Science.gov

Sample records for nuclear criticality accident

  1. [Chernobyl nuclear power plant accident and Tokaimura criticality accident].

    PubMed

    Takada, Jun

    2012-03-01

    It is clear from inspection of historical incidents that the scale of disasters in a nuclear power plant accident is quite low level overwhelmingly compared with a nuclear explosion in nuclear war. Two cities of Hiroshima and Nagasaki were destroyed by nuclear blast with about 20 kt TNT equivalent and then approximately 100,000 people have died respectively. On the other hand, the number of acute death is 30 in the Chernobyl nuclear reactor accident. In this chapter, we review health hazards and doses in two historical nuclear incidents of Chernobyl and Tokaimura criticality accident and then understand the feature of the radiation accident in peaceful utilization of nuclear power. PMID:22514916

  2. A neutron dosemeter for nuclear criticality accidents.

    PubMed

    d'Errico, F; Curzio, G; Ciolini, R; Del Gratta, A; Nath, R

    2004-01-01

    A neutron dosemeter which offers instant read-out has been developed for nuclear criticality accidents. The system is based on gels containing emulsions of superheated dichlorodifluoromethane droplets, which vaporise into bubbles upon neutron irradiation. The expansion of these bubbles displaces an equivalent volume of gel into a graduated pipette, providing an immediate measure of the dose. Instant read-out is achieved using an array of transmissive optical sensors which consist of coupled LED emitters and phototransistor receivers. When the gel displaced in the pipette crosses the sensing region of the photomicrosensors, it generates a signal collected on a computer through a dedicated acquisition board. The performance of the device was tested during the 2002 International Accident Dosimetry Intercomparison in Valduc, France. The dosemeter was able to follow the initial dose gradient of a simulated accident, providing accurate values of neutron kerma; however, the emulsion was rapidly depleted of all its drops. A model of the depletion effects was developed and it indicates that an adequate dynamic range of the dose response can be achieved by using emulsions of smaller droplets. PMID:15353696

  3. Improved dose estimates for nuclear criticality accidents

    SciTech Connect

    Wilkinson, A.D.; Basoglu, B.; Bentley, C.L.; Dunn, M.E.; Plaster, M.J.; Dodds, H.L.; Haught, C.F.; Yamamoto, T.; Hopper, C.M.

    1995-08-01

    Slide rules are improved for estimating doses and dose rates resulting from nuclear criticality accidents. The original slide rules were created for highly enriched uranium solutions and metals using hand calculations along with the decades old Way-Wigner radioactive decay relationship and the inverse square law. This work uses state-of-the-art methods and better data to improve the original slide rules and also to extend the slide rule concept to three additional systems; i.e., highly enriched (93.2 wt%) uranium damp (H/{sup 235}U = 10) powder (U{sub 3}O{sub 8}) and low-enriched (5 wt%) uranium mixtures (UO{sub 2}F{sub 2}) with a H/{sup 235}U ratio of 200 and 500. Although the improved slide rules differ only slightly from the original slide rules, the improved slide rules and also the new slide rules can be used with greater confidence since they are based on more rigorous methods and better nuclear data.

  4. Updated tool for nuclear criticality accident emergency response

    SciTech Connect

    Broadhead, B.L.; Hopper, C.M.

    1995-12-31

    Some 20 yr ago a hand-held slide rule was developed at the Oak Ridge Y-12 Plant to aid in the response to several postulated nuclear criticality accidents. These assumed accidents involved highly enriched uranium in either a bare metal or a uranyl nitrate system. The slide rule consisted of a sliding scale based on the total fission yield and four corresponding dose indicators: (1) a prompt radiation dose relationship as a function of distance; (2) a delayed fission product gamma dose rate relationship as a function of time and distance; (3) the total dose relationship with time and distance; and (4) the I-min integrated dose relationship with time and distance. The original slide rule was generated assuming very simplistic numerical procedures such as the inverse-square relationship of dose with distance and the Way-Wigner relationship to express the time dependence of the dose. The simple prescriptions were tied to actual dose measurements from similar systems to yield a meaningful, yet simple approach to emergency planning and response needs. This paper describes the application of an advanced procedure to the updating of the original slide rule for five critical systems. These five systems include (a) an unreflected sphere of 93.2 wt% enriched uranium metal, (b) an unreflected sphere of 93.2 wt% enriched uranyl nitrate solution with a H/{sup 235}U ratio of 500, (c) an unreflected sphere of damp 93.2 wt% enriched uranium oxide with a H/{sup 235}U ratio of 10, (d) an unreflected sphere of 4.95 wt% enriched uranyl fluoride solution having a H/{sup 235}U ratio of 410, and (e) an unreflected sphere of damp 5 wt% enriched uranium dioxide having a H/{sup 235}U ratio of 200.

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

    SciTech Connect

    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.

  6. First Responders and Criticality Accidents

    SciTech Connect

    Valerie L. Putman; Douglas M. Minnema

    2005-11-01

    Nuclear criticality accident descriptions typically include, but do not focus on, information useful to first responders. We studied these accidents, noting characteristics to help (1) first responders prepare for such an event and (2) emergency drill planners develop appropriate simulations for training. We also provide recommendations to help people prepare for such events in the future.

  7. Nuclear fuel cycle facility accident analysis handbook

    SciTech Connect

    Ayer, J E; Clark, A T; Loysen, P; Ballinger, M Y; Mishima, J; Owczarski, P C; Gregory, W S; Nichols, B D

    1988-05-01

    The Accident Analysis Handbook (AAH) covers four generic facilities: fuel manufacturing, fuel reprocessing, waste storage/solidification, and spent fuel storage; and six accident types: fire, explosion, tornado, criticality, spill, and equipment failure. These are the accident types considered to make major contributions to the radiological risk from accidents in nuclear fuel cycle facility operations. The AAH will enable the user to calculate source term releases from accident scenarios manually or by computer. A major feature of the AAH is development of accident sample problems to provide input to source term analysis methods and transport computer codes. Sample problems and illustrative examples for different accident types are included in the AAH.

  8. PNNL Results from 2009 Silene Criticality Accident Dosimeter Intercomparison Exercise

    SciTech Connect

    Hill, Robin L.; Conrady, Matthew M.

    2010-06-30

    This document reports the results of testing of the Hanford Personnel Nuclear Accident Dosimeter (PNAD) during a criticality accident dosimeter intercomparison exercise at the CEA Valduc Center on October 13, 14, and 15, 2009.

  9. Lessons learned from early criticality accidents

    SciTech Connect

    Malenfant, R.E.

    1996-06-01

    Four accidents involving the approach to criticality occurred during the period July, 1945, through May, 1996. These have been described in the format of the OPERATING EXPERIENCE WEEKLY SUMMARY which is distributed by the Office of Nuclear and Facility Safety. Although the lessons learned have been incorporated in standards, codes, and formal procedures during the last fifty years, this is their first presentation in this format. It is particularly appropriate that they be presented in the forum of the Nuclear Criticality Technology Safety Project Workshop closest to the fiftieth anniversary of the last of the four accidents, and that which was most instrumental in demonstrating the need to incorporate lessons learned.

  10. Nuclear accident dosimetry intercomparison studies.

    PubMed

    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

  11. A review of criticality accidents

    SciTech Connect

    Stratton, W R; Smith, D R

    1989-03-01

    Criticality accidents and the characteristics of prompt power excursions are discussed. Forty-one accidental power transients are reviewed. In each case where available, enough detail is given to help visualize the physical situation, the cause or causes of the accident, the history and characteristics of the transient, the energy release, and the consequences, if any, to personnel and property. Excursions associated with large power reactors are not included in this study, except that some information on the major accident at the Chernobyl reactor in April 1986 is provided in the Appendix. 67 refs., 21 figs., 2 tabs.

  12. 10 CFR 76.89 - Criticality accident requirements.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 2 2012-01-01 2012-01-01 false Criticality accident requirements. 76.89 Section 76.89 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) CERTIFICATION OF GASEOUS DIFFUSION PLANTS Safety § 76.89 Criticality accident requirements. (a) The Corporation must maintain and operate a criticality monitoring and audible alarm system meeting...

  13. 10 CFR 76.89 - Criticality accident requirements.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 2 2014-01-01 2014-01-01 false Criticality accident requirements. 76.89 Section 76.89 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) CERTIFICATION OF GASEOUS DIFFUSION PLANTS Safety § 76.89 Criticality accident requirements. (a) The Corporation must maintain and operate a criticality monitoring and audible alarm system meeting...

  14. 10 CFR 76.89 - Criticality accident requirements.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 2 2013-01-01 2013-01-01 false Criticality accident requirements. 76.89 Section 76.89 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) CERTIFICATION OF GASEOUS DIFFUSION PLANTS Safety § 76.89 Criticality accident requirements. (a) The Corporation must maintain and operate a criticality monitoring and audible alarm system meeting...

  15. 10 CFR 76.89 - Criticality accident requirements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 2 2011-01-01 2011-01-01 false Criticality accident requirements. 76.89 Section 76.89 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) CERTIFICATION OF GASEOUS DIFFUSION PLANTS Safety § 76.89 Criticality accident requirements. (a) The Corporation must maintain and operate a criticality monitoring and audible alarm system meeting...

  16. 10 CFR 76.89 - Criticality accident requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Criticality accident requirements. 76.89 Section 76.89 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) CERTIFICATION OF GASEOUS DIFFUSION PLANTS Safety § 76.89 Criticality accident requirements. (a) The Corporation must maintain and operate a criticality monitoring and audible alarm system meeting...

  17. Nuclear-accident dosimetry: measurements at the Los Alamos SHEBA critical assembly

    SciTech Connect

    Vasilik, D.G.; Martin, R.W.; Fuller, D.

    1981-07-01

    Criticality dosimeters were exposed to different degraded neutron and gamma-ray energy spectra from the Los Alamos Solution High Energy Burst Assembly (SHEBA). The liquid critical test assembly was operated in the continuous mode to provide a mixed source of neutron and gamma-ray radiation for the evaluation of Los Alamos criticality detector systems. Different neutron and gamma-ray spectra were generated by operating the reactor (a) shielded by 12 cm of Lucite, (b) unshielded, (c) shielded by 20 cm of concrete, and (d) shielded by 15 cm of steel. This report summarizes the dosimetry measurements conducted for these different configurations. In-air measurements were conducted with shielded and unshielded area and personnel dosimeters. Phantom measurements were made using personnel dosimeters. Combined blood-sodium and hair sulfur activation 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.

  18. Personal nuclear accident dosimetry at Sandia National Laboratories

    SciTech Connect

    Ward, D.C.; Mohagheghi, A.H.; Burrows, R.

    1996-09-01

    DOE installations possessing sufficient quantities of fissile material to potentially constitute a critical mass, such that the excessive exposure of personnel to radiation from a nuclear accident is possible, are required to provide nuclear accident dosimetry services. This document describes the personal nuclear accident dosimeter (PNAD) used by SNL and prescribes methodologies to initially screen, and to process PNAD results. In addition, this report describes PNAD dosimetry results obtained during the Nuclear Accident Dosimeter Intercomparison Study (NAD23), held during 12-16 June 1995, at Los Alamos National Laboratories. Biases for reported neutron doses ranged from -6% to +36% with an average bias of +12%.

  19. PNNL Results from 2010 CALIBAN Criticality Accident Dosimeter Intercomparison Exercise

    SciTech Connect

    Hill, Robin L.; Conrady, Matthew M.

    2011-10-28

    This document reports the results of the Hanford personnel nuclear accident dosimeter (PNAD) and fixed nuclear accident dosimeter (FNAD) during a criticality accident dosimeter intercomparison exercise at the CEA Valduc Center on September 20-23, 2010. Pacific Northwest National Laboratory (PNNL) participated in a criticality accident dosimeter intercomparison exercise at the Commissariat a Energie Atomique (CEA) Valduc Center near Dijon, France on September 20-23, 2010. The intercomparison exercise was funded by the U.S. Department of Energy, Nuclear Criticality Safety Program, with Lawrence Livermore National Laboratory as the lead Laboratory. PNNL was one of six invited DOE Laboratory participants. The other participating Laboratories were: Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), Savannah River Site (SRS), the Y-12 National Security Complex at Oak Ridge, and Sandia National Laboratory (SNL). The goals of PNNL's participation in the intercomparison exercise were to test and validate the procedures and algorithm currently used for the Hanford personnel nuclear accident dosimeters (PNADs) on the metallic reactor, CALIBAN, to test exposures to PNADs from the side and from behind a phantom, and to test PNADs that were taken from a historical batch of Hanford PNADs that had varying degrees of degradation of the bare indium foil. Similar testing of the PNADs was done on the Valduc SILENE test reactor in 2009 (Hill and Conrady, 2010). The CALIBAN results are reported here.

  20. Characterization of a nuclear accident dosimeter

    SciTech Connect

    Burrows, R.A.

    1995-12-01

    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.

  1. Nuclear criticality safety: 2-day training course

    SciTech Connect

    Schlesser, J.A.

    1997-02-01

    This compilation of notes is presented as a source reference for the criticality safety course. At the completion of this training course, the attendee will: be able to define terms commonly used in nuclear criticality safety; be able to appreciate the fundamentals of nuclear criticality safety; be able to identify factors which affect nuclear criticality safety; be able to identify examples of criticality controls as used as Los Alamos; be able to identify examples of circumstances present during criticality accidents; have participated in conducting two critical experiments; be asked to complete a critique of the nuclear criticality safety training course.

  2. Nuclear criticality safety guide

    SciTech Connect

    Pruvost, N.L.; Paxton, H.C.

    1996-09-01

    This technical reference document cites information related to nuclear criticality safety principles, experience, and practice. The document also provides general guidance for criticality safety personnel and regulators.

  3. A Review of Criticality Accidents 2000 Revision

    SciTech Connect

    Thomas P. McLaughlin; Shean P. Monahan; Norman L. Pruvost; Vladimir V. Frolov; Boris G. Ryazanov; Victor I. Sviridov

    2000-05-01

    Criticality accidents and the characteristics of prompt power excursions are discussed. Sixty accidental power excursions are reviewed. Sufficient detail is provided to enable the reader to understand the physical situation, the chemistry and material flow, and when available the administrative setting leading up to the time of the accident. Information on the power history, energy release, consequences, and causes are also included when available. For those accidents that occurred in process plants, two new sections have been included in this revision. The first is an analysis and summary of the physical and neutronic features of the chain reacting systems. The second is a compilation of observations and lessons learned. Excursions associated with large power reactors are not included in this report.

  4. An updated nuclear criticality slide rule

    SciTech Connect

    Hopper, C.M.; Broadhead, B.L.

    1998-04-01

    This Volume 2 contains the functional version of the updated nuclear criticality slide rule (more accurately, sliding graphs) that is referenced in An Updated Nuclear Criticality Slide Rule: Technical Basis, NUREG/CR-6504, Vol. 1 (ORNL/TM-13322/V1). This functional slide rule provides a readily usable {open_quotes}in-hand{close_quotes} method for estimating pertinent nuclear criticality accident information from sliding graphs, thereby permitting (1) the rapid estimation of pertinent criticality accident information without laborious or sophisticated calculations in a nuclear criticality emergency situation, (2) the appraisal of potential fission yields and external personnel radiation exposures for facility safety analyses, and (3) a technical basis for emergency preparedness and training programs at nonreactor nuclear facilities. The slide rule permits the estimation of neutron and gamma dose rates and integrated doses based upon estimated fission yields, distance from the fission source, and time-after criticality accidents for five different critical systems. Another sliding graph permits the estimation of critical solution fission yields based upon fissile material concentration, critical vessel geometry, and solution addition rate. Another graph provides neutron and gamma dose-reduction factors for water, steel, and concrete. Graphs from historic documents are provided as references for estimating critical parameters of various fissile material systems. Conversion factors for various English and metric units are provided for quick reference.

  5. Nuclear criticality safety: 5-day training course

    SciTech Connect

    Schlesser, J.A.

    1992-11-01

    This compilation of notes is presented as a source reference for the criticality safety course. It represents the contributions of many people, particularly Tom McLaughlin, the course's primary instructor. At the completion of this training course, the attendee will: be able to define terms commonly used in nuclear criticality safety; be able to appreciate the fundamentals of nuclear criticality safety; be able to identify factors which affect nuclear criticality safety; be able to identify examples of criticality controls as used at Los Alamos; be able to identify examples of circumstances present during criticality accidents; be able to identify examples of computer codes used by the nuclear criticality safety specialist; be able to identify examples of safety consciousness required in nuclear criticality safety.

  6. Nuclear criticality safety: 5-day training course

    SciTech Connect

    Schlesser, J.A.

    1992-11-01

    This compilation of notes is presented as a source reference for the criticality safety course. It represents the contributions of many people, particularly Tom McLaughlin, the course`s primary instructor. At the completion of this training course, the attendee will: be able to define terms commonly used in nuclear criticality safety; be able to appreciate the fundamentals of nuclear criticality safety; be able to identify factors which affect nuclear criticality safety; be able to identify examples of criticality controls as used at Los Alamos; be able to identify examples of circumstances present during criticality accidents; be able to identify examples of computer codes used by the nuclear criticality safety specialist; be able to identify examples of safety consciousness required in nuclear criticality safety.

  7. A general approach to critical infrastructure accident consequences analysis

    NASA Astrophysics Data System (ADS)

    Bogalecka, Magda; Kołowrocki, Krzysztof; Soszyńska-Budny, Joanna

    2016-06-01

    The probabilistic general model of critical infrastructure accident consequences including the process of the models of initiating events generated by its accident, the process of environment threats and the process of environment degradation is presented.

  8. Slide Rule for Rapid Response Estimation of Radiological Dose from Criticality Accidents

    SciTech Connect

    Broadhead, B L; Childs, R L; Hopper, C M; Parks, C V

    1999-09-20

    This paper describes a functional slide rule that provides a readily usable "in-hand" method for estimating nuclear criticality accident information from sliding graphs, thereby permitting (1) the rapid estimation of pertinent criticality accident information without laborious or sophisticated calculations in a nuclear criticality emergency situation, (2) the appraisal of potential fission yields and external personnel radiation exposures for facility safety analyses, and (3) a technical basis for emergency preparedness and training programs at nonreactor nuclear facilities. The slide rule permits the estimation of neutron and gamma dose rates and integrated doses based upon estimated fission yields, distance from the fission source, and time-after criticality accidents for five different critical systems. Another sliding graph permits the estimation of critical solution fission yields based upon fissile material concentration, critical vessel geometry, and solution addition rate. Another graph provides neutron and gamma dose-reduction factors for water, steel, and concrete shields.

  9. Nuclear criticality safety: 3-day training course

    SciTech Connect

    Schlesser, J.A.

    1992-11-01

    This compilation of notes is presented as a source reference for the criticality safety course. It represents the contributions of many people, particularly Tom McLaughlin, the course's primary instructor. At the completion of this training course, the attendee will: (1) be able to define terms commonly used in nuclear criticality safety; (2) be able to appreciate the fundamentals of nuclear criticality safety; (3) be able to identify factors which affect nuclear criticality safety; (4) be able to identify examples of criticality controls as used at Los Alamos; (5) be able to identify examples of circumstances present during criticality accidents; (6) be able to identify examples of safety consciousness required in nuclear criticality safety.

  10. Nuclear criticality safety: 3-day training course

    SciTech Connect

    Schlesser, J.A.

    1992-11-01

    This compilation of notes is presented as a source reference for the criticality safety course. It represents the contributions of many people, particularly Tom McLaughlin, the course`s primary instructor. At the completion of this training course, the attendee will: (1) be able to define terms commonly used in nuclear criticality safety; (2) be able to appreciate the fundamentals of nuclear criticality safety; (3) be able to identify factors which affect nuclear criticality safety; (4) be able to identify examples of criticality controls as used at Los Alamos; (5) be able to identify examples of circumstances present during criticality accidents; (6) be able to identify examples of safety consciousness required in nuclear criticality safety.

  11. 10 CFR 835.1304 - Nuclear accident dosimetry.

    Code of Federal Regulations, 2010 CFR

    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)...

  12. 10 CFR 835.1304 - Nuclear accident dosimetry.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 4 2011-01-01 2011-01-01 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)...

  13. Development of posture-specific computational phantoms using motion capture technology and application to radiation dose-reconstruction for the 1999 Tokai-Mura nuclear criticality accident

    NASA Astrophysics Data System (ADS)

    Vazquez, Justin A.; Caracappa, Peter F.; Xu, X. George

    2014-09-01

    The majority of existing computational phantoms are designed to represent workers in typical standing anatomical postures with fixed arm and leg positions. However, workers found in accident-related scenarios often assume varied postures. This paper describes the development and application of two phantoms with adjusted postures specified by data acquired from a motion capture system to simulate unique human postures found in a 1999 criticality accident that took place at a JCO facility in Tokai-Mura, Japan. In the course of this accident, two workers were fatally exposed to extremely high levels of radiation. Implementation of the emergent techniques discussed produced more accurate and more detailed dose estimates for the two workers than were reported in previous studies. A total-body dose of 6.43 and 26.38 Gy was estimated for the two workers, who assumed a crouching and a standing posture, respectively. Additionally, organ-specific dose estimates were determined, including a 7.93 Gy dose to the thyroid and 6.11 Gy dose to the stomach for the crouching worker and a 41.71 Gy dose to the liver and a 37.26 Gy dose to the stomach for the standing worker. Implications for the medical prognosis of the workers are discussed, and the results of this study were found to correlate better with the patient outcome than previous estimates, suggesting potential future applications of such methods for improved epidemiological studies involving next-generation computational phantom tools.

  14. SILENE Benchmark Critical Experiments for Criticality Accident Alarm Systems

    SciTech Connect

    Miller, Thomas Martin; Reynolds, Kevin H.

    2011-01-01

    In October 2010 a series of benchmark experiments was conducted at the Commissariat a Energie Atomique et aux Energies Alternatives (CEA) Valduc SILENE [1] facility. These experiments were a joint effort between the US Department of Energy (DOE) and the French 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 (CAASs). This presentation will discuss the geometric configuration of these experiments and the quantities that were measured and will present some preliminary comparisons between the measured data and calculations. This series consisted of three single-pulsed experiments with the SILENE reactor. During the first experiment the reactor was bare (unshielded), but during the second and third experiments it was shielded by lead and polyethylene, respectively. During each experiment several neutron activation foils and thermoluminescent dosimeters (TLDs) were placed around the reactor, and some of these detectors were themselves shielded from the reactor by high-density magnetite and barite concrete, standard concrete, and/or BoroBond. All the concrete was provided by CEA Saclay, and the BoroBond was provided by Y-12 National Security Complex. Figure 1 is a picture of the SILENE reactor cell configured for pulse 1. Also included in these experiments were measurements of the neutron and photon spectra with two BICRON BC-501A liquid scintillators. These two detectors were provided and operated by CEA Valduc. They were set up just outside the SILENE reactor cell with additional lead shielding to prevent the detectors from being saturated. The final detectors involved in the experiments were two different types of CAAS detectors. The Babcock International Group provided three CIDAS CAAS detectors, which measured photon dose and dose rate with a Geiger-Mueller tube. CIDAS detectors are currently in

  15. Fukushima nuclear power plant accident was preventable

    NASA Astrophysics Data System (ADS)

    Kanoglu, Utku; Synolakis, Costas

    2015-04-01

    On 11 March 2011, the fourth largest earthquake in recorded history triggered a large tsunami, which will probably be remembered from the dramatic live pictures in a country, which is possibly the most tsunami-prepared in the world. The earthquake and tsunami caused a major nuclear power plant (NPP) accident at the Fukushima Dai-ichi, owned by Tokyo Electric Power Company (TEPCO). The accident was likely more severe than the 1979 Three Mile Island and less severe than the Chernobyl 1986 accidents. Yet, after the 26 December 2004 Indian Ocean tsunami had hit the Madras Atomic Power Station there had been renewed interest in the resilience of NPPs to tsunamis. The 11 March 2011 tsunami hit the Onagawa, Fukushima Dai-ichi, Fukushima Dai-ni, and Tokai Dai-ni NPPs, all located approximately in a 230km stretch along the east coast of Honshu. The Onagawa NPP was the closest to the source and was hit by an approximately height of 13m tsunami, of the same height as the one that hit the Fukushima Dai-ichi. Even though the Onagawa site also subsided by 1m, the tsunami did not reach to the main critical facilities. As the International Atomic Energy Agency put it, the Onagawa NPP survived the event "remarkably undamaged." At Fukushima Dai-ichi, the three reactors in operation were shut down due to strong ground shaking. The earthquake damaged all offsite electric transmission facilities. Emergency diesel generators (EDGs) provided back up power and started cooling down the reactors. However, the tsunami flooded the facilities damaging 12 of its 13 EDGs and caused a blackout. Among the consequences were hydrogen explosions that released radioactive material in the environment. It is unfortunately clear that TEPCO and Japan's principal regulator Nuclear and Industrial Safety Agency (NISA) had failed in providing a professional hazard analysis for the plant, even though their last assessment had taken place only months before the accident. The main reasons are the following. One

  16. Chemical dosimetry system for criticality accidents.

    PubMed

    Miljanić, Saveta; Ilijas, Boris

    2004-01-01

    Ruder Bosković Institute (RBI) criticality dosimetry system consists of a chemical dosimetry system for measuring the total (neutron + gamma) dose, and a thermoluminescent (TL) dosimetry system for a separate determination of the gamma ray component. The use of the chemical dosemeter solution chlorobenzene-ethanol-trimethylpentane (CET) is based on the radiolytic formation of hydrochloric acid, which protonates a pH indicator, thymolsulphonphthalein. The high molar absorptivity of its red form at 552 nm is responsible for a high sensitivity of the system: doses in the range 0.2-15 Gy can be measured. The dosemeter has been designed as a glass ampoule filled with the CET solution and inserted into a pen-shaped plastic holder. For dose determinations, a newly constructed optoelectronic reader has been used. The RBI team took part in the International Intercomparison of Criticality Accident Dosimetry Systems at the SILENE Reactor, Valduc, June 2002, with the CET dosimetry system. For gamma ray dose determination TLD-700 TL detectors were used. The results obtained with CET dosemeter show very good agreement with the reference values. PMID:15353694

  17. Dose evaluation in criticality accident conditions using transient critical facilities fueled with a fissile solution.

    PubMed

    Nakamura, T; Tonoike, K; Miyoshi, Y

    2004-01-01

    Neutron dose measurement and evaluation techniques in criticality accident conditions using a thermo luminescence dosemeter (TLD) was studied at the Transient Experiment Critical Facility (TRACY) of Japan Atomic Energy Research Institute (JAERI). In the present approach, the absorbed dose is derived from the ambient dose equivalent measured with a TLD, using the appropriate conversion factor given by computation. Using this technique, the neutron dose around the SILENE reactor of the Institute for Radioprotection and Nuclear Safety (IRSN) of France was measured in the Accident Dosimetry Intercomparison Exercise (June 10-21, 2002) organized by OECD/NEA and IRSN. In this exercise, the gamma dose was also measured with a TLD. In this report, measurements and evaluation results at TRACY and SILENE are presented. PMID:15353695

  18. Criticality accident dosimetry by chromosomal analysis.

    PubMed

    Voisin, P; Roy, L; Hone, P A; Edwards, A A; Lloyd, D C; Stephan, G; Romm, H; Groer, P G; Brame, R

    2004-01-01

    The technique of measuring the frequency of dicentric chromosomal aberrations in blood lymphocytes was used to estimate doses in a simulated criticality accident. The simulation consisted of three exposures; approximately 5 Gy with a bare source and 1 and 2 Gy with a lead-shielded source. Three laboratories made separate estimates of the doses. These were made by the iterative method of apportioning the observed dicentric frequencies between the gamma and neutron components, taking account of a given gamma/neutron dose ratio, and referring the separated dicentric frequencies to dose-response calibration curves. An alternative method, based on Bayesian ideas, was employed. This was developed for interpreting dicentric frequencies in situations where the gamma/neutron ratio is uncertain. Both methods gave very similar results. One laboratory produced dose estimates close to the eventual exercise reference doses and the other laboratories estimated slightly higher values. The main reason for the higher values was the calibration relationships for fission neutrons. PMID:15353688

  19. Nuclear criticality information system

    SciTech Connect

    Koponen, B.L.; Hampel, V.E.

    1981-11-30

    The nuclear criticality safety program at LLNL began in the 1950's with a critical measurements program which produced benchmark data until the late 1960's. This same time period saw the rapid development of computer technology useful for both computer modeling of fissile systems and for computer-aided management and display of the computational benchmark data. Database management grew in importance as the amount of information increased and as experimental programs were terminated. Within the criticality safety program at LLNL we began at that time to develop a computer library of benchmark data for validation of computer codes and cross sections. As part of this effort, we prepared a computer-based bibliography of criticality measurements on relatively simple systems. However, it is only now that some of these computer-based resources can be made available to the nuclear criticality safety community at large. This technology transfer is being accomplished by the DOE Technology Information System (TIS), a dedicated, advanced information system. The NCIS database is described.

  20. Agricultural implications of the Fukushima nuclear accident

    PubMed Central

    Nakanishi, Tomoko M.

    2016-01-01

    More than 4 years has passed since the accident at the Fukushima Nuclear Power Plant. Immediately after the accident, 40 to 50 academic staff of the Graduate School of Agricultural and Life Sciences at the University of Tokyo created an independent team to monitor the behavior of the radioactive materials in the field and their effects on agricultural farm lands, forests, rivers, animals, etc. When the radioactive nuclides from the nuclear power plant fell, they were instantly adsorbed at the site where they first touched; consequently, the fallout was found as scattered spots on the surface of anything that was exposed to the air at the time of the accident. The adsorption has become stronger over time, so the radioactive nuclides are now difficult to remove. The findings of our study regarding the wide range of effects on agricultural fields are summarized in this report. PMID:27538845

  1. Agricultural implications of the Fukushima nuclear accident.

    PubMed

    Nakanishi, Tomoko M

    2016-08-01

    More than 4 years has passed since the accident at the Fukushima Nuclear Power Plant. Immediately after the accident, 40 to 50 academic staff of the Graduate School of Agricultural and Life Sciences at the University of Tokyo created an independent team to monitor the behavior of the radioactive materials in the field and their effects on agricultural farm lands, forests, rivers, animals, etc. When the radioactive nuclides from the nuclear power plant fell, they were instantly adsorbed at the site where they first touched; consequently, the fallout was found as scattered spots on the surface of anything that was exposed to the air at the time of the accident. The adsorption has become stronger over time, so the radioactive nuclides are now difficult to remove. The findings of our study regarding the wide range of effects on agricultural fields are summarized in this report. PMID:27538845

  2. Measurement of the Portsmouth Gaseous Diffusion Plant criticality accident alarm

    SciTech Connect

    Tayloe, R.W. Jr. ); McGinnis, B. )

    1990-08-31

    Measurements of the Portsmouth Gaseous Diffusion Plant's nuclear criticality accident radiation alarm signal response time, sound wave frequency, and sound volume levels were made to demonstrate compliance with ANSI/ANS-8.3-1986. A steady-state alarm signal is produced within one-half second of obtaining a two-out-of-three detector trip. The fundamental alarm sound wave frequency is 440 hertz. The sound volume levels are greater than 10 decibels above background and ranged from 100 to 125 A-weighted decibels. The requirements of the standard were met; however the recommended maximum sound volume level of 115 dBA was exceeded. Emergency procedures require immediate evacuation upon initiation of a facility's radiation alarm. Comparison with standards for allowable time of exposure at different noise levels indicate that the elevated noise level at this location does not represent an occupational injury hazard. 8 refs., 5 figs.

  3. Nuclear accident dosimetry studies at Los Alamos National Laboratory

    SciTech Connect

    Casson, W.H.; Buhl, T.E.; Upp, D.L.

    1995-12-01

    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.

  4. Nuclear Facilities Fire Accident Model

    Energy Science and Technology Software Center (ESTSC)

    1999-09-01

    4. NATURE OF PROBLEM SOLVED FIRAC predicts fire-induced flows, thermal and material transport, and radioactive and nonradioactive source terms in a ventilation system. It is designed to predict the radioactive and nonradioactive source terms that lead to gas dynamic, material transport, and heat transfer transients. FIRAC's capabilities are directed toward nuclear fuel cycle facilities and the primary release pathway, the ventilation system. However, it is applicable to other facilities and can be used to modelmore » other airflow pathways within a structure. The basic material transport capability of FIRAC includes estimates of entrainment, convection, deposition, and filtration of material. The interrelated effects of filter plugging, heat transfer, and gas dynamics are also simulated. A ventilation system model includes elements such as filters, dampers, ducts, and blowers connected at nodal points to form networks. A zone-type compartment fire model is incorporated to simulate fire-induced transients within a facility. 5. METHOD OF SOLUTION FIRAC solves one-dimensional, lumped-parameter, compressible flow equations by an implicit numerical scheme. The lumped-parameter method is the basic formulation that describes the gas dynamics system. No spatial distribution of parameters is considered in this approach, but an effect of spatial distribution can be approximated by noding. Network theory, using the lumped parameter method, includes a number of system elements, called branches, joined at certain points, called nodes. Ventilation system components that exhibit flow resistance and inertia, such as dampers, ducts, valves, and filters, and those that exhibit flow potential, such as blowers, are located within the branches of the system. The connection points of branches are nodes for components that have finite volumes, such as rooms, gloveboxes, and plenums, and for boundaries where the volume is practically infinite. All internal nodes, therefore, possess some

  5. Consequences of severe nuclear accidents in Europe

    NASA Astrophysics Data System (ADS)

    Seibert, Petra; Arnold, Delia; Mraz, Gabriele; Arnold, Nikolaus; Gufler, Klaus; Kromp-Kolb, Helga; Kromp, Wolfgang; Sutter, Philipp

    2013-04-01

    A first part of the presentation is devoted to the consequences of the severe accident in the 1986 Chernobyl NPP. It lead to a substantial radioactive contaminated of large parts of Europe and thus raised the awareness for off-site nuclear accident consequences. Spatial patterns of the (transient) contamination of the air and (persistent) contamination of the ground were studied by both measurements and model simulations. For a variety of reasons, ground contamination measurements have variability at a range of spatial scales. Results will be reviewed and discussed. Model simulations, including inverse modelling, have shown that the standard source term as defined in the ATMES study (1990) needs to be updated. Sensitive measurements of airborne activities still reveal the presence of low levels of airborne radiocaesium over the northern hemisphere which stems from resuspension. Over time scales of months and years, the distribution of radionuclides in the Earth system is constantly changing, for example relocated within plants, between plants and soil, in the soil, and into water bodies. Motivated by the permanent risk of transboundary impacts from potential major nuclear accidents, the multidisciplinary project flexRISK (see http://flexRISK.boku.ac.at) has been carried out from 2009 to 2012 in Austria to quantify such risks and hazards. An overview of methods and results of flexRISK is given as a second part of the presentation. For each of the 228 NPPs, severe accidents were identified together with relevant inventories, release fractions, and release frequencies. Then, Europe-wide dispersion and dose calculations were performed for 2788 cases, using the Lagrangian particle model FLEXPART. Maps of single-case results as well as various aggregated risk parameters were produced. It was found that substantial consequences (intervention measures) are possible for distances up to 500-1000 km, and occur more frequently for a distance range up to 100-300 km, which is in

  6. Seventeenth nuclear accident dosimetry intercomparison study: August 11-15, 1980

    SciTech Connect

    Swaja, R.E.; Greene, R.T.

    1981-04-01

    The Seventeenth Nuclear Accident Dosimetry Intercomparison Study was conducted August 11-15, 1980, 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 reported by participants showed that less than 60% of the neutron dose measurements using foil activation, thermoluminescent, or sodium activation methods and less than 20% of the gamma dose measurements using thermoluminescent dosimeters met nuclear criticality accident dosimetry guidelines which suggest accuracies of +-25% for neutron dose and +-20% for gamma dose. This indicates that continued development and evaluation of criticality accident dosimetry systems for area and personnel monitoring are required to improve measurement accuracy so that existing standards can be met.

  7. Training of nuclear criticality safety engineers

    SciTech Connect

    Taylor, R.G.

    1997-06-01

    The site specific analysis of nuclear criticality training needs is very briefly described. Analysis indicated that the four major components required were analysis, surveillance, business practices or administration, and emergency preparedness. The analysis component was further divided into process analysis, accident analysis, and transportation analysis. Ten subject matter areas for the process analysis component were identified as candidates for class development. Training classes developed from the job content analysis have demonstrated that the specialized information can be successfully delivered to new entrants. 1 fig.

  8. The Tokaimura Nuclear Accident: A Tragedy of Human Errors.

    ERIC Educational Resources Information Center

    Ryan, Michael E.

    2001-01-01

    Discusses nuclear power and the consequences of a nuclear accident. Covers issues ranging from chemical process safety to risk management of chemical industries to the ethical responsibilities of the chemical engineer. (Author/ASK)

  9. 10 CFR 835.1304 - Nuclear accident dosimetry.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 4 2012-01-01 2012-01-01 false Nuclear accident dosimetry. 835.1304 Section 835.1304 Energy DEPARTMENT OF ENERGY OCCUPATIONAL RADIATION PROTECTION Emergency Exposure Situations § 835.1304 Nuclear accident dosimetry. (a) Installations possessing sufficient quantities of fissile material...

  10. 10 CFR 835.1304 - Nuclear accident dosimetry.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 4 2013-01-01 2013-01-01 false Nuclear accident dosimetry. 835.1304 Section 835.1304 Energy DEPARTMENT OF ENERGY OCCUPATIONAL RADIATION PROTECTION Emergency Exposure Situations § 835.1304 Nuclear accident dosimetry. (a) Installations possessing sufficient quantities of fissile material...

  11. 10 CFR 835.1304 - Nuclear accident dosimetry.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 4 2014-01-01 2014-01-01 false Nuclear accident dosimetry. 835.1304 Section 835.1304 Energy DEPARTMENT OF ENERGY OCCUPATIONAL RADIATION PROTECTION Emergency Exposure Situations § 835.1304 Nuclear accident dosimetry. (a) Installations possessing sufficient quantities of fissile material...

  12. Medical intervention in a nuclear accident

    SciTech Connect

    Rabin, S.M.

    1986-11-15

    The medical care given to a victim of a radiation accident is one aspect of a larger emergency response that involves the establishment of control of the radiation source, prevention of secondary contamination of all persons having contact with the injured, organization of a general evacuation, and panic control. We have discussed the basic knowledge required to render medical care within the first few hours and days following an industrial nuclear incident. The fact that we have such knowledge should not be taken as an argument for the survivability of populations whose countries contemplate nuclear wars. At Chernobyl, radiation acutely injured about 300 persons and killed at least 31. And yet the enterprise needed to deal with the injured, the dying, and the evacuation of thousands taxed the medical resources of a superpower. Clearly, even the limited medical response available to physicians treating radiation victims rests on an infrastructure of facilities, equipment, drugs, transportation, communication, and organization that would surely be destroyed or severely incapacitated in a nuclear exchange.

  13. Thyroid consequences of the Chernobyl nuclear accident.

    PubMed

    Pacini, F; Vorontsova, T; Molinaro, E; Shavrova, E; Agate, L; Kuchinskaya, E; Elisei, R; Demidchik, E P; Pinchera, A

    1999-12-01

    It is well recognized that the use of external irradiation of the head and neck to treat patients with various non-thyroid disorders increases their risk of developing papillary thyroid carcinoma years after radiation exposure. An increased risk of thyroid cancer has also been reported in survivors of the atomic bombs in Japan, as well as in Marshall Island residents exposed to radiation during the testing of hydrogen bombs. More recently, exposure to radioactive fallout as a result of the Chernobyl nuclear reactor accident has clearly caused an enormous increase in the incidence of childhood thyroid carcinoma in Belarus, Ukraine, and, to a lesser extent, in the Russian Federation, starting in 1990. When clinical and epidemiological features of thyroid carcinomas diagnosed in Belarus after the Chernobyl accident are compared with those of naturally occurring thyroid carcinomas in patients of the same age group in Italy and France, it becomes apparent that the post-Chernobyl thyroid carcinomas were much less influenced by gender, virtually always papillary (solid and follicular variants), more aggressive at presentation and more frequently associated with thyroid autoimmunity. Gene mutations involving the RET proto-oncogene, and less frequently TRK, have been shown to be causative events specific for papillary cancer. RET activation was found in nearly 70% of the patients who developed papillary thyroid carcinomas following the Chernobyl accident. In addition to thyroid cancer, radiation-induced thyroid diseases include benign thyroid nodules, hypothyroidism and autoimmune thyroiditis, with or without thyroid insufficiency, as observed in populations after environmental exposure to radioisotopes of iodine and in the survivors of atomic bomb explosions. On this basis, the authors evaluated thyroid autoimmune phenomena in normal children exposed to radiation after the Chernobyl accident. The results demonstrated an increased prevalence of circulating thyroid

  14. Nuclear space propulsion critical technologies

    SciTech Connect

    Clark, J.S.; Borowski, S.K.; Doherty, M.P. )

    1993-01-01

    The National Aeronautics and Space Administration (NASA) has actively pursued technology development for nuclear rocket propulsion systems for possible use on lunar outpost missions, for exploration missions to Mars, and for outer planet and other solar system exploration missions. A number of these technologies have been broadly identified by the ANS National Critical Technologies Panel, as well as the Department of Commerce as [open quotes]Critical Technologies.[close quotes] A Nuclear Propulsion Office was established at the Lewis Research Center in Cleveland, Ohio, to lead nuclear propulsion development for NASA and to establish appropriate interagency working relationships with the U.S. Department of Energy national laboratories for nuclear technology development and with the Department of Defense (DoD). The NASA intercenter and interagency teams and NASA contractors have initiated conceptual design activities and other trade studies that provide the focus for appropriate critical technology development for both nuclear thermal propulsion (NTP) systems and nuclear electric propulsion (NEP) systems. Critical technology issues have been identified and are discussed in this paper. For NTP systems, the heat generated in the nuclear reactor is used to simply heat a propellant such as hydrogen, and then the high-temperature propellant expands through a nozzle to produce thrust. Specific impulse for NTP systems should be on the order of 900 to 950 s-approximately double the best chemical propulsion systems.

  15. French policy for managing the post-accident phase of a nuclear accident.

    PubMed

    Gallay, F; Godet, J L; Niel, J C

    2015-06-01

    In 2005, at the request of the French Government, the Nuclear Safety Authority (ASN) established a Steering Committee for the Management of the Post-Accident Phase of a Nuclear Accident or a Radiological Emergency, with the objective of establishing a policy framework. Under the supervision of ASN, this Committee, involving several tens of experts from different backgrounds (e.g. relevant ministerial offices, expert agencies, local information commissions around nuclear installations, non-governmental organisations, elected officials, licensees, and international experts), developed a number of recommendations over a 7-year period. First published in November 2012, these recommendations cover the immediate post-emergency situation, and the transition and longer-term periods of the post-accident phase in the case of medium-scale nuclear accidents causing short-term radioactive release (less than 24 h) that might occur at French nuclear facilities. They also apply to actions to be undertaken in the event of accidents during the transportation of radioactive materials. These recommendations are an important first step in preparation for the management of a post-accident situation in France in the case of a nuclear accident. PMID:25915552

  16. Immediate medical consequences of nuclear accidents: lessons from Chernobyl

    SciTech Connect

    Gale, R.P.

    1987-08-07

    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.

  17. Radiation accidents and nuclear energy: medical consequences and therapy.

    PubMed

    Champlin, R E; Kastenberg, W E; Gale, R P

    1988-11-01

    After the accidents at Chernobyl, the Soviet Union, and in Goiania, Brazil, there is increasing concern about the medical risks from radiation accidents. This overview summarizes the principles of nuclear energy, the biologic effects of accidental radiation exposure, the emergency response to nuclear accidents, and approaches to treating radiation injuries. Also discussed are the related issues of reactor safety, the disposal of radioactive waste, and the proliferation of nuclear weapons. With the increasing use of radioactive materials for power, weapons, and medical diagnostics, the medical community needs to understand the health consequences of radiation exposure. PMID:3056171

  18. Autoclave nuclear criticality safety analysis

    SciTech Connect

    D`Aquila, D.M.; Tayloe, R.W. Jr.

    1991-12-31

    Steam-heated autoclaves are used in gaseous diffusion uranium enrichment plants to heat large cylinders of UF{sub 6}. Nuclear criticality safety for these autoclaves is evaluated. To enhance criticality safety, systems are incorporated into the design of autoclaves to limit the amount of water present. These safety systems also increase the likelihood that any UF{sub 6} inadvertently released from a cylinder into an autoclave is not released to the environment. Up to 140 pounds of water can be held up in large autoclaves. This mass of water is sufficient to support a nuclear criticality when optimally combined with 125 pounds of UF{sub 6} enriched to 5 percent U{sup 235}. However, water in autoclaves is widely dispersed as condensed droplets and vapor, and is extremely unlikely to form a critical configuration with released UF{sub 6}.

  19. Radioactive fallout from the Chernobyl nuclear reactor accident

    SciTech Connect

    Beiriger, J.M.; Failor, R.A.; Marsh, K.V.; Shaw, G.E.

    1987-08-01

    This report describes the detection of fallout in the United States from the Chernobyl nuclear reactor accident. As part of its environmental surveillance program, Lawrence Livermore National Laboratory maintained detectors for gamma-emitting radionuclides. Following the reactor accident, additional air filters were set out. Several uncommon isotopes were detected at the time the plume passed into the US. (TEM)

  20. Nuclear accident dosimeter processing with attenuation filters

    SciTech Connect

    Gunter, R.J.

    1994-05-01

    An evaluation of the Martin Marietta Energy Systems, Inc., Personnel Nuclear Accident Dosimeters was undertaken to determine if they could meet DOE 5480.11 requirements for photon dose assessment. Dosimeters were irradiated with a {sup 137}Cs source to doses ranging from 0.5 to 10,000 rad and processed using transmission filters to prevent photomultiplier tube saturation. Dose equivalent responses were found to meet the requirements using dosimeter reader number 55. Use of reader number 11 revealed a problem with current procedures. While performing a normal calibration with transmission filters in place it was discovered that there was a high noise component in the calibration signal, resulting in a poor calibration. Dosimeters processed with reader number 11 using a 1% transmission filter determined element 3 response 30% below expectations. The low element 3 response resulted in a significantly lower dose calculation for affected dosimeters. Another factor affecting overall response was an excessive supralinearity correction applied to dosimeters exposed between 100 and 1,000 rad.

  1. Methods for nuclear air-cleaning-system accident-consequence assessment

    SciTech Connect

    Andrae, R.W.; Bolstad, J.W.; Gregory, W.S.

    1982-01-01

    This paper describes a multilaboratory research program that is directed toward addressing many questions that analysts face when performing air cleaning accident consequence assessments. The program involves developing analytical tools and supportive experimental data that will be useful in making more realistic assessments of accident source terms within and up to the atmospheric boundaries of nuclear fuel cycle facilities. The types of accidents considered in this study includes fires, explosions, spills, tornadoes, criticalities, and equipment failures. The main focus of the program is developing an accident analysis handbook (AAH). We will describe the contents of the AAH, which include descriptions of selected nuclear fuel cycle facilities, process unit operations, source-term development, and accident consequence analyses. Three computer codes designed to predict gas and material propagation through facility air cleaning systems are described. These computer codes address accidents involving fires (FIRAC), explosions (EXPAC), and tornadoes (TORAC). The handbook relies on many illustrative examples to show the analyst how to approach accident consequence assessments. We will use the FIRAC code and a hypothetical fire scenario to illustrate the accident analysis capability.

  2. Nuclear fuel cycle facility accident analysis handbook

    SciTech Connect

    1998-03-01

    The purpose of this Handbook is to provide guidance on how to calculate the characteristics of releases of radioactive materials and/or hazardous chemicals from nonreactor nuclear facilities. In addition, the Handbook provides guidance on how to calculate the consequences of those releases. There are four major chapters: Hazard Evaluation and Scenario Development; Source Term Determination; Transport Within Containment/Confinement; and Atmospheric Dispersion and Consequences Modeling. These chapters are supported by Appendices, including: a summary of chemical and nuclear information that contains descriptions of various fuel cycle facilities; details on how to calculate the characteristics of source terms for releases of hazardous chemicals; a comparison of NRC, EPA, and OSHA programs that address chemical safety; a summary of the performance of HEPA and other filters; and a discussion of uncertainties. Several sample problems are presented: a free-fall spill of powder, an explosion with radioactive release; a fire with radioactive release; filter failure; hydrogen fluoride release from a tankcar; a uranium hexafluoride cylinder rupture; a liquid spill in a vitrification plant; and a criticality incident. Finally, this Handbook includes a computer model, LPF No.1B, that is intended for use in calculating Leak Path Factors. A list of contributors to the Handbook is presented in Chapter 6. 39 figs., 35 tabs.

  3. Children's reactions to the threat of nuclear plant accidents.

    PubMed

    Schwebel, M; Schwebel, B

    1981-04-01

    In the wake of Three Mile Island nuclear plant accident, questionnaire and interview responses of children in elementary and secondary schools revealed their perceptions of the dangers entailed in the continued use of nuclear reactors. Results are compared with a parallel study conducted close to 20 years ago, and implications for mental health are examined. PMID:7223871

  4. Government: Nuclear Safety in Doubt a Year after Accident.

    ERIC Educational Resources Information Center

    Ember, Lois R.

    1980-01-01

    A year after the accident at Three Mile Island (TMI), the signals transmitted to the public are still confused. Industry says that nuclear power is safe and that the aftermath of TMI ushers in a new era of safety. Antinuclear activists say TMI sounded nuclear power's death knell. (Author/RE)

  5. Scientific aspects of the Tohoku earthquake and Fukushima nuclear accident

    NASA Astrophysics Data System (ADS)

    Koketsu, Kazuki

    2016-04-01

    We investigated the 2011 Tohoku earthquake, the accident of the Fukushima Daiichi nuclear power plant, and assessments conducted beforehand for earthquake and tsunami potential in the Pacific offshore region of the Tohoku District. The results of our investigation show that all the assessments failed to foresee the earthquake and its related tsunami, which was the main cause of the accident. Therefore, the disaster caused by the earthquake, and the accident were scientifically unforeseeable at the time. However, for a zone neighboring the reactors, a 2008 assessment showed tsunamis higher than the plant height. As a lesson learned from the accident, companies operating nuclear power plants should be prepared using even such assessment results for neighboring zones.

  6. Nuclear accident and incident public affairs (pa) guidance

    SciTech Connect

    Not Available

    1993-12-20

    This Directive reissues reference (a) DoD Directive 5230.16 to update DoD policy, responsibilities, and procedures for the prompt release of information to the public in the interest of public safety, and to prevent public alarm in the event of accidents or significant incidents involving nuclear weapons or nuclear components, radioactive material, nuclear weapon launch or transport vehicles (when a nuclear weapon is aboard), or nuclear reactors under DoD control. It updates DoD policy, responsibilities, and procedures during an improvised nuclear device (IND) incident.

  7. Evaluation of LLNL's Nuclear Accident Dosimeters at the CALIBAN Reactor September 2010

    SciTech Connect

    Hickman, D P; Wysong, A R; Heinrichs, D P; Wong, C T; Merritt, M J; Topper, J D; Gressmann, F A; Madden, D J

    2011-06-21

    The Lawrence Livermore National Laboratory uses neutron activation elements in a Panasonic TLD holder as a personnel nuclear accident dosimeter (PNAD). The LLNL PNAD has periodically been tested using a Cf-252 neutron source, however until 2009, it was more than 25 years since the PNAD has been tested against a source of neutrons that arise from a reactor generated neutron spectrum that simulates a criticality. In October 2009, LLNL participated in an intercomparison of nuclear accident dosimeters at the CEA Valduc Silene reactor (Hickman, et.al. 2010). In September 2010, LLNL participated in a second intercomparison of nuclear accident dosimeters at CEA Valduc. The reactor generated neutron irradiations for the 2010 exercise were performed at the Caliban reactor. The Caliban results are described in this report. The procedure for measuring the nuclear accident dosimeters in the event of an accident has a solid foundation based on many experimental results and comparisons. The entire process, from receiving the activated NADs to collecting and storing them after counting was executed successfully in a field based operation. Under normal conditions at LLNL, detectors are ready and available 24/7 to perform the necessary measurement of nuclear accident components. Likewise LLNL maintains processing laboratories that are separated from the areas where measurements occur, but contained within the same facility for easy movement from processing area to measurement area. In the event of a loss of LLNL permanent facilities, the Caliban and previous Silene exercises have demonstrated that LLNL can establish field operations that will very good nuclear accident dosimetry results. There are still several aspects of LLNL's nuclear accident dosimetry program that have not been tested or confirmed. For instance, LLNL's method for using of biological samples (blood and hair) has not been verified since the method was first developed in the 1980's. Because LLNL and the other DOE

  8. Effects of the Fukushima Daiichi nuclear accident on goshawk reproduction.

    PubMed

    Murase, Kaori; Murase, Joe; Horie, Reiko; Endo, Koichi

    2015-01-01

    Although the influence of nuclear accidents on the reproduction of top predators has not been investigated, it is important that we identify the effects of such accidents because humans are also top predators. We conducted field observation for 22 years and analysed the reproductive performance of the goshawk (Accipiter gentilis fujiyamae), a top avian predator in the North Kanto area of Japan, before and after the accidents at the Fukushima Daiichi nuclear power plant that occurred in 2011. The reproductive performance declined markedly compared with the pre-accident years and progressively decreased for the three post-accident study years. Moreover, it was suggested that these declines were primarily caused by an increase in the air dose rate of radio-active contaminants measured under the nests caused by the nuclear accidents, rather than by other factors. We consider the trends in the changes of the reproductive success rates and suggest that internal exposure may play an important role in the reproductive performance of the goshawk, as well as external exposure. PMID:25802117

  9. Effects of the Fukushima Daiichi nuclear accident on goshawk reproduction

    PubMed Central

    Murase, Kaori; Murase, Joe; Horie, Reiko; Endo, Koichi

    2015-01-01

    Although the influence of nuclear accidents on the reproduction of top predators has not been investigated, it is important that we identify the effects of such accidents because humans are also top predators. We conducted field observation for 22 years and analysed the reproductive performance of the goshawk (Accipiter gentilis fujiyamae), a top avian predator in the North Kanto area of Japan, before and after the accidents at the Fukushima Daiichi nuclear power plant that occurred in 2011. The reproductive performance declined markedly compared with the pre-accident years and progressively decreased for the three post-accident study years. Moreover, it was suggested that these declines were primarily caused by an increase in the air dose rate of radio-active contaminants measured under the nests caused by the nuclear accidents, rather than by other factors. We consider the trends in the changes of the reproductive success rates and suggest that internal exposure may play an important role in the reproductive performance of the goshawk, as well as external exposure. PMID:25802117

  10. NCIS - a Nuclear Criticality Information System (overview)

    SciTech Connect

    Koponen, B.L.; Hampel, V.E.

    1983-07-01

    A Nuclear Criticality Information System (NCIS) is being established at the Lawrence Livermore National Laboratory (LLNL) in order to serve personnel responsible for safe storage, transport, and handling of fissile materials and those concerned with the evaluation and analysis of nuclear, critical experiments. Public concern for nuclear safety provides the incentive for improved access to nuclear safety information.

  11. ACCIDENTS AND UNSCHEDULED EVENTS ASSOCIATED WITH NON-NUCLEAR ENERGY RESOURCES AND TECHNOLOGY

    EPA Science Inventory

    Accidents and unscheduled events associated with non-nuclear energy resources and technology are identified for each step in the energy cycle. Both natural and anthropogenic causes of accidents or unscheduled events are considered. Data concerning these accidents are summarized. ...

  12. Importance of risk communication during and after a nuclear accident.

    PubMed

    Perko, Tanja

    2011-07-01

    Past nuclear accidents highlight communication as one of the most important challenges in emergency management. In the early phase, communication increases awareness and understanding of protective actions and improves the population response. In the medium and long term, risk communication can facilitate the remediation process and the return to normal life. Mass media play a central role in risk communication. The recent nuclear accident in Japan, as expected, induced massive media coverage. Media were employed to communicate with the public during the contamination phase, and they will play the same important role in the clean-up and recovery phases. However, media also have to fulfill the economic aspects of publishing or broadcasting, with the "bad news is good news" slogan that is a well-known phenomenon in journalism. This article addresses the main communication challenges and suggests possible risk communication approaches to adopt in the case of a nuclear accident. PMID:21612010

  13. Consequences and countermeasures in a nuclear power accident: Chernobyl experience.

    PubMed

    Kirichenko, Vladimir A; Kirichenko, Alexander V; Werts, Day E

    2012-09-01

    Despite the tragic accidents in Fukushima and Chernobyl, the nuclear power industry will continue to contribute to the production of electric energy worldwide until there are efficient and sustainable alternative sources of energy. The Chernobyl nuclear accident, which occurred 26 years ago in the former Soviet Union, released an immense amount of radioactivity over vast territories of Belarus, Ukraine, and the Russian Federation, extending into northern Europe, and became the most severe accident in the history of the nuclear industry. This disaster was a result of numerous factors including inadequate nuclear power plant design, human errors, and violation of safety measures. The lessons learned from nuclear accidents will continue to strengthen the safety design of new reactor installations, but with more than 400 active nuclear power stations worldwide and 104 reactors in the Unites States, it is essential to reassess fundamental issues related to the Chernobyl experience as it continues to evolve. This article summarizes early and late events of the incident, the impact on thyroid health, and attempts to reduce agricultural radioactive contamination. PMID:22853775

  14. Stakeholder involvement facilitates decision making for UK nuclear accident recovery.

    PubMed

    Alexander, C; Burt, R; Nisbet, A F

    2005-01-01

    The importance of major stakeholders participating in the formulation of strategies for maintaining food safety and agricultural production following a nuclear accident has been successfully demonstrated by the UK 'Agriculture and Food Countermeasures Working Group' (AFCWG). The organisation, membership and terms of reference of the group are described. Details are given of the achievements of the AFCWG and its sub-groups, which include agreeing management options that would be included in a recovery handbook for decision-makers in the UK and tackling the disposal of large volumes of contaminated milk, potentially resulting from a nuclear accident. PMID:15921830

  15. Global risk of radioactive fallout after major nuclear reactor accidents

    NASA Astrophysics Data System (ADS)

    Lelieveld, J.; Kunkel, D.; Lawrence, M. G.

    2012-05-01

    Major reactor accidents of nuclear power plants are rare, yet the consequences are catastrophic. But what is meant by "rare"? And what can be learned from the Chernobyl and Fukushima incidents? Here we assess the cumulative, global risk of exposure to radioactivity due to atmospheric dispersion of gases and particles following severe nuclear accidents (the most severe ones on the International Nuclear Event Scale, INES 7), using particulate 137Cs and gaseous 131I as proxies for the fallout. Our results indicate that previously the occurrence of INES 7 major accidents and the risks of radioactive contamination have been underestimated. Using a global model of the atmosphere we compute that on average, in the event of a major reactor accident of any nuclear power plant worldwide, more than 90% of emitted 137Cs would be transported beyond 50 km and about 50% beyond 1000 km distance before being deposited. This corroborates that such accidents have large-scale and trans-boundary impacts. Although the emission strengths and atmospheric removal processes of 137Cs and 131I are quite different, the radioactive contamination patterns over land and the human exposure due to deposition are computed to be similar. High human exposure risks occur around reactors in densely populated regions, notably in West Europe and South Asia, where a major reactor accident can subject around 30 million people to radioactive contamination. The recent decision by Germany to phase out its nuclear reactors will reduce the national risk, though a large risk will still remain from the reactors in neighbouring countries.

  16. The simulation of a criticality accident excursion occurring in a simple fast metal system using the coupled neutronic-hydrodynamic method

    SciTech Connect

    Myers, W.L.

    1996-12-31

    Analysis of a criticality accident scenario occuring in a simple fast metal system using the coupled neutronic-hydrodynamic method is demonstrated by examining the last Godiva-I criticality accident. The basis tools and information for creating a coupled neutronic-hydrodynamic code are presented. Simplifying assumptions and approximations for creating an idealized model for the Godiva-I system are discussed. Estimates of the total energy generation and the maximum attainable kinetic energy yield are the most important results that are obtained from the code. With modifications, the methodology presented in this paper can be extended to analyze criticality accident excursions in other kinds of nuclear systems.

  17. [The Fukushima nuclear accident: consequences for Japan and for us].

    PubMed

    Grosche, B

    2013-04-01

    The Fukushima accident was the consequence of a preceding 2-fold natural catastrophe: the earth quake of 11 March 2011 and the subsequent tsunami. Due to favourable winds and to evacuation measures the radiation exposure to the general population in Japan as a whole and with some exceptions in the region outside the evacuation zone, too, was low. In this article the attempt is made to give an estimate of health consequences to the public. This is based upon WHO's dose estimates, knowledge of the consequences of the Chernobyl accident, of the atmospheric nuclear bomb testing in Kazakhstan and on the risk of childhood leukaemia after low dose radiation exposure. For Germany, there was no radiation threat due to the accident. Nonetheless, the events in Japan made clear that the rules and standards that were developed for the case of a reactor accident need to be revised. PMID:23576143

  18. Preliminary analysis of loss-of-coolant accident in Fukushima nuclear accident

    SciTech Connect

    Su'ud, Zaki; Anshari, Rio

    2012-06-06

    Loss-of-Coolant Accident (LOCA) in Boiling Water Reactor (BWR) especially on Fukushima Nuclear Accident will be discussed in this paper. The Tohoku earthquake triggered the shutdown of nuclear power reactors at Fukushima Nuclear Power station. Though shutdown process has been completely performed, cooling process, at much smaller level than in normal operation, is needed to remove decay heat from the reactor core until the reactor reach cold-shutdown condition. If LOCA happen at this condition, it will cause the increase of reactor fuel and other core temperatures and can lead to reactor core meltdown and exposure of radioactive material to the environment such as in the Fukushima Dai Ichi nuclear accident case. In this study numerical simulation has been performed to calculate pressure composition, water level and temperature distribution on reactor during this accident. There are two coolant regulating system that operational on reactor unit 1 at this accident, Isolation Condensers (IC) system and Safety Relief Valves (SRV) system. Average mass flow of steam to the IC system in this event is 10 kg/s and could keep reactor core from uncovered about 3,2 hours and fully uncovered in 4,7 hours later. There are two coolant regulating system at operational on reactor unit 2, Reactor Core Isolation Condenser (RCIC) System and Safety Relief Valves (SRV). Average mass flow of coolant that correspond this event is 20 kg/s and could keep reactor core from uncovered about 73 hours and fully uncovered in 75 hours later. There are three coolant regulating system at operational on reactor unit 3, Reactor Core Isolation Condenser (RCIC) system, High Pressure Coolant Injection (HPCI) system and Safety Relief Valves (SRV). Average mass flow of water that correspond this event is 15 kg/s and could keep reactor core from uncovered about 37 hours and fully uncovered in 40 hours later.

  19. Preliminary analysis of loss-of-coolant accident in Fukushima nuclear accident

    NASA Astrophysics Data System (ADS)

    Su'ud, Zaki; Anshari, Rio

    2012-06-01

    Loss-of-Coolant Accident (LOCA) in Boiling Water Reactor (BWR) especially on Fukushima Nuclear Accident will be discussed in this paper. The Tohoku earthquake triggered the shutdown of nuclear power reactors at Fukushima Nuclear Power station. Though shutdown process has been completely performed, cooling process, at much smaller level than in normal operation, is needed to remove decay heat from the reactor core until the reactor reach cold-shutdown condition. If LOCA happen at this condition, it will cause the increase of reactor fuel and other core temperatures and can lead to reactor core meltdown and exposure of radioactive material to the environment such as in the Fukushima Dai Ichi nuclear accident case. In this study numerical simulation has been performed to calculate pressure composition, water level and temperature distribution on reactor during this accident. There are two coolant regulating system that operational on reactor unit 1 at this accident, Isolation Condensers (IC) system and Safety Relief Valves (SRV) system. Average mass flow of steam to the IC system in this event is 10 kg/s and could keep reactor core from uncovered about 3,2 hours and fully uncovered in 4,7 hours later. There are two coolant regulating system at operational on reactor unit 2, Reactor Core Isolation Condenser (RCIC) System and Safety Relief Valves (SRV). Average mass flow of coolant that correspond this event is 20 kg/s and could keep reactor core from uncovered about 73 hours and fully uncovered in 75 hours later. There are three coolant regulating system at operational on reactor unit 3, Reactor Core Isolation Condenser (RCIC) system, High Pressure Coolant Injection (HPCI) system and Safety Relief Valves (SRV). Average mass flow of water that correspond this event is 15 kg/s and could keep reactor core from uncovered about 37 hours and fully uncovered in 40 hours later.

  20. Nuclear Accident Crisis and Liver Disease: A Summary on Evidences

    PubMed Central

    Wiwanitkit, Viroj

    2013-01-01

    The present global concern is on the adverse effect due to exposure to nuclides expelled from the disrupted nuclear power plant accident in Japan. The exposure can induce several adverse effects. In this specific brief review, the author summarizes the evidences on the effect on liver. Discussion is focused on several liver diseases. PMID:25125994

  1. Anomalies of Nuclear Criticality, Revision 6

    SciTech Connect

    Clayton, E. D.; Prichard, Andrew W.; Durst, Bonita E.; Erickson, David; Puigh, Raymond J.

