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Sample records for accident dosimetry experiment

  1. A second simulated criticality accident dosimetry experiment

    Adams, N

    1973-01-01

    This experiment was undertaken to facilitate training in criticality dose assessment by UKAEA and BNFL establishments with potential criticality hazards. Personal dosemeters, coins, samples of hair, etc. supplied by the seven participating establishments were attached to a man-phantom filled with a solution of sodium nitrate (simulating 'body-sodium'), and exposed to a burst of radiation from the AWRE pulsed reactor VIPER. The neutron and photon doses were each several hundred rads. Participants made two sets of dose assessments. The first, made solely from the evidence of their routine dosemeters the activation of body-sodium and standard monitoring data, simulated the initial dose assessment that would be made before the circumstances of a real incident were established. The second was made when the position and orientation of the phantom relative to the reactor and the shielding (20 cm of copper) between the reactor core and the phantom were disclosed. Neutron and photon dose assessments for comparison wit...

  2. Nuclear accident dosimetry intercomparison studies.

    Sims, C S

    1989-09-01

    Twenty-two nuclear accident dosimetry intercomparison studies utilizing the fast-pulse Health Physics Research Reactor at the Oak Ridge National Laboratory have been conducted since 1965. These studies have provided a total of 62 different organizations a forum for discussion of criticality accident dosimetry, an opportunity to test their neutron and gamma-ray dosimetry systems under a variety of simulated criticality accident conditions, and the experience of comparing results with reference dose values as well as with the measured results obtained by others making measurements under identical conditions. Sixty-nine nuclear accidents (27 with unmoderated neutron energy spectra and 42 with eight different shielded spectra) have been simulated in the studies. Neutron doses were in the 0.2-8.5 Gy range and gamma doses in the 0.1-2.0 Gy range. A total of 2,289 dose measurements (1,311 neutron, 978 gamma) were made during the intercomparisons. The primary methods of neutron dosimetry were activation foils, thermoluminescent dosimeters, and blood sodium activation. The main methods of gamma dose measurement were thermoluminescent dosimeters, radiophotoluminescent glass, and film. About 68% of the neutron measurements met the accuracy guidelines (+/- 25%) and about 52% of the gamma measurements met the accuracy criterion (+/- 20%) for accident dosimetry. PMID:2777549

  3. Radiation accidents and dosimetry

    On September 2nd 1982 one of the employees of the gamma-irradiation facility at Institute for Energy Technology, Kjeller, Norway entered the irradiation cell with a 65.7 kCi *sp60*Co- source in unshielded position. The victim received an unknown radiation dose and died after 13 days. Using electron spin resonance spectroscopy, the radiation dose in this accident was subsequently determined based on the production of longlived free radicals in nitroglycerol tablets borne by the operator during the accident. He used nitroglycerol for heart problems and free radical are easily formed and trapped in sugar which is the main component of the tablets. Calibration experiments were carried out and the dose given to the tablets during the accident was determined to 37.2 +- 0.5 Gy. The general use of free radicals for dose determinations is discussed. (Auth.)

  4. The Vinca dosimetry experiment

    On 15 October 1958 there occurred a very brief uncontrolled run of the zero-power reactor at the Boris Kidric Institute of Nuclear Science, Vinca, near Belgrade, Yugoslavia. During this run six persons received various doses of radiation. They were subsequently given medical treatment of a novel kind at the Curie Hospital, Paris. In atomic energy operations to date, very few accidents involving excessive radiation exposure to human beings have occurred. In fact, the cases of acute radiation injury are limited to about 30 known high exposures, few of which were in the lethal or near-lethal range. Since direct experiment to determine the effects of ionizing radiation on man is unacceptable, information on these effects has to be based on a consideration of data relating to accidental exposures, viewed in the light of the much more extensive data obtained from experiments on animals. Therefore, any direct information on the effects of radiation on humans is very valuable. The international dosimetry project described in this report was carried out at Vinca, Yugoslavia, under the auspices of the International Atomic Energy Agency to determine the precise amount of radiation to which the persons had been exposed during the accident. These dosimetry data, together with the record of the carefully observed clinical effects, are of importance both for the scientific study of radiation effects on man and for the development of methods of therapy. The experiment and measurements were carried out at the end of April 1960. The project formed part of the Agency's research programme in the field of health and safety. The results of the experiment are made available through this report to all Member States

  5. The Why and How of Nuclear Accident Dosimetry

    The objective of an effective nuclear accident dosimetry programme is to ensure that a means is provided for estimating the gamma neutron dose from a nuclear accident. In this connection, the limitation of the film badge is discussed, in addition to certain accident experiences which demonstrate the need for an effective accident dosimetry programme at facilities having a potential for nuclear accidents. Certain basic parameters should be considered in the development of an effective nuclear accident dosimetry programme. These are (a) a method for screening personnel involved in nuclear accidents, (b) a fixed system (primary unit) capable of determining first collision dose within some established degree of accuracy at its point of location, (c) the need for ''secondary units'', and (d) the need for a device worn by personnel which would afford spectrum and flux information to assist in dose extrapolation from the fixed unit to the location of man. The neutron component of the system should permit flux and spectral information in order to arrive at appropriate quality factors in the dose estimation. Accuracies should be established based upon the current state of the art. The gamma -ray component of the system should permit measuring gamma radiation within the biological area of interest, i. e. from 10 to 103r. Consideration for the number, placement and ease of recovery of accident units are indeed an integral part of an effective system of accident dosimetry. These considerations should enable reasonable data collection across the entire fission spectrum. (author)

  6. 10 CFR 835.1304 - Nuclear accident dosimetry.

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Nuclear accident dosimetry. 835.1304 Section 835.1304... Nuclear accident dosimetry. (a) Installations possessing sufficient quantities of fissile material to... nuclear accident is possible, shall provide nuclear accident dosimetry for those individuals. (b)...

  7. LLNL Results from CALIBAN-PROSPERO Nuclear Accident Dosimetry Experiments in September 2014

    Lobaugh, M. L. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hickman, D. P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Wong, C. W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Wysong, A. R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Merritt, M. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Heinrichs, D. P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Topper, J. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-05-21

    Lawrence Livermore National Laboratory (LLNL) uses thin neutron activation foils, sulfur, and threshold energy shielding to determine neutron component doses and the total dose from neutrons in the event of a nuclear criticality accident. The dosimeter also uses a DOELAP accredited Panasonic UD-810 (Panasonic Industrial Devices Sales Company of America, 2 Riverfront Plaza, Newark, NJ 07102, U.S.A.) thermoluminescent dosimetery system (TLD) for determining the gamma component of the total dose. LLNL has participated in three international intercomparisons of nuclear accident dosimeters. In October 2009, LLNL participated in an exercise at the French Commissariat à l’énergie atomique et aux énergies alternatives (Alternative Energies and Atomic Energy Commission- CEA) Research Center at Valduc utilizing the SILENE reactor (Hickman, et.al. 2010). In September 2010, LLNL participated in a second intercomparison at CEA Valduc, this time with exposures at the CALIBAN reactor (Hickman et al. 2011). This paper discusses LLNL’s results of a third intercomparison hosted by the French Institut de Radioprotection et de Sûreté Nucléaire (Institute for Radiation Protection and Nuclear Safety- IRSN) with exposures at two CEA Valduc reactors (CALIBAN and PROSPERO) in September 2014. Comparison results between the three participating facilities is presented elsewhere (Chevallier 2015; Duluc 2015).

  8. The principles of radioiodine dosimetry following a nuclear accident

    Based upon the experience of radioiodine dosimetry after the Chernobyl accident main principals of radioiodine measurements and dosimetry in thyroid glands of population in case of a radiation accident are discussed in the report. For the correct dose estimation following the radioiodine measurement in the thyroid one should know the ''history'' of radionuclide intake into the body of a contaminated person. So a measurement of radioiodine thyroid content should be accompanied by asking questions of investigated persons about, their life style and feeding after a nuclear incident. These data coincidently with data of radionuclides dynamic in the air and food (especially in milk products) are used for the development of radioiodine intake model and then for thyroid dose estimation. The influence of stable iodine prophylaxis and other countermeasures on values are discussed in dependence on the time of its using. Some methods of thyroid dose reconstruction used after the Chernobyl accident in Russia for a situation of thyroid radioiodine measurements lacking in a contaminated settlement are presented in the report. (author). 16 refs, 5 figs, 3 tabs

  9. Nuclear accident dosimetry studies at Los Alamos National Laboratory

    Two critical assemblies have been characterized at the Los Alamos Critical Experiments Facility (LACEF) for use in testing nuclear accident dosimeters and related devices. These device, Godiva IV and SHEBA II, have very different characteristics in both operation and emitted neutron energy spectra. The Godiva assembly is a bare metal fast burst device with a hard spectrum. This spectrum can be modified by use of several shields including steel, concrete, and plexiglas. The modified spectra vary in both average neutron energy and in the specific distribution of the neutron energies in the intermediate energy range. This makes for a very favorable test arrangement as the response ratios between different activation foils used in accident dosimeters are significantly altered such as the ratio between gold, copper, and sulfur elements. The SHEBA device is a solution assembly which has both a slow ramp and decay period and a much softer spectrum. The uncertainly introduced in the response of fast decay foils such as indium can therefore be evaluated into the test results. The neutron energy spectrum for each configuration was measured during low power operations with a multisphere system. These measurements were extended to high dose pulsed operation by use of TLDs moderated TLDs, and special activation techniques. The assemblies were used in the testing of several accident dosimetry devices in studies modeled after the Nuclear Accident Dosimetry Studies that were conducted at Oak Ridge National Laboratory for about 25 years using the Health Physics Research Reactor. It is our intention to conduct these studies approximately annually for the evaluation of the nuclear accident dosimeter systems currently in use within the DOE, alternative systems used internationally, and new dosimeter designs being developed or considered for field application. Participation in selected studies will be open to all participants

  10. The use of a portable electronic device in accident dosimetry.

    Beerten, Koen; Vanhavere, Filip

    2008-01-01

    The use of a portable electronic device in accident dosimetry has been investigated. The thermoluminescence properties of a surface-mount alumina-rich ceramic resonator from a USB flash drive were investigated. The following characteristics were verified: the absence of a zero-dose signal, gamma dose response, dose recycling behaviour, fading and optical bleaching. Finally, this component has been successfully used to determine a simulated accident dose (1 d following the irradiation event). It is concluded that it should be possible to perform rapid and reliable accident dose assessments with such components using conventional thermoluminescence dosimetry equipment. PMID:18703583

  11. The use of a portable electronic device in accident dosimetry

    The use of a portable electronic device in accident dosimetry has been investigated. The thermoluminescence properties of a surface-mount alumina-rich ceramic resonator from a USB flash drive were investigated. The following characteristics were verified: the absence of a zero-dose signal, gamma dose response, dose recycling behaviour, fading and optical bleaching. Finally, this component has been successfully used to determine a simulated accident dose (1 d following the irradiation event). It is concluded that it should be possible to perform rapid and reliable accident dose assessments with such components using conventional thermoluminescence dosimetry equipment. (authors)

  12. Third IAEA nuclear accident intercomparison experiment

    The purpose of this report is to present the results of the International Atomic Energy Agency intercomparison experiments held at the 'Boris Kidric' Institute, Vinca, in May 1973. The experiments are parts of a multilaboratory intercomparison programme sponsored by the IAEA for the evaluation of nuclear accident dosimetry systems and eventually recommendation of dosimetry systems that will provide adequate informations in the event of a criticality accident. The previous two studies were held at the Valduc Centre near Dijon (France) in June 1970 and at the ORNL in Oak Ridge (USA), in May 1971. Parts of the intercomparison studies were coordination meetings. The topics and conclusions of the Third coordination meeting are given in the Chairman's Report of F.F. Haywood. This paper will deal, therefore, only with data concerning the Third intercomparison experiments in which the RB reactor at Vinca was used as a source of mixed radiation. (author)

  13. Dosimetry

    Eight articles treat the dosimetry. Two articles evaluate the radiation doses in specific cases, dosimetry of patients in radiodiagnosis, three articles are devoted to detectors (neutrons and x and gamma radiations) and a computer code to build up the dosimetry of an accident due to an external exposure. (N.C.)

  14. Dosimetry studies for an industrial radiography accident

    On 5 June 1979, an industrial worker who was not involved with radiography found an 192Ir source that had accidently become detached and lost from its shielded camera. He placed the source in the hip pocket of his coveralls and returned to work, keeping the 192Ir source for some time before taking it to the plant manager. The biophysical calculations for the determination of exposure and depth-dose calculations are the basis for this paper

  15. The program of international intercomparison of accident dosimetry; Le programme d'intercomparaison internationale de dosimetrie d'accident 10-12 juin 2002

    NONE

    2002-06-01

    The French institute of radioprotection and nuclear safety (IRSN) has carried out in June 2002 an international intercomparison program for the testing of the physical and biological accident dosimetry techniques. The intercomparison is jointly organized by the IRSN and the OECD-NEA with the sustain of the European commission and the collaboration of the CEA centre of Valduc (France). About 30 countries have participated to this program. Each country has supplied its own dosimeters and biological samples which have been irradiated using the Silene reactor of CEA-Valduc or a {sup 60}Co source. These experiments allow to test the new dosimetric techniques that have been developed since the previous intercomparison program (1993) and to confirm or improve the performances of older techniques. Aside from the intercomparison exercise, this report makes a status of the known radiological accidents and of the effects of high doses of ionizing radiations on human health (symptoms, therapeutics). It explains the phenomenology of criticality accidents, the prevention means, and the history of such accidents up to the Tokai-Mura one in 1999. Finally, the dosimetry of criticality is presented with its physical and biological techniques. (J.S.)

  16. Performance of the CEDS Accident Dosimetry System at the 1995 Los Alamos National Laboratory Nuclear Accident Dosimetry Intercomparison

    In July 1995, LANL hosted an accident dosimetry intercomparison. When all reactors on the Oak Ridge Reservation were idled in 1988, the Health Physics Research Reactor (HPRR), which had been used for 22 previous intercomparisons dating from 1965, was shut down for an indefinite period. The LANL group began characterization of two critical assemblies for dosimetry purposes. As a result, NAD-23 was conceived and 10 DOE facilities accepted invitations to participate in the intercomparison. This report is a summary of the performance of one of the participants, the Centralized External Dosimetry System (CEDS). The CEDS is a cooperative personnel dosimetry arrangement between three DOE sites in Oak Ridge, Tennessee. Many successes and failures are reported herein. Generally, the TL dosimeters performed poorly and always over-reported the delivered dose. The TLD processing procedures contain efforts that would lead to large biases in the reported absorbed dose, and omit several key steps in the TLD reading process. The supralinear behavior of lithium fluoride (LiF) has not been characterized for this particular dosimeter and application (i.e., in high-dose mixed neutron/gamma fields). The use of TLD materials may also be precluded given the limitations of the LiF material itself, the TLD reading system, and the upper dose level to which accident dosimetry systems are required to perform as set forth in DOE regulations. The indium foil results confirm the expected inability of that material to predict the magnitude of the wearer's dose reliably, although it is quite suitable as a quick-sort material. Biological sample (hair) results were above the minimum detectable activity (MDA) for only one of the tests. Several questions as to the best methods for sample handling and processing remain

  17. Using soils for accident dosimetry: a preliminary study using optically stimulated luminescence from quartz

    Fujita, Hiroki; Jain, Mayank; Murray, Andrew S.

    2011-01-01

    . The objective was to assess the potential of SAROSL dosimetry using soils for retrospective assessment of a radiation accident. Variation in dose with depth was also measured. The SAR data showed good reproducibility and dose recovery, and there was no evidence of fading of the quartz signal based on...... “delayed” dose recovery experiments. The minimum detection limit (MDL) dose was about 0.1Gy. The dose dependence was measured using both the above SAR OSL protocol as well as a SAR thermoluminescence (TL, violet emission) protocol. The background doses were generally in the range of the MDL to several Gy......, and no clear trend in dose depth profile was observed. From these results, we conclude that SAR OSL dosimetry using natural quartz extracted from soil could be used to evaluate the dose of an accident....

  18. International intercomparison of criticality accident dosimetry system. SILENE 2002

    Sixty laboratories issued from 29 countries participated in an international intercomparison of criticality accident dosimetry systems, which took place in France in June 2002, at the SILENE reactor and at a pure gamma source. This intercomparison was jointly organised by the Institute for Radiological Protection and Nuclear Safety (IRSN) and the Atomic Energy Commission (CEA) with the help of the Organisation for Economic Co-operation and Development (OECD) and was partly supported by the European Communities. This paper describes the different aspects of this intercomparison. The dosimetric quantities measured and reported by the participants are summarised, analysed and compared to the reference values. (author)

  19. Nuclear accident dosimetry - report on the fourth IAEA intercomparison experiment at Harwell, UK - 7th-8th April 1975: Part 2 - Systems used by participants at the experiment

    Participants were invited to submit brief descriptions of the systems which they used to measure the neutron and γ-ray dose in the present experiment. This information is presented as a series of short papers giving details of (a) the system, (b) the measurement procedure, (c) the evaluation procedure and (d) references to more extensive details of their systems. Editing has been restricted mainly to minor corrections in the language and any requests for clarification or for more details should be addressed to the authors of the individual papers. The results of the measurements are contained in Part I of this paper (AERE-R8520, 1976, HMSO). (author)

  20. Proceedings of the III international workshop 'Actual problems of dosimetry (15 years after the Chernobyl accident)'

    Materials grouped to three main issues: normative, metrological and technical support of dosimetric and radiometric control; biological dosimetry and markers of radiation effects; monitoring and reconstruction of radiation doses at radiation accidents

  1. Personnel Dosimetry for Radiation Accidents. Proceedings of a Symposium on Personnel Dosimetry for Accidental High-Level Exposure to External and Internal Radiation

    Accidents involving the exposure of persons to high levels of radiation have been few in number and meticulous precautions are taken in an effort to maintain this good record. When, however, such an accident does occur, a timely estimate of the dose received can be of considerable help to the physician in deciding whether a particular person requires medical treatment, and in selecting the most appropriate treatment. Individual dosimetry provides the physical basis for relating the observed effects to those in other accident cases, to other human data, and to data from animal experiments, thus providing an important aid to rational treatment and to the accumulation of a meaningful body of knowledge on the subject. It is most important therefore that, where there is a possibility of receiving high-level exposure, methods of personnel dosimetry should be available that would provide the dosimetric information most useful to the physician. Provision of good personnel dosimetry for accidental high-level exposure is in many cases an essential part of emergency planning because the information provided may influence emergency and rescue operations, and can lead to improved accident preparedness. Accordingly, the International Atomic Energy Agency and the World Health Organization jointly organized the Symposium on Personnel Dosimetry for Accidental High-Level Exposure to External and Internal Radiation for the discussion of such methods and for a critical review of the procedures adopted in some of the radiation accidents that have already occurred. The meeting was attended by 179 participants from 34 countries and from five other international organizations. The papers presented and the ensuing discussions are published in these Proceedings. It is hoped that the Proceedings will be of help to those concerned with the organization and development of wide-range personnel monitoring systems, and with the interpretation of the results provided

  2. Radiation accident dosimetry: TL properties of mobile phone screen glass

    Mobile phones are carried by a large part of the population and previous studies have shown that they may be able to function as individual fortuitous dosimeters in case of radiological accident. This study deals with thermoluminescence (TL) properties of mobile phone screen glass. The presence of a significant background signal which partially overlaps with the radiation-induced signal is a serious issue for dose reconstruction. A mechanical method to reduce this signal using a diamond grinding bit is presented. An over-response at low energy (∼50 keV) is observed for two investigated glasses. The results of a dose recovery test using a single-aliquot regenerative-dose (SAR) procedure are discussed. - Highlights: • Mobile phone screen glass is a promising material for retrospective dosimetry. • The TL non-radiation induced background signal can be significantly reduced by a mechanical method. • A dose recovery test using an SAR procedure was successfully carried out for the investigated glass

  3. Development of a retrospective/fortuitous accident dosimetry service based on OSL of mobile phones

    Work is presented on the development of a retrospective/fortuitous accident dosimetry service using optically stimulated luminescence of resistors found in mobile phones to determine the doses of radiation to members of the public following a radiological accident or terrorist incident. The system is described and discussed in terms of its likely accuracy in a real incident. (authors)

  4. Using soils for accident dosimetry. A preliminary study using optically stimulated luminescence from quartz

    Fujita, H. [Japan Atomic Energy Agency, Ibaraki (Japan). Nuclear Fuel Cycle Engineering Labs.; Risoe National Laboratory for Sustainable Energy, Technical Univ. of Denmark, Roskilde (Denmark). Radiation Research Div.; Jain, M. [Risoe National Laboratory for Sustainable Energy, Technical Univ. of Denmark, Roskilde (Denmark). Radiation Research Div.; Murray, A.S. [Aarhus Univ., Risoe DTU, Roskilde (Denmark). Nordic Lab. for Luminescence Dating

    2011-07-01

    The optimum conditions of preheat temperature, stimulation temperature, etc. in the single-aliquot regenerative optically stimulated luminescence (SAR OSL) method were examined specifically for measuring background dose in natural quartz extracted from soils collected around Tokai-mura in Japan. The objective was to assess the potential of SAROSL dosimetry using soils for retrospective assessment of a radiation accident. Variation in dose with depth was also measured. The SAR data showed good reproducibility and dose recovery, and there was no evidence of fading of the quartz signal based on ''delayed'' dose recovery experiments. The minimum detection limit (MDL) dose was about 0.1 Gy. The dose dependence was measured using both the above SAR OSL protocol as well as a SAR thermoluminescence (TL, violet emission) protocol. The background doses were generally in the range of the MDL to several Gy, and no clear trend in dose depth profile was observed. From these results, we conclude that SAR OSL dosimetry using natural quartz extracted from soil could be used to evaluate the dose of an accident. (orig.)

  5. The Hanford Criticality Accident: Dosimetry Techniques, Interpretations and Problems

    The number and integrity of dosimetry techniques used for dose interpretations for the twenty-two personnel involved in the 1962 criticality accident occurring at the Hanford Project were unusually complete. Personnel who received excessive exposures were immediately detected and segregated by monitoring personnel using portable instrumentation for ''quick-sort'' procedures which rely on in vivo measurements of Na24 activation. The close correlation between this rapid method of dose interpretation and subsequent sophisticated laboratory procedures was noted. Primary reliance, however, was placed upon film-badge interpretations, as all persons involved were wearing film badges. An area threshold detector, located within twenty-six feet of the critical vessel, furnished data upon which the neutron spectrum and the gamma to neutron ratios were established. Even with sophisticated and complete dosimetry techniques which were available and which are discussed, including blood and whole-body Na24 activity, excreta and P32 analyses and gold activation, many practical problems became evident. Described are methods or alternatives used to cope with or minimize actual problems including those which could have but did not arise. The ''quick-sort'' in vivo procedures successfully used could have become worthless if interfering external contamination were encountered. Alternatively, blood samples taken at first aid may substitute; however, in the haste of the emergency, anticoagulants may be omitted and subsequent coagulation can produce concern as to the accuracy of the dose interpretations. The film badge can include material of high neutron cross-sections introducing sufficient activity to interfere with film interpretations. The activation of the silver in the film presents a correction factor which can delay and confuse personnel who, under stress, are attempting rapid evaluations. The support provided by fixed detectors still presents the problems that scattering

  6. Biological dosimetry following exposure to neutrons in a criticality accident

    Lindholm, C. (Radiation and Nuclear Safety Authority, STUK (Finland)); Wojcik, A. (Stockholm Univ. (SU), Stockholm (Sweden)); Jaworska, A. (Norwegian Radiation Protection Authority (NRPA) (Norway))

    2011-01-15

    The aim of the BIONCA project was to implement cytogenetic techniques for biodosimetry purposes in the Nordic countries. The previous NKS-funded biodosimetry activities (BIODOS and BIOPEX) concentrated on experiments using gamma-irradiation and on developing the PCC ring assay for biodosimetry. Experiments conducted during the present BIONCA project has broadened the biodosimetry capacity of the Nordic countries to include dose estimation of exposure to neutrons for both PCC ring and dicentric chromosome techniques. In 2009, experiments were conducted for establishing both PCC ring and dicentric dose calibration curves. Neutron irradiation of human whole blood obtained from two volunteers was conducted in the Netherlands at the Petten reactor. Cell cultures and analysis of whole blood exposed to eight doses between 0 and 10 Gy were performed for both techniques. For the dicentric assay, excellent uniformity in dose calibration for data from both SU and STUK was observed. For PCC rings, the SU and STUK curves were not equally congruent, probably due to the less uniform scoring criteria. However, both curves displayed strong linearity throughout the dose range. In 2010, an exercise was conducted to simulate a criticality accident and to test the validity of the established dose calibration curves. For accident simulation, 16 blood samples were irradiated in Norway at the Kjeller reactor and analysed for dose estimation with both assays. The results showed that, despite a different com-position of the radiation beams in Petten and Kjeller, good dose estimates were obtained. The activity has provided good experience on collaboration required in radiation emergency situations where the biodosimetry capacity and resources of one laboratory may be inadequate. In this respect, the project has strengthened the informal network between the Nordic countries: STUK, the Finnish Radiation and Nuclear Safety Authority, NRPA, the Norwegian Radiation Protection Authority and SU

  7. Eighteenth nuclear accident dosimetry intercomparison study: August 10-14, 1981

    The Eighteenth Nuclear Accident Dosimetry Intercomparison Study was conducted August 10-14, 1981, at the Oak Ridge National Laboratory. Nuclear criticality accidents with three different neutron and gamma ray energy spectra were simulated by operating the Health Physics Research Reactor in the pulse mode. Participants from 13 organizations exposed dosimeters set up as area monitors and mounted on phantoms for personnel monitoring. Analysis of experimental results showed that about 56% of the reported neutron doses measured using foil activation, thermoluminescent, or sodium activation methods and about 53% of the gamma doses measured using thermoluminescent methods met nuclear accident dosimetry guidelines which suggest accuracies of +- 25% for neutron dose and +- 20% for gamma dose. The greatest difficulties in measuring accident doses occurred in radiation fields with large fractions of low energy neutrons and a high gamma component (> 40%). Results of this study indicate that continued accident dosimetry intercomparisons are necessary to test dosimetry systems and training programs are needed to improve the technical competence of evaluating personnel

  8. Nuclear accident dosimetry: Los Alamos measurements at the seventeenth nuclear accident dosimetry intercomparison study at the Oak Ridge National Lab., DOSAR Facility, August 1980

    Teams from various US and foreign organizations participated in the Seventeenth Nuclear Accident Dosimetry Study held at the Oak Ridge National Laboratory's (ORNL) Dosimetry Applications Research (DOSAR) facility August 11 to 15, 1980. Criticality dosimeters were simultaneously exposed to pulses of mixed neutron and gamma radiation from the Health Physics Research Reactor (HPRR). This report summarizes the experimental work conducted by the Los Alamos team. In-air and phantom measurements were conducted by the Los Alamos team using area and personnel dosimeters. Combined blood sodium and sulfur fluence measurements of absorbed dose were also made. In addition, indium foils placed on phantoms were evaluated for the purpose of screening personnel for radiation exposure. All measurements were conducted for unshielded, 5-cm steel and 20-cm concrete shielding configurations. All participant dosimeters were exposed at 3 m from the center of the HPRR core

  9. Radiation protection experience in Yugoslavia from the Vinca accident to nowadays

    This Paper is the expression of the author opinion about development of radiation protection in Yugoslavia from its beginning forty years ago, which might affect its status in the foreseeable future at the first decades of the 21st century. It focuses on key events in this field starting from the Vinca Accident, which happened in the October 1958, to nowadays. Shortly reviewed some of key events are: Vinca Accident; Foundation of the Radiation Protection Laboratory in the Vinca Institute; International Vinca Dosimetry Experiment; First National Symposium and foundation of the Yugoslav Radiation Protection Association; International Intercomparison Experiment on Nuclear Accident Dosimetry and, International Summer Schools and Symposium on Radiation Protection organized in Yugoslavia. Finally, some specific experimental data obtained during and after Chernobyl Accident up to nowadays in radiation protection action in Yugoslavia are presented also. (author)

  10. OSL and TL of Resistors of Mobile Phones for Retrospective Accident Dosimetry

    Optically stimulated luminescence (OSL) and thermoluminescence (TL) of ubiquitous materials continue to draw wider attention for individual dosimetry in nuclear and radiation accidents. Use of ubiquitous objects for radiation dosimetry is preferred because the affected persons in such unexpected events are usually not covered by personal dosimetry services and do not carry personal dosimeters. Often accident sites do not have area monitoring system in place. As the main concern of the dosimetry is health effects, a quick distinction of level of exposures of the affected persons for the required medical care becomes important in all accidents involving radiation. Both in large scale nuclear accidents such Fukushima, Chernobyl or Hiroshima and Nagasaki where large population around the accident site get exposed to radiation (evacuation is based on doses) and in smaller but panicky events, such as misuse of radiological exposure device (RED), radiological dispersive device (RDD: 'Dirty Bomb'), improvised nuclear device (IND) and deliberate dispersal of radioactive contaminants, a need for an ubiquitous personal dosimeter is well recognized. As biological dosimetry systems are yet to become viable for measurements of doses with required accuracy and speed, use of physical dosimeters is often explored. Among the various types of physical dosimetry systems, use of TL and OSL by processing common material such as bricks or tiles and measuring the doses cumulated for long periods of time has already become an accepted tool for large scale nuclear accidents such as Hiroshima and Nagasaki or Chernobyl involving higher doses. In the other potential cases of unexpected situations where the doses encountered could be much lower (even to escape the range of remotely installed area monitors), the need to measure even the low doses in shortest possible time becomes important. It is often realized that in such situations, the main problem could become the panic at the work place

  11. EPR response characterization of drugs excipients for applying in accident dosimetry

    Some drugs are widely used by the population and can be employed to dose retrospective. The carbohydrates (saccharides), commonly used as excipients in the pharmaceutical industry, produce a quantity of free radicals after gamma irradiation, making them useful for dosimetry in emergency or accident situations that imply in dose evaluation from the materials found nearly or in contact with victims. In general, EPR signal from pulverized pills of some drugs are very complex due to the variety of components in the formulation. Because of this fact, some pharmaceutical excipients identified in the pill composition were also analysed by EPR spectrometry. On the counter drugs were studied: Cebion glucose, AAS, Aspirina, Conmel, Lacto-Purga and sugar substitutive ZeroCal. The excipients were: lactose, amide, anhydrous glucose and magnesium stearate. In some samples the number of radicals produced increased with the dose, showing a linear response for a dose range of interest and an adequate sensibility for dosimetry in accident cases

  12. On the use of new generation mobile phone (smart phone) for retrospective accident dosimetry

    Lee, J. I.; Chang, I.; Pradhan, A. S.; Kim, J. L.; Kim, B. H.; Chung, K. S.

    2015-11-01

    Optically stimulated luminescence (OSL) characteristics of resistors, inductors and integrated-circuit (IC) chips, extracted from new generation smart phones, were investigated for the purpose of retrospective accident dosimetry. Inductor samples were found to exhibit OSL sensitivity about 5 times and 40 times higher than that of the resistors and the IC chips, respectively. On post-irradiation storage, the resistors exhibited a much higher OSL fading (about 80 % in 36 h as compared to the value 3 min after irradiation) than IC chips (about 20 % after 36 h) and inductors (about 50 % in 36 h). Higher OSL sensitivity, linear dose response (from 8.7 mGy up to 8.9 Gy) and acceptable fading make inductors more attractive for accident dosimetry than widely studied resistors.

  13. MISTI Shielding and Dosimetry Experiment Project

    National Aeronautics and Space Administration — Reliable on-orbit dosimetry is necessary for understanding effects of space radiation environments on spacecraft microelectronics performance and comparison of...

  14. Radiation Accident Experience: Causes and Lessons Learned

    Since inception of the nuclear energy program in the United States of America, the Atomic. Energy Commission (USAEC) has maintained an extensive system for the reporting and review of radiation accidents in USAEC federal and licensing activities. Accidents required to be reported fall-into two main categories: (1) Accidents causing or threatening to cause radiation exposure to industrial workers or to the general public; (2) Accidents causing damage to or shutdown of facilities, or damage to public property. While many of the reported accidents carry with them the potential for exposure of persons to radioactivity, the cases reported, in this analysis are limited to those where certain prescribed levels of exposure have been exceeded or where significant uptake by the critical organ has occurred. This paper presents detailed analyses of the accident experience encountered in USAEC programs over the past nine years, including: (1) A breakdown of the types of work activities in the nuclear industry under which radiation accidents have occurred; (2) Characterization of the causes of such accidents as related to the types of work activities; (3) Lessons to be learned both in avoiding such accidents and in emergency planning, should such accidents occur. (author)

  15. Medical experience: Chernobyl and other accidents

    A radiation accident can be defined as an involuntary relevant exposure of man to ionising radiation or radioactive material. Provided one of the ensuing criteria is met with at least one person involved in an excursion of ionising radiation and or radioactive material, the respective incident can be considered a radiation accident in accordance with ICRP, NCRP (US), and WHO: ≥0.25 Sv total body irradiation with lesions of the rapidly dividing tissues; ≥6 Sv cutaneous and local irradiation; ≥0.4 Sv local irradiation of other organ systems through external sources; incorporation equal to or in excess of more than half of the maximum permissible organ burden; and medical accidents meeting one of the above criteria. Several actions have been taken to categorise radiation accidents in order to learn from previous accidents in terms of both managerial and medical experience. For this presentation three approaches will be discussed concerning their relevance to the individual treatment and risk management. This will be obtained by applying three classification schemes to all known radiation accidents: 1. classification with respect to the accident mechanism, 2. classification concerning the radiation injury, and 3. classification concerning the extent of the accident. In a fourth chapter the efficacy of bone marrow transplantation will briefly be commented on based on the accumulated experience of about 400 radiation accidents world-wide. (author)

  16. Dosimetry of accidents using thermoluminescence of dental restorative porcelains

    The thermoluminescence (TL) properties of dental restorative porcelain were investigated with the aim of using this material as a TL dosemeter to estimate high doses in radiological accidents. The irradiations were carried out with a 60Co gamma source and X rays with effective energies from 29 to 95 KeV. The samples have a limit of detection at about 50R and their reproducibility is better than 15%. Linearity was observed from 50 to 5000R. (Author)

  17. Accident analysis for the NCSC foil experiment

    An accident analysis has been performed for the nuclear criticality safety class (NCSC) foil experiment. The Los Alamos Critical Experiments Facility (LACEF) performs this experiment regularly during its 2-, 3-, and 5-day nuclear criticality safety classes. This accident analysis is part of an effort to modify the NCSC foil experiment plan so that the experiment may be operated at delayed critical. Currently, the NCSC foil experiment may only be operated up to a neutron multiplication of 100. The purpose of the accident analysis is to ensure that any accidental nuclear excursion does not exceed the boundary of the safety envelope described in the LACEF safety analysis report (SAR). The experiment consists of very thin, highly enriched (93% 235U) uranium metal foils (23 X 23 X 0.008 cm) interleaved between Lucite plates (36 X 36 X 1.27 cm). The fuel foils and Lucite plates are stacked vertically to form a critical assembly. Extra Lucite plates placed at the top and bottom of the assembly act as vertical reflectors. The assembly is operated remotely with the use of a general-purpose vertical-lift platform machine. The accident scenario consists of one additional fuel foil being added to an existing critical or nearly critical stack. The reactivity insertion rate is 0.05 $/s, based on the speed of the vertical-lift platform. It is assumed that none of the safety systems will function properly during the accident and that the operating crew is unable to mitigate the accident

  18. Nineteenth nuclear accident dosimetry intercomparison study, August 9-13, 1982

    The Nineteenth Nuclear Accident Dosimetry Intercomparison Study was held August 9 to 13, 1982, at the Oak Ridge National Laboratory using the Health Physics Research Reactor operated in the pulse mode to simulate nuclear criticality accidents. Participants from eight organizations measured neutron and gamma doses at air stations and on phantoms for three different shielding conditions. Measured results were compared to nuclear industry guidelines for criticality accident dosimeters which suggest accuracies of +-25% for neutron dose and +-20% for gamma dose. Seventy-two percent of the neutron dose measurements using foil activation, sodium activation, hair sulfur activation, and thermoluminescent methods met the guidelines while less than 40% of the gamma dose measurements were within +-20% of reference values. The softest neutron energy spectrum (also lowest neutron/gamma dose ratio) provided the most difficulty in measuring neutron and gamma doses. Results of this study indicate the need for continued intercomparison and testing of nuclear accident dosimetry systems and for training of evaluating personnel. 14 references, 7 figures, 16 tables

  19. Fading corrections to electronic component substrates in retrospective accident dosimetry

    Accurate and rapid assessments of accidentally accrued radiation doses are imperative so that medical authorities may correctly identify exposed individuals and then counsel and triage them appropriately for treatment. Previous investigations have demonstrated very high dose response efficiencies in a wide range of manufactured insulators, including a variety of alumina ceramics, silicon carbides, aluminum nitrides, and others. Many of these serve as circuit and resistor substrates or encapsulants in modern electronic devices and are generally housed in light-tight enclosures; thus, they could in principle serve as accurate and sensitive dosimeters for the general population, should a need for such dosimetry ever arise. The radiation-induced luminescence signal in alumina porcelain resistor substrates has previously been observed to exhibit anomalous fading when a low-temperature preheat is applied. In this study, measurements were carried out using several preheat temperatures in order to determine whether the unstable component of the OSL signal could be eliminated. It was determined that increasing the preheat temperature has a minimal effect on the signal fading rate but results in significantly decreased sensitivity; therefore, a low-temperature preheat (160 oC) may be more appropriate when maximum sensitivity is required.

  20. ESR accident dosimetry using medicine tablets coated with sugar

    Properties of radiation-induced radicals in medicine tablets were investigated using electron spin resonance (ESR). A sharp ESR signal sensitive to gamma ray irradiation was observed in the sugar coating part of the tablets. The signal has anisotropic g values of g1 = 2.0009, g2 = 2.0007 and g3 = 2.0002. The signal grows linearly with dose at least up to about 20 Gy. No fading was observed at room temperature even when exposed to sunlight. The dose to artificially irradiated tablets was estimated using the signal intensity and a previously determined calibration curve. The signal in sugar coated tablets can be utilised for dose measurements. In particular, the wide distribution of sugar coated tablets allows the use of the tablets as accident dosemeters. (author)

  1. Development of New Neutron Detectors for Accident Dosimetry

    New detectors and measuring techniques are proposed to improve the assessment of individual dose received from persons involved in a criticality accident. The aim was to reduce the number of detectors in the conventional detector combinations, to use sensitive activation reactions and to measure the dose of intermediate and fast neutrons directly. The proposed neutron detectors for the dosimeter combination are: (a) Arsenic, to detect slow and intermediate neutrons up to 1 MeV by the 75As(n, y) 76As reaction (half-life of 76As is 26.4 h); (b) Phosphorus, to detect fast neutrons above a threshold of 2 MeV by the 31P (n, γ) 31Si reaction (half-life of 31Si is 2.6 h), and slow neutrons by the 31P(n, γ) 32P reaction (half-life of 32P is 14 d); (d) A polycarbonate detector (Makrofol E) as a nuclear track detector to detect fast neutrons above a threshold of 0.5 MeV by elastic scattering and (n,a) reactions in carbon and oxygen. The S-activity of 76As, 31Si and 32P can be measured directly in As2S3 glass and in phosphate glass by means of the β-induced Cerenkov effect. It uses a liquid scintillation counter set up as for tritium measurements. The calibration of the detectors was performed by calculations of the detector sensitivity for different neutron spectra and by irradiation with different neutron sources at different ctiticality installations. After an accident a first estimation of the neutron dose is obtained by a β-counting of the arsenic phosphate glass, which indicates the surface adsorbed dose or the total neutron fluence directly. It is energy independent over the range of intermediate and fast neutrons. (author)

  2. Dosimetry for environmental radon: terradex experiment

    The dosimetry of gases like radon and thoron (222Rn and 220Rn) is important in several fields of general interest, such as radioprotection uranium mines, environmental health, house construction, geophysical research, medical therapy (i.e. radon baths), background measurements for experiments that study exotic processes, study of seismic events, since 222Rn is released in soil cavities prior to the earthquake and radiometric dating of materials. In this work we will present the Terradex project which is a system capable to perform accurate measurements of 219Rn, 222Rn and 220Rn (produced by the decay chains of 235U, 238U and 232Th respectively) gases concentration in air, water or other fluid. The instrument is based on silicon microstrip detectors inserted in a cylindrical fiducial volume, connected to the front-end data acquisition electronics and to a pneumatic system providing high vacuum. The experimental apparatus, data acquisition system, details of calibration procedures and of data analysis will also be discussed

  3. Accident dosimetry using the TL from dental restoration porcelains

    The thermoluminescence (TL) properties of dental restorative porcelain were investigated with the aim of using this material as a TL dosemeter to estimate high doses in radiological accidents. The irradiations were carried out with a 60Co gamma source and X rays with effective energies from 29 to 95 keV. The porcelain glow curve presents three peaks at about 393,463 and 543K. The samples have a limit of detection at about 1.29x10-2 C.kg-1(50 R) and their reproducibility is better than 15%. Linearity was observed from 1.29 x 10-2 to 12.9 C.kg-1(50 to 50,000 R). Over this exposure range, the dental porcelain TL response presents a maximum pre-dose sensitisation factor of 2.33. The porcelain TL sensitivity, normalised to 60Co, has a maximum of 4.8 at 29 keV due to its energy dependence. (author)

  4. Preliminary study of ESR dosimetry for nuclear accidents

    Electron spin resonance (RSE) technique was used to detect the ESR signal feature and the relations between signal intensity and irradiation dose of 0-50 Gy of 60Co γ ray for human bone, fingernail, hair and more than ten kinds of people carried materials such as materials from watch, clothes, plastic ball pen, cigarette and so on. The results showed that both bone and watch glass have a good linear relation between signal intensity and irradiation dose. The linear correlation factor γ is 0.995 for bone and 0.999 for watch glass. At room temperature, signal from human bone has excellent stability while watch glass has a decay of about 20% during 24 hours at 24 degree C. The decay rate of watch glass will fall down at lower temperature. The lower limit of detectable dose for these two materials is below 2 Gy. The results suggest that both human bone and watch glass can be applicable as ESR dosimeter materials for nuclear accidents. Other materials investigated in this work still have some problems to be solved for accidental dosimetric use

  5. Dosimetry at the Los Alamos Critical Experiments Facility: Past, present, and future

    Although the primary reason for the existence of the Los Alamos Critical Experiments Facility is to provide basic data on the physics of systems of fissile material, the physical arrangements and ability to provide sources of radiation have led to applications for all types of radiation dosimetry. In the broad definition of radiation phenomena, the facility has provided sources to evaluate biological effects, radiation shielding and transport, and measurements of basic parameters such as the evaluation of delayed neutron parameters. Within the last 15 years, many of the radiation measurements have been directed to calibration and intercomparison of dosimetry related to nuclear criticality safety. Future plans include (1) the new applications of Godiva IV, a bare-metal pulse assembly, for dosimetry (including an evaluation of neutron and gamma-ray room return); (2) a proposal to relocate the Health Physics Research Reactor from the Oak Ridge National Laboratory to Los Alamos, which will provide the opportunity to continue the application of a primary benchmark source to radiation dosimetry; and (3) a proposal to employ SHEBA, a low-enrichment solution assembly, for accident dosimetry and evaluation

  6. Individual monitoring and dosimetry: The Goiania experience

    Several people were contaminated with 137Cs in an accident involving the stealing and breaching of a radiotherapy source in Goiania, Brazil. A drug known as Prussian Blue was administered to some contaminated individuals to enhance Cs elimination from the body. Individuals internally contaminated were monitored for the two first months, exclusively by in vitro bioassay, i.e., urine and faeces analysis. After that period of time a field whole-body counter was set up in Goiania and individuals started to be monitored in vivo, on a regular basis. The total internal committed doses and the effect of Prussian blue treatment have been evaluated. For adults, the biological half-time (T2) under PB treatment was reduced to an average value around to 31% of the half-time after finished treatment. For adolescents (T2) was reduced to an average value around to 54% and for children was reduced to an average value around to 57%. A weight dependent biokinetic study of 137Cs retention in humans was conducted. Data from 10 girls and 7 boys, aged 1 to 10 y old, as well as from 10 adolescents: 4 females and 6 males, and from 30 adults: 15 females and 15 males, contaminated in the accident, were used in this study. A planned experiment with beagle dogs were carried out to furnish some further data for our study. Based on these data, a three terms exponential equation is suggested to describe the 137Cs retention in the body, the first-term associated with a very short half-time, the second with a longer half-time and the third term with a very long half-time, of the order of 400 to 570 days and relating to a retention fraction of only 0.1%. A table of weight, age and sex specific half-times for the second term is suggested. (author)

  7. EPR dosimetry of teeth in past and future accidents. A prospective look at a retrospective method

    Accurate assessments of doses received by individuals exposed to radiation from nuclear accidents and incidents such as those at Hiroshima and Nagasaki, the Nevada test site, Chelyabinsk and Mayak are required for epidemiological studies seeking to establish relationships between radiation dose and health effects. One method of retrospective dosimetry which allows for measurement of cumulative gamma ray doses received by exposed individuals is electron paramagnetic resonance spectroscopy (EPR) of tooth enamel. Tooth enamel stores and retains, indefinitely, information on absorbed radiation dose; and teeth are available in every population as a result of dental extraction for medical reasons including periodontal disease and impacted wisdom teeth. In the case of children, deciduous teeth, which are shed between the ages of 7 and 13, can be a very important dosimetric source if documented collection is implemented shortly following an accident. (author)

  8. Experiences with alanine dosimetry in afterloading brachytherapy

    At the present, the most commonly used dosimetry for radiotherapy applications are ionisation chambers and thermoluminescent dosimeters (TLD). However, there are some undesirable characteristics of these dosimetry systems, such as large detection volume (ionisation chamber) as well as fading of the radiation induced signal with time and destructive readout (TLG). The present study is an investigation into the use of the alanine/ESR dosimetry in fractionated afterloading brachytherapy during the whole radiotherapy course. There are some qualities which make alanine dosimetry attractive. These are the linear energy response, low fading under standard conditions, and the nondestructive readout. Thus the alanine dosimetry makes possible cumulative dose measurements during the radiotherapy course and an archival storage. By ionizing radiation (gamma, e, n, p, charged particles) free radicals (unpaired electrons) are produced in the amino acid alanine. The continuous wave electron spin resonance (ESR) spectroscopy is used to determine the number of free radicals, which is proportional to the absorbed dose and the alanine content of the dosimeter. The ESR measurements were made at room temperature using a Bruker EPR analyzer EMS-104. The dosimeters used in the test are alanine pellets (23.72 mg weight, 4.9 mm diameter, 1 mm height) as well as flexible alanine film dosimeters (thickness about 500 μm). The dosimeters consist of a blend of L-alpha-alanine and a binder. The alanine content of the pellets and the film dosimeters is about 88 % and 50 % by weight, respectively. The dosimeters for the calculation of the dose-effect-relationship were irradiated at the Physical-Technical Bundesanstalt in Braunschweig by a standard 60Co source. The maximum deviation from the calculated linear function is about 0.12 Gy in the dose range up to 80 Gy. The goal of medical applications was the superficial dose measurement in afterloading brachytherapy during the radiotherapy course in

  9. Probabilistic accident consequence uncertainty analysis -- Uncertainty assessment for internal dosimetry. Volume 2: Appendices

    Goossens, L.H.J.; Kraan, B.C.P.; Cooke, R.M. [Delft Univ. of Technology (Netherlands); Harrison, J.D. [National Radiological Protection Board (United Kingdom); Harper, F.T. [Sandia National Labs., Albuquerque, NM (United States); Hora, S.C. [Univ. of Hawaii, Hilo, HI (United States)

    1998-04-01

    The development of two new probabilistic accident consequence codes, MACCS and COSYMA, was completed in 1990. These codes estimate the consequence from the accidental releases of radiological material from hypothesized accidents at nuclear installations. In 1991, the US Nuclear Regulatory Commission and the Commission of the European Communities began cosponsoring a joint uncertainty analysis of the two codes. The ultimate objective of this joint effort was to systematically develop credible and traceable uncertainty distributions for the respective code input variables. A formal expert judgment elicitation and evaluation process was identified as the best technology available for developing a library of uncertainty distributions for these consequence parameters. This report focuses on the results of the study to develop distribution for variables related to the MACCS and COSYMA internal dosimetry models. This volume contains appendices that include (1) a summary of the MACCS and COSYMA consequence codes, (2) the elicitation questionnaires and case structures, (3) the rationales and results for the panel on internal dosimetry, (4) short biographies of the experts, and (5) the aggregated results of their responses.

  10. REWET, PWR LOCA accident experiments

    steam generators differ from the commonly used vertical steam generators. The fuel rods are arranged hexagonally, and the fuel bundles of 127 rods are in BWR-like channels. The lower plenum volume is large because of the fuel followers of the control rods. In particular, the ECC water is injected directly into the upper plenum and the downcomer of the reactor vessel. The main measurements in the experiments are coolant and rod cladding temperatures with thermocouples at different radial and axial locations. System pressure, pressure difference along the test section (core simulator), coolant flow rates and heating power are also measured. The data acquisition system consists of measurement and control processor, digital voltmeter and desk-top computer. The maximum speed to scan all 96 data channels during an experiment is once per second. With this speed it takes 10 minutes to collect a maximum of 58,800 readouts. Three different fuel rod simulator bundles have been used in experiments, two bundles with nine-step chopped cosine power distribution and one with uniform linear power. The simulator rods have been compared with the VVER-440 fuel rods by performing reflood calculations using the FLOOD4 computer code developed at the INEL, USA

  11. TL (thermoluminescence) accident dosimetry measurements on samples from the town of Pripyat

    In July 1990, several different types of ceramic samples were collected from the town of Pripyat, situated 3 km NW of the Chernobyl Nuclear Power Plant. The samples were distributed among several laboratories for thermoluminescence (TL) measurement to determine the total absorbed gamma dose at different points within a small area in the most polluted region and to assess the shielding given by the walls of buildings to the people inside apartment blocks. This paper discusses the types of samples and their suitability for accident dosimetry, the TL measurements, minimum limits of detection for various types of samples and the strengths and limitations of the method in this type of situation. The implication of the results are discussed. (author)

  12. Thermoluminescence of chip inductors from mobile phones for retrospective and accident dosimetry

    Electronic components in portable electronic devices such as mobile phones and portable media player have previously been shown to be useful tools for retrospective and accident dosimetry. In this study the properties of alumina rich inductors removed from mobile phones are investigated using thermoluminescence (TL). The typical glow curve of this component has two main peaks at 170 and 270 °C. With a suitable measurement protocol sensitivity changes of both peaks could be corrected so that the TL signal shows a linear increase in the investigated dose range from 100 mGy to 5 Gy. All inductors studied showed essentially no signal for zero dose. We investigated the fading of the TL signals and the detection limit of inductors extracted from different mobile phones.

  13. Improvement of dose determination using glass display of mobile phones for accident dosimetry

    Previous studies have demonstrated that mobile phones can be used as suitable emergency dosimeters in case of an accidental radiation overexposure. Glass samples extracted from displays of mobile phones are sensitive to ionizing radiation and can be measured using the thermoluminescence (TL) method. A non-radiation induced background signal (so-called zero dose signal) was observed which overlaps with the radiation induced signal and consequently limits the minimum detectable dose. Investigations of several glasses from different displays showed that it is possible to reduce the zero dose signal up to 90% by etching the glass surface with concentrated hydrofluoric acid. With this approach a reduction of the detection limit of a factor of four, corresponding to approximately 80 mGy, was achieved. Dosimetric properties of etched samples are presented and developed protocols validated by dose recovery tests under realistic conditions. With the improvements in sample preparation the proposed method of dose determination is a competitive alternative to OSL/TL measurements of electronic components and chip cards and provides a useful option for retrospective accident dosimetry. -- Highlights: ► Glass displays from mobile phones have good potential for emergency dosimetry. ► The background signal can be reduced by etching glass samples with hydrofluoric acid. ► The minimum detectable dose can be lowered to approximately 80 mGy

  14. Use of epr-dosimetry of dental enamel for persons exposed to radiation due to the Chernobyl accident

    Technique of epr-dosimetry of dental enamel enabling to measure the accumulated dose equivalents of the external irradiation with the accuracy equal to several sGr limits is studied. The PC code enabling to standardize the spectra processing is elaborated. The code is rather reliable and may be used when elaborating the methodical provision of the activity of the dosimetric services directed to determine the accumulated dose equivalents of the external irradiation using the dental enamel epr-dosimetry technique, in particular, in cases of people affected by the Chernobyl accident

  15. Dosimetry

    The fundamental units of dosimetry are defined, such as exposure rate, absorbed dose and equivalent dose. A table is given of relative biological effectiveness values for the different types of radiation. The relation between the roentgen and rad units is calculated and the concepts of physical half-life, biological half-life and effective half-life are discussed. Referring to internal dosimetry, a mathematical treatment is given to β particle-and γ radiation dosimetry. The absorbed dose is calculated and a practical example is given of the calculation of the exposure and of the dose rate for a gama source

  16. ATHLET validation using accident management experiments

    The computer code ATHLET is being developed as an advanced best-estimate code for the simulation of leaks and transients in PWRs and BWRs including beyond design basis accidents. The code has features that are of special interest for applications to small leaks and transients with accident management, e.g. initialisation by a steady-state calculation, full-range drift-flux model, and dynamic mixture level tracking. The General Control Simulation Module of ATHLET is a flexible tool for the simulation of the balance-of-plant and control systems including the various operator actions in the course of accident sequences with AM measures. The systematic validation of ATHLET is based on a well balanced set of integral and separate effect tests derived from the CSNI proposal emphasising, however, the German combined ECC injection system which was investigated in the UPTF, PKL and LOBI test facilities. PKL-III test B 2.1 simulates a cool-down procedure during an emergency power case with three steam generators isolated. Natural circulation under these conditions was investigated in detail in a pressure range of 4 to 2 MPa. The transient was calculated over 22000 s with complicated boundary conditions including manual control actions. The calculations demonstrations the capability to model the following processes successfully: (1) variation of the natural circulation caused by steam generator isolation, (2) vapour formation in the U-tubes of the isolated steam generators, (3) break-down of circulation in the loop containing the isolated steam generator following controlled cool-down of the secondary side, (4) accumulation of vapour in the pressure vessel dome. One conclusion with respect to the suitability of experiments simulating AM procedures for code validation purposes is that complete documentation of control actions during the experiment must be available. Special attention should be given to the documentation of operator actions in the course of the experiment

  17. Cuban experience in dosimetry quality audit program in radiotherapy

    Full text: Five years ago we started a National Program of Quality Assurance in Radiotherapy. This program was possible thanks to the cooperation between the Cuban Ministry of Health and the International Atomic Energy Agency (IAEA) in the Projects ARCAL XXX and CUB/6/011. In the framework of these projects a total of ten complete dosimetry set were acquired and a large number of medical physicists were trained. At the same time, the Cuban side signed a contract for nine cobalt units, which have been gradually installed and all of them are running at the moment. During more than 20 years Cuba has taken part in the IAEA/WHO TLD postal dose audit programs and our results have been inside the (+/-)5 % acceptance limit. Cuba also joined the IAEA Coordinated Research Program E2 40 07, to extend at a national level the experience of the TLD based audits, using the capability of our SSDL to measure TLD. At the same time the work of the already existing External Audit Group was consolidated. The National Program of Quality Assurance in Radiotherapy works on base of external on-site visits. The main objective is to avoid any accident and to improve the quality of the RT treatments. Every year each Radiotherapy service is visited by a qualified team of physicists with the objective to check the physical aspects of the quality of the RT treatment, it includes: Documents and Records, safety, mechanical and dosimetric aspects, treatment planning, also we use the fixed depth phantom to simulate and verify several techniques. Although the TLD postal audit results are acceptable, in our QA audits we have detected some problems that may deviate the dose delivery to patients in more than 5%, examples of which are: Not all the clinical plans are redundantly checked by an independent person; Not all the controls (daily, monthly and annual) are performed according to the protocols approved by the National QA Committee. In some cases the controls are not well recorded; Clinical

  18. Accreditation ISO/IEC 1705 in dosimetry: Experience and results

    The objective of this work is to present the experience in the process of accreditation of the radiation dosimetry service in which there are trials for the determination of radiation doses due to internal and external exhibitions. Is They describe the aspects that were considered for the design and development of a system of quality and results after its implementation. A review of the benefits accreditation has been reported to the organization is finally made. (Author)

  19. Sandia National Laboratories results for the 2010 criticality accident dosimetry exercise, at the CALIBAN reactor, CEA Valduc France.

    Ward, Dann C.

    2011-09-01

    This document describes the personal nuclear accident dosimeter (PNAD) used by Sandia National Laboratories (SNL) and presents PNAD dosimetry results obtained during the Nuclear Accident Dosimeter Intercomparison Study held 20-23 September, 2010, at CEA Valduc, France. SNL PNADs were exposed in two separate irradiations from the CALIBAN reactor. Biases for reported neutron doses ranged from -15% to +0.4% with an average bias of -7.7%. PNADs were also exposed on the back side of phantoms to assess orientation effects.

