Science.gov

Sample records for plant 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.

  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. Criticality accident alarm system

    SciTech Connect

    Malenfant, R.E.

    1991-01-01

    The American National Standard ANSI/ANS-8.3-1986, Criticality Accident Alarm System provides guidance for the establishment and maintenance of an alarm system to initiate personnel evacuation in the event of inadvertent criticality. In addition to identifying the physical features of the components of the system, the characteristics of accidents of concern are carefully delineated. Unfortunately, this ANSI Standard has led to considerable confusion in interpretation, and there is evidence that the minimum accident of concern'' may not be appropriate. Furthermore, although intended as a guide, the provisions of the standard are being rigorously applied, sometimes with interpretations that are not consistent. Although the standard is clear in the use of absorbed dose in free air of 20 rad, at least one installation has interpreted the requirement to apply to dose in soft tissue. The standard is also clear in specifying the response to both neutrons and gamma rays. An assembly of uranyl fluoride enriched to 5% {sup 235}U was operated to simulate a potential accident. The dose, delivered in a free run excursion 2 m from the surface of the vessel, was greater than 500 rad, without ever exceeding a rate of 20 rad/min, which is the set point for activating an alarm that meets the standard. The presence of an alarm system would not have prevented any of the five major accidents in chemical operations nor is it absolutely certain that the alarms were solely responsible for reducing personnel exposures following the accident. Nevertheless, criticality alarm systems are now the subject of great effort and expense. 13 refs.

  4. 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.

  5. 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.

  6. 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...

  7. 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...

  8. 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...

  9. 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.

  10. Analysis of criticality accident alarm system coverage in the X-700, X-705, and X-720 facilities at the Portsmouth Gaseous Diffusion plant

    SciTech Connect

    Skapik, C.W.; Dobelbower, M.C.; Woollard, J.E.

    1995-12-01

    Additional services for the uranium enrichment cascade process, such as maintenance and decontamination operations, are provided by several ancillary facilities at the PORTS site. These facilities include the X-700 Maintenance Facility, the X-705 Decontamination Facility, and the X-720 Maintenance and Stores Facility. As uranium operations are performed within these facilities, the potential for a criticality accident exists. In the event of a criticality accident within one of these facilities at PORTS, a Criticality Accident Alarm System (CAAS) is in place to detect the criticality accident and sound an alarm. In this report, an analysis was performed to provide verification that the existing CAAS at PORTS provides complete criticality accident coverage in the X-700, X-705, and X-720 facilities. The analysis has determined that the X-705 and X-720 facilities have complete CAAS coverage; the X-700 facility has not been shown to have complete CAAS coverage at this time.

  11. 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.

  12. Criticality accident dosimetry with ESR spectroscopy.

    PubMed

    d'Errico, F; Fattibene, P; Onori, S; Pantaloni, M

    1996-01-01

    The suitability of the ESR alanine and sugar detectors for criticality accident dosimetry was experimentally investigated during an intercomparison of dosimetry techniques. Tests were performed irradiating detectors both free-in-air and on-phantom during controlled critcality excursions at the SILENE reactor in Valduc, France. Several grays of absorbed dose were imparted in neutron gamma-ray fields of various relative intensities and spectral distributions. Analysed results confirmed the potential of these systems which can immediately provide an acute dose assessment with an average underestimate of 30%in the various fields. This performance allows for the screening of severely exposed individuals and meets the IAEA recommendations on the early estimate of accident absorbed doses.

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 10 CFR 50.68 - Criticality accident requirements.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Criticality accident requirements. 50.68 Section 50.68 Energy NUCLEAR REGULATORY COMMISSION DOMESTIC LICENSING OF PRODUCTION AND UTILIZATION FACILITIES Issuance, Limitations, and Conditions of Licenses and Construction Permits § 50.68 Criticality accident requirements....

  19. 10 CFR 50.68 - Criticality accident requirements.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Criticality accident requirements. 50.68 Section 50.68 Energy NUCLEAR REGULATORY COMMISSION DOMESTIC LICENSING OF PRODUCTION AND UTILIZATION FACILITIES Issuance, Limitations, and Conditions of Licenses and Construction Permits § 50.68 Criticality accident requirements....

  20. 10 CFR 50.68 - Criticality accident requirements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Criticality accident requirements. 50.68 Section 50.68 Energy NUCLEAR REGULATORY COMMISSION DOMESTIC LICENSING OF PRODUCTION AND UTILIZATION FACILITIES Issuance, Limitations, and Conditions of Licenses and Construction Permits § 50.68 Criticality accident requirements....

  1. 10 CFR 50.68 - Criticality accident requirements.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Criticality accident requirements. 50.68 Section 50.68 Energy NUCLEAR REGULATORY COMMISSION DOMESTIC LICENSING OF PRODUCTION AND UTILIZATION FACILITIES Issuance, Limitations, and Conditions of Licenses and Construction Permits § 50.68 Criticality accident requirements....

  2. 10 CFR 50.68 - Criticality accident requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Criticality accident requirements. 50.68 Section 50.68 Energy NUCLEAR REGULATORY COMMISSION DOMESTIC LICENSING OF PRODUCTION AND UTILIZATION FACILITIES Issuance, Limitations, and Conditions of Licenses and Construction Permits § 50.68 Criticality accident requirements....

  3. Computer simulation of hypothetical criticality accidents in aqueous fissile solutions

    SciTech Connect

    Hetrick, D.L. )

    1991-01-01

    The purpose of this paper is to describe recent developments in computer simulation of hypothetical criticality accidents in aqueous fissile solutions of uranium and plutonium such as might be encountered in fuel fabrication and reprocessing operations. Models for reactivity shutdown mechanisms and equations of state have been combined to permit estimates of fission yield, inertial pressure, and kinetic energy for a wide range of pulse sizes and time scales. Improvements to previously published models are reported along with some recent applications. Information obtained from pulsed solution assemblies (KEWB, CRAC, SILENE, and SHEBA) and from past criticality accidents was used in the development of computer models. Applications include slow events lasting many hours (hypothetical undetected laboratory accidents) and large-yield millisecond pulses in which evolution of radiolytic gas may be important (severe accidents and pulsed reactors).

  4. Exposure risks and intervention possibilities in solution criticality accidents

    SciTech Connect

    Barbry, F.Y. )

    1991-01-01

    All accidental criticality excursions are accompanied by neutron and gamma radiation that creates two possible types of radiation risk: (1) immediate risk for the personnel directly exposed; and (2) deferred risk in the case where an intervention team is required in the postaccident phase. These aspects, or more specifically dose measurement and the possibility of calling on intervention teams, were carefully examined in the CRAC and SILENE criticality accident experimental study programs carried out at the Valduc criticality laboratory. The resulting data are undeniably valuable as part of a nuclear safety policy that aims to evaluate and prevent the risks of accident situations, to define the consequences of such situations, and to propose an intervention strategy if the need arises. Note, however, that if criticality accident detection systems help to limit the doses to which personnel may be exposed, they provide no information that could contribute to accident diagnosis nor to understanding the postaccident phase, while such information is essential in deciding whether or not to call on an intervention team. This explains why the Commissariat a l'Energie Atomique decided to perfect its detection system, which is now capable of monitoring accident evolution, providing valuable information on dose rates.

  5. 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

  6. 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.

  7. Analysis of criticality accident alarm system coverage of the X-744G, X-744H, X-342/344A and X-343 facilities at the Portsmouth Gaseous Diffusion Plant

    SciTech Connect

    Dobelbower, M.C.; Woollard, J.; Lee, B.L. Jr.; Tayloe, R.W. Jr.

    1995-09-01

    Additional services for the uranium enrichment cascade process, such as UF{sub 6} feed, sampling, and material storage are provided by several ancillary Uranium Material Handling (UMH) facilities at the PORTS site. These facilities include the X-343 Feed Vaporization and Sampling Facility, the X-744G Bulk Non-Uranium Enrichment Service Activity (UESA) Storage Building, the X-744H Waste Separation and Storage Facility, the X-344A Toll Enrichment Services Facility and the X-342A Feed Vaporization and Fluorine Generation Facility. As uranium operations are performed within these facilities, the potential for a criticality accident exists. In the event of a criticality accident within a process facility at PORTS, a Criticality Accident Alarm System (CAAS) is in place to detect the criticality accident and sound an alarm. In this report, an analysis was performed to provide verification that the existing CAAS at PORTS provides complete criticality accident coverage in the X-343, X-744G. X-744H. X-344A and X-342A facilities. The analysis has determined that all of the above-mentioned facilities have complete CAAS coverage.

  8. Plant critical concept

    SciTech Connect

    O`Regan, P.J.

    1995-12-31

    The achievement of operation and maintenance (O&M) cost reductions is a prime concern for plant operators. Initiatives by the nuclear industry to address this concern are under way and/or in development. These efforts include plant reliability studies, reliability-centered maintenance, risk ranking and testing philosophies, performance-based testing philosophies, graded quality assurance, and so forth. This paper presents the results of an effort to develop a methodology that integrates and applies the common data and analysis requirements for a number of risk-based and performance-based initiatives. This initial phase of the effort applied the methodology and its results to two initiatives. These were the procurement function and the preventive maintenance function. This effort integrated multiple programs and functions to identify those components that are truly critical from an integrated plant performance perspective. The paper describes the scope of the effort, the development of a methodology to identify plant critical components, and the application of these results to the maintenance rule compliance, preventive maintenance, and procurement functions at the candidate plant.

  9. Biomedical Lessons from the Chernobyl Nuclear Power Plant Accident

    DTIC Science & Technology

    1990-10-01

    Lessons From the Lt Col Doris Browne, MC Chernobyl Nuclear Power Plant Accident The Chernobyl nuclear accident afforded the treating physicians a...radiation accident posited on the skin and mucous mem- A Lt Col Dori Browne, MC, is Chief, Medicaloccurred at the Chernobyl nuclear branes from the molten...Conclusion ulcers of oral mucosa, which required irradiation. He also had persistent The consequences ot the Chernobyl sterile saline irrigation and

  10. Recalibration of indium foil for personnel screening in criticality accidents.

    PubMed

    Takada, C; Tsujimura, N; Mikami, S

    2011-03-01

    At the Nuclear Fuel Cycle Engineering Laboratories of the Japan Atomic Energy Agency (JAEA), small pieces of indium foil incorporated into personal dosemeters have been used for personnel screening in criticality accidents. Irradiation tests of the badges were performed using the SILENE reactor to verify the calibration of the indium activation that had been made in the 1980s and to recalibrate them for simulated criticalities that would be the most likely to occur in the solution process line. In addition, Monte Carlo calculations of the indium activation using the badge model were also made to complement the spectral dependence. The results lead to a screening level of 15 kcpm being determined that corresponds to a total dose of 0.25 Gy, which is also applicable in posterior-anterior exposure. The recalibration based on the latest study will provide a sounder basis for the screening procedure in the event of a criticality accident.

  11. A critical review of macro models for road accidents.

    PubMed

    Hakim, S; Shefer, D; Hakkert, A S; Hocherman, I

    1991-10-01

    This paper presents a critical review of state-of-the-art macro models for road accidents. Such a review is meant to identify and establish the significance of policy and socioeconomic variables affecting the level of road accidents. The aim is to identify those variables associated with effective policies and interventions to enable decision makers to improve the level of road safety. The variables that appear to affect the number of fatalities or injuries are: vehicle miles travelled (VMT), vehicle population, income (in its various forms), percentage of young drivers, intervention policies such as speed limits, periodic vehicle inspection, and minimum alcohol-drinking age. Viewed critically, the state-of-the-art models being used to explain and predict road accidents are still deficient. One possible approach to correcting this deficiency draws from consumer utility theory, using analytical models built on a newly constructed theoretical framework. Success in estimating such models may improve predictions of road accidents, thus demonstrating the comparative cost effectiveness of alternative intervention policies.

  12. Impact of drum storage on criticality accident alarm systems

    SciTech Connect

    Finfrock, S.; Watson, T.; Byrd, J.; Miles, B.; Wilkinson, A.

    1997-12-01

    The changing mission from production to decommissioning that is taking place at many U.S. Department of Energy sites is producing an ever-increasing inventory of waste drums. These drums typically contain low-level radioactive waste and, in some cases, significant amounts of fissile materials. Such drums must be handled with all of the care necessary for radioactive materials and, where fissile materials are present, criticality safety controls. As the number of drums increases, the question inevitably arises as to where to store them. Old process buildings present one solution to that question. These buildings are typically large, designed to handle radioactive and fissile materials, and largely unused under the current mission and, as such, would seem ideal candidates for at least short-term storage of waste drums. When undergoing such a major change in mission, however, the building`s nuclear safety systems need to be reevaluated to ensure that they are appropriate for the new activity. One such system that must be evaluated is the building`s criticality accident alarm system (AAS). This system is designed to detect criticality accidents and is generally required anywhere that a criticality accident is credible. If drums are to be stored in a facility where a CAAS is required (either because of other activities in the building or because of the contents of the drums themselves), then those drums must be shown not to prevent the CAAS from functioning as designed.

  13. Preliminary Identification of Accident Initiating Events for IFE Power Plants

    SciTech Connect

    Cadwallader, Lee Charles; Latkowsk, J. F.

    2001-10-01

    This paper presents initial results of a task to identify accident initiating events for inertial fusion energy (IFE) power plant designs. Initiating events (IEs) are a fundamental building block of a probabilistic risk assessment; they are the ‘accident starters’ that are analyzed to determine the risks posed to members of the public in the vicinity of the power plant. The IE results for the SOMBRERO design are presented in tabular form. The SOMBRERO design was analyzed since it is representative of dry chamber wall, laser driven designs. This work is used to characterize IFE plant risk and to identify potential design changes that would mitigate the plant risk.

  14. Insights into the Societal Risk of Nuclear Power Plant Accidents.

    PubMed

    Denning, Richard; Mubayi, Vinod

    2017-01-01

    The elements of societal risk from a nuclear power plant accident are clearly illustrated by the Fukushima accident: land contamination, long-term relocation of large numbers of people, loss of productive farm area, loss of industrial production, and significant loss of electric capacity. NUREG-1150 and other studies have provided compelling evidence that the individual health risk of nuclear power plant accidents is effectively negligible relative to other comparable risks, even for people living in close proximity to a plant. The objective of this study is to compare the societal risk of nuclear power plant accidents to that of other events to which the public is exposed. We have characterized the monetized societal risk in the United States from major societally disruptive events, such as hurricanes, in the form of a complementary cumulative distribution function. These risks are compared with nuclear power plant risks, based on NUREG-1150 analyses and new MACCS code calculations to account for differences in source terms determined in the more recent SOARCA study. A candidate quantitative societal objective is discussed for potential adoption by the NRC. The results are also interpreted with regard to the acceptability of nuclear power as a major source of future energy supply.

  15. Development of Northeast Asia Nuclear Power Plant Accident Simulator.

    PubMed

    Kim, Juyub; Kim, Juyoul; Po, Li-Chi Cliff

    2016-11-24

    A conclusion from the lessons learned after the March 2011 Fukushima Daiichi accident was that Korea needs a tool to estimate consequences from a major accident that could occur at a nuclear power plant located in a neighboring country. This paper describes a suite of computer-based codes to be used by Korea's nuclear emergency response staff for training and potentially operational support in Korea's national emergency preparedness and response program. The systems of codes, Northeast Asia Nuclear Accident Simulator (NANAS), consist of three modules: source-term estimation, atmospheric dispersion prediction and dose assessment. To quickly assess potential doses to the public in Korea, NANAS includes specific reactor data from the nuclear power plants in China, Japan and Taiwan. The completed simulator is demonstrated using data for a hypothetical release.

  16. 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.

  17. Radiation Exposure and Thyroid Cancer Risk After the Fukushima Nuclear Power Plant Accident in Comparison with the Chernobyl Accident.

    PubMed

    Yamashita, S; Takamura, N; Ohtsuru, A; Suzuki, S

    2016-09-01

    The actual implementation of the epidemiological study on human health risk from low dose and low-dose rate radiation exposure and the comprehensive long-term radiation health effects survey are important especially after radiological and nuclear accidents because of public fear and concern about the long-term health effects of low-dose radiation exposure have increased considerably. Since the Great East Japan earthquake and the Fukushima Daiichi Nuclear Power Plant accident in Japan, Fukushima Prefecture has started the Fukushima Health Management Survey Project for the purpose of long-term health care administration and medical early diagnosis/treatment for the prefectural residents. Especially on a basis of the lessons learned from the Chernobyl accident, both thyroid examination and mental health care are critically important irrespective of the level of radiation exposure. There are considerable differences between Chernobyl and Fukushima regarding radiation dose to the public, and it is very difficult to estimate retrospectively internal exposure dose from the short-lived radioactive iodines. Therefore, the necessity of thyroid ultrasound examination in Fukushima and the intermediate results of this survey targeting children will be reviewed and discussed in order to avoid any misunderstanding or misinterpretation of the high detection rate of childhood thyroid cancer.

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

    SciTech Connect

    Hankins, D.E.

    1980-01-01

    The evaluation of the dose that a person received in a criticality accident can be difficult. Most accidents have occurred when the person was not wearing nuclear accident dosimetry and since the NRC no longer requires these dosimeters, future dose evaluations may have to be based on body activations and gamma-to-neutron dose ratios. To aid in a dose evaluation we have compiled in a table the results from numerous criticality accident studies using 10 different critical assemblies, each with different neutron leakage spectra. There are several problems involved in applying these results accurately, the most significant problem being the determination of the configuration of the fissile material at the time of the accident. Other problems include a lack of information concerning the location, orientation, and possible shielding between the person and the accident assembly.

  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. A criticism of ANSI/ANS-8. 3-1986: Criticality accident alarm system

    SciTech Connect

    Malenfant, R.E.

    1991-01-01

    The American National Standard on criticality accident alarm systems has given rise to confusion in interpretation and implementation of the requirements. In addition, some of the standards have recently been incorporated into US Department of Energy (DOE) orders, and others have been paraphrased in the DOE orders. Some of the DOE orders referencing these standards are being incorporated into law by means of the Code of Federal Regulations. As such, the intent of the authors of the standards to recommend a code of good practice is now being codified into law with attendant civil and criminal penalties for failure to comply. It is suggested that ANSI/ANS-8.3-1986, Critically Accident Alarm System, be carefully reviewed to alleviate the confusion that has been experienced in practice, to clarify the minimum accident of concern, to further define the dose (or dose rate) criteria for activation, and to stress the fact that a prime consideration in any safety system is the overall reduction of risk.

  1. TL detectors for gamma ray dose measurements in criticality accidents.

    PubMed

    Miljanić, Saveta; Zorko, Benjamin; Gregori, Beatriz; Knezević, Zeljka

    2007-01-01

    Determination of gamma ray dose in mixed neutron+gamma ray fields is still a demanding task. Dosemeters used for gamma ray dosimetry are usually in some extent sensitive to neutrons and their response variations depend on neutron energy i.e., on neutron spectra. Besides, it is necessary to take into account the energy dependence of dosemeter responses to gamma rays. In this work, several types of thermoluminescent detectors (TLD) placed in different holders used for gamma ray dose determination in the mixed fields were examined. Dosemeters were from three different institutions: Ruder Bosković Institute (RBI), Croatia, JoZef Stefan Institute (JSI), Slovenia and Autoridad Regulatoria Nuclear (ARN), Argentina. All dosemeters were irradiated during the International Intercomparison of Criticality Accident Dosimetry Systems at the SILENE Reactor, Valduc, June 2002. Three accidental scenarios were reproduced and in each irradiation the dosemeters were exposed placed on the front of phantom and 'free in air'. Following types of TLDs were used: 7LiF (TLD-700), CaF2:Mn and Al2O3:Mg,Y-all from RBI; CaF2:Mn from JSI and 7LiF (TLD-700) from ARN. Reported doses were compared with the reference values as well as with the values obtained from the results of all participants. The results show satisfactory agreement with other dosimetry systems used in the Intercomparison. The influence of different types of holders and applied corrections of dosemeters' readings are discussed.

  2. 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.

  3. 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.

  4. 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.

  5. Tracing nuclear elements released by Fukushima Nuclear Power Plant accident

    NASA Astrophysics Data System (ADS)

    Tsujimura, M.; Onda, Y.; Abe, Y.; Hada, M.; Pun, I.

    2011-12-01

    Radioactive contamination has been detected in Fukushima and the neighboring regions due to the nuclear accident at Fukushima Daiichi Nuclear Power Plant (NPP) following the earthquake and tsunami occurred on 11th March 2011. The small experimental catchments have been established in Yamakiya district, Kawamata Town, Fukushima Prefecture, located approximately 35 km west from the Fukushima NPP. The tritium (3H) concentration and stable isotopic compositions of deuterium and oxygen-18 have been determined on the water samples of precipitation, soil water at the depths of 10 to 30 cm, groundwater at the depths of 5 m to 50 m, spring water and stream water taken at the watersheds in the recharge and discharge zones from the view point of the groundwater flow system. The tritium concentration of the rain water fell just a few days after the earthquake showed a value of approximately 17 Tritium Unit (T.U.), whereas the average concentration of the tritium in the precipitation was less than 5 T.U. before the Fukushima accident. The spring water in the recharge zone showed a relatively high tritium concentration of approximately 12 T.U., whereas that of the discharge zone showed less than 5 T.U. Thus, the artificial tritium was apparently injected in the groundwater flow system due to the Fukushima NPP accident, whereas that has not reached at the discharge zone yet. The monitoring of the nuclear elements is now on going from the view points of the hydrological cycles and the drinking water security.

  6. 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

  7. Accident at the Chernobyl nuclear power plant and its consequences

    SciTech Connect

    Lewis, H.W.

    1986-11-01

    In the early morning of April 26, 1986, as the culmination of an almost incredible series of errors that began 24 hours earlier, Unit 4 of the Chernobyl nuclear complex, a so-called RBMK-1000 reactor, suffered the worst accident in the history of commercial nuclear power. There was an uncontrolled nuclear excursion, release of a large amount of energy, possibly comparable to hundreds of pounds of TNT, blowing the top off the reactor. There was no containment, in the traditional American sense, so the roof of the building was blown out, an unprecedented amount of radioactivity was released to the biosphere, and a graphite fire was ignited, which burned for days. The radiation that was released spread through Eastern Europe (the world first learned of it through Swedish observations), bringing with it both official and unofficial protests that the Soviet Union had made no announcement of the radiation release until they were, in effect, caught. In fact, after a few days, the Soviets seemed to recognize that nuclear safety is a matter of international concern, and became quite open in their search for cooperation. They invited officials of the International Atomic Energy Agency (IAEA) to visit the area and to fly over the plant, and agreed, in the end, to make a complete disclosure of the details of the accident at a special meeting of IAEA in Vienna, August 25 to 29, 1986. In preparation for that meeting they distributed a lengthy (400 pages) report on the event. This paper reviews this report.

  8. New developments under consideration at the CEA for criticality accident detection

    SciTech Connect

    Barbry, F.; Prigent, R.

    1986-01-01

    In spite of precautions to prevent criticality accidents from occurring in fuel cycle installations, there is nevertheless some very low probability of risk that remains. In this eventuality, and because the Commissariat a l'Energie Atomique (CEA) is involved in the vast French electronuclear program which includes reprocessing, a sustained effort by safety authorities has been devoted to accident study problems and particularly to criticality accidents, to be able to give optimum warning time to operators, order evacuation of personnel, and to set up an intervention strategy in the shortest time possible. The CRAC and SILENE experimental facilities in the 1970s defined a new generation of criticality accident detection systems known as EDAC, manufactured and sold by the French Intertechnique Company. Now, in light of the two main conclusions resulting from these test programs, namely, the difficulty of defining a standard accident and the fact that it is impossible to establish a dose/fission number ratio, the detection system in service at present corresponds to the following essential physical criteria: 1. It is capable of covering all accident kinetics. 2. The sensors used give a total dose response in neutrons and gammas.

  9. [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.

  10. Initial symptoms of acute radiation syndrome in the JCO criticality accident in Tokai-mura.

    PubMed

    Akashi, M; Hirama, T; Tanosaki, S; Kuroiwa, N; Nakagawa, K; Tsuji, H; Kato, H; Yamada, S; Kamata, T; Kinugasa, T; Ariga, H; Maekawa, K; Suzuki, G; Tsujii, H

    2001-09-01

    A criticality accident occurred on September 30, 1999, at the uranium conversion plant in Tokai-mura (Tokai-village), Ibaraki Prefecture, Japan. When the criticality occurred, three workers saw a "blue-white glow," and a radiation monitor alarm was sounded. They were severely exposed to neutron and gamma-ray irradiation, and subsequently developed acute radiation syndrome (ARS). One worker reported vomiting within minutes and loss of consciousness for 10-20 seconds. This worker also had diarrhea an hour after the exposure. The other worker started to vomit almost an hour after the exposure. The three workers, including their supervisor, who had no symptoms at the time, were brought to the National Mito Hospital by ambulance. Because of the detection of gamma-rays from their body surface by preliminary surveys and decreased numbers of lymphocytes in peripheral blood, they were transferred to the National Institute of Radiological Sciences (NIRS), which has been designated as a hospital responsible for radiation emergencies. Dose estimations for the three workers were performed by prodromal symptoms, serial changes of lymphocyte numbers, chromosomal analysis, and 24Na activity. The results obtained from these methods were fairly consistent. Most of the data, such as the dose rate of radiation, its distribution, and the quality needed to evaluate the average dose, were not available when the decision for hematopoitic stem cell transplantation had to be made. Therefore, prodromal symptoms may be important in making decisions for therapeutic strategies, such as stem-cell transplantation in heavily exposed victims.

  11. 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.

  12. Summary of the JCO criticality accident in Tokai-mura and a dose assessment.

    PubMed

    Tanaka, S I

    2001-09-01

    A criticality accident occurred on September 30, 1999, in a conversion test facility at the JCO Tokai site. The accident was triggered by pouring an 18.8% enriched uranyl nitrate solution into a precipitation vessel beyond the critical mass. The accident continued for about 19 hours before the criticality could be stopped. during which time neutrons and gamma-rays were emitted continuously due to fission reactions. The total number of fission reactions was 2.5 x 10(18), which was estimated by an activity analysis of the fission products in the solution of the precipitation vessel. The accident gave serious radiation dose to 3 employees and fatal dose to 2 of them. Neutrons and gamma-rays emitted by the accident caused meaningful doses to the residents of the surrounding area of JCO. The dominant dose to the residents and JCO employees was brought by neutrons and gamma-rays from the precipitation vessel, while the contribution of radioactive plume was negligible. The individual dose was estimated for 234 resident, 169 JCO employees and 260 emergency personnel. The maximum doses were 21 mSv for the residents, 48mSv for the JCO employees, and 9.4mSv for the emergency personnel, respectively. No deterministic effect, however, has been observed, except for the 3 workers.

  13. Key Parameters for Operator Diagnosis of BWR Plant Condition during a Severe Accident

    SciTech Connect

    Clayton, Dwight A.; Poore, III, Willis P.

    2015-01-01

    The objective of this research is to examine the key information needed from nuclear power plant instrumentation to guide severe accident management and mitigation for boiling water reactor (BWR) designs (specifically, a BWR/4-Mark I), estimate environmental conditions that the instrumentation will experience during a severe accident, and identify potential gaps in existing instrumentation that may require further research and development. This report notes the key parameters that instrumentation needs to measure to help operators respond to severe accidents. A follow-up report will assess severe accident environmental conditions as estimated by severe accident simulation model analysis for a specific US BWR/4-Mark I plant for those instrumentation systems considered most important for accident management purposes.

  14. Evaluation of Neutron Response of Criticality Accident Alarm System Detector to Quasi-Monoenergetic 24 keV Neutrons

    NASA Astrophysics Data System (ADS)

    Tsujimura, Norio; Yoshida, Tadayoshi; Yashima, Hiroshi

    The criticality accident alarm system (CAAS), which was recently developed and installed at the Japan Atomic Energy Agency's Tokai Reprocessing Plant, consists of a plastic scintillator combined with a cadmium-lined polyethylene moderator and thereby responds to both neutrons and gamma rays. To evaluate the neutron absorbed dose rate response of the CAAS detector, a 24 keV quasi-monoenergetic neutron irradiation experiment was performed at the B-1 facility of the Kyoto University Research Reactor. The detector's evaluated neutron response was confirmed to agree reasonably well with prior computer-predicted responses.

  15. Twenty-second ORNL intercomparison of criticality accident dosimetry systems, August 12-16, 1985

    SciTech Connect

    Swaja, R.E.; Oyan, R.; Sims, C.S.

    1986-05-01

    The twenty-second in a series of criticality accident dosimetry intercomparison studies was conducted at the Oak Ridge National Laboratory's Dosimetry Applications Research Facility during August 12-16, 1985. The Health Physics Research Reactor operated in the pulse mode over Storage Pit No. 1 was used to simulate three criticality accidents with different radiation fields. Participants from nine organizations measured neutron doses between 0.36 and 3.78 Gy and gamma doses between 0.22 and 0.80 Gy at area monitoring stations and on phantoms. Approximately 68% of all neutron dose estimates based on foil activation, thermoluminescent, hair activation, and blood sodium activation methods were within +-25% of reference values. About 44% of all gamma results measured using thermoluminescent dosimeters (TLD-700 or CaSO/sub 4/ phosphors) were within 20% of reference doses. The generally poor measurement accuracy exhibited in this study indicates a need for continuing ORNL accident dosimetry intercomparison and training programs.

  16. TECHNICAL BASIS FOR THE NUCLEAR CRITICALITY REPRESENTATIVE ACCIDENT & ASSOCIATED REPRESENTED HAZARDOUS CONDITIONS

    SciTech Connect

    GOETZ, T.G.

    2003-06-17

    This document was developed to support the documented safety analysis (DSA) and describes the process and basis for assigning risk bins for the nuclear criticality representative accident and associated hazardous conditions. Revision 1 incorporates ORP IRT comments to enhance the technical presentation and also makes editorial changes. This technical basis document was developed to support the documented safety analysis (DSA), and describes the risk binning process and the technical basis for assigning risk bins for the nuclear criticality representative accident and associated hazardous conditions. The purpose of the risk binning process is to determine the need for safety-significant structures, systems, and components (SSC) and technical safety requirement (TSR)-level controls for a given representative accident or represented hazardous condition based on an evaluation of the frequency and consequence.

  17. 10 CFR 70.24 - Criticality accident requirements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... meeting the requirements of either paragraph (a)(1) or (a)(2), as appropriate, and using gamma- or neutron-sensitive radiation detectors which will energize clearly audible alarm signals if accidental criticality... soft tissue of 20 rads of combined neutron and gamma radiation at an unshielded distance of 2...

  18. 10 CFR 76.89 - Criticality accident requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... annunciate a criticality that produces an absorbed dose in soft tissue of 20 rads of combined neutron and gamma radiation at an unshielded distance of 2 meters from the reacting material within 1 minute. Coverage of all monitored areas must be provided by two detectors....

  19. 10 CFR 76.89 - Criticality accident requirements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... annunciate a criticality that produces an absorbed dose in soft tissue of 20 rads of combined neutron and gamma radiation at an unshielded distance of 2 meters from the reacting material within 1 minute. Coverage of all monitored areas must be provided by two detectors....

  20. Progress in accident analysis of the HYLIFE-II inertial fusion energy power plant design

    SciTech Connect

    Reyes, S; Latkowski, J F; Gomez del Rio, J; Sanz, J

    2000-10-11

    The present work continues our effort to perform an integrated safety analysis for the HYLIFE-II inertial fusion energy (IFE) power plant design. Recently we developed a base case for a severe accident scenario in order to calculate accident doses for HYLIFE-II. It consisted of a total loss of coolant accident (LOCA) in which all the liquid flibe (Li{sub 2}BeF{sub 4}) was lost at the beginning of the accident. Results showed that the off-site dose was below the limit given by the DOE Fusion Safety Standards for public protection in case of accident, and that his dose was dominated by the tritium released during the accident.

  1. Review of studies on criticality accidents undertaken at CEA/Valduc

    SciTech Connect

    Barbry, F.Y. )

    1991-01-01

    Since 1977, the Commissariat a l'Energie Atomique (CEA) has led a program of study on criticality accidents to meet the needs and requirements of a realistic safety policy that, while taking all necessary measures to prevent accidents, must also seek to evaluate and cope with the consequences of such an event. In working to achieve this objective, the IPSN bases its work mainly on the resources available at the Valduc criticality laboratory. In view of the diversity of possible accident configurations at different installations and the fact that the shutdown mechanisms of power excursion are directly related to the medium involved, studies have focused on four major categories of media: liquids, solids, powders, and heterogeneous water-moderated systems. For each one, the most plausible hypothetical accident situation was defined, while trying to maintain a conservative view with respect to other situations. A part of the work consists of acquiring, either by experiments conducted in facilities or by neutronic calculations, a basic set of data or relationships such as temperature coefficient or physical characteristics of fuel to input in a computer code. The final goal is to provide a general calculation code able to predict criticality excursion for safety considerations.

  2. Source term estimation during incident response to severe nuclear power plant accidents

    SciTech Connect

    McKenna, T.J.; Glitter, J.G.

    1988-10-01

    This document presents a method of source term estimation that reflects the current understanding of source term behavior and that can be used during an event. The various methods of estimating radionuclide release to the environment (source terms) as a result of an accident at a nuclear power reactor are discussed. The major factors affecting potential radionuclide releases off site (source terms) as a result of nuclear power plant accidents are described. The quantification of these factors based on plant instrumentation also is discussed. A range of accident conditions from those within the design basis to the most severe accidents possible are included in the text. A method of gross estimation of accident source terms and their consequences off site is presented. 39 refs., 48 figs., 19 tabs.

  3. 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.

  4. The EDAC system and new developments under consideration at the Commissariat a l'Energie Atomique for criticality accident detection

    SciTech Connect

    Barbry, F.; Prigent, R.

    1987-09-01

    As a result of the Commissariat a l'Energie Atomique CRAC experimental program, which studied the phenomenology and the radiological consequences of a criticality excursion in fissile solution, the EDAC system has been developed. This system detects a criticality accident and warns personnel as early as possible by triggering the necessary audiovisual alarm. The main features of this equipment are its ability to cover all types of accidental kinetics and to use sensors giving a total dose response in neutron and gamma radiation. According to new results acquired with the SILENE reactor in the field of criticality accidents, an evolution is taking place in France. An improved EDAC system is being designed not only to trigger a criticality alarm but also to provide information on the accident, to assist in accident diagnosis, and to contribute to being better equipped to cope with an accident situation, for example, if intervention is needed or if reoccupation of evacuated areas is desired.

  5. ANSI/ANS-8.23-1997: nuclear criticality accident emergency planning and response.

    SciTech Connect

    Baker, J. S.

    2004-01-01

    American National Standard ANSUANS-8.23 was developed to expand upon the basic emergency response guidance given in American National Standard, 'Administrative Practices for Nuclear Criticality Safety' ANSI/ANS-8.19-1996 (Ref. 1). This standard provides guidance for minimizing risks to personnel during emergency response to a nuclear criticality accident outside reactors. This standard is intended to apply to those facilities for which a criticality accident alarm system, as specified in American National Standard, 'Criticality Accident Alarm System', ANSI/ANS-8.3-1997 (Ref. 2) is in use. The Working Group was established in 1990, with Norman L. Pruvost as chairman. The Working Group had up to twenty-three members representing a broad range of the nuclear industry, and has included members from Canada, Japan and the United Kingdom. The initial edition of ANSI/ANS-8.23 was approved by the American National Standards Institute on December 30, 1997. It provides guidance for the following topics: (1) Management and technical staff responsibilities; (2) Evaluation of a potential criticality accident; (3) Emergency plan provisions; (4) Evacuation; (5) Re-entry, rescue and stabilization; and (6) Classroom training, exercises and evacuation drills. This guidance is not for generic emergency planning issues, but is specific to nuclear criticality accidents. For example, it assumes that an Emergency Plan is already established at facilities that implement the standard. During the development of the initial edition of ANSI/ANS-8.23, each Working Group member evaluated potential use of the standard at a facility with which the member was familiar. This revealed areas where a facility could have difficulty complying with the standard. These reviews helped identify and eliminate many potential problems and ambiguities with the guidance. The Working Group has received very limited feedback from the user community since the first edition of the standard was published. Suggestions

  6. Tritium in Japanese precipitation following the March 2011 Fukushima Daiichi Nuclear Plant accident.

    PubMed

    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

    2013-02-15

    Tritium concentrations in Japanese precipitation samples collected after the March 2011 accident at the Fukushima Dai-ichi Nuclear Power Plant (FNPP1) were measured. Values exceeding the pre-accident background were detected at three out of seven localities (Tsukuba, Kashiwa and Hongo) southwest of the FNPP1 at 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; however concentrations were 500 times less than the regulatory limit for tritium in drinking water. Tritium concentrations decreased steadily and rapidly with time, becoming indistinguishable from the pre-accident values within five weeks. The atmospheric tritium activities in the vicinity of the FNPP1 during the earliest stage of the accident was estimated to be 1.5×10(3) Bq/m(3), which is potentially capable of producing rainwater exceeding the regulatory limit, but only in the immediate vicinity of the source.

  7. Criticality prompt gamma and neutron dose equations validated by Monte Carlo analyses and compared to known criticality accident doses

    NASA Astrophysics Data System (ADS)

    Hochhalter, Eugene

    The United States (US) Department of Energy [DOE] and the Nuclear Regulatory Commission [NRC] have provided the nuclear industry with requirements, goals, and objectives for the preparation of safety analysis and the finalization of that safety analysis in the form of a documented safety analysis (DSA) and technical safety requirements (TSRs). The deterministic guidance provided by the NRC in Regulatory Guide (RG) 3.33 for calculating the prompt gamma and neutron doses from a criticality has a number of potential issues associated with the semi-empirical equations, which make these equations potentially out dated. The NRC guidance for estimating the prompt gamma and neutron doses to a facility worker due to an accidental criticality was withdrawn without newer deterministic guidance being issued. This research project determined the original basis for the RG prompt gamma and neutron equations, evaluated the potential issues associated with the RG 3.33 prompt gamma and neutron equations, and modified the RG 3.33 point source prompt gamma and neutron equations to calculate the doses for the selected set of criticality accidents. The criticality accidents addressed by this dissertation include: 1. U-235, Pu-239, and Pu-241 point source criticality, 2. U-235, Pu-239, and Pu-241 sphere source criticality, 3. Uranyl nitrate and plutonium nitrate solutions in a cylindrical process vessel and 4. Low level waste in 55-gallon and 30-gallon drums. The prompt gamma and neutron equation doses (RG 3.33/3.34/3.35) are compared to actual nuclear industry criticality accident worker doses to assess the conservatism of the RG equations. Finally, the RG 3.33 prompt gamma and neutron dose equations are compared to MCNP5 results to investigate consistency with respect to the modified prompt gamma and neutron dose equations and the representative dose estimates for each of the criticality configurations (point source, spherical source, and cylindrical source). Knowledge and accurate

  8. Source term analysis for a criticality accident in metal production line glove boxes

    SciTech Connect

    Nguyen, D.H.

    1991-06-01

    A recent development in criticality accident analysis is the deterministic calculations of the transport of fission products and actinides through the barriers of the physical facility. The knowledge of the redistribution of the materials inside the facility will help determine the reentry and clean-up procedures. The amount of radioactive materials released to the environment is the source term for dispersion calculations. We have used an integrated computer model to determine the release of fission products to the environment from a hypothetical criticality event in a glove box of the metal production line (MPL) at the Lawrence Livermore National Laboratory (LLNL).

  9. A defense in depth approach for nuclear power plant accident management

    SciTech Connect

    Chih-Yao Hsieh; Hwai-Pwu Chou

    2015-07-01

    An initiating event may lead to a severe accident if the plant safety functions have been challenged or operators do not follow the appropriate accident management procedures. Beyond design basis accidents are those corresponding to events of very low occurrence probability but such an accident may lead to significant consequences. The defense in depth approach is important to assure nuclear safety even in a severe accident. Plant Damage States (PDS) can be defined by the combination of the possible values for each of the PDS parameters which are showed on the nuclear power plant simulator. PDS is used to identify what the initiating event is, and can also give the information of safety system's status whether they are bypassed, inoperable or not. Initiating event and safety system's status are used in the construction of Containment Event Tree (CET) to determine containment failure modes by using probabilistic risk assessment (PRA) technique. Different initiating events will correspond to different CETs. With these CETs, the core melt frequency of an initiating event can be found. The use of Plant Damage States (PDS) is a symptom-oriented approach. On the other hand, the use of Containment Event Tree (CET) is an event-oriented approach. In this study, the Taiwan's fourth nuclear power plants, the Lungmen nuclear power station (LNPS), which is an advanced boiling water reactor (ABWR) with fully digitized instrumentation and control (I and C) system is chosen as the target plant. The LNPS full scope engineering simulator is used to generate the testing data for method development. The following common initiating events are considered in this study: loss of coolant accidents (LOCA), total loss of feedwater (TLOFW), loss of offsite power (LOOP), station blackout (SBO). Studies have indicated that the combination of the symptom-oriented approach and the event-oriented approach can be helpful to find mitigation strategies and is useful for the accident management

  10. 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.

  11. 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).

  12. 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.

  13. 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.

  14. 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.

  15. Radiochemical approach to the JCO criticality accident in Tokai-mura, 1999--an overview of the radiochemistry group.

    PubMed

    Komura, K

    2001-09-01

    A few days after the JCO criticality accident in Tokai-mura, a collaborating scientific investigation group was organized to evaluate the environmental impact of the accident. The group consisted of two groups: an environmental research group (radiochemistry group) and a biological research group. This paper overviews the scientific activity of the former group based on 6 sampling campaigns conducted at the JCO campus, Tokai-mura and Naka-machi. Some of the topical results and our remaining tasks concerning the JCO accident are discussed.

  16. The Chernobyl Nuclear Power Plant accident: ecotoxicological update

    USGS Publications Warehouse

    Eisler, R.; Hoffman, David J.; Rattner, Barnett A.; Burton, G. Allen; Cairns, John=

    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.

  17. 2010 CRITICALITY ACCIDENT ALARM SYSTEM BENCHMARK EXPERIMENTS AT THE CEA VALDUC SILENE FACILITY

    SciTech Connect

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

    2011-01-01

    Several experiments were performed at the CEA Valduc SILENE reactor facility, which are intended to be published as evaluated benchmark experiments in the ICSBEP Handbook. These evaluated benchmarks will be useful for the verification and validation of radiation transport codes and evaluated nuclear data, particularly those that are used in the analysis of CAASs. During these experiments SILENE was operated in pulsed mode in order to be representative of a criticality accident, which is rare among shielding benchmarks. Measurements of the neutron flux were made with neutron activation foils and measurements of photon doses were made with TLDs. Also unique to these experiments was the presence of several detectors used in actual CAASs, which allowed for the observation of their behavior during an actual critical pulse. This paper presents the preliminary measurement data currently available from these experiments. Also presented are comparisons of preliminary computational results with Scale and TRIPOLI-4 to the preliminary measurement data.

  18. LOCA with consequential or delayed LOOP accidents: Unique issues, plant vulnerability, and CDF contributions

    SciTech Connect

    Martinez-Guridi, G.; Samanta, P.; Chu, L.; Yang, J.

    1998-08-01

    A loss-of-coolant accident (LOCA) can cause a loss-of-offsite power (LOOP) wherein the LOOP is usually delayed by few seconds or longer. Such an accident is called LOCA with consequential LOOP, or LOCA with delayed LOOP (here, abbreviated as LOCA/LOOP). This paper analyzes the unique conditions that are associated with a LOCA/LOOP, presents a model, and quantifies its contribution to core damage frequency (CDF). The results show that the CDF contribution can be a dominant contributor to risk for certain plant designs, although boiling water reactors (BWRs) are less vulnerable than pressurized water reactors (PWRs).

  19. Evacuation effect on excess mortality among institutionalized elderly after the fukushima daiichi nuclear power plant accident.

    PubMed

    Yasumura, Seiji

    2014-01-01

    The Great East Japan Earthquake hit Fukushima Prefecture on March 11, 2011, just over 3 years ago and it continues to affect our lives. In Fukushima, many people are confirmed dead or still missing due to the earthquake and/or tsunami. Additional "disaster-related deaths" have been attributed to the Fukushima Daiichi Nuclear Power Plant (NPP) accident. Mortality among the institutionalized elderly rates after the NPP accident were exceptionally high during the first 3 months, and persisted at a lower level for 9 months, in comparison with similar periods before the accident. This study demonstrates the great impact of evacuation on mortality of institutionalized elderly, excluding inpatients. We need to pay special attention to evacuation of the elderly, regardless of whether voluntary or forced.

  20. Environmental radiation at Izu-Oshima after the Fukushima Daiichi nuclear power plant accident.

    PubMed

    Inoue, K; Hosoda, M; Sugino, M; Simizu, H; Akimoto, A; Hori, K; Ishikawa, T; Sahoo, S K; Tokonami, S; Narita, H; Fukushi, M

    2012-11-01

    Environmental radiation at Izu-Oshima Island was observed 6 months after the accident at the Fukushima Daiichi Nuclear Power Plant (F1-NPP). A car-borne survey of the dose rate in air was conducted over the entire island and the results were compared with measurements performed in 2005 (i.e. before the accident). The activity concentrations of (134)Cs and (137)Cs were also measured using a germanium detector. The dose rate in air was found to be 2.9 ± 1.2 times higher than that in 2005 and (134)Cs was detected on Izu-Oshima Island. These results are attributed to the accident at the F1-NPP.

  1. 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.

  2. Protective action alternatives for accidents at nuclear power plants

    SciTech Connect

    Tingle, A.; Pratt, W.T.; McGuire, S.A.

    1987-06-01

    Protective action calculations have been performed for five different light water reactors (LWRs) and containment designs using high and low fission product releases for early and late containment failures for each plant. These fission product release estimates were obtained from studies performed for the recently published ''Reactor Risk Reference Document'' (NUREG-1150). Five protective actions were considered for the risks of exceeding various dose levels to the red marrow versus centerline distance from the plants using site-specific meteorology. The strategies considered were 4 hours of normal activity, basement sheltering, large building sheltering, evacuation at release, and evacuation 1 hour after release. The evacuations were computed using 10 mph evacuation speed for all sites. Additional calculations were performed for the dose contributions due to the cloud, ground, and inhalation pathways.

  3. 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.

  4. 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.

  5. Assessment of potential doses to workers during postulated accident conditions at the Waste Isolation Pilot Plant

    SciTech Connect

    Hoover, M.D.; Farrell, R.F.; Newton, G.J.

    1995-12-01

    The recent 1995 WIPP Safety Analysis Report (SAR) Update provided detailed analyses of potential radiation doses to members of the public at the site boundary during postulated accident scenarios at the U.S. Department of Energy`s Waste Isolation Pilot Plant (WIPP). The SAR Update addressed the complete spectrum of potential accidents associated with handling and emplacing transuranic waste at WIPP, including damage to waste drums from fires, punctures, drops, and other disruptions. The report focused on the adequacy of the multiple layers of safety practice ({open_quotes}defense-in-depth{close_quotes}) at WIPP, which are designed to (1) reduce the likelihood of accidents and (2) limit the consequences of those accidents. The safeguards which contribute to defense-in-depth at WIPP include a substantial array of inherent design features, engineered controls, and administrative procedures. The SAR Update confirmed that the defense-in-depth at WIPP is adequate to assure the protection of the public and environment. As a supplement to the 1995 SAR Update, we have conducted additional analyses to confirm that these controls will also provide adequate protection to workers at the WIPP. The approaches and results of the worker dose assessment are summarized here. In conformance with the guidance of DOE Standard 3009-94, we emphasize that use of these evaluation guidelines is not intended to imply that these numbers constitute acceptable limits for worker exposures under accident conditions. However, in conjunction with the extensive safety assessment in the 1995 SAR Update, these results indicate that the Carlsbad Area Office strategy for the assessment of hazards and accidents assures the protection of workers, members of the public, and the environment.

  6. 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.

  7. [Genetic effects in populations of plants growing in the zone of Kyshtym and Chernobyl accidents].

    PubMed

    Shevchenko, V A; Kal'chenko, V A; Abramov, V I; Rubanovich, A V; Shevchenko, V V; Grinikh, L I

    1999-01-01

    Studies to analyze the genetic processes in natural populations of plants were started on the territory of the East-Ural Radioactive Trace (EURT) in 1962 and in the zone of the Chernobyl accident in May 1986. The main directions of the genetic studies in both radioactive areas were similar: 1) study of the mutation process intensity depending on the dose and dose rate and analysis of dose-effect relationships for different genetic changes (point mutations, chromosome aberrations in mitosis and meiosis) in irradiated plant populations; 2) study of the mutation process dynamics in generations of chronically (prolongly) irradiated populations of plants; 3) analysis of microevolutionary processes in irradiated plant populations. The report presents an analysis of observed dose-effect relationships under the action of radiation on populations of Arabidopsis thaliana, Pinus sylvestris and a number of other plant species. Analysis of the mutation processes dynamics in 8 Arabidopsis populations growing in the zone of the Chernobyl catastrophe has demonstrated that the level of the embryo lethal mutations 10 years after the accident in the irradiated populations significantly exceeds the control level. The following phenomena observed in chronically irradiated populations have also been considered: increased radioresistance of irradiated populations (radioadaptation), the appearance of abnormal karyotypes and selective markers upon chronic irradiation. The authors call attention to the high importance of monitoring of genetic processes in irradiated plant populations for understanding of the action of radiation on human populations.

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. Determination of uranium isotopes in soil core samples collected on the JCO grounds after the criticality accident.

    PubMed

    Yoshida, S; Muramatsu, Y; Tagami, K

    2001-11-01

    To evaluate the impact of the 1999 criticality accident in Tokai-mura on the U isotope composition in soils, U isotopes (235U and 238U) were determined with inductively coupled plasma-mass spectrometry (ICP-MS) for soil core samples collected on the JCO grounds after the accident. The 235U/238U ratios were higher than the natural ratio in most samples. The highest ratio observed was 0.0262. Although vertical profiles of the 235U/238U ratio differed among the soil cores, the ratios tended to be high at the surface and decreased with depth. The U concentration also changed with depth. The percentages of 235U in the excess U, estimated from the positive correlation between U concentration and the 235U/238U ratio in soil samples, were less than 4% by mass (mostly 1-3%) and were much lower than the enrichment of the U used in the uranium conversion building at the time of the criticality accident (18.8%). These findings indicate that enriched U had been released before the criticality accident during the U processing at JCO in connection with the reconversion of light water reactor fuel. Since the range of the U concentrations found was comparable to the range of uncontaminated Japanese surface soils, the amount of U added to the soil was judged negligible from a radiation protection viewpoint.

  15. 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

  16. Risk of thyroid cancer after the Fukushima nuclear power plant accident.

    PubMed

    Yamashita, Shunichi; Suzuki, Shinichi

    2013-09-01

    The appropriateness of the initial response and countermeasures taken following the Fukushima nuclear power plant accident after the Great East Japan Earthquake on March 11, 2011 should be further examined. Implementation of a prospective epidemiological study on human health risks from low-dose radiation exposure and comprehensive health protection from radiation should be emphasized on a basis of the lessons learnt from the Chernobyl nuclear power plant accident. In contrast, the doses to a vast majority of the population in Fukushima were not high enough to expect to see any increase in incidence of cancer and health effects in the future, however, public concerns about the long-term health effects of radioactive environmental contamination have increased in Japan. Since May 2011, the Fukushima Prefecture started the Fukushima Health Management Survey Project with the purpose of long-term health care administration and early medical diagnosis/treatment for prefectural residents. In this report, risk and countermeasures of thyroid cancer occurrence after nuclear accidents, especially due to early exposure of radioactive iodine, will be focused upon to understand the current situation of risk of thyroid cancer in Fukushima, and the difficult challenges surrounding accurate estimations of low-dose and low-dose rate radiation exposures will be discussed.

  17. From Devastation to Recovery and Revival in the Aftermath of Fukushima's Nuclear Power Plants Accident.

    PubMed

    Ohto, Hitoshi; Yasumura, Seiji; Maeda, Masaharu; Kainuma, Hiroshi; Fujimori, Keiya; Nollet, Kenneth E

    2017-03-01

    Japan's earthquake, tsunami, and subsequent Fukushima nuclear power plant accident in March 2011 forced the evacuation of 185 000 residents. Psychological and social impacts exacerbated by long-term evacuation and widespread rumors have influenced residents' physical and mental health, despite the fact that no direct fatalities occurred from radiation exposure. However, during the 5 years following the accident, steady recovery in industrial and economic activity has lessened previously widespread, deeply rooted stigma and self-stigma among a significant number of affected victims. More than 21 000 of 62 800 people who evacuated from Fukushima are gradually returning, and concurrently, Fukushima's economic and social recovery are progressing, as can be seen from remarkable increases in residential construction, recovering agricultural production, job growth, and industrial output. Although post-disaster interventions such as seminars and dialogues with residents are credited with building resilience, a significant proportion of people in the area have depressive tendencies and loss of purpose.