    2010-02-19

    This report is revision 6 of the Anomalies of Nuclear Criticality. This report is required reading for the training of criticality professionals in many organizations both nationally and internationally. This report describes many different classes of nuclear criticality anomalies that are different than expected.

  2. Health effects of the nuclear accident at Three Mile Island

    SciTech Connect

    Fabrikant, J.I.

    1980-05-01

    Between March 28 and April 15, 1979 the collective dose resulting from the radioactivity released to the population living within a 50-mile radius of the Three Mile Island nuclear plant was about 2000 person-rems, less than 1% of the annual natural background level. The average dose to a person living within 5 miles of the nuclear plant was less than 10% of annual background radiation. The maximum estimated radiation dose received by any one individual in the general population (excluding the nuclear plant workers) during the accident was 70 mrem. The doses received by the general population as a result of the accident were so small that there will be no detectable additional cases of cancer, developmental abnormalities, or genetic ill-health. Three Three Mile Island nuclear workers received radiation doses of about 3 to 4 rem, exceeding maximum permissible quarterly dose of 3 rem. The major health effect of the accident at Three Mile Island was that of a pronounced demoralizing effect on the general population in the Three Mile Island area, including teenagers and mothers of preschool children and the nuclear plant workers. However, this effect proved transient in all groups studied except the nuclear workers.

  3. Chemistry of fission product iodine under nuclear reactor accident conditions

    SciTech Connect

    Malinauskas, A.P.; Bell, J.T.

    1986-01-01

    The radioisotopes of iodine are generally acknowledged to be the species whose release into the biosphere as a result of a nuclear reactor accident is of the greatest concern. In the course of its release, the fission product is subjected to differing chemical environments; these can alter the physicochemical form of the fission product and thus modify the manner and extent to which release occurs. Both the chemical environments which are characteristic of reactor accidents and their effect in determining physical and chemical form of fission product iodine have been studied extensively, and are reviewed in this report. 76 refs.

  4. A comparative study of nuclear accident consequences for Hong Kong

    SciTech Connect

    Ching, E.M.K.; Yeung, Mankit Ray )

    1993-02-01

    A two-dimensional dispersion and consequence model called RADIS has been developed and used to perform a site-specific investigation of the consequences and risks for Hong Kong as a result of a potential accident at the Daya Bay Nuclear Power Station. The study uses the 1986 Hong Kong weather and demographic data to determine the accident consequences for Hong Kong. The overall cumulative occurrence frequency distributions of early fatality, early injury, latent cancer, and thyroid nodule are compared with those of WASH-1400 and a United Kingdom Atomic Energy Authority (UKAEA) study. This study is generally consistent with the WASH-1400 results and exhibits less conservatism than the UKAEA study.

  5. Insights into the behavior of nuclear power plant containments during severe accidents

    SciTech Connect

    Horschel, D.S.; Ludwigsen, J.S.; Parks, M.B.; Lambert, L.D.; Dameron, R.A.; Rashid, Y.R.

    1993-06-01

    The containment building surrounding a nuclear reactor offers the last barrier to the release of radioactive materials from a severe accident into the environment. The loading environment of the containment under severe accident conditions may include much greater than design pressures and temperatures. Investigations into the performance of containments subject to ultimate or failure pressure and temperature conditions have been performed over the last several years through a program administered by the Nuclear Regulatory Commission (NRC). These NRC sponsored investigations are subsequently discussed. Reviewed are the results of large scale experiments on reinforced concrete, prestressed concrete, and steel containment models pressurized to failure. In conjunction with these major tests, the results of separate effect testing on many of the critical containment components; that is, aged and unaged seals, a personnel air lock and electrical penetration assemblies subjected to elevated temperature and pressure have been performed. An objective of the NRC program is to gain an understanding of the behavior of typical existing and planned containment designs subject to postulated severe accident conditions. This understanding has led to the development of experimentally verified analytical tools that can be applied to accurately predict their ultimate capacities useful in developing severe accident mitigation schemes. Finally, speculation on the response of containments subjected to severe accident conditions is presented.

  6. Site Specific Analyses of a Spent Nuclear Fuel Transportation Accident

    SciTech Connect

    Biwer, B. M.; Chen, S. Y.

    2003-02-24

    The number of spent nuclear fuel (SNF) shipments is expected to increase significantly during the time period that the United States' inventory of SNF is sent to a final disposal site. Prior work estimated that the highest accident risks of a SNF shipping campaign to the proposed geologic repository at Yucca Mountain were in the corridor states, such as Illinois. The largest potential human health impacts would be expected to occur in areas with high population densities such as urban settings. Thus, our current study examined the human health impacts from the most plausible severe SNF transportation accidents in the Chicago metropolitan area. The RISKIND 2.0 program was used to model site-specific data for an area where the largest impacts might occur. The results have shown that the radiological human health consequences of a severe SNF rail transportation accident on average might be similar to one year of exposure to natural background radiation for those persons living a nd working in the most affected areas downwind of the actual accident location. For maximally exposed individuals, an exposure similar to about two years of exposure to natural background radiation was estimated. In addition to the accident probabilities being very low (approximately 1 chance in 10,000 or less during the entire shipping campaign), the actual human health impacts are expected to be lower if any of the accidents considered did occur, because the results are dependent on the specific location and weather conditions, such as wind speed and direction, that were selected to maximize the results. Also, comparison of the results of longer duration accident scenarios against U.S. Environmental Protection Agency guidelines was made to demonstrate the usefulness of this site-specific analysis for emergency planning purposes.

  7. Global risk of radioactive fallout after nuclear reactor accidents

    NASA Astrophysics Data System (ADS)

    Kunkel, D.; Lelieveld, J.; Lawrence, M. G.

    2012-04-01

    Reactor core meltdowns of nuclear power plants are rare, yet the consequences are catastrophic. But what is meant by "rare"? And what can be learned from the Chernobyl and Fukushima incidents? Here we assess the risk of exposure to radioactivity due to atmospheric dispersion of gases and particles following severe nuclear accidents, using particulate 137Cs and gaseous 131I as proxies for the fallout. It appears that previously the occurrence of major accidents and the risks of radioactive contamination have been underestimated. Using a global model of the atmosphere we compute that on average, in the event of a core melt of any nuclear power plant worldwide, more than 90 % of emitted 137Cs would be transported beyond 50 km and about 50 % beyond 1000 km distance. This corroborates that such accidents have large-scale and trans-boundary impacts. Although the emission strengths and atmospheric removal processes of 137Cs and 131I are quite different, the radioactive contamination patterns over land and the human deposition exposure are computed to be similar. High human exposure risks occur around reactors in densely populated regions, notably in southern Asia where a core melt can subject 55 million people to radioactive contamination. The recent decision by Germany to phase out its nuclear reactors will reduce the national risk, though a large risk will still remain from the reactors in neighbouring countries.

  8. Global risk of radioactive fallout after nuclear reactor accidents

    NASA Astrophysics Data System (ADS)

    Lelieveld, J.; Kunkel, D.; Lawrence, M. G.

    2011-11-01

    Reactor core meltdowns of nuclear power plants are rare, yet the consequences are catastrophic. But what is meant by "rare"? And what can be learned from the Chernobyl and Fukushima incidents? Here we assess the risk of exposure to radioactivity due to atmospheric dispersion of gases and particles following severe nuclear accidents, using particulate 137Cs and gaseous 131I as proxies for the fallout. It appears that previously the occurrence of major accidents and the risks of radioactive contamination have been underestimated. Using a global model of the atmosphere we compute that on average, in the event of a core melt of any nuclear power plant worldwide, more than 90% of emitted 137Cs would be transported beyond 50km and about 50% beyond 1000 km distance. This corroborates that such accidents have large-scale and trans-boundary impacts. Although the emission strengths and atmospheric removal processes of 137Cs and 131I are quite different, the radioactive contamination patterns over land and the human deposition exposure are computed to be similar. High human exposure risks occur around reactors in densely populated regions, notably in southern Asia where a core melt can subject 55 million people to radioactive contamination. The recent decision by Germany to phase out its nuclear reactors will reduce the national risk, though a large risk will still remain from the reactors in neighbouring countries.

  9. Estimated consequences from severe spent nuclear fuel transportation accidents

    SciTech Connect

    Arnish, J.J.; Monette, F.; LePoire, D.; Biwer, B.M.

    1996-06-01

    The RISKIND software package is used to estimate radiological consequences of severe accident scenarios involving the transportation of spent nuclear fuel. Radiological risks are estimated for both a collective population and a maximally exposed individual based on representative truck and rail cask designs described in the U.S. Nuclear Regulatory Commission (NRC) modal study. The estimate of collective population risk considers all possible environmental pathways, including acute and long-term exposures, and is presented in terms of the 50-y committed effective dose equivalent. Radiological risks to a maximally exposed individual from acute exposure are estimated and presented in terms of the first year and 50-y committed effective dose equivalent. Consequences are estimated for accidents occurring in rural and urban population areas. The modeled pathways include inhalation during initial passing of the radioactive cloud, external exposure from a reduction of the cask shielding, long-term external exposure. from ground deposition, and ingestion from contaminated food (rural only). The major pathways and contributing radionuclides are identified, and the effects of possible mitigative actions are discussed. The cask accident responses and the radionuclide release fractions are modeled as described in the NRC modal study. Estimates of severe accident probabilities are presented for both truck and rail modes of transport. The assumptions made in this study tend to be conservative; however, a set of multiplicative factors are identified that can be applied to estimate more realistic conditions.

  10. Radioactivity impacts of the Fukushima Nuclear Accident on the atmosphere

    NASA Astrophysics Data System (ADS)

    Lin, W.; Chen, L.; Yu, W.; Ma, H.; Zeng, Z.; Lin, J.; Zeng, S.

    2015-02-01

    The Fukushima Nuclear Accident (FNA) resulted in a large amount of radionuclides released into the atmosphere and dispersed globally, which has greatly raised public concerns. The state of the art for source terms of 19 kinds of radionuclides derived from the FNA was comprehensively collected and compared with levels of the global fallout and the Chernobyl Nuclear Accident (CNA). The atmospheric impacts of the FNA were evaluated from three aspects including radioactive baseline of the atmosphere, the concentration limits in standards and radiological protection. The FNA should not impose significant radiological risk on the public members in the countries excluding Japan. A conceptual scheme of Fukushima-derived radionuclides with physical and physicochemical insights on different temporal-spatial timescales was discussed and illustrated to understand their fates in the atmosphere.

  11. Fukushima Nuclear Accident Recorded in Tibetan Plateau Snow Pits

    PubMed Central

    Wang, Ninglian; Wu, Xiaobo; Kehrwald, Natalie; Li, Zhen; Li, Quanlian; Jiang, Xi; Pu, Jianchen

    2015-01-01

    The β radioactivity of snow-pit samples collected in the spring of 2011 on four Tibetan Plateau glaciers demonstrate a remarkable peak in each snow pit profile, with peaks about ten to tens of times higher than background levels. The timing of these peaks suggests that the high radioactivity resulted from the Fukushima nuclear accident that occurred on March 11, 2011 in eastern Japan. Fallout monitoring studies demonstrate that this radioactive material was transported by the westerlies across the middle latitudes of the Northern Hemisphere. The depth of the peak β radioactivity in each snow pit compared with observational precipitation records, suggests that the radioactive fallout reached the Tibetan Plateau and was deposited on glacier surfaces in late March 2011, or approximately 20 days after the nuclear accident. The radioactive fallout existed in the atmosphere over the Tibetan Plateau for about one month. PMID:25658094

  12. Short-Term Medical Consequences of the Chernobyl Nuclear Accident: Lessons for the Future

    PubMed Central

    Gale, Robert Peter

    1988-01-01

    The author of this article discusses the world's most serious nuclear accident to date: the Chernobyl nuclear accident of April 1986. His major focus is on the short-term medical consequences of the accident, including reduction of exposure to persons at risk, evaluation of persons potentially affected, dosimetry, and specific medical interventions. PMID:21253129

  13. Reactor Accident Analysis Methodology for the Advanced Test Reactor Critical Facility Documented Safety Analysis Upgrade

    SciTech Connect

    Gregg L. Sharp; R. T. McCracken

    2003-06-01

    The regulatory requirement to develop an upgraded safety basis for a DOE nuclear facility was realized in January 2001 by issuance of a revision to Title 10 of the Code of Federal Regulations Section 830 (10 CFR 830).1 Subpart B of 10 CFR 830, “Safety Basis Requirements,” requires a contractor responsible for a DOE Hazard Category 1, 2, or 3 nuclear facility to either submit by April 9, 2001 the existing safety basis which already meets the requirements of Subpart B, or to submit by April 10, 2003 an upgraded facility safety basis that meets the revised requirements.1 10 CFR 830 identifies Nuclear Regulatory Commission (NRC) Regulatory Guide 1.70, “Standard Format and Content of Safety Analysis Reports for Nuclear Power Plants”2 as a safe harbor methodology for preparation of a DOE reactor documented safety analysis (DSA). The regulation also allows for use of a graded approach. This report presents the methodology that was developed for preparing the reactor accident analysis portion of the Advanced Test Reactor Critical Facility (ATRC) upgraded DSA. The methodology was approved by DOE for developing the ATRC safety basis as an appropriate application of a graded approach to the requirements of 10 CFR 830.

  14. Reactor Accident Analysis Methodology for the Advanced Test Reactor Critical Facility Documented Safety Analysis Upgrade

    SciTech Connect

    Sharp, G.L.; McCracken, R.T.

    2003-05-13

    The regulatory requirement to develop an upgraded safety basis for a DOE Nuclear Facility was realized in January 2001 by issuance of a revision to Title 10 of the Code of Federal Regulations Section 830 (10 CFR 830). Subpart B of 10 CFR 830, ''Safety Basis Requirements,'' requires a contractor responsible for a DOE Hazard Category 1, 2, or 3 nuclear facility to either submit by April 9, 2001 the existing safety basis which already meets the requirements of Subpart B, or to submit by April 10, 2003 an upgraded facility safety basis that meets the revised requirements. 10 CFR 830 identifies Nuclear Regulatory Commission (NRC) Regulatory Guide 1.70, ''Standard Format and Content of Safety Analysis Reports for Nuclear Power Plants'' as a safe harbor methodology for preparation of a DOE reactor documented safety analysis (DSA). The regulation also allows for use of a graded approach. This report presents the methodology that was developed for preparing the reactor accident analysis portion of the Advanced Test Reactor Critical Facility (ATRC) upgraded DSA. The methodology was approved by DOE for developing the ATRC safety basis as an appropriate application of a graded approach to the requirements of 10 CFR 830.

  15. Automations influence on nuclear power plants: a look at three accidents and how automation played a role.

    PubMed

    Schmitt, Kara

    2012-01-01

    Nuclear power is one of the ways that we can design an efficient sustainable future. Automation is the primary system used to assist operators in the task of monitoring and controlling nuclear power plants (NPP). Automation performs tasks such as assessing the status of the plant's operations as well as making real time life critical situational specific decisions. While the advantages and disadvantages of automation are well studied in variety of domains, accidents remind us that there is still vulnerability to unknown variables. This paper will look at the effects of automation within three NPP accidents and incidents and will consider why automation failed in preventing these accidents from occurring. It will also review the accidents at the Three Mile Island, Chernobyl, and Fukushima Daiichi NPP's in order to determine where better use of automation could have resulted in a more desirable outcome. PMID:22317420

  16. 1983 international intercomparison of nuclear accident dosimetry systems at Oak Ridge National Laboratory

    SciTech Connect

    Swaja, R.E.; Greene, R.T.; Sims, C.S.

    1985-04-01

    An international intercomparison of nuclear accident dosimetry systems was conducted during September 12-16, 1983, at Oak Ridge National Laboratory (ORNL) using the Health Physics Research Reactor operated in the pulse mode to simulate criticality accidents. This study marked the twentieth in a series of annual accident dosimetry intercomparisons conducted at ORNL. Participants from ten organizations attended this intercomparison and measured neutron and gamma doses at area monitoring stations and on phantoms for three different shield conditions. Results of this study indicate that foil activation techniques are the most popular and accurate method of determining accident-level neutron doses at area monitoring stations. For personnel monitoring, foil activation, blood sodium activation, and thermoluminescent (TL) methods are all capable of providing accurate dose estimates in a variety of radiation fields. All participants in this study used TLD's to determine gamma doses with very good results on the average. Chemical dosemeters were also shown to be capable of yielding accurate estimates of total neutron plus gamma doses in a variety of radiation fields. While 83% of all neutron measurements satisfied regulatory standards relative to reference values, only 39% of all gamma results satisfied corresponding guidelines for gamma measurements. These results indicate that continued improvement in accident dosimetry evaluation and measurement techniques is needed.

  17. Neutron absorbing coating for nuclear criticality control

    DOEpatents

    Mizia, Ronald E.; Wright, Richard N.; Swank, William D.; Lister, Tedd E.; Pinhero, Patrick J.

    2007-10-23

    A neutron absorbing coating for use on a substrate, and which provides nuclear criticality control is described and which includes a nickel, chromium, molybdenum, and gadolinium alloy having less than about 5% boron, by weight.

  18. The Nuclear Criticality Information System: An update

    SciTech Connect

    Koponen, B.L.

    1991-07-01

    The US Department of Energy`s Nuclear Criticality Information System (NCIS) has served the criticality community for the past ten years with publications and with an online information system. NCIS provides a mean for widely distributed nuclear criticality specialists to communicate and work together instantly. Users of the system may receive assistance from all members of the NCIS community, which provides a much broader base of support than is available at any single site. When unified by NCIS, these diverse specialists provide a resource that has proven to be very useful in the safe handling of fissile material. NCIS also is a source of current nuclear criticality safety information; the rapid access of such up-to-date information on the handling of fissile materials outside of nuclear reactors is international in scope, extending beyond political and geographical boundaries.

  19. The Nuclear Criticality Information System: An update

    SciTech Connect

    Koponen, B.L.

    1991-07-01

    The US Department of Energy's Nuclear Criticality Information System (NCIS) has served the criticality community for the past ten years with publications and with an online information system. NCIS provides a mean for widely distributed nuclear criticality specialists to communicate and work together instantly. Users of the system may receive assistance from all members of the NCIS community, which provides a much broader base of support than is available at any single site. When unified by NCIS, these diverse specialists provide a resource that has proven to be very useful in the safe handling of fissile material. NCIS also is a source of current nuclear criticality safety information; the rapid access of such up-to-date information on the handling of fissile materials outside of nuclear reactors is international in scope, extending beyond political and geographical boundaries.

  20. Nuclear data needs for application in nuclear criticality safety programs

    SciTech Connect

    Leal, L.C.; Westfall, R.M.; Jordan, W.C.; Wright, R.Q.

    1995-09-01

    In nuclear criticality safety applications, a number of important uncertainties have to be addressed to establish the required criticality safety margin of a nuclear system. One source of these uncertainties is the basic nuclear data used to calculate the effective multiplication factor of the system. Before criticality safety calculations are performed, the bias and uncertainties of the codes and cross sections that are used must be determined. Cross-section data are measured, evaluated, and tested prior to their inclusion in nuclear data libraries. Traditionally, nuclear data evaluations are performed to support the analysis and design of thermal and fast reactors. The neutron spectra characteristic of the thermal and fast systems used for data testing are predominantly in the low- and high-energy ranges, with a relatively minor influence from the intermediate-energy range. In the area of nuclear criticality safety, nuclear systems involving spent fuel elements from reactors can lead to situations very different from those most commonly found in reactor analysis and design. These systems are not limited to thermal or fast neutron spectra and may have their most significant influence from the intermediate energy range. This requires extending the range of applicability of the nuclear data evaluation beyond thermal and fast systems. The aim here is to focus on the evaluated nuclear data pertaining to applications in nuclear criticality safety.

  1. Nuclear data for criticality safety - current issues

    SciTech Connect

    Leal, L.C.; Jordan, W.C.; Wright, R.Q.

    1995-06-01

    Traditionally, nuclear data evaluations have been performed in support of the analysis and design of thermal and fast reactors. In general, the neutron spectra characteristic of the thermal and fast systems used for data testing are predominantly in the low- and high-energy range with a relatively small influence from the intermediate-energy range. In the area of nuclear criticality safety, nuclear systems arising from applications involving fissionable materials outside reactors can lead to situations very different from those most commonly found in reactor analysis and design. These systems are not limited to thermal or fast and may have significant influence from the intermediate energy range. The extension of the range of applicability of the nuclear data evaluation beyond thermal and fast systems is therefore needed to cover problems found in nuclear criticality safety. Before criticality safety calculations are performed, the bias and uncertainties of the codes and cross sections that are used must be determined. The most common sources of uncertainties, in general, are the calculational methodologies and the uncertainties related to the nuclear data, such as the microscopic cross sections, entering into the calculational procedure. The aim here is to focus on the evaluated nuclear data pertaining to applications in nuclear criticality safety.

  2. The Fukushima Nuclear Accident: What has been learned from it?

    NASA Astrophysics Data System (ADS)

    Ohska, Tokio

    2014-05-01

    The ill-fated Fukushima nuclear reactors are still in a state in which Japanese are struggling to find the end of the tunnel. They are now facing with the highly contaminated radioactive water. It is polluting the world unless confined in a small space for an incredibly long time. There have been many cases such as the crude oil leak from a deep-sea oil well polluting ocean or many volcanic eruptions that had globally polluted air. Why the Fukushima nuclear accident should be treated in a different way when these radioactive materials were originally from ground and they will eventually find their way back into a soil? The reality is not as simple and a remarkable difference needs to be put into consideration: nuclear wastes are highly condensed because humans worked to make them that way so that they can be used as nuclear fuel or atomic bomb. Trouble is that one finds in nuclear waste many radioactive substances with very long half-life times that would stay hazardous for many future generations. Most ashes from big volcanic eruption find their way to the ground within several years or so. Once they landed the surface of the ground, they are no different from the soil and will become basically harmless dusts. On the contrary, for some part of nuclear waste it will take over 10,000 years to become almost harmless. In general any human being does not feel a real threat on anything that would happen far beyond his/her life span. People usually are optimistic by saying that someone in a future would come up with a perfect solution to take care of the problems associated with nuclear waste. This argument reflects a very irresponsible attitude of people working on the project involving nuclear fuel. The problems in Fukushima nuclear accidents are mainly resulting from such an irresponsible attitude. Is it ever possible to see a happy end with any nuclear power station based on such a human mentality?

  3. Environmental assessment for consolidation of certain materials and machines for nuclear criticality experiments and training

    SciTech Connect

    1996-05-21

    In support of its assigned missions and because of the importance of avoiding nuclear criticality accidents, DOE has adopted a policy to reduce identifiable nuclear criticality safety risks and to protect the public, workers, government property and essential operations from the effects of a criticality accident. In support of this policy, the Los Alamos Critical Experiments Facility (LACEF) at the Los Alamos National Laboratory (LANL) Technical Area (TA) 18, provides a program of general purpose critical experiments. This program, the only remaining one of its kind in the United States, seeks to maintain a sound basis of information for criticality control in those physical situations that DOE will encounter in handling and storing fissionable material in the future, and ensuring the presence of a community of individuals competent in practicing this control.

  4. Dose and cost considerations for relocation after nuclear accidents.

    PubMed

    Qu, J; Ehrhardt, J

    1998-08-01

    The results of a comprehensive study of the dose and cost considerations for relocation after nuclear accidents are presented in this paper. These results include the quantification of the dependence of area affected by relocation on dose intervention level and source term, the countermeasures implementation cost-benefit estimate, as well as the application of cost-benefit analysis to optimize the dose intervention level for relocation. In order to explicitly consider the distribution of individual dose among the exposed population to determine the optimal dose intervention level for relocation, the concept of individual dose evaluation function has been introduced in the present work. PMID:9685065

  5. Radioactive fallout from the Chernobyl nuclear reactor accident

    SciTech Connect

    Beiriger, J.M.; Failor, R.A.; Marsh, K.V.; Shaw, G.E.

    1987-03-23

    Following the accident at the nuclear reactor at Chernobyl, in the Soviet Union on April 26, 1986, we performed a variety of measurements to determine the level of the radioactive fallout on the western United States. We used gamma-spectroscopy to analyze air filters from the areas around Lawrence Livermore National Laboratory (LLNL), California, and Barrow and Fairbanks, Alaska. Milk from California and imported vegetables were also analyzed. The levels of the various fission products detected were far below the maximum permissible concentration levels.

  6. Technical basis for nuclear accident dosimetry at the Oak Ridge National Laboratory

    SciTech Connect

    Kerr, G.D.; Mei, G.T.

    1993-08-01

    The Oak Ridge National Laboratory (ORNL) Environmental, Safety, and Health Emergency Response Organization has the responsibility of providing analyses of personnel exposures to neutrons and gamma rays from a nuclear accident. This report presents the technical and philosophical basis for the dose assessment aspects of the nuclear accident dosimetry (NAD) system at ORNL. The issues addressed are regulatory guidelines, ORNL NAD system components and performance, and the interpretation of dosimetric information that would be gathered following a nuclear accident.

  7. AQUATIC ASSESSMENT OF THE CHERNOBYL NUCLEAR ACCIDENT AND ITS REMEDIATION

    SciTech Connect

    Onishi, Yasuo; Kivva, Sergey L.; Zheleznyak, Mark J.; Voitsekhovitch, Oleg V.

    2007-11-01

    This modeling study evaluated aquatic environment affected by the Chernobyl nuclear accident and the effectiveness of remediation efforts. Study results indicate that radionuclide concentrations in the Pripyat and Dnieper rivers were well above the drinking water limits immediately after the Chernobyl accident, but have decreased significantly in subsequent years due to flashing, burying, and decay. Because high concentrations of 90Sr and 137Cs, the major radionuclides affecting human health through aquatic pathways, are associated with flooding, an earthen dike was constructed along the Pripyat River in its most contaminated floodplain. The dike was successful in reducing the 90Sr influx to the river by half. A 100-m-high movable dome called the New Safe Confinement is planned to cover the Chernobyl Shelter (formally called the sarcophagus) that was erected shortly after the accident. The NSC will reduce radionuclide contamination further in these rivers and nearby groundwater; however, even if the Chernobyl Shelter collapses before the NSC is built, the resulting peak concentrations of 90Sr and 137Cs in the Dnieper River would still be below the drinking water limits.

  8. Report to the American Physical Society of the Study Group on Radionuclide Release From Severe Accidents at Nuclear Power Plants

    NASA Astrophysics Data System (ADS)

    Shaw, George

    The release of radioiodine during the Three Mile Island (TMI) accident was more than an order of magnitude smaller than what had been predicted from analyses of hypothetical nuclear accidents. The Reactor Safety Study of 1975 (RSS), which carried out the analyses, is a fundamental factor in formulating regulations concerned with such accidents. This American Physical Society (APS) study group report is a result of the obvious need to reevaluate the RSS analysis of the “source term,” that is, the amount of various radionuclides that are predicted to be emitted under various reactor failure scenarios.The report includes an introductory background to the history of nuclear reactor accidents and accident studies and to the health aspects of radionuclide releases. It then describes nuclear reactors and reactor failure modes, including reasonably detailed descriptions of particular modes thought to be especially critical. The most extensive discussion concerns the chemical and physical processes important in the generation, transport, and release of radionuclides. The large computer codes used to model these processes are considered and evaluated. The results of some of the computer runs are examined in the light of a simplified but informative model to evaluate those features of an accident that are most likely to affect the source term. A review of the research programs currently underway precedes both the study group conclusions about the need to revise the source terms from those in the RSS and recommendations for further studies that are necessary to better evaluate the source term.

  9. Nuclear criticality safety: 300 Area

    SciTech Connect

    Not Available

    1991-07-31

    This Standard applies to the receipt, processing, storage, and shipment of fissionable material in the 300 Area and in any other facility under the control of the Reactor Materials Project Management Team (PMT). The objective is to establish practices and process conditions for the storage and handling of fissionable material that prevent the accidental assembly of a critical mass and that comply with DOE Orders as well as accepted industry practice.

  10. The 1983 international intercomparison of nuclear accident dosimetry systems at Oak Ridge National Laboratory

    NASA Astrophysics Data System (ADS)

    Swaja, R. E.; Greene, R. T.; Sims, C. S.

    1985-04-01

    An international intercomparison of nuclear accident dosimetry systems was conducted during September 12 to 16, 1983, at Oak Ridge National Laboratory (ORNL) using the Health Physics Research Reactor operated in the pulse mode to simulate criticality accidents. Participants measured neutron and gamma doses at area monitoring stations and on phantoms for three different shield conditions. Results indicate that foil activation techniques are the most popular and accurate method of determining accident level neutron doses at area monitoring stations. For personnel monitoring, foil activation, blood sodium activation, and thermoluminescent (TL) methods are all capable of providing accurate dose estimates in a variety of radiation fields. All participants used TLD's to determine gamma doses with very good results. Chemical dosimeters were also shown to be capable of yielding accurate estimates of total neutron plus gamma doses in a variety of radiation fields. While 83% of all neutron measurements satisfied regulatory standards relative to reference values, only 39% of all gamma results satisfied corresponding guidelines for gamma measurements. Results indicate that continued improvement in accident dosimetry evaluation and measurement techniques is needed.

  11. Assessment of the potential impact of Nuclear Power Plant accidents on aviation

    NASA Astrophysics Data System (ADS)

    Wotawa, Gerhard; Arnold, Delia; Maurer, Christian

    2014-05-01

    The nuclear accidents in Chernobyl in 1986 and in Fukushima in 2011 demonstrated the urgent need to provide adequate guidance for land-based, marine and airborne transport. Quick assessments of potential impacts are essential to avoid unnecessary traffic disruptions while guaranteeing appropriate safety levels for staff in the transport industry as well as travellers. Such estimates are to be provided under difficult circumstances, mostly due to the lack of reliable initial information on the severity of the accident and the exact source term of radionuclides. Regarding aviation, there are three equally relevant aspects to look at, namely aircraft in cruising altitude (about 40000 ft), aircraft approaching an airport, and finally the airports as such as critical infrastructure, including airport operations and ground transport. Based on the accident scenarios encountered in the Chernobyl and Fukushima cases, exemplary case studies shall be provided to assess the potential impacts of such events on aviation. The study is based on the Atmospheric Transport and Dispersion Model (ATDM) FLEXPART and a simplified scheme to calculate effective dose rates based on a few key radionuclides (Cs-137, I-131 and Xe-133). Besides the impact assessment, possible new products provided by WMO Regional Specialized Meteorological Centres in the event of an accident shall be discussed as well.

  12. [Accidents of the Fukushima Daiichi Nuclear Power Plants and future].

    PubMed

    Hoshi, Masaharu

    2012-01-01

    A massive earthquake of magnitude 9 terribly happened far out at sea of Tohoku area on 11 March, 2011. After this earthquake the hugest tsunami in the history came to the hundreds km of the seashore of Tohoku area. Due to this tsunami all of the four nuclear power plants of Fukushima Daiichi lost every electric power and, soon after this, loss nuclear fuels from number 1 to 3 reactors melt through their power containers. According to this phenomena, large amount of the radio-activities have been released in the air. There were some releases but major contaminations happened at the time of the two releases in the morning of 15 March, 2011. Due to this, to the direction of the northwest until the Iitate Village over 30km zone was contaminated. In this paper I explain the time course of the accidents and that how contaminated. PMID:24568025

  13. Radionuclide Analysis on Bamboos following the Fukushima Nuclear Accident

    PubMed Central

    Higaki, Takumi; Higaki, Shogo; Hirota, Masahiro; Akita, Kae; Hasezawa, Seiichiro

    2012-01-01

    In response to contamination from the recent Fukushima nuclear accident, we conducted radionuclide analysis on bamboos sampled from six sites within a 25 to 980 km radius of the Fukushima Daiichi nuclear power plant. Maximum activity concentrations of radiocesium 134Cs and 137Cs in samples from Fukushima city, 65 km away from the Fukushima Daiichi plant, were in excess of 71 and 79 kBq/kg, dry weight (DW), respectively. In Kashiwa city, 195 km away from the Fukushima Daiichi, the sample concentrations were in excess of 3.4 and 4.3 kBq/kg DW, respectively. In Toyohashi city, 440 km away from the Fukushima Daiichi, the concentrations were below the measurable limits of up to 4.5 Bq/kg DW. In the radiocesium contaminated samples, the radiocesium activity was higher in mature and fallen leaves than in young leaves, branches and culms. PMID:22496858

  14. Consequences of the nuclear power plant accident at Chernobyl

    SciTech Connect

    Ginzburg, H.M.; Reis, E. )

    1991-01-01

    The Chernobyl Nuclear Power Plant accident, in the Ukrainian Soviet Socialist Republic (SSR), on April 26, 1986, was the first major nuclear power plant accident that resulted in a large-scale fire and subsequent explosions, immediate and delayed deaths of plant operators and emergency service workers, and the radioactive contamination of a significant land area. The release of radioactive material, over a 10-day period, resulted in millions of Soviets, and other Europeans, being exposed to measurable levels of radioactive fallout. Because of the effects of wind and rain, the radioactive nuclide fallout distribution patterns are not well defined, though they appear to be focused in three contiguous Soviet Republics: the Ukrainian SSR, the Byelorussian SSR, and the Russian Soviet Federated Socialist Republic. Further, because of the many radioactive nuclides (krypton, xenon, cesium, iodine, strontium, plutonium) released by the prolonged fires at Chernobyl, the long-term medical, psychological, social, and economic effects will require careful and prolonged study. Specifically, studies on the medical (leukemia, cancers, thyroid disease) and psychological (reactive depressions, post-traumatic stress disorders, family disorganization) consequences of continued low dose radiation exposure in the affected villages and towns need to be conducted so that a coherent, comprehensive, community-oriented plan may evolve that will not cause those already affected any additional harm and confusion.

  15. Thyroid doses for evacuees from the Fukushima nuclear accident

    NASA Astrophysics Data System (ADS)

    Tokonami, Shinji; Hosoda, Masahiro; Akiba, Suminori; Sorimachi, Atsuyuki; Kashiwakura, Ikuo; Balonov, Mikhail

    2012-07-01

    A primary health concern among residents and evacuees in affected areas immediately after a nuclear accident is the internal exposure of the thyroid to radioiodine, particularly I-131, and subsequent thyroid cancer risk. In Japan, the natural disasters of the earthquake and tsunami in March 2011 destroyed an important function of the Fukushima Daiichi Nuclear Power Plant (F1-NPP) and a large amount of radioactive material was released to the environment. Here we report for the first time extensive measurements of the exposure to I-131 revealing I-131 activity in the thyroid of 46 out of the 62 residents and evacuees measured. The median thyroid equivalent dose was estimated to be 4.2 mSv and 3.5 mSv for children and adults, respectively, much smaller than the mean thyroid dose in the Chernobyl accident (490 mSv in evacuees). Maximum thyroid doses for children and adults were 23 mSv and 33 mSv, respectively.

  16. Thyroid doses for evacuees from the Fukushima nuclear accident

    PubMed Central

    Tokonami, Shinji; Hosoda, Masahiro; Akiba, Suminori; Sorimachi, Atsuyuki; Kashiwakura, Ikuo; Balonov, Mikhail

    2012-01-01

    A primary health concern among residents and evacuees in affected areas immediately after a nuclear accident is the internal exposure of the thyroid to radioiodine, particularly I-131, and subsequent thyroid cancer risk. In Japan, the natural disasters of the earthquake and tsunami in March 2011 destroyed an important function of the Fukushima Daiichi Nuclear Power Plant (F1-NPP) and a large amount of radioactive material was released to the environment. Here we report for the first time extensive measurements of the exposure to I-131 revealing I-131 activity in the thyroid of 46 out of the 62 residents and evacuees measured. The median thyroid equivalent dose was estimated to be 4.2 mSv and 3.5 mSv for children and adults, respectively, much smaller than the mean thyroid dose in the Chernobyl accident (490 mSv in evacuees). Maximum thyroid doses for children and adults were 23 mSv and 33 mSv, respectively. PMID:22792439

  17. Consequences of the nuclear power plant accident at Chernobyl.

    PubMed Central

    Ginzburg, H M; Reis, E

    1991-01-01

    The Chernobyl Nuclear Power Plant accident, in the Ukrainian Soviet Socialist Republic (SSR), on April 26, 1986, was the first major nuclear power plant accident that resulted in a large-scale fire and subsequent explosions, immediate and delayed deaths of plant operators and emergency service workers, and the radioactive contamination of a significant land area. The release of radioactive material, over a 10-day period, resulted in millions of Soviets, and other Europeans, being exposed to measurable levels of radioactive fallout. Because of the effects of wind and rain, the radioactive nuclide fallout distribution patterns are not well defined, though they appear to be focused in three contiguous Soviet Republics: the Ukrainian SSR, the Byelorussian SSR, and the Russian Soviet Federated Socialist Republic. Further, because of the many radioactive nuclides (krypton, xenon, cesium, iodine, strontium, plutonium) released by the prolonged fires at Chernobyl, the long-term medical, psychological, social, and economic effects will require careful and prolonged study. Specifically, studies on the medical (leukemia, cancers, thyroid disease) and psychological (reactive depressions, post-traumatic stress disorders, family disorganization) consequences of continued low dose radiation exposure in the affected villages and towns need to be conducted so that a coherent, comprehensive, community-oriented plan may evolve that will not cause those already affected any additional harm and confusion. Images p38-a p38-b PMID:1899937

  18. The Nuclear Accident at Three Mile Island a Practical Lesson in the Fundamental Importance of Effective Communications

    SciTech Connect

    DeVine Jr, J.C.

    2008-07-01

    The Three Mile Island Unit 2 (TMI-2) accident in March 1979 had a profound effect on the course of commercial nuclear generation in the United States and around the world. And while the central elements of the accident were matters of nuclear engineering, design and operations, its consequences were compounded, and in some respects superseded, by extraordinarily ineffective communications by all parties at all levels. Communications failures during the accident and its aftermath caused misunderstanding, distrust, and incorrect emergency response - and seeded or reinforced public opposition to nuclear power that persists to this day. There are communications lessons from TMI that have not yet been fully learned, and some that once were learned but are now gradually being forgotten. The more glaring TMI communications problems were in the arena of external interactions and communications among the plant owner, the Nuclear Regulatory Commission (NRC), the media, and the public. Confusing, fragmented, and contradictory public statements early in the accident, regardless of cause, undermined all possibility for reasonable discourse thereafter. And because the TMI accident was playing out on a world stage, the breakdown in public trust had long term and widespread implications. At the plant site, both TMI-2 cleanup and restart of the undamaged TMI-1 unit met with years of public and political criticism, and attendant regulatory pressure. Across the nation, public trust in nuclear power and those who operate it plummeted, unquestionably contributing to the 25+ year hiatus in new plant orders. There were other, less visible but equally important, consequences of ineffective communications at TMI. The unplanned 'precautionary' evacuation urged by the governor two days after the accident - a life changing, traumatic event for thousands of residents - was prompted primarily by misunderstandings and miscommunications regarding the condition of the plant. And today, nearly 30

  19. Reevaluation of radiation dose around the JCO site from the criticality accident in Tokai-mura.

    PubMed

    Imanaka, Tetsuji

    2005-04-01

    Based on the monitoring data periodically taken during the JCO criticality accident in Tokai-mura, neutron and gamma-ray doses were evaluated at 13 points around the site boundary ranging from 73 to 540 m from the conversion building where the criticality took place. Radiation doses obtained by the present study were compared with the dose-distance curves developed through the works of the Nuclear Safety Commission Investigation Committee. The latter values are larger by 30 to 120% than the former at the 6 nearest points within 150 m from the conversion building, while they agree well at the points beyond 250 m. It is suggested that the shielding effects by the surrounding buildings around the conversion building contributed to the difference of estimated doses near the JCO boundary. To reconstruct the radiation environment realistically at the residential area near the JCO facilities, it is necessary to employ radiation transport calculations with three-dimensional models of the configuration around the conversion building. Radiation doses evaluated in the present study can be used to check the validity of such calculations based on the three-dimensional model. PMID:15761301

  20. Twenty-first nuclear accident dosimetry intercomparison study, August 6-10, 1984

    SciTech Connect

    Swaja, R.E.; Ragan, G.E.; Sims, C.S.

    1985-05-01

    The twenty-first in a series of nuclear accident dosimetry (NAD) intercomparison (NAD) studies was conducted at the Oak Ridge National Laboratory's Dosimetry Applications Research Facility during August 6-10, 1984. The Health Physics Research Reactor operated in the pulse mode was used to simulate three criticality accidents with different radiation fields. Participants from five organizations measured neutron doses between 0.53 and 4.36 Gy and gamma doses between 0.19 and 1.01 Gy at area monitoring stations and on phantoms. About 75% of all neutron dose estimates based on foil activation, hair activation, simulated blood sodium activation, and thermoluminescent methods were within +-25% of reference values. Approximately 86% of all gamma results measured using thermoluminescent (TLD-700 or CaSO/sub 4/) systems were within +-20% of reference doses which represents a significant improvement over previous studies. Improvements observed in the ability of intercomparison participants to estimate neutron and gamma doses under criticality accident conditions can be partly attributed to experience in previous NAD studies which have provided practical tests of dosimetry systems, enabled participants to improve evaluation methods, and standardized dose reporting conventions. 16 refs., 15 tabs.

  1. Special committee review of the Nuclear Regulatory Commission's severe accident risks report (NUREG--1150)

    SciTech Connect

    Kouts, H.J.C. ); Apostolakis, G.; Kastenberg, W.E. ); Birkhofer, E.H.A. , Koeln ); Hoegberg, L.G. ); LeSage, L.G. ); Rasmussen, N.C. (Massachusetts Inst. of Tech., Camb

    1990-08-01

    In April 1989, the Nuclear Regulatory Commission's (NRC) Office of Nuclear Regulatory Research (RES) published a draft report Severe Accident Risks: An Assessment for Five US Nuclear Power Plants,'' NUREG-1150. This report updated, extended and improved upon the information presented in the 1974 Reactor Safety Study,'' WASH-1400. Because the information in NUREG-1150 will play a significant role in implementing the NRC's Severe Accident Policy, its quality and credibility are of critical importance. Accordingly, the Commission requested that the RES conduct a peer review of NUREG-1150 to ensure that the methods, safety insights and conclusions presented are appropriate and adequately reflect the current state of knowledge with respect to reactor safety. To this end, RES formed a special committee in June of 1989 under the provisions of the Federal Advisory Committee Act. The Committee, composed of a group of recognized national and international experts in nuclear reactor safety, was charged with preparing a report reflecting their review of NUREG-1150 with respect to the adequacy of the methods, data, analysis and conclusions it set forth. The report which precedes reflects the results of this peer review.

  2. Criticality accident alarm system at the Fernald Environmental Management Project

    SciTech Connect

    Marble, R.C.; Brown, T.D.; Wooldridge, J.C.

    1994-12-31

    This paper describes the staus of the Fernald Environmental Management Project (FEMP) criticality alarm system. A new radiation detection alarm system was installed in 1990. The anunciation system, calibration and maintenance, and detector placement is described.

  3. Radiation protection issues on preparedness and response for a severe nuclear accident: experiences of the Fukushima accident.

    PubMed

    Homma, T; Takahara, S; Kimura, M; Kinase, S

    2015-06-01

    Radiation protection issues on preparedness and response for a severe nuclear accident are discussed in this paper based on the experiences following the accident at Fukushima Daiichi nuclear power plant. The criteria for use in nuclear emergencies in the Japanese emergency preparedness guide were based on the recommendations of International Commission of Radiological Protection (ICRP) Publications 60 and 63. Although the decision-making process for implementing protective actions relied heavily on computer-based predictive models prior to the accident, urgent protective actions, such as evacuation and sheltering, were implemented effectively based on the plant conditions. As there were no recommendations and criteria for long-term protective actions in the emergency preparedness guide, the recommendations of ICRP Publications 103, 109, and 111 were taken into consideration in determining the temporary relocation of inhabitants of heavily contaminated areas. These recommendations were very useful in deciding the emergency protective actions to take in the early stages of the Fukushima accident. However, some suggestions have been made for improving emergency preparedness and response in the early stages of a severe nuclear accident. PMID:25915551

  4. 10 CFR 70.24 - Criticality accident requirements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... moderators or reflectors made of graphite, heavy water or beryllium may be present, shall maintain in each... handled or stored beneath water shielding or to require monitoring systems when special nuclear material... system shall have a preset alarm point of not less than 5 millirems per hour (in order to avoid...

  5. 10 CFR 70.24 - Criticality accident requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... moderators or reflectors made of graphite, heavy water or beryllium may be present, shall maintain in each... handled or stored beneath water shielding or to require monitoring systems when special nuclear material... system shall have a preset alarm point of not less than 5 millirems per hour (in order to avoid...

  6. Bone marrow transplantation after the Chernobyl nuclear accident

    SciTech Connect

    Baranov, A.; Gale, R.P.; Guskova, A.; Piatkin, E.; Selidovkin, G.; Muravyova, L.; Champlin, R.E.; Danilova, N.; Yevseeva, L.; Petrosyan, L. )

    1989-07-27

    On April 26, 1986, an accident at the Chernobyl nuclear power station in the Soviet Union exposed about 200 people to large doses of total-body radiation. Thirteen persons exposed to estimated total-body doses of 5.6 to 13.4 Gy received bone marrow transplants. Two transplant recipients, who received estimated doses of radiation of 5.6 and 8.7 Gy, are alive more than three years after the accident. The others died of various causes, including burns (the cause of death in five), interstitial pneumonitis (three), graft-versus-host disease (two), and acute renal failure and adult respiratory distress syndrome (one). There was hematopoietic (granulocytic) recovery in nine transplant recipients who could be evaluated, six of whom had transient partial engraftment before the recovery of their own marrow. Graft-versus-host disease was diagnosed clinically in four persons and suspected in two others. Although the recovery of endogenous hematopoiesis may occur after exposure to radiation doses of 5.6 to 13.4 Gy, we do not know whether it is more likely after the transient engraftment of transplanted stem cells. Because large doses of radiation affect multiple systems, bone marrow recovery does not necessarily ensure survival. Furthermore, the risk of graft-versus-host disease must be considered when the benefits of this treatment are being weighed.

  7. 10 CFR 50.68 - Criticality accident requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... comply with either 10 CFR 70.24 of this chapter or the requirements in paragraph (b) of this section. (b... capable of detecting a criticality as described in 10 CFR 70.24: (1) Plant procedures shall prohibit the... boron is taken, the k-effective of the spent fuel storage racks loaded with fuel of the maximum...

  8. 10 CFR 50.68 - Criticality accident requirements.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... comply with either 10 CFR 70.24 of this chapter or the requirements in paragraph (b) of this section. (b... capable of detecting a criticality as described in 10 CFR 70.24: (1) Plant procedures shall prohibit the... of neutron production to neutron absorption and leakage (k-effective) of the fresh fuel in the...

  9. 10 CFR 50.68 - Criticality accident requirements.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... comply with either 10 CFR 70.24 of this chapter or the requirements in paragraph (b) of this section. (b... capable of detecting a criticality as described in 10 CFR 70.24: (1) Plant procedures shall prohibit the... of neutron production to neutron absorption and leakage (k-effective) of the fresh fuel in the...

  10. 10 CFR 50.68 - Criticality accident requirements.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... comply with either 10 CFR 70.24 of this chapter or the requirements in paragraph (b) of this section. (b... capable of detecting a criticality as described in 10 CFR 70.24: (1) Plant procedures shall prohibit the... of neutron production to neutron absorption and leakage (k-effective) of the fresh fuel in the...

  11. 10 CFR 50.68 - Criticality accident requirements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... comply with either 10 CFR 70.24 of this chapter or the requirements in paragraph (b) of this section. (b... capable of detecting a criticality as described in 10 CFR 70.24: (1) Plant procedures shall prohibit the... of neutron production to neutron absorption and leakage (k-effective) of the fresh fuel in the...

  12. Evacuation Criteria after A Nuclear Accident: A Personal Perspective

    PubMed Central

    Wilson, Richard

    2012-01-01

    In any decision involving radiation a risk-risk or risk-benefit comparison should be done. This can be either explicit or implicit. When the adverse effect of an alternate action is less than the planned action, such as medical use of X rays or nuclear power in ordinary operation, the comparison is simple. But in this paper I argue that with the situation faced by the Japanese in Fukushima, the assumption that the risk of an alternate action is small is false. The risks of unnecessary evacuation exceeded the risk of radiation cancers hypothetically produced by staying in place. This was not realized by those that had to make a decision within hours. This realization suggests important changes, worldwide, in the guidelines for radiation protection in accident situations. PMID:23304100

  13. The Chernobyl Nuclear Power Plant accident: ecotoxicological update

    USGS Publications Warehouse

    Eisler, R.

    2003-01-01

    The accident at the Chernobyl, Ukraine, nuclear reactor on 26 April 1986 released large amounts of radiocesium and other radionuclides into the environment, contaminating much of the northern hemisphere, especially Europe. In the vicinity of Chernobyl, at least 30 people died, more than 115,000 others were evacuated, and consumption of milk and other foods was banned because of radiocontamination. At least 14,000 human cancer deaths are expected in Russia, Belarus, and the Ukraine as a direct result of Chernobyl. The most sensitive local ecosystems, as judged by survival, were the soil fauna, pine forest communities, and certain populations of rodents. Elsewhere, fallout from Chernobyl significantly contaminated freshwater and terrestrial ecosystems and flesh and milk of domestic livestock; in many cases, radionuclide concentrations in biological samples exceeded current radiation protection guidelines. Reindeer (Rangifer tarandus) in Scandinavia were among the most seriously afflicted by Chernobyl fallout, probably because their main food during winter (lichens) is an efficient absorber of airborne particles containing radiocesium. Some reindeer calves contaminated with 137Cs from Chernobyl showed 137Cs-dependent decreases in survival and increases in frequency of chromosomal aberrations. Although radiation levels in the biosphere are declining with time, latent effects of initial exposure--including an increased frequency of thyroid and other cancers--are now measurable. The full effect of the Chernobyl nuclear reactor accident on natural resources will probably not be known for at least several decades because of gaps in data on long-term genetic and reproductive effects and on radiocesium cycling and toxicokinetics.

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

    SciTech Connect

    Lobaugh, M. L.; Hickman, D. P.; Wong, C. W.; Wysong, A. R.; Merritt, M. J.; Heinrichs, D. P.; Topper, J. D.

    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).

  15. The health impact of major nuclear accidents: the case of Greece.

    PubMed

    Kollas, J G

    1993-10-01

    An assessment of the radiological consequences that would result for the population of Greece from postulated major nuclear accidents in the Kozloduy nuclear power station in Bulgaria is performed. Kozloduy lies at a distance of 225 km from the northern borders of Greece and contains six reactors, all of the Russian WWER type. The postulated accidents that are classified as level 7 accidents on the International Nuclear Event Scale, involve significant releases of radioactive materials into the environment, and widespread health and environmental effects. The analysis is performed by the MACCS code. The estimated consequences are compared to the corresponding actual impact of the Chernobyl accident in Greece. The results of the analysis indicate that, under the conservative assumptions adopted, the radiological consequences of the most severe accidents considered would be about 1.5 orders of magnitude larger than the actual radiological consequences of the Chernobyl accident. PMID:8259439

  16. Removal of criticality accident alarm systems at the Y-12 Plant waste management facilities

    SciTech Connect

    Marble, R.C.; Taylor, R.G.

    1998-09-01

    This paper discusses why criticality accident alarm systems (CAASs) were installed in certain waste management buildings at the Y-12 Plant, why the plant now wants to remove them, and what steps were taken to allow the US Department of Energy (DOE) to authorize the removal of the systems. To begin with, the systems in question were installed in the mid- to late-1980s. Some of the facilities were new, and there was no operating experience with the processes. A CAAS, although expensive, is an absolute necessity where criticality accidents are credible. But, they are a superfluous and unnecessary expense in those facilities where it has been determined that a criticality accident is incredible (defined as having a probability of <1 {times} 10{sup {minus}6}/yr). The PRAs have been performed to evaluate six Y-12 Plant waste management facilities, five storage facilities, and a nondestructive analysis facility, with an additional study now being performed on the West End Treatment Facility. The results to date have shown that the probability of various criticality accident scenarios at these facilities is <1 {times} 10{sup {minus}6}/yr and that the CAASs are not needed in these facilities.

  17. Guidelines for Exposure Assessment in Health Risk Studies Following a Nuclear Reactor Accident

    PubMed Central

    Bouville, André; Linet, Martha S.; Hatch, Maureen; Mabuchi, Kiyohiko

    2013-01-01

    Background: Worldwide concerns regarding health effects after the Chernobyl and Fukushima nuclear power plant accidents indicate a clear need to identify short- and long-term health impacts that might result from accidents in the future. Fundamental to addressing this problem are reliable and accurate radiation dose estimates for the affected populations. The available guidance for activities following nuclear accidents is limited with regard to strategies for dose assessment in health risk studies. Objectives: Here we propose a comprehensive systematic approach to estimating radiation doses for the evaluation of health risks resulting from a nuclear power plant accident, reflected in a set of seven guidelines. Discussion: Four major nuclear reactor accidents have occurred during the history of nuclear power production. The circumstances leading to these accidents were varied, as were the magnitude of the releases of radioactive materials, the pathways by which persons were exposed, the data collected afterward, and the lifestyle factors and dietary consumption that played an important role in the associated radiation exposure of the affected populations. Accidents involving nuclear reactors may occur in the future under a variety of conditions. The guidelines we recommend here are intended to facilitate obtaining reliable dose estimations for a range of different exposure conditions. We recognize that full implementation of the proposed approach may not always be feasible because of other priorities during the nuclear accident emergency and because of limited resources in manpower and equipment. Conclusions: The proposed approach can serve as a basis to optimize the value of radiation dose reconstruction following a nuclear reactor accident. Citation: Bouville A, Linet MS, Hatch M, Mabuchi K, Simon SL. 2014. Guidelines for exposure assessment in health risk studies following a nuclear reactor accident. Environ Health Perspect 122:1–5; http://dx.doi.org/10

  18. Radiocesium Distribution in Bamboo Shoots after the Fukushima Nuclear Accident

    PubMed Central

    Higaki, Takumi; Higaki, Shogo; Hirota, Masahiro; Hasezawa, Seiichiro

    2014-01-01

    The distribution of radiocesium was examined in bamboo shoots, Phyllostachys pubescens, collected from 10 sites located some 41 to 1140 km from the Fukushima Daiichi nuclear power plant, Japan, in the Spring of 2012, 1 year after the Fukushima nuclear accident. Maximum activity concentrations for radiocesium 134Cs and 137Cs in the edible bamboo shoot parts, 41 km away from the Fukushima Daiichi plant, were in excess of 15.3 and 21.8 kBq/kg (dry weight basis; 1.34 and 1.92 kBq/kg, fresh weight), respectively. In the radiocesium-contaminated samples, the radiocesium activities were higher in the inner tip parts, including the upper edible parts and the apical culm sheath, than in the hardened culm sheath and underground basal parts. The radiocesium/potassium ratios also tended to be higher in the inner tip parts. The radiocesium activities increased with bamboo shoot length in another bamboo species, Phyllostachys bambusoides, suggesting that radiocesium accumulated in the inner tip parts during growth of the shoots. PMID:24831096

  19. New Improved Nuclear Data for Nuclear Criticality and Safety

    SciTech Connect

    Guber, Klaus H; Leal, Luiz C; Lampoudis, C.; Kopecky, S.; Schillebeeckx, P.; Emiliani, F.; Wynants, R.; Siegler, P.

    2011-01-01

    The Geel Electron Linear Accelerator (GELINA) was used to measure neutron total and capture cross sections of {sup 182,183,184,186}W and {sup 63,65}Cu in the energy range from 100 eV to {approx}200 keV using the time-of-flight method. GELINA is the only high-power white neutron source with excellent timing resolution and ideally suited for these experiments. Concerns about the use of existing cross-section data in nuclear criticality calculations using Monte Carlo codes and benchmarks were a prime motivator for the new cross-section measurements. To support the Nuclear Criticality Safety Program, neutron cross-section measurements were initiated using GELINA at the EC-JRC-IRMM. Concerns about data deficiencies in some existing cross-section evaluations from libraries such as ENDF/B, JEFF, or JENDL for nuclear criticality calculations were the prime motivator for new cross-section measurements. Over the past years many troubles with existing nuclear data have emerged, such as problems related to proper normalization, neutron sensitivity backgrounds, poorly characterized samples, and use of improper pulse-height weighting functions. These deficiencies may occur in the resolved- and unresolved-resonance region and may lead to erroneous nuclear criticality calculations. An example is the use of the evaluated neutron cross-section data for tungsten in nuclear criticality safety calculations, which exhibit discrepancies in benchmark calculations and show the need for reliable covariance data. We measured the neutron total and capture cross sections of {sup 182,183,184,186}W and {sup 63,65}Cu in the neutron energy range from 100 eV to several hundred keV. This will help to improve the representation of the cross sections since most of the available evaluated data rely only on old measurements. Usually these measurements were done with poor experimental resolution or only over a very limited energy range, which is insufficient for the current application.

  20. Thyroid Consequences of the Fukushima Nuclear Reactor Accident

    PubMed Central

    Nagataki, Shigenobu

    2012-01-01

    Background A special report, ‘The Fukushima Accident’, was delivered at the 35th Annual Meeting of the European Thyroid Association in Krakow on September 11, 2011, and this study is the follow-up of the special report. Objectives To present a preliminary review of potential thyroid consequences of the 2011 Fukushima nuclear reactor accident. Methods Numerous new data have been presented in Japanese, and most of them are available on the website from each research institute and/or from each municipality. The review was made using these data from the website. Results When individual radiation doses were expressed as values in more than 99% of residents, radiation doses by behavior survey in evacuation and deliberate evacuation areas were less than 10 mSv in the first 4 months, and internal radiation doses measured by whole body counters were less than 1 mSv/year. Individual thyroid radiation doses were less than 50 mSv (intervention levels) even in evacuation areas. As for health consequences, no one died and no one suffered from acute effects. The thyroid ultrasound examination is in progress and following examination of almost 40,000 children, 35% of them have nodules and/or cysts but no cancers. Conclusions Countermeasures against radiation must consider current individual measured values, although every effort must be taken to reconstruct radiation doses as precisely as possible. At present, the difference of thyroid radiation dose between Chernobyl and Fukushima appears to be due to the strict control of milk started within a week after the accident in Fukushima. Since the iodine-131 plume moved around in wide areas and for a long time, the method of thyroid protection must be reconsidered. PMID:24783014

  1. PRELIMINARY NUCLEAR CRITICALITY NUCLEAR SAFETY EVLAUATION FOR THE CONTAINER SURVEILLANCE AND STORAGE CAPABILITY PROJECT

    SciTech Connect

    Low, M; Matthew02 Miller, M; Thomas Reilly, T

    2007-04-30

    Washington Safety Management Solutions (WSMS) provides criticality safety services to Washington Savannah River Company (WSRC) at the Savannah River Site. One activity at SRS is the Container Surveillance and Storage Capability (CSSC) Project, which will perform surveillances on 3013 containers (hereafter referred to as 3013s) to verify that they meet the Department of Energy (DOE) Standard (STD) 3013 for plutonium storage. The project will handle quantities of material that are greater than ANS/ANSI-8.1 single parameter mass limits, and thus required a Nuclear Criticality Safety Evaluation (NCSE). The WSMS methodology for conducting an NCSE is outlined in the WSMS methods manual. The WSMS methods manual currently follows the requirements of DOE-O-420.1B, DOE-STD-3007-2007, and the Washington Savannah River Company (WSRC) SCD-3 manual. DOE-STD-3007-2007 describes how a NCSE should be performed, while DOE-O-420.1B outlines the requirements for a Criticality Safety Program (CSP). The WSRC SCD-3 manual implements DOE requirements and ANS standards. NCSEs do not address the Nuclear Criticality Safety (NCS) of non-reactor nuclear facilities that may be affected by overt or covert activities of sabotage, espionage, terrorism or other security malevolence. Events which are beyond the Design Basis Accidents (DBAs) are outside the scope of a double contingency analysis.

  2. HANFORD NUCLEAR CRITICALITY SAFETY PROGRAM DATABASE

    SciTech Connect

    TOFFER, H.

    2005-05-02

    The Hanford Database is a useful information retrieval tool for a criticality safety practitioner. The database contains nuclear criticality literature screened for parameter studies. The entries, characterized with a value index, are segregated into 16 major and six minor categories. A majority of the screened entries have abstracts and a limited number are connected to the Office of Scientific and Technology Information (OSTI) database of full-size documents. Simple and complex searches of the data can be accomplished very rapidly and the end-product of the searches could be a full-size document. The paper contains a description of the database, user instructions, and a number of examples.

  3. Descriptions of selected accidents that have occurred at nuclear reactor facilities

    SciTech Connect

    Bertini, H.W.

    1980-04-01

    This report was prepared at the request of the President's Commission on the Accident at Three Mile Island to provide the members of the Commission with some insight into the nature and significance of accidents that have occurred at nuclear reactor facilities in the past. Toward that end, this report presents a brief description of 44 accidents which have occurred throughout the world and which meet at least one of the severity criteria that were established.

  4. Estimation Of 137Cs Using Atmospheric Dispersion Models After A Nuclear Reactor Accident

    NASA Astrophysics Data System (ADS)

    Simsek, V.; Kindap, T.; Unal, A.; Pozzoli, L.; Karaca, M.

    2012-04-01

    Nuclear energy will continue to have an important role in the production of electricity in the world as the need of energy grows up. But the safety of power plants will always be a question mark for people because of the accidents happened in the past. Chernobyl nuclear reactor accident which happened in 26 April 1986 was the biggest nuclear accident ever. Because of explosion and fire large quantities of radioactive material was released to the atmosphere. The release of the radioactive particles because of accident affected not only its region but the entire Northern hemisphere. But much of the radioactive material was spread over west USSR and Europe. There are many studies about distribution of radioactive particles and the deposition of radionuclides all over Europe. But this was not true for Turkey especially for the deposition of radionuclides released after Chernobyl nuclear reactor accident and the radiation doses received by people. The aim of this study is to determine the radiation doses received by people living in Turkish territory after Chernobyl nuclear reactor accident and use this method in case of an emergency. For this purpose The Weather Research and Forecasting (WRF) Model was used to simulate meteorological conditions after the accident. The results of WRF which were for the 12 days after accident were used as input data for the HYSPLIT model. NOAA-ARL's (National Oceanic and Atmospheric Administration Air Resources Laboratory) dispersion model HYSPLIT was used to simulate the 137Cs distrubition. The deposition values of 137Cs in our domain after Chernobyl Nuclear Reactor Accident were between 1.2E-37 Bq/m2 and 3.5E+08 Bq/m2. The results showed that Turkey was affected because of the accident especially the Black Sea Region. And the doses were calculated by using GENII-LIN which is multipurpose health physics code.

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

    SciTech Connect

    1991-09-01

    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.

  6. An extended critical review of twenty years of countermeasures used in agriculture after the Chernobyl accident.

    PubMed

    Fesenko, Sergey V; Alexakhin, Rudolf M; Balonov, Mikhail I; Bogdevitch, Iossif M; Howard, Brenda J; Kashparov, Valery A; Sanzharova, Natalia I; Panov, Alexey V; Voigt, Gabriele; Zhuchenka, Yury M

    2007-09-20

    A wide range of different countermeasures has been used to mitigate the consequences of the Chernobyl accident for agriculture in affected regions in Belarus, Russia and Ukraine. The paper comprehensively brings together key data on countermeasure application over twenty years for all three countries and critically evaluates the response to the accident with respect to agriculture. The extents of countermeasures implementation in various periods following the ChNPP accident are documented. Examples of best practices and drawbacks in remediation of affected areas are identified. Data on the effectiveness of agricultural countermeasures have been evaluated and the impact of countermeasures implementation to mitigate consequences of the accident has been assessed for the period 1986-2006. Implementation of agricultural countermeasures averted 30-40% of the internal collective dose that would have been received by the residents of affected regions without the use of countermeasures. The current situation in agriculture of areas subjected to contamination following the Chernobyl accident is described. Current and future needs for remediation, including a consideration of various strategies of rehabilitation of affected areas are presented. PMID:17573097

  7. Compartment model for long-term contamination prediction in deciduous fruit trees after a nuclear accident

    SciTech Connect

    Antonopoulos-Domis, M.; Clouvas, A.; Gagianas, A. )

    1990-06-01

    Radiocesium contamination from the Chernobyl accident of different parts (fruits, leaves, and shoots) of selected apricot trees in North Greece was systematically measured in 1987 and 1988. The results are presented and discussed in the framework of a simple compartment model describing the long-term contamination uptake mechanism of deciduous fruit trees after a nuclear accident.

  8. Elements of a national emergency response system for nuclear accidents

    SciTech Connect

    Dickerson, M.H.