  20. A micro-gap, air-filled ionisation chamber as a detector for criticality accident dosimetry

    A micro-gap air-filled ionisation chamber was designed for criticality dosimetry. The special feature of the chamber is its very small gap between electrodes of only 0.3 mm. This prevents ion recombination at high dose rates and minimises the influence of gas on secondary particles spectrum. The electrodes are made of polypropylene because of higher content of hydrogen in this material, when compared with soft tissue. The difference between neutron and gamma sensitivity in such chamber becomes practically negligible. The chamber's envelope contains two specially connected capacitors, one for polarising the electrodes and the other for collecting the ionisation charge. Air-filled ionisation chamber with very small gap is a simple dosemeter, which fulfills the most desired properties of criticality accident dosemeters. Short ion collection time is achieved by combination of small gap and relatively high polarising voltage. For the same reason, parasitic recombination of ions in the chamber is negligibly small even at high dose rates. The difference between neutron and gamma sensitivity is small for tissue-equivalent chamber and is expected to become practically negligible when the chamber electrodes are made of polypropylene. Additional capacitor provides a broad measuring range from ∼0.1 Gy up to ∼25 Gy; however, leakage of electrical charge from polarising capacitor has to be observed and taken into account. Periodical re-charging of the device is necessary. Obviously, final test of the device in conditions simulating criticality accident is needed and will be performed as soon as available. (authors)

  1. Photon energy dependence and angular response of glass display used in mobile phones for accident dosimetry

    Previous studies have shown that glass displays extracted from mobile phones are suitable as emergency dosimeters in case of an accidental radiation overexposure using the thermoluminescence (TL) method. So far these studies have focused only on recovering the absorbed dose to the material. However, dose in air or dose to the victim carrying the device might be significantly different. Therefore the aim of this work was to investigate photon energy dependence and angular response of glass display used in modern mobile phones. An over-response of about a factor of five is observed for low photon energies compared to the response to Cs-137 (662 keV) which is in reasonable agreement with calculated values mass energy-absorption coefficients of glass and air. Little variation in the energy dependence can be seen for glass displays coming from three different mobile phone models. The angular response for display glass is flat with regard to air kerma within the incident angle of ±60°, independent of the irradiation setup used (with a water phantom or with air kerma reference conditions). For incident angles of 90° the shielding effect of the mobile phones becomes important. With the dosimetric characterization of the photon energy and angular dependencies the absorbed dose in a glass display can be transferred to a reference air kerma dose and provides a useful option for retrospective accident dosimetry. - Highlights: • Determination of the photon energy dependence and angular response for display glass used as an accident dosimeter. • Over-response of about a factor of five for low photon energies. • Flat angular response within incident angles between ±60°

  2. Thermoluminescence of glass display from mobile phones for retrospective and accident dosimetry

    This paper deals with the thermoluminescence (TL) study of glass displays from mobile phones with the aim to use them as emergency dosimeters after an accident involving ionizing radiation. Dosimetric properties are analysed in order to examine and to critically evaluate the usability. Tests are carried out regarding the characterization of the radiation induced TL signal and the zero dose signal (intrinsic background) on a variety of display samples. Investigations on the thermal and optical stability of TL signals are carried out. The detection limit is mainly determined by the variability of the zero dose signal and lies in the range of 300–400 mGy. A linear relationship between the measured TL signal and the applied dose is observed for doses between 10 mGy and 20 Gy. A measurement protocol for the detection of absorbed radiation dose is developed, considering the experimental dosimetric properties. A reconstruction of the absorbed dose is possible using glass samples from mobile phones, if the signal loss due to storage and optical bleaching of the TL signal is adequately corrected for. This was confirmed by realistic tests. - Highlights: • Glass displays of mobile phones have potential for retrospective dosimetry. • Signal fading can be corrected with an universally fading curve. • Irradiation trials on intact mobile phones demonstrated a reasonable agreement between given and measured dose

  3. An EPR dosimetry method for rapid scanning of children following a radiation accident using deciduous teeth

    Electron paramagnetic resonance dosimetry may be applied to whole deciduous teeth of children. This makes it feasible to make direct measurement of absorbed gamma ray dose in the days and weeks following a nuclear accident, particularly if used in conjunction with a public awareness program. The technique reported here requires little sample preparation and has resulted in precision of approximately 30 mGy (1 σ) for a deciduous incisor. Under conditions for rapid screening procedures, the methodology is estimated to provide 0.5 Gy accuracy. The largest error in the process is the determination of an appropriate background native signal for subtraction from the whole tooth spectrum. The native signal is superimposed on the radiation-induced signal, and the subtraction requires knowledge of a sample's relative content of enamel and dentin along with their relative native signal intensities. Using a composite background standard, an equivalent absorbed dose of 70 ± 38 mGy (1 σ) was determined. The lower detection limit of the technique was achieved by the elimination of anisotropic effects through rotation of the sample during measurement, together with subtraction of the standard native background signal and empty tube background spectra from the sample spectra

  4. Dosimetry for radiobiology experiments at GANIL

    Durantel, Florent; Balanzat, Emmanuel; Cassimi, Amine; Chevalier, François; Ngono-Ravache, Yvette; Madi, Toiammou; Poully, Jean-Christophe; Ramillon, Jean-Marc; Rothard, Hermann; Ropars, Frédéric; Schwob, Lucas; Testard, Isabelle; Saintigny, Yannick

    2016-04-01

    Mainly encouraged by the increasing application of ion beams for cancer treatment (hadron-therapy) including carbon beams, the use of heavy ion facilities for radiobiology is expanding rapidly today. As an alternative to dedicated centers for treatment and medical research, accelerators like GANIL offer the possibility to undertake such experiments. Since 20 years, CIMAP, reinforced 15 years ago by the biological host laboratory LARIA, has been receiving researchers in radiobiology and assisted them in performing experiments in different fields such as hadron-therapy, space radioprotection and fundamental biological and physico-chemical mechanisms. We present here a short description of the beam line and the on-line equipments that allow the automatic irradiation of up to 24 biological samples at once. We also developed an original on-line beam monitoring procedure for low ion flux (low dose rates) based on the measurement of the K-shell X-rays emitted from a thin iron foil. This detector is calibrated on an absolute scale before each experiment by counting etched tracks on an irradiated CR39 polymer plate. We present the performances and limits of this method and finally give typical fluence (dose) uncertainties for a standard irradiation in radiobiology.

  5. Chernobyl NPP accident. Overcoming experience. Acquired lessons

    This book is devoted to the 20 anniversary of accident on the Chernobyl NPP unit 4. History of construction, causes of the accident and its consequences, actions for its mitigation are described. Modern situation with Chernobyl NPP decommissioning and transferring of 'Ukryttya' shelter into ecologically safe system are mentioned. The future of Chernobyl site and exclusion zone was discussed

  6. A TLD for whole body dosimetry our experience in neutron personnel dosimetry

    One of the Greek Atomic Energy, Commission's (GAEC) responsibilities is the personnel dosimetry and the record keeping for the workers occupationally exposed to ionising radiation. The personnel dosimetry laboratory of the GAEC assures the monitoring of almost 7000 workers in the whole country, including about 100 working in areas where neutrons might be present. For this purpose a thermoluminescence dosimetry system (TLD) in neutron dosimetry has been introduced. Scope of the present work is the quality control and the preliminary results on the implementation of the TLD system. The quality control of the system has been completed and the results are presented. (authors)

  7. Assessment of light water reactor accident management programs and experience

    The objective of this report is to provide an assessment of the current light water reactor experience regarding accident management programs and associated technology developments. This assessment for light water reactor (LWR) designs is provided as a resource and reference for the development of accident management capabilities for the production reactors at the Savannah River Site. The specific objectives of this assessment are as follows: 1. Perform a review of the NRC, utility, and industry (NUMARC, EPRI) accident management programs and implementation experience. 2. Provide an assessment of the problems and opportunities in developing an accident management program in conjunction or following the Individual Plant Examination process. 3. Review current NRC, utility, and industry technological developments in the areas of computational tools, severe accident predictive tools, diagnostic aids, and severe accident training and simulation

  8. Assessment of light water reactor accident management programs and experience

    Hammersley, R.J. [Fauske and Associates, Inc., Burr Ridge, IL (United States)

    1992-03-01

    The objective of this report is to provide an assessment of the current light water reactor experience regarding accident management programs and associated technology developments. This assessment for light water reactor (LWR) designs is provided as a resource and reference for the development of accident management capabilities for the production reactors at the Savannah River Site. The specific objectives of this assessment are as follows: 1. Perform a review of the NRC, utility, and industry (NUMARC, EPRI) accident management programs and implementation experience. 2. Provide an assessment of the problems and opportunities in developing an accident management program in conjunction or following the Individual Plant Examination process. 3. Review current NRC, utility, and industry technological developments in the areas of computational tools, severe accident predictive tools, diagnostic aids, and severe accident training and simulation.

  9. Recent experience in applying the cytogenetic dosimetry assay

    This paper considers how well standard calibration curve for translocations constructed for lymphocyte cultures irradiated in vitro with gamma-rays from 60Co compares with the translocations yield in lymphocytes taken from people at a long post-exposure time. Data were used from radiation accident victims overexposed to doses ranging from 0.2 to 8.5 Gy and who were cytogenetically followed-up for various times upto 50 y. Their cultured lymphocytes had been scored both by the conventional dicentric method and by FISH for all translocations involving painted chromosomes (2, 3, 8); (2, 3, 5) or (2, 4, 12). The in vivo dose response relationship was derived by fitting translocation frequencies to the contemporary individual doses obtained independently and confirmed by different biological assays and physical dosimetry. A comparison with the conventional in vitro curve indicates reductions of translocation frequencies with increasing time which would prejudice retrospective dose assessment by FISH. This has led to the possibility to amend the in vitro dose response curve for translocations to make it more suitable for use in retrospective biodosimetry. This approach for retrospective biodosimetry therefore uses a dose response relationship based on truly persisting translocations.

  10. Recent experience in applying the cytogenetic dosimetry assay

    Khvostunov, I.K., E-mail: 726727@mrrc.obninsk.ru [Medical Radiological Research Centre, Koroliov Str. 4, Obninsk, Kaluga Region, 249036 (Russian Federation); Sevan' kaev, A.V. [Medical Radiological Research Centre, Koroliov Str. 4, Obninsk, Kaluga Region, 249036 (Russian Federation); Lloyd, D.C. [Health Protection Agency, Centre for Radiation, Chemical and Environmental Hazards, Chilton, Didcot, Oxfordshire (United Kingdom); Nugis, V.Yu. [Burnasyan Federal Medical Biophysical Center of the Federal Medical Biological Agency, Marshala Novikova Str., 23, Moscow (Russian Federation); Voisin, P. [Institute for Radiation Protection and Nuclear Safety, SRBE, B.P. 17, 92262 Fontenay-aux-Roses Cedex (France)

    2011-09-15

    This paper considers how well standard calibration curve for translocations constructed for lymphocyte cultures irradiated in vitro with gamma-rays from {sup 60}Co compares with the translocations yield in lymphocytes taken from people at a long post-exposure time. Data were used from radiation accident victims overexposed to doses ranging from 0.2 to 8.5 Gy and who were cytogenetically followed-up for various times upto 50 y. Their cultured lymphocytes had been scored both by the conventional dicentric method and by FISH for all translocations involving painted chromosomes (2, 3, 8); (2, 3, 5) or (2, 4, 12). The in vivo dose response relationship was derived by fitting translocation frequencies to the contemporary individual doses obtained independently and confirmed by different biological assays and physical dosimetry. A comparison with the conventional in vitro curve indicates reductions of translocation frequencies with increasing time which would prejudice retrospective dose assessment by FISH. This has led to the possibility to amend the in vitro dose response curve for translocations to make it more suitable for use in retrospective biodosimetry. This approach for retrospective biodosimetry therefore uses a dose response relationship based on truly persisting translocations.

  11. Radiation defects in solid matrix as a physical base of EPR-dosimetry. The results of international experiment 'Intercomparison'

    Full text: The very high sensitivity of EPR method at radiation defects in solid matrixes registration caused for last decade an intensive development of a new field - EPR-dosimetry. The suitable work substances had been found in a result of prolonged wide investigations, that allowed successful development both an operative dosimetry, and, that is especially important, the retrospective one. Nowadays the retrospective dosimetry on tooth enamel is adopted by IAEA and WHO as the main method of the radiation accidents consequences analysis for suffered population. In the report the methodical peculiarities of EPR-dosimetry are reviewed, the possible sources of the dose characteristics nonlinearity occurrence are analyzed as well other sources of errors and the ways of their elimination are considered. The review of the results of the international experiments 'Intercomparison' on EPR-dosimetry on tooth enamel series, held for last years under IAEA aegis is given. Practically all leading worldwide labs, including NMR laboratory of the INP NNC RK, took part in these experiments. The main goal was estimation of accuracy, sensitivity and reproducibility of summary dose values, having been reconstructed on base of EPR-signal of radiation defects in tooth enamel. The last experiment 'Intercomparison 3' has shown a considerable progress achieved lately in this area. Now the Japanese scientists from Hiroshima are preparing a further continuation of these Intercomparisons. Researches of radiation-induced EPR signals, stabilized in solid matrix, have been found out also rather useful and productive for the purposes of geological and archaeological dating, in criminalistics, in radiation chemistry and so on. Probably, this method will be rather perspective and at identification of radiation-sterilized food-stuffs, which come up now on world markets more and more often, however, studies in this direction are still on an incipient stage only

  12. Survey of severe accident experiments and analyses in Japan

    An overview of Japanese activities in the field of Light Water Reactor (LWR) severe accident experiments and analyses is presented, covering various fields and topics of experimental investigation on severe accident phenomena such as fuel damage and melt progression, fission products release and transport, and component and containment integrity. The current status of analytical investigations on severe accidents is also described in the fields of the level-1 and level-2 (PSA) probabilistic safety assessment studies, code development and assessment activities. Basic considerations for accident management are summarized. (author)

  13. Production of analysis code for 'JOYO' dosimetry experiment

    As part of the measurement and analysis plan for the Dosimetry Experiment at the ''JOYO'' experimental fast reactor, neutron flux spectra analysis is performed using the NEUPAC (Neutron Unfolding Code Package) computer program. The code calculates the neutron flux spectra and other integral quantities from the activation data of the dosimeter foils. The NEUPAC code is based on the J1-type unfolding method, and the estimated neutron flux spectra is obtained as its solution. The program is able to determine the integral quantities and their sensitivities, together with an error estimate of the unfolded spectra and integral quantities. The code also performs a chi-square test of the input/output data, and contains many options for the calculational routines. This report presents the analytic theory, the program algorithms, and a description of the functions and use of the NEUPAC code. (author)

  14. Iodine-129 in soils from Northern Ukraine and the retrospective dosimetry of the iodine-131 exposure after the Chernobyl accident

    Forty-eight soil profiles down to a depth of 40 cm were taken in Russia and Ukraine in 1995 and 1997, respectively, in order to investigate the feasibility of retrospective dosimetry of the 131I exposure after the Chernobyl accident via the long-lived 129I. The sampling sites covered areas almost not affected by fallout from the Chernobyl accident such as Moscow/Russia and the Zhitomir district in Ukraine as well as the highly contaminated Korosten and Narodici districts in Ukraine. 129I was analyzed by radiochemical neutron activation analysis (RNAA) and accelerator mass spectrometry (AMS). 127I was measured for some profiles by RNAA or ion chromatography (IC). The results for 127I demonstrated large differences in the capabilities of the soils to store iodine over long time spans. The depth profiles of 129I and of 137Cs showed large differences in the migration behavior between the two nuclides but also for each nuclide among the different sampling sites. Though it cannot be quantified how much 129I and 137Cs was lost out of the soil columns into deeper depths, the inventories in the columns were taken as proxies for the total inventories. For 129I, these inventories were at least three orders of magnitude higher than a pre-nuclear value of 0.084±0.017 mBq m-2 derived from a soil profile taken in 1939 in Lutovinovo/Russia. From the samples from Moscow and Zhitomir, a pre-Chernobyl 129I inventory of (44±24) mBq m-2 was determined, limiting the feasibility of 129I retrospective dosimetry to areas where the 129I inventories exceed 100 mBq m-2. Higher average 129I inventories in the Korosten and Narodici districts of 130 and 848 mBq m-2, respectively, allowed determination of the 129I fallout due to the Chernobyl accident. Based on the total 129I inventories and on literature data for the atomic ratio of 129I/131I=13.6±2.8 for the Chernobyl emissions and on aggregated dose coefficients for 131I, the thyroid exposure due to 131I after the Chernobyl accident was

  15. ESR Dosimetry

    ESR dosimetry is widely used for several applications such as dose assessment in accidents, medical applications and sterilization of food and other materials. In this work the dosimetric properties of natural and synthetic Hydroxyapatite, Alanine, and 2-Methylalanine are presented. Recent results on the use of a K-Band (24 GHz) ESR spectrometer in dosimetry are also presented

  16. EPR dosimetry of teeth in past and future accidents: a prospective look at a retrospective method

    Electron paramagnetic resonance spectroscopy (EPR) of tooth enamel is a relatively new technique for retrospective dosimetry that in the past two years has seen increasing effort towards its development and evaluation. Efforts have centered on determining the accuracy which may be achieved with current measurement techniques as well as the minimum doses detectable. The study was focused on evaluating some factors which influence the accuracy of EPR dosimetry of enamel. Reported are studies on sample intercomparisions, instrumental considerations, and effects of dental x-rays, environmental sunlight and ultraviolet radiation

  17. Dosimetry for radiobiological experiments using energetic heavy ions

    The availability of the Bevalac facility of energetic heavy ions with range greater than the size of small mammals makes possible the determination of the biological effects of relatively well defined high LET, whole body irradiation. With the increasing application of high-energy heavy ions in radiobiology there is a corresponding need to develop reliable techniques of both relative and absolute absorbed dose measurement. This paper describes dosimetry studies by the Health Physics Department of the Lawrence Berkeley Laboratory with activation detectors, ionization chambers, nuclear emulsion, thermoluminescent dosimeters and X-ray film. The application of these techniques to an experiment designed to study the leukemogenic effect of the whole-body irradiation of mice by 250 MeV/amu carbon ions is briefly described. Values of absorbed dose in tissue, obtained during this experiment, with a nitrogen filled ionization chamber and 7LiF thermoluminescent dosimeters are compared and shown to be in good agreement. As a result of this work a value for the average energy to produce an ion pair (W) in nitrogen by 250 MeV/amu 6+C ions of 37 +- eV was determined. Values of the efficiency of 7LiF relative to 60Co γ-rays for ions with dE/dx in the range 110-260 MeV g-1 cm2 are reported

  18. Systematic Review of Accident Management Programs - Principles, Experiences

    Although all plants have some form of accident management, there is not always a proper review of the accident management program neither of its products, i.e. the various procedures and guidelines. Moreover, such reviews are often limited to Emergency Operating Procedures (EOPs) and Severe Accident Management Guidelines (SAMG). More complex events, which include large damage on the site, require additional tools and procedures / guidelines. The present paper describes a new review method that covers this larger area and is capable to identify problems and shortcomings, and offers solutions for those. It basically exists of a three-tier approach: 1. interviews with the national regulator and/or the plant to evaluate the scope of the accident management as required by the national regulation and in comparison with international regulation; 2. interviews with the plant staff to discuss the technical basis of the accident management program and its implementation; and 3. observation of an exercise to test the capability of the plant staff to execute the accident management procedures and guidelines, as well as the value of the exercise for such test. The method is an extension of the IAEA 'Review of Accident Management Program which is limited to review of EOPs and SAMG. It is based on extensive experience with plant reviews. (authors)

  19. Application of Radiothermoluminescence to Area Dosimetry in the Event of a Nuclear Accident Covering a Wide Area

    Although numerous systems have been studied and developed for providing γ-ray dosimetry at nuclear facilities in the event of an accident, very few of them are really satisfactory as regards their physical characteristics or the practical conditions under which they are applied. Most of them are not completely insensitive to neutrons and the response has to be corrected if the dose is to be evaluated with accuracy. This presupposes, inter alia, that the incident neutron spectrum is known, since the corrections that have to be made vary with the neutron energy. In most cases the systems require fairly large financial investment and some of them have to be regularly renewed (photographic dosimeters). We considered the possibility of using thermoluminescent materials to make an inexpensive dosimeter possessing low neutron sensitivity. Our choice fell on corundum, which is manufactured industrially and is available on the market at low cost. We analysed the radiothermoluminescent characteristics of the corundum selected by us and compared them to those of commercial lithium fluoride. We determined the practical conditions under which this material can be used. We advocate its use both for area dosimetry at nuclear facilities where there is potential risk of strong irradiation and for problems involving civil defence. (author)

  20. Researches and Applications of ESR Dosimetry for Radiation Accident Dose Assessment

    The aim of this work was to establish methods suitable for practical dose assessment of people involved in ionising radiation accidents. Some biological materials of the human body and materials possibly carried or worn by people were taken as detection samples. By using electron spin resonance (ESR) techniques, the basic dosimetric properties of selected materials were investigated in the range above the threshold dose of human acute haemopoietic radiation syndrome. The dosimetric properties involved included dose response properties of ESR signals, signal stabilities, distribution of background signals, the lowest detectable dose value, radiation conditions, environmental effects on the detecting process, etc. Several practical dose analytical indexes and detecting methods were set up. Some of them (bone, watch glass and tooth enamel) had also been successfully used in the dose assessment of people involved in three radiation accidents, including the Chernobyl reactor accident. This work further proves the important role of ESR techniques in radiation accident dose estimation. (author)

  1. Dosimetry of an accident in mixed field (neutrons, photons) using the spectrometry by electronic paramagnetic resonance(EPR); Dosimetrie d'accident en champ mixte (neutrons, photons) utilisant la spectrometrie par resonance paramagnetique electronique (RPE)

    Herve, M.L

    2006-03-15

    In a radiological accident, the assessment of the dose received by the victim is relevant information for the therapeutic strategy. Two complementary dosimetric techniques based on physical means are used in routine practice in the laboratory: EPR spectroscopy performed on materials removed from the victim or gathered from the vicinity of the victim and Monte Carlo calculations. EPR dosimetry, has been used successfully several times in cases of photon or electron overexposures. Accidental exposure may also occur with a neutron component. The aim of this work is to investigate the potentiality of EPR dosimetry for mixed photon and neutron field exposure with different organic materials (ascorbic acid, sorbitol, glucose, galactose, fructose, mannose, lactose and sucrose). The influence of irradiation parameters (dose, dose rate, photon energy) and of environmental parameters (temperature of heating, light exposure) on the EPR signal amplitude was studied. To assess the neutron sensitivity, the materials were exposed to a mixed radiation field of experimental reactors with different neutron to photon ratios. The relative neutron sensitivity was found to range from 10% to 43% according to the materials. Prior knowledge of the ratio between the dose in samples measured by EPR spectrometry and organ or whole body dose obtained by calculations previously performed for these different configurations, makes it possible to give a first estimation of the dose received by the victim in a short delay. The second aim of this work is to provide data relevant for a quick assessment of the dose distribution in case of accidental overexposure based on EPR measurements performed on one or several points of the body. The study consists in determining by calculation the relation between the dose to the organs and whole body and the dose to specific points of the body, like teeth, bones or samples located in the pockets of victim clothes, for different external exposures corresponding

  2. Validation of the Dosimetry Cross Sections by Integral Experiments

    Full text: A new version of the dosimetry library IRDFF has been released from the IAEA, featuring more reactions (compared to the older IRDF-2002), an extended energy range to 60 MeV, re-evaluation of several reaction channels with greatly improved covariance information, etc. The aim of the present CRP is the validation of the IRDFF library in order to enhance its reliability for the purposes it serves. Reaction rate measurements in well-defined neutron fields are a common method of validating the cross sections. This technique has been implemented to some extent in the preparation of the IRDFF library from the published data, namely the use of the published average cross sections in the 252Cf spontaneous fission neutron spectrum, thermal cross sections and resonance integrals. There is synergy with the community performing neutron activation analysis by the k0 standardisation technique. To some extent the k0 database has been used for a preliminary validation of the capture reactions in the IRDFF library, but one has to be very careful about the definition of the constants since the interpretation and the derivation of the commonly-used constants is often misleading. The proposed contribution of the Jozef Stefan Institute (JSI) is on the consistent definitions of the constants that allow unique interpretation of the measured reaction rate ratios (particularly for the capture reactions), together with advanced analysis techniques including Monte Carlo simulations of the experiments. The contribution can include the codes that are used at (JSI) for the purpose, namely the GRUPINT code for the analysis of measured reaction rate rations and spectrum unfolding and the RRUNC code for the calculation of the uncertainties in the calculated reaction rates due to the uncertainties in the cross sections and in the neutron spectrum. (author)

  3. Measuring patients' experiences in the Accident and Emergency department

    Bos, N.

    2013-01-01

    Two questionnaires were used to measure patients’ experiences in the Accident and Emergency department (A&E). First, the English A&E department questionnaire used in the English National Survey Programme, and after translation in Dutch used in the Netherlands. The second questionnaire concerned the

  4. Precision dosimetry system suited for low temperature radiation damage experiments

    Andersen, H.H.; Hanke, C.C.; Sørensen, H.

    1967-01-01

    A calorimetric system for dosimetry on a beam of charged particles is described. The calorimeter works at liquid helium temperature. The total dose may be measured with an accuracy of 0.3%, and the dose per area with 0.4%. No theoretical corrections are needed. © 1967 The American Institute of Ph...

  5. Dosimetry of an accident in mixed field (neutrons, photons) using the spectrometry by electronic paramagnetic resonance(EPR)

    In a radiological accident, the assessment of the dose received by the victim is relevant information for the therapeutic strategy. Two complementary dosimetric techniques based on physical means are used in routine practice in the laboratory: EPR spectroscopy performed on materials removed from the victim or gathered from the vicinity of the victim and Monte Carlo calculations. EPR dosimetry, has been used successfully several times in cases of photon or electron overexposures. Accidental exposure may also occur with a neutron component. The aim of this work is to investigate the potentiality of EPR dosimetry for mixed photon and neutron field exposure with different organic materials (ascorbic acid, sorbitol, glucose, galactose, fructose, mannose, lactose and sucrose). The influence of irradiation parameters (dose, dose rate, photon energy) and of environmental parameters (temperature of heating, light exposure) on the EPR signal amplitude was studied. To assess the neutron sensitivity, the materials were exposed to a mixed radiation field of experimental reactors with different neutron to photon ratios. The relative neutron sensitivity was found to range from 10% to 43% according to the materials. Prior knowledge of the ratio between the dose in samples measured by EPR spectrometry and organ or whole body dose obtained by calculations previously performed for these different configurations, makes it possible to give a first estimation of the dose received by the victim in a short delay. The second aim of this work is to provide data relevant for a quick assessment of the dose distribution in case of accidental overexposure based on EPR measurements performed on one or several points of the body. The study consists in determining by calculation the relation between the dose to the organs and whole body and the dose to specific points of the body, like teeth, bones or samples located in the pockets of victim clothes, for different external exposures corresponding

  6. Large-Scale Containment Cooler Performance Experiments under Accident Conditions

    Kapulla, Ralf; Mignot, Guillaume; Paladino, Domenico

    2012-01-01

    Computational Fluid Dynamics codes are increasingly used to simulate containment conditions after various transient accident scenarios. This paper presents validation experiments, conducted in the frame of the OECD/SETH-2 project. These experiments address the combined effects of mass sources and heat sinks related to gas mixing and hydrogen transport within containment compartments. A wall jet interacts with an operating containment cooler located in the middle (M-configuration) and the top ...

  7. Risk communication practice after the Tokyo Electric Power Company's Fukushima Daiichi Nuclear Power Station accident. Awareness of Fukushima residents in internal dosimetry

    This paper describes an analysis result of the opinion surveys that was carried out in internal dosimetry using whole body counters (WBC) in Japan Atomic Energy Agency (JAEA) Tokai Research and Development Center. At the request of Fukushima prefecture, JAEA has conducted the internal dosimetry for residents of Fukushima prefecture since July 2011. As of March 2013, JAEA screened approximately 22,000 residents. JAEA staffs do not only explained the examination results of WBC to the residents in private booths, but also provided necessary advice for them. We carried out the opinion surveys before the internal dosimetry and after personal dialogue. The purpose of these surveys was grasp of the views of residents on the nuclear accidents before the internal dosimetry and investigation of attitude change of the examinee after the personal dialogue. The survey before the internal dosimetry showed that residents' anxiety about radioactive exposure, hereditary influence on next generation, damage for primary industries by harmful rumor, and so on. In the survey after the personal dialogue, more than 90% examinee express reduction of uneasiness for the radiation damage by the dialogue with JAEA staffs. This analysis result elucidates validity of the direct dialogue with professional stuffs on the decrease of anxiety about radioactive problem. (author)

  8. Feedback from practical experience with large sodium fire accidents

    The paper reviews the important feedback from the practical experience from two large sodium fires; the first at ALMERIA in Spain and the second in the Na laboratories at Bensberg, Germany. One of the most important sodium fire accidents was the ALMERIA spray fire accident. The origin of this accident was the repair of a valve when about 14 t of sodium was spilled in the plant room over a period of 1/2 hour. The event has been reported (IAEA/IWGFR meeting in 1988) and this presentation gives a short review of important feedback. The Almeria accident was one of the reasons that from that time spray fires had to be taken into account in the safety analyses of nuclear power plants. Due to the fact that spray fire codes were not available in a sufficiently validated state, safety analyses were provisionally based on the feedback from sodium fire tests and also from the Almeria accident itself. The behaviour of spray fires showed that severe destruction, up to melting of metallic structures may occur, but even with a large spray fire is limited roughly within the spray fire zone itself. This could be subsequently be predicted by codes like NABRAND in Germany and FEUMIX in France. Almeria accident has accelerated R and D and code development with respect to spray fires. As example for a code validation some figures are given for the NABRAND code. Another large sodium fire accident happened in 1992 in the test facility at Bensberg in Germany (ILONA). This accident occurred during preheating of a sodium filled vessel which was provisionally installed in the basement of the ILONA test facility at Bensberg. Due to failure of a pressure relief valve the pressure in the vessel increased. As a consequence the plug in a dip tube for draining the vessel failed and about 4,5 t of sodium leaked slowly from the vessel. The plant room was not cladded with steel liners or collecting pans (it was not designed for permanent sodium plant operation). So leaking sodium came directly in

  9. Absolute and secondary dosimetry at the cyclotron ion beam radiation experiments

    One of the characteristic features of ion beam radiation experiments is that the absolute methods of dosimetry are more convenient than secondary ones. In this paper the absolute method used in the course of the radiation experiments performed on the U-400 Dubna cyclotron is presented in detail. Some remarks dealing with the secondary methods are also given. (author)

  10. On the use of OSL of wire-bond chip card modules for retrospective and accident dosimetry

    The potential of optically stimulated luminescence of wire-bond chip card modules, used in health insurance, ID, cash and credit cards for retrospective and accident dosimetry is investigated. Chip card modules obtained directly from the producer, using a widely spread UV-cured epoxy product for encapsulation, are used as basis for the study. The radiation sensitivity is due to silica grains added to the epoxy for controlling the thixotropic properties. Luminescence properties are complex due to the presumed thermo-optical release of electrons from the epoxy and transfer into the silica. Best results and highest sensitivity are obtained by using no or only low preheat treatments. A high degree of fading of the OSL signal during storage at room temperature is observed, which is tentatively explained by the superposition of thermal decay of shallow OSL traps and athermal (anomalous) decay of deeper OSL traps. The dose response of the OSL signal shows exponentially saturating behaviour, with saturation doses of 77 Gy or 9.6 Gy, depending on pretreatment. Dose recovery tests show that given doses can be recovered within a deviation of ±14%, if measured signals are corrected for fading. The minimum detectable dose is estimated at ∼3 mGy, ∼10 mGy and ∼20 mGy for readouts immediately, 1 day and 10 days after exposure, respectively.

  11. On the use of OSL of wire-bond chip card modules for retrospective and accident dosimetry

    Woda, Clemens [Helmholtz Zentrum Muenchen - German Research Centre for Environmental Health, Institute of Radiation Protection, Ingolstaedter Landstrasse 1, D-85764 Neuherberg (Germany)], E-mail: clemens.woda@helmholtz-muenchen.de; Spoettl, Thomas [Infineon Technologies AG, Wernerwerkstrasse 1, D-93049 Regensburg (Germany)

    2009-05-15

    The potential of optically stimulated luminescence of wire-bond chip card modules, used in health insurance, ID, cash and credit cards for retrospective and accident dosimetry is investigated. Chip card modules obtained directly from the producer, using a widely spread UV-cured epoxy product for encapsulation, are used as basis for the study. The radiation sensitivity is due to silica grains added to the epoxy for controlling the thixotropic properties. Luminescence properties are complex due to the presumed thermo-optical release of electrons from the epoxy and transfer into the silica. Best results and highest sensitivity are obtained by using no or only low preheat treatments. A high degree of fading of the OSL signal during storage at room temperature is observed, which is tentatively explained by the superposition of thermal decay of shallow OSL traps and athermal (anomalous) decay of deeper OSL traps. The dose response of the OSL signal shows exponentially saturating behaviour, with saturation doses of 77 Gy or 9.6 Gy, depending on pretreatment. Dose recovery tests show that given doses can be recovered within a deviation of {+-}14%, if measured signals are corrected for fading. The minimum detectable dose is estimated at {approx}3 mGy, {approx}10 mGy and {approx}20 mGy for readouts immediately, 1 day and 10 days after exposure, respectively.

  12. EPID based in vivo dosimetry system: clinical experience and results.

    Celi, Sofia; Costa, Emilie; Wessels, Claas; Mazal, Alejandro; Fourquet, Alain; Francois, Pascal

    2016-01-01

    Mandatory in several countries, in vivo dosimetry has been recognized as one of the next milestones in radiation oncology. Our department has implemented clinically an EPID based in vivo dosimetry system, EPIgray, by DOSISOFT S.A., since 2006. An analysis of the measurements per linac and energy over a two-year period was performed, which included a more detailed examination per technique and treat-ment site over a six-month period. A comparison of the treatment planning system doses and the doses estimated by EPIgray shows a mean of the differences of 1.9% (± 5.2%) for the two-year period. The 3D conformal treatment plans had a mean dose difference of 2.0% (± 4.9%), while for intensity-modulated radiotherapy and volumetric-modulated arc therapy treatments the mean dose difference was -3.0 (± 5.3%) and -2.5 (± 5.2%), respectively. In addition, root cause analyses were conducted on the in vivo dosimetry measurements of two breast cancer treatment techniques, as well as prostate treatments with intensity-modulated radiotherapy and volumetric-modulated arc therapy. During the breast study, the dose differences of breast treatments in supine position were correlated to patient setup and EPID positioning errors. Based on these observations, an automatic image shift correc-tion algorithm is developed by DOSIsoft S.A. The prostate study revealed that beams and arcs with out-of-tolerance in vivo dosimetry results tend to have more complex modulation and a lower exposure of the points of interest. The statistical studies indicate that in vivo dosimetry with EPIgray has been successfully imple-mented for classical and complex techniques in clinical routine at our institution. The additional breast and prostate studies exhibit the prospects of EPIgray as an easy supplementary quality assurance tool. The validation, the automatization, and the reduction of false-positive results represent an important step toward adaptive radiotherapy with EPIgray. PMID:27167283

  13. Planned Procedures for Fast Determination of Radiation Levels and Personnel Dosimetry in Connection with Radiological Accidents

    AB Atomenergi, Sweden, has an emergency organization which starts to function as soon as an alarm indicates that an extraordinary situation with considerable radiation hazards has occurred. This organization is operating from a headquarters where equipment is stored and different types of internal and external communications are available. As to determination of exposures, it is desirable both to obtain rough preliminary values for external and internal exposure rates as soon as possible and to get fairly accurate values for the exposure of each individual involved in the accident within reasonable time. Dose reconnaissance patrols make rapid surveys of the site to get a general estimate of the risks. These patrols start out immediately after the alarm equipped with portable instruments and go by car along fixed routes on the site. Practical tests have shown that results from these patrols reach the headquarters within 10 to 15 minutes after the alarm and make it possible to get a good picture of radiation levels inside and outside different buildings. The portable equipment includes air sampling equipment with very short sampling time working on the principle of the air ejector. Individual external doses are evaluated on the basis of film exposures, criticality dosimeter activation and analyses of hair and blood activity. Internal contamination is determined by whole-body counting and radiometric analyses of excreta. In order to determine the radiation fields created by an accident a number of fixed control points are equipped with different types of dosimeters which also are evaluated as soon as possible after the hypothetical accident. (author)

  14. Electron spin resonance dosimetry of teeth of Goiania radiation accident victims

    Electron spin resonance (ESR) spectroscopy is used to assess absorbed doses of six teeth belonging to victims of the highly irradiated group of Goiania accident. The influence of the broad background signal at g=2.0040 as well as of the unstable fraction of CO-2 radicals was taken into account in dose estimates. Three victims teeth showed absorbed doses comparable to those estimated by chromosomal analysis. For the other three teeth, the doses were higher by a factor of 1.3, 1.8 and 2.2

  15. To improve nuclear plant safety by learning from accident's experience

    The ultimate goal of this study is to produce an expert system that enables the experience (records and information) gained from accidents to be put to use towards improving nuclear plant safety. A number of examples have been investigated, both domestic and overseas, in which experience gained from accidents was utilized by utilities in managing and operating their nuclear power stations to improve safety. The result of investigation has been used to create a general 'basic flow' to make the best use of experience. The ultimate goal is achieved by carrying out this 'basic flow' with artificial intelligence (AI). To do this, it is necessary (1) to apply language analysis to process the source information (primary data base; domestic and overseas accident's reports) into the secondary data base, and (2) to establish an expert system for selecting (screening) significant events from the secondary data base. In the processing described in item (1), a multi-lingual thesaurus for nuclear-related terms become necessary because the source information (primary data bases) itself is multi-lingual. In the work described in item (2), the utilization of probabilistic safety assessment (PSA), for example, is a candidate method for judging the significance of events. Achieving the goal thus requires developing various new techniques. As the first step of the above long-term study project, this report proposes the 'basic flow' and presents the concept of how the nuclear-related AI can be used to carry out this 'basic flow'. (author)

  16. The new approach of the radiological emergency response team at the Brazilian National Nuclear Energy Commission's Institute of Radiation Protection and Dosimetry after the Goiania accident

    The evaluation of the emergency actions taken during the Goiania accident caused a complete revision of the Brazilian Nuclear Energy Commission's Institute of Radiation Protection and Dosimetry Emergency Response Team. The changes were in both the scope of the emergency responsibilities and in the organization of the emergency team. This new organization permits an emergency response to accidents in nuclear installations such as nuclear reactors or fuel cycle facilities, or accidents involving radiation sources in hospitals, industry, etc. The organization takes into account all the emergency phases, with emphasis on a quick response in the initial phase. Of a total emergency team of one hundred and four people, there are twenty-six members on call twenty-four hours a day. (author). 1 fig

  17. Subsidies to cytogenetic dosimetry technique generated from analysis of results of Goiania radiological accident

    Following the Goiania radiation accident, which occurred in September of 1987, peripheral lymphocytes from 129 exposed or potentially exposed individuals were analyzed for the frequency of unstable chromosomal aberrations (dicentrics and centric rings) to estimate absorbed radiation dose. During the emergency period, the doses were assessed to help immediate medical treatment. After this initial estimation, doses were reassessed using in vitro calibration curves produced after the accident, more suitable for the conditions prevailing in Goiania. Dose estimates for 24 subjects exceeded 0,5 Gy. Among those, 15 individuals exceeded 1,0 Gy and 5 exceeded 3,0 Gy. None of the estimates exceeded 6,0 Gy. Four of the subjects died. During the emergency period, a cytogenetic follow-up of 14 of the exposed patients was started, aiming to observe the mean lifetime of lymphocytes containing dicentric and ring aberrations. The results suggest that for the highly exposed individuals the disappearance rate of unstable aberrations follows a two- term exponential function. Up to 470 days after the exposure, there is a rapid fall in the aberration frequency. After 470 days, the disappearance rate is very slow, almost constant. The estimated average half-time of elimination of dicentrics and rings among the highly exposed group (> 1 Gy) was 140 days for the initial period after the exposure (up to 470 days). This value is significantly shorter than the usually accepted value of 3 years reported in the literature. Mean disappearance functions of unstable chromosome aberrations were inferred, to be applied in accident situations in which there is a blood sampling delay. Statistical analysis of possible correlations between the individual half-times and biological parameters, such as sex, age, leukopenia level shown during the critical period, absorbed dose (initial frequency of chromosomal aberrations) and the administration of the bone marrow stimulating factor (rHuGM-CSF) was

  18. Experiences and performance of the Harshaw dosimetry system at two major processing centres

    The installations, operating practice, dose algorithms and results and maintenance experience at two major dosimetry processing centres are described. System selection considerations and a comprehensive quality programme are described in the light of the publication of testing requirements by various dosimetry regulatory organisations. Reported information from Siemens Dosimetry Services comprises their selection of dosemeters and processing equipment including service history, a description of their dose computation algorithm, and detailed results of their testing against DOELAP standards. Battelle Pacific Northwest Laboratories (PNL) provides a description of their dosemeters and equipment with service history; in addition, a discussion of their new neural network approach to a dose computation algorithm and test results from that algorithm are presented. (Author)

  19. Optically stimulated luminescence of electronic components for forensic, retrospective, and accident dosimetry

    This study investigated the optically stimulated luminescence (OSL) response of electronic components found within portable electronic devices such as cell phones and pagers, portable computers, music and video players, global positioning system receivers, cameras, and digital watches. The analysis of components extracted from these ubiquitous devices was proposed for applications ranging from rapid accident dose reconstruction to the tracking and attribution of gamma-emitting radiological materials. Surface-mount resistors with alumina porcelain substrates consistently produced OSL following irradiation, with minimum detectable doses on the order of 10 mGy for a typical sample. Since the resistor ceramics were found to exhibit anomalous fading, dose reconstruction procedures were developed to correct for this using laboratory measurements of fading rates carried out over approximately 3 months. Two trials were conducted in which cellular phones were affixed to an anthropomorphic phantom and irradiated using gamma-ray sources; ultimately, analysis of the devices used in these trials succeeded in reconstructing doses in the range of 0.1-0.6Gy

  20. Dosimetry of criticality accidents using activations of the blood and hair

    The radiation dose received by a person in a criticality accident can be determined with reasonable accuracy from the activity induced in the blood or in the hair. However, both of these methods require a knowledge of the neutron spectra and the exposure conditions. In this report we have compiled results from numerous criticality studies to serve as a guide for neutron dose evaluations based on blood and hair activation. A technique is described in which a combination of these blood and hair activations can be used to determine the neutron dose. This evaluation technique is independent of the person's orientation, shielding provided by walls, equipment, etc. (except for massive shielding by metals), and the neutron leakage spectra. The technique will improve the accuracy of the dose determination, especially if there is little information available on the exposure conditions. This estimate is normally accurate to within +-20 to 30%. This paper also discusses the gamma-to-neutron ratio and its use in establishing the gamma dose (if no gamma exposure data is available) or the neutron dose (if the gamma exposure is known). The use of a G-M instrument at the abdomen is discussed and curves are given to convert the G-M readings to neutron dose. A simplified counting procedure for hair activation is recommended. (author)

  1. Importance of prototypic-corium experiments for severe accident research

    In case of a severe accident in a nuclear reactor, very complex physical and chemical phenomena would occur. Parallel to the development of mechanistic and scenario codes, experiments are needed to determine key phenomena and coupling, develop and qualify specific models, validate codes. Experiments with prototypic corium are performed to check the results obtained with corium-simulant materials and identify possible differences. In this context CEA has undertaken a large program on severe accidents with prototypic corium. In this paper, we discuss some specificities of the prototypic corium: 1) Spreading: experiments with simulant mixtures and prototypic corium performed in the VULCANO facility showed a behaviour involving gas formation during melt spreading. 2) Corium pool: the presence of miscibility gap in the U-Zr-O ternary system for liquid phases and the high density of uranium oxides affect solidification paths, stratification and/or macro-segregation. 3) Corium concrete interaction: the possible reactions between uranium oxide and concrete oxides are specific in terms of thermodynamics and kinetics. For instance, the limited solubility of uranium in zircon can lead to the formation of the solid solution called ''chernobylite'' (Ux,Zr1-x)SiO4 which is important for the long term behaviour (fission product release, handling,..) of solidified corium. 4) Fuel Coolant Interaction: experiments in the KROTOS facility have shown important differences of behaviour between molten alumina and molten 80%wt UO2 + 20%wt ZrO2, the latter inducing less violent explosions than the former

  2. KTH experiments on severe accident phenomena relevant to Swedish BWRs

    A significant fraction of national electricity production in Sweden is supplied by nuclear power plants with BWR reactors. Severe accident management concept of Swedish BWRs, which has been developed in 70-80s, envisages ex-vessel fragmentation and quenching of corium melt in a deep water-filled reactor pit and long term coolability of corium debris bed with water natural convection through the bed open porosity. The paper deals with experimental studies of several severe accident phenomena critical for the chosen SAM strategy: Corium melt jet fragmentation in water; debris bed formation and its properties; debris bed evolution and particle spreading; debris bed coolability; steam explosion during FCI in stratified configuration. Some observations, results and main conclusions from the listed experiments with high temperature corium simulants are presented. The experimental data were used for development and validation of different models and tools, such as MEWA and DECOSIM simulating melt arrest and coolability at the late phase of severe accident under quench and boil-off conditions. The studies were carried out in the Division of Nuclear Power Safety at the Royal Institute of Technology (KTH), Stockholm in the frames of different national and international projects and programs supported by industry, regulators, research organizations and EU. The EU part of the research was coordinated by the SARNET network. The SARNET collaboration will be continued in NUGENIA format. (author)

  3. CATHARE Assessment of PACTEL LOCA Experiments with Accident Management

    Luben Sabotinov

    2010-01-01

    Full Text Available This paper summarizes the analysis results of three PACTEL experiments, carried out with the advanced thermal-hydraulic system computer CATHARE 2 code as a part of the second work package WP2 (analytical work of the EC project “Improved Accident Management of VVER nuclear power plants” (IMPAM-VVER. The three LOCA experiments, conducted on the Finnish test facility PACTEL (VVER-440 model, represent 7.4% cold leg breaks with combination of secondary bleed and primary bleed and feed and different actuation modes of the passive safety injection. The code was used for both defining and analyzing the experiments, and to assess its capabilities in predicting the associated complex VVER-related phenomena. The code results are in reasonable agreement with the measurements, and the important physical phenomena are well predicted, although still further improvement and validation might be necessary.

  4. BNL severe accident sequence experiments and analysis program

    Analyses of LWR degraded core accidents require mathematical characterization of two major sources of pressure and temperature loading on the reactor containment buildings: (1) steam generation from core debris-water thermal interactions and (2) molten core-concrete interactions. Experiments are in progress at BNL in support of analytical model development related to aspects of the above containment loading mechanisms. The work supports development and evaluation of the CORCON, MARCH, CONTAIN and MEDICI computer under development at other NRC-contractor laboratories. The thermal-hydraulic behavior of hot debris located within the reactor core region upon sudden introduction of cooling water is being investigated in a joint experimental and analytical program. This work supports development and evaluation of the SCDAP computer code being developed at EG and G to characterize in-vessel severe core damage accident sequences. Progress is described in the two areas of: 1) core debris thermal-hydraulic phenomenology and 2) heat transfer in core-concrete interactions

  5. Description of the Babcock and Wilcox owners group cavity dosimetry benchmark experiment

    The Babcock and Wilcox Owners Group (B and WOG) Cavity Dosimetry Benchmark experiment is the first step in the B and WOG program to develop measurement-based methodology for use in monitoring vessel fluence in the post-Reactor Vessel Surveillance Program timeframe. Ex-vessel dosimetry has been chosen as the vehicle to provide fluence measurements for use in this measurement-based methodology. (Fluence is measured indirectly by first measuring a relatable quantity and then applying the known correspondence between the measured quantity and the fluence, (e.g., Cs137 activity of a fission foil or tracks on an SSTR). The results of the In-Out Experiment will be used in refining the analytical models and benchmarking the final methodology. The experiment will provide neutron and gamma fluence measurements, at points both inside and outside the reactor vessel, through the use of numerous fluence measuring devices. Four different categories of ex-vessel monitors have been specified. The in-vessel fluence will be measured using an unirradiated, standard B and W reactor vessel surveillance capsule that will be installed in a spare holder tube at the same azimuthal position as the main ex-vessel dosimetry stringer. This paper presents a detailed description of the experiment

  6. Large-Scale Containment Cooler Performance Experiments under Accident Conditions

    Computational Fluid Dynamics codes are increasingly used to simulate containment conditions after various transient accident scenarios. This paper presents validation experiments, conducted in the frame of the OECD/SETH-2 project. These experiments address the combined effects of mass sources and heat sinks related to gas mixing and hydrogen transport within containment compartments. A wall jet interacts with an operating containment cooler located in the middle (M-configuration) and the top (T-configuration) of the containment vessel. The experiments are characterized by a 3-phase injection scenario. In Phase I, pure steam is injected, while in Phase II, a helium-steam mixture is injected. Finally, in Phase III, pure steam is injected again. Results for the M-configuration show helium stratification build up during Phase II. During Phase III, a positively buoyant plume emerging from the cooler housing becomes negatively buoyant once it reaches the helium-steam layer and continuously erodes the layer. For the M-configuration, a strong degradation of the cooler performance was observed during the injection of the helium/steam mixture (Phase II). For the T-configuration, we observe a mainly downwards acting cooler resulting in a combination of forced and natural convection flow patterns. The cooler performance degradation was much weaker compared with the M-configuration and a good mixing was ensured by the operation of the cooler.

  7. Dosimetry experiments at the MEDUSA Facility (Little Mountain).

    Harper-Slaboszewicz, Victor Jozef; Shaneyfelt, Marty Ray; Sheridan, Timothy J.; Hartman, E. Frederick; Schwank, James Ralph

    2010-10-01

    A series of experiments on the MEDUSA linear accelerator radiation test facility were performed to evaluate the difference in dose measured using different methods. Significant differences in dosimeter-measured radiation dose were observed for the different dosimeter types for the same radiation environments, and the results are compared and discussed in this report.

  8. Experiments on the behaviour of ruthenium in air ingress accidents

    Kaerkelae, T.; Backman, Ul; Auvinen, A.; Zilliacus, R.; Lipponen, M.; Kekki, T.; Tapper, U.; Jokiniemi, J. [Technical Research Centre of Finland VTT (Finland)

    2007-03-15

    During routine nuclear reactor operation, ruthenium will accumulate in the fuel in relatively high concentrations. In a severe accident in a nuclear power plant it is possible that air gets into contact with the reactor core. In this case ruthenium may oxidise and form volatile ruthenium species, RuO3 and RuO4, which can be transported into the containment. In order to estimate the amount of gaseous ruthenium species, it is of interest to know, how they are formed and how they behave. In our experiments the formation and transport of volatile ruthenium oxides was studied by exposing RuO2 powder to diverse oxidising atmospheres at a relatively high temperature. Transport of gaseous RuO4 was further investigated by injecting it into the facility in similar conditions. Upon cooling of the gas flow RuO2 aerosol particles were formed in the system. They were removed from the gas stream with plane filters. Gaseous ruthenium species were trapped in 1M NaOH-water solution, which is capable of trapping RuO4 totally. Ruthenium in the solution was filtered for analysis. The determination of ruthenium both in aerosol and in liquid filters was made using instrumental neutron activation analysis (INAA). In order to close the mass balance and to achieve better time resolution seven experiment were carried out using radioactive tracer. In this report, the facility for the ruthenium behaviour study and results from experiments are presented. Preliminary conclusions from the experiments are reported as well. Final conclusions will be made after modelling of the facility is completed in a continuation work of this study. (au)

  9. Experiments on the behaviour of ruthenium in air ingress accidents

    During routine nuclear reactor operation, ruthenium will accumulate in the fuel in relatively high concentrations. In a severe accident in a nuclear power plant it is possible that air gets into contact with the reactor core. In this case ruthenium may oxidise and form volatile ruthenium species, RuO3 and RuO4, which can be transported into the containment. In order to estimate the amount of gaseous ruthenium species, it is of interest to know, how they are formed and how they behave. In our experiments the formation and transport of volatile ruthenium oxides was studied by exposing RuO2 powder to diverse oxidising atmospheres at a relatively high temperature. Transport of gaseous RuO4 was further investigated by injecting it into the facility in similar conditions. Upon cooling of the gas flow RuO2 aerosol particles were formed in the system. They were removed from the gas stream with plane filters. Gaseous ruthenium species were trapped in 1M NaOH-water solution, which is capable of trapping RuO4 totally. Ruthenium in the solution was filtered for analysis. The determination of ruthenium both in aerosol and in liquid filters was made using instrumental neutron activation analysis (INAA). In order to close the mass balance and to achieve better time resolution seven experiment were carried out using radioactive tracer. In this report, the facility for the ruthenium behaviour study and results from experiments are presented. Preliminary conclusions from the experiments are reported as well. Final conclusions will be made after modelling of the facility is completed in a continuation work of this study. (au)

  10. Analysis of SCRM experience in the area of quality assurance for retrospective EPR dosimetry technique with teeth

    EPR dosimetry with tooth enamel is commonly accepted as one of most precise and accurate methods for retrospective dosimetry. At the same time, regularly conducted international Intercomparisons and Inter-calibrations of EPR dosimetry techniques demonstrate the significant scatter of results among laboratories operation in this area. This is mainly caused by the lack of commonly adopted unified technique which would be based on clear and efficient scheme of quality assurance. In the present work we will summarize more than ten-year experience of Scientific Center for Radiation Medicine in the area of EPR dosimetry from the point of view of quality assurance. EPR dosimetry technique with teeth, which was developed and being used in SCRM for routine dosimetry of liquidators is characterized by two-level system of quality assurance. In-house level covers all steps of the technique and allows control and minimizing of uncertainties that arise on separate steps. Extramural level provides the control of reliability and accuracy of technique in whole by means of regular participation in bi- and multi-lateral intercomparisons. Cumulative uncertainty of EPR dosimetry technique determined based on the results of 6 different intercomparisons is 21 mGy for dose below 300 and 11% for dose higher that 300 mGy. (authors)

  11. Flash for Biological Dosimetry Experiments- A BEXUS 16 Project

    Bigge, K.; Cermak, D.; Schuberg, V.; Guerin, E. A.; Blessenohl, M. A.; Passenberg, F.; Bach, M.; Hausmann, M.; Hildenbrand, G.

    2015-09-01

    The effects of low dose radiation on living organisms are still topic of current research and radiation protection. Complex compound radiation, such as of cosmic origin, is of special interest, since it is of pivotal significance for human space flight and, in the long run, cancer research. Fluid LAb in the StratospHere (FLASH) is a Heidelberg University student project that transported specimens of living cells of human origin into the stratosphere to investigate the effects of cosmic radiation on the 3D chromatin nanostructure of their genome. Since, owing to its complexity, cosmic radiation is extremely difficult to replicate on the ground, the FLASH project took part in the BEXUS (Balloon Experiments for University Students) program of the German Aerospace Center (DLR) and the Swedish National Space Board (SNSB) to use a balloon to get better access to cosmic radiation over several hours. To keep the cells alive and allow for in-flight fixation after given radiation exposure times in order to prevent restorative processes, a compact and fully automated fluid lab suited for low-pressure environments was designed and built. Challenges included fluid exchange of specimen buffers and temperature control, as well as low-budget insulating mounting. After the flight, the specimens fixed during the flight were subjected to further analysis. After antibody labeling specific against heterochromatin, Spectral Precision Distance Microscopy (SPDM) (an embodiment of super-resolution localization microscopy) was used, which is a new approach for the sensitive detection and analysis of structure modifying irradiation effects on organisms. This technique allows light resolution on the order of tens of nanometers. Preliminary evaluation of the data indicated reasonable differences in chromatin conformation compared to control specimen data.

  12. Cavity Heating Experiments Supporting Shuttle Columbia Accident Investigation

    Everhart, Joel L.; Berger, Karen T.; Bey, Kim S.; Merski, N. Ronald; Wood, William A.

    2011-01-01

    The two-color thermographic phosphor method has been used to map the local heating augmentation of scaled idealized cavities at conditions simulating the windward surface of the Shuttle Orbiter Columbia during flight STS-107. Two experiments initiated in support of the Columbia Accident Investigation were conducted in the Langley 20-Inch Mach 6 Tunnel. Generally, the first test series evaluated open (length-to-depth less than 10) rectangular cavity geometries proposed as possible damage scenarios resulting from foam and ice impact during launch at several discrete locations on the vehicle windward surface, though some closed (length-to-depth greater than 13) geometries were briefly examined. The second test series was designed to parametrically evaluate heating augmentation in closed rectangular cavities. The tests were conducted under laminar cavity entry conditions over a range of local boundary layer edge-flow parameters typical of re-entry. Cavity design parameters were developed using laminar computational predictions, while the experimental boundary layer state conditions were inferred from the heating measurements. An analysis of the aeroheating caused by cavities allowed exclusion of non-breeching damage from the possible loss scenarios being considered during the investigation.

  13. Interview-survey of farmers. Experiences after the Chernobyl accident

    71 farm households in contaminated areas of Sweden were interviewed at visits to farms, where measurements of the contamination of pastures and fields had been made. The aim of the survey was to find out what remedial actions had been taken by the farmers, what their appreciation of the information from authorities was, how the Chernobyl accident had affected their situation, and if they were prepared to take similar actions in case of a new accident. 15 refs

  14. Analysis of HFIR Dosimetry Experiments Performed in Cycles 400 and 401

    Remec, Igor [ORNL; Baldwin, Charles A [ORNL

    2008-09-01

    The High Flux Isotope Reactor (HFIR) has been in operation at Oak Ridge National Laboratory since 1966. To upgrade and enhance capabilities for neutron science research at the reactor, a larger HB-2 beam tube was installed in April of 2002. To assess, experimentally, the impact of this larger beam tube on radiation damage rates [i.e., displacement-per-atom (dpa) rates] used in vessel life extension studies, dosimetry experiments were performed from April to August 2004 during fuel cycles 400 and 401. This report documents the analysis of the dosimetry experiments and the determination of best-estimate dpa rates. These dpa rates are obtained by performing a least-squares adjustment of calculated neutron and gamma-ray fluxes and the measured responses of radiometric monitors and beryllium helium accumulation fluence monitors. The best-estimate dpa rates provided here will be used to update HFIR pressure vessel life extension studies, which determine the pressure/temperature limits for reactor operation and the HFIR pressure vessel's remaining life. All irradiation parameters given in this report correspond to a reactor power of 85 MW.

  15. Radioactive waste management after NPP accident: Post-Chernobyl experience

    As a result of the Chernobyl NPP accident a very large amount of so-called 'Chernobyl waste' were generated in the territory of Belarus, which was contaminated much more than all other countries. These wastes relate mainly to two following categories: low-level waste (LLW) and new one 'Conventionally Radioactive Waste' (CRW). Neither regulations nor technology and equipment were sufficiently developed for such an amount and kind of waste before the accident. It required proper decisions in respect of regulations, treatment, transportation, disposal of waste, etc. (author)

  16. Consequences and experiences - ten years after the Chernobyl accident

    On 26 April 1986. the most serious accident in the history of the nuclear industry occurred at the Chernobyl nuclear power plant in the former Soviet Union, near the present borders of Ukraine, Belarus and Russia.Material released into the atmosphere dispersed and eventually deposited back on the surface of the earth,were it was measurable over the whole northern hemisphere. Millions of people and all segments of life and economy have been affected by the accident. Radioactive contamination has reached several tens of MBq/m2 in the area of 30 km diameter around the reactor in 1986., and plants and animals have been exposed to short lived radionuclides up to external doses of several tens of Gy. In the early phase after the accident, 237 persons were suspected to have acute radiation syndrome as a consequence of the Chernobyl accident, but diagnoses has been confirmed in 134 cases. In that phase 28 person have died as a consequence of exposure. There are significant non - related health disorders and symptoms, such as anxiety, depression and various psychosomatic disorders attributable to mental stress among the population in the region

  17. Management of a radiological emergency. Experience feedback and post-accident management

    In France, the organization of crisis situations and the management of radiological emergency situations are regularly tested through simulation exercises for a continuous improvement. Past severe accidents represent experience feedback resources of prime importance which have led to deep changes in crisis organizations. However, the management of the post-accident phase is still the object of considerations and reflections between the public authorities and the intervening parties. This document presents, first, the nuclear crisis exercises organized in France, then, the experience feedback of past accidents and exercises, and finally, the main aspects to consider for the post-accident management of such events: 1 - Crisis exercises: objectives, types (local, national and international exercises), principles and progress, limits; 2 - Experience feedback: real crises (major accidents, other recent accidental situations or incidents), crisis exercises (experience feedback organization, improvements); 3 - post-accident management: environmental contamination and people exposure, management of contaminated territories, management of populations (additional protection, living conditions, medical-psychological follow up), indemnification, organization during the post-accident phase; 4 - conclusion and perspectives. (J.S.)

  18. Monte Carlo neutron fluence calculations, activation measurements and spectrum adjustment for the KORPUS dosimetry experiment

    KORPUS is an irradiation facility located at the lateral core surface of the 6 MW experimental reactor RBT-6 in Dimitrovgrad. In this work the KORPUS irradiation experiment has been used to demonstrate the capability of the pressure vessel dosimetry methodology developed in Rossendorf to solve these problems. At the same time the experiments were used to test recent improvements of this methodology including a new procedure for treatment of elastic scattering in the Monte Carlo code TRAMO and a new multispectrum version of the adjustment code. By means of a series of calculations the influence of model and data approximations were investigated aiming at an evaluation of the uncertainties of the calculations. Further, uncertainty investigations were carried out in connection with spectrum adjustment resulting in covariances of spectra, measured reaction rates and fluence integrals. (orig.)