  18. Accident consequences analysis of the HYLIFE-II inertial fusion energy power plant design

    SciTech Connect

    Reyes, S; Gomez del Rio, J; Sanz, J

    2000-02-23

    Previous studies of the safety and environmental (S and E) aspects of the HYLIFE-II inertial fusion energy (IFE) power plant design have used simplistic assumptions in order to estimate radioactivity releases under accident conditions. Conservatisms associated with these traditional analyses can mask the actual behavior of the plant and have revealed the need for more accurate modeling and analysis of accident conditions and radioactivity mobilization mechanisms. In the present work a set of computer codes traditionally used for magnetic fusion safety analyses (CHEMCON, MELCOR) has been applied for simulating accident conditions in a simple model of the HYLIFE-II IFE design. Here the authors consider a severe lost of coolant accident (LOCA) producing simultaneous failures of the beam tubes (providing a pathway for radioactivity release from the vacuum vessel towards the containment) and of the two barriers surrounding the chamber (inner shielding and containment building it self). Even though containment failure would be a very unlikely event it would be needed in order to produce significant off-site doses. CHEMCON code allows calculation of long-term temperature transients in fusion reactor first wall, blanket, and shield structures resulting from decay heating. MELCOR is used to simulate a wide range of physical phenomena including thermal-hydraulics, heat transfer, aerosol physics and fusion product release and transport. The results of these calculations show that the estimated off-site dose is less than 6 mSv (0.6 rem), which is well below the value of 10 mSv (1 rem) given by the DOE Fusion Safety Standards for protection of the public from exposure to radiation during off-normal conditions.

  19. 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.

  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.

  1. 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.

  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. 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.

  4. Iodine-129 concentration in seawater near Fukushima before and after the accident at the Fukushima Daiichi Nuclear Power Plant

    NASA Astrophysics Data System (ADS)

    Suzuki, T.; Otosaka, S.; Kuwabara, J.; Kawamura, H.; Kobayashi, T.

    2013-06-01

    Anthropogenic radionuclides were released into the environment in large quantities by the Fukushima Daiichi Nuclear Power Plant (1FNPP) accident. To evaluate accident-derived 129I, the 129I concentrations in seawater before and after the accident were compared. Before the accident (2008-2009), the 129I concentrations in the western margin of the North Pacific between 32° N and 44° N showed a latitudinal gradient that was expressed as a linear function of latitude. The highest and average 129I concentrations after the accident were 73 times and approximately 8 times, respectively, higher than those before the accident in this study area. Considering the distribution of 129I in surface seawater, the accident-derived 129I in the southern and northern stations of the 1FNPP was predominantly supplied by seawater advection and atmospheric deposition (including microbial volatilization), respectively. As of October 2011, depth profiles of 129I revealed that 129I originating from the 1FNPP existed mainly in the upper 100 m depth. From the depth profiles, the cumulative inventories of accident-derived 129I were estimated to be (1.6-9.6) × 1012 atoms m-2 in this study area. On the basis of the 129I data in the seawater near Fukushima, the effective dose of 129I from seafood ingestion was much smaller than the annual dose limit.

  5. Iodine-129 concentration in seawater near Fukushima before and after the accident at the Fukushima Daiichi Nuclear Power Plant

    NASA Astrophysics Data System (ADS)

    Suzuki, T.; Otosaka, S.; Kuwabara, J.; Kawamura, H.; Kobayashi, T.

    2013-01-01

    Anthropogenic radionuclides were released into the environment in large quantities by the Fukushima Daiichi Nuclear Power Plant (1FNPP) accident. To evaluate accident-derived 129I, the 129I concentrations in seawater before and after the accident were compared. Before the accident (2009-2010), the 129I concentrations in the western margin of the North Pacific between 36° N and 44° N showed a atitudinal gradient that was expressed as a linear function of latitude. The highest and average 129I concentrations after the accident were 73 times and approximately 8 times, respectively, higher than those before the accident in this study area. Considering the distribution of 129I in surface seawater, the accident-derived 129I in the southern and northern stations of the 1FNPP was predominantly supplied by seawater advection and atmospheric deposition, respectively. As of October 2011, depth profiles of 129I revealed that 129I originating from the 1FNPP existed mainly in the upper 100 m depth. From the depth profiles, the cumulative inventories of accident-derived 129I were estimated to be (1.8-9.9) × 1012 atoms m-2 in this study area. On the basis of the 129I data in the seawater near Fukushima, the effective dose of 129I from seafood ingestion was much smaller than the annual dose limit.

  6. [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.

  7. 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.

  8. 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

    2013-09-03

    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.

  9. Emergency/disaster medical support in the restoration project for the Fukushima nuclear power plant accident.

    PubMed

    Morimura, Naoto; Asari, Yasushi; Yamaguchi, Yoshihiro; Asanuma, Kazunari; Tase, Choichiro; Sakamoto, Tetsuya; Aruga, Tohru

    2013-12-01

    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.

  10. 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.

  11. 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.

  12. 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

  13. Activation of soil and chemical reagents exposed to the neutrons released by the JCO criticality accident in Tokai-mura.

    PubMed

    Murata, Y; Muroyama, T; Kawabata, Y; Yamamoto, M; Komura, K

    2001-09-01

    Specific activities (Bq/g-element) of residual neutron-induced radionuclides by the JCO criticality accident were measured for soil, concrete block and chemical reagent samples collected in the JCO campus. Induced radionuclides such as 24Na, 46Sc, 54Mn, 59Fe, 60Co, 65Zn, 82Br, 122Sb, 134Cs and 140La were detected in the samples, depending on the ground distance from the accident point and the sampling date. Apparent thermal, epi-thermal and fast neutron fluences, which reached the sample at each point, were roughly estimated from the specific activities and cross sections of the target nuclides taken from a literature. The present data are believed to be important as validation data for a three-dimensional neutron transport model calculation.

  14. Space Shuttle Columbia and Fukushima Nuclear Plant, Similarities and Differences in Organizational Accidents and Lessons Learned

    NASA Astrophysics Data System (ADS)

    Mitsui, Masami; Takeuchi, Nobuo; Kawada, Yasuhiro; Kobayashi, Royoji; Nogami, Manami; Miki, Masami

    2013-09-01

    When records of success are accumulating, we should be most alert to maintain the safety culture we labored to establish and nurture.Space Shuttle Columbia Accident in 2002 and Fukushima Nuclear Power Station Accident in 2011 are seemingly unrelated. But, by studying the accident reports issued after these accidents, the authors found that the organizational causes that led to the accidents were surprisingly similar. The causes of these accidents were rooted in the history and culture of the respective organizations.In this paper, the authors will discuss differences and similarities in these two accidents based on the reports submitted by the accident investigation boards of these two accidents. This will be followed by the lessons learned the authors derived.

  15. Description of Survey Data Regarding the Chemical Repackaging Plant Accident West Helena, Arkansas

    SciTech Connect

    Sorensen, J.H.; Vogt, B.M.

    1999-03-01

    Shortly after 1:00 p.m. on Thursday, May 8, 1997, clouds of foul-smelling smoke began pouring from an herbicide and pesticide packaging plant in West Helena, Arkansas. An alert was sounded, employees evacuated, and the West Helena fire department was called. As three firefighters prepared to enter the plant, the chemical compounds exploded, collapsing a solid concrete block wall, and killing all three firefighters. As the odorous smoky cloud drifted away from the plant, authorities ordered residents in a 2-mile area downwind of the plant to evacuate and those in the 2- to 3-mile zone to shelter in place. This study examines and compares the responses to a mail survey of those ordered to evacuate and those told to shelter in place. Among the variables examined are compliance with official orders and perceived warnings, threat perception, time and source of first warning, response times, and behavior characteristics for both populations. The findings indicate that 90% of those that were told to evacuate did so but only 27% of those told to shelter-in-place did so, with 68% opting to evacuate instead. The implications of these findings for emergency managers is that people will likely choose to evacuate when both warnings to evacuate and warnings to shelter are issued to residents in close proximity to each other. The findings on warning times closely resemble other findings from evacuations when chemical accidents occur and route notification is used for warning residents.

  16. 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.

  17. Detection of Fukushima Daiichi nuclear power plant accident radioactive traces in Monaco.

    PubMed

    Pham, M K; Eriksson, M; Levy, I; Nies, H; Osvath, I; Betti, M

    2012-12-01

    Daily air monitoring of radionuclides in the Principality of Monaco (43°73'N, 7°43'E) after the Fukushima Daiichi nuclear power plant accident showed that only Iodine-131 ((131)I) and Caesium isotopes ((134)Cs and (137)Cs) were detected. The peak of (131)I varied and reached its maximum between March 29th and April 5th, meanwhile both peaks of (134)Cs and (137)Cs arrived later and attained a maximum between April 1st and 4th. Their maximum activity concentrations in air were 354, 30, and 37 μBq m(-3) respectively. The (134)Cs to (137)Cs activity ratio was close to 1, which is different from that one observed after the Chernobyl accident (around 0.54). Up to 95% of caesium isotopes were washed out by wet scavenging during 27-28th of March, where the maximum deposition rates of (134)Cs and (137)Cs (13.7 and 19.1 mBq m(-2) day(-1), respectively) were observed. The significant input of (134)Cs and (137)Cs into the Mediterranean seawater column (30 m depth) was detected later, on the 24th of May. Radioisotopes of caesium and iodine were found far above the applied detection limits, but still with no concern for harmful radiation exposure and public health. The contamination gradually decreased in air and activity concentrations returned to background values after one or two months.

  18. Estimating Loss-of-Coolant Accident Frequencies for the Standardized Plant Analysis Risk Models

    SciTech Connect

    S. A. Eide; D. M. Rasmuson; C. L. Atwood

    2008-09-01

    The U.S. Nuclear Regulatory Commission maintains a set of risk models covering the U.S. commercial nuclear power plants. These standardized plant analysis risk (SPAR) models include several loss-of-coolant accident (LOCA) initiating events such as small (SLOCA), medium (MLOCA), and large (LLOCA). All of these events involve a loss of coolant inventory from the reactor coolant system. In order to maintain a level of consistency across these models, initiating event frequencies generally are based on plant-type average performance, where the plant types are boiling water reactors and pressurized water reactors. For certain risk analyses, these plant-type initiating event frequencies may be replaced by plant-specific estimates. Frequencies for SPAR LOCA initiating events previously were based on results presented in NUREG/CR-5750, but the newest models use results documented in NUREG/CR-6928. The estimates in NUREG/CR-6928 are based on historical data from the initiating events database for pressurized water reactor SLOCA or an interpretation of results presented in the draft version of NUREG-1829. The information in NUREG-1829 can be used several ways, resulting in different estimates for the various LOCA frequencies. Various ways NUREG-1829 information can be used to estimate LOCA frequencies were investigated and this paper presents two methods for the SPAR model standard inputs, which differ from the method used in NUREG/CR-6928. In addition, results obtained from NUREG-1829 are compared with actual operating experience as contained in the initiating events database.

  19. Supplementary documentation for an Environmental Impact Statement regarding the Pantex Plant: dispersion analysis for postulated accidents

    SciTech Connect

    Dewart, J.M.; Bowen, B.M.; Elder, J.C.

    1982-12-01

    This report documents work performed in support of preparation of an Environmental Impact Statement (EIS) regarding the Department of Energy (DOE) Pantex Plant near Amarillo, Texas. The report covers the calculation of atmospheric dispersion and deposition of plutonium following postulated nonnuclear detonations of nuclear weapons. Downwind total integrated air concentrations and ground deposition values for each postulated accident are presented. The model used to perform these calculations is the DIFOUT model, developed at Sandia National Laboratories in conjunction with Operation Roller Coaster, a field experiment involving sampling and measurements of nuclear material dispersed by four detonations. The DIFOUT model is described along with the detonation cloud sizes, aerosol parameters, and meteorological data used as input data. A verification study of the DIFOUT model has also been performed; the results are presented.

  20. Radioactive contamination of fishes in lake and streams impacted by the Fukushima nuclear power plant accident.

    PubMed

    Yoshimura, Mayumi; Yokoduka, Tetsuya

    2014-06-01

    The Fukushima Daiichi Nuclear Power Plant (FDNPP) accident in March 2011 emitted radioactive substances into the environment, contaminating a wide array of organisms including fishes. We found higher concentrations of radioactive cesium ((137)Cs) in brown trout (Salmo trutta) than in rainbow trout (Oncorhynchus nerka), and (137)Cs concentrations in brown trout were higher in a lake than in a stream. Our analyses indicated that these differences were primarily due to differences in diet, but that habitat also had an effect. Radiocesium concentrations ((137)Cs) in stream charr (Salvelinus leucomaenis) were higher in regions with more concentrated aerial activity and in older fish. These results were also attributed to dietary and habitat differences. Preserving uncontaminated areas by remediating soils and releasing uncontaminated fish would help restore this popular fishing area but would require a significant effort, followed by a waiting period to allow activity concentrations to fall below the threshold limits for consumption.

  1. 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.

  2. 78 FR 39698 - Endangered and Threatened Wildlife and Plants; Designating Critical Habitat for Three Plant...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-02

    ... Fish and Wildlife Service 50 CFR Part 17 RIN 1018-AZ38 Endangered and Threatened Wildlife and Plants; Designating Critical Habitat for Three Plant Species on Hawaii Island AGENCY: Fish and Wildlife Service... of critical habitat for three plant species (Bidens micrantha ssp. ctenophylla...

  3. 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.

  4. 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.

  5. 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.

  6. 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.

    1991-01-01

    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.

  7. 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.

  8. 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

  9. The Causal Relationship between DNA Damage Induction in Bovine Lymphocytes and the Fukushima Nuclear Power Plant Accident.

    PubMed

    Nakamura, Asako J; Suzuki, Masatoshi; Redon, Christophe E; Kuwahara, Yoshikazu; Yamashiro, Hideaki; Abe, Yasuyuki; Takahashi, Shintaro; Fukuda, Tomokazu; Isogai, Emiko; Bonner, William M; Fukumoto, Manabu

    2017-02-27

    The Fukushima Daiichi Nuclear Power Plant (FNPP) accident, the largest nuclear incident since the 1986 Chernobyl disaster, occurred when the plant was hit by a tsunami triggered by the Great East Japan Earthquake on March 11, 2011. The subsequent uncontrolled release of radioactive substances resulted in massive evacuations in a 20-km zone. To better understand the biological consequences of the FNPP accident, we have been measuring DNA damage levels in cattle in the evacuation zone. DNA damage was evaluated by assessing the levels of DNA double-strand breaks in peripheral blood lymphocytes by immunocytofluorescence-based quantification of γ-H2AX foci. A greater than two-fold increase in the fraction of damaged lymphocytes was observed in all animal cohorts within the evacuation zone, and the levels of DNA damage decreased slightly over the 700-day sample collection period. While the extent of damage appeared to be independent of the distance from the accident site and the estimated radiation dose from radiocesium, we observed age-dependent accumulation of DNA damage. Thus, this study, which was the first to evaluate the biological impact of the FNPP accident utilizing the γ-H2AX assays, indicated the causal relation between high levels of DNA damage in animals living in the evacuation zone and the FNPP accident.

  10. Electrical equipment performance under severe accident conditions (BWR/Mark 1 plant analysis): Summary report

    SciTech Connect

    Bennett, P.R.; Kolaczkowski, A.M.; Medford, G.T.

    1986-09-01

    The purpose of the Performance Evaluation of Electrical Equipment during Severe Accident States Program is to determine the performance of electrical equipment, important to safety, under severe accident conditions. In FY85, a method was devised to identify important electrical equipment and the severe accident environments in which the equipment was likely to fail. This method was used to evaluate the equipment and severe accident environments for Browns Ferry Unit 1, a BWR/Mark I. Following this work, a test plan was written in FY86 to experimentally determine the performance of one selected component to two severe accident environments.

  11. PROBABILISTIC SAFETY ASSESSMENT OF OPERATIONAL ACCIDENTS AT THE WASTE ISOLATION PILOT PLANT

    SciTech Connect

    Rucker, D.F.

    2000-09-01

    This report presents a probabilistic safety assessment of radioactive doses as consequences from accident scenarios to complement the deterministic assessment presented in the Waste Isolation Pilot Plant (WIPP) Safety Analysis Report (SAR). The International Council of Radiation Protection (ICRP) recommends both assessments be conducted to ensure that ''an adequate level of safety has been achieved and that no major contributors to risk are overlooked'' (ICRP 1993). To that end, the probabilistic assessment for the WIPP accident scenarios addresses the wide range of assumptions, e.g. the range of values representing the radioactive source of an accident, that could possibly have been overlooked by the SAR. Routine releases of radionuclides from the WIPP repository to the environment during the waste emplacement operations are expected to be essentially zero. In contrast, potential accidental releases from postulated accident scenarios during waste handling and emplacement could be substantial, which necessitates the need for radiological air monitoring and confinement barriers (DOE 1999). The WIPP Safety Analysis Report (SAR) calculated doses from accidental releases to the on-site (at 100 m from the source) and off-site (at the Exclusive Use Boundary and Site Boundary) public by a deterministic approach. This approach, as demonstrated in the SAR, uses single-point values of key parameters to assess the 50-year, whole-body committed effective dose equivalent (CEDE). The basic assumptions used in the SAR to formulate the CEDE are retained for this report's probabilistic assessment. However, for the probabilistic assessment, single-point parameter values were replaced with probability density functions (PDF) and were sampled over an expected range. Monte Carlo simulations were run, in which 10,000 iterations were performed by randomly selecting one value for each parameter and calculating the dose. Statistical information was then derived from the 10,000 iteration

  12. Measurements of 60Co in spoons activated by neutrons during the JCO criticality accident at Tokai-mura in 1999.

    PubMed

    Gasparro, J; Hult, M; Komura, K; Arnold, D; Holmes, L; Johnston, P N; Laubenstein, M; Neumaier, S; Reyss, J-L; Schillebeeckx, P; Tagziria, H; Van Britsom, G; Vasselli, R

    2004-01-01

    Neutron activated items from the vicinity of the place where the JCO criticality accident occurred have been used to determine the fluence of neutrons around the facility and in nearby residential areas. By using underground laboratories for measuring the activation products, it is possible to extend the study to also cover radionuclides with very low activities from long-lived radionuclides. The present study describes gamma-ray spectrometry measurements undertaken in a range of underground laboratories for the purpose of measuring (60)Co more than 2 years after the criticality event. The measurements show that neutron fluence determined from (60)Co activity is in agreement with previous measurements using the short-lived radionuclides (51)Cr and (59)Fe. Limits on contamination of the samples with (60)Co are evaluated and shown to not greatly affect the utility of neutron fluence determinations using (60)Co activation.

  13. 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

  14. Increases in perinatal mortality in prefectures contaminated by the Fukushima nuclear power plant accident in Japan

    PubMed Central

    Scherb, Hagen Heinrich; Mori, Kuniyoshi; Hayashi, Keiji

    2016-01-01

    Abstract Descriptive observational studies showed upward jumps in secular European perinatal mortality trends after Chernobyl. The question arises whether the Fukushima nuclear power plant accident entailed similar phenomena in Japan. For 47 prefectures representing 15.2 million births from 2001 to 2014, the Japanese government provides monthly statistics on 69,171 cases of perinatal death of the fetus or the newborn after 22 weeks of pregnancy to 7 days after birth. Employing change-point methodology for detecting alterations in longitudinal data, we analyzed time trends in perinatal mortality in the Japanese prefectures stratified by exposure to estimate and test potential increases in perinatal death proportions after Fukushima possibly associated with the earthquake, the tsunami, or the estimated radiation exposure. Areas with moderate to high levels of radiation were compared with less exposed and unaffected areas, as were highly contaminated areas hit versus untroubled by the earthquake and the tsunami. Ten months after the earthquake and tsunami and the subsequent nuclear accident, perinatal mortality in 6 severely contaminated prefectures jumped up from January 2012 onward: jump odds ratio 1.156; 95% confidence interval (1.061, 1.259), P-value 0.0009. There were slight increases in areas with moderate levels of contamination and no increases in the rest of Japan. In severely contaminated areas, the increases of perinatal mortality 10 months after Fukushima were essentially independent of the numbers of dead and missing due to the earthquake and the tsunami. Perinatal mortality in areas contaminated with radioactive substances started to increase 10 months after the nuclear accident relative to the prevailing and stable secular downward trend. These results are consistent with findings in Europe after Chernobyl. Since observational studies as the one presented here may suggest but cannot prove causality because of unknown and uncontrolled factors or

  15. 50 CFR 17.96 - Critical habitat-plants.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 6 2014-10-01 2014-10-01 false Critical habitat-plants. 17.96 Section 17.96 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED) TAKING, POSSESSION, TRANSPORTATION, SALE, PURCHASE, BARTER, EXPORTATION, AND IMPORTATION OF WILDLIFE AND PLANTS (CONTINUED) ENDANGERED...

  16. 50 CFR 17.96 - Critical habitat-plants.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 5 2011-10-01 2011-10-01 false Critical habitat-plants. 17.96 Section 17.96 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED) TAKING, POSSESSION, TRANSPORTATION, SALE, PURCHASE, BARTER, EXPORTATION, AND IMPORTATION OF WILDLIFE AND PLANTS (CONTINUED) ENDANGERED...

  17. 50 CFR 17.96 - Critical habitat-plants.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 4 2010-10-01 2010-10-01 false Critical habitat-plants. 17.96 Section 17.96 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED) TAKING, POSSESSION, TRANSPORTATION, SALE, PURCHASE, BARTER, EXPORTATION, AND IMPORTATION OF WILDLIFE AND PLANTS (CONTINUED) ENDANGERED...

  18. 50 CFR 17.96 - Critical habitat-plants.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 6 2012-10-01 2012-10-01 false Critical habitat-plants. 17.96 Section 17.96 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED) TAKING, POSSESSION, TRANSPORTATION, SALE, PURCHASE, BARTER, EXPORTATION, AND IMPORTATION OF WILDLIFE AND PLANTS (CONTINUED) ENDANGERED...

  19. 50 CFR 17.96 - Critical habitat-plants.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 6 2013-10-01 2013-10-01 false Critical habitat-plants. 17.96 Section 17.96 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED) TAKING, POSSESSION, TRANSPORTATION, SALE, PURCHASE, BARTER, EXPORTATION, AND IMPORTATION OF WILDLIFE AND PLANTS (CONTINUED) ENDANGERED...

  20. [A questionnaire survey about public's image of radiation after the Fukushima Daiichi nuclear power plant accident].

    PubMed

    Okazaki, Ryuji; Ootsuyama, Akira; Abe, Toshiaki; Kuto, Tatsuhiko

    2012-03-01

    A questionnaire survey about the public's image of radiation was performed after the Fukushima Daiichi nuclear power plant (FDNPP) accident. The survey was taken by general citizens (200 and 1640 in Fukushima and 52 outside of Fukushima) and doctors (63 in Fukushima and 1942 outside of Fukushima (53 in Oita, 44 in Sagamihara and 1,845 in Kitakyushu)) in and outside of Fukushima and second year medical students in the University of Occupational and Environmental Health, Japan. The questionnaire surveys were performed during lectures about radiation. The response rates were 86% for the general citizens in Fukushima, 91% for the general citizens outside of Fukushima, 86% for doctors in Fukushima, and 85% and 86% for doctors in Sagamihara and Oita, respectively. The questionnaire surveys were sent to clinics and hospitals in Fukushima where the general citizens answered with a response rate of 50%. When the questionnaire surveys were sent to clinics and hospitals in Kitakyushu, doctors answered, with a response rate of 17%. The percentages of anxiety about future radiation effects after the FDNPP accident were the highest among the general citizens (71.6% in Fukushima and 40.4% outside of Fukushima), in the middle among the doctors (30.2% in Fukushima and 26.2% outside of Fukushima) and the lowest among the medical students (12.2%). The doctors in Fukushima and the medical students were anxious about food and soil pollution. The general citizens and the doctors outside of Fukushima were anxious about health problems and food and soil pollution. We concluded that a high level of education about radiation decreased the anxiety about the radiation effects. It is important to spread knowledge about radiation.

  1. 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.

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

    SciTech Connect

    Marusich, R.M., Westinghouse Hanford

    1996-09-06

    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.

  3. 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.

  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.

  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. Basic Scholarship in Biosafety Is Critically Needed To Reduce Risk of Laboratory Accidents

    PubMed Central

    Casagrande, Rocco

    2017-01-01

    ABSTRACT Our firm conducted a risk/benefit assessment of “gain-of-function” research, as part of the deliberative process following a U.S. moratorium on the research (U.S. Department of Health and Human Services, U.S. Government Gain-of-Function Deliberative Process and Research Funding Pause on Selected Gain-of-Function Research Involving Influenza, MERS, and SARS Viruses, 2014). Due to significant missing but theoretically acquirable data, our biosafety assessment faced limitations, and we were forced to provide a relative, instead of absolute, measure of risk (Gryphon Scientific, LLC, Risk and Benefit Analysis of Gain of Function Research, 2016). Here, we argue that many of these types of missing data represent large and stunning gaps in our knowledge of biosafety and argue that these missing data, once acquired via primary research efforts, would improve biosafety risk assessments and could be incorporated into biosafety practices to reduce risk of accidents. Governments invest billions in biological research; at least a small fraction of this support is warranted to prevent biological accidents.

  7. Radiocesium derived from the Fukushima Daiichi Nuclear Power Plant accident in seabed sediments: initial deposition and inventories.

    PubMed

    Otosaka, Shigeyoshi; Kato, Yoshihisa

    2014-05-01

    Since the accident at Fukushima Daiichi Nuclear Power Plant (1FNPP), significant levels of anthropogenic radionuclides have been detected in seabed sediments off the east coast of Japan. In this paper, the approximate amount of accident-derived radiocesium in seabed sediments off Fukushima, Miyagi and Ibaraki prefectures was estimated from a sediment integration algorithm. As of October 2011, about half a year after the accident, the total amount of sedimentary 134Cs was 0.20±0.06 PBq (decay corrected to March 11, 2011) and more than 90% of the radiocesium was accumulated in the regions shallower than 200 m depth. The large inventory in the coastal sediments was attributed to effective adsorption of dissolved radiocesium onto suspended particles and directly to sediments in the early post-accident stage. Although rivers are also an important source to supply radiocesium to the coastal regions, this flux was much lower than that of the above-mentioned process within half a year after the accident.

  8. 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.

  9. Transport calculation of neutrons leaked to the surroundings of the facilities by the JCO criticality accident in Tokai-mura.

    PubMed

    Imanaka, T

    2001-09-01

    A transport calculation of the neutrons leaked to the environment by the JCO criticality accident was carried out based on three-dimensional geometrical models of the buildings within the JCO territory. Our work started from an initial step to simulate the leakage process of neutrons from the precipitation tank, and proceeded to a step to calculate the neutron propagation throughout the JCO facilities. The total fission number during the accident in the precipitation tank was evaluated to be 2.5 x 10(18) by comparing the calculated neutron-induced activities per 235U fission with the measured values in a stainless-steel net sample taken 2 m from the precipitation tank. Shield effects by various structures within the JCO facilities were evaluated by comparing the present results with a previous calculation using two-dimensional models which suppose a point source of the fission spectrum in the air above the ground without any shield structures. The shield effect by the precipitation tank, itself, was obtained to be a factor of 3. The shield factor by the conversion building varied between 1.1 and 2, depending on the direction from the building. The shield effect by the surrounding buildings within the JCO territory was between I and 5, also depending on the direction.

  10. 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

  11. 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

  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

    2013-03-05

    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.

  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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Chromosome aberration analysis in persons exposed to low-level radiation from the JCO criticality accident in Tokai-mura.

    PubMed

    Sasaki, M S; Hayata, I; Kamada, N; Kodama, Y; Kodama, S

    2001-09-01

    Chromosome aberrations were studied in peripheral blood lymphocytes of 43 persons who were exposed to low-level radiation of mixed neutrons and gamma-rays resulting from the JCO criticality accident. When the age-adjusted frequencies of dicentric and ring chromosomes were compared with the dose calibration curve established in vitro for 60Co gamma-rays as a reference radiation, a significant correlation was observed between the chromosomally estimated doses and the documented doses evaluated by physical means. The regression coefficient of the chromosomal doses against the documented doses, 1.47 +/- 0.33, indicates that the relative biological effectiveness of fission neutrons at low doses is considerably higher than that currently adopted in the radiation protection standard.

  20. 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.

  1. 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.

  2. 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

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Time series changes in radiocaesium distribution in tea plants (Camellia sinensis (L.)) after the Fukushima Dai-ichi Nuclear Power Plant accident.

    PubMed

    Hirono, Yuhei; Nonaka, Kunihiko

    2016-02-01

    Radiocaesium ((134)Cs and (137)Cs) release following the accident at the Fukushima Dai-ichi Nuclear Power Plant, belonging to the Tokyo Electric Power Company caused severe contamination of new tea plant (Camellia sinensis (L.)) shoots by radiocaesium in many prefectures in eastern Japan. Because tea plants are perennial crops, there is the fear that the contamination might last for a long time. The objectives of this study were to reveal time series changes in the distribution of radiocaesium in tea plants after radioactive fallout and to evaluate the effect of pruning on reduction of radiocaesium concentrations in new shoots growing next year. The experimental tea field was located in Shizuoka, Japan, approximately 400 km away from the Fukushima Dai-ichi Nuclear Power Plant in a southwest direction. Time series changes in radiocaesium concentrations in unrefined tea, a tea product primarily produced for making Japanese green tea, from May 2011 to June 2013 and distribution of radiocaesium in tea plants from May 2011 to May 2012 were monitored. The radiocaesium concentrations in unrefined tea exponentially decreased; the effective half-lives for (134)Cs and (137)Cs were 0.30 and 0.36 y during the first 2 y after the accident, respectively. With time, the highest concentrations of (137)Cs moved from the upper to the lower parts of plants. Medium pruning 2-3 months after the accident reduced the concentration of (137)Cs in new shoots harvested in the first crop season of the following year by 56% compared with unpruned tea plants; thus, pruning is an effective measure for reducing radiocaesium concentration in tea.

  9. 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

  10. 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.

  11. Critical processes and parameters in the development of accident tolerant fuels drop-in capsule irradiation tests

    SciTech Connect

    Barrett, K. E.; Ellis, K. D.; Glass, C. R.; Roth, G. A.; Teague, M. P.; Johns, J.

    2015-12-01

    The goal of the Accident Tolerant Fuel (ATF) program is to develop the next generation of Light Water Reactor (LWR) fuels with improved performance, reliability, and safety characteristics during normal operations and accident conditions and with reduced waste generation. An irradiation test series has been defined to assess the performance of proposed ATF concepts under normal LWR operating conditions. The Phase I ATF irradiation test series is planned to be performed as a series of drop-in capsule tests to be irradiated in the Advanced Test Reactor (ATR) operated by the Idaho National Laboratory (INL). Design, analysis, and fabrication processes for ATR drop-in capsule experiment preparation are presented in this paper to demonstrate the importance of special design considerations, parameter sensitivity analysis, and precise fabrication and inspection techniques for figure innovative materials used in ATF experiment assemblies. A Taylor Series Method sensitivity analysis approach was used to identify the most critical variables in cladding and rodlet stress, temperature, and pressure calculations for design analyses. The results showed that internal rodlet pressure calculations are most sensitive to the fission gas release rate uncertainty while temperature calculations are most sensitive to cladding I.D. and O.D. dimensional uncertainty. The analysis showed that stress calculations are most sensitive to rodlet internal pressure uncertainties, however the results also indicated that the inside radius, outside radius, and internal pressure were all magnified as they propagate through the stress equation. This study demonstrates the importance for ATF concept development teams to provide the fabricators as much information as possible about the material properties and behavior observed in prototype testing, mock-up fabrication and assembly, and chemical and mechanical testing of the materials that may have been performed in the concept development phase. Special

  12. Critical processes and parameters in the development of accident tolerant fuels drop-in capsule irradiation tests

    DOE PAGES

    Barrett, K. E.; Ellis, K. D.; Glass, C. R.; ...

    2015-12-01

    The goal of the Accident Tolerant Fuel (ATF) program is to develop the next generation of Light Water Reactor (LWR) fuels with improved performance, reliability, and safety characteristics during normal operations and accident conditions and with reduced waste generation. An irradiation test series has been defined to assess the performance of proposed ATF concepts under normal LWR operating conditions. The Phase I ATF irradiation test series is planned to be performed as a series of drop-in capsule tests to be irradiated in the Advanced Test Reactor (ATR) operated by the Idaho National Laboratory (INL). Design, analysis, and fabrication processes formore » ATR drop-in capsule experiment preparation are presented in this paper to demonstrate the importance of special design considerations, parameter sensitivity analysis, and precise fabrication and inspection techniques for figure innovative materials used in ATF experiment assemblies. A Taylor Series Method sensitivity analysis approach was used to identify the most critical variables in cladding and rodlet stress, temperature, and pressure calculations for design analyses. The results showed that internal rodlet pressure calculations are most sensitive to the fission gas release rate uncertainty while temperature calculations are most sensitive to cladding I.D. and O.D. dimensional uncertainty. The analysis showed that stress calculations are most sensitive to rodlet internal pressure uncertainties, however the results also indicated that the inside radius, outside radius, and internal pressure were all magnified as they propagate through the stress equation. This study demonstrates the importance for ATF concept development teams to provide the fabricators as much information as possible about the material properties and behavior observed in prototype testing, mock-up fabrication and assembly, and chemical and mechanical testing of the materials that may have been performed in the concept development phase

  13. Evaluation of 129I mobility in the crop field soil contaminated by the Fukushima Daiichi nuclear power plant accident

    NASA Astrophysics Data System (ADS)

    Honda, Maki; Matsuzaki, Hiroyuki; Yamagata, Takeyasu; Tuchiya, Yoko Sunohara; Nakano, Chuichiro; Matsushi, Yuki; Maejima, Yuji; Nagai, Hisao

    2013-04-01

    Five soil cores from almost the same position in the crop field 20km apart from the Fukushima Daiichi nuclear power plant (F1NPP) for a period of May 2011 to June 2012 were analyzed. We previously know that the sampling site soil was tilled and well mixed by a farmer to the depth of 30cm until just before the F1NPP accident. Under the condition it is speculated that the crop field soil had been made homogeneous and then contaminated by F1NPP accident, so that the direct accumulation from the accident should be clearly observed. This was confirmed by the observations that depth profiles of 127I concentration (measured by ICP-MS), as well as carbon content (measured by NC analyzer), of these soil cores were roughly constant. In contrast, 129I (measured by AMS) concentration (or specific activity) was particularly high at the top most layer and immediately decreased exponentially along with depth. And below 10 cm depth, it went constant. This enhancement in the top 10cm layer can be considered as the direct accumulation from the F1NPP after the accident. Considering constant level at lower layer (0.0474mBq kg-1) as a background, 129I inventory was estimated as 46mBq m-2 (3.3×1013 atoms m-2). Similar 129I profile was also found in the soil cores of even one year and three months after the F1NPP accident. From these observations, it is concluded that accidental origin 129I had migrated little downward over the years, although the field should have experienced several times of rain and snow. More than 80% of the accidental origin 129I was still present within the top 5cm and more than 90% within the top 10cm.

  14. 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

  15. 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.

  16. 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.

  17. Verification and Validation of Neutronic/Thermalhydraulic 3D-Time Dependent Model for Treatment of Super-critical States of Light water Research Reactors Accidents

    SciTech Connect

    Khaled, S.M.

    2015-07-01

    This work presents the Verification and testing both the neutronic and thermal-hydraulics response of the positive reactivity-initiated power excursion accidents in small light water research reactors. Some research reactors have to build its own severe accidents code system. In this sense, a 3D space-time-dependent neutron diffusion models with thermal hydraulic feedback have been introduced, compared and tested both experimentally at criticality 14-cent and theoretically up to 1.5 $ with a number of similar codes. The results shows that no expected core failure or moderator boiling. (author)

  18. Evaluation of potential severe accidents during low power and shutdown operations at Grand Gulf, Unit 1: Evaluation of severe accident risks for plant operational state 5 during a refueling outage. Main report and appendices, Volume 6, Part 1

    SciTech Connect

    Brown, T.D.; Kmetyk, L.N.; Whitehead, D.; Miller, L.; Forester, J.; Johnson, J.

    1995-03-01

    Traditionally, probabilistic risk assessments (PRAS) of severe accidents in nuclear power plants have considered initiating events potentially occurring only during full power operation. Recent studies and operational experience have, however, implied that accidents during low power and shutdown could be significant contributors to risk. In response to this concern, in 1989 the Nuclear Regulatory Commission (NRC) initiated an extensive program to carefully examine the potential risks during low power and shutdown operations. Two plants, Surry (pressurized water reactor) and Grand Gulf (boiling water reactor), were selected as the plants to be studied. The program consists of two parallel projects being performed by Brookhaven National Laboratory (Surry) and Sandia National Laboratories (Grand Gulf). The program objectives include assessing the risks of severe accidents initiated during plant operational states other than full power operation and comparing the estimated risks with the risk associated with accidents initiated during full power operation as assessed in NUREG-1150. The scope of the program is that of a Level-3 PRA. The subject of this report is the PRA of the Grand Gulf Nuclear Station, Unit 1. The Grand Gulf plant utilizes a 3833 MWt BUR-6 boiling water reactor housed in a Mark III containment. The Grand Gulf plant is located near Port Gibson, Mississippi. The regime of shutdown analyzed in this study was plant operational state (POS) 5 during a refueling outage, which is approximately Cold Shutdown as defined by Grand Gulf Technical Specifications. The entire PRA of POS 5 is documented in a multi-volume NUREG report (NUREG/CR-6143). The internal events accident sequence analysis (Level 1) is documented in Volume 2. The Level 1 internal fire and internal flood analyses are documented in Vols 3 and 4, respectively.

  19. Bioassay for neutron-dose estimations of three patients in the JCO criticality accident in Tokai-mura by measuring beta-ray emitters.

    PubMed

    Takeda, H; Miyamoto, K; Yukawa, M; Nishimura, Y; Watanabe, Y; Kim, H S; Fuma, S; Kuroda, N; Kouno, F; Joshima, H; Hirama, T; Akashi, M

    2001-09-01

    The measurement of beta-emitters in biological samples (hair, urine and bone) from three patients in the JCO criticality accident was performed to assess the neutron dose to individuals. The result of the measurements of 32P in hair and urine collected immediately after the accident showed that sufficient 32P activities had been induced in the hair by fast neutrons and in the urine by thermal neutrons to know the severity of the exposure to the individuals and to the position. From the measurement of 32P and 45Ca in bone from various anatomical parts of two patients who died 82 and 210 days after the accident, it was suggested that the distribution of the induced beta-emitters activities could prove the position and posture of the patients at the moment of exposure.

  20. 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.

  1. Effects of wire rope in a Waste Isolation Pilot Plant (WIPP) waste shaft accident

    SciTech Connect

    Ellett, D.M.

    1982-12-01

    This report describes the empirical test program conducted on a 1/22-scale model of the WIPP facility. The model was designed to study the actions and effects of the wire rope used in the Koepe or friction-type hoist planned for use in the WIPP waste shaft during various accident scenarios. It is assumed that the hoist cable breaks and the cab (or shaft conveyance) falls to the bottom of the shaft during such an accident. The report gives the results of the study and makes recommendations for a continuing program of testing and redesign of the shaft to mitigate the effects of such an accident. The wire rope is shown to act as a good shock-absorbing material.

  2. MELCOR code analysis of a severe accident LOCA at Peach Bottom Plant

    SciTech Connect

    Carbajo, J.J. )

    1993-01-01

    A design-basis loss-of-coolant accident (LOCA) concurrent with complete loss of the emergency core cooling systems (ECCSs) has been analyzed for the Peach Bottom atomic station unit 2 using the MELCOR code, version 1.8.1. The purpose of this analysis is to calculate best-estimate times for the important events of this accident sequence and best-estimate source terms. Calculated pressures and temperatures at the beginning of the transient have been compared to results from the Peach Bottom final safety analysis report (FSAR). MELCOR-calculated source terms have been compared to source terms reported in the NUREG-1465 draft.

  3. Variation of radiocesium concentrations in cedar pollen in the Okutama area since the Fukushima Daiichi Nuclear Power Plant accident.

    PubMed

    Tsuruoka, H; Inoue, K; Sakano, Y; Hamada, M; Shimizu, H; Fukushi, M

    2015-11-01

    Due to releases of radionuclides in the Fukushima Daiichi Nuclear Power Plant accident, radiocesium ((134)Cs and (137)Cs) has been incorporated into large varieties of plant species and soil types. There is a possibility that radiocesium taken into plants is being diffused by pollen. Radiocesium concentrations in cedar pollen have been measured in Ome City, located in the Okutama area of metropolitan Tokyo, for the past 3 y. In this research, the variation of radiocesium concentrations was analysed by comparing data from 2011 to 2014. Air dose rates at 1 m above the ground surface in Ome City from 2011 to 2014 showed no significant difference. Concentration of (137)Cs contained in the cedar pollen in 2012 was about half that in 2011. Between 2012 and 2014, the concentration decreased by approximately one-fifth, which was similar to the result of a press release distributed by the Japanese Ministry of Agriculture, Forestry and Fisheries.

  4. In-vessel melt retention as a severe accident management strategy for the Loviisa Nuclear Power Plant

    SciTech Connect

    Kymaelaeinen, O.; Tuomisto, H.; Theofanous, T.G.

    1997-02-01

    The concept of lower head coolability and in-vessel retention of corium has been approved as a basic element of the severe accident management strategy for IVO`s Loviisa Plant (VVER-440) in Finland. The selected approach takes advantage of the unique features of the plant such as low power density, reactor pressure vessel without penetrations at the bottom and ice-condenser containment which ensures flooded cavity in all risk significant sequences. The thermal analyses, which are supported by experimental program, demonstrate that in Loviisa the molten corium on the lower head of the reactor vessel is coolable externally with wide margins. This paper summarizes the approach and the plant modifications being implemented. During the approval process some technical concerns were raised, particularly with regard to thermal loadings caused by contact of cool cavity water and hot corium with the reactor vessel. Resolution of these concerns is also discussed.

  5. Cytogenetical dose estimation for 3 severely exposed patients in the JCO criticality accident in Tokai-mura.

    PubMed

    Hayata, I; Kanda, R; Minamihisamatsu, M; Furukawa, M; Sasaki, M S

    2001-09-01

    A dose estimation by chromosome analysis was performed on the 3 severely exposed patients in the Tokai-mura criticality accident. Drastically reduced lymphocyte counts suggested that the whole-body dose of radiation which they had been exposed to was unprecedentedly high. Because the number of lymphocytes in the white blood cells in two patients was very low, we could not culture and harvest cells by the conventional method. To collect the number of lymphocytes necessary for chromosome preparation, we processed blood samples by a modified method, called the high-yield chromosome preparation method. With this technique, we could culture and harvest cells, and then make air-dried chromosome slides. We applied a new dose-estimation method involving an artificially induced prematurely condensed ring chromosome, the PCC-ring method, to estimate an unusually high dose with a short time. The estimated doses by the PCC-ring method were in fairly good accordance with those by the conventional dicentric and ring chromosome (Dic+R) method. The biologically estimated dose was comparable with that estimated by a physical method. As far as we know, the estimated dose of the most severely exposed patient in the present study is the highest recorded among that chromosome analyses have been able to estimate in humans.

  6. 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.

  7. 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

  8. 137Cs vertical migration in a deciduous forest soil following the Fukushima Dai-ichi Nuclear Power Plant accident.

    PubMed

    Nakanishi, Takahiro; Matsunaga, Takeshi; Koarashi, Jun; Atarashi-Andoh, Mariko

    2014-02-01

    The large amount of (137)Cs deposited on the forest floor because of the Fukushima Dai-ichi Nuclear Power Plant accident represents a major potential long-term source for mobile (137)Cs. To investigate (137)Cs mobility in forest soils, we investigated the vertical migration of (137)Cs through seepage water, using a lysimetric method. The study was conducted in a deciduous forest soil over a period spanning 2 month to 2 y after the Fukushima nuclear accident. Our observations demonstrated that the major part of (137)Cs in the litter layer moved into the mineral soil within one year after the accident. On the other hand, the topsoil prevented migration of (137)Cs, and only 2% of (137)Cs in the leachate from litter and humus layer penetrated below a 10 cm depth. The annual migration below a 10 cm depth accounted for 0.1% of the total (137)Cs inventory. Therefore, the migration of (137)Cs by seepage water comprised only a very small part of the total (137)Cs inventory in the mineral soil, which was undetectable from the vertical distribution of (137)Cs in the soil profile. In the present and immediate future, most of the (137)Cs deposited on the forest floor will probably remain in the topsoil successively, although a small but certain amount of bioavailable (137)Cs exists in forest surface soil.

  9. 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.

  10. 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

  11. 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.

  12. Determination of radionuclides induced by fast neutrons from the JCO criticality accident in Tokai-mura, Japan for estimating neutron doses.

    PubMed

    Kojima, S; Imanaka, T; Takada, J; Mitsugashira, T; Nakanishi, T; Seki, R; Kondo, M; Sasaki, K I; Saito, T; Yamaguchi, Y; Furukawa, M

    2001-09-01

    A criticality accident occurred at a uranium conversion facility in Tokai-mura, Japan on September 30, 1999, and fission neutrons were continuously emitted for about 20 hours. Materials of stainless steel or iron, and chemical reagents were collected at places between 2 m and 270 m from the criticality accident site on October 25 and 26, 1999, November 27, 1999 and February 11, 2000. Neutron-induced radionuclides. such as 54Mn and 58Co, in the materials exposed to fast neutrons from the accident were measured to estimate the neutron fluences and energy distributions. Highly sensitive y-ray spectrometry with a well-type Ge detector was performed after radiochemical separation of Mn and Co from the materials. An instrumental neutron activation analysis was mainly applied for determinations of the target elements and chemical yields. The concentrations of 54Mn and 58Co in a mesh screen of stainless steel collected at a location 2.0 m from the accident site were determined. The total number of fission events was evaluated to be 2.5 x 10(18) by Monte-Carlo calculations of neutron transfer by considering the observed values of 54Mn and 58Co. The results presented here are fundamental to estimate the neutron doses at various distances.

  13. 135Cs activity and 135Cs/137Cs atom ratio in environmental samples before and after the Fukushima Daiichi Nuclear Power Plant accident

    NASA Astrophysics Data System (ADS)

    Yang, Guosheng; Tazoe, Hirofumi; Yamada, Masatoshi

    2016-04-01

    135Cs/137Cs is a potential tracer for radiocesium source identification. However, due to the challenge to measure 135Cs, there were no 135Cs data available for Japanese environmental samples before the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. It was only 3 years after the accident that limited 135Cs values could be measured in heavily contaminated environmental samples. In the present study, activities of 134Cs, 135Cs, and 137Cs, along with their ratios in 67 soil and plant samples heavily and lightly contaminated by the FDNPP accident were measured by combining γ spectrometry with ICP-MS/MS. The arithmetic means of the 134Cs/137Cs activity ratio (1.033 ± 0.006) and 135Cs/137Cs atom ratio (0.334 ± 0.005) (decay corrected to March 11, 2011), from old leaves of plants collected immediately after the FDNPP accident, were confirmed to represent the FDNPP derived radiocesium signature. Subsequently, for the first time, trace 135Cs amounts before the FDNPP accident were deduced according to the contribution of global and FDNPP accident-derived fallout. Apart from two soil samples with a tiny global fallout contribution, contributions of global fallout radiocesium in other soil samples were observed to be 0.338%–52.6%. The obtained 135Cs/137Cs database will be useful for its application as a geochemical tracer in the future.

  14. 135Cs activity and 135Cs/137Cs atom ratio in environmental samples before and after the Fukushima Daiichi Nuclear Power Plant accident.

    PubMed

    Yang, Guosheng; Tazoe, Hirofumi; Yamada, Masatoshi

    2016-04-07

    (135)Cs/(137)Cs is a potential tracer for radiocesium source identification. However, due to the challenge to measure (135)Cs, there were no (135)Cs data available for Japanese environmental samples before the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. It was only 3 years after the accident that limited (135)Cs values could be measured in heavily contaminated environmental samples. In the present study, activities of (134)Cs, (135)Cs, and (137)Cs, along with their ratios in 67 soil and plant samples heavily and lightly contaminated by the FDNPP accident were measured by combining γ spectrometry with ICP-MS/MS. The arithmetic means of the (134)Cs/(137)Cs activity ratio (1.033 ± 0.006) and (135)Cs/(137)Cs atom ratio (0.334 ± 0.005) (decay corrected to March 11, 2011), from old leaves of plants collected immediately after the FDNPP accident, were confirmed to represent the FDNPP derived radiocesium signature. Subsequently, for the first time, trace (135)Cs amounts before the FDNPP accident were deduced according to the contribution of global and FDNPP accident-derived fallout. Apart from two soil samples with a tiny global fallout contribution, contributions of global fallout radiocesium in other soil samples were observed to be 0.338%-52.6%. The obtained (135)Cs/(137)Cs database will be useful for its application as a geochemical tracer in the future.

  15. 135Cs activity and 135Cs/137Cs atom ratio in environmental samples before and after the Fukushima Daiichi Nuclear Power Plant accident

    PubMed Central

    Yang, Guosheng; Tazoe, Hirofumi; Yamada, Masatoshi

    2016-01-01

    135Cs/137Cs is a potential tracer for radiocesium source identification. However, due to the challenge to measure 135Cs, there were no 135Cs data available for Japanese environmental samples before the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. It was only 3 years after the accident that limited 135Cs values could be measured in heavily contaminated environmental samples. In the present study, activities of 134Cs, 135Cs, and 137Cs, along with their ratios in 67 soil and plant samples heavily and lightly contaminated by the FDNPP accident were measured by combining γ spectrometry with ICP-MS/MS. The arithmetic means of the 134Cs/137Cs activity ratio (1.033 ± 0.006) and 135Cs/137Cs atom ratio (0.334 ± 0.005) (decay corrected to March 11, 2011), from old leaves of plants collected immediately after the FDNPP accident, were confirmed to represent the FDNPP derived radiocesium signature. Subsequently, for the first time, trace 135Cs amounts before the FDNPP accident were deduced according to the contribution of global and FDNPP accident-derived fallout. Apart from two soil samples with a tiny global fallout contribution, contributions of global fallout radiocesium in other soil samples were observed to be 0.338%–52.6%. The obtained 135Cs/137Cs database will be useful for its application as a geochemical tracer in the future. PMID:27052481

  16. 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.

  17. 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

  18. 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

  19. 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.

  20. 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

    2015-03-03

    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.

  1. 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

  2. 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

  3. 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.

  4. CRITICALITY CONTROL DURING THE DISMANTLING OF A URANIUM CONVERSION PLANT

    SciTech Connect

    LADURELLE, Laurent; LISBONNE, Pierre

    2003-02-27

    Within the Commissariat a l'Energie Atomique, in the Cadarache Research Center in southern France, the production at the Enriched Uranium Treatment Workshops started in 1965 and ended in 1995. The dismantling is in progress and will last until 2006. The decommissioning is planned in 2007. Since the authorized enrichment in 235U was 10% in some parts of the plant, and unlimited in others, the equipment and procedures were designed for criticality control during the operating period. Despite the best previous removing of the uranium in the inner parts of the equipment, evaluation of the mass of remaining fissile material by in site gamma spectrometry measurement shows that the safety of the ''clean up'' operations requires specific criticality control procedures, this mass being higher than the safe mass. The chosen method is therefore based on the mapping of fissile material in the contaminated parts of the equipment and on the respect of particular rules set for meeting the criticality control standards through mass control. The process equipment is partitioned in separated campaign, and for each campaign the equipment dismantling is conducted with a precise traceability of the pieces, from the equipment to the drum of waste, and the best final evaluation of the mass of fissile material in the drum. The first results show that the mass of uranium found in the dismantled equipment is less than the previous evaluation, and they enable us to confirm that the criticality was safely controlled during the operations. The mass of fissile material remaining in the equipment can be then carefully calculated, when it is lower than the minimal critical mass, and on the basis of a safety analysis, we will be free of any constraints regarding criticality control, this allowing to make procedures easier, and to speed up the operations.

  5. Temporal changes in radiocesium contamination derived from the Fukushima Dai-ichi Nuclear Power Plant accident in oceanic zooplankton in the western North Pacific.

    PubMed

    Kitamura, Minoru; Honda, Makio C; Hamajima, Yasunori; Kumamoto, Yuichiro; Aoyama, Michio; Kawakami, Hajime; Aono, Tatsuo; Fukuda, Miho; Mino, Yoshihisa

    2017-04-02

    We investigated temporal changes of the contamination of oceanic zooplankton with radiocesium ((134)Cs and (137)Cs) derived from the Fukushima Dai-ichi Nuclear Power Plant accident one month to three years after the accident at subarctic and subtropical stations (1900 and 900-1000 km from the plant, respectively) in the western North Pacific. The maximum activity concentrations of (137)Cs in zooplankton were two orders of magnitude higher than the pre-accident level. In the first four months after the accident, the activity concentrations of radiocesium in subtropical zooplankton decreased rapidly, but no similar change was observed at the subarctic station. The radiocesium derived from atmospheric deposition rapidly decreased as a result of seawater mixing. Thus, most of the subtropical zooplankton (with short lifespans) that had taken up radiocesium just after the accident were probably replaced by newly hatched zooplankton within four months of the accident, whereas subarctic zooplankton (with long lifespans) that were highly contaminated with radiocesium were still alive four months after the accident. By the end of the study, (137)Cs activity concentrations in subtropical zooplankton were still high, whereas the activity concentrations in subarctic zooplankton had decreased to nearly the pre-accident level. The former concentrations were probably influenced by a secondary supply of radiocesium via advection of subtropical mode water that was highly contaminated with Fukushima-derived radiocesium. Unexpectedly, at the subarctic station, the radiocesium activity concentrations in surface zooplankton were lower than those in subsurface zooplankton, whereas the opposite relationship was observed in surface and subsurface seawater. Because carnivores predominated in the subsurface zooplankton community, we hypothesize that the higher radiocesium activity concentrations in subsurface zooplankton were influenced by bioaccumulation. We conclude that radiocesium

  6. [Genetic disorders in house mice after the accident at Chernobyl power plant].