    1987-02-10

    The purpose of this paper is to suggest elements for a general emergency response system, employed at a national level, to detect, evaluate and assess the consequences of a radiological atmospheric release occurring within or outside of national boundaries. These elements are focused on the total aspect of emergency response ranging from providing an initial alarm to a total assessment of the environmental and health effects. Elements of the emergency response system are described in such a way that existing resources can be directly applied if appropriate; if not, newly developed or an expansion of existing resources can be employed. The major thrust of this paper is toward a philosophical discussion and general description of resources that would be required to implementation. If the major features of this proposal system are judged desirable for implementation, then the next level of detail can be added. The philosophy underlying this paper is preparedness - preparedness through planning, awareness and the application of technology. More specifically, it is establishment of reasonable guidelines including the definition of reference and protective action levels for public exposure to accidents involving nuclear material; education of the public, government officials and the news media; and the application of models and measurements coupled to computer systems to address a series of questions related to emergency planning, response and assessment. It is the role of a proven national emergency response system to provide reliable, quality-controlled information to decision makers for the management of environmental crises.

  9. Radioactivity from Fukushima nuclear accident detected in Lisbon, Portugal.

    PubMed

    Carvalho, F P; Reis, M C; Oliveira, J M; Malta, M; Silva, L

    2012-12-01

    The radioactivity released from the Fukushima Dai-ichi nuclear accident was transported around the globe by atmospheric processes. Several artificial radionuclides were detected and measured in aerosols and atmospheric surface depositions in the Lisbon area during late March and early April 2011. The highest concentrations measured in aerosols were those of particulate (131)I, 1.39 ± 0.08 mBq m(-3). Cesium-134, (137)Cs and (132)Te were also determined but at lower concentrations. The total atmospheric depositions on the ground were higher on the first week of April with values for (131)I, (134)Cs, and (137)Cs of 0.92 ± 0.11, 0.59 ± 0.06, and 0.62 ± 0.12 Bq m(-2), respectively. The four artificial radionuclides measurable, (131)I, (132)Te (134)Cs, and (137)Cs, caused little radiation exposure to the members of the public, that was five orders of magnitude lower than the ionizing radiation effective dose limits for members of the public for one year (1 mSv y(-1)). PMID:22503401

  10. Evaluation of the 17 June 1997 Criticality Accident at Arzamas-16

    SciTech Connect

    Morris Klein

    1999-04-01

    On June 17, 1997, a critically accident occurred at Arzamas-16, which resulted in the death (within three days) of A. N. Zakharov, a Russian scientist with 20 years' experience conducting multiassembly experiments. In this case, the multiplying assembly was a fast metal system consisting of a {sup 235}U (90% enriched) core and a copper reflector. According to the Russian press, ''Zakharov misjudged the degree of criticality of the breeding system and committed several gross violations of regulations.'' As we see it, there were three major causes of this accident. First, the experiment was flawed by Zakharov's misreading of the appropriate size of the assembly, which he took from a notebook that described the old experiment he was attempting to repeat. Second, he disregarded the appropriate procedures and safety regulations. Third, these two mistakes were compounded by an improperly set audible alarm system and Zakharov's unsafe use of the table. We also discuss our reconstruction of the accident based on information given by the Russians to US scientists and information culled from Russian newspaper and magazine articles. We also describe our thoughts on the behavior of the assembly following the accident and the radiation dose level Zakharov may have received. These levels match values we have lately obtained from translations of Russian news articles. This accident clearly points out the penalty for weak administrative control of work with multiplying systems. Criticality experimentation requires formality of operation. The experimenter, his peers, and a trained safety person need to document that they understand the experiment and how it will be conducted. Knowing that the experiment was successfully run several decades ago does not justify bypassing a safety evaluation.

  11. Community emergency response to nuclear power plant accidents: A selected and partially annotated bibliography

    SciTech Connect

    Youngen, G.

    1988-10-01

    The role of responding to emergencies at nuclear power plants is often considered the responsibility of the personnel onsite. This is true for most, if not all, of the incidents that may happen during the course of the plant`s operating lifetime. There is however, the possibility of a major accident occurring at anytime. Major nuclear accidents at Chernobyl and Three Mile Island have taught their respective countries and communities a significant lesson in local emergency preparedness and response. Through these accidents, the rest of the world can also learn a great deal about planning, preparing and responding to the emergencies unique to nuclear power. This bibliography contains books, journal articles, conference papers and government reports on emergency response to nuclear power plant accidents. It does not contain citations for ``onsite`` response or planning, nor does it cover the areas of radiation releases from transportation accidents. The compiler has attempted to bring together a sampling of the world`s collective written experience on dealing with nuclear reactor accidents on the sate, local and community levels. Since the accidents at Three Mile Island and Chernobyl, that written experience has grown enormously.

  12. Code System for Calculating Early Offsite Consequences from Nuclear Reactor Accidents.

    Energy Science and Technology Software Center (ESTSC)

    1992-06-10

    SMART calculates early offsite consequences from nuclear reactor accidents. Once the air and ground concentrations of the radionuclide are estimated, the early dose to an individual is calculated via three pathways: cloudshine, short-term groundshine, and inhalation.

  13. Fukushima Nuclear Accident Report Calls for More Focus on Threats From Extreme Events

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2014-08-01

    Nuclear plant licensees and their regulators "must actively seek out and act on new information about hazards that have the potential to affect the safety of nuclear plants." That is the overarching lesson from the 2011 Fukushima Daiichi nuclear accident in Japan, according to a 24 July report issued by a committee of the U.S. National Research Council.

  14. A comparative analysis of accident risks in fossil, hydro, and nuclear energy chains

    SciTech Connect

    Burgherr, P.; Hirschberg, S.

    2008-07-01

    This study presents a comparative assessment of severe accident risks in the energy sector, based on the historical experience of fossil (coal, oil, natural gas, and LPG (Liquefied Petroleum Gas)) and hydro chains contained in the comprehensive Energy-related Severe Accident Database (ENSAD), as well as Probabilistic Safety Assessment (PSA) for the nuclear chain. Full energy chains were considered because accidents can take place at every stage of the chain. Comparative analyses for the years 1969-2000 included a total of 1870 severe ({>=} 5 fatalities) accidents, amounting to 81,258 fatalities. Although 79.1% of all accidents and 88.9% of associated fatalities occurred in less developed, non-OECD countries, industrialized OECD countries dominated insured losses (78.0%), reflecting their substantially higher insurance density and stricter safety regulations. Aggregated indicators and frequency-consequence (F-N) curves showed that energy-related accident risks in non-OECD countries are distinctly higher than in OECD countries. Hydropower in non-OECD countries and upstream stages within fossil energy chains are most accident-prone. Expected fatality rates are lowest for Western hydropower and nuclear power plants; however, the maximum credible consequences can be very large. Total economic damages due to severe accidents are substantial, but small when compared with natural disasters. Similarly, external costs associated with severe accidents are generally much smaller than monetized damages caused by air pollution.

  15. Fukushima nuclear accident: preliminary assessment of the risks to non-human biota.

    PubMed

    Aliyu, Abubakar Sadiq; Ramli, Ahmad Termizi; Garba, Nuraddeen Nasiru; Saleh, Muneer Aziz; Gabdo, Hamman Tukur; Liman, Muhammad Sanusi

    2015-02-01

    This study assesses the 'radio-ecological' impacts of Fukushima nuclear accident on non-human biota using the ERICA Tool, which adopts an internationally verified methodology. The paper estimates the impacts of the accident on terrestrial and marine biota based on the environmental data reported in literature for Japan, China, South Korea and the USA. Discernible impacts have been detected in the marine biota around Fukushima Daiichi nuclear power plant. This study confirms that the Fukushima accident had caused heavier damage to marine bionts compared with terrestrial flora and fauna, in Japan. PMID:24827576

  16. Airway accidents in critical care unit: A 3-year retrospective study in a Public Teaching Hospital of Eastern India

    PubMed Central

    Dasgupta, Sugata; Singh, Shipti Shradha; Chaudhuri, Arunima; Bhattacharya, Dipasri; Choudhury, Sourav Das

    2016-01-01

    Background: Although tracheal tubes are essential devices to control and protect airway in a critical care unit (CCU), they are not free from complications. Aims: To document the incidence and nature of airway accidents in the CCU of a government teaching hospital in Eastern India. Methods: Retrospective analysis of all airway accidents in a 5-bedded (medical and surgical) CCU. The number, types, timing, and severity of airway accidents were analyzed. Results: The total accident rate was 19 in 233 intubated and/or tracheostomized patients over 1657 tube days (TDs) during 3 years. Fourteen occurred in 232 endotracheally intubated patients over 1075 endotracheal tube (ETT) days, and five occurred in 44 tracheostomized patients over 580 tracheostomy TDs. Fifteen accidents were due to blocked tubes. Rest four were unplanned extubations (UEs), all being accidental extubations. All blockages occurred during night shifts and all UEs during day shifts. Five accidents were mild, the rest moderate. No major accident led to cardiorespiratory arrest or death. All blockages occurred after 7th day of intubation. The outcome of accidents were more favorable in tracheostomy group compared to ETT group (P = 0.001). Conclusions: The prevalence of airway accidents was 8.2 accidents per 100 patients. Blockages were the most common accidents followed by UEs. Ten out of the 15 blockages and all 4 UEs were in endotracheally intubated patients. Tracheostomized patients had 5 blockages and no UEs. PMID:27076709

  17. Accident at the Fukushima Dai-ichi nuclear power stations of TEPCO--outline & lessons learned.

    PubMed

    Tanaka, Shun-ichi

    2012-01-01

    The severe accident that broke out at Fukushima Dai-ichi nuclear power stations on March 11, 2011, caused seemingly infinite damage to the daily life of residents. Serious and wide-spread contamination of the environment occurred due to radioactive materials discharged from nuclear power stations (NPSs). At the same time, many issues were highlighted concerning countermeasures to severe nuclear accidents. The accident is outlined, and lessons learned are extracted with respect to the safety of NPSs, as well as radiation protection of residents under the emergency involving the accident. The materials of the current paper are those released by governmental agencies, academic societies, interim reports of committees under the government, and others. PMID:23138450

  18. Effect of the duration time of a nuclear accident on radiological health consequences.

    PubMed

    Jeong, Hyojoon; Park, Misun; Jeong, Haesun; Hwang, Wontae; Kim, Eunhan; Han, Moonhee

    2014-03-01

    This study aimed to quantify the effect of duration time of a nuclear accident on the radiation dose of a densely populated area and the resulting acute health effects. In the case of nuclear accidents, the total emissions of radioactive materials can be classified into several categories. Therefore, the release information is very important for the assessment of risk to the public. We confirmed that when the duration time of the emissions are prolonged to 7 hours, the concentrations of radioactive substances in the ambient air are reduced by 50% compared to that when the duration time of emission is one hour. This means that the risk evaluation using only the first wind direction of an accident is very conservative, so it has to be used as a screening level for the risk assessment. Furthermore, it is judged that the proper control of the emission time of a nuclear accident can minimize the health effects on residents. PMID:24619120

  19. Effect of the Duration Time of a Nuclear Accident on Radiological Health Consequences

    PubMed Central

    Jeong, Hyojoon; Park, Misun; Jeong, Haesun; Hwang, Wontae; Kim, Eunhan; Han, Moonhee

    2014-01-01

    This study aimed to quantify the effect of duration time of a nuclear accident on the radiation dose of a densely populated area and the resulting acute health effects. In the case of nuclear accidents, the total emissions of radioactive materials can be classified into several categories. Therefore, the release information is very important for the assessment of risk to the public. We confirmed that when the duration time of the emissions are prolonged to 7 hours, the concentrations of radioactive substances in the ambient air are reduced by 50% compared to that when the duration time of emission is one hour. This means that the risk evaluation using only the first wind direction of an accident is very conservative, so it has to be used as a screening level for the risk assessment. Furthermore, it is judged that the proper control of the emission time of a nuclear accident can minimize the health effects on residents. PMID:24619120

  20. Root causes and impacts of severe accidents at large nuclear power plants.

    PubMed

    Högberg, Lars

    2013-04-01

    The root causes and impacts of three severe accidents at large civilian nuclear power plants are reviewed: the Three Mile Island accident in 1979, the Chernobyl accident in 1986, and the Fukushima Daiichi accident in 2011. Impacts include health effects, evacuation of contaminated areas as well as cost estimates and impacts on energy policies and nuclear safety work in various countries. It is concluded that essential objectives for reactor safety work must be: (1) to prevent accidents from developing into severe core damage, even if they are initiated by very unlikely natural or man-made events, and, recognizing that accidents with severe core damage may nevertheless occur; (2) to prevent large-scale and long-lived ground contamination by limiting releases of radioactive nuclides such as cesium to less than about 100 TBq. To achieve these objectives the importance of maintaining high global standards of safety management and safety culture cannot be emphasized enough. All three severe accidents discussed in this paper had their root causes in system deficiencies indicative of poor safety management and poor safety culture in both the nuclear industry and government authorities. PMID:23423737

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

    SciTech Connect

    Adler, V.; Sorensen, J.H.; Rogers, G.O.

    1989-01-01

    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.

  2. Decontamination of the populated areas contaminated as a result of nuclear accident

    SciTech Connect

    Voronik, N.I.; Shatilo, N.N.; Davydov, Y.P.

    1996-12-31

    Decontamination tests on urban surfaces contaminated by the Chernobyl accident have shown that Chernobyl fallout behaves differently from fallout from nuclear weapons tests and contamination on surfaces in nuclear power plant. The effectiveness of various decontamination compositions for removing Chernobyl fallout from urban surfaces and machinery was determined in a series of laboratory experiments and field trials.

  3. Nuclear Criticism: In Pursuit of a "Politically Enabling" Deconstructive Voice.

    ERIC Educational Resources Information Center

    Williams, David Cratis

    1988-01-01

    Argues that the nuclear threat is fundamentally a textual problem, a problem created and perpetuated by argumentative and rhetorical practices. Maintains that argument critics need to formulate a politically powerful "nuclear criticism" in order to subvert and dismantle argument formations which might motivate nations to engage in nuclear war. (MS)

  4. Behavioral differences of irradiated persons associated with the Kyshtym, Chelyabinsk, and Chernobyl nuclear accidents.

    PubMed

    Collins, D L

    1992-10-01

    Three nuclear accidents besides Chernobyl have occurred in the former Soviet Union. The accidents occurred around Kyshtym and Chelyabinsk in the Ural Mountains between 1949 and 1967 and contaminated over one-half million people. The health ministries are now interested in the data previously collected on these irradiated populations in order to examine the health (e.g., psychological, hereditary, genome damage, etc.) implications of long-term radiation exposure. PMID:1454181

  5. Energy situations in Japan before and after the Fukushima nuclear accident

    NASA Astrophysics Data System (ADS)

    Muraoka, K.

    2015-08-01

    This article describes the various effects on the public conception on nuclear energy and more generally on energy policies in Japan due to the nuclear accident that occurred on 11th March 2011 at the Fukushima Dai-ichi nuclear power station, which is owned and operated by Tokyo Electric Power Company (TEPCO). Before the accident, nuclear energy had been conceived as the main energy source of electricity in Japan for reducing CO2 emission beyond 2020. However, public opinion has turned almost completely against nuclear energy after observing how vulnerable the nuclear system had been. The present Japanese government is now trying to buy time before taking a decision. After explaining these circumstances, the author tries to chart his personal projection of energy sources for Japan to 2050.

  6. A highway accident involving unirradiated nuclear fuel in Springfield, Massachusetts, on December 16, 1991

    SciTech Connect

    Carlson, R.W.; Fischer, L.E.

    1992-06-01

    In the early morning of Dec. 16, 1991, a severe accident occurred when a passenger vehicle traveling in the wrong direction collided with a tractor trailer carrying 24 unirradiated nuclear fuel assemblies in 12 containers on Interstate I-91 in Springfield, Massachusetts. The purpose of this report is to document the mechanical circumstances of the severe accident, confirm the nature and quantity of the radioactive materials involved, and assess the physical environment to which the containers were exposed and the response of the containers and their contents. The report consists of five major sections. The first section describes the circumstances and conditions of the accident and the finding of facts. The second describes the containers, the unirradiated nuclear fuel assemblies, and the tie down arrangement used for the trailer. The third describes the damage sustained during the accident to the tractor, trailer, containers, and unirradiated nuclear fuel assemblies. The fourth evaluates the accident environment and its effects on the containers and their contents. The final section gives conclusions derived from the analysis and fact finding investigation. During this severe accident, only minor injuries occurred, and at no time was the public health and safety at risk.

  7. Status, plans, and capabilities of the Nuclear Criticality Information System

    SciTech Connect

    Koponen, B.L.

    1984-01-06

    The Nuclear Criticality Information System (NCIS), in preparation since 1981, has substantially evolved and now contains a growing number of resources pertinent to nuclear criticality safety. These resources include bibliographic compilations, experimental data, communications media, and the International Directory of Nuclear Criticality Safety Personnel. These resources are part of the LLNL Technology Information System (TIS) which provides the host computer for NCIS. The TIS provides nationwide access to authorized members of the nuclear criticality community via interactive dial-up from computer terminals that utilize communication facilities such as commercial and federal telephone networks, toll-free WATS lines, TYMNET, and the ARPANET/MILNET computer network.

  8. Guide to radiological accident considerations for siting and design of DOE nonreactor nuclear facilities

    SciTech Connect

    Elder, J.C.; Graf, J.M.; Dewart, J.M.; Buhl, T.E.; Wenzel, W.J.; Walker, L.J.; Stoker, A.K.

    1986-01-01

    This guide was prepared to provide the experienced safety analyst with accident analysis guidance in greater detail than is possible in Department of Energy (DOE) Orders. The guide addresses analysis of postulated serious accidents considered in the siting and selection of major design features of DOE nuclear facilities. Its scope has been limited to radiological accidents at nonreactor nuclear facilities. The analysis steps addressed in the guide lead to evaluation of radiological dose to exposed persons for comparison with siting guideline doses. Other possible consequences considered are environmental contamination, population dose, and public health effects. Choices of models and parameters leading to estimation of source terms, release fractions, reduction and removal factors, dispersion and dose factors are discussed. Although requirements for risk analysis have not been established, risk estimates are finding increased use in siting of major nuclear facilities, and are discussed in the guide. 3 figs., 9 tabs.

  9. Cooperative measures to support the Indo-Pak Agreement Reducing Risk from Accidents Relating to Nuclear Weapons.

    SciTech Connect

    Mishra, Sitakanta; Ahmed, Mansoor

    2014-04-01

    In 2012, India and Pakistan reaffirmed the Agreement on Reducing the Risk from Accidents Relating to Nuclear Weapons. Despite a history of mutual animosity and persistent conflict between the two countries, this agreement derives strength from a few successful nuclear confidence building measures that have stood the test of time. It also rests on the hope that the region would be spared a nuclear holocaust from an accidental nuclear weapon detonation that might be misconstrued as a deliberate use of a weapon by the other side. This study brings together two emerging strategic analysts from South Asia to explore measures to support the Agreement and further develop cooperation around this critical issue. This study briefly dwells upon the strategic landscape of nuclear South Asia with the respective nuclear force management structures, doctrines, and postures of India and Pakistan. It outlines the measures in place for the physical protection and safety of nuclear warheads, nuclear materials, and command and control mechanisms in the two countries, and it goes on to identify the prominent, emerging challenges posed by the introduction of new weapon technologies and modernization of the respective strategic forces. This is followed by an analysis of the agreement itself leading up to a proposed framework for cooperative measures that might enhance the spirit and implementation of the agreement.

  10. 32P measurement and dose conversion factor evaluation of activated human hair by criticality accident.

    PubMed

    Yoon, Seokwon; Ha, Wi-Ho; Park, Seyoung; Shin, Seongwook; Yoo, Jaeryong; Park, Sunhoo; Lee, Seung-Sook

    2014-10-01

    In order to conduct dose assessment of victims in criticality accidents, a method of fast neutron capture-activated (32)P measurement of hair in which samples are treated by a chemical and analytical procedure that takes 9 h and measurement is conducted by liquid scintillation counting is presented. To validate this measurement method, hair samples spiked with a (32)P reference source were measured and the results analysed and the optimal sample mass and detection efficiency were determined. To verify the correlation between (32)P-specific activity and absorbed dose for spectra with two neutron mean energies, samples collected from three normal individuals were irradiated at various neutron energies and irradiation times using the MC50 Cyclotron of the Korea Institute of Radiological and Medical Sciences. The (32)P-specific activity trend of the irradiated hair agreed well with the absorbed doses. Based on the results, dose conversion factors, which were 0.67 ± 0.15 and 0.59 ± 0.06 Gy (Bq g(-1))(-1) at neutron mean energies of 2.33 and 5.36 MeV, respectively, were calculated as a guide for medical treatment of criticality accident victims. PMID:24516187

  11. External doses in the environment from the Tokai-mura criticality accident.

    PubMed

    Endo, A; Yamaguchi, Y; Sakamoto, Y; Yoshizawa, M; Tsuda, S

    2001-01-01

    On 30 September 1999, a criticality accident occurred at a uranium processing plant operated by JCO in Tokai-mura, Japan and the criticality remained for about 20 h. Almost all doses to the neighbouring residents were brought by neutrons and gamma rays emitted from the facility rather than fission products released to the environment. External doses in the environment were evaluated using radiation monitoring data and radiation transport calculation. A pattern of the dose rate evolution was modelled based on the records of gamma ray monitors in the JCO facilities. Relations between the ambient dose equivalent rates of neutrons/gamma rays and the distance from the facility were determined from the monitoring data obtained around the accident site. Conversion from the ambient dose equivalent to the effective dose equivalent was made assuming the energy spectra calculated by the radiation transport code, ANISN. It was estimated that the people who stayed outside the 350 m zone would receive doses of less than 1 mSv. PMID:11548346

  12. Radioactivity inspection of Taiwan for food products imported from Japan after the Fukushima nuclear accident.

    PubMed

    Chiu, Huang-Sheng; Huang, Ping-Ji; Wuu, Jyi-Lan; Wang, Jeng-Jong

    2013-11-01

    The 3-11 Earthquake occurred in Japan last year had greatly damaged the lives and properties and also caused the core meltdown accident in the Fukushima nuclear power plant followed by the leakage of radioactive materials into biosphere. In order to protect against the detriment of radiation from foods which were imported from Japan, the Institute of Nuclear Energy Research (INER) in Taiwan started to conduct radioactivity inspection of food products from Japan after the accident. A total of about 20,000 samples had been tested from March 24 2011 to March 31 2012. PMID:23583088

  13. Nuclear Criticality Information System. Database examples

    SciTech Connect

    Foret, C.A.

    1984-06-01

    The purpose of this publication is to provide our users with a guide to using the Nuclear Criticality Information System (NCIS). It is comprised of an introduction, an information and resources section, a how-to-use section, and several useful appendices. The main objective of this report is to present a clear picture of the NCIS project and its available resources as well as assisting our users in accessing the database and using the TIS computer to process data. The introduction gives a brief description of the NCIS project, the Technology Information System (TIS), online user information, future plans and lists individuals to contact for additional information about the NCIS project. The information and resources section outlines the NCIS database and describes the resources that are available. The how-to-use section illustrates access to the NCIS database as well as searching datafiles for general or specific data. It also shows how to access and read the NCIS news section as well as connecting to other information centers through the TIS computer.

  14. Continuously improving safety of nuclear installations: An approach to be reinforced after the Fukushima accident

    NASA Astrophysics Data System (ADS)

    Repussard, Jacques; Schwarz, Michel

    2012-05-01

    After the Three Mile Island accident in 1979 and the Chernobyl accident in 1986, the Fukushima accident shows that the probability of a core meltdown accident in an LWR (Light Water Reactor) has been largely underestimated. The consequences of such an accident are unacceptable: except in the case of TMI2 (Three Mile Island 2) large areas around the damaged plants are contaminated for decades and populations have to be relocated for long periods. This article presents the French approach which consists in improving continuously the safety of the Nuclear Power Plants (NPP) on the basis of lessons learned from operating experience and from the progress in R&D (Research and Development). It details the key role played by IRSN (Institut de radioprotection et de sûreté nucléaire), the French TSO (Technical and scientific Safety Organization), and shows how the Fukushima accident contributes to this approach in improving NPP robustness. It concludes on the necessity to keep on networking TSOs, to share knowledge as well as R&D resources, with the ultimate goal of enhancing and harmonizing nuclear safety worldwide.

  15. Post-crisis efforts towards recovery and resilience after the Fukushima Daiichi Nuclear Power Plant accident.

    PubMed

    Yamashita, Shunichi; Takamura, Noboru

    2015-08-01

    One of the well-known radiation-associated late-onset cancers is childhood thyroid cancer as demonstrated around Chernobyl apparently from 1991. Therefore, immediately after the Fukushima Daiichi Nuclear Power Plant accident on March 2011, iodine thyroid blocking was considered regardless of its successful implementation or not at the indicated timing and places as one of the radiation protection measurements, in addition to evacuation and indoor sheltering, because a short-lived radioactive iodine was massively released into the environment which might crucially affect thyroid glands through inhalation and unrestricted consumption of contaminated food and milk. However, very fortunately, it is now increasingly believed that the exposure doses on the thyroid as well as whole body are too low to detect any radiation-associated cancer risk in Fukushima. Although the risk of radiation-associated health consequences of residents in Fukushima is quite different from that of Chernobyl and is considerably low based on the estimated radiation doses received during the accident for individuals, a large number of people have received psychosocial and mental stresses aggravated by radiation fear and anxiety, and remained in indeterminate and uncertain situation having been evacuated but not relocated. It is, therefore, critically important that best activities and practices related to recovery and resilience should be encouraged, supported and implemented at local and regional levels. Since psychosocial well-being of individuals and communities is the core element of resilience, local individuals, health professionals and authorities are uniquely positioned to identify and provide insight into what would provide the best resolution for their specific needs. PMID:26059007

  16. Lessons Learned from the Fukushima Nuclear Accident due to Tohoku Region Pacific Coast Earthquake

    NASA Astrophysics Data System (ADS)

    Miki, M.; Wada, M.; Takeuchi, N.

    2012-01-01

    On March 11 2011, Great Eastern Japan Earthquake hit Japan and caused the devastating damage. Fukushima Nuclear Power Station (NPS) also suffered damages and provided the environmental effect with radioactive products. The situation has been settled to some extent about two months after the accidents, and currently, the cooling of reactor is continuing towards settling the situation. Japanese NPSs are designed based on safety requirements and have multiple-folds of hazard controls. However, according to publicly available information, due to the lager-than-anticipated Tsunami, all the power supply were lost, which resulted in loss of hazard controls. Also, although nuclear power plants are equipped with system/procedure in case of loss of all controls, recovery was not made as planned in Fukushima NPSs because assumptions for hazard controls became impractical or found insufficient. In consequence, a state of emergency was declared. Through this accident, many lessons learned have been obtained from the several perspectives. There are many commonality between nuclear safety and space safety. Both industries perform thorough hazard assessments because hazards in both industries can result in loss of life. Therefore, space industry must learn from this accident and reconsider more robust space safety. This paper will introduce lessons learned from Fukushima nuclear accident described in the "Report of the Japanese Government to the IAEA Ministerial Conference on Nuclear Safety" [1], and discuss the considerations to establish more robust safety in the space systems. Detailed information of Fukushima Dai-ichi NPS are referred to this report.

  17. Absorbed dose rate in air in metropolitan Tokyo before the Fukushima Daiichi Nuclear Power Plant accident.

    PubMed

    Inoue, K; Hosoda, M; Fukushi, M; Furukawa, M; Tokonami, S

    2015-11-01

    The monitoring of absorbed dose rate in air has been carried out continually at various locations in metropolitan Tokyo after the accident of the Fukushima Daiichi Nuclear Power Plant. While the data obtained before the accident are needed to more accurately assess the effects of radionuclide contamination from the accident, detailed data for metropolitan Tokyo obtained before the accident have not been reported. A car-borne survey of the absorbed dose rate in air in metropolitan Tokyo was carried out during August to September 2003. The average absorbed dose rate in air in metropolitan Tokyo was 49±6 nGy h(-1). The absorbed dose rate in air in western Tokyo was higher compared with that in central Tokyo. Here, if the absorbed dose rate indoors in Tokyo is equivalent to that outdoors, the annual effective dose would be calculated as 0.32 mSv y(-1). PMID:25944962

  18. Long-term transport and dispersion of 137Cs released into ocean off Fukushima nuclear accident

    NASA Astrophysics Data System (ADS)

    Zhao, Chang; Qiao, Fangli; Wang, Guansuo; Xia, Changshui; Jung, KyungTae

    2014-05-01

    In the following days after the Fukushima nuclear accident which happened in 11th March 2011, significant amounts of radioactive materials (131I, 134Cs and 137Cs) had been leaking into the terrestrial and marine environments. The radionuclides model was used to study the distribution of the 137Cs in the Pacific and the Indian Ocean released from the Fukushima accident. The simulation on the distribution of 137Cs agrees well with the the observed profiles in the 9th November 2011, which proved the validaty of the model. In the first year of our model run, the 137Cs is carried eastward by the Kuroshio and its extension, spreading southward and northword meanwhile. Four or five years after the accident, the 137Cs reaches the US coast with the surface waters of the Pacific Ocean; its concentration is no higher than 3 Bq/m3. Ten years after the accident, all the North Pacific Ocean is labeled with the 137Cs from the Fukushima. The concentration is less than 1 Bq/m3 at that time. Thirty years after the accident, the concentration of 137Cs in both the Pacific and the Indian Ocean is below 0.1 Bq/m3. Since the spreading path of 137Cs from the Fukushima nuclear accident is just the migration route of the Pacific tuna, a kind of fish inhabit the western and eastern North Pacific, it may cause radioactive contamination to the fish. In the offshore seas of China, the 137Cs from Fukushima nuclear accident is very low (<0.2 Bq/m3) .

  19. Thyroid side effects prophylaxis in front of nuclear power plant accidents.

    PubMed

    Agopiantz, Mikaël; Elhanbali, Ouifak; Demore, Béatrice; Cuny, Thomas; Demarquet, Léa; Ndiaye, Cumba; Barbe, Françoise; Brunaud, Laurent; Weryha, Georges; Klein, Marc

    2016-02-01

    The better knowledge of the mechanisms of nuclear incidents and lessons learned from accidents in the recent past to improve the effectiveness of measures taken following a nuclear accident exposure to fallout of radioactive iodine isotopes. Thus, immediate, passive measures, such as containment, and stopping consumption of contaminated products are paramount. The earliest possible administration of stable iodine as potassium iodide (KI) reduces significantly (up to 90% if taken at the same time of the accident) thyroid radioactive contamination. These tablets should be given in priority to children and pregnant women. The side effects are minor. KI is not recommended for persons aged over 60 years, or for adults suffering from cardiovascular disorders. PMID:26830953

  20. The Fukushima Dai-ichi Accident and its implications for the safety of nuclear power

    NASA Astrophysics Data System (ADS)

    Barletta, William

    2016-05-01

    Five years ago the dramatic events in Fukushima that followed the massive earthquake and subsequent tsunami that struck Japan on March 11, 2011 sharpened the focus of scientists, engineers and general public on the broad range of technical, environmental and societal issues involved in assuring the safety of the world's nuclear power complex. They also called into question the potential of nuclear power to provide a growing, sustainable resource of CO2-free energy. The issues raised by Fukushima Dai-ichi have provoked urgent concern, not only because of the potential harm that could result from severe accidents or from intentional damage to nuclear reactors or to facilities involved in the nuclear fuel cycle, but also because of the extensive economic impact of those accidents and of the measures taken to avoid them.

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

    SciTech Connect

    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.

  2. 10 CFR 72.124 - Criteria for nuclear criticality safety.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 2 2012-01-01 2012-01-01 false Criteria for nuclear criticality safety. 72.124 Section 72.124 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSING REQUIREMENTS FOR THE INDEPENDENT STORAGE OF SPENT NUCLEAR FUEL, HIGH-LEVEL RADIOACTIVE WASTE, AND REACTOR-RELATED GREATER THAN CLASS...

  3. 10 CFR 72.124 - Criteria for nuclear criticality safety.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 2 2014-01-01 2014-01-01 false Criteria for nuclear criticality safety. 72.124 Section 72.124 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSING REQUIREMENTS FOR THE INDEPENDENT STORAGE OF SPENT NUCLEAR FUEL, HIGH-LEVEL RADIOACTIVE WASTE, AND REACTOR-RELATED GREATER THAN CLASS...

  4. 10 CFR 72.124 - Criteria for nuclear criticality safety.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 2 2013-01-01 2013-01-01 false Criteria for nuclear criticality safety. 72.124 Section 72.124 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSING REQUIREMENTS FOR THE INDEPENDENT STORAGE OF SPENT NUCLEAR FUEL, HIGH-LEVEL RADIOACTIVE WASTE, AND REACTOR-RELATED GREATER THAN CLASS...

  5. 10 CFR 72.124 - Criteria for nuclear criticality safety.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 2 2011-01-01 2011-01-01 false Criteria for nuclear criticality safety. 72.124 Section 72.124 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSING REQUIREMENTS FOR THE INDEPENDENT STORAGE OF SPENT NUCLEAR FUEL, HIGH-LEVEL RADIOACTIVE WASTE, AND REACTOR-RELATED GREATER THAN CLASS...

  6. 10 CFR 72.124 - Criteria for nuclear criticality safety.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Criteria for nuclear criticality safety. 72.124 Section 72.124 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSING REQUIREMENTS FOR THE INDEPENDENT STORAGE OF SPENT NUCLEAR FUEL, HIGH-LEVEL RADIOACTIVE WASTE, AND REACTOR-RELATED GREATER THAN CLASS...

  7. "What--me worry?" "Why so serious?": a personal view on the Fukushima nuclear reactor accidents.

    PubMed

    Gallucci, Raymond

    2012-09-01

    Infrequently, it seems that a significant accident precursor or, worse, an actual accident, involving a commercial nuclear power reactor occurs to remind us of the need to reexamine the safety of this important electrical power technology from a risk perspective. Twenty-five years since the major core damage accident at Chernobyl in the Ukraine, the Fukushima reactor complex in Japan experienced multiple core damages as a result of an earthquake-induced tsunami beyond either the earthquake or tsunami design basis for the site. Although the tsunami itself killed tens of thousands of people and left the area devastated and virtually uninhabitable, much concern still arose from the potential radioactive releases from the damaged reactors, even though there was little population left in the area to be affected. As a lifelong probabilistic safety analyst in nuclear engineering, even I must admit to a recurrence of the doubt regarding nuclear power safety after Fukushima that I had experienced after Three Mile Island and Chernobyl. This article is my attempt to "recover" my personal perspective on acceptable risk by examining both the domestic and worldwide history of commercial nuclear power plant accidents and attempting to quantify the risk in terms of the frequency of core damage that one might glean from a review of operational history. PMID:22394214

  8. Risk Analysis for Public Consumption: Media Coverage of the Ginna Nuclear Reactor Accident.

    ERIC Educational Resources Information Center

    Dunwoody, Sharon; And Others

    Researchers have determined that the lay public makes risk judgments in ways that are very different from those advocated by scientists. Noting that these differences have caused considerable concern among those who promote and regulate health and safety, a study examined media coverage of the accident at the Robert E. Ginna nuclear power plant…

  9. Providing Nuclear Criticality Safety Analysis Education through Benchmark Experiment Evaluation

    SciTech Connect

    John D. Bess; J. Blair Briggs; David W. Nigg

    2009-11-01

    One of the challenges that today's new workforce of nuclear criticality safety engineers face is the opportunity to provide assessment of nuclear systems and establish safety guidelines without having received significant experience or hands-on training prior to graduation. Participation in the International Criticality Safety Benchmark Evaluation Project (ICSBEP) and/or the International Reactor Physics Experiment Evaluation Project (IRPhEP) provides students and young professionals the opportunity to gain experience and enhance critical engineering skills.

  10. Accident risks in nuclear facilities. (Latest citations from the NTIS bibliographic database). Published Search

    SciTech Connect

    1993-09-01

    The bibliography contains citations concerning risk analysis and hazards evaluation of the design, construction, and operation of nuclear facilities. The citations also explore the risk and hazards of transporting radioactive materials to and from these facilities. Radiological calculations for environmental effects of nuclear accidents and the use of computer models in risk analysis are also included. (Contains 250 citations and includes a subject term index and title list.)

  11. Accident risks in nuclear facilities. (Latest citations from the NTIS bibliographic database). Published Search

    SciTech Connect

    Not Available

    1994-11-01

    The bibliography contains citations concerning risk analysis and hazards evaluation of the design, construction, and operation of nuclear facilities. The citations also explore the risk and hazards of transporting radioactive materials to and from these facilities. Radiological calculations for environmental effects of nuclear accidents and the use of computer models in risk analysis are also included. (Contains 250 citations and includes a subject term index and title list.)

  12. Modeling & analysis of criticality-induced severe accidents during refueling for the Advanced Neutron Source Reactor

    SciTech Connect

    Georgevich, V.; Kim, S.H.; Taleyarkhan, R.P.; Jackson, S.

    1992-10-01

    This paper describes work done at the Oak Ridge National Laboratory (ORNL) for evaluating the potential and resulting consequences of a hypothetical criticality accident during refueling of the 330-MW Advanced Neutron Source (ANS) research reactor. The development of an analytical capability is described. Modeling and problem formulation were conducted using concepts of reactor neutronic theory for determining power level escalation, coupled with ORIGEN and MELCOR code simulations for radionuclide buildup and containment transport Gaussian plume transport modeling was done for determining off-site radiological consequences. Nuances associated with modeling this blast-type scenario are described. Analysis results for ANS containment response under a variety of postulated scenarios and containment failure modes are presented. It is demonstrated that individuals at the reactor site boundary will not receive doses beyond regulatory limits for any of the containment configurations studied.

  13. Sodium in man and the assessment of radiation dose after criticality accidents.

    PubMed

    Mole, R H

    1984-11-01

    Recent observations on the sodium content of the human body, both total and exchangeable, using isotope dilution methods and activation of sodium by whole-body irradiation with neutrons in the course of clinical research, suggest that ICRP Reference Man is a misleading guide to the sodium content of the body and of the skeleton and its parts. They also show that reasonable predictions of body sodium content can be made from body weight, height and age, or even from body weight alone. Mean sodium in the average man is about 1.04 g per kg and in the average women about 0.98 g per kg in British and N. American populations. Within each sex mean tissue concentration is inversely related to body weight. Review of the dosimetry for the criticality accident at Y-12 Oak Ridge shows that dose estimates should be increased by about 10% because whole blood values of 24Na were relied on instead of plasma values. Taking account of body build reduces the range of dose amongst the four most heavily irradiated subjects. The absorbed doses reported for the subjects exposed at the criticality accident at Vinca, Yugoslavia, need to be increased by about 30% because the normal sodium content of the body was grossly overestimated. The more severe clinical picture at Vinca than at Y-12 is now more easily understood in terms of differences in dose. These changes are solely the result of improved information about sodium in the body. Other uncertainties in the dosimetry at Y-12 and Vinca are unaltered. PMID:6505014

  14. Elevated Radioxenon Detected Remotely Following the Fukushima Nuclear Accident

    SciTech Connect

    Bowyer, Ted W.; Biegalski, Steven R.; Cooper, Matthew W.; Eslinger, Paul W.; Haas, Derek A.; Hayes, James C.; Miley, Harry S.; Strom, Daniel J.; Woods, Vincent T.

    2011-04-21

    We report on the first measurements of short-lived gaseous fission products detected outside of Japan following the Fukushima nuclear releases, which occurred after a 9.0 magnitude earthquake and tsunami on March 11, 2011.

  15. Retrospection of Chernobyl nuclear accident for decision analysis concerning remedial actions in Ukraine

    SciTech Connect

    Georgievskiy, Vladimir

    2007-07-01

    It is considered the efficacy of decisions concerning remedial actions when of-site radiological monitoring in the early and (or) in the intermediate phases was absent or was not informative. There are examples of such situations in the former Soviet Union where many people have been exposed: releases of radioactive materials from 'Krasnoyarsk-26' into Enisey River, releases of radioactive materials from 'Chelabinsk-65' (the Kishtim accident), nuclear tests at the Semipalatinsk Test Site, the Chernobyl nuclear accident etc. If monitoring in the early and (or) in the intermediate phases is absent the decisions concerning remedial actions are usually developed on the base of permanent monitoring. However decisions of this kind may be essentially erroneous. For these cases it is proposed to make retrospection of radiological data of the early and intermediate phases of nuclear accident and to project decisions concerning remedial actions on the base of both retrospective data and permanent monitoring data. In this Report the indicated problem is considered by the example of the Chernobyl accident for Ukraine. Their of-site radiological monitoring in the early and intermediate phases was unsatisfactory. In particular, the pasture-cow-milk monitoring had not been made. All official decisions concerning dose estimations had been made on the base of measurements of {sup 137}Cs in body (40 measurements in 135 days and 55 measurements in 229 days after the Chernobyl accident). For the retrospection of radiological data of the Chernobyl accident dynamic model has been developed. This model has structure similar to the structure of Pathway model and Farmland model. Parameters of the developed model have been identified for agricultural conditions of Russia and Ukraine. By means of this model dynamics of 20 radionuclides in pathways and dynamics of doses have been estimated for the early, intermediate and late phases of the Chernobyl accident. The main results are following

  16. Surveillance of Strontium-90 in Foods after the Fukushima Daiichi Nuclear Power Plant Accident.

    PubMed

    Nabeshi, Hiromi; Tsutsumi, Tomoaki; Uekusa, Yoshinori; Hachisuka, Akiko; Matsuda, Rieko; Teshima, Reiko

    2015-01-01

    As a result of the Fukushima Daiichi nuclear power plant (NPP) accident, various radionuclides were released into the environment. In this study, we surveyed strontium-90 ((90)Sr) concentrations in several foodstuffs. Strontium-90 is thought to be the third most important residual radionuclide in food collected after the Fukushima Daiichi, NPP accident after following cesium-137 ((137)Cs) and cesium-134 ((134)Cs). Results of (90)Sr analyses indicated that (90)Sr was detect in 25 of the 40 radioactive cesium (r-Cs) positive samples collected in areas around the Fukushima Daiichi NPP, ranging in distance from 50 to 250 km. R-Cs positive samples were defined as containing both (134)Cs and (137)Cs which are considered to be indicators of the after-effects of the Fukushima Daiichi NPP accident. We also detected (90)Sr in 8 of 13 r-Cs negative samples, in which (134)Cs was not detected. Strontium-90 concentrations in the r-Cs positive samples did not significantly exceed the (90)Sr concentrations in r-Cs negative samples or the (90)Sr concentration ranges in comparable food groups found in previous surveys before the Fukushima Daiichi NPP accident. Thus, (90)Sr concentrations in r-Cs positive samples were indistinguishable from the background (90)Sr concentrations arising from global fallout prior to the Fukushima accident, suggesting that no marked increase of (90)Sr concentrations has occurred in r-Cs positive samples as a result of the Fukushima Daiichi NPP accident. PMID:26346857

  17. Tritium in Japanese precipitation following the March 2011 Fukushima Daiichi Nuclear Plant Accident

    NASA Astrophysics Data System (ADS)

    Matsumoto, Takuya; Maruoka, Teruyuki; Shimoda, Gen; Obata, Hajime; Kagi, Hiroyuki; Suzuki, Katsuhiko; Yamamoto, Koshi; Mitsuguchi, Takehiro; Hagino, Kyoko; Tomioka, Naotaka; Sambandam, Chinmaya; Brummer, Daniela; Klaus, Philipp Martin; Aggarwal, Pradeep

    2013-04-01

    We have measured the concentrations of tritium in Japanese precipitation samples collected after the March 2011 accident at the Fukushima Dai-ichi Nuclear Power Plant (FNPP1). Tritium concentrations exceeding the pre-accident background level were detected at three out of seven localities (Tsukuba, Kashiwa and Hongo) southwest of the FNPP1, with their distances varying between 170 and 220 km from the source. The highest tritium content was found in the first rainfall in Tsukuba after the accident, but its tritium content was about 500 times less than the regulatory limit for tritium in drinking water, so that the risk of radiation from tritium released in the accident can be considered negligible. Tritium levels at the localities studied here decreased steadily and rapidly with time and became indistinguishable from the pre-accident values within five weeks. The atmospheric tritium level in the vicinity of the FNPP1 during the earliest stage of the accident was roughly estimated to be 1.5 × 103 Bq/m3, which is potentially capable of producing rainwater exceeding the regulatory limit, but only in the immediate vicinity of the source.

  18. Radiation accidents and their management: emphasis on the role of nuclear medicine professionals

    PubMed Central

    Novruzov, Fuad; Vinjamuri, Sobhan

    2014-01-01

    Large-scale radiation accidents are few in number, but those that have occurred have subsequently led to strict regulation in most countries. Here, different accident scenarios involving exposure to radiation have been reviewed. A triage of injured persons has been summarized and guidance on management has been provided in accordance with the early symptoms. Types of casualty to be expected in atomic blasts have been discussed. Management at the scene of an accident has been described, with explanation of the role of the radiation protection officer, the nature of contaminants, and monitoring for surface contamination. Methods for early diagnosis of radiation injuries have been then described. The need for individualization of treatment according to the nature and grade of the combined injuries has been emphasized, and different approaches to the treatment of internal contamination have been presented. The role of nuclear medicine professionals, including physicians and physicists, has been reviewed. It has been concluded that the management of radiation accidents is a very challenging process and that nuclear medicine physicians have to be well organized in order to deliver suitable management in any type of radiation accident. PMID:25004166

  19. Environmental Remediation Strategic Planning of Fukushima Nuclear Accident

    SciTech Connect

    Onishi, Yasuo

    2011-12-01

    Environmntal Remediation Assessment and other respons decision making on Environmental monitoring, experiments and assessment. Preliminary assessment to grasp the overall picture and determine critical locations, phenomena, people, etc. Using simple methods and models.

  20. The Communication of Information Such as Evacuation Orders at the Time of a Nuclear Power Station Accident

    PubMed Central

    HATANAKA, Takashi; YOSHIDA, Sumito; OJINO, Mayo; ISHII, Masami

    2014-01-01

    This research was carried out from the perspective that the damage to the people of Fukushima and others from the Fukushima Daiichi Nuclear Power Station (NPS) accident was an “information disaster.” It evaluated the critical problems raised by and actual condition analysis on the process of events in the Fukushima Daiichi NPS disaster and responses of the governments and others, notification of the occurrence of the accident and evacuation order by the national and local governments and the evacuation of residents, and guidance for distribution and intake of stable iodine tablets. The research aimed to provide a basis for the implementation of effective distribution and intake of stable iodine tablets and responses to the “information disaster” in the nuclear power disaster. On March 15 at the time that the most radioactive substances were dispersed, even when the average wind speed at the site area was 1.6 m/s, the radioactive substances had reached the outer boundary of Urgent Protective action planning Zone (UPZ, the region with a radius of 30 km) within about five hours. Because of this, every second counted in the provision of information about the accident and the issuance of evacuation orders. This study evaluated the actual condition of information provision by the national government and others from the perspective of this awareness of the importance of time. On the basis of the results of this kind of consideration, we come to the following recommendations: The Nuclear Emergency Response Guidelines and the system for communication of information to medical providers should be revised. The national government should make preparations for the effective advance distribution and intake of stable iodine tablets. PMID:26557446

  1. Radioactive impact of the Fukushima nuclear accident on Shenyang in the northeast of China.

    PubMed

    Shi, Erwei; Cui, Yong; Zhang, Qian; Li, Di; Li, Xin; Yao, Shuang; Liu, Ming-hui; Guo, Jun-qiao

    2014-03-01

    Environmental monitoring was carried out in Shenyang in the northeast of China after the Fukushima Daiichi nuclear accident which was caused by the earthquake and tsunami on 11 March 2011. The fission product radionuclide (131)I was detected as present in the atmosphere on the 20th day after the nuclear accident, while the radionuclides (134)Cs and (137)Cs were found in the atmosphere on the 27th day after the accident. The radionuclides (131)I, (134)Cs and (137)Cs continued to be present in the atmosphere for 25, 4 and 6 days, respectively, with maximum concentrations of 4.60 ± 0.2, 0.29 ± 0.06 and 0.42 ± 0.08 mBq m(-3). The contents of fission radionuclides in vegetables, drinking water and milk from Shenyang were below the detection limits. The atmosphere was slightly contaminated in Shenyang due to the Fukushima nuclear accident, but no contamination was detected in vegetables, milk and drinking water. PMID:24487274

  2. Fukushima nuclear power plant accident and comprehensive health risk management-global radiocontamination and information disaster.

    PubMed

    Yamashita, Shunichi

    2014-06-01

    The Great East Japan Earthquake on March 11, 2011, besides further studying the appropriateness of the initial response and post-countermeasures against the severe Fukushima nuclear accident, has now increased the importance of the epidemiological study in comprehensive health risk management and radiation protection; lessons learnt from the Chernobyl accident should be also implemented. Therefore, since May 2011, Fukushima Prefecture has started the "Fukushima Health Management Survey Project" for the purpose of long-term health care administration and early diagnosis/treatment for the prefectural residents. Basic survey is under investigation on a retrospective estimation of external exposure of the first four months. As one of the four detailed surveys, the thyroid ultrasound examination has clarified the increased detection rate of childhood thyroid cancers as a screening effect in the past three years and so thyroid cancer occurrence by Fukushima nuclear power plant accident, especially due to radioactive iodine will be discussed despite of difficult challenge of accurate estimation of low dose and low-dose rate radiation exposures. Through the on-site valuable experience and a difficult challenge for recovery, we should learn the lessons from this severe and large-scale nuclear accident, especially how to countermeasure against public health emergency at the standpoint of health risk and also social risk management. PMID:25425958

  3. SL-1 Accident Briefing Report - 1961 Nuclear Reactor Meltdown Educational Documentary

    ScienceCinema

    None

    2014-03-11

    U.S. Atomic Energy Commission (Idaho Operations Office) briefing about the SL-1 Nuclear Reactor Meltdown. The SL-1, or Stationary Low-Power Reactor Number One, was a United States Army experimental nuclear power reactor which underwent a steam explosion and meltdown on January 3, 1961, killing its three operators. The direct cause was the improper withdrawal of the central control rod, responsible for absorbing neutrons in the reactor core. The event is the only known fatal reactor accident in the United States. The accident released about 80 curies (3.0 TBq) of Iodine-131, which was not considered significant due to its location in a remote desert of Idaho. About 1,100 curies (41 TBq) of fission products were released into the atmosphere. The facility, located at the National Reactor Testing Station approximately 40 miles (64 km) west of Idaho Falls, Idaho, was part of the Army Nuclear Power Program and was known as the Argonne Low Power Reactor (ALPR) during its design and build phase. It was intended to provide electrical power and heat for small, remote military facilities, such as radar sites near the Arctic Circle, and those in the DEW Line. The design power was 3 MW (thermal). Operating power was 200 kW electrical and 400 kW thermal for space heating. In the accident, the core power level reached nearly 20 GW in just four milliseconds, precipitating the reactor accident and steam explosion.

  4. SL-1 Accident Briefing Report - 1961 Nuclear Reactor Meltdown Educational Documentary

    SciTech Connect

    2013-09-25

    U.S. Atomic Energy Commission (Idaho Operations Office) briefing about the SL-1 Nuclear Reactor Meltdown. The SL-1, or Stationary Low-Power Reactor Number One, was a United States Army experimental nuclear power reactor which underwent a steam explosion and meltdown on January 3, 1961, killing its three operators. The direct cause was the improper withdrawal of the central control rod, responsible for absorbing neutrons in the reactor core. The event is the only known fatal reactor accident in the United States. The accident released about 80 curies (3.0 TBq) of Iodine-131, which was not considered significant due to its location in a remote desert of Idaho. About 1,100 curies (41 TBq) of fission products were released into the atmosphere. The facility, located at the National Reactor Testing Station approximately 40 miles (64 km) west of Idaho Falls, Idaho, was part of the Army Nuclear Power Program and was known as the Argonne Low Power Reactor (ALPR) during its design and build phase. It was intended to provide electrical power and heat for small, remote military facilities, such as radar sites near the Arctic Circle, and those in the DEW Line. The design power was 3 MW (thermal). Operating power was 200 kW electrical and 400 kW thermal for space heating. In the accident, the core power level reached nearly 20 GW in just four milliseconds, precipitating the reactor accident and steam explosion.

  5. Fukushima Nuclear Power Plant Accident and Comprehensive Health Risk Management—Global Radiocontamination and Information Disaster

    PubMed Central

    2014-01-01

    The Great East Japan Earthquake on March 11, 2011, besides further studying the appropriateness of the initial response and post-countermeasures against the severe Fukushima nuclear accident, has now increased the importance of the epidemiological study in comprehensive health risk management and radiation protection; lessons learnt from the Chernobyl accident should be also implemented. Therefore, since May 2011, Fukushima Prefecture has started the “Fukushima Health Management Survey Project” for the purpose of long-term health care administration and early diagnosis/treatment for the prefectural residents. Basic survey is under investigation on a retrospective estimation of external exposure of the first four months. As one of the four detailed surveys, the thyroid ultrasound examination has clarified the increased detection rate of childhood thyroid cancers as a screening effect in the past three years and so thyroid cancer occurrence by Fukushima nuclear power plant accident, especially due to radioactive iodine will be discussed despite of difficult challenge of accurate estimation of low dose and low-dose rate radiation exposures. Through the on-site valuable experience and a difficult challenge for recovery, we should learn the lessons from this severe and large-scale nuclear accident, especially how to countermeasure against public health emergency at the standpoint of health risk and also social risk management. PMID:25425958

  6. Probabilistic analysis of accident precursors in the nuclear industry.

    PubMed

    Hulsmans, M; De Gelder, P

    2004-07-26

    Feedback of operating experience has always been an important issue in the nuclear industry. A probabilistic safety analysis (PSA) can be used as a tool to analyse how an operational event might have developed adversely in order to obtain a quantitative assessment of the safety significance of the event. This process is called PSA-based event analysis (PSAEA). A comprehensive set of PSAEA guidelines was developed by an international project. The main characteristics of this methodology are summarised. This approach to analyse incidents can be used to meet different objectives of utilities or nuclear regulators. The paper describes the main objectives and the experiences of the Belgian nuclear regulatory organisation AVN with the application of PSA-based event analysis. Some interesting aspects of the process of PSAEA are further developed and underlined. Several case studies are discussed and an overview of the obtained results is given. Finally, the interest of a broad and interactive forum on PSAEA is highlighted. PMID:15231351

  7. Nuclear source term evaluation for launch accident environments

    SciTech Connect

    McCulloch, W.H.

    1996-05-01

    When United States space missions involve launching vehicles carrying significant quantities of nuclear material, US law requires that prior to launch the mission be approved by the Office of the President. This approval is to be based on an evaluation of the nuclear safety risks associated with the mission and the projected benefits. To assist in the technical evaluation of risks for each mission, an Interagency Nuclear Safety Review Panel (INSRP) is instituted to provide an independent assessment of the mission risks. INSRP`s assessment begins with a review of the safety analysis for the mission completed by the organization proposing the mission and documented in a Safety Analysis Report (SAR). In addition, INSRP may execute other analyses it deems necessary. Results are documented and passed to the decision maker in a Safety Evaluation Report (SER). The INSRP review and evaluation process has been described in some detail in a number of papers.

  8. The ENEA criticality accident dosimetry system: a contribution to the 2002 international intercomparison at the SILENE reactor.

    PubMed

    Gualdrini, G; Bedogni, R; Fantuzzi, E; Mariotti, F

    2004-01-01

    The present paper summarises the activity carried out at the ENEA Radiation Protection Institute for updating the methodologies employed for the evaluation of the neutron and photon dose to the exposed workers in case of a criticality accident, in the framework of the 'International Intercomparison of Criticality Accident Dosimetry Systems' (Silène reactor, IRSN-CEA-Valduc June 2002). The evaluation of the neutron spectra and the neutron dosimetric quantities relies on activation detectors and on unfolding algorithms. Thermoluminescent detectors are employed for the gamma dose measurement. The work is aimed at accurately characterising the measurement system and, at the same time, testing the algorithms. Useful spectral information were included, based on Monte Carlo simulations, to take into account the potential accident scenarios of practical interest. All along this exercise intercomparison a particular attention was devoted to the 'traceability' of all the experimental and computational parameters and therefore, aimed at an easy treatment by the user. PMID:15353692

  9. Development of hydrogeological modelling approaches for assessment of consequences of hazardous accidents at nuclear power plants

    SciTech Connect

    Rumynin, V.G.; Mironenko, V.A.; Konosavsky, P.K.; Pereverzeva, S.A.

    1994-07-01

    This paper introduces some modeling approaches for predicting the influence of hazardous accidents at nuclear reactors on groundwater quality. Possible pathways for radioactive releases from nuclear power plants were considered to conceptualize boundary conditions for solving the subsurface radionuclides transport problems. Some approaches to incorporate physical-and-chemical interactions into transport simulators have been developed. The hydrogeological forecasts were based on numerical and semi-analytical scale-dependent models. They have been applied to assess the possible impact of the nuclear power plants designed in Russia on groundwater reservoirs.

  10. A Web-Based Nuclear Criticality Safety Bibliographic Database

    SciTech Connect

    Koponen, B L; Huang, S

    2007-02-22

    A bibliographic criticality safety database of over 13,000 records is available on the Internet as part of the U.S. Department of Energy's (DOE) Nuclear Criticality Safety Program (NCSP) website. This database is easy to access via the Internet and gets substantial daily usage. This database and other criticality safety resources are available at ncsp.llnl.gov. The web database has evolved from more than thirty years of effort at Lawrence Livermore National Laboratory (LLNL), beginning with compilations of critical experiment reports and American Nuclear Society Transactions.

  11. Assessment of environmental public exposure from a hypothetical nuclear accident for Unit-1 Bushehr nuclear power plant.

    PubMed

    Sohrabi, M; Ghasemi, M; Amrollahi, R; Khamooshi, C; Parsouzi, Z

    2013-05-01

    Unit-1 of the Bushehr nuclear power plant (BNPP-1) is a VVER-type reactor with 1,000-MWe power constructed near Bushehr city at the coast of the Persian Gulf, Iran. The reactor has been recently operational to near its full power. The radiological impact of nuclear power plant (NPP) accidents is of public concern, and the assessment of radiological consequences of any hypothetical nuclear accident on public exposure is vital. The hypothetical accident scenario considered in this paper is a design-basis accident, that is, a primary coolant leakage to the secondary circuit. This scenario was selected in order to compare and verify the results obtained in the present paper with those reported in the Final Safety Analysis Report (FSAR 2007) of the BNPP-1 and to develop a well-proven methodology that can be used to study other and more severe hypothetical accident scenarios for this reactor. In the present study, the version 2.01 of the PC COSYMA code was applied. In the early phase of the accidental releases, effective doses (from external and internal exposures) as well as individual and collective doses (due to the late phase of accidental releases) were evaluated. The surrounding area of the BNPP-1 within a radius of 80 km was subdivided into seven concentric rings and 16 sectors, and distribution of population and agricultural products was calculated for this grid. The results show that during the first year following the modeled hypothetical accident, the effective doses do not exceed the limit of 5 mSv, for the considered distances from the BNPP-1. The results obtained in this study are in good agreement with those in the FSAR-2007 report. The agreement obtained is in light of many inherent uncertainties and variables existing in the two modeling procedures applied and proves that the methodology applied here can also be used to model other severe hypothetical accident scenarios of the BNPP-1 such as a small and large break in the reactor coolant system as well

  12. Estimates of the financial consequences of nuclear-power-reactor accidents

    SciTech Connect

    Strip, D.R.

    1982-09-01

    This report develops preliminary techniques for estimating the financial consequences of potential nuclear power reactor accidents. Offsite cost estimates are based on CRAC2 calculations. Costs are assigned to health effects as well as property damage. Onsite costs are estimated for worker health effects, replacement power, and cleanup costs. Several classes of costs are not included, such as indirect costs, socio-economic costs, and health care costs. Present value discounting is explained and then used to calculate the life cycle cost of the risks of potential reactor accidents. Results of the financial consequence estimates for 156 reactor-site combinations are summarized, and detailed estimates are provided in an appendix. The results indicate that, in general, onsite costs dominate the consequences of potential accidents.

  13. Emission of spherical cesium-bearing particles from an early stage of the Fukushima nuclear accident.

    PubMed

    Adachi, Kouji; Kajino, Mizuo; Zaizen, Yuji; Igarashi, Yasuhito

    2013-01-01

    The Fukushima nuclear accident released radioactive materials into the environment over the entire Northern Hemisphere in March 2011, and the Japanese government is spending large amounts of money to clean up the contaminated residential areas and agricultural fields. However, we still do not know the exact physical and chemical properties of the radioactive materials. This study directly observed spherical Cs-bearing particles emitted during a relatively early stage (March 14-15) of the accident. In contrast to the Cs-bearing radioactive materials that are currently assumed, these particles are larger, contain Fe, Zn, and Cs, and are water insoluble. Our simulation indicates that the spherical Cs-bearing particles mainly fell onto the ground by dry deposition. The finding of the spherical Cs particles will be a key to understand the processes of the accident and to accurately evaluate the health impacts and the residence time in the environment. PMID:23989894

  14. Emission of spherical cesium-bearing particles from an early stage of the Fukushima nuclear accident

    PubMed Central

    Adachi, Kouji; Kajino, Mizuo; Zaizen, Yuji; Igarashi, Yasuhito

    2013-01-01

    The Fukushima nuclear accident released radioactive materials into the environment over the entire Northern Hemisphere in March 2011, and the Japanese government is spending large amounts of money to clean up the contaminated residential areas and agricultural fields. However, we still do not know the exact physical and chemical properties of the radioactive materials. This study directly observed spherical Cs-bearing particles emitted during a relatively early stage (March 14–15) of the accident. In contrast to the Cs-bearing radioactive materials that are currently assumed, these particles are larger, contain Fe, Zn, and Cs, and are water insoluble. Our simulation indicates that the spherical Cs-bearing particles mainly fell onto the ground by dry deposition. The finding of the spherical Cs particles will be a key to understand the processes of the accident and to accurately evaluate the health impacts and the residence time in the environment. PMID:23989894

  15. Predicted spatio-temporal dynamics of radiocesium deposited onto forests following the Fukushima nuclear accident

    PubMed Central

    Hashimoto, Shoji; Matsuura, Toshiya; Nanko, Kazuki; Linkov, Igor; Shaw, George; Kaneko, Shinji

    2013-01-01

    The majority of the area contaminated by the Fukushima Dai-ichi nuclear power plant accident is covered by forest. To facilitate effective countermeasure strategies to mitigate forest contamination, we simulated the spatio-temporal dynamics of radiocesium deposited into Japanese forest ecosystems in 2011 using a model that was developed after the Chernobyl accident in 1986. The simulation revealed that the radiocesium inventories in tree and soil surface organic layer components drop rapidly during the first two years after the fallout. Over a period of one to two years, the radiocesium is predicted to move from the tree and surface organic soil to the mineral soil, which eventually becomes the largest radiocesium reservoir within forest ecosystems. Although the uncertainty of our simulations should be considered, the results provide a basis for understanding and anticipating the future dynamics of radiocesium in Japanese forests following the Fukushima accident. PMID:23995073

  16. A dose-reconstruction study of the 1997 Sarov criticality accident using animated dosimetry techniques.

    PubMed

    Vazquez, Justin A; Ding, Aiping; Haley, Thomas; Caracappa, Peter F; Xu, X George

    2014-05-01

    Most computational human phantoms are static, representing a standing individual. There are, however, cases when these phantoms fail to represent accurately the detailed effects on dose that result from considering varying human posture and even whole sequences of motion. In this study, the feasibility of a dynamic and deformable phantom is demonstrated with the development of the Computational Human for Animated Dosimetry (CHAD) phantom. Based on modifications to the limb structure of the previously developed RPI Adult Male, CHAD's posture is adjustable using an optical motion capture system that records real-life human movement. To demonstrate its ability to produce dose results that reflect the changes brought about by posture-deformation, CHAD is employed to perform a dose-reconstruction analysis of the 1997 Sarov criticality accident, and a simulated total body dose of 13.3 Gy is observed, with the total body dose rate dropping from 1.4 Gy s to 0.25 Gy s over the first 4 s of retreat time. Additionally, dose measurements are calculated for individual organs and body regions, including a 36.8-Gy dose to the breast tissue, a 3.8-Gy dose to the bladder, and a 31.1-Gy dose to the thyroid, as well as the changes in dose rates for the individual organs over the course of the accident sequence. Comparison of results obtained using CHAD in an animated dosimetry simulation with reported information on dose and the medical outcome of the case shows that the consideration of posture and movement in dosimetry simulation allows for more detailed and precise analysis of dosimetry information, consideration of the evolution of the dose profile over time in the course of a given scenario, and a better understanding of the physiological impacts of radiation exposure for a given set of circumstances. PMID:24670906

  17. Effect of the Fukushima nuclear accident on the risk perception of residents near a nuclear power plant in China

    PubMed Central

    Huang, Lei; Zhou, Ying; Han, Yuting; Hammitt, James K.; Bi, Jun; Liu, Yang

    2013-01-01

    We assessed the influence of the Fukushima nuclear accident (FNA) on the Chinese public’s attitude and acceptance of nuclear power plants in China. Two surveys (before and after the FNA) were administered to separate subsamples of residents near the Tianwan nuclear power plant in Lianyungang, China. A structural equation model was constructed to describe the public acceptance of nuclear power and four risk perception factors: knowledge, perceived risk, benefit, and trust. Regression analysis was conducted to estimate the relationship between acceptance of nuclear power and the risk perception factors while controlling for demographic variables. Meanwhile, we assessed the median public acceptable frequencies for three levels of nuclear events. The FNA had a significant impact on risk perception of the Chinese public, especially on the factor of perceived risk, which increased from limited risk to great risk. Public acceptance of nuclear power decreased significantly after the FNA. The most sensitive groups include females, those not in public service, those with lower income, and those living close to the Tianwan nuclear power plant. Fifty percent of the survey respondents considered it acceptable to have a nuclear anomaly no more than once in 50 y. For nuclear incidents and serious incidents, the frequencies are once in 100 y and 150 y, respectively. The change in risk perception and acceptance may be attributed to the FNA. Decreased acceptance of nuclear power after the FNA among the Chinese public creates additional obstacles to further development of nuclear power in China and require effective communication strategies. PMID:24248341

  18. Weather and Dispersion Modeling of the Fukushima Daiichi Nuclear Power Station Accident

    NASA Astrophysics Data System (ADS)

    Dunn, Thomas; Businger, Steven

    2014-05-01

    The surface deposition of radioactive material from the accident at the Fukushima Daiichi nuclear power station was investigated for 11 March to 17 March 2011. A coupled weather and dispersion modeling system was developed and simulations of the accident performed using two independent source terms that differed in emission rate and height and in the total amount of radioactive material released. Observations in Japan during the first week of the accident revealed a natural grouping between periods of dry (12-14 March) and wet (15-17 March) weather. The distinct weather regimes served as convenient validation periods for the model predictions. Results show significant differences in the distribution of cumulative surface deposition of 137Cs due to wet and dry removal processes. A comparison of 137Cs deposition predicted by the model with aircraft observations of surface-deposited gamma radiation showed reasonable agreement in surface contamination patterns during the dry phase of the accident for both source terms. It is suggested that this agreement is because of the weather model's ability to simulate the extent and timing of onshore flow associated with a sea breeze circulation that developed around the time of the first reactor explosion. During the wet phase of the accident the pattern is not as well predicted. It is suggested that this discrepancy is because of differences between model predicted and observed precipitation distributions.