  19. Chemical and nuclear emergencies: Interchanging lessons learned from planning and accident experience

    Because the goal of emergency preparedness for both chemical and nuclear hazards is to reduce human exposure to hazardous materials, this paper examines the interchange of lessons learned from emergency planning and accident experience in both industries. While the concerns are slightly different, sufficient similarity is found for each to draw implications from the others experience. Principally the chemical industry can learn from the dominant planning experience associated with nuclear power plants, while the nuclear industry can chiefly learn from the chemical industry's accident experience. 23 refs

  20. RADIATION ACCIDENTS: EXPERIENCE OF MEDICAL PROTECTION AND MODERN STRATEGY OF PHARMACOLOGICAL MAINTENANCE

    A. N. Grebenyuk

    2012-01-01

    Full Text Available Experience of medical protection at radiation accidents is analyzed. It is shown, that medicines that have been in the arsenal of medical service during the liquidation of consequences of the Chernobyl nuclear power plant accident satisfied their predestination in a whole and were rather effective for radiation protection. The modern strategy of pharmacological maintenance based on use of means and methods, allowing to keeping a life, health and professional serviceability of people in conditions of amazing action of a complex of factors of radiation accidents, is submitted.

  1. Commitment of involved actors in the preparation of accidental and post-accident situations: European experiments

    The author briefly describes some approaches developed within the EURANOS European research programme between 2004 and 2009 which aims at promoting the building up of a European network (NERIS) for the management of nuclear accidental and post-accident situations. Notably, he comments the experiment which took place in the Montbeliard district where two types of radiological events have been modelled and simulated: an accident in the Fessenheim nuclear power plant with two scenarios of release, and a transportation accident with a release of radioactive caesium 137. He also evokes the Norwegian experience and some other actions in Finland, Great-Britain, Spain and Slovakia where reflections on the management of accidental and post-accident situations or crisis exercises have been organized

  2. The 1987 radiation accident in Goiania: medical and organizational experiences

    The present works describes the circumstances of the accident occurred on 13 September 1987, in Goiania (Brazil), when two scavengers removed a teletherapy device a 50.9 TBq (1375Ci) cesium source, from a clinic. They took the apparatus home and tried to dismantled it. The authors describe the circumstances of the event, the first aid measures taken on the site, and the medical structure organized to triage and treat the casualties. Aspects relating to hospital contamination control, the environment, and radioprotection and decontamination procedures are also discussed. (L.M.J.)

  3. RADIATION ACCIDENTS: EXPERIENCE OF MEDICAL PROTECTION AND MODERN STRATEGY OF PHARMACOLOGICAL MAINTENANCE

    A. N. Grebenyuk; V. I. Legeza; V. V. Zatsepin

    2012-01-01

    Experience of medical protection at radiation accidents is analyzed. It is shown, that medicines that have been in the arsenal of medical service during the liquidation of consequences of the Chernobyl nuclear power plant accident satisfied their predestination in a whole and were rather effective for radiation protection. The modern strategy of pharmacological maintenance based on use of means and methods, allowing to keeping a life, health and professional serviceability of people in condit...

  4. Road Traffic Accident Victims’ Experiences of Return to Normal Life: A Qualitative Study

    Pashaei Sabet, Fatemeh; Norouzi Tabrizi, Kian; Khankeh, Hamid Reza; Saadat, Soheil; Abedi, Heidar Ali; Bastami, Alireza

    2016-01-01

    Background Road traffic accident (RTA) victims also suffer from different types of injuries and disabilities, which can affect their quality of life. They usually face with various physical, mental, and social problems. Most traffic accident victims had difficulty to return to normal life. Objectives This study aimed to understand the experiences of return to normal life in RTA victims. Patients and Methods This qualitative study with content analysis approach was conducted on 18 Iranian pati...

  5. Links between operating experience feedback of industrial accidents and nuclear safety

    Since 1992, the bureau for analysis of industrial risks and pollutions (BARPI) collects, analyzes and publishes information on industrial accidents. The ARIA database lists over 40.000 accidents or incidents, most of which occurred in French classified facilities (ICPE). Events occurring in nuclear facilities are rarely reported in ARIA because they are reported in other databases. This paper describes the process of selection, characterization and review of these accidents, as well as the following consultation with industry trade groups. It is essential to publicize widely the lessons learned from analyzing industrial accidents. To this end, a web site (www.aria.developpement-durable.gouv.fr) gives free access to the accidents summaries, detailed sheets, studies, etc. to professionals and the general public. In addition, the accidents descriptions and characteristics serve as inputs to new regulation projects or risk analyses. Finally, the question of the links between operating experience feedback of industrial accidents and nuclear safety is explored: if the rigorous and well-documented methods of experience feedback in the nuclear field certainly set an example for other activities, nuclear safety can also benefit from inputs coming from the vast diversity of accidents arisen into industrial facilities because of common grounds. Among these common grounds we can find: -) the fuel cycle facilities use many chemicals and chemical processes that are also used by chemical industries; -) the problems resulting from the ageing of equipment affect both heavy and nuclear industries; -) the risk of hydrogen explosion; -) the risk of ammonia, ammonia is a gas used by nuclear power plants as an ingredient in the onsite production of mono-chloramine and ammonia is involved in numerous accidents in the industry: at least 900 entries can be found in the ARIA database. The paper is followed by the slides of the presentation

  6. Bibliography for nuclear criticality accident experience, alarm systems, and emergency management

    Putman, V.L.

    1995-09-01

    The characteristics, detection, and emergency management of nuclear criticality accidents outside reactors has been an important component of criticality safety for as long as the need for this specialized safety discipline has been recognized. The general interest and importance of such topics receives special emphasis because of the potentially lethal, albeit highly localized, effects of criticality accidents and because of heightened public and regulatory concerns for any undesirable event in nuclear and radiological fields. This bibliography lists references which are potentially applicable to or interesting for criticality alarm, detection, and warning systems; criticality accident emergency management; and their associated programs. The lists are annotated to assist bibliography users in identifying applicable: industry and regulatory guidance and requirements, with historical development information and comments; criticality accident characteristics, consequences, experiences, and responses; hazard-, risk-, or safety-analysis criteria; CAS design and qualification criteria; CAS calibration, maintenance, repair, and testing criteria; experiences of CAS designers and maintainers; criticality accident emergency management (planning, preparedness, response, and recovery) requirements and guidance; criticality accident emergency management experience, plans, and techniques; methods and tools for analysis; and additional bibliographies.

  7. Bibliography for nuclear criticality accident experience, alarm systems, and emergency management

    The characteristics, detection, and emergency management of nuclear criticality accidents outside reactors has been an important component of criticality safety for as long as the need for this specialized safety discipline has been recognized. The general interest and importance of such topics receives special emphasis because of the potentially lethal, albeit highly localized, effects of criticality accidents and because of heightened public and regulatory concerns for any undesirable event in nuclear and radiological fields. This bibliography lists references which are potentially applicable to or interesting for criticality alarm, detection, and warning systems; criticality accident emergency management; and their associated programs. The lists are annotated to assist bibliography users in identifying applicable: industry and regulatory guidance and requirements, with historical development information and comments; criticality accident characteristics, consequences, experiences, and responses; hazard-, risk-, or safety-analysis criteria; CAS design and qualification criteria; CAS calibration, maintenance, repair, and testing criteria; experiences of CAS designers and maintainers; criticality accident emergency management (planning, preparedness, response, and recovery) requirements and guidance; criticality accident emergency management experience, plans, and techniques; methods and tools for analysis; and additional bibliographies

  8. BiodosEPR-2006 Meeting: Acute dosimetry consensus committee recommendations on biodosimetry applications in events involving uses of radiation by terrorists and radiation accidents

    In the aftermath of a radiological terrorism incident or mass-casualty radiation accident, first responders and receivers require prior guidance and pre-positioned resources for assessment, triage and medical management of affected individuals [NCRP, 2005. Key elements of preparing emergency responders for nuclear and radiological terrorism. NCRP Commentary No. 19, Bethesda, Maryland, USA]. Several recent articles [Dainiak, N., Waselenko, J.K., Armitage, J.O., MacVittie, T.J., Farese, A.M., 2003. The hematologist and radiation casualties. Hematology (Am. Soc. Hematol. Educ. Program) 473-496; Waselenko, J.K., MacVittie, T.J., Blakely, W.F., Pesik, N., Wiley, A.L., Dickerson, W.E., Tsu, H., Confer, D.L., Coleman, C.N., Seed, T., Lowry, P., Armitage, J.O., Dainiak, N., Strategic National Stockpile Radiation Working Group, 2004. Medical management of the acute radiation syndrome: recommendations of the Strategic National Stockpile Radiation Working Group. Ann. Intern. Med. 140(12), 1037-1051; Blakely, W.F., Salter, C.A., Prasanna, P.G., 2005. Early-response biological dosimetry-recommended countermeasure enhancements for mass-casualty radiological incidents and terrorism. Health Phys. 89(5), 494-504; Goans, R.E., Waselenko, J.K., 2005. Medical management of radiation casualties. Health Phys. 89(5), 505-512; Swartz, H.M., Iwasaki, A., Walczak, T., Demidenko, E., Salikhov, I., Lesniewski, P., Starewicz, P., Schauer, D., Romanyukha, A., 2005. Measurements of clinically significant doses of ionizing radiation using non-invasive in vivo EPR spectroscopy of teeth in situ. Appl. Radiat. Isot. 62, 293-299; . Acute radiation injury: contingency planning for triage, supportive care, and transplantation. Biol. Blood Marrow Transplant. 12(6), 672-682], national [. Management of persons accidentally contaminated with radionuclides. NCRP Report No. 65, Bethesda, Maryland, USA; . Management of terrorist events involving radioactive material. NCRP Report No. 138, Bethesda, Maryland

  9. BiodosEPR-2006 Meeting: Acute dosimetry consensus committee recommendations on biodosimetry applications in events involving uses of radiation by terrorists and radiation accidents

    Alexander, George A. [U.S. Department of Health and Human Services, Office of Preparedness and Emergency Operations, 200 Independence Avenue, SW, Room 403B-1, Washington, DC 20201 (United States); Swartz, Harold M. [Dept. of Radiology and Physiology Dept., Dartmouth Medical School, HB 7785, Vail 702, Rubin 601, Hanover, NH 03755 (United States); Amundson, Sally A. [Center for Radiological Research, Columbia University Medical Center, 630 W. 168th Street, VC11-215, New York, NY 10032 (United States); Blakely, William F. [Armed Forces Radiobiology Research Inst., 8901 Wisconsin Avenue, Bethesda, MD 20889-5603 (United States)], E-mail: blakely@afrri.usuhs.mil; Buddemeier, Brooke [Science and Technology, U.S. Department of Homeland Security, Washington, DC 20528 (United States); Gallez, Bernard [Biomedical Magnetic Resonance Unit and Lab. of Medicinal Chemistry and Radiopharmacy, Univ. Catholique de Louvain, Brussels (Belgium); Dainiak, Nicholas [Dept. of Medicine, Bridgeport Hospital, 267 Grant Street, Bridgeport, CT 06610 (United States); Goans, Ronald E. [MJW Corporation, 1422 Eagle Bend Drive, Clinton, TN 37716-4029 (United States); Hayes, Robert B. [Remote Sensing Lab., MS RSL-47, P.O. Box 98421, Las Vegas, NV 89193 (United States); Lowry, Patrick C. [Radiation Emergency Assistance Center/Training Site (REAC/TS), Oak Ridge Associated Universities, P.O. Box 117, Oak Ridge, TN 37831-0117 (United States); Noska, Michael A. [Food and Drug Administration, FDA/CDRH, 1350 Piccard Drive, HFZ-240, Rockville, MD 20850 (United States); Okunieff, Paul [Dept. of Radiation Oncology (Box 647), Univ. of Rochester, 601 Elmwood Avenue, Rochester, NY 14642 (United States); Salner, Andrew L. [Helen and Harry Gray Cancer Center, Hartford Hospital, 80 Seymour Street, Hartford, CT 06102 (United States); Schauer, David A. [National Council on Radiation Protection and Measurements, 7910 Woodmont Avenue, Suite 400, Bethesda, MD 20814-3095 (United States)] (and others)

    2007-07-15

    In the aftermath of a radiological terrorism incident or mass-casualty radiation accident, first responders and receivers require prior guidance and pre-positioned resources for assessment, triage and medical management of affected individuals [NCRP, 2005. Key elements of preparing emergency responders for nuclear and radiological terrorism. NCRP Commentary No. 19, Bethesda, Maryland, USA]. Several recent articles [Dainiak, N., Waselenko, J.K., Armitage, J.O., MacVittie, T.J., Farese, A.M., 2003. The hematologist and radiation casualties. Hematology (Am. Soc. Hematol. Educ. Program) 473-496; Waselenko, J.K., MacVittie, T.J., Blakely, W.F., Pesik, N., Wiley, A.L., Dickerson, W.E., Tsu, H., Confer, D.L., Coleman, C.N., Seed, T., Lowry, P., Armitage, J.O., Dainiak, N., Strategic National Stockpile Radiation Working Group, 2004. Medical management of the acute radiation syndrome: recommendations of the Strategic National Stockpile Radiation Working Group. Ann. Intern. Med. 140(12), 1037-1051; Blakely, W.F., Salter, C.A., Prasanna, P.G., 2005. Early-response biological dosimetry-recommended countermeasure enhancements for mass-casualty radiological incidents and terrorism. Health Phys. 89(5), 494-504; Goans, R.E., Waselenko, J.K., 2005. Medical management of radiation casualties. Health Phys. 89(5), 505-512; Swartz, H.M., Iwasaki, A., Walczak, T., Demidenko, E., Salikhov, I., Lesniewski, P., Starewicz, P., Schauer, D., Romanyukha, A., 2005. Measurements of clinically significant doses of ionizing radiation using non-invasive in vivo EPR spectroscopy of teeth in situ. Appl. Radiat. Isot. 62, 293-299; . Acute radiation injury: contingency planning for triage, supportive care, and transplantation. Biol. Blood Marrow Transplant. 12(6), 672-682], national [. Management of persons accidentally contaminated with radionuclides. NCRP Report No. 65, Bethesda, Maryland, USA; . Management of terrorist events involving radioactive material. NCRP Report No. 138, Bethesda, Maryland

  10. Modern methods of personnel dosimetry

    The physical properties of radiation detectors for personnel dosimetry are described and compared. The suitability of different types of dosimeters for operational and central monitoring of normal occupational exposure, for accident and catastrophe dosimetry and for background and space-flight dosimetry is discussed. The difficulties in interpreting the dosimeter reading with respect to the dose in individual body organs are discussed briefly. 430 literature citations (up to Spring 1966) are given

  11. Proceedings of the third conference on radiation protection and dosimetry

    The Third Conference on Radiation Protection and Dosimetry was held during October 21--24, 1991, at the Sheraton Plaza Hotel in Orlando, Florida. This meeting was designed with the objectives of promoting communication among applied, research, regulatory, and standards personnel involved in radiation protection, and providing them with sufficient information to evaluate their programs. To meet these objectives, a technical program consisting of more than 75 invited and contributed oral presentations encompassing all aspects of radiation protection was prepared. General topics considered in the technical session included external dosimetry, internal dosimetry, instruments, accident dosimetry, regulations and standards, research advances, and applied program experience. In addition, special sessions were held to afford attendees the opportunity to make short presentations of recent work or to discuss topics of general interest. Individual reports are processed separately on the database

  12. Proceedings of the third conference on radiation protection and dosimetry

    Swaja, R.E.; Sims, C.S.; Casson, W.H. [eds.

    1991-10-01

    The Third Conference on Radiation Protection and Dosimetry was held during October 21--24, 1991, at the Sheraton Plaza Hotel in Orlando, Florida. This meeting was designed with the objectives of promoting communication among applied, research, regulatory, and standards personnel involved in radiation protection, and providing them with sufficient information to evaluate their programs. To meet these objectives, a technical program consisting of more than 75 invited and contributed oral presentations encompassing all aspects of radiation protection was prepared. General topics considered in the technical session included external dosimetry, internal dosimetry, instruments, accident dosimetry, regulations and standards, research advances, and applied program experience. In addition, special sessions were held to afford attendees the opportunity to make short presentations of recent work or to discuss topics of general interest. Individual reports are processed separately on the database.

  13. Retrospective Dosimetry and Clinical Follow-up Programme of Chernobyl Accident Clean-up Workers in Latvia

    Full text: About 6500 Latvian inhabitants were recruited for clean-up works at Chernobyl Nuclear Power Plant during 1986-1991. Absorbed doses for them are usually unknown, because only less then half of the clean-up workers cohort had officially documented external exposure. Clinical investigations show high morbidity rate of clean-up workers compared with general population. The results of Electronic Spin Resonance (ESR) dose reconstruction (doses absorbed in the tooth enamel) for the clean-up workers were always higher as documented of exposure doses of physical measurements. In many cases more than half of total absorbed dose is due to 90Sr accumulated in teeth. Most of the clean-up workers have poli-symptomatic sicknesses that exhibit tendency to progress, and their morbidity exceeds that observed in general population. ESR dosimetry programs and clinical follow-up improved existing knowledge in the field of radiation medicine. These data will help to develop and apply the proper treatment and rehabilitation procedures for clean-up workers. (author)

  14. Alpha alumina exoemissive and thermoluminescent properties. Application to the dosimetry of ionizing radiations in case of accident

    This work consists of two parts. In the first part, a phenomenon of phototransfer in Thermostimulated Exoelectronic Emission (T.S.E.E.) is pointed out. Study of intrinsic T.S.E.E. of alpha alumina exposed to ultraviolet (U.V.) excitation of energy superior to 4 eV shows three T.S.E.E. peaks situated at 240, 325, 5350C (heating rate of 20C.s-1). The phototransfer phenomenon is then characterized notably by the lowering of the U.V. excitation threshold to 3.5 eV and the increasing of T.S.E.E. response for U.V. energies between 3.5 and 6 eV. Discussion and interpretation of the results obtained are based on the perfect analogy with the phototransfer of Thermoluminescence (T.L.) observed on a similar type of alpha alumina. The second part describes the application of alpha alumina dosimetric properties to accidental irradiation dosimetry and cartography. The material is bound to a textile support to be used for clothes manufacturing for irradiation risking workers. T.S.E.E. and T.L. properties of the selected fabric have been studied. - T.S.E.E. response to a beta irradiation of strontium 90 covers the region [0.01 - 10 Gy], with a dispersion of ± 20%, a non significant thermic fading beyond 72 hours after irradiation and a very important optical fading; - the region in T.L. extends from 0.25 to 10 Gy with X irradiation (45 kV) and from 0.5 to 10 Gy with gamma irradiation of cobalt 60 and caesium 137; the dispersion is ± 20%, the thermic fading is weak and the optical fading is negligible in artificial light or does not vary any more after 5 days of sunlight exposition

  15. Proceedings of the international workshop 'Actual problems of dosimetry'

    Materials grouped to six main issues: dosimetry and radiometry equipment, dosimetry of the medical irradiation, standard and metrology support of dosimetric and radiometric control, biological dosimetry and markers of radiation effects, monitoring and reconstruction of radiation doses at radiation accidents and dosimetry of unionizing radiations

  16. Intercomparison of luminescence detectors for space radiation dosimetry within Proton-ICCHIBAN experiments

    Uchihori, Yukio; Ploc, Ondrej; Yasuda, Nakahiro; Berger, Thomas; Hajek, Michael; Kodaira, Satoshi; Benton, Eric; Ambrozova, Iva; Kitamura, Hisashi

    2012-07-01

    Luminescence detectors for space radiation dosimetry are frequently used to estimate personal and environmental doses in the International Space Station and other space vehicles. Detector responses for cosmic rays and their secondaries were investigated for a long time and it is well-known that luminescence detectors have dependencies of response on LET (Linear Energy Transfer). Some of luminescence detectors show over-response to gamma rays (used for routine calibration) and others have similar responses to gamma rays. But, because of lack of sufficient and reliable calibration data in the low LET region (about 1 keV/μm), it is the responses of these detectors at LET is poorly known. Protons make up the dominant portion of the fluence from space radiation, so the LET region corresponding to energetic protons must be characterized very well. For that purpose, calibration and intercomparison experiments were performed using relatively low energy (30 to 80 MeV) proton beams at the National Institute of Radiological Sciences, Chiba, Japan. In this paper, the results of these intercomparison experiments, including high energy protons and light ions, are reported and illustrate the response of luminescence detectors in the low LET region. This research will help improve our understanding of space dosimeters and reliable dose measurement for astronauts and cosmonauts in low earth orbit.

  17. BNL severe accident sequence experiments and analysis program

    A major source of containment pressurization during severe accidents is the transfer of stored energy from the hot core material to available cooling water. One mode of thermal interaction involves the quench of superheated beds of debris which could be present in the reactor cavity following melt-through or failure of the reactor vessel. This work supports development of models of superheated bed quench phenomena which are to be incorporated into containment analysis computer codes such as MARCH, CONTAIN, and MEDICI. A program directed towards characterization of the behavior of superheated debris beds has been completed. This work addressed the quench of superheated debris which is postulated to exist in the reactor cavity of a PWR following melt ejection from the primary system. The debris is assumed to be cooled by a pool of water overlying the bed of hot debris. This work has led to the development of models to predict rate of steam generation during the quench process and, in addition, the ability to assess the coolability of the debris during the transient quench process. A final report on this work has been completed. This report presents a brief description of some relevant results and conclusions. 15 refs

  18. Radiation safety and accident experience at gamma irradiation plants

    Gamma irradiation plants for the sterilization of medical products, preservation of food grains and for various other applications employ multikilocurie 60Co sealed sources inside shielded irradiation cells. A number of interlocks are provided between the cell entry door and the source raise mechanisms, in order to prevent the entry of any person to the cell when the source is in the exposed condition. The present paper gives the general safety features and the interlocks employed in these plants along with the safety features of irradiation plants at BARC, namely 106 Ci Isomed plant for the sterilization of medical products, 105 Ci FIPLY plant for research in food preservation and 105 Ci PANBIT plant for industrial research. Over the last two decades five cases of accidental exposure have been reported in literature in which the operator gained entry to the irradiation cell when the source was in the exposed condition. Two of these cases resulted in fatalities while the remaining three cases resulted in hospitalization of the exposed individuals for six to seven weeks. A brief outline of these accidental exposure cases and the causes of the accidents are discussed in this paper. (author). 19 refs

  19. Thermoluminescence Dosimetry Applied to Radiation Protection

    Christensen, Poul; Bøtter-Jensen, Lars; Majborn, Benny

    1982-01-01

    This is a general review of the present state of the development and application of thermoluminescence dosimetry (TLD) for radiation protection purposes. A description is given of commonly used thermoluminescent dosimeters and their main dosimetric properties, e.g. energy response, dose range......, fading, and LET dependence. The applications of thermoluminescence dosimetry in routine personnel monitoring, accident dosimetry, u.v. radiation dosimetry, and environmental monitoring are discussed with particular emphasis on current problems in routine personnel monitoring. Finally, the present state...

  20. Internal dosimetry for continuous chronic intake of caesium-137 in cedar pollen after the Fukushima Daiichi nuclear power plant accident

    Internal exposures of members of the public were assessed for chronic intake of caesium-137 in cedar pollen after the Fukushima Daiichi nuclear power plant accident. Committed effective doses were evaluated using the DSYS-chronic code, which was developed at the Japan Atomic Energy Agency (JAEA). The Activity Median Aerodynamic Diameter (AMAD) and particle density for cedar pollen were assumed to be 32 μm and 0.7 g·cm-3, respectively. The observation period was from early February to the end of May, 2012. It was found that the committed effective doses for adults in Fukushima, Ibaraki, and Tokyo were 1.6-1.8×10-3 μSv, 4.5×10-4 μSv, and 3.0×10-4 μSv, respectively. Hence, it can be stated that internal doses from chronic intake of caesium-137 in cedar pollen were insignificant in 2012. In addition, retention and excretion functions for caesium-137 in the whole body were found to be dependent on the times of intake and the fractional activity related to chronic intake. (author)

  1. Criticality dosimetry using a sulfur disk and a priori neutron spectral knowledge

    This paper proposes the design of a new approach to criticality accident dosimetry, which uses a priori knowledge of the neutron spectra for criticality accident conditions, and depends upon accurate detector spectral response characterization and environmental modeling. The sulfur disk was selected as a potential neutron detector, for neutrons of higher energies. Several sulfur disks were exposed to a critical Godiva experiment, the spectral response function determined using Monte Carlo methods, and the activity determined using knowledge of the known criticality spectrum. The new method, possibly with two or more different detectors to measure other energy ranges, holds promise as a practical approach to neutron criticality dosimetry

  2. Accreditation ISO/IEC 1705 in dosimetry: Experience and results; Acreditacion ISO/IEC 17025 en dosimetria: Experiencia y resultados

    Martin Garcia, R.; Navarro Bravo, T.

    2013-07-01

    The objective of this work is to present the experience in the process of accreditation of the radiation dosimetry service in which there are trials for the determination of radiation doses due to internal and external exhibitions. Is They describe the aspects that were considered for the design and development of a system of quality and results after its implementation. A review of the benefits accreditation has been reported to the organization is finally made. (Author)

  3. Radioiodine dosimetry and prediction of consequences of thyroid exposure of the Russian population following the Chernobyl accident

    In the early period after the Chernobyl accident, analysis of patterns of 131I exposure of the human thyroid showed that contaminated milk was the basic source of 131I intake among the inhabitants of Russia. The equipment and techniques used for measurement of the 131I content in the thyroids of these individuals are described in this work. A model of the 131I intake, taking into account protective actions, and a method of thyroid dose calculation are discussed. The mean thyroid dose and frequency distributions of the thyroid doses to inhabitants of towns and villages of the Bryansk, Tula and Orel regions of Russia are presented. The mean dose to the thyroids of children living in the villages was 2 to 5 times higher than the dose to adult thyroids; for children living in the towns, the mean dose was 1.5 to 12 times higher. The mean thyroid mass in adult inhabitants of the Bryansk region was 27 g, which exceeded the value for a standard man (20 g) and was taken into account in the dosimetric calculations. The technique for reconstructing the mean and individual thyroid doses was based on the correlation between thyroid dose and several parameters: Surface 137Cs activity in soil, dose rate in air in May of 1986, 131I content in local milk, milk consumption rate, and 134Cs + 137Cs content in the body. The collective thyroid dose to inhabitants of the most contaminated regions of Russia is estimated and a thyroid cancer rate prognosis is derived. The need for intensified medical care for the critical group - children of preschool age during 1986 - is based on a significant increase in the number of projected thyroid cancers and adenomas. 32 refs., 10 figs., 15 tabs

  4. A study on accident prevention of liquid metal reactors through operating experience analysis

    A demonstration LMR (Liquid Metal Reactor), called as KALIMER (Korea Advanced LIquid MEtal Reactor), has been being developed as part of the nuclear mid and long-term projects of the government since 1997. To ensure the safety of the KALIMER, the capability to cope with accidents must be enhanced by incorporating means and measures to prevent and mitigate accidents into the design of the KALIMER. The means and measures can be found out through analyzing operating experience in LMRs. Therefore, operating experience reported in published literature was collected and analyzed for the following 9 foreign LMRs: MONJU, Superphenix, Phenix, PFR, JOYO, EBR-II, FFTF, BN-350, BN-600. The analyses results show that accidents can be categorized into the following major groups: sodium leakage, sodium fire, sodium-water reaction, abnormal decrease of core reactivity, components vibrations, sodium aerosol deposits. Based on the results of accident cause analysis for each category, the means and measures to prevent and mitigate the each accident category were obtained

  5. High temperature measurements in severe accident experiments on the PLINIUS Platform

    Severe accident experiments are conducted on the PLINIUS platform in Cadarache, using prototypic corium. During these experiments, it is essential to measure the temperature to know the thermo-physical state of the corium in static and dynamic conditions or to monitor the concrete ablation phenomenology. Temperature in the corium can reach about 2000 to 3000 K. Such aggressive conditions restrict the type of diagnostics that can be employed to do high temperature measurements during the experiments. We employ both non-intrusive (pyrometers) and intrusive (K-type and C-type thermocouples) diagnostics. In this paper, we present the different high temperature measurements techniques and the results that can be obtained in severe accident experiments as corium heating tests and molten core concrete interaction experiments. (authors)

  6. Experiments on natural circulation during PWR severe accidents and their analysis

    Buoyancy-induced natural circulation flows will occur during the early-part of PWR high pressure accident scenarios. These flows affect several key parameters; in particular, the course of such accidents will most probably change due to local failures occurring in the primary coolant system (CS) before substantial core degradation. Natural circulation flow patterns were measured in a one-seventh scale PWR PCS facility at Westinghouse RandD laboratories. The measured flow and temperature distributions are report in this paper. The experiments were analyzed with the COMMIX code and good agreement was obtained between data and calculations. 10 refs., 8 figs., 2 tabs

  7. The assessment of containment codes by experiments simulating severe accident scenarios

    Hitherto, a generally applicable validation matrix for codes simulating the containment behaviour under severe accident conditions did not exist. Past code applications have shown that most problems may be traced back to inaccurate thermalhydraulic parameters governing gas- or aerosol-distribution events. A provisional code-validation matrix is proposed, based on a careful selection of containment experiments performed during recent years in relevant test facilities under various operating conditions. The matrix focuses on the thermalhydraulic aspects of the containment behaviour after severe accidents as a first important step. It may be supplemented in the future by additional suitable tests

  8. Review of optically stimulated luminescence (OSL) instrumental developments for retrospective dosimetry

    Bøtter-Jensen, Lars; Thomsen, Kristina Jørkov; Jain, Mayank

    2010-01-01

    This review describes 40 years of experience gained at Risø National Laboratory in the development of facilities for irradiation, thermal/optical stimulation and luminescence signal detection. These facilities have mainly been used in luminescence dating and nuclear accident dosimetry. We focus...

  9. Benchmark experiments for validation of reaction rates determination in reactor dosimetry

    The precision of Monte Carlo calculations of quantities of neutron dosimetry strongly depends on precision of reaction rates prediction. Research reactor represents a very useful tool for validation of the ability of a code to calculate such quantities as it can provide environments with various types of neutron energy spectra. Especially, a zero power research reactor with well-defined core geometry and neutronic properties enables precise comparison between experimental and calculated data. Thus, at the VR-1 zero power research reactor, a set of benchmark experiments were proposed and carried out to verify the MCNP Monte Carlo code ability to predict correctly the reaction rates. For that purpose two frequently used reactions were chosen: He-3(n,p)H-3 and Au-197(n,γ)Au-198. The benchmark consists of response measurement of small He-3 gas filled detector in various positions of reactor core and of activated gold wires placed inside the core or to its vicinity. The reaction rates were calculated in MCNP5 code utilizing a detailed model of VR-1 reactor which was validated for neutronic calculations at the reactor. The paper describes in detail the experimental set-up of the benchmark, the MCNP model of the VR-1 reactor and provides a comparison between experimental and calculated data. - Highlights: • Use of zero power reactor for validation of reaction rates calculations. • Reaction rates measurement in reactor core by He-3 detector and Au wires. • Validation of reaction rates calculation by MCNP5. • Comparison of measured and calculated RR for different positions in core

  10. Road Traffic Accident Victims’ Experiences of Return to Normal Life: A Qualitative Study

    Pashaei Sabet, Fatemeh; Norouzi Tabrizi, Kian; Khankeh, Hamid Reza; Saadat, Soheil; Abedi, Heidar Ali; Bastami, Alireza

    2016-01-01

    Background Road traffic accident (RTA) victims also suffer from different types of injuries and disabilities, which can affect their quality of life. They usually face with various physical, mental, and social problems. Most traffic accident victims had difficulty to return to normal life. Objectives This study aimed to understand the experiences of return to normal life in RTA victims. Patients and Methods This qualitative study with content analysis approach was conducted on 18 Iranian patients with disability in the upper or lower limbs caused by traffic accidents, who had passed a time between 3 months till 2 years. A purposeful sampling method was applied until reaching data saturation. Data were collected using semi-structured interviews. Afterwards, the gathered data were analyzed through conventional content analysis. Results By analyzing 498 primary codes, four main categories, including supportive needs, adaptation to the new situation, seeking information, and transition from functional limitation, were extracted from traffic accident victims’ experiences of reintegration to normal life. Conclusions The results of this study may help policy-makers to take steps toward health promotion and recovery of RTA victims. Considering the results of this study, it is a need for further research to investigate RTAs victims’ needs for reintegration to home and community. Access to training and supportive facilities like strong therapeutic, nursing and social support, and the possibility to participate in self-care activities is essential for reintegration to community in RTA victims. PMID:27275399

  11. The COLIMA experiment on aerosol retention in containment leak paths under severe nuclear accidents

    Parozzi, Flavio, E-mail: flavio.parozzi@rse-web.it [RSE, Power Generation Department, via Rubattino 54, I-20134 Milano (Italy); Caracciolo, Eduardo D.J., E-mail: eduardo.caracciolo@rse-web.it [RSE, Power Generation Department, via Rubattino 54, I-20134 Milano (Italy); Journeau, Christophe, E-mail: christophe.journeau@cea.fr [CEA Cadarache (France); Piluso, Pascal, E-mail: pascal.piluso@cea.fr [CEA Cadarache (France)

    2013-08-15

    Highlights: ► Experiment investigating aerosol retention within concrete containment cracks under nuclear severe accident conditions. ► Provided representative conditions of the aerosols suspended inside the containment of PWRs under a severe accident. ► Prototypical aerosol particles generated with a thermite reaction and transported through the crack sample reproducing surface characteristics, temperature, pressure drop and gas leakage. ► The results indicate the significant retention due to zig-zag path. -- Abstract: CEA and RSE managed an experimental research concerning the investigation of aerosol retention within concrete containment cracks under severe accident conditions. The main experiment was carried out in November 2008 with aerosol generated from the COLIMA facility and a sample of cracked concrete with defined geometric characteristics manufactured by RSE. The facility provided representative conditions of the aerosols suspended inside the containment of PWRs under a severe accident. Prototypical aerosol particles were generated with a thermite reaction and transported through the crack sample, where surface characteristics, temperature, pressure drop and gas leakage were properly reproduced. The paper describes the approach adopted for the preparation of the cracked concrete sample and the dimensioning of the experimental apparatus, the test procedure and the measured parameters. The preliminary results, obtained from this single test, are also discussed in the light of the present knowledge about aerosol phenomena and the theoretical analyses of particle behaviour with the crack path.

  12. Experiences and lessons learned worldwide in the cleanup and decommissioning of nuclear facilities in the aftermath of accidents

    This publication reviews experiences in IAEA Member States relevant to the cleanup and decommissioning of nuclear facilities in the aftermath of accidents and provides an overview of lessons learned worldwide. It also updates information from earlier publications on this topic, according to the different phases of activity after the accident has been declared ended (site stabilization, post-accident cleanup, safe enclosure) and, in the longer term, final decommissioning and site remediation

  13. Clinical experience with EPID dosimetry for prostate IMRT pre-treatment dose verification.

    McDermott, L N; Wendling, M; van Asselen, B; Stroom, J; Sonke, J J; van Herk, M; Mijnheer, B J

    2006-10-01

    The aim of this study was to demonstrate how dosimetry with an amorphous silicon electronic portal imaging device (a-Si EPID) replaced film and ionization chamber measurements for routine pre-treatment dosimetry in our clinic. Furthermore, we described how EPID dosimetry was used to solve a clinical problem. IMRT prostate plans were delivered to a homogeneous slab phantom. EPID transit images were acquired for each segment. A previously developed in-house back-projection algorithm was used to reconstruct the dose distribution in the phantom mid-plane (intersecting the isocenter). Segment dose images were summed to obtain an EPID mid-plane dose image for each field. Fields were compared using profiles and in two dimensions with the y evaluation (criteria: 3%/3 mm). To quantify results, the average gamma (gamma avg), maximum gamma (gamma max), and the percentage of points with gamma chamber (IC(iso)). The average ratio, (EPID(iso)/IC(iso)), was 1.00 (0.01 SD). Both measurements were systematically lower than planned, with (EPID(iso)/plan(iso)) and (IC(iso)/plan(iso))=0.99 (0.01 SD). EPID mid-plane dose images for each field were also compared with the corresponding plane derived from the three dimensional (3D) dose grid calculated with the phantom CT scan. Comparisons of 100 fields yielded (gamma avg)=0.39, gamma max=2.52, and (P gamma chamber also agreed. The EPID can therefore replace these dosimetry devices for field-by-field and isocenter IMRT pre-treatment verification. Systematic errors were detected using EPID dosimetry, resulting in the adjustment of a TPS parameter and alteration of two clinical patient plans. One set of EPID measurements (i.e., one open and transit image acquired for each segment of the plan) is sufficient to check each IMRT plan field-by-field and at the isocenter, making it a useful, efficient, and accurate dosimetric tool. PMID:17089854

  14. Automation of the particle dosimetry and the dose application for radiobiological experiments at a vertical proton beam

    Moertel, H; Eyrich, W; Fritsch, M; Distel, L

    2002-01-01

    A facility with a vertical beam for radiobiological experiments with low-energy protons has been setup at the Tandem accelerator at Erlangen. This energy region is optimal to investigate the biological effects of the linear energy transfer in the Bragg region under physiological conditions. A new automated data acquisition system for dosimetry and monitoring based on a personal computer was developed and optimized for this setup. A specially designed sample holder offers possibilities of cooling or changing of atmosphere during irradiation. First irradiations of biological samples have shown the functionality of the setup.

  15. Automation of the particle dosimetry and the dose application for radiobiological experiments at a vertical proton beam

    Mörtel, H.; Georgi, J.; Eyrich, W.; Fritsch, M.; Distel, L.

    2002-08-01

    A facility with a vertical beam for radiobiological experiments with low-energy protons has been setup at the Tandem accelerator at Erlangen. This energy region is optimal to investigate the biological effects of the linear energy transfer in the Bragg region under physiological conditions. A new automated data acquisition system for dosimetry and monitoring based on a personal computer was developed and optimized for this setup. A specially designed sample holder offers possibilities of cooling or changing of atmosphere during irradiation. First irradiations of biological samples have shown the functionality of the setup.

  16. Dosimetry experience of 192IR sources used In HDR brachytherapy for cervical cancer

    Purpose/Objective: The 192IR Sources are the most commonly used in radiotherapy treatments HDR worldwide. According to international recommendations on quality assurance in HDR brachytherapy, an acceptance test based on the determination of the source strength of any new source shall be carried out before first application to verify the manufacturer’s calibration data. The present paper gives the experimental determination of the source strength for our brachytherapy sources used until now in brachytherapy treatments. Materials/Methods: At Mother Teresa University Hospital we have a cost-effective gynecological brachytherapy unit from Eckert & Ziegler BEBIG named GyneSource® that is a five channel HDR after loader equipped with an 192IR source. The software used is HDR plus™ 2.5 that delivers an optimized treatment plan and makes the process especially fast and we use intracavitary BEBIG applicators. From April 2009 up to December 2012, we have imported nine HDR 192IR Sources. The exchange of the source and acceptance test is done by the physicist of the clinic once the source is imported. The measurements are done with a Well-type ionization chamber HDR1000 Plus and the electrometer used is MAX4000. Only seven sources are compared as we miss the dosimetry data of the first source, and the forth source was not measured and not used because the machine was not working in that time. Results/Conclusions: Eight sources were accepted for clinically use as the measurement were within the tolerance. The source number four with e deviation of -1.92% has been double checked compared with a free in-air measurement with farmer type chamber that gave a deviation to source certificate of 4% that is still inside the tolerance to accept a source for clinical use. The deviations of measured Air Kerma rate to the value of the sources certificates of all our used 192IR sources are less than 2%, which are within the tolerance. The checked value of updated source strength in

  17. Analysis of TRACY experiment and JCO criticality accident by using AGNES code

    A one-point kinetics code, AGNES, has been developed in JAERI for the purpose of the analysis of TRACY experiment. Four of the experiments performed in ramp feed mode were simulated by AGNES code, and the power, temperature and total fission number were evaluated. The calculated values of them were in agreement with the experimental values with ±15% error. In the analysis of JCO criticality accident, three supposed cases were considered, and the total fission number was evaluated at 4 - 6x1017 by insertion of 1.5 - 3.0$ excess reactivity. (author)

  18. Reactivity initiated accident (RIA) type tests and annular core pulse reactor (ACPR) operational experience

    This paper describes the test conducted to investigate the failure threshold of the fuel when subject to RIA, accomplished in the TRIGA ACPR Nuclear Research Institute, Pitesti. The reactor facility, the capsule used in experiments and the experimental results are presented. The failure threshold was determined at 200 cal/g for an atmospheric gap pressure comparable with similar tests. The failure threshold decreases with increasing gap pressure. The tests proved useful for a better understanding of the fuel behavior in the transient conditions. As it is known RIA is not a common accident for the CANDU reactors, but the fuel failure mechanism can be similar to other type of accidents as LOCA and PCM. The program will be continued, with better instrumentation for the fuel sample and also independent instrumentation to measure pulse characteristics with better statistics. A new project for the experimental fuel elements must be considered to eliminate fuel-endcap interactions. (author)

  19. Desktop exposure system and dosimetry for small scale in vivo radiofrequency exposure experiments.

    Gong, Yijian; Capstick, Myles; Tillmann, Thomas; Dasenbrock, Clemens; Samaras, Theodoros; Kuster, Niels

    2016-01-01

    This paper describes a new approach to the risk assessment of exposure from wireless network devices, including an exposure setup and dosimetric assessment for in vivo studies. A novel desktop reverberation chamber has been developed for well-controlled exposure of mice for up to 24 h per day to address the biological impact of human exposure scenarios by wireless networks. The carrier frequency of 2.45 GHz corresponds to one of the major bands used in data communication networks and is modulated by various modulation schemes, including Global System for Mobile Communications (GSM), Universal Mobile Telecommunications System (UMTS), Radio Frequency Identification (RFID), and wireless local area network, etc. The system has been designed to enable exposures of whole-body averaged specific absorption rate (SAR) of up to 15 W/kg for six mice of an average weight of 25 g or of up to 320 V/m incident time-averaged fields under loaded conditions without distortion of the signal. The dosimetry for whole-body SAR and organ-averaged SAR of the exposed mice, with analysis of uncertainty and variation analysis, is assessed. The experimental dosimetry based on temperature measurement agrees well with the numerical dosimetry, with a very good SAR uniformity of 0.4 dB in the chamber. Furthermore, a thermal analysis and measurements were performed to provide better understanding of the temperature load and distribution in the mice during exposure. PMID:26769169

  20. Proceedings of the International Workshop on Occupational Radiation Protection in Severe Accident Management 'sharing practices and experiences'

    The objective of the Workshop on Occupational Radiation Protection in Severe Accident Management was to share practices and experiences in approaches to severe accident management. The workshop: provided an international forum for information and experience exchange amongst nuclear electricity utilities and national regulatory authorities on approaches to, and issues in severe accident management, including national and international implications. Focus was placed on sharing practices and experiences in many countries on approaches to severe accident management; identified best occupational radiation protection approaches in strategies, practices, as well as limitations for developing effective management. This included experiences in various countries; identified national experiences to be incorporated into the final version of ISOE EG-SAM report. The workshop included a series of plenary presentations that provided participants with an overview of practices and experiences in severe accident management from various countries. Furthermore, by taking into account the structure of the interim report, common themes and issues were discussed in follow-up breakout sessions. Sessions included invited speakers, moderated by designated experts, allowing participants to discuss their national experiences and possible inputs into the report. The outcomes of the breakout sessions were presented in plenary by the respective moderators followed by an open discussion, with a view towards elaborating ways forward to achieve more effective severe accident management. This document brings together the abstracts and the slides of the available presentations

  1. Optimization of the Severe Accident Management Strategy for Domestic Plants and Validation Experiments

    Kim, S. B.; Kim, H. D.; Koo, K. M.; Park, R. J.; Hong, S. H.; Cho, Y. R.; Kim, J. T.; Ha, K. S.; Kang, K. H

    2007-04-15

    nuclear power plants, a technical basis report and computational aid tools were developed in parallel with the experimental and analytical works for the resolution of the uncertain safety issues. ELIAS experiments were carried out to quantify the boiling heat removal rate at the upper surface of a metallic layer for precise evaluations on the effect of a late in-vessel coolant injection. T-HERMES experiments were performed to examine the two-phase natural circulation phenomena through the gap between the reactor vessel and the insulator in the APR1400. Detailed analyses on the hydrogen control in the APR1400 containment were performed focused on the effect of spray system actuation on the hydrogen burning and the evaluation of the hydrogen behavior in the IRWST. To develop the technical basis report for the severe accident management, analyses using SCDAP/RELAP5 code were performed for the accident sequences of the OPR1000. Based on the experimental and analytical results performed in this study, the computational aids for the evaluations of hydrogen flammability in the containment, criteria of the in-vessel corium cooling, criteria of the external reactor vessel cooling were developed. An ASSA code was developed to validate the signal from the instrumentations during the severe accidents and to process the abnormal signal. Since ASSA can perform the signal processing from the direct input of the nuclear power plant during the severe accident, it can be platform of the computational aids. In this study, the ASSA was linked with the computaional aids for the hydrogen flammability.

  2. Results from 2010 Caliban Criticality Dosimetry Intercomparison

    The external dosimetry program participated in a criticality dosimetry intercomparison conducted at the Caliban facility in Valduc, France in 2010. Representatives from the dosimetry and instrumentation groups were present during testing which included irradiations of whole-body beta/gamma (HBGT) and neutron thermoluminescent dosimeters (TLDs), a fixed nuclear accident dosimeter (FNAD), electronic alarming dosimeters, and a humanoid phantom filled with reference man concentrations of sodium. This report reviews the testing procedures, preparations, irradiations, and presents results of the tests.

  3. Operational accidents and radiation exposure experience within the United States Atomic Energy Commission, 1943--1975

    The occupational injury and fatality experience during 32 years of the development of the atomic energy industry under the direction of the Atomic Energy Commission (AEC) and its predecessor, the Manhattan Engineering District, is reviewed. Data are included on the cause of all accidents, including fires and transportation accidents, and the cost of AEC property damage. Fatalities of AEC and contractor personnel from all causes during the 32-year period totaled 321, of which 184 occurred in construction; 121 in AEC operations such as production, research, and services; and 16 in Government functions. There were 19,225 lost-time injuries attributable to all accidental causes, or a 32-year frequency rate of 2.75 based on the number of injuries per million man-hours. There were six deaths attributable to nuclear causes, thee of which were due to blast and flying missiles and three caused by whole-body radiation exposure. Forty-one workers were involved in lost-time radiation accidents, of whom 26 showed clinical manifestations attributable to radiation, resulting in permanent partial-disability of three workers and the loss of a digit by four workers, while the others did not develop evidence of radiation injury

  4. Radiation dosimetry

    Hine, Gerald J; Hine, Gerald J

    1956-01-01

    Radiation Dosimetry focuses on the advancements, processes, technologies, techniques, and principles involved in radiation dosimetry, including counters and calibration and standardization techniques. The selection first offers information on radiation units and the theory of ionization dosimetry and interaction of radiation with matter. Topics include quantities derivable from roentgens, determination of dose in roentgens, ionization dosimetry of high-energy photons and corpuscular radiations, and heavy charged particles. The text then examines the biological and medical effects of radiation,

  5. Dosimetry Service

    2004-01-01

    We wish to remind the people who are invited to the dosimetry service to exchange the new CERN dosimeter that the hours are from Monday to Friday 8.30 to 11.00 and 14.00 to 16.00. http://service-rp-dosimetry.web.cern.ch/service-rp-dosimetry/

  6. Methods and procedures for internal radiation dosimetry at ORNL

    Procedures, methods, materials, records, and reports used for accomplishing the personnel, internal radiation monitoring program at Oak Ridge National Laboratory are described for the purpose of documenting what is done now for future reference. This document does not include procedures for nuclear accident dosimetry except insofar as routine techniques may apply also to nuclear accident dosimetry capability

  7. Experience and lessons learned from emergency disposal of Fukushima nuclear power station accident

    After Fukushima nuclear accident, we visited the related medical aid agencies for nuclear accidents and conducted investigations in disaster-affected areas in Japan. This article summarizes the problems with emergency disposal of Fukushima nuclear accident while disclosing problems should be solved during the emergency force construction for nuclear accidents. (authors)

  8. Nuclear accidents

    On 27 May 1986 the Norwegian government appointed an inter-ministerial committee of senior officials to prepare a report on experiences in connection with the Chernobyl accident. The present second part of the committee's report describes proposals for measures to prevent and deal with similar accidents in the future. The committee's evaluations and proposals are grouped into four main sections: Safety and risk at nuclear power plants; the Norwegian contingency organization for dealing with nuclear accidents; compensation issues; and international cooperation

  9. Heat transfer analysis of experiments simulating a loss-of-coolant accident

    Thermodynamic out-of-pile experiments simulating a loss-of-coolant accident (LOCA) are performed with electrically heated rods, which are instrumented with internal thermo-couples because surface measurements would influence the coolant flow. The data analysis problem is therefore the solution of the nonlinear problem to determine the surface temperature, the surface heat transfer coefficient, and the surface heat flux from internal temperature measurements. A digital computer code was developed for the analysis of the experimental data. The code has different options. The major application of the code is the numerical solution of the inverse heat conduction problem involving temperature dependent material properties and complex multilayer geometries. (author)

  10. Dosimetry Service

    2006-01-01

    Cern Staff and Users can now consult their dose records for an individual or an organizational unit with HRT. Please see more information on our web page: http://cern.ch/rp-dosimetry Dosimetry Service is open every morning from 8.30 - 12.00. Closed in the afternoons. We would like to remind you that dosimeters cannot be sent to customers by internal mail. Short-term dosimeters (VCT's) must always be returned to the Service after the use and must not be left on the racks in the experimental areas or in the secretariats. Dosimetry Service Tel. 7 2155 Dosimetry.service@cern.ch http://cern.ch/rp-dosimetry

  11. Water equivalence of various materials for clinical proton dosimetry by experiment and Monte Carlo simulation

    Al-Sulaiti, Leena; Shipley, David; Thomas, Russell; Kacperek, Andrzej; Regan, Patrick; Palmans, Hugo

    2010-07-01

    The accurate conversion of dose to various materials used in clinical proton dosimetry to dose-to-water is based on fluence correction factors, accounting for attenuation of primary protons and production of secondary particles due to non-elastic nuclear interactions. This work aims to investigate the depth dose distribution and the fluence correction with respect to water or graphite at water equivalent depths (WED) in different target materials relevant for dosimetry such as polymethyl methacrylate (PMMA), graphite, A-150, aluminium and copper at 60 and 200 MeV. This was done through a comparison between Monte Carlo simulation using MCNPX 2.5.0, analytical model calculations and experimental measurements at Clatterbridge Centre of Oncology (CCO) in a 60 MeV modulated and un-modulated proton beam. MCNPX simulations indicated small fluence corrections for all materials with respect to graphite and water in 60 and 200 MeV except for aluminium. The analytical calculations showed an increase in the fluence correction factor to a few percent for all materials with respect to water at 200 MeV. The experimental measurements for 60 MeV un-modulated beam indicated a good agreement with MCNPX. For the modulated beam the fluence correction factor was found to be decreasing below unity by up to few percent with depth for aluminium and copper but almost constant and unity for A-150.

  12. Benchmark experiment for the verification of radiation transport calculations for the radiotherapy dosimetry; Benchmark-Experiment zur Verifikation von Strahlungstransportrechnungen fuer die Dosimetrie in der Strahlentherapie

    Renner, Franziska

    2014-10-02

    Monte Carlo simulations are regarded as the most accurate method of solving complex problems of radiation transport. Therefore, they have great potential to realize more exact dose calculations for treatment planning in radiation therapy. However, there is a lack of information on how correct the results of Monte Carlo calculations are on an absolute basis. A practical verification of the calculations can be performed by direct comparison with a benchmark experiment. Thereby, the uncertainties of the experimental result and of the simulation also have to be considered to make a meaningful comparison between the experiment and the simulation possible. This dissertation presents a benchmark experiment and its results, including the uncertainty, which can be used to test the accuracy of Monte Carlo calculations in the field of radiation therapy. The experiment was planned to have parallels to clinical radiation therapy, among other things, with respect to the radiation applied, the materials used and the manner of dose detection. The benchmark experiment aimed at an absolute comparison with a simulation result and because of this it was necessary to use a special research accelerator as a radiation source in the experiment. The accurate characterization of the accelerator beam was a precondition to define a realistic radiation source for the Monte Carlo simulation. Therefore, this work also deals with the characterization of the source and investigations regarding the X-ray target used. Additionally, the dissertation contains the verification of the widely used Monte Carlo program EGSnrc by the benchmark experiment. The simulation of the experiment by EGSnrc, the results and the estimation of the uncertainty related to the simulation are documented in this work.The results and findings of this dissertation end in a comparison between the results of the benchmark experiment and the corresponding calculations with EGSnrc. The benchmark experiment and the simulations

  13. International comparison of criticality accident evaluation methods. Evaluation plan of super-critical benchmark based on TRACY experiment

    In order to evaluate criticality accident analysis codes, a criticality accident benchmark problem was made based on the TRACY experiment. It is evaluated by the contributors of the expert group on criticality excursion analysis, a group of criticality safety WP of OECD/NEA/NSC. This paper reports the detail of TRACY Benchmark I and II, and preliminary results of its analysis using AGNES code. (author)

  14. THAI experiments on hydrogen and fission product behavior in the LWR containment during a severe accident

    In case of a severe accident in a nuclear reactor, a large amount of hydrogen and fission products may be generated by interactions of the core melt with containment structures and water. The behaviour and the distribution of hydrogen and the fission products can be affected by a variety of chemical and physical phenomena taking place inside the containment. These phenomena involve the disciplines of thermal hydraulics, hydrogen distribution and deflagrations, fission products chemistry and material interactions, aerosol physics, and effectiveness of mitigation measures among others. Predictions of the consequences of a severe accident by conventional Lumped Parameter (LP) and Computational Fluid Dynamics (CFD) codes need to be based on large scale coupled-phenomenon experiments to minimize the scale effect in extrapolation to reactor safety analysis purpose. In this context, an extensive experimental program on nuclear severe accident has been pursuing at the THAI (Thermal-hydraulics, Hydrogen, Aerosol, and Iodine) test facility for many years. Main component of the facility is a 60-m3 stainless steel vessel, 9.2m high and 3.2m in diameter, with exchangeable internals for multi-compartment investigations. The test facility is operated by Becker Technologies under sponsorship of the German Federal Ministry of Economics and Technology. Since its construction in 2000, sponsorship of the German Federal Ministry of Economics and Technology. Since its construction in 2000, THAI facility has been engaged in the field of reactor safety in the frame of various national (THAI-I to THAI-IV) and international programs (OECD-THAI and THAI2 projects). Additionally, experimental data has been provided in the frame of several International Standard Problems (ISP 41, 46, 47, and 49) for code validation exercises. The THAI test facility allows investigating various accident scenarios, ranging from turbulent free convection to stagnant stratified containment atmospheres, and can be

  15. Radiation Dosimetry Experiment (RaD-X): High-Altitude Balloon Flight Mission for Improving the NAIRAS Model

    Norman, Ryan B.; Gronoff, Guillaume P.; Mertens, Christopher J.; Alston, Erica J.; Straume, Tore; Gersey, Brad; Lusby, Terry C.; Tobiska, W. Kent; Wilkins, Rick

    2015-01-01

    The NASA Radiation Dosimetry Experiment (RaD-X) high-altitude balloon mission was successfully launched from Fort Sumner, New Mexico USA on 25 September, 2015. Over 15 hours of science data were obtained from four dosimeters at altitudes above about 25 km. One of the main goals of the RaD-X mission is to improve aviation radiation model characterization of cosmic ray primaries by taking dosimetric measurements above the Pfotzer maximum before the production of secondary particles occurs. The second goal of the RaD-X mission is to facilitate the pathway toward real-time, data assimilative predictions of atmospheric cosmic radiation exposure by identifying and characterizing low-cost radiation measurement solutions.

  16. Dosimetry experiment 'Dompac'. Neutronic simulation of the thickness of a PWR pressure vessel. Irradiation damage characterization

    For suitable extrapolation of irradiated PWR ferritic steel results, proper irradiation of the pressure vessel has been 'simulated' in test reactor. For this purpose, a huge steel block (20 cm in depth) was loaded with Saclay's graphite (GAMIN) and tungsten damage detectors. Core-block water gap was optimized through spectrum indexes method, by ANISN and SABINE codes so that spectrum in 1/4 thickness matches with ANISN computations for PWR Fessenheim 1. A good experimental agreement is found with calculated dpa damage gradient. 3D Monte Carlo computation (TRIPOLI) was performed on the DOMPAC device, and spectrum indexes evolution was found consistent with experimental results. Surveillance rigs behind a 'thermal shield' were also simulated, including damage and activation monitors. Dosimetry results give an order of magnitude of accuracies involved in projecting steel sample embrittlement to the pressure vessel

  17. University of Tennessee Comparative Animal Research Laboratory accident in 1971

    On 4 February 1971, a 32-year-old research technologist performing seed irradiated experiments at the University of Tennessee Comparative Animal Research Laboratory was exposed to a Cobalt 60 source of 7700 curies for 40 seconds. Details of the accident, dose estimates from dosimetry studies, and acute biological clinical findings are discussed. Follow-up clinical data on the hematopoietic system, biochemistry, fingers, and blood counts are discussed

  18. Service experience, structural integrity, severe accidents, and erosion in nuclear and fossil plants. PVP-Volume 303

    Paterson, S.R.; Bamford, W.H; Geraets, L.H.; Okazaki, M.; Cipolla, R.C.; Cowfer, C.D.; Means, K.H. [eds.

    1995-12-01

    The objective of this symposium was to disseminate information on service degradation and its prevention. Papers have been divided into the following topical sections: Service experience in nuclear plants; DOE high-level waste tank structural integrity panel--Summary reports; Severe accidents; Service experience in operating fossil power plants; and Erosion. Papers have been processed separately for inclusion on the data base.

  19. Protective Behaviour of Citizens to Transport Accidents Involving Hazardous Materials: A Discrete Choice Experiment Applied to Populated Areas nearby Waterways.