    PubMed

    Pomerantseva, M D; Ramaĭa, L K; Chekhovich, A V

    1997-01-01

    Genetic effects were studied in house mice caught from 1986 to 1994 in regions polluted by radionuclides as a result of the Chernobyl disaster. The dose rates of gamma-radiation on the soil surface ranged from 0.02 to 200 mR/h. The frequency of reciprocal translocations in mouse spermatocytes was relatively low, but increased with the dose rate. Embryo mortality was increased only in the progeny of male mice caught in 1987 in the area with maximum contamination. The frequency of mice heterozygous for recessive lethal mutations decreased with the time after the accident.

  7. [Genetic sequelae of the accident at the Chernobyl nuclear power plant in house mice (Mus musculus)].

    PubMed

    Pomerantseva, M D; Ramaĭa, L K; Chekhovich, A V

    1996-02-01

    Genetic disorders were studied in house mice caught from 1986 to 1993 in areas contaminated by radionuclides after the Chernobyl disaster. Dose rates on soil surface ranged from 0.02 to 200 mR/h. Frequency of reciprocal translocations in spermatocytes of the mice studied was relatively low, but increased with dose rate. In populations, frequency of mice heterozygous for recessive lethal mutations decreased with time after the accident. The data obtained allow us to assume that induced mutations may lead to elimination of germ cells and decreased viability in mice heterozygous for the mutations. These processes result in removing excess mutations from the population.

  8. Estimation of radionuclide ((137)Cs) emission rates from a nuclear power plant accident using the Lagrangian Particle Dispersion Model (LPDM).

    PubMed

    Park, Soon-Ung; Lee, In-Hye; Ju, Jae-Won; Joo, Seung Jin

    2016-10-01

    A methodology for the estimation of the emission rate of (137)Cs by the Lagrangian Particle Dispersion Model (LPDM) with the use of monitored (137)Cs concentrations around a nuclear power plant has been developed. This method has been employed with the MM5 meteorological model in the 600 km × 600 km model domain with the horizontal grid scale of 3 km × 3 km centered at the Fukushima nuclear power plant to estimate (137)Cs emission rate for the accidental period from 00 UTC 12 March to 00 UTC 6 April 2011. The Lagrangian Particles are released continuously with the rate of one particle per minute at the first level modelled, about 15 m above the power plant site. The presently developed method was able to simulate quite reasonably the estimated (137)Cs emission rate compared with other studies, suggesting the potential usefulness of the present method for the estimation of the emission rate from the accidental power plant without detailed inventories of reactors and fuel assemblies and spent fuels. The advantage of this method is not so complicated but can be applied only based on one-time forward LPDM simulation with monitored concentrations around the power plant, in contrast to other inverse models. It was also found that continuously monitored radionuclides concentrations from possibly many sites located in all directions around the power plant are required to get accurate continuous emission rates from the accident power plant. The current methodology can also be used to verify the previous version of radionuclides emissions used among other modeling groups for the cases of intermittent or discontinuous samplings.

  9. 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

  10. 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.

  11. 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)

  12. Internal radiation exposure dose in Iwaki city, Fukushima prefecture after the accident at Fukushima Dai-ichi Nuclear Power Plant.

    PubMed

    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.

  13. 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.

  14. Impact on ambient dose rate in metropolitan Tokyo from the Fukushima Daiichi Nuclear Power Plant accident.

    PubMed

    Inoue, Kazumasa; Tsuruoka, Hiroshi; Van Le, Tan; Arai, Moeko; Saito, Kyoko; Fukushi, Masahiro

    2016-07-01

    A car-borne survey was made in metropolitan Tokyo, Japan, in December 2014 to estimate external dose. This survey was conducted for all municipalities of Tokyo and the results were compared with measurements done in 2003. The ambient dose rate measured in the whole area of Tokyo in December 2014 was 60 nGy h(-1) (23-142 nGy h(-1)), which was 24% higher than the rate in 2003. Higher dose rates (>70 nGy h(-1)) were observed on the eastern and western ends of Tokyo; furthermore, the contribution ratio from artificial radionuclides ((134)Cs and (137)Cs) to ambient dose rate in eastern Tokyo was twice as high as that of western Tokyo. Based on the measured ambient dose rate, the effective dose rate after the accident was estimated to be 0.45 μSv h(-1) in Tokyo. This value was 22% higher than the value before the accident as of December 2014.

  15. 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.

  16. 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.

  17. 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.

  18. The generation of aerosols by accidents which may occur during plant-scale production of micro-organisms.

    PubMed Central

    Ashcroft, J.; Pomeroy, N. P.

    1983-01-01

    Experiments have been performed to simulate accidents which may occur during large-scale production of micro-organisms. Four types of accident, which were considered to be the most likely to result in the greatest hazard to health, were simulated using a bacterial model. The accidents were all concerned with faults occurring in the operation of the microbial fermenter. Gross contamination of surfaces occurred in all experiments, but only three types of accident produced a measurable aerosol. PMID:6350448

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

    PubMed

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

    2013-12-03

    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.

  20. 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

  1. State and future of super critical PC power plants

    SciTech Connect

    Kjaer, S.

    1996-12-31

    Construction work on two seawater-cooled 400 MW pulverized coal-fired and gas-fired power plants with advanced design parameters for operation in 1997 and 1998 has been initiated by the Danish power company ELSAM. Main steam pressure at the turbine inlet will be 285 Bar (4130 psia) and main steam temperature 580{degrees}C (1076{degrees}F). Double reheat is foreseen at 580{degrees}C (1076{degrees}F) and final feed water temperature will be 300{degrees}C (572{degrees}F). Net efficiency will be 47% on coal and 49% on gas. Information on the design of the super critical tower boilers and the five casing turbo-groups will be presented. ELSAM`s investigations into further improvements in the conversion from coal to electricity above an efficiency of 50% will also be presented. 8 refs., 5 figs.

  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.

  3. Visualization of Traffic Accidents

    NASA Technical Reports Server (NTRS)

    Wang, Jie; Shen, Yuzhong; Khattak, Asad

    2010-01-01

    Traffic accidents have tremendous impact on society. Annually approximately 6.4 million vehicle accidents are reported by police in the US and nearly half of them result in catastrophic injuries. Visualizations of traffic accidents using geographic information systems (GIS) greatly facilitate handling and analysis of traffic accidents in many aspects. Environmental Systems Research Institute (ESRI), Inc. is the world leader in GIS research and development. ArcGIS, a software package developed by ESRI, has the capabilities to display events associated with a road network, such as accident locations, and pavement quality. But when event locations related to a road network are processed, the existing algorithm used by ArcGIS does not utilize all the information related to the routes of the road network and produces erroneous visualization results of event locations. This software bug causes serious problems for applications in which accurate location information is critical for emergency responses, such as traffic accidents. This paper aims to address this problem and proposes an improved method that utilizes all relevant information of traffic accidents, namely, route number, direction, and mile post, and extracts correct event locations for accurate traffic accident visualization and analysis. The proposed method generates a new shape file for traffic accidents and displays them on top of the existing road network in ArcGIS. Visualization of traffic accidents along Hampton Roads Bridge Tunnel is included to demonstrate the effectiveness of the proposed method.

  4. 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.

  5. Evaluation of radiocesium concentrations in new leaves of wild plants two years after the Fukushima Dai-ichi Nuclear Power Plant accident.

    PubMed

    Sugiura, Yuki; Shibata, Michihiro; Ogata, Yoshimune; Ozawa, Hajime; Kanasashi, Tsutomu; Takenaka, Chisato

    2016-08-01

    Radiocesium ((137)Cs) transfer to plants immediately after the Fukushima Dai-ichi Nuclear Power Plant accident was investigated by collecting newly emerged leaf and soil samples between May 2011 and November 2012 from 20 sites in the Fukushima prefecture. Radiocesium concentrations in leaf and soil samples were measured to calculate concentration ratios (CR). Woody plants exhibited high CR values because (137)Cs deposited on stems and/or leaves were transferred to newly emerging tissues. The CR values in 2012 declined as compared to that in 2011. Exchangeable (137)Cs rates in soil (extraction rate) samples were measured at five sites. These rates decreased at four sites in 2012 and depended on environmental conditions and soil type. Both CR values and extraction rates decreased in 2012. However, CR values reflected the changes in extraction rates and characteristics of each species. Amaranthaceae, Chenopodiaceae, and Polygonaceae, which had been identified as Cs accumulators, presented no clear (137)Cs accumulation ability. In 2012, the perennial plant Houttuynia cordata and deciduous trees Chengiopanax sciadophylloides and Acer crataegifolium displayed high CR values, indicating that these species are (137)Cs accumulators and may be considered as potential species for phytoremediation.

  6. 75 FR 59899 - Endangered and Threatened Wildlife and Plants: Proposed Rulemaking To Designate Critical Habitat...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-28

    ... and Plants: Proposed Rulemaking To Designate Critical Habitat for Black Abalone; Proposed Rule #0;#0... Threatened Wildlife and Plants: Proposed Rulemaking To Designate Critical Habitat for Black Abalone AGENCY...), propose to designate approximately 390 square kilometers of critical habitat for the endangered...

  7. 77 FR 40705 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Buena Vista...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-10

    ... and Threatened Wildlife and Plants; Designation of Critical Habitat for Buena Vista Lake Shrew... Wildlife and Plants; Designation of Critical Habitat for Buena Vista Lake Shrew AGENCY: Fish and Wildlife... designation of critical habitat for the Buena Vista Lake shrew (Sorex ornatus relictus) under the...

  8. Estimation of immediate fallout after the accident at Fukushima Daiichi Nuclear Power Plant by using HPGe detector and EGS5 code.

    PubMed

    Unno, Yasuhiro; Yunoki, Akira; Sato, Yasushi; Hino, Yoshio

    2013-11-01

    After the accident at the Fukushima Daiichi nuclear power plant, we managed to carry out emergency measurements of the radioactive fallout. The included nuclides were identified via gamma-ray spectrometry using an HPGe detector. Quantifications of each radionuclide in the fallout were determined based on the efficiency calibrations and relevant corrections. The collected samples had a variety of shapes, densities, and compositions. EGS5 Monte Carlo code was used for the flexible estimation of these parameters. The measurement results show the temporal changes in the fallout quantity about a month after the accident.

  9. Health effects model for nuclear power plant accident consequence analysis. Part I. Introduction, integration, and summary. Part II. Scientific basis for health effects models

    SciTech Connect

    Evans, J.S.; Moeller, D.W.; Cooper, D.W.

    1985-07-01

    Analysis of the radiological health effects of nuclear power plant accidents requires models for predicting early health effects, cancers and benign thyroid nodules, and genetic effects. Since the publication of the Reactor Safety Study, additional information on radiological health effects has become available. This report summarizes the efforts of a program designed to provide revised health effects models for nuclear power plant accident consequence modeling. The new models for early effects address four causes of mortality and nine categories of morbidity. The models for early effects are based upon two parameter Weibull functions. They permit evaluation of the influence of dose protraction and address the issue of variation in radiosensitivity among the population. The piecewise-linear dose-response models used in the Reactor Safety Study to predict cancers and thyroid nodules have been replaced by linear and linear-quadratic models. The new models reflect the most recently reported results of the follow-up of the survivors of the bombings of Hiroshima and Nagasaki and permit analysis of both morbidity and mortality. The new models for genetic effects allow prediction of genetic risks in each of the first five generations after an accident and include information on the relative severity of various classes of genetic effects. The uncertainty in modeloling radiological health risks is addressed by providing central, upper, and lower estimates of risks. An approach is outlined for summarizing the health consequences of nuclear power plant accidents. 298 refs., 9 figs., 49 tabs.

  10. Experimental investigation on the chemical precipitation generation under the loss of coolant accident of nuclear power plants

    SciTech Connect

    Kim, C. H.; Sung, J. J.; Chung, Y. W.

    2012-07-01

    The PWR containment buildings are designed to facilitate core cooling in the event of a Loss of Coolant Accident (LOCA). The cooling process requires water discharged from the break and containment spray to be collected in a sump for recirculation. The containment sump contains screens to protect the components of the Emergency Core Cooling System (ECCS) and Containment Spray System (CSS) from debris. Since the containment materials may dissolve or corrode when exposed to the reactor coolant and spray solutions, various chemical precipitations can be generated in a post-LOCA environment. These chemical precipitations may become another source of debris loading to be considered in sump screen performance and downstream effects. In this study, new experimental methodology to predict the type and quantity of chemical precipitations has been developed. To generate the plant-specific chemical precipitation in a post-LOCA environment, the plant specific chemical condition of the recirculation sump during post-LOCA is simulated with the experimental reactor for the chemical effect. The plant-specific containment materials are used in the present experiment such as glass fibers, concrete blocks, aluminum specimens, and chemical reagent - boric acid, spray additives or buffering chemicals (sodium hydroxide, Tri-Sodium Phosphate (TSP), or others). The inside temperature of the reactor is controlled to simulate the plant-specific temperature profile of the recirculation sump. The total amount of aluminum released from aluminum specimens is evaluated by ICP-AES analysis to determine the amount of AlOOH and NaAlSi{sub 3}O{sub 8} which induce very adverse effect on the head loss across the sump screens. The amount of these precipitations generated in the present experimental study is compared with the results of WCAP-16530-NP-A. (authors)

  11. Feasibility study on phyto-remediation techniques for soil contaminated by the Fukushima Dai-Ichi nuclear power plant accident

    SciTech Connect

    Yuu Ishimori; Akihiro Sakoda; Mina Yamada; Yuko Makino; Satoshi Yamada; Hideyasu Fujiyama

    2013-07-01

    Tottori University and the Japan Atomic Energy Agency carried out jointly the feasibility study on phyto-remediation techniques, which apply to soil contaminated by the TEPCO's Fukushima Dai-ichi NPP accident. This paper illustrates the results from experimental investigations. Experimental investigations include both water-culture tests and field tests. Several plants, mainly halophytes that can specifically absorb more Na than K, and others like sunflower demonstrated for other domestic large-scale tests, were water-cultured and examined for screening. Easily cultivated and harvested plants without harmful effects on subsequent cultivation were also considered. New Zealand spinach was selected as a candidate for demonstrations in fields. The field tests were carried out at two sites of different agricultural types in Minami-soma, Fukushima prefecture. Concentration of {sup 137}Cs in soil is about 4.5 Bq/g-dry as the average of 10 cm depth. The aims of the field tests are to confirm absorption ability and environmental adaptation of the test plants and to document the cost and performance of projects. In conclusion, the absorption of {sup 137}Cs activity per unit area (Bq/m{sup 2}) by New Zealand spinach could be approximately 0.5%. To achieve an effective result in removal of {sup 137}Cs from soil in around a decade, it is required to find the plant which has ten or more times higher absorption capacity than New Zealand spinach. From the consistency of both results in water-culture and field tests, the water-culture test can be valid for screening. In addition, applicable sites will be limited to fields which are too steep or too narrow to use mechanical diggers, and which are free from any restrictions to enter. (authors)

  12. 137Cs dynamics in the forest of Fukushima after the nuclear power plant accident in March 2011

    NASA Astrophysics Data System (ADS)

    Endo, I.; Ohte, N.; Iseda, K.; Kobayashi, N.; Hirose, A.; Tanoi, K.

    2013-12-01

    The accident of Fukushima Daiichi nuclear power plant after the earthquake and Tsunami in March 11th 2011, caused large amount of radioactive Cesium (137Cs) emission into the environment. In the region of Fukushima Prefecture, forest dominates more than 70 % of the land area. River water from the forest area is used for food production and also for drinking water. Thus, it is important to understand the dynamics of 137Cs deposited in the forest to predict how the radioactive Cs diffuse and discharge from the forest catchments. We measured 137Cs concentration of the tree body, litter fall, throughfall, and stemflow, in order to clarify how 137Cs deposited on the above ground biomass of the forest are transported to the forest floor. We set forest site at the upstream part of Kami-Oguni River catchment, northern part of Fukushima Prefecture. Three plots (2 deciduous stands and 1 Japanese cedar (Cryptomeria japonica) plantation stand) were set in the forest site. Quercus serrata and C. japonica, which are representative tree species, were chosen at each plot and concentration of 137Cs on the bark, sapwood and heartwood were measured every 2 m from the ground to tree top. From each plot, 137Cs concentration of leaf litter was measured among species. Water samples of throughfall and stemflow were filtered and 137Cs concentration in suspended matter was measured. 137Cs was deposited on the bark of Q. serrata at high concentration (9-18 kBq/kg) but there were no clear relationship between tree height and concentration. 137Cs concentration of the sapwood (41 Bq/kg) was relatively higher than that of the heartwood (5 Bq/kg). It was suggested that 137Cs may be absorbed from bark and/or root. The concentration of 137Cs deposited in leaf litter varied from non-detected level to above 30 kBq/kg. The concentration was higher at evergreen tree than deciduous tree. It is considered that the litter of evergreen tree was derived from leaves on the tree canopy at the time of the

  13. Lessons Learned for Space Safety from the Fukushima Nuclear Power Plant Accident

    NASA Astrophysics Data System (ADS)

    Nogami, Manami; Miki, Masami; Mitsui, Masami; Kawada, Ysuhiro; Takeuchi, Nobuo

    2013-09-01

    On March 11 2011, Tohoku Region Pacific Coast Earthquake hit Japan and caused the devastating damage. The Fukushima Nuclear Power Station (NPS) was also severely damaged.The Japanese NPSs are designed based on the detailed safety requirements and have multiple-folds of hazard controls to the catastrophic hazards as in space system. However, according to the initial information from the Tokyo Electric Power Company (TEPCO) and the Japanese government, the larger-than-expected tsunami and subsequent events lost the all hazard controls to the release of radioactive materials.At the 5th IAASS, Lessons Learned from this disaster was reported [1] mainly based on the "Report of the Japanese Government to the IAEA Ministerial Conference on Nuclear Safety" [2] published by Nuclear Emergency Response Headquarters in June 2011, three months after the earthquake.Up to 2012 summer, the major investigation boards, including the Japanese Diet, the Japanese Cabinet and TEPCO, published their final reports, in which detailed causes of this accident and several recommendations are assessed from each perspective.In this paper, the authors examine to introduce the lessons learned to be applied to the space safety as findings from these reports.

  14. Evaluation of vegetables in Tsukuba for contamination with radioactive materials from the accident at Fukushima Daiichi nuclear power plant.

    PubMed

    Isobe, Tomonori; Mori, Yutaro; Takada, Kenta; Sato, Eisuke; Takahashi, Hideki; Sekiguchi, Takao; Yoshimura, Yousuke; Sakurai, Hideyuki; Sakae, Takeji

    2013-10-01

    A large amount of radioactive material was released into the atmosphere after the accident of the Fukushima Daiichi Nuclear Power Plant following the Tohoku earthquake on 11 March 2011, and traces of these materials were detected in Tsukuba. Because radioactive materials can adhere to vegetables, the authors made a qualitative evaluation of vegetables in Tsukuba, estimated internal exposure dose based on quantitative measurement results, and investigated several decontamination methods. Qualitative analysis of vegetable contamination was done by autoradiography. Quantitative analysis was done using a high-purity germanium detector. To assess decontamination, two methods were tested: one with running water and the other with boiling water. In addition, boiled soup stock was measured. In the qualitative evaluation by autoradiography, radioactive materials were not uniformly distributed but adhered to vegetables in clumps and hot spots. In the quantitative evaluation to measure contamination of outer and inner leaves of sanchu lettuce, it was observed that the concentration of I was 8,031.35 ± 764.79 Bq kg in the outer leaves and 115.28 ± 20.63 Bq kg in the inner leaves. In addition, the concentration of Cs was 1,371.93 ± 366.45 Bq kg in the outer leaves and 9.68 ± 15.03 Bq kg in the inner leaves. This suggests that one can greatly reduce internal exposure dose by removing the outer leaves if one has to eat vegetables just after a nuclear accident. In the decontamination assessment, a decontamination efficiency of up to 70% was achieved by boiling vegetables for 20 min.

  15. Radiological impact of TEPCO's Fukushima Dai-ichi Nuclear Power Plant accident on invertebrates in the coastal benthic food web.

    PubMed

    Sohtome, Tadahiro; Wada, Toshihiro; Mizuno, Takuji; Nemoto, Yoshiharu; Igarashi, Satoshi; Nishimune, Atsushi; Aono, Tatsuo; Ito, Yukari; Kanda, Jota; Ishimaru, Takashi

    2014-12-01

    Radioactive cesium ((134)Cs and (137)Cs) concentrations in invertebrates of benthic food web (10 taxonomic classes with 46 identified families) collected from wide areas off Fukushima Prefecture (3-500 m depth) were inspected from July 2011, four months after the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident, to August 2013 to elucidate time-series trends among taxa and areas. Cesium-137 was detected in seven classes (77% of 592 specimens). Higher (137)Cs concentrations within detected data were often found in areas near or south of the FDNPP, which is consistent with the reported spatial distribution of (137)Cs concentrations in highly contaminated seawater and sediments after the FDNPP accident. Overall (137)Cs concentrations in invertebrates, the maxima of which (290 Bq kg(-1)-wet in the sea urchin Glyptocidaris crenularis) were lower than in many demersal fishes, had decreased exponentially with time, and exhibited taxon-specific decreasing trends. Concentrations in Bivalvia and Gastropoda decreased clearly with respective ecological half-lives of 188 d and 102 d. In contrast, decreasing trends in Malacostraca and Polychaeta were more gradual, with longer respective ecological half-lives of 208 d and 487 d. Echinoidea showed no consistent trend, presumably because of effects of contaminated sediments taken into their digestive tract. Comparison of (137)Cs concentrations in the invertebrates and those in seawater and sediments suggest that contaminated sediments are the major source of continuing contamination in benthic invertebrates, especially in Malacostraca and Polychaeta.

  16. Over Three years of Monitoring 129I spread in Pacific Ocean After the 2011 Fukushima Daiichi Nuclear Power Plant Accident

    NASA Astrophysics Data System (ADS)

    Chang, C. C.; Burr, G.; Jull, A. J. T.; Priyadarshi, A.; Thiemens, M. H.; Biddulph, D.; Russell, J. L.

    2014-12-01

    129I is a long-lived radionuclide that has been used as a useful environmental tracer. At present, the global 129I in surface water is about 1-2 orders of magnitude higher than pre-1990 levels. The anthropogenic 129I signal produced from industrial nuclear fuel reprocessing plants is known to be the primary source of 129I in marine surface waters of the Atlantic, and elevated 129I values are found globally. The Great East Japan Earthquake and the induced tsunami in 2011 triggered the nuclear shutdowns, failures, and partial meltdowns of Fukushima Daiichi Nuclear Power Plant. The accident resulted in a series of radioactive material releases into the environment and spread out through atmospheric and ocean circulation. We will present 129I results of water samples collected weekly near Scripps Institution of Oceanography, San Diego, CA for the past 3 years. We also have several measurements collected a year apart from Kaohsiung, Taiwan, which represent west margin of Pacific Ocean, and from Alaska, Washington, and Oregon. By establishing 129I time series, we can observe the spread of 129I in the surface waters of the Pacific Ocean that resulted from the accidental releases.

  17. Radiological and geophysical changes around the Fukushima Daiichi Nuclear Power Plant since the accident to the present time

    NASA Astrophysics Data System (ADS)

    Kolotkov, Gennady

    2013-04-01

    Detailed analysis of accidental released of radioactive material from Fukushima Daiichi nuclear power plant has shown that long-lived radionuclides add considerable support for intensity of ion formation. Based on the results of airborne monitoring by MEXT and DOE (total surface deposition of Cs134 and Cs137 inside 80 km zone of Fukushima Daiichi NPP) it has been calculated the spatial distribution of the intensity of ion formation and atmospheric electric conductivity. The evidence of plutonium in the Fukushima radioactive trace allows calculates the concentration of small, intermediate and large ions. The results show the excess of these parameters by several orders of magnitude since the accident to the present time. For example the concentration of small air ion in the area of Chernobyl is 7±2?102 cm-3, the Fukushima Daiichi NPP ones is 1.3?106 cm-3. The difference in the atmospheric bipolar electric conductivity is about 24 fS/m between the Chernobyl and the Fukushima Daiichi ones. The evaluation technique was used after Chernobyl disaster allows to make an analysis of ecological, hygiene requirements and other problems into the troposphere and on the soil intensity of ion formation in the area of Fukushima Daiichi nuclear power plant. The standard ion air differ by four orders of magnitude in the case for Fukushima Daiichi ones. Comparative study of the radiophysical characteristics of the atmosphere with the analogous ones in Chernobyl and application of identification of various types of the air pollution is discussed.

  18. Global risk from the atmospheric dispersion of radionuclides by nuclear power plant accidents in the coming decades

    NASA Astrophysics Data System (ADS)

    Christoudias, T.; Proestos, Y.; Lelieveld, J.

    2013-11-01

    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 implemented constant continuous emissions from each location in the model and simulated atmospheric transport and removal via dry and wet deposition processes over 20 yr (2010-2030), driven by boundary conditions based on the IPCC A2 future emissions scenario. We present global overall and seasonal risk maps for potential surface layer concentrations and ground deposition of radionuclides, and estimate potential dosages to humans from the inhalation and the exposure to ground deposited radionuclides. We find that the risk of harmful doses due to inhalation is typically highest during boreal winter due to relatively shallow boundary layer development and reduced mixing. Based on the continued operation of the current nuclear power plants, we calculate that the risk of radioactive contamination to the citizens of the USA will remain to be highest worldwide, followed by India and France. By including stations under construction and those that are planned and proposed our results suggest that the risk will become highest in China, followed by India and the USA.

  19. Global risk from the atmospheric dispersion of radionuclides by nuclear power plant accidents in the coming decades

    NASA Astrophysics Data System (ADS)

    Christoudias, T.; Proestos, Y.; Lelieveld, J.

    2014-05-01

    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 implemented constant continuous emissions from each location in the model and simulated atmospheric transport and removal via dry and wet deposition processes over 20 years (2010-2030), driven by boundary conditions based on the IPCC A2 future emissions scenario. We present global overall and seasonal risk maps for potential surface layer concentrations and ground deposition of radionuclides, and estimate potential doses to humans from inhalation and ground-deposition exposures to radionuclides. We find that the risk of harmful doses due to inhalation is typically highest in the Northern Hemisphere during boreal winter, due to relatively shallow boundary layer development and limited mixing. Based on the continued operation of the current nuclear power plants, we calculate that the risk of radioactive contamination to the citizens of the USA will remain to be highest worldwide, followed by India and France. By including stations under construction and those that are planned and proposed, our results suggest that the risk will become highest in China, followed by India and the USA.

  20. Global Risk from the Atmospheric Dispersion of Radionuclides by Nuclear Power Plant Accidents in the Coming Decades

    NASA Astrophysics Data System (ADS)

    Christoudias, T.; Proestos, Y.; Lelieveld, J.

    2014-12-01

    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 implemented constant continuous emissions from each location in the model and simulated atmospheric transport and removal via dry and wet deposition processes over 20 years (2010-2030), driven by boundary conditions based on the IPCC A2 future emissions scenario. We present global overall and seasonal risk maps for potential surface layer concentrations and ground deposition of radionuclides, and estimate potential doses to humans from inhalation and ground-deposition exposures to radionuclides. We find that the risk of harmful doses due to inhalation is typically highest in the Northern Hemisphere during boreal winter, due to relatively shallow boundary layer development and limited mixing. Based on the continued operation of the current nuclear power plants, we calculate that the risk of radioactive contamination to the citizens of the USA will remain to be highest worldwide, followed by India and France. By including stations under construction and those that are planned and proposed, our results suggest that the risk will become highest in China, followed by India and the USA.

  1. Radiocesium concentrations in wild mushrooms collected in Kawauchi Village after the accident at the Fukushima Daiichi Nuclear Power Plant

    PubMed Central

    Nakashima, Kanami; Orita, Makiko; Fukuda, Naoko; Taira, Yasuyuki; Hayashida, Naomi; Matsuda, Naoki

    2015-01-01

    It is well known from the experience after the 1986 accident at the Chernobyl Nuclear Power Plant that radiocesium tends to concentrate in wild mushrooms. In this study, we collected wild mushrooms from the Kawauchi Village of Fukushima Prefecture, located within 30 km of the Fukushima Daiichi Nuclear Power Plant, and evaluated their radiocesium concentrations to estimate the risk of internal radiation exposure in local residents. We found that radioactive cesium exceeding 100 Bq/kg was detected in 125 of 154 mushrooms (81.2%). We calculated committed effective doses based on 6,278 g per year (age > 20 years, 17.2 g/day), the average intake of Japanese citizens, ranging from doses of 0.11–1.60 mSv, respectively. Although committed effective doses are limited even if residents eat contaminated foods several times, we believe that comprehensive risk-communication based on the results of the radiocesium measurements of food, water, and soil is necessary for the recovery of Fukushima after this nuclear disaster. PMID:26623189

  2. A comprehensive dose evaluation project concerning animals affected by the Fukushima Daiichi Nuclear Power Plant accident: its set-up and progress.

    PubMed

    Takahashi, Shintaro; Inoue, Kazuya; Suzuki, Masatoshi; Urushihara, Yusuke; Kuwahara, Yoshikazu; Hayashi, Gohei; Shiga, Soichiro; Fukumoto, Motoi; Kino, Yasushi; Sekine, Tsutomu; Abe, Yasuyuki; Fukuda, Tomokazu; Isogai, Emiko; Yamashiro, Hideaki; Fukumoto, Manabu

    2015-12-01

    It is not an exaggeration to say that, without nuclear accidents or the analysis of radiation therapy, there is no way in which we are able to quantify radiation effects on humans. Therefore, the livestock abandoned in the ex-evacuation zone and euthanized due to the Fukushima Daiichi Nuclear Power Plant (FNPP) accident are extremely valuable for analyzing the environmental pollution, its biodistribution, the metabolism of radionuclides, dose evaluation and the influence of internal exposure. We, therefore, sought to establish an archive system and to open it to researchers for increasing our understanding of radiation biology and improving protection against radiation. The sample bank of animals affected by the FNPP accident consists of frozen tissue samples, formalin-fixed paraffin-embedded specimens, dose of radionuclides deposited, etc., with individual sampling data.

  3. A comprehensive dose evaluation project concerning animals affected by the Fukushima Daiichi Nuclear Power Plant accident: its set-up and progress

    PubMed Central

    Takahashi, Shintaro; Inoue, Kazuya; Suzuki, Masatoshi; Urushihara, Yusuke; Kuwahara, Yoshikazu; Hayashi, Gohei; Shiga, Soichiro; Fukumoto, Motoi; Kino, Yasushi; Sekine, Tsutomu; Abe, Yasuyuki; Fukuda, Tomokazu; Isogai, Emiko; Yamashiro, Hideaki; Fukumoto, Manabu

    2015-01-01

    It is not an exaggeration to say that, without nuclear accidents or the analysis of radiation therapy, there is no way in which we are able to quantify radiation effects on humans. Therefore, the livestock abandoned in the ex-evacuation zone and euthanized due to the Fukushima Daiichi Nuclear Power Plant (FNPP) accident are extremely valuable for analyzing the environmental pollution, its biodistribution, the metabolism of radionuclides, dose evaluation and the influence of internal exposure. We, therefore, sought to establish an archive system and to open it to researchers for increasing our understanding of radiation biology and improving protection against radiation. The sample bank of animals affected by the FNPP accident consists of frozen tissue samples, formalin-fixed paraffin-embedded specimens, dose of radionuclides deposited, etc., with individual sampling data. PMID:26687285

  4. Aerial Radiation Measurements from the Fukushima Dai-ichi Nuclear Power Plant Accident

    SciTech Connect

    Guss, P. P.

    2012-07-16

    This document is a slide show type presentation concerning DOE and Aerial Measuring System (AMS) activities and results with respect to assessing the consequences of the releases from the Fukushima Dai-ichi Nuclear Power Plant. These include ground monitoring and aerial monitoring.

  5. Isotopic Pu, Am and Cm signatures in environmental samples contaminated by the Fukushima Dai-ichi Nuclear Power Plant accident.

    PubMed

    Yamamoto, M; Sakaguchi, A; Ochiai, S; Takada, T; Hamataka, K; Murakami, T; Nagao, S

    2014-06-01

    Dust samples from the sides of roads (black substances) have been collected together with litter and soil samples at more than 100 sites contaminated heavily in the 20-km exclusion zones around Fukushima Dai-ichi Nuclear Power Plant (FDNPP) (Minamisoma City, and Namie, Futaba and Okuma Towns), in Iitate Village located from 25 to 45 km northwest of the plant and in southern areas from the plant. Isotopes of Pu, Am and Cm have been measured in the samples to evaluate their total releases into the environment from the FDNPP and to get the isotopic compositions among these nuclides. For black substances and litter samples, in addition to Pu isotopes, (241)Am, (242)Cm and (243,244)Cm were determined for most of samples examined, while for soil samples, only Pu isotopes were determined. The results provided a coherent data set on (239,240)Pu inventories and isotopic composition among these transuranic nuclides. When these activity ratios were compared with those for fuel core inventories in the FDNPP accident estimated by a group at JAEA, except (239,240)Pu/(137)Cs activity ratios, fairly good agreements were found, indicating that transuranic nuclides, probably in the forms of fine particles, were released into the environment without their large fractionations. The obtained data may lead to more accurate information about the on-site situation (e.g., burn-up, conditions of fuel during the release phase, etc.), which would be difficult to get otherwise, and more detailed information on the dispersion and deposition processes of transuranic nuclides and the behavior of these nuclides in the environment.

  6. A model for the release, dispersion and environmental impact of a postulated reactor accident from a submerged commercial nuclear power plant

    NASA Astrophysics Data System (ADS)

    Bertch, Timothy Creston

    1998-12-01

    Nuclear power plants are inherently suitable for submerged applications and could provide power to the shore power grid or support future underwater applications. The technology exists today and the construction of a submerged commercial nuclear power plant may become desirable. A submerged reactor is safer to humans because the infinite supply of water for heat removal, particulate retention in the water column, sedimentation to the ocean floor and inherent shielding of the aquatic environment would significantly mitigate the effects of a reactor accident. A better understanding of reactor operation in this new environment is required to quantify the radioecological impact and to determine the suitability of this concept. The impact of release to the environment from a severe reactor accident is a new aspect of the field of marine radioecology. Current efforts have been centered on radioecological impacts of nuclear waste disposal, nuclear weapons testing fallout and shore nuclear plant discharges. This dissertation examines the environmental impact of a severe reactor accident in a submerged commercial nuclear power plant, modeling a postulated site on the Atlantic continental shelf adjacent to the United States. This effort models the effects of geography, decay, particle transport/dispersion, bioaccumulation and elimination with associated dose commitment. The use of a source term equivalent to the release from Chernobyl allows comparison between the impacts of that accident and the postulated submerged commercial reactor plant accident. All input parameters are evaluated using sensitivity analysis. The effect of the release on marine biota is determined. Study of the pathways to humans from gaseous radionuclides, consumption of contaminated marine biota and direct exposure as contaminated water reaches the shoreline is conducted. The model developed by this effort predicts a significant mitigation of the radioecological impact of the reactor accident release

  7. Artificial radionuclides in surface air in Finland following the Fukushima Dai-ichi nuclear power plant accident.

    PubMed

    Leppänen, Ari-Pekka; Mattila, Aleksi; Kettunen, Markku; Kontro, Riitta

    2013-12-01

    We present observations of radionuclides released during the Fukushima Dai-ichi nuclear power plant accident in ambient air and in deposition made in Finland during March-May 2011. The first observed fission product was (131)I, which arrived in Finland 8-9 days after the accident. Detections of (137)Cs and (134)Cs were made 2-3 days after the first (131)I observations. The highest concentrations of fission products in Finland were observed during March 31st and April 1st. The highest observed concentrations of the following isotopes were: (131)I (10.6 ± 0.4 mBq/m(3)), (134)Cs (0.397 ± 0.020 mBq/m(3)), (137)Cs (0.405 ± 0.017 mBq/m(3)), (136)Cs (28 ± 2 μBq/m(3)), (129)Te (129 ± 9 μBq/m(3)), (129m)Te (234 ± 20 μBq/m(3)), (132)Te (51 ± 3 μBq/m(3)) and (132)I (54 ± 3 μBq/m(3)). Generally, higher concentrations of fission product were observed in Southern Finland than in Northern Finland. The variations in the (137)Cs and (134)Cs activity concentration data suggest that three separate plumes passed over Finland with decreasing concentrations. The first plume, with highest cesium concentrations, passed over Finland during March 31st - April 2nd, the second plume during April 4th - 6th and the third and smallest one during April 10th - April 11th. Both aerosol and gaseous iodine fractions were sampled simultaneously and thus an accurate view of the behaviour of aerosol and gaseous fractions was obtained. Large variations between different fractions were observed with the gaseous fraction representing 65-98% of the total (131)I. The (134)Cs/(137)Cs ratio was determined to be 0.99 ± 0.10, which indicates a fuel burnup of approximately 30 MWd/t. The (136)Cs/(137)Cs and (129m)Te/(132)Te ratios were used to estimate the time lapse after the accident. The differences between true time lapse and the ones deduced from the isotope ratios were from the correct time lapse to 0-3 days for (136)Cs/(137)Cs and 5 days for (129m)Te/(132)Te, respectively. Radionuclides from

  8. Thermodynamic evaluation of the solidification phase of molten core-concrete under estimated Fukushima Daiichi nuclear power plant accident conditions

    NASA Astrophysics Data System (ADS)

    Kitagaki, Toru; Yano, Kimihiko; Ogino, Hideki; Washiya, Tadahiro

    2017-04-01

    The solidification phases of molten core-concrete under the estimated molten core-concrete interaction (MCCI) conditions in the Fukushima Daiichi Nuclear Power Plant Unit 1 were predicted using the thermodynamic equilibrium calculation tool, FactSage 6.2, and the NUCLEA database in order to contribute toward the 1F decommissioning work and to understand the accident progression via the analytical results for the 1F MCCI products. We showed that most of the U and Zr in the molten core-concrete forms (U,Zr)O2 and (Zr,U)SiO4, and the formation of other phases with these elements is limited. However, the formation of (Zr,U)SiO4 requires a relatively long time because it involves a change in the crystal structure from fcc-(U,Zr)O2 to tet-(U,Zr)O2, followed by the formation of (Zr,U)SiO4 by reaction with SiO2. Therefore, the formation of (Zr,U)SiO4 is limited under quenching conditions. Other common phases are the oxide phases, CaAl2Si2O8, SiO2, and CaSiO3, and the metallic phases of the Fe-Si and Fe-Ni alloys. The solidification phenomenon of the crust under quenching conditions and that of the molten pool under thermodynamic equilibrium conditions in the 1F MCCI progression are discussed.

  9. Mineralogical and geomicrobial examination of soil contamination by radioactive Cs due to 2011 Fukushima Daiichi Nuclear Power Plant accident

    NASA Astrophysics Data System (ADS)

    Akai, Junji; Nomura, Nao; Matsushita, Shin; Kudo, Hisaaki; Fukuhara, Haruo; Matsuoka, Shiro; Matsumoto, Jinko

    Soil contamination by radioactive Cs from Fukushima Daiichi Nuclear Power Plant accident was investigated. Absorption and desorption experiments of Cs were conducted for several phyllosillicates (kaolinite, sericite, montmorillonite, vermiculite, chrysotile and biotite), zeolite and solid organic matter (dead and green leaves). The results confirmed the characteristic sorption and desorption of Cs by these materials. The 2:1 type phyllosilicate, especially, vermiculite and montmorillonite absorbed Cs well. Heated vermiculite for agricultural use and weathered montmorillonite also adsorbed Cs. Leaves also absorbed Cs considerably but easily desorbed it. In summary, the relative capacity and strength of different materials for sorption of Cs followed the order: zeolite (clinoptilolite) > 2:1 type clay mineral > 1:1 type clay mineral > dead and green leaves. Culture experiments using bacteria of both naturally living on dead leaves in Iitate village, Fukushima Pref. and bacterial strains of Bacillus subtillis, Rhodococus erythropolis, Streptomyces aomiensis and Actinomycetospora chlora were carried out. Non-radioactive 1% Cs solution (CsCl) was added to the culture media. Two types of strong or considerable bacterial uptakes of Cs were found in bacterial cells. One is that Cs was contained mainly as globules inside bacteria and the other is that Cs was absorbed in the whole bacterial cells. The globules consisted mainly of Cs and P. Based on all these results, future diffusion and re-circulation behavior of Cs in the surface environment was discussed.

  10. Temporal changes in radiocesium deposition in various forest stands following the Fukushima Dai-ichi Nuclear Power Plant accident.

    PubMed

    Kato, Hiroaki; Onda, Yuichi; Hisadome, Keigo; Loffredo, Nicolas; Kawamori, Ayumi

    2017-01-01

    In this study, we investigated the transfer of canopy-intercepted radiocesium to the forest floor following the Fukushima Dai-ichi Nuclear Power Plant accident. The (137)Cs content of throughfall, stemflow, and litterfall were monitored in two coniferous stands (plantations of Japanese cedar) and a deciduous mixed broad-leaved forest stand (oak with red pine) from July 2011 to December 2012. The forest floor of cedar stands had received higher levels of additional (137)Cs deposition compared with the mixed broad-leaved stand during the sampling period. The cumulative (137)Cs deposition during the study period was 119 kBq m(-2) for the mature cedar stand, 105 kBq m(-2) for the young cedar stand, and 41.5 kBq m(-2) for the broad-leaved stand. The deposition of (137)Cs to the forest floor occurred mainly in throughfall during the first rainy season, from July to September 2011 (<200 d after the initial fallout); thereafter, the transfer of (137)Cs from the canopy to forest floor occurred mainly through litterfall. A double exponential field-loss model, which was used to simulate the removal of (137)Cs from canopies, was the best fit for the temporal changes in the canopy (137)Cs inventory.

  11. Numerical reconstruction of high dose rate zones due to the Fukushima Dai-ichi Nuclear Power Plant accident.

    PubMed

    Katata, Genki; Terada, Hiroaki; Nagai, Haruyasu; Chino, Masamichi

    2012-09-01

    To understand how the high dose rate zones were created during the Fukushima Dai-ichi Nuclear Power Plant (FNPP1) accident on March 2011, the atmospheric dispersion of radionuclides during the period from 15 to 17 March was reproduced by using a computer-based nuclear emergency response system, WSPEEDI-II. With use of limited environmental monitoring data, prediction accuracy of meteorological and radiological fields by the system was improved to obtain best estimates of release rates, radiation dose maps, and plume movements. A large part of current high dose rate zones in Fukushima was explained by simulated surface deposition of radionuclides due to major releases of radionuclides on 15 March. In the simulation, the highest dose rate zones to the northwest of FNPP1 were created by a significant deposition of radionuclides discharged from FNPP1 during the afternoon. The results indicate that two environmental factors, i.e., rainfall and topography, strongly affected the spatial patterns of surface deposition of radionuclides. The wet deposition due to rainfall particularly played an important role in the formation of wide and heterogeneous distributions of high dose rate zones. The simulation also demonstrated that the radioactive plume flowed along the valleys to its leeward, which can expand the areas of a large amount of surface deposition in complex topography.

  12. U.S. EPA response to the Fukushima Daiichi Nuclear Power Plant accident.

    PubMed

    Tupin, Edward A; Boyd, Michael A; Mosser, Jennifer E; Wieder, Jessica S

    2012-05-01

    During the spring of 2011, the U.S. Environmental Protection Agency (EPA) used its national radiation monitoring and sampling system, RadNet, to detect, identify, and inform the public about radioactive material in the United States resulting from Japan's Fukushima Daiichi Nuclear Power Plant release. The RadNet system monitors ambient air, drinking water, precipitation, and pasteurized milk for radionuclides. To supplement its existing stationary (fixed) continuous air monitoring system, EPA deployed additional air monitors to Saipan, Guam, and locations in the western United States. The Agency also accelerated the regular quarterly sampling of milk and drinking water and collected an additional round of samples. For two months, staff located at EPA's Headquarters Emergency Operations Center, west coast regional offices, and National Air and Radiation Environmental Lab worked seven days a week to handle the increased radiochemical sample analysis from air filters, precipitation, drinking water, and milk; provide interagency scientific input; and answer press and public inquiries. EPA's data was consistent with what was expected from the Fukushima Daiichi Nuclear Power Plant release. The levels of radioactivity were so low that the readings from the near-real-time RadNet air monitors stayed within normal background ranges. Detailed sample analyses were needed to identify the radionuclides associated with the release. Starting at the end of April and continuing through May 2011, levels of radioactive material decreased as expected.

  13. National Plant Germplasm System: Critical Role of Customer Service

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The National Plant Germplasm System (NPGS) conserves plant genetic resources, not only for use by future generations, but for immediate use by scientists and educators around the world. With a great deal of interaction between genebank curators and users of plant genetic resources, customer service...

  14. Physical properties, structure, and shape of radioactive Cs from the Fukushima Daiichi Nuclear Power Plant accident derived from soil, bamboo and shiitake mushroom measurements.

    PubMed

    Niimura, Nobuo; Kikuchi, Kenji; Tuyen, Ninh Duc; Komatsuzaki, Masakazu; Motohashi, Yoshinobu

    2015-01-01

    We conducted an elution experiment with contaminated soils using various aqueous reagent solutions and autoradiography measurements of contaminated bamboo shoots and shiitake mushrooms to determine the physical and chemical characteristics of radioactive Cs from the Fukushima Daiichi Nuclear Power Plant accident. Based on our study results and data in the literature, we conclude that the active Cs emitted by the accident fell to the ground as granular non-ionic materials. Therefore, they were not adsorbed or trapped by minerals in the soil, but instead physically adhere to the rough surfaces of the soil mineral particles. Granular Cs* can be transferred among media, such as soils and plants. The physical properties and dynamic behavior of the granular Cs* is expected to be helpful in considering methods for decontamination of soil, litter, and other media.

  15. World Meteorological Organization's model simulations of the radionuclide dispersion and deposition from the Fukushima Daiichi nuclear power plant accident.

    PubMed

    Draxler, Roland; Arnold, Dèlia; Chino, Masamichi; Galmarini, Stefano; Hort, Matthew; Jones, Andrew; Leadbetter, Susan; Malo, Alain; Maurer, Christian; Rolph, Glenn; Saito, Kazuo; Servranckx, René; Shimbori, Toshiki; Solazzo, Efisio; Wotawa, Gerhard

    2015-01-01

    Five different atmospheric transport and dispersion model's (ATDM) deposition and air concentration results for atmospheric releases from the Fukushima Daiichi nuclear power plant accident were evaluated over Japan using regional (137)Cs deposition measurements and (137)Cs and (131)I air concentration time series at one location about 110 km from the plant. Some of the ATDMs used the same and others different meteorological data consistent with their normal operating practices. There were four global meteorological analyses data sets available and two regional high-resolution analyses. Not all of the ATDMs were able to use all of the meteorological data combinations. The ATDMs were configured identically as much as possible with respect to the release duration, release height, concentration grid size, and averaging time. However, each ATDM retained its unique treatment of the vertical velocity field and the wet and dry deposition, one of the largest uncertainties in these calculations. There were 18 ATDM-meteorology combinations available for evaluation. The deposition results showed that even when using the same meteorological analysis, each ATDM can produce quite different deposition patterns. The better calculations in terms of both deposition and air concentration were associated with the smoother ATDM deposition patterns. The best model with respect to the deposition was not always the best model with respect to air concentrations. The use of high-resolution mesoscale analyses improved ATDM performance; however, high-resolution precipitation analyses did not improve ATDM predictions. Although some ATDMs could be identified as better performers for either deposition or air concentration calculations, overall, the ensemble mean of a subset of better performing members provided more consistent results for both types of calculations.

  16. Applying STAMP in Accident Analysis

    NASA Technical Reports Server (NTRS)

    Leveson, Nancy; Daouk, Mirna; Dulac, Nicolas; Marais, Karen

    2003-01-01

    Accident models play a critical role in accident investigation and analysis. Most traditional models are based on an underlying chain of events. These models, however, have serious limitations when used for complex, socio-technical systems. Previously, Leveson proposed a new accident model (STAMP) based on system theory. In STAMP, the basic concept is not an event but a constraint. This paper shows how STAMP can be applied to accident analysis using three different views or models of the accident process and proposes a notation for describing this process.

  17. Radiological impact of the nuclear power plant accident on freshwater fish in Fukushima: An overview of monitoring results.

    PubMed

    Wada, Toshihiro; Tomiya, Atsushi; Enomoto, Masahiro; Sato, Toshiyuki; Morishita, Daigo; Izumi, Shigehiko; Niizeki, Kouji; Suzuki, Shunji; Morita, Takami; Kawata, Gyo

    2016-01-01

    Radionuclide ((131)I, (134)Cs, and (137)Cs) concentrations of monitored freshwater fish species collected from different habitats (rivers, lakes, and culture ponds) in Fukushima Prefecture during March 2011-December 2014 (total 16 species, n = 2692) were analyzed to present a detailed description of radionuclide contamination after the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident, and to elucidate species-specific spatiotemporal declining trends of (137)Cs concentration for their respective habitats. Low concentrations of (131)I (≤24 Bq kg(-1)-wet) were detected from only 11 samples collected during March-June 2011, demonstrating that (131)I transferred to freshwater fish were not intense. In river and lake fishes, a more gradual decrease and higher radiocesium ((134)Cs, (137)Cs) concentrations were observed than in culture pond fishes, which strongly implied that radiocesium in freshwater fish species was mainly bioaccumulated through the food web in the wild. During 2011-2014, percentages above the Japanese regulatory limit of 100 Bq kg(-1)-wet for radiocesium in river and lake fish (14.0% and 39.6%, respectively) were higher than in monitored marine fish (9.9%), indicating longer-term contamination of freshwater fish species, especially in lakes. Higher radiocesium concentrations (maximum 18.7 kBq kg(-1)-wet in Oncorhynchus masou) were found in the northwestern areas from the FDNPP with higher deposition. However, radiocesium contamination levels were regarded as 1-2 orders of magnitude less than those after the Chernobyl accident. Lagged increase of (137)Cs concentration and longer ecological half-lives (Teco: 1.2-2.6 y in the central part of Fukushima Prefecture) were observed in carnivorous salmonids (O. masou, Salvelinus leucomaenis), whereas a rapid increase and decrease of (137)Cs concentration and shorter Teco (0.99 and 0.69 y) were found in herbivorous and planktivorous osmerids (Plecoglossus altivelis, Hypomesus nipponensis) with

  18. Investigation report on the powered platform lift-truck accident at the U.S. Department of Energy Pinellas Plant on January 28, 1991, in Area 119 West

    SciTech Connect

    Not Available

    1991-02-01

    This investigation was performed to collect and examine the evidence associated with an incident occurring on a platform lift-truck inside Building 100 at Pinellas Plant on January 28, 1991. The incident resulted in head injuries to the employee operating the device. The direct cause of the accident was operation of the platform lift-truck in an area incompatible with its design, i.e., in an area with low overhead obstructions.

  19. Retrospective dosimetry after criticality accidents using low-frequency EPR: a study of whole human teeth irradiated in a mixed neutron and gamma-radiation field.

    PubMed

    Zdravkova, M; Crokart, N; Trompier, F; Asselineau, B; Gallez, B; Gaillard-Lecanu, E; Debuyst, R

    2003-08-01

    In the context of accidental or intentional radiation exposures (nuclear terrorism), it is essential to separate rapidly those individuals with substantial exposures from those with exposures that do not constitute an immediate threat to health. Low-frequency electron paramagnetic resonance (EPR) spectroscopy provides the potential advantage of making accurate and sensitive measurements of absorbed radiation dose in teeth without removing the teeth from the potential victims. Up to now, most studies focused on the dose-response curves obtained for gamma radiation. In radiation accidents, however, the contribution of neutrons to the total radiation dose should not be neglected. To determine how neutrons contribute to the apparent dose estimated by EPR dosimetry, extracted whole human teeth were irradiated at the SILENE reactor in a mixed neutron and gamma-radiation field simulating criticality accidents. The teeth were irradiated in free air as well as in a paraffin head phantom. Lead screens were also used to eliminate to a large extent the contribution of the gamma radiation to the dose received by the teeth. The EPR signals, obtained with a low-frequency (1.2 GHz) spectrometer, were compared to dosimetry measurements at the same location. The contribution of neutrons to the EPR dosimetric signal was negligible in the range of 0 to 10 Gy and was rather small (neutron/gamma-ray sensitivity in the range 0-0.2) at higher doses. This indicates that the method essentially provides information on the dose received from the gamma-ray component of the radiation.

  20. Variation of uranium isotopic composition in soil within the JCO grounds from the 30 September 1999 criticality accident at JCO, Tokai-mura, Japan.

    PubMed

    Yamamoto, Masayoshi; Kawabata, Yoshiko; Murata, Yoshimasa; Komura, Kazuhisa

    2002-08-01

    Following the 30 September 1999 criticality accident at JCO, 29 surface and 3 core soil samples were collected inside and outside the JCO grounds to evaluate possible contamination by 235U-enriched uranium (18.8%) being handled at the time of the accident. Uranium (234U, 235U, and 238U) and thorium (228Th, 230Th, and 232Th) isotopes were determined by alpha-spectrometry and ICP-MS after radiochemical separation. Concentrations of 238U and 234U ranged from 11.3 to 63.5 and 11.6 to 360 mBq g(-1), respectively. Higher amounts of 238U and/or 234U were found in the vicinity of the uranium conversion building. The calculated 234U/235U activity ratios ranged from a 1.0 radioactive equilibrium value to an unusually high 5.7 value. Several of the soil samples showed considerably higher 235U/238U atomic ratios (1.06-4.37%) than 0.725% for natural uranium. Based on the assumption that measured U-series nuclides in soil samples taken from the JCO grounds were almost at radioactive equilibrium up to 230Th, excess uranium could be calculated for each sample. The results suggest that the excess uranium in the soils have lower 235U/238U atomic ratios (a few %) than the 18.8% enrichment of the precipitation tank uranium.