  19. Chernobyl and Fukushima nuclear accidents: what has changed in the use of atmospheric dispersion modeling?

    PubMed

    Benamrane, Y; Wybo, J-L; Armand, P

    2013-12-01

    The threat of a major accidental or deliberate event that would lead to hazardous materials emission in the atmosphere is a great cause of concern to societies. This is due to the potential large scale of casualties and damages that could result from the release of explosive, flammable or toxic gases from industrial plants or transport accidents, radioactive material from nuclear power plants (NPPs), and chemical, biological, radiological or nuclear (CBRN) terrorist attacks. In order to respond efficiently to such events, emergency services and authorities resort to appropriate planning and organizational patterns. This paper focuses on the use of atmospheric dispersion modeling (ADM) as a support tool for emergency planning and response, to assess the propagation of the hazardous cloud and thereby, take adequate counter measures. This paper intends to illustrate the noticeable evolution in the operational use of ADM tools over 25 y and especially in emergency situations. This study is based on data available in scientific publications and exemplified using the two most severe nuclear accidents: Chernobyl (1986) and Fukushima (2011). It appears that during the Chernobyl accident, ADM were used few days after the beginning of the accident mainly in a diagnosis approach trying to reconstruct what happened, whereas 25 y later, ADM was also used during the first days and weeks of the Fukushima accident to anticipate the potentially threatened areas. We argue that the recent developments in ADM tools play an increasing role in emergencies and crises management, by supporting stakeholders in anticipating, monitoring and assessing post-event damages. However, despite technological evolutions, its prognostic and diagnostic use in emergency situations still arise many issues. PMID:24077309

  20. SAMPSON Parallel Computation for Sensitivity Analysis of TEPCO's Fukushima Daiichi Nuclear Power Plant Accident

    NASA Astrophysics Data System (ADS)

    Pellegrini, M.; Bautista Gomez, L.; Maruyama, N.; Naitoh, M.; Matsuoka, S.; Cappello, F.

    2014-06-01

    On March 11th 2011 a high magnitude earthquake and consequent tsunami struck the east coast of Japan, resulting in a nuclear accident unprecedented in time and extents. After scram started at all power stations affected by the earthquake, diesel generators began operation as designed until tsunami waves reached the power plants located on the east coast. This had a catastrophic impact on the availability of plant safety systems at TEPCO's Fukushima Daiichi, leading to the condition of station black-out from unit 1 to 3. In this article the accident scenario is studied with the SAMPSON code. SAMPSON is a severe accident computer code composed of hierarchical modules to account for the diverse physics involved in the various phases of the accident evolution. A preliminary parallelization analysis of the code was performed using state-of-the-art tools and we demonstrate how this work can be beneficial to the nuclear safety analysis. This paper shows that inter-module parallelization can reduce the time to solution by more than 20%. Furthermore, the parallel code was applied to a sensitivity study for the alternative water injection into TEPCO's Fukushima Daiichi unit 3. Results show that the core melting progression is extremely sensitive to the amount and timing of water injection, resulting in a high probability of partial core melting for unit 3.

  1. The impact of the Fukushima nuclear accident on marine biota: retrospective assessment of the first year and perspectives.

    PubMed

    Vives I Batlle, Jordi; Aono, Tatsuo; Brown, Justin E; Hosseini, Ali; Garnier-Laplace, Jacqueline; Sazykina, Tatiana; Steenhuisen, Frits; Strand, Per

    2014-07-15

    An international study under the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) was performed to assess radiological impact of the nuclear accident at the Fukushima-Daiichi Nuclear Power Station (FDNPS) on the marine environment. This work constitutes the first international assessment of this type, drawing upon methodologies that incorporate the most up-to-date radioecological models and knowledge. To quantify the radiological impact on marine wildlife, a suite of state-of-the-art approaches to assess exposures to Fukushima derived radionuclides of marine biota, including predictive dynamic transfer modelling, was applied to a comprehensive dataset consisting of over 500 sediment, 6000 seawater and 5000 biota data points representative of the geographically relevant area during the first year after the accident. The dataset covers the period from May 2011 to August 2012. The method used to evaluate the ecological impact consists of comparing dose (rates) to which living species of interest are exposed during a defined period to critical effects values arising from the literature. The assessed doses follow a highly variable pattern and generally do not seem to indicate the potential for effects. A possible exception of a transient nature is the relatively contaminated area in the vicinity of the discharge point, where effects on sensitive endpoints in individual plants and animals might have occurred in the weeks directly following the accident. However, impacts on population integrity would have been unlikely due to the short duration and the limited space area of the initially high exposures. Our understanding of the biological impact of radiation on chronically exposed plants and animals continues to evolve, and still needs to be improved through future studies in the FDNPS marine environment. PMID:24784739

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

    SciTech Connect

    McMahan, K.L.; Schwanke, L.J.

    1996-12-01

    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.

  3. Atmospheric radionuclides transported to Fukuoka, Japan remote from the Fukushima Dai-ichi nuclear power complex following the nuclear accident.

    PubMed

    Momoshima, N; Sugihara, S; Ichikawa, R; Yokoyama, H

    2012-09-01

    Radionuclides were detected from the Fukushima nuclear accident at Fukuoka, Japan, 1000 km west of the Fukushima Dai-ichi nuclear power complex. Iodine-131 was first detected 3 d after the accident, indicating that it was probably transported dispersively because of local meteorological conditions, and not global air circulation. The maximum concentrations, 5.07 mBq m(-3) for (131)I, 4.04 mBq m(-3) for (134)Cs, and 4.12 mBq m(-3) for (137)Cs, were recorded in particles collected on April 6, 2011. However, these concentration levels decreased below the detection limit by April 26, 2011. Gaseous (131)I accounted for 30%-67% of the total (131)I content. The increase in dose by inhalation was negligible at Fukuoka. PMID:21962481

  4. Examination of criticality accident alarm coverage on the operating floors of Buildings X-333, X-330, and X-326 at the Portsmouth Gaseous Diffusion Plant. Revision 1

    SciTech Connect

    Brown, A.S.; Tayloe, R.W. Jr.; Wollard, J.; Dobelbower, M.C.

    1997-03-01

    The diffusion cascade processing equipment at the Portsmouth Gaseous Diffusion Plant (PORTS) is located in Buildings X-333, X-330, and X-326. These buildings were referred to as the cascade buildings. Because enriched uranium operations are performed within the cascade buildings, the potential for a criticality accident in these buildings exists. A Criticality Accident Alarm System (CAAS) is in place to alarm in the event of a criticality accident. The CAAS is required to be designed to immediately detect the minimum accident-of-concern. A minimum accident-of-concern in an area with nominal shielding delivers the equivalent of an absorbed dose rate in free air of 20 rads per minute at a distance of 2 meters from the reacting material [Am86]. This report summarizes the analysis that was performed to evaluate the CAAS response to selected minimum accidents-of-concern on the operating floor of the cascade buildings. Selection of potential accident locations was based, in part, on the maximum distance to the closest CAAS detector. The other factor in selecting potential accident locations for analysis was the amount of intervening shielding between the accident location and CAAS detector. If the CAAS was predicted to alarm under conditions of significant shielding, then the system presumably would alarm in response to all accidents greater than the minimum accident-of-concern, at closer distances, and with less shielding.

  5. Nuclear criticality safety engineer qualification program utilizing SAT

    SciTech Connect

    Baltimore, C.J.; Dean, J.C.; Henson, T.L.

    1996-12-31

    As part of the privatization process of the U.S. uranium enrichment plants, the Paducah Gaseous Diffusion Plant (PGDP) and the Portsmouth Gaseous Diffusion Plant (PORTS) have been in transition from U.S. Department of Energy (DOE) regulatory oversight to U.S. Nuclear Regulatory Commission (NRC) oversight since July 1993. One of the focus areas of this transition has been training and qualification of plant personnel who perform tasks important to nuclear safety, such as nuclear criticality safety (NCS) engineers.

  6. Proceedings of the Nuclear Criticality Technology and Safety Project Workshop

    SciTech Connect

    Sanchez, R.G.

    1994-01-01

    This report is the proceedings of the annual Nuclear Criticality Technology and Safety Project (NCTSP) Workshop held in Monterey, California, on April 16--28, 1993. The NCTSP was sponsored by the Department of Energy and organized by the Los Alamos Critical Experiments Facility. The report is divided into six sections reflecting the sessions outlined on the workshop agenda.

  7. [Personal computer interactive algorithm for estimating radiologic contamination and doses after a nuclear accident in Europe].

    PubMed

    Tabet, E

    2001-01-01

    The algorithm RANA (radiological assessment of nuclear accidents) is a tool which can be exploited to estimate the space and time structure of the radiological consequences of a radioactive release following a nuclear accident in Europe. The algorithm, formulated in the language of Mathematica, can be run on a personal computer. It uses simplified physical assumptions as for the the diffusion of the cloud and the transfer of the contamination to the food chain. The user gets the needed information by means of interactive windows that allow a fast evaluation of dose and contamination profiles. Calculations are performed either starting from the source terms or from the knowledge of experimental contamination data. Radiological consequences, such as individual or collective doses from several exposure paths, are parametrized in terms of the atmospheric diffusion categories. PMID:11758278

  8. Using cost/risk procedures to establish recovery criteria following a nuclear reactor accident.

    PubMed

    Tawil, J J; Strenge, D L

    1987-02-01

    In the event of a major accidental release of radionuclides at a nuclear power plant, large populated areas could become seriously contaminated. Local officials would be responsible for establishing radiation recovery criteria that would permit the evacuated population to return safely to their jobs and homes. The range of acceptable criteria could imply variations in property losses in the billions of dollars. Given the likely public concern over the health consequences and the enormity of the potential property losses, a cost/risk analysis can provide important input to establishing the recovery criteria. This paper describes procedures for conducting a cost/risk analysis of a site radiologically contaminated by a nuclear power plant accident. The procedures are illustrated by analyzing a hypothetically contaminated site, using software developed for determining the property and health effects of major reactor accidents. PMID:3818283

  9. Input-output model for MACCS nuclear accident impacts estimation¹

    SciTech Connect

    Outkin, Alexander V.; Bixler, Nathan E.; Vargas, Vanessa N

    2015-01-27

    Since the original economic model for MACCS was developed, better quality economic data (as well as the tools to gather and process it) and better computational capabilities have become available. The update of the economic impacts component of the MACCS legacy model will provide improved estimates of business disruptions through the use of Input-Output based economic impact estimation. This paper presents an updated MACCS model, bases on Input-Output methodology, in which economic impacts are calculated using the Regional Economic Accounting analysis tool (REAcct) created at Sandia National Laboratories. This new GDP-based model allows quick and consistent estimation of gross domestic product (GDP) losses due to nuclear power plant accidents. This paper outlines the steps taken to combine the REAcct Input-Output-based model with the MACCS code, describes the GDP loss calculation, and discusses the parameters and modeling assumptions necessary for the estimation of long-term effects of nuclear power plant accidents.

  10. Reactions of psychiatric patients to the Three Mile Island nuclear accident

    SciTech Connect

    Bromet, E.; Schulberg, H.C.; Dunn, L.

    1982-06-01

    The reaction of patients in the community mental health system to the nuclear accident at Three Mile Island (TMI), Middletown, Pa, were assessed. The sample was composed of 151 patients from the TMI area and 64 patients from a comparison site where a similar nuclear plant is located. Mental health status was determined for the period immediately after the accident, nine to ten months later, and one year later. No significant differences were found between the TMI group and the comparison group. To isolate risk factors within the TMI group, patients who were most distressed were compared with patients with the least distress. The results showed that quality of network support and viewing TMI as dangerous were significantly associated with mental health.

  11. Reactions of psychiatric patients to the Three Mile Island nuclear accident.

    PubMed

    Bromet, E; Schulberg, H C; Dunn, L

    1982-06-01

    The reaction of patients in the community mental health system to the nuclear accident at Three Mile Island (TMI), Middletown, Pa, were assessed. The sample was composed of 151 patients from the TMI area and 64 patients from a comparison site where a similar nuclear plant is located. Mental health status was determined for the period immediately after the accident, nine to ten months later, and one year later. No significant differences were found between the TMI group and the comparison group. To isolate risk factors within the TMI group, patients who were most distressed were compared with patients with the least distress. The results showed that quality of network support and viewing TMI as dangerous were significantly associated with mental health. PMID:7092506

  12. Fission products behaviour in UO2 submitted to nuclear severe accident conditions

    NASA Astrophysics Data System (ADS)

    Geiger, E.; Bès, R.; Martin, P.; Pontillon, Y.; Solari, P. L.; Salome, M.

    2016-05-01

    The objective of this work was to study the molybdenum chemistry in UO2 based materials, known as SIMFUELS. These materials could be used as an alternative to irradiated nuclear fuels in the study of fission products behaviour during a nuclear severe accident. UO2 samples doped with 12 stable isotopes of fission products were submitted to annealing tests in conditions representative to intermediate steps of severe accidents. Samples were characterized by SEM-EDS and XAS. It was found that Mo chemistry seems to be more complex than what is normally estimated by thermodynamic calculations: XAS spectra indicate the presence of Mo species such as metallic Mo, MoO2, MoO3 and Cs2MoO4.

  13. Aerosol Sample Inhomogeneity with Debris from the Fukushima Daiichi Nuclear Accident

    SciTech Connect

    Gomez, Reynaido; Biegalski, Steven R.; Woods, Vincent T.

    2014-09-01

    Radionuclide aerosol sampling is a vital component in the detection of nuclear explosions, nuclear accidents, and other radiation releases. This was proven by the detection and tracking of emissions from the Fukushima Daiichi incident across the globe by IMS stations. Two separate aerosol samplers were operated in Richland, WA following the event and debris from the accident were measured at levels well above detection limits. While the atmospheric activity concentration of radionuclides generally compared well between the two stations, they did not agree within uncertainties. This paper includes a detailed study of the aerosol sample homogeneity of 134Cs and 137Cs, then relates it to the overall uncertainty of the original measurement. Our results show that sample inhomogeneity adds an additional 5–10% uncertainty to each aerosol measurement and that this uncertainty is in the same range as the discrepancies between the two aerosol sample measurements from Richland, WA.

  14. Phase-Change Modelling in Severe Nuclear Accidents

    NASA Astrophysics Data System (ADS)

    Pain, Christopher; Pavlidis, Dimitrios; Xie, Zhihua; Percival, James; Gomes, Jefferson; Matar, Omar; Moatamedi, Moji; Tehrani, Ali; Jones, Alan; Smith, Paul

    2014-11-01

    This paper describes progress on a consistent approach for multi-phase flow modelling with phase-change. Although, the developed methods are general purpose the applications presented here cover core melt phenomena at the lower vessel head. These include corium pool formation, coolability and solidification. With respect to external cooling, comparison with the LIVE experiments (from Karlsruhe) is undertaken. Preliminary re-flooding simulation results are also presented. These include water injection into porous media (debris bed) and boiling. Numerical simulations follow IRSN's PEARL experimental programme on quenching/re-flooding. The authors wish to thank Prof. Timothy Haste of IRSN. Dr. D. Pavlidis is funded by EPSRC Consortium ``Computational Modelling for Advanced Nuclear Plants,'' Grant Number EP/I003010/1.

  15. Two-Phase flow instrumentation for nuclear accidents simulation

    NASA Astrophysics Data System (ADS)

    Monni, G.; De Salve, M.; Panella, B.

    2014-11-01

    The paper presents the research work performed at the Energy Department of the Politecnico di Torino, concerning the development of two-phase flow instrumentation and of models, based on the analysis of experimental data, that are able to interpret the measurement signals. The study has been performed with particular reference to the design of power plants, such as nuclear water reactors, where the two-phase flow thermal fluid dynamics must be accurately modeled and predicted. In two-phase flow typically a set of different measurement instruments (Spool Piece - SP) must be installed in order to evaluate the mass flow rate of the phases in a large range of flow conditions (flow patterns, pressures and temperatures); moreover, an interpretative model of the SP need to be developed and experimentally verified. The investigated meters are: Turbine, Venturi, Impedance Probes, Concave sensors, Wire mesh sensor, Electrical Capacitance Probe. Different instrument combinations have been tested, and the performance of each one has been analyzed.

  16. Full-Scale Accident Testing in Support of Used Nuclear Fuel Transportation.

    SciTech Connect

    Durbin, Samuel G.; Lindgren, Eric R.; Rechard, Rob P.; Sorenson, Ken B.

    2014-09-01

    The safe transport of spent nuclear fuel and high-level radioactive waste is an important aspect of the waste management system of the United States. The Nuclear Regulatory Commission (NRC) currently certifies spent nuclear fuel rail cask designs based primarily on numerical modeling of hypothetical accident conditions augmented with some small scale testing. However, NRC initiated a Package Performance Study (PPS) in 2001 to examine the response of full-scale rail casks in extreme transportation accidents. The objectives of PPS were to demonstrate the safety of transportation casks and to provide high-fidelity data for validating the modeling. Although work on the PPS eventually stopped, the Blue Ribbon Commission on America’s Nuclear Future recommended in 2012 that the test plans be re-examined. This recommendation was in recognition of substantial public feedback calling for a full-scale severe accident test of a rail cask to verify evaluations by NRC, which find that risk from the transport of spent fuel in certified casks is extremely low. This report, which serves as the re-assessment, provides a summary of the history of the PPS planning, identifies the objectives and technical issues that drove the scope of the PPS, and presents a possible path for moving forward in planning to conduct a full-scale cask test. Because full-scale testing is expensive, the value of such testing on public perceptions and public acceptance is important. Consequently, the path forward starts with a public perception component followed by two additional components: accident simulation and first responder training. The proposed path forward presents a series of study options with several points where the package performance study could be redirected if warranted.

  17. Determination of possible damage/degradation of the Sandia National Laboratories Personal Nuclear Accident Dosimeter (PNAD).

    SciTech Connect

    Potter, Charles Augustus; Ward, Dann C.

    2008-05-01

    This report describes the results of an inspection performed on the existing stock of SNL Personal Nuclear Accident Dosimeters (PNADs). The current stock is approximately 20 years old, and has not been examined since their initial acceptance. A small random sample of PNADs were opened (a destructive process) and the contents visually examined. Sample contents were not degraded and indicate that the existing stock of SNL PNADs is acceptable for continued use.

  18. Web-based nuclear criticality safety bibliographic database

    SciTech Connect

    Koponen, B L; Huang, S T

    2000-06-21

    The Lawrence Livermore National Laboratory has prepared a Nuclear Criticality Safety Bibliographic Database that is now available via the Internet. This database is a component of the U.S. DOE Nuclear Criticality Safety Program (NCSP) Web site. This WWW resource was developed as part of the DOE response to the DNFSB Recommendation 97-2, which reflected the need to make criticality safety information available to a wide audience. To the extent possible, the hyperlinks on the Web pages direct the user to original source of the reference material in order to ensure accuracy and access to the latest versions. A master index is in place for simple navigation through the site. A search capability is available to assist in locating the on-line reference materials. Among the features included are: A user-friendly site map for ease of use; A personnel registry; Links to all major laboratories and organizations involved in the many aspects of criticality safety; General help for new criticality safety practitioners, including basic technical references and training modules; A discussion of computational methods; An interactive question and answer forum for the criticality safety community; and Collections of bibliographic references mdvahdation experiments. This paper will focus on the bibliographic database. This database evolved from earlier work done by the DOE's Nuclear Criticality Information System (NCIS) maintained at LLNL during the 1980s. The bibliographic database at the time of the termination of NCIS were composed principally of three parts: (1) A critical experiment bibliography of 1067 citations (reported in UCRL-52769); (2) A compilation of criticality safety papers from Volumes 1 through 41 of the Transactions of the American Nuclear Society (reported in UCRL-53369); and (3) A general criticality bibliography of several thousand citations (unpublished). When the NCIS project was terminated the database was nearly lost but, fortunately, several years later

  19. Criticality accident dosimetry systems: an international intercomparison at the SILENE reactor in 2002.

    PubMed

    Médioni, R; Asselineau, B; Verrey, B; Trompier, F; Itié, C; Texier, C; Muller, H; Pelcot, G; Clairand, I; Jacquet, X; Pochat, J L

    2004-01-01

    In criticality accident dosimetry and more generally for high dose measurements, special techniques are used to measure separately the gamma ray and neutron components of the dose. To improve these techniques and to check their dosimetry systems (physical and/or biological), a total of 60 laboratories from 29 countries (America, Europe, Asia) participated in an international intercomparaison, which took place in France from 9 to 21 June 2002, at the SILENE reactor in Valduc and at a pure gamma source in Fontenay-aux-Roses. This intercomparison was jointly organised by the IRSN and the CEA with the help of the NEA/OCDE and was partly supported by the European Communities. This paper describes the aim of this intercomparison, the techniques used by the participants and the two radiation sources and their characteristics. The experimental arrangements of the dosemeters for the irradiations in free air or on phantoms are given. Then the dosimetric quantities measured and reported by the participants are summarised, analysed and compared with the reference values. The present paper concerns only the physical dosimetry and essentially experiments performed on the SILENE facility. The results obtained with the biological dosimetry are published in two other papers of this issue. PMID:15353686

  20. Computation of cross sections and dose conversion factors for criticality accident dosimetry.

    PubMed

    Devine, R T

    2004-01-01

    In the application of criticality accident dosemeters the cross sections and fluence-to-dose conversion factors have to be computed. The cross section and fluence-to-dose conversion factor for the thermal and epi-thermal contributions to neutron dose are well documented; for higher energy regions (>100 keV) these depend on the spectrum assumed. Fluence is determined using threshold detectors. The cross sections require the folding of an expected spectrum with the reaction cross sections. The fluence-to-dose conversion factors also require a similar computation. The true and effective thresholds are used to include the information on the expected spectrum. The spectra can either be taken from compendia or measured at the facility at which the exposures are to be expected. The cross sections can be taken from data computations or analytic representations and the fluence-to-dose conversion factors are determined by various standards making bodies. The problem remaining is the method of computation. The purpose of this paper is to compare two methods for computing these factors: analytic and Monte Carlo. PMID:15353697

  1. Fractal Dimensions for Radioisotope Pollution Patterns by Nuclear Power Plant Accidents

    NASA Astrophysics Data System (ADS)

    Saito, K.; Ogawa, S.

    2015-04-01

    The radioisotope pollution shows two types of patterns: dry and wet deposits for nuclear power plant accidents. Two surface pollution patterns were analysed by fractal. In Fukushima nuclear power plant accident, surface pollution by wet deposits was estimated to occur. However, actually it was no rain and white crystals were observed on the surface. Then, fractal analysis was carried out for the spatial distribution patterns of radio isotopes on the surface to judge the types of deposits. As a reference, Chernobyl nuclear power plant accident was checked for the spatial distribution patterns of radioisotopes on the surface. The objective patterns by fractal analysis were the surface pollution maps in Fukushima and Chernobyl, Abukuma river watershed map, and NOAA/AVHRR. The calculation of fractal dimensions was carried out with the box counting for binarized images. Fractal analysis results suggested the next conclusions. The radioisotope pollution in Fukushima might occur in both dry and wet deposits. The dry deposit might make the pollution pattern similar to the watershed, while the wet deposit might make the pollution pattern similar to cloud images. Moreover, most radioisotope contaminants might flow on the road in the forest valley and deposit on forest with and without rainfall in Fukushima.

  2. Criticality safety assessment of a TRIGA reactor spent-fuel pool under accident conditions

    SciTech Connect

    Glumac, B; Ravnik, M.; Logar, M.

    1997-02-01

    Additional criticality safety analysis of a pool-type storage for TRIGA spent fuel at the Jozef Stefan Institute in Ljubljana, Slovenia, is presented. Previous results have shown that subcriticality is not guaranteed for some postulated accidents (earthquake with subsequent fuel rack disintegration resulting in contact fuel pitch) under the assumption that the fuel rack is loaded with fresh 12 wt% standard fuel. To mitigate this deficiency, a study was done on replacing a certain number of fuel elements in the rack with cadmium-loaded absorber rods. The Monte Carlo computer code MCNP4A with an ENDF/B-V library and detailed three-dimensional geometrical model of the spent-fuel rack was used for this purpose. First, a minimum critical number of fuel elements was determined for contact pitch, and two possible geometries of rack disintegration were considered. Next, it was shown that subcriticality can be ensured when pitch is decreased from a rack design pitch of 8 cm to contact, if a certain number of fuel elements (8 to 20 out of 70) are replaced by absorber rods, which are uniformly mixed into the lattice. To account for the possibility that random mixing of fuel elements and absorber rods can occur during rack disintegration and result in a supercritical configuration, a probabilistic study was made to sample the probability density functions for random absorber rod lattice loadings. Results of the calculations show that reasonably low probabilities for supercriticality can be achieved (down to 10{sup {minus}6} per severe earthquake, which would result in rack disintegration and subsequent maximum possible pitch decrease) even in the case where fresh 12 wt% standard TRIGA fuel would be stored in the spent-fuel pool.

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

    SciTech Connect

    Feng, Y.; Miller, L.F.; Brown, K.S.; Casson, W.H.; Mei, G.T.; Thein, M.

    1993-06-01

    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 {sup 24}Na in blood and {sup 32}P in hair for nuclear accident dosimetry. An operating procedure was established for the measurement of {sup 24}Na 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 {sup 32}P in hair and {sup 24}Na in blood can provide information related to the neutron spectrum for dose assessment.

  4. Fukushima Daiichi Nuclear Power Plant accident: facts, environmental contamination, possible biological effects, and countermeasures.

    PubMed

    Anzai, Kazunori; Ban, Nobuhiko; Ozawa, Toshihiko; Tokonami, Shinji

    2012-01-01

    On March 11, 2011, an earthquake led to major problems at the Fukushima Daiichi Nuclear Power Plant. A 14-m high tsunami triggered by the earthquake disabled all AC power to Units 1, 2, and 3 of the Power Plant, and carried off fuel tanks for emergency diesel generators. Despite many efforts, cooling systems did not work and hydrogen explosions damaged the facilities, releasing a large amount of radioactive material into the environment. In this review, we describe the environmental impact of the nuclear accident, and the fundamental biological effects, acute and late, of the radiation. Possible medical countermeasures to radiation exposure are also discussed. PMID:22247595

  5. Fukushima Daiichi Nuclear Power Plant accident: facts, environmental contamination, possible biological effects, and countermeasures

    PubMed Central

    Anzai, Kazunori; Ban, Nobuhiko; Ozawa, Toshihiko; Tokonami, Shinji

    2012-01-01

    On March 11, 2011, an earthquake led to major problems at the Fukushima Daiichi Nuclear Power Plant. A 14-m high tsunami triggered by the earthquake disabled all AC power to Units 1, 2, and 3 of the Power Plant, and carried off fuel tanks for emergency diesel generators. Despite many efforts, cooling systems did not work and hydrogen explosions damaged the facilities, releasing a large amount of radioactive material into the environment. In this review, we describe the environmental impact of the nuclear accident, and the fundamental biological effects, acute and late, of the radiation. Possible medical countermeasures to radiation exposure are also discussed. PMID:22247595

  6. Hospital organizational response to the nuclear accident at Three Mile Island: implications for future-oriented disaster planning.

    PubMed Central

    Maxwell, C

    1982-01-01

    The 1979 nuclear accident at Three Mile Island (TMI) near Harrisburg, Pennsylvania, caused severe organizational problems for neighboring health care institutions. Dauphin County, just north of TMI, contained four hospitals ranging in distance from 9.5 to 13.5 miles from the stricken plant. Crash plans put into effect within 48 hours of the initial incident successfully reduced hospital census to below 50 per cent of capacity, but retained bedridden and critically ill patients within the risk-zone. No plans existed for area-wide evacuation of hospitalized patients. Future-oriented disaster planning should include resource files of host institution bed capacity and transportation capabilities for the crash evacuation of hospitalized patients during non-traditional disasters. PMID:7058968

  7. Hospital organizational response to the nuclear accident at Three Mile Island: implications for future-oriented disaster planning.

    PubMed

    Maxwell, C

    1982-03-01

    The 1979 nuclear accident at Three Mile Island (TMI) near Harrisburg, Pennsylvania, caused severe organizational problems for neighboring health care institutions. Dauphin County, just north of TMI, contained four hospitals ranging in distance from 9.5 to 13.5 miles from the stricken plant. Crash plans put into effect within 48 hours of the initial incident successfully reduced hospital census to below 50 per cent of capacity, but retained bedridden and critically ill patients within the risk-zone. No plans existed for area-wide evacuation of hospitalized patients. Future-oriented disaster planning should include resource files of host institution bed capacity and transportation capabilities for the crash evacuation of hospitalized patients during non-traditional disasters. PMID:7058968

  8. Investigation of criticality safety control infraction data at a nuclear facility

    SciTech Connect

    Cournoyer, Michael E.; Merhege, James F.; Costa, David A.; Art, Blair M.; Gubernatis, David C.

    2014-10-27

    Chemical and metallurgical operations involving plutonium and other nuclear materials account for most activities performed at the LANL's Plutonium Facility (PF-4). The presence of large quantities of fissile materials in numerous forms at PF-4 makes it necessary to maintain an active criticality safety program. The LANL Nuclear Criticality Safety (NCS) Program provides guidance to enable efficient operations while ensuring prevention of criticality accidents in the handling, storing, processing and transportation of fissionable material at PF-4. In order to achieve and sustain lower criticality safety control infraction (CSCI) rates, PF-4 operations are continuously improved, through the use of Lean Manufacturing and Six Sigma (LSS) business practices. Employing LSS, statistically significant variations (trends) can be identified in PF-4 CSCI reports. In this study, trends have been identified in the NCS Program using the NCS Database. An output metric has been developed that measures ADPSM Management progress toward meeting its NCS objectives and goals. Using a Pareto Chart, the primary CSCI attributes have been determined in order of those requiring the most management support. Data generated from analysis of CSCI data help identify and reduce number of corresponding attributes. In-field monitoring of CSCI's contribute to an organization's scientific and technological excellence by providing information that can be used to improve criticality safety operation safety. This increases technical knowledge and augments operational safety.

  9. Investigation of criticality safety control infraction data at a nuclear facility

    DOE PAGESBeta

    Cournoyer, Michael E.; Merhege, James F.; Costa, David A.; Art, Blair M.; Gubernatis, David C.

    2014-10-27

    Chemical and metallurgical operations involving plutonium and other nuclear materials account for most activities performed at the LANL's Plutonium Facility (PF-4). The presence of large quantities of fissile materials in numerous forms at PF-4 makes it necessary to maintain an active criticality safety program. The LANL Nuclear Criticality Safety (NCS) Program provides guidance to enable efficient operations while ensuring prevention of criticality accidents in the handling, storing, processing and transportation of fissionable material at PF-4. In order to achieve and sustain lower criticality safety control infraction (CSCI) rates, PF-4 operations are continuously improved, through the use of Lean Manufacturing andmore » Six Sigma (LSS) business practices. Employing LSS, statistically significant variations (trends) can be identified in PF-4 CSCI reports. In this study, trends have been identified in the NCS Program using the NCS Database. An output metric has been developed that measures ADPSM Management progress toward meeting its NCS objectives and goals. Using a Pareto Chart, the primary CSCI attributes have been determined in order of those requiring the most management support. Data generated from analysis of CSCI data help identify and reduce number of corresponding attributes. In-field monitoring of CSCI's contribute to an organization's scientific and technological excellence by providing information that can be used to improve criticality safety operation safety. This increases technical knowledge and augments operational safety.« less

  10. RAPID RADIOCHEMICAL ANALYSES IN SUPPORT OF FUKUSHIMA NUCLEAR ACCIDENT

    SciTech Connect

    Maxwell, S.

    2012-11-07

    There is an increasing need to develop faster analytical methods for emergency response, including emergency soil and air filter samples. The Savannah River National Laboratory (SRNL) performed analyses on samples received from Japan in April, 2011 as part of a U.S. Department of Energy effort to provide assistance to the government of Japan, following the nuclear event at Fukushima Daiichi, resulting from the earthquake and tsunami on March 11, 2011. Of particular concern was whether it was safe to plant rice in certain areas (prefectures) near Fukushima. The primary objectives of the sample collection, sample analysis, and data assessment teams were to evaluate personnel exposure hazards, identify the nuclear power plant radiological source term and plume deposition, and assist the government of Japan in assessing any environmental and agricultural impacts associated with the nuclear event. SRNL analyzed approximately 250 samples and reported approximately 500 analytical method determinations. Samples included soil from farmland surrounding the Fukushima reactors and air monitoring samples of national interest, including those collected at the U.S. Embassy and American military bases. Samples were analyzed for a wide range of radionuclides, including strontium-89, strontium-90, gamma-emitting radionuclides, and plutonium, uranium, americium and curium isotopes. Technical aspects of the rapid soil and air filter analyses will be described. The extent of radiostrontium contamination was a significant concern. For {sup 89,90}Sr analyses on soil samples, a rapid fusion technique using 1.5 gram soil aliquots to enable a Minimum Detectable Activity (MDA) of <1 pCi {sup 89,90} Sr /g of soil was employed. This sequential technique has been published recently by this laboratory for actinides and radiostrontium in soil and vegetation. It consists of a rapid sodium hydroxide fusion, pre-concentration steps using iron hydroxide and calcium fluoride precipitations, followed

  11. Rapid Radiochemical Analyses in Support of Fukushima Nuclear Accident - 13196

    SciTech Connect

    Maxwell, Sherrod L.; Culligan, Brian K.; Hutchison, Jay B.

    2013-07-01

    There is an increasing need to develop faster analytical methods for emergency response, including emergency soil and air filter samples [1, 2]. The Savannah River National Laboratory (SRNL) performed analyses on samples received from Japan in April, 2011 as part of a U.S. Department of Energy effort to provide assistance to the government of Japan, following the nuclear event at Fukushima Daiichi, resulting from the earthquake and tsunami on March 11, 2011. Of particular concern was whether it was safe to plant rice in certain areas (prefectures) near Fukushima. The primary objectives of the sample collection, sample analysis, and data assessment teams were to evaluate personnel exposure hazards, identify the nuclear power plant radiological source term and plume deposition, and assist the government of Japan in assessing any environmental and agricultural impacts associated with the nuclear event. SRNL analyzed approximately 250 samples and reported approximately 500 analytical method determinations. Samples included soil from farmland surrounding the Fukushima reactors and air monitoring samples of national interest, including those collected at the U.S. Embassy and American military bases. Samples were analyzed for a wide range of radionuclides, including strontium-89, strontium-90, gamma-emitting radionuclides, and plutonium, uranium, americium and curium isotopes. Technical aspects of the rapid soil and air filter analyses will be described. The extent of radiostrontium contamination was a significant concern. For {sup 89,90}Sr analyses on soil samples, a rapid fusion technique using 1.5 gram soil aliquots to enable a Minimum Detectable Activity (MDA) of <1 pCi {sup 89,90}Sr /g of soil was employed. This sequential technique has been published recently by this laboratory for actinides and radiostrontium in soil and vegetation [3, 4]. It consists of a rapid sodium hydroxide fusion, pre-concentration steps using iron hydroxide and calcium fluoride

  12. Seminar in Critical Inquiry Twenty-first Century Nuclear Systems

    SciTech Connect

    LeMone, D. V.

    2002-02-25

    Critical Inquiry, has not only been successful in increasing university student retention rate but also in improving student academic performance beyond the initial year of transition into the University. The seminar course herein reviewed is a balanced combination of student personal and academic skill development combined with a solid background in modern nuclear systems. It is a valid premise to assume that entering students as well as stakeholders of the general public demonstrate equal levels of capability. Nuclear systems is designed to give a broad and basic knowledge of nuclear power, medical, industrial, research, and military systems (nuclear systems) in 20-25 hours.

  13. Fukushima Nuclear Accident: Sticking to the facts, not to the political correctness

    NASA Astrophysics Data System (ADS)

    Ohska, Tokio

    2014-05-01

    The Fukushima Nuclear Reactor disaster of 2011 is still a continuing disaster three years later, although some experts have proclaimed the 4 reactors being already under control. It is surely an incredibly difficult task to properly terminate nuclear accidents. However, I should point out that the process of termination plan has been marred by too much of politics and business messing up a scientific approach to do it in a rational way. This blame must to go to both pro-nuclear and anti-nuclear power people. It makes me feel sad to see people not respecting science in executing such a difficult task. I shall list up where things went wrong with the hope that this kind of action, as I do here, would trigger people to get back to science to straighten out the execution process. I will show a few examples of published papers presenting the opinion that it is inappropriate what the Japanese government considers to be safe.

  14. Radiological protection issues arising during and after the Fukushima nuclear reactor accident.

    PubMed

    González, Abel J; Akashi, Makoto; Boice, John D; Chino, Masamichi; Homma, Toshimitsu; Ishigure, Nobuhito; Kai, Michiaki; Kusumi, Shizuyo; Lee, Jai-Ki; Menzel, Hans-Georg; Niwa, Ohtsura; Sakai, Kazuo; Weiss, Wolfgang; Yamashita, Shunichi; Yonekura, Yoshiharu

    2013-09-01

    Following the Fukushima accident, the International Commission on Radiological Protection (ICRP) convened a task group to compile lessons learned from the nuclear reactor accident at the Fukushima Daiichi nuclear power plant in Japan, with respect to the ICRP system of radiological protection. In this memorandum the members of the task group express their personal views on issues arising during and after the accident, without explicit endorsement of or approval by the ICRP. While the affected people were largely protected against radiation exposure and no one incurred a lethal dose of radiation (or a dose sufficiently large to cause radiation sickness), many radiological protection questions were raised. The following issues were identified: inferring radiation risks (and the misunderstanding of nominal risk coefficients); attributing radiation effects from low dose exposures; quantifying radiation exposure; assessing the importance of internal exposures; managing emergency crises; protecting rescuers and volunteers; responding with medical aid; justifying necessary but disruptive protective actions; transiting from an emergency to an existing situation; rehabilitating evacuated areas; restricting individual doses of members of the public; caring for infants and children; categorising public exposures due to an accident; considering pregnant women and their foetuses and embryos; monitoring public protection; dealing with 'contamination' of territories, rubble and residues and consumer products; recognising the importance of psychological consequences; and fostering the sharing of information. Relevant ICRP Recommendations were scrutinised, lessons were collected and suggestions were compiled. It was concluded that the radiological protection community has an ethical duty to learn from the lessons of Fukushima and resolve any identified challenges. Before another large accident occurs, it should be ensured that inter alia: radiation risk coefficients of potential

  15. Comprehensive Health Risk Management after the Fukushima Nuclear Power Plant Accident.

    PubMed

    Yamashita, S

    2016-04-01

    Five years have passed since the Great East Japan Earthquake and the subsequent Fukushima Daiichi Nuclear Power Plant accident on 11 March 2011. Countermeasures aimed at human protection during the emergency period, including evacuation, sheltering and control of the food chain were implemented in a timely manner by the Japanese Government. However, there is an apparent need for improvement, especially in the areas of nuclear safety and protection, and also in the management of radiation health risk during and even after the accident. Continuous monitoring and characterisation of the levels of radioactivity in the environment and foods in Fukushima are now essential for obtaining informed consent to the decisions on living in the radio-contaminated areas and also on returning back to the evacuated areas once re-entry is allowed; it is also important to carry out a realistic assessment of the radiation doses on the basis of measurements. Until now, various types of radiation health risk management projects and research have been implemented in Fukushima, among which the Fukushima Health Management Survey is the largest health monitoring project. It includes the Basic Survey for the estimation of external radiation doses received during the first 4 months after the accident and four detailed surveys: thyroid ultrasound examination, comprehensive health check-up, mental health and lifestyle survey, and survey on pregnant women and nursing mothers, with the aim to prospectively take care of the health of all the residents of Fukushima Prefecture for a long time. In particular, among evacuees of the Fukushima Nuclear Power Plant accident, concern about radiation risk is associated with psychological stresses. Here, ongoing health risk management will be reviewed, focusing on the difficult challenge of post-disaster recovery and resilience in Fukushima. PMID:26817782

  16. Spontaneous abortions after the Three Mile Island nuclear accident: a life table analysis.

    PubMed

    Goldhaber, M K; Staub, S L; Tokuhata, G K

    1983-07-01

    A study was conducted to determine whether the incidence of spontaneous abortion was greater than expected near the Three Mile Island (TMI) nuclear power plant during the months following the March 28, 1979 accident. All persons living within five miles of TMI were registered shortly after the accident, and information on pregnancy at the time of the accident was collected. After one year, all pregnancy cases were followed up and outcomes ascertained. Using the life table method, it was found that, given pregnancies after four completed weeks of gestation counting from the first day of the last menstrual period, the estimated incidence of spontaneous abortion (miscarriage before completion of 16 weeks of gestation) was 15.1 per cent for women pregnant at the time of the TMI accident. Combining spontaneous abortions and stillbirths (delivery of a dead fetus after 16 weeks of gestation), the estimated incidence was 16.1 per cent for pregnancies after four completed weeks of gestation. Both incidences are comparable to baseline studies of fetal loss. PMID:6859357

  17. Spontaneous abortions after the Three Mile Island nuclear accident: a life table analysis

    SciTech Connect

    Goldhaber, M.K.; Staub, S.L.; Tokuhata, G.K.

    1983-07-01

    A study was conducted to determine whether the incidence of spontaneous abortion was greater than expected near the Three Mile Island (TMI) nuclear power plant during the months following the March 28, 1979 accident. All persons living within five miles of TMI were registered shortly after the accident, and information on pregnancy at the time of the accident was collected. After one year, all pregnancy cases were followed up and outcomes ascertained. Using the life table method, it was found that, given pregnancies after four completed weeks of gestation counting from the first day of the last menstrual period, the estimated incidence of spontaneous abortion (miscarriage before completion of 16 weeks of gestation) was 15.1 per cent for women pregnant at the time of the TMI accident. Combining spontaneous abortions and stillbirths (delivery of a dead fetus after 16 weeks of gestation), the estimated incidence was 16.1 per cent for pregnancies after four completed weeks of gestation. Both incidences are comparable to baseline studies of fetal loss.

  18. Nuclear accidents in the former Soviet Union: Kyshtym, Chelyabinsk and Chernobyl

    SciTech Connect

    Collins, D.L.

    1991-01-01

    Three nuclear accidents besides Chernobyl have occurred in the Former Soviet Union (FSU). The accidents occurred over the geographic area around Kyshtym and Chelyabinsk in the Urals between 1949 and 1967 and contaminated over half a million people. The first accident occurred in 1949-1951, the second on 29 September 1957, and the third in 1967, and involved the air transfer of irradiated sand particles. Although these accidents occurred between 25 and 43 years ago, the first official admission by the FSU was made in June 1989, and it was only during late November 1991 that the FSU declared a national disaster emergency concerning the affected area. The health ministries are now interested in data previously collected from these irradiated populations to examine health effects, including cancer, and genetic damage in humans. Data collected from these large populations and occupationally exposed workers offer a unique opportunity to quantify the adverse health effects of chronic exposure to fission products, reactor neutrons and environmental chemicals.

  19. Cancer rates after the Three Mile Island nuclear accident and proximity of residence to the plant.

    PubMed Central

    Hatch, M C; Wallenstein, S; Beyea, J; Nieves, J W; Susser, M

    1991-01-01

    BACKGROUND: In the light of a possible link between stress and cancer promotion or progression, and of previously reported distress in residents near the Three Mile Island (TMI) nuclear power plant, we attempted to evaluate the impact of the March 1979 accident on community cancer rates. METHODS: Proximity of residence to the plant, which related to distress in previous studies, was taken as a possible indicator of accident stress; the postaccident pattern in cancer rates was examined in 69 "study tracts" within a 10-mile radius of TMI, in relation to residential proximity. RESULTS: A modest association was found between postaccident cancer rates and proximity (OR = 1.4; 95% CI = 1.3, 1.6). After adjusting for a gradient in cancer risk prior to the accident, the odds ratio contrasting those closest to the plant with those living farther out was 1.2 (95% CI = 1.0, 1.4). A postaccident increase in cancer rates near the Three Mile Island plant was notable in 1982, persisted for another year, and then declined. Radiation emissions, as modeled mathematically, did not account for the observed increase. CONCLUSION: Interpretation in terms of accident stress is limited by the lack of an individual measure of stress and by uncertainty about whether stress has a biological effect on cancer in humans. An alternative mechanism for the cancer increase near the plant is through changes in care-seeking and diagnostic practice arising from postaccident concern. PMID:2029040

  20. Spontaneous abortions after the Three Mile Island nuclear accident: a life table analysis.

    PubMed Central

    Goldhaber, M K; Staub, S L; Tokuhata, G K

    1983-01-01

    A study was conducted to determine whether the incidence of spontaneous abortion was greater than expected near the Three Mile Island (TMI) nuclear power plant during the months following the March 28, 1979 accident. All persons living within five miles of TMI were registered shortly after the accident, and information on pregnancy at the time of the accident was collected. After one year, all pregnancy cases were followed up and outcomes ascertained. Using the life table method, it was found that, given pregnancies after four completed weeks of gestation counting from the first day of the last menstrual period, the estimated incidence of spontaneous abortion (miscarriage before completion of 16 weeks of gestation) was 15.1 per cent for women pregnant at the time of the TMI accident. Combining spontaneous abortions and stillbirths (delivery of a dead fetus after 16 weeks of gestation), the estimated incidence was 16.1 per cent for pregnancies after four completed weeks of gestation. Both incidences are comparable to baseline studies of fetal loss. PMID:6859357

  1. Management of Ultimate Risk of Nuclear Power Plants by Source Terms - Lessons Learned from the Chernobyl Accident

    SciTech Connect

    Genn Saji

    2006-07-01

    The term 'ultimate risk' is used here to describe the probabilities and radiological consequences that should be incorporated in siting, containment design and accident management of nuclear power plants for hypothetical accidents. It is closely related with the source terms specified in siting criteria which assures an adequate separation of radioactive inventories of the plants from the public, in the event of a hypothetical and severe accident situation. The author would like to point out that current source terms which are based on the information from the Windscale accident (1957) through TID-14844 are very outdated and do not incorporate lessons learned from either the Three Miles Island (TMI, 1979) nor Chernobyl accident (1986), two of the most severe accidents ever experienced. As a result of the observations of benign radionuclides released at TMI, the technical community in the US felt that a more realistic evaluation of severe reactor accident source terms was necessary. In this background, the 'source term research project' was organized in 1984 to respond to these challenges. Unfortunately, soon after the time of the final report from this project was released, the Chernobyl accident occurred. Due to the enormous consequences induced by then accident, the one time optimistic perspectives in establishing a more realistic source term were completely shattered. The Chernobyl accident, with its human death toll and dispersion of a large part of the fission fragments inventories into the environment, created a significant degradation in the public's acceptance of nuclear energy throughout the world. In spite of this, nuclear communities have been prudent in responding to the public's anxiety towards the ultimate safety of nuclear plants, since there still remained many unknown points revolving around the mechanism of the Chernobyl accident. In order to resolve some of these mysteries, the author has performed a scoping study of the dispersion and deposition

  2. Proceedings of the Nuclear Criticality Technology Safety Workshop

    SciTech Connect

    Rene G. Sanchez

    1998-04-01

    This document contains summaries of most of the papers presented at the 1995 Nuclear Criticality Technology Safety Project (NCTSP) meeting, which was held May 16 and 17 at San Diego, Ca. The meeting was broken up into seven sessions, which covered the following topics: (1) Criticality Safety of Project Sapphire; (2) Relevant Experiments For Criticality Safety; (3) Interactions with the Former Soviet Union; (4) Misapplications and Limitations of Monte Carlo Methods Directed Toward Criticality Safety Analyses; (5) Monte Carlo Vulnerabilities of Execution and Interpretation; (6) Monte Carlo Vulnerabilities of Representation; and (7) Benchmark Comparisons.

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

    SciTech Connect

    Miller, Thomas Martin; Celik, Cihangir; Dunn, Michael E; Wagner, John C; McMahan, Kimberly L; Authier, Nicolas; Jacquet, Xavier; Rousseau, Guillaume; Wolff, Herve; Savanier, Laurence; Baclet, Nathalie; Lee, Yi-kang; Trama, Jean-Christophe; Masse, Veronique; Gagnier, Emmanuel; Naury, Sylvie; Blanc-Tranchant, Patrick; Hunter, Richard; Kim, Soon; Dulik, George Michael; Reynolds, Kevin H.

    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 that

  4. [Nuclear accidents and iodine prophylaxis. Part 1: Risks due to irradiation of the thyroid gland].

    PubMed

    Smeesters, P; Frühling, J; Van Bladel, L; Wambersie, A

    1998-12-01

    In the frame of the emergency procedures in the case of an accident in a nuclear plant, this paper presents a survey of the information available on the risks related to the irradiation of the thyroid gland. Attention is focused on thyroid cancer resulting from an exposure to radioactive isotopes of iodine and especially and iodine-131. The consequences of the medical exposures as well as of the Hiroshima and Nagasaki irradiations are recalled first. Then the recently available informations on the effects on the populations exposed after the Tchernobyl accident are analysed more in details. Ten years after the accident, the most striking and the least questionable effects is a significant increase of the incidence of differentiated thyroid cancer in children, in the areas most exposed to the initial radioactive clouds. Young children are particularly vulnerable to this type of cancer which is of aggressive nature and shows a short latency period. These observations justify an iodine prophylaxis for the populations living in the vicinity of nuclear plants. Special attention should be paid to the protection of young children. PMID:9916494

  5. Accident at the Fukushima Dai-ichi Nuclear Power Stations of TEPCO —Outline & lessons learned—

    PubMed Central

    TANAKA, Shun-ichi

    2012-01-01

    The severe accident that broke out at Fukushima Dai-ichi nuclear power stations on March 11, 2011, caused seemingly infinite damage to the daily life of residents. Serious and wide-spread contamination of the environment occurred due to radioactive materials discharged from nuclear power stations (NPSs). At the same time, many issues were highlighted concerning countermeasures to severe nuclear accidents. The accident is outlined, and lessons learned are extracted with respect to the safety of NPSs, as well as radiation protection of residents under the emergency involving the accident. The materials of the current paper are those released by governmental agencies, academic societies, interim reports of committees under the government, and others. PMID:23138450

  6. Formation of hot particles during the Chernobyl nuclear power plant accident

    SciTech Connect

    Kashparov, V.A.; Ivanov, Y.A.; Zvarisch, S.I.; Protsak, V.P.; Khomutinin, Y.V.; Kurepin, A.D.; Pazukhin, E.M.

    1996-05-01

    The oxidation of irradiated Chernobyl nuclear fuel at 670 to 1,170 K for 3 to 21 h resulted in its destruction into fine particles, the dispersal composition of which is well described by lognormal distribution regularity. The median radius of the formed particles does not depend on the annealing temperature and decreases with the increase of the annealing period from 10 to 3 {micro}m. Proceeding from the dispersal composition and matrix composition of the Chernobyl hot fuel particles, it can be concluded that the oxidation of nuclear fuel was one of the basic mechanisms of hot fuel particle formation during the accident at the Chernobyl nuclear power plant. With oxidation in air and the dispersal of irradiated oxide nuclear fuel at as low as 670 K, ruthenium, located on the granular borders, is released. Ruthenium is oxidized to volatile RuO{sub 4}, sublimated, and condensed on materials of iron. Nickel and stainless steel can be efficiently used at high temperatures (tested to 1,200 K) for radioruthenium adsorption in accidents and for some technological operations. As the temperature of hot fuel particles annealed in inert media increases from 1,270 to 2,270 K, the relative release of radionuclides increases in the following sequence: cesium isotopes; europium isotopes; cerium isotopes; americium isotopes; and ruthenium, plutonium, and curium isotopes.

  7. [Protection of the thyroid in children and fetuses in case of nuclear accident].

    PubMed

    Vernis, M; Hindie, E; Galle, P

    1997-05-01

    The administration of stable iodine in order to keep the thyroid gland away from radioactive iodine isotope contamination has long been regarded with caution by the health authorities, mainly because of the potential toxicity of iodine in newborns, young children and adults with thyroid pathology. Therefore, the risk of oral stable iodine given for a limited period of time must be compared to the risk of cancer due to radioactive exposure. The analysis of complications following the nuclear accidents of Marshall Islands in 1954 and Tchernobyl in 1986 has shown that newborn infants and young children, have the highest risk, the main complications being cancer (papillary carcinoma) and hypothyroidism. In the most exposed areas of Bielorussia, the incidence of child thyroid cancer has been approximately multiplied by 100. On the other hand, studies of children from Utah who were contaminated after nuclear tests in the Nevada desert have shown that following mild iodine radioactive exposure, the risk is not significant. Among complications attributed to stable iodine, only those related to an oral intake over a limited period of time should be considered. On the basis of nuclear medicine experience and scientific literature, the risk can be considered as negligible in adults but not in children. However, the Polish experience in children has reported a low risk and only benign complications, mainly transient hypothyroidism. Thus from current knowledge, it appears that the potent risks linked to stable iodine administration should not contraindicate the collective preventive stable iodine administration in case of nuclear accident. PMID:9230999

  8. Insights on fission products behaviour in nuclear severe accident conditions by X-ray absorption spectroscopy

    NASA Astrophysics Data System (ADS)

    Geiger, E.; Bès, R.; Martin, Ph; Pontillon, Y.; Ducros, G.; Solari, P. L.

    2016-04-01

    Many research programs have been carried out aiming to understand the fission products behaviour during a Nuclear Severe Accident. Most of these programs used highly radioactive irradiated nuclear fuel, which requires complex instrumentation. Moreover, the radioactive character of samples hinders an accurate chemical characterisation. In order to overcome these difficulties, SIMFUEL stand out as an alternative to perform complementary tests. A sample made of UO2 doped with 11 fission products was submitted to an annealing test up to 1973 K in reducing atmosphere. The sample was characterized before and after the annealing test using SEM-EDS and XAS at the MARS beam-line, SOLEIL Synchrotron. It was found that the overall behaviour of several fission products (such as Mo, Ba, Pd and Ru) was similar to that observed experimentally in irradiated fuels and consistent with thermodynamic estimations. The experimental approach presented in this work has allowed obtaining information on chemical phases evolution under nuclear severe accident conditions, that are yet difficult to obtain using irradiated nuclear fuel samples.

  9. Insights on fission products behaviour in nuclear severe accident conditions by X-ray absorption spectroscopy

    NASA Astrophysics Data System (ADS)

    Geiger, E.; Bès, R.; Martin, Ph; Pontillon, Y.; Ducros, G.; Solari, P. L.

    2016-04-01

    Many research programs have been carried out aiming to understand the fission products behaviour during a Nuclear Severe Accident. Most of these programs used highly radioactive irradiated nuclear fuel, which requires complex instrumentation. Moreover, the radioactive character of samples hinders an accurate chemical characterisation. In order to overcome these difficulties, SIMFUEL stand out as an alternative to perform complementary tests. A sample made of UO2 doped with 11 fission products was submitted to an annealing test up to 1973 K in reducing atmosphere. The sample was characterized before and after the annealing test using SEM-EDS and XAS at the MARS beam-line, SOLEIL Synchrotron. It was found that the overall behaviour of several fission products (such as Mo, Ba, Pd and Ru) was similar to that observed experimentally in irradiated fuels and consistent with thermodynamic estimations. The experimental approach presented in this work has allowed obtaining information on chemical phases evolution under nuclear severe accident conditions, that are yet difficult to obtain using irradiated nuclear fuel samples.

  10. Observation of radioactive iodine ((131)I, (129)I) in cropland soil after the Fukushima nuclear accident.

    PubMed

    Fujiwara, Hideshi

    2016-10-01

    During the early stages of the Fukushima nuclear accident, the temporal variations of (131)I deposited on the ground and of (131)I accumulated in cropland soil were monitored at a fixed location in Japan. Moreover, concentrations of long-lived radioactive iodine ((129)I) in atmospheric deposits and soil were measured to examine the feasibility of retrospectively reconstructing (131)I levels from the levels of accident-derived (129)I. The exceptionally high levels of (131)I in deposits and soil were attributed to rainfall-related deposition of radionuclides. In the crop field studied, the losses of deposited (131)I and (129)I due to volatilization were small. The atomic ratio (129)I/(131)I in the topsoil corresponded to the same ratio in deposits. The (131)I concentrations measured in the topsoil were very consistent with the (131)I concentrations reconstructed from the (129)I concentrations in the soil. PMID:27320744

  11. A Magnetic Carbon Sorbent for Radioactive Material from the Fukushima Nuclear Accident

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Daizo; Furukawa, Kazumi; Takasuga, Masaya; Watanabe, Koki

    2014-08-01

    Here we present the first report of a carbon-γ-Fe2O3 nanoparticle composite of mesoporous carbon, bearing COOH- and phenolic OH- functional groups on its surface, a remarkable and magnetically separable adsorbent, for the radioactive material emitted by the Fukushima Daiichi nuclear power plant accident. Contaminated water and soil at a level of 1,739 Bq kg-1 (134Cs and 137Cs at 509 Bq kg-1 and 1,230 Bq kg-1, respectively) and 114,000 Bq kg-1 (134Cs and 137Cs at 38,700 Bq kg-1 and 75,300 Bq kg-1, respectively) were decontaminated by 99% and 90% respectively with just one treatment carried out in Nihonmatsu city in Fukushima. Since this material is remarkably high performance, magnetically separable, and a readily applicable technology, it would reduce the environmental impact of the Fukushima accident if it were used.

  12. Radiological protection from radioactive waste management in existing exposure situations resulting from a nuclear accident.

    PubMed

    Sugiyama, Daisuke; Hattori, Takatoshi

    2013-01-01

    In environmental remediation after nuclear accidents, radioactive wastes have to be appropriately managed in existing exposure situations with contamination resulting from the emission of radionuclides by such accidents. In this paper, a framework of radiation protection from radioactive waste management in existing exposure situations for application to the practical and reasonable waste management in contaminated areas, referring to related ICRP recommendations was proposed. In the proposed concept, intermediate reference levels for waste management are adopted gradually according to the progress of the reduction in the existing ambient dose in the environment on the basis of the principles of justification and optimisation by taking into account the practicability of the management of radioactive waste and environmental remediation. It is essential to include the participation of relevant stakeholders living in existing exposure situations in the selection of reference levels for the existing ambient dose and waste management. PMID:22719047

  13. Radionuclide monitoring in Northern Ireland of the Chernobyl nuclear reactor accident

    PubMed Central

    Gilmore, B J; Cranley, K

    1987-01-01

    Northern Ireland received higher radiation doses due to the radionuclide contamination from the Chernobyl nuclear reactor accident than did the south of England. Levels of radioactive iodine (131I) and caesium (137Cs) in cows' milk in Northern Ireland increased to 166 and 120 Bq/l respectively in May 1986, but had decreased by factors of one million, and of twenty-five, respectively, by 1 September 1986. The resultant radiation doses represent less than one per cent of those received by a Northern Ireland individual over a period of 40 years from natural background radiation sources. The added risk to any individual from the Chernobyl accident will therefore be very small and may best be judged in the context of the enormously greater risk of death due to potentially preventable diseases, such as smoking-related lung cancer, and coronary heart disease. PMID:3590387

  14. Radiological protection from radioactive waste management in existing exposure situations resulting from a nuclear accident

    PubMed Central

    Sugiyama, Daisuke; Hattori, Takatoshi

    2013-01-01

    In environmental remediation after nuclear accidents, radioactive wastes have to be appropriately managed in existing exposure situations with contamination resulting from the emission of radionuclides by such accidents. In this paper, a framework of radiation protection from radioactive waste management in existing exposure situations for application to the practical and reasonable waste management in contaminated areas, referring to related ICRP recommendations was proposed. In the proposed concept, intermediate reference levels for waste management are adopted gradually according to the progress of the reduction in the existing ambient dose in the environment on the basis of the principles of justification and optimisation by taking into account the practicability of the management of radioactive waste and environmental remediation. It is essential to include the participation of relevant stakeholders living in existing exposure situations in the selection of reference levels for the existing ambient dose and waste management. PMID:22719047

  15. Nuclear Criticality Safety Organization training implementation. Revision 4

    SciTech Connect

    Carroll, K.J.; Taylor, R.G.; Worley, C.A.

    1997-05-19

    The Nuclear Criticality Safety Organization (NCSO) is committed to developing and maintaining a staff of qualified personnel to meet the current and anticipated needs in Nuclear Criticality Safety (NCS) at the Oak Ridge Y-12 Plant. This document provides a listing of the roles and responsibilities of NCSO personnel with respect to training and details of the Training Management System (TMS) programs, Mentoring Checklists and Checksheets, as well as other documentation utilized to implement the program. This Training Implementation document is applicable to all technical and managerial NCSO personnel, including temporary personnel, sub-contractors and/or LMES employees on loan to the NCSO, who are in a qualification program.

  16. Design of an advanced TLD-based fixed nuclear accident dosimeter

    SciTech Connect

    Casson, W.H.; Mei, G.T.

    1993-08-01

    A new system has been designed for use as a fixed nuclear accident dosimeter based upon the thermoluminescent dosimeter (TLD) system used for personnel dosimetry at US Department of Energy facilities managed by Martin Marietta Energy Systems, Inc. The system is made up of a small phantom consisting of two main parts measuring 20 x 20 x 5 cm and made from polymethylmethacrylate. A neutron-sensitive TLD card is placed in the center between the two pieces. Also, TLD cards in standard holders are mounted on the front and back of the phantom. A derivation is made of a linear combination of the responses from the TLD elements which results in calculation of the neutron fluence, absorbed dose, and dose equivalent. By using the right linear combinations, a crude spectrum can be estimated, which allows further calculation of the average fluence-to-dose-equivalent conversion factor. The response of the system was tested and found to be applicable for the evaluation of typical nuclear accident spectra, although considerable improvement can be made by the addition of a sulfur pellet. The system was also tested for angular dependence. In order to move the development of this system from the proof-of-principle to full application, the calculation of the TLD resonse curves must be improved, additional measurements must be made, and the system must be tested in a simulated accident neutron field. The advantages of the new fixed dosimeter system are its simplicity, easy maintenance, and lower operational cost. The system uses standard TLD cards that are already in place throughout Energy Systems facilities. The TLD process personnel are famliiar with evaluating doses from TLDs and can provide information necessary to ensure timely and accurate assessment of exposures that may result from riticality accidents. Most of the quality control requirements are part of the existing personnel dosimetry system.

  17. Development of the preliminary procedure for a national nuclear safety authority staff acting during the PWR NPP accident

    SciTech Connect

    Kostadinov, V.

