RADIATION PROTECTION MEASURES
Regarding external exposure, the measurement has to be done by means of operational quantities as
defined by ICRU.
There is a dichotomy between the two lines of development, and some discussions on this issue was
carried out /De 94, Le 93/.
Another issue is, however, not discussed at all in the present discussion: a possible spatial
inhomogeneity of the radiation field. This problem is existing in many practical cases as inhomogeneous
shielding, slits im walls etc.
No information is available on the size or radiation field to be considered in a radiation survey and to
set in relation with the limitation quantity.
This paper is concerned with two approaches to assess compliance with limits for spatial
inhomogeneous exposure conditions. One approach is based upon judgment of measuring results, the
other with compliance with limits.
References:
/De 94/ J.A.Dennis, R.V.Griffith: Rad.Prot.Dos. 54 (1994)373.
/Le 93/ A.Leitner, M,Tschurlovits: Proc. Au-Hu-It Radiation Protection Symp. Obergurgl(1993), Vol
III p.386
NEW ORGANIZATIONAL FRAMEWORK OF THE RADIATION PROTECTION IN THE
CZECH REPUBLIC
THE LABORATORY-TYPE DATA INPUT AND PROCESSING SUBSYSTEM OF
THE COUNTRY-WIDE ENVIRONMENTAL RADIATION MONITORING SYSTEM IN HUNGARY
The information centre of the country-wide monitoring system has been equipped with a SUN
SPARCserver-20 computer, INGRES data manager software and other main accessories. The data
collection in the radiological laboratories is based on a local PC-network (Novell) with the running
version of the INGRES and on-line connections to the centre by X.25 lines. As a first step of the
development the user programs for data collections and some restricted processing written in INGRES
were introduced for testing.
The data bank is to be operated both for normal and accidental situations with direct data transmission
capabilities to the information center of the early warning system operated by the national organisations
of the nuclear emergency. The extension of the number of laboratories is planned step-wise and the
regular operation is to be started at the beginning of the next year with about 20 local stations.
AN OUTLOOK TO RADIATION PROTECTION DEVELOPMENT
* Zagreb, Croatia
Some events in the last decade had essential impact on radiation protection principles and doctrine. Among
them are available data of some long term radio-epidemiological studies of populations exposed to
radiation, several big radiation accidents and new data on measurable effects of chronic exposure resulting
from natural radiation.
The evolution of radiation protection technology is expected to continue with improvements in
instrumentation, modelling, assessment methods and quality control. Scientific knowledge constitutes an
acceptable basis for a conservative system of protection. However, future scientific advances in biology
might have a profound effect on many aspects of radiation protection. New practices are currently being
developed or are expected to be introduced in near future.
All that indicates that, regardless of the achieved status of radiation protection, this is still a dynamic filed.
The assessment of the present status and possible future developments of radiation protection and safety
are discussed in the paper in more detail.
Last update June 29, 1995