  1. Determination of radionuclides produced by neutrons in heavily exposed workers of the JCO criticality accident in Tokai-mura for estimating an individual's neutron fluence.

    PubMed

    Muramatsu, Y; Noda, Y; Yonehara, H; Ishigure, N; Yoshida, S; Yukawa, M; Tagami, K; Ban-Nai, T; Uchida, S; Hirama, T; Akashi, M; Nakamura, Y

    2001-09-01

    In the Tokai-mura criticality accident, three workers were heavily exposed. Biological materials, such as blood, urine, vomit and hair, were collected from the workers and analyzed for radioactivities, produced by the neutron irradiation. Activation products. such as 24Na, -K and 82Br, were found in these materials by gamma-ray spectrometry. The radionuclide of the highest activity observed in biological materials was 24Na, e.g. the concentrations of this nuclide in the blood samples from the three patients at the accident time were 169, 92 and 23 Bq/ml, respectively. The concentrations of stable sodium in the same samples were determined by ICP-AES to obtain specific activities of 24Na (concentration ratio between the produced 24Na and stable 23Na), which are essential for estimating the neutron fluences and radiation doses. The specific activities of 24Na obtained for the three patients through the blood analysis were 8.2 x 10(4),4.3 x 10(4) and 1.2 x 10(4) Bq24Na/g23Na. Based on these values, individual's neutron fluences were estimated to be 5.7 x 10(11), 3.0 x 10(-1) and 0.85 x 10(11) cm(-2), respectively.

  2. Radiocesium transfer from hillslopes to the Pacific Ocean after the Fukushima Nuclear Power Plant accident: A review.

    PubMed

    Evrard, Olivier; Laceby, J Patrick; Lepage, Hugo; Onda, Yuichi; Cerdan, Olivier; Ayrault, Sophie

    2015-10-01

    The devastating tsunami triggered by the Great East Japan Earthquake on March 11, 2011 inundated the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) resulting in a loss of cooling and a series of explosions releasing the largest quantity of radioactive material into the atmosphere since the Chernobyl nuclear accident. Although 80% of the radionuclides from this accidental release were transported over the Pacific Ocean, 20% were deposited over Japanese coastal catchments that are subject to frequent typhoons. Among the radioisotopes released during the FDNPP accident, radiocesium ((134)Cs and (137)Cs) is considered the most serious current and future health risk for the local population. The goal of this review is to synthesize research relevant to the transfer of FDNPP derived radiocesium from hillslopes to the Pacific Ocean. After radiocesium fallout deposition on vegetation and soils, the contamination may remain stored in forest canopies, in vegetative litter on the ground, or in the soil. Once radiocesium contacts soil, it is quickly and almost irreversibly bound to fine soil particles. The kinetic energy of raindrops instigates the displacement of soil particles, and their bound radiocesium, which may be mobilized and transported with overland flow. Soil erosion is one of the main processes transferring particle-bound radiocesium from hillslopes through rivers and streams, and ultimately to the Pacific Ocean. Accordingly this review will summarize results regarding the fundamental processes and dynamics that govern radiocesium transfer from hillslopes to the Pacific Ocean published in the literature within the first four years after the FDNPP accident. The majority of radiocesium is reported to be transported in the particulate fraction, attached to fine particles. The contribution of the dissolved fraction to radiocesium migration is only relevant in base flows and is hypothesized to decline over time. Owing to the hydro-meteorological context of the

  3. Radiocesium Transfer in Forest Insect Communities after the Fukushima Dai-ichi Nuclear Power Plant Accident

    PubMed Central

    Hayashi, Seiji; Takamura, Noriko

    2017-01-01

    To understand radiocesium transfer in the forest insect food web, we investigated the activity concentrations of radiocesium in forest insects in the Fukushima and Ibaraki Prefectures approximately 1.5–2.5 years after the Fukushima Dai-ichi Nuclear Power Plant. We analyzed 34 species of insects sampled from 4 orders and 4 feeding functional groups (herbivore, carnivore, omnivore, and detritivore) from three sites in each prefecture. 137Cs activity concentrations were lowest in herbivorous species and were especially high in detritivorous and omnivorous species that feed on forest litter and fungi. Radiocesium activity concentrations in any given species reflected the degree of contamination of that species’ primary food sources since radiocesium activity concentrations were found to be the lowest in leaves and grass and the highest in litter, bark, and fungi. This study confirmed that litter and other highly contaminated forest components such as fungi, decaying wood, bryophytes, and lichens serve as sources of 137Cs transfer into the forest insect community. PMID:28125745

  4. Radioactive fallout in the United States due to the Fukushima nuclear plant accident.

    PubMed

    Thakur, P; Ballard, S; Nelson, R

    2012-05-01

    The release of radioactivity into the atmosphere from the damaged Fukushima Daiichi nuclear power plant started on March 12th, 2011. Among the various radionuclides released, iodine -131 ((131)I) and cesium isotopes ((137)Cs and (134)Cs) were transported across the Pacific Ocean and reached the United States on 17-18 March 2011. Consequently, an elevated level of fission products (131)I, (132)I, (132)Te, (134)Cs and (137)Cs were detected in air, water, and milk samples collected across the United States between March 17 and April 4, 2011. The continuous monitoring of activities over a period of 25 days and spatial variations across more than 100 sampling locations in the United States made it possible to characterize the contaminated air masses. For the entire period, the highest detected activity values ranged from less than 1 m Bq m(-3) to 31 m Bq m(-3) for the particulate (131)I, and up to 96 m Bq m(-3) for the gaseous (131)I fraction.

  5. The Critical Role of Potassium in Plant Stress Response

    PubMed Central

    Wang, Min; Zheng, Qingsong; Shen, Qirong; Guo, Shiwei

    2013-01-01

    Agricultural production continues to be constrained by a number of biotic and abiotic factors that can reduce crop yield quantity and quality. Potassium (K) is an essential nutrient that affects most of the biochemical and physiological processes that influence plant growth and metabolism. It also contributes to the survival of plants exposed to various biotic and abiotic stresses. The following review focuses on the emerging role of K in defending against a number of biotic and abiotic stresses, including diseases, pests, drought, salinity, cold and frost and waterlogging. The availability of K and its effects on plant growth, anatomy, morphology and plant metabolism are discussed. The physiological and molecular mechanisms of K function in plant stress resistance are reviewed. This article also evaluates the potential for improving plant stress resistance by modifying K fertilizer inputs and highlights the future needs for research about the role of K in agriculture. PMID:23549270

  6. Accident source terms for light-water nuclear power plants using high-burnup or MOX fuel.

    SciTech Connect

    Salay, Michael; Gauntt, Randall O.; Lee, Richard Y.; Powers, Dana Auburn; Leonard, Mark Thomas

    2011-01-01

    Representative accident source terms patterned after the NUREG-1465 Source Term have been developed for high burnup fuel in BWRs and PWRs and for MOX fuel in a PWR with an ice-condenser containment. These source terms have been derived using nonparametric order statistics to develop distributions for the timing of radionuclide release during four accident phases and for release fractions of nine chemical classes of radionuclides as calculated with the MELCOR 1.8.5 accident analysis computer code. The accident phases are those defined in the NUREG-1465 Source Term - gap release, in-vessel release, ex-vessel release, and late in-vessel release. Important differences among the accident source terms derived here and the NUREG-1465 Source Term are not attributable to either fuel burnup or use of MOX fuel. Rather, differences among the source terms are due predominantly to improved understanding of the physics of core meltdown accidents. Heat losses from the degrading reactor core prolong the process of in-vessel release of radionuclides. Improved understanding of the chemistries of tellurium and cesium under reactor accidents changes the predicted behavior characteristics of these radioactive elements relative to what was assumed in the derivation of the NUREG-1465 Source Term. An additional radionuclide chemical class has been defined to account for release of cesium as cesium molybdate which enhances molybdenum release relative to other metallic fission products.

  7. 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.

  8. 78 FR 38895 - Endangered and Threatened Wildlife and Plants; Threatened Status and Designation of Critical...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-28

    ... Wildlife and Plants; Threatened Status and Designation of Critical Habitat for Eriogonum codium (Umtanum... reopening of the comment period on our May 15, 2012, proposed listing and designation of critical habitat... (proposed designation of critical habitat) for Umtanum desert buckwheat and White Bluffs bladderpod;...

  9. 77 FR 37867 - Endangered and Threatened Wildlife and Plants; Proposed Rulemaking To Revise Critical Habitat for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-25

    ... Wildlife and Plants; Proposed Rulemaking To Revise Critical Habitat for Hawaiian Monk Seals AGENCY.... ACTION: Proposed rule; notice of 6-month extension of the deadline for a final critical habitat... Register on June 2, 2011, proposing to revise critical habitat for the Hawaiian monk seal under...

  10. Determination of 32P in urine for early estimation of the neutron exposure level for three victims of the JCO criticality accident.

    PubMed

    Nishimura, Yoshikazu; Takeda, Hiroshi; Miyamoto, Kiriko; Watanabe, Yoshito; Kouno, Fuyuki; Kuroda, Noriko; Kim, Hee Sun; Yukawa, Masae

    2002-03-01

    In the criticality accident which occurred on 30 September 1999 at a uranium conversion facility in Tokai-mura, Japan, three workers were severely exposed to neutron and gamma-ray irradiation. Preliminary estimations of doses from blood properties and 24Na concentration in blood were 16-20, 6-10 and 1-4 gamma-ray gray-equivalent (gammaGyEq) respectively for the three workers. For apparent dose estimation, neutron-induced radionuclides in biological materials such as blood, hair and urine were measured. Accordingly, we detected 32p in urine samples. The concentration ratios of 32P in the urine for the three workers showed a similar tendency to those of 24Na in blood. This result indicated that the radioactivity of 32P in urine could be used to estimate the neutron exposure level.

  11. Evaluation of potential severe accidents during low power and shutdown operations at Grand Gulf, Unit 1: Evaluation of severe accident risks for plant operational state 5 during a refueling outage. Supporting MELCOR calculations, Volume 6, Part 2

    SciTech Connect

    Kmetyk, L.N.; Brown, T.D.

    1995-03-01

    To gain a better understanding of the risk significance of low power and shutdown modes of operation, the Office of Nuclear Regulatory Research at the NRC established programs to investigate the likelihood and severity of postulated accidents that could occur during low power and shutdown (LP&S) modes of operation at commercial nuclear power plants. To investigate the likelihood of severe core damage accidents during off power conditions, probabilistic risk assessments (PRAs) were performed for two nuclear plants: Unit 1 of the Grand Gulf Nuclear Station, which is a BWR-6 Mark III boiling water reactor (BWR), and Unit 1 of the Surry Power Station, which is a three-loop, subatmospheric, pressurized water reactor (PWR). The analysis of the BWR was conducted at Sandia National Laboratories while the analysis of the PWR was performed at Brookhaven National Laboratory. This multi-volume report presents and discusses the results of the BWR analysis. The subject of this part presents the deterministic code calculations, performed with the MELCOR code, that were used to support the development and quantification of the PRA models. The background for the work documented in this report is summarized, including how deterministic codes are used in PRAS, why the MELCOR code is used, what the capabilities and features of MELCOR are, and how the code has been used by others in the past. Brief descriptions of the Grand Gulf plant and its configuration during LP&S operation and of the MELCOR input model developed for the Grand Gulf plant in its LP&S configuration are given.

  12. The accident at the Fukushima Daiichi Nuclear Power Plant in 2011.

    PubMed

    Tominaga, Takako; Hachiya, Misao; Tatsuzaki, Hideo; Akashi, Makoto

    2014-06-01

    A huge earthquake struck the northeast coast of the main island of Japan on 11 March 2011, triggering a tsunami with more than 10-m-high waves hitting the area. The earthquake was followed by numerous sustained aftershocks. The earthquake and aftershocks left almost 16,000 people dead and more than 2,800 missing (as of 11 March 2014). The earthquake affected the Fukushima Daiichi Nuclear Power Plant (NPP) of Tokyo Electric Power Company (TEPCO), causing serious damage to the NPP and resulting in large amounts of radioactive materials being released into not only controlled areas but also the environment. Damage was caused to the cooling systems of the NPP, although they automatically shut down after the earthquake. The trouble with the cooling systems led to hydrogen explosions and core meltdown. The major nuclides released on land were ¹³¹I, ¹³⁴Cs, and ¹³⁷Cs. The release of these radioactive materials resulted in contamination of first responders and workers and also a high ambient dose of radiation around the NPP. The local hospital system, including that for radiation emergency medicine, was dysfunctional. Hospitals that had been designated as radiation emergency facilities were not able to function because the earthquake and tsunami had caused damage to their facilities; some of these were located within a 20-km radius of the NPP and in the evacuation areas. Local fire department personnel were also ordered to evacuate. Fukushima prefecture changed the screening level required for decontamination from 13,000 to 100,000 cpm, with decontamination by wiping being performed for over 13,000 cpm. However, as hospitals and fire departments had to abide by lower levels than that of the prefecture for receiving or transporting contaminated patients, these personnel could not accept or transport contaminated people from the NPPs. In addition, hospitals not designated as radiation emergency facilities would not receive patients from the NPPs because of concerns

  13. 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.

  14. Modeling of leachable 137Cs in throughfall and stemflow for Japanese forest canopies after Fukushima Daiichi Nuclear Power Plant accident.

    PubMed

    Loffredo, Nicolas; Onda, Yuichi; Kawamori, Ayumi; Kato, Hiroaki

    2014-09-15

    The Fukushima accident dispersed significant amounts of radioactive cesium (Cs) in the landscape. Our research investigated, from June 2011 to November 2013, the mobility of leachable Cs in forests canopies. In particular, (137)Cs and (134)Cs activity concentrations were measured in rainfall, throughfall, and stemflow in broad-leaf and cedar forests in an area located 40 km from the power plant. Leachable (137)Cs loss was modeled by a double exponential (DE) model. This model could not reproduce the variation in activity concentration observed. In order to refine the DE model, the main physical measurable parameters (rainfall intensity, wind velocity, and snowfall occurrence) were assessed, and rainfall was identified as the dominant factor controlling observed variation. A corrective factor was then developed to incorporate rainfall intensity in an improved DE model. With the original DE model, we estimated total (137)Cs loss by leaching from canopies to be 72 ± 4%, 67 ± 4%, and 48 ± 2% of the total plume deposition under mature cedar, young cedar, and broad-leaf forests, respectively. In contrast, with the improved DE model, the total (137)Cs loss by leaching was estimated to be 34 ± 2%, 34 ± 2%, and 16 ± 1% of the total plume deposition under mature cedar, young cedar, and broad-leaf forests, respectively. The improved DE model corresponds better to observed data in literature. Understanding (137)Cs and (134)Cs forest dynamics is important for forecasting future contamination of forest soils around the FDNPP. It also provides a basis for understanding forest transfers in future potential nuclear disasters.

  15. (14)C levels in the vicinity of the Fukushima Dai-ichi Nuclear Power Plant prior to the 2011 accident.

    PubMed

    Xu, Sheng; Cook, Gordon T; Cresswell, Alan J; Dunbar, Elaine; Freeman, Stewart P H T; Hastie, Helen; Hou, Xiaolin; Jacobsson, Piotr; Naysmith, Philip; Sanderson, David C W; Tripney, Brian G; Yamaguchi, Katsuhiko

    2016-06-01

    A 50-year-old Japanese cedar (Cryptomeria japonica) from Okuma, ∼1 km southwest of the Fukushima Dai-ichi Nuclear Power Plant, was cored and each annual ring was analysed for (14)C. The (14)C specific activity values varied from 330.4 Bq kg(-1) C in the tree ring formed in 1971 to 231.2 Bq kg(-1) C in the 2014 ring. During the periods 1971-1976 and 2011-2014, the (14)C specific activities are indistinguishable from the ambient background values. However, compared with the ambient atmospheric levels, the (14)C specific activities between 1977 and 2010 are significantly elevated, clearly indicating (14)C discharges from the reactors during their normal operations. In addition, the specific activities are positively correlated with the annual electricity generation values. The excess (14)C specific activities were <36 Bq kg(-1) C, corresponding to an additional annual effective dose of <2 μSv via the food ingestion pathway in the study location. The primary wind direction is east-southeast/southeast with a frequency of ∼30%, in comparison to ∼20% frequency for the direction of the site under study (north-northeast/northeast). This would tend to indicate a similar magnitude of additional effective dose and consequently no significant radiological impact of atmospheric (14)C discharges from the FDNPP during the entire period of normal operations. Additionally, no (14)C pulse in activity can be observed in the year 2011 ring. This might be caused by a limited (14)C release from the damaged reactors during the accident or that the prevailing wind during the short period of release (11th-25th March 2011) was not in the direction of Okuma.

  16. Radioactive Cs-137 discharge from Headwater Forested Catchment in Fukushima after Fukushima Dai-ichi Nuclear Power Plant Accident

    NASA Astrophysics Data System (ADS)

    Iwagami, S.; Onda, Y.; Tsujimura, M.; Sakakibara, K.; Konuma, R.

    2015-12-01

    Radiocesium migration from headwater forested catchment is important perception as output from the forest which is also input to the subsequent various land use and downstream rivers after Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident. In this study, Cs-137 concentration of dissolved water, suspended sediment and coarse organic matter such as leaf and branch were monitored. Discharge amount of stream water, suspended sediment and coarse organic matter were measured to investigate the discharge amount of radiocesium and composition of radiocesium discharge form through the headwater stream. Observation were conducted at stream site in four headwater catchments in Yamakiya district, located ~35 km north west of FDNPP from June 2011 (suspended sediment and coarse organic matter: August 2012) to December 2014.The Cs-137 concentration of dissolved water was around 1Bq/l at June 2011. Then declined to 0.1 Bq/l at December 2011. And in December 2014, it declined to 0.01 Bq/l order. Declining trend of Cs-137 concentration in dissolved water was expressed in double exponential model. Also temporary increase was observed in dissolved Cs-137 during the rainfall event. The Cs-137 concentration of suspended sediment and coarse organic matter were 170-49000 Bq/kg and 350-14000 Bq/kg respectably. The Cs-137 concentration of suspended sediment showed good correlation with average deposition density of catchment. The effect of decontamination works appeared in declining of Cs-137 concentration in suspended sediment. Contribution rate of Cs-137 discharge by suspended sediment was 96-99% during a year. Total annual Cs-137 discharge from the catchment were 0.02-0.3% of the deposition.

  17. External doses to 350 m zone residents due to anisotropic radiation from the JCO criticality accident in Tokai-mura.

    PubMed

    Takada, J

    2001-09-01

    The validity of a method for individual dose reconstruction based on the anisotropic radiation distribution was confirmed by a comparison with the dose from Na-24 whole-body counting for seven persons at a neighboring company located on the western side of the JCO campus. The successful coincidence between Di (Na-24) and Di (present) also supports the validity of the second version of D(r) reported by the Head Office of Countermeasure. The present dose reconstruction for the 350 m zone at the western side showed an average value of 0.7 mSv and a maximal value of 3.1 mSv, as indoor-dose under the assumption of an effective transmittance of 0.4 for all of the houses. If all of the residents in 350 m zone were indoors during the accident, 83% of them might have received external doses of less than 1 mSv. The radiation exposure to the nearest residential area in the southern-west direction was significantly reduced with phi(theta(i)) between 0.4 and 0.2 by several buildings on the JCO campus. The present study on the public dose confirms that the official report on the public dose (the maximal value of 21 mSv for individual doses) from Head Office of Countermeasure is significantly overestimated due to their isotropic treatment of radiation from the source.

  18. Plant Mediator complex and its critical functions in transcription regulation.

    PubMed

    Yang, Yan; Li, Ling; Qu, Li-Jia

    2016-02-01

    The Mediator complex is an important component of the eukaryotic transcriptional machinery. As an essential link between transcription factors and RNA polymerase II, the Mediator complex transduces diverse signals to genes involved in different pathways. The plant Mediator complex was recently purified and comprises conserved and specific subunits. It functions in concert with transcription factors to modulate various responses. In this review, we summarize the recent advances in understanding the plant Mediator complex and its diverse roles in plant growth, development, defense, non-coding RNA production, response to abiotic stresses, flowering, genomic stability and metabolic homeostasis. In addition, the transcription factors interacting with the Mediator complex are also highlighted.

  19. Estimation of the time-dependent radioactive source-term from the Fukushima nuclear power plant accident using atmospheric transport modelling

    NASA Astrophysics Data System (ADS)

    Schoeppner, M.; Plastino, W.; Budano, A.; De Vincenzi, M.; Ruggieri, F.

    2012-04-01

    Several nuclear reactors at the Fukushima Dai-ichi power plant have been severely damaged from the Tōhoku earthquake and the subsequent tsunami in March 2011. Due to the extremely difficult on-site situation it has been not been possible to directly determine the emissions of radioactive material. However, during the following days and weeks radionuclides of 137-Caesium and 131-Iodine (amongst others) were detected at monitoring stations throughout the world. Atmospheric transport models are able to simulate the worldwide dispersion of particles accordant to location, time and meteorological conditions following the release. The Lagrangian atmospheric transport model Flexpart is used by many authorities and has been proven to make valid predictions in this regard. The Flexpart software has first has been ported to a local cluster computer at the Grid Lab of INFN and Department of Physics of University of Roma Tre (Rome, Italy) and subsequently also to the European Mediterranean Grid (EUMEDGRID). Due to this computing power being available it has been possible to simulate the transport of particles originating from the Fukushima Dai-ichi plant site. Using the time series of the sampled concentration data and the assumption that the Fukushima accident was the only source of these radionuclides, it has been possible to estimate the time-dependent source-term for fourteen days following the accident using the atmospheric transport model. A reasonable agreement has been obtained between the modelling results and the estimated radionuclide release rates from the Fukushima accident.

  20. INITIAL AND PRESENT SITUATION OF FOOD CONTAMINATION IN JAPAN AFTER THE ACCIDENT AT THE FUKUSHIMA DAI-ICHI NUCLEAR POWER PLANT.

    PubMed

    Aono, Tatsuo; Yoshida, Satoshi; Akashi, Makoto

    2016-09-01

    The accident at the Fukushima Dai-ichi Nuclear Power Plant (NPP) in March 2011 affected not only the terrestrial environment of Fukushima prefecture and the surrounding area, but also the marine area facing the NPP. Our present study is focused on the concentrations of radionuclides in agricultural products of Fukushima and sea-foods collected off Fukushima after the accident. The regulation value for radiocesium in vegetables, meat and fish was revised from 500 Bq/kg-wet to 100 Bq/kg-wet on 1 April 2012. The overall activity of radiocesium in these products was found to be within the limit of tolerance in respect to Japanese and also international regulations, but there is still radiocesium found at activities greater than this level in edible wild plants, wild mushrooms and game such as boar meat. Although the activities of radionuclides exceeding the regulatory limits were not detected in marine products collected off Fukushima after April 2015, the commercial marine fishery has not received approval in the affected areas except for certain species. We learned from the Fukushima accident that long-term kinetic studies of radionuclides in terrestrial and marine environments is extremely important for prevention of internal contamination, since contamination with radionuclides occurs via the food chain in the environment.

  1. Simulation of ¹³⁷Cs transport and deposition after the Chernobyl Nuclear Power Plant accident and radiological doses over the Anatolian peninsula.

    PubMed

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

    2014-11-15

    The Chernobyl Nuclear Power Plant (CNPP) accident occurred on April 26 of 1986, it is still an episode of interest, due to the large amount of radionuclides dispersed in the atmosphere. Caesium-137 ((137)Cs) is one of the main radionuclides emitted during the Chernobyl accident, with a half-life of 30years, which can be accumulated in humans and animals, and for this reason the impacts on population are still monitored today. One of the main parameters in order to estimate the exposure of population to (137)Cs is the concentration in the air, during the days after the accident, and the deposition at surface. The transport and deposition of (137)Cs over Europe occurred after the CNPP accident has been simulated using the WRF-HYSPLIT modeling system. Four different vertical and temporal emission rate profiles have been simulated, as well as two different dry deposition velocities. The model simulations could reproduce fairly well the observations of (137)Cs concentrations and deposition, which were used to generate the 'Atlas of Caesium deposition on Europe after the Chernobyl accident' and published in 1998. An additional focus was given on (137)Cs deposition and air concentrations over Turkey, which was one of the main affected countries, but not included in the results of the Atlas. We estimated a total deposition of 2-3.5 PBq over Turkey, with 2 main regions affected, East Turkey and Central Black Sea coast until Central Anatolia, with values between 10 kBq m(-2) and 100 kBq m(-2). Mean radiological effective doses from simulated air concentrations and deposition has been estimated for Turkey reaching 0.15 mSv/year in the North Eastern part of Turkey, even if the contribution from ingestion of contaminated food and water is not considered, the estimated levels are largely below the 1 mSv limit indicated by the International Commission on Radiological Protection.

  2. Plutonium Finishing Plant (PFP) Criticality Alarm System Commercial Grade Item (CGI) Critical Characteristics

    SciTech Connect

    WHITE, W.F.

    1999-09-16

    This document specifies the critical characteristics for Commercial Grade Items (CGI) procured for PFP's criticality alarm system as required by HNF-PRO-268 and HNF-PRO-1819. These are the minimum specifications that the equipment must meet in order to properly perform its safety function. There may be several manufacturers or models that meet the critical characteristics for any one item. PFP's Criticality Alarm System includes the nine criticality alarm system panels and their associated hardware. This includes all parts up to the first breaker in the electrical distribution system. Specific system boundaries and justifications are contained in HNF-SD-CP-SDD-003, ''Definition and Means of Maintaining the Criticality Detectors and Alarms Portion of the PFP Safety Envelope.'' The procurement requirements associated with the system necessitates procurement of some system equipment as Commercial Grade Items in accordance with HNF-PRO-268, ''Control of Purchased Items and Services.''

  3. Physical dosimetry and biological indicators of carcinogenic risk in a cohort of persons exposed to unhealthy ecological factors following the Chernobyl Nuclear Power Plant accident.

    PubMed

    Orel, V E; Tereschenki, V M; Czyatkovskaya, N N; Mazepa, M G; Buzunov, V A

    1998-01-01

    The April 1986 Chernobyl Nuclear Power Plant accident caused ecological changes in the Ovruch State forests in the Zhytomir oblast in the Ukraine. The highest radioactivity existed in moss, followed by the pine-forest substrate and soil. During 1984-1985, the pine needles were primarily surface contaminated, whereas during 1986-1988, they were contaminated secondarily. Radioactivity in air was highest (1.07+/-0.185 Bq/l) during dry and sunny weather and when trees were felled; the lowest levels (0.196+/-0.044 Bq/l) occurred during periods of stable snow coverage. Between 1987 and 1989 (i.e., after the Chernobyl accident), the caesium levels in forestry employees exceeded by 13.9-fold the average levels found in the Ukrainian Polessje population. Ovruch forest guards and woodcutters had the highest effective equivalent doses of radiation, and they therefore exhibited the highest carcinogenic risk.

  4. Global and local cancer risks after the Fukushima Nuclear Power Plant accident as seen from Chernobyl: a modeling study for radiocaesium ((134)Cs &(137)Cs).

    PubMed

    Evangeliou, Nikolaos; Balkanski, Yves; Cozic, Anne; Møller, Anders Pape

    2014-03-01

    The accident at the Fukushima Daiichi Nuclear Power Plant (NPP) in Japan resulted in the release of a large number of fission products that were transported worldwide. We study the effects of two of the most dangerous radionuclides emitted, (137)Cs (half-life: 30.2years) and (134)Cs (half-life: 2.06years), which were transported across the world constituting the global fallout (together with iodine isotopes and noble gasses) after nuclear releases. The main purpose is to provide preliminary cancer risk estimates after the Fukushima NPP accident, in terms of excess lifetime incident and death risks, prior to epidemiology, and compare them with those occurred after the Chernobyl accident. Moreover, cancer risks are presented for the local population in the form of high-resolution risk maps for 3 population classes and for both sexes. The atmospheric transport model LMDZORINCA was used to simulate the global dispersion of radiocaesium after the accident. Air and ground activity concentrations have been incorporated with monitoring data as input to the LNT-model (Linear Non-Threshold) frequently used in risk assessments of all solid cancers. Cancer risks were estimated to be small for the global population in regions outside Japan. Women are more sensitive to radiation than men, although the largest risks were recorded for infants; the risk is not depended on the sex at the age-at-exposure. Radiation risks from Fukushima were more enhanced near the plant, while the evacuation measures were crucial for its reduction. According to our estimations, 730-1700 excess cancer incidents are expected of which around 65% may be fatal, which are very close to what has been already published (see references therein). Finally, we applied the same calculations using the DDREF (Dose and Dose Rate Effectiveness Factor), which is recommended by the ICRP, UNSCEAR and EPA as an alternative reduction factor instead of using a threshold value (which is still unknown). Excess lifetime cancer

  5. Dynamic and Spatio-temporal variability of leachable 137Cs by throughfall and stemflow in Japanese forest canopies after Fukushima Daiichi Nuclear Power Plant accident

    NASA Astrophysics Data System (ADS)

    Loffredo, Nicolas; Onda, Yuichi; Patin, Jeremy; Kawamori, Ayumi; Kato, Hiroaki

    2014-05-01

    In the context of Fukushima Daiichi Nuclear Power Plant Accident (FDNPPA), this study focuses on the mobility of leachable Caesium by throughfall and stemflow mechanisms in forests canopies, for the period going from June 2011 (four months after the accident), and until April 2013. In this period, 137Cs and 134Cs activity has been periodically measured, in an area located at 40 km from the power plant, in rainfall, throughfall and stemflow for broad-leaf and cedar forests. Specifically, our study deals with the seasonal effect, the dynamic and the spatio-temporal variability on leachable Cs in these forests. Except for rainfall intensity, no weather impact (wind velocity and snow fall episodes) was observed for the Cs loss. Concerning the seasonal effect, two periods for which Cs significantly increased could be identify: autumn and spring. During the period of investigation, compared to stemflow, the main flux of Cs was induced by throughfall mechanisms, whereas for rainfall, no Cs was detected. By using a double exponential model, the Cs loss by throughfall and stemflow was estimated from the initial deposition to 2 years after the accident. Since the accident, the total Cs loss by leaching was estimated to 35-70%, 31-62% and 49-99% of the total deposition for respectively mature cedar, young cedar and broad-leaf forests. In term of qualitative spatial variability no variation was observed in throughfall collectors with time. However, a high quantitative variability can be observed, due to the difference of leaf density above each throughfall collectors.

  6. Modelling Accident Tolerant Fuel Concepts

    SciTech Connect

    Hales, Jason Dean; Gamble, Kyle Allan Lawrence

    2016-05-01

    The catastrophic events that occurred at the Fukushima-Daiichi nuclear power plant in 2011 have led to widespread interest in research of alternative fuels and claddings that are proposed to be accident tolerant. The United States Department of Energy (DOE) through its Nuclear Energy Advanced Modeling and Simulation (NEAMS) program has funded an Accident Tolerant Fuel (ATF) High Impact Problem (HIP). The ATF HIP is a three-year project to perform research on two accident tolerant concepts. The final outcome of the ATF HIP will be an in-depth report to the DOE Advanced Fuels Campaign (AFC) giving a recommendation on whether either of the two concepts should be included in their lead test assembly scheduled for placement into a commercial reactor in 2022. The two ATF concepts under investigation in the HIP are uranium silicide fuel and iron-chromium-aluminum (FeCrAl) alloy cladding. Utilizing the expertise of three national laboratory participants (Idaho National Laboratory, Los Alamos National Laboratory, and Argonne National Laboratory), a comprehensive multiscale approach to modeling is being used that includes atomistic modeling, molecular dynamics, rate theory, phase-field, and fuel performance simulations. Model development and fuel performance analysis are critical since a full suite of experimental studies will not be complete before AFC must prioritize concepts for focused development. In this paper, we present simulations of the two proposed accident tolerance fuel systems: U3Si2 fuel with Zircaloy-4 cladding, and UO2 fuel with FeCrAl cladding. Sensitivity analyses are completed using Sandia National Laboratories’ Dakota software to determine which input parameters (e.g., fuel specific heat) have the greatest influence on the output metrics of interest (e.g., fuel centerline temperature). We also outline the multiscale modelling approach being employed. Considerable additional work is required prior to preparing the recommendation report for the Advanced

  7. 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

  8. The TMI-2 accident evaluation program

    SciTech Connect

    Osetek, D.J.; Broughton, J.M.; Hobbins, R.R.

    1989-01-01

    The accident at the Three Mile Island Unit 2 (TMI-2) reactor, now 10 years old, remains as the United States' worst commercial nuclear reactor accident. Although the consequences of the accident were restricted primarily to the plant itself, the potential consequences of the accident, should it have progressed further, are large enough to warrant close scrutiny of all aspects of the event. TMI-2 accident research is being conducted by the US Department of Energy (DOE) to provide the basis for more accurate calculations of source terms for postulated severe accidents. Research objectives supporting this goal include developing a comprehensive and consistent understanding of the mechanisms that controlled the progression of core damage and subsequent fission product behavior during the TMI-2 accident, and applying that understanding to the resolution of important severe accident safety issues. Developing a best-estimate scenario of the core melt progression during the accident is the focal point of the research and involves analytical work to interpret and integrate: (1) data recorded during the accident from plant instrumentation, (2) the post-accident state of the core, (3) results of the examination of material from the damaged core, and (4) related severe-accident research results. This paper summarizes the TMI-2 Accident Evaluation Program that is being conducted for the USDOE and briefly describes the important results that have been achieved. The Program is divided into four parts: Sample Acquisition and Plant Examination, Accident Scenario, Standard Problem Exercise, and Information and Industry Coordination.

  9. Think Tank Critics Plant a Stake in Policy World

    ERIC Educational Resources Information Center

    Sparks, Sarah D.

    2010-01-01

    After five years of providing critical reviews of education-related reports by nonacademic think tanks, education professors Alex Molnar and Kevin G. Welner hope to expand their own reach with a new, broader research center. The new National Education Policy Center, based at Welner's academic home, the University of Colorado at Boulder, will…

  10. Childhood and Adolescent Thyroid Cancer in Fukushima after the Fukushima Daiichi Nuclear Power Plant Accident: 5 Years On.

    PubMed

    Suzuki, S

    2016-04-01

    The accident at the Fukushima Daiichi Nuclear Power Plant occurred after the Great East Japan Earthquake on 11 March 2011, releasing a large amount of radioactive materials into the atmosphere. Questions were raised regarding the health effects of radiation exposure, which led to increased anxiety among the Fukushima residents about the possible development of thyroid cancer. Thus, thyroid ultrasound examinations began for those who were from the areas where the radiation doses were highest, and will continue for the long term. In total, 300 476 subjects aged 18 years or younger at the time of the disaster were screened from 9 October 2011 to 31 March 2014. The participation rate was 81.7% of the total population of this age and in the affected area. Among them, the proportions of those who fell into the categories A1 (no nodules or cysts present), A2 (nodule ≤ 5 mm or cyst ≤ 20 mm diameter), B (nodule > 5 mm or cyst > 20 mm diameter) and C (immediate need for further investigation) were 51.5, 47.8, 0.8 and 0%, respectively; 2294 subjects in categories B and C were recommended to undergo a confirmatory examination; 113 were subsequently diagnosed with malignancy or suspected malignancy by fine needle aspiration cytology. The full-scale survey (second round survey) began in April 2014, and was completed by 30 June 2015, and comprised 169 455 subjects (participation rate; 44.7%). The proportions of those who fell into the categories A1, A2, B and C were 41.6, 57.6, 0.8 and 0% (no case), respectively; 1223 subjects in category B were recommended to undergo a confirmatory examination, 25 of these were subsequently diagnosed with malignancy or suspected malignancy by fine needle aspiration cytology. The thyroid cancers identified in this survey so far are unlikely to be due to radiation exposure, and are more likely to be the result of screening using highly sophisticated ultrasound techniques. However, it would be advisable to continue long

  11. IMMEDIATE MENTAL CONSEQUENCES OF THE GREAT EAST JAPAN EARTHQUAKE AND FUKUSHIMA NUCLEAR POWER PLANT ACCIDENT ON MOTHERS EXPERIENCING MISCARRIAGE, ABORTION, AND STILLBIRTH: THE FUKUSHIMA HEALTH MANAGEMENT SURVEY

    PubMed Central

    YOSHIDA-KOMIYA, HIROMI; GOTO, AYA; YASUMURA, SEIJI; FUJIMORI, KEIYA; ABE, MASAFUMI; FOR THE PREGNANCY AND BIRTH SURVEY GROUP OF THE FUKUSHIMA HEALTH MANAGEMENT SURVEY

    2015-01-01

    ABSTRACT Background: The Fukushima Pregnancy and Birth Survey was launched to monitor pregnant mothers’ health after the Great East Japan Earthquake and Fukushima Daiichi Nuclear Power Plant (NPP) accident. Several lines of investigations have indicated that a disaster impacts maternal mental health with childbirth. However, there is no research regarding mental health of mothers with fetal loss after a disaster. In this report, we focus on those women immediately after the Great East Japan Earthquake and Fukushima NPP accident and discuss their support needs. Materials and Methods: Data regarding 61 miscarriages, 5 abortions, and 22 stillbirths were analyzed among the women who were pregnant at the time of the accident in the present study. We used a two-item case-finding instrument for depression screening, and compared the childbirth group with the fetal loss groups. We also analyzed mothers’ opinions written as free-form text. Results: Among the three fetal loss groups, the proportion of positive depression screens was significantly higher in the miscarriage and stillbirth group than in the childbirth group. Mothers’ opinions were grouped into six categories, with pregnancy-related items being most common, especially in the miscarriage and stillbirth groups. Conclusion: A higher proportion of Fukushima mothers with fetal loss, especially those with miscarriage and stillbirth, had depressive symptoms compared to those who experienced childbirth. Health care providers need to pay close attention to this vulnerable group and respond to their concerns regarding the effects on their fertility. PMID:26063510

  12. An influential factor for external radiation dose estimation for residents after the Fukushima Daiichi Nuclear Power Plant accident-time spent outdoors for residents in Iitate Village.

    PubMed

    Ishikawa, Tetsuo; Yasumura, Seiji; Ohtsuru, Akira; Sakai, Akira; Akahane, Keiichi; Yonai, Shunsuke; Sakata, Ritsu; Ozasa, Kotaro; Hayashi, Masayuki; Ohira, Tetsuya; Kamiya, Kenji; Abe, Masafumi

    2016-06-01

    Many studies have been conducted on radiation doses to residents after the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. Time spent outdoors is an influential factor for external dose estimation. Since little information was available on actual time spent outdoors for residents, different values of average time spent outdoors per day have been used in dose estimation studies on the FDNPP accident. The most conservative value of 24 h was sometimes used, while 2.4 h was adopted for indoor workers in the UNSCEAR 2013 report. Fukushima Medical University has been estimating individual external doses received by residents as a part of the Fukushima Health Management Survey by collecting information on the records of moves and activities (the Basic Survey) after the accident from each resident. In the present study, these records were analyzed to estimate an average time spent outdoors per day. As an example, in Iitate Village, its arithmetic mean was 2.08 h (95% CI: 1.64-2.51) for a total of 170 persons selected from respondents to the Basic Survey. This is a much smaller value than commonly assumed. When 2.08 h is used for the external dose estimation, the dose is about 25% (23-26% when using the above 95% CI) less compared with the dose estimated for the commonly used value of 8 h.

  13. Novel method for estimation of the indoor-to-outdoor airborne radioactivity ratio following the Fukushima Daiichi Nuclear Power Plant accident.

    PubMed

    Tan, Yanliang; Ishikawa, Tetsuo; Janik, Miroslaw; Tokonami, Shinji; Hosoda, Masahiro; Sorimachi, Atsuyuki; Kearfott, Kimberlee

    2015-12-01

    The accident at the Fukushima Daiichi Nuclear Power Plant (FDNPP) in Japan resulted in significant releases of fission products. While substantial data exist concerning outdoor air radioactivity following the accident, the resulting indoor radioactivity remains pure speculation without a proper method for estimating the ratio of the indoor to outdoor airborne radioactivity, termed the airborne sheltering factor (ASF). Lacking a meaningful value of the ASF, it is difficult to assess the inhalation doses to residents and evacuees even when outdoor radionuclide concentrations are available. A simple model was developed and the key parameters needed to estimate the ASF were obtained through data fitting of selected indoor and outdoor airborne radioactivity measurement data obtained following the accident at a single location. Using the new model with values of the air exchange rate, interior air volume, and the inner surface area of the dwellings, the ASF can be estimated for a variety of dwelling types. Assessment of the inhalation dose to individuals readily follows from the value of the ASF, the person's indoor occupancy factor, and the measured outdoor radioactivity concentration.

  14. Radiocaesium contamination and dose rate estimation of terrestrial and freshwater wildlife in the exclusion zone of the Fukushima Dai-ichi Nuclear Power Plant accident.

    PubMed

    Fuma, Shoichi; Ihara, Sadao; Takahashi, Hiroyuki; Inaba, Osamu; Sato, Youji; Kubota, Yoshihisa; Watanabe, Yoshito; Kawaguchi, Isao; Aono, Tatsuo; Soeda, Haruhi; Yoshida, Satoshi

    2017-03-02

    To characterise the radioactive contamination of terrestrial and freshwater wildlife caused by the Fukushima Dai-ichi Nuclear Power Plant accident, biological samples, namely, fungi, mosses, plants, amphibians, reptiles, insects, molluscs, and earthworms, were collected mainly from the forests of the exclusion zone in the Fukushima Prefecture from 2011 to 2012. Caesium-134 and (137)Cs were detected by gamma spectrometry in almost all the samples. Fungi, ferns, and mosses accumulated high amounts of radiocaesium, as they did in Chernobyl, with (134)Cs + (137)Cs activity concentrations of 10(4)-10(6) Bq kg(-1) fresh mass (FM). Earthworms, amphibians, and the soft tissue of the garden snail Acusta despecta sieboldiana, also had levels as high as 10(4)-10(5) Bq kg(-1) FM of (134)Cs + (137)Cs. Most of the estimated total (internal + external) dose rates to herbaceous plants, amphibians, insects, and earthworms were below the corresponding derived consideration reference levels (DCRLs) recommended by the ICRP. This suggests that, in most cases, there was little chance of deleterious effects of ionising radiation on these organisms in the exclusion zone for the first year after the accident, though the dose rates were underestimated mainly due to the lack of consideration of short-lived radionuclides.

  15. The Great East Japan Earthquake, tsunami, and Fukushima Daiichi nuclear power plant accident: a triple disaster affecting the mental health of the country.

    PubMed

    Yamashita, Jun; Shigemura, Jun

    2013-09-01

    The Great East Japan Earthquake in 2011 caused 2 other serious disasters: a tsunami and a nuclear power plant accident. A chronic shortage of mental health resources had been previously reported in the Tohoku region, and the triple disaster worsened the situation. Eventually a public health approach was implemented by providing a common room in temporary housing developments to build a sense of community and to approach evacuees so that they could be triaged and referred to mental health teams. Japan now advocates using psychological first aid to educate first responders. This article extracts key lessons from relevant literature.

  16. Evaluation of thyroid antibodies and benign disease prevalence among young adults exposed to 131I more than 25 years after the accident at the Chernobyl Nuclear Power Plant

    PubMed Central

    Kimura, Yuko; Hayashida, Naomi; Takahashi, Jumpei; Rafalsky, Ruslan; Saiko, Alexsey; Gutevich, Alexander; Chorniy, Sergiy; Kudo, Takashi

    2016-01-01

    Background. The Chernobyl Nuclear Power Plant (CNPP) accident exposed a large number of inhabitants to internal 131I radiation. The associations between internal 131I exposure and thyroid autoimmunity and benign thyroid diseases remain controversial in the population living in the contaminated area around the CNNP. In this study, we evaluate the association of 131I with benign thyroid diseases. Methods. We compared the prevalence of Anti-Thyroid Autoantibodies (ATAs), thyroid function, and prevalence of thyroid ultrasound finding outcomes in 300 residents of the contaminated area of Ukraine who were 0–5 years of age at the time of the CNPP accident (group 1) and 300 sex-matched residents who were born after the accident (group 2). Results. We did not find any differences of the prevalence of Antithyroglobulin Antibodies (TGAb) positive, Antithyroid Peroxidase Antibodies (TPOAb) positive, and TGAb and/or TPOAb positive between the study groups. (11.7% vs 10.3%; p = 0.602, 17.3% vs 13.0%; p = 0.136, 21.0% vs 17.3%; p = 0.254, respectively); after adjusting for age and sex, the prevalence was not associated with the 131I exposure status in the study groups. The prevalence of subclinical and overt hypothyroidism cases was not significantly different (p = 0.093 and p = 0.320) in the two groups, nor was the prevalence of goiter (p = 0.482). On the other hand, the prevalence of nodules was significantly higher in group 1 (p = 0.003), though not significantly so after adjustment for age and sex. Discussion. Working 26–27 years after the CNNP accident, we found no increased prevalence of ATAs or benign thyroid diseases in young adults exposed to 131I fallout during early childhood in the contaminated area of Ukraine. Long-term follow-up is needed to clarify the effects of radiation exposure on autoimmunity reaction in the thyroid. PMID:27019779

  17. Reconstructing the Chernobyl Nuclear Power Plant (CNPP) accident 30 years after. A unique database of air concentration and deposition measurements over Europe.

    PubMed

    Evangeliou, Nikolaos; Hamburger, Thomas; Talerko, Nikolai; Zibtsev, Sergey; Bondar, Yuri; Stohl, Andreas; Balkanski, Yves; Mousseau, Timothy A; Møller, Anders P

    2016-09-01

    30 years after the Chernobyl Nuclear Power Plant (CNPP) accident, its radioactive releases still remain of great interest mainly due to the long half-lives of many radionuclides emitted. Observations from the terrestrial environment, which hosts radionuclides for many years after initial deposition, are important for health and environmental assessments. Furthermore, such measurements are the basis for validation of atmospheric transport models and can be used for constraining the still not accurately known source terms. However, although the "Atlas of cesium deposition on Europe after the Chernobyl accident" (hereafter referred to as "Atlas") has been published since 1998, less than 1% of the direct observations of (137)Cs deposition has been made publicly available. The remaining ones are neither accessible nor traceable to specific data providers and a large fraction of these data might have been lost entirely. The present paper is an effort to rescue some of the data collected over the years following the CNPP accident and make them publicly available. The database includes surface air activity concentrations and deposition observations for (131)I, (134)Cs and (137)Cs measured and provided by Former Soviet Union authorities the years that followed the accident. Using the same interpolation tool as the official authorities, we have reconstructed a deposition map of (137)Cs based on about 3% of the data used to create the Atlas map. The reconstructed deposition map is very similar to the official one, but it has the advantage that it is based exclusively on documented data sources, which are all made available within this publication. In contrast to the official map, our deposition map is therefore reproducible and all underlying data can be used also for other purposes. The efficacy of the database was proved using simulated activity concentrations and deposition of (137)Cs from a Langrangian and a Euleurian transport model.

  18. Evaluation of thyroid antibodies and benign disease prevalence among young adults exposed to (131)I more than 25 years after the accident at the Chernobyl Nuclear Power Plant.

    PubMed

    Kimura, Yuko; Hayashida, Naomi; Takahashi, Jumpei; Rafalsky, Ruslan; Saiko, Alexsey; Gutevich, Alexander; Chorniy, Sergiy; Kudo, Takashi; Takamura, Noboru

    2016-01-01

    Background. The Chernobyl Nuclear Power Plant (CNPP) accident exposed a large number of inhabitants to internal (131)I radiation. The associations between internal (131)I exposure and thyroid autoimmunity and benign thyroid diseases remain controversial in the population living in the contaminated area around the CNNP. In this study, we evaluate the association of (131)I with benign thyroid diseases. Methods. We compared the prevalence of Anti-Thyroid Autoantibodies (ATAs), thyroid function, and prevalence of thyroid ultrasound finding outcomes in 300 residents of the contaminated area of Ukraine who were 0-5 years of age at the time of the CNPP accident (group 1) and 300 sex-matched residents who were born after the accident (group 2). Results. We did not find any differences of the prevalence of Antithyroglobulin Antibodies (TGAb) positive, Antithyroid Peroxidase Antibodies (TPOAb) positive, and TGAb and/or TPOAb positive between the study groups. (11.7% vs 10.3%; p = 0.602, 17.3% vs 13.0%; p = 0.136, 21.0% vs 17.3%; p = 0.254, respectively); after adjusting for age and sex, the prevalence was not associated with the (131)I exposure status in the study groups. The prevalence of subclinical and overt hypothyroidism cases was not significantly different (p = 0.093 and p = 0.320) in the two groups, nor was the prevalence of goiter (p = 0.482). On the other hand, the prevalence of nodules was significantly higher in group 1 (p = 0.003), though not significantly so after adjustment for age and sex. Discussion. Working 26-27 years after the CNNP accident, we found no increased prevalence of ATAs or benign thyroid diseases in young adults exposed to (131)I fallout during early childhood in the contaminated area of Ukraine. Long-term follow-up is needed to clarify the effects of radiation exposure on autoimmunity reaction in the thyroid.

  19. Analysis of 129I in the soils of Fukushima Prefecture: preliminary reconstruction of 131I deposition related to the accident at Fukushima Daiichi Nuclear Power Plant (FDNPP).

    PubMed

    Muramatsu, Yasuyuki; Matsuzaki, Hiroyuki; Toyama, Chiaki; Ohno, Takeshi

    2015-01-01

    Iodine-131 is one of the most critical radionuclides to be monitored after release from reactor accidents due to the tendency for this nuclide to accumulate in the human thyroid gland. However, there are not enough data related to the reactor accident in Fukushima, Japan to provide regional information on the deposition of this short-lived nuclide (half-life = 8.02 d). In this study we have focused on the long-lived iodine isotope, (129)I (half-life of 1.57 × 10(7) y), and analyzed it by accelerator mass spectrometry (AMS) for surface soil samples collected at various locations in Fukushima Prefecture. In order to obtain information on the (131)I/(129)I ratio released from the accident, we have determined (129)I concentrations in 82 soil samples in which (131)I concentrations were previously determined. There was a strong correlation (R(2) = 0.84) between the two nuclides, suggesting that the (131)I levels in soil samples following the accident can be estimated through the analysis of (129)I. We have also examined the possible influence from (129m)Te on (129)I, and found no significant effect. In order to construct a deposition map of (131)I, we determined the (129)I concentrations (Bq/kg) in 388 soil samples collected from different locations in Fukushima Prefecture and the deposition densities (Bq/m(2)) of (131)I were reconstructed from the results.

  20. [Effect of infrared laser irradiation on the arterial blood pressure in liquidators of the accident at the Chernobyl power plant].

    PubMed

    Korkushko, O O

    2003-01-01

    Liquidators of Tchernobyl accident with discirculatory post-irradiation encephalopathy were treated with infra-red lazer irradiation together with a half doze of pharmacological agents usually used. Infra-red lazer irradiation has been shown to result in a significant reduce in the arterial pressure level, so it can be effective in correcting the disturbances in haemodynamics.

  1. Paddy-field contamination with 134Cs and 137Cs due to Fukushima Dai-ichi Nuclear Power Plant accident and soil-to-rice transfer coefficients.

    PubMed

    Endo, Satoru; Kajimoto, Tsuyoshi; Shizuma, Kiyoshi

    2013-02-01

    The transfer coefficient (TF) from soil to rice plants of (134)Cs and (137)Cs in the form of radioactive deposition from the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident in March 2011 was investigated in three rice paddy fields in Minami-Soma City. Rice crops were planted in the following May and harvested at the end of September. Soil cores of 30-cm depth were sampled from rice-planted paddy fields to measure (134)Cs and (137)Cs radioactivity at 5-cm intervals. (134)Cs and (137)Cs radioactivity was also measured in rice ears (rice with chaff), straws and roots. The rice ears were subdivided into chaff, brown rice, polished rice and rice bran, and the (134)Cs and (137)Cs radioactivity concentration of each plant part was measured to calculate the respective TF from the soil. The TF of roots was highest at 0.48 ± 0.10 in the field where the (40)K concentration in the soil core was relatively low, in comparison with TF values of 0.31 and 0.38 in other fields. Similar trends could be found for the TF of whole rice plants, excluding roots. The TF of rice ears was relatively low at 0.019-0.026. The TF of chaff, rice bran, brown rice and polished rice was estimated to be 0.049, 0.10-0.16, 0.013-0.017 and 0.005-0.013, respectively.

  2. Radioactive nuclides in the incinerator ashes of municipal solid wastes before and after the accident at the Fukushima nuclear power plant.