    1997-12-01

    We present the development of the new preliminary procedure for a National Nuclear Safety Authority staff preparedness for action in the case of a Pressurized Water Reactor Nuclear Power Plant accident. The procedures are generic and equally applicable for advanced nuclear plants. The basic goal of the procedure is systematic determination of the responsibilities of the staff expert group(s) members for accident analysis and consequences prediction. Moreover, the procedure describes anticipated practices of an expert group acting during a plant accident. Different sources will define the state(s) of the plant as: the plant form for initial notification of an accident, the particular form for specific plant information, etc. By this procedure we propose three expert groups successively to work up to eight hours each, in the circumstances of an accident. We suppose the expert group to have mostly five members each. The members should have different tasks for resolution, defined by the procedure. The head of the group will coordinate group members work during an accident. Group members have to be qualified and acquainted with all adequate references. In the paper we present a newly devised agenda with presumed duties of each member of the group. Furthermore, we also composed a special form for information exchange between the utility and regulatory staff member during an accident. 8 refs., 1 fig.

  18. Detection of radioxenon in Darwin, Australia following the Fukushima Dai-ichi nuclear power plant accident.

    PubMed

    Orr, Blake; Schöppner, Michael; Tinker, Rick; Plastino, Wolfango

    2013-12-01

    A series of (133)Xe detections in April 2011 made at the Comprehensive Nuclear-Test-Ban Treaty Organisation (CTBTO) International Monitoring System noble gas station in Darwin, Australia, were analysed to determine the most likely source location. Forward and backwards atmospheric transport modelling simulations using FLEXPART were conducted. It was shown that the most likely source location was the Fukushima Dai-ichi nuclear power plant accident. Other potential sources in the southern hemisphere were analysed, including the Australian Nuclear Science and Technology Organisation (ANSTO) radiopharmaceutical facility, but it was shown that sources originating from these locations were highly unlikely to be the source of the observed (133)Xe Darwin detections. PMID:23933085

  19. Reclaiming Our Lives in the Wake of a Nuclear Plant Accident.

    PubMed

    Ando, R

    2016-04-01

    Ryoko Ando lives and works in Iwaki-shi, which is located in the coastal area of Fukushima Prefecture. On 11 March 2011, Iwaki was hit by the Great East Japan Earthquake and tsunami. Then the nuclear plant accident at Fukushima No. 1 nuclear power plant, also located in the coastal area of Fukushima Prefecture, added to the woes of Iwaki residents. Although Iwaki-shi is outside of the ‘restricted area’ set up by the government in the 20 km radius around the nuclear power plant, some municipalities in Iwaki-shi lie within the 30 km radius zone. The residents of Iwaki were naturally concerned about the effects of radioactive contamination. On top of these, they had to confront a wide range of issues, including confusion and miscommunication, reputation risk and infrastructural constraints due to the influx of residents from the ‘restricted area’. PMID:27386587

  20. Nuclear Data Activities in Support of the DOE Nuclear Criticality Safety Program

    SciTech Connect

    Westfall, R.M.; McKnight, R.D.

    2005-05-24

    The DOE Nuclear Criticality Safety Program (NCSP) provides the technical infrastructure maintenance for those technologies applied in the evaluation and performance of safe fissionable-material operations in the DOE complex. These technologies include an Analytical Methods element for neutron transport as well as the development of sensitivity/uncertainty methods, the performance of Critical Experiments, evaluation and qualification of experiments as Benchmarks, and a comprehensive Nuclear Data program coordinated by the NCSP Nuclear Data Advisory Group (NDAG).The NDAG gathers and evaluates differential and integral nuclear data, identifies deficiencies, and recommends priorities on meeting DOE criticality safety needs to the NCSP Criticality Safety Support Group (CSSG). Then the NDAG identifies the required resources and unique capabilities for meeting these needs, not only for performing measurements but also for data evaluation with nuclear model codes as well as for data processing for criticality safety applications. The NDAG coordinates effort with the leadership of the National Nuclear Data Center, the Cross Section Evaluation Working Group (CSEWG), and the Working Party on International Evaluation Cooperation (WPEC) of the OECD/NEA Nuclear Science Committee. The overall objective is to expedite the issuance of new data and methods to the DOE criticality safety user. This paper describes these activities in detail, with examples based upon special studies being performed in support of criticality safety for a variety of DOE operations.

  1. RADIOACTIVE WASTE MANAGEMENT IN THE CHERNOBYL EXCLUSION ZONE - 25 YEARS SINCE THE CHERNOBYL NUCLEAR POWER PLANT ACCIDENT

    SciTech Connect

    Farfan, E.; Jannik, T.

    2011-10-01

    Radioactive waste management is an important component of the Chernobyl Nuclear Power Plant accident mitigation and remediation activities of the so-called Chernobyl Exclusion Zone. This article describes the localization and characteristics of the radioactive waste present in the Chernobyl Exclusion Zone and summarizes the pathways and strategy for handling the radioactive waste related problems in Ukraine and the Chernobyl Exclusion Zone, and in particular, the pathways and strategies stipulated by the National Radioactive Waste Management Program. The brief overview of the radioactive waste issues in the ChEZ presented in this article demonstrates that management of radioactive waste resulting from a beyond-designbasis accident at a nuclear power plant becomes the most challenging and the costliest effort during the mitigation and remediation activities. The costs of these activities are so high that the provision of radioactive waste final disposal facilities compliant with existing radiation safety requirements becomes an intolerable burden for the current generation of a single country, Ukraine. The nuclear accident at the Fukushima-1 NPP strongly indicates that accidents at nuclear sites may occur in any, even in a most technologically advanced country, and the Chernobyl experience shows that the scope of the radioactive waste management activities associated with the mitigation of such accidents may exceed the capabilities of a single country. Development of a special international program for broad international cooperation in accident related radioactive waste management activities is required to handle these issues. It would also be reasonable to consider establishment of a dedicated international fund for mitigation of accidents at nuclear sites, specifically, for handling radioactive waste problems in the ChEZ. The experience of handling Chernobyl radioactive waste management issues, including large volumes of radioactive soils and complex structures

  2. A Suite of Criticality Benchmarks for Validating Nuclear Data

    SciTech Connect

    Stephanie C. Frankle

    1999-04-01

    The continuous-energy neutron data library ENDF60 for use with MCNP{trademark} was released in the fall of 1994, and was based on ENDF/B-Vl evaluations through Release 2. As part of the data validation process for this library, a number of criticality benchmark calculations were performed. The original suite of nine criticality benchmarks used to test ENDF60 has now been expanded to 86 benchmarks. This report documents the specifications for the suite of 86 criticality benchmarks that have been developed for validating nuclear data.

  3. Nuclear criticality research at the University of New Mexico

    SciTech Connect

    Busch, R.D.

    1997-06-01

    Two projects at the University of New Mexico are briefly described. The university`s Chemical and Nuclear Engineering Department has completed the final draft of a primer for MCNP4A, which it plans to publish soon. The primer was written to help an analyst who has little experience with the MCNP code to perform criticality safety analyses. In addition, the department has carried out a series of approach-to-critical experiments on the SHEBA-II, a UO{sub 2}F{sub 2} solution critical assembly at Los Alamos National Laboratory. The results obtained differed slightly from what was predicted by the TWODANT code.

  4. Soil sampling and analytical strategies for mapping fallout in nuclear emergencies based on the Fukushima Dai-ichi Nuclear Power Plant accident.

    PubMed

    Onda, Yuichi; Kato, Hiroaki; Hoshi, Masaharu; Takahashi, Yoshio; Nguyen, Minh-Long

    2015-01-01

    The Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident resulted in extensive radioactive contamination of the environment via deposited radionuclides such as radiocesium and (131)I. Evaluating the extent and level of environmental contamination is critical to protecting citizens in affected areas and to planning decontamination efforts. However, a standardized soil sampling protocol is needed in such emergencies to facilitate the collection of large, tractable samples for measuring gamma-emitting radionuclides. In this study, we developed an emergency soil sampling protocol based on preliminary sampling from the FDNPP accident-affected area. We also present the results of a preliminary experiment aimed to evaluate the influence of various procedures (e.g., mixing, number of samples) on measured radioactivity. Results show that sample mixing strongly affects measured radioactivity in soil samples. Furthermore, for homogenization, shaking the plastic sample container at least 150 times or disaggregating soil by hand-rolling in a disposable plastic bag is required. Finally, we determined that five soil samples within a 3 m × 3-m area are the minimum number required for reducing measurement uncertainty in the emergency soil sampling protocol proposed here. PMID:24965965

  5. Impact of the Fukushima nuclear accident on background radiation doses measured by control dosimeters in Japan.

    PubMed

    Romanyukha, Alexander; King, David L; Kennemur, Lisa K

    2012-05-01

    After the 9.0 magnitude earthquake and subsequent massive tsunami on 11 March 2011 in Japan, several reactors at the Fukushima Daiichi Nuclear Power Plant suffered severe damage. There was immediate participation of U.S. Navy vessels and other United States Department of Defense (DoD) teams that were already in the area at the time of the disaster or arrived shortly thereafter. The correct determination of occupational dose equivalent requires estimation of the background dose component measured by control dosimeters, which is subsequently subtracted from the total dose equivalent measured by personal dosimeters. The purpose of the control dosimeters is to determine the amount of radiation dose equivalent that has accumulated on the dosimeter from background or other non-occupational sources while they are in transit or being stored. Given the release of radioactive material and potential exposure to radiation from the Fukushima Daiichi Nuclear Power Plant and the process by which the U.S. Navy calculates occupational exposure to ionizing radiation, analysis of pre- and post-event control dosimeters is warranted. Several hundred historical dose records from the Naval Dosimetry Center (NDC) database were analyzed and compared with the post-accident dose equivalent data of control dosimeters. As result, it was shown that the dose contribution of the radiation and released radiological materials from the Fukushima nuclear accident to background radiation doses is less than 0.375 μSv d for shallow and deep photon dose equivalent. There is no measurable effect on neutron background exposure. The latter has at least two important conclusions. First, the NDC can use doses measured by control dosimeters at issuing sites in Japan for determination of personnel dose equivalents; second, the dose data from control dosimeters prior to and after the Fukushima accident may be used to assist in dose reconstruction of non-radiological (non-badged) personnel at these locations

  6. Proceedings of the nuclear criticality technology safety project

    SciTech Connect

    Sanchez, R.G.

    1997-06-01

    This document contains summaries of the most of the papers presented at the 1994 Nuclear Criticality Technology Safety Project (NCTSP) meeting, which was held May 10 and 11 at Williamsburg, Va. The meeting was broken up into seven sessions, which covered the following topics: (1) Validation and Application of Calculations; (2) Relevant Experiments for Criticality Safety; (3) Experimental Facilities and Capabilities; (4) Rad-Waste and Weapons Disassembly; (5) Criticality Safety Software and Development; (6) Criticality Safety Studies at Universities; and (7) Training. The minutes and list of participants of the Critical Experiment Needs Identification Workgroup meeting, which was held on May 9 at the same venue, has been included as an appendix. A second appendix contains the names and addresses of all NCTSP meeting participants. Separate abstracts have been indexed to the database for contributions to this proceedings.

  7. Public dialogue on physics and related technology after the Fukushima Daiichi nuclear accident

    NASA Astrophysics Data System (ADS)

    Sasao, Mamiko

    2015-12-01

    After the Fukushima Daiichi Nuclear Accident, the importance of bottom-up and two-way dialogue between scientists and the public has been recognized. In such dialogue, information provided must accurately match the public's interest and ability regarding science and technology. We have started to investigate what people want to know about physics. Some were interested in energy security (a particular concern in Japan), but others were concerned about radioactivity in food and natural radiation background. The conversations revealed that physicists often give insufficient explanations of the biological effects of radiation and highlighted key points for physicists to make when talking with the public.

  8. Public dialogue on physics and related technology after the Fukushima Daiichi nuclear accident

    SciTech Connect

    Sasao, Mamiko

    2015-12-31

    After the Fukushima Daiichi Nuclear Accident, the importance of bottom-up and two-way dialogue between scientists and the public has been recognized. In such dialogue, information provided must accurately match the public’s interest and ability regarding science and technology. We have started to investigate what people want to know about physics. Some were interested in energy security (a particular concern in Japan), but others were concerned about radioactivity in food and natural radiation background. The conversations revealed that physicists often give insufficient explanations of the biological effects of radiation and highlighted key points for physicists to make when talking with the public.

  9. A simplified model for calculating early offsite consequences from nuclear reactor accidents

    SciTech Connect

    Madni, I.K.; Cazzoli, E.G.; Khatib-Rahbar, M.

    1988-07-01

    A personal computer-based model, SMART, has been developed that uses an integral approach for calculating early offsite consequences from nuclear reactor accidents. The solution procedure uses simplified meteorology and involves direct analytic integration of air concentration equations over time and position. This is different from the discretization approach currently used in the CRAC2 and MACCS codes. The SMART code is fast-running, thereby providing a valuable tool for sensitivity and uncertainty studies. The code was benchmarked against both MACCS version 1.4 and CRAC2. Results of benchmarking and detailed sensitivity/uncertainty analyses using SMART are presented. 34 refs., 21 figs., 24 tabs.

  10. [Radiation measures and trend after the Fukushima Daiichi Nuclear Power Plant accident].

    PubMed

    Okazaki, Ryuji

    2014-02-01

    The radioactive materials spread by the Fukushima Daiichi Nuclear Power Plant (NPP) accident in March, 2011 caused NPP workers to be exposed to radiation above ordinance limits. The number of workers exposed to radiation within ordinance limits is increasing. Decontamination began at many places in Fukushima, although new laws were enforced in the decontamination work, in the current situation, medical examinations for radiation are limited due to a shortage of doctors. In this paper, I introduce the ordinances on the prevention of ionizing radiation hazards and the revised points about radiation exposure doses of the NPP workers, as well as the new ordinance for decontamination. PMID:24605520

  11. Public meetings on radiation and its health effects caused by the Fukushima nuclear accident

    SciTech Connect

    Sugiyama, K.; Ayame, J.; Takashita, H.; Yamamoto, R.

    2013-07-01

    The Japan Atomic Energy Agency (JAEA) has held public meetings on radiation and its health effects mainly for parents of students in kindergartens, elementary schools, and junior high schools in Fukushima and Ibaraki prefectures after the Fukushima nuclear accident. These meetings are held based on our experience of practicing risk communication activities for a decade in JAEA with local residents. By analyzing questionnaires collected after the meetings, we confirmed that interactive communication is effective in increasing participants' understanding and in decreasing their anxiety. Most of the participants answered that they understood the contents and that it eased their mind. (authors)

  12. Nuclear reactor accidents: Chernobyl, TMI, and Windscale. (Latest citations from Pollution abstracts). Published Search

    SciTech Connect

    1995-12-01

    The bibliography contains citations concerning studies and measurements of the radiological consequences of nuclear reactor accidents. The citations cover specifically the Chernobyl reactor in the USSR, the Three Mile Island (TMI) reactor in the US, and the Windscale reactor in the UK. Included are detection and monitoring of the fallout; the resultant runoff into rivers, lakes, and the sea; the radiation effects on people; and the transfrontier radioactive contamination of the environment. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  13. Nuclear reactor accidents: Chernobyl, TMI, and windscale. (Latest citations from Pollution Abstracts). Published Search

    SciTech Connect

    Not Available

    1994-11-01

    The bibliography contains citations concerning studies and measurements of the radiological consequences of nuclear reactor accidents. The citations cover specifically the Chernobyl reactor in the USSR, the Three Mile Island (TMI) reactor in the US, and the Windscale reactor in the UK. Included are detection and monitoring of the fallout; the resultant runoff into rivers, lakes, and the sea; the radiation effects on people; and the transfrontier radioactive contamination of the environment. (Contains 250 citations and includes a subject term index and title list.)

  14. Radioiodine in the atmosphere after the Fukushima Dai-ichi nuclear accident.

    PubMed

    Lebel, Luke S; Dickson, Raymond S; Glowa, Glenn A

    2016-01-01

    About 160 PBq of (131)I was released into the atmosphere during the accident at the Fukushima Dai-ichi Nuclear Power Plant. The chemistry of radioiodine is complicated, and it can be released in several different forms. In addition, the different physical forms, like molecular iodine, aerosol-form iodine, or organic iodine, would have all behaved differently once in the atmosphere, and would have been removed at different rates. These releases were detected by monitoring stations throughout Japan, and from these measurements, key insights can be made about the different chemical forms that were released, as well as the persistence of each in the environment. PMID:26440698

  15. Nuclear relaxation and critical fluctuations in membranes containing cholesterol

    NASA Astrophysics Data System (ADS)

    McConnell, Harden

    2009-04-01

    Nuclear resonance frequencies in bilayer membranes depend on lipid composition. Our calculations describe the combined effects of composition fluctuations and diffusion on nuclear relaxation near a miscibility critical point. Both tracer and gradient diffusion are included. The calculations involve correlation functions and a correlation length ξ =ξ0T/(T -Tc), where T -Tc is temperature above the critical temperature and ξ0 is a parameter of molecular length. Several correlation functions are examined, each of which is related in some degree to the Ising model correlation function. These correlation functions are used in the calculation of transverse deuterium relaxation rates in magic angle spinning and quadrupole echo experiments. The calculations are compared with experiments that report maxima in deuterium and proton nuclear relaxation rates at the critical temperature [Veatch et al., Proc. Nat. Acad. Sci. U.S.A. 104, 17650 (2007)]. One Ising-model-related correlation function yields a maximum 1/T2 relaxation rate at the critical temperature for both magic angle spinning and quadrupole echo experiments. The calculated rates at the critical temperature are close to the experimental rates. The rate maxima involve relatively rapid tracer diffusion in a static composition gradient over distances of up to 10-100 nm.

  16. Verification the data on critical facilities inventory and vulnerability for seismic risk assessment taking into account possible accidents

    NASA Astrophysics Data System (ADS)

    Frolova, Nina; Larionov, Valery; Bonnin, Jean; Ugarov, Aleksander

    2015-04-01

    The paper contains the results of the recent study that has been done by Seismological Center of IGE, Russian Academy of Sciences and Extreme Situations Research Center within the Russian Academy of Sciences Project "Theoretical and Methodological basis for seismic risk assessment taking into account technological accidents at local level; constructing the seismic risk maps for the Big Sochi City territory including the venue of Olympic Games facilities." The procedure of critical facilities inventory and vulnerability verification which makes use of space images and web technologies in social networks is presented. The numerical values of the criteria of accidents at fire and chemical hazardous facilities triggered by strong earthquakes are obtained. The seismic risk maps for Big Sochi City territory including the Olympic Games venue constructed taking into account new data on critical facilities obtained with application panorama photos of these facilities, space images of high resolution and web technologies. The obtained values of individual seismic risk taking into account secondary technological accidents exceed the values seismic risk without taking secondary hazard, return period T= 500 years, at 0.5-1.0 10-51/year.

  17. Radiation-driven migration: the case of Minamisoma City, Fukushima, Japan, after the Fukushima nuclear accident.

    PubMed

    Zhang, Hui; Yan, Wanglin; Oba, Akihiro; Zhang, Wei

    2014-09-01

    The emigration of residents following the Fukushima nuclear accident has resulted in aging and depopulation problems in radiation-contaminated areas. The recovery of affected areas, and even those areas with low radioactive pollution levels, is still heavily affected by this problem. This slow recovery consequently affects immigration patterns. This review aims to present possible factors that have contributed to this dilemma. We first present an overview of the evacuation protocol that was administered in the study area following the Fukushima accident. We then analyze characteristics of the subsequent exodus by comparing population data for both before and after the accident. Based on the findings of existing literature, we identify three causes of emigration: (1) The health risks of living in a low radiation zone are still unknown; (2) The post-disaster psychological disturbance and distrust of government information promotes the emigration of evacuees; (3) an absence of economic vitality and of a leading industry renders the area less attractive to individuals residing outside of the city. Further research is needed on this issue, especially with respect to countermeasures for addressing this problem. PMID:25207491

  18. Fukushima Daiichi Nuclear Plant accident: Atmospheric and oceanic impacts over the five years.

    PubMed

    Hirose, Katsumi

    2016-06-01

    The Fukushima Daiichi Nuclear Plant (FDNPP) accident resulted in huge environmental and socioeconomic impacts to Japan. To document the actual environmental and socioeconomic effects of the FDNPP accident, we describe here atmospheric and marine contamination due to radionuclides released from the FDNPP accident using papers published during past five years, in which temporal and spatial variations of FDNPP-derived radionuclides in air, deposition and seawater and their mapping are recorded by local, regional and global monitoring activities. High radioactivity-contaminated area in land were formed by the dispersion of the radioactive cloud and precipitation, depending on land topography and local meteorological conditions, whereas extremely high concentrations of (131)I and radiocesium in seawater occurred due to direct release of radioactivity-contaminated stagnant water in addition to atmospheric deposition. For both of atmosphere and ocean, numerical model simulations, including local, regional and global-scale modeling, were extensively employed to evaluate source terms of the FDNPP-derived radionuclides from the monitoring data. These models also provided predictions of the dispersion and high deposition areas of the FDNPP-derived radionuclides. However, there are significant differences between the observed and simulated values. Then, the monitoring data would give a good opportunity to improve numerical modeling. PMID:27032342

  19. Impact of the Fukushima nuclear accident on obesity of children in Japan (2008-2014).

    PubMed

    Yamamura, Eiji

    2016-05-01

    This study used prefecture-level panel data from Japan for the period 2008-2014 to investigate the influence of the 2011 Fukushima nuclear accident on the body mass index (BMI) z-score and obesity rates of children over time. I adopted a difference-in-differences approach and found the following: (1) for the cohort aged 5-7 years in 2010, the BMI z-score and obesity rates in disaster-affected areas were higher than in other areas, although this was not observed for the other cohorts; (2) for the cohort aged 5-7 years in 2010, the influence of the accident persisted even after 3 years; and (3) the differences in the BMI z-score and obesity rate before and after the accident were greater for Fukushima Prefecture than for the other affected areas (Iwate and Miyagi prefectures). I infer that health-conscious parents, whose children had lower BMIs, may have moved from Fukushima, thereby increasing the BMI z-score of the child population living in Fukushima by around 0.05 for the cohort aged 5-7 years. The enforced reduction in physical activity increased the BMI z-score of children living in Fukushima by around 0.19 for that cohort. PMID:26849534

  20. Linear free energy correlations for fission product release from the Fukushima-Daiichi nuclear accident.

    PubMed

    Abrecht, David G; Schwantes, Jon M

    2015-03-01

    This paper extends the preliminary linear free energy correlations for radionuclide release performed by Schwantes et al., following the Fukushima-Daiichi Nuclear Power Plant accident. Through evaluations of the molar fractionations of radionuclides deposited in the soil relative to modeled radionuclide inventories, we confirm the initial source of the radionuclides to the environment to be from active reactors rather than the spent fuel pool. Linear correlations of the form In χ = −α ((ΔGrxn°(TC))/(RTC)) + β were obtained between the deposited concentrations, and the reduction potentials of the fission product oxide species using multiple reduction schemes to calculate ΔG°rxn (TC). These models allowed an estimate of the upper bound for the reactor temperatures of TC between 2015 and 2060 K, providing insight into the limiting factors to vaporization and release of fission products during the reactor accident. Estimates of the release of medium-lived fission products 90Sr, 121mSn, 147Pm, 144Ce, 152Eu, 154Eu, 155Eu, and 151Sm through atmospheric venting during the first month following the accident were obtained, indicating that large quantities of 90Sr and radioactive lanthanides were likely to remain in the damaged reactor cores. PMID:25675358

  1. Analysis of Radionuclide Releases from the Fukushima Dai-ichi Nuclear Power Plant Accident Part II

    NASA Astrophysics Data System (ADS)

    Achim, Pascal; Monfort, Marguerite; Le Petit, Gilbert; Gross, Philippe; Douysset, Guilhem; Taffary, Thomas; Blanchard, Xavier; Moulin, Christophe

    2014-03-01

    The present part of the publication (Part II) deals with long range dispersion of radionuclides emitted into the atmosphere during the Fukushima Dai-ichi accident that occurred after the March 11, 2011 tsunami. The first part (Part I) is dedicated to the accident features relying on radionuclide detections performed by monitoring stations of the Comprehensive Nuclear Test Ban Treaty Organization network. In this study, the emissions of the three fission products Cs-137, I-131 and Xe-133 are investigated. Regarding Xe-133, the total release is estimated to be of the order of 6 × 1018 Bq emitted during the explosions of units 1, 2 and 3. The total source term estimated gives a fraction of core inventory of about 8 × 1018 Bq at the time of reactors shutdown. This result suggests that at least 80 % of the core inventory has been released into the atmosphere and indicates a broad meltdown of reactor cores. Total atmospheric releases of Cs-137 and I-131 aerosols are estimated to be 1016 and 1017 Bq, respectively. By neglecting gas/particulate conversion phenomena, the total release of I-131 (gas + aerosol) could be estimated to be 4 × 1017 Bq. Atmospheric transport simulations suggest that the main air emissions have occurred during the events of March 14, 2011 (UTC) and that no major release occurred after March 23. The radioactivity emitted into the atmosphere could represent 10 % of the Chernobyl accident releases for I-131 and Cs-137.

  2. Linear Free Energy Correlations for Fission Product Release from the Fukushima-Daiichi Nuclear Accident

    SciTech Connect

    Abrecht, David G.; Schwantes, Jon M.

    2015-03-03

    This paper extends the preliminary linear free energy correlations for radionuclide release performed by Schwantes, et al., following the Fukushima-Daiichi Nuclear Power Plant accident. Through evaluations of the molar fractionations of radionuclides deposited in the soil relative to modeled radionuclide inventories, we confirm the source of the radionuclides to be from active reactors rather than the spent fuel pool. Linear correlations of the form ln χ = -α (ΔGrxn°(TC))/(RTC)+β were obtained between the deposited concentration and the reduction potential of the fission product oxide species using multiple reduction schemes to calculate ΔG°rxn(TC). These models allowed an estimate of the upper bound for the reactor temperatures of TC between 2130 K and 2220 K, providing insight into the limiting factors to vaporization and release of fission products during the reactor accident. Estimates of the release of medium-lived fission products 90Sr, 121mSn, 147Pm, 144Ce, 152Eu, 154Eu, 155Eu, 151Sm through atmospheric venting and releases during the first month following the accident were performed, and indicate large quantities of 90Sr and radioactive lanthanides were likely to remain in the damaged reactor cores.

  3. Radiation-Driven Migration: The Case of Minamisoma City, Fukushima, Japan, after the Fukushima Nuclear Accident

    PubMed Central

    Zhang, Hui; Yan, Wanglin; Oba, Akihiro; Zhang, Wei

    2014-01-01

    The emigration of residents following the Fukushima nuclear accident has resulted in aging and depopulation problems in radiation-contaminated areas. The recovery of affected areas, and even those areas with low radioactive pollution levels, is still heavily affected by this problem. This slow recovery consequently affects immigration patterns. This review aims to present possible factors that have contributed to this dilemma. We first present an overview of the evacuation protocol that was administered in the study area following the Fukushima accident. We then analyze characteristics of the subsequent exodus by comparing population data for both before and after the accident. Based on the findings of existing literature, we identify three causes of emigration: (1) The health risks of living in a low radiation zone are still unknown; (2) The post-disaster psychological disturbance and distrust of government information promotes the emigration of evacuees; (3) an absence of economic vitality and of a leading industry renders the area less attractive to individuals residing outside of the city. Further research is needed on this issue, especially with respect to countermeasures for addressing this problem. PMID:25207491

  4. Postanalysis of the CNPS (Compact Nuclear Power Source) critical experiment

    NASA Astrophysics Data System (ADS)

    Palmer, R. G.

    The Compact Nuclear Power Source (CNPS) was designed to produce electric power for remote sites where fuel logistics and costs would justify a remotely sited nuclear power plant. Since the reactor was of novel design with no appropriate benchmarks, a series of critical experiments was carried out at LANL. This paper describes the methodology and reports the results of the postanalysis that was performed on the critical experiments, which included several distinct critical configurations, the measurement of the isothermal temperature coefficient of reactivity and various material worths. Comparisons with measurements indicate that current methods and cross sections are adequate for calculating at least the beginning of life conditions in low enriched U-235-graphite cores.

  5. Postanalysis of the CNPS (Compact Nuclear Power Source) critical experiment

    SciTech Connect

    Palmer, R.G.

    1988-01-01

    The Compact Nuclear Power Source (CNPS) was designed to produce electric power for remote sites where fuel logistics and costs would justify a remotely sited nuclear power plant. Since the reactor was of novel design with no appropriate benchmarks, a series of critical experiments was carried out at LANL. This paper describes the methodology and reports the results of the postanalysis that was performed on the critical experiments, which included several distinct critical configurations, the measurement of the isothermal temperature coefficient of reactivity and various material worths. Comparisons with measurements indicate that current methods and cross sections are adequate for calculating at least the beginning of life conditions in low enriched /sup 235/U-graphite cores. 7 refs., 4 figs., 4 tabs.

  6. Behavioral differences of irradiated persons associated with the Kyshtym, Chelyabinsk, and Chernobyl Nuclear Accidents. (Reannouncement with new availability information)

    SciTech Connect

    Collins, D.L.

    1992-12-31

    Three nuclear accidents besides Chernobyl have occurred in the former Soviet Union. The accidents occurred around Kyshtym and Chelyabinsk in the Ural Mountains between 1949 and 1967 and contaminated over one-half million people. The health ministries are now interested in the data previously collected on these irradiated populations in order to examine the health (e.g., psychological, hereditary, genome damage, etc.) implications of long-term radiation exposure.

  7. Release of plutonium isotopes into the environment from the Fukushima Daiichi Nuclear Power Plant accident: what is known and what needs to be known.

    PubMed

    Zheng, Jian; Tagami, Keiko; Uchida, Shigeo

    2013-09-01

    The Fukushima Daiichi Nuclear Power Plant (FDNPP) accident has caused serious contamination in the environment. The release of Pu isotopes renewed considerable public concern because they present a large risk for internal radiation exposure. In this Critical Review, we summarize and analyze published studies related to the release of Pu from the FDNPP accident based on environmental sample analyses and the ORIGEN model simulations. Our analysis emphasizes the environmental distribution of released Pu isotopes, information on Pu isotopic composition for source identification of Pu releases in the FDNPP-damaged reactors or spent fuel pools, and estimation of the amounts of Pu isotopes released from the FDNPP accident. Our analysis indicates that a trace amount of Pu isotopes (∼2 × 10(-5)% of core inventory) was released into the environment from the damaged reactors but not from the spent fuel pools located in the reactor buildings. Regarding the possible Pu contamination in the marine environment, limited studies suggest that no extra Pu input from the FDNPP accident could be detected in the western North Pacific 30 km off the Fukushima coast. Finally, we identified knowledge gaps remained on the release of Pu into the environment and recommended issues for future studies. PMID:23899337

  8. Genetic aberrations in Chernobyl-related thyroid cancers: implications for possible future nuclear accidents or nuclear attacks.

    PubMed

    Ermak, Gennady; Figge, James J; Kartel, Nikolai A; Davies, Kelvin J A

    2003-12-01

    Cases of thyroid cancer among children in Belarus represent a unique model system in which the cause of the cancer is known--radiation. Although other sources of radiation-induced cancers are diminishing (survivors of Hiroshima and Nagasaki, and individuals exposed to diagnostic or therapeutic radiation) fears of radiation exposure from accidents and terrorism are increasing. Our analysis of current data reveals that Chernobyl-related cancer cases might have a specific pattern of genetic aberrations. These data strongly confirm the hypothesis that radiation-induced cancers might arise as a result of specific gene aberrations that are distinct from those in sporadic cancers, suggesting that methods of prevention and treatment of radiation-induced cancers might require a different approach. Understanding of the molecular mechanisms of Chernobyl-related papillary thyroid carcinomas will help to identify mechanisms by which radiation causes aberrations and oncogenic cell transformation. Thus, in turn, it will be important in the development of new treatments or technologies to minimize the effects of radiation damage from nuclear accidents or nuclear attacks. PMID:14768999

  9. Radiological health effects models for nuclear power plant accident consequence analysis.

    PubMed

    Evans, J S; Moeller, D W

    1989-04-01

    Improved health effects models have been developed for assessing the early effects, late somatic effects and genetic effects that might result from low-LET radiation exposures to populations following a major accident in a nuclear power plant. All the models have been developed in such a way that the dynamics of population risks can be analyzed. Estimates of life years lost and the duration of illnesses were generated and a framework recommended for summarizing health impacts. Uncertainty is addressed by providing models for upper, central and lower estimates of most effects. The models are believed to be a significant improvement over the models used in the U.S. Nuclear Regulatory Commission's Reactor Safety Study, and they can easily be modified to reflect advances in scientific understanding of the health effects of ionizing radiation. PMID:2925380

  10. Global risk from the atmospheric dispersion of radionuclides by nuclear power plant accidents

    NASA Astrophysics Data System (ADS)

    Christoudias, Theodoros; Proestos, Yiannis; Lelieveld, Jos

    2015-04-01

    We estimate the global risk from the release and atmospheric dispersion of radionuclides from nuclear power plant accidents using the EMAC atmospheric chemistry-general circulation model. We included all nuclear reactors that are currently operational, under construction and planned or proposed. We simulated atmospheric transport and decay, focusing on 137Cs and 131I as proxies for particulate and gaseous radionuclides, respectively. We implemented constant continuous emissions from each location in the model and simulated atmospheric transport and removal via dry and wet deposition processes. We present risk maps for potential surface layer concentrations, deposition and doses to humans from the inhalation exposure of 131I. The estimated risks exhibit seasonal variability, with the highest surface level concentrations of gaseous radionuclides in the Northern Hemisphere during winter.

  11. Assessment of individual radionuclide distributions from the Fukushima nuclear accident covering central-east Japan.

    PubMed

    Kinoshita, Norikazu; Sueki, Keisuke; Sasa, Kimikazu; Kitagawa, Jun-ichi; Ikarashi, Satoshi; Nishimura, Tomohiro; Wong, Ying-Shee; Satou, Yukihiko; Handa, Koji; Takahashi, Tsutomu; Sato, Masanori; Yamagata, Takeyasu

    2011-12-01

    A tremendous amount of radioactivity was discharged because of the damage to cooling systems of nuclear reactors in the Fukushima No. 1 nuclear power plant in March 2011. Fukushima and its adjacent prefectures were contaminated with fission products from the accident. Here, we show a geographical distribution of radioactive iodine, tellurium, and cesium in the surface soils of central-east Japan as determined by gamma-ray spectrometry. Especially in Fukushima prefecture, contaminated area spreads around Iitate and Naka-Dori for all the radionuclides we measured. Distributions of the radionuclides were affected by the physical state of each nuclide as well as geographical features. Considering meteorological conditions, it is concluded that the radioactive material transported on March 15 was the major contributor to contamination in Fukushima prefecture, whereas the radioactive material transported on March 21 was the major source in Ibaraki, Tochigi, Saitama, and Chiba prefectures and in Tokyo. PMID:22084070

  12. Assessment of individual radionuclide distributions from the Fukushima nuclear accident covering central-east Japan

    PubMed Central

    Kinoshita, Norikazu; Sueki, Keisuke; Sasa, Kimikazu; Kitagawa, Jun-ichi; Ikarashi, Satoshi; Nishimura, Tomohiro; Wong, Ying-Shee; Satou, Yukihiko; Handa, Koji; Takahashi, Tsutomu; Sato, Masanori; Yamagata, Takeyasu

    2011-01-01

    A tremendous amount of radioactivity was discharged because of the damage to cooling systems of nuclear reactors in the Fukushima No. 1 nuclear power plant in March 2011. Fukushima and its adjacent prefectures were contaminated with fission products from the accident. Here, we show a geographical distribution of radioactive iodine, tellurium, and cesium in the surface soils of central-east Japan as determined by gamma-ray spectrometry. Especially in Fukushima prefecture, contaminated area spreads around Iitate and Naka-Dori for all the radionuclides we measured. Distributions of the radionuclides were affected by the physical state of each nuclide as well as geographical features. Considering meteorological conditions, it is concluded that the radioactive material transported on March 15 was the major contributor to contamination in Fukushima prefecture, whereas the radioactive material transported on March 21 was the major source in Ibaraki, Tochigi, Saitama, and Chiba prefectures and in Tokyo. PMID:22084070

  13. Analysis of Japanese Radionuclide Monitoring Data of Food Before and After the Fukushima Nuclear Accident

    PubMed Central

    2015-01-01

    In an unprecedented food monitoring campaign for radionuclides, the Japanese government took action to secure food safety after the Fukushima nuclear accident (Mar. 11, 2011). In this work we analyze a part of the immense data set, in particular radiocesium contaminations in food from the first year after the accident. Activity concentrations in vegetables peaked immediately after the campaign had commenced, but they decreased quickly, so that by early summer 2011 only a few samples exceeded the regulatory limits. Later, accumulating mushrooms and dried produce led to several exceedances of the limits again. Monitoring of meat started with significant delay, especially outside Fukushima prefecture. After a buildup period, contamination levels of meat peaked by July 2011 (beef). Levels then decreased quickly, but peaked again in September 2011, which was primarily due to boar meat (a known accumulator of radiocesium). Tap water was less contaminated; any restrictions for tap water were canceled by April 1, 2011. Pre-Fukushima 137Cs and 90Sr levels (resulting from atmospheric nuclear explosions) in food were typically lower than 0.5 Bq/kg, whereby meat was typically higher in 137Cs and vegetarian produce was usually higher in 90Sr. The correlation of background radiostrontium and radiocesium indicated that the regulatory assumption after the Fukushima accident of a maximum activity of 90Sr being 10% of the respective 137Cs concentrations may soon be at risk, as the 90Sr/137Cs ratio increases with time. This should be taken into account for the current Japanese food policy as the current regulation will soon underestimate the 90Sr content of Japanese foods. PMID:25621976

  14. Daily variation of radiation dose rate after the Fukushima Nuclear Accident

    NASA Astrophysics Data System (ADS)

    Yamauchi, Masatoshi

    2015-04-01

    After the radioactive contamination of the lands from the Fukushima Nuclear Power Plant accident, the radiation dose rates observed by the dosimeters often shows daily variations, at different local times at different places or time. These variations are caused by different reasons: the temperature-dependent characteristics of the dosimeter (instrumental effect), the daily convective wind that lifts up the radioactive small particle on the ground (local effect), and the daily sea-land wind that transports the radioactive small particle from highly contaminated area (regional effect). The last type is most important in understanding the internal dose by air taking. However, while very regular patterns can easily be judged as instrumental effect, variations that strongly depend on the weather conditions are not easily judged. Combining the atmospheric electric field measurement near the ground (potential gradient, PG) with the wind and weather data, some of these unclear cases can be classified into above three reasoning, which will be shown in the presentation. Thus, the PG measurement is important right after any nuclear accidents in the future.

  15. The impact of accident attention, ideology, and environmentalism on American attitudes toward nuclear energy.

    PubMed

    Besley, John C; Oh, Sang-Hwa

    2014-05-01

    This study involves the analysis of three waves of survey data about nuclear energy using a probability-based online panel of respondents in the United States. Survey waves included an initial baseline survey conducted in early 2010, a follow-up survey conducted in 2010 following the Deepwater Horizon oil spill in the Gulf of Mexico, and an additional follow-up conducted just after the 2011 Fukushima, Japan, nuclear accident. The central goal is to assess the degree to which changes in public views following an accident are contingent on individual attention and respondent predispositions. Such results would provide real-world evidence of motivated reasoning. The primary analysis focuses on the impact of Fukushima and how the impact of individual attention to energy issues is moderated by both environmental views and political ideology over time. The analysis uses both mean comparisons and multivariate statistics to test key relationships. Additional variables common in the study of emerging technologies are included in the analysis, including demographics, risk and benefit perceptions, and views about the fairness of decisionmakers in both government and the private sector. PMID:24329941

  16. The biological impacts of the Fukushima nuclear accident on the pale grass blue butterfly

    PubMed Central

    Hiyama, Atsuki; Nohara, Chiyo; Kinjo, Seira; Taira, Wataru; Gima, Shinichi; Tanahara, Akira; Otaki, Joji M.

    2012-01-01

    The collapse of the Fukushima Dai-ichi Nuclear Power Plant caused a massive release of radioactive materials to the environment. A prompt and reliable system for evaluating the biological impacts of this accident on animals has not been available. Here we show that the accident caused physiological and genetic damage to the pale grass blue Zizeeria maha, a common lycaenid butterfly in Japan. We collected the first-voltine adults in the Fukushima area in May 2011, some of which showed relatively mild abnormalities. The F1 offspring from the first-voltine females showed more severe abnormalities, which were inherited by the F2 generation. Adult butterflies collected in September 2011 showed more severe abnormalities than those collected in May. Similar abnormalities were experimentally reproduced in individuals from a non-contaminated area by external and internal low-dose exposures. We conclude that artificial radionuclides from the Fukushima Nuclear Power Plant caused physiological and genetic damage to this species. PMID:22880161

  17. Fukushima Daiichi Nuclear Accident; based on the Final Report of Atomic Energy Society of Japan

    NASA Astrophysics Data System (ADS)

    Sekimura, Naoto

    2014-09-01

    The Atomic Energy Society of Japan (AESJ) published the Final Report of the AESJ Investigation Committee on Fukushima Daiichi NPS Accident in March 2014. The AESJ is responsible to identify the underlying root causes of the accident through technical surveys and analyses, and to offer solutions for nuclear safety. At the Fukushima Daiichi, Units 1 to 3, which were under operation, were automatically shut down at 14:46 on March 11, 2011 by the Tohoku District-off the Pacific Ocean Earthquake. About 50 minutes later, the tsunami flooded and destroyed the emergency diesel generators, the seawater cooling pumps, the electric wiring system and the DC power for Units 1, 2 and 4, resulting in loss of all power except for an air-cooled emergency diesel generator at Unit 6. Unit 3 lost all AC power, and later lost DC before dawn of March 13. Cooling the reactors and monitoring the results were heavily dependent on electricity for high-pressure water injection, depressurizing the reactor, low pressure water injection, and following continuous cooling. In Unit 3, for example, recent re-evaluation in August 2014 by TEPCO shows that no cooling water was injected into the reactor core region after 8 PM on March 12, leading to the fuel melting from 5:30 AM on March 13. Even though seawater was injected from fire engines afterwards, the rupture of pressure vessel was caused and the majority of melted fuel dropped into the containment vessel of Unit 3. The estimation of amount of radioactive materials such as Xe-133, I-131, Cs-137 and Cs-134, emitted to the environment from Units 1 to 3 is discussed in the presentation. Direct causes of the accident identified in the AESJ Report were, 1) inadequate tsunami measures, 2) inadequate severe accident management measures and 3) inadequate emergency response, post-accident management/mitigation, and recovery measures. These were caused by the following underlying factors, i.e., a) lack of awareness on the roles and responsibilities by

  18. Cancer incidence in northern Sweden before and after the Chernobyl nuclear power plant accident.

    PubMed

    Alinaghizadeh, Hassan; Tondel, Martin; Walinder, Robert

    2014-08-01

    Sweden received about 5 % of the total release of (137)Cs from the Chernobyl nuclear power plant accident in 1986. The distribution of the fallout mainly affected northern Sweden, where some parts of the population could have received an estimated annual effective dose of 1-2 mSv per year. It is disputed whether an increased incidence of cancer can be detected in epidemiological studies after the Chernobyl nuclear power plant accident outside the former Union of Soviet Socialist Republics. In the present paper, a possible exposure-response pattern between deposition of (137)Cs and cancer incidence after the Chernobyl nuclear power plant accident was investigated in the nine northernmost counties of Sweden (2.2 million inhabitants in 1986). The activity of (137)Cs from the fallout maps at 1986 was used as a proxy for the received dose of ionizing radiation. Diagnoses of cancer (ICD-7 code 140-209) from 1980 to 2009 were received from the Swedish Cancer Registry (273,222 cases). Age-adjusted incidence rate ratios, stratified by gender, were calculated with Poisson regression in two closed cohorts of the population in the nine counties 1980 and 1986, respectively. The follow-up periods were 1980-1985 and 1986-2009, respectively. The average surface-weighted deposition of (137)Cs at three geographical levels; county (n = 9), municipality (n = 95) and parish level (n = 612) was applied for the two cohorts to study the pre- and the post-Chernobyl periods separately. To analyze time trends, the age-standardized total cancer incidence was calculated for the general Swedish population and the population in the nine counties. Joinpoint regression was used to compare the average annual percent change in the general population and the study population within each gender. No obvious exposure-response pattern was seen in the age-adjusted total cancer incidence rate ratios. A spurious association between fallout and cancer incidence was present, where areas with the

  19. U.S. Department of Energy Accident Resistant SiC Clad Nuclear Fuel Development

    SciTech Connect

    George W. Griffith

    2011-10-01

    A significant effort is being placed on silicon carbide ceramic matrix composite (SiC CMC) nuclear fuel cladding by Light Water Reactor Sustainability (LWRS) Advanced Light Water Reactor Nuclear Fuels Pathway. The intent of this work is to invest in a high-risk, high-reward technology that can be introduced in a relatively short time. The LWRS goal is to demonstrate successful advanced fuels technology that suitable for commercial development to support nuclear relicensing. Ceramic matrix composites are an established non-nuclear technology that utilizes ceramic fibers embedded in a ceramic matrix. A thin interfacial layer between the fibers and the matrix allows for ductile behavior. The SiC CMC has relatively high strength at high reactor accident temperatures when compared to metallic cladding. SiC also has a very low chemical reactivity and doesn't react exothermically with the reactor cooling water. The radiation behavior of SiC has also been studied extensively as structural fusion system components. The SiC CMC technology is in the early stages of development and will need to mature before confidence in the developed designs can created. The advanced SiC CMC materials do offer the potential for greatly improved safety because of their high temperature strength, chemical stability and reduced hydrogen generation.

  20. Transgenic plants are sensitive bioindicators of nuclear pollution caused by the Chernobyl accident

    SciTech Connect

    Kovalchuk, I.; Kovalchuk, O. |; Arkhipov, A.; Hohn, B.

    1998-11-01

    To evaluate the genetic consequences of radioactive contamination originating from the Nuclear reactor accident of Chernobyl on indigenous populations of plants and animals, it is essential to determine the rates of accumulating genetic changes in chronically irradiated populations. An increase in germline mutation rates in humans living close to the Chernobyl Nuclear Power Plant site, and a two- to tenfold increase in germline mutations in barn swallows breeding in Chernobyl have been reported. Little is known, however, about the effects of chronic irradiation on plant genomes. Ionizing radiation causes double-strand breaks in DNA, which are repaired via illegitimate or homologous recombination. The authors make use of Arabidopsis thaliana plants carrying a {beta}-glucuronidase marker gene as a recombination substrate to monitor genetic alterations in plant populations, which are caused by nuclear pollution of the environment around Chernobyl. A significant increase in somatic intrachromosomal recombination frequencies was observed at nuclear pollution levels from 0.1--900 Ci/km{sup 2}, consistent with an increase in chromosomal aberrations. This bioindicator may serve as a convenient and ethically acceptable alternative to animal systems.

  1. Evaluation of a potential nuclear fuel repository criticality: Lessons learned

    SciTech Connect

    Wilson, J.R.; Evans, D.

    1995-10-01

    This paper presents lessons learned from a Probabilistic Risk Assessment (PRA) of the potential for a criticality in a repository containing spent nuclear fuel with high enriched uranium. The insights gained consisted of remarkably detailed conclusions about design issues, failure mechanisms, frequencies and source terms for events up to 10,000 years in the future. Also discussed are the approaches taken by the analysts in presenting this very technical report to a nontechnical and possibly antagonistic audience.

  2. Follow-up studies on genome damage in children after Chernobyl nuclear power plant accident.

    PubMed

    Fucic, Aleksandra; Aghajanyan, Anna; Druzhinin, Vladimir; Minina, Varvara; Neronova, Elizaveta

    2016-09-01

    As children are more susceptible to ionizing radiation than adults, each nuclear accident demands special attention and care of this vulnerable population. The Chernobyl nuclear disaster occurred in a region populated with a large number of children, but despite all efforts and expertise of nuclear specialists, it was not possible to avoid casualties. As vast regions of Ukraine, Belarus and Russia were exposed to doses of ionizing radiation, which are known to be related with different diseases, shortly after the accident medical surveillance was launched, which also included analysis of genome damage. Child population affected by internal and external radiation consisted of subjects exposed prenatally, postnatally (both evacuated and non-evacuated), born by irradiated fathers who worked as liquidators, and parents exposed environmentally. In all groups of children during the last 30 years who were exposed to doses which were significantly higher than that recommended for general population of 1 mSv per year, increased genome damage was detected. Increased genome damage includes statistically higher frequency of dicentric and ring chromosomes, chromated and chromosome breaks, acentric fragments, translocations, and micronuclei. The presence of rogue cells confirmed internal contamination. Genome instability and radiosensitivity in children was detected both in evacuated and continuously exposed children. Today the population exposed to ionizing radiation in 1986 is in reproductive period of life and follow-up of this population and their offspring is of great importance. This review aims to give insight in results of studies, which reported genome damage in children in journals without language restrictions. PMID:27329326

  3. Calculation notes that support accident scenario and consequence determination of a waste tank criticality

    SciTech Connect

    Crowe, R.D.

    1996-09-27

    The purpose of this calculation note is to provide the basis for criticality consequences for the Tank Farm Safety Analysis Report (FSAR). Criticality scenario is developed and details and description of the analysis methods are provided.

  4. Criticality Safety Analysis Of As-loaded Spent Nuclear Fuel Casks

    SciTech Connect

    Banerjee, Kaushik; Scaglione, John M

    2015-01-01

    The final safety analysis report (FSAR) or the safety analysis report (SAR) for a particular spent nuclear fuel (SNF) cask system documents models and calculations used to demonstrate that a system meets the regulatory requirements under all normal, off-normal, and accident conditions of spent fuel storage, and normal and accident conditions of transportation. FSAR/SAR calculations and approved content specifications are intended to be bounding in nature to certify cask systems for a variety of fuel characteristics with simplified SNF loading requirements. Therefore, in general, loaded cask systems possess excess and uncredited criticality margins (i.e., the difference between the licensing basis and the as-loaded calculations). This uncredited margin could be quantified by employing more detailed cask-specific evaluations that credit the actual as-loaded cask inventory, and taking into account full (actinide and fission product) burnup credit. This uncredited criticality margin could be potentially used to offset (1) uncertainties in the safety basis that needs to account for the effects of system aging during extended dry storage prior to transportation, and (2) increases in SNF system reactivity over a repository performance period (e.g., 10,000 years or more) as the system undergoes degradation and internal geometry changes. This paper summarizes an assessment of cask-specific, as-loaded criticality margins for SNF stored at eight reactor sites (215 loaded casks were analyzed) under fully flooded conditions to assess the margins available during transportation after extended storage. It is observed that the calculated keff margin varies from 0.05 to almost 0.3 Δkeff for the eight selected reactor sites, demonstrating that significant uncredited safety margins are present. In addition, this paper evaluates the sufficiency of this excess margin in applications involving direct disposal of currently loaded SNF casks.

  5. Associations between Disaster Exposures, Peritraumatic Distress, and Posttraumatic Stress Responses in Fukushima Nuclear Plant Workers following the 2011 Nuclear Accident: The Fukushima NEWS Project Study

    PubMed Central

    Shigemura, Jun; Tanigawa, Takeshi; Nishi, Daisuke; Matsuoka, Yutaka; Nomura, Soichiro; Yoshino, Aihide

    2014-01-01

    Background The 2011 Fukushima Daiichi Nuclear Power Plant accident was the worst nuclear disaster since Chernobyl. The nearby Daini plant also experienced substantial damage but remained intact. Workers for the both plants experienced multiple stressors as disaster victims and workers, as well as the criticism from the public due to their company's post-disaster management. Little is known about the psychological pathway mechanism from nuclear disaster exposures, distress during and immediately after the event (peritraumatic distress; PD), to posttraumatic stress responses (PTSR). Methods A self-report questionnaire was administered to 1,411 plant employees (Daiichi, n = 831; Daini, n = 580) 2–3 months post-disaster (total response rate: 80.2%). The socio-demographic characteristics and disaster-related experiences were assessed as independent variables. PD and PTSR were measured by the Japanese versions of Peritraumatic Distress Inventory and the Impact of Event Scale-Revised, respectively. The analysis was conducted separately for the two groups. Bivariate regression analyses were performed to assess the relationships between independent variables, PD, and PTSR. Significant variables were subsequently entered in the multiple regression analyses to explore the pathway mechanism for development of PTSR. Results For both groups, PTSR highly associated with PD (Daiichi: adjusted β, 0.66; p<0.001; vs. Daini: adjusted β, 0.67; p<0.001). PTSR also associated with discrimination/slurs experience (Daiichi: 0.11; p<0.001; vs. Daini, 0.09; p = 0.005) and presence of preexisting illness(es) (Daiichi: 0.07; p = 0.005; vs. Daini: 0.15; p<.0001). Other disaster-related variables were likely to be associated with PD than PTSR. Conclusion Among the Fukushima nuclear plant workers, disaster exposures associated with PD. PTSR was highly affected by PD along with discrimination/slurs experience. PMID:24586278

  6. Atmospheric Radionuclides from the Fukushima Nuclear Accident-Two years observations in Tsukuba, Japan

    NASA Astrophysics Data System (ADS)

    Igarashi, Yasuhito; Kajino, Mizuo; Zaizen, Yuji; Adachi, Koji; Mikami, Masao; Kita, Kazuyuki; Hatano, Yuko

    2013-04-01

    The accident of Fukushima Dai-Ichi Nuclear Power Plant of the Tokyo Electric Power Corporation arisen by the hit of great earthquake and tsunami in March 11, 2011, emitted abundant fresh radioactive material to the atmospheric environment. The amount has been estimated to be at least a few-tenth of those from the Chernobyl accident (by NISA, etc.). By this large-scale contamination, atmospheric environments over Japan, especially the eastern part, were seriously impacted with such a massive amount of the anthropogenic radionuclides (e.g. typical hotspots). So the persisting aftermath is one of the concerns. Although the heavy primary emission seems to be terminated until April of 2011, 2ndary emissions from contaminated ground surface, coppices, fields, roads, any burnings of the contaminated materials generated the resuspension of radionuclides into the atmosphere. With 2-years observation for the Fukushima radioactivity at the Meteorological Research Institute, Japan (MRI) such persisting resuspension is considered in this presentation. The resuspension seems still in difficulty to give forecast by computer modeling; the observations are indispensable bodies of the research even in the future. The MRI has carried out observations of the atmospheric radionuclides, which are long-lived with potentials of environmental and health impacts, for more than 50 years. Aiming at to clarify temporal change in concentration of anthropogenic radionuclides in the atmosphere and its control factors, the observations have continued over the long period. The long-lasting impacts of the Fukushima accident are addressed with our long-term time series of the atmospheric radioactivity as a reference.

  7. A comparison of the dose from natural radionuclides and artificial radionuclides after the Fukushima nuclear accident

    PubMed Central

    Hosoda, Masahiro; Tokonami, Shinji; Omori, Yasutaka; Ishikawa, Tetsuo; Iwaoka, Kazuki

    2016-01-01

    Due to the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident, the evacuees from Namie Town still cannot reside in the town, and some continue to live in temporary housing units. In this study, the radon activity concentrations were measured at temporary housing facilities, apartments and detached houses in Fukushima Prefecture in order to estimate the annual internal exposure dose of residents. A passive radon–thoron monitor (using a CR-39) and a pulse-type ionization chamber were used to evaluate the radon activity concentration. The average radon activity concentrations at temporary housing units, including a medical clinic, apartments and detached houses, were 5, 7 and 9 Bq m−3, respectively. Assuming the residents lived in these facilities for one year, the average annual effective doses due to indoor radon in each housing type were evaluated as 0.18, 0.22 and 0.29 mSv, respectively. The average effective doses to all residents in Fukushima Prefecture due to natural and artificial sources were estimated using the results of the indoor radon measurements and published data. The average effective dose due to natural sources for the evacuees from Namie Town was estimated to be 1.9 mSv. In comparison, for the first year after the FDNPP accident, the average effective dose for the evacuees due to artificial sources from the accident was 5.0 mSv. Although residents' internal and external exposures due to natural radionuclides cannot be avoided, it might be possible to lower external exposure due to the artificial radionuclides by changing some behaviors of residents. PMID:26838130

  8. Environmental radioactivity measurements in Greece following the Fukushima Daichi nuclear accident.

    PubMed

    Potiriadis, C; Kolovou, M; Clouvas, A; Xanthos, S

    2012-07-01

    Since the double disaster of the 9.0 magnitude earthquake and tsunami that affected hundreds of thousands of people and seriously damaged the Fukushima Daichi power plant in Japan on 11 March 2011, traces of radioactive emissions from Fukushima have spread across the entire northern hemisphere. The radioactive isotope of iodine (131)I that was generated by the nuclear accident in Fukushima arrived in Greece on 24 March 2011. Radioactive iodine is present in the air either as gas or bound to particles (aerosols). The maximum (131)I concentrations were measured between 3 and 5 April 2011. In aerosols the maximum (131)I values measured in Southern Greece (Athens) and Northern Greece (Thessaloniki) were 585±70 and 408±61 μΒq m(-3), respectively. (131)I concentrations in gas were about 3.5 times higher than in aerosols. Since 29 April 2011, the (131)I concentration has been below detection limits. Traces of (137)Cs and (134)Cs were also measured in the air filters with an activity ratio of (137)Cs/(134)Cs equal to 1 and (131)I/(137)Cs activity ratio of about 3. Since 16 May 2011, the (137)Cs concentration in air has been determined to be about the same as before the Fukushima accident. Traces of (131)I were also measured in grass and milk. The maximum measured activity of (131)I in sheep milk was about 2 Bq l(-1) which is 5000 times less than that measured in Greece immediately after the Chernobyl accident. The measured activity concentrations of artificial radionuclides in Greece due to the Fukushima release, have been very low, with no impact on human health. PMID:22090415

  9. Iodine isotopes in precipitation: temporal responses to (129)i emissions from the fukushima nuclear accident.

    PubMed

    Xu, Sheng; Freeman, Stewart P H T; Hou, Xiaolin; Watanabe, Akira; Yamaguchi, Katsuhiko; Zhang, Luyuan

    2013-10-01

    The Fukushima Dai-ichi Nuclear Power Plant accident in 2011 has released a large amount of radionuclides to the atmosphere, and the radioactive plume has been dispersed to a large area in Europe and returned to Asia. To explore long-term trend of the Fukushima-derived radioactive plume and the behavior of harmful radioiodine in the atmosphere, long-term precipitation samples have been collected over 2010-2012 at Fukushima, Japan for determination of long-lived (129)I. It was observed that (129)I concentrations of 1.2 × 10(8) atom/L in 2010 before the accident dramatically increased by ∼4 orders of magnitude to 7.6 × 10(11) atom/L in March 2011 immediately after the accident, with a (129)I/(127)I ratio up to 6.9 × 10(-5). Afterward, the (129)I concentrations in precipitation decreased exponentially to ∼3 × 10(9) atom/L by October 2011 with a half-life of about 29 days. This declining trend of (129)I concentrations in precipitation was interrupted around October 2011 by a new input of (129)I to the atmosphere following a second exponential decrease. Such a cycle has occurred three times until the present. This temporal variation can be attributed to alternating (129)I dispersion and resuspension from the contaminated local environment. A (129)I/(131)I atomic ratio of 16 ± 1 obtained from rainwater samples is comparable with a value estimated for surface soil samples. (129)I results from Denmark suggest an insignificant effect of (129)I released from Fukushima to the (129)I levels in Europe. PMID:24000802

  10. A comparison of the dose from natural radionuclides and artificial radionuclides after the Fukushima nuclear accident.

    PubMed

    Hosoda, Masahiro; Tokonami, Shinji; Omori, Yasutaka; Ishikawa, Tetsuo; Iwaoka, Kazuki

    2016-07-01

    Due to the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident, the evacuees from Namie Town still cannot reside in the town, and some continue to live in temporary housing units. In this study, the radon activity concentrations were measured at temporary housing facilities, apartments and detached houses in Fukushima Prefecture in order to estimate the annual internal exposure dose of residents. A passive radon-thoron monitor (using a CR-39) and a pulse-type ionization chamber were used to evaluate the radon activity concentration. The average radon activity concentrations at temporary housing units, including a medical clinic, apartments and detached houses, were 5, 7 and 9 Bq m(-3), respectively. Assuming the residents lived in these facilities for one year, the average annual effective doses due to indoor radon in each housing type were evaluated as 0.18, 0.22 and 0.29 mSv, respectively. The average effective doses to all residents in Fukushima Prefecture due to natural and artificial sources were estimated using the results of the indoor radon measurements and published data. The average effective dose due to natural sources for the evacuees from Namie Town was estimated to be 1.9 mSv. In comparison, for the first year after the FDNPP accident, the average effective dose for the evacuees due to artificial sources from the accident was 5.0 mSv. Although residents' internal and external exposures due to natural radionuclides cannot be avoided, it might be possible to lower external exposure due to the artificial radionuclides by changing some behaviors of residents. PMID:26838130

  11. Monitoring radionuclides in the atmosphere over the Czech Republic after the Fukushima Nuclear Power Plant accident.

    PubMed

    Rulík, Petr; Hýža, Miroslav; Bečková, Věra; Borecký, Zdeněk; Havránek, Jiří; Hölgye, Zoltán; Lušňák, Jan; Malá, Helena; Matzner, Jan; Pilátová, Helena; Rada, Jiří; Schlesingerová, Eva; Šindelková, Eva; Dragounová, Lenka; Vlček, Jaroslav

    2015-02-01

    This paper presents the results of atmospheric radioactivity monitoring over the Czech Republic, as obtained by the Radiation Monitoring Network, following the Fukushima Dai-Ichi Nuclear Power Plant accident. Maximum values for (131)I were 5.6 mBq m(-3) in aerosol form and 13 mBq m(-3) in gaseous form. The maximum values for (134)Cs and (137)Cs were 0.64 and 0.72 mBq m(-3), respectively. The estimated effective half-time for removing the activity from the atmosphere was 6-7 d and 3.5 d for caesium and iodine, respectively. The gaseous-to-total activity ratios of (131)I ranged between 0.3 and 0.9, with an arithmetic mean value of 0.77. The mean value for the (134)Cs/(137)Cs ratios was close to 1.0. The effective inhalation dose due to the accident for an adult living in the Czech Republic was estimated at <4 × 10(-5) mSv, out of which the proportion of (131)I was 88%. PMID:24813185

  12. A magnetic carbon sorbent for radioactive material from the Fukushima nuclear accident.

    PubMed

    Yamaguchi, Daizo; Furukawa, Kazumi; Takasuga, Masaya; Watanabe, Koki

    2014-01-01

    Here we present the first report of a carbon-γ-Fe₂O₃ nanoparticle composite of mesoporous carbon, bearing COOH- and phenolic OH- functional groups on its surface, a remarkable and magnetically separable adsorbent, for the radioactive material emitted by the Fukushima Daiichi nuclear power plant accident. Contaminated water and soil at a level of 1,739 Bq kg(-1) ((134)Cs and (137)Cs at 509 Bq kg(-1) and 1,230 Bq kg(-1), respectively) and 114,000 Bq kg(-1) ((134)Cs and (137)Cs at 38,700 Bq kg(-1) and 75,300 Bq kg(-1), respectively) were decontaminated by 99% and 90% respectively with just one treatment carried out in Nihonmatsu city in Fukushima. Since this material is remarkably high performance, magnetically separable, and a readily applicable technology, it would reduce the environmental impact of the Fukushima accident if it were used. PMID:25116650

  13. Simultaneous sampling of indoor and outdoor airborne radioactivity after the Fukushima Daiichi nuclear power plant accident.