    Esther W de Bekker-Grob

    Full Text Available To improve the information for and preparation of citizens at risk to hazardous material transport accidents, a first important step is to determine how different characteristics of hazardous material transport accidents will influence citizens' protective behaviour. However, quantitative studies investigating citizens' protective behaviour in case of hazardous material transport accidents are scarce.A discrete choice experiment was conducted among subjects (19-64 years living in the direct vicinity of a large waterway. Scenarios were described by three transport accident characteristics: odour perception, smoke/vapour perception, and the proportion of people in the environment that were leaving at their own discretion. Subjects were asked to consider each scenario as realistic and to choose the alternative that was most appealing to them: staying, seeking shelter, or escaping. A panel error component model was used to quantify how different transport accident characteristics influenced subjects' protective behaviour.The response was 44% (881/1,994. The predicted probability that a subject would stay ranged from 1% in case of a severe looking accident till 62% in case of a mild looking accident. All three transport accident characteristics proved to influence protective behaviour. Particularly a perception of strong ammonia or mercaptan odours and visible smoke/vapour close to citizens had the strongest positive influence on escaping. In general, 'escaping' was more preferred than 'seeking shelter', although stated preference heterogeneity among subjects for these protective behaviour options was substantial. Males were less willing to seek shelter than females, whereas elderly people were more willing to escape than younger people.Various characteristics of transport accident involving hazardous materials influence subjects' protective behaviour. The preference heterogeneity shows that information needs to be targeted differently depending on

  20. Overviews of sodium combustion experiments and fire accidents along with safety considerations

    Summaries are described on the sodium combustion experiments conducted by HEDL (F1, F2, F4, F5), KfK, Cadarashe (IGNA402 and 2002, IGNA3602 and 3604), the former PNC, etc. The sodium fires of Almeria Solar Plant and ILONA Test Facility are taken up as the examples of large-scale accidents. Fast breeder reactor (FBR) safety considerations are discussed, with attentions paid to the integrity of steel liner and sodium-concrete reaction, in relation to the secondary sodium leakage of MONJU. The author suggests that injection of nitrogen gas is an effective measure against sodium fires, suppressing the temperature rises, chemical reactions and also surely excluding a hydrogen explosion in case of sodium-concrete reaction. (author)

  1. QA experience at the University of Wisconsin accredited dosimetry calibration laboratory

    The University of Wisconsin Accredited Dosimetry Calibration Laboratory (UW ADCL) employs procedure manuals as part of its Quality Assurance (QA) program. One of these manuals covers the QA procedures and results for all of the UW ADCL measurement equipment. The QA procedures are divided into two main areas: QA for laboratory equipment and QA for external chambers sent for calibration. All internal laboratory equipment is checked and recalibrated on an annual basis, after establishing its consistency on a 6-month basis. QA for external instruments involves checking past calibration history as well as comparing to a range of calibration values for specific instrument models. Generally, the authors find that a chamber will have a variation of less than 0.5 % from previous Co-60 calibration factors, and falls within two standard deviations of previous calibrations. If x-ray calibrations are also performed, the energy response of the chamber is plotted and compared to previous instruments of the same model. These procedures give the authors confidence in the transfer of calibration values from National Institute of Standards and Technology (NIST)

  2. QA experience at the University of Wisconsin accredited dosimetry calibration laboratory

    DeWard, L.A.; Micka, J.A. [Univ. of Wisconsin, Madison, WI (United States)

    1993-12-31

    The University of Wisconsin Accredited Dosimetry Calibration Laboratory (UW ADCL) employs procedure manuals as part of its Quality Assurance (QA) program. One of these manuals covers the QA procedures and results for all of the UW ADCL measurement equipment. The QA procedures are divided into two main areas: QA for laboratory equipment and QA for external chambers sent for calibration. All internal laboratory equipment is checked and recalibrated on an annual basis, after establishing its consistency on a 6-month basis. QA for external instruments involves checking past calibration history as well as comparing to a range of calibration values for specific instrument models. Generally, the authors find that a chamber will have a variation of less than 0.5 % from previous Co-60 calibration factors, and falls within two standard deviations of previous calibrations. If x-ray calibrations are also performed, the energy response of the chamber is plotted and compared to previous instruments of the same model. These procedures give the authors confidence in the transfer of calibration values from National Institute of Standards and Technology (NIST).

  3. MOSFET dosimetry mission inside the ISS as part of the Matroshka-R experiment.

    Hallil, A; Brown, M; Akatov, Yu; Arkhangelsky, V; Chernykh, I; Mitrikas, V; Petrov, V; Shurshakov, V; Tomi, L; Kartsev, I; Lyagushin, V

    2010-03-01

    Radiation measurements of surface and deep organ doses were performed aboard the International Space Station, for the period of January 2006 to April 2007, using a MOSFET dosimetry system combined with the Matroshka-R spherical phantom. The averaged internal and surface dose rates are found to be 0.19 and 0.29 mGy d(-1), respectively. The levels of radiation dose to blood-forming organs (BFO) and to surface organs are compared with recommended safe limits. The maximum measured BFO dose has an average dose rate of 0.23 mGy d(-1) (84 mGy y(-1)), corresponding to 44 % of the recommended annual limit of 0.5 Sv, for a space radiation quality factor of 2.6. The annual surface dose is found to be higher at 126 mGy, corresponding to 16 % of the eye dose limit and to 11 % of the skin dose limit. Doses calculated using the Spenvis software showed deviations of up to 37 % from measurements. PMID:19933696

  4. Experiments on the behaviour of ruthenium in air ingress accidents - Progress report

    During routine nuclear reactor operation, ruthenium will accumulate in the fuel in relatively high concentrations. In an accident in a nuclear power plant it is possible that air gets into contact with the reactor core. In this case ruthenium can oxidise and form volatile ruthenium species, RuO3 and RuO4, which can be transported into the containment. In order to estimate the amount of gaseous ruthenium species it is of interest to know, how it is formed and how it behaves. In our experiments RuO2 is exposed to diverse oxidising atmospheres at a relatively high temperature. In this report, the experimental system for the ruthenium behaviour study is presented. Also preliminary results from experiments carried out during year 2005 are reported. In the experiments gaseous ruthenium oxides were produced in a furnace. Upon cooling RuO2 aerosol particles were formed in the system. They were removed with plane filters from the gas stream. Gaseous ruthenium species were trapped in 1M NaOH-water solution, which is capable of trapping RuO4 totally. Ruthenium in the solution was filtered for analysis. The determination of ruthenium both in aerosol and in liquid filters was made using instrumental neutron activation analysis (INAA). In order to close mass balance and achieve better time resolution three experiment using radioactive tracer were carried out. (au)

  5. Dosimetry Service

    2005-01-01

    Please remember to read your dosimeter at least once a month. Regular read-outs are vital to ensure that your personal dose is periodically monitored. Dosimeters should be read even if you have not visited the controlled areas. Dosimetry Service - Tel. 72155 http://cern.ch/rp-dosimetry

  6. Dosimetry Service

    Dosimetry Service

    2005-01-01

    Please remember to read your dosimeter at least once a month. Regular read-outs are vital to ensure that your personal dose is periodically monitored. Dosimeters should be read even if you have not visited the controlled areas. Dosimetry Service Tel. 7 2155 http://cern.ch/rp-dosimetry

  7. Dosimetry Service

    2005-01-01

    Please remember to read your dosimeter at least once a month. Regular read-outs are vital to ensure that your personal dose is periodically monitored. Dosimeters should be read even if you have not visited the controlled areas. Dosimetry Service - Tel. 7 2155 http://cern.ch/rp-dosimetry

  8. Learning lessons from accidents with a human and organisational factors perspective: deficiencies and failures of operating experience feedback systems

    This paper aims at reminding the failures of operating experience feedback (OEF) systems through the lessons of accidents and provides a framework for improving the efficiency of OEF processes. The risk is for example to miss lessons from other companies and industrial sectors, or to miss the implementation of adequate corrective actions with the risk to repeat accidents. Most of major accidents have been caused by a learning failure or other organisational factors as a contributing cause among several root causes. Some of the recurring organisational factors are: -) poor recognition of critical components, of critical activities or deficiency in anticipation and detection of errors, -) excessive production pressure, -) deficiency of communication or lack of quality of dialogue, -) Excessive formalism, -) organisational complexity, -) learning deficiencies (OEF, closing feedback loops, lack of listening of whistle-blowers). Some major accidents occurred in the nuclear industry. Although the Three Mile Island accident has multiple causes, in particular, an inappropriate design of the man-machine interface, it is a striking example of the loss of external lessons from incidents. As for Fukushima it is too early to have established evidence on learning failures. The systematic study and organisational analysis of OEF failures in industrial accidents whatever their sector has enabled us to provide a framework for OEF improvements. Five key OEF issues to improve in priority: 1) human and organisational factors analysis of the root causes of the events, 2) listening to the field staff, dissenting voices and whistle-blowers, 3) monitoring of the external events that provide generic lessons, 4) building an alive memory through a culture of accidents with people who become experiences pillars, and 5) the setting of external audit or organisational analysis of the OEF system by independent experts. The paper is followed by the slides of the presentation

  9. Experiments to quantify airborne release from packages with dispersible radioactive materials under accident conditions

    Martens, R.; Lange, F. [Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) mbH, Schwertnergasse 1, 50667 Koeln (Germany); Koch, W.; Nolte, O. [Fraunhofer-Institut fuer Toxikologie und Experimentelle Medizin (ITEM), Nikolai-Fuchs-Str.1, 30625 Hannover (Germany)

    2005-07-01

    For transport or handling accidents involving packages with radioactive materials and the assessment of potential radiological consequences, for the review of current requirements of the IAEA Transport Regulations, and for their possible further development reliable release data following mechanical impact are required. Within this context a research project was carried out which extends the basis for a well-founded examination of the contemporary system of requirements of 'Low Specific Activity' (LSA)-type materials and allows for its further development where appropriate. This project comprises a prior system-analytical examination and an experimental programme aiming at improving the general physical understanding of the release process as well as the quantity and the characteristics of airborne released material for non-fixed dispersible LSA-II material upon mechanical impact. Impaction experiments applying small, medium and real sized specimens of different dispersible materials revealed that the release behaviour of dispersible powders strongly depends upon material properties, e.g. particle size distribution and cohesion forces. The highest experimentally determined release fraction of respirable mass (AED < 10 {mu}m) amounted to about 2 % and was obtained for 2 kg of un-contained easily dispersible pulverized fly ash (PFA). For larger un-contained PFA specimen the release fraction decreases. However, packaging containing powdery material substantially reduces the airborne release fraction. The measured airborne release fractions for a 200 l drum with Type A certificate containing PFA were about a factor of 50 to 100 lower than for un-contained material. For a drop height of 9 m the airborne release fraction amounted to about 4 x 10{sup -5}. This value should be applicable for most of transport and handling accidents with mechanical impact. For a metal container of Type IP-2 or better which contains powder masses of 100 kg or more this release

  10. Electron paramagnetic resonance technique for radiation dosimetry: emerging trends for laboratory and accidental dosimetry

    The applications of Electron Paramagnetic Resonance (EPR) for radiation dosimetry are briefly reviewed. In particular, EPR-alanine dosimetry and accidental dosimetry using EPR signals from human tooth enamel have been discussed. The alanine dosimetry was found to be useful from low doses such as 1 Gy to high doses such as 100 kGy. The signals from tooth enamel are found to be invaluable in assessing the absorbed dose of people exposed to radiation accidents and also survivors of atomic bomb explosions. New emerging trends using EPR signals from bones exposed to radiation have also been briefly reviewed. (author)

  11. Review of optically stimulated luminescence (OSL) instrumental developments for retrospective dosimetry

    Botter-Jensen, L., E-mail: boetter@youmail.d [Radiation Research Division, Riso National Laboratory for Sustainable Energy, Technical University of Denmark, Frederiksborgvej 399, DK-4000 Roskilde (Denmark); Thomsen, K.J.; Jain, M. [Radiation Research Division, Riso National Laboratory for Sustainable Energy, Technical University of Denmark, Frederiksborgvej 399, DK-4000 Roskilde (Denmark)

    2010-03-15

    This review describes 40 years of experience gained at Riso National Laboratory in the development of facilities for irradiation, thermal/optical stimulation and luminescence signal detection. These facilities have mainly been used in luminescence dating and nuclear accident dosimetry. We focus especially on methods for light stimulation and irradiation, and developments of new portable TL/OSL readers for determining doses directly in the field on both Earth and the planet Mars.

  12. Fallout: The experiences of a medical team in the care of a Marshallese population accidently exposed to fallout radiation

    This report presents an historical account of the experiences of the Brookhaven Medical Team in the examination and treatment of the Marshallese people following their accidental exposure to radioactive fallout in 1954. This is the first time that a population has been heavily exposed to radioactive fallout, and even though this was a tragic mishap, the medical findings have provided valuable information for other accidents involving fallout such as the recent reactor accident at Chernobyl. Noteworthy has been the unexpected importance of radioactive iodine in the fallout in producing thyroid abnormalities

  13. Fallout: The experiences of a medical team in the care of a Marshallese population accidently exposed to fallout radiation

    Conard, R.A.

    1992-09-01

    This report presents an historical account of the experiences of the Brookhaven Medical Team in the examination and treatment of the Marshallese people following their accidental exposure to radioactive fallout in 1954. This is the first time that a population has been heavily exposed to radioactive fallout, and even though this was a tragic mishap, the medical findings have provided valuable information for other accidents involving fallout such as the recent reactor accident at Chernobyl. Noteworthy has been the unexpected importance of radioactive iodine in the fallout in producing thyroid abnormalities.

  14. Retrospective reconstruction of emergency dose exposed to the population of belarus affected by the Chernobyl accident by the method of tooth enamel epr dosimetry

    An approach to the retrospective reconstruction of emergency doses for EPR of tooth enamel was developed, which allows to take into account the contribution to the dose load of side electromagnetic radiation (background radiation, medical X-rays, ultraviolet light) and the mechanical effect of dental borers on enamel during dental treatment. It was found that the highest emergency doses of radiation were received by the liquidators in 1986 accident involvement, then in a descending order by the citizens of areas with soil contamination of 137Cs 15-40, 5-15 and 1-5 Ci/km2 (authors)

  15. LWR severe accident simulation: Iodine behaviour in FPT2 experiment and advances on containment iodine chemistry

    Highlights: ► Short term gaseous iodine fraction can be produced either in primary circuit or on containment condensing surfaces. ► Gaseous radiolytic reactions convert volatile iodine into non-volatile iodine oxide particulates. ► Alkaline and evaporating sump decrease the iodine volatility in containment. ► Release of volatile iodine from containment surfaces explained the long term stationary residual gaseous iodine concentration. - Abstract: The Phebus Fission Product (FP) Program studies key phenomena of severe accidents in water-cooled nuclear reactors. In the framework of the Phebus program, five in-pile experiments have been performed that cover fuel rod degradation and behaviour of fission products released via the coolant circuit into the containment vessel. The focus of this paper is on iodine behaviour during the Phebus FPT2 test. FPT2 used a 33 GWd/t uranium dioxide fuel enriched to 4.5%, re-irradiated in situ for 7 days to a burn-up of 130 MWd/t. This test was performed to study the impact of steam-poor conditions and boric acid on the fission product chemistry. For the containment vessel, more specifically, the objective was to study iodine chemistry in an alkaline sump under evaporating conditions. The iodine results of the Phebus FPT2 test confirmed many of the essential features of iodine behaviour in the containment vessel provided by the first two Phebus tests, FPT0 and FPT1. These are the existence of an early gaseous iodine fraction, the persistence of low gaseous iodine concentrations and the importance of the sump in suppressing the iodine partitioning from sump to atmosphere. The main new insights provided by the Phebus FPT2 test were the iodine desorption from stainless steel walls deposits and the role of the evaporating sump in further iodine depletion in the containment atmosphere. The current paper presents an interpretation of the iodine behaviour in the FPT2 containment vessel based on dedicated small-scale analytical

  16. Characterization and performances of DOSION, a dosimetry equipment dedicated to radiobiology experiments taking place at GANIL

    Boissonnat, G; Balanzat, E; Boumard, F; Carniol, B; Colin, J; Cussol, D; Etasse, D; Fontbonne, C; Frelin, A -M; Hommet, J; Peronnel, J; Salvador, S

    2016-01-01

    Currently, radiobiology experiments using heavy ions at GANIL(Grand Acc\\'el\\'erateur National d'Ions Lourds) are conducted under the supervision of the CIMAP (Center for research on Ions, MAterials and Photonics). In this context, a new beam monitoring equipment named DOSION has been developed. It allows to perform measurements of accurate fluence and dose maps in near real time for each biological sample irradiated. In this paper, we present the detection system, its design, performances, calibration protocol and measurements performed during radiobiology experiments. This setup is currently available for any radiobiology experiments if one wishes to correlate one's own sample analysis to state of the art dosimetric references.

  17. Neutron dosimetry and damage calculation for the JP-10, 11, 13, and 16 experiments in HFIR

    Greenwood, L.R.; Ratner, R.T.

    1996-04-01

    Neutron fluence measurements and radiation damage calculations are reported for the joint U.S./Japanese experiments JP-10, 11, 13, and 16 in the target of the High Flux Isotope Reactor (HFIR) at Oak Ridge National Lab (ORNL). These experiments were irradiated at 85 MW for 238.5 EFPD. The maximum fast neutron fluence >0.1 MeV was about 2.1E + 22 n/cm{sup 2} for all of the experiments resulting in about 17.3 dpa in 316 stainless steel.

  18. Dosimetry Service

    Dosimetry Service

    2004-01-01

    We wish to remind the people who are invited to the dosimetry service to exchange the new CERN dosimeter that the hours are from Monday to Friday 8:30 to 11:00 and 14:00 to 16:00. For all other services we are at your disposition from 8:30 to 12:00 and 14:00 to 17:00. Do not forget to read your dosimeter. A regular read-out is indispensable in order to ensure a periodic monitoring of personal dose. This read-out should be done during the first week of every month. Thank you for your cooperation. The personnel of the Dosimetry Service wish you a Merry Christmas and a Happy New Year. Dosimetry Service Tel. 767 21 55 http://cern.ch/rp-dosimetry

  19. Benchmark experiment for the verification of radiation transport calculations for the radiotherapy dosimetry

    Monte Carlo simulations are regarded as the most accurate method of solving complex problems of radiation transport. Therefore, they have great potential to realize more exact dose calculations for treatment planning in radiation therapy. However, there is a lack of information on how correct the results of Monte Carlo calculations are on an absolute basis. A practical verification of the calculations can be performed by direct comparison with a benchmark experiment. Thereby, the uncertainties of the experimental result and of the simulation also have to be considered to make a meaningful comparison between the experiment and the simulation possible. This dissertation presents a benchmark experiment and its results, including the uncertainty, which can be used to test the accuracy of Monte Carlo calculations in the field of radiation therapy. The experiment was planned to have parallels to clinical radiation therapy, among other things, with respect to the radiation applied, the materials used and the manner of dose detection. The benchmark experiment aimed at an absolute comparison with a simulation result and because of this it was necessary to use a special research accelerator as a radiation source in the experiment. The accurate characterization of the accelerator beam was a precondition to define a realistic radiation source for the Monte Carlo simulation. Therefore, this work also deals with the characterization of the source and investigations regarding the X-ray target used. Additionally, the dissertation contains the verification of the widely used Monte Carlo program EGSnrc by the benchmark experiment. The simulation of the experiment by EGSnrc, the results and the estimation of the uncertainty related to the simulation are documented in this work.The results and findings of this dissertation end in a comparison between the results of the benchmark experiment and the corresponding calculations with EGSnrc. The benchmark experiment and the simulations

  20. Dosimetry methods

    McLaughlin, W.L.; Miller, A.; Kovacs, A.; Mehta, K. K.

    Chemical and physical radiation dosimetry methods, used for the measurement of absorbed dose mainly during the practical use of ionizing radiation, are discussed with respect to their characteristics and fields of application.......Chemical and physical radiation dosimetry methods, used for the measurement of absorbed dose mainly during the practical use of ionizing radiation, are discussed with respect to their characteristics and fields of application....

  1. Dosimetry Service

    Dosimetry Service

    2005-01-01

    Please remember to read your dosimeter at least once every month. A regular read-out is indispensable to ensure periodic monitoring of your personal dose. You must read your dosimeter even if you have not visited the controlled areas. Film badges are no longer valid at CERN and holders of film badges are no longer allowed to enter the controlled radiation areas or work with a source. Dosimetry Service Tel. 72155 http://cern.ch/rp-dosimetry

  2. Fission-product chemistry in severe reactor accidents: Review of relevant integral experiments

    The attenuation of the radioactive fission-product emission from a severe reactor accident will depend on a combination of chemical, physical and thermal-hydraulic effects. Chemical species stabilised under the prevailing conditions will determine the extent of aerosol formation and any subsequent interaction, so defining the magnitude and physical forms of the eventual release into the environment. While several important integral tests have taken place in recent years, these experiments have tended to focus on the generation of mass-balance and aerosol-related data to test and validate materials-transport codes rather than study the impact of important chemical phenomena. This emphasis on thermal hydraulics, fuel behaviour and aerosol properties has occurred in many test (e.g. PBF, DEMONA, Marviken-V, LACE and ACE). Nevertheless, the generation and reaction of the chemical species in all of these programmes determined the transport properties of the resulting vapours and aerosols. Chemical effects have been studied in measurements somewhat subsidiary to the main aims of the tests. This work has been reviewed in detail with respect to Marviken-V, LACE, ACE and Falcon. Specific issues remain to be addressed, and these are discussed in terms of the proposed Phebus-FB programme. (author). 58 refs, 9 figs, 1 tab

  3. Fission-product chemistry in severe reactor accidents: review of relevant integral experiments

    The attenuation of the radioactive fission-product emission from a severe reactor accident will depend on a combination of chemical, physical and thermal-hydraulic effects. Chemical species stabilised under the prevailing conditions will determine the extent of aerosol formation and any subsequent interaction, so defining the magnitude and physical forms of the eventual release into the environment. While several important integral tests have taken place in recent years, these experiments have tended to focus on the generation of mass-balance and aerosol-related data to test and validate materials-transport codes rather than study the impact of important chemical phenomena. This emphasis on thermal hydraulics, fuel behaviour and aerosol properties has occurred in many tests. Nevertheless, the generation and reaction of the chemical species in all of these programmes determined the transport properties of the resulting vapours and aerosols. Chemical effects have been studied in measurements somewhat subsidiary to the main aims of the tests. This work has been reviewed in detail with respect to other research programs. Specific issues remain to be addressed, and these are discussed in terms of the proposed Phebus-Fission Product programme. (author)

  4. Iterative ensemble Kalman filter for atmospheric dispersion in nuclear accidents: An application to Kincaid tracer experiment.

    Zhang, X L; Su, G F; Chen, J G; Raskob, W; Yuan, H Y; Huang, Q Y

    2015-10-30

    Information about atmospheric dispersion of radionuclides is vitally important for planning effective countermeasures during nuclear accidents. Results of dispersion models have high spatial and temporal resolutions, but they are not accurate enough due to the uncertain source term and the errors in meteorological data. Environmental measurements are more reliable, but they are scarce and unable to give forecasts. In this study, our newly proposed iterative ensemble Kalman filter (EnKF) data assimilation scheme is used to combine model results and environmental measurements. The system is thoroughly validated against the observations in the Kincaid tracer experiment. The initial first-guess emissions are assumed to be six magnitudes underestimated. The iterative EnKF system rapidly corrects the errors in the emission rate and wind data, thereby significantly improving the model results (>80% reduction of the normalized mean square error, r=0.71). Sensitivity tests are conducted to investigate the influence of meteorological parameters. The results indicate that the system is sensitive to boundary layer height. When the heights from the numerical weather prediction model are used, only 62.5% of reconstructed emission rates are within a factor two of the actual emissions. This increases to 87.5% when the heights derived from the on-site observations are used. PMID:26026852

  5. When the social discourse on violation behaviours is challenged by the perception of everyday life experiences: Effects of non-accident experiences on offending attitudes and habits.

    Lheureux, Florent; Auzoult, Laurent

    2016-09-01

    The aim of this article is to introduce the concept of the Non-Accident Experience (NAE) with regard to violations of traffic safety regulations. An NAE refers to the fact of not having been involved in an accident following the adoption of a behaviour socially recognised as promoting its occurrence. We hypothesise that this type of experiences has a strong effect on attitudes (valence and strength) and habits with regard to traffic offences such as speeding and drink-drive. An empirical study was conducted to test the relevance of this set of hypotheses. 543 French drivers participated to a survey designed to measure all these theoretical constructs. As expected, the results showed that the more frequently NAEs were experienced the more individuals had a favourable and weak (less certain, less important, more ambivalent) attitude towards violations, as well as strong habits. In addition, the more numerous NAEs experienced by others were perceived to be, the more ambivalent was the attitude. The discussion firstly concerns the methodological limitations of this study (e.g. use of cross-sectional design) as well as the integration of this concept into current research, especially in relation to the attitude strength concept and the theory of planned behaviour. Then, we discuss its practical implications (use of the experience based analysis technique, with consideration of both accident and non-accident experiences). PMID:27269997

  6. Accidents - Chernobyl accident; Accidents - accident de Tchernobyl

    NONE

    2004-07-01

    This file is devoted to the Chernobyl accident. It is divided in four parts. The first part concerns the accident itself and its technical management. The second part is relative to the radiation doses and the different contaminations. The third part reports the sanitary effects, the determinists ones and the stochastic ones. The fourth and last part relates the consequences for the other European countries with the case of France. Through the different parts a point is tackled with the measures taken after the accident by the other countries to manage an accident, the cooperation between the different countries and the groups of research and studies about the reactors safety, and also with the international medical cooperation, specially for the children, everything in relation with the Chernobyl accident. (N.C.)

  7. The unique field experiments on the assessment of accident consequences at industrial enterprises of gas-chemical complexes

    Sour natural gas fields are the unique raw material base for setting up such large enterprises as gas chemical complexes. The presence of high toxic H2S in natural gas results in widening a range of dangerous and harmful factors for biosphere. Emission of such gases into atmosphere during accidents at gas wells and gas pipelines is of especial danger for environment and first of all for people. Development of mathematical forecast models for assessment of accidents progression and consequences is one of the main elements of works on safety analysis and risk assessment. The critical step in development of such models is their validation using the experimental material. Full-scale experiments have been conducted by the All-Union Scientific-Research institute of Natural Gases and Gas Technology (VNIIGAZ) for grounding of sizes of hazard zones in case of the severe accidents with the gas pipelines. The source of emergency gas release was the working gas pipelines with 100 mm dia. And 110 km length. This pipeline was used for transportation of natural gas with significant amount of hydrogen sulphide. During these experiments significant quantities of the gas including H2S were released into the atmosphere and then concentrations of gas and H2S were measured in the accident region. The results of these experiments are used for validation of atmospheric dispersion models including the new Lagrangian trace stochastic model that takes into account a wide range of meteorological factors. This model was developed as a part of computer system for decision-making support in case of accident release of toxic gases into atmosphere at the enterprises of Russian gas industry. (authors)

  8. Neutron dosimetry and damage calculations for the JP-17, 18 and 19 experiments in HFIR

    Greenwood, L.R.; Baldwin, C.A.

    1996-04-01

    Neutron fluence measurements and radiation damage calculations are reported for the joint US-Japanese experiments JP-17, 18, and 19 in the target of the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory (ORNL). These experiments were irradiated at 85 MW for two cycles resulting in 43.55 EFPD for JP-17 and 42.06 EFPD for JP-18 and 19. The maximum fast neutron fluence > 0.1 MeV was about 3.7E + 21 n/cm{sup 2} for all three irradiations, resulting in about 3 dpa in 316 stainless steel.

  9. Report on external occupational dosimetry in Canada

    In light of the new recommendations of the ICRP in Report 60 on dose quantities and dose limits, this working group was set up to examine the implications for external dosimetry in Canada. The operational quantities proposed by the ICRU are discussed in detail with regard to their applicability in Canada. The current occupational dosimetry services available in Canada are described as well as the several performance intercomparisons that have been carried out within the country as well as internationally. Recommendations are given with respect to standards for dosimetry, including accuracy and precision. More practical advice is given on the choice of dosimeter to use for external dosimetry, frequency of monitoring, and who should be monitored. Specific advice is given on the monitoring of pregnant workers and problem of non-uniform irradiation. Accident and emergency dosimetry are dealt with briefly. Suggestions are given regarding record keeping both for employers and for the national dose registry. 48 refs., 6 tabs., 1 fig

  10. Characterization of a nuclear accident dosimeter

    The 23rd nuclear accident dosimetry intercomparison was held during the week of June 12--16, 1995 at Los Alamos National Laboratory. This report presents the results of this event, referred to as NAD 23, as related to the performance of Sandia National Laboratories (SNL) personal nuclear accident dosimeter (PNAD). Two separate critical assemblies, SHEBA and Godiva, were used to generate seven separate neutron spectra for use in dose comparisons. SNL's PNAD measured absorbed doses that were within +16 to +26% of the reference doses. In addition, a preliminary investigation was undertaken to determine the feasibility of using the data obtained from an irradiated PNAD to correct for body orientation. This portion of the experiment was performed with a TRIGA reactor at the Nuclear Science Center at Texas A and M University

  11. The role of dosimetry audits in radiotherapy quality assurance: The 8 year experience in Greek radiotherapy and brachytherapy centers

    Twenty six (26) radiotherapy (RT) centers (public and private) operate in Greece up to date (Apr. 2010), where 36 linacs and 8 Co-60 teletherapy units are being used, producing 64 photon beams (Co60, 6-23 MV) and 126 electron beams (4-21 MeV) in total. Furthermore, 7 HDR Ir192 and 2 MDR/LDR Cs137 remote afterloading brachytherapy systems operate. The Ionizing Radiation Calibration Laboratory (IRCL) of the Greek Atomic Energy Commission (GAEC) runs dosimetry audits in all Greek radiotherapy centers by means of on-site visits, in order to assess the dose accuracy, to identify and resolve problems on dosimetry, to provide intercomparisons to hospitals and disseminate the IAEA TRS 398 protocol. Additionally, the GAEC's IRCL calibrates the reference dosimetry equipment of all RT centers, in terms of absorbed dose in water at Co60 beam quality and air kerma strength at Ir192 qualities. The GAEC's dosimetry audit is a continuous process: The 1st round has been completed for the photons beams (2002 - 2006), electrons (2002 - 2008) and brachytherapy (2006-2009). The 2nd round is at the final stage for photons (2006-2010) and in progress for the rest, while a 3rd round for photons has already been initiated. The audit results for the photons 1st round have been published. This work presents the results of these audits and focuses on the improvements of RT centers' dosimetry during the successive audit rounds

  12. [Registration of accidents and injuries in primary health care. Methods and the users' experiences].

    Lund, H; Lium, E

    1997-11-10

    The registration of accidents and injuries in primary health care is inadequate. One of the reasons for this inadequacy is most certainly lack of enthusiasm although lack of to-the-point registration methods is just as much to blame. We have used an automatic accident registration mode in the PC programme Profdoc. This accident registration programme is very useful and time cost-effective. In Os municipality, where the registration took place in 1996, the results have proved to be very helpful in accident prevention. Nevertheless, the programme still needs EDB-knowledgeable doctors, to collect the data. In the near future it will hopefully be possible to feed the raw material to a server, which would then organize the data. This would provide general practitioners with a completed report in exchange for raw material. PMID:9441426

  13. Retrospective dosimetry of Iodine-131 exposures using Iodine-129 and Caesium-137 inventories in soils--A critical evaluation of the consequences of the Chernobyl accident in parts of Northern Ukraine.

    Michel, R; Daraoui, A; Gorny, M; Jakob, D; Sachse, R; Romantschuk, L D; Alfimov, V; Synal, H-A

    2015-12-01

    The radiation exposure of thyroid glands due to (131)I as a consequence of the Chernobyl accident was investigated retrospectively based on (129)I and (137)Cs inventories in soils in Northern Ukraine. To this end, soil samples from 60 settlements were investigated for (129)I, (127)I, and (137)Cs by AMS, ICP-MS and gamma-spectrometry, respectively. Sampling was performed between 2004 und 2007. In those parts of Northern Ukraine investigated here the (129)I and (137)Cs inventories are well correlated, the variability of the individual (129)I/(137)Cs ratios being, however, high. Both the (129)I and (137)Cs inventories in the individual 5 samples for each settlement allowed estimating the uncertainties of the inventories due to the variability of the radionuclide deposition and consequently of the retrospective dosimetry. Thyroid equivalent doses were calculated from the (129)I and the (137)Cs inventories using aggregated dose coefficients for 5-year old and 10-year-old children as well as for adults. The highest thyroid equivalent doses (calculated from (129)I inventories) were calculated for Wladimirowka with 30 Gy for 5-years-old children and 7 Gy for adults. In 35 settlements of contamination zone II the geometric mean of the thyroid equivalent doses was 2.0 Gy for 5-years-old children with a geometric standard deviation (GSD) of 3.0. For adults the geometric mean was 0.47 Gy also with a GSD of 3.0. In more than 25 settlements of contamination zone III the geometric means were 0.82 Gy for 5-years old children with a GSD of 1.8 and 0.21 Gy for adults (GSD 1.8). For 45 settlements, the results of the retrospective dosimetry could be compared with thyroid equivalent doses calculated using time-integrated (131)I activities of thyroids which were measured in 1986. Thus, a critical evaluation of the results was possible which demonstrated the general feasibility of the method, but also the associated uncertainties and limitations. PMID:26254721

  14. Proceedings of the V. international symposium 'Actual problems of dosimetry'

    The main topics of the workshop were: monitoring and reconstruction of radiation doses at radiation accidents, biological dosimetry and markers of radiation effects as well as normative, metrological and technical aspects of dosimetric and radiometric monitoring

  15. Proceedings of the IV International Symposium 'Actual Problems of Dosimetry'

    The main topic of the workshop were: monitoring and reconstruction of radiation doses at radiation accidents, biological dosimetry and markers of radiation effects as well as normative, metrological and technical aspects of dosimetric and radiometric monitoring

  16. Four decades of thermoluminescence dosimetry research in India

    Last four decades have witnessed tremendous progress in the field of thermo-luminescence dosimetry. During this period development of new and sensitive TL phosphors was reported. Application of these phosphors was exploited in different fields, such as personnel and environmental monitoring, accident and retrospective dosimetry, high dose dosimetry, archaeological and geological dating. Commensurate with these developments, progress in TL instrumentation also took place. This paper reviews some of these developments in the last four decades in India. (author)

  17. Optically stimulated luminescence in retrospective dosimetry

    Bøtter-Jensen, L.; Murray, A.S.

    2002-01-01

    Since the beginning of the 1990s the exploration of optically stimulated luminescence (OSL) in retrospective accident dosimetry has driven an intensive investigation and development programme at Riso into measurement facilities and techniques. This paper reviews some of the outcomes of this progr......Since the beginning of the 1990s the exploration of optically stimulated luminescence (OSL) in retrospective accident dosimetry has driven an intensive investigation and development programme at Riso into measurement facilities and techniques. This paper reviews some of the outcomes...

  18. Simulation of experiment on aerosol behaviour at severe accident conditions in the LACE experimental facility with the ASTEC CPA code

    The experiment LACE LA4 on thermal-hydraulics and aerosol behavior in a nuclear power plant containment, which was performed in the LACE experimental facility, was simulated with the ASTEC CPA module of the severe accident computer code ASTEC V1.2. The specific purpose of the work was to assess the capability of the module (code) to simulate thermal-hydraulic conditions and aerosol behavior in the containment of a light-water-reactor nuclear power plant at severe accident conditions. The test was simulated with boundary conditions, described in the experiment report. Results of thermal-hydraulic conditions in the test vessel, as well as dry aerosol concentrations in the test vessel atmosphere, are compared to experimental results and analyzed. (author)

  19. Neutron dosimetry for the MOTA-1F experiment in FFTF (Fast Flux Test Facility)

    Greenwood, L.R.; Kellogg, L.S.

    1990-11-01

    Neutron fluence and spectral measurements are reported for the MOTA-1F experiment in the Fast Flux Test Facility (FFTF). The irradiation was conducted from November 18, 1987, to January 8, 1989, for a total exposure of 335.4 EFPD. The maximum fluence was 12.7 {times} 10{sup 22} n/cm{sup 2}, 9.56 {times} 10{sup 22} above 0.1 MeV producing 39.1 dpa in iron. Neutron energy spectra were adjusted at three positions and gradients were measured at nine other locations.

  20. An exploration of nurses experience of alcohol related violence and caring for intoxicated patients in Accident and Emergency

    Locker, Emily

    2008-01-01

    This study aims to explore the violence that Accident and Emergency nurses encounter. Current literature and health policies emphasis the seriousness and prevalence of violent attacks on nurses in A&E. There is also a push towards a new Government agenda based on Zero-tolerance. The study adopted a qualitative approach using semi-structured interviews. It contained six participants who were asked about their experiences of violence encountered in the A&E department. They were also asked to lo...

  1. Experience of a specialised centre in the organisation of medical care of persons exposed during a nuclear reactor accident

    Following the Chernobyl accident, selection for emergency hospitalisation, from among the exposed persons, those in whom the development of acute radiation disease (ARD) was predicted with the highest degree of probability was made within 36 h. This selection was based on the criteria for early diagnosis adopted in the USSR: time and manifestations of primary and local reactions, expression of lymphopenia and neutrophilic leukocytosis. This note outlines the experiences with 129 patients at the Moscow Centre. (author)

  2. Iterative ensemble Kalman filter for atmospheric dispersion in nuclear accidents: An application to Kincaid tracer experiment

    Zhang, X.L.; Su, G.F.; Chen, J.G. [Institute of Public Safety Research, Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); Raskob, W. [Institute for Nuclear and Energy Technologies, Karlsruhe Institute of Technology, Karlsruhe, D-76021 (Germany); Yuan, H.Y., E-mail: hy-yuan@outlook.com [Institute of Public Safety Research, Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); Huang, Q.Y. [Institute of Public Safety Research, Department of Engineering Physics, Tsinghua University, Beijing 100084 (China)

    2015-10-30

    Highlights: • We integrate the iterative EnKF method into the POLYPHEMUS platform. • We thoroughly evaluate the data assimilation system against the Kincaid dataset. • The data assimilation system substantially improves the model predictions. • More than 60% of the retrieved emissions are within a factor two of actual values. • The results reveal that the boundary layer height is the key influential factor. - Abstract: Information about atmospheric dispersion of radionuclides is vitally important for planning effective countermeasures during nuclear accidents. Results of dispersion models have high spatial and temporal resolutions, but they are not accurate enough due to the uncertain source term and the errors in meteorological data. Environmental measurements are more reliable, but they are scarce and unable to give forecasts. In this study, our newly proposed iterative ensemble Kalman filter (EnKF) data assimilation scheme is used to combine model results and environmental measurements. The system is thoroughly validated against the observations in the Kincaid tracer experiment. The initial first-guess emissions are assumed to be six magnitudes underestimated. The iterative EnKF system rapidly corrects the errors in the emission rate and wind data, thereby significantly improving the model results (>80% reduction of the normalized mean square error, r = 0.71). Sensitivity tests are conducted to investigate the influence of meteorological parameters. The results indicate that the system is sensitive to boundary layer height. When the heights from the numerical weather prediction model are used, only 62.5% of reconstructed emission rates are within a factor two of the actual emissions. This increases to 87.5% when the heights derived from the on-site observations are used.

  3. Experience in training of health personnel for response to radiological and nuclear accidents

    Eletronuclear Healthcare Foundation is the Institution responsible for the actions of health response involving ionizing radiation in the area of Nuclear Power Plant Almirante Alvaro Alberto in Angra dos Reis. Because of their specific assignments and references for being in training health manpower in the field of ionizing radiation developed a range of Training Courses for Professionals Area Health to prepare them for Response to Radiological and Nuclear Accidents. Modules are proposed specifically for the professional response of the Technical Level and Higher Level, the level Pre-hospital and hospital. These modules are further divided into specific levels or modules, Basic or Introductory, Intermediate and Advanced. Are applied pretests and post tests to monitor the content of fixing, maintaining a historical series of reviews. Your content is theoretical and practical applications developed in 30 to 48 hours, with simulations (drills) and distribution of educational materials. We already have more than 80 applications training, focusing on internal staff and external to the institution, developing interesting partner with the Armed Forces and Civil Defense. It still maintained a link on the institution seeking access and download over 400 titles on the subject and exchange of information and experiences. For improving the teaching material, the authors launched in 2011 the first manual in Portuguese on the subject with new revised edition in 2013: 'Manual of Medical Actions In Radiological Emergencies'. The results indicate increased knowledge and appropriateness of the themes and the strategy proposed for this activity, demonstrating yet passed that information can be multiplied and meets the growing demand of the country that has hosted and will host international events relevant at QBNRE risk. (author)

  4. Iterative ensemble Kalman filter for atmospheric dispersion in nuclear accidents: An application to Kincaid tracer experiment

    Highlights: • We integrate the iterative EnKF method into the POLYPHEMUS platform. • We thoroughly evaluate the data assimilation system against the Kincaid dataset. • The data assimilation system substantially improves the model predictions. • More than 60% of the retrieved emissions are within a factor two of actual values. • The results reveal that the boundary layer height is the key influential factor. - Abstract: Information about atmospheric dispersion of radionuclides is vitally important for planning effective countermeasures during nuclear accidents. Results of dispersion models have high spatial and temporal resolutions, but they are not accurate enough due to the uncertain source term and the errors in meteorological data. Environmental measurements are more reliable, but they are scarce and unable to give forecasts. In this study, our newly proposed iterative ensemble Kalman filter (EnKF) data assimilation scheme is used to combine model results and environmental measurements. The system is thoroughly validated against the observations in the Kincaid tracer experiment. The initial first-guess emissions are assumed to be six magnitudes underestimated. The iterative EnKF system rapidly corrects the errors in the emission rate and wind data, thereby significantly improving the model results (>80% reduction of the normalized mean square error, r = 0.71). Sensitivity tests are conducted to investigate the influence of meteorological parameters. The results indicate that the system is sensitive to boundary layer height. When the heights from the numerical weather prediction model are used, only 62.5% of reconstructed emission rates are within a factor two of the actual emissions. This increases to 87.5% when the heights derived from the on-site observations are used

  5. Dosimetry experiences and lessons learned for radiation dose assessment in Korean nuclear power plants.

    Choi, Jong Rak; Kim, Hee Geun; Kong, Tae Young; Son, Jung Kwon

    2013-07-01

    Since the first Korean nuclear power plant (NPP), Kori 1, commenced operation in 1978, a total of 21 NPPs had been put into operation in Korea by the end of 2011. Radiation doses of NPP workers have been periodically evaluated and controlled within the prescribed dose limit. Radiation dose assessment is carried out monthly by reading personal dosemeters for external radiation exposure, which have traceability in compliance with strict technical guidelines. In the case of the internal radiation exposure, workers who have access to the possible area of polluted air are also evaluated for their internal dose after maintenance task. In this article, the overall situation and experience for the assessment and distribution of radiation doses in Korean NPPs is described. PMID:23204558

  6. Experience with E-beam process dosimetry at the Whiteshell irradiator

    Currently a quality assurance (QA) programme at the Whiteshell Irradiator is being established, designed to encompass the Good Manufacturing Practices regulations of the US Food and Drug Administration. The paper reports on preliminary experiences in implementing this programme. Robust devices are being developed that can measure on-line electron energy and current density by intercepting the electron beam. These measurements, combined with continuous automated recording of the operating parameters of the Whiteshell industrial electron accelerator I-10/1 (10 MeV, 1 kW) throughout the entire radiation process cycle, provide a high degree of assurance that all the product units receive the correct dose. Also, daily measurements of absorbed dose and electron energy with a standard irradiation geometry are used to demonstrate that the irradiator performance remains under control over long time of periods. To hold the surface dose constant during a production run, the speed of the conveyor in the beam path is slaved to the beam current to counteract fluctuations in the beam current. Dosimeters are presently calibrated in a Gamma-Cell 220 60Co irradiator manufactured by Nordion International, Canada. However, a graphite calorimeter is being developed as an in-house reverence standard for use in calibrating routine dosimeters in electron fields. Several types of products have been qualified at Whiteshell for processing with 10 MeV electrons: medical disposables, Petri dishes, sample bottles, and rubber/metal laminates. On occasion, substantiating dose-mapping results with computer modelling has been found to be helpful in qualifying the process. Experience at the Whiteshell Irradiator suggests that an effective QA programme is very relevant to radiation processing and must be an integral part of each electron radiation facility. (author). 4 refs, 4 figs

  7. 134Cs and 137Cs whole-body measurements and internal dosimetry of the population living in areas contaminated by radioactivity after the Chernobyl accident

    Six western districts of the Bryansk region, Russia, were heavily contaminated with radioactive fallout after the Chernobyl NPP accident. Annually, between 1991 and 1994, inhabitants of four settlements were studied. Whole-body 134+137Cs contents were measured in about 500 inhabitants. No correlation between Cs whole-body content and Cs soil contamination was found; Cs accumulation in a body depends greatly on natural factors such as type of soil, on social factors such as food habits including consumption of forest products, and on countermeasures to reduce internal exposure. During 1991-1994 average whole-body content of 134+137Cs in adult inhabitants was about 3-60 kBq, corresponding to an effective dose of 0.1-2.4 mSv.y-1. Cs whole-body content increases equally for girls and boys up to adult age. Cs content in adults does not depend significantly on age and is usually 1.2-2 times higher in men than in women. The average annual internal effective dose varies with age significantly less than 134+137Cs whole-body content. In children (0-5 years) the mean absorbed dose is usually 1.2-1.5 times less than in adults. (author)

  8. Analysis of gamma-ray dosimetry experiments in the zero power MINERVE facility

    The objective of this study is to develop nuclear heating measurement methods in zero power experimental reactors. These developments contribute to the qualification of photonics calculation schemes for the assessment of gamma heating in the future Jules Horowitz Material Testing Reactor. This paper presents the analysis of thermoluminescent detector (TLD) experiments in the UO2 core of the MINERVE Research Reactor at the French Alternative Energies and Atomic Energy Commission center in Cadarache. The experimental sources of uncertainty in the gamma dose have been reduced by improving the measurement conditions and the repeatability of the calibration step for each individual TLD. The interpretation of these measurements needs to take into account the calculation of cavity correction factors related to calibration and irradiation configurations, as well as neutron correction calculations. These calculations are based on Monte Carlo simulations of neutron-gamma and gamma-electron transport coupled particles. The comparison between calculated and measured integral gamma-ray absorbed doses in the aluminum material surrounding the TLD shows that calculations slightly overestimate the measurement, with a calculated versus experimental ratio equal to 1.04 ± 5.7 % (k=2). (authors)

  9. Analysis of gamma-ray dosimetry experiments in the zero power MINERVE facility

    Amharrak, H.; Di Salvo, J.; Lyoussi, A.; Roche, A.; Masson-Fauchier, M.; Bosq, J. C. [CEA, DEN, DER, F-13108 Saint-Paul-lez-Durance (France); Carette, M. [Aix-Marseille Univ., LCP UMR 6264, 13397, Marseille (France)

    2011-07-01

    The objective of this study is to develop nuclear heating measurement methods in zero power experimental reactors. These developments contribute to the qualification of photonics calculation schemes for the assessment of gamma heating in the future Jules Horowitz Material Testing Reactor. This paper presents the analysis of thermoluminescent detector (TLD) experiments in the UO{sub 2} core of the MINERVE Research Reactor at the French Alternative Energies and Atomic Energy Commission center in Cadarache. The experimental sources of uncertainty in the gamma dose have been reduced by improving the measurement conditions and the repeatability of the calibration step for each individual TLD. The interpretation of these measurements needs to take into account the calculation of cavity correction factors related to calibration and irradiation configurations, as well as neutron correction calculations. These calculations are based on Monte Carlo simulations of neutron-gamma and gamma-electron transport coupled particles. The comparison between calculated and measured integral gamma-ray absorbed doses in the aluminum material surrounding the TLD shows that calculations slightly overestimate the measurement, with a calculated versus experimental ratio equal to 1.04 {+-} 5.7 % (k=2). (authors)

  10. Accreditation of a personal dosimetry service in Switzerland: Practical experience and transition from EN 45004 to ISO 17025

    In compliance with the Swiss legislation on radiological protection, the Paul Scherrer Institute (PSI) operates a dosimetry service that is approved by the Swiss Federal Nuclear Safety Inspectorate. In 1997, the dosimetry service was also accredited by the Swiss Federal Office of Metrology and Accreditation as an inspection body for legal personal and environmental dosimetry, according to EN 45004. The accreditation covers determination of personal dose equivalent for photon, neutron and beta radiation, and ambient dose equivalent for photon and neutron radiation, by means of thermoluminescence and solid state track detection techniques. Within this formal accreditation it was confirmed that the relevant requirements of ISO 9002 are also fulfilled. The first re-accreditation will take place in 2001 and work is going on to achieve the transition from EN 45004 to ISO 17025. Accreditation is a feasible, practicable and acceptable way to achieve harmonisation in the field of dosimetry. However, before starting on the path to formal accreditation, a careful analysis should be made, taking into consideration not only cost-benefit aspects but also national legal requirements. (author)

  11. Experiences in the continuous improvement of quality assurance of the dosimetry services of SLDC-MD-ININ

    From 2003 the Secondary Laboratory of Dosimetric Calibration (SLDC) of Metrology Department of Ionizing Radiations (MD), has complemented the Quality Manual of National Institute of Nuclear Research (ININ) according to the standard ISO 9001: 2000. However, due to that the National Center of Metrology of Mexico delegates its functions in the dosimetry and activity area for the field of the ionizing radiations to the ININ: one of the requirements so that the ININ has been designated as -Declared Institute- before the International Office of Weights and Measurements, it is to demonstrate before the Inter-American System of Metrology that the quality system of the SLDC fulfills the standard ISO/IEC 17025: 2005, satisfied this requirement the Inter-American System of Metrology in their meeting of evaluation of quality systems, Ottawa (2007) grants a certification document to the SLDC that guarantees their capacities of calibration measurements for dosimetry services. Concretely, inside the standard activities ISO 9000 with respect to the point 8 on measurement, analysis and improvement the Management of Quality Assurance of ININ carries out at year two interns auditing and every month is given continuation to the non conformities detected in the procedures that support the services of the SLDC for dosimetry with purposes of radiological protection and clinical dosimetry. (Author)

  12. Dosimetry standards

    The following leaflets are contained in this folder concerning the National Physical Laboratory's measurement services available in relation to dosimetry standards: Primary standards of X-ray exposure and X-ray irradiation facilities, X-ray dosimetry at therapy levels, Protection-level X-ray calibrations, Therapy-level gamma-ray facility, Fricke dosemeter reference service, Low-dose-rate gamma-ray facility, Penetrameter and kV meter calibration, Measurement services for radiation processing, Dichromate dosemeter reference service, Electron linear accelerator. (U.K.)

  13. Experiment on Density Gradient Driven Flow in Small Break Air Ingress Accident of VHTRs

    This study measures amount of air-ingress rates through a small hole in a circular pipe for various break conditions. The main parameters considered are break orientation, break size, main flow velocity, and density ratio. The main objectives are summarized below: □ Understanding on fundamental air-ingress phenomena in the small break accident □ Development of flow regime map for the small break air-ingress □ Development of air-ingress model for VHTR safety analysis code. A Very High Temperature Reactor (VHTR) is one of the six Gen-IV reactor concepts which is adapting carbon layered TRISO-fuel, graphite-moderator, and helium-coolant. In spite of its inherent safety concept, the VHTR could be detrimental if a LOCA type accident occurs, which is followed by a pipe break. After the break, the air in the cavity starts to ingress into the reactor by either local density-gradient driven flow or molecular diffusion. The main concern of this accident is that it could eventually lead to structural degradation or release of the toxic and explosive gasses (CO) by oxidation of graphite. Previously, majority of the air-ingress studies have been focused on the large size break accident, which is called a double-ended-guillotine-break (DEGB). However, in this study, more focus in put on the small break (or leakage) accident, which is more realistic and probable in the VHTRs. According to the previous studies, the phenomena in the small break accident appear to be much more complicated than those in the DEGB, but little studies have been conducted and reported so far

  14. Experience in therapy of persons affected at the Chernobyl accident and direct outcomes of disease

    The paper is concerned with the results of therapy of 115 patients with acute radiation syndrome after the Chernobyl accident. The chief methods of the effective therapy of bone marrow syndrome are antimicrobial drugs and fresh donor platelet mass transfusions. Homopoietic stem cell transplantation (allogenetic bone marrow or embryonic hepatocytes) is indicated and effective in a very limited number of patients in accident irradiation. Severe β-burns of the skin remain an unsolved problem as a result of their spreading. Organizational principles of therapy of a great number of patients with acute radiation syndrome in a specialized hospital were described

  15. Accidental neutron dosimetry with human hair

    Human hair contains sulfur, which can be activated by fast neutrons. The 32S(n,p)32P reaction with a threshold of 2.5 MeV was used for fast neutron dose estimation. It is a very important parameter for individual dose reconstruction with regards to the heterogeneity of the neutron transfer to the human body. Samples of human hair were irradiated in a radial channel of a training reactor VR-1. 32P activity in hair was measured both, directly by means of a proportional counter, and as ash dispersed in a liquid scintillator. Based on neutron spectrum estimation, a relationship between the neutron dose and induced activity was derived. The experiment verified the practical feasibility of this dosimetry method in cases of criticality accidents or malevolent acts with nuclear materials. - Highlights: • Human hair contains sulfur. • Reaction 32S(n,p)32P can be used for dosimetry of fast neutrons. • Relation between 32P activity and neutron dose can be derived for a specific neutron spectrum

  16. Strategy for the restoration of rural settlements in Belarus contaminated as a result of the Chernobyl accident. Problems and experience

    The experience of the protective actions taken in Belarus in the wake of the Chernobyl nuclear power plant accident can provide useful insights for specialists who are considering strategies for restoring areas contaminated with radionuclides. Data on the protective actions performed in Belarus after this accident are presented briefly, and the efficiency assessment used for the resettlement of certain categories of population is discussed, The levels allowed by the state for radioactive contamination in food and the averted doses are reviewed. The current number of contaminated settlements and their population are given. Particulars concerning the nature of the doses and the differences in their formation for the urban and rural populations are examined. Existing criteria for decision making, radiological and non-radiological factors which affect the decision making processes are explained. The experience in Belarus after the Chernobyl accident shows that the decision making process for remediation actions must consider both radiological and non-radiological factors. Moreover, as the annual dose tends to approach established limits over time, non-radiological factors start to play a more important role in the decision making process. (author)

  17. Radiotherapy quality insurance by individualized in vivo dosimetry: state of the art

    The quality insurance in radiotherapy in the frame of highly complex technical process as Intensity modulated radiotherapy (I.M.R.T.) needs independent control of the delivered dose to the patient. Actually, up to now, most of the radiotherapy treatments rely only on computed dosimetry through a rather complicated series of linked simulation tool. This dosimetry approach requires also qualified treatment means based on cautious quality insurance procedures. However, erroneous parameters could be difficult to detect and systematical errors could happen leading to radiotherapy accidents. In this context, in vivo dosimetry has a critical role of final control of the delivered dose. As many beam incidences and ports are used for any photon therapy treatment, external control could be very tedious and time consuming. Therefore, innovations are needed for in vivo dosimetry to provide ergonomic and efficient tools for these controls. This paper presents a review of technologies and products that can be used for in vivo dosimetry. It proposes also a reflection on the concepts to develop future devices suitable for this purpose. The technical means with their physical principles are reviewed, the clinical experiences demonstrating the feasibility of new techniques are then summarized and finally, the early clinical use and its impact on clinical practice is review. (authors)

  18. The Sheffield experiment: the effects of centralising accident and emergency services in a large urban setting

    Simpson, A; Wardrope, J.; Burke, D

    2001-01-01

    Objectives—To assess the effects of centralisation of accident and emergency (A&E) services in a large urban setting. The end points were the quality of patient care judged by time to see a doctor or nurse practitioner, time to admission and the cost of the A&E service as a whole.

  19. Experience of domestic violence by women attending an inner city accident and emergency department

    Sethi, D; Watts, S.; Zwi, A.; Watson, J; McCarthy, C.

    2004-01-01

    Objectives: To identify the prevalence of domestic violence (DV) (defined as physical abuse perpetrated by intimate partners) in women attending an inner city accident and emergency department and to elicit women's response about being asked routinely about domestic violence in this setting.

  20. Intervention during late phase of the Chernobyl accident in Belarus: Gained experience and future strategy

    Various measures, introduced to reduce external and internal radiation doses of inhabitants of territories contaminated by the Chernobyl accident, are described. Average annual doses are given. It is concluded that while factors such as reduction of psychoemotional tension need to be explored, risk coefficients for chronic exposure at low doses should be specified. (author)

  1. Dosimetry Service

    2005-01-01

    The Dosimetry Service will be closed every afternoon the week of 21st to 25th February 2005. The opening hours will be from 8.30 am to 12.00 midday. Don't forget to read your dosimeter, as regular read-outs are indispensable to ensure periodic monitoring of personal doses. Thank you for you cooperation.

  2. Water simulation experiments on the instantaneous source term of a severe breeder reactor accident

    FAUST is an experimental program to give contributions to the assessment of the instantaneous source term in case of an LMFBR loss-of-flow accident with expanding fuel or sodium vapor. In the FAUST 1a-series, experiments with discharge of a gas-particle mixture (nitrogen from 0.3 to 2.0 MPa with iron or nickel powder of different particle size) from a 1.45 liter source into a water pool cylinder of 28.8 cm diameter and 1 m height by rupture disks were performed at different pool height (0.90 cm). The system was closed, i.e. no openings were provided in the cover plate. Important measuring instruments were high-speed cameras, pressure transducers and magnets for article trapping in the cover gas. The most important quantity to be determined was the retention factor RF, defined as the ratio of the amount of particles discharged to the amount trapped in the cover gas. Furthermore, the expansion characteristics of the bubble, the correlated cover gas phenomena, the oscillation period and the entrainment were considered. In most cases, particle release stayed below detection limit, which corresponds to RF > 104. For the 1B series, using the same source, a larger pool vessel (63 cm diameter, 60 cm height) was installed and a cover plate with two openings of 4 cm diameter to simulate leaks. The discharge pressure was varied from 0.002 to 4 MPa. Other experimental parameters were pool height (0.50 cm), particles size (1 to 100 μm), and leak size. A release of airborne particles was found only at very low discharge pressure. At high pressure, major amounts of water were released, whereas the release of particles remained below detection limit (retention factor > 104). The oscillation period was of the order of 80 msec for 1A and 50 msec for 1B. Approximative calculations have shown that the large particle absorption may be explained by impaction during the bubble oscillations. (orig.)

  3. Methods and procedures for external radiation dosimetry at ORNL

    Procedures, methods, materials, records, and reports used for accomplishing the personnel, external radiation monitoring program at Oak Ridge National Laboratory are described for the purpose of documenting what is done now for future reference. This document provides a description of the methods and procedures for external radiation metering, monitoring, dosimetry, and records which are in effect at ORNL July 1, 1981. This document does not include procedures for nuclear accident dosimetry except insofar as routine techniques may apply also to nuclear accident dosimetry capability

  4. Determining the radiation load of the human body during a space flight. Participation of ''radiation protection and dosimetry'' laboratory in the international space experiment ''dose-integral''

    In order to determine the radiation load of the human body during a space flight and to examine the dosimetric characterisrics of the radiation fields, on the cosmic station ''Salut'' the international experiment ''Dose'' was planned within the Intercosmos programme. At the present stage of experiment different dosimetric systems are exhibited on board the station ''Salut-6'' for long time intervals. In the ''Dose'' experiment, the laboratory ''Radiation protection and dosimetry'' at the Research Institute of Rentgenology and Radiobiology assembly containing two types of dosimeters - film and thermoluminescent. The preliminary data from the processing of the results from the experiment show that the mean equivalent day and night radiation dose on board the cosmic station ranges between 0.15 - 0.20 milli Siverts. (authors)

  5. Experience in the analysis of accidents and incidents involving the transport of radioactive materials

    Some half a million packages containing radioactive materials are transported to, from and within the UK annually. Accidents and incidents involving these shipments are rare. However, there is always the potential for such an event, which could lead to a release of the contents of a package or an increase in radiation level caused by damaged shielding. These events could result in radiological consequences for transport workers. As transport occurs in the public environment, such events could also lead to radiation exposures of members of the public. The UK Department for Transport (DfT), together with the Health and Safety Executive (HSE) have supported, for almost 20 years, work to compile, analyse and report on accidents and incidents that occur during the transport of radioactive materials. Annual reports on these events have been produced for twelve years. The details of these events are recorded in the Radioactive Materials Transport Event Database (RAMTED) maintained by the National Radiological Protection Board on behalf of the DfT and HSE. Information on accidents and incidents dates back to 1958. RAMTED currently includes information of 708 accidents and incidents, covering the period 1958 to 2000. This paper presents a summary of the data covering this period, identifying trends and lessons learned together with a discussion of some examples. It was found that, historically, the most significant exposures were received as a result of accidents involving the transport of industrial radiography sources. However, the frequency and severity of these events has decreased considerably in the later years of this study due to improvements in training, awareness and equipment. The International Atomic Energy Agency and the Nuclear Energy Agency, have established the international nuclear event scale (INES), which is described in detail in a users' guide. The INES has been revised to fully include transport events, and the information in RAMTED has been reviewed

  6. Accident consequence assessment code development

    This paper describes the new computer code system, OSCAAR developed for off-site consequence assessment of a potential nuclear accident. OSCAAR consists of several modules which have modeling capabilities in atmospheric transport, foodchain transport, dosimetry, emergency response and radiological health effects. The major modules of the consequence assessment code are described, highlighting the validation and verification of the models. (author)

  7. Reassessment of fuel failure behavior in the SPERT and PBF experiments for irradiated fuel rods under reactivity initiated accident conditions

    The current safety guideline for the evaluation of postulated reactivity initiated events in light water reactors was established by the Nuclear Safety Commission in January, 1984 on the basis of the experimental results from the NSRR program using fresh fuels. As for the burnup effects on fuel failure, the results of the previous American SPERT-CDC experiments were considered in the guideline. However, failure threshold and failure mechanism for preirradiated fuel rods were not established because only a few irradiated fuel rods were tested. Experiments with preirradiated fuel rods are now in progress as the next major research items in the NSRR program. This paper presents behavior of fuel failure for irradiated fuel rods under reactivity initiated accident conditions. Results from the previous SPERT and PBF experiments which should be compared with the experiments of the NSRR program are reviewed. The modes of fuel failure in the SPERT and PBF experiments were different from those in the experiments with fresh fuels. Cladding rupture and PCMI failure came out in the SPERT experiments, Cladding rupture in the SPERT experiments might be related to a FP gas release during both preirradiation and power burst. The rod with burnup of 31,800 MWd/t and total energy of 190 cal/g·UO2 in the SPERT experiments failed at low energy deposition (85 cal/g·UO2) with PCMI. The observed cracks appeared to be brittle fractures along the whole active length of the rod. The failure of this ROd was probably related to the cladding embrittlement by the excessive corrosion during preirradiation. Moreover, relationship between supposed failure mechanisms and influencing factor for generally irradiated fuel rod under reactivity initiated accident conditions is discussed. (author)

  8. Dosimetry at a 400 keV accelerator

    Miller, A.