    PubMed

    Iwahana, Yuki; Ohbuchi, Atsushi; Koike, Yuya; Kitano, Masaru; Nakamura, Toshihiro

    2013-01-01

    Radioactive nuclides in the incinerator ashes of municipal solid wastes were determined by γ-ray spectrometry before and after the accident at the Fukushima nuclear power plant (March 11, 2011). Incinerator ash samples were collected in northern Kyushu, Japan, which is located approximately 1200 km west-southwest (WSW) of the Fukushima nuclear power plant, from April 2006 to March 2007 and from March 2011 to October 2011. (40)K, (137)Cs, (208)Tl, (212)Pb, (214)Pb, (212)Bi, (214)Bi, and (228)Ac were identified in the ashes before the accident (~February 2011) and (134)Cs was identified along with these eight nuclides in the ashes after the accident (March 2011~). A sequential extraction procedure based on a modified Tessier method with added water extraction was used for 1st fly ash sampled in August 2011 because the highest activity concentrations of (134)Cs and (137)Cs were observed for this sample. The speciation of radioactive nuclides in the fly ash was achieved by γ-ray spectrometry and powder X-ray diffractometry for the extraction residues. Little variation was observed in the distribution of the chemical forms of (134)Cs and (137)Cs in 1st fly ash of municipal solid waste; one half of (134)Cs existed as water soluble salts and the other half as carbonate compounds, whereas 75% of (137)Cs existed as water soluble salts with the remainder as carbonates(10%) and sulfides (15%). These results show that 88% of the total radioactive Cs existed in water soluble and ion extractive forms and might be at risk for elution and diffusion with rain and wind.

  3. Criticality analysis for weapon disassembly at the Pantex Plant - part I: Bare pits

    SciTech Connect

    Knief, R.A.

    1997-06-01

    This paper briefly describes criticality investigations for weapon assembly and dismantlement at the Pantex Plant. Results are summarized for calculations performed for safety analyses, radiological hazards assessments, and a study to justify the criticality alarm exemption. Pits and pits in containers were modeled in their most reactive configuration. Criticality calculations were performed with the KENO and MCNP code packages. Configurations involving bare pits were subcritical by a substantial amount even with very conservative model assumptions. Thus, it is concluded that a critical configuration involving the bare pits is not credible.

  4. [Content of free amino acids in blood plasma of the clean-up personnel at the Chernobyl nuclear power plant accident].

    PubMed

    Kuznetsov, H P; Chaialo, P P

    2002-01-01

    In two groups of the persons participating in liquidation of the Chornobyl Power Plant Catastrophe (individuals which suffered from acute radiation sickness and those ones who were exposed to irradiation at doses 0.25-1.0 Gy) in a year after medical treatment the free amino acids, their derivatives, glucose, sodium lactate and pyruvate homeostasis changed in comparison with the control. The causes and possible mechanisms of these substances exchange regulation disorders in the key biochemical reactions ensuring the body organs and systems functioning were estimated. The experimental findings received can be used at planning the further examination and treatment-and-prophylactic measures for the persons which have been affected by ionizing radiation consequently the accident at the Chornobyl Nuclear Power Plant.

  5. Critical Evaluation of Ayurvedic Plants for Stimulating Intrinsic Antioxidant Response

    PubMed Central

    Shukla, Sunil Dutt; Bhatnagar, Maheep; Khurana, Sukant

    2012-01-01

    Oxidative damage caused by free radicals plays an important role in the causation and progression of many diseases, including aging. Free-radical damage is countered by many mechanisms, including both active antioxidant enzymatic activity in our body and passive antioxidants. Antioxidant response of our body can accommodate increased oxidative damage in diseased states to a level but beyond that level, additional antioxidants are required to combat the increased stress. Apart from the regular dietary sources of antioxidants, many traditional herbal medicines demonstrate a potential to boost antioxidant activity. Rasayana chikitsa that deals with rejuvenation and revitalization is a branch of the Indian traditional medical system of ayurveda. We review some select herbs described in rasayana chikitsa that have been assessed by modern means for stimulating intrinsic antioxidant responses in humans. A critical evaluation of rasayana chikitsa will likely provide urgently needed, actual stimulants of our physiological antioxidant responses and not just more passive antioxidants to add to an already large catalog. PMID:22855669

  6. The Roll of Canopy on Interception and Redistribution of Anthropogenic Radionuclides Derived from Fukushima Daiichi Nuclear Power Plant Accident in Coniferous Forest Plantations

    NASA Astrophysics Data System (ADS)

    Kato, H.; Onda, Y.; Kawaguchi, S.; Gomi, T.

    2011-12-01

    Soil, vegetation and other ecological compartments are expected to be highly contaminated by the deposited radionuclides after the Fukushima Daiichi nuclear power plant (NPP) accident triggered by a magnitude 9.1 earthquake and the resulting tsunami on Marchi 11, 2011. A large proportion of radionuclides which deposited on forest area are trapped by canopies, throughfall and stemflow are the most important pathways for the input of radionuclides into the soil of forest floor. In this study, to investigate the roll of forest canopy on interception and redistribution of the deposited radionuclides, a series of field monitoring experiment of throughfall and stemflow were conducted in coniferous forest plantations in Tochigi prefecture, 170 km southwest from the NPP. A set of 20 throughfall collectors with latticelike distribution and 5 stemflow collectors were located in the 10m × 10m interception plot, and the activities of caesium (137Cs, 134Cs) and radioiodine (131I) in throughfall and stemflow were quantified by using a high purity n-type germanium coaxial gamma ray detectors. Rainfall, throughfall, and stemflow samples were collected from 10 rainfall events, which includes first rainfall event after the NPP accident. The cumulative fallout of radionuclides in the study site was 3400 Bq m-2 for 137Cs, 3300 Bq m-2 for 134Cs, and 26000 Bq m-2 for 131I, respectively. The 137Cs in rainfall decreased exponentially with time since the NPP accident. For the rainfall event of 28 March, which is first rainfall event after the NPP accident, both the amount and concentration of caesium clearly increased with throughfall, whereas the concentration of radioiodine decreased with throughfall. For the subsequent rainfall events, the concentration of caesium decreased with throughfall, whereas radioiodine was not detected as a result of decay due to short half-life. At the end of May, approximately 30% and 60% of total caesium deposited after the NPP accident remained on the

  7. An inverse modeling method to assess the source term of the Fukushima nuclear power plant accident using gamma dose rate observations

    NASA Astrophysics Data System (ADS)

    Saunier, O.; Mathieu, A.; Didier, D.; Tombette, M.; Quélo, D.; Winiarek, V.; Bocquet, M.

    2013-06-01

    The Chernobyl nuclear accident and more recently the Fukushima accident highlighted that the largest source of error on consequences assessment is the source term including the time evolution of the release rate and its distribution between radioisotopes. Inverse modeling methods, which combine environmental measurements and atmospheric dispersion models, have proven efficient in assessing source term due to an accidental situation (Gudiksen, 1989; Krysta and Bocquet, 2007; Stohl et al., 2012a; Winiarek et al., 2012). Most existing approaches are designed to use air sampling measurements (Winiarek et al., 2012) and some of them also use deposition measurements (Stohl et al., 2012a; Winiarek et al., 2013) but none of them uses dose rate measurements. However, it is the most widespread measurement system, and in the event of a nuclear accident, these data constitute the main source of measurements of the plume and radioactive fallout during releases. This paper proposes a method to use dose rate measurements as part of an inverse modeling approach to assess source terms. The method is proven efficient and reliable when applied to the accident at the Fukushima Daiichi nuclear power plant (FD-NPP). The emissions for the eight main isotopes 133Xe, 134Cs, 136Cs, 137Cs, 137mBa, 131I, 132I and 132Te have been assessed. Accordingly, 103 PBq of 131I, 35.5 PBq of 132I, 15.5 PBq of 137Cs and 12 100 PBq of noble gases were released. The events at FD-NPP (such as venting, explosions, etc.) known to have caused atmospheric releases are well identified in the retrieved source term. The estimated source term is validated by comparing simulations of atmospheric dispersion and deposition with environmental observations. The result is that the model-measurement agreement for all of the monitoring locations is correct for 80% of simulated dose rates that are within a factor of 2 of the observed values. Changes in dose rates over time have been overall properly reconstructed, especially

  8. Vertical distribution of radiocesium in soils of the area affected by the Fukushima Dai-ichi nuclear power plant accident

    NASA Astrophysics Data System (ADS)

    Konoplev, A. V.; Golosov, V. N.; Yoschenko, V. I.; Nanba, K.; Onda, Y.; Takase, T.; Wakiyama, Y.

    2016-05-01

    Presented are results of the study of radiocesium vertical distribution in the soils of the irrigation pond catchments in the near field 0.25 to 8 km from the Fukushima Dai-ichi NPP, on sections of the Niida River floodplain, and in a forest ecosystem typical of the territory contaminated after the accident. It is shown that the vertical migration of radiocesium in undisturbed forest and grassland soils in the zone affected by the Fukushima accident is faster than it was in the soils of the 30-km zone of the Chernobyl NPP for a similar time interval after the accident. The effective dispersion coefficients in the Fukushima soils are several times higher than those for the Chernobyl soils. This may be associated with higher annual precipitation (by about 2.5 times) in Fukushima as compared to the Chernobyl zone. In the forest soils the radiocesium dispersion is faster as compared to grassland soils, both in the Fukushima and Chernobyl zones. The study and analysis of the vertical distribution of the Fukushima origin radiocesium in the Niida gawa floodplain soils has made it possible to identify areas of contaminated sediment accumulation on the floodplain. The average accumulation rate for sediments at the study locations on the Niida gawa floodplain varied from 0.3 to 3.3 cm/year. Taking into account the sediments accumulation leading to an increase in the radiocesium inventory in alluvial soils is key for predicting redistribution of radioactive contamination after the Fukushima accident on the river catchments, as well as for decision-making on contaminated territories remediation and clean-up. Clean-up of alluvial soils does not seem to be worthwhile because of the following accumulation of contaminated sediments originating from more contaminated areas, including the exclusion zone.

  9. Nuclear accidents

    SciTech Connect

    Mobley, J.A.

    1982-05-01

    A nuclear accident with radioactive contamination can happen anywhere in the world. Because expert nuclear emergency teams may take several hours to arrive at the scene, local authorities must have a plan of action for the hours immediately following an accident. The site should be left untouched except to remove casualties. Treatment of victims includes decontamination and meticulous wound debridement. Acute radiation syndrome may be an overwhelming sequela.

  10. Radiocesium contamination of the web spider Nephila clavata (Nephilidae: Arachnida) 1.5 years after the Fukushima Dai-ichi Nuclear Power Plant accident.

    PubMed

    Ayabe, Yoshiko; Kanasashi, Tsutomu; Hijii, Naoki; Takenaka, Chisato

    2014-01-01

    We measured the concentrations of radiocesium ((134)Cs and (137)Cs) in a large web spider, Nephila clavata L. Koch (Nephilidae: Arachnida), collected at three sites at different distances from the Fukushima Dai-ichi Nuclear Power Plant about 1.5 y after the accident in March 2011. The radiocesium concentrations in spiders were highest in a streamside secondary forest 33 km northwest of the power plant: mean ± a standard deviation of 2.401 ± 1.197 Bq g(-1) dry for (134)Cs and 3.955 ± 1.756 Bq g(-1) dry for (137)Cs. In a hillside secondary forest 37 km northwest of the power plant, the mean concentrations of (134)Cs and (137)Cs were 0.825 ± 0.247 Bq g(-1) dry and 1.470 ± 0.454 Bq g(-1) dry, respectively. In a pine forest 62 km west of the power plant, very low radiocesium concentrations were detected, but in only a few individuals. The concentrations of (134)Cs and (137)Cs in spiders collected at each site tended to be correlated with the air radiation dose rate at each site. Since spiders are key components of food webs in forests, the high concentrations in this species at contaminated sites suggested that the radiocesium from the accident has transferred through food chains and reached to higher trophic level of the food chains.

  11. Organizational culture during the accident response process

    SciTech Connect

    Shurberg, D.A.; Haber, S.B. )

    1992-01-01

    A large volume of literature hypothesizes a direct relationship between organizational culture and organizational effectiveness. Culture data have been collected by the authors and others at nuclear power plants (NPPs) and other organizations that demand high reliability. In this paper, the literature and data are used to explore a critical dimension of the accident response process in an NPP: the transition from an anticipatory strategy to an ad hoc strategy. In particular, the effect of organizational culture on the implementation of each of these strategies is examined.

  12. An inverse modeling method to assess the source term of the Fukushima Nuclear Power Plant accident using gamma dose rate observations

    NASA Astrophysics Data System (ADS)

    Saunier, O.; Mathieu, A.; Didier, D.; Tombette, M.; Quélo, D.; Winiarek, V.; Bocquet, M.

    2013-11-01

    The Chernobyl nuclear accident, and more recently the Fukushima accident, highlighted that the largest source of error on consequences assessment is the source term, including the time evolution of the release rate and its distribution between radioisotopes. Inverse modeling methods, which combine environmental measurements and atmospheric dispersion models, have proven efficient in assessing source term due to an accidental situation (Gudiksen, 1989; Krysta and Bocquet, 2007; Stohl et al., 2012a; Winiarek et al., 2012). Most existing approaches are designed to use air sampling measurements (Winiarek et al., 2012) and some of them also use deposition measurements (Stohl et al., 2012a; Winiarek et al., 2014). Some studies have been performed to use dose rate measurements (Duranova et al., 1999; Astrup et al., 2004; Drews et al., 2004; Tsiouri et al., 2012) but none of the developed methods were carried out to assess the complex source term of a real accident situation like the Fukushima accident. However, dose rate measurements are generated by the most widespread measurement system, and in the event of a nuclear accident, these data constitute the main source of measurements of the plume and radioactive fallout during releases. This paper proposes a method to use dose rate measurements as part of an inverse modeling approach to assess source terms. The method is proven efficient and reliable when applied to the accident at the Fukushima Daiichi Nuclear Power Plant (FD-NPP). The emissions for the eight main isotopes 133Xe, 134Cs, 136Cs, 137Cs, 137mBa, 131I, 132I and 132Te have been assessed. Accordingly, 105.9 PBq of 131I, 35.8 PBq of 132I, 15.5 PBq of 137Cs and 12 134 PBq of noble gases were released. The events at FD-NPP (such as venting, explosions, etc.) known to have caused atmospheric releases are well identified in the retrieved source term. The estimated source term is validated by comparing simulations of atmospheric dispersion and deposition with

  13. Final report for the field-reversed configuration power plant critical-issue scoping study

    SciTech Connect

    Santarius, John F.; Mogahed, Elsayed A.; Emmert, Gilbert A.; Khater, Hesham Y.; Nguyen, Canh N.; Ryzhkov, Sergei V.; Stubna, Michael D.; Steinhauer, Loren C.; Miley, George H.

    2001-03-01

    This report describes research in which a team from the Universities of Wisconsin, Washington, and Illinois performed a scoping study of critical issues for field-reversed configuration (FRC) power plants. The key tasks for this research were (1) systems analysis of deuterium-tritium (D-T) FRC fusion power plants, and (2) conceptual design of the blanket and shield module for an FRC fusion core.

  14. 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.

  15. Comparison of childhood thyroid cancer prevalence among 3 areas based on external radiation dose after the Fukushima Daiichi nuclear power plant accident: The Fukushima health management survey.

    PubMed

    Ohira, Tetsuya; Takahashi, Hideto; Yasumura, Seiji; Ohtsuru, Akira; Midorikawa, Sanae; Suzuki, Satoru; Fukushima, Toshihiko; Shimura, Hiroki; Ishikawa, Tetsuo; Sakai, Akira; Yamashita, Shunichi; Tanigawa, Koichi; Ohto, Hitoshi; Abe, Masafumi; Suzuki, Shinichi

    2016-08-01

    The 2011 Great East Japan Earthquake led to a subsequent nuclear accident at the Fukushima Daiichi Nuclear Power Plant. In its wake, we sought to examine the association between external radiation dose and thyroid cancer in Fukushima Prefecture. We applied a cross-sectional study design with 300,476 participants aged 18 years and younger who underwent thyroid examinations between October 2011 and June 2015. Areas within Fukushima Prefecture were divided into three groups based on individual external doses (≥1% of 5 mSv, <99% of 1 mSv/y, and the other). The odds ratios (ORs) and 95% confidence intervals of thyroid cancer for all areas, with the lowest dose area as reference, were calculated using logistic regression models adjusted for age and sex. Furthermore, the ORs of thyroid cancer for individual external doses of 1 mSv or more and 2 mSv or more, with the external dose less than 1 mSv as reference, were calculated. Prevalence of thyroid cancer for the location groups were 48/100,000 for the highest dose area, 36/100,000 for the middle dose area, and 41/100,000 for the lowest dose area. Compared with the lowest dose area, age-, and sex-adjusted ORs (95% confidence intervals) for the highest-dose and middle-dose areas were 1.49 (0.36-6.23) and 1.00 (0.67-1.50), respectively. The duration between accident and thyroid examination was not associated with thyroid cancer prevalence. There were no significant associations between individual external doses and prevalence of thyroid cancer. External radiation dose was not associated with thyroid cancer prevalence among Fukushima children within the first 4 years after the nuclear accident.

  16. Comparison of childhood thyroid cancer prevalence among 3 areas based on external radiation dose after the Fukushima Daiichi nuclear power plant accident

    PubMed Central

    Ohira, Tetsuya; Takahashi, Hideto; Yasumura, Seiji; Ohtsuru, Akira; Midorikawa, Sanae; Suzuki, Satoru; Fukushima, Toshihiko; Shimura, Hiroki; Ishikawa, Tetsuo; Sakai, Akira; Yamashita, Shunichi; Tanigawa, Koichi; Ohto, Hitoshi; Abe, Masafumi; Suzuki, Shinichi

    2016-01-01

    Abstract The 2011 Great East Japan Earthquake led to a subsequent nuclear accident at the Fukushima Daiichi Nuclear Power Plant. In its wake, we sought to examine the association between external radiation dose and thyroid cancer in Fukushima Prefecture. We applied a cross-sectional study design with 300,476 participants aged 18 years and younger who underwent thyroid examinations between October 2011 and June 2015. Areas within Fukushima Prefecture were divided into three groups based on individual external doses (≥1% of 5 mSv, <99% of 1 mSv/y, and the other). The odds ratios (ORs) and 95% confidence intervals of thyroid cancer for all areas, with the lowest dose area as reference, were calculated using logistic regression models adjusted for age and sex. Furthermore, the ORs of thyroid cancer for individual external doses of 1 mSv or more and 2 mSv or more, with the external dose less than 1 mSv as reference, were calculated. Prevalence of thyroid cancer for the location groups were 48/100,000 for the highest dose area, 36/100,000 for the middle dose area, and 41/100,000 for the lowest dose area. Compared with the lowest dose area, age-, and sex-adjusted ORs (95% confidence intervals) for the highest-dose and middle-dose areas were 1.49 (0.36–6.23) and 1.00 (0.67–1.50), respectively. The duration between accident and thyroid examination was not associated with thyroid cancer prevalence. There were no significant associations between individual external doses and prevalence of thyroid cancer. External radiation dose was not associated with thyroid cancer prevalence among Fukushima children within the first 4 years after the nuclear accident. PMID:27583855

  17. Severe Psychological Distress of Evacuees in Evacuation Zone Caused by the Fukushima Daiichi Nuclear Power Plant Accident: The Fukushima Health Management Survey

    PubMed Central

    Kunii, Yasuto; Suzuki, Yuriko; Shiga, Tetsuya; Yabe, Hirooki; Yasumura, Seiji; Maeda, Masaharu; Niwa, Shin-ichi; Otsuru, Akira; Mashiko, Hirobumi; Abe, Masafumi

    2016-01-01

    Background Following the Great East Japan Earthquake on March 11, 2011, the nuclear disaster at the Fukushima Daiichi Nuclear Power Plant has continued to affect the mental health status of residents in the evacuation zone. To examine the mental health status of evacuee after the nuclear accident, we conducted the Mental Health and Lifestyle Survey as part of the ongoing Fukushima Health Management Survey. Methods We measured mental health status using the Kessler 6-item psychological distress scale (K6) in a total of 73,569 (response rate: 40.7%) evacuees aged 15 and over who lived in the evacuation zone in Fukushima Prefecture. We then dichotomized responders using a 12/13 cutoff on the K6, and compared the proportion of K6 scores ≥13 and ≤12 in each risk factor including demographic information, socioeconomic variables, and disaster-related variables. We also performed bivariate analyses between mental health status and possible risk factors using the chi-square test. Furthermore, we performed multivariate regression analysis using modified Poisson regression models. Results The median K6 score was 5 (interquartile range: 1–10). The number of psychological distress was 8,717 (14.6%). We found that significant differences in the prevalence of psychological distress by almost all survey items, including disaster-related risk factors, most of which were also associated with increased Prevalence ratios (PRs). Additionally, we found that psychological distress in each evacuation zone was significantly positively associated with the radiation levels in their environment (r = 0.768, p = 0.002). Conclusion The earthquake, tsunami and subsequent nuclear accident likely caused severe psychological distress among residents in the evacuation zone in Fukushima Prefecture. The close association between psychological distress and the radiation levels shows that the nuclear accident seriously influenced the mental health of the residents, which might be exacerbated by

  18. Impact of Fukushima-derived radiocesium in the western North Pacific Ocean about ten months after the Fukushima Dai-ichi nuclear power plant accident.

    PubMed

    Kumamoto, Yuichiro; Aoyama, Michio; Hamajima, Yasunori; Murata, Akihiko; Kawano, Takeshi

    2015-02-01

    We measured vertical distributions of radiocesium ((134)Cs and (137)Cs) at stations along the 149°E meridian in the western North Pacific during winter 2012, about ten months after the Fukushima Dai-ichi Nuclear Power Plant (FNPP1) accident. The Fukushima-derived (134)Cs activity concentration and water-column inventory were largest in the transition region between 35 and 40°N approximately due to the directed discharge of the contaminated water from the FNPP1. The bomb-derived (137)Cs activity concentration just before the FNPP1 accident was derived from the excess (137)Cs activity concentration relative to the (134)Cs activity concentration. The water-column inventory of the bomb-derived (137)Cs was largest in the subtropical region south of 35°N, which implies that the Fukushima-derived (134)Cs will also be transported from the transition region to the subtropical region in the coming decades. Mean values of the water-column inventories decay-corrected for the Fukushima-derived (134)Cs and the bomb-derived (137)Cs were estimated to be 1020 ± 80 and 820 ± 120 Bq m(-2), respectively, suggesting that in winter 2012 the impact of the FNPP1 accident in the western North Pacific Ocean was nearly the same as that of nuclear weapons testing. Relationship between the water-column inventory and the activity concentration in surface water for the radiocesium is essential information for future evaluation of the total amount of Fukushima-derived radiocesium released into the North Pacific Ocean.

  19. Imaging of radioactive material and its host particle from the nuclear power plant accident in Japan by using imaging plate and electron microscopy

    NASA Astrophysics Data System (ADS)

    Adachi, Kouji; Zaizen, Yuji; Kimura, Tohru; Sakoh, Hiroshi; Igarashi, Yasuhito

    2013-04-01

    The Fukushima Daiichi Nuclear Power Plant accident in Japan on March, 2012, dispersed radioactive materials. In the Meteorological Research Institute, where locates 170 km south west from the power plant, we collected two types of filter aerosol samples and wet and dry deposition particles before and after the accident. Using these samples, we analyzed 1) radioactivity using an imaging plate (IP), which visualizes the radioactivity of samples in a two-dimensional plane with space resolution ~0.05 mm and 2) shape and compositions of particles that host radioactive materials using a scanning electron microscope (SEM) with energy-dispersive X-ray spectrometer (EDS). From the samples collected on March 15 and 21, we found radioactive spots on the filter samples using the IP, suggesting that radioactive materials, presumably Cs, were carried from the power plant. Radioactivity was also detected over the aggregates of dust particles in wet and dry deposition samples collected from March 2011. We did not find any detectable radioactive materials after the April when using the IP. We further investigated the radioactive spots using the SEM to identify the host particles of the radioactive materials and to detect radioactive materials from the EDS analysis. From the SEM analysis, we found that the particles on the filters include sulfate, mineral dust, and metals, but there were no particular particles or materials in the radioactive spots comparing to those in other area. The result suggests that the radioactive materials are hosted on the surface of other particles or inside them. We, so far, did not obtain any evidences that the radioactive materials are particulate with larger than 0.1 micro meter. Further analysis will need to identify the source of radioactive spots from individual particles using a manipulator as well as SEM and IP. Such studies will reveal where the radioactive materials exist in the environment, how they resuspend in the air, and how they could

  20. The Accident at TEPCO's Fukushima-Daiichi Nuclear Power Plant: Technical Description of What Happened and Lessons Learned for the Future

    NASA Astrophysics Data System (ADS)

    Omoto, Akira

    2012-02-01

    Tsunami that followed M9.0 earthquake on March 11^th left the Fukushima-Daiichi Nuclear Power Plants without power and heat sink. While water makeup continued by AC-independent systems to keep the fuel core covered by coolant, operating team tried to depressurize and enable low pressure injection to the reactor to avoid overheating but was not successful enough primarily due to limited available resources. This resulted in core melt, hydrogen explosion and release of radioactivity to the environment. Key lessons learned are; 1) safety regulation and safety culture, 2) workable/executable severe accident management procedure, 3) crisis management and 4) design. Implications on security include revealed vulnerability and the nexus of safety and security. Given the scale of damage to the environmental, attention must be paid to defense against it and to societal safety goal of nuclear power by considering offsite remedial costs, compensation to damage, energy replacement cost etc. A sort of root cause analysis first by asking ``Why nuclear community failed to prevent this accident?'' was initiated by the University of Tokyo.

  1. Detailed deposition density maps constructed by large-scale soil sampling for gamma-ray emitting radioactive nuclides from the Fukushima Dai-ichi Nuclear Power Plant accident.

    PubMed

    Saito, Kimiaki; Tanihata, Isao; Fujiwara, Mamoru; Saito, Takashi; Shimoura, Susumu; Otsuka, Takaharu; Onda, Yuichi; Hoshi, Masaharu; Ikeuchi, Yoshihiro; Takahashi, Fumiaki; Kinouchi, Nobuyuki; Saegusa, Jun; Seki, Akiyuki; Takemiya, Hiroshi; Shibata, Tokushi

    2015-01-01

    Soil deposition density maps of gamma-ray emitting radioactive nuclides from the Fukushima Dai-ichi Nuclear Power Plant (NPP) accident were constructed on the basis of results from large-scale soil sampling. In total 10,915 soil samples were collected at 2168 locations. Gamma rays emitted from the samples were measured by Ge detectors and analyzed using a reliable unified method. The determined radioactivity was corrected to that of June 14, 2011 by considering the intrinsic decay constant of each nuclide. Finally the deposition maps were created for (134)Cs, (137)Cs, (131)I, (129m)Te and (110m)Ag. The radioactivity ratio of (134)Cs-(137)Cs was almost constant at 0.91 regardless of the locations of soil sampling. The radioactivity ratios of (131)I and (129m)Te-(137)Cs were relatively high in the regions south of the Fukushima NPP site. Effective doses for 50 y after the accident were evaluated for external and inhalation exposures due to the observed radioactive nuclides. The radiation doses from radioactive cesium were found to be much higher than those from the other radioactive nuclides.

  2. (90)Sr in teeth of cattle abandoned in evacuation zone: Record of pollution from the Fukushima-Daiichi Nuclear Power Plant accident.

    PubMed

    Koarai, Kazuma; Kino, Yasushi; Takahashi, Atsushi; Suzuki, Toshihiko; Shimizu, Yoshinaka; Chiba, Mirei; Osaka, Ken; Sasaki, Keiichi; Fukuda, Tomokazu; Isogai, Emiko; Yamashiro, Hideaki; Oka, Toshitaka; Sekine, Tsutomu; Fukumoto, Manabu; Shinoda, Hisashi

    2016-04-05

    Here we determined the (90)Sr concentrations in the teeth of cattle abandoned in the evacuation area of the Fukushima-Daiichi Nuclear Power Plant (FNPP) accident. (90)Sr activity concentrations in the teeth varied from 6-831 mBq (g Ca)(-1) and exhibited a positive relationship with the degree of radioactive contamination that the cattle experienced. Even within an individual animal, the specific activity of (90)Sr (Bq (g Sr)(-1)) varied depending on the development stage of the teeth during the FNPP accident: teeth that were early in development exhibited high (90)Sr specific activities, while teeth that were late in development exhibited low specific activities. These findings demonstrate that (90)Sr is incorporated into the teeth during tooth development; thus, tooth (90)Sr activity concentrations reflect environmental (90)Sr levels during tooth formation. Assessment of (90)Sr in teeth could provide useful information about internal exposure to (90)Sr radiation and allow for the measurement of time-course changes in the degree of environmental (90)Sr pollution.

  3. 90Sr in teeth of cattle abandoned in evacuation zone: Record of pollution from the Fukushima-Daiichi Nuclear Power Plant accident

    NASA Astrophysics Data System (ADS)

    Koarai, Kazuma; Kino, Yasushi; Takahashi, Atsushi; Suzuki, Toshihiko; Shimizu, Yoshinaka; Chiba, Mirei; Osaka, Ken; Sasaki, Keiichi; Fukuda, Tomokazu; Isogai, Emiko; Yamashiro, Hideaki; Oka, Toshitaka; Sekine, Tsutomu; Fukumoto, Manabu; Shinoda, Hisashi

    2016-04-01

    Here we determined the 90Sr concentrations in the teeth of cattle abandoned in the evacuation area of the Fukushima-Daiichi Nuclear Power Plant (FNPP) accident. 90Sr activity concentrations in the teeth varied from 6–831 mBq (g Ca)‑1 and exhibited a positive relationship with the degree of radioactive contamination that the cattle experienced. Even within an individual animal, the specific activity of 90Sr (Bq (g Sr)‑1) varied depending on the development stage of the teeth during the FNPP accident: teeth that were early in development exhibited high 90Sr specific activities, while teeth that were late in development exhibited low specific activities. These findings demonstrate that 90Sr is incorporated into the teeth during tooth development; thus, tooth 90Sr activity concentrations reflect environmental 90Sr levels during tooth formation. Assessment of 90Sr in teeth could provide useful information about internal exposure to 90Sr radiation and allow for the measurement of time-course changes in the degree of environmental 90Sr pollution.

  4. 90Sr in teeth of cattle abandoned in evacuation zone: Record of pollution from the Fukushima-Daiichi Nuclear Power Plant accident

    PubMed Central

    Koarai, Kazuma; Kino, Yasushi; Takahashi, Atsushi; Suzuki, Toshihiko; Shimizu, Yoshinaka; Chiba, Mirei; Osaka, Ken; Sasaki, Keiichi; Fukuda, Tomokazu; Isogai, Emiko; Yamashiro, Hideaki; Oka, Toshitaka; Sekine, Tsutomu; Fukumoto, Manabu; Shinoda, Hisashi

    2016-01-01

    Here we determined the 90Sr concentrations in the teeth of cattle abandoned in the evacuation area of the Fukushima-Daiichi Nuclear Power Plant (FNPP) accident. 90Sr activity concentrations in the teeth varied from 6–831 mBq (g Ca)−1 and exhibited a positive relationship with the degree of radioactive contamination that the cattle experienced. Even within an individual animal, the specific activity of 90Sr (Bq (g Sr)−1) varied depending on the development stage of the teeth during the FNPP accident: teeth that were early in development exhibited high 90Sr specific activities, while teeth that were late in development exhibited low specific activities. These findings demonstrate that 90Sr is incorporated into the teeth during tooth development; thus, tooth 90Sr activity concentrations reflect environmental 90Sr levels during tooth formation. Assessment of 90Sr in teeth could provide useful information about internal exposure to 90Sr radiation and allow for the measurement of time-course changes in the degree of environmental 90Sr pollution. PMID:27045764

  5. Supplementary documentation for an Environmental Impact Statement regarding the Pantex Plant: radiological consequences of immediate inhalation of plutonium dispersed by postulated accidents

    SciTech Connect

    Elder, J.C.; Olsher, R.H.; Graf, J.M.

    1982-12-01

    This report documents work performed in support of preparation of an Environmental Impact Statement (EIS) regarding the Department of Energy's (DOE) Pantex Plant near Amarillo, Texas. It describes methods used to estimate potential health consequences offsite resulting from inhalation of plutonium dispersed by each of several postulated accidents. The primary topic of this report is the delayed health effects of the plutonium in a nonnuclear detonation debris inhaled directly by members of the population in the cloud path. The expected form and size of the plutonium particles are derived from experimental data obatined in the Roller Coaster test series of 1963. Retention characteristics based on the International Commission on Radiation Protection (ICRP) Task Group Lung Model and organ dose calculations based on a modified computer model are described. Health risk estimates based on organ dose are made using appropriate risk factors recommended by international radiation protection organizations. The relative seriousness of each accident at each alternative site is assessed on the basis of the health risk estiamtes.

  6. 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.

  7. Criticality analysis for weapon disassembly at the Pantex-Plant part II: Staging

    SciTech Connect

    Knief, R.A.

    1997-06-01

    This paper very briefly describes criticality investigations for nuclear weapon dismantlement at the Pantex Plant. The investigations performed were for pit staging, and build on previous criticality calculations for single pits. The KENO and MCNP computer models were used for pit and container combinations. Scenarios were based on administrative limits and actual or potential physical conditions in the facilities. Essentially all of the pit configurations modeled were subcritical by a substantial amount. It was concluded that a critical configuration involving pit/container combinations is not credible.

  8. 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

  9. Cytogenetic biodosimetry for Fukushima travelers after the nuclear power plant accident: no evidence of enhanced yield of dicentrics.

    PubMed

    Lee, Jin Kyung; Han, Eun-Ae; Lee, Seung-Sook; Ha, Wi-Ho; Barquinero, Joan Francesc; Lee, Hyo Rak; Cho, Min Su

    2012-11-01

    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.

  10. Characteristics of initial deposition and behavior of radiocesium in forest ecosystems of different locations and species affected by the Fukushima Daiichi Nuclear Power Plant accident.

    PubMed

    Komatsu, Masabumi; Kaneko, Shinji; Ohashi, Shinta; Kuroda, Katsushi; Sano, Tetsuya; Ikeda, Shigeto; Saito, Satoshi; Kiyono, Yoshiyuki; Tonosaki, Mario; Miura, Satoru; Akama, Akio; Kajimoto, Takuya; Takahashi, Masamichi

    2016-09-01

    After the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident, information about stand-level spatial patterns of radiocesium initially deposited in the surrounding forests was essential for predicting the future dynamics of radiocesium and suggesting a management plan for contaminated forests. In the first summer (approximately 6 months after the accident), we separately estimated the amounts of radiocesium ((134)Cs and (137)Cs; Bq m(-2)) in the major components (trees, organic layers, and soils) in forests of three sites with different contamination levels. For a Japanese cedar (Cryptomeria japonica) forest studied at each of the three sites, the radiocesium concentration greatly differed among the components, with the needle and organic layer having the highest concentrations. For these cedar forests, the proportion of the (137)Cs stock in the aboveground tree biomass varied from 22% to 44% of the total (137)Cs stock; it was 44% in highly contaminated sites (7.0 × 10(5) Bq m(-2)) but reduced to 22% in less contaminated sites (1.1 × 10(4) Bq m(-2)). In the intermediate contaminated site (5.0-5.8 × 10(4) Bq m(-2)), 34% of radiocesium was observed in the aboveground tree biomass of the Japanese cedar stand. However, this proportion was considerably smaller (18-19%) in the nearby mixed forests of the Japanese red pine (Pinus densiflora) and deciduous broad-leaved trees. Non-negligible amounts of (134)Cs and (137)Cs were detected in both the sapwood and heartwood of all the studied tree species. This finding suggested that the uptake or translocation of radiocesium had already started within 6 months after the accident. The belowground compartments were mostly present in the organic layer and the uppermost (0-5 cm deep) mineral soil layer at all the study sites. We discussed the initial transfer process of radiocesium deposited in the forest and inferred that the type of initial deposition (i.e., dry versus wet radiocesium deposition), the amount of

  11. One-year, regional-scale simulation of 137Cs radioactivity in the ocean following the Fukushima Daiichi Nuclear Power Plant accident

    NASA Astrophysics Data System (ADS)

    Tsumune, D.; Tsubono, T.; Aoyama, M.; Uematsu, M.; Misumi, K.; Maeda, Y.; Yoshida, Y.; Hayami, H.

    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. A 1 yr, regional-scale simulation of 137Cs activity in the ocean offshore of Fukushima was 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. Direct releases of 131I, 134Cs, and 137Cs were estimated for 1 yr after the accident by comparing simulated results and measured activities. The estimated total amounts of directly released 131I, 134Cs, and 137Cs were 11.1 ± 2.2 PBq, 3.5 ± 0.7 PBq, and 3.6 ± 0.7 PBq, respectively. 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 to measured activities. The rate of atmospheric deposition onto the ocean was underestimated because of a~lack of measurements of deposition onto the ocean when atmospheric deposition rates were being estimated. Measured 137Cs activities attributable to atmospheric deposition helped to improve the accuracy of simulated atmospheric deposition rates. Simulated 137Cs activities attributable to the inflow of 137Cs deposited onto the ocean outside the domain of the model were in good agreement with measured activities in the open ocean within the model domain after June 2012. The contribution of inflow increased with time and was dominant (more than 99%) by the end of

  12. Barriers, pathways and processes for uptake, translocation and accumulation of nanomaterials in plants--Critical review.

    PubMed

    Schwab, Fabienne; Zhai, Guangshu; Kern, Meaghan; Turner, Amalia; Schnoor, Jerald L; Wiesner, Mark R

    2016-01-01

    Uptake, transport and toxicity of engineered nanomaterials (ENMs) into plant cells are complex processes that are currently still not well understood. Parts of this problem are the multifaceted plant anatomy, and analytical challenges to visualize and quantify ENMs in plants. We critically reviewed the currently known ENM uptake, translocation, and accumulation processes in plants. A vast number of studies showed uptake, clogging, or translocation in the apoplast of plants, most notably of nanoparticles with diameters much larger than the commonly assumed size exclusion limit of the cell walls of ∼5-20 nm. Plants that tended to translocate less ENMs were those with low transpiration, drought-tolerance, tough cell wall architecture, and tall growth. In the absence of toxicity, accumulation was often linearly proportional to exposure concentration. Further important factors strongly affecting ENM internalization are the cell wall composition, mucilage, symbiotic microorganisms (mycorrhiza), the absence of a cuticle (submerged plants) and stomata aperture. Mostly unexplored are the roles of root hairs, leaf repellency, pit membrane porosity, xylem segmentation, wounding, lateral roots, nodes, the Casparian band, hydathodes, lenticels and trichomes. The next steps towards a realistic risk assessment of nanoparticles in plants are to measure ENM uptake rates, the size exclusion limit of the apoplast and to unravel plant physiological features favoring uptake.

  13. 76 FR 61599 - Endangered and Threatened Wildlife and Plants; Revised Critical Habitat for the Marbled Murrelet

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-05

    ... Fish and Wildlife Service 50 CFR Part 17 RIN 1018-AW84 Endangered and Threatened Wildlife and Plants; Revised Critical Habitat for the Marbled Murrelet AGENCY: Fish and Wildlife Service, Interior. ACTION: Final rule. SUMMARY: We, the U.S. Fish and Wildlife Service (Service), are revising designated...

  14. Radiocesium contaminations of 20 wood species and the corresponding gamma-ray dose rates around the canopies at 5 months after the Fukushima nuclear power plant accident.

    PubMed

    Yoshihara, Toshihiro; Matsumura, Hideyuki; Hashida, Shin-nosuke; Nagaoka, Toru

    2013-01-01

    Radiocesium ((134)Cs + (137)Cs) deposition from the Fukushima nuclear power plant accident was measured in 20 woody plants (12 evergreen and 8 deciduous species) grown in Abiko (approximately 200 km SSW from the NPP). Leaves (needles) and twigs were sampled from each of three foliar positions (top, middle, and bottom) in the plant canopy in early August 2011. At the time, soils around the plants were also sampled, and gamma radiation dose rates were measured at each sampling position. The average radiocesium activity in the observed leaves of the evergreen species was 7.7 times that in the leaves of the deciduous species. Among the observed evergreen coniferous species, the activity in pre-fallout-expanded leaves was 2.4 times that in the post-fallout-expanded leaves. Notably, a distinct variation in the activity among the evergreen coniferous species could be observed for the post-fallout-expanded leaves but not for the pre-fallout-expanded leaves. Although these differences depend on whether the leaves had expanded at the time of the fallout, it is probable that a considerable amount of radiocesium was translocated to newly developed leaves at a species-specific rate. In addition, it was demonstrated that dose rates around woody plants were not consistent with the prevailing prediction that general dose rates correspondingly decrease with monitoring height from the ground. Thus, the dose rates in the top foliar layer of the deciduous species decreased more than predicted, whereas those in the top foliar layer of the coniferous species did not decrease. This may be due to differences in the balance between the attenuation resulting from a shielding effect of the plant bodies and the higher radiocesium accumulation in the leaves.

  15. Size-dependent distribution of radiocesium in riverbed sediments and its relevance to the migration of radiocesium in river systems after the Fukushima Daiichi Nuclear Power Plant accident.

    PubMed

    Tanaka, Kazuya; Iwatani, Hokuto; Sakaguchi, Aya; Fan, Qiaohui; Takahashi, Yoshio

    2015-01-01

    We investigated the particle size distribution of radiocesium in riverbed sediments after the Fukushima Daiichi Nuclear Power Plant accident. Riverbed sediments were collected in the Abukuma River system in Fukushima and Miyagi Prefectures. The collected sediments were separated into 11 fractions, ranging from granular size (>2000 μm) to clay size (<2 μm) fractions. Cesium-137 concentrations were higher in the smaller particle size fractions, possibly reflecting specific surface areas and the mineralogy, in particular the clay mineral content. A gap in (137)Cs concentration was observed between the silt size and sand size fractions of riverbed sediments at downstream sites, whereas riverbed sediments at an upstream site did not show such a concentration gap. It is likely that selective transport of small particles in suspended state from upstream areas resulted in an accumulation of radiocesium in downstream areas.

  16. Apparatus development for measurement of (134)Cs and (137)Cs radioactivity of soil contaminated by the Fukushima Daiichi Nuclear Power Plant accident.

    PubMed

    Kajimoto, Tsuyoshi; Endo, Satoru; Tanaka, Kenichi; Okashiro, Yasuharu; Kai, Hiroaki; Fujii, Syuuji; Mishima, Atsushi; Matsubara, Takahide; Yoshida, Shinji

    2016-09-01

    We developed an apparatus containing a NaI(Tl) scintillator to measure the (134)Cs and (137)Cs radioactivity of soil contaminated by the Fukushima Daiichi Nuclear Power Plant accident. The unfolding method with the least-squares technique was used to determine the radioactivity. Detector responses for each radionuclide in soil were calculated with EGS5 code for the unfolding method. The radionuclides that were measured were (40)K, (134)Cs, (137)Cs, (208)Tl, (214)Bi, and (228)Ac. The measured spectrum agreed well with the spectrum calculated from the response matrix and measured radioactivities. The unfolding method allows us to use the NaI(Tl) scintillator despite the overlap of peaks.

  17. Natural variation of ambient dose rate in the air of Izu-Oshima Island after the Fukushima Daiichi Nuclear Power Plant accident.

    PubMed

    Maedera, Fumihiko; Inoue, Kazumasa; Sugino, Masato; Sano, Ryosuke; Furue, Mai; Shimizu, Hideo; Tsuruoka, Hiroshi; Le Van, Tan; Fukushi, Masahiro

    2016-03-01

    The ambient dose rate in air and radioactivity concentration in soil samples collected on Izu-Oshima Island were observed in 2012, 2013 and 2014, i.e. 1, 2 and 3 years after the severe accident at the Fukushima Daiichi Nuclear Power Plant. A car-borne survey for the ambient dose rate in air was carried out for the entire island. Soil samples were collected for the radioactivity concentration measurements from 22 points. The ambient dose rates in air were 36 nGy h(-1) in 2012, 34 nGy h(-1) in 2013 and 29 nGy h(-1) in 2014. The corresponding radioactivity concentrations in those years for (134)Cs were 53, 39 and 29 Bq kg(-1) and for (137)Cs, 87, 73 and 75 Bq kg(-1). All the values have decreased every year.

  18. Can we remove iodine-131 from tap water in Japan by boiling? - Experimental testing in response to the Fukushima Daiichi Nuclear Power Plant accident.

    PubMed

    Tagami, K; Uchida, S

    2011-08-01

    Iodine-131 concentrations in tap water higher than 100 BqL(-1) were reported by several local governments in Japan following the Fukushima Daiichi Nuclear Power Plant accident. Some individuals in the emergency-response community recommended the boiling of tap water to remove iodine-131. However, the tap water boiling tests in this study showed no iodine-131 loss from the tap water with either short-term boiling (1-10 min) or prolonged boiling (up to 30 min) resulting in up to 3-fold volume reductions. In this situation, boiling was shown to be not effective in removing iodine-131 from tap water; indeed even higher concentrations may result from the liquid-volume reduction accompanying this process.

  19. The Chornobyl Accident: A Comprehensive Risk Assessment

    SciTech Connect

    Poyarkov, Victor A.; Vargo, George J.; George J. Vargo

    2000-01-01

    This book provides a comprehensive of the April 1986 Chornobyl Nuclear Power Plant accident and its short and long-term effects in the fourteen years since the accident. Chapters include: cause and description of the accident; the Shelter constructed to contain the remains the destroyed reactor, radioactive wastes arising from the accident, environmental contamination, individual and collective radiation doses, societal aspects, economic impact and conclusions. Appendices on radiological units, the medical consequences of the accident, and a list of acronym and abbreviations are included.

  20. A review of accidents, prevention and mitigation options related to hazardous gases

    SciTech Connect

    Fthenakis, V.M.

    1993-05-01

    Statistics on industrial accidents are incomplete due to lack of specific criteria on what constitutes a release or accident. In this country, most major industrial accidents were related to explosions and fires of flammable materials, not to releases of chemicals into the environment. The EPA in a study of 6,928 accidental releases of toxic chemicals revealed that accidents at stationary facilities accounted for 75% of the total number of releases, and transportation accidents for the other 25%. About 7% of all reported accidents (468 cases) resulted in 138 deaths and 4,717 injuries ranging from temporary respiratory problems to critical injuries. In-plant accidents accounted for 65% of the casualties. The most efficient strategy to reduce hazards is to choose technologies which do not require the use of large quantities of hazardous gases. For new technologies this approach can be implemented early in development, before large financial resources and efforts are committed to specific options. Once specific materials and options have been selected, strategies to prevent accident initiating events need to be evaluated and implemented. The next step is to implement safety options which suppress a hazard when an accident initiating event occurs. Releases can be prevented or reduced with fail-safe equipment and valves, adequate warning systems and controls to reduce and interrupt gas leakage. If an accident occurs and safety systems fail to contain a hazardous gas release, then engineering control systems will be relied on to reduce/minimize environmental releases. As a final defensive barrier, the prevention of human exposure is needed if a hazardous gas is released, in spite of previous strategies. Prevention of consequences forms the final defensive barrier. Medical facilities close by that can accommodate victims of the worst accident can reduce the consequences of personnel exposure to hazardous gases.

  1. A critical comparison of two high-throughput ascorbate analyses methods for plant samples.

    PubMed

    Ueda, Yoshiaki; Wu, Linbo; Frei, Michael

    2013-09-01

    Ascorbate (AsA) is an important metabolite involved in stress response and development of plants. Therefore it is necessary to quantify the AsA content in many fields of plant science, including high throughput and critical applications. In this study we compared two different microplate-based AsA assays, which are suitable for high throughput applications: an ascorbate oxidase (AO)-based assay and a dipyridyl (DPD)-based assay. These methods were compared in critical applications, i.e. (i) when AsA concentrations were very low such as in apoplastic extracts, (ii) when plants contained pigments interfering with the spectrometric measurements, and (iii) when plants contained high iron concentration interfering with the color reactions. The precision of measurements was higher with the DPD method, as illustrated by higher recovery rates of internal AsA standards. On the other hand, the AO method was more sensitive to low levels of AsA. This was an advantage in determining apoplastic AsA concentration in rice, which was substantially lower than that of whole tissues. The AO method also had the advantage that plant pigments and high iron concentrations in plants tissues did not interfere with the analysis, as opposed to the DPD assay. In conclusion, both assays had advantages and the choice of a suitable method depends on the specific application.

  2. Predicting the long-term (137)Cs distribution in Fukushima after the Fukushima Dai-ichi nuclear power plant accident: a parameter sensitivity analysis.

    PubMed

    Yamaguchi, Masaaki; Kitamura, Akihiro; Oda, Yoshihiro; Onishi, Yasuo

    2014-09-01

    than those of the other rivers. Annual sediment outflows from the Abukuma River and the total from the other 13 river basins were calculated as 3.2 × 10(4)-3.1 × 10(5) and 3.4 × 10(4)-2.1 × 10(5)ty(-1), respectively. The values vary between calculation cases because of the critical shear stress, the rainfall factor, and other differences. On the other hand, contributions of those parameters were relatively small for (137)Cs concentration within transported soil. This indicates that the total amount of (137)Cs outflow into the ocean would mainly be controlled by the amount of soil erosion and transport and the total amount of (137)Cs concentration remaining within the basin. Outflows of (137)Cs from the Abukuma River and the total from the other 13 river basins during the first year after the accident were calculated to be 2.3 × 10(11)-3.7 × 10(12) and 4.6 × 10(11)-6.5 × 10(12)Bqy(-1), respectively. The former results were compared with the field investigation results, and the order of magnitude was matched between the two, but the value of the investigation result was beyond the upper limit of model prediction.

  3. Evaluation of Risk Perception and Risk-Comparison Information Regarding Dietary Radionuclides after the 2011 Fukushima Nuclear Power Plant Accident

    PubMed Central

    Murakami, Michio; Nakatani, Jun; Oki, Taikan

    2016-01-01

    In the wake of the 2011 Fukushima Daiichi Nuclear Power Station accident, to facilitate evidence-based risk communication we need to understand radiation risk perception and the effectiveness of risk-comparison information. We measured and characterized perceptions of dread risks and unknown risks regarding dietary radionuclides in residents of Fukushima, Tokyo, and Osaka to identify the primary factors among location, evacuation experience, gender, age, employment status, absence/presence of spouse, children and grandchildren, educational background, humanities/science courses, smoking habits, and various types of trustworthy information sources. We then evaluated the effects of these factors and risk-comparison information on multiple outcomes, including subjective and objective understanding, perceived magnitude of risk, perceived accuracy of information, backlash against information, and risk acceptance. We also assessed how risk-comparison information affected these multiple outcomes for people with high risk perception. Online questionnaires were completed by people (n = 9249) aged from 20 to 69 years in the three prefectures approximately 5 years after the accident. We gave each participant one of 15 combinations of numerical risk data and risk-comparison information, including information on standards, smoking-associated risk, and cancer risk, in accordance with Covello’s guidelines. Dread-risk perception among Fukushima residents with no experience of evacuation was much lower than that in Osaka residents, whereas evacuees had strikingly higher dread-risk perception, irrespective of whether their evacuation had been compulsory or voluntary. We identified location (distance from the nuclear power station), evacuation experience, and trust of central government as primary factors. Location (including evacuation experience) and trust of central government were significantly associated with the multiple outcomes above. Only information on “cancer risk from

  4. Evaluation of Risk Perception and Risk-Comparison Information Regarding Dietary Radionuclides after the 2011 Fukushima Nuclear Power Plant Accident.

    PubMed

    Murakami, Michio; Nakatani, Jun; Oki, Taikan

    2016-01-01

    In the wake of the 2011 Fukushima Daiichi Nuclear Power Station accident, to facilitate evidence-based risk communication we need to understand radiation risk perception and the effectiveness of risk-comparison information. We measured and characterized perceptions of dread risks and unknown risks regarding dietary radionuclides in residents of Fukushima, Tokyo, and Osaka to identify the primary factors among location, evacuation experience, gender, age, employment status, absence/presence of spouse, children and grandchildren, educational background, humanities/science courses, smoking habits, and various types of trustworthy information sources. We then evaluated the effects of these factors and risk-comparison information on multiple outcomes, including subjective and objective understanding, perceived magnitude of risk, perceived accuracy of information, backlash against information, and risk acceptance. We also assessed how risk-comparison information affected these multiple outcomes for people with high risk perception. Online questionnaires were completed by people (n = 9249) aged from 20 to 69 years in the three prefectures approximately 5 years after the accident. We gave each participant one of 15 combinations of numerical risk data and risk-comparison information, including information on standards, smoking-associated risk, and cancer risk, in accordance with Covello's guidelines. Dread-risk perception among Fukushima residents with no experience of evacuation was much lower than that in Osaka residents, whereas evacuees had strikingly higher dread-risk perception, irrespective of whether their evacuation had been compulsory or voluntary. We identified location (distance from the nuclear power station), evacuation experience, and trust of central government as primary factors. Location (including evacuation experience) and trust of central government were significantly associated with the multiple outcomes above. Only information on "cancer risk from

  5. Consideration of nuclear criticality when disposing of transuranic waste at the Waste Isolation Pilot Plant

    SciTech Connect

    RECHARD,ROBERT P.; SANCHEZ,LAWRENCE C.; STOCKMAN,CHRISTINE T.; TRELLUE,HOLLY R.

    2000-04-01

    Based on general arguments presented in this report, nuclear criticality was eliminated from performance assessment calculations for the Waste Isolation Pilot Plant (WIPP), a repository for waste contaminated with transuranic (TRU) radioisotopes, located in southeastern New Mexico. At the WIPP, the probability of criticality within the repository is low because mechanisms to concentrate the fissile radioisotopes dispersed throughout the waste are absent. In addition, following an inadvertent human intrusion into the repository (an event that must be considered because of safety regulations), the probability of nuclear criticality away from the repository is low because (1) the amount of fissile mass transported over 10,000 yr is predicted to be small, (2) often there are insufficient spaces in the advective pore space (e.g., macroscopic fractures) to provide sufficient thickness for precipitation of fissile material, and (3) there is no credible mechanism to counteract the natural tendency of the material to disperse during transport and instead concentrate fissile material in a small enough volume for it to form a critical concentration. Furthermore, before a criticality would have the potential to affect human health after closure of the repository--assuming that a criticality could occur--it would have to either (1) degrade the ability of the disposal system to contain nuclear waste or (2) produce significantly more radioisotopes than originally present. Neither of these situations can occur at the WIPP; thus, the consequences of a criticality are also low.