    PubMed

    Ishikawa, Tetsuo; Sorimachi, Atsuyuki; Arae, Hideki; Sahoo, Sarata Kumar; Janik, Miroslaw; Hosoda, Masahiro; Tokonami, Shinji

    2014-02-18

    Several studies have estimated inhalation doses for the public because of the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. Most of them were based on measurement of radioactivity in outdoor air and included the assumption that people stayed outdoors all day. Although this assumption gives a conservative estimate, it is not realistic. The "air decontamination factor" (ratio of indoor to outdoor air radionuclide concentrations) was estimated from simultaneous sampling of radioactivity in both inside and outside air of one building. The building was a workplace and located at the National Institute of Radiological Sciences (NIRS) in Chiba Prefecture, Japan. Aerosol-associated radioactive materials in air were collected onto filters, and the filters were analyzed by γ spectrometry at NIRS. The filter sampling was started on March 15, 2011 and was continued for more than 1 year. Several radionuclides, such as (131)I, (134)Cs, and (137)Cs were found by measuring the filters with a germanium detector. The air decontamination factor was around 0.64 for particulate (131)I and 0.58 for (137)Cs. These values could give implications for the ratio of indoor to outdoor radionuclide concentrations after the FDNPP accident for a similar type of building. PMID:24450729

  14. Establishing protective long term measures after severe nuclear accidents using multiple criteria.

    PubMed

    Papazoglou, I A; Kollas, J G

    1997-05-01

    This paper proposes a methodology supporting decisions on protective measures following severe nuclear accidents and demonstrates its use. A multicriteria decision analysis approach is adopted where value tradeoffs are postponed until the very last stage of the decision process. All feasible solutions are implicitly considered and evaluated in the chosen criteria. Technically inferior solutions are excluded. Only the non-dominated or efficient solutions forming the "efficient frontier" are retained and presented to the decision makers. Implementation of inefficient solutions is in this way avoided. A choice among the efficient solutions, although it implies value tradeoffs among the multiple criteria, avoids the direct and apriori assessment of preferences. An interactive computer package has been developed with which the decision maker can choose a point on the efficient frontier in the consequence space and immediately see the corresponding alternative in the decision space. The methodology is demonstrated through an application on the choice among possible protective measures in contaminated areas of the former USSR after the Chernobyl accident using as criteria the collective effective life-time dose received by the population and the cost associated with each possible decision. PMID:9106708

  15. Radiation situation in Kamchatka after the Fukushima nuclear power station accident

    NASA Astrophysics Data System (ADS)

    Sidorin, A. I.

    2013-12-01

    The chronology of events in Kamchatka related to the threat of radioactive contamination of the territory as a result of the Fukushima-1 nuclear power station (NPS) accident in Japan is briefly reviewed based on the published data. The accident happened on March 11, 2011, after a strong earthquake near the coast of Japan and the giant tsunami followed by the earthquake. The power supply was damaged and, as a result, the cooling system of NPS reactors was destroyed. Although the reactors did not explode, radioactive emissions from the damaged NPS discharged into the atmosphere and spread over large areas by the air flows. Information about the radiation situation in Kamchatka is controversial. Therefore, the author carried out regular monitoring of the radiation background during a hiking trip in Kamchatka in August 2011. The data are presented in this paper. It was concluded that the radiation background along the route of the trip was consistent (within the accuracy of measurement methods) with the normal values of a natural background. A thorough analysis of air, soil, food samples, etc., is required for a more detailed study to identify the presence of radionuclides in the atmospheric emissions from the damaged NPS in Japan.

  16. Geo-Space observation of atmospheric environmental effects associated with 2011 Fukushima nuclear accident

    NASA Astrophysics Data System (ADS)

    Pulinets, Sergey; Ouzounov, Dimitar; Hernandez-Pajares, Manuel; Hattori, Katsumi; Garcia-Rigo, Alberto

    2014-05-01

    Our approach of using multiple geo-space observation is based on the LAIC (Lithosphere- Atmosphere- Ionosphere Coupling) model and the gained experience during similar analysis of Three-Mile Island and Chernobyl accidents. We do collect a unique dataset of geophysical data for the period around the time of the most active phase of Fukushima explosions (from 12 March till 31 March, 71-90 DOY). We analyzed following data sets: (i) ground temperature and relative humidity data from the JMA network of Japan, (ii) satellite meteorological data and assimilative models to obtain the integrated water vapor chemical potential; (iii) the infrared emission on the top of atmosphere measured by NOAA and GEOS satellites estimated as Outgoing Longwave Radiation; and (iv) multiple ionospheric measurements , including ground based ionosondes, GPS vTEC from GEONET network, COSMIC/FORMOSAT constellation occultation data, JASON satellite TEC measurements, and tomography reconstruction technique to obtain 3D distribution of electron concentration around the Fukushima power plant. As a result we were able to detect the anomalies in different geophysical parameters representing the dynamics of the Fukushima nuclear accident development and the effects on the atmospheric environment. Their temporal evolution demonstrates the synergy in different atmospheric anomalies development what implies the existence of the common physical mechanism described by the LAIC model.

  17. A simplified model for calculating atmospheric radionuclide transport and early health effects from nuclear reactor accidents

    SciTech Connect

    Madni, I.K.; Cazzoli, E.G.; Khatib-Rahbar, M.

    1995-11-01

    During certain hypothetical severe accidents in a nuclear power plant, radionuclides could be released to the environment as a plume. Prediction of the atmospheric dispersion and transport of these radionuclides is important for assessment of the risk to the public from such accidents. A simplified PC-based model was developed that predicts time-integrated air concentration of each radionuclide at any location from release as a function of time integrated source strength using the Gaussian plume model. The solution procedure involves direct analytic integration of air concentration equations over time and position, using simplified meteorology. The formulation allows for dry and wet deposition, radioactive decay and daughter buildup, reactor building wake effects, the inversion lid effect, plume rise due to buoyancy or momentum, release duration, and grass height. Based on air and ground concentrations of the radionuclides, the early dose to an individual is calculated via cloudshine, groundshine, and inhalation. The model also calculates early health effects based on the doses. This paper presents aspects of the model that would be of interest to the prediction of environmental flows and their public consequences.

  18. Compendium of the Environmental Measurements Laboratory's research projects related to the Chernobyl nuclear accident

    SciTech Connect

    Volchok, H L; Chieco, N

    1986-10-01

    Following the accident at the Chernobyl nuclear reactor power station in the USSR on April 26, 1986, the Environmental Measurements Laboratory (EML) initiated a number of research projects as follows: (1) selected sites in both the Deposition and Surface Air networks were alerted and their sampling protocols adjusted to accommodate the anticipated arrival times and activity concentrations of the Chernobyl debris; (2) a number of cooperative programs involving field work, sampling, analysis and data interpretation were set up with institutions and scientists in other countries; (3) EML's Regional Baseline Station at Chester, NJ, as well as the roof of the Laboratory in New York City, provided bases for sampling and measurements to study the radionuclide concentrations, radiation levels, physical characteristics and potential biological implications of the Chernobyl fallout on the northeastern United States; and (4) the resulting fallout from the Chernobyl accident provided an 'experiment of opportunity' in that it enabled us to study fresh fission product deposition using collection systems resurrected from the 1950's and 1960's for comparison with current state-of-the-art methodology. The 13 reports of this volume have been entered separately into the data base.

  19. A Magnetic Carbon Sorbent for Radioactive Material from the Fukushima Nuclear Accident

    PubMed Central

    Yamaguchi, Daizo; Furukawa, Kazumi; Takasuga, Masaya; Watanabe, Koki

    2014-01-01

    Here we present the first report of a carbon-γ-Fe2O3 nanoparticle composite of mesoporous carbon, bearing COOH- and phenolic OH- functional groups on its surface, a remarkable and magnetically separable adsorbent, for the radioactive material emitted by the Fukushima Daiichi nuclear power plant accident. Contaminated water and soil at a level of 1,739 Bq kg−1 (134Cs and 137Cs at 509 Bq kg−1 and 1,230 Bq kg−1, respectively) and 114,000 Bq kg−1 (134Cs and 137Cs at 38,700 Bq kg−1 and 75,300 Bq kg−1, respectively) were decontaminated by 99% and 90% respectively with just one treatment carried out in Nihonmatsu city in Fukushima. Since this material is remarkably high performance, magnetically separable, and a readily applicable technology, it would reduce the environmental impact of the Fukushima accident if it were used. PMID:25116650

  20. Severe-accident-sequence assessment of hypothetical complete-station blackout at the Browns Ferry Nuclear Plant

    SciTech Connect

    Yue, D.D.; Condon, W.A.

    1981-01-01

    An investigation has been made of various accident sequence which may occur following a complete loss of offsite and onsite ac power at a Boiling Water Reactor nuclear power plant. The investigation was performed for the Browns Ferry Nuclear Power Plant, and all accident sequences resulted in a hypothetical core meltdown. Detailed calculations were performed with the MARCH computer meltdown. Detailed calcuations were performed with the MARCH computer code containing a decay power calculation which was modified to include the actinides. This change has resulted in shortening the time before core uncovery by approx. 18%, and reducing the time before the start of core melting by approx. 26%. Following the hypothetical core meltdown accident, the drywell electric penetration assembly seals have been identified as the most likely leak pathway outside the containment. This potential mode of containment failure occurs at a pressure approx. 30% lower than that analyzed in the Reactor Safety Study.

  1. Impact of Fuel Failure on Criticality Safety of Used Nuclear Fuel

    SciTech Connect

    Marshall, William BJ J; Wagner, John C

    2012-01-01

    Commercial used nuclear fuel (UNF) in the United States is expected to remain in storage for considerably longer periods than originally intended (e.g., <40 years). Extended storage (ES) time and irradiation of nuclear fuel to high-burnup values (>45 GWd/t) may increase the potential for fuel failure during normal and accident conditions involving storage and transportation. Fuel failure, depending on the severity, can result in changes to the geometric configuration of the fuel, which has safety and regulatory implications. The likelihood and extent of fuel reconfiguration and its impact on the safety of the UNF is not well understood. The objective of this work is to assess and quantify the impact of fuel reconfiguration due to fuel failure on criticality safety of UNF in storage and transportation casks. This effort is primarily motivated by concerns related to the potential for fuel degradation during ES periods and transportation following ES. The criticality analyses consider representative UNF designs and cask systems and a range of fuel enrichments, burnups, and cooling times. The various failed-fuel configurations considered are designed to bound the anticipated effects of individual rod and general cladding failure, fuel rod deformation, loss of neutron absorber materials, degradation of canister internals, and gross assembly failure. The results quantify the potential impact on criticality safety associated with fuel reconfiguration and may be used to guide future research, design, and regulatory activities. Although it can be concluded that the criticality safety impacts of fuel reconfiguration during transportation subsequent to ES are manageable, the results indicate that certain configurations can result in a large increase in the effective neutron multiplication factor, k{sub eff}. Future work to inform decision making relative to which configurations are credible, and therefore need to be considered in a safety evaluation, is recommended.

  2. Decrease of total activity with time at long distances from a nuclear accident or explosion.

    PubMed

    Dolejs, Josef

    2005-05-01

    Two data groups were analyzed: (1) the exposure rate in the former Czechoslovakia after the Chernobyl accident in 1986, and (2) the decrease of beta activity of an atmospheric fallout sample taken in Bratislava during 24 h on 30 May 1965. Both quantities decreased with the first power of time. This pattern of decrease is explained by applying the same mathematical formalism as is also used to describe the decrease in postnatal mortality with age. Following this formalism, the decrease of total activity with the first power of time could be seen as a consequence of a log-normal distribution of decay constants in the fallout. This differs slightly from earlier results that show the total activity decreasing with a power of 1.2 immediately after the nuclear explosion. PMID:15818480

  3. Distribution and risk assessment of radionuclides released by Fukushima nuclear accident at the northwest Pacific.

    PubMed

    Yu, Wen; He, Jianhua; Lin, Wuhui; Li, Yiliang; Men, Wu; Wang, Fenfen; Huang, Jiang

    2015-04-01

    In order to understand the impact of Fukushima Nuclear Accident (FNA) on the marine environment, seawater and a composite squid (Ommastrephe bartrami) sample were collected on the monitoring cruise XT01 during June 16-July 4, 2011. The concentration levels of Cesium-134, Cesium-137, Strontium-90, Silver-110 m, Cobalt-58 and Cobalt-60 were measured both for the seawater and squid samples. The elevated activity levels of Cesium-134 and Cesium-137 were found in the sampling area. Cesium-134 and Silver-110 m, which were usually undetectable before FNA, were also found in the squid sample, with the activity levels of 1.65 ± 0.13 Bq/kg-wet and 0.07 ± 0.01 Bq/kg-wet, respectively. The radiological assessment result showed that the radioactive release from the FNA would not have a significant adverse effect on marine biota at the population level. PMID:25644751

  4. Relative radiological impact from a reactor accident in the case of emerging nuclear fuels.

    PubMed

    Nicolaou, G

    2009-08-01

    An assessment has been carried out on the radiological impact on an area contaminated from an accident of a nuclear reactor loaded with different actinide fuels considered in transmutation and recycling schemes. The impact of these schemes is compared to reference cases of commercial UO2 and MOX fuels. The effective dose equivalent delivered to permanent residents has been calculated using the RESRAD code and used as an index for the assessment purposes. The highest and lowest doses would be delivered from the self-generating recycling of actinides in fast and thermal reactors, respectively. External irradiation is the main contributor to the dose delivered to the target population in comparison to ingestion and inhalation. The external dose delivered would be attributed for the first few years to 134Cs and for the following several tens of years to 137Cs. PMID:19590275

  5. [Characteristics of morphogenesis and growth processes of conifers in the Chernobyl nuclear accident zone].

    PubMed

    Kozubov, G M; Taskaev, A I

    2007-01-01

    In the article we present data on the study of morphogenesis and of growth processes of Scotch pine (Pinus sylvestris L.) and of Norwey spruce (Picea abies (L.) Karst.) vegetative organs after radiation exposure in the Chernobyl nuclear accident zone. The anomalies in morphogenesis processes at different absorbed doses are described in detail. It is established that the death of pine forest began under absorbed dose 80-100 Gy and more, mass yellowing of needles at 50-60 Gy, and maximal morphosis at 8-12 Gy. Inhibition phenomenon of growth processes under acute irradiation and giantism under durable chronic irradiation were also put under investigation. Features of radiation exposure on pine and fir growth processes at different ontogeny phases were characterized. High radio-sensitivity of Norwey spruce is established. PMID:17571730

  6. Global harmonization of food safety regulations: perspectives from Japan after the Fukushima nuclear accident.

    PubMed

    Yoshida, Mitsuru

    2014-08-01

    Japanese food self-sufficiency was only 39% on the basis of kcal in 2012, so Japan relies heavily on imported food. Hence the necessity of having international rules on the regulation of food contaminants is important especially for countries like Japan that depend on food imports. A One-Stop-Testing system is desired, in which the test result obtained from a single testing laboratory is accepted as valid worldwide. To establish this system, laboratory accreditation under international standards is a necessary step. Furthermore, the importance of supply of reference materials for internal quality control and proficiency testing for external quality control of each laboratory's analytical system is reviewed in connection with the experience of radioactive nuclide contamination resulting from the Fukushima nuclear power plant accident in March 2011. PMID:24105746

  7. Hematopoietic cell infusion for the treatment of nuclear disaster victims: New data from the Chernobyl accident

    PubMed Central

    KLYMENKO, SERGIY V.; BELYI, DAVID A.; ROSS, JOEL R.; OWZAR, KOUROS; JIANG, CHEN; LI, ZHIGUO; MINCHENKO, JANNA N.; KOVALENKO, ALEKSANDR N.; BEBESHKO, VOLODYMYR G.; CHAO, NELSON J.

    2011-01-01

    Purpose To present previously unavailable data on the use of stem cell administration to aid recovery of victims of the Chernobyl disaster. On 26 April 1986, an accident at Unit 4 of the Chernobyl Nuclear Power Plant took place during the planned test of one of the safety systems. The diagnosis of acute radiation syndrome (ARS) was confirmed in 134 individuals exposed to high levels of radiation. There were nine patients heretofore unreported in the scientific literature who underwent intraosseous injections of allogeneic bone marrow cells in Kyiv. Conclusions Transplantation was associated with significantly shortened time to recovery of granulocyte and platelet counts in these patients. While current guidelines would certainly include the use of cytokines, these data provide an indication of the effectiveness of stem cell transplant to treat victims of radiation exposure. PMID:21406047

  8. Verification of screening level for decontamination implemented after Fukushima nuclear accident

    PubMed Central

    Ogino, Haruyuki; Ichiji, Takeshi; Hattori, Takatoshi

    2012-01-01

    The screening level for decontamination that has been applied for the surface of the human body and contaminated handled objects after the Fukushima nuclear accident was verified by assessing the doses that arise from external irradiation, ingestion, inhalation and skin contamination. The result shows that the annual effective dose that arises from handled objects contaminated with the screening level for decontamination (i.e. 100 000 counts per minute) is <1 mSv y−1, which can be considered as the intervention exemption level in accordance with the International Commission on Radiological Protection recommendations. Furthermore, the screening level is also found to protect the skin from the incidence of a deterministic effect because the absorbed dose of the skin that arises from direct deposition on the surface of the human body is calculated to be lower than the threshold of the deterministic effect assuming a practical exposure duration. PMID:22228683

  9. Observations on the geology and geohydrology of the Chernobyl' nuclear accident site, Ukraine

    USGS Publications Warehouse

    Matzko, J.R.; Percious, D.J.; Rachlin, J.; Marples, D.R.

    1994-01-01

    The most highly contaminated surface areas from cesium-137 fallout from the April 1986 accident at the Chernobyl' nuclear power station in Ukraine occur within the 30-km radius evacuation zone set up around the station, and an 80-km lobe extending to the west-southwest. Lower levels of contamination extend 300 km to the west of the power station. The geology, the presence of surface water, a shallow water table, and leaky aquifers at depth make this an unfavorable environment for the long-term containment and storage of the radioactive debris. An understanding of the general geology and hydrology of the area is important to assess the environmental impact of this unintended waste storage site, and to evaluate the potential for radionuclide migration through the soil and rock and into subsurface aquifers and nearby rivers. -from Authors

  10. Simulating experimental investigation on the safety of nuclear heating reactor in loss-of-coolant accidents

    NASA Astrophysics Data System (ADS)

    Xu, Zhanjie

    1996-12-01

    The 5MW low temperature nuclear heating reactor (NHR-5) is a new and advanced type of nuclear reactor developed by Institute of Nuclear Energy Technology (INET) of Tsinghua University of China in 1989. Its main loop is a thermal-hydraulic system with natural circulation. This paper studies the safety of NHR under the condition of loss-of-coolant accidents (LOCAs) by means of simulant experiments. First, the background and necessity of the experiments are presented, then the experimental system, including the thermal-hydraulic system and the data collection system, and similarity criteria are introduced. Up to now, the discharge experiments with the residual heating power (20% rated heating power) have been carried out on the experimental system. The system parameters including circulation flow rate, system pressure, system temperature, void fraction, discharge mass and so on have been recorded and analyzed. Based on the results of the experiments, the conclusions are shown as follos: on the whole, the reactor is safe under the condition of LOCAs, but the thermal vacillations resulting from the vibration of the circulation flow rate are disadvantageous to the internal parts of the reactor core.

  11. Absorption of radionuclides from the Fukushima nuclear accident by a novel algal strain.

    PubMed

    Shimura, Hiroki; Itoh, Katsuhiko; Sugiyama, Atsushi; Ichijo, Sayaka; Ichijo, Masashi; Furuya, Fumihiko; Nakamura, Yuji; Kitahara, Ken; Kobayashi, Kazuhiko; Yukawa, Yasuhiro; Kobayashi, Tetsuro

    2012-01-01

    Large quantities of radionuclides have leaked from the Fukushima Daiichi Nuclear Power Plant into the surrounding environment. Effective prevention of health hazards resulting from radiation exposure will require the development of efficient and economical methods for decontaminating radioactive wastewater and aquatic ecosystems. Here we describe the accumulation of water-soluble radionuclides released by nuclear reactors by a novel strain of alga. The newly discovered green microalgae, Parachlorella sp. binos (Binos) has a thick alginate-containing extracellular matrix and abundant chloroplasts. When this strain was cultured with radioiodine, a light-dependent uptake of radioiodine was observed. In dark conditions, radioiodine uptake was induced by addition of hydrogen superoxide. High-resolution secondary ion mass spectrometry (SIMS) showed a localization of accumulated iodine in the cytosol. This alga also exhibited highly efficient incorporation of the radioactive isotopes strontium and cesium in a light-independent manner. SIMS analysis showed that strontium was distributed in the extracellular matrix of Binos. Finally we also showed the ability of this strain to accumulate radioactive nuclides from water and soil samples collected from a heavily contaminated area in Fukushima. Our results demonstrate that Binos could be applied to the decontamination of iodine, strontium and cesium radioisotopes, which are most commonly encountered after nuclear reactor accidents. PMID:22984475

  12. Absorption of Radionuclides from the Fukushima Nuclear Accident by a Novel Algal Strain

    PubMed Central

    Shimura, Hiroki; Itoh, Katsuhiko; Sugiyama, Atsushi; Ichijo, Sayaka; Ichijo, Masashi; Furuya, Fumihiko; Nakamura, Yuji; Kitahara, Ken; Kobayashi, Kazuhiko; Yukawa, Yasuhiro; Kobayashi, Tetsuro

    2012-01-01

    Large quantities of radionuclides have leaked from the Fukushima Daiichi Nuclear Power Plant into the surrounding environment. Effective prevention of health hazards resulting from radiation exposure will require the development of efficient and economical methods for decontaminating radioactive wastewater and aquatic ecosystems. Here we describe the accumulation of water-soluble radionuclides released by nuclear reactors by a novel strain of alga. The newly discovered green microalgae, Parachlorella sp. binos (Binos) has a thick alginate-containing extracellular matrix and abundant chloroplasts. When this strain was cultured with radioiodine, a light-dependent uptake of radioiodine was observed. In dark conditions, radioiodine uptake was induced by addition of hydrogen superoxide. High-resolution secondary ion mass spectrometry (SIMS) showed a localization of accumulated iodine in the cytosol. This alga also exhibited highly efficient incorporation of the radioactive isotopes strontium and cesium in a light-independent manner. SIMS analysis showed that strontium was distributed in the extracellular matrix of Binos. Finally we also showed the ability of this strain to accumulate radioactive nuclides from water and soil samples collected from a heavily contaminated area in Fukushima. Our results demonstrate that Binos could be applied to the decontamination of iodine, strontium and cesium radioisotopes, which are most commonly encountered after nuclear reactor accidents. PMID:22984475

  13. Dose evaluation in criticality accidents using response of Panasonic TL personal dosemeters (UD-809/UD-802).

    PubMed

    Zeyrek, C T; Gündüz, H

    2012-09-01

    This study gives the results of dosimetry measurements carried out in the Silène reactor at Valduc (France) with neutron and photon personal thermoluminescence dosemeters (TLDs) in mixed neutron and gamma radiation fields, in the frame of the international accident dosimetry intercomparison programme in 2002. The intercomparison consisted of a series of three irradiation scenarios. The scenarios took place at the Valduc site (France) by using the Silène experimental reactor. For neutron and photon dosimetry, Panasonic model UD-809 and UD-802 personal TLDs were used together. PMID:22389154

  14. SRTC criticality safety technical review: Nuclear Criticality Safety Evaluation 93-04 enriched uranium receipt

    SciTech Connect

    Rathbun, R.

    1993-10-13

    Review of NMP-NCS-930087, {open_quotes}Nuclear Criticality Safety Evaluation 93-04 Enriched Uranium Receipt (U), July 30, 1993, {close_quotes} was requested of SRTC (Savannah River Technology Center) Applied Physics Group. The NCSE is a criticality assessment to determine the mass limit for Engineered Low Level Trench (ELLT) waste uranium burial. The intent is to bury uranium in pits that would be separated by a specified amount of undisturbed soil. The scope of the technical review, documented in this report, consisted of (1) an independent check of the methods and models employed, (2) independent HRXN/KENO-V.a calculations of alternate configurations, (3) application of ANSI/ANS 8.1, and (4) verification of WSRC Nuclear Criticality Safety Manual procedures. The NCSE under review concludes that a 500 gram limit per burial position is acceptable to ensure the burial site remains in a critically safe configuration for all normal and single credible abnormal conditions. This reviewer agrees with that conclusion.

  15. Novel insights into Fukushima nuclear accident from isotopic evidence of plutonium spread along coastal rivers.

    PubMed

    Evrard, Olivier; Pointurier, Fabien; Onda, Yuichi; Chartin, Caroline; Hubert, Amélie; Lepage, Hugo; Pottin, Anne-Claire; Lefèvre, Irène; Bonté, Philippe; Laceby, J Patrick; Ayrault, Sophie

    2014-08-19

    The Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident led to important releases of radionuclides into the environment, and trace levels of plutonium (Pu) were detected in northeastern Japan. However, measurements of Pu isotopic atom and activity ratios are required to differentiate between the contributions of global nuclear test fallout and FDNPP emissions. In this study, we used a double-focusing sector field ICP-MS to measure Pu atom and activity ratios in recently deposited sediment along rivers draining the most contaminated part of the inland radioactive plume. Results showed that plutonium isotopes (i.e., (239)Pu, (240)Pu, (241)Pu, and (242)Pu) were detected in all samples, although in extremely low concentrations. The (241)Pu/(239)Pu atom ratios measured in sediment deposits (0.0017-0.0884) were significantly higher than the corresponding values attributed to the global fallout (0.00113 ± 0.00008 on average for the Northern Hemisphere between 31°-71° N: Kelley, J. M.; Bond, L. A.; Beasley, T. M. Global distribution of Pu isotopes and (237)Np. Sci. Total. Env. 1999, 237/238, 483-500). The results indicated the presence of Pu from FDNPP, in slight excess compared to the Pu background from global fallout that represented up to ca. 60% of Pu in the analyzed samples. These results demonstrate that this radionuclide has been transported relatively long distances (∼45 km) from FDNPP and been deposited in rivers representing a potential source of Pu to the ocean. In future, the high (241)Pu/(239)Pu atom ratio of the Fukushima accident sourced-Pu should be measured to quantify the supply of continental-originating material from Fukushima Prefecture to the Pacific Ocean. PMID:25014620

  16. Indication of the radioactive fallout in Riyadh, Saudi Arabia following the Fukushima nuclear accident.

    PubMed

    Alkhomashi, N; Almasoud, Fahad I

    2016-02-01

    On March 2011, a severe damage has occurred to Fukushima Di-iachi nuclear reactor complex in Japan following the huge earthquake and the resulting Tsunami. Consequently, vast amounts of radioactive fallout were released into the atmosphere and contaminated the environment in Japan. Soon after the accident, traces of anthropogenic radionuclides were detected in environmental samples collected in many parts in the northern hemisphere even very far away from Japan creating a global concern. There is no information about radioactive contamination in the Arabian Peninsula caused by the Japanese Fukushima nuclear accident. The first evidence of Fukushima radioactive fallout in Riyadh (24° 43' N, 46° 38' E), Saudi Arabia has been confirmed in April 8, 2011. The airborne fission products (131)I, (134)Cs and (137)Cs were measured in air samples. The radionuclide concentrations were determined by identifying their characteristic gamma rays using a germanium detector. Their activity concentrations were studied as a function of time over a period of 20 days at the end of which they had mostly fallen below our limit of detection. The maximum activity concentration of (131)I, (134)Cs and (137)Cs in air of, respectively, 323.7 ± 18.5, 17.2 ± 1.0 and 26.0 ± 1.8 μBq m(-3) were observed on April 10-11, 2011. The (131)I/(137)Cs and (134)Cs/(137)Cs activity ratio values in air were presented and discussed. Finally, the effective doses to the public of Riyadh city from inhalation of (131)I, (134)Cs and (137)Cs due to contribution from Fukushima incident was found far below levels of concern. PMID:26650827

  17. Chernobyl nuclear reactor accident fallout: Measurement and consequences. (Latest citations from the NTIS bibliographic database). Published Search

    SciTech Connect

    1994-01-01

    The bibliography contains citations concerning the consequences of radioactive fallout from the Chernobyl nuclear reactor accident. Citations discuss radioactive monitoring, health hazards, and radiation dosimetry. Radiation contamination in the air, soil, vegetation, and food is examined. (Contains a minimum of 210 citations and includes a subject term index and title list.)

  18. Chernobyl Nuclear Reactor accident fallout: Measurement and consequences. (Latest citations from the NTIS bibliographic database). Published Search

    SciTech Connect

    1996-11-01

    The bibliography contains citations concerning the consequences of radioactive fallout from the Chernobyl nuclear reactor accident. Citations discuss radioactive monitoring, health hazards, and radiation dosimetry. Radiation contamination in the air, soil, vegetation, and food is examined. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  19. Chernobyl nuclear accident: Effects on food. (Latest citations from the Food Science and Technology Abstracts database). Published Search

    SciTech Connect

    1993-09-01

    The bibliography contains citations concerning studies and measurements of the radioactive contamination by the Chernobyl nuclear reactor accident of food and the food chain. The studies cover meat and dairy products, vegetables, fish, food chains, and radioactive contamination of agricultural farms and lands. (Contains 250 citations and includes a subject term index and title list.)

  20. Chernobyl nuclear reactor accident fallout: Measurement and consequences. (Latest citations from the NTIS Bibliographic database). Published Search

    SciTech Connect

    1993-09-01

    The bibliography contains citations concerning the consequences of radioactive fallout from the Chernobyl nuclear reactor accident. Citations discuss radioactive monitoring, health hazards, and radiation dosimetry. Radiation contamination in the air, soil, vegetation, and food is examined. (Contains a minimum of 208 citations and includes a subject term index and title list.)

  1. Chernobyl nuclear reactor accident fallout: Measurement and consequences. (Latest citations from the NTIS bibliographic database). Published Search

    SciTech Connect

    1995-02-01

    The bibliography contains citations concerning the consequences of radioactive fallout from the Chernobyl nuclear reactor accident. Citations discuss radioactive monitoring, health hazards, and radiation dosimetry. Radiation contamination in the air, soil, vegetation, and food is examined. (Contains a minimum of 247 citations and includes a subject term index and title list.)

  2. Chernobyl nuclear reactor accident fallout: Measurement and consequences. (Latest citations from the NTIS bibliographic database). Published Search

    SciTech Connect

    1996-01-01

    The bibliography contains citations concerning the consequences of radioactive fallout from the Chernobyl nuclear reactor accident. Citations discuss radioactive monitoring, health hazards, and radiation dosimetry. Radiation contamination in the air, soil, vegetation, and food is examined. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  3. [Principles and methods of evaluation of radiation risk and pilots' health in accidents of nuclear power objects].

    PubMed

    Ushakov, I B; Davydov, B I; Soldatov, S K; Zuev, V G

    1999-01-01

    The article deals with methodic approaches to health state evaluation of pilots who participated in liquidation of events following accidents at nuclear power objects. The main approaches are indeterminancy principle for late radiation effects, economic approach to evaluation of radiation risk, principle of risks comparison, consideration of summarized effect of environmental factors, etc. Some authors' viewpoints are presented. PMID:10097562

  4. Radioactive pollution in Athens, Greece due to the Fukushima nuclear accident.

    PubMed

    Kritidis, P; Florou, H; Eleftheriadis, K; Evangeliou, N; Gini, M; Sotiropoulou, M; Diapouli, E; Vratolis, S

    2012-12-01

    As a result of the nuclear accident in Fukushima Dai-ichi power plant, which started on March 11, 2011, radioactive pollutants were transferred by air masses to various regions of the Northern hemisphere, including Europe. Very low concentrations of (131)I, (137)Cs and (134)Cs in airborne particulate matter were measured in Athens, Greece during the period of March 24 to April 28, 2011. The maximum air concentration of (131)I was measured on April 6, 2011 and equaled 490 ± 35 μBq m(-3). The maximum values of the two cesium isotopes were measured on the same day and equaled 180 ± 40 μBq m(-3) for (137)Cs and 160 ± 30 μBq m(-3) for (134)Cs. The average activity ratio of (131)I/(137)Cs in air was 3.0 ± 0.5, while the corresponding ratio of (137)Cs/(134)Cs equaled 1.1 ± 0.3. No artificial radionuclides could be detected in air after April 28, 2011. Traces of (131)I as a result of radioactive deposition were measured in grass, soil, sheep milk and meat. The total deposition of (131)I (dry + wet) was 34 ± 4 Bq m(-2), and of (137)Cs was less than 10 Bq m(-2). The maximum concentration of (131)I in grass was 2.1 ± 0.4 Bg kg(-1), while (134)Cs was not detected. The maximum concentrations of (131)I and (137)Cs in sheep milk were 1.7 ± 0.16 Bq kg(-1) and 0.6 ± 0.12 Bq kg(-1) respectively. Concentrations of (131)I up to 1.3 ± 0.2 Bq kg(-1) were measured in sheep meat. Traces of (131)I were found in a number of soil samples. The radiological impact of the Fukushima nuclear accident in Athens region was practically negligible, especially as compared to that of the Chernobyl accident and also to that of natural radioactivity. PMID:22197531

  5. Release of Pu isotopes from the Fukushima Daiichi Nuclear Power Plant accident to the marine environment was negligible.

    PubMed

    Bu, Wenting; Fukuda, Miho; Zheng, Jian; Aono, Tatsuo; Ishimaru, Takashi; Kanda, Jota; Yang, Guosheng; Tagami, Keiko; Uchida, Shigeo; Guo, Qiuju; Yamada, Masatoshi

    2014-08-19

    Atmospheric deposition of Pu isotopes from the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident has been observed in the terrestrial environment around the FDNPP site; however, their deposition in the marine environment has not been studied. The possible contamination of Pu in the marine environment has attracted great scientific and public concern. To fully understand this possible contamination of Pu isotopes from the FDNPP accident to the marine environment, we collected marine sediment core samples within the 30 km zone around the FDNPP site in the western North Pacific about two years after the accident. Pu isotopes ((239)Pu, (240)Pu, and (241)Pu) and radiocesium isotopes ((134)Cs and (137)Cs) in the samples were determined. The high activities of radiocesium and the (134)Cs/(137)Cs activity ratios with values around 1 (decay corrected to 15 March 2011) suggested that these samples were contaminated by the FDNPP accident-released radionuclides. However, the activities of (239+240)Pu and (241)Pu were low compared with the background level before the FDNPP accident. The Pu atom ratios ((240)Pu/(239)Pu and (241)Pu/(239)Pu) suggested that global fallout and the pacific proving ground (PPG) close-in fallout are the main sources for Pu contamination in the marine sediments. As Pu isotopes are particle-reactive and they can be easily incorporated with the marine sediments, we concluded that the release of Pu isotopes from the FDNPP accident to the marine environment was negligible. PMID:25050458

  6. Status and Value of International Standards for Nuclear Criticality Safety

    SciTech Connect

    Hopper, Calvin Mitchell

    2011-01-01

    This presentation provides an update to the author's standards report provided at the ICNC-2007 meeting. It includes a discussion about the difference between, and the value of participating in, the development of international 'consensus' standards as opposed to nonconsensus standards. Standards are developed for a myriad of reasons. Generally, standards represent an agreed upon, repeatable way of doing something as defined by an individual or group of people. They come in various types. Examples include personal, family, business, industrial, commercial, and regulatory such as military, community, state, federal, and international standards. Typically, national and international 'consensus' standards are developed by individuals and organizations of diverse backgrounds representing the subject matter users and developers of a service or product and other interested parties or organizations. Within the International Organization for Standardization (ISO), Technical Committee 85 (TC85) on nuclear energy, Subcommittee 5 (SC5) on nuclear fuel technology, there is a Working Group 8 (WG8) on standardization of calculations, procedures, and practices related to criticality safety. WG8 has developed, and is developing, ISO standards within the category of nuclear criticality safety of fissionable materials outside of reactors (i.e., nonreactor fissionable material nuclear fuel cycle facilities). Since the presentation of the ICNC-2007 report, WG8 has issued three new finalized international standards and is developing two more new standards. Nearly all elements of the published WG8 ISO standards have been incorporated into IAEA nonconsensus guides and standards. The progression of consensus standards development among international partners in a collegial environment establishes a synergy of different concepts that broadens the perspectives of the members. This breadth of perspectives benefits the working group members in their considerations of consensus standards

  7. Facial baroparesis: a critical differential diagnosis for scuba diving accidents--case report.

    PubMed

    Iakovlev, E V; Iakovlev, V V

    2014-01-01

    Facial nerve baroparesis is a rare and potentially under-reported complication of scuba diving. A diver, after surfacing from a shallow dive, developed isolated left-sided facial palsy accompanied by pain and decreased hearing in the left ear. No other signs or symptoms attributable to a scuba diving accident were detected. Forty minutes later, he heard a "pop" in the affected ear, after which all symptoms quickly resolved. Repeat neurological and ear examinations were normal. He showed no residual or new symptoms 24 hours later. The differential diagnosis of facial neurological deficit after diving includes decompression sickness, cerebral air embolism due to pulmonary barotrauma, facial nerve barotrauma and common conditions such as stroke and Bell's palsy. It is important to recognize the condition since recompression treatment can further damage the facial nerve. PMID:25558550

  8. Calculation notes that support accident scenario and consequence determination of a waste tank criticality

    SciTech Connect

    Crowe, R.D., Westinghouse Hanford

    1996-08-02

    The purpose of this calculation note is to provide the basis forcriticality consequences for the Tank Farm Safety Analysis Report(FSAR). Criticality scenario is developed and details and description of the analysis methods are provided.

  9. Dose estimation for nuclear power plant 4 accident in Taiwan at Fukushima nuclear meltdown emission level.

    PubMed

    Tang, Mei-Ling; Tsuang, Ben-Jei; Kuo, Pei-Hsuan

    2016-05-01

    An advanced Gaussian trajectory dispersion model is used to evaluate the evacuation zone due to a nuclear meltdown at the Nuclear Power Plant 4 (NPP4) in Taiwan, with the same emission level as that occurred at Fukushima nuclear meltdown (FNM) in 2011. Our study demonstrates that a FNM emission level would pollute 9% of the island's land area with annual effective dose ≥50 mSv using the meteorological data on 11 March 2011 in Taiwan. This high dose area is also called permanent evacuation zone (denoted as PEZ). The PEZ as well as the emergency-planning zone (EPZ) are found to be sensitive to meteorological conditions on the event. In a sunny day under the dominated NE wind conditions, the EPZ can be as far as 100 km with the first 7-day dose ≥20 mSv. Three hundred sixty-five daily events using the meteorological data from 11 March 2011 to 9 March 2012 are evaluated. It is found that the mean land area of Taiwan in becoming the PEZ is 11%. Especially, the probabilities of the northern counties/cities (Keelung, New Taipei, Taipei, Taoyuan, Hsinchu City, Hsinchu County and Ilan County) to be PEZs are high, ranging from 15% in Ilan County to 51% in Keelung City. Note that the total population of the above cities/counties is as high as 10 million people. Moreover, the western valleys of the Central Mountain Range are also found to be probable being PEZs, where all of the reservoirs in western Taiwan are located. For example, the probability can be as high as 3% in the far southern-most tip of Taiwan Island in Pingtung County. This shows that the entire populations in western Taiwan can be at risk due to the shortage of clean water sources under an event at FNM emission level, especially during the NE monsoon period. PMID:26913979

  10. A Perspective on Long-Term Recovery Following the Fukushima Nuclear Accident - 12075

    SciTech Connect

    Chen, S.Y.

    2012-07-01

    The tragic events at the Fukushima Daiichi Nuclear Power Station began occurring on March 11, 2011, following Japan's unprecedented earthquake and tsunami. The subsequent loss of external power and on-site cooling capacity severely compromised the plant's safety systems, and subsequently, led to core melt in the affected reactors and damage to spent nuclear fuel in the storage pools. Together with hydrogen explosions, this resulted in a substantial release of radioactive material to the environment (mostly Iodine-131 and Cesium- 137), prompting an extensive evacuation effort. The latest release estimate places the event at the highest severity level (Level 7) on the International Nuclear Event Scale, the same as the Chernobyl accident of 1986. As the utility owner endeavored to stabilize the damaged facility, environmental contamination continued to propagate and affect every aspect of daily life in the affected region of Japan. Elevated levels of radioactivity (mostly dominated by Cs-137 with the passage of time) were found in soil, drinking water, vegetation, produce, seafood, and other foodstuffs. An estimated 80,000 to 90,000 people were evacuated; more evacuations are being contemplated months after the accident, and a vast amount of land has become contaminated. Early actions were taken to ban the shipment and sale of contaminated food and drinking water, followed by later actions to ban the shipment and sale of contaminated beef, mushrooms, and seafood. As the event continues to evolve toward stabilization, the long-term recovery effort needs to commence - a process that doubtless will involve rather complex decision-making interactions between various stakeholders. Key issues that may be encountered and considered in such a process include (1) socio-political factors, (2) local economic considerations, (3) land use options, (4) remediation approaches, (5) decontamination methods, (6) radioactive waste management, (7) cleanup levels and options, and (8

  11. Fate of radiocesium in sewage treatment process released by the nuclear accident at Fukushima.

    PubMed

    Kamei-Ishikawa, Nao; Ito, Ayumi; Tagami, Keiko; Umita, Teruyuki

    2013-10-01

    The nuclear accident at the Fukushima Daiichi Nuclear Power Plant (FDNPP) which occurred after the Great East Japan Earthquake on March 11, 2011 resulted in releases of radionuclides such as (134)Cs (half-life:T1/2=2.06 yr), (137)Cs (T1/2=30.04 yr) and (131)I (T1/2=8.05 d) to the environment. For this paper, we observed the monthly variations of radiocesium ((134)Cs and (137)Cs) and stable Cs concentrations in influent, effluent, sewage sludge, and sludge ash collected from a sewage treatment plant 280 km north of the FDNPP from July to December, 2011. Using the stable Cs results, we concluded the mass balance of Cs in the sewage treatment plant showed that about 10% of the Cs entering the sewage treatment plant would be transferred to the sewage sludge, and then Cs in the sewage sludge was totally recovered in the sludge ash. The behavior of Cs was similar to that of Rb, but it was not similar to that of K in the sewage treatment process. PMID:23838042

  12. Episode analysis of deposition of radiocesium from the Fukushima Daiichi nuclear power plant accident.

    PubMed

    Morino, Yu; Ohara, Toshimasa; Watanabe, Mirai; Hayashi, Seiji; Nishizawa, Masato

    2013-03-01

    Chemical transport models played key roles in understanding the atmospheric behaviors and deposition patterns of radioactive materials emitted from the Fukushima Daiichi nuclear power plant after the nuclear accident that accompanied the great Tohoku earthquake and tsunami on 11 March 2011. However, model results could not be sufficiently evaluated because of limited observational data. We assess the model performance to simulate the deposition patterns of radiocesium ((137)Cs) by making use of airborne monitoring survey data for the first time. We conducted ten sensitivity simulations to evaluate the atmospheric model uncertainties associated with key model settings including emission data and wet deposition modules. We found that simulation using emissions estimated with a regional-scale (∼ 500 km) model better reproduced the observed (137)Cs deposition pattern in eastern Japan than simulation using emissions estimated with local-scale (∼ 50 km) or global-scale models. In addition, simulation using a process-based wet deposition module reproduced the observations well, whereas simulation using scavenging coefficients showed large uncertainties associated with empirical parameters. The best-available simulation reproduced the observed (137)Cs deposition rates in high-deposition areas (≥ 10 kBq m(-2)) within 1 order of magnitude and showed that deposition of radiocesium over land occurred predominantly during 15-16, 20-23, and 30-31 March 2011. PMID:23391028

  13. Post-Accident Sporadic Releases of Airborne Radionuclides from the Fukushima Daiichi Nuclear Power Plant Site.

    PubMed

    Steinhauser, Georg; Niisoe, Tamon; Harada, Kouji H; Shozugawa, Katsumi; Schneider, Stephanie; Synal, Hans-Arno; Walther, Clemens; Christl, Marcus; Nanba, Kenji; Ishikawa, Hirohiko; Koizumi, Akio

    2015-12-15

    The Fukushima nuclear accident (March 11, 2011) caused the widespread contamination of Japan by direct deposition of airborne radionuclides. Analysis of weekly air filters has revealed sporadic releases of radionuclides long after the Fukushima Daiichi reactors were stabilized. One major discharge was observed in August 2013 in monitoring stations north of the Fukushima Daiichi nuclear power plant (FDNPP). During this event, an air monitoring station in this previously scarcely contaminated area suddenly reported (137)Cs activity levels that were 30-fold above the background. Together with atmospheric dispersion and deposition simulation, radionuclide analysis in soil indicated that debris removal operations conducted on the FDNPP site on August 19, 2013 are likely to be responsible for this late release of radionuclides. One soil sample in the center of the simulated plume exhibited a high (90)Sr contamination (78 ± 8 Bq kg(-1)) as well as a high (90)Sr/(137)Cs ratio (0.04); both phenomena have usually been observed only in very close vicinity around the FDNPP. We estimate that through the resuspension of highly contaminated particles in the course of these earthmoving operations, gross (137)Cs activity of ca. 2.8 × 10(11) Bq has been released. PMID:26448161

  14. Forecasting Radiation Effects on Wildlife in Japan After the Fukushima Nuclear Accident, Based on Limited Information of Post-Accident Early Stage in 2011

    NASA Astrophysics Data System (ADS)

    Saito, M. U.; Doko, T.; Koike, F.

    2014-11-01

    Due to the 11 March 2011 Tohoku earthquake, massive radioactive materials were released from the Fukushima Daiichi Nuclear Power Plant (Fukushima NPP). It is crucial to predict the regional distribution and magnitude of the effects on wildlife by radioactive materials. However, during the post-accident early stage in 2011, limited information on large-scale pollution and prediction maps was open to public. Hence, this paper aimed to provide (1) the pollution map covering areas within 300 km from the Fukushima NPP where the radiation intensity exceeded 0.5 μSv/h, (2) pollution maps which predicted air dose for the next 30 years after the accident, and (3) maps of areas where wildlife might be affected by radioactive isotopes by the Fukushima nuclear accident. First, the relative contributions of 131I, 134Cs, and 137Cs were estimated from time series observation data. Second, a 30-year prediction of the pollution was calculated based on the isotope half-lives. Third, the chronic radiation effects on vertebrates were estimated using the threshold dose rate proposed by Sazykina et al. (2009). We examined the chronic radiation effects on morbidity, reproduction, and longevity. The results indicated that radioactive materials could have affected vertebrate morbidity within a 350 km2 area in early April 2011; the threshold level was the median result of Sazykina et al. (2009) with bootstrapping. Based on the prediction, a 15.5 km2 region will remain affected after 30 years. These areas should be monitored to confirm the effects of radioactivity on wildlife.

  15. Energy choices and risk beliefs: is it just global warming and fear of a nuclear power plant accident?

    PubMed

    Greenberg, Michael; Truelove, Heather Barnes

    2011-05-01

    A survey of 3,200 U.S. residents focused on two issues associated with the use of nuclear and coal fuels to produce electrical energy. The first was the association between risk beliefs and preferences for coal and nuclear energy. As expected, concern about nuclear power plant accidents led to decreased support for nuclear power, and those who believed that coal causes global warming preferred less coal use. Yet other risk beliefs about the coal and nuclear energy fuel cycles were stronger or equal correlates of public preferences. The second issue is the existence of what we call acknowledged risk takers, respondents who favored increased reliance on nuclear energy, although also noting that there could be a serious nuclear plant accident, and those who favored greater coal use, despite acknowledging a link to global warming. The pro-nuclear group disproportionately was affluent educated white males, and the pro-coal group was relatively poor less educated African-American and Latino females. Yet both shared four similarities: older age, trust in management, belief that the energy facilities help the local economy, and individualistic personal values. These findings show that there is no single public with regard to energy preferences and risk beliefs. Rather, there are multiple populations with different viewpoints that surely would benefit by hearing a clear and comprehensive national energy life cycle policy from the national government. PMID:21143259

  16. Examination of criticality accident alarm coverage on the operating floors of the X-333, X-330, and X-326 facilities at the Portsmouth Gaseous Diffusion Plant

    SciTech Connect

    Lee, B.L. Jr.; Dobelbower, M.C.; Woollard, J.; Skapik, C.W.

    1996-01-01

    This report summarizes the results of an evaluation of Criticality Accident Alarm System (CAAS) coverage of the operating floors (first floors) of the X-333, X-330, and X-326 buildings. CAAS coverage of the process cell floors (second floors) has been evaluated in previous reports. Coverage of the roadways around the three processing buildings by the cell floor detectors in these buildings has also been verified in a previous report. In order to evaluate coverage, the facilities were modeled using the Monte Carlo N-Particle Transport Computer Code (MCNP). MCNP was then used to simulate criticality accidents at various locations throughout the operating floors of the buildings and the associated neutron flux at the current detector locations was calculated. The neutron flux was then converted to an absorbed dose rate (in tissue) and compared with the Portsmouth criticality accident alarm set-point of 5mrad/hr. The parameters defining the simulated criticality accidents have been calculated as ``the minimum accident of concern`` as defined in ANSI Standard ANS 8.3-1986. These calculations are documented in Portsmouth report number POEF-SH-31. The results of this evaluation indicate that the X-333 Operating Floor CAAS may not alarm in response to a minimum accident of concern. This is primarily because of shielding provided by the numerous concrete columns used to support the second floor of this building and the large distances between the CAAS detectors. Conversely, the results indicate that the X-326 and the X-330 CAAS systems would alarm in response to a minimum accident of concern occurring on the operating floors of these buildings. It should be noted that the cell floors in these two buildings are supported with steel I-beams instead of the concrete columns used in the X-333 building.

  17. Dose evaluation based on 24Na activity in the human body at the JCO criticality accident in Tokai-mura.

    PubMed

    Momose, T; Tsujimura, N; Tasaki, T; Kanai, K; Kurihara, O; Hayashi, N; Shinohara, K

    2001-09-01

    24Na in the human body, activated by neutrons emitted at the JCO criticality accident, was observed for 62 subjects, where 148 subjects were measured by the whole body counter of JNC Tokai Works. The 148 subjects, including JCO employees and the contractors, residents neighboring the site and emergency service officers, were measured by the whole-body counter. The neutron-energy spectrum around the facility was calculated using neutron transport codes (ANISN and MCNP), and the relation between an amount of activated sodium in human body and neutron dose was evaluated from the calculated neutron energy spectrum and theoretical neutron capture probability by the human body. The maximum 24Na activity in the body was 7.7 kBq (83 Bq(24Na)/g(23Na)) and the relevant effective dose equivalent was 47 mSv. PMID:11791757

  18. Reference dosimetry measurements for the international intercomparison of criticality accident dosimetry SILENE 9-21 June 2002.

    PubMed

    Asselineau, B; Trompier, F; Texier, C; Itié, C; Médioni, R; Tikunov, D; Muller, H; Pelcot, G

    2004-01-01

    An international intercomparison of criticality accident dosimetry systems took place in the SILENE reactor, in June 2002. Participants from 60 laboratories irradiated their dosemeters (physical and biological) using two different configurations of the reactor. In preparation for this intercomparison, the leakage radiation fields were characterised by spectrometry and dosimetry measurements using the ROSPEC spectrometer associated with a NE-213 scintillator, ionisation chambers, GM counters, diodes and thermoluminescence dosemeters (TLDs). For this intercomparison, a large area was required to irradiate the dosemeters both in free air and on phantoms. Therefore, measurements of the uniformity of the field were performed with activation detectors and TLDs for neutron and gammas, respectively. This paper describes the procedures used and the results obtained. PMID:15353691

  19. GASFLOW: A computational model to analyze accidents in nuclear containment and facility buildings

    SciTech Connect

    Travis, J.R. ); Nichols, B.D.; Wilson, T.L.; Lam, K.L.; Spore, J.W.; Niederauer, G.F. )

    1993-01-01

    GASFLOW is a finite-volume computer code that solves the time-dependent, compressible Navier-Stokes equations for multiple gas species. The fluid-dynamics algorithm is coupled to the chemical kinetics of combusting liquids or gases to simulate diffusion or propagating flames in complex geometries of nuclear containment or confinement and facilities' buildings. Fluid turbulence is calculated to enhance the transport and mixing of gases in rooms and volumes that may be connected by a ventilation system. The ventilation system may consist of extensive ductwork, filters, dampers or valves, and fans. Condensation and heat transfer to walls, floors, ceilings, and internal structures are calculated to model the appropriate energy sinks. Solid and liquid aerosol behavior is simulated to give the time and space inventory of radionuclides. The solution procedure of the governing equations is a modified Los Alamos ICE'd-ALE methodology. Complex facilities can be represented by separate computational domains (multiblocks) that communicate through overlapping boundary conditions. The ventilation system is superimposed throughout the multiblock mesh. Gas mixtures and aerosols are transported through the free three-dimensional volumes and the restricted one-dimensional ventilation components as the accident and fluid flow fields evolve. Combustion may occur if sufficient fuel and reactant or oxidizer are present and have an ignition source. Pressure and thermal loads on the building, structural components, and safety-related equipment can be determined for specific accident scenarios. GASFLOW calculations have been compared with large oil-pool fire tests in the 1986 HDR containment test T52.14, which is a 3000-kW fire experiment. The computed results are in good agreement with the observed data.

  20. Reconstruction of 137Cs activity in the ocean following the Fukushima Daiichi Nuclear Power Plant Accident

    NASA Astrophysics Data System (ADS)

    Tsumune, Daisuke; Aoyama, Michio; Tsubono, Takaki; Tateda, Yutaka; Misumi, Kazuhiro; Hayami, Hiroshi; Toyoda, Yasuhiro; Maeda, Yoshiaki; Yoshida, Yoshikatsu; Uematsu, Mitsuo

    2014-05-01

    A series of accidents at the Fukushima Dai-ichi Nuclear Power Plant following the earthquake and tsunami of 11 March 2011 resulted in the release of radioactive materials to the ocean by two major pathways, direct release from the accident site and atmospheric deposition. We reconstructed spatiotemporal variability of 137Cs activity in the ocean by the comparison model simulations and observed data. We employed a regional scale and the North Pacific scale oceanic dispersion models, an atmospheric transport model, a sediment transport model, a dynamic biological compartment model for marine biota and river runoff model to investigate the oceanic contamination. Direct releases of 137Cs were estimated for more than 2 years after the accident by comparing simulated results and observed activities very close to the site. The estimated total amounts of directly released 137Cs was 3.6±0.7 PBq. Directly release rate of 137Cs decreased exponentially with time by the end of December 2012 and then, was almost constant. The daily release rate of 137Cs was estimated to be 3.0 x 1010 Bq day-1 by the end of September 2013. The activity of directly released 137Cs was detectable only in the coastal zone after December 2012. Simulated 137Cs activities attributable to direct release were in good agreement with observed activities, a result that implies the estimated direct release rate was reasonable, while simulated 137Cs activities attributable to atmospheric deposition were low compared to measured activities. The rate of atmospheric deposition onto the ocean was underestimated because of a lack of measurements of dose rate and air activity of 137Cs over the ocean when atmospheric deposition rates were being estimated. Observed 137Cs activities attributable to atmospheric deposition in the ocean helped to improve the accuracy of simulated atmospheric deposition rates. Although there is no observed data of 137Cs activity in the ocean from 11 to 21 March 2011, observed data of

  1. The Nuclear Criticality Information System's project to archive unpublished critical experiment data

    SciTech Connect

    Koponen, B.L. ); Clayton, E.D.; Doherty, A.L. )

    1991-07-01

    Critical experiment facilities produced a large amount of important data during the past forty-five years. However, much useful data remains unpublished. The unpublished material exists in the form of experimenters' logbooks, notes, photographs, material descriptions, etc. These data could be important for computer code validation, understanding the physics of criticality, facility design, or for setting process limits. In the past, criticality specialists have been able to obtain unpublished details by direct contact with the experimenters. Obviously, this will not be possible indefinitely. Most of the US critical experiment facilities are now closed, the experimenters are moving the other jobs, retiring, or otherwise becoming unavailable for this informal assistance. The closure of the facilities and the loss of personnel is likely to lead to the loss of the facility records unless an effort is made to assure that the records are preserved. It has been recognized for some time that the unpublished records of critical experiment facilities comprise a valuable resource, thus the Nuclear Criticality Information System (NCIS) is working to insure that the records are preserved and made available via NCIS. As a first step in the archiving project, we identified criteria to help judge which series of experiments should be considered for archiving. Data that are used for validating calculations or the basis for subcritical limits in standards, handbooks, and guides are of particular importance. In this paper we will discuss the criteria for archiving, the priority list of experiments for archiving, and progress in developing an NCIS image database using current CD-ROM technology.

  2. The Nuclear Criticality Information System`s project to archive unpublished critical experiment data

    SciTech Connect

    Koponen, B.L.; Clayton, E.D.; Doherty, A.L.

    1991-07-01

    Critical experiment facilities produced a large amount of important data during the past forty-five years. However, much useful data remains unpublished. The unpublished material exists in the form of experimenters` logbooks, notes, photographs, material descriptions, etc. These data could be important for computer code validation, understanding the physics of criticality, facility design, or for setting process limits. In the past, criticality specialists have been able to obtain unpublished details by direct contact with the experimenters. Obviously, this will not be possible indefinitely. Most of the US critical experiment facilities are now closed, the experimenters are moving the other jobs, retiring, or otherwise becoming unavailable for this informal assistance. The closure of the facilities and the loss of personnel is likely to lead to the loss of the facility records unless an effort is made to assure that the records are preserved. It has been recognized for some time that the unpublished records of critical experiment facilities comprise a valuable resource, thus the Nuclear Criticality Information System (NCIS) is working to insure that the records are preserved and made available via NCIS. As a first step in the archiving project, we identified criteria to help judge which series of experiments should be considered for archiving. Data that are used for validating calculations or the basis for subcritical limits in standards, handbooks, and guides are of particular importance. In this paper we will discuss the criteria for archiving, the priority list of experiments for archiving, and progress in developing an NCIS image database using current CD-ROM technology.

  3. Predictors of temporal patterns of psychiatric distress during 10 years following the nuclear accident at Three Mile Island.

    PubMed

    Dew, M A; Bromet, E J

    1993-04-01

    The present study examines psychiatric symptom levels during a 10-year period in a community sample of mothers of young children. All were identified in the early aftermath of the 1979 Three Mile Island nuclear accident, and followed through the accident's 1989 anniversary. Cluster analysis was used to identify long-term distress profiles during the study period; women's temporal profiles were found to be either (a) stable and at low, clinically nonsignificant levels of distress across all measurement points or (b) at consistently elevated, clinically significant levels that varied with the timing of postaccident events such as the restart of the undamaged reactor and the 10th anniversary. Subsequent multivariate analyses indicated that preaccident characteristics, as well as parameters reflecting respondents' initial involvement with, and reactions to the accident, were important for distinguishing between women within the two temporal profile groups. Implications of the results for both policy formulation and continued research on significant environmental stressors is discussed. PMID:8511662

  4. Factors associated with nurses' intention to leave their jobs after the Fukushima Daiichi Nuclear Power plant accident.

    PubMed

    Sato, Yoshinobu; Hayashida, Naomi; Orita, Makiko; Urata, Hideko; Shinkawa, Tetsuko; Fukushima, Yoshiko; Nakashima, Yumiko; Kudo, Takashi; Yamashita, Shunichi; Takamura, Noboru

    2015-01-01

    We conducted a survey among nurses who were working at the Fukushima Medical University Hospital at the time of the Fukushima Daiichi Nuclear Power Plant accident to clarify the factors associated with their intention to leave their jobs during the radiation emergency. We asked 345 nurses (17 men and 328 women) about their intention to leave their jobs after the accident. We also asked about relevant factors including the participants' demographic factors, living situation, working status, and knowledge of radiation health effects. We found that living with preschoolers (OR = 1.87, 95%CI: 1.02-3.44, p = 0.042), anxiety about life in Fukushima City after the accident (OR = 5.55, 95%CI: 1.18-26.13, p = 0.030), consideration of evacuation from Fukushima after the accident (OR = 2.42, 95%CI: 1.45-4.06, p = 0.001), consideration of the possible radiation health effects in children (OR = 1.90, 95%CI: 1.02-3.44, p = 0.042), and anxiety about relationships with colleagues in the hospital after the accident (OR = 3.23, p = 0.001) were independently associated with the nurses' intention to leave their jobs after the accident. On the other hand, the percentage of nurses with knowledge on radiation health effects was relatively low among those who had the intention to leave the job and among those who did not have the intention to leave the job after the accident, with no significant differences between the two groups. Our results suggest the need for an education program for nurses regarding radiation health effects. PMID:25816345

  5. Factors Associated with Nurses’ Intention to Leave Their Jobs after the Fukushima Daiichi Nuclear Power Plant Accident

    PubMed Central

    Sato, Yoshinobu; Hayashida, Naomi; Orita, Makiko; Urata, Hideko; Shinkawa, Tetsuko; Fukushima, Yoshiko; Nakashima, Yumiko; Kudo, Takashi; Yamashita, Shunichi; Takamura, Noboru

    2015-01-01

    We conducted a survey among nurses who were working at the Fukushima Medical University Hospital at the time of the Fukushima Daiichi Nuclear Power Plant accident to clarify the factors associated with their intention to leave their jobs during the radiation emergency. We asked 345 nurses (17 men and 328 women) about their intention to leave their jobs after the accident. We also asked about relevant factors including the participants’ demographic factors, living situation, working status, and knowledge of radiation health effects. We found that living with preschoolers (OR = 1.87, 95%CI: 1.02–3.44, p = 0.042), anxiety about life in Fukushima City after the accident (OR = 5.55, 95%CI: 1.18–26.13, p = 0.030), consideration of evacuation from Fukushima after the accident (OR = 2.42, 95%CI: 1.45–4.06, p = 0.001), consideration of the possible radiation health effects in children (OR = 1.90, 95%CI: 1.02–3.44, p = 0.042), and anxiety about relationships with colleagues in the hospital after the accident (OR = 3.23, p = 0.001) were independently associated with the nurses’ intention to leave their jobs after the accident. On the other hand, the percentage of nurses with knowledge on radiation health effects was relatively low among those who had the intention to leave the job and among those who did not have the intention to leave the job after the accident, with no significant differences between the two groups. Our results suggest the need for an education program for nurses regarding radiation health effects. PMID:25816345

  6. Tenth Warren K. Sinclair keynote address-the Fukushima nuclear power plant accident and comprehensive health risk management.

    PubMed

    Yamashita, Shunichi

    2014-02-01

    Just two years have passed since the Tokyo Electric Power Company-Fukushima Daiichi Nuclear Power Plant (NPP) accident, a multidimensional disaster that combined to destroy the local infrastructure on which the safety system depended and gave a serious impact to the world. Countermeasures including evacuation, sheltering, and control of the food chain were implemented in a timely manner by the Japanese government. However, there is a clear need for improvement, especially in the areas of nuclear safety and protection and also in the management of the radiation health risk during and even after the accident. To date there have been no acute radiation injuries. The radiation-related physical health consequences to the general public, including evacuees, are likely to be much lower than those arising from the Chernobyl nuclear reactor accident, because the radiation fallout and the subsequent environmental contamination were much more limited. However, the social, psychological, and economic impacts of the Fukushima NPP accident are expected to be considerable. Currently, continued monitoring and characterization of the levels of radioactivity in the environment and foods in Fukushima are vital for obtaining informed consent to the decisions on living in the areas already radiocontaminated and returning back to the evacuated areas once re-entry is permitted; it is also important to perform a realistic assessment of the radiation doses on the basis of measurements. We are currently implementing the official plans of the Fukushima Health Management Survey, which includes a basic survey for the estimation of the external doses that were received during the first 4 mo after the accident and four more detailed surveys (thyroid ultrasound examination, comprehensive health check-up, mental health and life-style survey, and survey of pregnant women and nursing mothers), with the aim to take care of the health of all of the residents of the Fukushima Prefecture for a long time

  7. Nuclear Criticality Safety of the DOT 9975 Container for237NpO2Storage, Handling, and Transport

    SciTech Connect

    Reed, D.A.

    2003-08-29

    Nuclear criticality safety considerations are presented to address use of the DOT 9975 shipping container for {sup 237}NpO{sub 2}. The DOT 9975 container will be used by multiple DOE sites and contractors. Various of site- and activity-specific NCS and facility safety documents are yet to be developed. For these reasons, an overall assessment of criticality safety of {sup 237}NpO{sub 2}-loaded DOT 9975 containers is considered useful to personnel involved in generating, reviewing, or approving these various documents. It is concluded that inherent container features, the loading per container (maximum of 6 kg {sup 237}Np), and the nuclear physics properties of {sup 237}NpO{sub 2} combine to preclude the potential for a nuclear criticality accident. This conclusion applies to storage, handling, and transport operations involving closed DOT 9975 packages, including credible off-normal conditions that may result in damage to packages during those operations.

  8. Modeling operator actions during a small break loss-of-coolant accident in a Babcock and Wilcox nuclear power plant

    SciTech Connect

    Ghan, L.S.; Ortiz, M.G.

    1991-12-31

    A small break loss-of-accident (SBLOCA) in a typical Babcock and Wilcox (B&W) nuclear power plant was modeled using RELAP5/MOD3. This work was performed as part of the United States Regulatory Commission`s (USNRC) Code, Scaling, Applicability and Uncertainty (CSAU) study. The break was initiated by severing one high pressure injection (HPI) line at the cold leg. Thus, the small break was further aggravated by reduced HPI flow. Comparisons between scoping runs with minimal operator action, and full operator action, clearly showed that the operator plays a key role in recovering the plant. Operator actions were modeled based on the emergency operating procedures (EOPs) and the Technical Bases Document for the EOPs. The sequence of operator actions modeled here is only one of several possibilities. Different sequences of operator actions are possible for a given accident because of the subjective decisions the operator must make when determining the status of the plant, hence, which branch of the EOP to follow. To assess the credibility of the modeled operator actions, these actions and results of the simulated accident scenario were presented to operator examiners who are familiar with B&W nuclear power plants. They agreed that, in general, the modeled operator actions conform to the requirements set forth in the EOPs and are therefore plausible. This paper presents the method for modeling the operator actions and discusses the simulated accident scenario from the viewpoint of operator actions.