    1992-01-01

    Absolute calorimetric dosimetry and relative dose mapping methods are described for a 400 keV electron accelerator used for polymer curing and crosslinking experiments. These methods of dosimetry are also useful at accelerators used in gas cleaning processes.......Absolute calorimetric dosimetry and relative dose mapping methods are described for a 400 keV electron accelerator used for polymer curing and crosslinking experiments. These methods of dosimetry are also useful at accelerators used in gas cleaning processes....

  9. Hot-particle dosimetry recommendations and associated problems

    Hot-particle issues have been in current focus since the Three Mile Island Unit 2 (TMI-2) accident dosimetry highlighted the basic problems. The 1979 Report to the President's Commission on the Accident at TMI discussed beta dosimetry problems in the health physics sections. Both the U.S. Nuclear Regulatory Commission's (NRC's) Rogovin Report on TMI as well as the health physics blue ribbon committee report discussed beta dosimetry problems. Participants in a U.S. Department of Energy/Environmental Measurements Laboratory (DOE-EML) Beta Dosimetry Workshop recommended an International Beta Dosimetry Symposium, which was held in 1983, sponsored by DOE, NRC, and the Health Physics Society. The conclusions drawn from this symposium are discussed. History and present status of related regulations are presented

  10. Dosimetry on the radiological risks prevention in radiotherapy

    Dosimetry in its various forms plays a determining role on the radiological risks prevention in radiotherapy. To prove this in this paper is shown an analysis based on the risk matrix method, how the dosimetry can influence in each stages of a radiotherapy service; installation and acceptance, operation, maintenance and calibration. For each one of these stages the role that can play is analyzed as either the initiating event of a radiological accident or limiting barrier of these events of the dosimetric processes used for the individual dosimetry, the area monitoring, fixed or portable, for radiation beam dosimetry and of the patients for a radiotherapy service with cobalt-therapy equipment. The result of the study shows that the application of a prospective approach in the role evaluation of dosimetry in the prevention and mitigation of the consequences of a radiological accident in radiotherapy is crucial and should be subject to permanent evaluation at each development stage of these services. (author)

  11. Post-test analysis of two accident management experiments performed at the BETHSY test facility using the code ATHLET

    In the framework of the external validation of the thermal-hydraulic code ATHLET, which has been developed by the GRS, post test analyses of two experiments were done, which were performed at the french integral test facility BETHSY. During the experiment 5.2 C the complete loss of steam generator feedwater was simulated. The de-pressurization of the primary circuit and high pressure injection is assumed as an emergency measure. During the experiment 9.3 the break of a steam generator U-tube is simulated. The failure of the high pressure injection is assumed. As accident management measures, the depressurization of the steam generator secondary sides and finally of the primary circuit by opening of the pressurizer valve were investigated. The results show, that the code ATHLET is able to describe the complex scenario in good accordance with the experiment. For both tests the safety related statement could be reproduced. (author)

  12. Optically stimulated luminescence in retrospective dosimetry

    Bøtter-Jensen, L.; Murray, A.S.

    Since the beginning of the 1990s the exploration of optically stimulated luminescence (OSL) in retrospective accident dosimetry has driven an intensive investigation and development programme at Riso into measurement facilities and techniques. This paper reviews some of the outcomes of this...

  13. Optically stimulated luminescence techniques in retrospective dosimetry

    Bøtter-Jensen, L.; Murray, A.S.

    2001-01-01

    Optically stimulated luminescence signals from natural quartz and feldspar are now used routinely in dating geological and archaeological materials. More recently they have also been employed in accident dosimetry, i.e. the retrospective assessment of doses received as a result of a nuclear...

  14. Environmental consequences of the Chernobyl accident and their remediation: Twenty years of experience

    The explosion on 26 April 1986 at the Chernobyl Nuclear Power Plant located just 100 km from the city of Kyiv in what was then the Soviet Union and now is Ukraine, and consequent ten days' reactor fire resulted in an unprecedented release of radiation and unpredicted adverse consequences both for the public and the environment. Indeed, the IAEA has characterized the event as the 'foremost nuclear catastrophe in human history' and the largest regional release of radionuclides into the atmosphere. Massive radioactive contamination forced the evacuation of more than 100,000 people from the affected region during 1986, and the relocation, after 1986, of another 200,000 from Belarus, the Russian Federation and Ukraine. Some five million people continue to live in areas contaminated by the accident and have to deal with its environmental, health, social and economic consequences. The national governments of the three affected countries, supported by international organizations, have undertaken costly efforts to remedy contamination, provide medical services and restore the region's social and economic well-being. The accident's consequences were not limited to the territories of Belarus, Russia and Ukraine but resulted in substantial transboundary atmospheric transfer and subsequent contamination of numerous European countries that also encountered problems of radiation protection of their populations, although to less extent than the three more affected countries. Although the accident occurred nearly two decades ago, controversy still surrounds the impact of the nuclear disaster. Therefore the IAEA, in cooperation with FAO, UNDP, UNEP, UNOCHA, UNSCEAR, WHO and The World Bank, as well as the competent authorities of Belarus, the Russian Federation and Ukraine, established the Chernobyl Forum in 2003. The mission of the Forum was - through a series of managerial and expert meetings to generate 'authoritative consensual statements' on the environmental consequences and

  15. Radioactive material transportation accident and incident experiences in the USA (1971-1997)

    The Radioactive Incident Report (RMIR) database was developed in 1981 at the Transportation Technology Center of Sandia National Laboratories to support its research and development activities for the U.S. Department of Energy (DOE). This database contains information about radioactive materials transportation incidents that have occurred in the U.S. since 1971. These data were drawn from the U.S. Department of Transportation's (DOT) Hazardous Materials Incident Report system, from Nuclear Regulatory Commission (NRC) files, and from various agencies including state radiological control offices. Transportation events in RMIR are classified in one of the following ways: as a transportation accident, as a handling accident, or as a reported incident. This presentation provides definitions for these classifications and gives examples of each. (authors)

  16. Neutron personnel dosimetry

    The current state-of-the-art in neutron personnel dosimetry is reviewed. Topics covered include dosimetry needs and alternatives, current dosimetry approaches, personnel monitoring devices, calibration strategies, and future developments

  17. Rehabilitation process experience after a cerebral vascular accident: a qualitative study

    Joselany Áfio Caetano; Marta Maria Coelho Damasceno; Enedina Soares; Ana Virgínia de Melo Fialho

    2007-01-01

    We tried to learn the process of cerebrovascular accident holders’ rehabilitation and identify factors that make this process difficult. Twelve individuals living in the city of Sobral-Ce participated in this study. Data were collected by means of consultations to medical registers and semi-structured interviews, carried out in residences, along the months of October and November, 2004. The statements highlighted that the rehabilitation process is permeated by financial difficulties, by lack ...

  18. Biological dosimetry - Dose estimation method using biomakers

    The individual radiation dose estimation is an important step in the radiation risk assessment. In case of radiation incident or radiation accident, sometime, physical dosimetry method can not be used for calculating the individual radiation dose, the other complement method such as biological dosimetry is very necessary. This method is based on the quantitative specific biomarkers induced by ionizing radiation, such as dicentric chromosomes, translocations, micronuclei... in human peripheral blood lymphocytes. The basis of the biological dosimetry method is the close relationship between the biomarkers and absorbed dose or dose rate; the effects of in vitro and in vivo are similar, so it is able to generate the calibration dose-effect curve in vitro for in vivo assessment. Possibilities and perspectives for performing biological dosimetry method in radiation protection area are presented in this report. (author)

  19. Emerging technological bases for retrospective dosimetry.

    Straume, T; Anspaugh, L R; Haskell, E H; Lucas, J N; Marchetti, A A; Likhtarev, I A; Chumak, V V; Romanyukha, A A; Khrouch, V T; Gavrilin YuI; Minenko, V F

    1997-01-01

    In this article we discuss examples of challenging problems in retrospective dosimetry and describe some promising solutions. The ability to make measurements by accelerator mass spectrometry and luminescence techniques promises to provide improved dosimetry for regions of Belarus, Ukraine and Russian Federation contaminated by radionuclides from the Chernobyl accident. In addition, it may soon be possible to resolve the large neutron discrepancy in the dosimetry system for Hiroshima through novel measurement techniques that can be used to reconstruct the fast-neutron fluence emitted by the bomb some 51 years ago. Important advances in molecular cytogenetics and electron paramagnetic resonance measurements have produced biodosimeters that show potential in retrospective dosimetry. The most promising of these are the frequency of reciprocal translocations measured in chromosomes of blood lymphocytes using fluorescence in situ hybridization and the electron paramagnetic resonance signal in tooth enamel. PMID:9368303

  20. Dosimetry Service

    Dosimetry Service

    2005-01-01

    Please remember to read your dosimeter every month at least once and preferably during the first week. A regular read-out is indispensable in order to ensure a periodic monitoring of the personal dose. You should read your dosimeter even if you have not visited the controlled areas. If you still have the old dosimeter (film badge), please send it immediately for evaluation to us (Bdg 24 E-011). After January 2005 there will be no developing process for the old film system. Information for Contractors: Please remember also to bring the form ‘Confirm Reception of a CERN Dosimeter' signed with ‘Feuille d'enregistrement du CERN'. Without these forms the dosimeter cannot be assigned. Thank you for your cooperation. Dosimetry Service Tel 767 2155 http://cern.ch/rp-dosimetry

  1. Hematological dosimetry

    The principles of hematological dosimetry after acute or protracted whole-body irradiation are reviewed. In both cases, over-exposure is never homogeneous and the clinical consequences, viz medullary aplasia, are directly associated with the mean absorbed dose and the seriousness and location of the overexposure. The main hematological data required to assess the seriousness of exposure are the following: repeated blood analysis, blood precursor cultures, as indicators of whole-body exposure; bone marrow puncture, medullary precursor cultures and medullary scintigraphy as indicators of the importance of a local over-exposure and capacity for spontaneous repair. These paraclinical investigations, which are essential for diagnosis and dosimetry, are also used for surveillance and for the main therapeutic issues

  2. Radiation dosimetry.

    Cameron, J.

    1991-01-01

    This article summarizes the basic facts about the measurement of ionizing radiation, usually referred to as radiation dosimetry. The article defines the common radiation quantities and units; gives typical levels of natural radiation and medical exposures; and describes the most important biological effects of radiation and the methods used to measure radiation. Finally, a proposal is made for a new radiation risk unit to make radiation risks more understandable to nonspecialists.

  3. Dosimetry Service

    2004-01-01

    We wish to remind the people who are invited to the Dosimetry Service to exchange the new CERN dosimeter that the hours are from Monday to Friday 8.30 to 11.00 and 14.00 to 16.00. Do not forget to read your dosimeter. The reading should be done during the first week of every month. Thank you for your cooperation.

  4. Accidents - Chernobyl accident

    This file is devoted to the Chernobyl accident. It is divided in four parts. The first part concerns the accident itself and its technical management. The second part is relative to the radiation doses and the different contaminations. The third part reports the sanitary effects, the determinists ones and the stochastic ones. The fourth and last part relates the consequences for the other European countries with the case of France. Through the different parts a point is tackled with the measures taken after the accident by the other countries to manage an accident, the cooperation between the different countries and the groups of research and studies about the reactors safety, and also with the international medical cooperation, specially for the children, everything in relation with the Chernobyl accident. (N.C.)

  5. Mortality and cancer registration experience of the Sellafield employees known to have been involved in the 1957 Windscale accident

    The mortality and cancer morbidity experience of the 470 male Sellafield employees known to be involved in the 1957 Windscale accident is reported. All these employees are known to have been involved in dealing with the fire itself, or in the clean-up operation afterwards. The size of the study population is small, leading to predicted low power to reveal any effects, but the cohort is of interest because of the involvement of the workers in the accident. For 1957-97, using rates for England and Wales to calculate the expected numbers, the all causes standardised mortality ratio (SMR) is 100 (observed=258, expected=258.80), and the all malignant neoplasms SMR is 79 (observed=58, expected=73.12) which is not significantly different from 100. For 1971-91, the all malignant neoplasms standardised registration ratio (SRR) of 85 (observed=59, expected=69.23) is not significantly different from 100. Significant excesses of deaths from diseases of the circulatory system (SMR=121) and from ischaemic heart disease (SMR=128), and a significant deficit of deaths from cancer of the genito-urinary organs (SMR=31), were found. There were no significant differences in mortality rates between workers who had received high recorded external doses during the fire and those who had received low doses, though the power of this comparison was low. Comparison of the mortality rates of workers directly involved in the accident with workers in post, but not so involved, showed no significant differences. This study has been unable to detect any effect of the 1957 fire upon the mortality and cancer morbidity experience of those workers involved in it. (author)

  6. Medical activities at nuclear disaster. Experience in the accident of Fukushima nuclear power plant

    The Great East Japan Earthquake brought multiple disaster resulting nuclear accident at Fukushima. Existing medical system for emergency radiation exposure did not work well. Present medical system for the nuclear disaster is maintained temporary with supports by teams from regions other than Fukushima Pref. The radiation protection action must be both for the public and the medical persons. Medical activities for nuclear disaster are still in progress now. Medical system for radiation exposure should be maintained in future for works of decommissioning of reactors. Problems, however, may exist in economy and education of medical personnel. (K.Y.)

  7. Environmental consequences of the Chernobyl accident and their remediation: 20 years of experience

    The Chernobyl Forum was organized by the United Nations to examine the health and environmental effects of the accident at the Chernobyl Nuclear Power Station Unit Number 4. This paper is concerned with the environmental effects, including human exposure, as determined by the Expert Group on Environment. The accident on 26 April 1986 resulted in the release of a large amount of radioactive materials over a period of ten days. These materials were deposited throughout Europe (and to a minor extent throughout the remainder of the northern hemisphere) with the three more affected countries being Belarus, the Russian Federation and Ukraine. The more important radionuclides from a human dosimetric standpoint were 131I, 134Cs and 137Cs, with half-lives of 8 d, 2 a and 30 a, respectively. More than five million persons lived on territories in these three countries judged to be contaminated at >37 kBq/m2. Many countermeasures were employed to mitigate the effects of the accident, with the main focus being on urban and agricultural areas. The collective effective dose to the residents of the contaminated territories is estimated to be about 55 000 man Sv; the collective thyroid dose is estimated to be 1.6 x 106 man Gy. Effects on non-human biota were observed that ranged from minor to lethal; a notable effect was the killing of a pine forest near the accident site. The current increase in the number and diversity of species in the most contaminated area is due to the absence of human pressure. The current shelter over the damaged reactor was constructed under time pressure, and it has significant leakage or airborne radionuclides and inflow of rainwater. The immediate waste management practices were chaotic and remediation is needed. It is planned to build an NSC structure over the top of the existing structure and to eventually dismantle the damaged reactor. This will put additional pressure on waste management, including the need for a new site for geologic disposal of

  8. EXPERIENCE OF RADIATION-HYGIENIC MONITORING MANAGEMENT AND ASSESSMENT OF RADIATION SITUATION IN THE BRYANSK REGION TERRITORY AFTER 25 YEARS SINCE THE DAY OF THE CHERNOBYL ACCIDENT

    L. N. Trapeznikova

    2011-01-01

    Full Text Available The article briefly presents the experience of the radiation-hygienic monitoring system creation in the territory contaminated with the radionuclides due to the Chernobyl accident and application of the radiation hygienic monitoring data for the assessment of protective measures efficiency. Radiation situation data for the territory of the Bryansk region after 25 years of Chernobyl accident and dynamics of the population average annual effective exposure dose are being presented.

  9. Dosimetry methods for fuels, cladding and structural materials

    This volume of the proceedings of the symposium on reactor dosimetry covers the following topics: the metallurgy and dosimetry interface, radiation damage correlations of structural materials and damage analyses techniques, dosimetry for fusion materials, light water reactor pressure vessel surveillance in practice and irradiation experiments, fast reactor and reseach reactor characterization

  10. Post test calculations of a severe accident experiment for VVER-440 reactors by the ATHLET code

    Gyoergy, Hunor [Budapest Univ. of Technology and Economics (Hungary). Inst. of Nuclear Techniques (BME NTI); Trosztel, Istvan [Hungarian Academy of Sciences, Budapest (Hungary). Centre for Energy Research (MTA EK)

    2013-09-15

    Severe accident - if no mitigation action is taken - leads to core melt. An effective severe accident management strategy can be the external reactor pressure vessel cooling for corium localization and stabilization. For some time discussion was going on, whether the in-vessel retention can be applied for the VVER-440 type reactors. It had to be demonstrated that the available space between the reactor vessel and biological protection allows sufficient cooling to keep the melted core in the vessel, without the reactor pressure vessel losing its integrity. In order to demonstrate the feasibility of the concept an experimental facility was realized in Hungary. The facility called Cooling Effectiveness on the Reactor External Surface (CERES) is modeling the vessel external surface and the biological protection of Paks NPP. A model of the CERES facility for the ATHLET TH system code was developed. The results of the ATHLET calculation agree well with the measurements showing that the vessel cooling can be insured for a long time in a VVER-440 reactor. (orig.)

  11. Effects of sodium fires on structures and materials. Practical experience with sodium leakage accidents

    A few sodium leakage, incidents happened in SNR 300 nuclear power plant during pre-nuclear operation which were of minor importance with respect to sodium fires. The most important sodium fire accident in the past happened in the Almeria Solar platform in Spain during the attempt to repair a valve while leaving accidentally the circuit under 4 bar overpressure. Considerable damage to pipes, valves, its insulation and its support structures was observed in the influence zone of the fire. Post accident analysis gave a leaked mass of about 14 m3, at a sodium temperature of 225 deg. C, the leakage lasting approximately half an hour, and burning under convective heat exchange with the external air in a section of 40 m2 up to a height of 6 m down to the catch pans. Some local temperatures were determined by metallurgical means, integral support temperatures estimated from mechanical deformation observed. From these temperatures it was concluded that a massive spray type fire must have happened. The results fall in the interpretation range of sodium-spray fire test results. (author)

  12. A synergistic use of CFD, experiments and effective convectivity model to reduce uncertainty in BWR severe accident analysis

    In a previous work we presented an analysis approach developed to effectively and accurately assess thermal loads on vessel and structures in a Boiling Water Reactor (BWR) lower head during a severe accident. Central to the assessment is the Effective Convectivity Model (ECM) that makes use of experimental heat transfer correlations to capture the effect of turbulent natural convection in a volumetrically heated liquid pool, while retaining the pool three-dimensional energy splitting and ability to represent local heat transfer effects. Thanking to its features, the ECM is unique in enabling calculations of complex heat transfer phenomena during long severe accident transients that would not be otherwise feasible using higher-fidelity methods such as Computational Fluid Dynamics (CFD). Efficiency notwithstanding, the natural questions are: (i) how good are those ECM-calculated results, and, (ii) if required, what can be done (with the highest return-on-investment) to improve the quality of ECM prediction results. The approach refers to experiments and CFD simulations as the main resources to address (i) and (ii). However, validation of ECM against simulant-fluid experiments by itself does not reveal deficiencies (due to non-prototypicality factors). In the present work we focus on the use of CFD-based numerical 'experiments' to identify and quantify source of epistemic uncertainty in the calculated thermal loads due to modeling assumptions in ECM. Specifically, heat transfer correlations that underlie the ECM are obtained as surface-averaged (even though implemented as spatially distributed) and derived from experiments conducted at different geometries and using fluids that are not reactor prototypical (molten corium in the present case of severe accident). The CFD simulations exhibit so-called fluid Prandtl number effect on local peaking of the pool's downward heat flux for corium as working fluid. The main premise is a synergistic use of a fast-running model

  13. Electron paramagnetic resonance biophysical radiation dosimetry with tooth enamel

    This thesis deals with the advancements made in the field of Electron Paramagnetic Resonance (EPR) for biophysical dosimetry with tooth enamel for accident, emergency, and retrospective radiation dose reconstruction. A methodology has been developed to measure retrospective radiation exposures in human tooth enamel. This entails novel sample preparation procedures with minimum mechanical treatment to reduce the preparation induced uncertainties, establish optimum measurement conditions inside the EPR cavity, post-process the measured spectrum with functional simulation of dosimetric and other interfering signals, and reconstruct dose. By using this technique, retrospective gamma exposures as low as 80±30 mGy have been successfully deciphered. The notion of dose modifier was introduced in EPR biodosimetry for low dose measurements. It has been demonstrated that by using the modified zero added dose (MZAD) technique for low radiation exposures, doses in 100 mGy ranges can be easily reconstructed in teeth that were previously thought useless for EPR dosimetry. Also, the use of a dose modifier makes robust dose reconstruction possible for higher radiation exposures. The EPR dosimetry technique was also developed for tooth samples extracted from rodents, which represent small tooth sizing. EPR doses in the molars, extracted from the mice irradiated with whole body exposures, were reassessed and shown to be correct within the experimental uncertainty. The sensitivity of human tooth enamel for neutron irradiation, obtained from the 3 MV McMaster K.N. Van de Graaff accelerator, was also studied. For the first time this work has shown that the neutron sensitivity of the tooth enamel is approximately 1/10th of the equivalent gamma sensitivity. Parametric studies for neutron dose rate and neutron energy within the available range of the accelerator, showed no impact on the sensitivity of the tooth enamel. Therefore, tooth enamel can be used as a dosimeter for both neutrons

  14. Experience of technological and natural disasters and their impact on the perceived risk of nuclear accidents after the Fukushima nuclear disaster in Japan 2011: A cross-country analysis

    YAMAMURA, Eiji

    2011-01-01

    This paper uses cross-country data compiled immediately after the Fukushima nuclear accident to investigate how the experience of such disasters affects the perception of the risk of nuclear accidents. Estimation results show that the perceived risk of a nuclear accident is positively associated with experiencing technological disasters but not with that of natural disasters.

  15. Problems of clinical dosimetry in Russian radiotherapy centers

    Due to the general catastrophic situation of radiation oncology in Russia, its outdated equipment and shortage of medical physicists, the clinical dosimetry is also in a very poor state and doesn't meet the modern requirements of the quality assurance in radiotherapy. In Russia there are 140 radiotherapy departments, 100 medical accelerators and 250 gamma apparatus but only 150 clinical dosimeters and 75 dose field analyzers, 90% of which are morally and physically obsolete and do not meet the requirements of the quality assurance. Ten percent of the radiotherapy departments are not equipped with clinical dosimeters at all. There is no national program of quality assurance in radiotherapy. Service for dosimetry equipment calibration is lacking. The national standards and protocols of clinical dosimetry haven't been elaborated. Two-hundred-and-sixty medical physicists work in radiotherapy, 90% of whom have insufficient experience and qualification. Ten percent of radiotherapy departments do not have medical physicists in its staff at all and the rest of the departments face a shortage of medical physicists. The number of medical physicists is not enough to provide the full medical physics service. Qualified medical physicists do not stay long in clinics because of the small salary. As a result of these drawbacks the accuracy of the therapeutic dose delivery to the tumour often achieves 30% instead of the 5% admissible error. This situation leads to high radiation risks, particularly for radiation overdosage or underdosage during the patient's treatment. However, there are no radiation accident statistics in Russia; therefore it's impossible to evaluate them in terms of quantity. Unfortunately, this is the outcome of the lack of the state policy in this field. Neither the Health Ministry nor the Rosatom is concerned about this problem. The only thing that the Health Ministry is undertaking now is the purchase of the new equipment, dosimetry equipment included, for

  16. Radiation dosimetry and radiation biophysics

    Radiation dosimetry and radiation biophysics are two closely integrated programs whose joint purpose is to explore the connections between the primary physical events produced by radiation and their biological consequences in cellular systems. The radiation dosimetry program includes the theoretical description of primary events and their connection with the observable biological effects. This program also is concerned with the design and measurement of physical parameters used in theory or to support biological experiments. The radiation biophysics program tests and uses the theoretical developments for experimental design, and provides information for further theoretical development through experiments on cellular systems

  17. Radiation dosimetry and radiation biophysics

    Radiation dosimetry and radiation biophysics are two closely integrated programs whose joint purpose is to explore the connections between the primary physical events produced by radiation and their biological consequences in cellular systems. The radiation dosimetry program includes the theoretical description of primary events and their connection with the observable biological effects. This program also is concerned with design and measurement of those physical parameters used in the theory or to support biological experiments. The radiation biophysics program tests and makes use of the theoretical developments for experimental design. Also, this program provides information for further theoretical development through experiments on cellular systems

  18. Fuel pin behaviour under conditions of control rod withdrawal accident in CABRI-2 experiments

    Simulation of the control rod withdrawal accident has been performed in the international CABRI-2 experimental programme. The tests realized with industrial pins led to clarification of the influence of the pellet design and have shown the important role of fission products on the solid fuel swelling which promotes early pin failure with solid fuel pellet. With annular pellet design, large fuel swelling combined to low smear density leads to degradation of fuel thermal conductivity and thus reduces power to melt. However, the high margin to deterministic failure is confirmed with hollow pellets. Improvements of the modelling were necessary to describe such behaviours in computer codes as SAS-4A, PAPAS-2S and PHYSURAC. (author)

  19. Nuclear Accident Dosimetry at Argonne National Laboratory

    This report summarizes current planning at Argonne National Laboratory with respect to dose determination following a criticality incident. The discussion relates chiefly to two types of commercially obtained dosimeter packages, and includes the results of independent calibrations performed at the Laboratory. The primary dosimeter system incorporates threshold detectors developed at Oak Ridge National Laboratory for neutron spectrum measurement. Fission foil decay calibration curves have been determined experimentally for scintillation counting equipment routinely used at Argonne. This equipment also has been calibrated for determination of sodium-24 activity in blood. Dosimeter units of the type designed at Savannah River Laboratory are deployed as secondary stations. Data from the neutron activation components of these units will be used to make corrections to, the neutron spectrum for intermediate as well as thermal energies. The epicadmium copper foil activation, for a given fluence of intermediate energy neutrons, has been shown relatively insensitive to neutron spectrum variations within the region, and a meaningful average of copper cross-section has been determined. Counter calibration factors determined at Argonne are presented for the copper, indium, and sulphur components. The total neutron fluence is computed using the corrected spectrum in conjunction with a capture probability function and the blood sodium result. One or more specifications of neutron dose then may be calculated by applying the spectral information to the appropriate conversion function. The gamma portion of the primary dosimeter package contains fluorescent rods and a thermoluminescent dosimeter in addition to a two-phase chemical dosimeter. The gamma dosimeter in the secondary package is a polyacrylamide solution which is degraded by exposure to gamma radiation. The absorbed dose is derived from a measured change insolution viscosity. Difficulties in evaluation, placement, and storage stability are discussed. Plans have been formulated to determine phosphorus-32 in biological materials in order to obtain a fast- neutron dose, to analyse environmental materials for neutron activation products, and to determine the total number of fissions. Administrative control of dose determination will be facilitated with a manual which lists dosimeter locations and handling and counting procedures as well as formulae for dose calculations. (author)

  20. Topics in radiation dosimetry radiation dosimetry

    1972-01-01

    Radiation Dosimetry, Supplement 1: Topics in Radiation Dosimetry covers instruments and techniques in dealing with special dosimetry problems. The book discusses thermoluminescence dosimetry in archeological dating; dosimetric applications of track etching; vacuum chambers of radiation measurement. The text also describes wall-less detectors in microdosimetry; dosimetry of low-energy X-rays; and the theory and general applicability of the gamma-ray theory of track effects to various systems. Dose equivalent determinations in neutron fields by means of moderator techniques; as well as developm

  1. International experience with a multidisciplinary table top exercise for response to a PWR accident

    Table Top Exercises are used for the training of emergency response personnel from a wide range of disciplines whose duties range from strategic to tactical, from managerial to operational. The exercise reported in this paper simulates the first two or three hours of an imaginary accident on a generic PWR site (named Seaside or Lakeside depending on its location). It is designed to exercise the early response of staff of the utility, government, local authority and the media and some players represent the public. The relatively few scenarios used for this exercise are based on actual events scaled to give off-site consequences which demand early assessment and therefore stress the communication procedures. The exercise is applicable in different cultures and has been used in over 20 short courses held in the USA, UK, Sweden, Prague, and Hong Kong. There are two styles of support for players: a linear program which ensures that all players follow the desired path through the event and an open program which is triggered by umpires (who play the reactor crew from a script) and by requests from other players. In both cases the exercise ends with a Press Conference. Players have an initial briefing and are assigned to roles; those who must speak at interviews and at the Press Conference arc given separate briefing by an expert in Public Affairs. The exercise runs with up to six groups and the communication rate reaches about 30 to 40 messages per hour for each group. The exercise can be applied to test management and communication systems and to study human response to emergencies because the merits of individual players are highlighted in the relatively stressful conditions of the initial stage of an accident. For some players the exercise is the first time that they have been required to carry out their task in front of other people

  2. Accident of radiation exposure and/or contamination with radionuclide

    The accident of exposure is defined to be an unintentional one leading to deleterious outcome. This paper reviews the historical and recent accidents involving those mainly dealt in National Institute of Radiological Sciences (NIRS) in Japan and reported in foreign countries, and describes Japanese medical system for coping with the exposure. Hazardous events of radiation exposure are reported as early as within 1 year after discovery of X-ray by Roentgen (1895). In Japan, there are accidents of exposure to the crew of fishing boat Daigo Fukuryu Maru by nuclear experiment at Bikini Atoll (1954), of exposure by stolen 192Ir source (1972) and by Tokai Criticality Accident (1999). More recently, accidents dealt in NIRS are 13 incidents in 2000-2011: serious cases are 3 skin injuries of electronic industry workers by soft X-ray at 50-91 Gy (2000), and of a high school student at 9 Gy (2001) in the science lesson. The decontamination, dosimetry, radiological protection and support of temporary entrance of evacuees have been conducted by NIRS at Fukushima Nuclear Power Plant Accident (2011). Foreign information of 19 severely exposed accidents from 2000 to 2012 are described partly or thoroughly for 18 countries. In Japan, the medical system for coping with the exposure is now under re-construction on the impact of the Fukushima Accident. Its concept stands on the aspects that the system is essentially built up not only for prefectures having nuclear power plant and their neighboring ones, but also those with facilities dealing with radioisotopes, and that those undertaking subjects are thoroughly responsible for concurrent support of medicare at radiation emergency. The guideline for medical education published in 2011 contains the item concerning the radiation/humans. (T.T.)

  3. Review of off-site emergency preparedness and response plan of Indian NPPs based on experience of Fukushima nuclear accident

    Nuclear power plants in India are designed, constructed and operated based on the principle of the highest priority to nuclear safety. To deal with any unlikely situation of radiological emergency, the emergency preparedness and response plans are ensured to be in place at all NPPs prior to their commissioning. These plans are periodically reviewed and tested by conducting emergency exercise with the participation of various agencies such as Nuclear Power Corporation of India Limited, NDMA, district authorities, regulatory body and general public. On March 11, 2011 an earthquake of magnitude 9.0 hit the Fukushima Dai-ichi and Dai-ni followed by tsunami waves of height 15 meters above reference sea level. This resulted in large scale release of radioactive material from Fukushima Dai-ichi NPS. This led to the evacuation of a large number of people from the areas surrounding the affected nuclear power plants. The event was rated as level 7 event in International Nuclear Event Scale (INES). The event also revealed the challenges in handling radiological emergency situation in adverse environmental conditions, The experience of managing radiological emergency situation during Fukushima nuclear accident provides opportunities to review and improve emergency preparedness and response programme. The present paper presents the chronology of the emergency situation, challenges faced and handled in Fukushima. Even though the possibility of a Fukushima type nuclear accident in India is very remote due to the low probability of a high intensity earthquake followed by tsunami at NPP sites, the efforts needs to be initiated from the regulatory point of view for an effective Nuclear and Radiological Emergency Preparedness and Response Plans. The Emergency Preparedness and Response Plans of NPP sites were reviewed in the light of unique challenges of accident at Fukushima. It is realized that multi unit events are the realities that must be addressed as part of Emergency

  4. ESR dosimetry: achievements and challenges

    Baffa, O., E-mail: baffa@usp.br [Universidade de Sao Paulo, Departamento de Fisica, Av. Bandeirantes 3900, 14040-901 Ribeirao Preto, Sao Paulo (Brazil)

    2015-10-15

    Full text: Electron Spin Resonance (ESR), also known as Electron Paramagnetic Resonance (EPR) and more recently as Electron Magnetic Resonance (Emr), is a spectroscopy technique able to detect unpaired electrons such as those created by the interaction ionizing radiation with matter. When the unpaired electrons created by ionizing radiation are stable over some reasonable time, ESR can be used to measure the radiation dose deposited in the material under study. In principle, any insulating material that satisfies this requisite can be used as a dosimeter. ESR has been used in retrospective dosimetry in case of radiological accidents using natural constituents of human body such as teeth, bones and nails as well as fortuitous materials as sugar, sweeteners and plastics. When using teeth the typical detected dose is 0.5 Gy for, for X-Band spectrometers (9 GHz) and even lower doses if higher frequency spectrometers are used. Clinical dosimetry is another area of potential use of this dosimetric modality. In this application the amino acid alanine has been proposed and being used. Alanine dosimeters are very easy to prepare and require no complicated treatments for use. Alanine/ESR dosimetry satisfies many of the required properties for clinical applications such as water equivalent composition, independence of response for the energy range used in therapy and high precision. Other organic materials such as ammonium tartrate are being investigated to increase the sensitivity of ESR for clinical applications. Finally, industrial applications can also benefit from this dosimetry. The challenges to expand applications, the number of users and research groups of ESR dosimetry will be discussed. (Author)

  5. ESR dosimetry: achievements and challenges

    Full text: Electron Spin Resonance (ESR), also known as Electron Paramagnetic Resonance (EPR) and more recently as Electron Magnetic Resonance (Emr), is a spectroscopy technique able to detect unpaired electrons such as those created by the interaction ionizing radiation with matter. When the unpaired electrons created by ionizing radiation are stable over some reasonable time, ESR can be used to measure the radiation dose deposited in the material under study. In principle, any insulating material that satisfies this requisite can be used as a dosimeter. ESR has been used in retrospective dosimetry in case of radiological accidents using natural constituents of human body such as teeth, bones and nails as well as fortuitous materials as sugar, sweeteners and plastics. When using teeth the typical detected dose is 0.5 Gy for, for X-Band spectrometers (9 GHz) and even lower doses if higher frequency spectrometers are used. Clinical dosimetry is another area of potential use of this dosimetric modality. In this application the amino acid alanine has been proposed and being used. Alanine dosimeters are very easy to prepare and require no complicated treatments for use. Alanine/ESR dosimetry satisfies many of the required properties for clinical applications such as water equivalent composition, independence of response for the energy range used in therapy and high precision. Other organic materials such as ammonium tartrate are being investigated to increase the sensitivity of ESR for clinical applications. Finally, industrial applications can also benefit from this dosimetry. The challenges to expand applications, the number of users and research groups of ESR dosimetry will be discussed. (Author)

  6. Experiments on the transfer of heat and mass as a result of natural convection in the event of an air ingress accident in a high-temperature reactor

    To facilitate nuclear technology with high-temperature reactors without any risk of serious accidents, it is necessary to ensure that even the largest accidents will not have any significant effect on the area around the power station. In this case, it is vital to ensure the chemical stability of those reactors if there is an ingress of air as a result of an accident. A large-scale test installation is currently in operation at the Institute of Safety Research and Reactor Technology in the Research Centre Juelich. It is used to investigate the sequence of events and consequences of air ingress accidents of that kind. The experiments are designed to ascertain what the possible extent of the damage will be in certain scenarios and also to develop possible concepts for counteracting the damage and safeguarding the chemical stability of the system. Numerous experiments have been conducted on flow and mass transfer in the course of this study. These experiments describe the individual physical processes within the test installation. The findings derived from this on plant-specific loss of pressure, transfer of heat and material allow to interpret accident simulation experiments reliably and ensure that this data can be applied to the situation in high-temperature reactors using computer programs. (orig.)

  7. Experiences in methods to involve key players in planning protective actions in a case of nuclear accident

    , it is necessary to take production, economical, demographical and geographical information into account. Also the feasibility and constraints, such as logistics, of protective actions need further investigation. The study supports the view that those who are responsible on technical issues should prepare relevant information for decision-making process. A definition of possible action alternatives and attributes in advance can help communication and save time. In a case of an accident a written report describing the accident scenario, consequences of protective actions and tentative decision analysis shares insight an issue and helps the key players to produce a recommendation for open debate before formal decision. The experience gained strongly supports the format of a facilitated workshop method to tackle a decision problem that concerns many different key players. The participants considered the workshop and the decision analysis very useful in planning the actions in advance. They also expected a similar approach to be applicable in a real accident situation, although the suitability was not rated as high as for planning. The suitability for the early phase of an accident was rated the lowest. The pros and Ions of the facilitated workshop method can be compared with conventional methods, especially how they support decision-making process. They all provide insight and create a network of key players to be better prepared for accident situation. Facilitated workshop is analytical and open in values behind decision but can be applied only by a case-a-case base. Meetings attended by key players could weigh up and augment generic countermeasures but the whole vast number of alternatives cannot be justified and optimized in depths. (author)

  8. Severe accident experiments on PLINIUS platform. Results of first experiments on COLIMA facility related to VVER-440. Presentation of planned VULCANO and KROTOS tests

    In the hypothetical case of a nuclear reactor severe accident, the reactor core could melt and form a mixture of nuclear fuel (UO2+ Fission Products), metallic or oxidized cladding + steel, called corium, of highly refractory oxides (UO2, ZrO2) and metallic or oxidized steel, that could eventually flow out of the vessel and mix with the substrate decomposition products (generally oxides such as SiO2, Al2O3, CaO, Fe2O3). The French Atomic Energy Commission (CEA) has launched a R and D programme aimed at providing the tools for improving the mastering of severe accidents. It encompasses the development of models and codes, performance of experiments in simulant and prototypic materials and the analysis of international experiments. The experiments with prototypic corium (i.e. material containing depleted UO2) are performed in the PLINIUS experimental platform at CEA Cadarache. It comprises the VULCANO facility for 50-100 kg tests (corium-material interactions, corium solidification etc.), the COLIMA facility for smaller scale (∼1 kg) experiments, the VITI facility for corium properties measurement and the KROTOS facility for corium-water interaction (a few kg). In the framework of the 5th European Framework Programme, free trans-national access to these facilities has been offered to EU and Associated States researchers. For the first PLINIUS access, COLIMA experiments have been conducted with a Bulgarian Team (TU/SOFIA, BAS/INRNE and NPP/KOZLODUY). This series of tests was devoted to experimental studies on fission products release and corium behaviour in the late phase in a hypothetic case of severe accident in a PWR type VVER-440. The COLIMA experimental results are consistent with previous experiments on irradiated fuels (VERCORS, PHEBUS) with small differences for some fission products and show new results for the remaining corium. For the second visit, scientific users from FZK in Germany were selected to validate the COMET core-catcher with prototypic corium

  9. French experience in the field of internal dosimetry assessment at a nuclear workplace. Methods and results on industrial uranium dioxide

    The implementation of the new ICRP recommendations and the diversity of industrial exposure materials make it necessary to modify our approach of assessing internal dosimetry. This paper describes a methodology developed to asses different parameters such as activity concentration and particle size distribution at the workplace; physico-chemical characteristics of industrial dust handled; and in vitro and in vivo solubility in order to determine the absorption rate blood. The determination of such specific parameters will lead to dose calculation in terms of committed effective Dose Per Unit of Intake (DPUI). Results obtained for an industrial uranium dioxide, UO2, at a French nuclear facility are presented. (author). 21 refs., 2 figs., 4 tabs

  10. TMI Unit 2 post-accident defueling. Experience and lessons learned

    The 1979 accident at Three Mile Island Unit 2 left a bowl shaped, hardened mass of core components and fuel in the upper third of the fuel assembly region. The area of core damage was defined by the steam blanketing that had pushed down from the upper head. As the liquefied core mass formed, it began to run down the intact fuel rods and solidified when it encountered liquid coolant. The liquid core material flowed down into the undamaged fuel rods a short distance prior to solidifying, defining the bowl thickness and anchoring the bowl to the remaining, intact fuel rods. After the bowl formed - creating a container for the liquefied fuel - the remaining, melted core material collected in the bowl. The bowl filled and eventually melted through a core former plate, spilling down to the vessel lower head. As cooling was restored, the liquefied bowl solidified forming a monolith. Initial defueling attempts were blocked by the presence of this monolithic mass. A computerized well drilling machine was used to capture 'as found' vertical samples of the core and then break up the monolithic mass. This process left a rubble bed of fuel, fuel rods, and other core fragments. A significant challenge was imposed by the fuel fines that were created by the accident and by the breakup of the monolith. The fines eliminated visibility and greatly retarded effective cleanup work in the core until engineering solutions were applied. Unknown fissile material configuration, high levels of radiation from the deranged core, and the need for human access to complete the work also required extensive engineering to resolve. A workforce, skilled in the use of 40 foot (12m) long, camera guided, under water tools was non-existent at the beginning of the cleanup process, but was rapidly developed out of necessity. At one point in the cleanup process, high levels of bacteria present in the coolant threatened to stop the project. Many issues surfaced during the cleanup that required specialty

  11. Investigation of fragmentation phenomena and debris bed formation during core meltdown accident in SFR using simulated experiments

    Mathai, Amala M., E-mail: amala@igcar.gov.in [Safety Engineering Division, RDG, IGCAR, Kalpakkam, Tamilnadu 603102 (India); Sharma, Anil Kumar, E-mail: aksharma@igcar.gov.in [Safety Engineering Division, RDG, IGCAR, Kalpakkam, Tamilnadu 603102 (India); Anandan, J., E-mail: janand@igcar.gov.in [Safety Engineering Division, RDG, IGCAR, Kalpakkam, Tamilnadu 603102 (India); Malarvizhi, B., E-mail: malar@igcar.gov.in [Safety Engineering Division, RDG, IGCAR, Kalpakkam, Tamilnadu 603102 (India); Das, Sanjay Kumar, E-mail: skd@igcar.gov.in [Safety Engineering Division, RDG, IGCAR, Kalpakkam, Tamilnadu 603102 (India); Nashine, B.K., E-mail: bknash@igcar.gov.in [Safety Engineering Division, RDG, IGCAR, Kalpakkam, Tamilnadu 603102 (India); Chellapandi, P., E-mail: pcp@igcar.gov.in [Reactor Design Group (RDG), IGCAR, Kalpakkam, Tamilnadu 603102 (India)

    2015-10-15

    Highlights: • Study on settling characteristics of debris after severe accident in SFR. • Understanding fragmentation mechanisms of liquid molten simulant. • Correlation between key parameters of PSD in the ULLN expression. • Investigation of debris bed formation and radial stratification on collector tray. - Abstract: The event of a severe core melt down accident, resulting in the relocation of the active core is analyzed as a part of the nuclear reactor safety research in order to ensure safe removal of decay heat. Molten Fuel Coolant Interaction (MFCI) and debris bed configuration on the core catcher plate assumes importance in assessing the post accident heat removal capability. The key factors affecting the coolability of the debris bed are the bed porosity, morphology of the fragmented particles, degree of spreading/heaping of the debris on the core catcher and the fraction of lump formed. A well defined debris bed is helpful in fixing a prototypical source term for the PAHR studies. Towards this, a series of experiments on fragmentation kinetics and subsequent debris bed formation is conducted with molten Wood's metal (an alloy of Bi 50%, Pb 25%, Sn 12.5% and Cd 12.5% with melting point of 346 K) in water simulant system. The experiments are carried out using 2 kg, 5 kg and 20 kg melt inventories. The particle size distribution obtained for the fragmented debris is fit using an Upper Limit Log Normal (ULLN) distribution. The dependence of particle size distribution on initial melt temperature and interaction height is quantified by correlating them to the key parameters i.e. shape factor and location factor in the ULLN expression. Morphology of the debris particles is investigated to understand the fragmentation mechanisms involved. Three major mechanisms of fragmentation are identified namely melt entrainment mechanism, boundary layer stripping and hydrodynamic breakup due to capillary forces. Finally, an approach to quantify the stratification

  12. Investigation of fragmentation phenomena and debris bed formation during core meltdown accident in SFR using simulated experiments

    Highlights: • Study on settling characteristics of debris after severe accident in SFR. • Understanding fragmentation mechanisms of liquid molten simulant. • Correlation between key parameters of PSD in the ULLN expression. • Investigation of debris bed formation and radial stratification on collector tray. - Abstract: The event of a severe core melt down accident, resulting in the relocation of the active core is analyzed as a part of the nuclear reactor safety research in order to ensure safe removal of decay heat. Molten Fuel Coolant Interaction (MFCI) and debris bed configuration on the core catcher plate assumes importance in assessing the post accident heat removal capability. The key factors affecting the coolability of the debris bed are the bed porosity, morphology of the fragmented particles, degree of spreading/heaping of the debris on the core catcher and the fraction of lump formed. A well defined debris bed is helpful in fixing a prototypical source term for the PAHR studies. Towards this, a series of experiments on fragmentation kinetics and subsequent debris bed formation is conducted with molten Wood's metal (an alloy of Bi 50%, Pb 25%, Sn 12.5% and Cd 12.5% with melting point of 346 K) in water simulant system. The experiments are carried out using 2 kg, 5 kg and 20 kg melt inventories. The particle size distribution obtained for the fragmented debris is fit using an Upper Limit Log Normal (ULLN) distribution. The dependence of particle size distribution on initial melt temperature and interaction height is quantified by correlating them to the key parameters i.e. shape factor and location factor in the ULLN expression. Morphology of the debris particles is investigated to understand the fragmentation mechanisms involved. Three major mechanisms of fragmentation are identified namely melt entrainment mechanism, boundary layer stripping and hydrodynamic breakup due to capillary forces. Finally, an approach to quantify the stratification

  13. Effects of task complexity on operators' performance in eight medium loss of coolant accident scenarios (recovery experiment 2002/03)

    This experiment was the first in a series intended to inform Human Reliability Analysis (HRA). The experiment studied eight loss of coolant accident (LOCA) scenarios with varying levels of task complexity using the HAMMLAB BWR simulator. We grouped the scenarios into a low complexity category, a medium complexity category and a high complexity category according to a rating of the scenarios' Time pressure, Information load, and Masking. Assessment of scenarios by using the HRA method SPAR-H, showed that the scenarios ranged from about nominal to highly complex. Eight fully manned control room crews consisting of licensed operators participated in the study. Each crew consisted of a shift supervisor, a reactor operator and a turbine operator. The task complexity categories showed statistically significant effects on the crews' general performance. An observational analysis of one low complexity scenario and one high complexity scenario was performed based on transcripts of the crews' communication during the scenarios. The analysis confirmed that the scenarios' planned task complexity became manifest for the crews, since their operation and communication reflected the impact of high time pressure, high information load, and high masking. The analysis of the crews' behaviour revealed a dependency between the scenarios' individual tasks and showed that if some expected actions were not performed this escalated the severity of the scenarios. The results show, not surprisingly, that planning and decision-making are difficult in highly complex scenarios. Existing procedures did not seem to support planning and decision making sufficiently in highly complex accident scenarios. The results suggest that for assessment of reliability, and for design improvements, it is important to understand how the task becomes complex for the crew and how, and to what extent, types of procedures and type of training can improve human performance. (Author)

  14. Dosimetric reconstruction of radiological accident by numerical simulations by means associating an anthropomorphic model and a Monte Carlo computation code

    After a description of the context of radiological accidents (definition, history, context, exposure types, associated clinic symptoms of irradiation and contamination, medical treatment, return on experience) and a presentation of dose assessment in the case of external exposure (clinic, biological and physical dosimetry), this research thesis describes the principles of numerical reconstruction of a radiological accident, presents some computation codes (Monte Carlo code, MCNPX code) and the SESAME tool, and reports an application to an actual case (an accident which occurred in Equator in April 2009). The next part reports the developments performed to modify the posture of voxelized phantoms and the experimental and numerical validations. The last part reports a feasibility study for the reconstruction of radiological accidents occurring in external radiotherapy. This work is based on a Monte Carlo simulation of a linear accelerator, with the aim of identifying the most relevant parameters to be implemented in SESAME in the case of external radiotherapy

  15. Neutron dosimetry, damage calculations, and helium measurements for the HFIR-MFE-60J-1 and MFE-330J-1 spectral tailoring experiments

    Greenwood, L.R. [Pacific Northwest Laboratory, Richland, WA (United States); Baldwin, C.A. [Oak Ridge National Lab., TN (United States); Oliver, B.M.

    1995-04-01

    The objective is to provide dosimetry and damage analysis for fusion materials irradiation experiments. Neutron fluence measurements and radiation damage calculations are reported for the joint US -Japanese MFE-60J-1 and MFE-330J-1 experiments in the hafnium-lined removable beryllium (RB{sup *}) position of the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory. These experiments were continuations of the ORR-6J and 7J irradiations performed in the Oak Ridge Research Reactor. The combination of irradiations was designed to tailor the neutron spectrum in order to achieve fusion reactor helium/dpa levels in stainless steel. These experiments produced maximum helium (appm)/dpa(displacement per atom) levels of 10.2 at 18.5 dpa for the ORR-6J and HFIR-MFE-60J-1 combination and 11.8 at 19.0 dpa for the ORR-7J and HFIR-MFE-330J-1 combination. A helium measurement in one JPCA sample was in good agreement with helium calculations.

  16. Neutron dosimetry, damage calculations, and helium measurements for the HFIR-MFE-60J-1 and MFE-330J-1 spectral tailoring experiments

    The objective is to provide dosimetry and damage analysis for fusion materials irradiation experiments. Neutron fluence measurements and radiation damage calculations are reported for the joint US -Japanese MFE-60J-1 and MFE-330J-1 experiments in the hafnium-lined removable beryllium (RB*) position of the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory. These experiments were continuations of the ORR-6J and 7J irradiations performed in the Oak Ridge Research Reactor. The combination of irradiations was designed to tailor the neutron spectrum in order to achieve fusion reactor helium/dpa levels in stainless steel. These experiments produced maximum helium (appm)/dpa(displacement per atom) levels of 10.2 at 18.5 dpa for the ORR-6J and HFIR-MFE-60J-1 combination and 11.8 at 19.0 dpa for the ORR-7J and HFIR-MFE-330J-1 combination. A helium measurement in one JPCA sample was in good agreement with helium calculations

  17. Experiments and analyses on melt-structure-water interactions during severe accidents

    This report is the final report for the research project Melt Structure Water Interactions (MSWI). It describes results of analytical and experimental studies concerning MSWI during the course of a hypothetical core meltdown accident in a LWR. Emphasis has been placed on phenomena which govern vessel failure mode and timing and the mechanisms and properties which govern the fragmentation and breakup of melt jets and droplets. It was found that: 2-D effects significantly diminished the focusing effect of an overlying metallic layer on top of an oxide melt pool. This result improves the feasibility of in-vessel retention of a melt pool through external cooling of the lower head; phenomena related to hole ablation and melt discharge, in the event of vessel failure, are affected significantly by crust formation; the jet fragmentation process is a function of many related phenomena. The fragmentation rate depends not only on the traditional parameters but also on the melt physical properties, which change as the melt cools down from liquid to solid temperature; film boiling was investigated by developing a two-phase flow model and inserting it in a multi-D fluid dynamics code. It was concluded that the thickness of the film on the surface of a melt jet would be small and that the effects of the film on the process should not be large. This conclusion is contrary to the modeling employed in some other codes. The computer codes were developed and validated against the data obtained in the MSWI Project. The melt vessel interaction thermal analysis code describes the process of melt pool formation and convection and the resulting vessel thermal loadings. In addition, several innovative models were developed to describe the melt-water interaction process. The code MELT-3D treats the melt jet as a collection of particles whose movement is described with a three-dimensional Eulerian formulation. The model (SIPHRA) tracks the melt jet with an additional equation, using the

  18. Experiments and analyses on melt-structure-water interactions during severe accidents

    Seghal, B.R.; Dinh, T.N.; Bui, V.A.; Green, J.A.; Nourgaliev, R.R.; Okkonen, T.O.; Dinh, A.T. [Royal Inst. of Tech., Stockholm (Sweden). Div. of Nuclear Power Safety

    1998-04-01

    This report is the final report for the research project Melt Structure Water Interactions (MSWI). It describes results of analytical and experimental studies concerning MSWI during the course of a hypothetical core meltdown accident in a LWR. Emphasis has been placed on phenomena which govern vessel failure mode and timing and the mechanisms and properties which govern the fragmentation and breakup of melt jets and droplets. It was found that: 2-D effects significantly diminished the focusing effect of an overlying metallic layer on top of an oxide melt pool. This result improves the feasibility of in-vessel retention of a melt pool through external cooling of the lower head; phenomena related to hole ablation and melt discharge, in the event of vessel failure, are affected significantly by crust formation; the jet fragmentation process is a function of many related phenomena. The fragmentation rate depends not only on the traditional parameters but also on the melt physical properties, which change as the melt cools down from liquid to solid temperature; film boiling was investigated by developing a two-phase flow model and inserting it in a multi-D fluid dynamics code. It was concluded that the thickness of the film on the surface of a melt jet would be small and that the effects of the film on the process should not be large. This conclusion is contrary to the modeling employed in some other codes. The computer codes were developed and validated against the data obtained in the MSWI Project. The melt vessel interaction thermal analysis code describes the process of melt pool formation and convection and the resulting vessel thermal loadings. In addition, several innovative models were developed to describe the melt-water interaction process. The code MELT-3D treats the melt jet as a collection of particles whose movement is described with a three-dimensional Eulerian formulation. The model (SIPHRA) tracks the melt jet with an additional equation, using the

  19. Commitment of involved actors in the preparation of accidental and post-accident situations: European experiments; Engagement des parties prenantes a la preparation aux situations accidentelles et post-accidentelles: experiences Europeennes

    Schneider, Th. [CEPN, 28 rue de la Redoute, 92260 Fontenay-aux-Roses (France)

    2010-07-01

    The author briefly describes some approaches developed within the EURANOS European research programme between 2004 and 2009 which aims at promoting the building up of a European network (NERIS) for the management of nuclear accidental and post-accident situations. Notably, he comments the experiment which took place in the Montbeliard district where two types of radiological events have been modelled and simulated: an accident in the Fessenheim nuclear power plant with two scenarios of release, and a transportation accident with a release of radioactive caesium 137. He also evokes the Norwegian experience and some other actions in Finland, Great-Britain, Spain and Slovakia where reflections on the management of accidental and post-accident situations or crisis exercises have been organized

  20. ESR dosimetry using eggshells and tooth enamel for accidental dosimetry

    The CO2- signal of eggshells showed a good dose linearity and was appropriate in the wide dose range from 1 to 10 kGy, while ESR signal of CO2- in sea and fresh water shells were saturated at a dose od below 10 kGy. The minimum detectable dose and G-value of CO2- in eggshells were estimated 0.3 Gy and 0.28, respectively. The lifetime of CO2- in eggshells could not be determined exactly because of overlapping organic signals, however it is still sufficiently long for practical use as ESR dosimeter materials. Various bird's or reptile's eggshells would be available as natural retrospective ESR dosimeter materials after nuclear accidents. Eggshells will be useful for the food irradiation dosimetry in the dose range of about a few kGy. Tooth enamel is one of the most useful dosimeter materials in public at a accident because of its high sensitivity. ESR dosimetry will replace TLD in near future if the cost of an ESR reader is further reduced . (author)

  1. Heat transfer from fuel rod surface under reactivity-initiated accident conditions. NSRR experiments under varied cooling conditions

    The temperature evolution of fuel cladding during a reactivity-initiated accident (RIA) involves rapid changes in the mechanical properties of the cladding tube and is believed to play the primary role in fuel behaviors such as deformation and failure. Cladding-temperature behavior accompanied by boiling of coolant water, which is the case of an RIA in light-water reactors, is influenced by cooling conditions such as subcooling, pressure, and flow velocity. In order to study the effects of cooling conditions on the boiling heat transfer from the fuel rod surface to the coolant water, RIA-simulating experiments with fresh fuels had been conducted in the nuclear safety research reactor (NSRR) under cooling conditions with subcoolings of ∼10 to 80 K, flow velocities of 0 to ∼3 m/s, pressures of 0.1 to ∼16 MPa. In addition, pre-irradiated fuels had been subjected to the NSRR experiments under cooling conditions with subcoolings of ∼80 K, stagnant water, and atmospheric pressure. Out of the NSRR experiments, this report presents the fuel specifications, the test conditions, and the transient records during the pulse operations for the cases that the cladding temperature had been successfully measured. Characteristic parameters such as cladding peak temperatures were extracted from the transient records for summarizing the effects of cooling conditions and pre-irradiation on the heat transfer from the cladding surface. A CD-ROM's attached as an appendix. (J.P.N.)