  6. Nuclear criticality safety evaluation of large cylinder cleaning operations in X-705, Portsmouth Gaseous diffusion Plant

    SciTech Connect

    Sheaffer, M.K.; Keeton, S.C.; Lutz, H.F.

    1995-06-01

    This report evaluates nuclear criticality safety for large cylinder cleaning operations in the Decontamination and Recovery Facility, X-705, at the Portsmouth Gaseous Diffusion Plant. A general description of current cleaning procedures and required hardware/equipment is presented, and documentation for large cylinder cleaning operations is identified and described. Control parameters, design features, administrative controls, and safety systems relevant to nuclear criticality are discussed individually, followed by an overall assessment based on the Double Contingency Principle. Recommendations for enhanced safety are suggested, and issues for increased efficiency are presented.

  7. Behaviour of oceanic 137Cs following the Fukushima Daiichi Nuclear Power Plant accident for four years simulated numerically by a regional ocean model

    NASA Astrophysics Data System (ADS)

    Torn, M. S.; Koven, C. D.; Riley, W. J.; Zhu, B.; Hicks Pries, C.; Phillips, C. L.

    2014-12-01

    A series of accidents at the Fukushima Dai-ichi Nuclear Power Plant (1F NPP) 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 regional ocean for four years by numerical model, such as 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. Direct release rate of 137Cs were estimated for four years after the accident by comparing simulated results and observed activities very close to the site. The estimated total amounts of directly release 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. Decrease rate were quite small after 2013. The daily release rate of 137Cs was estimated to be the order of magnitude of 1010 Bq/day by the end of March 2015. 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. There is no observed data of 137Cs activity in the ocean from 11 to 21 March 2011. Observed data of marine biota should reflect the history of 137Cs activity in this early period. We reconstructed the history of 137Cs activity in this early period by considering atmospheric deposition, river input, rain water runoff from the 1F NPP site. The comparisons between simulated 137Cs activity of marine biota by a dynamic biological compartment and observed data also suggest that simulated 137Cs activity attributable to atmospheric deposition was underestimated in this early period. The

  8. Behaviour of oceanic 137Cs following the Fukushima Daiichi Nuclear Power Plant accident for four years simulated numerically by a regional ocean model

    NASA Astrophysics Data System (ADS)

    Tsumune, D.; Tsubono, T.; Aoyama, M.; Misumi, K.; Tateda, Y.

    2015-12-01

    A series of accidents at the Fukushima Dai-ichi Nuclear Power Plant (1F NPP) 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 regional ocean for four years by numerical model, such as 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. Direct release rate of 137Cs were estimated for four years after the accident by comparing simulated results and observed activities very close to the site. The estimated total amounts of directly release 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. Decrease rate were quite small after 2013. The daily release rate of 137Cs was estimated to be the order of magnitude of 1010 Bq/day by the end of March 2015. 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. There is no observed data of 137Cs activity in the ocean from 11 to 21 March 2011. Observed data of marine biota should reflect the history of 137Cs activity in this early period. We reconstructed the history of 137Cs activity in this early period by considering atmospheric deposition, river input, rain water runoff from the 1F NPP site. The comparisons between simulated 137Cs activity of marine biota by a dynamic biological compartment and observed data also suggest that simulated 137Cs activity attributable to atmospheric deposition was underestimated in this early period. The

  9. Availability of Japanese Government's supplemental texts on radiation reflecting the Fukushima Daiichi Nuclear Power Plant accident for elementary and secondary education from dental students' understanding.

    PubMed

    Yoshida, Midori; Honda, Eiichi; Dashpuntsag, Oyunbat; Maeda, Naoki; Hosoki, Hidehiko; Sakama, Minoru; Tada, Toshiko

    2016-05-01

    Following the Fukushima Nuclear Power Plant accident, the Japanese government created two supplemental texts about radiation reflecting the accident for elementary, middle school, and high school students. These texts were made to explain radiation and consequently to obtain public consent for the continuation of the nuclear program. The present study aimed to evaluate the appropriateness of the content of the texts and to collect the basic data on the level of understanding necessary to improve radiation education. Lectures on radiology including nuclear energy and the Fukushima accident were given to 44 fourth-year dental students in 2013. The questionnaire was administered in 2014 when these students were in their sixth-year. The survey was also administered to 40 first-year students and 41 fourth-year students who hadn't any radiology lectures. Students rated their level of understanding of 50 phrases used in the texts on a four-point scale (understanding = 3, a little knowledge = 2, having heard = 1, no knowledge = 0). Questions on taking an advanced physics course in high school and means of learning about radiation in daily life were also asked. The level of understanding of phrases in the supplemental text for middle and high school students was significantly higher among sixth-year students (mean = 1.43) than among first-year (mean = 1.12) or fourth-year (mean = 0.93) students (p < 0.05). Overall, the level of understanding was low, with scores indicating that most students knew only a little. First-year students learning about radiation from television but four-year and six-year students learning about radiation from newspaper scored significantly higher (p < 0.05). It was concluded that radiation education should be improved by using visual material and preparing educators to teach the material for improving the public's understanding of radiation use-especially nuclear power generation because the phrases used in the supplementary texts are very

  10. Increases in perinatal mortality in prefectures contaminated by the Fukushima nuclear power plant accident in Japan: A spatially stratified longitudinal study.

    PubMed

    Scherb, Hagen Heinrich; Mori, Kuniyoshi; Hayashi, Keiji

    2016-09-01

    Descriptive observational studies showed upward jumps in secular European perinatal mortality trends after Chernobyl. The question arises whether the Fukushima nuclear power plant accident entailed similar phenomena in Japan. For 47 prefectures representing 15.2 million births from 2001 to 2014, the Japanese government provides monthly statistics on 69,171 cases of perinatal death of the fetus or the newborn after 22 weeks of pregnancy to 7 days after birth. Employing change-point methodology for detecting alterations in longitudinal data, we analyzed time trends in perinatal mortality in the Japanese prefectures stratified by exposure to estimate and test potential increases in perinatal death proportions after Fukushima possibly associated with the earthquake, the tsunami, or the estimated radiation exposure. Areas with moderate to high levels of radiation were compared with less exposed and unaffected areas, as were highly contaminated areas hit versus untroubled by the earthquake and the tsunami. Ten months after the earthquake and tsunami and the subsequent nuclear accident, perinatal mortality in 6 severely contaminated prefectures jumped up from January 2012 onward: jump odds ratio 1.156; 95% confidence interval (1.061, 1.259), P-value 0.0009. There were slight increases in areas with moderate levels of contamination and no increases in the rest of Japan. In severely contaminated areas, the increases of perinatal mortality 10 months after Fukushima were essentially independent of the numbers of dead and missing due to the earthquake and the tsunami. Perinatal mortality in areas contaminated with radioactive substances started to increase 10 months after the nuclear accident relative to the prevailing and stable secular downward trend. These results are consistent with findings in Europe after Chernobyl. Since observational studies as the one presented here may suggest but cannot prove causality because of unknown and uncontrolled factors or confounders

  11. JMA's regional atmospheric transport model calculations for the WMO technical task team on meteorological analyses for Fukushima Daiichi Nuclear Power Plant accident.

    PubMed

    Saito, Kazuo; Shimbori, Toshiki; Draxler, Roland

    2015-01-01

    The World Meteorological Organization (WMO) convened a small technical task team of experts to produce a set of meteorological analyses to drive atmospheric transport, dispersion and deposition models (ATDMs) for the United Nations Scientific Committee on the Effects of Atomic Radiation's assessment of the Fukushima Daiichi Nuclear Power Plant (DNPP) accident. The Japan Meteorological Agency (JMA) collaborated with the WMO task team as the regional specialized meteorological center of the country where the accident occurred, and provided its operational 5-km resolution mesoscale (MESO) analysis and its 1-km resolution radar/rain gauge-analyzed precipitation (RAP) data. The JMA's mesoscale tracer transport model was modified to a regional ATDM for radionuclides (RATM), which included newly implemented algorithms for dry deposition, wet scavenging, and gravitational settling of radionuclide aerosol particles. Preliminary and revised calculations of the JMA-RATM were conducted according to the task team's protocol. Verification against Cesium 137 ((137)Cs) deposition measurements and observed air concentration time series showed that the performance of RATM with MESO data was significantly improved by the revisions to the model. The use of RAP data improved the (137)Cs deposition pattern but not the time series of air concentrations at Tokai-mura compared with calculations just using the MESO data. Sensitivity tests of some of the more uncertain parameters were conducted to determine their impacts on ATDM calculations, and the dispersion and deposition of radionuclides on 15 March 2011, the period of some of the largest emissions and deposition to the land areas of Japan. The area with high deposition in the northwest of Fukushima DNPP and the hotspot in the central part of Fukushima prefecture were primarily formed by wet scavenging influenced by the orographic effect of the mountainous area in the west of the Fukushima prefecture.

  12. Analysis of Plasma Protein Concentrations and Enzyme Activities in Cattle within the Ex-Evacuation Zone of the Fukushima Daiichi Nuclear Plant Accident

    PubMed Central

    Endo, Satoru; Tanaka, Kenichi; Hirakawa, Yasuko; Hayashi, Gohei; Sekine, Tsutomu; Kino, Yasushi; Kuwahara, Yoshikazu; Suzuki, Masatoshi; Fukumoto, Motoi; Yamashiro, Hideaki; Abe, Yasuyuki; Fukuda, Tomokazu; Shinoda, Hisashi; Isogai, Emiko; Arai, Toshiro; Fukumoto, Manabu

    2016-01-01

    The effect of the Fukushima Daiichi Nuclear Power Plant (FNPP) accident on humans and the environment is a global concern. We performed biochemical analyses of plasma from 49 Japanese Black cattle that were euthanized in the ex-evacuation zone set within a 20-km radius of FNPP. Among radionuclides attributable to the FNPP accident, germanium gamma-ray spectrometry detected photopeaks only from 134Cs and 137Cs (radiocesium) commonly in the organs and in soil examined. Radioactivity concentration of radiocesium was the highest in skeletal muscles. Assuming that the animal body was composed of only skeletal muscles, the median of internal dose rate from radiocesium was 12.5 μGy/day (ranging from 1.6 to 33.9 μGy/day). The median of external dose rate calculating from the place the cattle were caught was 18.8 μGy/day (6.0–133.4 μGy/day). The median of internal and external (total) dose rate of the individual cattle was 26.9 μGy/day (9.1–155.1 μGy/day). Plasma levels of malondialdehyde and superoxide dismutase activity were positively and glutathione peroxidase activity was negatively correlated with internal dose rate. Plasma alanine transaminase activity and percent activity of lactate dehydrogenase (LDH)-2, LDH-3 and LDH-4 were positively and LDH-1 was negatively correlated with both internal and total dose rate. These suggest that chronic exposure to low-dose rate of ionizing radiation induces slight stress resulting in modified plasma protein and enzyme levels. PMID:27159386

  13. Measurement of soil contamination by radionuclides due to the Fukushima Dai-ichi Nuclear Power Plant accident and associated estimated cumulative external dose estimation.

    PubMed

    Endo, S; Kimura, S; Takatsuji, T; Nanasawa, K; Imanaka, T; Shizuma, K

    2012-09-01

    Soil sampling was carried out at an early stage of the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident. Samples were taken from areas around FDNPP, at four locations northwest of FDNPP, at four schools and in four cities, including Fukushima City. Radioactive contaminants in soil samples were identified and measured by using a Ge detector and included (129 m)Te, (129)Te, (131)I, (132)Te, (132)I, (134)Cs, (136)Cs, (137)Cs, (140)Ba and (140)La. The highest soil depositions were measured to the northwest of FDNPP. From this soil deposition data, variations in dose rates over time and the cumulative external doses at the locations for 3 months and 1y after deposition were estimated. At locations northwest of FDNPP, the external dose rate at 3 months after deposition was 4.8-98 μSv/h and the cumulative dose for 1 y was 51 to 1.0 × 10(3)mSv; the highest values were at Futaba Yamada. At the four schools, which were used as evacuation shelters, and in the four urban cities, the external dose rate at 3 months after deposition ranged from 0.03 to 3.8μSv/h and the cumulative doses for 1 y ranged from 3 to 40 mSv. The cumulative dose at Fukushima Niihama Park was estimated as the highest in the four cities. The estimated external dose rates and cumulative doses show that careful countermeasures and remediation will be needed as a result of the accident, and detailed measurements of radionuclide deposition densities in soil will be important input data to conduct these activities.

  14. Radiation measurements in the Chiba Metropolitan Area and radiological aspects of fallout from the Fukushima Dai-ichi Nuclear Power Plants accident.

    PubMed

    Amano, Hikaru; Akiyama, Masakazu; Chunlei, Bi; Kawamura, Takao; Kishimoto, Takeshi; Kuroda, Tomotaka; Muroi, Takahiko; Odaira, Tomoaki; Ohta, Yuji; Takeda, Kenji; Watanabe, Yushu; Morimoto, Takao

    2012-09-01

    Large amounts of radioactive substances were released into the environment from the Fukushima Dai-ichi Nuclear Power Plants in eastern Japan as a consequence of the great earthquake (M 9.0) and tsunami of 11 March 2011. Radioactive substances discharged into the atmosphere first reached the Chiba Metropolitan Area on 15 March. We collected daily samples of air, fallout deposition, and tap water starting directly after the incident and measured their radioactivity. During the first two months maximum daily concentrations of airborne radionuclides observed at the Japan Chemical Analysis Center in the Chiba Metropolitan Area were as follows: 4.7 × 10(1) Bq m(-3) of (131)I, 7.5 Bq m(-3) of (137)Cs, and 6.1 Bq m(-3) of (134)Cs. The ratio of gaseous iodine to total iodine ranged from 5.2 × 10(-1) to 7.1 × 10(-1). Observed deposition rate maxima were as follows: 1.7 × 10(4) Bq m(-2) d(-1) of (131)I, 2.9 × 10(3) Bq m(-2) d(-1) of (137)Cs, and 2.9 × 10(3) Bq m(-2) d(-1) of (134)Cs. The deposition velocities (ratio of deposition rate to concentration) of cesium radionuclides and (131)I were detectably different. Radioactivity in tap water caused by the accident was detected several days after detection of radioactivity in fallout in the area. Radiation doses were estimated from external radiation and internal radiation by inhalation and ingestion of tap water for people living outdoor in the Chiba Metropolitan Area following the Fukushima accident.

  15. Use of artificial intelligence in severe accident diagnosis for PWRs

    SciTech Connect

    Wu, Zheng; Okrent, D.; Kastenberg, W.E.

    1995-12-31

    A combination approach of an expert system and neural networks is used to implement a prototype severe accident diagnostic system which would monitor the progression of the severe accident and provide necessary plant status information to assist the plant staff in accident management during the accident. The station blackout accident in a pressurized water reactor (PWR) is used as the study case. The current phase of research focus is on distinguishing different primary system failure modes and following the accident transient before and up to vessel breach.

  16. Introduction to the nuclear criticality safety evaluation of facility X-705, Portsmouth Gaseous Diffusion Plant

    SciTech Connect

    Sheaffer, M.K.; Keeton, S.C.

    1993-08-16

    This report is the first in a series of documents that will evaluate nuclear criticality safety in the Decontamination and Recovery Facility, X-705, Portsmouth Gaseous Diffusion Plant. It provides an overview of the facility, categorizes its functions for future analysis, reviews existing NCS documentation, and explains the follow-on effort planned for X-705. A detailed breakdown of systems, subsystems, and operational areas is presented and cross-referenced to existing NCS documentation.

  17. Criticality safety evaluation of Rocky Flats Plant one-gallon shipping containers

    SciTech Connect

    Shaw, M.E.

    1991-12-01

    Criticality safety calculations have been performed to provide an analytical basis for handling, storage and transport of Rocky Flats Plant (RFP) one-gallon shipping containers. A mass limit was establish for metal (solid uranium or plutonium) and slurries (undissolved U or Pu solids in a ``mud,`` ``sludge,`` or ``slurry``). A separate volume limit was developed for plutonium solutions (liquids, either aqueous or organic, containing no visible undissolved solids).

  18. Criticality safety evaluation of Rocky Flats Plant one-gallon shipping containers

    SciTech Connect

    Shaw, M.E.

    1991-12-01

    Criticality safety calculations have been performed to provide an analytical basis for handling, storage and transport of Rocky Flats Plant (RFP) one-gallon shipping containers. A mass limit was establish for metal (solid uranium or plutonium) and slurries (undissolved U or Pu solids in a mud,'' sludge,'' or slurry''). A separate volume limit was developed for plutonium solutions (liquids, either aqueous or organic, containing no visible undissolved solids).

  19. Inferring the chemical form of 137Cs deposited by the Fukushima Dai-ichi Nuclear Power Plant accident by measuring (137)Cs incorporated into needle leaves and male cones of Japanese cedar trees.

    PubMed

    Kanasashi, Tsutomu; Takenaka, Chisato; Sugiura, Yuki

    2016-05-15

    We hypothesized that the water-soluble (ionic) and water-insoluble (stable) radiocesium from the initial fallout of the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident was distributed in various proportions in the surrounding areas and that this distribution was reflected in the trees that suffered deposition from the initial fallout. This study attempted to evaluate local variations in the chemical form of (137)Cs derived from the initial fallout of the FDNPP accident and whether its chemical form affected the radiocesium concentration in the tissues currently growing in trees, even after the initial fallout ceased. For these estimations, the ratio between the (137)Cs concentration in Cryptomeria japonica needle leaves in the tree crown, which existed before the FDNPP accident and subsequently directly exposed to the initial fallout ((137)Cs pre-accident N), and the amount of (137)Cs in the initial fallout itself ((137)Cs fallout) was determined ((137)Cs pre-accident N/(137)Cs fallout) at 66 sites. In addition, the (137)Cs ratios between the male cones produced in 2012 ((137)Cs male cone) and needle leaves that had elongated in the spring of 2011 ((137)Cs 2011N) was determined at 82 sites ((137)Cs male cone/(137) Cs 2011N). Most of the sites with lower (137)Cs pre-accident N /(137)Cs fallout ratios were distributed in eastern Fukushima, relatively close to the Pacific Ocean coastline. Lower (137)Cs pre-accident N/(137)Cs fallout and higher (137)Cs malecone/(137)Cs 2011N were found to be associated with higher proportions of (137)Cs in ionic forms. These observations are consistent with the hypothesis, and likely reflect regional variations in the chemical form of the deposited radiocesium.

  20. 75 FR 76085 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for the Polar Bear...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-07

    ...; Designation of Critical Habitat for the Polar Bear (Ursus maritimus) in the United States; Final Rule #0;#0... Wildlife and Plants; Designation of Critical Habitat for the Polar Bear (Ursus maritimus) in the United... Wildlife Service (Service), designate critical habitat for polar bear (Ursus maritimus) populations in...

  1. Multi-Phased, Post-Accident Support of the Fukushima Dai-Ichi Nuclear Power Plant - 12246

    SciTech Connect

    Gay, Arnaud; Gillet, Philippe; Ytournel, Bertrand; Varet, Thierry; David, Laurent; Prevost, Thierry; Redonnet, Carol; Piot, Gregoire; Jouaville, Stephane; Pagis, Georges

    2012-07-01

    operation results to date. AREVA's response to the Fukushima Dai-Ichi crisis was multi-phased: emergency aid and relief supply was sent within days after the accident; AREVA-Veolia engineering teams designed and implemented a water treatment solution in record time, only 3 months; and AREVA continues to support TEPCO and propose solutions for waste management, soil remediation and decontamination of the Fukushima Dai-Ichi site. Despite the huge challenges, the Actiflo{sup TM}-Rad project has been a success: the water treatment unit started on time and performed as expected. The performance is the result of many key elements: AREVA expertise in radioactive effluents decontamination, Veolia know-how in water treatment equipments in crisis environment, and of course AREVA and Veolia teams' creativity. The project success is also due to AREVA and Veolia teams' reactivity and high level of commitment with engineering teams working 24/7 in Japan, France and Germany. AREVA and Veolia deep knowledge of the Japanese industry ensured that the multi-cultural exchanges were not an issue. Finally the excellent overall project management and execution by TEPCO and other Japanese stakeholders was very efficient. The emergency water treatment was a key step of the roadmap towards restoration from the accident at Fukushima Dai-Ichi that TEPCO designed and keeps executing with success. (authors)

  2. Field-Reversed Configuration Power Plant Critical-Issue Scoping Study

    SciTech Connect

    Santarius, J. F.; Mogahed, E. A.; Emmert, G. A.; Khater, H. Y.; Nguyen, C. N.; Ryzhkov, S. V.; Stubna, M. D.

    2000-03-31

    A team from the Universities of Wisconsin, Washington, and Illinois performed an engineering scoping study of critical issues for field-reversed configuration (FRC) power plants. The key tasks for this research were (1) systems analysis for deuterium-tritium (D-T) FRC fusion power plants, and (2) conceptual design of the blanket and shield module for an FRC fusion core. For the engineering conceptual design of the fusion core, the project team focused on intermediate-term technology. For example, one decision was to use steele structure. The FRC systems analysis led to a fusion power plant with attractive features including modest size, cylindrical symmetry, good thermal efficiency (52%), relatively easy maintenance, and a high ratio of electric power to fusion core mass, indicating that it would have favorable economics.

  3. Temporal Statistic of Traffic Accidents in Turkey

    NASA Astrophysics Data System (ADS)

    Erdogan, S.; Yalcin, M.; Yilmaz, M.; Korkmaz Takim, A.

    2015-10-01

    Traffic accidents form clusters in terms of geographic space and over time which themselves exhibit distinct spatial and temporal patterns. There is an imperative need to understand how, where and when traffic accidents occur in order to develop appropriate accident reduction strategies. An improved understanding of the location, time and reasons for traffic accidents makes a significant contribution to preventing them. Traffic accident occurrences have been extensively studied from different spatial and temporal points of view using a variety of methodological approaches. In literature, less research has been dedicated to the temporal patterns of traffic accidents. In this paper, the numbers of traffic accidents are normalized according to the traffic volume and the distribution and fluctuation of these accidents is examined in terms of Islamic time intervals. The daily activities and worship of Muslims are arranged according to these time intervals that are spaced fairly throughout the day according to the position of the sun. The Islamic time intervals are never been used before to identify the critical hour for traffic accidents in the world. The results show that the sunrise is the critical time that acts as a threshold in the rate of traffic accidents throughout Turkey in Islamic time intervals.

  4. Thermal neutron fluence from ultra low-level gamma-ray spectrometry of spoons activated during the JCO criticality accident at Tokai-mura in 1999.

    PubMed

    Hult, Mikael; Martínez Canet, María Jose; Johnston, Peter N; Komura, Kazuhisa

    2002-01-01

    During the JCO-accident in Tokai-mura in 1999, the surrounding village was irradiated by an uncontrolled neutron flux. At some locations in that village, the thermal neutron flux was determined retrospectively by measurement of the very low activity of 51Cr and 60Co in stainless-steel spoons using gamma-ray spectrometry in underground laboratories. Activities determined in the HADES underground facility are presented here, together with calibrations performed using a well-defined thermal neutron flux to directly estimate the fluence of thermal neutrons independent of most assumptions. The results show measurable 51Cr in three samples and 60Co in four samples taken from locations at distances of up to 430m from the accident location despite the elapse of 4 half-lives of 51Cr before measurement. Effects of air transport of the samples were considered and shown to be negligible.

  5. Radiocesium discharge from paddy fields with different initial scrapings for decontamination after the Fukushima Dai-ichi Nuclear Power Plant accident.

    PubMed

    Wakahara, Taeko; Onda, Yuich; Kato, Hiroaki; Sakaguchi, Aya; Yoshimura, Kazuya

    2014-11-01

    To explore the behavior of radionuclides released after the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident in March 2011, and the distribution of radiocesium in paddy fields, we monitored radiocesium (Cs) and suspended sediment (SS) discharge from paddy fields. We proposed a rating scale for measuring the effectiveness of surface soil removal. Our experimental plots in paddy fields were located ∼40 km from the FDNPP. Two plots were established: one in a paddy field where surface soil was not removed (the "normally cultivated paddy field") and the second in a paddy field where the top 5-10 cm of soil was removed before cultivation (the "surface-removed paddy field"). The amounts of Cs and SS discharge from the paddy fields were continuously measured from June to August 2011. The Cs soil inventory measured 3 months after the FDNPP accident was approximately 200 kBq m(-2). However, after removing the surface soil, the concentration of Cs-137 decreased to 5 kBq m(-2). SS discharged from the normally cultivated and surface-removed paddy fields after puddling (mixing of soil and water before planting rice) was 11.0 kg and 3.1 kg, respectively, and Cs-137 discharge was 630,000 Bq (1240 Bq m(-2)) and 24,800 Bq (47.8 Bq m(-2)), respectively. The total amount of SS discharge after irrigation (natural rainfall-runoff) was 5.5 kg for the normally cultivated field and 70 kg for the surface-removed field, and the total amounts of Cs-137 discharge were 51,900 Bq (102 Bq m(-2)) and 165,000 Bq (317 Bq m(-2)), respectively. During the irrigation period, discharge from the surface-removed plot showed a twofold greater inflow than that from the normally cultivated plot. Thus, Cs inflow may originate from the upper canal. The topsoil removal process eliminated at least approximately 95% of the Cs-137, but upstream water contaminated with Cs-137 flowed into the paddy field. Therefore, to accurately determine the Cs discharge, it is important to examine Cs inflow from the

  6. Risk-informed regulation and safety management of nuclear power plants--on the prevention of severe accidents.

    PubMed

    Himanen, Risto; Julin, Ari; Jänkälä, Kalle; Holmberg, Jan-Erik; Virolainen, Reino

    2012-11-01

    There are four operating nuclear power plant (NPP) units in Finland. The Teollisuuden Voima (TVO) power company has two 840 MWe BWR units supplied by Asea-Atom at the Olkiluoto site. The Fortum corporation (formerly IVO) has two 500 MWe VVER 440/213 units at the Loviisa site. In addition, a 1600 MWe European Pressurized Water Reactor supplied by AREVA NP (formerly the Framatome ANP--Siemens AG Consortium) is under construction at the Olkiluoto site. Recently, the Finnish Parliament ratified the government Decision in Principle that the utilities' applications to build two new NPP units are in line with the total good of the society. The Finnish utilities, Fenno power company, and TVO company are in progress of qualifying the type of the new nuclear builds. In Finland, risk-informed applications are formally integrated in the regulatory process of NPPs that are already in the early design phase and these are to run through the construction and operation phases all through the entire plant service time. A plant-specific full-scope probabilistic risk assessment (PRA) is required for each NPP. PRAs shall cover internal events, area events (fires, floods), and external events such as harsh weather conditions and seismic events in all operating modes. Special attention is devoted to the use of various risk-informed PRA applications in the licensing of Olkiluoto 3 NPP.

  7. Radiation accidents

    SciTech Connect

    Saenger, E.L.

    1986-09-01

    It is essential that emergency physicians understand ways to manage patients contaminated by radioactive materials and/or exposed to external radiation sources. Contamination accidents require careful surveys to identify the metabolic pathway of the radionuclides to guide prognosis and treatment. The level of treatment required will depend on careful surveys and meticulous decontamination. There is no specific therapy for the acute radiation syndrome. Prophylactic antibodies are desirable. For severely exposed patients treatment is similar to the supportive care given to patients undergoing organ transplantation. For high-dose extremity injury, no methods have been developed to reverse the fibrosing endarteritis that eventually leads to tissue death so frequently found with this type of injury. Although the Three Mile Island episode of March 1979 created tremendous public concern, there were no radiation injuries. The contamination outside the reactor building and the release of radioiodine were negligible. The accidental fuel element meltdown at Chernobyl, USSR, resulted in many cases of acute radiation syndrome. More than 100,000 people were exposed to high levels of radioactive fallout. The general principles outlined here are applicable to accidents of that degree of severity.

  8. Normal Accident at Three Mile Island.

    ERIC Educational Resources Information Center

    Perrow, Charles

    1981-01-01

    Discusses some aspects of the accident at the Three Mile Island nuclear power plant. Explains a number of factors involved including the type of accident, warnings, design and equipment failure, operator error, and negative synergy. Presents alternatives to systems with catastrophic potential. (MK)

  9. Severe accident simulation at Olkiuoto

    SciTech Connect

    Tirkkonen, H.; Saarenpaeae, T.; Cliff Po, L.C.

    1995-09-01

    A personal computer-based simulator was developed for the Olkiluoto nuclear plant in Finland for training in severe accident management. The generic software PCTRAN was expanded to model the plant-specific features of the ABB Atom designed BWR including its containment over-pressure protection and filtered vent systems. Scenarios including core heat-up, hydrogen generation, core melt and vessel penetration were developed in this work. Radiation leakage paths and dose rate distribution are presented graphically for operator use in diagnosis and mitigation of accidents. Operating on an graphically for operator use in diagnosis and mitigation of accidents. Operating on an 486 DX2-66, PCTRAN-TVO achieves a speed about 15 times faster than real-time. A convenient and user-friendly graphic interface allows full interactive control. In this paper a review of the component models and verification runs are presented.

  10. Ecological half-lives of radiocesium in 16 species in marine biota after the TEPCO's Fukushima Daiichi nuclear power plant accident.

    PubMed

    Iwata, Kayoko; Tagami, Keiko; Uchida, Shigeo

    2013-07-16

    TEPCO's Fukushima Daiichi Nuclear Power Plant (FDNPP) accident of March 2011 caused the discharge of a considerable quantity of radionuclides, including (137)Cs. Because of its long half-life (30.17 years), the fate of (137)Cs in the marine biota is of great interest. This study aims to evaluate, using food monitoring data, ecological half-lives (Teco) of (137)Cs in marine biota caught offshore of Fukushima. The data were categorized into two regional groups (north and south) with respect to the FDNPP site, and the regional (137)Cs concentration trend and estimated Teco in the marine biota were appraised. Although the (137)Cs concentration in the seawater in the south was higher than that in the north, Teco values remained relatively consistent among common species of both regions. Teco was then compared to biological half-life (Tb) estimated in laboratory settings. The ratios of Teco/Tb were inconsistent among different groups of marine species. The ratios of Teco/Tb for brown seaweed and bivalves were approximately 1, and the ratios of Teco/Tb for demersal fish ranged from 4.4 to 16.1. The reasons for different ratios of Teco and Tb values may be attributed to environmental and ecological factors, such as different trophic levels.

  11. Atmospheric dispersion and ground deposition induced by the Fukushima Nuclear Power Plant accident: A local-scale simulation and sensitivity study

    NASA Astrophysics Data System (ADS)

    Korsakissok, I.; Mathieu, A.; Didier, D.

    2013-05-01

    Following the Fukushima Daiichi Nuclear Power Plant (FNPP1) accident on March 2011, radioactive products were released in the atmosphere. Simulations at local scale (within 80 km of FNPP1) were carried out by the Institute of Radiation Protection and Nuclear Safety (IRSN) with the Gaussian Puff model pX, during the crisis and since then, to assess the radiological and environmental consequences. The evolution of atmospheric and ground activity simulated at local scale is presented with a “reference” simulation, whose performance is assessed through comparisons with environmental monitoring data (gamma dose rate and deposition). The results are within a factor of 2-5 of the observations for gamma dose rates (0.52 and 0.85 for FAC2 and FAC5), and 5-10 for deposition (0.31 for FAC2, 0.73 for FAC5 and 0.90 for FAC10). A sensitivity analysis is also made to highlight the most sensitive parameters. A source term comparison is made between IRSN's estimation, and those from Katata et al. (2012) and Stohl et al. (2011). Results are quite sensitive to the source term, but also to wind direction and dispersion parameters. Dry deposition budget is more sensitive than wet deposition. Gamma dose rates are more sensitive than deposition, in particular peak values.

  12. Radioactive contamination of arthropods from different trophic levels in hilly and mountainous areas after the Fukushima Daiichi nuclear power plant accident.

    PubMed

    Tanaka, Sota; Hatakeyama, Kaho; Takahashi, Sentaro; Adati, Tarô

    2016-11-01

    In order to understand the influence of the Fukushima Daiichi nuclear power plant accident on the ecosystem in hilly and mountainous areas of Fukushima Prefecture, chronological changes in the levels of radiocesium in arthropod species were investigated. From 2012 to 2014, arthropods from different trophic levels were sampled and the air radiation dose rates at the sampling sites were analyzed. The air radiation dose rates showed a significant and constant reduction over the 2 years at the sampling sites in Fukushima. The median radiocesium concentration ((134)Cs + (137)Cs) detected in the rice grasshopper, Oxya yezoensis, and the Emma field cricket, Teleogryllus emma, dropped continuously to 0.080 and 0.078 Bq/g fresh weight, respectively, in 2014. In contrast, no significant reduction in radioactive contamination was observed in the Jorô spider, Nephila clavata, in which the level remained at 0.204 Bq/g in 2014. A significant positive correlation between radiocesium concentration and the air radiation dose rate was observed in the rice grasshopper, the Emma field cricket and the Jorô spider. The highest correlation coefficient (ρ = 0.946) was measured in the grasshopper.

  13. Large-eddy simulation of turbulent winds during the Fukushima Daiichi Nuclear Power Plant accident by coupling with a meso-scale meteorological simulation model

    NASA Astrophysics Data System (ADS)

    Nakayama, H.; Takemi, T.; Nagai, H.

    2015-06-01

    A significant amount of radioactive material was accidentally discharged into the atmosphere from the Fukushima Dai-ichi Nuclear Power Plant from 12 March 2011, which produced high contaminated areas over a wide region in Japan. In conducting regional-scale atmospheric dispersion simulations, the computer-based nuclear emergency response system WSPEEDI-II developed by Japan Atomic Energy Agency was used. Because this system is driven by a meso-scale meteorological (MM) model, it is difficult to reproduce small-scale wind fluctuations due to the effects of local terrain variability and buildings within a nuclear facility that are not explicitly represented in MM models. In this study, we propose a computational approach to couple an LES-based CFD model with a MM model for detailed simulations of turbulent winds with buoyancy effects under real meteorological conditions using turbulent inflow technique. Compared to the simple measurement data, especially, the 10 min averaged wind directions of the LES differ by more than 30 degrees during some period of time. However, distribution patterns of wind speeds, directions, and potential temperature are similar to the MM data. This implies that our coupling technique has potential performance to provide detailed data on contaminated area in the nuclear accidents.

  14. Distribution of dissolved and particulate radiocesium concentrations along rivers and the relations between radiocesium concentration and deposition after the nuclear power plant accident in Fukushima.

    PubMed

    Tsuji, Hideki; Yasutaka, Tetsuo; Kawabe, Yoshishige; Onishi, Takeo; Komai, Takeshi

    2014-09-01

    This study involved measurement of concentrations of dissolved and particulate radiocesium ((134)Cs and (137)Cs) in river water, and determination of the quantitative relations between the amount of deposited (137)Cs and (137)Cs concentrations in river waters after the Fukushima Daiichi nuclear power plant accident. First, the current concentrations of dissolved and particulate (134)Cs·(137)Cs were determined in a river watershed from 20 sampling locations in four contaminated rivers (Abukuma, Kuchibuto, Shakado, and Ota). Distribution characteristics of different (137)Cs forms varied with rivers. Moreover, a higher dissolved (137)Cs concentration was observed at the sampling location where the (137)Cs deposition occurred much more heavily. In contrast, particulate (137)Cs concentration along the river was quite irregular, because fluctuations in suspended solids concentrations occur easily from disturbance and heavy precipitation. A similar tendency with dissolved (137)Cs distribution was observed for the (137)Cs concentration per unit weight of suspended solids. Regression analysis between deposited (137)Cs and dissolved/particulate (137)Cs concentrations was performed for the four rivers. The results showed a strong correlation between deposited (137)Cs and dissolved (137)Cs, and a relatively weak correlation between deposited (137)Cs and particulate (137)Cs concentration for each river. However, if the particulate (137)Cs concentration was converted to (137)Cs concentration per unit weight of suspended solid, the values showed a strong correlation with deposited (137)Cs.

  15. Input and output budgets of radiocesium concerning the forest floor in the mountain forest of Fukushima released from the TEPCO's Fukushima Dai-ichi nuclear power plant accident.

    PubMed

    Niizato, Tadafumi; Abe, Hironobu; Mitachi, Katsuaki; Sasaki, Yoshito; Ishii, Yasuo; Watanabe, Takayoshi

    2016-09-01

    Estimations of radiocesium input and output concerning the forest floor within a mountain forest region have been conducted in the north and central part of the Abukuma Mountains of Fukushima, northeast Japan, after a 2-3 year period following the TEPCO Fukushima Dai-ichi nuclear power plant accident. The radiocesium input and output associated with surface washoff, throughfall, stemflow, and litterfall processes at experimental plots installed on the forest floor of evergreen Japanese cedars and deciduous Konara oaks have been monitored. Despite the high output potential in the mountainous forest of Fukushima, the results at both monitoring locations show the radiocesium input to be 4-50 times higher than the output during the summer monsoon in Fukushima. These results indicate that the radiocesium tends to be preserved in the forest ecosystem due to extremely low output ratios (0.05%-0.19%). Thus, the associated fluxes throughout the circulation process are key issues for the projecting the environmental fate of the radiocesium levels, along with the subsequent reconstruction of life emphasized within the setting.

  16. Health effects models for nuclear power plant accident consequence analysis: Low LET radiation: Part 2, Scientific bases for health effects models

    SciTech Connect

    Abrahamson, S.; Bender, M.; Book, S.; Buncher, C.; Denniston, C.; Gilbert, E.; Hahn, F.; Hertzberg, V.; Maxon, H.; Scott, B.

    1989-05-01

    This report provides 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. Two-parameter Weibull hazard functions are recommended for estimating 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 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 provided. For most cancers, both incidence and mortality are addressed. Linear and linear-quadratic models are also recommended for assessing genetic risks. Five classes of genetic disease -- dominant, x-linked, aneuploidy, unbalanced translocation and multifactorial diseases --are considered. In addition, the impact of radiation-induced genetic damage on the incidence of peri-implantation embryo losses is discussed. The uncertainty in modeling radiological health risks is addressed by providing central, upper, and lower estimates of all model parameters. Data are provided which should enable analysts to consider the timing and severity of each type of health risk. 22 refs., 14 figs., 51 tabs.

  17. One-year Monitoring of Iodine-129 spread in Pacific Ocean After the 2011 Fukushima Daiichi Nuclear Power Plant Accident

    NASA Astrophysics Data System (ADS)

    Chang, C.; Burr, G. S.; Jull, A. T.; Pandey, A.; Thiemens, M. H.; Biddulph, D.; Russell, J. L.

    2012-12-01

    The long-lived radionuclide Iodine-129 is well known as a useful environmental tracer. At present, the global I-129 in surface water is about 1-2 orders of magnitude higher than pre-1990 levels. The anthropogenic I-129 signal produced from industrial nuclear fuel reprocessing plants is known to be the primary source of I-129 in marine surface waters of the Atlantic, and elevated I-129 values are found globally. On March 11, 2011, the Great East Japan Earthquake produced a devastating tsunami that severely damaged the Fukushima Daiichi Nuclear Power Plant. The damage caused a substantial release of radionuclides into the atmosphere and ocean in the weeks following the catastrophe. We expect to be able to identify I-129 from surface seawater in the Pacific Ocean. We will present I-129 results of water samples collected weekly near Scripps Institution of Oceanography, San Diego, CA for a year. We also have a pair of measurements collected a year apart from Kaohsiung, Taiwan. By establishing I-129 time series, we can observe the spread of I-129 in the surface waters of the Pacific Ocean that resulted from the accidental releases. This information can also be used to better understand surface ocean circulation.

  18. Severe accident analysis using dynamic accident progression event trees

    NASA Astrophysics Data System (ADS)

    Hakobyan, Aram P.

    In present, the development and analysis of Accident Progression Event Trees (APETs) are performed in a manner that is computationally time consuming, difficult to reproduce and also can be phenomenologically inconsistent. One of the principal deficiencies lies in the static nature of conventional APETs. In the conventional event tree techniques, the sequence of events is pre-determined in a fixed order based on the expert judgments. The main objective of this PhD dissertation was to develop a software tool (ADAPT) for automated APET generation using the concept of dynamic event trees. As implied by the name, in dynamic event trees the order and timing of events are determined by the progression of the accident. The tool determines the branching times from a severe accident analysis code based on user specified criteria for branching. It assigns user specified probabilities to every branch, tracks the total branch probability, and truncates branches based on the given pruning/truncation rules to avoid an unmanageable number of scenarios. The function of a dynamic APET developed includes prediction of the conditions, timing, and location of containment failure or bypass leading to the release of radioactive material, and calculation of probabilities of those failures. Thus, scenarios that can potentially lead to early containment failure or bypass, such as through accident induced failure of steam generator tubes, are of particular interest. Also, the work is focused on treatment of uncertainties in severe accident phenomena such as creep rupture of major RCS components, hydrogen burn, containment failure, timing of power recovery, etc. Although the ADAPT methodology (Analysis of Dynamic Accident Progression Trees) could be applied to any severe accident analysis code, in this dissertation the approach is demonstrated by applying it to the MELCOR code [1]. A case study is presented involving station blackout with the loss of auxiliary feedwater system for a

  19. Scoping Study Investigating PWR Instrumentation during a Severe Accident Scenario

    SciTech Connect

    Rempe, J. L.; Knudson, D. L.; Lutz, R. J.

    2015-09-01

    The accidents at the Three Mile Island Unit 2 (TMI-2) and Fukushima Daiichi Units 1, 2, and 3 nuclear power plants demonstrate the critical importance of accurate, relevant, and timely information on the status of reactor systems during a severe accident. These events also highlight the critical importance of understanding and focusing on the key elements of system status information in an environment where operators may be overwhelmed with superfluous and sometimes conflicting data. While progress in these areas has been made since TMI-2, the events at Fukushima suggests that there may still be a potential need to ensure that critical plant information is available to plant operators. Recognizing the significant technical and economic challenges associated with plant modifications, it is important to focus on instrumentation that can address these information critical needs. As part of a program initiated by the Department of Energy, Office of Nuclear Energy (DOE-NE), a scoping effort was initiated to assess critical information needs identified for severe accident management and mitigation in commercial Light Water Reactors (LWRs), to quantify the environment instruments monitoring this data would have to survive, and to identify gaps where predicted environments exceed instrumentation qualification envelop (QE) limits. Results from the Pressurized Water Reactor (PWR) scoping evaluations are documented in this report. The PWR evaluations were limited in this scoping evaluation to quantifying the environmental conditions for an unmitigated Short-Term Station BlackOut (STSBO) sequence in one unit at the Surry nuclear power station. Results were obtained using the MELCOR models developed for the US Nuclear Regulatory Commission (NRC)-sponsored State of the Art Consequence Assessment (SOARCA) program project. Results from this scoping evaluation indicate that some instrumentation identified to provide critical information would be exposed to conditions that

  20. How a nuclear power plant accident influences acceptance of nuclear power: results of a longitudinal study before and after the Fukushima disaster.

    PubMed

    Visschers, Vivianne H M; Siegrist, Michael

    2013-02-01

    Major nuclear accidents, such as the recent accident in Fukushima, Japan, have been shown to decrease the public's acceptance of nuclear power. However, little is known about how a serious accident affects people's acceptance of nuclear power and the determinants of acceptance. We conducted a longitudinal study (N= 790) in Switzerland: one survey was done five months before and one directly after the accident in Fukushima. We assessed acceptance, perceived risks, perceived benefits, and trust related to nuclear power stations. In our model, we assumed that both benefit and risk perceptions determine acceptance of nuclear power. We further hypothesized that trust influences benefit and risk perceptions and that trust before a disaster relates to trust after a disaster. Results showed that the acceptance and perceptions of nuclear power as well as its trust were more negative after the accident. In our model, perceived benefits and risks determined the acceptance of nuclear power stations both before and after Fukushima. Trust had strong effects on perceived benefits and risks, at both times. People's trust before Fukushima strongly influenced their trust after the accident. In addition, perceived benefits before Fukushima correlated with perceived benefits after the accident. Thus, the nuclear accident did not seem to have changed the relations between the determinants of acceptance. Even after a severe accident, the public may still consider the benefits as relevant, and trust remains important for determining their risk and benefit perceptions. A discussion of the benefits of nuclear power seems most likely to affect the public's acceptance of nuclear power, even after a nuclear accident.

  1. Mental Health Status of Children After the Great East Japan Earthquake and Fukushima Daiichi Nuclear Power Plant Accident.

    PubMed

    Mashiko, Hirobumi; Yabe, Hirooki; Maeda, Masaharu; Itagaki, Syuntaro; Kunii, Yasuto; Shiga, Tetsuya; Miura, Itaru; Suzuki, Yuriko; Yasumura, Seiji; Iwasa, Hajime; Niwa, Shin-Ichi; Ohtsuru, Akira; Abe, Masafumi

    2017-03-01

    The disaster at the Fukushima Daiichi Nuclear Power Plant after the Great East Japan Earthquake on March 11, 2011, might have affected the mental health status of children. To assess the mental health status, we measured the Strengths and Difficulties Questionnaire (SDQ) in 15 274 children (aged 4-15 years). The proportions of those who scored above the cutoff (≥16) of SDQ, reflecting the clinical range of the mental health status, were 25.0% (aged 4-6 years), 22.0% (aged 7-12 years, and 16.3% (aged 13-15 years), which were higher than that in the usual state (9.5%). We also explored the possibility that the distribution on the Fukushima prefectural map of the proportions of those who scored above the cutoff (≥16) of SDQ might correspond with the environmental radiation levels, but there was no significant correlation.

  2. Aerial Survey Results for 131I Deposition on the Ground after the Fukushima Daiichi Nuclear Power Plant Accident

    SciTech Connect

    Torii, Tatsuo; Sugita, Takeshi; Okada, Colin E.; Reed, Michael S.; Blumenthal, Daniel J.

    2013-08-01

    In March 2011 the second largest accidental release of radioactivity in history occurred at the Fukushima Daiichi nuclear power plant following a magnitude 9.0 earthquake and subsequent tsunami. Teams from the U.S. Department of Energy, National Nuclear Security Administration Office of Emergency Response performed aerial surveys to provide initial maps of the dispersal of radioactive material in Japan. The initial results from the surveys did not report the concentration of 131I. This work reports on analyses performed on the initial survey data by a joint Japan-US collaboration to determine 131I ground concentration. This information is potentially useful in reconstruction of the inhalation and external exposure doses from this short-lived radionuclide. The deposited concentration of 134Cs is also reported.

  3. Relationship between Individual External Doses, Ambient Dose Rates and Individuals' Activity-Patterns in Affected Areas in Fukushima following the Fukushima Daiichi Nuclear Power Plant Accident.

    PubMed

    Naito, Wataru; Uesaka, Motoki; Yamada, Chie; Kurosawa, Tadahiro; Yasutaka, Tetsuo; Ishii, Hideki

    2016-01-01

    The accident at Fukushima Daiichi Nuclear Power Plant on March 11, 2011, released radioactive material into the atmosphere and contaminated the land in Fukushima and several neighboring prefectures. Five years after the nuclear disaster, the radiation levels have greatly decreased due to physical decay, weathering, and decontamination operations in Fukushima. The populations of 12 communities were forced to evacuate after the accident; as of March 2016, the evacuation order has been lifted in only a limited area, and permanent habitation is still prohibited in most of the areas. In order for the government to lift the evacuation order and for individuals to return to their original residential areas, it is important to assess current and future realistic individual external doses. Here, we used personal dosimeters along with the Global Positioning System and Geographic Information System to understand realistic individual external doses and to relate individual external doses, ambient doses, and activity-patterns of individuals in the affected areas in Fukushima. The results showed that the additional individual external doses were well correlated to the additional ambient doses based on the airborne monitoring survey. The results of linear regression analysis suggested that the additional individual external doses were on average about one-fifth that of the additional ambient doses. The reduction factors, which are defined as the ratios of the additional individual external doses to the additional ambient doses, were calculated to be on average 0.14 and 0.32 for time spent at home and outdoors, respectively. Analysis of the contribution of various activity patterns to the total individual external dose demonstrated good agreement with the average fraction of time spent daily in each activity, but the contribution due to being outdoors varied widely. These results are a valuable contribution to understanding realistic individual external doses and the corresponding

  4. The existence state in the soil of radioactive cesium from the Fukushima Dai-ichi nuclear power plant accident by imaging plate photograph

    NASA Astrophysics Data System (ADS)

    Satou, Yukihiko; Sueki, Keisuke

    2013-04-01

    In the accident of the Fukushima Daiichi nuclear power plant, the wide area in east Japan was polluted seriously with radioactive cesium. But, unlike Chernobyl, reactor core explosion did not occur in Fukushima. Therefore, it is thought that many radioactive nuclides emitted into the atmosphere were in the gas state and aerosol. However, when the imaging plate photographs of the surface soils in Fukushima was observed, many granular radionuclides existed. Then, in order to confirm a radioactive cesium of particle state, the treatment for the soils contaminated with radioactive cesium by using chemical operation was tried. Three type soils, that is, paddy soil, river sediment, and sea sand, were made applicable to research. The contaminated soil samples were collected in Fukushima and Ibaraki prefecture. Radioactivity concentrations of 137Cs and 134Cs were measured by using gamma-ray spectrometry with a high pure germanium (HPGe) detector. After the radioactively measurement, soils had been burned in oven for five hours in 500 degree Celsius. Concentrated hydrochloric acid was added to soil samples, and they were heated for three hours. These samples were divided into residue and elution by centrifugal separation, and then radioactivity of cesium contained in residue was measured. After chemical operations, 70% and 85% of radioactive cesium from river sediment and sea sand were extracted approximately into elution, respectively. In contrast, in the soil of the paddy field, only 30% of radioactive cesium was approximately eluted. When radiation image photograph of the residues of all three types of soils were taken and observed, the granular radioactive nuclides remained clearly in paddy soil and river sediment. In contrast, all the granular radioactive nuclides in sea sand disappeared after treatment. The results of above things that desorption of radioactive cesium depend on the kind of soil. Furthermore, it was suggested that there was radioactive cesium of

  5. Relationship between Individual External Doses, Ambient Dose Rates and Individuals’ Activity-Patterns in Affected Areas in Fukushima following the Fukushima Daiichi Nuclear Power Plant Accident

    PubMed Central

    Kurosawa, Tadahiro; Yasutaka, Tetsuo; Ishii, Hideki

    2016-01-01

    The accident at Fukushima Daiichi Nuclear Power Plant on March 11, 2011, released radioactive material into the atmosphere and contaminated the land in Fukushima and several neighboring prefectures. Five years after the nuclear disaster, the radiation levels have greatly decreased due to physical decay, weathering, and decontamination operations in Fukushima. The populations of 12 communities were forced to evacuate after the accident; as of March 2016, the evacuation order has been lifted in only a limited area, and permanent habitation is still prohibited in most of the areas. In order for the government to lift the evacuation order and for individuals to return to their original residential areas, it is important to assess current and future realistic individual external doses. Here, we used personal dosimeters along with the Global Positioning System and Geographic Information System to understand realistic individual external doses and to relate individual external doses, ambient doses, and activity-patterns of individuals in the affected areas in Fukushima. The results showed that the additional individual external doses were well correlated to the additional ambient doses based on the airborne monitoring survey. The results of linear regression analysis suggested that the additional individual external doses were on average about one-fifth that of the additional ambient doses. The reduction factors, which are defined as the ratios of the additional individual external doses to the additional ambient doses, were calculated to be on average 0.14 and 0.32 for time spent at home and outdoors, respectively. Analysis of the contribution of various activity patterns to the total individual external dose demonstrated good agreement with the average fraction of time spent daily in each activity, but the contribution due to being outdoors varied widely. These results are a valuable contribution to understanding realistic individual external doses and the corresponding

  6. Detailed source term estimation of atmospheric release during the Fukushima Dai-ichi nuclear power plant accident by coupling atmospheric and oceanic dispersion models

    NASA Astrophysics Data System (ADS)

    Katata, Genki; Chino, Masamichi; Terada, Hiroaki; Kobayashi, Takuya; Ota, Masakazu; Nagai, Haruyasu; Kajino, Mizuo

    2014-05-01

    Temporal variations of release amounts of radionuclides during the Fukushima Dai-ichi Nuclear Power Plant (FNPP1) accident and their dispersion process are essential to evaluate the environmental impacts and resultant radiological doses to the public. Here, we estimated a detailed time trend of atmospheric releases during the accident by combining environmental monitoring data and coupling atmospheric and oceanic dispersion simulations by WSPEEDI-II (Worldwide version of System for Prediction of Environmental Emergency Dose Information) and SEA-GEARN developed by the authors. New schemes for wet, dry, and fog depositions of radioactive iodine gas (I2 and CH3I) and other particles (I-131, Te-132, Cs-137, and Cs-134) were incorporated into WSPEEDI-II. The deposition calculated by WSPEEDI-II was used as input data of ocean dispersion calculations by SEA-GEARN. The reverse estimation method based on the simulation by both models assuming unit release rate (1 Bq h-1) was adopted to estimate the source term at the FNPP1 using air dose rate, and air sea surface concentrations. The results suggested that the major release of radionuclides from the FNPP1 occurred in the following periods during March 2011: afternoon on the 12th when the venting and hydrogen explosion occurred at Unit 1, morning on the 13th after the venting event at Unit 3, midnight on the 14th when several openings of SRV (steam relief valve) were conducted at Unit 2, morning and night on the 15th, and morning on the 16th. The modified WSPEEDI-II using the newly estimated source term well reproduced local and regional patterns of air dose rate and surface deposition of I-131 and Cs-137 obtained by airborne observations. Our dispersion simulations also revealed that the highest radioactive contamination areas around FNPP1 were created from 15th to 16th March by complicated interactions among rainfall (wet deposition), plume movements, and phase properties (gas or particle) of I-131 and release rates

  7. Self-organization of plants in a dryland ecosystem: Symmetry breaking and critical cluster size.

    PubMed

    Meyra, Ariel G; Zarragoicoechea, Guillermo J; Kuz, Victor A

    2015-05-01

    Periodical patterns of vegetation in an arid or semiarid ecosystem are described using statistical mechanics and Monte Carlo numerical simulation technique. Plants are characterized by the area that each individual occupies and a facilitation-competition pairwise interaction. Assuming that external resources (precipitation, solar radiation, nutrients, etc.) are available to the ecosystem, it is possible to obtain the persistent configurations of plants compatible with an equitable distribution of resources maximizing the Shannon entropy. Variation of vegetation patterns with density, critical cluster size, and facilitation distance are predicted. Morphological changes of clusters are shown to be a function of the external resources. As a final remark, it is proposed that an early warning of desertification could be detected from the coefficient of variation of the mean cluster size together with the distribution of cluster sizes.