  9. Nuclear power after Chernobyl.

    PubMed

    Ahearne, J F

    1987-05-01

    The causes and progress of the accident at Chernobyl are described, and a comparison between the Chernobyl accident and the 1979 accident at the Three Mile Island nuclear power station is made. Significant similarities between Chernobyl and Three Mile Island include complacency of operators and industry, deliberate negation of safety systems, and a lack of understanding of their plant on the part of the operators, which shows the critical importance of the human element. The Chernobyl accident has implications for nuclear power in the United States; it will affect the research program of the Nuclear Regulatory Commission, regulation of Department of Energy reactors, new reactor designs, and public attitudes. PMID:3576192

  10. Decontamination of outdoor school swimming pools in Fukushima after the nuclear accident in March 2011.

    PubMed

    Saegusa, J; Kurikami, H; Yasuda, R; Kurihara, K; Arai, S; Kuroki, R; Matsuhashi, S; Ozawa, T; Goto, H; Takano, T; Mitamura, H; Nagano, T; Naganawa, H; Yoshida, Z; Funaki, H; Tokizawa, T; Nakayama, S

    2013-03-01

    Because of radioactive fallout resulting from the Fukushima Daiichi Nuclear Power Plant (NPP) accident, water discharge from many outdoor swimming pools in Fukushima was suspended out of concern that radiocesium in the pool water would flow into farmlands. The Japan Atomic Energy Agency has reviewed the existing flocculation method for decontaminating pool water and established a practical decontamination method by demonstrating the process at eight pools in Fukushima. In this method, zeolite powder and a flocculant are used for capturing radiocesium present in pool water. The supernatant is discharged if the radiocesium concentration is less than the targeted level. The radioactive residue is collected and stored in a temporary storage space. Radioactivity concentration in water is measured with a NaI(Tl) or Ge detector installed near the pool. The demonstration results showed that the pool water in which the radiocesium concentration was more than a few hundred Bq L was readily purified by the method, and the radiocesium concentration was reduced to less than 100 Bq L. The ambient dose rates around the temporary storage space were slightly elevated; however, the total increase was up to 30% of the background dose rates when the residue was shielded with sandbags. PMID:23361418

  11. Probabilistic assessment of decoupling loss-of-coolant accident and earthquake in nuclear power plant design

    SciTech Connect

    Lu, S.C.; Harris, D.O.

    1981-01-01

    This paper describes a research project conducted at Lawrence Livermore National Laboratory to establish a technical basis for reassessing the requirement of combining large loss-of-coolant-accident (LOCA) and earthquake loads in nuclear power plant design. A large LOCA is defined herein as a double-ended guillotine break of the primary reactor coolant loop piping (the hot leg, cold leg, and crossover) of a pressureized water reactor (PWR). A systematic probability approach has been employed to estimate the probability of a large LOCA directly and indirectly induced by earthquakes. The probability of a LOCA directly induced by earthquakes was assessed by a numerical simulation of pipe rupture of a reactor coolant system. The simulation employed a deterministic fracture mechanics model which dictates the fatigue growth of pre-existing cracks in the pipe. The simulation accounts for the stochastic nature of input elements such as the initial crack size distribution, the crack occurrence rate, crack and leak detection probabilities as functions of crack size, plant transient occurrence rates, the seismic hazard, stress histories, and crack growth model parameters. Effects on final results due to variation an uncertainty of input elements were assessed by a limited sensitivity study. Results of the simulation indicate that the probability of a double-ended guillotine break, either with or without an earthquake, is very small (on the orer of 10/sup -12/). The probability of a leak was found to be several orders of magnitudes greater than that of a complete break.

  12. Retention of potentially mobile radiocesium in forest surface soils affected by the Fukushima nuclear accident.

    PubMed

    Koarashi, Jun; Moriya, Koichi; Atarashi-Andoh, Mariko; Matsunaga, Takeshi; Fujita, Hiroki; Nagaoka, Mika

    2012-01-01

    The fate of (137)Cs derived from the Fukushima nuclear accident fallout and associated radiological hazards are largely dependent on its mobility in the surface soils of forest ecosystems. Thus, we quantified microbial and adsorptive retentions of (137)Cs in forest surface (0-3 cm) soils. The K(2)SO(4) extraction process liberated 2.1%-12.8% of the total (137)Cs from the soils. Two soils with a higher content of clay- and silt-sized particles, organic carbon content, and cation exchange capacity showed higher (137)Cs extractability. Microbial biomass was observed in all of the soils. However, the (137)Cs extractability did not increase after destruction of the microbial biomass by chloroform fumigation, providing no evidence for microbial retention of the Fukushima-fallout (137)Cs. The results indicate that uptake of (137)Cs by soil microorganisms is less important for retention of potentially mobile (137)Cs in the forest surface soils compared to ion-exchange adsorption on non-specific sites provided by abiotic components. PMID:23256039

  13. Japanese consumers' valuation of domestic beef after the Fukushima Daiichi Nuclear Power Plant accident.

    PubMed

    Sawada, Manabu; Aizaki, Hideo; Sato, Kazuo

    2014-09-01

    After the radioactive contamination of agricultural and livestock products caused by the Fukushima Daiichi Nuclear Power Plant accident of March 11, 2011, consumer aversion against purchasing food products from the affected areas has become a major social problem in Japan. We examine how test results for radioactive materials in beef affect consumer valuation of beef produced in no-risk and affected areas using a choice experiment survey of consumers in the Tokyo metropolitan area (N = 392). Respondents were divided into two groups: one faced choice experiment tasks under the current test condition (the test status was only "under the limit"), and the other faced choice experiment tasks under the tightened test condition (with three levels: "below the limit," "below one-tenth of the limit," and "undetected"). We found that consumer valuation of "below the limit" beef in the affected area did not differ from that of "below one-tenth of the limit" beef in the affected area. Introducing the tightened status improved consumer valuations of all types of beef in the no-risk area regardless of the test status. However, consumer valuation of "undetected" beef in the affected area was lower than that in the no-risk area. The same measures need to be implemented with great care in both no-risk and affected areas. Otherwise, the effects of measures taken in the affected areas may be diluted. PMID:24859113

  14. Dealing with the aftermath of Fukushima Daiichi nuclear accident: decontamination of radioactive cesium enriched ash.

    PubMed

    Parajuli, Durga; Tanaka, Hisashi; Hakuta, Yukiya; Minami, Kimitaka; Fukuda, Shigeharu; Umeoka, Kuniyoshi; Kamimura, Ryuichi; Hayashi, Yukie; Ouchi, Masatoshi; Kawamoto, Tohru

    2013-04-16

    Environmental radioactivity, mainly in the Tohoku and Kanto areas, due to the long living radioisotopes of cesium is an obstacle to speedy recovery from the impacts of the Fukushima Daiichi Nuclear Power Plant accident. Although incineration of the contaminated wastes is encouraged, safe disposal of the Cs enriched ash is the big challenge. To address this issue, safe incineration of contaminated wastes while restricting the release of volatile Cs to the atmosphere was studied. Detailed study on effective removal of Cs from ash samples generated from wood bark, household garbage, and municipal sewage sludge was performed. For wood ash and garbage ash, washing only with water at ambient conditions removed radioactivity due to (134)Cs and (137)Cs, retaining most of the components other than the alkali metals with the residue. However, removing Cs from sludge ash needed acid treatment at high temperature. This difference in Cs solubility is due to the presence of soil particle originated clay minerals in the sludge ash. Because only removing the contaminated vegetation is found to sharply decrease the environmental radioactivity, volume reduction of contaminated biomass by incineration makes great sense. In addition, need for a long-term leachate monitoring system in the landfill can be avoided by washing the ash with water. Once the Cs in solids is extracted to the solution, it can be loaded to Cs selective adsorbents such as Prussian blue and safely stored in a small volume. PMID:23484742

  15. Deposition of fission and activation products after the Fukushima Dai-ichi nuclear power plant accident.

    PubMed

    Shozugawa, Katsumi; Nogawa, Norio; Matsuo, Motoyuki

    2012-04-01

    The Great Eastern Japan Earthquake on March 11, 2011, damaged reactor cooling systems at Fukushima Dai-ichi nuclear power plant. The subsequent venting operation and hydrogen explosion resulted in a large radioactive nuclide emission from reactor containers into the environment. Here, we collected environmental samples such as soil, plant species, and water on April 10, 2011, in front of the power plant main gate as well as 35 km away in Iitate village, and observed gamma-rays with a Ge(Li) semiconductor detector. We observed activation products ((239)Np and (59)Fe) and fission products ((131)I, (134)Cs ((133)Cs), (137)Cs, (110m)Ag ((109)Ag), (132)Te, (132)I, (140)Ba, (140)La, (91)Sr, (91)Y, (95)Zr, and (95)Nb). (239)Np is the parent nuclide of (239)Pu; (59)Fe are presumably activation products of (58)Fe obtained by corrosion of cooling pipes. The results show that these activation and fission products, diffused within a month of the accident. PMID:22266366

  16. Effects of molybdenum and silver on iodine transport in primary circuit on severe nuclear accidents

    SciTech Connect

    Kalilainen, J.; Rantanen, P.; Karkela, T.; Lipponen, M.; Auvinen, A.; Jokiniemi, J.

    2012-07-01

    This experimental study was a continuation of the study conducted at VTT to investigate the effects of reactions on primary circuit surfaces to transport of gaseous and aerosol phase iodine during the hypothetical severe nuclear accident. Cesium iodide was used as a precursor in every experiment. In the experiments it was observed that the hydrogen in the atmosphere decreased the fraction of released gaseous iodine. As the temperature was lowered, less iodine was released, but the fraction of gaseous iodine from the overall released iodine was increased. As molybdenum trioxide was introduced to the precursor, the fraction of gaseous iodine from the overall released iodine was increased significantly. Also, Mo decreased the transport of Cs and caused significant depositions to the reaction furnace. Addition of silver to the CsI precursor at 650 deg. C decreased the release of iodine as well as the fraction of gaseous iodine. At 400 deg. C, Ag + CsI as well as Ag + MoO{sub 3} + CsI precursor significantly increased the release of gaseous iodine, where almost no aerosol particles were released. With B{sub 2}O{sub 3} + CsI precursor it was observed that in the atmosphere without H{sub 2}O, the released iodine was mostly in gaseous form. (authors)

  17. Health effects models for nuclear power plant accident consequence analysis: Low LET radiation

    SciTech Connect

    Evans, J.S. . School of Public Health)

    1990-01-01

    This report describes dose-response models intended to be used in estimating the radiological health effects of nuclear power plant accidents. Models of early and continuing effects, cancers and thyroid nodules, and genetic effects are provided. Weibull dose-response functions are recommended for evaluating the risks of early and continuing health effects. Three potentially lethal early effects -- the hematopoietic, pulmonary, and gastrointestinal syndromes -- are considered. In addition, models are included for assessing the risks of several nonlethal early and continuing effects -- including prodromal vomiting and diarrhea, hypothyroidism and radiation thyroiditis, skin burns, reproductive effects, and pregnancy losses. Linear and linear-quadratic models are recommended for estimating cancer risks. Parameters are given for analyzing the risks of seven types of cancer in adults -- leukemia, bone, lung, breast, gastrointestinal, thyroid, and other.'' The category, other'' cancers, is intended to reflect the combined risks of multiple myeloma, lymphoma, and cancers of the bladder, kidney, brain, ovary, uterus and cervix. Models of childhood cancers due to in utero exposure are also developed. For most cancers, both incidence and mortality are addressed. The models of cancer risk are derived largely from information summarized in BEIR III -- with some adjustment to reflect more recent studies. 64 refs., 18 figs., 46 tabs.

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

    PubMed

    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

  19. Atmospheric radionuclides from the Fukushima Dai-ichi nuclear reactor accident observed in Vietnam.

    PubMed

    Long, N Q; Truong, Y; Hien, P D; Binh, N T; Sieu, L N; Giap, T V; Phan, N T

    2012-09-01

    Radionuclides from the reactor accident at the Fukushima Dai-ichi Nuclear Power Plant were observed in the surface air at stations in Hanoi, Dalat, and Ho Chi Minh City (HCMC) in Vietnam, about 4500 km southwest of Japan, during the period from March 27 to April 22, 2011. The maximum activity concentrations in the air measured at those three sites were 193, 33, and 37 μBq m(-3) for (131)I, (13)(4)Cs, and (13)(7)Cs, respectively. Peaks of radionuclide concentrations in the air corresponded to arrival of the air mass from Fukushima to Vietnam after traveling for 8 d over the Pacific Ocean. Cesium-134 was detected with the (134)Cs/(137)Cs activity ratio of about 0.85 in line with observations made elsewhere. The (131)I/(137)Cs activity ratio was observed to decrease exponentially with time as expected from radioactive decay. The ratio at Dalat, where is 1500 m high, was higher than those at Hanoi and HCMC in low lands, indicating the relative enrichment of the iodine in comparison to cesium at high altitudes. The time-integrated surface air concentrations of the Fukushima-derived radionuclides in the Southeast Asia showed exponential decrease with distance from Fukushima. PMID:22200554

  20. A flexible tool for calculating the consequences of a hypothetical nuclear accident.

    PubMed

    Tabet, Eugenio

    2011-01-01

    The paper presents a parametric model, implemented on a personal computer, for calculating contamination and doses following a hypothetical nuclear accident. The model is embedded in the high level environment of Mathematica and uses the Gaussian solution for the plume structure at short and medium distances and a wedge-like behaviour for long distances calculation. Along with the usual effects, like the influence of a local wet ground deposition or the corrections due to build-up, the model deals also with other aspects, such as the long distance behaviour of the plume, by taking into account random wind direction variations. A rather sophisticated approach is used, in particular, when evaluating food contamination and doses, allowing also for consideration of a possible ban of food consumption. Several tens of functions are on hand of the user who can take full advantage of the very flexible tools introduced in the recent version 7 of Mathematica. Some examples of the power of the tool are shown with reference to the radiological consequences of an hypothetical accidental release in a EPR reactor. PMID:21709394

  1. Thermochemistry of Ruthenium Oxyhydroxide Species and Their Impact on Volatile Speciations in Severe Nuclear Accident Conditions.

    PubMed

    Miradji, Faoulat; Virot, François; Souvi, Sidi; Cantrel, Laurent; Louis, Florent; Vallet, Valérie

    2016-02-01

    Literature thermodynamic data of ruthenium oxyhydroxides reveal large uncertainties in some of the standard enthalpies of formation, motivating the use of high-level relativistic correlated quantum chemical methods to reduce the level of discrepancies. Reaction energies leading to the formation of all possible oxyhydroxide species RuOx(OH)y(H2O)z have been calculated for a series of reactions combining DFT (TPSSh-5%HF) geometries and partition functions, CCSD(T) energies extrapolated to the complete basis set limits. The highly accurate ab initio thermodynamic data were used as input data of thermodynamic equilibrium computations to derive the speciation of gaseous ruthenium species in the temperature, pressure and concentration conditions of severe nuclear accidents occurring in pressurized water reactors. At temperatures lower than 1000 K, gaseous ruthenium tetraoxide is the dominating species, between 1000 and 2000 K ruthenium trioxide becomes preponderant, whereas at higher temperatures gaseous ruthenium oxide, dioxide and even Ru in gaseous phase are formed. Although earlier studies predicted the formation of oxyhydroxides in significant quantities, the use of highly accurate ab initio thermodynamic data for ruthenium gaseous species leads to a more reliable inventory of gaseous ruthenium species in which gaseous oxyhydroxide ruthenium molecules are formed only in negligible amounts. PMID:26789932

  2. Retention of potentially mobile radiocesium in forest surface soils affected by the Fukushima nuclear accident

    PubMed Central

    Koarashi, Jun; Moriya, Koichi; Atarashi-Andoh, Mariko; Matsunaga, Takeshi; Fujita, Hiroki; Nagaoka, Mika

    2012-01-01

    The fate of 137Cs derived from the Fukushima nuclear accident fallout and associated radiological hazards are largely dependent on its mobility in the surface soils of forest ecosystems. Thus, we quantified microbial and adsorptive retentions of 137Cs in forest surface (0–3 cm) soils. The K2SO4 extraction process liberated 2.1%–12.8% of the total 137Cs from the soils. Two soils with a higher content of clay- and silt-sized particles, organic carbon content, and cation exchange capacity showed higher 137Cs extractability. Microbial biomass was observed in all of the soils. However, the 137Cs extractability did not increase after destruction of the microbial biomass by chloroform fumigation, providing no evidence for microbial retention of the Fukushima-fallout 137Cs. The results indicate that uptake of 137Cs by soil microorganisms is less important for retention of potentially mobile 137Cs in the forest surface soils compared to ion-exchange adsorption on non-specific sites provided by abiotic components. PMID:23256039

  3. Effects of radioactive caesium on bull testes after the Fukushima nuclear plant accident

    PubMed Central

    Yamashiro, Hideaki; Abe, Yasuyuki; Fukuda, Tomokazu; Kino, Yasushi; Kawaguchi, Isao; Kuwahara, Yoshikazu; Fukumoto, Motoi; Takahashi, Shintaro; Suzuki, Masatoshi; Kobayashi, Jin; Uematsu, Emi; Tong, Bin; Yamada, Takahisa; Yoshida, Satoshi; Sato, Eimei; Shinoda, Hisashi; Sekine, Tsutomu; Isogai, Emiko; Fukumoto, Manabu

    2013-01-01

    We aimed to investigate the effect of chronic radiation exposure associated with the Fukushima Daiichi Nuclear Plant accident on the testis from 2 bulls. Estimated dose of internal exposure in one bull was 0.7–1.2 mGy (134Cs) and 0.4–0.6 mGy (137Cs) and external exposure was 2.0 mGy (134Cs) and 0.8 mGy (137Cs) (196 days). Internal dose in the other was 3.2–6.1 mGy (134Cs) and 1.8–3.4 mGy (137Cs) and external dose was 1.3 mGy (134Cs) and 0.6 mGy (137Cs) (315 days). Sperm morphology and spermatogenesis were within normal ranges. 134, 137Cs radioactivity was detected but Cs was not detectable in the testis by electron probe microanalysis. Thus, adverse radiation-induced effects were not observed in bull testes following chronic exposure to the above levels of radiation for up to 10 months. Since we could analyse a limited number of testes, further investigation on the effects of ionizing radiation on spermatogenesis should be extended to more animals. PMID:24100305

  4. Assessment of nuclear safety and nuclear criticality potential in the Defense Waste Processing Facility. Revision 1

    SciTech Connect

    Ha, B.C.

    1993-07-20

    The S-Area Defense Waste Processing Facility (DWPF) will initially process Batch 1 sludge in the sludge-only processing mode, with simulated non-radioactive Precipitate Hydrolysis, Aqueous (PHA) product, without the risk of nuclear criticality. The dilute concentration of fissile material in the sludge combined with excess of neutron absorbers during normal operations make criticality throughout the whole process incredible. Subsequent batches of the DWPF involving radioactive precipitate slurry and PHA will require additional analysis. Any abnormal or upset process operations, which are not considered in this report and could potentially separate fissile material, must be individually evaluated. Scheduled maintenance operation procedures are not considered to be abnormal.

  5. 48 CFR 952.223-72 - Radiation protection and nuclear criticality.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... nuclear criticality. 952.223-72 Section 952.223-72 Federal Acquisition Regulations System DEPARTMENT OF....223-72 Radiation protection and nuclear criticality. As prescribed in 923.7003 the clause set forth... contract or subcontract rather than by reliance upon Nuclear Regulatory Commission licensing...

  6. 48 CFR 952.223-72 - Radiation protection and nuclear criticality.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... nuclear criticality. 952.223-72 Section 952.223-72 Federal Acquisition Regulations System DEPARTMENT OF....223-72 Radiation protection and nuclear criticality. As prescribed in 923.7003 the clause set forth... contract or subcontract rather than by reliance upon Nuclear Regulatory Commission licensing...

  7. Mortality Risk amongst Nursing Home Residents Evacuated after the Fukushima Nuclear Accident: A Retrospective Cohort Study

    PubMed Central

    Nomura, Shuhei; Gilmour, Stuart; Tsubokura, Masaharu; Yoneoka, Daisuke; Sugimoto, Amina; Oikawa, Tomoyoshi; Kami, Masahiro; Shibuya, Kenji

    2013-01-01

    Background Safety of evacuation is of paramount importance in disaster planning for elderly people; however, little effort has been made to investigate evacuation-related mortality risks. After the Fukushima Daiichi Nuclear Plant accident we conducted a retrospective cohort survival survey of elderly evacuees. Methods A total of 715 residents admitted to five nursing homes in Minamisoma city, Fukushima Prefecture in the five years before 11th March 2011 joined this retrospective cohort study. Demographic and clinical characteristics were drawn from facility medical records. Evacuation histories were tracked until the end of 2011. The evacuation's impact on mortality was assessed using mortality incidence density and hazard ratios in Cox proportional hazards regression. Results Overall relative mortality risk before and after the earthquake was 2.68 (95% CI: 2.04–3.49). There was a substantial variation in mortality risks across the facilities ranging from 0.77 (95% CI: 0.34–1.76) to 2.88 (95% CI: 1.74–4.76). No meaningful influence of evacuation distance on mortality was observed although the first evacuation from the original facility caused significantly higher mortality than subsequent evacuations, with a hazard ratio of 1.94 (95% CI: 1.07–3.49). Conclusion High mortality, due to initial evacuation, suggests that evacuation of the elderly was not the best life-saving strategy for the Fukushima nuclear disaster. Careful consideration of the relative risks of radiation exposure and the risks and benefits of evacuation is essential. Facility-specific disaster response strategies, including in-site relief and care, may have a strong influence on survival. Where evacuation is necessary, careful planning and coordination with other nursing homes, evacuation sites and government disaster agencies is essential to reduce the risk of mortality. PMID:23555921

  8. Emergency/disaster medical support in the restoration project for the Fukushima nuclear power plant accident

    PubMed Central

    Morimura, Naoto; Asari, Yasushi; Yamaguchi, Yoshihiro; Asanuma, Kazunari; Tase, Choichiro; Sakamoto, Tetsuya; Aruga, Tohru

    2013-01-01

    The Fukushima Daiichi Nuclear Power Plant (1F) suffered a series of radiation accidents after the Great East Japan Earthquake on 11 March 2011. In a situation where halting or delaying restoration work was thought to translate directly into a very serious risk for the entire country, it was of the utmost importance to strengthen the emergency and disaster medical system in addition to radiation emergency medical care for staff at the frontlines working in an environment that posed a risk of radiation exposure and a large-scale secondary disaster. The Japanese Association for Acute Medicine (JAAM) launched the ‘Emergency Task Force on the Fukushima Nuclear Power Plant Accident’ and sent physicians to the local response headquarters. Thirty-four physicians were dispatched as disaster medical advisors, response guidelines in the event of multitudinous injury victims were created and revised and, along with execution of drills, coordination and advice was given on transport of patients. Forty-nine physicians acted as directing physicians, taking on the tasks of triage, initial treatment and decontamination. A total of 261 patients were attended to by the dispatched physicians. None of the eight patients with external contamination developed acute radiation syndrome. In an environment where the collaboration between organisations in the framework of a vertically bound government and multiple agencies and institutions was certainly not seamless, the participation of the JAAM as the medical academic organisation in the local system presented the opportunity to laterally integrate the physicians affiliated with the respective organisations from the perspective of specialisation. PMID:23184925

  9. Health effects of radiation and other health problems in the aftermath of nuclear accidents, with an emphasis on Fukushima.

    PubMed

    Hasegawa, Arifumi; Tanigawa, Koichi; Ohtsuru, Akira; Yabe, Hirooki; Maeda, Masaharu; Shigemura, Jun; Ohira, Tetsuya; Tominaga, Takako; Akashi, Makoto; Hirohashi, Nobuyuki; Ishikawa, Tetsuo; Kamiya, Kenji; Shibuya, Kenji; Yamashita, Shunichi; Chhem, Rethy K

    2015-08-01

    437 nuclear power plants are in operation at present around the world to meet increasing energy demands. Unfortunately, five major nuclear accidents have occurred in the past--ie, at Kyshtym (Russia [then USSR], 1957), Windscale Piles (UK, 1957), Three Mile Island (USA, 1979), Chernobyl (Ukraine [then USSR], 1986), and Fukushima (Japan, 2011). The effects of these accidents on individuals and societies are diverse and enduring. Accumulated evidence about radiation health effects on atomic bomb survivors and other radiation-exposed people has formed the basis for national and international regulations about radiation protection. However, past experiences suggest that common issues were not necessarily physical health problems directly attributable to radiation exposure, but rather psychological and social effects. Additionally, evacuation and long-term displacement created severe health-care problems for the most vulnerable people, such as hospital inpatients and elderly people. PMID:26251393

  10. A view of treatment process of melted nuclear fuel on a severe accident plant using a molten salt system

    SciTech Connect

    Fujita, R.; Takahashi, Y.; Nakamura, H.; Mizuguchi, K.; Oomori, T.

    2013-07-01

    At severe accident such as Fukushima Daiichi Nuclear Power Plant Accident, the nuclear fuels in the reactor would melt and form debris which contains stable UO2-ZrO2 mixture corium and parts of vessel such as zircaloy and iron component. The requirements for solution of issues are below; -) the reasonable treatment process of the debris should be simple and in-situ in Fukushima Daiichi power plant, -) the desirable treatment process is to take out UO{sub 2} and PuO{sub 2} or metallic U and TRU metal, and dispose other fission products as high level radioactive waste; and -) the candidate of treatment process should generate the smallest secondary waste. Pyro-process has advantages to treat the debris because of the high solubility of the debris and its total process feasibility. Toshiba proposes a new pyro-process in molten salts using electrolysing Zr before debris fuel being treated.

  11. Panasonic dosimetry system performance testing and results at nuclear accident dose levels 500 rad to 10,000 rad

    SciTech Connect

    Klueber, M.R.

    1998-04-06

    Panasonic thermoluminescent dosimeters (TLDs) are used as the photon dose assessment part of the personal nuclear accident dosimeter (PNAD) and may be used for the same purpose with the fixed nuclear accident dosimeter (FNAD). To demonstrate compliance with 10CFR835.1304 (and, its predecessor, DOE Order 5480.11), several sets of dosimeters were irradiated to photon doses above the upper limit of the DOELAP testing standard, DOE/EH-0026 and DOE/EH-0027. The upper range of the test was 10,000 rads, using both low energy (70 keV) and high energy (662 keV and 1,332 keV) sources. The testing indicated that the Panasonic TLD system is capable of meeting the requirements of 10CFR835.1304 and DOE Order 5480.11.

  12. Development of the simulation system {open_quotes}IMPACT{close_quotes} for analysis of nuclear power plant severe accidents

    SciTech Connect

    Naitoh, Masanori; Ujita, Hiroshi; Nagumo, Hiroichi

    1997-07-01

    The Nuclear Power Engineering Corporation (NUPEC) has initiated a long-term program to develop the simulation system {open_quotes}IMPACT{close_quotes} for analysis of hypothetical severe accidents in nuclear power plants. IMPACT employs advanced methods of physical modeling and numerical computation, and can simulate a wide spectrum of senarios ranging from normal operation to hypothetical, beyond-design-basis-accident events. Designed as a large-scale system of interconnected, hierarchical modules, IMPACT`s distinguishing features include mechanistic models based on first principles and high speed simulation on parallel processing computers. The present plan is a ten-year program starting from 1993, consisting of the initial one-year of preparatory work followed by three technical phases: Phase-1 for development of a prototype system; Phase-2 for completion of the simulation system, incorporating new achievements from basic studies; and Phase-3 for refinement through extensive verification and validation against test results and available real plant data.

  13. Dose to man from a hypothetical loss-of-coolant accident at the Rancho Seco Nuclear Power Plant

    SciTech Connect

    Peterson, K.R.; Greenly, G.D.

    1981-02-01

    At the request of the Sacramento Municipal Utilities District, we used our computer codes, MATHEW and ADPIC, to assess the environmental impact of a loss-of-coolant accident at the Rancho Seco Nuclear Power Plant, about 40 kilometres southeast of Sacramento, California. Meteorological input was selected so that the effluent released by the accident would be transported over the Sacramento metropolitan area. With the release rates provided by the Sacramento Municipal Utilities District, we calculated the largest total dose for a 24-hour release as 70 rem about one kilometre northwest of the reactor. The largest total dose in the Sacramento metropolitan area is 780 millirem. Both doses are from iodine-131, via the forage-cow-milk pathway to an infant's thyroid. The largest dose near the nuclear plant can be minimized by replacing contaminated milk and by giving the cows dry feed. To our knowledge, there are no milk cows within the Sacramento metropolitan area.

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

    PubMed

    Murawski, Ł; Zielczyński, M; Golnik, N; Gryziński, M A

    2014-10-01

    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. PMID:24324250

  15. Preservation and Dissemination of the Hardcopy Documentation Portion of the NCSP Nuclear Criticality Bibliographic Database

    SciTech Connect

    Koponen, B L; Heinrichs, D

    2009-05-18

    The U.S. Department of Energy supports a nuclear criticality safety bibliographic internet database that contains approximately 15,000 records. We are working to ensure that a substantial portion of the corresponding hardcopy documents are preserved, digitized, and made available to criticality safety practitioners via the Nuclear Criticality Safety Program web site.

  16. Radioactive waste management in the Chernobyl exclusion zone: 25 years since the Chernobyl nuclear power plant accident.

    PubMed

    Oskolkov, Boris Y; Bondarkov, Mikhail D; Zinkevich, Lubov I; Proskura, Nikolai I; Farfán, Eduardo B; Jannik, G Timothy

    2011-10-01

    Radioactive waste management is an important component of the Chernobyl Nuclear Power Plant accident mitigation and remediation activities in the so-called Chernobyl Exclusion Zone. This article describes the localization and characteristics of the radioactive waste present in the Chernobyl Exclusion Zone and summarizes the pathways and strategy for handling the radioactive waste-related problems in Ukraine and the Chernobyl Exclusion Zone and, in particular, the pathways and strategies stipulated by the National Radioactive Waste Management Program. PMID:21878768

  17. Influence of the Fukushima Dai-ichi Nuclear Power Plant accident on environmental radioactivity in Aomori Prefecture.

    PubMed

    Kudo, S; Igarashi, K; Kimura, H

    2015-11-01

    Radioactive nuclides with a short half-life, such as (131)I and (134)Cs, were detected in environmental samples collected in Aomori Prefecture after the Tokyo Electric Power Company Fukushima Dai-ichi Nuclear Power Plant accident in March 2011. In addition, the observed (137)Cs concentration was increased over the background level. The gaseous (131)I concentration in air observed in April was higher than that observed in March immediately after the accident. Using a backward trajectory analysis, the authors found that the air mass had passed the vicinity of the Fukushima Dai-ichi Nuclear Power Plant when the gaseous (131)I concentration in air was increasing. Maximum (131)I and radioactive Cs concentrations in daily fallout samples collected in Aomori city were observed on 28 April, when (131)I was also detected in air. (134)Cs and (137)Cs concentration ratios in pine needles and pasture grass were nearly equal to 1, which indicates that the source of these radionuclides was the nuclear power plant accident. PMID:25953795

  18. Debye-like shielding effect on low-cloud electricity by the radioactive aerosol after the Fukushima nuclear accident

    NASA Astrophysics Data System (ADS)

    Yamauchi, Masatoshi; Takeda, Masahiko; Makino, Masahiko; Owada, Takeshi

    2014-05-01

    The vertical (downward) component of the DC atmospheric electric field, or potential gradient (PG) at Kakioka, 150 km southwest of the Fukushima Dai-ichi Nuclear Power Plant (FNPP1) was analyzed before and after the FNPP1 accident to examine whether the influence of floating radioactive is visible in the PG data under the rain cloud. We used one-minute PG data since 2006 (digital data is available), and obtained the following statistical tendencies. (1) Ten-minute averaged PG during or just before the rain during 13-31 March shows less excursion toward the negative (upward field) side after the accident in 2011 than the average from 2006 to 2013, (2) occurrence frequency of negative PG peaks of about -200 to -700 V/m (corresponding to light rain) is consistently low during March-April period after the accident than the average of the same months of the other years, and (3) time constant around the negative PG peaks during March-April period is shorter after the accident than before the accident beyond annual differences for peak PGs of -200 to -800 V/m (corresponding to light rain), while no difference is seen in May between 2011 and the other years. The end of April 2011 corresponds to the time when the floating radioactive materials significantly decreased. The results suggest that the radioactive aerosol that was originated from the FNPP1 accident might have affected the PG under electrified clouds during light rain. Since the effect is not seen during heavy rain or positive PG reflecting high clouds, it is quite possible that the increased ion density in the atmosphere, that is still very low compared to ordinary plasma, enhanced the Debye shielding effect over the negative charges at the lower part of the cloud.

  19. {sup 129}I, {sup 131}I and {sup 127}I in animal thyroids after the Chernobyl nuclear accident

    SciTech Connect

    VanMiddleworth, L.; Handle, J.

    1997-10-01

    A small number of animal thyroids from Bad Hall, Austria; Ulm, Germany; and Steinkjer, Norway had {sup 131}I (half-life 8.06 d) measured between 21 and 72 d following the nuclear accident at Chernobyl on 26 April 1986. Nine years later {sup 129}I (half-life 1.57 x 10{sup 7} y) fission product and natural {sup 127}I were measured in the same thyroids. The mass ratios, {sup 129}I/{sup 131}I were calculated to the date of the Chernobyl accident and they ranged between 13 and 71. These ratios are compared to the expected ratios within an operating nuclear reactor during 2 y of operation, where the {sup 129}I/{sup 131}I{sup -1} ratio never exceeded 30. The observed ratio of {sup 129}I to natural {sup 127}I in thyroids ranged from 5 to 200 times the ratio before the accident, except that the Norwegian thyroids had {sup 129}I/{sup 127}I ratios which were less than the ratios of pre-Chernobyl thyroids from Ulm. These studies show the {sup 129}I and {sup 131}I from the Chernobyl accident were accumulated with natural {sup 127}I in animal thyroids but the isotope ratios, calculated to the release date, had wide ranges. The {sup 131}I radioactive exposure might be estimated from a fission product mixture by measuring {sup 129}I in thyroids long after the exposure to {sup 131}I, but the results would probably show a wide range of possibilities. The determining variables should be evaluated. We know of no previous data regarding both {sup 131}I and {sup 129}I in thyroid glands during the first 3 mo after the Chernobyl accident. 16 refs., 1 fig., 2 tabs.

  20. Remediation of radiocesium-contaminated liquid waste, soil, and ash: a mini review since the Fukushima Daiichi Nuclear Power Plant accident.

    PubMed

    Ding, Dahu; Zhang, Zhenya; Lei, Zhongfang; Yang, Yingnan; Cai, Tianming

    2016-02-01

    The radiation contamination after the Fukushima Daiichi Nuclear Power Plant accident attracts considerable concern all over the world. Many countries, areas, and oceans are greatly affected by the emergency situation other than Japan. An effective remediation strategy is in a highly urgent demand. Though plenty of works have been carried out, progressive achievements have not yet been well summarized. Here, we review the recent advances on the remediation of radiocesium-contaminated liquid waste, soil, and ash. The overview of the radiation contamination is firstly given. Afterwards, the current remediation strategies are critically reviewed in terms of the environmental medium. Special attentions are paid on the adsorption/ion exchange and electrically switched ion exchange methods. Finally, the present review outlines the possible works to do for the large-scale application of the novel remediation strategies. PMID:26604196

  1. Applications of nuclear data covariances to criticality safety and spent fuel characterization

    SciTech Connect

    Williams, Mark L; Ilas, Germina; Marshall, William BJ J; Rearden, Bradley T

    2014-01-01

    Covariance data computational methods and data used for sensitivity and uncertainty analysis within the SCALE nuclear analysis code system are presented. Applications in criticality safety calculations and used nuclear fuel analysis are discussed.

  2. Applications of Nuclear Data Covariances to Criticality Safety and Spent Fuel Characterization

    NASA Astrophysics Data System (ADS)

    Williams, M. L.; Ilas, G.; Marshall, W. J.; Rearden, B. T.

    2014-04-01

    Covariance data computational methods and data used for sensitivity and uncertainty analysis within the SCALE nuclear analysis code system are presented. Applications in criticality safety calculations and used nuclear fuel analysis are discussed.

  3. 10 CFR 72.74 - Reports of accidental criticality or loss of special nuclear material.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... nuclear material. 72.74 Section 72.74 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSING REQUIREMENTS FOR THE INDEPENDENT STORAGE OF SPENT NUCLEAR FUEL, HIGH-LEVEL RADIOACTIVE WASTE, AND REACTOR... accidental criticality or loss of special nuclear material. (a) Each licensee shall notify the NRC...

  4. 10 CFR 72.74 - Reports of accidental criticality or loss of special nuclear material.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... nuclear material. 72.74 Section 72.74 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSING REQUIREMENTS FOR THE INDEPENDENT STORAGE OF SPENT NUCLEAR FUEL, HIGH-LEVEL RADIOACTIVE WASTE, AND REACTOR... accidental criticality or loss of special nuclear material. (a) Each licensee shall notify the NRC...

  5. 10 CFR 72.74 - Reports of accidental criticality or loss of special nuclear material.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... nuclear material. 72.74 Section 72.74 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSING REQUIREMENTS FOR THE INDEPENDENT STORAGE OF SPENT NUCLEAR FUEL, HIGH-LEVEL RADIOACTIVE WASTE, AND REACTOR... accidental criticality or loss of special nuclear material. (a) Each licensee shall notify the NRC...

  6. Nuclear criticality safety calculational analysis for small-diameter containers

    SciTech Connect

    LeTellier, M.S.; Smallwood, D.J.; Henkel, J.A.

    1995-11-01

    This report documents calculations performed to establish a technical basis for the nuclear criticality safety of favorable geometry containers, sometimes referred to as 5-inch containers, in use at the Portsmouth Gaseous Diffusion Plant. A list of containers currently used in the plant is shown in Table 1.0-1. These containers are currently used throughout the plant with no mass limits. The use of containers with geometries or material types other than those addressed in this evaluation must be bounded by this analysis or have an additional analysis performed. The following five basic container geometries were modeled and bound all container geometries in Table 1.0-1: (1) 4.32-inch-diameter by 50-inch-high polyethylene bottle; (2) 5.0-inch-diameter by 24-inch-high polyethylene bottle; (3) 5.25-inch-diameter by 24-inch-high steel can ({open_quotes}F-can{close_quotes}); (4) 5.25-inch-diameter by 15-inch-high steel can ({open_quotes}Z-can{close_quotes}); and (5) 5.0-inch-diameter by 9-inch-high polybottle ({open_quotes}CO-4{close_quotes}). Each container type is evaluated using five basic reflection and interaction models that include single containers and multiple containers in normal and in credible abnormal conditions. The uranium materials evaluated are UO{sub 2}F{sub 2}+H{sub 2}O and UF{sub 4}+oil materials at 100% and 10% enrichments and U{sub 3}O{sub 8}, and H{sub 2}O at 100% enrichment. The design basis safe criticality limit for the Portsmouth facility is k{sub eff} + 2{sigma} < 0.95. The KENO study results may be used as the basis for evaluating general use of these containers in the plant.

  7. Speciation of radiocesium and radioiodine in aerosols from Tsukuba after the Fukushima nuclear accident.

    PubMed

    Xu, Sheng; Zhang, Luyuan; Freeman, Stewart P H T; Hou, Xiaolin; Shibata, Yasuyuki; Sanderson, David; Cresswell, Alan; Doi, Taeko; Tanaka, Atsushi

    2015-01-20

    Aerosol samples were collected from Tsukuba, Japan, soon after the 2011 Fukushima nuclear accident and analyzed for speciation of radiocesium and radioiodine to explore their chemical behavior and isotopic ratios after the release. Most (134)Cs and (137)Cs were bound in organic matter (53–91%) and some in water-soluble fractions (5–15%), whereas a negligible proportion of radiocesium remained in minerals. This pattern suggests that sulfate salts and organic matter may be the main carrier of Cs-bearing particles. The (129)I in aerosol samples is contained in various proportions as soluble inorganic iodine (I(–) and IO3(–)), soluble organic iodine, and unextractable iodine. The measured mean (129)I/(131)I atomic ratio of 16.0 ± 2.2 is in good agreement with that measured from rainwater and consistent with ratios measured in surface soil samples. Together with other aerosols and seawater samples, an initial (129)I/(137)Cs activity ratio of ∼4 × 10(–7) was obtained. In contrast to the effectively constant (134)Cs/(137)Cs activity ratios (1.04 ± 0.04) and (129)I/(131)I atomic ratios (16.0 ± 2.2), the (129)I/(137)Cs activity ratios scattered from 3.5 × 10(–7) to 5 × 10(–6) and showed temporally and spatially different dispersion and deposition patterns between radiocesium and radioiodine. These findings confirm that (129)I, instead of (137)Cs, should be considered as a proxy for (131)I reconstruction. PMID:25522224

  8. A dynamic model for evaluating radionuclide distribution in forests from nuclear accidents.

    PubMed

    Schell, W R; Linkov, I; Myttenaere, C; Morel, B

    1996-03-01

    The Chernobyl Nuclear Power Plant accident in 1986 caused radionuclide contamination in most countries in Eastern and Western Europe. A prime example is Belarus where 23% of the total land area received chronic levels; about 1.5 x 10(6) ha of forested lands were contaminated with 40--190 kBq m-2 and 2.5 x 10(4) ha received greater than 1,480 kBq m-2 of 137Cs and other long-lived radionuclides such as 90Sr and 239,240Pu. Since the radiological dose to the forest ecosystem will tend to accumulate over long time periods (decades to centuries), we need to determine what countermeasures can be taken to limit this dose so that the affected regions can, once again, safely provide habitat and natural forest products. To address some of these problems, our initial objective is to formulate a generic model, FORESTPATH, which describes the major kinetic processes and pathways of radionuclide movement in forests and natural ecosystems and which can be used to predict future radionuclide concentrations. The model calculates the time-dependent radionuclide concentrations in different compartments of the forest ecosystem based on the information available on residence half-times in two forest types: coniferous and deciduous. The results show that the model reproduces well the radionuclide cycling pattern found in the literature for deciduous and coniferous forests. Variability analysis was used to access the relative importance of specific parameter values in the generic model performance. The FORESTPASTH model can be easily adjusted for site-specific applications. PMID:8609024

  9. Radioactive fallout cesium in sewage sludge ash produced after the Fukushima Daiichi nuclear accident.

    PubMed

    Kozai, Naofumi; Suzuki, Shinichi; Aoyagi, Noboru; Sakamoto, Fuminori; Ohnuki, Toshihiko

    2015-01-01

    The radioactive fallout cesium (¹³⁷Cs) in the sewage sludge ashes (SSAs) produced in Japan after the Fukushima Daiichi Nuclear Accident was tested. Five samples of SSAs produced in 2011 and 2012 were tested. Two of the samples contained ¹³⁷Cs (23 and 9.6 kBq/kg, respectively) above the radioactivity criterion (8 kBq of radioactive Cs/kg of solid) for controlled landfill disposal in Japan. The mineral components of SSA are roughly divided into two groups: an HCl-soluble phase mainly composed of phosphates and oxides; and silicates, including quartz, feldspar, and clay. Both phases contained ¹³⁷Cs. The majority (up to 90%) of ¹³⁷Cs was contained in the HCl-soluble phase. Among the HCl-soluble subphases, Fe-bearing phases that were probably iron oxides were mainly responsible for ¹³⁷Cs retention. No positive evidence was obtained that showed that phosphate-bearing phases, which were included most in SSAs along with the silicate phase, retained ¹³⁷Cs. Pre-pulverizing SSAs and heating them at 95 °C in a 6 M or a concentrated aqueous HCl was the most effective method of dissolving the HCl-soluble phase. The radioactivity concentrations of ¹³⁷Cs in all the HCl-treatment residues were below the radioactivity criterion. This residue was mostly composed of silicates. After static leaching tests of the residue at 60 °C for 28 days, no ¹³⁷Cs was detected in simulated environmental water leachates (pure water and synthetic seawater), demonstrating that 137Cs in the residue is very stably immobilized in the silicates. PMID:25462767

  10. A dynamic model for evaluating radionuclide distribution in forests from nuclear accidents

    SciTech Connect

    Schell, W.R.; Linkov, I.; Myttenaere, C.

    1996-03-01

    The Chernobyl Nuclear Power Plant accident in 1986 caused radionuclide contamination in most countries in Eastern and Western Europe. A prime example is Belarus where 23% of the total land area received chronic levels; about 1.5 X 10{sup 6} ha of forested lands were contaminated with 40-190 kBq m{sup -2} and 2.5 X 10{sup 4} ha received greater than 1,480 kBq m{sup -2} of {sup 137}Cs and other long-lived radionuclides such as {sup 90}Sr and {sup 239,240}Pu. Since the radiological dose to the forest ecosystem will tend to accumulate over long time periods (decades to centuries), we need to determine what countermeasures can be taken to limit this dose so that the affected regions can, once again, safely provide habitat and natural forest products. To address some of these problems, our initial objective is to formulate a generic model, FORESTPATH, which describes the major kinetic processes and pathways of radionuclide movement in forests and natural ecosystems and which can be used to predict future radionuclide concentrations. The model calculates the time-dependent radionuclide concentrations in different compartments of the forest ecosystem based on the information available on residence half-times in two forest types: coniferous and deciduous. The results show that the model reproduces well the radionuclide cycling pattern found in the literature for deciduous and coniferous forests. Variability analysis was used to access the relative importance of specific parameter values in the generic model performance. The FORESTPASTH model can be easily adjusted for site-specific applications. 92 refs., 5 figs., 6 tabs.

  11. Rainfall erosivity in catchments contaminated with fallout from the Fukushima Daiichi nuclear power plant accident

    NASA Astrophysics Data System (ADS)

    Laceby, J. Patrick; Chartin, Caroline; Evrard, Olivier; Onda, Yuichi; Garcia-Sanchez, Laurent; Cerdan, Olivier

    2016-06-01

    The Fukushima Daiichi nuclear power plant (FDNPP) accident in March 2011 resulted in the fallout of significant quantities of radiocesium over the Fukushima region. After reaching the soil surface, radiocesium is quickly bound to fine soil particles. Thereafter, rainfall and snowmelt run-off events transfer particle-bound radiocesium downstream. Characterizing the precipitation regime of the fallout-impacted region is thus important for understanding post-deposition radiocesium dynamics. Accordingly, 10 min (1995-2015) and daily precipitation data (1977-2015) from 42 meteorological stations within a 100 km radius of the FDNPP were analyzed. Monthly rainfall erosivity maps were developed to depict the spatial heterogeneity of rainfall erosivity for catchments entirely contained within this radius. The mean average precipitation in the region surrounding the FDNPP is 1420 mm yr-1 (SD 235) with a mean rainfall erosivity of 3696 MJ mm ha-1 h-1 yr-1 (SD 1327). Tropical cyclones contribute 22 % of the precipitation (422 mm yr-1) and 40 % of the rainfall erosivity (1462 MJ mm ha-1 h-1 yr-1 (SD 637)). The majority of precipitation (60 %) and rainfall erosivity (82 %) occurs between June and October. At a regional scale, rainfall erosivity increases from the north to the south during July and August, the most erosive months. For the remainder of the year, this gradient occurs mostly from northwest to southeast. Relief features strongly influence the spatial distribution of rainfall erosivity at a smaller scale, with the coastal plains and coastal mountain range having greater rainfall erosivity than the inland Abukuma River valley. Understanding these patterns, particularly their spatial and temporal (both inter- and intraannual) variation, is important for contextualizing soil and particle-bound radiocesium transfers in the Fukushima region. Moreover, understanding the impact of tropical cyclones will be important for managing sediment and sediment-bound contaminant

  12. Calculation of the absorbed dose for the overexposed patients at the JCO criticality accident in Tokai-mura.

    PubMed

    Ishigure, N; Endo, A; Yamaguchi, Y; Kawachi, K

    2001-09-01

    The doses for the overexposed patients were estimated by the measurement result of specific activity of 24Na in blood. The present method is almost based on documents of the International Atomic Energy Agency (IAEA) and the Oak Ridge National Laboratory. The neutron energy spectrum obtained using the ANISN code (Multigroup One-Dimensional Discrete Ordinates Transport Code System with Anisotropic Scattering) was assumed. The values in ICRP Publication 74 were applied for the doses in each organ per unit neutron fluence. Gamma-ray dose was indirectly estimated based on (a) the result of environmental monitoring around the accident site and (b) a graph in IAEA manual, which gives the kerma ratio of neutrons and gamma-rays as a function of the critical volume or the atomic ratio of hydrogen to 235U. The estimated neutron doses were 5.4 Gy for patient A. 2.9 Gy for patient B and 0.81 Gy for patient C. The estimated gamma-ray doses were 8.5 or 13 Gy for patient A, 4.5 or 6.9 Gy for patient B, and 1.3 or 2.0 Gy for patient C. PMID:11791747

  13. Post-accident cleanup of radioactivity at the Three Mile Island Nuclear Power Station

    SciTech Connect

    Brooksbank, R.E.; Armento, W.J.

    1980-02-01

    The technical staff of the President's Commission on the Accident at Three Mile Island (TMI) requested that Oak Ridge National Laboratory (ORNL) prepare documentation concerned with the cleanup of radioactivity on the Three Mile Island site following the March 28, 1979 accident. The objective of this report is to provide information in a summarized form, which will be of direct usefulness to the commissioners. The information contained herein includes discussion of on-site assistance and accomplishments following the accident, flowsheet development for the TMI recovery team (by the Technical Advisory Group), and the numerous reports already generated on the TMI cleanup and recovery.

  14. Analysis of a uranium solution for evaluating the total number of fissions in the JCO criticality accident in Tokai-mura.

    PubMed

    Uchiyama, G; Watanabe, K; Miyauchi, M; Togashi, Y; Nakahara, Y; Fukaya, H; Inagawa, J; Suzuki, D; Sonoda, T; Kohno, N; Gunji, K; Ito, M; Sato, T

    2001-09-01

    The uranium solution in the precipitation tank in the JCO's uranium conversion facility was analyzed in order to evaluate the total number of fissions in the criticality accident. Two analytical groups at JAERI performed chemical analyses independently in order to check the validity of the results: the concentration of the fission products (95Zr, 99Mo, 103Ru, 131I, 140Ba, etc), uranium, boron and impurity elements in the solution. The analytical results obtained by the two groups were almost in agreement within the analytical error. The number of fissions per one gram of uranium in the accident was determined to be (1.5 +/- 0.1 ) x 10(14). Also, the total number of events was evaluated to be (2.5 +/- 0.1) x 10(18) fissions using the total amount of uranium (16.6 kg) fed into the precipitation tank at the accident. PMID:11791744

  15. Recent condition of Fukushima-Daiichi nuclear plant accident in Japan

    NASA Astrophysics Data System (ADS)

    Ohnishi, Takeo

    2012-07-01

    Japanese government pronounced that the second step had been succeeded in the cooling down of the reactors on the middle of Dec 2011 at Fukushima-Daiichi nuclear power plant. In future, government aims to take out fuels from 4 reactors and shields their units. The nuclear power plants in Japan are gradually decreasing, because the checking for them has been performed and the permission of the re-start of them are difficult to be gained. On January 1st 2012, only 7 units are operating in Japan, though the about 54 units were set before the accident. At the end of December 2011, most radiations are emitted from cesium. The radioactivity in air and land around the plant was daily reported in newspaper. Government often gave the information about some RI-contamination in foods. They were taken off from the markets. At now stage, the most important project is the decontamination of radioactive materials from houses, schools, public facilities and industries. Government will newly classify three evacuation areas from April 2012. At the end of March, evacuees under 20 mSv/year possibly can go back their homes (evacuation-free area). The environmental doses will be depressed by decontamination under 10 mSv/year. At the range of 20-50 mSv, people will be controlled to live these area, they can go back their houses temporally (evacuation area). Over 50 mSv/year, however, people can go back house until 5 years at least (prohibited area). In new radiation limitation for a risk of human health, government made 100 mSv and 20 mSv for life span for one year, respectively. The aim of decontamination was set up to 10 mSv for 1 year and 5 mSv for next stage. A target at school is under1 mSv for children. Government accepted a new severe limitation per1 Kg at four groups; milk of baby (100 Bq) and milk (100 Bq), drinking water (10 Bq) and food (100 Bq). Tokyo electric Power Company and government should pay the sufficient compensation to evacuees. In future, they should keep health

  16. Atmospheric Direct Uptake and Long-term Fate of Radiocesium in Trees after the Fukushima Nuclear Accident

    NASA Astrophysics Data System (ADS)

    Mahara, Yasunori; Ohta, Tomoko; Ogawa, Hideki; Kumata, Atsushi

    2014-11-01

    Large areas of forests were radioactively contaminated by the Fukushima nuclear accident of 2011, and forest decontamination is now an important problem in Japan. However, whether trees absorb radioactive fallout from soil via the roots or directly from the atmosphere through the bark and leaves is unclear. We measured the uptake of radiocesium by trees in forests heavily contaminated by the Fukushima nuclear accident. The radiocesium concentrations in sapwood of two tree species, the deciduous broadleaved konara (Quercus serrata) and the evergreen coniferous sugi (Cryptomeria japonica), were higher than that in heartwood. The concentration profiles showed anomalous directionality in konara and non-directionality in sugi, indicating that most radiocesium in the tree rings was directly absorbed from the atmosphere via bark and leaves rather than via roots. Numerical modelling shows that the maximum 137Cs concentration in the xylem of konara will be achieved 28 years after the accident. Conversely, the values for sugi will monotonously decrease because of the small transfer factor in this species. Overall, xylem 137Cs concentrations will not be affected by root uptake if active root systems occur 10 cm below the soil.

  17. Atmospheric direct uptake and long-term fate of radiocesium in trees after the Fukushima nuclear accident.

    PubMed

    Mahara, Yasunori; Ohta, Tomoko; Ogawa, Hideki; Kumata, Atsushi

    2014-01-01

    Large areas of forests were radioactively contaminated by the Fukushima nuclear accident of 2011, and forest decontamination is now an important problem in Japan. However, whether trees absorb radioactive fallout from soil via the roots or directly from the atmosphere through the bark and leaves is unclear. We measured the uptake of radiocesium by trees in forests heavily contaminated by the Fukushima nuclear accident. The radiocesium concentrations in sapwood of two tree species, the deciduous broadleaved konara (Quercus serrata) and the evergreen coniferous sugi (Cryptomeria japonica), were higher than that in heartwood. The concentration profiles showed anomalous directionality in konara and non-directionality in sugi, indicating that most radiocesium in the tree rings was directly absorbed from the atmosphere via bark and leaves rather than via roots. Numerical modelling shows that the maximum (137)Cs concentration in the xylem of konara will be achieved 28 years after the accident. Conversely, the values for sugi will monotonously decrease because of the small transfer factor in this species. Overall, xylem (137)Cs concentrations will not be affected by root uptake if active root systems occur 10 cm below the soil. PMID:25409781

  18. Inspections of radiocesium concentration levels in rice from Fukushima Prefecture after the Fukushima Dai-ichi Nuclear Power Plant accident.

    PubMed

    Nihei, Naoto; Tanoi, Keitaro; Nakanishi, Tomoko M

    2015-01-01

    We summarize the inspections of radiocesium concentration levels in rice produced in Fukushima Prefecture, Japan, for 3 years from the nuclear accident in 2011. In 2011, three types of verifications, preliminary survey, main inspection, and emergency survey, revealed that rice with radiocesium concentration levels over 500 Bq/kg (the provisional regulation level until March 2012 in Japan) was identified in the areas north and west of the Fukushima nuclear power plant. The internal exposure of an average adult eating rice grown in the area north of the nuclear plant was estimated as 0.05 mSv/year. In 2012, Fukushima Prefecture authorities decided to investigate the radiocesium concentration levels in all rice using custom-made belt conveyor testers. Notably, rice with radiocesium concentration levels over 100 Bq/kg (the new standard since April 2012 in Japan) were detected in only 71 and 28 bags out of the total 10,338,000 in 2012 and 11,001,000 in 2013, respectively. We considered that there were almost no rice exceeding 100 Bq/kg produced in Fukushima Prefecture after 3 years from the nuclear accident, and the safety of Fukushima's rice were ensured because of the investigation of all rice. PMID:25731663

  19. Inspections of radiocesium concentration levels in rice from Fukushima Prefecture after the Fukushima Dai-ichi Nuclear Power Plant accident

    NASA Astrophysics Data System (ADS)

    Nihei, Naoto; Tanoi, Keitaro; Nakanishi, Tomoko M.

    2015-03-01

    We summarize the inspections of radiocesium concentration levels in rice produced in Fukushima Prefecture, Japan, for 3 years from the nuclear accident in 2011. In 2011, three types of verifications, preliminary survey, main inspection, and emergency survey, revealed that rice with radiocesium concentration levels over 500 Bq/kg (the provisional regulation level until March 2012 in Japan) was identified in the areas north and west of the Fukushima nuclear power plant. The internal exposure of an average adult eating rice grown in the area north of the nuclear plant was estimated as 0.05 mSv/year. In 2012, Fukushima Prefecture authorities decided to investigate the radiocesium concentration levels in all rice using custom-made belt conveyor testers. Notably, rice with radiocesium concentration levels over 100 Bq/kg (the new standard since April 2012 in Japan) were detected in only 71 and 28 bags out of the total 10,338,000 in 2012 and 11,001,000 in 2013, respectively. We considered that there were almost no rice exceeding 100 Bq/kg produced in Fukushima Prefecture after 3 years from the nuclear accident, and the safety of Fukushima's rice were ensured because of the investigation of all rice.

  20. Inspections of radiocesium concentration levels in rice from Fukushima Prefecture after the Fukushima Dai-ichi Nuclear Power Plant accident

    PubMed Central

    Nihei, Naoto; Tanoi, Keitaro; Nakanishi, Tomoko M.

    2015-01-01

    We summarize the inspections of radiocesium concentration levels in rice produced in Fukushima Prefecture, Japan, for 3 years from the nuclear accident in 2011. In 2011, three types of verifications, preliminary survey, main inspection, and emergency survey, revealed that rice with radiocesium concentration levels over 500 Bq/kg (the provisional regulation level until March 2012 in Japan) was identified in the areas north and west of the Fukushima nuclear power plant. The internal exposure of an average adult eating rice grown in the area north of the nuclear plant was estimated as 0.05 mSv/year. In 2012, Fukushima Prefecture authorities decided to investigate the radiocesium concentration levels in all rice using custom-made belt conveyor testers. Notably, rice with radiocesium concentration levels over 100 Bq/kg (the new standard since April 2012 in Japan) were detected in only 71 and 28 bags out of the total 10,338,000 in 2012 and 11,001,000 in 2013, respectively. We considered that there were almost no rice exceeding 100 Bq/kg produced in Fukushima Prefecture after 3 years from the nuclear accident, and the safety of Fukushima's rice were ensured because of the investigation of all rice. PMID:25731663

  1. Nuclear criticality safety modeling of an LEU deposit

    SciTech Connect

    Haire, M.J.; Elam, K.R.; Jordan, W.C.; Dahl, T.L.

    1996-11-01

    The construction of the Oak Ridge Gaseous Diffusion Plant (now known as the K-25 Site) began during World War H and eventually consisted of five major process buildings: K-25, K-27, K-29, K-31, and K-33. The plant took natural (0.711% {sup 231}U) uranium as feed and processed it into both low-enriched uranium (LEU) and high-enriched uranium (HEU) with concentrations up to {approximately}93% {sup 231}U. The K-25 and K-27 buildings were shut down in 1964, but the rest of the plant produced LEU until 1985. During operation, inleakage of humid air into process piping and equipment caused reactions with gaseous uranium hexafluoride (UF{sub 6}) that produced nonvolatile uranyl fluoride (UO{sub 2}F{sub 2}) deposits. As part of shutdown, most of the uranium was evacuated as volatile UF{sub 6}. The UO{sub 2}F{sub 2} deposits remained. The U.S. Department of Energy has mitiated a program to unprove nuclear criticality safety by removing the larger enriched uranium deposits.

  2. Critical nuclear charge for two-electron atoms.

    PubMed

    Estienne, C S; Busuttil, M; Moini, A; Drake, G W F

    2014-05-01

    The critical nuclear charge Z(c) required to bind a nucleus plus two electrons in a heliumlike atom has recently been an area of active study, resulting in a disagreement with earlier calculations and with the value obtained from the radius of convergence 1/Z* of a 1/Z expansion of the energy. In order to resolve the disagreement, have performed high-precision variational calculations in Hylleraas coordinates. With the double basis set method, we have been able to obtain good convergence for Z very close to Z(c), which together with the Hellmann-Feynman theorem yields the value Z(c) = 0.911,028,224,077,255,73(4), corresponding to 1/Z(c) = 1.097,660,833,738,559,80(5). This value is in agreement with the value obtained by Baker et al. [Phys. Rev. A 41, 1247 (1990)]. A significant feature of the results is that the outer electron remains localized near the nucleus, even at Z = Z(c), and the bound state evidently changes smoothly into a shape resonance for Z

  3. Application of the Bulgarian emergency response system in case of nuclear accident in environmental assessment study

    NASA Astrophysics Data System (ADS)

    Syrakov, Dimiter; Veleva, Blagorodka; Georgievs, Emilia; Prodanova, Maria; Slavov, Kiril; Kolarova, Maria

    2014-05-01

    The development of the Bulgarian Emergency Response System (BERS) for short term forecast in case of accidental radioactive releases to the atmosphere has been started in the mid 1990's [1]. BERS comprises of two main parts - operational and accidental, for two regions 'Europe' and 'Northern Hemisphere'. The operational part runs automatically since 2001 using the 72 hours meteorological forecast from DWD Global model, resolution in space of 1.5o and in time - 12 hours. For specified Nuclear power plants (NPPs), 3 days trajectories are calculated and presented on NIMH's specialized Web-site (http://info.meteo.bg/ews/). The accidental part is applied when radioactive releases are reported or in case of emergency exercises. BERS is based on numerical weather forecast information and long-range dispersion model accounting for the transport, dispersion, and radioactive transformations of pollutants. The core of the accidental part of the system is the Eulerian 3D dispersion model EMAP calculating concentration and deposition fields [2]. The system is upgraded with a 'dose calculation module' for estimation of the prognostic dose fields of 31 important radioactive gaseous and aerosol pollutants. The prognostic doses significant for the early stage of a nuclear accident are calculated as follows: the effective doses from external irradiation (air submersion + ground shinning); effective dose from inhalation; summarized effective dose and absorbed thyroid dose [3]. The output is given as 12, 24, 36, 48, 60 and 72 hours prognostic dose fields according the updated meteorology. The BERS was upgraded to simulate the dispersion of nuclear materials from Fukushima NPP [4], and results were presented in NIMH web-site. In addition BERS took part in the respective ENSEMBLE exercises to model 131I and 137Cs in Fukushima source term. In case of governmental request for expertise BERS was applied for environmental impact assessment of hypothetical accidental transboundary

  4. [What kind of accidents can happen in a nuclear power plant].

    PubMed

    Debes, M

    1995-03-15

    The lessons drawn from real reactor accidents are of great value. The safety approach in France relies on defence in depth and takes into account accidents in the plant design, completed by a probabilistic approach and experience feedback. Ultimate procedures are implemented on the basis of severe accidents studies which include core melting or partial containment defect, in order to mitigate their consequences even if they are improbable, and to enable a proper implementation of emergency planning countermeasures. The accident hypothesis and consequences are considered to draw the emergency planning procedures. Off site countermeasures, such as in house-confinement, limited evacuation or iodine distribution, are efficient in limiting the consequences for the public. Experience feedback, in association with a proactive vigilance and prevention policy, is developed in order to detect and correct in a proactive way the root causes of any deviation, even minor, so as to avoid multiple failures and ensure safety. PMID:7754324

  5. Additional Studies of the Criticality Safety of Failed Used Nuclear Fuel

    SciTech Connect

    Marshall, William BJ J; Wagner, John C

    2013-01-01

    Commercial used nuclear fuel (UNF) in the United States is expected to remain in storage for periods potentially greater than 40 years. Extended storage (ES) time and irradiation to high-burnup values (>45 GWd/t) may increase the potential for fuel failure during normal and accident conditions involving storage and transportation. Fuel failure, depending on the severity, could result in changes to the geometric configuration of the fuel, which has safety and regulatory implications. The likelihood and extent of fuel reconfiguration and its impact on the safety of the UNF is not well understood. The objective of this work is to assess and quantify the impact of fuel reconfiguration due to fuel failure on criticality safety of UNF in storage and transportation casks. Criticality analyses are conducted considering representative UNF designs covering a range of enrichments and burnups in multiple cask systems. Prior work developed a set of failed fuel configuration categories and specific configurations were evaluated to understand trends and quantify the consequences of worst-case potential reconfiguration progressions. These results will be summarized here and indicate that the potential impacts on subcriticality can be rather significant for certain configurations (e.g., >20% keff). It can be concluded that the consequences of credible fuel failure configurations from ES or transportation following ES are manageable (e.g., <5% keff). The current work expands on these efforts and examines some modified scenarios and modified approaches to investigate the effectiveness of some techniques for reducing the calculated increase in keff. The areas included here are more realistic modeling of some assembly types and the effect of reconfiguration of some assemblies in the storage and transportation canister.