  2. EPR Dosimetry - Present and Future

    In the past, IAEA has played a central role in stipulating research and development in EPR high-dose standardisation as well as in coordinating and organising international dose intercomparison programs, within the Member States of the United Nations from the mid-seventies till today. The future tasks of EPR dosimetry seem to tend towards different subjects such as bio markers, biological radiation effects, post-accident dose reconstruction in the environment, and retrospective human dosimetry. The latter may be considered a promising tool for epidemiology on the way to re-define radiation risk of man for chronicle radiation exposures, based on e.g. South Ural civil population and radiation workers. There are on-going international activities in the field of standardising high-level dosimetry by the American Standards on Testing and Materials (Astm), and by the International Organisation of Standards (ISO). The International Commission on Radiation Units and Measurements (ICRU) is considering the establishment of relevant recommendations concerning industrial radiation processing, but also human dose reconstruction. (Author)

  3. EPR Dosimetry - Present and Future

    Regulla, D.F. [GSF - National Research Centre for Environment and Health, Institute of Radiation Protection, 85764 Neuherberg (Germany)

    1999-07-01

    In the past, IAEA has played a central role in stipulating research and development in EPR high-dose standardisation as well as in coordinating and organising international dose intercomparison programs, within the Member States of the United Nations from the mid-seventies till today. The future tasks of EPR dosimetry seem to tend towards different subjects such as bio markers, biological radiation effects, post-accident dose reconstruction in the environment, and retrospective human dosimetry. The latter may be considered a promising tool for epidemiology on the way to re-define radiation risk of man for chronicle radiation exposures, based on e.g. South Ural civil population and radiation workers. There are on-going international activities in the field of standardising high-level dosimetry by the American Standards on Testing and Materials (Astm), and by the International Organisation of Standards (ISO). The International Commission on Radiation Units and Measurements (ICRU) is considering the establishment of relevant recommendations concerning industrial radiation processing, but also human dose reconstruction. (Author)

  4. Dosimetry studies in Zaborie village

    Takada, J. E-mail: jtakada@ipc.hiroshima-u.ac.jp; Hoshi, M.; Endo, S.; Stepanenko, V.F.; Kondrashov, A.E.; Petin, D.; Skvortsov, V.; Ivannikov, A.; Tikounov, D.; Gavrilin, Y.; Snykov, V.P

    2000-05-15

    Dosimetry studies in Zaborie, a territory in Russia highly contaminated by the Chernobyl accident, were carried out in July, 1997. Studies on dosimetry for people are important not only for epidemiology but also for recovery of local social activity. The local contamination of the soil was measured to be 1.5-6.3 MBq/m{sup 2} of Cs-137 with 0.7-4 {mu}Sv/h of dose rate. A case study for a villager presently 40 years old indicates estimations of 72 and 269 mSv as the expected internal and external doses during 50 years starting in 1997 based on data of a whole-body measurement of Cs-137 and environmental dose rates. Mean values of accumulated external and internal doses for the period from the year 1986 till 1996 are also estimated to be 130 mSv and 16 mSv for Zaborie. The estimation of the 1986-1996 accumulated dose on the basis of large scale ESR teeth enamel dosimetry provides for this village, the value of 180 mSv. For a short term visitor from Japan to this area, external and internal dose are estimated to be 0.13 mSv/9d (during visit in 1997) and 0.024 mSv/50y (during 50 years starting from 1997), respectively.

  5. EPR dosimetry - present and future

    In the past, IAEA has played a central role in stipulating research and development in EPR high-dose standardisation as well as co-ordinating and organising international dose intercomparison programs, within the Member States of the United Nations from the mid-seventies till today. The future tasks of EPR dosimetry seem to tend towards different subjects such as biomarkers, biological radiation effects, post-accident dose reconstruction in the environment, and retrospective human dosimetry. The latter may be considered a promising tool for epidemiology on the way to re-define radiation risk of man for chronicle radiation exposures, based on e.g. South Ural civil population and radiation workers. There are on-going international activities in the field of standardising high-level dosimetry by the American Standards on Testing and Materials (ASTM), and the International Organisation of Standards (ISO) as well as those of the International Commission on Radiation Units and Measurements (ICRU) considering the establishment of relevant recommendations concerning industrial radiation processing, but also human dose reconstruction. (author)

  6. Handling of Radiation Accidents. Proceedings of a Symposium on the Handling of Radiation Accidents

    Many types of radiation accidents can theoretically be foreseen, ranging from minor spills of radioactive materials within a laboratory to serious accidents characterized by the presence of intense radiation fields and the uncontrolled release of large quantities of radioactive contaminants. They could lead to the irradiation and contamination of persons and the contamination of premises and the natural environment. As a result of the great emphasis that has been placed on safety in the development of nuclear energy programmes and in the use of radiation sources, accidents involving the serious overexposure of persons are in fact very rare. Nevertheless such accidents can occur and it is necessary to plan in advance for those that can be,reasonably foreseen. The handling of serious radiation accidents requires the co-operation of experts with diverse qualifications and experience: radiation monitoring and dosimetry specialists; medical doctors experienced in diagnosing and treating radiation injury; nuclear safety, decontamination and waste management specialists; public relations officers; and many others. This symposium, organized by the International Atomic Energy Agency and the World Health Organization as part of a co-ordinated programme, was designed to enable these specialists to discuss their problems on a very broad basis. The meeting was attended by 212 participants from 34 countries and 9 international organizations. In his opening address Professor Zheludev reminded the participants that the good safety record of the nuclear industry must not give rise to complacency and that we must all learn as much as possible from reported accidents in order to be ready to deal promptly and effectively with those that may be encountered in the future. It is noteworthy that some of the most severe injuries reported were suffered by persons who found lost-sources and carried them for long periods without any knowledge of the dangers involved. Organizational

  7. Bayesian Methods for Radiation Detection and Dosimetry

    Groer, Peter G

    2002-01-01

    We performed work in three areas: radiation detection, external and internal radiation dosimetry. In radiation detection we developed Bayesian techniques to estimate the net activity of high and low activity radioactive samples. These techniques have the advantage that the remaining uncertainty about the net activity is described by probability densities. Graphs of the densities show the uncertainty in pictorial form. Figure 1 below demonstrates this point. We applied stochastic processes for a method to obtain Bayesian estimates of 222Rn-daughter products from observed counting rates. In external radiation dosimetry we studied and developed Bayesian methods to estimate radiation doses to an individual with radiation induced chromosome aberrations. We analyzed chromosome aberrations after exposure to gammas and neutrons and developed a method for dose-estimation after criticality accidents. The research in internal radiation dosimetry focused on parameter estimation for compartmental models from observed comp...

  8. Individual dosimetry of workers and patients: implementation and perspectives

    These days organised by the section of the technical protection of the S.F.R.P. review the different techniques of dosimetry used in France and Europe, and present the future orientations.The different interventions are as follow: Individual exposures of the workers: historic assessment and perspectives; medical exposure: where are the doses; legal obligations in individual dosimetry: which are the objective and the need on the subject; the dosimetry follow-up of workers by the S.I.S.E.R.I. system: assessment and perspectives; impact of the norm ISO 20553 on the follow-up of internal exposure; the implementation of the patient dose measurement in Belgium; techniques of passive dosimetry used in Europe; Supervision radiation protection at EDF: long term and short term approach; Comparison active and passive dosimetry at Melox; methodology for the choice of new neutron dosemeters; the working group M.E.D.O.R.: guide of internal dosimetry for the use of practitioners; O.E.D.I.P.E.: tool of modeling for the personalized internal dosimetry; the use of the Monte-Carlo method for the planning of the cancer treatment by radiotherapy becomes a reality; the works of the committee 2 of the ICRP; passive dosimetry versus operational dosimetry: situation in Europe; Implementation of the in vivo dosimetry in a radiotherapy department: experience of the Gustave Roussy institute; experience feedback on the in vivo measures in radiotherapy, based on the use of O.S.L. pellets; multi points O.S.L. instrumentation for the radiation dose monitoring in radiotherapy; dosimetry for extremities for medical applications: principle results of the European contract C.O.N.R.A.D.; references and perspectives in dosimetry; what perspectives for numerical dosimetry, an example: Sievert; system of dose management: how to answer to needs; the last technical evolutions in terms of electronic dosimetry in nuclear power plant; the fourth generation type reactors: what dosimetry. (N.C.)

  9. Computer Aided Dosimetry and Verification of Exposure to Radiation

    Waller, Edward; Stodilka, Robert Z.; Leach, Karen E.; Lalonde, Louise

    2002-06-01

    In the timeframe following the September 11th attacks on the United States, increased emphasis has been placed on Chemical, Biological, Radiological and Nuclear (CBRN) preparedness. Of prime importance is rapid field assessment of potential radiation exposure to Canadian Forces field personnel. This work set up a framework for generating an 'expert' computer system for aiding and assisting field personnel in determining the extent of radiation insult to military personnel. Data was gathered by review of the available literature, discussions with medical and health physics personnel having hands-on experience dealing with radiation accident victims, and from experience of the principal investigator. Flow charts and generic data fusion algorithms were developed. Relationships between known exposure parameters, patient interview and history, clinical symptoms, clinical work-ups, physical dosimetry, biological dosimetry, and dose reconstruction as critical data indicators were investigated. The data obtained was examined in terms of information theory. A main goal was to determine how best to generate an adaptive model (i.e. when more data becomes available, how is the prediction improved). Consideration was given to determination of predictive algorithms for health outcome. In addition. the concept of coding an expert medical treatment advisor system was developed (U)

  10. Radiological dose assessment for bounding accident scenarios at the Critical Experiment Facility, TA-18, Los Alamos National Laboratory

    A computer modeling code, CRIT8, was written to allow prediction of the radiological doses to workers and members of the public resulting from these postulated maximum-effect accidents. The code accounts for the relationships of the initial parent radionuclide inventory at the time of the accident to the growth of radioactive daughter products, and considers the atmospheric conditions at time of release. The code then calculates a dose at chosen receptor locations for the sum of radionuclides produced as a result of the accident. Both criticality and non-criticality accidents are examined

  11. EXPERIENCE OF THE ORGANIZATION OF THE RADIATION CONTROL FOR PEOPLE ARRIVED FROM THE AREAS RADIOACTIVELY CONTAMINATED DUE TO THE CHERNOBYL NUCLEAR POWER PLANT ACCIDENT

    E. B. Ershov

    2015-09-01

    Full Text Available An article considers issues related to the radiological examination of the people arrived in Leningrad from the areas radioactively contaminated due to the Chernobyl nuclear power plant accident. It also describes the experience of creation and functioning of the specialized station for radiation control and sanitary treatment of people and their personal clothes. The article specifies basic requirements for such stations.

  12. Local overexposure: the role of physical dosimetry

    The role of physical dosimetry in cases of local overexposure is limited. However, if dosimetry, which is usually of no use for diagnosis, is combined with clinical and biological data, it can be useful for therapy and prognosis. This paper, based on cases treated at the Hopital Curie, proposes a method which may be used. It consists of: determination of isodose curves at the surface (skin) by an experimental reconstruction of the accident or by calculation; comparison of these isodoses with the skin pathology: area of erythema (3-8 Gy), area of dry desquamation (> 5 Gy), area of exudative desquamation (12-20 Gy) and area of necrosis (> 25 Gy); calibration of the depth-dose curves after this comparison and the determination of the dose to essential organs or tissues. Examples illustrating this approach are given for accidents involving X rays and 192Ir and 60Co sources. (author)

  13. HSE performance tests for dosimetry services

    In the United Kingdom a dosimetry service that measures and assesses whole-body or part-body doses arising from external radiation must successfully complete a performance test. Results of the performance tests for routine whole-body, routine extremity/skin and special accident dosimetry, carried out over the past six years by the AEA Technology Calibration Service at Winfrith, and DRaStaC, the AWE Calibration Service at Aldermaston, are presented. The test involves irradiating groups of dosemeters to known doses of gamma radiation and determining the bias and relative standard deviations for each dose group. The results are compared with the pass criteria specified by the UK Health and Safety Executive. For routine whole-body dosimetry, both the film badge and thermoluminescent dosemeter (TLD) perform adequately for irradiations between 0.6 and 30 mSv. For higher doses up to 250 mSv, where the slow emulsion of the film is used, the film badge shows poorer performance with a tendency to overestimate the dose. For routine extremity/skin dosimetry there is a wider spread of relative standard deviation results than is seen for routine whole-body dosimetry. This is to be expected since the results will include dosemeters that are based on 'disposable' TLDs and ones based on lithium fluoride powder in sachets. For special accident dosimetry the dosemeters are tested between 0.26 and 6 Gy. For the highest dose group the film badge invariably underestimates the true dose, whereas the TLD has a tendency to overestimate it. (author)

  14. Nursering assistance to the radiological accident patients in Goiania-an experience report

    In september, 1987, a caesium-137 source was disrupted and caused a serious radiological acident. The victims were hospitalized in the General Hospital in city of Goiania, Goias state, Brazil. This is a report of a personal experience, during the two months of nursering care. (author)

  15. Determination of neutron dose from criticality accidents with bioassays for sodium-24 in blood and phosphorus-32 in hair

    A comprehensive review of accident neutron dosimetry using blood and hair analysis was performed and is summarized in this report. Experiments and calculations were conducted at Oak Ridge National Laboratory (ORNL) and the University of Tennessee (UT) to develop measurement techniques for the activity of 24Na in blood and 32P in hair for nuclear accident dosimetry. An operating procedure was established for the measurement of 24Na in blood using an HPGe detector system. The sensitivity of the measurement for a 20-mL sample is 0.01-0.02 Gy of total neutron dose for hard spectra and below 0.005 Gy for soft spectra based on a 30- to 60-min counting time. The operating procedures for direct counting of hair samples are established using a liquid scintillation detector. Approximately 0.06-0.1 Gy of total neutron dose can be measured from a 1-g hair sample using this procedure. Detailed procedures for chemical dissolution and ashing of hair samples are also developed. A method is proposed to use blood and hair analysis for assessing neutron dose based on a collection of 98 neutron spectra. Ninety-eight blood activity-to-dose conversion factors were calculated. The calculated results for an uncollided fission spectrum compare favorably with previously published data for fission neutrons. This nuclear accident dosimetry system makes it possible to estimate an individual's neutron dose within a few hours after an accident if the accident spectrum can be approximated from one of 98 tabulated neutron spectrum descriptions. If the information on accident and spectrum description is not available, the activity ratio of 32P in hair and 24Na in blood can provide information related to the neutron spectrum for dose assessment

  16. Initial clinical experience with Epid-based in-vivo dosimetry for VMAT treatments of head-and-neck tumors.

    Cilla, Savino; Meluccio, Daniela; Fidanzio, Andrea; Azario, Luigi; Ianiro, Anna; Macchia, Gabriella; Digesù, Cinzia; Deodato, Francesco; Valentini, Vincenzo; Morganti, Alessio G; Piermattei, Angelo

    2016-01-01

    We evaluated an EPID-based in-vivo dosimetry algorithm (IVD) for complex VMAT treatments in clinical routine. 19 consecutive patients with head-and-neck tumors and treated with Elekta VMAT technique using Simultaneous Integrated Boost strategy were enrolled. In-vivo tests were evaluated by means of (i) ratio R between daily in-vivo isocenter dose and planned dose and (ii) γ-analysis between EPID integral portal images in terms of percentage of points with γ-value smaller than one (γ%) and mean γ-values (γmean), using a global 3%-3 mm criteria. Alert criteria of ±5% for R ratio, γ%  0.67 were chosen. A total of 350 transit EPID images were acquired during the treatment fractions. The overall mean R ratio was equal to 1.002 ± 0.019 (1 SD), with 95.9% of tests within ±5%. The 2D portal images of γ-analysis showed an overall γmean of 0.42 ± 0.16 with 93.3% of tests within alert criteria, and a mean γ% equal to 92.9 ± 5.1% with 85.9% of tests within alert criteria. Relevant discrepancies were observed in three patients: a set-up error was detected for one patient and two patients showed major anatomical variations (weight loss/tumor shrinkage) in the second half of treatment. The results are supplied in quasi real-time, with IVD tests displayed after only 1 minute from the end of arc delivery. This procedure was able to detect when delivery was inconsistent with the original plans, allowing physics and medical staff to promptly act in case of major deviations between measured and planned dose. PMID:26511150

  17. EPR TOOTH DOSIMETRY OF SNTS AREA INHABITANTS

    Sholom, Sergey; Desrosiers, Marc; Bouville, André; Luckyanov, Nicholas; Chumak, Vadim; Simon, Steven L.

    2007-01-01

    The determination of external dose to teeth of inhabitants of settlements near the Semipalatinsk Nuclear Test Site (SNTS) was conducted using the EPR dosimetry technique to assess radiation doses associated with exposure to radioactive fallout from the test site. In this study, tooth doses have been reconstructed for 103 persons with all studied teeth having been formed before the first nuclear test in 1949. Doses above those received from natural background radiation, termed “accident doses”...

  18. Developments in optically stimulated luminescence techniques for dating and retrospective dosimetry

    Bøtter-Jensen, L.; Murray, A.S.

    Optically stimulated luminescence signals from natural quartz and feldspar are now used routinely in dating geological and archaeological materials. More recently they have also been employed in accident dosimetry, i.e. the retrospective assessment of doses received as a result of a nuclear......-precision single-aliquot measurement protocols. These offer exciting possibilities in dating and accident dosimetry, and are already leading to new demands on measurement techniques and facilities....

  19. Breast dosimetry

    The estimation of the absorbed dose to the breast is an important part of the quality control of the mammographic examination. Knowledge of breast dose is essential for the design and performance assessment of mammographic imaging systems. This review gives a historical introduction to the measurement of breast dose. The mean glandular dose (MGD) is introduced as an appropriate measure of breast dose. MGD can be estimated from measurements of the incident air kerma at the surface of the breast and the application of an appropriate conversion factor. Methods of calculating and measuring this conversion factor are described and the results discussed. The incident air kerma itself may be measured for patients or for a test phantom simulating the breast. In each case the dose may be determined using TLD measurements, or known exposure parameters and measurements of tube output. The methodology appropriate to each case is considered and the results from sample surveys of breast dose are presented. Finally the various national protocols for breast dosimetry are compared

  20. Neutron dosimetry - A review

    This review summarizes information on the following subjects: (1) physical processes of importance in neutron dosimetry; (2) biological effects of neutrons; (3) neutron sources; and (4) instruments and methods used in neutron dosimetry. Also, possible improvements in dosimetry instrumentation are outlined and discussed. (author)

  1. Probability of spent fuel transportation accidents

    McClure, J. D.

    1981-07-01

    The transported volume of spent fuel, incident/accident experience and accident environment probabilities were reviewed in order to provide an estimate of spent fuel accident probabilities. In particular, the accident review assessed the accident experience for large casks of the type that could transport spent (irradiated) nuclear fuel. This review determined that since 1971, the beginning of official US Department of Transportation record keeping for accidents/incidents, there has been one spent fuel transportation accident. This information, coupled with estimated annual shipping volumes for spent fuel, indicated an estimated annual probability of a spent fuel transport accident of 5 x 10/sup -7/ spent fuel accidents per mile. This is consistent with ordinary truck accident rates. A comparison of accident environments and regulatory test environments suggests that the probability of truck accidents exceeding regulatory test for impact is approximately 10/sup -9//mile.

  2. An aftermath analysis of the 2014 coal mine accident in Soma, Turkey: Use of risk performance indicators based on historical experience.

    Spada, Matteo; Burgherr, Peter

    2016-02-01

    On the 13th of May 2014 a fire related incident in the Soma coal mine in Turkey caused 301 fatalities and more than 80 injuries. This has been the largest coal mine accident in Turkey, and in the OECD country group, so far. This study investigated if such a disastrous event should be expected, in a statistical sense, based on historical observations. For this purpose, PSI's ENSAD database is used to extract accident data for the period 1970-2014. Four different cases are analyzed, i.e., OECD, OECD w/o Turkey, Turkey and USA. Analysis of temporal trends for annual numbers of accidents and fatalities indicated a non-significant decreasing tendency for OECD and OECD w/o Turkey and a significant one for USA, whereas for Turkey both measures showed an increase over time. The expectation analysis revealed clearly that an event with the consequences of the Soma accident is rather unlikely for OECD, OECD w/o Turkey and USA. In contrast, such a severe accident has a substantially higher expectation for Turkey, i.e. it cannot be considered an extremely rare event, based on historical experience. This indicates a need for improved safety measures and stricter regulations in the Turkish coal mining sector in order to get closer to the rest of OECD. PMID:26687539

  3. Reconstructive dosimetry for cutaneous radiation syndrome

    Lima, C.M.A.; Lima, A.R.; Degenhardt, Ä.L.; Da Silva, F.C.A., E-mail: dasilva@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Valverde, N.J. [Fundacao Eletronuclear de Assistencia Medica, Rio de Janeiro, RJ (Brazil)

    2015-10-15

    According to the International Atomic Energy Agency (IAEA), a relatively significant number of radiological accidents have occurred in recent years mainly because of the practices referred to as potentially high-risk activities, such as radiotherapy, large irradiators and industrial radiography, especially in gammagraphy assays. In some instances, severe injuries have occurred in exposed persons due to high radiation doses. In industrial radiography, 80 cases involving a total of 120 radiation workers, 110 members of the public including 12 deaths have been recorded up to 2014. Radiological accidents in industrial practices in Brazil have mainly resulted in development of cutaneous radiation syndrome (CRS) in hands and fingers. Brazilian data include 5 serious cases related to industrial gammagraphy, affecting 7 radiation workers and 19 members of the public; however, none of them were fatal. Some methods of reconstructive dosimetry have been used to estimate the radiation dose to assist in prescribing medical treatment. The type and development of cutaneous manifestations in the exposed areas of a person is the first achievable gross dose estimation. This review article presents the state-of-the-art reconstructive dosimetry methods enabling estimation of local radiation doses and provides guidelines for medical handling of the exposed individuals. The review also presents the Chilean and Brazilian radiological accident cases to highlight the importance of reconstructive dosimetry. (author)

  4. CHF experiments under realistic severe accident condition for IVR-ERVC strategy

    This study describes critical heat flux (CHF) experiments using a 2-D curved test section with trisodium phosphate (TSP : Na3PO4) and boric acid (BA : H3BO5). The CHF values of TSP solution, BA solution, and TSP + BA solution were enhanced by as much as 50% for all experimental conditions except the condition of 150 mm radius with BA solution. The enhancement can be explained by wettability enhancement and decrease of bubble departure diameter. This CHF enhancement could provide additional thermal margin for the IVR-ERVC strategy. (author)

  5. Developments in optically stimulated luminescence techniques for dating and retrospective dosimetry

    Bøtter-Jensen, L.; Murray, A.S.

    1999-01-01

    Optically stimulated luminescence signals from natural quartz and feldspar are now used routinely in dating geological and archaeological materials. More recently they have also been employed in accident dosimetry, i.e. the retrospective assessment of doses received as a result of a nuclear...... accident. Since 1990, the exploration of this wide variety of applications has driven an intensive investigation and development programme at Riso in measurement facilities and techniques. This paper reviews some of the outcomes of this programme, including (i) optimisation of stimulation and emission...... windows, and detection sensitivity, (ii) experience with various stimulation light sources, including filtered incandescent lamps and high intensity light emitting diodes and laser diodes (infrared at 830-850 nm, blue-green at 420-550 nm and blue at 470 nm). Also discussed are recently developed high...

  6. Occupational Radiation Protection in Severe Accident Management

    As an early response to the Fukushima Daiichi NPP accident, the Information System on Occupational Exposure (ISOE) Bureau decided to focus on the following issues as an initial response of the joint program after having direct communications with the Japanese official participants in April 2011: - Management of high radiation area worker doses: It has been decided to make available the experience and information from the Chernobyl accident in terms of how emergency worker / responder doses were legally and practically managed, - Personal protective equipment for highly-contaminated areas: It was agreed to collect information about the types of personnel protective equipment and other equipment (e.g. air bottles, respirators, air-hoods or plastic suits, etc.), as well as high-radiation area worker dosimetry use (e.g. type, number and placement of dosimetry) for different types of emergency and high-radiation work situations. Detailed information was collected on dose criteria which are used for emergency workers /responders and their basis, dose management criteria for high dose/dose rate areas, protective equipment which is recommended for emergency workers / responders, recommended individual monitoring procedures, and any special requirement for assessment from the ISOE participating nuclear utilities and regulatory authorities and made available for Japanese utilities. With this positive response of the ISOE official participants and interest in the situation in Fukushima, the Expert Group on Occupational Radiation Protection in Severe Accident Management (EG-SAM) was established by the ISOE Management Board in May 2011. The overall objective of the EG-SAM is to contribute to occupational exposure management (providing a view on management of high radiation area worker doses) within the Fukushima plant boundary with the ISOE participants and to develop a state-of-the-art ISOE report on best radiation protection management practices for proper radiation

  7. Air medical transport of patients from offshore oil and gas facilities. Historical accident data and initial experience.

    Taylor, D H; Casta, R; Walker, V; Collier, F; Fromm, R E

    1993-01-01

    The offshore petroleum exploration and production industry (OSI) is isolated from traditional means of access to emergent health care and may benefit from the unique attributes of helicopter air medical transport. This study was undertaken to review the incidence of OSI-related incidents, injuries and deaths, and report the initial experience of a civilian hospital-based helicopter air transport program in the evacuation of offshore patients. It was learned that the mean annual incidence of major OSI accidents from 1980 to 1986 was 19.1 (+/- 7.0). Mean annual mortality and reported injury were 14.7 (+/- 7.6) and 36.7 (+/- 25.4) patients respectively. Fires and explosions were the most frequently reported events at 62 per year (+/- 11.5/year). Nine OSI patients were evacuated by helicopter during the study's eight-month pilot period (seven for trauma and two for medical illness). One of the nine patients had been exposed to a potentially hazardous substance, requiring changes in the air medical team's operations, aircraft and equipment. The study shows that the offshore petroleum environment is ideally suited for air medical transport, as injuries are common and medical illnesses are to be expected. However, air medical programs operating offshore must deal with additional regulatory requirements and develop operational procedures to ensure safety during these flights. PMID:10127859

  8. Medical preparedness and response in nuclear accidents. The health team's experience in joint work with the radiological protection area

    The interaction between the health and the radiological protection areas has proved fundamental, in our work experience, for the quality of response to victims of accidents, involving ionizing radiation. The conceptions and basic needs comprehension of the adequate response, on these two areas, have brought changes to the essential behavior related to the victim's care, the protection response, the environment and waste production. The joint task of health professionals and radiological protection staff, as first responders, demonstrates that it is possible to adjust practices and procedures. The training of professionals of the radiological protection area by health workers, has qualified them on the basic notions of pre-hospital attendance, entitling the immediate response to the victim prior to the health team arrival, as well as the discussion on the basic concepts of radiological protection with the health professionals, along with the understanding of the health area with its specific needs on the quick response to imminent death risk, or even the necessary procedures of decontamination. (author)

  9. Severe accident research at the Transuranium Institute Karlsruhe: A review of past experience and its application to future challenges

    Highlights: • Severe accident research at the Transuranium Institute, Karlsruhe has been reviewed. • Large (Phébus, TMI-2) and smaller tests have improved understanding of core degradation. • Cladding/structural materials interaction and attack of fuel are important in degradation. • Formation and composition of molten fuel pool in the lower bundle was reproducible. • This mechanistic knowledge has greatly assisted severe accident modelling. - Abstract: With the current situation in Japan one should examine previous research into severe accidents and the current state of European severe accident research to assess what are the priorities for research for existing and future nuclear reactors. The European Commission’s SARNET 2 (Severe Accident NETwork of Excellence) programme and its SARP (Severe Accident Research Priorities) assessments have been made and have outlined the future needs as seen from the EU point of view. There is already considerable research that will be very valuable in analysing and guiding the investigation and remediation activities at Fukushima Dai-ichi. This includes investigations into previous major accidents and international severe fuel damage projects. Facilities using analogue materials are able to analyse large-scale behaviour of materials, while smaller-scale testing of irradiated fuel for detailed property measurements are important for mechanistic studies. The final (and very important) aspect is application of this information to formulate codes to model the identified mechanisms and also to have their predictions validated by the data. This paper will take examples from the Transuranium Institute’s (ITU Karlsruhe’s) contribution to projects such as the TMI-2 accident investigation and the Phébus PF bundle and fission product deposit investigations as well as some of the smaller scale testing and modelling support that ITU has performed over the last 20 years. This will show what has been learnt about fuel and

  10. Experiments on high temperature graphite and steam reactions under loss of coolant accident conditions

    To obtain fundamental data for safety analyses of fusion reactors with regard to loss of coolant inside the vacuum vessel, the rate of corrosion reaction between high temperature graphite and steam was measured experimentally between 1000 and 1600 C. A preliminary experiment gave an activation energy for reaction between oxygen and isotropic graphite as 45kJmol-1. The reaction rate with steam depended on temperature, with an inflection point near 1300 C. The activation energy was about 270kJmol-1 at temperatures below 1300 C, and 104kJmol-1 at higher temperatures. The energy was not strongly dependent on the graphite properties, but the reaction rate varied with them. The reactivity of the isotropic graphite was more than twice as high as that of C/C composite. The molar ratio of the product gases [H2]/[CO] increased slightly with increasing temperature. Although the [CO]/[CO2] ratio also increased with temperature to 1300 C, it decreased above this temperature. This behavior reflects a change in reaction mechanism near this temperature; the composition of the product gas could be estimated numerically using elementary reaction rates. (orig.)

  11. In-pile experiments on the fuel rod behavior in a loss-of-coolant accident

    This report describes the results of the destructive postirradiation examination of Test Series F with respect to the mechanical behavior of Zircaloy-4 cladding material, the oxidation and corrosion behavior of the cladding, the mechanical behavior of the fuel, and the fission gas release and volume change of the fuel. No difference between the behavior of unirradiated and preirradiated rods has been found, with the exception of the fuel condition. In the preirradiated fuel rods the fuel underwent considerable fragmentation during the experiments. Oxidation of the inside surface of the cladding was observed at and near the rupture and was caused primarily by penetrating steam. The fuel contributes slightly to oxidation of the cladding inside surface. No influence of iodine or other volatile fission products on the deformation and fracture behavior due to stress corrosion cracking has been found. The maximum fission gas release during preirradiation was 5.5% with an additional 6% release during the in-pile LOCA transient. (orig./HP)

  12. ADASIR system: a Cuban learning experience from accidents and promotion of radiation safety culture

    The Cuban Regulatory Authority is carrying out a National Program for fostering and development of Safety Culture taking into account the wide recognition of the Human factors contribution to radiological events. The program includes the introduction of new regulatory practices and initiatives in order to increase the safety culture in Cuban facilities. The most recent of those initiatives is the System for Radiological Event Analysis, Dissemination and Learning, called ADASIR (Initials of the System's name in Spanish). The main purpose of this system is to provide a better understanding and knowledge of any radiological event reported both in the country and abroad reducing, this way, the possibility of a new occurrence of a similar event in our facilities. A team of regulatory and external experts make together a detailed review of all available information about the event and identify possible root causes, failed barriers and other important data of national interest. The results of such review are documented and sent to any Cuban facility or organization with potential for similar occurrence according to the equipment and practices they have. The document includes an specific checklist which could be used by the facilities to make a self-assessment and evaluate theirs strength and weakness in regards to a similar event. This paper presents the main characteristics and results of this new experience of Cuban Regulatory Authority. (author)

  13. A study on an ultrasonic thermometry system for measuring very high temperatures in severe accident experiments

    LAVA (Lower-plenum Arrested Vessel Attack) experiments have been performed using high temperature molten material to be relocated into a linearly scaled lower head vessel, in which temperature measuring is a very important factor. In this paper, the measure of very high temperatures includes out of reactor room temperature studies of ultrasonic thermometer design, high temperature investigations of probe materials, and the implementation of a high resolution signal processing system using the split spectrum processing technique based on PC software control. This system is composed of sensors, a transducer, ultrasonic instruments, and a PC control system. To match the sensors, a tungsten rod was inserted in the centerline of the transducer, and the measured temperature was converted into an ultrasonic delay time from the reflected signal at the notch fabricated by an electric beam. The two sensor's lengths are 500 mm and 1000 mm, and the two notches at 50 and 80 mm from the end of the rods could be used to measure the axial temperature in a molten material pool heated to about 2000degC. (author)

  14. Analysis of the experience in participation of army medical service in medical arrangement in case of radiation accident

    The paper presented calculations of manpower and money funds for rendering aid to the injured persons in case of radiation accident. The authors offered a scheme of using medical anti-radial aids on various stages of radiation accident; immediately after the accident in case of non-predicted and controlled radiation exposure. Army Medical Service is capable of solving promptly the tasks of medical aid with the help of highly mobile specialized medical units, the use of which is stipulated in the system of the Russian Service of disaster medicine. 10 refs.; 1 tab

  15. Scoping Experiments for Pressure Drop Measurement for the Ex-Vessel Debris Bed Coolability in Severe Accidents

    Park, Jin Ho; Kim, Eun Ho; Park, Hyun Sun [POSTECH, Pohang (Korea, Republic of); Kim, Moo Hwan [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of); Ma, Weimin; Bechta, Sevostian [Nuclear Power Safety Division, Stockholm (Sweden)

    2014-05-15

    To ensure the long-term cooling of corium in the reactor cavity, it is important to ensure the coolant ingression into the internally heat generated corium debris bed governed by pressure drop in the porous media. According to the previous investigations on molten fuel-coolant interactions (FCIs) experiments, the debris beds are expected to form channels in the bed due to intensive boiling and flow. And also, it was found that quenched particulate debris bed was composed of multi-sized (0∼10 mm), irregular shape particles and it has a micro/macro inhomogeneity such as axially and radially stratified debris bed, where a layer of smaller particles covers the main bed part. In this particulate debris bed with the internal heat generation by decay heat, not only co- but also counter-current two-phase flow may be occurred by the water inflow through sides of bed combined with steam outflow to top of bed. To investigate the effect of each characteristics of heterogeneous debris bed expected in real severe accident scenarios on pressure drop with various conditions, an experimental facility called as PICASSO (Pressure drop Investigation and Coolability ASSessment through Observation) facility was constructed. With the experimental facility, the scoping test was conducted as injecting upward air flow into the bottom of particle bed composed of 2 mm, 5 mm spherical SUJ-2 balls respectively, and the experimental data compared with Ergun equation. As a result of the single phase flow experiment using air, Ergun equation predicts the experimental data for the spherical particles with the diameter of 2 mm and 5 mm with a mean deviation of 14.62 %.

  16. Neutron dosimetry

    A neutron irradiation facility was designed and built in order to establish a procedure for calibrating neutron monitors and dosemeters. A 185 GBq 241 Am Be source of known is used as a reference source. The irradiation facility using this source in the air provides neutron dose rates between 9 nSv s-1 and 0,5 μSv s-1. A calibrated 50 nSv s-1 thermal neutron field is obtained by using a specially designed paraffin block in conjunction with the 241 Am Be source. A Bonner multisphere spectrometer was calibrated, using a procedure based on three methods proposed by international standards. The unfold 241 Am Be neutron spectrum was determined from the Bonner spheres data and resulted in a good agreement with expected values for fluence rate, dose rate and mean energy. A dosimetric system based on the electrochemical etching of CR-39 was developed for personal dosimetry. The dosemeter badge using a (n,α) converter, the etching chamber and high frequency power supply were designed and built specially for this project. The electrochemical etching (ECE) parameters used were: a 6N KOH solution, 59 deg C, 20 kVpp cm-1, 2,0 kHz, 3 hours of ECE for thermal and intermediate neutrons and 6 hours for fast neutrons. The calibration factors for thermal, intermediate and fast neutrons were determined for this personal dosemeter. The sensitivities determined for the developed dosimetric system were (1,46± 0,09) 104 tracks cm-2 mSv-1 for thermal neutrons, (9±3) 102 tracks cm-2 mSV-1 for intermediate neutrons and (26±4) tracks cm-2 mSv-1 for fast neutrons. The lower and upper limits of detection were respectively 0,002 mSv and 0,6 mSv for thermal neutrons, 0,04 mSv and 8 mSv for intermediate neutrons and 1 mSv and 12 mSv for fast neutrons. In view of the 1990's ICRP recommendations, it is possible to conclude that the personal dosemeter described in this work is sufficiently sensitive to thermal and intermediate neutrons but fast neutron monitoring ar radiological protection level

  17. Dosimetric support of the International Programme on the Health Effects of the Chernobyl Accident (IPHECA) pilot project: main results and problems.

    Likhtarev, I A; Kovgan, L N; Repin, V S; Los', I P; Chumak, V V; Novak, D N; Sobolev, B G; Kairo, I A; Chepurnoy, N I; Perevosnikov, O N; Litvinets, L A

    1996-01-01

    The problem of post-Chernobyl dosimetry is unique in its complexity in the history of radiation medicine and radiation protection. This is because the early experience of mass exposure of people (bombing of Hiroshima and Nagasaki, Windscale and South-Ural accidents, exposure of inhabitants of Nevada in the United States of America, the Semipalatinsk area in the former USSR, the Marshall Islands, and the Goiånia accident in Brazil, and others) differed both in the much simpler structure of the irradiation source and in the number and characteristics of exposed persons. It is obvious that post-Chernobyl dosimetry, both as an independent problem, and as a tool for epidemiological studies, requires significant expertise and economic and technical expenditures. Extensive and deep research has been carried out in Ukraine for the past 10 years. This article reviews the main results of these studies. PMID:8896257

  18. Radioactive material (RAM) transportation accident and incident experience in the U.S.A. (1971-1997)

    The Radioactive Materials Incident Report (RMIR) database was developed in 1981 at the Transportation Technology Center of Sandia National Laboratories to support its research and development activities for the US Department of Energy (DOE). This database contains information about radioactive materials transportation incidents that have occurred in the US since 1971. These data were drawn from the US Department of Transportation's (DOT) Hazardous Materials Incident Report system, from Nuclear Regulatory Commission (NRC) files, and from various agencies including state radiological control offices. Support for the RMIR data base is funded by the National Transportation Program (EM-70) of the US Department of Energy. Transportation events in RMIR are classified in one of the following ways: as a transportation accident, as a handling accident, or as a reported incident. This presentation will provide definitions for these classifications and give examples of each. The primary objective of this presentation is to provide information on nuclear materials transportation accident incident events in the US for the period 1971--1997. Among the areas to be examined are: transportation accidents by mode, package response during accidents and an examination of accidents where release of contents has occurred

  19. Considering lessons learned about safety culture and their reflection to activity. After Fukushima Daiichi Nuclear Power Plant accident experience

    Fukushima Daiichi Nuclear Power Plant accident forced neighboring residents to evacuate for a long time and gave Public anxieties greatly and significant effects to social activities in Japan. Public trust of nuclear power was lost by not preventing the accident and future of nuclear power became reconsidered, which nuclear industry people regretted deeply. Japan Nuclear Technology Institute (JANTI) had conducted activities enhancing safety culture in nuclear industry. It would be necessary to consider improvements of accident prevention and mitigation measures after evaluating the accident in a viewpoint of 'safety culture'. Based on published information and knowledge accumulated by activities of JANTI, the accident was examined taking account of greatness of nuclear accident and its effects from the side of safety culture. Lessons learned about safety culture were pointed out as; (1) reconfirmation of specialty of nuclear technology. (2) reinforcement of questioning and learning attitudes and (3) improvement of evaluation capability of nuclear safety and safety assurance against external event. These were reflected in activities such as; (1) reconsideration of safety culture assessment, (2) strengthening further support to improve safety culture consciousness and (3) improvement of peer review activity. (T. Tanaka)

  20. Radiation-induced damage analysed by luminescence methods in retrospective dosimetry and emergency response

    The increasing risk of a mass casualty scenario following a large scale radiological accident or attack necessitates the development of appropriate dosimetric tools for emergency response. Luminescence dosimetry has been reliably applied for dose reconstruction in contaminated settlements for several decades and recent research into new materials carried close to the human body opens the possibility of estimating individual doses for accident and emergency dosimetry using the same technique. This paper reviews the luminescence research into materials useful for accident dosimetry and applications in retrospective dosimetry. The properties of the materials are critically discussed with regard to the requirements for population triage. It is concluded that electronic components found within portable electronic devices, such as e.g. mobile phones, are at present the most promising material to function as a fortuitous dosimeter in an emergency response.

  1. 49 CFR 195.54 - Accident reports.

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Accident reports. 195.54 Section 195.54... PIPELINE Annual, Accident, and Safety-Related Condition Reporting § 195.54 Accident reports. (a) Each operator that experiences an accident that is required to be reported under § 195.50 shall as soon...

  2. Alanine - ESR dosimetry, feasibility and possible applications

    Alanine ESR dosimetry presents a great interest for quality controls in radiotherapy. This new developed water equivalent alanine dosimeter allows a reproducible dose measurement, by a non-destructive readout technique in a large dose range. In this paper the stability of the dosimeter response has been shown but also its independence with the energy or the dose rate of the absorbed radiation. Through this different studies, one can broaden the application field of alanine / ESR dosimetry especially for in-vivo dosimetry. The results of the experiments and the intra operative treatment, indicate that this kind of dosimetry seems to be a promising technique for in-vivo quality controls in electron beam, γ ray or X ray radiotherapy. (authors)

  3. The BNFL legal electronic dosimetry service

    BNFL Magnox Generation started a three year scheme in April 1996 to introduce Siemens Electronic Personal Dosimetry (EPD) systems into its reactor sites as part of an initiative to improve the control of doses and the accuracy of dose statistics and to record personal legal dose. Concurrent with the installation of the EPD systems a successful application was made to the United Kingdom Health and Safety Executive (HSE) for approval of the BNFL dosimetry service to use the Siemens EPD Mk 1.2 for recording legal doses. This paper discusses the experiences of the BNFL dosimetry service in operating the approved dosimetry service since it's approval by the HSE in January 2000. (authors)

  4. Radiation dosimetry for microbial experiments in the International Space Station using different etched track and luminescent detectors

    Goossens, O.; Vanhavere, F.; Leys, N.; De Boever, P.; O'Sullivan, D.; Zhou, D.; Spurný, František; Yukihara, E.; Gaza, R.; McKeever, S.

    2006-01-01

    Roč. 120, 1- 4 (2006), s. 433-437. ISSN 0144-8420 R&D Projects: GA MŠk 1P05OC032 Institutional research plan: CEZ:AV0Z10480505 Keywords : bacterial experiments * space flight * etched track detectors * thermoluminescent detectors Subject RIV: DN - Health Impact of the Environment Quality Impact factor: 0.446, year: 2006

  5. Beam-Port Design of a Radiobiological Dosimetry Experiment for 10B-Enhanced 252Cf Brachytherapy

    It has been previously suggested that the incorporation of 10B-labeled drugs into tumor cells might significantly increase the dose to the peripheral tumor cells in 252Cf brachytherapy. The dose enhancement comes from the thermal neutron capture reactions of 10B(n, α)7Li. As a new cancer treatment modality, this so-called 10und B-und Enhanced 252und Cf und Brachyund therapy (BECBT) is currently being commercialized by Isotron. One of the challenges for implementing BECBT has been to determine the maximum tolerable dose (MTD) to the normal tissue surrounding a tumor. Because the relative biological effectiveness for the 10B(n, α)7Li reaction products is greater than that for fission neutrons, the MTD should decrease as 10B concentration increases for BECBT. To more precisely determine the MTD for BECBT, we intend to conduct both in vitro (cell culture) and in vivo (rat) experiments with a 50-mg 252Cf source. We will use cell survival fraction and normal brain necrosis as the biological end points for the cell-culture experiments and rat experiments, respectively. To carry out these experiments, the neutron field to which the samples are exposed must contain a significant portion of thermal neutrons. The rat experiments further require the use of a very small and well-collimated neutron beam to effectively irradiate the rat brain while minimizing the dose to its whole body. This paper discusses the design criteria for the experimental neutron beam port and the computational work leading to its optimal configuration

  6. Review of retrospective dosimetry techniques for external ionising radiation exposures

    The current focus on networking and mutual assistance in the management of radiation accidents or incidents has demonstrated the importance of a joined-up approach in physical and biological dosimetry. To this end, the European Radiation Dosimetry Working Group 10 on 'Retrospective Dosimetry' has been set up by individuals from a wide range of disciplines across Europe. Here, established and emerging dosimetry methods are reviewed, which can be used immediately and retrospectively following external ionising radiation exposure. Endpoints and assays include dicentrics, translocations, premature chromosome condensation, micronuclei, somatic mutations, gene expression, electron paramagnetic resonance, thermoluminescence, optically stimulated luminescence, neutron activation, haematology, protein biomarkers and analytical dose reconstruction. Individual characteristics of these techniques, their limitations and potential for further development are reviewed, and their usefulness in specific exposure scenarios is discussed. Whilst no single technique fulfils the criteria of an ideal dosemeter, an integrated approach using multiple techniques tailored to the exposure scenario can cover most requirements. (authors)

  7. Development of radiation biological dosimetry

    Up until now, only a few methods have been developed for radiation biological dosimetry such as conventional chromosome aberration and micronucleus in peripheral blood cell. However, because these methods not only can be estimated by the expert, but also have a little limitation due to need high technique and many times in the case of radiation accident, it is very difficult to evaluate the absorbed dose of victims. Therefore, we should develop effective, easy, simple and rapid biodosimetry and its guideline (triage) to be able to be treated the victims as fast as possible. We established the premature chromosome condensation assay and apoptotic fragment assay which was the significant relationship between dose and cell damages to evaluate the irradiation dose as correct and rapid as possible using lymphocytes and crypt cells, and compared with conventional chromosome aberration assay and micronuclei assay

  8. Development of radiation biological dosimetry

    Cho, Chul Koo; Kim, Tae Hwan; Lee, Yun Sil; Son, Young Sook; Kim, Soo Kwan; Jang, Won Suk; Le, Sun Joo; Jee, Young Heun; Jung, Woo Jung

    1999-04-01

    Up until now, only a few methods have been developed for radiation biological dosimetry such as conventional chromosome aberration and micronucleus in peripheral blood cell. However, because these methods not only can be estimated by the expert, but also have a little limitation due to need high technique and many times in the case of radiation accident, it is very difficult to evaluate the absorbed dose of victims. Therefore, we should develop effective, easy, simple and rapid biodosimetry and its guideline (triage) to be able to be treated the victims as fast as possible. We established the premature chromosome condensation assay and apoptotic fragment assay which was the significant relationship between dose and cell damages to evaluate the irradiation dose as correct and rapid as possible using lymphocytes and crypt cells, and compared with conventional chromosome aberration assay and micronuclei assay.

  9. Silicon diode dosimetry

    The theory of silicon dosimetry is briefly reviewed with respect to operation of these diodes without reverse bias in the short-circuit current mode. The problems of temperature dependence, radiation damage, and the dependence on photon energy are discussed. Various applications of the diodes to practical radiation dosimetry are then described with a view toward pointing out the pitfalls as well as the advantages of using these diodes for dosimetry. (author)

  10. Silicon diode dosimetry

    Dixon, R.L.; Ekstrand, K.E. (Wake Forest Univ., Winston-Salem, NC (USA). Bowman Gray School of Medicine)

    1982-11-01

    The theory of silicon dosimetry is briefly reviewed with respect to operation of these diodes without reverse bias in the short-circuit current mode. The problems of temperature dependence, radiation damage, and the dependence on photon energy are discussed. Various applications of the diodes to practical radiation dosimetry are then described with a view toward pointing out the pitfalls as well as the advantages of using these diodes for dosimetry.

  11. Advances in biomedical dosimetry

    The symposium was organized in order to focus on the problems, developments and areas of further research in the life sciences. Forty-nine papers were presented dealing with instrumentation, techniques, experimental and theoretical studies. They included neutron sources and mixed-field dosimetry; developments (e.g. thermocurrent dosimetry) in dosimetry; physical aspects of radiation therapy, and treatment planning; international, national and regional radiation metrology programmes; diagnostic medical x-ray sources, imaging systems and patient doses; high-energy electron and γ-ray dosimetry; and doses determination for ingested or administered radionuclides

  12. Measurement assurance in dosimetry

    The uses of radiation in medicine and industry are today wide in scope and diversity and there is a need for reliable dosimetry in most applications. In particular, high accuracy in dosimetry is required in the therapeutic use of radiation. Consequently, calibration procedures for radiotherapy generally meet also the accuracy requirements for applications in other fields, such as diagnostic radiology, radiation protection and industrial radiation processing. The emphasis at this symposium was therefore mainly or radiotherapy dosimetry, but the meeting also included one session devoted to dosimetry in diagnostic radiology. Refs, fig and tabs

  13. Internal sources dosimetry

    The absorbed dose, need of estimation in risk evaluation in the application of radiopharmaceuticals in Nuclear Medicine practice,internal dosimetry,internal and external sources. Calculation methodology,Marinelli model,MIRD system for absorbed dose calculation based on biological parameters of radiopharmaceutical in human body or individual,energy of emitted radiations by administered radionuclide, fraction of emitted energy that is absorbed by target body.Limitation of the MIRD calculation model. A explanation of Marinelli method of dosimetry calculation,β dosimetry. Y dosimetry, effective dose, calculation in organs and tissues, examples. Bibliography .

  14. Dosimetry of ionizing radiation

    The publication deals with a major field of ionizing radiation dosimetry, viz., integrating dosimetric methods, which are the basic means of operative dose determination. It is divided into the following sections: physical and chemical effects of ionizing radiation; integrating dosimetric methods for low radiation doses (film dosimetry, nuclear emulsions, thermoluminescence, radiophotoluminescence, solid-state track detectors, integrating ionization dosemeters); dosimetry of high ionizing radiation doses (chemical dosimetric methods, dosemeters based on the coloring effect, activation detectors); additional methods applicable to integrating dosimetry (exoelectron emission, electron spin resonance, lyoluminescence, etc.); and calibration techniques for dosimetric instrumentation. (Z.S.). 422 refs

  15. Dosimetry problems encountered with re-irradiation experiments at the ''OB 70'' irradiation facility (Sr90 radiation source)

    Various dosemeters have been used for the re-irradiation experiments for determination of the radiation dose applied at the ''OB 70'' facility, for post factum irradiation detection by means of the TL method. The dosemeter values indicated irradiation times of 50 min and 90 min for application of a dose of 1 kGy. From this it is concluded that the values determined with quartz sand specimens, 70 min, are the most reliable. Since termination of the dosimetric measurements, the specimens are regularly irradiated for 70 min at our facility. The results of our TL measurements are comparable with those published by a TL intercomparison study. (orig./CB)

  16. Thermoluminescence, optically stimulated luminescence and radiophotoluminescence dosimetry: an overall perspective

    Radiation dosimetric methods are used for the estimation of dose absorbed by radiation in a detector material. These methods are required for estimation of absorbed dose in various applications of radiation, such as personnel and environmental dosimetry, retrospective/accident dosimetry and medical applications of radiation. The use of thermoluminescence (TL) as a method for radiation dosimetry of ionizing radiation has been established for many decades and has found many useful applications in various fields, such as personnel and environmental monitoring, medical dosimetry, archaeological and geological dating, space dosimetry. Several high sensitivity TL phosphor materials and thermoluminescent dosimeters (TLDs) are now commercially available in different physical forms. There are many commercial TLD systems which are being used for various dosimetric applications and even presently, TL is a major player in the field of radiation dosimetry, particularly in personnel dosimetry. In the last two decades an alternative technique, optically stimulated luminescence (OSL), has been developed, as the optical nature of the readout process does not involve problems of blackbody radiation and thermal quenching. Due to this and some other advantages OSL is also being used for various applications in radiation dosimetry, such as personnel and environmental dosimetry, retrospective/accident dosimetry and medical dosimetry. The development of Al2O3:C TL/OSL phosphor by Akselrod et al. and later investigation of its suitability for personnel dosimetry using pulsed OSL (POSL) technique of stimulation by Akselrod and McKeever, resulted in the development of a personnel dosimetry system based on Al2O3:C OSL phosphor. Therefore, thrust of modern luminescence dosimetry development is more towards OSL. The main advantages of the small size optic fiber based OSL dosimeter over the currently available radiation detectors, such as TLD, used in clinical applications, are the capabilities

  17. Radiation accidents

    Radiation accidents may be viewed as unusual exposure event which provide possible high exposure to a few people and, in the case of nuclear plants events, low exposure to large population. A number of radiation accidents have occurred over the past 50 years, involving radiation machines, radioactive materials and uncontrolled nuclear reactors. These accidents have resulted in number of people have been exposed to a range of internal and external radiation doses and those involving radioactive materials have involved multiple routs of exposure. Some of the more important accidents involving significant radiation doses or releases of radioactive materials, including any known health effects involves in it. An analysis of the common characteristics of accidents is useful resolving overarching issues, as has been done following nuclear power, industrial radiography and medical accidents. Success in avoiding accidents and responding when they do occur requires planning in order to have adequately trained and prepared health physics organization; well defined and developed instrument program; close cooperation among radiation protection experts, local and state authorities. Focus is given to the successful avoidance of accidents and response in the events they do occur. Palomares, spain in late 1960, Goiania, Brazil in 1987, Thule, Greenland in 1968, Rocky flats, Colorado in 1957 and 1969, Three mile island, Pennsylvania in 1979, Chernobyl Ukraine in april 1986, Kyshtym, former Soviet Union in 1957, Windscale, UK in Oct. 1957 Tomsk, Russian Federation in 1993, and many others are the important examples of major radiation accidents. (author)

  18. Chemical forms of radioactive Cs in soils originated from Fukushima Dai-ichi Nuclear Power Plant accident, as studied by extraction experiments

    We conducted extraction experiments on soil samples contaminated with radioactive cesium originated from the Fukushima Dai-ichi nuclear power plant (FDNPP) accident in Japan in March 2011. The experimental results suggested that the majority of the radioactive cesium deposited on land surface was first adsorbed on exchangeable sites of clay minerals, and eventually it was strongly fixed in interlayer spaces of some 2:1 clay minerals. The experiment revealed that a very small amount of Cs-137 extractable with acetic acid solution existed in the surface soil layer. (author)

  19. 25 years after Chernobyl NPP accident: experience and trends of radioactive contaminated soils rehabilitation in Belarus - 59242

    Document available in abstract form only. Full text of publication follows: The paper describes the developed and applied soil decontamination measures and methods in Belarus after the Chernobyl NPP accident. It is considered the possibility of using of organo-mineral amendments based on natural raw materials (sapropel) and industrial wastes (hydrolyzed lignin, clay-salt slimes) for rehabilitation of radioactive contaminated soils. (author)

  20. Radiation protection dosimetry and calibrations

    At the SCK-CEN different specialised services are delivered for a whole range of external and internal customers in the radiation protection area. For the expertise group of radiation protection dosimetry and calibrations, these services are organized in four different laboratories: dosimetry, anthropogammametry, nuclear calibrations and non-nuclear calibrations. The services are given by a dedicated technical staff who has experience in the handling of routine and specialised cases. The scientific research that is performed by the expertise group makes sure that state-of-the-art techniques are being used, and that constant improvements and developments are implemented. Quality Assurance is an important aspect for the different services, and accreditation according national and international standards is achieved for all laboratories

  1. Experience of the new service of dosimetry internal by Bio elimination of Tecnatom; Experiencia del nuevo servicio de dosimetria interna por bioeliminacion de Tecnatom

    Duran, T.; Navas Menchen, C.; Campos Mendia, J.

    2012-07-01

    Internal dosimetry is of particular relevance for occupationally exposed workers in the field of nuclear decommissioning and radioactive facilities. The tasks to be performed at these facilities involve an increase in the risk of incorporation of radioactive material into the body, the radioactive waste generated diverse in nature and involve work that may lead to a greater dispersion of radioactive material.