  8. A Critical Assessment of the Effects of Bt Transgenic Plants on Parasitoids

    PubMed Central

    Chen, Mao; Zhao, Jian-Zhou; Collins, Hilda L.; Earle, Elizabeth D.; Cao, Jun; Shelton, Anthony M.

    2008-01-01

    The ecological safety of transgenic insecticidal plants expressing crystal proteins (Cry toxins) from the bacterium Bacillus thuringiensis (Bt) continues to be debated. Much of the debate has focused on nontarget organisms, especially predators and parasitoids that help control populations of pest insects in many crops. Although many studies have been conducted on predators, few reports have examined parasitoids but some of them have reported negative impacts. None of the previous reports were able to clearly characterize the cause of the negative impact. In order to provide a critical assessment, we used a novel paradigm consisting of a strain of the insect pest, Plutella xylostella (herbivore), resistant to Cry1C and allowed it to feed on Bt plants and then become parasitized by Diadegma insulare, an important endoparasitoid of P. xylostella. Our results indicated that the parasitoid was exposed to a biologically active form of the Cy1C protein while in the host but was not harmed by such exposure. Parallel studies conducted with several commonly used insecticides indicated they significantly reduced parasitism rates on strains of P. xylostella resistant to these insecticides. These results provide the first clear evidence of the lack of hazard to a parasitoid by a Bt plant, compared to traditional insecticides, and describe a test to rigorously evaluate the risks Bt plants pose to predators and parasitoids. PMID:18523682

  9. Monitoring of radioactive substances in foods distributed in Kyoto, Japan (1991-2011). - Comparison of detection rates and concentrations before and after the Fukushima Daiichi Nuclear Power Plant accident - .

    PubMed

    Banno, Yukinori; Namikawa, Mikio; Miwa, Mariko; Ban, Soichirou; Orito, Taichi; Semura, Shunsuke; Kawakami, Masahiro; Doi, Naoya; Miyake, Shiro; Ishikawa, Yasuhiro

    2013-01-01

    Since the Chernobyl Nuclear Power Plant accident, radioactive substances have been continually monitored in foods collected in the city of Kyoto, Japan. The importance of the monitoring was increased by the Fukushima Daiichi Nuclear Power Plant accident in March 2011. Here, the detection rates and concentrations of radioactive substances were compared among food samples collected before and after the accident in Fukushima prefecture. Before the accident, (137)Cs was the only radioactive substance detected in foods. The detection rate was 70% for fish and shellfish samples and the highest concentration was 1.7 Bq/kg. It was also 83% for fresh mushroom samples and the highest concentration was 7.5 Bq/kg. In contrast, the detection rate was low for vegetables and the concentrations were also lower than those of the above samples. On the other hand, after the accident, (131)I was detected in food produced in the Tohoku and Kanto areas. Actually, (131)I (3,400 Bq/kg), (134)Cs (280 Bq/kg), and (137)Cs (280 Bq/kg) were detected in mizuna, a leaf vegetable, on March 23, 2011. These radioactive substances were detected in all leaf vegetable samples examined in March and April 2011, but they were not detected in samples examined in November 2011. (131)I was not detected in any food sample examined after May 2011. However, (137)Cs (average=7.9 Bq/kg) was consistently detected in fish and shellfish samples until November, although the concentrations were less than the regulatory limits. It appears unlikely that foods containing radioactive substances over the regulatory limits are currently being distributed in Kyoto.

  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.

  11. Fluvial discharges of radiocaesium from watersheds contaminated by the Fukushima Dai-ichi Nuclear Power Plant accident, Japan.

    PubMed

    Ueda, Shinji; Hasegawa, Hidenao; Kakiuchi, Hideki; Akata, Naofumi; Ohtsuka, Yoshihito; Hisamatsu, Shun'ichi

    2013-04-01

    A large amount of radiocaesium, (134)Cs and (137)Cs, was released to the atmosphere and Pacific Ocean from the Tokyo Electric Power Company's Fukushima Dai-ichi Nuclear Power Plant (FDNPP) that was damaged by the tsunami caused by the Tohoku earthquake on 11 March 2011. Radiocaesium deposited on the ground is now the most important consideration in assessing the risk to people in the vicinity of the FDNPP and remediating the contaminated area. Transfer of radiocaesium from the ground through rivers is an important factor in the downstream contamination of irrigation waters, paddy fields, lakes, and the sea. We estimated the transport of radiocaesium through two small rivers, the Hiso River and Wariki River, that traverse mountainous areas in Fukushima Prefecture. Areal depositions of radiocaesium in their watersheds (catchments) were high (1-3 MBq m(-2)). Water samples were collected from the rivers twice during each of two baseflow and two flood stages in 2011 and analysed for radiocaesium in particulate and dissolved forms. The radiocaesium concentrations depended strongly on the rates of water discharge. Maximum activities of radiocaesium in the samples from the Hiso River and Wariki River when there was precipitation or flooding (July and September) were 25 ± 0.31 and 35 ± 0.25 Bq L(-1), respectively. Particulate radiocaesium during periods of flooding contributed over 90% of the total radiocaesium activity in the samples. The discharge of radiocaesium from the catchments during 2011 was estimated to be 0.5% and 0.3% of the total amount of radiocaesium deposited on the catchments of the Hiso River and Wariki River, respectively. It is considered that the most of the radiocaesium deposited in the catchment remains on the soil surface.

  12. Acoustical performance of power plant enclosure walls-a critical assessment of needs

    NASA Astrophysics Data System (ADS)

    Putnam, Robert A.; Frederick, Noel

    2005-09-01

    The acoustical design of power generating facilities invariably requires knowledge of the transmission loss characteristics of acoustical enclosures, from component specific housings to generation buildings. Many of the composite wall configurations used by vendors are either proprietary or of such recent design that laboratory test data (TL per ASTM E90) are not available. Several factors contribute to uncertainty in the application of test data. At frequencies of 125 Hz and below, all such laboratory based test data should be considered suspect, especially since for plants in which sound emissions are heavily attenuated, the low frequencies tend to become progressively more dominant at far field positions. Thus the far field A-weighted sound levels from power plants, especially those of low noise design, are governed by sound energy in precisely the frequency range for which the TL's for walls and enclosures are least reliable. Further, the size and mounting of power plant walls differs significantly from the same walls mounted in an ASTM E90 test facility. This paper gives a critical assessment of the sources of the uncertainties, suggestions for methodologies to obtain more reliable TL data and discusses the effects to be expected, illustrated by way of selected examples.

  13. Karyopathological Traits of Thyrocytes and Exposure to Radioiodines in Belarusian Children and Adolescents following the Accident at the Chernobyl Nuclear Power Plant

    PubMed Central

    Nadyrov, Eldar; Rozhko, Alexander; Kravtsov, Viacheslav; Mabuchi, Kiyohiko; Hatch, Maureen; Nakamura, Nori; Nikonovich, Sergey; Aleksanin, Sergey

    2013-01-01

    The Belarus-American (BelAm) Thyroid Study cohort consists of persons 0–18 years of age at the time of exposure to radioiodines from the 1986 Chernobyl nuclear power plant accident who have undergone serial thyroid screenings with referral for fine-needle aspiration biopsy (FNAB) using standardized criteria. We investigated thyrocyte nuclear abnormalities in cytological samples from FNABs in 50 BelAm subjects with thyroid nodules and 43 control patients from Leningrad, Russia, unexposed to Chernobyl fallout. Nuclear abnormalities such as internuclear chromosome bridges and derivative nuclei with broken bridges (i.e., “tailed” nuclei), formed from dicentric and ring chromosomes, may be cellular markers of radiation exposure. In the exposed BelAm cohort, thyrocytes with bridges were present in 80% of subjects with single-nodular goiters compared with 27% of unexposed controls. The average frequency of thyrocytes with bridges was also significantly higher in the BelAm subjects than in controls as was the mean frequency of thyrocytes with tailed nuclei. In the case of multi-nodular goiters, thyrocytes with bridges were present in 75.0% of exposed BelAm patients compared with 16.7% of unexposed controls. Thyrocytes with tailed nuclei were observed in all of the BelAm subjects but in only 35% of controls, and the mean frequency of tailed nuclei was significantly higher. Unusually long bridges were detected in 29% of BelAm patients with single-nodular goiters and 35% of cases with multi-nodular goiters, while no such abnormalities were observed in the follicular thyroid epithelium of patients from the Leningrad region. Further study is needed to understand whether these phenomena represent irradiation consequences in the human organism. PMID:22382464

  14. Inverse modeling of the (137)Cs source term of the Fukushima Dai-ichi Nuclear Power Plant accident constrained by a deposition map monitored by aircraft.

    PubMed

    Yumimoto, Keiya; Morino, Yu; Ohara, Toshimasa; Oura, Yasuji; Ebihara, Mitsuru; Tsuruta, Haruo; Nakajima, Teruyuki

    2016-11-01

    The amount of (137)Cs released by the Fukushima Dai-ichi Nuclear Power Plant accident of 11 March 2011 was inversely estimated by integrating an atmospheric dispersion model, an a priori source term, and map of deposition recorded by aircraft. An a posteriori source term refined finer (hourly) variations comparing with the a priori term, and estimated (137)Cs released 11 March to 2 April to be 8.12 PBq. Although time series of the a posteriori source term was generally similar to those of the a priori source term, notable modifications were found in the periods when the a posteriori source term was well-constrained by the observations. Spatial pattern of (137)Cs deposition with the a posteriori source term showed better agreement with the (137)Cs deposition monitored by aircraft. The a posteriori source term increased (137)Cs deposition in the Naka-dori region (the central part of Fukushima Prefecture) by 32.9%, and considerably improved the underestimated a priori (137)Cs deposition. Observed values of deposition measured at 16 stations and surface atmospheric concentrations collected on a filter tape of suspended particulate matter were used for validation of the a posteriori results. A great improvement was found in surface atmospheric concentration on 15 March; the a posteriori source term reduced root mean square error, normalized mean error, and normalized mean bias by 13.4, 22.3, and 92.0% for the hourly values, respectively. However, limited improvements were observed in some periods and areas due to the difficulty in simulating accurate wind fields and the lack of the observational constraints.

  15. Radioactive cesium accumulation in seaweeds by the Fukushima 1 Nuclear Power Plant accident-two years' monitoring at Iwaki and its vicinity.

    PubMed

    Kawai, Hiroshi; Kitamura, Akira; Mimura, Mari; Mimura, Tetsuro; Tahara, Tomoya; Aida, Daiki; Sato, Kenji; Sasaki, Hideaki

    2014-01-01

    Accumulations of radionuclides in marine macroalgae (seaweeds) resulting from the Fukushima 1 Nuclear Power Plant (F1NPP) accident in March 2011 have been monitored for two years using high-purity germanium detectors. Algal specimens were collected seasonally by snorkeling at Nagasaki, Iwaki, Fukushima Prefecture (Pref.), Japan, ca. 50 km perimeter from the F1NPP. Additional collections were done at Soma, Hironocho, Hisanohama and Shioyazaki in Fukushima Pref. as well as at Chiba Pref. and Hyogo Pref. as controls. In May 2011, specimens of most macroalgal species showed ¹³⁷Cs levels greater than 3,000 Bq kg⁻¹ at Shioyazaki and Nagasaki. The highest ¹³⁷Cs level recorded 7371.20 ± 173.95 Bq kg⁻¹ in Undaria pinnatifida (Harvey) Suringar on 2 May 2011, whereas seawater collected at the same time at Shioyazaki and Nagasaki measured 8.41 ± 3.21 and 9.74 ± 3.43 Bq L⁻¹, respectively. The concentration factor of marine macroalgae was estimated to be ca. 8-50, depending on taxa and considering a weight ratio of wet/dry samples of ca. 10. ¹³⁷Cs level declined remarkably during the following 5-6 months. In contrast, the ¹³⁷Cs level remained rather stable during the following 12-16 months, and maintained the range of 10-110 Bq kg⁻¹. Contamination was still detectable in many samples in March 2013, 24 months after the most significant pollution.

  16. Isotopic ratio and vertical distribution of radionuclides in soil affected by the accident of Fukushima Dai-ichi nuclear power plants.

    PubMed

    Fujiwara, Takeshi; Saito, Takumi; Muroya, Yusa; Sawahata, Hiroyuki; Yamashita, Yuji; Nagasaki, Shinya; Okamoto, Koji; Takahashi, Hiroyuki; Uesaka, Mitsuru; Katsumura, Yosuke; Tanaka, Satoru

    2012-11-01

    The results of γ analyses of soil samples obtained from 50 locations in Fukushima prefecture on April 20, 2011, revealed the presence of a spectrum of radionuclides resulted from the accident of the Fukushima Dai-ichi nuclear power plant (FDNPP). The sum γ radioactivity concentration ranged in more than 3 orders of magnitude, depending on the sampling locations. The contamination of soils in the northwest of the FDNPP was considerable. The (131)I/(137)Cs activity ratios of the soil samples plotted as a function of the distance from the F1 NPPs exhibited three distinctive patterns. Such patterns would reflect not only the different deposition behaviors of these radionuclides, but also on the conditions of associated release events such as temperature and compositions and physicochemical forms of released radionuclides. The (136)Cs/(137)Cs activity ratio, on the other hand, was considered to only reflect the difference in isotopic compositions of source materials. Two locations close to the NPP in the northwest direction were found to be depleted in short-lived (136)Cs. This likely suggested the presence of distinct sources with different (136)Cs/(137)Cs isotopic ratios, although their details were unknown at present. Vertical γ activity profiles of (131)I and (137)Cs were also investigated, using 20-30 cm soil cores in several locations. About 70% or more of the radionuclides were present in the uppermost 2-cm regions. It was found that the profiles of (131)I/(137)Cs activity ratios showed maxima in the 2-4 cm regions, suggesting slightly larger migration of the former nuclide.

  17. Total cancer incidence in relation to 137Cs fallout in the most contaminated counties in Sweden after the Chernobyl nuclear power plant accident: a register-based study

    PubMed Central

    Alinaghizadeh, Hassan; Wålinder, Robert; Vingård, Eva; Tondel, Martin

    2016-01-01

    Objectives To determine the total cancer incidence in relation to a 5-year exposure to caesium-137 (137Cs) from the 1986 Chernobyl nuclear power plant accident. Methods A closed cohort was defined as all individuals living in the three most contaminated counties in mid-Sweden in 1986. Fallout of 137Cs was retrieved as a digital map from the Geological Survey of Sweden, demographic data from Statistics Sweden, and cancer diagnosis from the National Board of Health and Welfare. Individuals were assigned an annual 137Cs exposure based on their place of residence (1986–1990), from which 5-year cumulative 137Cs exposures were calculated, accounting for the physical decay of 137Cs and changing residencies. HRs were adjusted for age, sex, rural/non-rural residence and pre-Chernobyl total cancer incidence. Results The 734 537 people identified were categorised by exposure: the first quartile was low exposure (0.0–45.4 kBq/m2), the second and third quartiles were intermediate exposure (45.41–118.8 kBq/m2), and the fourth quartile was the highest exposure (118.81–564.71 kBq/m2). Between 1991 and 2010, 82 495 cancer cases were registered in the 3 counties. Adjusted HRs (95% CI) were 1.03 (1.01 to 1.05) for intermediate exposure and 1.05 (1.03 to 1.07) for the highest exposure compared to the reference exposure. Conclusions We found a small overall exposure–response pattern of the total cancer incidence related to 137Cs after adjustment for age, sex, rural residence and pre-Chernobyl cancer incidence. PMID:27998898

  18. Cesium-134 and 137 activities in the central North Pacific Ocean after the Fukushima Dai-ichi nuclear power plant accident

    NASA Astrophysics Data System (ADS)

    Kameník, J.; Dulaiova, H.; Buesseler, K. O.; Pike, S. M.; Št'astná, K.

    2013-03-01

    Surface seawater 134Cs and 137Cs samples were collected in the central and western North Pacific Ocean during the 1.5 yr after the Fukushima Dai-ichi nuclear power plant accident to monitor dispersion patterns of these radioisotopes towards the Hawaiian Islands. In the absence of other recent sources and due to its short half-life only those parts of the Pacific Ocean would have detectable 134Cs that were impacted by Fukushima releases. Between March and May 2011, 134Cs was not detected around the Hawaiian Islands and Guam. Here, most 137Cs activities (1.2-1.5 Bq m-3) were in the range of expected preexisting levels. Some samples north of the Hawaiian Islands (1.6-1.8 Bq m-3) were elevated above the 18-month baseline established in surface seawater in Hawaii indicating that those might carry atmospheric fallout. The 18-month time-series analysis of surface seawater from Hawaii did not reveal any seasonal variability or trends, with an average activity of 1.46 ± 0.06 Bq m-3 (Station Aloha, 17 values). In contrast, samples collected between Japan and Hawaii contained 134Cs activities in the range of 1-4 Bq m-3 and 137Cs levels were about 2-3 times above the preexisting activities. We found that the southern boundary of the Kuroshio and Kuroshio extension currents represented a boundary for radiation dispersion with higher activities detected within and north of the major currents. The radiation plume has not been detected over the past 1.5 yr at the main Hawaiian Islands due to the transport patterns across the Kuroshio and Kuroshio extension currents.

  19. Cesium-134 and 137 activities in the central North Pacific Ocean after the Fukushima Dai-ichi Nuclear Power Plant accident

    NASA Astrophysics Data System (ADS)

    Kameník, J.; Dulaiova, H.; Buesseler, K. O.; Pike, S. M.; Št'astná, K.

    2013-09-01

    Surface seawater 134Cs and 137Cs samples were collected in the central and western North Pacific Ocean during the 2 yr after the Fukushima Dai-ichi Nuclear Power Plant accident to monitor dispersion patterns of these radioisotopes towards the Hawaiian Islands. In the absence of other recent sources and due to its short half-life, only those parts of the Pacific Ocean would have detectable 134Cs values that were impacted by Fukushima releases. Between March and May 2011, 134Cs was not detected around the Hawaiian Islands and Guam. Here, most 137Cs activities (1.2-1.5 Bq m-3) were in the range of expected preexisting levels. Some samples north of the Hawaiian Islands (1.6-1.8 Bq m-3) were elevated above the 23-month baseline established in surface seawater in Hawaii indicating that those might carry atmospheric fallout. The 23-month time-series analysis of surface seawater from Hawaii did not reveal any seasonal variability or trends, with an average activity of 1.46 ± 0.06 Bq m-3 (Station Aloha, 18 values). In contrast, samples collected between Japan and Hawaii contained 134Cs activities in the range of 1-4 Bq m-3, and 137Cs levels were about 2-3 times above the preexisting activities. We found that the southern boundary of the Kuroshio and Kuroshio extension currents represented a boundary for radiation dispersion with higher activities detected within and north of the major currents. The radiation plume has not been detected over the past 2 yr at the main Hawaiian Islands due to the transport patterns across the Kuroshio and Kuroshio extension currents.

  20. Effective half-lives of ¹³⁷Cs from persimmon tree tissue parts in Japan after Fukushima Dai-ichi Nuclear Power Plant accident.

    PubMed

    Tagami, Keiko; Uchida, Shigeo

    2015-03-01

    To estimate the radiocesium decreasing rates from persimmon trees during a period of about 3 y following the accident at Tokyo Electric Power Company's Fukushima Dai-ichi Nuclear Power Plant (FDNPP), we conducted measurements of tree tissue parts collected in 2011-2013. The sampling was carried out in Chiba, 220 km south of FDNPP; radioactive fallouts discharged from FDNPP had mainly been observed in March-April 2011 on the sampling site. We measured (137)Cs concentrations in the tree tissue parts, i.e., fruits (flesh, skin and seeds), leaves and newly emerged branches, and then the effective half-lives (T(eff)) of (137)Cs were calculated. Leaf samples were classified into two types by sampling months according to the growing stages, that is, immature (April-May) and mature (June-November) leaves. All these parts showed exponential declines in (137)Cs concentration with good adjusted contribution ratios of higher than ca. 0.7. The calculated T(eff) values from all tissue parts were similar with the average of 229 d (range: 216-243 d). From these results, we concluded that each tree tissue was representative for the calculation of Teff. For comparison to these observation results, open source food monitoring data from 2011 to 2013 including (137)Cs data for persimmon fruits collected in Fukushima Prefecture were used to calculate T(eff) for persimmon trees. Values of Teff were obtained for persimmon fruits grown in each local government area in Fukushima Prefecture and they ranged from 303 to 475 d.

  1. Pre- and post-accident (129)I and (137)Cs levels, and (129)I/(137)Cs ratios in soil near the Fukushima Dai-ichi Nuclear Power Plant, Japan.

    PubMed

    Matsunaka, Tetsuya; Sasa, Kimikazu; Sueki, Keisuke; Takahashi, Tsutomu; Satou, Yukihiko; Matsumura, Masumi; Kinoshita, Norikazu; Kitagawa, Jun-ichi; Matsuzaki, Hiroyuki

    2016-01-01

    To evaluate the deposition density and extent of subsurface infiltration of (129)I and (137)Cs in the restricted area that was highly contaminated by the accident of Fukushima Dai-ichi Nuclear Power Plant, cumulative inventories of (129)I and (137)Cs, concentrations of (129)I and (137)Cs, and (129)I/(137)Cs ratio in 30-cm-long soil columns were compared with pre-accident levels from the same area. The cores were collected before and after the accident from locations of S-1 (4 km west of FDNPP) and S-2 (8 km west of FDNPP). Deposition densities of (129)I and (137)Cs in the soil following the accident were 0.90-2.33 Bq m(-2) and 0.80-4.04 MBq m(-2), respectively, which were 14-39 and 320-510 times larger than the pre-accident levels of (129)I (59.3-63.3 mBq m(-2)) and (137)Cs (2.51-7.88 kBq m(-2)), respectively. Approximately 90% of accident-derived (129)I and (137)Cs deposited in the 30-cm soil cores was concentrated in the surface layer from 0 to 44-95 kg m(-2) of mass depth (0-4.3-6.2 cm depth) and from 0 to 16-25 kg m(-2) of mass depth (0-1.0-3.1 cm depth), respectively. The relaxation mass depths (h0) of 10.8-11.2 kg m(-2) for (129)I estimated in the previous study were larger than those of 8.1-10.6 kg m(-2) for (137)Cs at both sites, owing to the larger infiltration depth of radioiodine mainly by the gravitational water penetration in the surface soil in our study sites. Approximately 7-9% of the accident-derived (129)I was present in the lower layer from 44 to 100 kg m(-2) (4.3-8.6 cm depth) at S-1, and from 95 to 160 kg m(-2) (6.2-10.2 cm depth) at S-2. Approximately 1% of (137)Cs seems to infiltrate deeper than (129)I in the lower layer at each site in contrast to the surface layer.

  2. Aging effect of 137Cs obtained from 137Cs in the Kanto loam layer from the Fukushima nuclear power plant accident and in the Nishiyama loam layer from the Nagasaki A-bomb explosion.

    PubMed

    Ohta, Tomoko; Mahara, Yasunori; Kubota, Takumi; Igarashi, Toshifumi

    2013-01-01

    We measured (134)Cs and (137)Cs in the surface soil of the Kanto loam in the eastern Tokyo metropolitan area and the Nishiyama loam in Nagasaki, Japan. The observed (137)Cs deposition in the Kanto loam from the Fukushima nuclear power plant (NPP) accident ranged from 4.0 to 77 kBq m(-2), which corresponds to 0.3-5 times of that in the Nishiyama loam. The (137)Cs retardation factor in the Kanto loam obtained seven months after the Fukusima NPP accident and in the Nishiyama loam after 36 and 38 years from the detonation of the Pu atomic bomb (A-bomb) ranged from 180 to 260 and 2000 to 10,000, respectively. This difference in the retardation factors is attributed to an aging effect that corresponds to seven months and 36 to 38 years after the deposition of (137)Cs occurred on the soil minerals.

  3. 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

  4. Criticality safety analysis for remote handled TRU waste at the Waste Isolation Pilot Plant

    SciTech Connect

    Not Available

    1988-07-01

    The Waste Isolation Pilot Plant (WIPP) is a facility designed to store transuranic (TRU) waste underground in a mined salt bed. All fissile nuclides except U/sup 235/ are considered TRU nuclides. This report presents the results of the nuclear criticality analysis for Remote-Handled (RH) TRU waste stored at the WIPP site. The RH waste material will be contained in steel canisters that are five feet or ten feet long. Each ten foot canister is capable of holding three 55 gallon drums of waste material. The five foot canisters are to be welded together to form one ten foot long canister. In general the fissile waste material is mainly surface contamination on clothing, wipes, wrappings, tools, etc., or mixed in a borosilicate glass matrix or concrete. Other fissile material may be contained in absorbent mixtures. As a result, the fissile material will typically be spread over a large fraction of the volume in most of the waste storage canisters. Typical isotopic content of the fissile/other radioactive material is shown in Table 1-1. This analysis will analyze the RH waste storage and handling configurations at the WIPP site to show that up to 600 grams of fissile material per ten foot canister can be received and stored at the site without criticality safety concerns. 6 refs., 14 figs., 1 tab.

  5. Delineation of plant caleosin residues critical for functional divergence, positive selection and coevolution

    PubMed Central

    2014-01-01

    Background The caleosin genes encode proteins with a single conserved EF hand calcium-binding domain and comprise small gene families found in a wide range of plant species. These proteins may be involved in many cellular and biological processes coupled closely to the synthesis, degradation, or stability of oil bodies. Although previous studies of this protein family have been reported for Arabidopsis and other species, understanding of the evolution of the caleosin gene family in plants remains inadequate. Results In this study, comparative genomic analysis was performed to investigate the phylogenetic relationships, evolutionary history, functional divergence, positive selection, and coevolution of caleosins. First, 84 caleosin genes were identified from five main lineages that included 15 species. Phylogenetic analysis placed these caleosins into five distinct subfamilies (sub I–V), including two subfamilies that have not been previously identified. Among these subfamilies, sub II coincided with the distinct P-caleosin isoform recently identified in the pollen oil bodies of lily; caleosin genes from the same lineage tended to be clustered together in the phylogenetic tree. A special motif was determined to be related with the classification of caleosins, which may have resulted from a deletion in sub I and sub III occurring after the evolutionary divergence of monocot and dicot species. Additionally, several segmentally and tandem-duplicated gene pairs were identified from seven species, and further analysis revealed that caleosins of different species did not share a common expansion model. The ages of each pair of duplications were calculated, and most were consistent with the time of genome-wide duplication events in each species. Functional divergence analysis showed that changes in functional constraints have occurred between subfamilies I/IV, II/IV, and II/V, and some critical amino acid sites were identified during the functional divergence. Additional

  6. Radiocesium fallout in the grasslands on Sakhalin, Kunashir and Shikotan Islands due to Fukushima accident: the radioactive contamination of soil and plants in 2011.

    PubMed

    Ramzaev, V; Barkovsky, A; Goncharova, Yu; Gromov, A; Kaduka, M; Romanovich, I

    2013-04-01

    The accident at the Fukushima Dai-ichi Nuclear Power Plant has resulted in radioactive contamination of environmental media and food in the Far East of Russia, particularly in the Sakhalin Region. To obtain the knowledge about the (134)Cs and (137)Cs spatial distribution in the Sakhalin Region, soil samples were collected at 31 representative grassland sites on Sakhalin, Kunashir and Shikotan islands (43.80°-46.40° N and 142.73°-146.84° E) in the middle of May and around the end of September to early October 2011. In the autumn, vegetation samples (mixed grass/forb crop and bamboo, Sasa sp.) were collected together with soil samples. Maximum measured activity concentrations (on dry weight) of (134)Cs and (137)Cs in soil were 30 Bq kg(-1) and 210 Bq kg(-1), respectively. Within soil profile, (134)Cs activity concentrations declined rapidly with depth. Although for both sampling occasions (in the spring and autumn) the radionuclide was completely retained in the upper 3-4 cm of soil, a deeper penetration of the contaminant into the ground was observed in the autumn. In contrast with (134)Cs, activity concentrations of (137)Cs demonstrated a broad range of the vertical distribution in soil; at most sites, the radionuclide was found down to a depth of 20 cm. This resulted from interfering the aged pre-accidental (137)Cs and the new Fukushima-borne (137)Cs. To calculate contribution of these sources to the inventory of (137)Cs, the (134)Cs:(137)Cs activity ratio of 1:1 in Fukushima fallout (the reference date 15 March 2011) was used. The maximum deposition density of Fukushima-derived (137)Cs was found on Shikotan and Kunashir Islands with average density of 0.124 ± 0.018 kBq m(-2) and 0.086 ± 0.026 kBq m(-2), respectively. Sakhalin Island was less contaminated by Fukushima-derived (137)Cs of 0.021 ± 0.018 kBq m(-2). For the south of Sakhalin Island, the reference inventory of pre-Fukushima (137)Cs was calculated as 1.93 ± 0.25 kBq m(-2

  7. Temporal changes in dissolved (137)Cs concentrations in groundwater and stream water in Fukushima after the Fukushima Dai-ichi Nuclear Power Plant accident.

    PubMed

    Iwagami, Sho; Tsujimura, Maki; Onda, Yuichi; Nishino, Masataka; Konuma, Ryohei; Abe, Yutaka; Hada, Manami; Pun, Ishwar; Sakaguchi, Aya; Kondo, Hiroaki; Yamamoto, Masayoshi; Miyata, Yoshiki; Igarashi, Yasuhito

    2017-01-01

    The concentration of dissolved (137)Cs in groundwater and stream water in the headwater catchments in Yamakiya district, located ∼35 km north west of Fukushima Dai-ichi Nuclear Power Plant (FDNPP), was monitored from June 2011 to July 2013, after the earthquake and tsunami disaster. Groundwater and stream water were sampled at intervals of approximately 2 months at each site. Intensive sampling was also conducted during rainstorm events. Compared with previous data from the Chernobyl NPP accident, the concentration of dissolved (137)Cs in stream water was low. In the Iboishi-yama catchment, a trend was observed for the concentration of dissolved (137)Cs in stream water to decline, which could be divided into two phases by October 2011 (a fast flush of activity as a result of rapid washoff and a slow decline as a result of soil fixation and redistribution processes). The highest (137)Cs concentration recorded at Iboishi-yama was 1.2 Bq/L on August 6, 2011, which then declined to 0.021-0.049 Bq/L during 2013 (in stream water under normal water-flow conditions). During the rainfall events, the concentration of dissolved (137)Cs in stream water increased temporarily. The concentration of dissolved (137)Cs in groundwater at a depth of 30 m at Iboishi-yama displayed a decreasing trend from 2011 to 2013, with a range from 0.039 Bq/L to 0.0025 Bq/L. The effective half-lives of stream water in the initial fast flush and secondary phases were 0.10-0.21 and 0.69-1.5 y, respectively in the three catchments. The effective half-life of groundwater was 0.46-0.58 y at Koutaishi-yama and 0.50-3.3 y at Iboishi-yama. The trend for the concentration of dissolved (137)Cs to decline in groundwater and stream water was similar throughout 2012-2013, and the concentrations recorded in deeper groundwater were closer to those in stream water. The declining trend of dissolved (137)Cs concentrations in stream water was similar to that of the loss of canopy (137)Cs by throughfall, as

  8. Vertical distribution and temporal changes of 137Cs in soil profiles under various land uses after the Fukushima Dai-ichi Nuclear Power Plant accident.

    PubMed

    Takahashi, Junko; Tamura, Kenji; Suda, Tomoya; Matsumura, Ryo; Onda, Yuichi

    2015-01-01

    We monitored the vertical distribution of (137)Cs in soil profiles under eight different land uses for the 2 y after the Fukushima Dai-ichi Nuclear Power Plant accident, and discussed the temporal changes in the early-stage of the migration and the determinants of the initial distribution. The soil samples were collected for four surveys using a scraper plate at each study site, which consisted of three forests (mixed forest, mature cedar, and young cedar), two grasslands (pasture and meadow) and three abandoned agricultural fields (farm land, tobacco field, and paddy field). The land use patterns have a large influence on some soil properties and the migration processes of (137)Cs above ground, resulting in different distribution of (137)Cs in those soil profiles. Specifically, the secondary deposition of (137)Cs from the coniferous canopy, retention of (137)Cs by litter layer, and the homogenization of (137)Cs concentrations in surface soil by natural soil mixing such as the disturbance by cattle grazing, roots growing and the formation of needle ice were important to cause redistribution of the deposited (137)Cs. Only in the paddy field, the (137)Cs inventory in subsurface soils (5-10 cm) gradually increased and comprised 26% of the total (137)Cs in 2 y, showing the downward migration of (137)Cs to subsurface soil. In the other sites, it was considered that (137)Cs were strongly adsorbed by soil particles and rarely migrated downward as soluble form. Vertical distributions during the first survey were able to be used as the initial distributions and were well fitted to the exponential equation. The distribution parameters α (relaxation depth) and β (relaxation mass depth), calculated by the exponential equation were correlated with RIP (r = -0.806, p < 0.05), macro pore (r = 0.651, p = 0.11), and dispersible fine particle content (r = 0.856, p < 0.05). It indicated that the initial distribution would be influenced by the Cs fixation ability of

  9. Determinants of participation in a longitudinal two-stage study of the health consequences of the Chornobyl nuclear power plant accident

    PubMed Central

    Guey, Lin T; Bromet, Evelyn J; Gluzman, Semyon F; Zakhozha, Victoria; Paniotto, Vlodomyr

    2008-01-01

    Background The determinants of participation in long-term follow-up studies of disasters have rarely been delineated. Even less is known from studies of events that occurred in eastern Europe. We examined the factors associated with participation in a longitudinal two-stage study conducted in Kyiv following the 1986 Chornobyl nuclear power plant accident. Methods Six hundred child-mother dyads (300 evacuees and 300 classmate controls) were initially assessed in 1997 when the children were 11 years old, and followed up in 2005–6 when they were 19 years old. A population control group (304 mothers and 327 children) was added in 2005–6. Each assessment point involved home interviews with the children and mothers (stage 1), followed by medical examinations of the children at a clinic (stage 2). Background characteristics, health status, and Chornobyl risk perceptions were examined. Results The participation rates in the follow-up home interviews were 87.8% for the children (88.6% for evacuees; 87.0% for classmates) and 83.7% for their mothers (86.4% for evacuees and 81.0% for classmates). Children's and mothers' participation was predicted by one another's study participation and attendance at the medical examination at time 1. Mother's participation was also predicted by initial concerns about her child's health, greater psychological distress, and Chornobyl risk perceptions. In 1997, 91.2% of the children had a medical examination (91.7% of evacuees and 90.7% of classmates); in 2005–6, 85.2% were examined (83.0% of evacuees, 87.7% of classmates, 85.0% of population controls). At both times, poor health perceptions were associated with receiving a medical examination. In 2005–6, clinic attendance was also associated with the young adults' risk perceptions, depression or generalized anxiety disorder, lower standard of living, and female gender. Conclusion Despite our low attrition rates, we identified several determinants of selective participation consistent

  10. Instrumentation availability during severe accidents for a boiling water reactor with a Mark I containment

    SciTech Connect

    Arcieri, W.C.; Hanson, D.J. )

    1992-02-01

    In support of the US Nuclear Regulatory Commission Accident Management Research Program, the availability of instruments to supply accident management information during a broad range of severe accidents is evaluated for a Boiling Water Reactor with a Mark I containment. Results from this evaluation include: (1) the identification of plant conditions that would impact instrument performance and information needs during severe accidents; (2) the definition of envelopes of parameters that would be important in assessing the performance of plant instrumentation for a broad range of severe accident sequences; and (3) assessment of the availability of plant instrumentation during severe accidents.

  11. Measurements of gamma (γ)-emitting radionuclides with a high-purity germanium detector: the methods and reliability of our environmental assessments on the Fukushima 1 Nuclear Power Plant accident.

    PubMed

    Mimura, Tetsuro; Mimura, Mari; Komiyama, Chiyo; Miyamoto, Masaaki; Kitamura, Akira

    2014-01-01

    The severe accident of Fukushima 1 Nuclear Power Plant due to the Tohoku Region Pacific Coast Earthquake in 11 March 2011 caused wide contamination and pollution by radionuclides in Fukushima and surrounding prefectures. In the current JPR symposium, a group of plant scientists attempted to examine the impact of the radioactive contamination on wild and cultivated plants. Measurements of gamma (γ) radiation from radionuclides in "Fukushima samples", which we called and collected from natural and agricultural areas in Fukushima prefecture were mostly done with a high-purity Ge detector in the Graduate School of Maritime Sciences, Kobe University. In this technical note, we describe the methods of sample preparation and measurements of radioactivity of the samples and discuss the reliability of our data in regards to the International Atomic Energy Agency (IAEA) Interlaboratory comparisons and proficiency test (IAEA proficiency test).

  12. Design analysis of the molten core confinement within the reactor vessel in the case of severe accidents at nuclear power plants equipped with a reactor of the VVER type

    NASA Astrophysics Data System (ADS)

    Zvonaryov, Yu. A.; Budaev, M. A.; Volchek, A. M.; Gorbaev, V. A.; Zagryazkin, V. N.; Kiselyov, N. P.; Kobzar', V. L.; Konobeev, A. V.; Tsurikov, D. F.

    2013-12-01

    The present paper reports the results of the preliminary design estimate of the behavior of the core melt in vessels of reactors of the VVER-600 and VVER-1300 types (a standard optimized and informative nuclear power unit based on VVER technology—VVER TOI) in the case of beyond-design-basis severe accidents. The basic processes determining the state of the core melt in the reactor vessel are analyzed. The concept of molten core confinement within the vessel based on the idea of outside cooling is discussed. Basic assumptions and models, as well as the results of calculation of the interaction between molten materials of the core and the wall of the reactor vessel performed by means of the SOCRAT severe accident code, are presented and discussed. On the basis of the data obtained, the requirements on the operation of the safety systems are determined, upon the fulfillment of which there will appear potential prerequisites for implementing the concept of the confinement of the core melt within the reactor in cases of severe accidents at nuclear power plants equipped with VVER reactors.

  13. MELCOR analysis of the TMI-2 accident

    SciTech Connect

    Boucheron, E.A.

    1990-01-01

    This paper describes the analysis of the Three Mile Island-2 (TMI-2) standard problem that was performed with MELCOR. The MELCOR computer code is being developed by Sandia National Laboratories for the Nuclear Regulatory Commission for the purpose of analyzing severe accident in nuclear power plants. The primary role of MELCOR is to provide realistic predictions of severe accident phenomena and the radiological source team. The analysis of the TMI-2 standard problem allowed for comparison of the model predictions in MELCOR to plant data and to the results of more mechanistic analyses. This exercise was, therefore valuable for verifying and assessing the models in the code. The major trends in the TMI-2 accident are reasonably well predicted with MELCOR, even with its simplified modeling. Comparison of the calculated and measured results is presented and, based on this comparison, conclusions can be drawn concerning the applicability of MELCOR to severe accident analysis. 5 refs., 10 figs., 3 tabs.

  14. 78 FR 38897 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Arctostaphylos...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-28

    ...; Designation of Critical Habitat for Arctostaphylos franciscana AGENCY: Fish and Wildlife Service, Interior... designation of critical habitat for Arctostaphylos franciscana (Franciscan manzanita) under the Endangered... (DEA) for the proposed critical habitat designation and an amended required determinations section...

  15. Practical approaches in accident analysis

    NASA Astrophysics Data System (ADS)

    Stock, M.

    An accident analysis technique based on successive application of structural response, explosion dynamics, gas cloud formation, and plant operation failure mode models is proposed. The method takes into account the nonideal explosion characteristic of a deflagration in the unconfined cloud. The resulting pressure wave differs significantly from a shock wave and the response of structures like lamp posts and walls can differ correspondingly. This gives a more realistic insight into explosion courses than a simple TNT-equivalent approach.

  16. Accident prevention in radiotherapy

    PubMed Central

    Holmberg, O

    2007-01-01

    In order to prevent accidents in radiotherapy, it is important to learn from accidents that have occurred previously. Lessons learned from a number of accidents are summarised and underlying patterns are looked for in this paper. Accidents can be prevented by applying several safety layers of preventive actions. Categories of these preventive actions are discussed together with specific actions belonging to each category of safety layer. PMID:21614274

  17. Changes in radiocesium concentrations in epigeic earthworms in relation to the organic layer 2.5 years after the 2011 Fukushima Dai-ichi Nuclear Power Plant accident.

    PubMed

    Hasegawa, Motohiro; Kaneko, Shinji; Ikeda, Shigeto; Akama, Akio; Komatsu, Masabumi; Ito, Masamichi T

    2015-07-01

    We reported previously that radiocesium ((137)Cs) concentrations in earthworms increased with those in litter and/or soil in Fukushima Prefecture forests 0.5 y after the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident. This study provides further results for 1.5 and 2.5 y after the accident and discusses temporal changes in (137)Cs concentrations and transfer factors (TF) from litter to earthworms to better understand the mechanisms by which (137)Cs enters soil food webs. The concentration of (137)Cs in accumulated litter on the forest floor rapidly decreased, and the concentration in soil (0-5-cm depth) increased over time from 0.5 to 1.5 y, but changed only moderately from 1.5 to 2.5 y. The concentration of (137)Cs in earthworms consistently decreased during the study period; values 2.5 y after the accident were 18.8-68.5% of those 0.5 y after the accident. The TFs from accumulated litter to earthworms decreased over time: 0.24 ± 0.08 (mean ± SD) at 0.5 y and 0.16 ± 0.04 at 2.5 y. This decrease may be a result of decreases in the bioavailability of (137)Cs in litter and the surface soil layer. Changes in (137)Cs bioavailability should be continuously tracked to determine any changes in the relationship between radiocesium concentrations in earthworms and that in accumulated litter or soil.

  18. Ecosystem model-based approach for modelling the dynamics of 137Cs transfer to marine plankton populations: application to the western North Pacific Ocean after the Fukushima nuclear power plant accident

    NASA Astrophysics Data System (ADS)

    Belharet, M.; Estournel, C.; Charmasson, S.

    2015-06-01

    Huge amounts of radionuclides, especially 137Cs, were released into the western North Pacific Ocean after the Fukushima nuclear power plant (FNPP) accident that occurred on 11 March 2011, resulting in contamination of the marine biota. In this study we developed a radioecological model to estimate 137Cs concentrations in phytoplankton and zooplankton populations representing the lower levels of the pelagic trophic chain. We coupled this model to a lower trophic level ecosystem model and an ocean circulation model to take into account the site-specific environmental conditions in the area. The different radioecological parameters of the model were estimated by calibration, and a sensitivity analysis to parameter uncertainties was carried out, showing a high sensitivity of the model results, especially to the 137Cs concentration in seawater, to the rates of uptake from water and to the radionuclide assimilation efficiency for zooplankton. The results of the 137Cs concentrations in planktonic populations simulated in this study were then validated through comparison with the some data available in the region after the accident. The model results have shown that the maximum concentrations in plankton after the accident were about two to four orders of magnitude higher than those observed before the accident depending on the distance from FNPP. Finally, the maximum 137Cs absorbed dose rate for phyto- and zooplankton populations was estimated to be about 10-2 μGy h-1, and was, therefore, lower than the 10 μGy h-1 benchmark value defined in the ERICA assessment approach from which a measurable effect on the marine biota can be observed.

  19. Accident Tolerant Fuel Analysis

    SciTech Connect

    Smith, Curtis; Chichester, Heather; Johns, Jesse; Teague, Melissa; Tonks, Michael; Youngblood, Robert

    2014-09-01

    Safety is central to the design, licensing, operation, and economics of Nuclear Power Plants (NPPs). Consequently, the ability to better characterize and quantify safety margin holds the key to improved decision making about light water reactor design, operation, and plant life extension. A systematic approach to characterization of safety margins and the subsequent margins management options represents a vital input to the licensee and regulatory analysis and decision making that will be involved. The purpose of the Risk Informed Safety Margin Characterization (RISMC) Pathway research and development (R&D) is to support plant decisions for risk-informed margins management by improving economics and reliability, and sustaining safety, of current NPPs. Goals of the RISMC Pathway are twofold: (1) Develop and demonstrate a risk-assessment method coupled to safety margin quantification that can be used by NPP decision makers as part of their margin recovery strategies. (2) Create an advanced “RISMC toolkit” that enables more accurate representation of NPP safety margin. In order to carry out the R&D needed for the Pathway, the Idaho National Laboratory is performing a series of case studies that will explore methods- and tools-development issues, in addition to being of current interest in their own right. One such study is a comparative analysis of safety margins of plants using different fuel cladding types: specifically, a comparison between current-technology Zircaloy cladding and a notional “accident-tolerant” (e.g., SiC-based) cladding. The present report begins the process of applying capabilities that are still under development to the problem of assessing new fuel designs. The approach and lessons learned from this case study will be included in future Technical Basis Guides produced by the RISMC Pathway. These guides will be the mechanism for developing the specifications for RISMC tools and for defining how plant decision makers should propose and

  20. 50 CFR 17.99 - Critical habitat; plants on the islands of Kauai, Niihau, Molokai, Maui, Kahoolawe, Oahu, and...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 6 2011-10-01 2011-10-01 false Critical habitat; plants on the islands of Kauai, Niihau, Molokai, Maui, Kahoolawe, Oahu, and Hawaii, HI, and on the Northwestern Hawaiian Islands. 17.99 Section 17.99 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED) TAKING,...

  1. 50 CFR 17.99 - Critical habitat; plants on the islands of Kauai, Niihau, Molokai, Maui, Kahoolawe, Oahu, and...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 4 2010-10-01 2010-10-01 false Critical habitat; plants on the islands of Kauai, Niihau, Molokai, Maui, Kahoolawe, Oahu, and Hawaii, HI, and on the Northwestern Hawaiian Islands. 17.99 Section 17.99 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED) TAKING,...

  2. 50 CFR 17.99 - Critical habitat; plants on the islands of Kauai, Niihau, Molokai, Maui, Kahoolawe, Oahu, and...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 5 2010-10-01 2010-10-01 true Critical habitat; plants on the islands of Kauai, Niihau, Molokai, Maui, Kahoolawe, Oahu, and Hawaii, HI, and on the Northwestern Hawaiian Islands. (Continued) 17.99 Section 17.99 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED)...

  3. 50 CFR 17.99 - Critical habitat; plants on the islands of Kauai, Niihau, Molokai, Maui, Kahoolawe, Oahu, and...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 8 2014-10-01 2013-10-01 true Critical habitat; plants on the islands of Kauai, Niihau, Molokai, Maui, Kahoolawe, Oahu, and Hawaii, HI, and on the Northwestern Hawaiian Islands. (Continued) 17.99 Section 17.99 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED)...

  4. 50 CFR 17.99 - Critical habitat; plants on the islands of Kauai, Niihau, Molokai, Maui, Kahoolawe, Oahu, and...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 8 2013-10-01 2013-10-01 false Critical habitat; plants on the islands of Kauai, Niihau, Molokai, Maui, Kahoolawe, Oahu, and Hawaii, HI, and on the Northwestern Hawaiian Islands. (Continued) 17.99 Section 17.99 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED)...

  5. 50 CFR 17.99 - Critical habitat; plants on the islands of Kauai, Niihau, Molokai, Maui, Kahoolawe, Oahu, and...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 8 2012-10-01 2012-10-01 false Critical habitat; plants on the islands of Kauai, Niihau, Molokai, Maui, Kahoolawe, Oahu, and Hawaii, HI, and on the Northwestern Hawaiian Islands. (Continued) 17.99 Section 17.99 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED)...

  6. 50 CFR 17.99 - Critical habitat; plants on the islands of Kauai, Niihau, Molokai, Maui, Kahoolawe, Oahu, and...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 7 2013-10-01 2013-10-01 false Critical habitat; plants on the islands of Kauai, Niihau, Molokai, Maui, Kahoolawe, Oahu, and Hawaii, HI, and on the Northwestern Hawaiian Islands. 17.99 Section 17.99 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED) TAKING,...

  7. 50 CFR 17.99 - Critical habitat; plants on the islands of Kauai, Niihau, Molokai, Maui, Kahoolawe, Oahu, and...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 7 2012-10-01 2012-10-01 false Critical habitat; plants on the islands of Kauai, Niihau, Molokai, Maui, Kahoolawe, Oahu, and Hawaii, HI, and on the Northwestern Hawaiian Islands. 17.99 Section 17.99 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED) TAKING,...

  8. 50 CFR 17.99 - Critical habitat; plants on the islands of Kauai, Niihau, Molokai, Maui, Kahoolawe, Oahu, and...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 7 2014-10-01 2013-10-01 true Critical habitat; plants on the islands of Kauai, Niihau, Molokai, Maui, Kahoolawe, Oahu, and Hawaii, HI, and on the Northwestern Hawaiian Islands. 17.99 Section 17.99 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED) TAKING,...

  9. 50 CFR 17.99 - Critical habitat; plants on the islands of Kauai, Niihau, Molokai, Maui, Kahoolawe, Oahu, and...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 7 2011-10-01 2005-10-01 true Critical habitat; plants on the islands of Kauai, Niihau, Molokai, Maui, Kahoolawe, Oahu, and Hawaii, HI, and on the Northwestern Hawaiian Islands. (Continued) 17.99 Section 17.99 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED)...

  10. Evaluation of potential severe accidents during low power and shutdown operations at Grand Gulf, Unit 1. Volume 5: Analysis of core damage frequency from seismic events for plant operational state 5 during a refueling outage

    SciTech Connect

    Budnitz, R.J.; Davis, P.R.; Ravindra, M.K.; Tong, W.H.

    1994-08-01

    In 1989 the US Nuclear Regulatory Commission (NRC) initiated an extensive program to examine carefully the potential risks during low-power and shutdown operations. The program included two parallel projects, one at Sandia National Laboratories studying a boiling water reactor (Grand Gulf), and the other at Brookhaven National Laboratory studying a pressurized water reactor (Surry Unit 1). Both the Sandia and Brookhaven projects have examined only accidents initiated by internal plant faults---so-called ``internal initiators.`` This project, which has explored the likelihood of seismic-initiated core damage accidents during refueling outage conditions, is complementary to the internal-initiator analyses at Brookhaven and Sandia. This report covers the seismic analysis at Grand Gulf. All of the many systems modeling assumptions, component non-seismic failure rates, and human effort rates that were used in the internal-initiator study at Grand Gulf have been adopted here, so that the results of the study can be as comparable as possible. Both the Sandia study and this study examine only one shutdown plant operating state (POS) at Grand Gulf, namely POS 5 representing cold shutdown during a refueling outage. This analysis has been limited to work analogous to a level-1 seismic PRA, in which estimates have been developed for the core-damage frequency from seismic events during POS 5. The results of the analysis are that the core-damage frequency for earthquake-initiated accidents during refueling outages in POS 5 is found to be quite low in absolute terms, less than 10{sup {minus}7}/year.

  11. Enhanced analysis methods to derive the spatial distribution of 131I deposition on the ground by airborne surveys at an early stage after the Fukushima Daiichi nuclear power plant accident.

    PubMed

    Torii, Tatsuo; Sugita, Takeshi; Okada, Colin E; Reed, Michael S; Blumenthal, Daniel J

    2013-08-01

    This paper applies both new and well tested analysis methods to aerial radiological surveys to extract the I ground concentrations present after the March 2011 Fukushima Daiichi nuclear power plant (NPP) accident. The analysis provides a complete map of I deposition, an important quantity incalculable at the time of the accident due to the short half-life of I and the complexity of the analysis. A map of I deposition is the first step in conducting internal exposure assessments, population dose reconstruction, and follow-up epidemiological studies. The short half-life of I necessitates the use of aerial radiological surveys to cover the large area quickly, thoroughly, and safely. Teams from the U.S. Department of Energy National Nuclear Security Administration (DOE/NNSA) performed aerial radiological surveys to provide initial maps of the dispersal of radioactive material in Japan. This work reports on analyses performed on a subset of the initial survey data by a joint Japan-U.S. collaboration to determine I ground concentrations. The analytical results show a high concentration of I northwest of the NPP, consistent with the previously reported radioactive cesium deposition, but also shows a significant I concentration south of the plant, which was not observed in the original cesium analysis. The difference in the radioactive iodine and cesium patterns is possibly the result of differences in the ways these materials settle out of the air.