  6. Clinical aspects of the health disturbances in Chernobyl Nuclear Power Plant accident clean-up workers (liquidators) from Latvia.

    PubMed

    Eglite, M E; Zvagule, T J; Rainsford, K D; Reste, J D; Curbakova, E V; Kurjane, N N

    2009-06-01

    The health status of some 6,000 workers from Latvia who went to clean-up the Chernobyl Nuclear Power Plant (CNPP) site following the explosion on 26 April 1986 has been analyzed. The data on these workers have been recorded in the Latvian State Register of Occupational disease patients and people exposed to ionizing radiation due to Chernobyl NPP accident (Latvian State Register) that was established in 1994. From these data, estimates have been made of external ionizing radiation to which these workers were exposed together with observations on the impact of exposure to heavy metals (especially lead and zinc) and radioactive isotopes released during the reactor 'meltdown'. These factors along with psycho-emotional and social-economic stresses account for a marked excess of mortality and morbidity in the group of CNPP accident clean-up workers compared with that of the non-exposed normal Latvian population adjusted for age and sex. The number of diseases or conditions in the CNPP accident clean-up workers has progressively risen from an average of 1.3 in 1986 to 10.9 in 2007. This exceeds for the Latvian population when adjusted for age and sex. The most serious conditions affect the nervous, digestive, respiratory, cardiovascular, endocrine (especially thyroid) and immunological systems. While the morbidity associated with diseases of the respiratory and digestive systems has decreased in recent years that in the other systems is increasing. In recent years, there has been an increased occurrence of cancers affecting the thyroid, prostate and stomach. Clinical and laboratory investigations suggest that surviving CNPP accident clean-up workers exhibit signs of immuno-inflammatory reactions causing premature aging with evidence of autoimmune diseases and immunological deficiencies or abnormalities. It is suggested that the CNPP accident clean-up workers may have a specific syndrome, the 'Chernobyl post-radiation neurosomatic polypathy', due to sustained oxidant

  7. Cancer risk estimation in Belarussian children due to thyroid irradiation as a consequence of the Chernobyl nuclear accident

    SciTech Connect

    Buglova, E.; Kenigsberg, J.E.; Sergeeva, N.V.

    1996-07-01

    The thyroid doses received by the juvenile population of Belarus following the Chernobyl accident ranged up to about 10 Gy. The thyroid cancer risk estimate recommended in NCRP Report No. 80 was used to predict the number of thyroid cancer cases among children during 1990-1992 in selected Belarussian regions and cities. The results obtained using this risk estimate show an excess of thyroid cancer cases being registered vs. the predicted cases. Thyroid cancer incidence rate among boys under investigation is higher than among girls in the postaccident period. The excess of the observed over the expected incidence in the general juvenile population is caused by the high thyroid cancer incidence rate among boys. These results, which can be considered part of the first stage of a thorough thyroid cancer risk estimation after the Chernobyl accident, demonstrate the critical need to complete these studies in depth. 6 refs., 5 figs., 3 tabs.

  8. Three-dimensional dose evaluation system using real-time wind field information for nuclear accidents in Taiwan

    NASA Astrophysics Data System (ADS)

    Wu, Jay; Lu, Chung-Hsin; Chang, Shu-Jun; Yang, Yung-Muh; Chang, Bor-Jing; Teng, Jen-Hsin

    2006-09-01

    In Taiwan, the three operating nuclear power plants are all built along the coast over complex terrain. Dose estimates after a nuclear accident with releases of radioactive materials, therefore, cannot be accurately calculated using simple dispersion models. We developed a three-dimensional dose evaluation system, which incorporates real-time prognostic wind field information with three-dimensional numerical models to predict dose results. The proposed system consists of three models: a three-dimensional mesoscale atmospheric model (HOTMAC), a three-dimensional transport and diffusion model (RAPTAD), and a dose calculation model (DOSE). The whole-body dose and thyroid dose as well as dose rates can be rapidly estimated and displayed on the three-dimensional terrain model constructed by satellite images. The developed three-dimensional dose evaluation system could accurately forecast the dose results and has been used in the annual nuclear emergency response exercise to provide suggestions for protective measures.

  9. Public health activities for mitigation of radiation exposures and risk communication challenges after the Fukushima nuclear accident.

    PubMed

    Shimura, Tsutomu; Yamaguchi, Ichiro; Terada, Hiroshi; Robert Svendsen, Erik; Kunugita, Naoki

    2015-05-01

    Herein we summarize the public health actions taken to mitigate exposure of the public to radiation after the Fukushima accident that occurred on 11 March 2011 in order to record valuable lessons learned for disaster preparedness. Evacuations from the radiation-affected areas and control of the distribution of various food products contributed to the reduction of external and internal radiation exposure resulting from the Fukushima incident. However, risk communication is also an important issue during the emergency response effort and subsequent phases of dealiing with a nuclear disaster. To assist with their healing process, sound, reliable scientific information should continue to be disseminated to the radiation-affected communities via two-way communication. We will describe the essential public health actions following a nuclear disaster for the early, intermediate and late phases that will be useful for radiological preparedness planning in response to other nuclear or radiological disasters. PMID:25862700

  10. Assessment in marine environment for a hypothetic nuclear accident based on the database of tidal harmonic constants.

    PubMed

    Min, Byung-Il; Periáñez, Raúl; Park, Kihyun; Kim, In-Gyu; Suh, Kyung-Suk

    2014-10-15

    The eleven nuclear power plants in operation, under construction and a well-planned plant in the east coast of China generally use seawater for reactor cooling. In this study, an oceanic dispersion assessment system based on a database of tidal harmonic constants is developed. This system can calculate the tidal current without a large computational cost, and it is possible to calculate real-time predictions of pollutant dispersions in the ocean. Calculated amplitudes and phases have maximum errors of 10% and 20% with observations, respectively. A number of hypothetical simulations were performed according to varying of the release starting time and duration of pollutant for the six nuclear sites in China. The developed system requires a computational time of one hour for one month of real-time forecasting in Linux OS. Thus, it can use to evaluate rapidly the dispersion characteristics of the pollutants released into the sea from a nuclear accident. PMID:25103904

  11. Public health activities for mitigation of radiation exposures and risk communication challenges after the Fukushima nuclear accident

    PubMed Central

    Shimura, Tsutomu; Yamaguchi, Ichiro; Terada, Hiroshi; Robert Svendsen, Erik; Kunugita, Naoki

    2015-01-01

    Herein we summarize the public health actions taken to mitigate exposure of the public to radiation after the Fukushima accident that occurred on 11 March 2011 in order to record valuable lessons learned for disaster preparedness. Evacuations from the radiation-affected areas and control of the distribution of various food products contributed to the reduction of external and internal radiation exposure resulting from the Fukushima incident. However, risk communication is also an important issue during the emergency response effort and subsequent phases of dealiing with a nuclear disaster. To assist with their healing process, sound, reliable scientific information should continue to be disseminated to the radiation-affected communities via two-way communication. We will describe the essential public health actions following a nuclear disaster for the early, intermediate and late phases that will be useful for radiological preparedness planning in response to other nuclear or radiological disasters. PMID:25862700

  12. Size distribution of radioactive particles collected at Tokai, Japan 6 days after the nuclear accident.

    PubMed

    Miyamoto, Yutaka; Yasuda, Kenichiro; Magara, Masaaki

    2014-06-01

    Airborne radioactive particles released by the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident in 2011 were collected with a cascade low-pressure impactor at the Japan Atomic Energy Agency (JAEA) in Tokai, Japan, 114 km south of the FDNPP. Size-fractionated samples were collected twice, in the periods of March 17-April 1, 2011, and May 9-13, 2011. These size-fractionated samplings were carried out in the earliest days at a short distance from the FDNPP. Radioactivity of short-lived nuclides (several ten days of half-life) was determined as well as (134)Cs and (137)Cs. The elemental composition of size-fractionated samples was also measured. In the first collection, the activity median aerodynamic diameter (AMAD) of (129m)Te, (140)Ba, (134)Cs, (136)Cs and (137)Cs was 1.5-1.6 μm, while the diameter of (131)I was 0.45 μm. The diameters of (134)Cs and (137)Cs in the second collection were expressed as three peaks at <0.5 μm, 0.94 μm, and 7.8 μm. The (134)Cs/(137)Cs ratio of the first collection was 1.02 in total, but the ratio in the fine fractions was 0.91. A distribution map of (134)Cs/(137)Cs - (136)Cs/(137)Cs ratios was helpful in understanding the change of radioactive Cs composition. The Cs composition of size fractions <0.43 μm and the composition in the 1.1-2.1 μm range (including the AMAD of 1.5-1.6 μm) were similar to the calculated compositions of fuels in the reactors No. 1 and No. 3 at the FDNPP using the ORIGEN-II code. The Cs composition collected in May, 2011 was similar to the calculation results of reactor No. 2 fuel composition. The change of Cs composition implies that the radioactive Cs was released from the three reactors at the FDNPP via different processes. PMID:24508948

  13. 10 CFR 72.74 - Reports of accidental criticality or loss of special nuclear material.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 2 2012-01-01 2012-01-01 false Reports of accidental criticality or loss of special nuclear material. 72.74 Section 72.74 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSING REQUIREMENTS FOR THE INDEPENDENT STORAGE OF SPENT NUCLEAR FUEL, HIGH-LEVEL RADIOACTIVE WASTE, AND...

  14. 10 CFR 72.74 - Reports of accidental criticality or loss of special nuclear material.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 2 2013-01-01 2013-01-01 false Reports of accidental criticality or loss of special nuclear material. 72.74 Section 72.74 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSING REQUIREMENTS FOR THE INDEPENDENT STORAGE OF SPENT NUCLEAR FUEL, HIGH-LEVEL RADIOACTIVE WASTE, AND...

  15. Severe Accident Sequence Analysis Program: Anticipated transient without scram simulations for Browns Ferry Nuclear Plant Unit 1

    SciTech Connect

    Dallman, R J; Gottula, R C; Holcomb, E E; Jouse, W C; Wagoner, S R; Wheatley, P D

    1987-05-01

    An analysis of five anticipated transients without scram (ATWS) was conducted at the Idaho National Engineering Laboratory (INEL). The five detailed deterministic simulations of postulated ATWS sequences were initiated from a main steamline isolation valve (MSIV) closure. The subject of the analysis was the Browns Ferry Nuclear Plant Unit 1, a boiling water reactor (BWR) of the BWR/4 product line with a Mark I containment. The simulations yielded insights to the possible consequences resulting from a MSIV closure ATWS. An evaluation of the effects of plant safety systems and operator actions on accident progression and mitigation is presented.

  16. [Regularities of changes in 137Cs content in milk in the long term after the Chernobyl nuclear reactor accident].

    PubMed

    Fesenko, S V; Pakhomov, A Iu; Pasternak, A D; Goriainov, V A; Fesenko, G A; Panov, A V

    2004-01-01

    Regularities of changes in 137Cs content in cattle milk in the long term after the Chernobyl accident have been analyzed. Contamination levels of haylands and pastures, soil properties, specific features of agricultural production and time after the fallout play a crucial role in 137Cs concentration changes in animal products. Trends have been studied that reflect the influence of these factors and their significance assessed. The half-life periods of 137Cs decay in milk vary over the period of 1994 to 2000 between 7.1 and 14.8 years and approach similar periods calculated for the long term after global radioactive fallout from nuclear weapons tests. PMID:15287266

  17. Radiation risk models for all solid cancers other than those types of cancer requiring individual assessments after a nuclear accident.

    PubMed

    Walsh, Linda; Zhang, Wei

    2016-03-01

    In the assessment of health risks after nuclear accidents, some health consequences require special attention. For example, in their 2013 report on health risk assessment after the Fukushima nuclear accident, the World Health Organisation (WHO) panel of experts considered risks of breast cancer, thyroid cancer and leukaemia. For these specific cancer types, use was made of already published excess relative risk (ERR) and excess absolute risk (EAR) models for radiation-related cancer incidence fitted to the epidemiological data from the Japanese A-bomb Life Span Study (LSS). However, it was also considered important to assess all other types of solid cancer together and the WHO, in their above-mentioned report, stated "No model to calculate the risk for all other solid cancer excluding breast and thyroid cancer risks is available from the LSS data". Applying the LSS models for all solid cancers along with the models for the specific sites means that some cancers have an overlap in the risk evaluations. Thus, calculating the total solid cancer risk plus the breast cancer risk plus the thyroid cancer risk can overestimate the total risk by several per cent. Therefore, the purpose of this paper was to publish the required models for all other solid cancers, i.e. all solid cancers other than those types of cancer requiring special attention after a nuclear accident. The new models presented here have been fitted to the same LSS data set from which the risks provided by the WHO were derived. Although it is known already that the EAR and ERR effect modifications by sex are statistically significant for the outcome "all solid cancer", it is shown here that sex modification is not statistically significant for the outcome "all solid cancer other than thyroid and breast cancer". It is also shown here that the sex-averaged solid cancer risks with and without the sex modification are very similar once breast and thyroid cancers are factored out. Some other notable model

  18. A tool for site restoration planning following a nuclear weapons accident: Part 2, Developing a site restoration strategy

    SciTech Connect

    Tawil, J.J.

    1988-05-01

    The objectives of this paper are to describe a process for developing site restoration strategies following a nuclear weapons accident, and demonstrate how to carry out this process using actual data from a military exercise. The exercise that I will be discussing is the Survey Response Force Exercise conducted in Savanna, Illinois in July 1986. It is called SRFX-86 for short. While a site restoration analysis using the SRP was conducted during the exercise, the present analysis is somewhat different in that it contains illustrations of some of the recent revisions and enhancements to the SRP. 5 figs., 3 tabs.

  19. An assessment of criticality safety at the Department of Energy Rocky Flats Plant, Golden, Colorado, July--September 1989

    SciTech Connect

    Mattson, Roger J.

    1989-09-01

    This is a report on the 1989 independent Criticality Safety Assessment of the Rocky Flats Plant, primarily in response to public concerns that nuclear criticality accidents involving plutonium may have occurred at this nuclear weapon component fabrication and processing plant. The report evaluates environmental issues, fissile material storage practices, ventilation system problem areas, and criticality safety practices. While no evidence of a criticality accident was found, several recommendations are made for criticality safety improvements. 9 tabs.

  20. Bipolarization of Risk Perception about the Health Effects of Radiation in Residents after the Accident at Fukushima Nuclear Power Plant.

    PubMed

    Orita, Makiko; Hayashida, Naomi; Nakayama, Yumi; Shinkawa, Tetsuko; Urata, Hideko; Fukushima, Yoshiko; Endo, Yuuko; Yamashita, Shunichi; Takamura, Noboru

    2015-01-01

    The late health effects of low-dose rate radiation exposure are still a serious public concern in the Fukushima area even four years after the accident at Fukushima Daiichi Nuclear Power Plant (FNPP). To clarify the factors associated with residents' risk perception of radiation exposure and consequent health effects, we conducted a survey among residents of Kawauchi village in May and June 2014, which is located within 30 km of FNPP. 85 of 285 residents (29.8%) answered that acute radiation syndrome might develop in residents after the accident, 154 (54.0%) residents responded that they had anxieties about the health effects of radiation on children, and 140 (49.1%) residents indicated that they had anxieties about the health effects of radiation on offspring. Furthermore, 107 (37.5%) residents answered that they had concerns about health effects that would appear in the general population simply by living in an environment with a 0.23 μSv per hour ambient dose for one year, 149 (52.2%) residents reported that they were reluctant to eat locally produced foods, and 164 (57.5%) residents believed that adverse health effects would occur in the general population by eating 100 Bq per kg of mushrooms every day for one year. The present study shows that a marked bipolarization of the risk perception about the health effects of radiation among residents could have a major impact on social well-being after the accident at FNPP. PMID:26057539

  1. Nuclear power plant accident simulations of gasket materials under simultaneous radiation plus thermal plus mechanical stress conditions

    SciTech Connect

    Gillen, K.T.; Malone, G.M.

    1997-07-01

    In order to probe the response of silicone door gasket materials to a postulated severe accident in an Italian nuclear power plant, compression stress relaxation (CSR) and compression set (CS) measurements were conducted under combined radiation (approximately 6 kGy/h) and temperature (up to 230{degrees}C) conditions. By making some reasonable initial assumptions, simplified constant temperature and dose rates were derived that should do a reasonable job of simulating the complex environments for worst-case severe events that combine overall aging plus accidents. Further simplification coupled with thermal-only experiments allowed us to derive thermal-only conditions that can be used to achieve CSR and CS responses similar to those expected from the combined environments that are more difficult to simulate. Although the thermal-only simulations should lead to sealing forces similar to those expected during a severe accident, modulus and density results indicate that significant differences in underlying chemistry are expected for the thermal-only and the combined environment simulations. 15 refs., 31 figs., 15 tabs.

  2. Bipolarization of Risk Perception about the Health Effects of Radiation in Residents after the Accident at Fukushima Nuclear Power Plant

    PubMed Central

    Orita, Makiko; Hayashida, Naomi; Nakayama, Yumi; Shinkawa, Tetsuko; Urata, Hideko; Fukushima, Yoshiko; Endo, Yuuko; Yamashita, Shunichi; Takamura, Noboru

    2015-01-01

    The late health effects of low-dose rate radiation exposure are still a serious public concern in the Fukushima area even four years after the accident at Fukushima Daiichi Nuclear Power Plant (FNPP). To clarify the factors associated with residents’ risk perception of radiation exposure and consequent health effects, we conducted a survey among residents of Kawauchi village in May and June 2014, which is located within 30 km of FNPP. 85 of 285 residents (29.8%) answered that acute radiation syndrome might develop in residents after the accident, 154 (54.0%) residents responded that they had anxieties about the health effects of radiation on children, and 140 (49.1%) residents indicated that they had anxieties about the health effects of radiation on offspring. Furthermore, 107 (37.5%) residents answered that they had concerns about health effects that would appear in the general population simply by living in an environment with a 0.23 μSv per hour ambient dose for one year, 149 (52.2%) residents reported that they were reluctant to eat locally produced foods, and 164 (57.5%) residents believed that adverse health effects would occur in the general population by eating 100 Bq per kg of mushrooms every day for one year. The present study shows that a marked bipolarization of the risk perception about the health effects of radiation among residents could have a major impact on social well-being after the accident at FNPP. PMID:26057539

  3. Consideration of criticality in a nuclear waste repository

    SciTech Connect

    Rechard, R.P.; Sanchez, L.C.; Stockman, C.T.; Ramsey, J.L. Jr.; Martell, M.

    1995-07-01

    The preliminary criticality analysis that was done suggests that the possibility of achieving critical conditions cannot be easily ruled out without looking at the geochemical process of assembly or the dynamics of the operation of a critical assembly. The evaluation of a critical assembly requires an integrated, consistent approach that includes evaluating the following: (1) the alteration rates of the layers of the container and spent fuel, (2) the transport of fissile material or neutron absorbers, and (3) the assembly mechanisms that can achieve critical conditions. The above is a non-trivial analysis and preliminary work suggests that with the loading assumed, enough fissile mass will leach from the HEU multi-purpose canisters to support a criticality. In addition, the consequences of an unpressurized Oklo type criticality would be insignificant to the performance of an unsaturated, tuff repository.

  4. Thirty-Five-Year-Old Woman with Signet Ring Cell Gastric Carcinoma Secondary to the Chernobyl Nuclear Accident: A Case Report

    PubMed Central

    Mayhall, Kim; Ghayouri, Masoumeh; Henry, Katherine; Margin, Veronica; Copolla, Domeinico; Shackelford, Rodney

    2013-01-01

    The 1986 Chernobyl nuclear accident resulted in radiation exposures throughout much of Europe, with the highest exposures within the city of Pripyat, Ukraine, where the accident occurred. We report a woman who was exposed to the Chernobyl accident at age 13. Beginning in her early thirties, she experienced several years of upper abdominal pain that became progressively more severe. At age 35, she underwent upper endoscopy and gastric biopsy. Histological examination revealed a signet ring cell (SRC) gastric carcinoma. The tumor was discovered at an advanced stage and proved unresectable. She died 3 months following her diagnosis. The mean age for SRC gastric carcinoma diagnosis is about 62 years; the median survival following diagnosis is 13 months. The early appearance and aggressive clinical course of this malignancy in relation to the Chernobyl nuclear accident is discussed. PMID:23626554

  5. Forecast of criticality experiments and experimental programs needed to support nuclear operations in the United States of America: 1994--1999

    SciTech Connect

    Rutherford, D.

    1994-03-01

    This Forecast is generated by the Chair of the Experiment Needs Identification Workgroup (ENIWG), with input from Department of Energy and the nuclear community. One of the current concerns addressed by ENIWG was the Defense Nuclear Facilities Safety Board`s Recommendation 93-2. This Recommendation delineated the need for a critical experimental capability, which includes (1) a program of general-purpose experiments, (2) improving the information base, and (3) ongoing departmental programs. The nuclear community also recognizes the importance of criticality theory, which, as a stepping stone to computational analysis and safety code development, needs to be benchmarked against well-characterized critical experiments. A summary project of the Department`s needs with respect to criticality information includes (1) hands-on training, (2) criticality and nuclear data, (3) detector systems, (4) uranium- and plutonium-based reactors, and (5) accident analysis. The Workgroup has evaluated, prioritized, and categorized each proposed experiment and program. Transportation/Applications is a new category intended to cover the areas of storage, training, emergency response, and standards. This category has the highest number of priority-1 experiments (nine). Facilities capable of performing experiments include the Los Alamos Critical Experiment Facility (LACEF) along with Area V at Sandia National Laboratory. The LACEF continues to house the most significant collection of critical assemblies in the Western Hemisphere. The staff of this facility and Area V are trained and certified, and documentation is current. ENIWG will continue to work with the nuclear community to identify and prioritize experiments because there is an overwhelming need for critical experiments to be performed for basic research and code validation.

  6. Spatial and temporal variations and budget of radiocesium in the ocean following the Fukushima Daiichi Nuclear Power Plant accident

    NASA Astrophysics Data System (ADS)

    Tsumune, Daisuke; Aoyama, Michio; Kajino, Mizuo; Tanaka, Taichu; Sekiyama, Tsuyoshi; Tsubono, Takaki; Misumi, Kazuhiro; Maeda, Yoshiaki; Yoshida, Yoshikatsu; Hayami, Hiroshi; Hamajima, Yasunori; Gamo, Toshitaka; Uematsu, Mitsuo; Kawano, Takeshi; Murata, Akihiro; Kumamoto, Yuichiro; Fukasawa, Masao; Chino, Masamichi

    2013-04-01

    A series of accidents at the Fukushima Dai-ichi Nuclear Power Plant following the earthquake and tsunami of 11 March 2011 resulted in the release of radioactive materials to the ocean by two major pathways, direct release from the accident site and atmospheric deposition. We determined the inventory of radiocesium released by the TEPCO Fukushima Dai-ichi Nuclear Power Plant (FNPP1) accident to the North Pacific Ocean based on measurements of seawater samples collected in the North Pacific Ocean after the accident. Comparison of the observed inventory with the model-simulated results allowed us to obtain realistic values of 10-13 PBq for the total atmospheric deposition of 134Cs and 137Cs released by the FNPP1 accident in the North Pacific. Before the Fukushima accident, 137Cs inventory in the North Pacific Ocean was about 69 PBq, the 12 - 15 PBq of 137Cs newly added by atmospheric deposition and the 3.5 ± 0.7 PBq added by direct discharge, therefore increased the total 137Cs inventory in the North Pacific Ocean by 22-27 %. We also determined that the total atmospheric release of 134Cs and 137Cs by the FNPP1 accident was about 14-17 PBq, respectively. Using global simulated results as boundary conditions, a 1-year, regional-scale simulation of 137Cs activity in the ocean offshore of Fukushima was also carried out, the sources of radioactivity being direct release, atmospheric deposition, and the inflow of 137Cs deposited on the ocean by atmospheric deposition outside the domain of the model. The contributions of each source were estimated by analysis of 131I/137Cs and 134Cs/137Cs activity ratios and comparisons between simulated results and measured activities of 137Cs. Simulated 137Cs activities attributable to direct release were in good agreement with measured activities close to the accident site, a result that implies that the estimated direct release rate was reasonable, while simulated 137Cs activities attributable to atmospheric deposition were low compared

  7. Effect of radiocesium transfer on ambient dose rate in forest environments affected by the Fukushima Nuclear Power Plant accident

    NASA Astrophysics Data System (ADS)

    Kato, H.

    2015-12-01

    We investigated the transfer of canopy-intercepted radiocesium to the forest floor during 3 years following the Fukushima Daiichi Nuclear Power Plant accident. The cesium-137 (Cs-137) contents in throughfall, stemflow, and litterfall were monitored in two coniferous stands (plantation of Japanese cedar) and a deciduous broad-leaved forest stand (Japanese oak with red pine). We also measured the ambient dose rate (ADR) at different heights in the forest using a survey meter and a portable Ge gamma-ray detector. Total Cs-137 deposition flux from the canopy to forest floor for the mature cedar, young cedar, and the mixed broad-leaved stands were 166 kBq/m2, 174 kBq/m2, and 60 kBq/m2, respectively. These values correspond to 38%, 40% and 13% of total atmospheric input after the accident. The ambient dose rate in forest exhibited height dependency and its vertical distribution varied with forest type and stand age. The ambient dose rate showed an exponential decrease with time for all the forest sites, however the decreasing trend differed depending on the height of dose measurement and forest type. The ambient dose rate at the canopy (approx. 10 m-height) decreased faster than that expected from physical decay of the two radiocesium isotopes, whereas those at the forest floor varied between the three forest stands. The radiocesium deposition via throughfall seemed to increase ambient dose rate during the first 200 days after the accident, however there was no clear relationship between litterfall and ambient dose rate since 400 days after the accident. These data suggested that the ambient dose rate in forest environment varied both spatially and temporally reflecting the transfer of radiocesium from canopy to forest floor. However, further monitoring investigation and analysis are required to determine the effect of litterfall on long-term trend of ambient dose rate in forest environments.

  8. SRTC criticality safety technical review: Nuclear criticality safety evaluation 94-02, uranium solidification facility pencil tank module spacing

    SciTech Connect

    Rathbun, R.

    1994-04-26

    Review of NMP-NCS-94-0087, ``Nuclear Criticality Safety Evaluation 94-02: Uranium Solidification Facility Pencil Tank Module Spacing (U), April 18, 1994,`` was requested of the SRTC Applied Physics Group. The NCSE is a criticality assessment to show that the USF process module spacing, as given in Non-Conformance Report SHM-0045, remains safe for operation. The NCSE under review concludes that the module spacing as given in Non-Conformance Report SHM-0045 remains in a critically safe configuration for all normal and single credible abnormal conditions. After a thorough review of the NCSE, this reviewer agrees with that conclusion.

  9. THREE MILE ISLAND NUCLEAR REACTOR ACCIDENT OF MARCH 1979. ENVIRONMENTAL RADIATION DATA: UPDATE 2, VOLUME III

    EPA Science Inventory

    The original report contains a listing of environmental radiation monitoring data collected in the vicinity of Three Mile Island (TMI) following the March 28, 1979 accident. These data were collected by the EPA, NRC, DOE, HHS, the Commonwealth of Pennsylvania, or the Bethlehem St...

  10. THREE MILE ISLAND NUCLEAR REACTOR ACCIDENT OF MARCH 1979. ENVIRONMENTAL RADIATION DATA: UPDATE 2, VOLUME II

    EPA Science Inventory

    The original report contains a listing of environmental radiation monitoring data collected in the vicinity of Three Mile Island (TMI) following the March 28, 1979 accident. These data were collected by the EPA, NRC, DOE, HHS, the Commonwealth of Pennsylvania, or the Bethlehem St...

  11. THREE MILE ISLAND NUCLEAR REACTOR ACCIDENT OF MARCH 1979. ENVIRONMENTAL RADIATION DATA: UPDATE 2, VOLUME I

    EPA Science Inventory

    The original report contains a listing of environmental radiation monitoring data collected in the vicinity of Three Mile Island (TMI) following the March 28, 1979 accident. These data were collected by the EPA, NRC, DOE, HHS, the Commonwealth of Pennsylvania, or the Bethlehem St...

  12. Oxidation rate of nuclear-grade graphite IG-110 in the kinetic regime for VHTR air ingress accident scenarios

    NASA Astrophysics Data System (ADS)

    Lee, Jo Jo; Ghosh, Tushar K.; Loyalka, Sudarshan K.

    2014-03-01

    The oxidation rates of nuclear-grade graphite IG-110 in the kinetically-controlled temperature regime of graphite oxidation were predicted and compared in Very High Temperature Reactor air ingress accident scenarios. The oxidative mass loss of graphite was measured thermogravimetrically from 873 to 1873 K in 100% air (21 mol%). The activation energy was found to be 222.07 kJ/mol, and the order of reaction with respect to oxygen concentration is 0.76. The surfaces of the samples were characterized by Scanning Electron Microscopy, Energy Dispersive Spectroscopy, Fourier Transform Infrared Spectroscopy and X-ray Photoelectron Spectroscopy before and after oxidation. These results are compared with those available in the literature, and our recently reported results for NBG-18 nuclear-grade graphite using the same technique.

  13. An overview of current knowledge concerning the health and environmental consequences of the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident.

    PubMed

    Aliyu, Abubakar Sadiq; Evangeliou, Nikolaos; Mousseau, Timothy Alexander; Wu, Junwen; Ramli, Ahmad Termizi

    2015-12-01

    Since 2011, the scientific community has worked to identify the exact transport and deposition patterns of radionuclides released from the accident at the Fukushima Daiichi Nuclear Power Plant (FDNPP) in Japan. Nevertheless, there still remain many unknowns concerning the health and environmental impacts of these radionuclides. The present paper reviews the current understanding of the FDNPP accident with respect to interactions of the released radionuclides with the environment and impacts on human and non-human biota. Here, we scrutinize existing literature and combine and interpret observations and modeling assessments derived after Fukushima. Finally, we discuss the behavior and applications of radionuclides that might be used as tracers of environmental processes. This review focuses on (137)Cs and (131)I releases derived from Fukushima. Published estimates suggest total release amounts of 12-36.7PBq of (137)Cs and 150-160PBq of (131)I. Maximum estimated human mortality due to the Fukushima nuclear accident is 10,000 (due to all causes) and the maximum estimates for lifetime cancer mortality and morbidity are 1500 and 1800, respectively. Studies of plants and animals in the forests of Fukushima have recorded a range of physiological, developmental, morphological, and behavioral consequences of exposure to radioactivity. Some of the effects observed in the exposed populations include the following: hematological aberrations in Fukushima monkeys; genetic, developmental and morphological aberrations in a butterfly; declines in abundances of birds, butterflies and cicadas; aberrant growth forms in trees; and morphological abnormalities in aphids. These findings are discussed from the perspective of conservation biology. PMID:26425805

  14. Cytogenetic biodosimetry for Fukushima travelers after the nuclear power plant accident: no evidence of enhanced yield of dicentrics

    PubMed Central

    Lee, Jin Kyung; Han, Eun-Ae; Lee, Seung-Sook; Ha, Wi-Ho; Barquinero, Joan Francesc; Lee, Hyo Rak; Cho, Min Su

    2012-01-01

    Individuals who traveled to contaminated areas after the Fukushima nuclear accident have concerns about the health effects. However, medical follow-up for any adverse health effects will be difficult without personal dose measurements. Cytogenetic biodosimetry is a reasonable method of assessing absorbed doses retrospectively. We analyzed dicentric chromosomes for 265 Fukushima travelers, mostly journalists and rescue workers, who had been dispatched to northeastern Japan during the nuclear emergency. As a control group, 37 healthy volunteers who had not visited Japan since the accident were enrolled. Yields of dicentrics and absorbed doses calculated from a dose-response calibration curve for travelers and the control group were compared. The cut-off level for dicentric chromosomes in the controls was 3.5 per 1000 cells. Of the 265 travelers, 31 had elevated numbers of dicentrics (High-Dics group) while 234 were below the cut-off (Normal-Dics group). All but one of the individuals in the High-Dics group also reported a significantly higher number of medical exposures to radiation within the past three years compared with the Normal-Dics or control groups. The 225 travelers with no history of medical exposure showed no difference of dicentrics yield compared to the control group. Our data indicate that Fukushima travel alone did not enhance the yield of dicentrics. PMID:22859566

  15. Models and numerical methods for the simulation of loss-of-coolant accidents in nuclear reactors

    NASA Astrophysics Data System (ADS)

    Seguin, Nicolas

    2014-05-01

    In view of the simulation of the water flows in pressurized water reactors (PWR), many models are available in the literature and their complexity deeply depends on the required accuracy, see for instance [1]. The loss-of-coolant accident (LOCA) may appear when a pipe is broken through. The coolant is composed by light water in its liquid form at very high temperature and pressure (around 300 °C and 155 bar), it then flashes and becomes instantaneously vapor in case of LOCA. A front of liquid/vapor phase transition appears in the pipes and may propagate towards the critical parts of the PWR. It is crucial to propose accurate models for the whole phenomenon, but also sufficiently robust to obtain relevant numerical results. Due to the application we have in mind, a complete description of the two-phase flow (with all the bubbles, droplets, interfaces…) is out of reach and irrelevant. We investigate averaged models, based on the use of void fractions for each phase, which represent the probability of presence of a phase at a given position and at a given time. The most accurate averaged model, based on the so-called Baer-Nunziato model, describes separately each phase by its own density, velocity and pressure. The two phases are coupled by non-conservative terms due to gradients of the void fractions and by source terms for mechanical relaxation, drag force and mass transfer. With appropriate closure laws, it has been proved [2] that this model complies with all the expected physical requirements: positivity of densities and temperatures, maximum principle for the void fraction, conservation of the mixture quantities, decrease of the global entropy… On the basis of this model, it is possible to derive simpler models, which can be used where the flow is still, see [3]. From the numerical point of view, we develop new Finite Volume schemes in [4], which also satisfy the requirements mentioned above. Since they are based on a partial linearization of the physical

  16. Retrospective reconstruction of Ioidne-131 distribution at the Fukushima Daiichi Nuclear Power Plant accident by analysis of Ioidne-129

    NASA Astrophysics Data System (ADS)

    Matsuzaki, Hiroyuki; Muramatsu, Yasuyuki; Toyama, Chiaki; Ohno, Takeshi; Kusuno, Haruka; Miyake, Yasuto; Honda, Maki

    2014-05-01

    Among various radioactive nuclides emitted from the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident, Iodine-131 displayed high radioactivity just after the accident. Moreover if taken into human body, Iodine-131 concentrates in the thyroid and may cause the thyroid cancer. The recognition about the risk of Iodine-131 dose originated from the experience of the Chernobyl accident based on the epidemiological study [1]. It is thus important to investigate the detailed deposition distribution of I-131 to evaluate the radiation dose due to I-131 and watch the influence on the human health. However I-131 decays so rapidly (half life = 8.02 d) that it cannot be detected several months after the accident. At the recognition of the risk of I-131 on the Chernobyl occasion, it had gone several years after the accident. The reconstruction of I-131 distribution from Cs-137 distribution was not successful because the behavior of iodine and cesium was different because they have different chemical properties. Long lived radioactive isotope I-129 (half life = 1.57E+7 yr,), which is also a fission product as well as I-131, is ideal proxy for I-131 because they are chemically identical. Several studies had tried to quantify I-129 in 1990's but the analytical technique, especially AMS (Accelerator Mass Spectrometry), had not been developed well and available AMS facility was limited. Moreover because of the lack of enough data on I-131 just after the accident, the isotopic ratio I-129/I-131 of the Chernobyl derived iodine could not been estimated precisely [2]. Calculated estimation of the isotopic ratio showed scattered results. On the other hand, at the FDNPP accident detailed I-131 distribution is going to be successfully reconstructed by the systematical I-129 measurements by our group. We measured soil samples selected from a series of soil collection taken from every 2 km (or 5km, in the distant area) meshed region around FDNPP conducted by the Japanese Ministry of

  17. Optimization of a Dry, Mixed Nuclear Fuel Storage Array for Nuclear Criticality Safety

    NASA Astrophysics Data System (ADS)

    Baranko, Benjamin T.

    A dry storage array of used nuclear fuel at the Idaho National Laboratory contains a mixture of more than twenty different research and test reactor fuel types in up to 636 fuel storage canisters. New analysis demonstrates that the current arrangement of the different fuel-type canisters does not minimize the system neutron multiplication factor (keff), and that the entire facility storage capacity cannot be utilized without exceeding the subcritical limit (ksafe) for ensuring nuclear criticality safety. This work determines a more optimal arrangement of the stored fuels with a goal to minimize the system keff, but with a minimum of potential fuel canister relocation movements. The solution to this multiple-objective optimization problem will allow for both an improvement in the facility utilization while also offering an enhancement in the safety margin. The solution method applies stochastic approximation and a Tabu search metaheuristic to an empirical model developed from supporting MCNP calculations. The results establish an optimal relocation of between four to sixty canisters, which will allow the current thirty-one empty canisters to be used for storage while reducing the array keff by up to 0.018 +/- 0.003 relative to the current arrangement.

  18. Chlorine Release from Hypalon Cable Insulation During Severe Nuclear Reactor Accidents

    SciTech Connect

    Auvinen, Ari; Zilliacus, Riitta; Jokiniemi, Jorma

    2005-02-15

    Pyrolytic dehydrochlorination of the electrical cable insulation Hypalon was studied as a function of time and temperature. The chlorine evolution was determined separately by means of on-line activity measurements and by neutron activation analysis in the temperature range 200 deg. C to 300 deg. C, with one test conducted at 500 deg. C. The object of the research was to determine the chlorine release and the chlorine release fraction as a function of temperature. The data obtained were needed to formulate conclusions regarding the release mechanisms of chlorine. Estimates of the amount of hydrochloric acid released to the containment building in a severe reactor accident were also calculated. It can be concluded that the amount of chlorine release from the Hypalon cable is significant and will have an effect on iodine behavior in a severe accident.

  19. Plutonium contamination twenty years after the nuclear weapons accident in Spain

    SciTech Connect

    Iranzo, E.; Richmond, C.R.

    1987-01-01

    An accident involving two US Air Force planes engaged in a refueling operation occurred at 0922 GMT on January 17, 1966 over the town of Palomares in southeastern Spain. Three of the bombs, one intact, were found on land, in or near Palomares while the fourth was removed from the Mediterranean Sea. The parachutes of two of the bombs did not deploy resulting in the detonation of their conventional explosives and release of fissile material upon impact. Partial burning of the fissile material formed an aerosol that contaminated approximately 226 hectares of uncultivated, farmed, and urban land. The objective of this study was to determine the magnitude of the risk from internal contamination of the area inhabitants immediately after the accident and during the emergency phase and to determine the short, medium and long-term risk of internal contamination for the inhabitants of Palomares and its environs and to those who consume planet products cultivated in that area.

  20. MACCS usage at Rocky Flats Plant for consequence analysis of postulated accidents

    SciTech Connect

    Foppe, T.L.; Peterson, V.L.

    1993-10-01

    The MELCOR Accident Consequence Code System (MACCS) has been applied to the radiological consequence assessment of potential accidents from a non-reactor nuclear facility. MACCS has been used in a variety of applications to evaluate radiological dose and health effects to the public from postulated plutonium releases and from postulated criticalities. These applications were conducted to support deterministic and probabilistic accident analyses for safety analyses for safety analysis reports, radiological sabotage studies, and other regulatory requests.

  1. The SAM software system for modeling severe accidents at nuclear power plants equipped with VVER reactors on full-scale and analytic training simulators

    NASA Astrophysics Data System (ADS)

    Osadchaya, D. Yu.; Fuks, R. L.

    2014-04-01

    The architecture of the SAM software package intended for modeling beyond-design-basis accidents at nuclear power plants equipped with VVER reactors evolving into a severe stage with core melting and failure of the reactor pressure vessel is presented. By using the SAM software package it is possible to perform comprehensive modeling of the entire emergency process from the failure initiating event to the stage of severe accident involving meltdown of nuclear fuel, failure of the reactor pressure vessel, and escape of corium onto the concrete basement or into the corium catcher with retention of molten products in it.

  2. The long-term impact of a man-made disaster: An examination of a small town in the aftermath of the Three Mile Island Nuclear Reactor Accident.

    PubMed

    Goldsteen, R; Schorr, J K

    1982-03-01

    This paper explores the long-term effects of a nuclear accident on residents' perceptions of their physical and mental health, their trust of public officials, and their attitudes toward the future risks of nuclear power generation In their community. We find that in the period after the accident at Three Mile Island that there are constant or Increasing levels of distress reported by community residents. We conclude that the effects of a technological disaster may often be more enduring than those natural disaster and that greater research efforts should be made to Investigate the long-term consequences of man-made catastrophies of all types. PMID:20958512

  3. Dynamic modelling of radionuclide uptake by marine biota: application to the Fukushima nuclear power plant accident.

    PubMed

    Vives i Batlle, Jordi

    2016-01-01

    The dynamic model D-DAT was developed to study the dynamics of radionuclide uptake and turnover in biota and sediments in the immediate aftermath of the Fukushima accident. This dynamics is determined by the interplay between the residence time of radionuclides in seawater/sediments and the biological half-lives of elimination by the biota. The model calculates time-variable activity concentration of (131)I, (134)Cs, (137)Cs and (90)Sr in seabed sediment, fish, crustaceans, molluscs and macroalgae from surrounding activity concentrations in seawater, with which to derive internal and external dose rates. A central element of the model is the inclusion of dynamic transfer of radionuclides to/from sediments by factorising the depletion of radionuclides adsorbed onto suspended particulates, molecular diffusion, pore water mixing and bioturbation, represented by a simple set of differential equations coupled with the biological uptake/turnover processes. In this way, the model is capable of reproducing activity concentration in sediment more realistically. The model was used to assess the radiological impact of the Fukushima accident on marine biota in the acute phase of the accident. Sediment and biota activity concentrations are within the wide range of actual monitoring data. Activity concentrations in marine biota are thus shown to be better calculated by a dynamic model than with the simpler equilibrium approach based on concentration factors, which tends to overestimate for the acute accident period. Modelled dose rates from external exposure from sediment are also significantly below equilibrium predictions. The model calculations confirm previous studies showing that radioactivity levels in marine biota have been generally below the levels necessary to cause a measurable effect on populations. The model was used in mass-balance mode to calculate total integrated releases of 103, 30 and 3 PBq for (131)I, (137)Cs and (90)Sr, reasonably in line with previous

  4. Accident source terms for Light-Water Nuclear Power Plants. Final report

    SciTech Connect

    Soffer, L.; Burson, S.B.; Ferrell, C.M.; Lee, R.Y.; Ridgely, J.N.

    1995-02-01

    In 1962 tile US Atomic Energy Commission published TID-14844, ``Calculation of Distance Factors for Power and Test Reactors`` which specified a release of fission products from the core to the reactor containment for a postulated accident involving ``substantial meltdown of the core``. This ``source term``, tile basis for tile NRC`s Regulatory Guides 1.3 and 1.4, has been used to determine compliance with tile NRC`s reactor site criteria, 10 CFR Part 100, and to evaluate other important plant performance requirements. During the past 30 years substantial additional information on fission product releases has been developed based on significant severe accident research. This document utilizes this research by providing more realistic estimates of the ``source term`` release into containment, in terms of timing, nuclide types, quantities and chemical form, given a severe core-melt accident. This revised ``source term`` is to be applied to the design of future light water reactors (LWRs). Current LWR licensees may voluntarily propose applications based upon it.

  5. Nuclear criticality safety experiments, calculations, and analyses: 1958 to 1982. Volume 1. Lookup tables

    SciTech Connect

    Koponen, B.L.; Hampel, V.E.

    1982-10-21

    This compilation contains 688 complete summaries of papers on nuclear criticality safety as presented at meetings of the American Nuclear Society (ANS). The selected papers contain criticality parameters for fissile materials derived from experiments and calculations, as well as criticality safety analyses for fissile material processing, transport, and storage. The compilation was developed as a component of the Nuclear Criticality Information System (NCIS) now under development at the Lawrence Livermore National Laboratory. The compilation is presented in two volumes: Volume 1 contains a directory to the ANS Transaction volume and page number where each summary was originally published, the author concordance, and the subject concordance derived from the keyphrases in titles. Volume 2 contains - in chronological order - the full-text summaries, reproduced here by permission of the American Nuclear Society from their Transactions, volumes 1-41.

  6. Lessons learned from Fukushima Daiichi nuclear power plant accident: efficient education items of radiation safety for general public.

    PubMed

    Ohno, K; Endo, K

    2015-07-01

    The Fukushima Daiichi nuclear power plant (FNP-1) accident, while as tragic as the tsunami, was a man-made disaster created by the ignorance of the effects of radiation and radioactive materials. Therefore, it is important that all specialists in radiation protection in medicine sympathize with the anxiety of the general public regarding the harmful effects of radiation and advise people accordingly. All questions and answers were collected related to inquiries from the general public that were posted to reliable websites, including those of the government and radiation-related organizations, from March 2011 to November 2012. The questions were summarized and classified by similarity of content. (1) The total number of questions is 372. The content was broadly classified into three categories: inquiries for radiation-related knowledge and about health effects and foods. The questions asked to obtain radiation-related knowledge were the most common, accounting for 38 %. Thirty-six percentage of the questions were related to health effects, and 26 % involved foods, whereas 18 % of the questions were related to children and pregnancy. (2) The change over time was investigated in 290 questions for which the time of inquiry was known. Directly after the earthquake, the questions were primarily from people seeking radiation-related knowledge. Later, questions related to health effects increased. The anxiety experienced by residents following the nuclear accident was caused primarily by insufficient knowledge related to radiation, concerns about health effects and uncertainties about food and water safety. The development of educational materials focusing on such content will be important for risk communication with the general public in countries with nuclear power plants. Physicians and medical physicist should possess the ability to respond to questions such as these and should continue with medical examinations and treatments in a safe and appropriate manner. PMID

  7. The accident at TEPCO's Fukushima-Daiichi Nuclear Power Station: What went wrong and what lessons are universal?

    NASA Astrophysics Data System (ADS)

    Omoto, Akira

    2013-12-01

    After a short summary of the nuclear accident at the Fukushima Daiichi Nuclear Power Station, this paper discusses “what went wrong” by illustrating the problems of the specific layers of defense-in-depth (basic strategy for assuring nuclear safety) and “what lessons are universal.” Breaches in the multiple layers of defense were particularly significant in respective protection (a) against natural disasters (first layer of defense) as well as (b) against severe conditions, specifically in this case, a complete loss of AC/DC power and isolation from the primary heat sink (fourth layer of defense). Confusion in crisis management by the government and insufficient implementation of offsite emergency plans revealed problems in the fifth layer of defense. By taking into consideration managerial and safety culture that might have relevance to this accident, in the author's view, universal lessons are as follows: Resilience: the need to enhance organizational capabilities to respond, monitor, anticipate, and learn in changing conditions, especially to prepare for the unexpected. This includes increasing distance to cliff edge by knowing where it exists and how to increase safety margin. Responsibility: the operator is primarily responsible for safety, and the government is responsible for protecting public health and environment. For both, their right decisions are supported by competence, knowledge, and an understanding of the technology, as well as humble attitudes toward the limitations of what we know and what we can learn from others. Social license to operate: the need to avoid, as much as possible regardless of its probability of occurrence, the reasonably anticipated environmental impact (such as land contamination), as well as to build public confidence/trust and a renewed liability scheme.

  8. Little impact of tsunami-stricken nuclear accident on awareness of radiation dose of cardiac computed tomography: A questionnaire study

    PubMed Central

    2013-01-01

    Background With the increased use of cardiac computed tomography (CT), radiation dose remains a major issue, although physicians are trying to reduce the substantial risks associated with use of this diagnostic tool. This study was performed to investigate recognition of the level of radiation exposure from cardiac CT and the differences in the level of awareness of radiation before and after the Fukushima nuclear plant accident. Methods We asked 30 physicians who were undergoing training in internal medicine to determine the equivalent doses of radiation for common radiological examinations when a normal chest X-ray is accepted as one unit; questions about the absolute radiation dose of cardiac CT data were also asked. Results According to the results, 86.6% of respondents believed the exposure to be 1 mSv at most, and 93.3% thought that the exposure was less than that of 100 chest X-rays. This finding indicates that their perceptions were far lower than the actual amounts. Even after the occurrence of such a large nuclear disaster in Fukushima, there were no significant differences in the same subjects’ overall awareness of radiation amounts. Conclusions Even after such a major social issue as the Fukushima nuclear accident, the level of awareness of the accurate radiation amount used in 64-channel multidetector CT (MDCT) by clinical physicians who order this test was not satisfactory. Thus, there is a need for the development of effective continuing education programs to improve awareness of radiation from ionizing radiation devices, including cardiac CT, and emphasis on risk-benefit evaluation based on accurate knowledge during medical training. PMID:23631688

  9. Nuclear criticality safety evaluation of Spray Booth Operations in X-705, Portsmouth Gaseous Diffusion Plant

    SciTech Connect

    Sheaffer, M.K.; Keeton, S.C.

    1993-09-20

    This report evaluates nuclear criticality safety for Spray Booth Operations in the Decontamination and Recovery Facility, X-705, at the Portsmouth Gaseous Diffusion Plant. A general description of current procedures and related hardware/equipment is presented. Control parameters relevant to nuclear criticality safety are explained, and a consolidated listing of administrative controls and safety systems is developed. Based on compliance with DOE Orders and MMES practices, the overall operation is evaluated, and recommendations for enhanced safety are suggested.

  10. Trans-oceanic transport of 137Cs from the Fukushima nuclear accident and impact of hypothetical Fukushima-like events of future nuclear plants in Southern China.

    PubMed

    Wai, Ka-Ming; Yu, Peter K N

    2015-03-01

    A Lagrangian model was adopted to assess the potential impact of (137)Cs released from hypothetical Fukushima-like accidents occurring on three potential nuclear power plant sites in Southern China in the near future (planned within 10 years) in four different seasons. The maximum surface (0-500 m) (137)Cs air concentrations would be reached 10 Bq m(-3) near the source, comparable to the Fukushima case. In January, Southeast Asian countries would be mostly affected by the radioactive plume due to the effects of winter monsoon. In April, the impact would be mainly on Southern and Northern China. Debris of radioactive plume (~1 mBq m(-3)) would carry out long-range transport to North America. The area of influence would be the smallest in July due to the frequent and intense wet removal events by trough of low pressure and tropical cyclone. The maximum worst-case areas of influence were 2382000, 2327000, 517000 and 1395000 km(2) in January, April, July and October, respectively. Prior to the above calculations, the model was employed to simulate the trans-oceanic transport of (137)Cs from the Fukushima nuclear accident. Observed and modeled (137)Cs concentrations were comparable. Sensitivity runs were performed to optimize the wet scavenging parameterization. The adoption of higher-resolution (1° × 1°) meteorological fields improved the prediction. The computed large-scale plume transport pattern over the Pacific Ocean was compared with that reported in the literature. PMID:25474170

  11. Iodine isotopes in precipitation: Four-year time series variations before and after 2011 Fukushima nuclear accident.

    PubMed

    Xu, Sheng; Zhang, Luyuan; Freeman, Stewart P H T; Hou, Xiaolin; Watanabe, Akira; Sanderson, David C W; Cresswell, Alan; Yamaguchi, Katsuhiko

    2016-05-01

    Rainwater samples were collected monthly from Fukushima, Japan, in 2012-2014 and analysed for (127)I and (129)I. These are combined with previously reported data to investigate atmospheric levels and behaviour of Fukushima-derived (129)I before and after the 2011 nuclear accident. In the new datasets, (127)I and (129)I concentrations between October 2012 and October 2014 varied from 0.5 to 10 μg/L and from 1.2 × 10(8) to 6.9 × 10(9) atoms/L respectively, resulting in (129)I/(127)I atomic ratio ranges from 3 × 10(-8) to 2 × 10(-7). The (127)I concentrations were in good agreement with those in the previous period from March 2011 to September 2012, whereas the (129)I concentrations and (129)I/(127)I ratios followed declining trends since the accident. Although (129)I concentrations in five samples during the period of 2013-2014 have approached the pre-accident levels, (129)I concentrations in most samples remained higher values in winter and spring-summer. The high (129)I levels in winter and spring-summer are most likely attributed to local resuspension of the Fukushima-derived radionuclide-bearing fine soil particles deposited on land surfaces, and re-emission through vegetation taking up (129)I from contaminated soil and water, respectively. Long-term declining rate suggests that contribution of the Fukushima-derived (129)I to the atmosphere would become less since 2014. PMID:26913975

  12. Investigation of Depth Distribution of Radionuclides in Soil Contaminated by the Fukushima Dai-ichi Nuclear Power Plant Accident

    NASA Astrophysics Data System (ADS)

    Sato, Haruo; Niizato, Tadafumi; Tanaka, Shingo; Abe, Hironobu; Aoki, Kazuhiro

    2014-05-01

    This work was conducted as one of the researches relating to distribution maps of radiation dose rate etc. which the government has promoted as one of the counter-measures to the Fukushima Dai-ichi Nuclear Power Plant accident in March 2011, and the 2nd investigation on the depth distribution of radionuclides (RNs) in soil was conducted after about 1 year from the accident, succeedingly to the 1st investigation which was conducted after about 3 months from the accident. Soil core samples to about 50cm deep were taken at 11 locations in Nihonmatsu-city, Kawamata-town and Namie-town. Sorption-desorption experiments of Cs-137 and I-131, CEC and AEC measurements and mineralogical analyses by XRD were conducted for 3 types of soils (sandy, clayey, organic) and those elutriated components (clay, silt, sand). Radiocaesium (Cs-134 and Cs-137) and Ag-110m were detected at all locations investigated and only at locations where radiation dose rate is high, respectively. Radiocaesium more than 95% and 99% of the inventory distributed within 5cm and 10cm deep in soil in the surface layer (mainly sandy soil), respectively, and distributed within 16cm and 20cm deep in organic soil and soil at locations where are supposed to have been used as farmland, respectively. Radiocaesium tended to extend to deeper parts in soil that organic and clayey soils are the support layer, particularly in organic soil, compared with the 1st investigation. Distribution coefficients of Cs-137 onto organic soil and its elutriated components were also lower than that onto other soils. This is consistent with trend of penetration profile.

  13. Effects of the Chernobyl and Fukushima nuclear accidents on atmospheric electricity parameters recorded at Polish observation stations

    NASA Astrophysics Data System (ADS)

    Kubicki, Marek; Baranski, Piotr; Odzimek, Anna; Michnowski, Stanislaw; Myslek-Laurikainen, Bogna

    2013-04-01

    We analyse the atmospheric electricity parameters, measured at Polish geophysical stations in Swider, Poland, and Hornsund, Spitsbergen, in connection with the radioactive incident in Fukushima, Japan, beginning on 11 March 2011, following the 9.0 earthquake and tsunami. We compare our results with the situation during and after the Chernobyl disaster on April 26, 1986, when the radioactive fallout detected at Swider increased in the last week of April 1986, from 4.111 to 238.7 Bq/m2 and up to 967.0 Bq/m2 in the second week of May 1986 - what was more than 235 times greater than the values measured prior to that accident. Besides the electric field especially the electric conductivity is very sensitive to the radioactive contamination of the air. Thus we postulate that these two measurements should be run at geophysical stations over the world and used as a relatively simple and low-cost tool for continuous monitoring of possible hazard caused by nuclear power plant accidents.

  14. (135)Cs/(137)Cs isotopic ratio as a new tracer of radiocesium released from the Fukushima nuclear accident.

    PubMed

    Zheng, Jian; Tagami, Keiko; Bu, Wenting; Uchida, Shigeo; Watanabe, Yoshito; Kubota, Yoshihisa; Fuma, Shoichi; Ihara, Sadao

    2014-05-20

    Since the Fukushima Daiichi nuclear power plant (FDNPP) accident in 2011, intensive studies of the distribution of released fission products, in particular (134)Cs and (137)Cs, in the environment have been conducted. However, the release sources, that is, the damaged reactors or the spent fuel pools, have not been identified, which resulted in great variation in the estimated amounts of (137)Cs released. Here, we investigated heavily contaminated environmental samples (litter, lichen, and soil) collected from Fukushima forests for the long-lived (135)Cs (half-life of 2 × 10(6) years), which is usually difficult to measure using decay-counting techniques. Using a newly developed triple-quadrupole inductively coupled plasma tandem mass spectrometry method, we analyzed the (135)Cs/(137)Cs isotopic ratio of the FDNPP-released radiocesium in environmental samples. We demonstrated that radiocesium was mainly released from the Unit 2 reactor. Considering the fact that the widely used tracer for the released Fukushima accident-sourced radiocesium in the environment, the (134)Cs/(137)Cs activity ratio, will become unavailable in the near future because of the short half-life of (134)Cs (2.06 years), the (135)Cs/(137)Cs isotopic ratio can be considered as a new tracer for source identification and long-term estimation of the mobility of released radiocesium in the environment. PMID:24779957

  15. Radiocesium concentrations in epigeic earthworms at various distances from the Fukushima Nuclear Power Plant 6 months after the 2011 accident.

    PubMed

    Hasegawa, Motohiro; Ito, Masamichi T; Kaneko, Shinji; Kiyono, Yoshiyuki; Ikeda, Shigeto; Makino, Shun'ichi

    2013-12-01

    We investigated the concentrations of radiocesium in epigeic earthworms, litter, and soil samples collected from forests in Fukushima Prefecture 6 months after the Fukushima Dai-ichi Nuclear Power Plant accident in 2011. Radiocesium concentrations in litter accumulated on the forest floor were higher than those in the soil (0-5 cm depth). The highest average (134+137)Cs concentrations in earthworms (approximately 19 Bq g(-1) of wet weight with gut contents and 108 Bq g(-1) of dry weight without gut contents) were recorded from a plot that experienced an air dose rate of 3.1 μSv h(-1), and earthworm concentrations were found to increase with litter and/or soil concentrations. Average (134)Cs and (137)Cs concentrations (with or without gut contents) were intermediate between accumulated litter and soil. Different species in the same ecological groups on the same plots had similar concentrations because of their use of the same habitats or their similar physiological characteristics. The contribution of global fallout (137)Cs to earthworms with gut contents was calculated to be very low, and most (137)Cs in earthworms was derived from the Fukushima accident. Transfer factors from accumulated litter to earthworms, based on their dry weights, ranged from 0.21 to 0.35, in agreement with previous field studies. PMID:23933081

  16. Health effects models for nuclear power plant accident consequence analysis. Part 1, Introduction, integration, and summary: Revision 2

    SciTech Connect

    Evans, J.S.; Abrahmson, S.; Bender, M.A.; Boecker, B.B.; Scott, B.R.; Gilbert, E.S.

    1993-10-01

    This report is a revision of NUREG/CR-4214, Rev. 1, Part 1 (1990), Health Effects Models for Nuclear Power Plant Accident Consequence Analysis. This revision has been made to incorporate changes to the Health Effects Models recommended in two addenda to the NUREG/CR-4214, Rev. 1, Part 11, 1989 report. The first of these addenda provided recommended changes to the health effects models for low-LET radiations based on recent reports from UNSCEAR, ICRP and NAS/NRC (BEIR V). The second addendum presented changes needed to incorporate alpha-emitting radionuclides into the accident exposure source term. As in the earlier version of this report, models are provided for early and continuing effects, cancers and thyroid nodules, and genetic effects. Weibull dose-response functions are recommended for evaluating the risks of early and continuing health effects. Three potentially lethal early effects -- the hematopoietic, pulmonary, and gastrointestinal syndromes are considered. Linear and linear-quadratic models are recommended for estimating the risks of seven types of cancer in adults - leukemia, bone, lung, breast, gastrointestinal, thyroid, and ``other``. For most cancers, both incidence and mortality are addressed. Five classes of genetic diseases -- dominant, x-linked, aneuploidy, unbalanced translocations, and multifactorial diseases are also considered. Data are provided that should enable analysts to consider the timing and severity of each type of health risk.

  17. Oxidation rate of nuclear-grade graphite NBG-18 in the kinetic regime for VHTR air ingress accident scenarios

    NASA Astrophysics Data System (ADS)

    Lee, Jo Jo; Ghosh, Tushar K.; Loyalka, Sudarshan K.

    2013-07-01

    One of the most severe accident scenarios anticipated for VHTRs is an air ingress accident caused by a pipe break. Graphite oxidation could be severe under these conditions. In this work, the oxidation rate of NBG-18 nuclear-grade graphite was studied thermogravimetrically for different oxygen concentrations and with temperatures from 873 to 1873 K. A semi-empirical Arrhenius rate equation was developed for the temperature range of 873-1023 K. The activation energy of NBG-18 was 187 kJ/mol and the order of reaction was 1.25. The penetration depth of oxidant was about 3-4 mm for NBG-18 oxidized at 973 K. Increased porosity and changes in external geometry became more prominent at higher temperatures from about 1173 to 1873 K. The surface of oxidized NBG-18 was characterized by SEM, EDS, FTIR and XPS. Diffusion of oxygen to the graphite surface and walls of open volume pores. Adsorption of oxygen atoms on the graphite surface free active sites and complexes inducing the simultaneous forming of Csbnd O and Csbnd H bonds and breaking of Csbnd C bonds (dissociative chemisorption). Chemical reactions occur at the surface. Desorption of gaseous products, CO and CO2, from the graphite surface and transport to the bulk gas mixture.

  18. Removal of Radiocesium from Food by Processing: Data Collected after the Fukushima Daiichi Nuclear Power Plant Accident - 13167

    SciTech Connect

    Uchida, Shigeo; Tagami, Keiko

    2013-07-01

    Removal of radiocesium from food by processing is of great concern following the accident of TEPCO's Fukushima Daiichi Nuclear Power Plant accident. Foods in markets are monitored and recent monitoring results have shown that almost all food materials were under the standard limit concentration levels for radiocesium (Cs-134+137), that is, 100 Bq kg{sup -1} in raw foods, 50 Bq kg{sup -1} in baby foods, and 10 Bq kg{sup -1} in drinking water; those food materials above the limit cannot be sold. However, one of the most frequently asked questions from the public is how much radiocesium in food would be removed by processing. Hence, information about radioactivity removal by processing of food crops native to Japan is actively sought by consumers. In this study, the food processing retention factor, F{sub r}, which is expressed as total activity in processed food divided by total activity in raw food, is reported for various types of corps. For white rice at a typical polishing yield of 90-92% from brown rice, the F{sub r} value range was 0.42-0.47. For leafy vegetable (indirect contamination), the average F{sub r} values were 0.92 (range: 0.27-1.2) after washing and 0.55 (range: 0.22-0.93) after washing and boiling. The data for some fruits are also reported. (authors)

  19. Internal Radiation Exposure Dose in Iwaki City, Fukushima Prefecture after the Accident at Fukushima Dai-ichi Nuclear Power Plant

    PubMed Central

    Orita, Makiko; Hayashida, Naomi; Nukui, Hiroshi; Fukuda, Naoko; Kudo, Takashi; Matsuda, Naoki; Fukushima, Yoshiko; Takamura, Noboru

    2014-01-01

    As a result of the accident at the Fukushima Daiichi Nuclear Power Plant (FNPP) on 11 March 2011, a huge amount of radionuclides, including radiocesium, was released and spread over a wide area of eastern Japan. Although three years have passed since the accident, residents around the FNPP are anxious about internal radiation exposure due to radiocesium. In this study, we screened internal radiation exposure doses in Iwaki city of Fukushima prefecture, using a whole-body counter. The first screening was conducted from October 2012 to February 2013, and the second screening was conducted from May to November 2013. Study participants were employees of ALPINE and their families who underwent examination. A total of 2,839 participants (1,366 men and 1,473 women, 1–86 years old) underwent the first screening, and 2,092 (1,022 men and 1,070 women, 1–86 years old) underwent the second screening. The results showed that 99% of subjects registered below 300 Bq per body in the first screening, and all subjects registered below 300 Bq per body in the second screening. The committed effective dose ranged from 0.01–0.06 mSv in the first screening and 0.01–0.02 mSv in the second screening. Long-term follow-up studies are needed to avoid unnecessary chronic internal exposure and to reduce anxiety among the residents by communicating radiation health risks. PMID:25478794

  20. Guidelines for preparing criticality safety evaluations at Department of Energy non-reactor nuclear facilities

    SciTech Connect

    Not Available

    1993-11-01

    This document contains guidelines that should be followed when preparing Criticality Safety Evaluations that will be used to demonstrate the safety of operations performed at DOE non-reactor nuclear facilities. Adherence to these guidelines will provide consistency and uniformity in criticality safety evaluations (CSEs) across the complex and will document compliance with the requirements of DOE Order 5480.24.