  2. Dosimetry service removal

    Safety Commission

    2010-01-01

    Dear personal dosimeter user, Please note that the Dosimetry service has moved in building 55, the service is now located in the main floor: 55-R-004. Main floor instead of second floor. On your right hand when accessing in the building. Thank you Dosimetry Service

  3. Radiation therapy dosimetry system

    New therapeutic treatments generally aim to increase therapeutic efficacy while minimizing toxicity. Many aspects of radiation dosimetry have been studied and developed particularly in the field of external radiation. The success of radiotherapy relies on monitoring the dose of radiation to which the tumor and the adjacent tissues are exposed. Radiotherapy techniques have evolved through a rapid transition from conventional three-dimensional (3D) conformal radiation therapy to intensity-modulated radiation therapy (IMRT) treatments or radiosurgery and robotic radiation therapy. These advances push the frontiers in our effort to provide better patient care by improving the precision of the absorbed dose delivered. This paper presents state-of-the art radiation therapy dosimetry techniques as well as the value of integral dosimetry (INDOS), which shows promise in the fulfillment of radiation therapy dosimetry requirements. - highlights: • Pre-treatment delivery and phantom dosimetry in brachytherapy treatments were analyzed. • Dose distribution in the head and neck was estimated by physical and mathematical dosimetry. • Electron beam flattening was acquired by means of mathematical, physical and “in vivo” dosimetry. • Integral dosimetry (INDOS) has been suggested as a routine dosimetric method in all radiation therapy treatments

  4. Dosimetry in process control

    Measurement of absorbed dose and dose distribution in irradiated medical products relies on the use of quality dosimetry systems, trained personnel and a thorough understanding of the energy deposition process. The interrelationship of these factors will be discussed with emphasis on the current and future practices of process control dosimetry. (author)

  5. Usage of JENDL dosimetry file for material dosimetry in JOYO

    A cross section set with covariance error matrix for neutron spectrum unfolding has been newly prepared from JENDL-3 dosimetry file and was applied to the dosimetry test in the MK-II core (the irradiation core) of Experimental Fast Reactor 'JOYO'. The dosimetry results by the new cross section set were compared with the previous ones by ENDF/B-V dosimetry file to evaluate the applicability and accuracy for the fast reactor dosimetry. In this work, it has been concluded that more improvement can be expected for the JOYO dosimetry test by employing JENDL-3 dosimetry file. (author)

  6. Central collecting and evaluating of major accidents and near-miss-events in the Federal Republic of Germany--results, experiences, perspectives

    Uth, Hans-Joachim; Wiese, Norbert

    2004-07-26

    Lessons learnt from accidents are essential sources for updating state of the art requirements in process safety. To improve this input by a systematic way in the FRG, a central body for collecting and evaluating major accident (ZEMA) was established in 1993. ZEMA is part of the Federal Environmental Agency. All events which are to be notified due to the German Regulation on Major Accidents (Stoerfall-Verordnung) are centrally collected, analysed (deducing lessons learnt) and documented by ZEMA. The bureau is also responsible for the dissemination of the lessons learnt to all stake holders. This work is done in co-operation with the German Major-Accident Hazard Commission (Stoerfallkommission) and other international bodies like European MAHB. At the time being, over 375 events from 1980 to 2002 are registered in Germany. For each event, a separate data sheet is published in annual reports, first started in 1993. All information is also available at http://www.umweltbundesamt.de/zema/. A summary evaluation on the events from 1993 to 1999 is presented and some basic lessons learnt are shown. The results from root cause analysis underline the importance of maintenance, detailed knowledge of chemical properties, human factor issues and the role of safety organisation especially connected with subcontractors. The German notification system is described in detail and some experience with the system is reported. Keeping in mind that collecting reports from notified major accidents is only a small amount compared with all the events which might be interesting to learn from, the German Major-Accident Hazard Commission has established a separate body, the subcommittee 'Incident Evaluation', which is in charge with collecting and evaluating of minor and near-miss events. Since 1994, a concept for the registration and evaluation of those non-notifiable events was developed. From 2000 on, the concept has been put into operation. Its main elements are: - reporting of

  7. Central collecting and evaluating of major accidents and near-miss-events in the Federal Republic of Germany--results, experiences, perspectives

    Lessons learnt from accidents are essential sources for updating state of the art requirements in process safety. To improve this input by a systematic way in the FRG, a central body for collecting and evaluating major accident (ZEMA) was established in 1993. ZEMA is part of the Federal Environmental Agency. All events which are to be notified due to the German Regulation on Major Accidents (Stoerfall-Verordnung) are centrally collected, analysed (deducing lessons learnt) and documented by ZEMA. The bureau is also responsible for the dissemination of the lessons learnt to all stake holders. This work is done in co-operation with the German Major-Accident Hazard Commission (Stoerfallkommission) and other international bodies like European MAHB. At the time being, over 375 events from 1980 to 2002 are registered in Germany. For each event, a separate data sheet is published in annual reports, first started in 1993. All information is also available at http://www.umweltbundesamt.de/zema/. A summary evaluation on the events from 1993 to 1999 is presented and some basic lessons learnt are shown. The results from root cause analysis underline the importance of maintenance, detailed knowledge of chemical properties, human factor issues and the role of safety organisation especially connected with subcontractors. The German notification system is described in detail and some experience with the system is reported. Keeping in mind that collecting reports from notified major accidents is only a small amount compared with all the events which might be interesting to learn from, the German Major-Accident Hazard Commission has established a separate body, the subcommittee 'Incident Evaluation', which is in charge with collecting and evaluating of minor and near-miss events. Since 1994, a concept for the registration and evaluation of those non-notifiable events was developed. From 2000 on, the concept has been put into operation. Its main elements are: - reporting of the

  8. High-level exposure: Progress in dosimetry

    In the event of people being accidentally exposed to unusually high levels of radiation, it becomes important to obtain as quickly as possible a reasonably accurate indication of the dose which each individual may have received. This serves in the first place to show which, if any, of the persons who may have been involved should receive medical treatment or be kept under observation. In the second place the information supplements clinical observation as a guide to treatment. A symposium in Vienna, held from 8 to 12 March 1965, discussed the assessment of doses received by persons who have been accidentally irradiated, by exposure to external radiation fields, by the intake of radioactive materials, or by radioactive contamination being deposited on the surface of the body. The symposium, organised jointly by IAEA and the World Health Organisation, was entitled Personnel Dosimetry for Accidental High-Level Exposure to External and Internal Radiation. There were 179 participants from 34 countries and five international organisations. This was a specialized conference, fairly narrow in scope, since it formed one in a succession of meetings on kindred subjects. For example, a symposium held in May 1964 dealt with general methods of assessing radioactive body burdens in man; a joint IAEA/WHO meeting in October 1960, and another in October 1962, dealt with medical aspects of radiation injury and of radioactive poisoning. About half the proceedings were devoted to discussion of measurement techniques for external radiation, with detailed discussion of various kinds of warning and recording devices, monitors and personal dosimeters. From these the meeting passed on to consider supplementary methods such as estimation of neutron dosage by analysis of blood or hair, and experiments conducted by means of polyethylene phantoms to establish the dose likely to be received under particular circumstances. Other sessions dealt with the determination of internal contamination, and

  9. Operational accidents and radiation exposure experience within the United States Atomic Energy Commission, 1943--1975. [AEC health and safety during first 32 years

    1975-01-01

    The occupational injury and fatality experience during 32 years of the development of the atomic energy industry under the direction of the Atomic Energy Commission (AEC) and its predecessor, the Manhattan Engineering District, is reviewed. Data are included on the cause of all accidents, including fires and transportation accidents, and the cost of AEC property damage. Fatalities of AEC and contractor personnel from all causes during the 32-year period totaled 321, of which 184 occurred in construction; 121 in AEC operations such as production, research, and services; and 16 in Government functions. There were 19,225 lost-time injuries attributable to all accidental causes, or a 32-year frequency rate of 2.75 based on the number of injuries per million man-hours. There were six deaths attributable to nuclear causes, thee of which were due to blast and flying missiles and three caused by whole-body radiation exposure. Forty-one workers were involved in lost-time radiation accidents, of whom 26 showed clinical manifestations attributable to radiation, resulting in permanent partial-disability of three workers and the loss of a digit by four workers, while the others did not develop evidence of radiation injury. (CH)

  10. Results of Semiscale Mod-2C small-break (5%) loss-of-coolant accident. Experiments S-LH-1 and S-LH-2

    Two experiments simulating small break (5%) loss-of-coolant accidents (5% SBLOCAs) were performed in the Semiscale Mod-2C facility. These experiments were identical except for downcomer-to-upper-head bypass flow (0.9% in Experiment S-LH-1 and 3.0% in Experiment S-LH-2) and were performed at high pressure and temperature [15.6 MPa (2262 psia) system pressure; 37 K (670F) core differential temperature; 595 K(6100F) hot leg fluid temperature]. From the experimental results, the signature response and transient mass distribution are determined for a 5% SBLOCA. The core thermal-hydraulic response is characterized, including core void distribution maps, and the effect of core bypass flow on transient severity is assessed. Comparisons are made between postexperiment RELAP5 calculations and the experimental results, and the capability of RELAP5 to calculate the phenomena is assessed. 115 figs

  11. Experiences in methods to involve key players in planning protective actions in the case of a nuclear accident

    A widely used method in the planning of protective actions is to establish a stakeholder network to generate a comprehensive set of generic protective actions. The aim is to increase competence and build links for communication and coordination. The approach of this work was to systematically evaluate protective action strategies in the case of a nuclear accident. This was done in a way that the concerns and issues of all key players could be transparently and equally included in the decision taken. An approach called Facilitated Decision Analysis Workshop has been developed and tested. The work builds on case studies in which it was assumed that a hypothetical accident had led to a release of considerable amounts of radionuclides and, therefore, various types of countermeasures had to be considered. Six workshops were organised in the Nordic countries where the key players were represented, i.e. authorities, expert organisations, industry and agricultural producers. (authors)

  12. Contribution of Case Based Reasoning (CBR) in the Exploitation of Return of Experience. Application to Accident Scenarii in Railroad Transport

    Maalel, Ahmed

    2012-01-01

    The study is from a base of accident scenarii in rail transport (feedback) in order to develop a tool to share build and sustain knowledge and safety and secondly to exploit the knowledge stored to prevent the reproduction of accidents / incidents. This tool should ultimately lead to the proposal of prevention and protection measures to minimize the risk level of a new transport system and thus to improve safety. The approach to achieving this goal largely depends on the use of artificial intelligence techniques and rarely the use of a method of automatic learning in order to develop a feasibility model of a software tool based on case based reasoning (CBR) to exploit stored knowledge in order to create know-how that can help stimulate domain experts in the task of analysis, evaluation and certification of a new system.

  13. Radiation accidents in the former Soviet Union: Medical consequences and experience in the application of radiation protection measures

    The Institute of Biophysics of the Russian Federation is a scientific center which has extensive archives containing scientific studies and information on radiation safety problems and occurrences since the early days of nuclear science and research and nuclear weapons tests in the Soviet Union. Some of this classified, top secret material has recently been published by Prof. L.A. Iljin in a renowned Russian scientific journal in the form of a review of radiation accidents in the Soviet Union, general medical reports, case reports, and the effects of nuclear weapons tests. He also added his own expert view of the accidents and their effects, and his conclusions relating to public health effects and required radiation protection policy. The article in this issue of Strahlenschutz Praxis is a German translation of excerpts from the original journal article. (orig./CB)

  14. Radiological accidents: education for prevention and confrontation

    The purpose of this work is to train and inform on radiological accidents as a preventive measure to improve the people life quality. Radiological accidents are part of the events of technological origin which are composed of nuclear and radiological accidents. As a notable figure is determined that there have been 423 radiological accidents from 1944 to 2005 and among the causes prevail industrial accidents, by irradiations, medical accidents and of laboratories, among others. Latin American countries such as Argentina, Brazil, Mexico and Peru are some where most accidents have occurred by radioactivity. The radiological accidents can have sociological, environmental, economic, social and political consequences. In addition, there are scenarios of potential nuclear accidents and in them the potential human consequences. Also, the importance of the organization and planning in a nuclear emergency is highlighted. Finally, the experience that Cuba has lived on the subject of radiological accidents is described

  15. Individual dosimetry of workers and patients: implementation and perspectives; La dosimetrie individuelle des travailleurs et de patients: mise en oeuvre et perspectives

    Rannou, A.; Aubert, B.; Lahaye, Th.; Scaff, P.; Casanova, Ph.; Van Bladel, L.; Queinnec, F.; Valendru, N.; Jehanno, J.; Grude, E.; Berard, Ph.; Desbree, A.; Kafrouni, H.; Paquet, F.; Vanhavere, F.; Bridier, A.; Ginestet, Ch.; Magne, S.; Donadille, L.; Bordy, J.M.; Bottollier-Depois, J.F.; Barrere, J.L.; Ferragut, A.; Metivier, H.; Gaillard-Lecanu, E

    2008-07-01

    These days organised by the section of the technical protection of the S.F.R.P. review the different techniques of dosimetry used in France and Europe, and present the future orientations.The different interventions are as follow: Individual exposures of the workers: historic assessment and perspectives; medical exposure: where are the doses; legal obligations in individual dosimetry: which are the objective and the need on the subject; the dosimetry follow-up of workers by the S.I.S.E.R.I. system: assessment and perspectives; impact of the norm ISO 20553 on the follow-up of internal exposure; the implementation of the patient dose measurement in Belgium; techniques of passive dosimetry used in Europe; Supervision radiation protection at EDF: long term and short term approach; Comparison active and passive dosimetry at Melox; methodology for the choice of new neutron dosemeters; the working group M.E.D.O.R.: guide of internal dosimetry for the use of practitioners; O.E.D.I.P.E.: tool of modeling for the personalized internal dosimetry; the use of the Monte-Carlo method for the planning of the cancer treatment by radiotherapy becomes a reality; the works of the committee 2 of the ICRP; passive dosimetry versus operational dosimetry: situation in Europe; Implementation of the in vivo dosimetry in a radiotherapy department: experience of the Gustave Roussy institute; experience feedback on the in vivo measures in radiotherapy, based on the use of O.S.L. pellets; multi points O.S.L. instrumentation for the radiation dose monitoring in radiotherapy; dosimetry for extremities for medical applications: principle results of the European contract C.O.N.R.A.D.; references and perspectives in dosimetry; what perspectives for numerical dosimetry, an example: Sievert; system of dose management: how to answer to needs; the last technical evolutions in terms of electronic dosimetry in nuclear power plant; the fourth generation type reactors: what dosimetry. (N.C.)

  16. Chemical forms of radioactive Cs in soils originated from Fukushima Dai-ichi nuclear power plant accident studied by extraction experiments

    We performed three-step sequential extraction experiments, with Milli-Q water, 1 M ammonium acetate solution and 0.11 M acetic acid as extractants of Cs, on soils radiologically contaminated by Fukushima Dai-ichi Nuclear Power Plant accident. Though aqueous solutions containing ammonium salts are effective to extract Cs from soils, the obtained overall extracted fractions of radioactive Cs by the three-step sequential extraction process were less than 30 %. Thus, the most of the radioactive Cs deposited on soils is probably incorporated in the non- or hardly exchangeable site of clay minerals, components of the soils. (author)

  17. Accident Statistics

    Department of Homeland Security — Accident statistics available on the Coast Guard’s website by state, year, and one variable to obtain tables and/or graphs. Data from reports has been loaded for...

  18. Establishment of ANSI N13.11 X-ray radiation fields for personal dosimetry performance test by computation and experiment.

    Kim, J L; Kim, B. H.(Seoul National University, 151-742, Seoul, South Korea); Chang, S Y; J. K. Lee

    1997-01-01

    This paper describes establishment by computational and experimental methods of the American National Standard Institute (ANSI) N13.11 X-ray radiation fields by the Korea Atomic Energy Research Institute (KAERI). These fields were used in the standard irradiations of various personal dosimeters for the personal dosimetry performance test program performed by the Ministry of Science and Technology of Korea in the autumn of 1995. Theoretical X-ray spectra produced from two KAERI X-ray generator...

  19. Internal dose assessment in radiation accidents

    Although numerous models have been developed for occupational and medical internal dosimetry, they may not be applicable to an accident situation. Published dose coefficients relate effective dose to intake, but if acute deterministic effects are possible, effective dose is not a useful parameter. Consequently, dose rates to the organs of interest need to be computed from first principles. Standard bioassay methods may be used to assess body contents, but, again, the standard models for bioassay interpretation may not be applicable because of the circumstances of the accident and the prompt initiation of decorporation therapy. Examples of modifications to the standard methodologies include adjustment of biological half-times under therapy, such as in the Goiania accident, and the same effect, complicated by continued input from contaminated wounds, in the Hanford 241Am accident. (author)

  20. Improvement of dosimetry for I-131 therapy of lung metastases with special regard to children with thyroid cancer from Belarus following the Chernobyl accident. Final report 1997-1999

    The main problem in treating disseminated pulmonary metastases in children with papillary thyroid cancer is to find a balance between an insufficient dose for the ablation of metastatic tissue and unnecessary high radiation exposure to the lungs and the bone marrow. This can hardly be achieved without quantitative dosimetry for the more or less inhomogeneously distributed 1-131 in high dosed radioiodine therapy. The major goal of this project is to improve the concept for treating patients with lung metastases induced by thyroid carcinoma. Almost all of the patients with lung metastases are treated in more than one therapy course. After each course the knowledge of the doses to the tumor tissue, the lung, and the bone marrow is of crucial importance for a well funded decision about further treatment. In the cases of either the tumor doses being inefficient for ablation or substantial impairment of residuing pulmonary metastases or the cumulated doses to lung and bone marrow exceeds empirically defined ''critical'' limits the fractionated radioiodine treatment has to be stopped to avoid side effects such as lung fibrosis or leukemia in patients with papillary thyroid cancer. The decision which has to be taken must consider that prognosis with respect to mortality and quality of life even in the case of persisting lung metastases may be better than after the induction of progressive pulmonary fibrosis. Up to now, patients are treated more or less empirically until complete remission is achieved and no tumor uptake is visible in post-therapeutic scans with a gamma camera or the cumulative activity of 1-131 taken up by the lungs exceeds 3 GBq (80 mCi) according to recommendations given by Benua and Leaper in 1962. This project combines empirical approaches with theoretical research at cellular level to optimize the dose to the tumor cells with protection of healthy lung tissue. (orig.)

  1. Experience of past radiation accidents and problems of response to possible dispersion of radioactive materials in urban conditions

    The report studies into key problems associated with direct and indirect consequences of possible radiological terrorist acts committed in urban conditions. Much attention is paid to the analysis of lessons learned from elimination of consequences of past radiation accidents in the territory of the former USSR, especially as regards radioactive contamination of cities. The report contains recommendations on necessary improvements of instrumentation, methodological, legal and organizational bases of managerial decision-making to reduce a probability of radiological terrorism acts and minimize their direct and indirect consequences. (author)

  2. The micronucleus assay in radiation accidents

    The cytokinesis-block micronucleus assay in peripheral blood lymphocytes is a standardised and validated technique for bio dosimetry. Automated scoring of micronuclei allows large scale applications as in population triage in case of radiation accidents or malevolent use of radioactive sources. The dose detection limit (95% confidence) of the micronucleus assay for individual dose assessment is restricted to 0.2 Gy but can be decreased to 0.1 Gy by scoring centromeres in micronuclei using fluorescence in situ hybridization (FISH). In the past the micronucleus assay was applied for a number of large scale bio monitoring studies of nuclear power plant workers and hospital workers. Baseline micronucleus frequencies depend strongly on age and gender. The assay was also already used for bio dosimetry of radiation accidents. In a multiple endpoint bio dosimetry study for dose assessment of a worker exposed accidentally in 2003 to X-rays, a good agreement was obtained between dose estimates resulting from the micronucleus assay, the scoring of dicentrics and translocations. Automated scoring of micronuclei in combination with centromere signals, allowing systematic bio dosimetry of exposed populations, remains a challenge for the future.

  3. Dosimetry on the radiological risks prevention in radiotherapy; La dosimetria en la prevencion de riesgos radiologicos en radioterapia

    Fornet R, O. M.; Perez G, F., E-mail: nuclear2@citmahlg.holguin.inf.cu [Delegacion Territorial del CITMA, Peralta 16 esq. P. Feria, Rpto. Peralta, 80400 Holguin (Cuba)

    2014-08-15

    Dosimetry in its various forms plays a determining role on the radiological risks prevention in radiotherapy. To prove this in this paper is shown an analysis based on the risk matrix method, how the dosimetry can influence in each stages of a radiotherapy service; installation and acceptance, operation, maintenance and calibration. For each one of these stages the role that can play is analyzed as either the initiating event of a radiological accident or limiting barrier of these events of the dosimetric processes used for the individual dosimetry, the area monitoring, fixed or portable, for radiation beam dosimetry and of the patients for a radiotherapy service with cobalt-therapy equipment. The result of the study shows that the application of a prospective approach in the role evaluation of dosimetry in the prevention and mitigation of the consequences of a radiological accident in radiotherapy is crucial and should be subject to permanent evaluation at each development stage of these services. (author)

  4. INFORMATION: INDIVIDUAL DOSIMETRY SERVICE

    2004-01-01

    We inform you that the Individual Dosimetry Service will be exceptionally closed on April 13 and 14 (Tuesday and Wednesday). Only the very urgent cases will be handled during the days mentioned above.

  5. Dosimetry for radiation processing

    Miller, Arne

    1986-01-01

    During the past few years significant advances have taken place in the different areas of dosimetry for radiation processing, mainly stimulated by the increased interest in radiation for food preservation, plastic processing and sterilization of medical products. Reference services both by...... and sterilization dosimetry, optichromic dosimeters in the shape of small tubes for food processing, and ESR spectroscopy of alanine for reference dosimetry. In this paper the special features of radiation processing dosimetry are discussed, several commonly used dosimeters are reviewed, and factors...... international organizations (IAEA) and national laboratories have helped to improve the reliability of dose measurements. Several dosimeter systems like calorimetry, perspex, and radiochromic dye films are being improved and new systems have emerged, e.g. spectrophotometry of dichromate solution for reference...

  6. Performance of Core Exit Thermocouple for PWR Accident Management Action in Vessel Top Break LOCA Simulation Experiment at OECD/NEA ROSA Project

    Suzuki, Mitsuhiro; Takeda, Takeshi; Nakamura, Hideo

    Presented are experiment results of the Large Scale Test Facility (LSTF) conducted at the Japan Atomic Energy Agency (JAEA) with a focus on core exit thermocouple (CET) performance to detect core overheat during a vessel top break loss-of-coolant accident (LOCA) simulation experiment. The CET temperatures are used to start accident management (AM) action to quickly depressurize steam generator (SG) secondary side in case of core temperature excursion. Test 6-1 is the first test of the OECD/NEA ROSA Project started in 2005, simulating withdraw of a control rod drive mechanism penetration nozzle at the vessel top head. The break size is equivalent to 1.9% cold leg break. The AM action was initiated when CET temperature rose up to 623K. There was no reflux water fallback onto the CETs during the core heat-up period. The core overheat, however, was detected with a time delay of about 230s. In addition, a large temperature discrepancy was observed between the CETs and the hottest core region. This paper clarifies the reasons of time delay and temperature discrepancy between the CETs and heated core during boil-off including three-dimensional steam flows in the core and core exit. The paper discusses applicability of the LSTF CET performance to pressurized water reactor (PWR) conditions and a possibility of alternative indicators for earlier AM action than in Test 6-1 is studied by using symptom-based plant parameters such as a reactor vessel water level detection.

  7. Individual Dosimetry Service

    2004-01-01

    Individual Dosimetry Service will be closed on Thursday 9 September (Jeûne genevois) and on Friday 10 September. We inform all staffs and users under regular dosimetry control that the dosimeters for the monitoring period SEPTEMBER-OCTOBER 2004 are available from their usual dispatchers. Please have your films changed before the 13 SEPTEMBER 2004. The color of the dosimeter valid in SEPTEMBER-OCTOBER 2004 is RED.

  8. News on personal dosimetry

    What is going on in personal monitoring? The DIS-1 dosimeter (Rados/Mirion Technologies), on the market since 2000, is being introduced in the 4th dosimetry service in Switzerland. In Germany, dosimetry services are looking for alternatives to the film dosimeter. They have recently taken the decision for two technical solutions. IEC has published a standard which shall regulate technical requirements for dosimeters world-wide. (orig.)

  9. Fast neutron dosimetry

    During 1988--1990 the magnetic resonance dosimetry project was completed, as were the 250 MeV proton shielding measurements. The first cellular experiment using human cells in vitro at the 1 GeV electron storage ring was also accomplished. More detail may be found in DOE Report number-sign DOE/EV/60417-002 and the open literature cited in the individual progress subsections. We report Kinetic Energy Released in Matter (KERMA), factor measurements in several elements of critical importance to neutron radiation therapy and radiation protection for space habitation and exploration for neutron energies below 30 MeV. The results of this effort provide the only direct measurements of the oxygen and magnesium kerma factors above 20 MeV neutron energy, and the only measurements of the iron kerma factor above 15 MeV. They provide data of immediate relevance to neutron radiotherapy and impose strict criteria for normalizing and testing nuclear models used to calculate kerma factors at higher neutron energies

  10. Dosimetry and Calibration Section

    The Dosimetry and Calibration Section fulfils two tasks within CERN's Radiation Protection Group: the Individual Dosimetry Service monitors more than 5000 persons potentially exposed to ionizing radiation on the CERN sites, and the Calibration Laboratory verifies throughout the year, at regular intervals, over 1000 instruments, monitors, and electronic dosimeters used by RP Group. The establishment of a Quality Assurance System for the Individual Dosimetry Service, a requirement of the new Swiss Ordinance for personal dosimetry, put a considerable workload on the section. Together with an external consultant it was decided to identify and then describe the different 'processes' of the routine work performed in the dosimetry service. The resulting Quality Manual was submitted to the Federal Office for Public Health in Bern in autumn. The CERN Individual Dosimetry Service will eventually be officially endorsed after a successful technical test in March 1999. On the technical side, the introduction of an automatic development machine for gamma films was very successful. It processes the dosimetric films without an operator being present, and its built-in regeneration mechanism keeps the concentration of the processing chemicals at a constant level

  11. Evaluation of the concrete shield compositions from the 2010 criticality accident alarm system benchmark experiments at the CEA Valduc SILENE facility

    Miller, Thomas Martin [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Celik, Cihangir [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Dunn, Michael E [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wagner, John C [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); McMahan, Kimberly L [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Authier, Nicolas [French Atomic Energy Commission (CEA), Centre de Valduc, Is-sur-Tille (France); Jacquet, Xavier [French Atomic Energy Commission (CEA), Centre de Valduc, Is-sur-Tille (France); Rousseau, Guillaume [French Atomic Energy Commission (CEA), Centre de Valduc, Is-sur-Tille (France); Wolff, Herve [French Atomic Energy Commission (CEA), Centre de Valduc, Is-sur-Tille (France); Savanier, Laurence [French Atomic Energy Commission (CEA), Centre de Valduc, Is-sur-Tille (France); Baclet, Nathalie [French Atomic Energy Commission (CEA), Centre de Valduc, Is-sur-Tille (France); Lee, Yi-kang [French Atomic Energy Commission (CEA), Centre de Saclay, Gif sur Yvette (France); Trama, Jean-Christophe [French Atomic Energy Commission (CEA), Centre de Saclay, Gif sur Yvette (France); Masse, Veronique [French Atomic Energy Commission (CEA), Centre de Saclay, Gif sur Yvette (France); Gagnier, Emmanuel [French Atomic Energy Commission (CEA), Centre de Saclay, Gif sur Yvette (France); Naury, Sylvie [French Atomic Energy Commission (CEA), Centre de Saclay, Gif sur Yvette (France); Blanc-Tranchant, Patrick [French Atomic Energy Commission (CEA), Centre de Saclay, Gif sur Yvette (France); Hunter, Richard [Babcock International Group (United Kingdom); Kim, Soon [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Dulik, George Michael [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Reynolds, Kevin H. [Y-12 National Security Complex, Oak Ridge, TN (United States)

    2015-01-01

    In October 2010, a series of benchmark experiments were conducted at the French Commissariat a l'Energie Atomique et aux Energies Alternatives (CEA) Valduc SILENE facility. These experiments were a joint effort between the United States Department of Energy Nuclear Criticality Safety Program and the CEA. The purpose of these experiments was to create three benchmarks for the verification and validation of radiation transport codes and evaluated nuclear data used in the analysis of criticality accident alarm systems. This series of experiments consisted of three single-pulsed experiments with the SILENE reactor. For the first experiment, the reactor was bare (unshielded), whereas in the second and third experiments, it was shielded by lead and polyethylene, respectively. The polyethylene shield of the third experiment had a cadmium liner on its internal and external surfaces, which vertically was located near the fuel region of SILENE. During each experiment, several neutron activation foils and thermoluminescent dosimeters (TLDs) were placed around the reactor. Nearly half of the foils and TLDs had additional high-density magnetite concrete, high-density barite concrete, standard concrete, and/or BoroBond shields. CEA Saclay provided all the concrete, and the US Y-12 National Security Complex provided the BoroBond. Measurement data from the experiments were published at the 2011 International Conference on Nuclear Criticality (ICNC 2011) and the 2013 Nuclear Criticality Safety Division (NCSD 2013) topical meeting. Preliminary computational results for the first experiment were presented in the ICNC 2011 paper, which showed poor agreement between the computational results and the measured values of the foils shielded by concrete. Recently the hydrogen content, boron content, and density of these concrete shields were further investigated within the constraints of the previously available data. New computational results for the first experiment are now available

  12. Third conference on radiation protection and dosimetry

    1991-01-01

    This conference has been designed with the objectives of promoting communication among applied, research, regulatory, and standards personnel involved in radiation protection and providing them with sufficient information to evaluate their programs. To partly fulfill these objectives, a technical program consisting of more than 75 invited and contributed oral presentations encompassing all aspects of radiation protection has been prepared. General topics include external dosimetry, internal dosimetry, instruments, regulations and standards, accreditation and test programs, research advances, and applied program experience. This publication provides a summary of the technical program and a collection of abstracts of the oral presentations.

  13. Third conference on radiation protection and dosimetry

    This conference has been designed with the objectives of promoting communication among applied, research, regulatory, and standards personnel involved in radiation protection and providing them with sufficient information to evaluate their programs. To partly fulfill these objectives, a technical program consisting of more than 75 invited and contributed oral presentations encompassing all aspects of radiation protection has been prepared. General topics include external dosimetry, internal dosimetry, instruments, regulations and standards, accreditation and test programs, research advances, and applied program experience. This publication provides a summary of the technical program and a collection of abstracts of the oral presentations

  14. Personnel radiation dosimetry symposium: program and abstracts

    The purpose was to provide applied and research dosimetrists with sufficient information to evaluate the status and direction of their programs relative to the latest guidelines and techniques. A technical program was presented concerning experience, requirements, and advances in gamma, beta, and neutron personnel dosimetry

  15. Dosimetry procedures for an industrial irradiation plant

    Grahn, Ch.

    Accurate and reliable dosimetry procedures constitute a very important part of process control and quality assurance at a radiation processing plant. γ-Dose measurements were made on the GBS 84 irradiator for food and other products on pallets or in containers. Chemical dosimeters wre exposed in the facility under conditions of the typical plant operation. The choice of the dosimeter systems employed was based on the experience in chemical dosimetry gained over several years. Dose uniformity information was obtained in air, spices, bulbs, feeds, cosmetics, plastics and surgical goods. Most products currently irradiated require dose uniformity which can be efficiently provided by pallet or box irradiators like GBS 84. The radiation performance characteristics and some dosimetry procedures are discussed.

  16. Factors influencing EPR dosimetry in fingernails

    The technique based on the detection of ionizing radiation induced radicals by EPR in tooth enamel is an established method for the dosimetry of exposed persons in radiological emergencies. Dosimetry based on EPR spectral analysis of fingernail clippings, currently under development, has the practical advantage of the easier sample collection. A limiting factor is that overlapping the radiation induced signal (RIS), fingernails have shown the presence of two mechanically induced signals, called MIS1 and MIS2, due to elastic and plastic deformation respectively, at the time of fingernails cutting. With a water treatment, MIS1 is eliminated while MIS2 is considerably reduced. The calibration curves needed for radiation accident dosimetry should have 'universal' characteristics, ie. Represent the variability that can be found in different individuals. Early studies were directed to the analysis of factors affecting the development of such universal calibration curves. The peak to peak amplitude of the signal before and after the water treatment as well as the effect of size and number of clippings were studied. Furthermore, the interpersonal and intrapersonal variability were analyzed. Taking into account these previous studies, the optimal conditions for measurement were determined and EPR spectra of samples irradiated at different doses were used for the developing of dose-response curves. This paper presents the analysis of the results.(authors)

  17. Bayesian Methods for Radiation Detection and Dosimetry

    We performed work in three areas: radiation detection, external and internal radiation dosimetry. In radiation detection we developed Bayesian techniques to estimate the net activity of high and low activity radioactive samples. These techniques have the advantage that the remaining uncertainty about the net activity is described by probability densities. Graphs of the densities show the uncertainty in pictorial form. Figure 1 below demonstrates this point. We applied stochastic processes for a method to obtain Bayesian estimates of 222Rn-daughter products from observed counting rates. In external radiation dosimetry we studied and developed Bayesian methods to estimate radiation doses to an individual with radiation induced chromosome aberrations. We analyzed chromosome aberrations after exposure to gammas and neutrons and developed a method for dose-estimation after criticality accidents. The research in internal radiation dosimetry focused on parameter estimation for compartmental models from observed compartmental activities. From the estimated probability densities of the model parameters we were able to derive the densities for compartmental activities for a two compartment catenary model at different times. We also calculated the average activities and their standard deviation for a simple two compartment model

  18. Usability of VTL from natural quartz grains for retrospective dosimetry.

    Fujita, Hiroki; Hashimoto, Tetsuo

    2007-01-01

    To develop retrospective dosimetry of unexpected radiation accident, basic studies on violet thermoluminescence (VTL) phenomena were conducted using natural quartz grains. All VTL glowcurves of as-received samples did not exhibit peaks VTL peaks in the temperature region VTL measurements from natural quartz. The mean lives of VTL were evaluated by the various heating rates method and the range of values was found to be between some days and ten thousands of years depending on each peak. Especially, the mean life of VTL peak at 200 degrees C was years order. Furthermore, the lower detection limit was calculated to be tens of mGy from the response curve. This value was lower than that of other methods such as ESR dosimetry. From these results, we conclude that VTL dosimetry can be preferred for accidental evaluation. PMID:16936290

  19. Computer aided dosimetry and verification of exposure to radiation. Technical report

    Waller, D. [SAIC Canada (Canada); Stodilka, R.Z.; Leach, K.E.; Prud' homme-Lalonde, L. [Defence R and D Canada (DRDC), Radiation Effects Group, Space Systems and Technology, Ottawa, Ontario (Canada)

    2002-06-15

    In the timeframe following the September 11th attacks on the United States, increased emphasis has been placed on Chemical, Biological, Radiological and Nuclear (CBRN) preparedness. Of prime importance is rapid field assessment of potential radiation exposure to Canadian Forces field personnel. This work set up a framework for generating an 'expert' computer system for aiding and assisting field personnel in determining the extent of radiation insult to military personnel. Data was gathered by review of the available literature, discussions with medical and health physics personnel having hands-on experience dealing with radiation accident victims, and from experience of the principal investigator. Flow charts and generic data fusion algorithms were developed. Relationships between known exposure parameters, patient interview and history, clinical symptoms, clinical work-ups, physical dosimetry, biological dosimetry, and dose reconstruction as critical data indicators were investigated. The data obtained was examined in terms of information theory. A main goal was to determine how best to generate an adaptive model (i.e. when more data becomes available, how is the prediction improved). Consideration was given to determination of predictive algorithms for health outcome. In addition, the concept of coding an expert medical treatment advisor system was developed. (author)

  20. Computer aided dosimetry and verification of exposure to radiation. Technical report

    In the timeframe following the September 11th attacks on the United States, increased emphasis has been placed on Chemical, Biological, Radiological and Nuclear (CBRN) preparedness. Of prime importance is rapid field assessment of potential radiation exposure to Canadian Forces field personnel. This work set up a framework for generating an 'expert' computer system for aiding and assisting field personnel in determining the extent of radiation insult to military personnel. Data was gathered by review of the available literature, discussions with medical and health physics personnel having hands-on experience dealing with radiation accident victims, and from experience of the principal investigator. Flow charts and generic data fusion algorithms were developed. Relationships between known exposure parameters, patient interview and history, clinical symptoms, clinical work-ups, physical dosimetry, biological dosimetry, and dose reconstruction as critical data indicators were investigated. The data obtained was examined in terms of information theory. A main goal was to determine how best to generate an adaptive model (i.e. when more data becomes available, how is the prediction improved). Consideration was given to determination of predictive algorithms for health outcome. In addition, the concept of coding an expert medical treatment advisor system was developed. (author)

  1. Dosimetry of x-ray beams: The measure of the problem

    This document contains the text of an oral presentation on dosimetry of analytical x-ray equipment presented at the Denver X-Ray Conference. Included are discussions of sources of background radiation, exposure limits from occupational sources, and the relationship of these sources to the high dose source of x-rays found in analytical machines. The mathematical basis of x-ray dosimetry is reviewed in preparation for more detailed notes on personnel dosimetry and the selection of the most appropriate dosimeter for a specific application. The presentation concludes with a discussion common to previous x-ray equipment accidents. 2 refs

  2. USA experiences in conducting and implementing the protective measures in a case of the nuclear accident and their possible implementation

    Looking at the field of emergency planning and preparedness, it can be noticed that the situation in Europe is more or less quite different than the one found in the USA, despite the fact that, for example, lots of International Atomic Energy Agency (IAEA) material comes from the Nuclear Regulatory Commission (NRC) material. Comparison between these two approaches was very interesting and instructive. Croatia, if looking at the particular country, can learn a lot from the overall organization of the Emergency Planning and Preparedness in USA (Louisiana). Everybody has his predefined place, plan and task to be fulfilled. Mutual cooperation between different organizations and Inst.ions involved is accordingly developed and on very high level. Geographic Information System (GIS), which is also available to us, showed its usefulness during the exercises and map development, and not so much during the actual accident.(author)

  3. The experience of RELAP4/MOD6 adaptation to analysis of RBMK accidents resulting from postulated coolant loop ruptures

    RELAP4-MOD6 program widely used for PWR and BWR reactors is applied to the study of channel-type reactors RBMK-1000 and RBMK-1500 coolant loops thermohydraulics processes by accidents resulting from postulated ruptures of a pressure circuit pipelines. At the first stage of calculations is solved the general circuit problem. Then the service channel model is used for elaborate investigations of different power channels. The detailed description of the nodalization diagrams and used models is given. It is shown that fuel element can temperature variation during the first 20-30 s of the process has the character of a short-time splash. The temperature is maximal at ruptures with area of 25-30% of the pressure circuit pipeline cross section area. 2 refs.; 7 figs.; 6 tabs

  4. The Role of Dosimetry Audits in Radiotherapy Quality Assurance: Eight Years of Experience in Greek External Beam Radiotherapy and Brachytherapy Centres

    The Greek Atomic Energy Commission (GAEC) runs dosimetry audits through on-site visits for photon and electron beams and for 192Ir brachytherapy high dose rate systems in all Greek radiotherapy centres. In audits, absolute and relative dosimetry measurements are being performed. The deviation, expressed as the percentage difference of the measured values by the GAEC to the respective stated values by the radiotherapy centre of absorbed dose to water or air kerma strength were recorded and compared to the action levels of ±3% (preventive actions needed) and ±5% (immediate corrective actions needed). The results of the subsequent audit rounds, each one lasting for approximately four years, are presented in this work. During the first round, 79.2% of photon beams exhibited deviations of less than 3%, while during the second round this photon beam percentage increased to 96.9%. During the first round, 76.4% of the electron beams recorded deviations less than 3% and 12.9% higher than 5%. All brachytherapy sources showed deviations less than 3%. An improvement in dose accuracy was recorded during the subsequent rounds of the audits. (author)

  5. Experiments in the Underground Laboratory for Dosimetry and Spectrometry (UDO) of the PTB in the Asse II salt mine - summary highlighting work performed and outlook

    Neumaier, S; Zwiener, R

    2003-01-01

    Due to its extremely low area dose rate, the Underground Laboratory for Dosimetry and Spectrometry (UDO) of the PTB at the 925 m level of the Asse II Salt Mine offers unique possibilities for the investigation and calibration of dosimetry systems of high sensitivity as are used, for example, in environmental monitoring. Due to its low area dose rate, this laboratory has an outstanding position worldwide. The low ambient dose equivalent rate in the UDO of approx. 1 nSv/h, that means of only approx. 1 percent of the ambient dose rate typically encountered at the Earth's surface, is mainly due to the following reasons: - At the depth at which the UDO is situated, the penetrating muon component of cosmic radiation which considerably contributes to the environmental equivalent dose rate at the Earth's surface (in Braunschweig, for example, approx. one third) is already attenuated by more than five orders of magnitude and is therefore completely negligible for dosimetric investigations; - The activity concentration...

  6. Secondary standard dosimetry laboratory (SSDL)

    A secondary Standard Dosimetry Laboratory has been established in the Tun Ismail Research Centre, Malaysia as a national laboratory for reference and standardization purposes in the field of radiation dosimetry. This article gives brief accounts on the general information, development of the facility, programmes to be carried out as well as other information on the relevant aspects of the secondary standard dosimetry laboratory. (author)

  7. Direct measurements of employees involved in the Fukushima Daiichi Nuclear Power Station accident for internal dose estimates. JAEA's experiences

    Japan Atomic Energy Agency (JAEA) performed internal dose measurements of employees involved in the Fukushima Daiichi nuclear power station accident. Nuclear Fuel Cycle Engineering Laboratories (NFCEL), one of the JAEA's core centers, examined 560 of these employees by direct (in vivo) measurements during the period from April 20 to August 5 in 2011. These measurements consisted of whole-body counting for radiocesium and thyroid counting for radioiodine. The whole-body counting was conducted with two types of whole-body counters (WBCs): a standing-type WBC with two large NaI(Tl) detectors (FastscanTM, Canberra Inc.) and a chair-type WBC with HPGe detectors (GC5021, Canberra Inc.) installed in a shielded chamber made of 20-cm-thick steel. The thyroid counting was mainly performed using one of the two HPGe detectors equipped with the chair-type WBC. The subjects examined in this work were divided into two groups: Group 1 was the first 39 subjects who were measured up to June 17, 2011 and Group 2 was the remaining 521 subjects who were measured on and after June 18, 2011. The performance of our direct measurements was validated by comparing measurement results of the Group 1 subjects using two different methods (e.g., the standing-type WBC vs. the chair-type WBC). Tentative internal dose estimates of the subjects of Group 1 were also performed based on the assumption of a single intake scenario on either March 12, when the first hydrogen explosion occurred at the station or the first day of work after the accident. It was found that the contribution of 131I to the total internal dose greatly exceeded those of 134Cs and 137Cs, the other major nuclides detected in the measurements. The maximum committed effective dose (CED) was found in a male subject whose thyroid content of 131I was 9760 Bq on May 23, 2011; the CED of this subject was estimated to be 600 mSv including a small contribution of 134Cs and 137Cs. The typical minimum detectable activity for 131I in the

  8. Topics in radiation dosimetry radiation dosimetry, v.1

    Attix, Frank H

    2013-01-01

    Radiation Dosimetry, Supplement 1: Topics in Radiation Dosimetry covers instruments and techniques in dealing with special dosimetry problems. The book discusses thermoluminescence dosimetry in archeological dating; dosimetric applications of track etching; vacuum chambers of radiation measurement. The text also describes wall-less detectors in microdosimetry; dosimetry of low-energy X-rays; and the theory and general applicability of the gamma-ray theory of track effects to various systems. Dose equivalent determinations in neutron fields by means of moderator techniques; as well as developm

  9. Measurement of neutron and gamma-ray absorbed doses inside human body in criticality accident situations using phantom and tissue-equivalent dosimeters

    Personal dosimeters provide a fundamental evaluation of external exposures to human bodies in radiation accidents. For emergency medical treatment to heavily exposed patients, the evaluation of dose distribution inside the body has been tried by computational simulations. Experimental data on dose distributions inside the body are necessary for accurate simulation of human dosimetry, particularly in complex radiation fields of neutrons and gamma-rays such as criticality accidents. A preliminary experiment on the human dosimetry was carried out at the Transient Experiment Critical Facility (TRACY) to acquire such experimental data in criticality accident situations. A combined use of two kinds of tissue-equivalent dosimeters together with a human phantom was employed to measure neutron and gamma-ray absorbed doses inside the body. The neutron and gamma-ray absorbed doses measured on the phantom were found to be in roughly the same level as those averaged over the phantom inside or those measured in free air. The dose distributions measured inside and on the phantom could be qualitatively interpreted from reflection an attenuation of neutrons and gamma-rays in the phantom, neutron-induced secondary gamma-rays emitted in the phantom, and so forth. (author)

  10. Experience in treatment of the radiation syndrome in accident victims exposed with non-uniform distribution of the dose within a body

    Experience in diagnosis and treatment of radiation accident victims undergone to radiation expose with non-uniform distribution of the dose within a body is presented and the most significant features of medical management of such patients are discussed. The term 'compound radiation injure' is proposed to use for this form of radiation disease. Treatment of compound radiation injure demands a participation of very qualified specialists. The first medical aid and management should include careful body surface monitoring. Beside daily haematological observation and cytogenetic study with corresponding treatment, careful observation and registration of skin reaction are necessary. Some features of treatment are the following: more early administration of anti infection means, including isolation in sterile room, timely surgical intervention, prophylacsis and treatment of endorganic intoxication improving of microcirculation, long time follow up study with pathogenic therapy. (author)

  11. Dosimetry of neutron irradiations

    Biological dosimetry of neutron irradiation appears to be of great difficulty due to the multiparametric aspect of the relative biological effectiveness and the heterogeneity of the neutron dose distribution. Dosimetry by sodium 24 activation which can be performed by means of portable radiameters appears to be very useful for early triage within the 3 h following neutron irradiation, whereas hematological dosimetry by slope and level analysis of the lymphocyte drop cannot be used in this case. Chromosomic aberration analysis allows to evaluate the neutron dose heterogeneity by the frequency measurement of acentric fragments not originating from the formation of dicentrics or rings. Finally, recent experimental data on large primate models (baboons) have shown that some plasma hemostasia factors appear to be reliable biological indicators and noticeable markers of the prognosis of neutron irradiation

  12. Interstitial brachytherapy dosimetry update

    In March 2004, the American Association of Physicists in Medicine (AAPM) published an update to the AAPM Task Group No. 43 Report (TG-43) which was initially published in 1995. This update was pursued primarily due to the marked increase in permanent implantation of low-energy photon-emitting brachytherapy sources in the United States over the past decade, and clinical rationale for the need of accurate dosimetry in the implementation of interstitial brachytherapy. Additionally, there were substantial improvements in the brachytherapy dosimetry formalism, accuracy of related parameters and methods for determining these parameters. With salient background, these improvements are discussed in the context of radiation dosimetry. As an example, the impact of this update on the administered dose is assessed for the model 200 103Pd brachytherapy source. (authors)

  13. Secondary standards dosimetry laboratories

    The Secondary Standards Dosimetry Laboratory (SSDL) is part of an international network of dosimetry laboratories established by the IAEA and WHO. The network services maintain the consistency and accuracy of the therapeutic dose by exercising a national and international intercomparison program as well as providing calibration services to the end users, mainly radiotherapy departments in hospitals. The SSDL's are designated by national laboratories (such as Primary Standards Dosimetry Laboratories, PSDL's) to provide national and international absorbed dose traceability for users in that country. The advantage of the SSDL is that the absorbed dose measurements are consistent among the stakeholder countries.The Physics and Safety divisions have recently re-established an SSDL at ANSTO. The SSDL utilises a collimated cobalt-60 source of activity 170 TBq and dose rate of SmGy/sec at 1 metre (within ±2%), and provides a service to calibrate therapy level thimble ionisation chambers and electrometers

  14. Reactor Dosimetry State of the Art 2008

    Voorbraak, Wim; Debarberis, Luigi; D'Hondt, Pierre; Wagemans, Jan

    2009-08-01

    . Williams, A. P. Ribaric and T. Schnauber. Agile high-fidelity MCNP model development techniques for rapid mechanical design iteration / J. A. Kulesza.Extension of Raptor-M3G to r-8-z geometry for use in reactor dosimetry applications / M. A. Hunter, G. Longoni and S. L. Anderson. In vessel exposure distributions evaluated with MCNP5 for Atucha II / J. M. Longhino, H. Blaumann and G. Zamonsky. Atucha I nuclear power plant azimutal ex-vessel flux profile evaluation / J. M. Longhino ... [et al.]. UFTR thermal column characterization and redesign for maximized thermal flux / C. Polit and A. Haghighat. Activation counter using liquid light-guide for dosimetry of neutron burst / M. Hayashi ... [et al.]. Control rod reactivity curves for the annular core research reactor / K. R. DePriest ... [et al.]. Specification of irradiation conditions in VVER-440 surveillance positions / V. Kochkin ... [et al.]. Simulations of Mg-Ar ionisation and TE-TE ionisation chambers with MCNPX in a straightforward gamma and beta irradiation field / S. Nievaart ... [et al.]. The change of austenitic stainless steel elements content in the inner parts of VVER-440 reactor during operation / V. Smutný, J. Hep and P. Novosad. Fast neutron environmental spectrometry using disk activation / G. Lövestam ... [et al.]. Optimization of the neutron activation detector location scheme for VVER-lOOO ex-vessel dosimetry / V. N. Bukanov ... [et al.]. Irradiation conditions for surveillance specimens located into plane containers installed in the WWER-lOOO reactor of unit 2 of the South-Ukrainian NPP / O. V. Grytsenko. V. N. Bukanov and S. M. Pugach. Conformity between LRO mock-ups and VVERS NPP RPV neutron flux attenuation / S. Belousov. Kr. Ilieva and D. Kirilova. FLUOLE: a new relevant experiment for PWR pressure vessel surveillance / D. Beretz ... [et al.]. Transport of neutrons and photons through the iron and water layers / M. J. Kost'ál ... [et al.]. Condition evaluation of spent nuclear fuel assemblies

  15. Computational methods in several fields of radiation dosimetry

    Full text: Radiation dosimetry has to cope with a wide spectrum of applications and requirements in time and size. The ubiquitous presence of various radiation fields or radionuclides in the human home, working, urban or agricultural environment can lead to various dosimetric tasks starting from radioecology, retrospective and predictive dosimetry, personal dosimetry, up to measurements of radionuclide concentrations in environmental and food product and, finally in persons and their excreta. In all these fields measurements and computational models for the interpretation or understanding of observations are employed explicitly or implicitly. In this lecture some examples of own computational models will be given from the various dosimetric fields, including a) Radioecology (e.g. with the code systems based on ECOSYS, which was developed far before the Chernobyl reactor accident, and tested thoroughly afterwards), b) Internal dosimetry (improved metabolism models based on our own data), c) External dosimetry (with the new ICRU-ICRP-Voxelphantom developed by our lab), d) Radiation therapy (with GEANT IV as applied to mixed reactor radiation incident on individualized voxel phantoms), e) Some aspects of nanodosimetric track structure computations (not dealt with in the other presentation of this author). Finally, some general remarks will be made on the high explicit or implicit importance of computational models in radiation protection and other research field dealing with large systems, as well as on good scientific practices which should generally be followed when developing and applying such computational models

  16. The resuspension and redeposition of 137Cs in an urban area: the experience after the Goiania accident

    In Goiania, Brazil, the accidental opening of a 137Cs teletherapy source led to the contamination of an urban area of approximately 1 km2. The restricted, local contamination patterns without any significant influence from previous contaminations (Chernobyl reactor accident and atmospheric atomic bomb test fall-out) provided a unique opportunity to study the resuspension and redeposition mechanisms in an urban area under tropical climate characteristics. Air, total deposition, rainwater, surface soil and street dust were sampled over 2 years at a garden of a house and the surroundings and analysed for 137Cs. The local meteorological conditions were recorded. In addition, some size fractionation measurements were performed. The data show a significant seasonality and a very slow long-term decrease with time for the activity concentration in air and deposition rate. The data as a whole suggest that in Goiania, resuspension and deposition are mainly local phenomena and no evidence was found for a significant spreading of 137Cs from the place of primary contamination. (author)

  17. Nuclear medicine radiation dosimetry

    McParland, Brian J

    2010-01-01

    Complexities of the requirements for accurate radiation dosimetry evaluation in both diagnostic and therapeutic nuclear medicine (including PET) have grown over the past decade. This is due primarily to four factors: growing consideration of accurate patient-specific treatment planning for radionuclide therapy as a means of improving the therapeutic benefit, development of more realistic anthropomorphic phantoms and their use in estimating radiation transport and dosimetry in patients, design and use of advanced Monte Carlo algorithms in calculating the above-mentioned radiation transport and

  18. Assessment of conservatism embedded in licensing calculations of loss of coolant accident via RELAP5-3D/K simulation of LOFT L2-3 experiment

    Experiment L2-3 is one of loss-of-coolant experiment (LOCE) in Loss of Fluid Test (LOFT) program conducted by Idaho National Engineering and Environmental Laboratory (INEEL). The experiment mimics the double-ended cold leg large break Loss of Coolant Accident (LOCA) of a commercial Pressurized Water Reactor (PWR). The primary objectives of experiment are to determine fuel rod cladding thermal response, determine the performance of the Emergency Core Cooling System (ECCS) and determine the core reflood characteristics during a LOCA. In the present study, 1-D version of RELAP5-3D and RELAP5-3DK codes are used to simulate L2-3 LOCE. RELAP5-3D is a best estimated system thermal hydraulic analysis code of commercial nuclear power reactors. RELAP5-3D/K is a modified version of RELAP5 code series, which embedded RELAP5-3D with evaluation models required in U.S. Code of Federal Regulations 10 CFR 50 Appendix K for LOCA licensing calculation. The simulation and experiment results are compared with one another to assess the conservatism embedded in RELAP5-3D/K code. The result shows that both RELAPD5-3D and RELAP5-3D/K have reasonable system responses in simulation of L2-3 test. RELAP5-3D result shows cladding temperature behavior similar to experiment result at hot spot. RELAP5-3D/K demonstrates conservatism in LOCA calculation. The peak cladding temperature is 60 K higher than experiment result. Sensitivity studies show that the way that the crossflow junctions in the core are connected has significant impact on the predicted peak cladding temperature of RELAP5-3D results. (author)

  19. Accident management insights after the Fukushima Daiichi NPP accident

    events and accidents at NPPs, and what additional measures should be considered as an accident progresses to the severe accident stage. Insights are provided on the experiences and practices existing or being proposed in the NEA member states, as well as new findings from post-Fukushima studies. Emphasis is placed on identifying commendable practices that support enhanced and integrated on-site accident management response and decision-making by NPP operators. The report provides information (including commendable practices) useful for regulatory authorities to consider as they implement enhancements to their regulatory framework in the area of integrated accident management building on the lessons learnt from the Fukushima Daiichi NPP accident. The report's insights also should be useful to regulatory authorities, operating organisations and others in the nuclear safety community for addressing accident management issues such as procedures and guidelines, equipment, infrastructure and instrumentation, and human and organisational resources. Factors such as accidents involving spent fuel pools, multi-unit aspects of accident management, the interface between onsite and off-site organisations and resources, and degradation of the surrounding infrastructure are also discussed. (authors)

  20. The management of accidents

    R. B. Ward

    2009-01-01

    Full Text Available Purpose: This author’s experiences in investigating well over a hundred accident occurrences has led to questioning how such events can be managed - - - while immediately recognising that the idea of managing accidents is an oxymoron, we don’t want to manage them, we don’t want not to manage them, what we desire is not to have to manage not-them, that is, manage matters so they don’t happen and then we don’t have to manage the consequences.Design/methodology/approach: The research will begin by defining some common classes of accidents in manufacturing industry, with examples taken from cases investigated, and by working backwards (too late, of course show how those involved could have managed these sample events so they didn’t happen, finishing with the question whether any of that can be applied to other situations.Findings: As shown that the management actions needed to prevent accidents are control of design and application of technology, and control and integration of people.Research limitations/implications: This paper has shown in some of the examples provided, management actions have been know to lead to accidents being committed by others, lower in the organization.Originality/value: Today’s management activities involve, generally, the use of technology in many forms, varying from simple tools (such as knives to the use of heavy equipment, electric power, and explosives. Against these we commit, in control of those items, the comparatively frail human mind and body, which, again generally, does succeed in controlling these resources, with (another generality by appropriate management. However, sometimes the control slips and an accident occurs.

  1. How to reduce the number of accidents

    2012-01-01

    Among the safety objectives that the Director-General has established for CERN in 2012 is a reduction in the number of workplace accidents.   The best way to prevent workplace accidents is to learn from experience. This is why any accident, fire, instance of pollution, or even a near-miss, should be reported using the EDH form that can be found here. All accident reports are followed up. The departments investigate all accidents that result in sick leave, as well as all the more common categories of accidents at CERN, essentially falls (slipping, falling on stairs, etc.), regardless of whether or not they lead to sick leave. By studying the accident causes that come to light in this way, it is possible to take preventive action to avoid such accidents in the future. If you have any questions, the HSE Unit will be happy to answer them. Contact us at safety-general@cern.ch. HSE Unit

  2. The measuring and modelling of strontium-90: an integrated retrospective dosimetry issue

    Dose reconstruction for internal exposure is generally structured on a paradigm of release-transport-intake-uptake-dose. In some cases when it is necessary to reconstruct individual dose for the long time after intake and historical information on the releases is limited, bioassay measurements can be used for retrospective dosimetry of long-lived radionuclides with long biological residence times. Internal dose is related to the time integral of the body burden, therefore, individual measurements of body burden, metabolic model and some general suggestions on intake pattern are three necessary parts for dose reconstruction process in such cases. 90Sr is long-lived bone-seeking radionuclide with a long biological residence time in the body. The world list of data on strontium in man was restricted to a few experimental findings with a single intake, information on global fallout and the measurements of dial painters. A large multitude of measurements of 90Sr in human body for the residents of the Techa river (Southern Urals, Russia) contaminated by fission products in 1949-1956 has been published in open literature only recently (Kozheurov, 1994; Degteva et al., 1994). The necessity of dose reconstruction from long-lived radionuclides for the population living on the territories contaminated as a result of Chernobyl Accident calls the utilization of the Urals experience to optimize the efforts. An analysis of a unique and abundant Urals data set on strontium in humans presents also a great interest for general purposes of retrospective dosimetry. (author)

  3. Thermoluminescence characteristics of Israeli household salts for retrospective dosimetry in radiological events

    Druzhyna, S.; Datz, H.; Horowitz, Y. S.; Oster, L.; Orion, I.

    2016-06-01

    Following a nuclear accident or terror attack involving the dispersal of radioactive substances, radiation dose assessment to first responders and the members of the public is essential. The need for a retrospective assessment of the radiation dose to those possibly affected is, therefore, obligatory. The present study examines the potential use of Israeli household salt as a retrospective dosimeter (RD). The experiments were carried out on Israeli salt samples (NaCl) following a Nielsen market track survey based on scanning data representing the barcoded market, including organized and independent retail chains and a sample of private minimarkets and supermarkets. The technique used was thermoluminescence (TL) dosimetry. Salt samples were exposed to levels of dose from 0.5 mGy to 300 Gy at the Israeli Secondary Standard Dosimetry Laboratory of the Soreq Nuclear Research Center using a calibrated 137Cs source. Our emphasis has been on a detailed investigation of the basic dosimetric characteristics of the salts including: (i) glow curve analysis (ii) individual glow peak dose response (iii) reproducibility (iv) estimation of minimal measurable dose (v) effect of nitrogen readout, (vi) influence of humidity during pre-irradiation storage and (vii) light induced fading. The results are sufficiently favorable to lead to the conclusion that the Israeli household salts can serve as a pragmatic potential candidate for RD under certain restricted conditions. Occasional pre-calibration of the major salt brands in a dedicated laboratory may be essential depending on the required accuracy in the estimation of dose and consequent clinical evaluation.

  4. Experience on IMRT treatment for prostate cancer. Planning, dosimetry and quality assurance; Experiencia en el tratamiento de IMRT en cancer de prostata. Planificacion, dosimetria y garantia de calidad

    Gomez Barrado, A.; Garcia Vicente, F.; Fernandez Bedoya, V.; Zapatero Laborda, A.; Fernandez, I.; Bermudez Luna, R.; Perez Gonzalez, L.; Torres Escobar, J. J.

    2011-07-01

    In this study a revision concerning the treatment of prostate cancer with intensity-modulated radiation therapy (IMRT) is performed. Planning and verification of treatments involving dose calculations and image positioning are considered. A set of 110 patients is analysed concerning dosimetry and 92 considering image verification. Dose calculation is verified both experimentally and by means of a monitor unit (MU) calculation system. Positioning control of the prostate is achieved using intraprostatic fiducial markers and digitally reconstructed radiographs (DRRs) as well as a home-made software. All patients studied were consistent with the specifications of the treatment protocol regarding dose prescription in planning target volume (PTV), organ at risk (OAR) dose limitations, dosimetric quality assurance and positioning control. The procedure includes a learning curve considering every aspect of the treatment. The MU calculation system itself has been proved as an effective and functional tool for treatment verification. (Author) 12 refs.

  5. Status of the personnel dosimetry service of the National Institute of Radiation Hygiene in Norway, including practical experience from a Scandinavian intercomparison study

    A status report of the nationwide personnel monitoring service at the National Institute of Radiation Hygiene (SIS) in Norway is presented, together with the results from a Scandinavian intercomparison study. The personnel dosimetry service at SIS covered approx. 5,200 workers in 1983, corresponding to 70% of all occupational exposed individuals being monitored. The service covers mainly medical and industrial radiography, but also various other applications within medicine and industry. Nuclear installations are not included. The collective doses for 1983 amount to 4.7 manSv for medical occupations, and 1.1. manSv for industrial radiography. These figures include estimates of the unrecorded collective doses below the detection limit, calculated on the basis of log-probability distributions. A Scandinavian filmbadge intercomparison study was performed in spring 1984. The random uncertainty of the filmbadge measurements was below 20% for all countries, and the total uncertainty was within the factor of 2 as recommended by the ICRP. (author)

  6. Status of radiation processing dosimetry

    Miller, A.

    Several milestones have marked the field of radiation processing dosimetry since IMRP 7. Among them are the IAEA symposium on High Dose Dosimetry for Radiation Processing and the international Workshops on Dosimetry for Radiation Processing organized by the ASTM. Several standards have been or are...... being published by the ASTM in this field, both on dosimetry procedures and on the proper use of specific dosimeter systems. Several individuals are involved in this international cooperation which contribute significantly to the broader understanding of the role of dosimetry in radiation processing....... The importance of dosimetry is emphasized in the standards on radiation sterilization which are currently drafted by the European standards organization CEN and by the international standards organization ISO. In both standards, dosimetry plays key roles in characterization of the facility, in...