  12. Measurement of dissolved Cs-137 in stream water, soil water and groundwater at Headwater Forested Catchment in Fukushima after Fukushima Dai-ichi Nuclear Power Plant Accident

    NASA Astrophysics Data System (ADS)

    Iwagami, Sho; Tsujimura, Maki; Onda, Yuichi; Sakakibara, Koichi; Konuma, Ryohei; Sato, Yutaro

    2016-04-01

    Radiocesium migration from headwater forested catchment is important perception as output from the forest which is also input to the subsequent various land use and downstream rivers after Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident. In this study, dissolved Cs-137 concentration of stream water, soil water and groundwater were measured. Observations were conducted at headwater catchment in Yamakiya district, located 35 km northwest of FDNPP from April 2014 to November 2015. Stream water discharge was monitored and stream water samples were taken at main channel and sub channel. Stream water discharge was monitored by combination of parshallflume and v-notch weir. Stream water was sampled manually at steady state condition in 3-4 month interval and also intense few hours interval sampling were conducted during rainfall events using automated water sampler. Around the sub channel, it is found that there is a regularly saturated area at the bottom of the slope, temporary saturated area which saturate during the rainy season in summer and regularly dry area. 6 interval cameras were installed to monitor the changing situation of saturated area. Suction lysimeters were installed at three areas (regularly saturated area, temporary saturated area and dry area) for sampling soil water in depth of 0.1 m and 0.3 m. Boreholes were installed at three points along the sub channel. Three boreholes with depth of 3 m, 5 m and 10 m were installed at temporary saturated area, 20 m upstream of sub channel weir. Another three boreholes with depth of 3 m, 5 m and 10 m were installed at dry area, 40 m upstream of sub channel weir. And a borehole with depth of 20 m was installed at ridge of sub catchment, 52 m upstream of sub channel weir. Groundwater was sampled by electrically powered pump and groundwater level was monitored. Also suction-free lysimeter was installed at temporary saturated area for sampling the near surface subsurface water. Soil water samples were collected

  13. Comment on "radioactive fallout in the United States due to the Fukushima nuclear plant accident" by P. Thakur, S. Ballard and R. Nelson, J. Environ. Monit., 2012, 14, 1317-1324.

    PubMed

    Rose, Paula S

    2014-07-01

    The May 2012 paper "Radioactive fallout in the United States due to the Fukushima nuclear plant accident" (P. Thakur, S. Ballard and R. Nelson, J. Environ. Monit., 2012, 14, 1317-1324), does not address medical patient excreta as a source of (131)I (t1/2 = 8.04 d) to the environment. While (131)I is generated during fission reactions and may be released to the environment from nuclear power plants, nuclear weapons tests, nuclear fuel reprocessing and weapons production facilities, it is also produced for medical use. Iodine-131 administered to patients, excreted and discharged to sewer systems is readily measureable in sewage and the environment; the patient-to-sewage pathway is the only source of (131)I in many locations.

  14. iWitness pollution map: crowdsourcing petrochemical accident research.

    PubMed

    Bera, Risha; Hrybyk, Anna

    2013-01-01

    Community members living near any one of Louisiana's 160 chemical plants or refineries have always said that accidents occurring in these petrochemical facilities significantly impact their health and safety. This article reviews the iWitness Pollution Map tool and Rapid Response Team (RRT) approach led by the Louisiana Bucket Brigade, an environmental nonprofit group, and their effectiveness in documenting these health and safety impacts during petrochemical accidents. Analysis of a January 2013 RRT deployment in Chalmette, LA, showed increased documentation of current petrochemical accidents and suggested increased preparedness to report future accidents. The RRT model encourages government response and enforcement agencies to integrate with organized community groups to fully document the impacts during ongoing accidents, lead a more timely response to the accident, and prevent future accidents from occurring.

  15. Health effects models for nuclear power plant accident consequence analysis. Modification of models resulting from addition of effects of exposure to alpha-emitting radionuclides: Revision 1, Part 2, Scientific bases for health effects models, Addendum 2

    SciTech Connect

    Abrahamson, S.; Bender, M.A.; Boecker, B.B.; Scott, B.R.; Gilbert, E.S.

    1993-05-01

    The Nuclear Regulatory Commission (NRC) has sponsored several studies to identify and quantify, through the use of models, the potential health effects of accidental releases of radionuclides from nuclear power plants. The Reactor Safety Study provided the basis for most of the earlier estimates related to these health effects. Subsequent efforts by NRC-supported groups resulted in improved health effects models that were published in the report entitled {open_quotes}Health Effects Models for Nuclear Power Plant Consequence Analysis{close_quotes}, NUREG/CR-4214, 1985 and revised further in the 1989 report NUREG/CR-4214, Rev. 1, Part 2. The health effects models presented in the 1989 NUREG/CR-4214 report were developed for exposure to low-linear energy transfer (LET) (beta and gamma) radiation based on the best scientific information available at that time. Since the 1989 report was published, two addenda to that report have been prepared to (1) incorporate other scientific information related to low-LET health effects models and (2) extend the models to consider the possible health consequences of the addition of alpha-emitting radionuclides to the exposure source term. The first addendum report, entitled {open_quotes}Health Effects Models for Nuclear Power Plant Accident Consequence Analysis, Modifications of Models Resulting from Recent Reports on Health Effects of Ionizing Radiation, Low LET Radiation, Part 2: Scientific Bases for Health Effects Models,{close_quotes} was published in 1991 as NUREG/CR-4214, Rev. 1, Part 2, Addendum 1. This second addendum addresses the possibility that some fraction of the accident source term from an operating nuclear power plant comprises alpha-emitting radionuclides. Consideration of chronic high-LET exposure from alpha radiation as well as acute and chronic exposure to low-LET beta and gamma radiations is a reasonable extension of the health effects model.

  16. TMI-2 - A Case Study for PWR Instrumentation Performance during a Severe Accident

    SciTech Connect

    Joy L. Rempe; Darrell L. Knudson

    2014-05-01

    The accident at the Three Mile Island Unit 2 (TMI-2) reactor provided a unique opportunity to evaluate sensors exposed to severe accident conditions. Conditions associated with the release of coolant and the hydrogen burn that occurred during this accident exposed instrumentation to harsh conditions, including direct radiation, radioactive contamination, and high humidity with elevated temperatures and pressures. As part of a program initiated in 2012 by the Department of Energy Office of Nuclear Energy (DOE-NE), a review was completed to gain insights from prior TMI-2 sensor survivability and data qualification efforts. This new effort focussed upon a set of sensors that provided critical data to TMI-2 operators for assessing the condition of the plant and the effects of mitigating actions taken by these operators. In addition, the effort considered sensors providing data required for subsequent accident simulations. Over 100 references related to instrumentation performance and post-accident evaluations of TMI-2 sensors and measurements were reviewed. Insights gained from this review are summarized within this report. For each sensor, a description is provided with the measured data and conclusions related to the sensor’s survivability, and the basis for conclusions about its survivability. As noted within this document, several techniques were invoked in the TMI-2 post-accident evaluation program to assess sensor status, including comparisons with data from other sensors, analytical calculations, laboratory testing, and comparisons with sensors subjected to similar conditions in large-scale integral tests and with sensors that were similar in design but more easily removed from the TMI-2 plant for evaluations. Conclusions from this review provide important insights related to sensor survivability and enhancement options for improving sensor performance. In addition, this document provides recommendations related to the sensor survivability and data evaluation

  17. TMI-2 - A Case Study for PWR Instrumentation Performance during a Severe Accident

    SciTech Connect

    Joy L. Rempe; Darrell L. Knudson

    2013-03-01

    The accident at the Three Mile Island Unit 2 (TMI-2) reactor provided a unique opportunity to evaluate sensors exposed to severe accident conditions. Conditions associated with the release of coolant and the hydrogen burn that occurred during this accident exposed instrumentation to harsh conditions, including direct radiation, radioactive contamination, and high humidity with elevated temperatures and pressures. As part of a program initiated in 2012 by the Department of Energy Office of Nuclear Energy (DOE-NE), a review was completed to gain insights from prior TMI-2 sensor survivability and data qualification efforts. This new effort focussed upon a set of sensors that provided critical data to TMI-2 operators for assessing the condition of the plant and the effects of mitigating actions taken by these operators. In addition, the effort considered sensors providing data required for subsequent accident simulations. Over 100 references related to instrumentation performance and post-accident evaluations of TMI-2 sensors and measurements were reviewed. Insights gained from this review are summarized within this report. For each sensor, a description is provided with the measured data and conclusions related to the sensor’s survivability, and the basis for conclusions about its survivability. As noted within this document, several techniques were invoked in the TMI-2 post-accident evaluation program to assess sensor status, including comparisons with data from other sensors, analytical calculations, laboratory testing, and comparisons with sensors subjected to similar conditions in large-scale integral tests and with sensors that were similar in design but more easily removed from the TMI-2 plant for evaluations. Conclusions from this review provide important insights related to sensor survivability and enhancement options for improving sensor performance. In addition, this document provides recommendations related to the sensor survivability and data evaluation

  18. 77 FR 18157 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Ipomopsis...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-27

    ...; Designation of Critical Habitat for Ipomopsis polyantha (Pagosa skyrocket), Penstemon debilis (Parachute... of critical habitat for Ipomopsis polyantha (Pagosa skyrocket), Penstemon debilis (Parachute... habitat unit boundaries for Ipomopsis polyantha units 2 and 4, and for Phacelia submutica units 6, 7,...

  19. A dynamic modelling approach for estimating critical loads of nitrogen based on plant community changes under a changing climate.

    PubMed

    Belyazid, Salim; Kurz, Dani; Braun, Sabine; Sverdrup, Harald; Rihm, Beat; Hettelingh, Jean-Paul

    2011-03-01

    A dynamic model of forest ecosystems was used to investigate the effects of climate change, atmospheric deposition and harvest intensity on 48 forest sites in Sweden (n = 16) and Switzerland (n = 32). The model was used to investigate the feasibility of deriving critical loads for nitrogen (N) deposition based on changes in plant community composition. The simulations show that climate and atmospheric deposition have comparably important effects on N mobilization in the soil, as climate triggers the release of organically bound nitrogen stored in the soil during the elevated deposition period. Climate has the most important effect on plant community composition, underlining the fact that this cannot be ignored in future simulations of vegetation dynamics. Harvest intensity has comparatively little effect on the plant community in the long term, while it may be detrimental in the short term following cutting. This study shows: that critical loads of N deposition can be estimated using the plant community as an indicator; that future climatic changes must be taken into account; and that the definition of the reference deposition is critical for the outcome of this estimate.

  20. 78 FR 31479 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Leavenworthia...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-24

    ... shallow soil in which occur natural, long-persisting (edaphic climax) plant communities dominated by... year when conditions are unfavorable for reproduction (e.g., damage (natural or manmade) to plants... competition from nonnative or invasive plants. The natural areas supporting L. exigua var. laciniata are...

  1. 76 FR 59990 - Endangered and Threatened Wildlife and Plants; Revised Endangered Status, Revised Critical...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-28

    .... stoneana in Mexico other than observations of plants directly across the Mexican border from occurrences in... Fish and Wildlife Service 50 CFR Part 17 RIN 1018-AX18 Endangered and Threatened Wildlife and Plants... follows: ``The term `species' includes any subspecies of fish or wildlife or plants, and any...

  2. 76 FR 64995 - Endangered and Threatened Wildlife and Plants; Designation of Revised Critical Habitat for the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-19

    ...We, the U.S. Fish and Wildlife Service (Service), propose to revise critical habitat for the tidewater goby (Eucyclogobius newberryi) under the Endangered Species Act of 1973, as amended (Act). In total, approximately 12,157 acres (4,920 hectares) are being proposed for designation as critical habitat. The proposed revised critical habitat is located in Del Norte, Humboldt, Mendocino, Sonoma,......

  3. 75 FR 13715 - Endangered and Threatened Wildlife and Plants; Revised Designation of Critical Habitat for Bull...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-23

    ...; Revised Designation of Critical Habitat for Bull Trout in the Coterminous United States AGENCY: Fish and... of critical habitat for the bull trout (Salvelinus confluentus) ] under the Endangered Species Act of... January 14, 2010, we published our proposed revised designation of critical habitat for bull trout in...

  4. 75 FR 12815 - Endangered and Threatened Wildlife and Plants; Revised Designation of Critical Habitat for the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-17

    ...We, the U.S. Fish and Wildlife Service (Service), designate revised critical habitat for the California red-legged frog (Rana draytonii) under the Endangered Species Act of 1973, as amended (Act). In total, approximately 1,636,609 acres (ac) (662,312 hectares (ha)) of critical habitat in 27 California counties fall within the boundaries of the final revised critical habitat...

  5. 77 FR 2254 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Mississippi...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-17

    ...; Designation of Critical Habitat for Mississippi Gopher Frog AGENCY: Fish and Wildlife Service, Interior... September 27, 2011, revised proposed rule to designate critical habitat for the Mississippi gopher frog... discuss only those topics directly relevant to the revised proposed rule to designate critical habitat...

  6. 75 FR 18107 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Oregon Chub...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-09

    ...; Designation of Critical Habitat for Oregon Chub (Oregonichthys crameri); Correction AGENCY: Fish and Wildlife... (Service), published a final rule to designate critical habitat for the Oregon chub (Oregonichthys crameri... INFORMATION: Background Our March 10, 2010, final rule (75 FR 11010) to designate critical habitat for...

  7. 75 FR 42054 - Endangered and Threatened Wildlife and Plants; Revised Critical Habitat for Brodiaea filifolia

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-20

    ...; Revised Critical Habitat for Brodiaea filifolia (Thread-leaved Brodiaea) AGENCY: Fish and Wildlife Service... revised designation of critical habitat for Brodiaea filifolia (thread-leaved brodiaea) under the... comment period on our proposed rule to revise critical habitat for Brodiaea filifolia, which we...

  8. 78 FR 39628 - Endangered and Threatened Wildlife and Plants; Critical Habitat Map for the Fountain Darter

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-02

    ...; Critical Habitat Map for the Fountain Darter AGENCY: Fish and Wildlife Service, Interior. ACTION: Final rule. SUMMARY: We, the U.S. Fish and Wildlife Service (Service), are correcting the critical habitat... ensure regulated entities and the general public have an accurate critical habitat map for the...

  9. 78 FR 53390 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for the Jaguar

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-29

    ...; Designation of Critical Habitat for the Jaguar AGENCY: Fish and Wildlife Service, Interior. ACTION: Proposed... critical habitat for the jaguar (Panthera onca), as revised on July 1, 2013, under the Endangered Species... critical habitat. Accordingly, the final designation may differ from our proposal. If you...

  10. 78 FR 15925 - Endangered and Threatened Wildlife and Plants; Endangered Status and Critical Habitat Designation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-13

    ...; Endangered Status and Critical Habitat Designation for Gunnison Sage-Grouse AGENCY: Fish and Wildlife Service... sage-grouse (Centrocercus minimus) as endangered and to propose critical habitat for the Gunnison sage... the proposed rule to designate critical habitat published in the Federal Register on January 11,...

  11. United States Department of Energy severe accident research following the Fukushima Daiichi accidents

    SciTech Connect

    Farmer, M. T.; Corradini, M.; Rempe, J.; Reister, R.; Peko, D.

    2016-11-02

    The U.S. Department of Energy (DOE) has played a major role in the U.S. response to the events at Fukushima Daiichi. During the first several weeks following the accident, U.S. assistance efforts were guided by results from a significant and diverse set of analyses. In the months that followed, a coordinated analysis activity aimed at gaining a more thorough understanding of the accident sequence was completed using laboratory-developed, system-level best-estimate accident analysis codes, while a parallel analysis was conducted by U.S. industry. A comparison of predictions for Unit 1 from these two studies indicated significant differences between MAAP and MELCOR results for key plant parameters, such as in-core hydrogen production. On that basis, a crosswalk was completed to determine the key modeling variations that led to these differences. In parallel with these activities, it became clear that there was a need to perform a technology gap evaluation on accident-tolerant components and severe accident analysis methodologies with the goal of identifying any data and/or knowledge gaps that may exist given the current state of light water reactor (LWR) severe accident research and augmented by insights from Fukushima. In addition, there is growing international recognition that data from Fukushima could significantly reduce uncertainties related to severe accident progression, particularly for boiling water reactors. On these bases, a group of U. S. experts in LWR safety and plant operations was convened by the DOE Office of Nuclear Energy (DOE-NE) to complete technology gap analysis and Fukushima forensics data needs identification activities. The results from these activities were used as the basis for refining DOE-NE's severe accident research and development (R&D) plan. Finally, this paper provides a high-level review of DOE-sponsored R&D efforts in these areas, including planned activities on accident-tolerant components and accident analysis methods.

  12. United States Department of Energy severe accident research following the Fukushima Daiichi accidents

    DOE PAGES

    Farmer, M. T.; Corradini, M.; Rempe, J.; ...

    2016-11-02

    The U.S. Department of Energy (DOE) has played a major role in the U.S. response to the events at Fukushima Daiichi. During the first several weeks following the accident, U.S. assistance efforts were guided by results from a significant and diverse set of analyses. In the months that followed, a coordinated analysis activity aimed at gaining a more thorough understanding of the accident sequence was completed using laboratory-developed, system-level best-estimate accident analysis codes, while a parallel analysis was conducted by U.S. industry. A comparison of predictions for Unit 1 from these two studies indicated significant differences between MAAP and MELCORmore » results for key plant parameters, such as in-core hydrogen production. On that basis, a crosswalk was completed to determine the key modeling variations that led to these differences. In parallel with these activities, it became clear that there was a need to perform a technology gap evaluation on accident-tolerant components and severe accident analysis methodologies with the goal of identifying any data and/or knowledge gaps that may exist given the current state of light water reactor (LWR) severe accident research and augmented by insights from Fukushima. In addition, there is growing international recognition that data from Fukushima could significantly reduce uncertainties related to severe accident progression, particularly for boiling water reactors. On these bases, a group of U. S. experts in LWR safety and plant operations was convened by the DOE Office of Nuclear Energy (DOE-NE) to complete technology gap analysis and Fukushima forensics data needs identification activities. The results from these activities were used as the basis for refining DOE-NE's severe accident research and development (R&D) plan. Finally, this paper provides a high-level review of DOE-sponsored R&D efforts in these areas, including planned activities on accident-tolerant components and accident analysis methods.« less

  13. Chernobyl accident: A comprehensive risk assessment

    SciTech Connect

    Vargo, G.J.; Poyarkov, V.; Baryakhtar, V.; Kukhar, V.; Los, I.

    1999-11-01

    The authors, all of whom are Ukrainian and Russian scientists involved with Chernobyl nuclear power plant since the April 1986 accident, present a comprehensive review of the accident. In addition, they present a risk assessment of the remains of the destroyed reactor and its surrounding shelter, Chernobyl radioactive waste storage and disposal sites, and environmental contamination in the region. The authors explore such questions as the risks posed by a collapse of the shelter, radionuclide migration from storage and disposal facilities in the exclusion zone, and transfer from soil to vegetation and its potential regional impact. The answers to these questions provide a scientific basis for the development of countermeasures against the Chernobyl accident in particular and the mitigation of environmental radioactive contamination in general. They also provide an important basis for understanding the human health and ecological risks posed by the accident.

  14. The Chornobyl accident: A comprehensive risk assessment

    SciTech Connect

    Vargo, G.J.; Poyarkov, V.; Bar`yakhtar, V.; Kukhar, V.; Los, I.; Kholosha, V.; Shestopalov, V.

    1999-10-01

    The authors, all of whom are Ukrainian and Russian scientists involved with Chornobyl nuclear power plant since the April 1986 accident, present a comprehensive review of the accident. In addition, they present a risk assessment of the remains of the destroyed reactor and its surrounding shelter, Chornobyl radioactive waste storage and disposal sites, and environmental contamination in the region. The authors explore such questions as the risks posed by a collapse of the shelter, radionuclide migration from storage and disposal facilities in the exclusion zone, and transfer from soil to vegetation and its potential regional impact. The answers to these questions provide a scientific basis for the development of countermeasures against the Chornobyl accident in particular and the mitigation of environmental radioactive contamination in general. They also provide an important basis for understanding the human health and ecological risks posed by the accident.

  15. Chernobyl accident: A comprehensive risk assessment

    SciTech Connect

    Vargo, G.J.; Poyarkov, V.; Baryakhtar, V.; Kukhar, V.; Los, I.

    1999-01-01

    The authors, all of whom are Ukrainian and Russian scientists involved with Chernobyl nuclear power plant since the April 1986 accident, present a comprehensive review of the accident. In addition, they present a risk assessment of the remains of the destroyed reactor and its surrounding shelter, Chernobyl radioactive waste storage and disposal sites, and environmental contamination in the region. The authors explore such questions as the risks posed by a collapse of the shelter, radionuclide migration from storage and disposal facilities in the exclusion zone, and transfer from soil to vegetation and its potential regional impact. The answers to these questions provide a scientific basis for the development of countermeasures against the Chernobyl accident in particular and the mitigation of environmental radioactive contamination in general. They also provide an important basis for understanding the human health and ecological risks posed by the accident.

  16. TMI-2 accident: core heat-up analysis

    SciTech Connect

    Ardron, K.H.; Cain, D.G.

    1981-01-01

    This report summarizes NSAC study of reactor core thermal conditions during the accident at Three Mile Island, Unit 2. The study focuses primarily on the time period from core uncovery (approximately 113 minutes after turbine trip) through the initiation of sustained high pressure injection (after 202 minutes). The transient analysis is based upon established sequences of events; plant data; post-accident measurements; interpretation or indirect use of instrument responses to accident conditions.

  17. Plant Production Systems for Microgravity: Critical Issues in Water, Air, and Solute Transport Through Unsaturated Porous Media

    NASA Technical Reports Server (NTRS)

    Steinberg, Susan L. (Editor); Ming, Doug W. (Editor); Henninger, Don (Editor)

    2002-01-01

    This NASA Technical Memorandum is a compilation of presentations and discussions in the form of minutes from a workshop entitled 'Plant Production Systems for Microgravity: Critical Issues in Water, Air, and Solute Transport Through Unsaturated Porous Media' held at NASA's Johnson Space Center, July 24-25, 2000. This workshop arose from the growing belief within NASA's Advanced Life Support Program that further advances and improvements in plant production systems for microgravity would benefit from additional knowledge of fundamental processes occurring in the root zone. The objective of the workshop was to bring together individuals who had expertise in various areas of fluid physics, soil physics, plant physiology, hardware development, and flight tests to identify, discuss, and prioritize critical issues of water and air flow through porous media in microgravity. Participants of the workshop included representatives from private companies involved in flight hardware development and scientists from universities and NASA Centers with expertise in plant flight tests, plant physiology, fluid physics, and soil physics.

  18. Nuclear criticality safety controls for uranium deposits during D and D at the Oak Ridge Gaseous Diffusion Plant

    SciTech Connect

    Haire, M.J.; Jordan, W.C.; Jollay, L.J. III; Dahl, T.L.

    1997-02-01

    The US Department of Energy (DOE) Deputy Assistant Secretary of Energy for Environmental Management has issued a challenge to complete DOE environmental cleanup within a decade. The response for Oak Ridge facilities is in accordance with the DOE ten-year plan which calls for completion of > 95% of environmental management work by the year 2006. This will result in a 99% risk reduction and in a significant savings in base line costs in waste management (legacy waste); remedial action (groundwater, soil, etc.); and decontamination and decommissioning (D and D). It is assumed that there will be long-term institutional control of cascade equipment, i.e., there will be no walk away from sites, and that there will be firm radioactivity release limits by 1999 for recycle metals. An integral part of these plants is the removal of uranium deposits which pose nuclear criticality safety concerns in the shut down of the Oak Ridge Gaseous Diffusion Plant. DOE has initiated the Nuclear Criticality Stabilization Program to improve nuclear criticality safety by removing the larger uranium deposits from unfavorable geometry equipment. Nondestructive assay (NDA) measurements have identified the location of these deposits. The objective of the K-25 Site Nuclear Criticality Stabilization Program is to remove and place uranium deposits into safe geometry storage containers to meet the double contingency principle. Each step of the removal process results in safer conditions where multiple controls are present. Upon completion of the Program, nuclear criticality risks will be greatly reduced.

  19. Repository preclosure accident scenarios

    SciTech Connect

    Yook, H.R.; Arbital, J.G.; Keeton, J.M.; Mosier, J.E.; Weaver, B.S.

    1984-09-01

    Waste-handling operations at a spent-fuel repository were investigated to identify operational accidents that could occur. The facility was subdivided, through systems engineering procedures, into individual operations that involve the waste and one specific component of the waste package, in one specific area of the handling facility. From this subdivision approximately 600 potential accidents involving waste package components were identified and then discussed. Supporting descriptive data included for each accident scenario are distance of drop, speed of collision, weight of package component, and weight of equipment involved. The energy of impact associated with each potential accident is calculated to provide a basis for comparison of the relative severities of all the accidents. The results and conclusions suggest approaches to accident consequence mitigation through waste package and facility design. 35 figures, 9 tables.

  20. Laser accidents: Being Prepared

    SciTech Connect

    Barat, K

    2003-01-24

    The goal of the Laser Safety Officer and any laser safety program is to prevent a laser accident from occurring, in particular an injury to a person's eyes. Most laser safety courses talk about laser accidents, causes, and types of injury. The purpose of this presentation is to present a plan for safety offices and users to follow in case of accident or injury from laser radiation.

  1. Spatial and temporal distributions of (134)Cs and (137)Cs derived from the TEPCO Fukushima Daiichi Nuclear Power Plant accident in the North Pacific Ocean by using optimal interpolation analysis.

    PubMed

    Inomata, Y; Aoyama, M; Tsubono, T; Tsumune, D; Hirose, K

    2016-01-01

    Optimal interpolation (OI) analysis was used to investigate the oceanic distributions of (134)Cs and (137)Cs released from the Tokyo Electric Power Company Fukushima Daiichi Nuclear Power Plant (FNPP1) accident. From the end of March to early April 2011, extremely high activities were observed in the coastal surface seawater near the FNPP1. The high activities spread to a region near 165°E in the western North Pacific Ocean, with a latitudinal center of 40°N. Atmospheric deposition also caused high activities in the region between 180° and 130°W in the North Pacific Ocean. The inventory of FNPP1-released (134)Cs in the North Pacific Ocean was estimated to be 15.3 ± 2.6 PBq. About half of this activity (8.4 ± 2.6 PBq) was found in the coastal region near the FNPP1. After 6 April 2011, when major direct releases ceased, the FNPP1-released (134)Cs in the coastal region decreased exponentially with an apparent half-time of about 4.2 ± 0.5 days and declined to about 2 ± 0.4 PBq by the middle of May 2011. Taking into account that the (134)Cs/(137)Cs activity ratio was about 1 just after release and was extremely uniform during the first month after the accident, the amount of (137)Cs released by the FNPP1 accident increased the North Pacific inventory of (137)Cs due to bomb testing during the 1950s and early 1960s by 20%.

  2. Speciation analysis of I-127,129 in the crop field soil contaminated by the Fukushima Dai-ichi nuclear power plant accident with newly developed chemical separation techniques

    NASA Astrophysics Data System (ADS)

    Honda, Maki; Matsuzaki, Hiroyuki; Saito, Takumi; Nagai, Hisao

    2014-05-01

    In previous study, we investigated the depth profile of the accident derived I-129 and downward migration speed in soils of near-field of Fukushima Dai-ichi Nuclear Power Plant, including crop fields and man-made fields. I-129 in soil was measured by AMS and stable iodine (I-127) was measured by ICP-MS at MALT (Micro Analysis Laboratory, Tandem accelerator), The University of Tokyo. It was found that I-129 was concentrated near surface but distributed deeper compared with Cs-137. It was also found that I-129 seems to move downward more quickly than Cs-137. To investigate the adsorption mechanism and the elemental process of migration of the accident derived I-129 in soil, it is important to know what kind of component the I-129 combines with. Recent studies on the X-ray absorption fine structure (XAFS), especially near edge structure (XANES), reported that the stable iodine (I-127) in soil existed as an organic component. However, it had not yet been proved that it was also the case with the accident derived I-129 because it had been incorporated in the soil system only recently and the abundance of I-129 in soil was more than 8 orders of magnitude smaller than sub-ppm level stable iodine (I-127). In this study a progressive sequential extraction method including the dialysis and the dynamic headspace method was newly developed to obtain only the iodine sticking to the soil organic component. The stable iodine can be quantified by direct analysis of the fraction and I-129 can be quantified by AMS method of the fraction added with carrier. The fraction of the organic component for I-127 and I-129 can be evaluated respectively by comparing with the other fraction and/or with the total concentration obtained by the bulk analysis (e.g. by the pyrohydrolysis).

  3. Estimation of soil-to-plant transfer factors of radiocesium in 99 wild plant species grown in arable lands 1 year after the Fukushima 1 Nuclear Power Plant accident.

    PubMed

    Yamashita, Jun; Enomoto, Takashi; Yamada, Masao; Ono, Toshiro; Hanafusa, Tadashi; Nagamatsu, Tomohiro; Sonoda, Shoji; Yamamoto, Yoko

    2014-01-01

    One year after the deposition of radionuclides from the Fukushima 1 Nuclear Power Plant (A formal name is Fukushima Daiichi Nuclear Power Station) in March 2011, radiocesium (¹³⁴Cs, ¹³⁷Cs) concentrations ([Cs]) were comprehensively investigated in the wild plants of 99 species most of which were annual or summer green perennial herbs and started to grow from April 2012 at the heavily contaminated fields of paddy (three study sites) and upland (one study site) in Fukushima Prefecture. The survey was conducted three times (April, July and October) in the year. In each site, soils (soil cores of 5-cm depth) and plants (aerial shoots) were collected for determination of [Cs] on a dry weight basis, and then the transfer factor (TF) of radiocesium from soil to plant ([Cs]plant/[Cs]soil) was estimated in each species. The [Cs] values of both soils and plants largely varied. However, some species exhibited relatively high TF values (more than 0.4) (e.g., Athyrium yokoscense, Dryopteris tokyoensis, and Cyperus brevifolius), while others exhibited almost negligible values (less than 0.01) (e.g., Salix miyabeana, Humulus scandens, and Elymus tsukushiensis). In addition, judging from the 11 species grown in both paddy and upland fields, TF values were generally higher in the paddy fields. The estimation of phytoextraction efficiency of soil radiocesium by weed communities in the paddy fields suggests that the weed community is not a practical candidate for phytoremediation technique.

  4. [Accidents with the "paraglider"].

    PubMed

    Lang, T H; Dengg, C; Gabl, M

    1988-09-01

    With a collective of 46 patients we show the details and kinds of accidents caused by paragliding. The base for the casuistry of the accidents was a questionnaire which was answered by most of the injured persons. These were questions about the theoretical and practical training, the course of the flight during the different phases, and the subjective point of view of the course of the accident. The patterns of the injuries showed a high incidence of injuries of the spinal column and high risks for the ankles. At the end, we give some advice how to prevent these accidents.

  5. Accident mortality among children

    PubMed Central

    Swaroop, S.; Albrecht, R. M.; Grab, B.

    1956-01-01

    The authors present statistics on mortality from accidents, with special reference to those relating to the age-group 1-19 years. For a number of countries figures are given for the proportional mortality from accidents (the number of accident deaths expressed as a percentage of the number of deaths from all causes) and for the specific death-rates, per 100 000 population, from all causes of death, from selected causes, from all causes of accidents, and from various types of accident. From these figures it appears that, in most countries, accidents are becoming relatively increasingly prominent as a cause of death in childhood, primarily because of the conquest of other causes of death—such as infectious and parasitic diseases, which formerly took a heavy toll of children and adolescents—but also to some extent because the death-rate from motor-vehicle accidents is rising and cancelling out the reduction in the rate for other causes of accidental death. In the authors' opinion, further epidemiological investigations into accident causation are required for the purpose of devising quicker and more effective methods of accident prevention. PMID:13383361

  6. 75 FR 21394 - Endangered and Threatened Wildlife and Plants; Final Revised Critical Habitat for Hine's Emerald...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-23

    ...We, the U.S. Fish and Wildlife Service (Service), are designating critical habitat for the Hine's emerald dragonfly (Somatochlora hineana) under the Endangered Species Act of 1973, as amended (Act). In total, approximately 26,531.8 acres (ac) (10,737 hectares (ha)) in 37 units fall within the boundaries of our critical habitat designation. The critical habitat units are located in Cook,......

  7. 78 FR 2539 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Gunnison Sage...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-11

    ...We, the U.S. Fish and Wildlife Service, propose to designate critical habitat for the Gunnison sage-grouse (Centrocercus minimus) under the Endangered Species Act of 1973, as amended (Act). If we finalize this rule as proposed, it would extend the Act's protections to this species' critical habitat. The effect of this regulation is to designate critical habitat for the Gunnison sage-grouse......

  8. Adverse effects of plant food supplements and botanical preparations: a systematic review with critical evaluation of causality

    PubMed Central

    Di Lorenzo, Chiara; Ceschi, Alessandro; Kupferschmidt, Hugo; Lüde, Saskia; De Souza Nascimento, Elizabeth; Dos Santos, Ariana; Colombo, Francesca; Frigerio, Gianfranco; Nørby, Karin; Plumb, Jenny; Finglas, Paul; Restani, Patrizia

    2015-01-01

    AIMS The objective of this review was to collect available data on the following: (i) adverse effects observed in humans from the intake of plant food supplements or botanical preparations; (ii) the misidentification of poisonous plants; and (iii) interactions between plant food supplements/botanicals and conventional drugs or nutrients. METHODS PubMed/MEDLINE and Embase were searched from database inception to June 2014, using the terms ‘adverse effect/s’, ‘poisoning/s’, ‘plant food supplement/s’, ‘misidentification/s’ and ‘interaction/s’ in combination with the relevant plant name. All papers were critically evaluated according to the World Health Organization Guidelines for causality assessment. RESULTS Data were obtained for 66 plants that are common ingredients of plant food supplements; of the 492 papers selected, 402 (81.7%) dealt with adverse effects directly associated with the botanical and 89 (18.1%) concerned interactions with conventional drugs. Only one case was associated with misidentification. Adverse effects were reported for 39 of the 66 botanical substances searched. Of the total references, 86.6% were associated with 14 plants, including Glycine max/soybean (19.3%), Glycyrrhiza glabra/liquorice (12.2%), Camellia sinensis/green tea ( 8.7%) and Ginkgo biloba/gingko (8.5%). CONCLUSIONS Considering the length of time examined and the number of plants included in the review, it is remarkable that: (i) the adverse effects due to botanical ingredients were relatively infrequent, if assessed for causality; and (ii) the number of severe clinical reactions was very limited, but some fatal cases have been described. Data presented in this review were assessed for quality in order to make the results maximally useful for clinicians in identifying or excluding deleterious effects of botanicals. PMID:25251944

  9. Biochar soil amendment on alleviation of drought and salt stress in plants: a critical review.

    PubMed

    Ali, Shafaqat; Rizwan, Muhammad; Qayyum, Muhammad Farooq; Ok, Yong Sik; Ibrahim, Muhammad; Riaz, Muhammad; Arif, Muhammad Saleem; Hafeez, Farhan; Al-Wabel, Mohammad I; Shahzad, Ahmad Naeem

    2017-04-03

    Drought and salt stress negatively affect soil fertility and plant growth. Application of biochar, carbon-rich material developed from combustion of biomass under no or limited oxygen supply, ameliorates the negative effects of drought and salt stress on plants. The biochar application increased the plant growth, biomass, and yield under either drought and/or salt stress and also increased photosynthesis, nutrient uptake, and modified gas exchange characteristics in drought and salt-stressed plants. Under drought stress, biochar increased the water holding capacity of soil and improved the physical and biological properties of soils. Under salt stress, biochar decreased Na(+) uptake, while increased K(+) uptake by plants. Biochar-mediated increase in salt tolerance of plants is primarily associated with improvement in soil properties, thus increasing plant water status, reduction of Na(+) uptake, increasing uptake of minerals, and regulation of stomatal conductance and phytohormones. This review highlights both the potential of biochar in alleviating drought and salt stress in plants and future prospect of the role of biochar under drought and salt stress in plants.

  10. A critical test of the two prevailing theories of plant response to nutrient availability.

    PubMed

    Rubio, Gerardo; Zhu, Jinming; Lynch, Jonathan P

    2003-01-01

    Whereas the "law of the minimum" (LM) states that plant growth is limited by a single resource at any one time, the "multiple limitation hypothesis" (MLH) proposes that optimum plant behavior results from balancing resource costs and benefits so that all resources limit plant growth simultaneously. We tested the hypothesis that neither the LM nor the MLH account for plant responses to all mineral nutrients. Fronds of the aquatic plant Lemna minor were grown in nutrient solutions with increasing levels of four nutrients: nitrogen, phosphorus, potassium, and magnesium. Neither LM or MLH adequately predicted plant responses to all of these nutrients: 23 of the 60 responses analyzed were classified as belonging to the LM; 20 cases were classified as undefined; and 17 cases as MLH. The type of response strongly depended on the specific pair of nutrients considered. The validity of the MLH model would depend on the accompanying resource limiting plant growth and on the severity of the stress. We propose that a "nutrient-specific" analysis, considering the biology of each mineral nutrient rather than grouping plant resources as a whole, is more appropriate than general models in understanding plant responses to nutrient availability.

  11. Copper and cobalt accumulation in plants: a critical assessment of the current state of knowledge.

    PubMed

    Lange, Bastien; van der Ent, Antony; Baker, Alan John Martin; Echevarria, Guillaume; Mahy, Grégory; Malaisse, François; Meerts, Pierre; Pourret, Olivier; Verbruggen, Nathalie; Faucon, Michel-Pierre

    2017-01-01

    This review synthesizes contemporary understanding of copper-cobalt (Cu-Co) tolerance and accumulation in plants. Accumulation of foliar Cu and Co to > 300 μg g(-1) is exceptionally rare globally, and known principally from the Copperbelt of Central Africa. Cobalt accumulation is also observed in a limited number of nickel (Ni) hyperaccumulator plants occurring on ultramafic soils around the world. None of the putative Cu or Co hyperaccumulator plants appears to comply with the fundamental principle of hyperaccumulation, as foliar Cu-Co accumulation is strongly dose-dependent. Abnormally high plant tissue Cu concentrations occur only when plants are exposed to high soil Cu with a low root to shoot translocation factor. Most Cu-tolerant plants are Excluders sensu Baker and therefore setting nominal threshold values for Cu hyperaccumulation is not informative. Abnormal accumulation of Co occurs under similar circumstances in the Copperbelt of Central Africa as well as sporadically in Ni hyperaccumulator plants on ultramafic soils; however, Co-tolerant plants behave physiologically as Indicators sensu Baker. Practical application of Cu-Co accumulator plants in phytomining is limited due to their dose-dependent accumulation characteristics, although for Co field trials may be warranted on highly Co-contaminated mineral wastes because of its relatively high metal value.

  12. 75 FR 27690 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Ambrosia...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-18

    ... INFORMATION CONTACT). Author(s) The primary authors of this notice are the staff members of the Carlsbad Fish...) Flowering plants. * * * * * Family Asteraceae: Ambrosia pumila (San Diego ambrosia) * * * * *...

  13. Detailed Distribution Map of Absorbed Dose Rate in Air in Tokatsu Area of Chiba Prefecture, Japan, Constructed by Car-Borne Survey 4 Years after the Fukushima Daiichi Nuclear Power Plant Accident.

    PubMed

    Inoue, Kazumasa; Arai, Moeko; Fujisawa, Makoto; Saito, Kyouko; Fukushi, Masahiro

    2017-01-01

    A car-borne survey was carried out in the northwestern, or Tokatsu, area of Chiba Prefecture, Japan, to make a detailed distribution map of absorbed dose rate in air four years after the Fukushima Daiichi Nuclear Power Plant accident. This area was chosen because it was the most heavily radionuclide contaminated part of Chiba Prefecture and it neighbors metropolitan Tokyo. Measurements were performed using a 3-in × 3-in NaI(Tl) scintillation spectrometer in June 2015. The survey route covered the whole Tokatsu area which includes six cities. A heterogeneous distribution of absorbed dose rate in air was observed on the dose distribution map. Especially, higher absorbed dose rates in air exceeding 80 nGy h-1 were observed along national roads constructed using high porosity asphalt, whereas lower absorbed dose rates in air were observed along local roads constructed using low porosity asphalt. The difference between these asphalt types resulted in a heterogeneous dose distribution in the Tokatsu area. The mean of the contribution ratio of artificial radionuclides to absorbed dose rate in air measured 4 years after the accident was 29% (9-50%) in the Tokatsu area. The maximum absorbed dose rate in air, 201 nGy h-1 was observed at Kashiwa City. Radiocesium was deposited in the upper 1 cm surface layer of the high porosity asphalt which was collected in Kashiwa City and the environmental half-life of the absorbed dose rate in air was estimated to be 1.7 years.

  14. A dual pathways transfer model to account for changes in the radioactive caesium level in demersal and pelagic fish after the Fukushima Daï-ichi nuclear power plant accident.

    PubMed

    Fiévet, Bruno; Bailly-du-Bois, Pascal; Laguionie, Philippe; Morillon, Mehdi; Arnaud, Mireille; Cunin, Pascal

    2017-01-01

    The Fukushima Daï-ichi nuclear power plant (FDNPP) accident resulted in radioactive Cs being discharged into the local marine environment. While Cs bioaccumulates in biota and slowly depurates, the Cs concentrated in biota constitutes a source of Cs for animals feeding on each other. The marine biota therefore serves as a pool that recycles Cs, and this recycling process delays depuration in the fish feeding on this biota pool. Because the continental shelf is squeezed between the coast and very deep sea, the demersal marine species are confined to a narrow strip along the coast, close to the source of the radioactive input. Unlike demersal species, however, pelagic species are not restricted to the most contaminated area but instead spend some, if not most, of their time and feeding off-shore, far from the input source. We suggest that the feeding pathway for fish is a box whose size depends on their mobility, and that this feeding box is much larger and less contaminated (because of dilution through distance) for pelagic fish than for demersal fish. The aim of this paper is to test this hypothesis and to propose a simple operational model implementing two transfer routes: from seawater and from feeding. The model is then used to match the observational data in the aftermath of the FDNPP accident.

  15. Implications for accident management of adding water to a degrading reactor core

    SciTech Connect

    Kuan, P.; Hanson, D.J.; Pafford, D.J.; Quick, K.S.; Witt, R.J.

    1994-02-01

    This report evaluates both the positive and negative consequences of adding water to a degraded reactor core during a severe accident. The evaluation discusses the earliest possible stage at which an accident can be terminated and how plant personnel can best respond to undesired results. Specifically discussed are (a) the potential for plant personnel to add water for a range of severe accidents, (b) the time available for plant personnel to act, (c) possible plant responses to water added during the various stages of core degradation, (d) plant instrumentation available to understand the core condition and (e) the expected response of the instrumentation during the various stages of severe accidents.

  16. Minimum Accident of Concern - A Different Basis for CAS Analysis

    SciTech Connect

    Biswas, D.

    2002-01-31

    A Criticality Alarm System is normally designed to detect immediately the minimum accident of concern. This report covers the methodology to establish a different minimum accident of concern developed for shielded facilities and applied to a case of the canyon sump excursion in a Savannah River Site facility.

  17. Accident Avoidance Skill Training and Performance Testing. Final Report.

    ERIC Educational Resources Information Center

    Hatterick, G. Richard; Barthurst, James R.

    A two-phased study was conducted to determine the feasibility of training drivers to acquire skills needed to avoid critical conflict motor vehicle accidents, and to develop the procedures and materials necessary for such training. Basic data were derived from indepth accident investigations and task analyses of driver behavior. Principal…

  18. The transfer of radiocesium from the bark to the stemflow of chestnut trees (Castanea crenata) contaminated by radionuclides from the Fukushima Dai-ichi nuclear power plant accident.

    PubMed

    Sasaki, Yoshito; Abe, Hironobu; Mitachi, Katsuaki; Watanabe, Takayoshi; Ishii, Yasuo; Niizato, Tadafumi

    2016-09-01

    We report on the behavior of radiocesium in tree bark and its transfer into the stemflows of chestnut trees in a forest in the Fukushima Prefecture, Japan. In stems that were present at the time of the accident, the radiocesium concentration of the bark was found to be approximately 10 times that of the wood. The average (137)Cs concentration of the dissolved fraction (<0.45 μm) in the stemflow was measured to be around 10 Bq/L. The (137)Cs concentration ratio [present at the time of the accident (Bq/kg) in the bark/the dissolved fraction in the stemflow (Bq/L)] was approximately 10(3). A strong positive correlation was observed between the radiocesium concentration and the electrical conductivity of the dissolved fraction of the stemflow; this result suggests that radiocesium and electrolytes have the same elution mechanism from the tree. The size fractionation analysis of the <0.45 μm fraction through ultrafiltration revealed that the radiocesium was present as an almost dissolved species. Some of the particles in the particulate fraction (>0.45 μm) of the stemflow were strongly adsorbed radiocesium.

  19. Glycerol-3-phosphate is a critical mobile inducer of systemic immunity in plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Glycerol-3-phosphate (G3P) is an important metabolite that contributes to the growth and disease-related physiologies of prokaryotes, plants, animals and humans alike. Here we show that G3P serves as the inducer of an important form of broad-spectrum immunity in plants, termed systemic acquired resi...

  20. 78 FR 61293 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Brickellia...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-03

    ... essential for the conservation of the plants, to provide for the necessary expansion of current Brickellia... constitute ``physical or biological features essential to the conservation of the species,'' within the... essential to the conservation of these plants, should be included in the designation and why; and ] (f)...

  1. 78 FR 52363 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for the Diamond...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-22

    ...We, the U.S. Fish and Wildlife Service (Service), designate critical habitat for the diamond darter (Crystallaria cincotta), a small fish in West Virginia, under the Endangered Species Act (Act). In total, approximately 197.1 river kilometers (122.5 river miles) in Kanawha and Clay Counties, West Virginia, and Edmonson, Hart, and Green Counties, Kentucky, are being designated as critical......

  2. 76 FR 66805 - Endangered and Threatened Wildlife and Plants: Final Rulemaking To Designate Critical Habitat for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-27

    ... for Black Abalone; Final Rule #0;#0;Federal Register / Vol. 76 , No. 208 / Thursday, October 27, 2011... Designate Critical Habitat for Black Abalone AGENCY: National Marine Fisheries Service (NMFS), National... Marine Fisheries Service (NMFS), hereby designate critical habitat for the endangered black abalone...

  3. 76 FR 7245 - Endangered and Threatened Wildlife and Plants; Revised Critical Habitat for the Arroyo Toad

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-09

    ...We, the U.S. Fish and Wildlife Service (Service), are designating final revised critical habitat for the arroyo toad (Anaxyrus californicus, Bufo californicus). We are designating approximately 98,366 acres (ac) (39,807 hectares (ha)) of habitat in Santa Barbara, Ventura, Los Angeles, San Bernardino, Riverside, Orange, and San Diego Counties, California, as critical habitat for the arroyo......

  4. 77 FR 23007 - Endangered and Threatened Wildlife and Plants; Designation of Revised Critical Habitat for Allium...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-17

    ... designated that is considered to be critical habitat. Section 4(b)(2) of the Endangered Species Act states...) The amount and distribution of Allium munzii and Atriplex coronata var. notatior habitat, (b) Which... critical habitat should be considered for exclusion under section 4(b)(2) of the Act and for those...

  5. 78 FR 59429 - Endangered and Threatened Wildlife and Plants; Revised Designation of Critical Habitat for the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-26

    ... critical habitat proposed rule also addresses issues raised by two courts in 2010. If we finalize this rule... introduction efforts in Colorado. This rule would revise the designation of critical habitat for the lynx DPS... of the DPS should be included in the designation and why; (c) Special management considerations...

  6. 77 FR 16512 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for the Southern...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-21

    ...; Designation of Critical Habitat for the Southern Selkirk Mountains Population of Woodland Caribou (Rangifer...), announce the reopening of the comment period on our November 30, 2011, proposed rule to designate critical...: Written Comments: We will consider comments received or postmarked on or before May 21, 2012....

  7. 78 FR 25679 - Endangered and Threatened Wildlife and Plants; Proposed Revision of Critical Habitat for the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-02

    ... salamander (Eurycea nana), and Texas wild-rice (Zizania texana). Comal Springs has critical habitat... affecting the critical habitat of the listed fountain darter, San Marcos salamander, and Texas wild- rice... in place for the fountain darter, San Marcos salamander, and Texas wild-rice. In...

  8. 75 FR 31387 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Mississippi...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-03

    ... critical habitat designation. The proposed critical habitat is located within Forrest, Harrison, Jackson... 2001, this species occurred at only one site, Glen's Pond, in the DeSoto National Forest in Harrison... potential. These sites occur on the DeSoto National Forest (Harrison, Forrest, and Perry Counties), the...

  9. 75 FR 77817 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Mississippi...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-14

    ...; Designation of Critical Habitat for Mississippi Gopher Frog AGENCY: Fish and Wildlife Service, Interior... habitat for the Mississippi gopher frog (Rana sevosa) under the Endangered Species Act of 1973, as amended... interested parties an opportunity to comment simultaneously on the proposed critical habitat designation,...

  10. 77 FR 43222 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for the Tidewater...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-24

    ...; Designation of Critical Habitat for the Tidewater Goby AGENCY: Fish and Wildlife Service, Interior. ACTION... habitat for the tidewater goby (Eucyclogobius newberryi) under the Endangered Species Act of 1973, as... revised designation of critical habitat for tidewater goby and an amended required determinations...

  11. 78 FR 51705 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Ivesia webberi

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-21

    ...; Designation of Critical Habitat for Ivesia webberi (Webber's ivesia) AGENCY: Fish and Wildlife Service... habitat for Ivesia webberi. DATES: We will hold a public meeting on the proposed rule on September 10... INFORMATION: In our August 2, 2013, proposed rule to designate critical habitat for Ivesia webberi,...

  12. 77 FR 41147 - Endangered and Threatened Wildlife and Plants; Designation of Revised Critical Habitat for the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-12

    ...; Designation of Revised Critical Habitat for the Southwestern Willow Flycatcher AGENCY: Fish and Wildlife..., proposed designation of revised critical habitat for the southwestern willow flycatcher (Empidonax traillii... Willow Flycatcher Recovery Plan (Recovery Plan) (Service 2002) and included in this proposed rule,...

  13. 78 FR 24007 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Eriogonum codium

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-23

    ... INFORMATION CONTACT). Any additional tools or supporting information that we may develop for this critical... current best assessment of the areas that meet the definition of critical habitat for Umtanum desert... assessments, or other unpublished materials and expert opinion or personal knowledge. Habitat is dynamic,...

  14. 76 FR 36068 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for the Sonoma...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-21

    ...; Designation of Critical Habitat for the Sonoma County Distinct Population Segment of the California Tiger... Sonoma County Distinct Population Segment of the California tiger salamander (Ambystoma californiense... (ac) (22,580 hectares (ha)) of land as critical habitat for the Sonoma California tiger salamander....

  15. 77 FR 71875 - Endangered and Threatened Wildlife and Plants; Designation of Revised Critical Habitat for the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-04

    ...We, the U.S. Fish and Wildlife Service, designate revised critical habitat for the northern spotted owl (Strix occidentalis caurina) under the Endangered Species Act. In total, approximately 9,577,969 acres (ac) (3,876,064 hectares (ha)) in 11 units and 60 subunits in California, Oregon, and Washington fall within the boundaries of the critical habitat...

  16. 78 FR 59334 - Endangered and Threatened Wildlife and Plants; Threatened Status and Designation of Critical...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-26

    ...; Threatened Status and Designation of Critical Habitat for Oregon Spotted Frog (Rana pretiosa) AGENCY: Fish... proposed listing and proposed designation of critical habitat for the Oregon spotted frog (Rana pretiosa... Hearing: The public hearing for the Oregon spotted frog will be held on Monday, October 21, 2013,...

  17. 75 FR 74545 - Endangered and Threatened Wildlife and Plants; Final Rule Designating Critical Habitat for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-30

    ...We, the U.S. Fish and Wildlife Service (Service), are designating critical habitat for Ambrosia pumila (San Diego ambrosia) under the Endangered Species Act of 1973, as amended. Approximately 783 acres (317 hectares) are being designated as critical habitat for A. pumila in Riverside and San Diego counties,...

  18. 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

  19. Structural aspects of the Chernobyl accident

    SciTech Connect

    Murray, R.C.; Cummings, G.E.

    1988-09-02

    On April 26, 1986 the world's worst nuclear power plant accident occurred at the Unit 4 of the Chernobyl Nuclear Power Station in the USSR. This paper presents a discussion of the design of the Chernobyl Power Plant, the sequence of events that led to the accident and the damage caused by the resulting explosion. The structural design features that contributed to the accident and resulting damage will be highlighted. Photographs and sketches obtained from various worldwide news agencies will be shown to try and gain a perspective of the extent of the damage. The aftermath, clean-up, and current situation will be discussed and the important lessons learned for the structural engineer will be presented. 15 refs., 10 figs.

  20. A primer on criticality safety

    DOE PAGES

    Costa, David A.; Cournoyer, Michael E.; Merhege, James F.; ...

    2017-05-01

    Criticality is the state of a nuclear chain reacting medium when the chain reaction is just self-sustaining (or critical). Criticality is dependent on nine interrelated parameters. Moreover, we design criticality safety controls in order to constrain these parameters to minimize fissions and maximize neutron leakage and absorption in other materials, which makes criticality more difficult or impossible to achieve. We present the consequences of criticality accidents are discussed, the nine interrelated parameters that combine to affect criticality are described, and criticality safety controls used to minimize the likelihood of a criticality accident are presented.