  7. Tchernobyl accident

    First, R.M.B.K type reactors are described. Then, safety problems are dealt with reactor control, behavior during transients, normal loss of power and behavior of the reactor in case of leak. A possible scenario of the accident of Tchernobyl is proposed: events before the explosion, possible initiators, possible scenario and events subsequent to the core meltdown (corium-concrete interaction, interaction with the groundwater table). An estimation of the source term is proposed first from the installation characteristics and the supposed scenario of the accident, and from the measurements in Europe; radiological consequences are also estimated. Radioactivity measurements (Europe, Scandinavia, Western Europe, France) are given in tables (meteorological maps and fallouts in Europe). Finally, a description of the site is given

  8. Containment severe accident thermohydraulic phenomena

    This report describes and discusses the containment accident progression and the important severe accident containment thermohydraulic phenomena. The overall objective of the report is to provide a rather detailed presentation of the present status of phenomenological knowledge, including an account of relevant experimental investigations and to discuss, to some extent, the modelling approach used in the MAAP 3.0 computer code. The MAAP code has been used in Sweden as the main tool in the analysis of severe accidents. The dependence of the containment accident progression and containment phenomena on the initial conditions, which in turn are heavily dependent on the in-vessel accident progression and phenomena as well as associated uncertainties, is emphasized. The report is in three parts dealing with: * Swedish reactor containments, the severe accident mitigation programme in Sweden and containment accident progression in Swedish PWRs and BWRs as predicted by the MAAP 3.0 code. * Key non-energetic ex-vessel phenomena (melt fragmentation in water, melt quenching and coolability, core-concrete interaction and high temperature in containment). * Early containment threats due to energetic events (hydrogen combustion, high pressure melt ejection and direct containment heating, and ex-vessel steam explosions). The report concludes that our understanding of the containment severe accident progression and phenomena has improved very significantly over the parts ten years and, thereby, our ability to assess containment threats, to quantify uncertainties, and to interpret the results of experiments and computer code calculations have also increased. (au)

  9. Accident: Reminder

    2003-01-01

    There is no left turn to Point 1 from the customs, direction CERN. A terrible accident happened last week on the Route de Meyrin just outside Entrance B because traffic regulations were not respected. You are reminded that when travelling from the customs, direction CERN, turning left to Point 1 is forbidden. Access to Point 1 from the customs is only via entering CERN, going down to the roundabout and coming back up to the traffic lights at Entrance B

  10. Retrospective dosimetry by chromosomal analysis

    The joint EU/CIS project ECP-6, was set up to examine whether cytogenetic dosimetry is possible for persons irradiated years previously at Chernobyl. The paper describes the possibility of achieving this by the examination of blood lymphocytes for unstable and stable chromosome aberrations; dicentrics and translocations. Emphasis was placed on the relatively new fluorescence in situ hybridization (FISH) method for rapid screening for stable translocations. In a collaborative experiment in vitro dose response calibration curves for dicentrics and FISH were produced with gamma radiation over the range 0-1.0 Gy. A pilot study of about 60 liquidators with registered doses ranging from 0-300 mSv was undertaken to determine whether the chromosomal methods may verify the recorded doses. It was concluded that the dicentric is no longer valid as a measured endpoint. Translocations may be used to verify early dosimetry carried out on highly irradiated persons. For the vast majority of lesser exposed subjects FISH is impractical as an individual dosimeter; it may have some value for comparing groups of subjects

  11. The Chernobyl accident as a source of new radiological knowledge: implications for Fukushima rehabilitation and research programmes

    The accident at the Chernobyl nuclear power plant in Ukraine in 1986 caused a huge release of radionuclides over large areas of Europe. During large scale activities focused on overcoming of its negative consequences for public health, various research programmes in radioecology, dosimetry and radiation medicine were conducted. New knowledge was applied internationally in substantial updating of radiation protection systems for emergency and existing situations of human exposure, for improvement of emergency preparedness and response. Radioecological and dosimetry models were significantly improved and validated with numerous measurement data, guidance on environmental countermeasures and monitoring elaborated and tested. New radiological knowledge can be of use in the planning and implementation of rehabilitation programmes in Japan following the Fukushima nuclear accident. In particular, the following activity areas would benefit from application of the Chernobyl experience: strategy of rehabilitation, and technology of settlement decontamination and of countermeasures applied in agriculture and forestry. The Chernobyl experience could be very helpful in planning research activities initiated by the Fukushima radionuclide fallout, i.e. environmental transfer of radionuclides, effectiveness of site-specific countermeasures, nationwide dose assessment, health effect studies, etc. (paper)

  12. The Chernobyl accident as a source of new radiological knowledge: implications for Fukushima rehabilitation and research programmes.

    Balonov, Mikhail

    2013-03-01

    The accident at the Chernobyl nuclear power plant in Ukraine in 1986 caused a huge release of radionuclides over large areas of Europe. During large scale activities focused on overcoming of its negative consequences for public health, various research programmes in radioecology, dosimetry and radiation medicine were conducted. New knowledge was applied internationally in substantial updating of radiation protection systems for emergency and existing situations of human exposure, for improvement of emergency preparedness and response. Radioecological and dosimetry models were significantly improved and validated with numerous measurement data, guidance on environmental countermeasures and monitoring elaborated and tested.New radiological knowledge can be of use in the planning and implementation of rehabilitation programmes in Japan following the Fukushima nuclear accident. In particular, the following activity areas would benefit from application of the Chernobyl experience: strategy of rehabilitation, and technology of settlement decontamination and of countermeasures applied in agriculture and forestry. The Chernobyl experience could be very helpful in planning research activities initiated by the Fukushima radionuclide fallout, i.e. environmental transfer of radionuclides, effectiveness of site-specific countermeasures, nationwide dose assessment, health effect studies, etc. PMID:23295495

  13. Extremity dosimetry at US Department of Energy facilities

    A questionnaire on extremity dosimetry was distributed to DOE facilities along with a questionnaire on beta dosimetry. An informal telephone survey was conducted as a follow-up survey to answer a few additional questions concerning extremity monitoring practices. The responses to the questionnaire and the telephone survey are summarized in this report. Background information, developed from operational experience and a review of the current literature, is presented as a basis for understanding the information obtained by the survey and questionnaire

  14. Ion storage dosimetry

    Mathur, V. K.

    2001-09-01

    The availability of a reliable, accurate and cost-effective real-time personnel dosimetry system is fascinating to radiation workers. Electronic dosimeters are contemplated to meet this demand of active dosimetry. The development of direct ion storage (DIS) dosimeters, a member of the electronic dosimeter family, for personnel dosimetry is also an attempt in this direction. DIS dosimeter is a hybrid of the well-established technology of ion chambers and the latest advances in data storage using metal oxide semiconductor field effect transistor (MOSFET) analog memory device. This dosimeter is capable of monitoring legal occupational radiation doses of gamma, X-rays, beta and neutron radiation. Similar to an ion chamber, the performance of the dosimeter for a particular application can be optimized through the selection of appropriate wall materials. The use of the floating gate of a MOSFET as one of the electrodes of the ion chamber allows the miniaturization of the device to the size of a dosimetry badge and avoids the use of power supplies during dose accumulation. The concept of the device, underlying physics and the design of the DIS dosimeter are discussed. The results of preliminary testing of the device are also provided.

  15. Individual Dosimetry Service

    2004-01-01

    We inform all staffs and users under regular dosimetry control that the dosimeters for the monitoring period MAY-JUNE 2004 are available from their usual dispatchers. Please have your films changed before the 11th MAY 2004. The color of the dosimeter valid in MAY-JUNE 2004 is YELLOW.

  16. Individual dosimetry service

    2004-01-01

    We inform all staffs and users under regular dosimetry control that the dosimeters for the monitoring period MARCH/APRIL 2004 are available from their usual dispatchers. Please have your films changed before the 11th MARCH 2004. The color of the dosimeter valid in MARCH/APRIL 2004 is BLUE.

  17. Individual dosimetry service

    2004-01-01

    We inform all staff and users under regular dosimetry control that the dosimeters for the monitoring period JULY-AUGUST 2004 are available from their usual dispatchers. Please have your films changed before the 15 JULY 2004. The color of the dosimeter valid in July-August 2004 is PINK.

  18. Dosimetry and Calibration Section

    The two tasks of the Dosimetry and Calibration Section at CERN are the Individual Dosimetry Service which assures the personal monitoring of about 5000 persons potentially exposed to ionizing radiation at CERN, and the Calibration Laboratory which verifies all the instruments and monitors. This equipment is used by the sections of the RP Group for assuring radiation protection around CERN's accelerators, and by the Environmental Section of TISTE. In addition, nearly 250 electronic and 300 quartz fibre dosimeters, employed in operational dosimetry, are calibrated at least once a year. The Individual Dosimetry Service uses an extended database (INDOS) which contains information about all the individual doses ever received at CERN. For most of 1997 it was operated without the support of a database administrator as the technician who had assured this work retired. The Software Support Section of TIS-TE took over the technical responsibility of the database, but in view of the many other tasks of this Section and the lack of personnel, only a few interventions for solving immediate problems were possible

  19. Dosimetry in diagnostic radiology

    Dosimetry is an area of increasing importance in diagnostic radiology. There is a realisation amongst health professionals that the radiation dose received by patients from modern X-ray examinations and procedures can be at a level of significance for the induction of cancer across a population, and in some unfortunate instances, in the acute damage to particular body organs such as skin and eyes. The formulation and measurement procedures for diagnostic radiology dosimetry have recently been standardised through an international code of practice which describes the methodologies necessary to address the diverging imaging modalities used in diagnostic radiology. Common to all dosimetry methodologies is the measurement of the air kerma from the X-ray device under defined conditions. To ensure the accuracy of the dosimetric determination, such measurements need to be made with appropriate instrumentation that has a calibration that is traceable to a standards laboratory. Dosimetric methods are used in radiology departments for a variety of purposes including the determination of patient dose levels to allow examinations to be optimized and to assist in decisions on the justification of examination choices. Patient dosimetry is important for special cases such as for X-ray examinations of children and pregnant patients. It is also a key component of the quality control of X-ray equipment and procedures.

  20. Ion-kill dosimetry

    Katz, R.; Cucinotta, F. A.; Fromm, M.; Chambaudet, A.

    2001-01-01

    Unanticipated late effects in neutron and heavy ion therapy, not attributable to overdose, imply a qualitative difference between low and high LET therapy. We identify that difference as 'ion kill', associated with the spectrum of z/beta in the radiation field, whose measurement we label 'ion-kill dosimetry'.

  1. High frequency electromagnetic dosimetry

    Sánchez-Hernández, David A

    2009-01-01

    Along with the growth of RF and microwave technology applications, there is a mounting concern about the possible adverse effects over human health from electromagnetic radiation. Addressing this issue and putting it into perspective, this groundbreaking resource provides critical details on the latest advances in high frequency electromagnetic dosimetry.

  2. Dosimetry of pion beams

    Negative pion beams are probably the most esoteric and most complicated type of radiation which has been suggested for use in clinical radiotherapy. Because of the limited availability of pion beams in the past, even to nuclear physicists, there exist relatively fewer basic data for this modality. Pion dosimetry is discussed

  3. Construction of new education system on nuclear energy and radiation after experience of Fukushima Daiichi Nuclear Power Plant accident. Improvement of response capability of educational fields against nuclear power plant accident

    Fukushima Daiichi Nuclear Power Plant (NPP) accident brought about confusion in elementary and secondary educational fields due to lack of teacher's knowledge of nuclear power, radiation safety and protection, and information about regional radiation and radioactivity data. In order to improve their response capability against NPP accident to secure safety of the pupil and student, new education system on nuclear energy and radiation was constructed such as educational course of 'nuclear energy and radiation safety' for pre-service teacher training system faculty students and training course of 'radiation dose measurement and evaluation' for in-service teacher and professors. Feasibility studies were also performed to construct information network for supporting schools at NPP accident so as to provide effective information about radiation and radioactivity data for educational fields. (T. Tanaka)

  4. The ARN critical dosimetry system

    Accident Dosimetry Systems at Silene Reactor in 2002, showing a good performance. (author)

  5. Immediate medical consequences of nuclear accidents: lessons from Chernobyl

    The immediate medical response to the nuclear accident at the Chernobyl nuclear power station involved containment of the radioactivity and evacuation of the nearby population. The next step consisted of assessment of the radiation dose received by individuals, based on biological dosimetry, and treatment of those exposed. Medical care involved treatment of skin burns; measures to support bone marrow failure, gastrointestinal tract injury, and other organ damage (i.e., infection prophylaxis and transfusions) for those with lower radiation dose exposure; and bone marrow transplantation for those exposed to a high dose of radiation. At Chernobyl, two victims died immediately and 29 died of radiation or thermal injuries in the next three months. The remaining victims of the accident are currently well. A nuclear accident anywhere is a nuclear accident everywhere. Prevention and cooperation in response to these accidents are essential goals

  6. Alanine-ESR in vivo dosimetry: a feasibility study and possible applications

    A new alanine-ESR dosimeter has been developed at AERIAL in order to study its potential use in radiotherapy. Alanine-ESR results are compared with ion chamber for depth-dose measurements. A good concordance has been found between provisional dosimetry and absorbed dose during high dose rate and intra operative treatments. The results of the experiments indicate that alanine-ESR dosimetry is suited to check dose optimisation routines and seems to be a promising in vivo dosimetry technique. (Author)

  7. Experience with a contact point (CP) for psychological and medical care after an NPP accident or another R/N disaster situation in Switzerland

    Mission The Swiss Federal Concept for Emergency Protection in the Vicinity of Nuclear Power Plants requires the preparation of a 'Contact Point' (C.P.) for psychological and medical care of the affected public in case of an accident in a nuclear power plant. Purpose The central questions, which during a release of radioactivity could cause anxiety within the population, are: - Have I come into contact with radioactive substances? - If so, what are the short-term and long-term radiological consequences? - How dangerous is the dose I have received? These questions are answered with the following procedures: - Examination of all persons arriving at the contact point with respect to radioactive contamination and, if necessary decontamination (showers). - Screening of the thyroid for the purpose of checking for incorporation of radioactive iodine and dose measurement in case screening is positive. - Answering of personal questions related to radioactivity and radiological consequences. - Information and advisory service concerning impact of radiation and possibilities of protective measures. Experience The Paper will discusses the experience from an exercise taken place 18./19. november 2005. In this exercise 100 players will be involved. The background of the exercise is a scenario taken from a federal exercise with a NPP. In addition to the direct support at the contact point a telephone hot line will be exercised. We expect lessons learned in man y areas of the management of psychological and medical care. (authors)

  8. Transportation accidents

    Predicting the possible consequences of transportation accidents provides a severe challenge to an analyst who must make a judgment of the likely consequences of a release event at an unpredictable time and place. Since it is impractical to try to obtain detailed knowledge of the meteorology and terrain for every potential accident location on a route or to obtain accurate descriptions of population distributions or sensitive property to be protected (data which are more likely to be more readily available when one deals with fixed-site problems), he is constrained to make conservative assumptions in response to a demanding public audience. These conservative assumptions are frequently offset by very small source terms (relative to a fixed site) created when a transport vehicle is involved in an accident. For radioactive materials, which are the principal interest of the authors, only the most elementary models have been used for assessing the consequences of release of these materials in the transportation setting. Risk analysis and environmental impact statements frequently have used the Pasquill-Gifford/gaussian techniques for releases of short duration, which are both simple and easy to apply and require a minimum amount of detailed information. However, after deciding to use such a model, the problem of selecting what specific parameters to use in specific transportation situations still presents itself. Additional complications arise because source terms are not well characterized, release rates can be variable over short and long time periods, and mechanisms by which source aerosols become entrained in air are not always obvious. Some approaches that have been used to address these problems will be reviewed with emphasis on guidelines to avoid the Worst-Case Scenario Syndrome

  9. Retrospective dosimetry: Dose evaluation using unheated and heated quartz from a radioactive waste storage building

    Jain, M.; Bøtter-Jensen, L.; Murray, A.S.; Jungner, H.

    In the assessment of dose received from a nuclear accident, considerable attention has been paid to retrospective dosimetry using heated materials such as household ceramics and bricks. However, unheated materials such as mortar and concrete are more commonly found in industrial sites and...

  10. Analysis of the FPT-0, FPT-1 and FPT-2 experiments of the PHEBUS FP program investigating in-vessel phenomena during a LWR accidents

    This paper describes the results and the current status of the analysis of the core degradation aspects for the FPT0, FPT1 and FPT2 tests, using the mechanistic ICARE/CATHARE code system developed by IRSN 'Institut de Radioprotection et de Surete Nucleaire'. The objective of those experiments, in the framework of the International Phebus Fission Product program, was to get a significant FP release induced by fuel rod degradation and fuel melting in a prototypical way using real materials as present in a PWR fuel assembly. During the transient, most of the phenomena that could occur in-vessel during a PWR severe accident (thermo mechanical fuel rod rupture, absorber rod degradation, steam-zircaloy chemical reaction and hydrogen generation, fuel dissolution and molten pool formation) have been observed. They are quite well simulated with the ICARE2 V3mod1 code version, in particular the hydrogen generation. The experiments showed core degradation far beyond any other integral experiment (PBF SFD, Phebus-SFD, CORA, FLHT, and LOFT-FP-2). The severe damage observed in the bundle seems to be due to significant material interactions, initiated by structural materials possibly enhanced by the fuel swelling and fragmentation, and its changes in stoichiometry. The fuel burn-up and the oxygen potential during cladding oxidation are probably important factors. It was observed that fuel liquefaction and transition from rod like geometry to molten pool could occur at a temperature (2600+/-200K) largely below the actual melting point of the pure UO2 (3110K). Though the detailed modeling of such interactions has still to be improved, the ICARE2 code simulates fairly well the observed fuel degradation. The Phebus FP series of integral experiments have proved the capability of the program to significantly improve our understanding of the source term issue and important aspects of core degradation

  11. SAFETY devices for prevention of early containment melt-through during severe accident of light water reactor VVER-1000. Design, experiments, production and installation

    An analysis performed during a European Union pre-accession instrument (PHARE project) in Bulgaria at Units 5&6 of the VVER-1000, V-320 Kozloduy Nuclear Power Plant discovered a vulnerability of this design consisting of early (up to one hour) containment melt-through via ionization chambers channels situated around the reactor pit. After a Reactor Pressure Vessel break, as an end of in-vessel phase of severe accident, the ex-vessel phase starts. The melt falling down into the reactor pit begins to ablate the concrete in both axial and radial directions. The axial melt-through towards of the internal ring of Ionization Chambers (IC), which are situated close to the wall of reactor pit, will bring the melt to fall down on the bottom of the channels. The further ablation would lead to melt-concrete penetration into the premise below the containment. To prevent the penetration of the melt outside of the Containment, the authors proposed an engineering solution to plug the bottom of IC channels by high-temperature-resistant materials, which is an original know-how. Thermo-mechanical analyses were done by simulation of the process of penetrating of melt in IC channels. Finite-element model (FEM) was built, which include the proposed plugging devices and the adjacent parts that would be influenced during the process. The analyses of the results have shown that the thermal and mechanical stability of all parts of the proposed device and adjacent components is guaranteed. Two experiments – cold and hot ones, - were performed to prove the operability of the proposed device for plugging the IC channels under normal operation and severe accident conditions. The cold experiment was aimed to prove the behaviour of the plugging device during normal operation. The hot experiment consisted in preparation of a melt simulant and pouring it in a sample tube with a plug to prove the not-penetrating of the melt and its falling below. The process of production of these safety devices

  12. The CIEMAT programme on radiation dosimetry: a space for collaboration

    This communication presents an overview of the technical and scientific activities presently carried-out at the CIEMAT Radiation Dosimetry Unit. The aim of the presentation is to facilitate the identification of possible areas of common interest with the Portuguese dosimetry community. The activities described are in areas of both, external and internal dosimetry, and include research and also services. The CIEMAT dosimetry services have evolved and nowadays they are more focused towards quality control activities serving the whole national community rather than to routine services, whenever these kind of services can be provided by other Spanish companies or institutions. Several research lines have been implemented, some of them very recently, chosen with criteria of opportunity and interest and also considering our technical possibilities and experience. (author)

  13. Dosimetry for food irradiation

    A Manual of Food Irradiation Dosimetry was published in 1977 under the auspices of the IAEA as Technical Reports Series No. 178. It was the first monograph of its kind and served as a reference in the field of radiation processing and in the development of standards. While the essential information about radiation dosimetry in this publication has not become obsolete, other publications on radiation dosimetry have become available which have provided useful information for incorporation in this updated version. There is already a Codex General Standard for Irradiated Foods and an associated Code of Practice for Operation of Irradiation Facilities used for Treatment of Food, issued in 1984 by the Codex Alimentarius Commission of the FAO/WHO Food Standard Programme. The Codex Standard contains provisions on irradiation facilities and process control which include, among other requirements, that control of the processes within facilities shall include the keeping of adequate records including quantitative dosimetry. Appendix A of the Standard provides an explanation of process control and dosimetric requirements in compliance with the Codex Standard. By 1999, over 40 countries had implemented national regulations or issued specific approval for certain irradiated food items/classes of food based on the principles of the Codex Standard and its Code of Practice. Food irradiation is thus expanding, as over 30 countries are now actually applying this process for the treatment of one or more food products for commercial purposes. Irradiated foods are being marketed at retail level in several countries. With the increasing recognition and application of irradiation as a sanitary and phytosanitary treatment of food based on the provisions of the Agreement on the Application of Sanitary and Phytosanitary Measures of the World Trade Organization, international trade in irradiated food is expected to expand during the next decade. It is therefore essential that proper dosimetry

  14. Establishment of ANSI N13.11 X-ray radiation fields for personal dosimetry performance test by computation and experiment.

    Kim, J L; Kim, B H; Chang, S Y; Lee, J K

    1997-12-01

    This paper describes establishment by computational and experimental methods of the American National Standard Institute (ANSI) N13.11 X-ray radiation fields by the Korea Atomic Energy Research Institute (KAERI). These fields were used in the standard irradiations of various personal dosimeters for the personal dosimetry performance test program performed by the Ministry of Science and Technology of Korea in the autumn of 1995. Theoretical X-ray spectra produced from two KAERI X-ray generators were estimated using a modified Kramers' theory with target attenuation and backscatter correction and their spectral distributions experimentally measured by a high-purity germanium semiconductor detector through proper corrections for measured pulse height distributions with photopeak efficiency, Compton fraction, and K-escape fraction. The average energies and conversion coefficients obtained from the computation and experimental methods, when compared with ANSI N13.11 and the recently published National Institute of Standards and Technology X-ray beams, appeared to be in good agreement--(+/-)3% between corresponding values--and thus, could be satisfactorily applied in the performance test of personal dosimeters. PMID:9467054

  15. Usefulness and limits of biological dosimetry based on cytogenetic methods

    , in theory, both deterministic damage and aberrations might be repaired to a similar degree; a comparison of aberrations following a linear relationship might also help when the doses have been sufficiently large. (3) Investigations might have been possible only a certain time after the exposure. The relatively rapid disappearance of lymphocytes carrying unstable aberrations limits their use in retrospective dosimetry, years after exposure. Scoring stable aberrations, thought to persist in the circulating lymphocytes, might appear more appropriate in such situations. However, the examination of a representative number of cells by G-banding is extremely laborious, and the FISH method is not only expensive but has not yet been fully validated in different laboratories. In conclusion, biological dosimetry has serious limitations exactly for situations where the need for information is most urgent. It renders its most useful results when an individual has been exposed to a rather homogeneous high-level radiation over a short time interval, i.e. accidents at high-intensity radiation devices. On the other hand, it yielded less satisfactory information even when the most recent techniques were used for situations, where a low level, low dose rate exposure has occurred at some time in the past, for example for persons living in areas contaminated from the Chernobyl accident. Such negative experiences should be kept in mind in order to avoid futile and expensive investigations in the case of populations exposed from radioactivity and, notably, also from potentially clastogenic chemical agents. (authors)

  16. Usefulness and limits of biological dosimetry based on cytogenetic methods.

    Léonard, A; Rueff, J; Gerber, G B; Léonard, E D

    2005-01-01

    , in theory, both deterministic damage and aberrations might be repaired to a similar degree; a comparison of aberrations following a linear dose relationship might also help when the doses have been sufficiently large. (3) Investigations might have been possible only a certain time after the exposure. The relatively rapid disappearance of lymphocytes carrying unstable aberrations limits their use in retrospective dosimetry, years after exposure. Scoring stable aberrations, thought to persist in the circulating lymphocytes, might appear more appropriate in such situations. However, the examination of a representative number of cells by G-banding is extremely laborious, and the FISH method is not only expensive but has not yet been fully validated in different laboratories. In conclusion, biological dosimetry has serious limitations exactly for situations where the need for information is most urgent. It renders its most useful results when an individual has been exposed to a rather homogeneous high-level radiation over a short time interval, i.e. accidents at high-intensity radiation devices. On the other hand, it yielded less satisfactory information even when the most recent techniques were used for situations, where a low level, low dose rate exposure has occurred at some time in the past, for example for persons living in areas contaminated from the Chernobyl accident. Such negative experiences should be kept in mind in order to avoid futile and expensive investigations in the case of populations exposed from radioactivity and, notably, also from potentially clastogenic chemical agents. PMID:16381765

  17. Audits for advanced treatment dosimetry

    Radiation therapy has advanced rapidly over the last few decades, progressing from 3D conformal treatment to image-guided intensity modulated therapy of several different flavors, both 3D and 4D and to adaptive radiotherapy. The use of intensity modulation has increased the complexity of quality assurance and essentially eliminated the physicist's ability to judge the validity of a treatment plan, even approximately, on the basis of appearance and experience. Instead, complex QA devices and procedures are required at the institutional level. Similarly, the assessment of treatment quality through remote and on-site audits also requires greater sophistication. The introduction of 3D and 4D dosimetry into external audit systems must follow, to enable quality assurance systems to perform meaningful and thorough audits

  18. Occupational Radiation Protection in Severe Accident Management. EG-SAM Interim Report

    As an early response to the Fukushima NPP accident, the ISOE Bureau decided to focus on the following issues as an initial response of the joint program after having direct communications with the Japanese official participants in April 2011; - Management of high radiation area worker doses: It has been decided to make available the experience and information from the Chernobyl accident in terms of how emergency worker / responder doses were legally and practically managed, - Personal protective equipment for highly-contaminated areas: It was agreed to collect information about the types of personnel protective equipment and other equipment (e.g. air bottles, respirators, air-hoods or plastic suits, etc.), as well as high-radiation area worker dosimetry use (e.g. type, number and placement of dosimetry) for different types of emergency and high-radiation work situations. Detailed information was collected on dose criteria which are used for emergency workers/responders and their basis, dose management criteria for high dose/dose rate areas, protective equipment which is recommended for emergency workers / responders, recommended individual monitoring procedures, and any special requirement for assessment from the ISOE participating nuclear utilities and regulatory authorities and made available for Japanese utilities. With this positive response of the ISOE actors and interest in the situation in Fukushima, the Expert Group on Occupational Radiation Protection in Severe Accident Management (EG-SAM) was established by the ISOE Management Board in May 2011. The overall objective of the EG-SAM is to contribute to occupational exposure management (providing a view on management of high radiation area worker doses) within the Fukushima plant boundary with the ISOE participants and to develop a state-of-the- art ISOE report on best radiation protection management practices for proper radiation protection job coverage during severe accident initial response and recovery

  19. Guidance on approval of dosimetry services under the ionising radiations regulations 1985

    Regulation 15 of the Ionising Radiations Regulations 1985 gives the Health and Safety Executive the power to approve suitable dosimetry services for the purpose of Regulations 13 (dose assessment), 14 (accident dosimetry) and 27 (contingency plans). Part 3 of notes for guidance for dosimetry services wishing to apply to the HSE for approval is presented. This describes those aspects which are relevant to co-ordination of inputs from contributing approved dosimetry services (ADS's) and record keeping of assessed doses. It sets out the functions of the co-ordinating ADS's, gives guidance on interpretation of dose quantities, specifies the minimum content of dose records and describes suitable types of dose record storage. Finally the basis on which HSE will assess a service for approval is outlined. (U.K.)

  20. The dosimetry of ionizing radiation

    1990-01-01

    A continuation of the treatise The Dosimetry of Ionizing Radiation, Volume III builds upon the foundations of Volumes I and II and the tradition of the preceeding treatise Radiation Dosimetry. Volume III contains three comprehensive chapters on the applications of radiation dosimetry in particular research and medical settings, a chapter on unique and useful detectors, and two chapters on Monte Carlo techniques and their applications.

  1. IAEA supported national thermoluminescence dosimetry audit networks for radiotherapy dosimetry: Summary of the posters presented in session 12b

    The IAEA has supported its Member States over many years by providing thermoluminescence dosimetry (TLD) based quality assurance audits for radiotherapy dosimetry. Over recent years it has extended this role by encouraging, supporting and assisting the development of national audit programmes, building on the IAEA's experience of operating a TLD system.Whenever possible, the IAEA establishes links between the national programmes and the IAEA Dosimetry Laboratory. The IAEA disseminates its standardized TLD methodology and provides technical backup to national TLD networks, ensuring at the same time traceability to primary dosimetry standards. Several countries have established TLD programmes to audit radiotherapy beams in hospitals with assistance from the IAEA, and the paper presents an overview of the activities in Algeria, Argentina, Australia, Brazil, China, Colombia, Cuba, India, the Republic of Korea, the Philippines and Poland. (author)

  2. Neutron beam measurement dosimetry

    This report describes animal dosimetry studies and phantom measurements. During 1994, 12 dogs were irradiated at BMRR as part of a 4 fraction dose tolerance study. The animals were first infused with BSH and irradiated daily for 4 consecutive days. BNL irradiated 2 beagles as part of their dose tolerance study using BPA fructose. In addition, a dog at WSU was irradiated at BMRR after an infusion of BPA fructose. During 1994, the INEL BNCT dosimetry team measured neutron flux and gamma dose profiles in two phantoms exposed to the epithermal neutron beam at the BMRR. These measurements were performed as a preparatory step to the commencement of human clinical trials in progress at the BMRR

  3. Ambiguities in thermoluminescence dosimetry

    On one hand, thermoluminescence dosimetry is one of most reliable, rugged and economical system of passive dosimetry but on the other hand there are several ambiguities, which need attention. The PTTL is a complex phenomenon and it is difficult to identify the source for the transfer of the charge carrier to repopulate the traps related to the glow peaks. For the photon energy dependence it is difficult to explain the change in the response for 662 keV gamma rays of 137Cs as compared to the response for 1.25 MeV gamma rays of 60Co. The increase in the response of a TLD with increasing heating rate poses another ambiguity and so is the case with the observations of the supra linearity of different glow peaks. To over come the ambiguities, efforts have to continue to enhance the understanding and to harmonize the protocol for reliable experimental data

  4. Neutron beam measurement dosimetry

    Amaro, C.R. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

    1995-11-01

    This report describes animal dosimetry studies and phantom measurements. During 1994, 12 dogs were irradiated at BMRR as part of a 4 fraction dose tolerance study. The animals were first infused with BSH and irradiated daily for 4 consecutive days. BNL irradiated 2 beagles as part of their dose tolerance study using BPA fructose. In addition, a dog at WSU was irradiated at BMRR after an infusion of BPA fructose. During 1994, the INEL BNCT dosimetry team measured neutron flux and gamma dose profiles in two phantoms exposed to the epithermal neutron beam at the BMRR. These measurements were performed as a preparatory step to the commencement of human clinical trials in progress at the BMRR.

  5. Sixth symposium on neutron dosimetry

    This booklet contains all abstracts of papers presented in 13 sessions. Main topics: Cross sections and Kerma factors; analytical radiobiology; detectors for personnel monitoring; secondary charged particles and microdosimetric basis of q-value for neutrons; personnel dosimetry; concepts for radiation protection; ambient monitoring; TEPC and ion chambers in radiation protection; beam dosimetry; track detectors (CR-39); dosimetry at biomedical irradiation facilities; health physics at therapy facilities; calibration for radiation protection; devices for beam dosimetry (TLD and miscellaneous); therapy and biomedical irradiation facilities; treatment planning. (HP)

  6. Personal radon daughter dosimetry

    The conventional means of radon daughter exposure estimatikn for uranium miners in Canada is by grab sampling and time weighting. Personal dosimetry is a possible alternative method with its own advantages and limitations. The author poses basic questions with regard to two methods of radon daughter detection, thermoluminescent chips and track-etch film. An historical review of previous and current research and development programs in Canada and in other countries is presented, as are brief results and conclusions of each dosimeter evaluation

  7. Personnel radiation dosimetry

    The book contains the 21 technical papers presented at the Technical Committee Meeting to Elaborate Procedures and Data for the Intercomparison of Personnel Dosimeters organizaed by the IAEA on 22-26 April 1985. A separate abstract was prepared for each of these papers. A list of areas in which additional research and development work is needed and recommendations for an IAEA-sponsored intercomparison program on personnel dosimetry is also included

  8. Utilisation of OSL from table salt in retrospective dosimetry

    Common salt (NaCl) has previously been suggested for use in dose estimation in accident dosimetry. In this study, we investigated the optically stimulated luminescence (OSL) and violet thermoluminescence (VTL) characteristics of 'Aji-Shio' (Ajinomoto), a Japanese commercial salt. A comparison of OSL and TL signals allowed identification of common source traps. The initial OSL signal contained a dominant thermally unstable component, which necessitated prior heat treatment. Based on these luminescence characteristics, a single-aliquot regenerative-dose (SAR) OSL protocol was modified and tested. The protocol worked very well for six types of salt, but not for four other types of salt. A minimum detection limit of ∼15 mGy was estimated using the OSL protocol; this is lower than the value obtained from other forms of OSL retrospective dosimetry and lower than that obtained using electron spin resonance (ESR) dosimetry. It was concluded that the OSL from Japanese commercial salt could be used successfully to derive precise estimates of accident dose. (author)

  9. Usability of VTL from natural quartz grains for retrospective dosimetry

    To develop retrospective dosimetry of unexpected radiation accident, basic studies on violet thermoluminescence (VTL) phenomena were conducted using natural quartz grains. All VTL glow curves of as-received samples did not exhibit peaks <250 deg. C, although for artificially irradiated quartz samples there were VTL peaks in the temperature region <250 deg. C. Therefore, accident doses could be estimated without the interference of naturally accumulated doses by VTL measurements from natural quartz. The mean lives of VTL were evaluated by the various heating rates method and the range of values was found to be between some days and ten thousands of years depending on each peak. Especially, the mean life of VTL peak at 200 deg. C was years order. Furthermore, the lower detection limit was calculated to be tens of mGy from the response curve. This value was lower than that of other methods such as ESR dosimetry. From these results, we conclude that VTL dosimetry can be preferred for accidental evaluation. (authors)

  10. Dosimetry: an ARDENT topic

    CERN Bulletin

    2012-01-01

    The first annual ARDENT workshop took place in Vienna from 20 to 23 November. The workshop gathered together the Early-Stage Researchers (ESR) and their supervisors, plus other people involved from all the participating institutions.   “The meeting, which was organised with the local support of the Austrian Institute of Technology, was a nice opportunity for the ESRs to get together, meet each other, and present their research plans and some preliminary results of their work,” says Marco Silari, a member of CERN Radiation Protection Group and the scientist in charge of the programme. Two full days were devoted to a training course on radiation dosimetry, delivered by renowned experts. The workshop closed with a half-day visit to the MedAustron facility in Wiener Neustadt. ARDENT (Advanced Radiation Dosimetry European Network Training) is a Marie Curie ITN project funded under EU FP7 with €4 million. The project focuses on radiation dosimetry exploiting se...

  11. International aspects of nuclear accidents

    The accident at Chernobyl revealed that there were shortcomings and gaps in the existing international mechanisms and brought home to governments the need for stronger measures to provide better protection against the risks of severe accidents. The main thrust of international co-operation with regard to nuclear safety issues is aimed at achieving a uniformly high level of safety in nuclear power plants through continuous exchanges of research findings and feedback from reactor operating experience. The second type of problem posed in the event of an accident resulting in radioactive contamination of several countries relates to the obligation to notify details of the circumstances and nature of the accident speedily so that the countries affected can take appropriate protective measures and, if necessary, organize mutual assistance. Giving the public accurate information is also an important aspect of managing an emergency situation arising from a severe accident. Finally, the confusion resulting from the unwarranted variety of protective measures implemented after the Chernobyl accident has highlighted the need for international harmonization of the principles and scientific criteria applicable to the protection of the public in the event of an accident and for a more consistent approach to emergency plans. The international conventions on third party liability in the nuclear energy sector (Paris/Brussels Conventions and the Vienna Convention) provide for compensation for damage caused by nuclear accidents in accordance with the rules and jurisdiction that they lay down. These provisions impose obligations on the operator responsible for an accident, and the State where the nuclear facility is located, towards the victims of damage caused in another country

  12. Medical preparedness and response in nuclear accidents. The health team's experience in joint work with the radiological protection area

    Maurmo, Alexandre Mesquita [Eletronuclear Medical Assistance Foundation - FEAM, Angra dos Reis, RJ (Brazil). Ionizing Radiation Medical Center; Leite, Teresa Cristina S.B. [Eletronuclear Medical Assistance Foundation - FEAM, Angra dos Reis, RJ (Brazil)

    2007-07-01

    The interaction between the health and the radiological protection areas has proved fundamental, in our work experience, for the quality of response to victims of accidents, involving ionizing radiation. The conceptions and basic needs comprehension of the adequate response, on these two areas, have brought changes to the essential behavior related to the victim's care, the protection response, the environment and waste production. The joint task of health professionals and radiological protection staff, as first responders, demonstrates that it is possible to adjust practices and procedures. The training of professionals of the radiological protection area by health workers, has qualified them on the basic notions of pre-hospital attendance, entitling the immediate response to the victim prior to the health team arrival, as well as the discussion on the basic concepts of radiological protection with the health professionals, along with the understanding of the health area with its specific needs on the quick response to imminent death risk, or even the necessary procedures of decontamination. (author)

  13. Need of reactor dosimetry preservation

    community experience and competency. Common research projects of the IAEA and EC will be a good base for development of common methodology as well as for involving more young researchers. Young scientists and engineers urgently has to be attracted to the field of reactor dosimetry in order to transfer and further develop the available know-how. The interest of young researchers could be find between: receiving additional financial support, doing new professional contacts, involving in team work, involving in research/work community, creating feeling for usefulness and necessity, create feeling for proper pride. The mentioned efforts for knowledge preservation will allow the RD to meet the demand of Gen IV reactors that is the RD to be used for determination of fast and epithermal neutron spectra, which will challenge materials performance with increased radiation damage. It will be applied as an important tool for growing number of reactors that will be decommissioned. (author)

  14. Advances in biomedical dosimetry

    Full text: Radiation dosimetry, the accurate determination of the absorbed dose within an irradiated body or a piece of material, is a prerequisite for all applications of ionizing radiation. This has been known since the very first radiation applications in medicine and biology, and increasing efforts are being made by radiation researchers to develop more reliable, effective and safe instruments, and to further improve dosimetric accuracy for all types of radiation used. Development of new techniques and instrumentation was particularly fast in the field of both medical diagnostic and therapeutic radiology. Thus, in Paris in October the IAEA held the latest symposium in its continuing series on dosimetry in medicine and biology. The last one was held in Vienna in 1975. High-quality dosimetry is obviously of great importance for human health, whether the objectives lie in the prevention and control of risks associated with the nuclear industry, in medical uses of radioactive substances or X-ray beams for diagnostic purposes, or in the application of photon, electron or neutron beams in radiotherapy. The symposium dealt with the following subjects: General aspects of dosimetry; Special physical and biomedical aspects; Determination of absorbed dose; Standardization and calibration of dosimetric systems; and Development of dosimetric systems. The forty or so papers presented and the discussions that followed them brought out a certain number of dominant themes, among which three deserve particular mention. - The recent generalization of the International System of Units having prompted a fundamental reassessment of the dosimetric quantities to be considered in calibrating measuring instruments, various proposals were advanced by the representatives of national metrology laboratories to replace the quantity 'exposure' (SI unit = coulomb/kg) by 'Kerma' or 'absorbed dose' (unit joule/kg, the special name of which is 'gray'), this latter being closer to the practical

  15. The Chernobyl accident: EPR dosimetry on dental enamel of children

    The radiation dose on tooth enamel of children living close to Chernobyl has been evaluated by EPR. The sample preparation was reduced to a minimum of mechanical steps to remove a piece of enamel. A standard X-ray tube at low energy was used for additive irradiation. The filtration effect of facial soft tissue was taken into account. The radiation dose for a group of teeth slightly exceeds the annual dose, whereas for another group the dose very much exceeds the annual dose. Since the higher dose is found in teeth whose enamel have much lower EPR sensitivity to the radiation, it can be suggested that for these teeth the native signal could alter the evaluation of the smaller radiation signal

  16. Compendium on neutron spectra in criticality accident dosimetry

    Graphical and tabulated neutron spectra are presented: from selected critical assemblies; from critical solutions; of fission neutrons through shielding; of H2O-moderated fission neutrons through shielding; of D2O-moderated fission neutrons through shielding; of fission neutrons reflected from various materials; from the D(T,4He)n reaction (''14 MeV'' neutrons) through shielding and of ''14 MeV'' neutrons reflected from various materials

  17. Personnel neutron dosimetry using electrochemically etched CR-39 foils

    A personnel neutron dosimetry system has been developed based on the electrochemical etching of CR-39 plastic at elevated temperatures. The doses obtained using this dosimeter system are more accurate than those obtained using other dosimetry systems, especially when varied neutron spectra are encountered. This Cr-39 dosimetry system does not have the severe energy dependence that exists with albedo neutron dosimeters or the fading and reading problems encountered with NTA film. The dosimetry system employs an electrochemical etch procedure that be used to process large numbers of Cr-39 dosimeters. The etch procedure is suitable for operations where the number of personnel requires that many CR-39 dosimeters be processed. Experience shows that one full-time technician can etch and evaluate 2000 foils per month. The energy response to neutrons is fairly flat from about 80 keV to 3.5 MeV, but drops by about a factor of three in the 13 to 16 MeV range. The sensitivity of the dosimetry system is about 7 tracks/cm2/mrem, with a background equivalent to about 8 mrem for new CR-39 foils. The limit of sensitivity is approximately 10 mrem. The dosimeter has a significant variation in directional dependence, dropping to about 20% at 900. This dosimeter has been used for personnel neutron dosimetry at the Lawrence Livermore National Laboratory for more tha 18 months. 6 refs., 23 figs., 2 tabs

  18. Report of a consultants meeting on dosimetry in diagnostic radiology

    During its biennial meeting in 1996, the Standing Advisory Committee 'SSDL Scientific Committee', recommended extending the long experience of the Agency in the field of standardization and monitoring dosimetry calibrations at radiotherapy and radiation protection level for the Secondary Standard Dosimetry Laboratory (SSDL) Network, to the field of diagnostic x-ray dosimetry. It was emphasized that 'Measurements on diagnostic x-ray machines have become increasingly important and some SSDLs are involved in such measurements. The Agency's dosimetry laboratory should, therefore, have proper radiation sources available to provide traceable calibrations to the SSDLs'. The purpose of the consultants' meeting was to advise the Agency on dosimetry in diagnostic radiology. They were specifically requested to overview scientific achievements in the field and to give advice to the Agency on the need for further developments. The purpose of the consultants' meeting was to advise the Agency on dosimetry in diagnostic radiology. They were specifically requested to overview scientific achievements in the field and to give advice to the Agency on the need for further developments

  19. Problems of dosimetric evaluation of radiation accident situations with external irradiation in neutron and gamma field

    The problems are discussed of the dosimetric evaluation of radiation accident situations in a mixed gamma and neutron field. The methods and means of accident dosimetry should allow evaluation basically in three stages: (1) within 6 hours following an accident to classify persons according to radiation exposure; (2) to obtain data on the maximum absorbed dose with accuracy better than +-50% within 48 hours; (3) to establish depth dose values with accuracy better than +-20 to 25% within 3 to 6 days. Recommendations are shown related to safeguarding dosimetric systems for radiation accident situations in nuclear facilities. (B.S.)

  20. Barriers to learning from incidents and accidents

    Dechy, N.; Dien, Y.; Drupsteen, L.; Felicio, A.; Cunha, C; Roed-Larsen, S.; Marsden, E.; Tulonen, T.; Stoop, J.; Strucic, M.; Vetere Arellano, A.L.; Vorm, J.K.J. van der; Benner, L.

    2015-01-01

    This document provides an overview of knowledge concerning barriers to learning from incidents and accidents. It focuses on learning from accident investigations, public inquiries and operational experience feedback, in industrial sectors that are exposed to major accident hazards. The document discusses learning at organizational, cross-organizational and societal levels (impact on regulations and standards). From an operational standpoint, the document aims to help practitioners to identify...

  1. Individualized dosimetry in the management of metastatic differentiated thyroid cancer

    Aim. This paper analyzes the available data on the dosimetric approach and describes the use of dosimetry in the Division of Nuclear Medicine of the National Cancer Institute in Milan. Dosimetry is rarely performed when planning radio-iodine activity, although most of the available guidelines do mention this possibility, without giving any well defined indication. Aim of the present research was to validate the usefulness of dosimetry in the management of metastatic thyroid cancer. Benua (1962) set the limit of blood absorbed dose at 2 Gy to avoid hematological toxicity. Maxon (1983) determined at 80 Gy the dose to achieve complete destruction of a metastatic lesion. Dorn (2003) combined red marrow and lesion dosimetry showing that high activity administrations with less that 3 Gy to the red marrow are a safe and more effective with respect to fixed activities administrations. Lee (2008) reported 50% responses with high activity administrations based on blood dosimetry, in 47 patients which were unsuccessfully previously treated with fixed activities. Sgouros (2005) and Song (2006) introduced key parameters as Biological Effective Dose and Uniform Equivalent Dose in order to describe the effects of continuos low dose rate irradiation and non uniform activity uptake, typical of nuclear medicine treatments. Methods: Red marrow and lesion dosimetry (planar view) were performed during the treatment, without changing the fixed activity schema. Results: This experience demonstrate first of all, that dosimetry is feasible in the clinical routine, and that it can provide the clinician with important information, no matter its often quoted limited numerical accuracy. A total of 17/20 lesion doses below 80 Gy have been detected. Three/17 (doses between 40 and 80 Gy) disappeared in the follow-up scintigram. Two/17 were undetectable at computed tomography or nuclear magnetic resonance. These data suggest that repetition of treatment on a lesion drastically reduces its uptake

  2. Alternative statistical methods for cytogenetic radiation biological dosimetry

    Fornalski, Krzysztof Wojciech

    2014-01-01

    The paper presents alternative statistical methods for biological dosimetry, such as the Bayesian and Monte Carlo method. The classical Gaussian and robust Bayesian fit algorithms for the linear, linear-quadratic as well as saturated and critical calibration curves are described. The Bayesian model selection algorithm for those curves is also presented. In addition, five methods of dose estimation for a mixed neutron and gamma irradiation field were described: two classical methods, two Bayesian methods and one Monte Carlo method. Bayesian methods were also enhanced and generalized for situations with many types of mixed radiation. All algorithms were presented in easy-to-use form, which can be applied to any computational programming language. The presented algorithm is universal, although it was originally dedicated to cytogenetic biological dosimetry of victims of a nuclear reactor accident.

  3. EVA dosimetry in manned spacecraft

    Extra Vehicular Activity (EVA) will become a large part of the astronaut's work on board the International Space Station (ISS). It is already well known that long duration space missions inside a spacecraft lead to radiation doses which are high enough to be a significant health risk to the crew. The doses received during EVA, however, have not been quantified to the same degree. This paper reviews the space radiation environment and the current dose limits to critical organs. Results of preliminary radiation dosimetry experiments on the external surface of the BION series of satellites indicate that EVA doses will vary considerably due to a number of factors such as EVA suit shielding, temporal fluctuations and spacecraft orbit and shielding. It is concluded that measurement of doses to crew members who engage in EVA should be done on board the spacecraft. An experiment is described which will lead the way to implementing this plan on the ISS. It is expected that results of this experiment will help future crew mitigate the risks of ionising radiation in space

  4. Criticality Accident

    At a meeting of electric utility presidents in October, 1999, the Federation Power Companies (FEPCO) officially decided to establish a Japanese version of WANO, following the JCO criticality accident. The Japanese WANO is expected to be launched by the end of the year: initially, with some 30 private sector companies concerned with nuclear fuel. It is said that the private sector had to make efforts to ensure that safety was the most important value in management policy throughout the industry, and that comprehensive inspections would be implemented. In anything related to nuclear energy, sufficient safety checks are required even for the most seemingly trivial matters. Therefore, the All-Japan Council of Local Governments with Atomic Power Stations has already proposed to the Japanese government that it should enact the special law for nuclear emergency, providing that the unified responsibility for nuclear disaster prevention should be shifted to the national government, since the nuclear disaster was quite special from the viewpoint of its safety regulation and technical aspects. (G.K.)

  5. Critical evaluation of the experiments and mathematical models for the determination of fission product release from the spherical fuel elements in cases of core heating accidents in modular HTR's

    In this work, the thermal behaviour of modular reactors in cases of core heating accidents and the physical phenomena relevant for a release of radioactive materials from HTR fuel elements are explained as far as is necessary for understanding the work. The present mathematical models by which the release of radioactive materials from HTR fuel elements due to diffusion or breaking particles in cases of core heating accidents are also described, examined and evaluated with regard to their applicability to module reactors. The experiments used to verify the mathematical models are also evaluated. The mathematical models are in nearly all cases computer programs, which describe the complicated process of releasing radioactive materials quantitative mathematically. One should point out that these models are constantly being developed further, in line with the increasing amount of knowledge. To conclude the work, proposals are made for improving the certainty of information from experiments and mathematical models to determine the release behaviour of modular reactors. (orig./GL)

  6. Spanish National Dosimetry Bank

    The National Dosimetry Bank (BDN) was designed to be a useful instrument for the protection of exposed workers. On the basis of individual doses, in conjunction with the type of facility where they were received and the type of work involved, it is possible to monitor and control the individual conditions of an exposed worker. In addition to this primary objective, the BDN's structure and utilities are such that it can be used for applications such as determining the suitability of the working conditions in various areas of ionizing radiation applications, evaluating exposure trends and the most affected areas, and supplying statistical data that can be used for legal studies

  7. Relocation of Dosimetry Service

    2007-01-01

    The Dosimetry Service is moving from Building 24 to Building 55 and will therefore be closed on Friday, March 30. From Monday, April 2 onwards you will find us in building 55/1-001. Please note that during that day we might still have some problems with the internet connections and cannot fully guarantee normal service procedures. The service's opening hours and telephone number will not change as a result of the move 8.30 - 12.00, afternoons closed Tel. 72155

  8. Individual dosimetry and calibration

    In 1995 both the Individual Dosimetry and Calibration Sections worked under the condition of a status quo and concentrated fully on the routine part of their work. Nevertheless, the machine for printing the bar code which will be glued onto the film holder and hence identify the people when entering into high radiation areas was put into operation and most of the holders were equipped with the new identification. As far as the Calibration Section is concerned the project of the new source control system that is realized by the Technical Support Section was somewhat accelerated

  9. Dosimetry in Radiology

    The steady growth in the use of ionizing radiation in diagnostic imaging requires to maintain a proper management of patient’s dose. Dosimetry in Radiology is a difficult topic to address, but vital for proper estimation of the dose the patient is receiving. The awareness that every day is perceived in our country on these issues is the appropriate response to this problem. This article describes the main dosimetric units used and easily exemplifies doses in radiology through internationally known reference values. (authors)

  10. Fast neutron dosimetry

    DeLuca, P.M. Jr.; Pearson, D.W.

    1992-01-01

    This progress report concentrates on two major areas of dosimetry research: measurement of fast neutron kerma factors for several elements for monochromatic and white spectrum neutron fields and determination of the response of thermoluminescent phosphors to various ultra-soft X-ray energies and beta-rays. Dr. Zhixin Zhou from the Shanghai Institute of Radiation Medicine, People's Republic of China brought with him special expertise in the fabrication and use of ultra-thin TLD materials. Such materials are not available in the USA. The rather unique properties of these materials were investigated during this grant period.

  11. Persistence on airline accidents.

    L. A. GIL-ALANA; Barros, C.P. (Carlos P.); J.R. Faria

    2009-01-01

    This paper analyses airline accidents data from 1927-2006. The fractional integration methodology is adopted. It is shown that airline accidents are persistent and (fractionally) cointegrated with airline traffic. Thus, there exists an equilibrium relation between air accidents and airline traffic, with the effect of the shocks to that relationship disappearing in the long run. Policy implications are derived for countering accidents events.

  12. Persistence in Airline Accidents

    Carlos Pestana Barros; João Ricardo Faria; Luis A. Gil-Alana

    2008-01-01

    This paper analyses airline accident data from 1927-2006, through fractional integration. It is shown that airline accidents are persistent and (fractionally) cointegrated with airline traffic. There exists a negative relation between air accidents and airline traffic, with the effect of the shocks to that relationship disappearing in the long run. Policy implications are derived for countering accident events.

  13. Three-Dimensional (X,Y,Z) Deterministic Analysis of the PCA-Replica Neutron Shielding Benchmark Experiment using the TORT-3.2 Code and Group Cross Section Libraries for LWR Shielding and Pressure Vessel Dosimetry

    Pescarini, Massimo; Orsi, Roberto; Frisoni, Manuela

    2016-02-01

    The PCA-Replica 12/13 (H2O/Fe) neutron shielding benchmark experiment was analysed using the ORNL TORT-3.2 3D SN code. PCA-Replica, specifically conceived to test the accuracy of nuclear data and transport codes employed in LWR shielding and radiation damage calculations, reproduces a PWR ex-core radial geometry with alternate layers of water and steel including a PWR pressure vessel simulator. Three broad-group coupled neutron/photon working cross section libraries in FIDO-ANISN format with the same energy group structure (47 n + 20 γ) and based on different nuclear data were alternatively used: the ENEA BUGJEFF311.BOLIB (JEFF-3.1.1) and BUGENDF70.BOLIB (ENDF/B-VII.0) libraries and the ORNL BUGLE-96 (ENDF/B-VI.3) library. Dosimeter cross sections derived from the IAEA IRDF-2002 dosimetry file were employed. The calculated reaction rates for the Rh-103(n,n')Rh-103 m, In-115(n,n')In-115m and S-32(n,p)P-32 threshold activation dosimeters and the calculated neutron spectra are compared with the corresponding experimental results.

  14. Three-Dimensional (X,Y,Z Deterministic Analysis of the PCA-Replica Neutron Shielding Benchmark Experiment using the TORT-3.2 Code and Group Cross Section Libraries for LWR Shielding and Pressure Vessel Dosimetry

    Pescarini Massimo

    2016-01-01

    Full Text Available The PCA-Replica 12/13 (H2O/Fe neutron shielding benchmark experiment was analysed using the ORNL TORT-3.2 3D SN code. PCA-Replica, specifically conceived to test the accuracy of nuclear data and transport codes employed in LWR shielding and radiation damage calculations, reproduces a PWR ex-core radial geometry with alternate layers of water and steel including a PWR pressure vessel simulator. Three broad-group coupled neutron/photon working cross section libraries in FIDO-ANISN format with the same energy group structure (47 n + 20 γ and based on different nuclear data were alternatively used: the ENEA BUGJEFF311.BOLIB (JEFF-3.1.1 and BUGENDF70.BOLIB (ENDF/B-VII.0 libraries and the ORNL BUGLE-96 (ENDF/B-VI.3 library. Dosimeter cross sections derived from the IAEA IRDF-2002 dosimetry file were employed. The calculated reaction rates for the Rh-103(n,n′Rh-103 m, In-115(n,n′In-115m and S-32(n,pP-32 threshold activation dosimeters and the calculated neutron spectra are compared with the corresponding experimental results.

  15. Experience in training of health personnel for response to radiological and nuclear accidents; Experiencia na capacitacao de profissionais de saude para a resposta a acidentes radiologicos e nucleares

    Maurmo, Alexandre M., E-mail: ammaurmo@gmail.com [Fundacao Eletronuclear de Assistencia Medica (CMRI/CTNV/FEAM), Praia Brava, RJ (Brazil). Centro de Medicina das Radiacoes Ionizantes. Centro de Treinamento Prof. Nelson Valverde; Leite, Teresa C.S.B., E-mail: feam@feam-etn.org.br [Fundacao Eletronuclear de Assistencia Medica (CIRA/FEAM), Praia Brava, RJ (Brazil). Centro de Informacoes em Radioepidemiologia

    2013-07-01

    Eletronuclear Healthcare Foundation is the Institution responsible for the actions of health response involving ionizing radiation in the area of Nuclear Power Plant Almirante Alvaro Alberto in Angra dos Reis. Because of their specific assignments and references for being in training health manpower in the field of ionizing radiation developed a range of Training Courses for Professionals Area Health to prepare them for Response to Radiological and Nuclear Accidents. Modules are proposed specifically for the professional response of the Technical Level and Higher Level, the level Pre-hospital and hospital. These modules are further divided into specific levels or modules, Basic or Introductory, Intermediate and Advanced. Are applied pretests and post tests to monitor the content of fixing, maintaining a historical series of reviews. Your content is theoretical and practical applications developed in 30 to 48 hours, with simulations (drills) and distribution of educational materials. We already have more than 80 applications training, focusing on internal staff and external to the institution, developing interesting partner with the Armed Forces and Civil Defense. It still maintained a link on the institution seeking access and download over 400 titles on the subject and exchange of information and experiences. For improving the teaching material, the authors launched in 2011 the first manual in Portuguese on the subject with new revised edition in 2013: 'Manual of Medical Actions In Radiological Emergencies'. The results indicate increased knowledge and appropriateness of the themes and the strategy proposed for this activity, demonstrating yet passed that information can be multiplied and meets the growing demand of the country that has hosted and will host international events relevant at QBNRE risk. (author)

  16. Severe accident phenomena

    Severe accidents are nuclear reactor accidents in which the reactor core is substantially damaged. The report describes severe reactor accident phenomena and their significance for the safety of nuclear power plants. A comprehensive set of phenomena ranging from accident initiation to containment behaviour and containment integrity questions are covered. The report is based on expertise gained in the severe accident assessment projects conducted at the Technical Research Centre of Finland (VTT). (49 refs., 32 figs., 12 tabs.)

  17. Dosimetry and biological effects of fast neutrons

    This thesis contains studies on two types of cellular damage: cell reproductive death and chromosome aberrations induced by irradiation with X rays, gamma rays and fast neutrons of different energies. A prerequisite for the performance of radiobiological experiments is the determination of the absorbed dose with a sufficient degree of accuracy and precision. Basic concepts of energy deposition by ionizing radiation and practical aspects of neutron dosimetry for biomedical purposes are discussed. Information on the relative neutron sensitivity of GM counters and on the effective point of measurement of ionization chambers for dosimetry of neutron and photon beams under free-in-air conditions and inside phantoms which are used to simulate the biological objects is presented. Different methods for neutron dosimetry are compared and the experimental techniques used for the investigations of cell reproductive death and chromosome aberrations induced by ionizing radiation of different qualities are presented. Dose-effect relations for induction cell inactivation and chromsome aberrations in three cultured cell lines for different radiation qualities are presented. (Auth.)

  18. In-core dosimetry in CAGR - measurements on power reactors and laboratory facilities

    The problem of radiolytic corrosion of the graphite moderator in CAGR has led to a need for more accurate information on the radiation dose to the coolant gas in the pores of the graphite. An experimental in-core dosimetry programme is in progress to acquire this data. The problems of in-core dosimetry, particularly that of measuring gamma dose in the presence of high thermal neutron fluences, are described with reference to calorimetry, ionisation chambers and thermoluminescence dosimeters. Progress made in the refinement of these techniques for reactor dosimetry is described. An experiment is described in which dosimetry measurements in components of a Heysham Power Station reactor were made during its commissioning. The major facility of this dosimetry programme is a zero-energy research reactor constructed from CAGR components; this reactor and its experimental facilities are described, together with the results of some of the first experiments. (author)

  19. Worst case reactor accidents: a paradox

    The preliminary results from the application of improved source term methodology indicate a diversity of results for plants of different design, and for different accident sequences postulated for the same plant. While significant reductions from previous estimates are calculated with the new methodology for some accident scenarios, the same methodology predicts release magnitudes of minor difference from those produced with earlier methods for other accident sequences and plants. This divergence of calculated results precludes the adoption of a worst case as a meaningful characterization of severe accident consequences. This situation reinforces the need to consider the consequences of severe accidents only in light of their probability, even in those applications outside the traditional risk assessment process, and may necessitate re-consideration of a probability threshold for extremely low probability events. A practical approach to such a threshold value is discussed, based on NRC's experience with severe accident considerations in environmental impact statements

  20. Assessment of off-site consequences of nuclear accidents (MARIA)

    A brief report is given of a workshop held in Luxembourg in 1985 on methods for assessing the off-site radiological consequences of nuclear accidents (MARIA). The sessions included topics such as atmospheric dispersion; foodchain transfer; urban contamination; demographic and land use data; dosimetry, health effects, economic and countermeasures models; uncertainty analysis; and application of probabilistic risk assessment results as input to decision aids. (U.K.)