WorldWideScience

Sample records for nuclear criticality accident

  1. Character and consequence of nuclear criticality accident

    International Nuclear Information System (INIS)

    Liu Xinhua; Liu Hua; Wu Deqiang; Li Bing

    2001-01-01

    The author describes some concepts, the process and magnitude of energy release and the destruction of the nuclear criticality accident and also describes the radiation consequence of criticality accidents from three aspects: prompt radiation, contamination in working place and release of fission products to the environment. It shows that the effects of radioactivity release from criticality accidents in the nuclear fuel processing plants on the environment and the public is minor, the main danger is from the external exposure of prompt rays. The paper make as have a correct understanding of the nuclear criticality accident and it would be helpful to take appropriate emergency response to potential criticality accident

  2. Criticality accident of nuclear fuel facility. Think back on JCO criticality accident

    International Nuclear Information System (INIS)

    Naito, Keiji

    2003-09-01

    This book is written in order to understand the fundamental knowledge of criticality safety or criticality accident of nuclear fuel facility by the citizens. It consists of four chapters such as critical conditions and criticality accident of nuclear facility, risk of criticality accident, prevention of criticality accident and a measure at an occurrence of criticality accident. A definition of criticality, control of critical conditions, an aspect of accident, a rate of incident, damage, three sufferers, safety control method of criticality, engineering and administrative control, safety design of criticality, investigation of failure of safety control of JCO criticality accident, safety culture are explained. JCO criticality accident was caused with intention of disregarding regulation. It is important that we recognize the correct risk of criticality accident of nuclear fuel facility and prevent disasters. On the basis of them, we should establish safety culture. (S.Y.)

  3. Improved dose estimates for nuclear criticality accidents

    International Nuclear Information System (INIS)

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

    1995-01-01

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

  4. A neutron dosemeter for nuclear criticality accidents.

    Science.gov (United States)

    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.

  5. A neutron dosemeter for nuclear criticality accidents

    International Nuclear Information System (INIS)

    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 photo microsensors, 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. (authors)

  6. Criticality accident:

    International Nuclear Information System (INIS)

    Canavese, Susana I.

    2000-01-01

    A criticality accident occurred at 10:35 on September 30, 1999. It occurred in a precipitation tank in a Conversion Test Building at the JCO Tokai Works site in Tokaimura (Tokai Village) in the Ibaraki Prefecture of Japan. STA provisionally rated this accident a 4 on the seven-level, logarithmic International Nuclear Event Scale (INES). The September 30, 1999 criticality accident at the JCO Tokai Works Site in Tokaimura, Japan in described in preliminary, technical detail. Information is based on preliminary presentations to technical groups by Japanese scientists and spokespersons, translations by technical and non-technical persons of technical web postings by various nuclear authorities, and English-language non-technical reports from various news media and nuclear-interest groups. (author)

  7. Update of the Nuclear Criticality Slide Rule for the Emergency Response to a Nuclear Criticality Accident

    Science.gov (United States)

    Duluc, Matthieu; Bardelay, Aurélie; Celik, Cihangir; Heinrichs, Dave; Hopper, Calvin; Jones, Richard; Kim, Soon; Miller, Thomas; Troisne, Marc; Wilson, Chris

    2017-09-01

    AWE (UK), IRSN (France), LLNL (USA) and ORNL (USA) began a long term collaboration effort in 2015 to update the nuclear criticality Slide Rule for the emergency response to a nuclear criticality accident. This document, published almost 20 years ago, gives order of magnitude estimates of key parameters, such as number of fissions and doses (neutron and gamma), useful for emergency response teams and public authorities. This paper will present, firstly the motivation and the long term objectives for this update, then the overview of the initial configurations for updated calculations and preliminary results obtained with modern 3D codes.

  8. Update of the Nuclear Criticality Slide Rule for the Emergency Response to a Nuclear Criticality Accident

    Directory of Open Access Journals (Sweden)

    Duluc Matthieu

    2017-01-01

    Full Text Available AWE (UK, IRSN (France, LLNL (USA and ORNL (USA began a long term collaboration effort in 2015 to update the nuclear criticality Slide Rule for the emergency response to a nuclear criticality accident. This document, published almost 20 years ago, gives order of magnitude estimates of key parameters, such as number of fissions and doses (neutron and gamma, useful for emergency response teams and public authorities. This paper will present, firstly the motivation and the long term objectives for this update, then the overview of the initial configurations for updated calculations and preliminary results obtained with modern 3D codes.

  9. Locations of criticality alarms and nuclear accident dosimeters at Hanford

    International Nuclear Information System (INIS)

    1992-08-01

    Hanford facilities that contain fissionable materials capable of achieving critical mass are monitored with nuclear accident dosimeters (NADS) in compliance with the requirements of DOE Order 5480.11, Chapter XI, Section 4.c. (DOE 1988). The US Department of Energy (DOE) Richland Field Office (RL) has assigned the responsibility for maintaining and evaluating the Hanford NAD system to the Instrumentation and External Dosimetry (I ampersand ED) Section of Pacific Northwest Laboratory's (PNL's) Health Physics Department. This manual provides a description of the Hanford NAD, criteria and instructions for proper NAD placement, and the locations of these dosimeters onsite

  10. Updated tool for nuclear criticality accident emergency response

    International Nuclear Information System (INIS)

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

    1995-01-01

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

  11. Review and compilation of criticality accidents in nuclear fuel processing facilities outside of Japan

    International Nuclear Information System (INIS)

    Watanabe, Norio; Tamaki, Hitoshi

    2000-04-01

    On September 30, 1999, a criticality accident occurred at the Tokai-mura uranium processing plant operated by JCO Co., Ltd., which resulted in the first nuclear accident involving a fatality, in Japan, and forced the residents in the vicinity of the site to be evacuated and be sheltered indoors. There have now been 21 criticality accidents reported in nuclear fuel processing facilities in foreign countries: seven in the United States, one in the United Kingdom and thirteen in Russia. Most of them occurred during the period from mid-1950's to mid-1960's, but one criticality accident tool place in Russian in 1997. This report reviews and compiles the published information on these accidents, including the latest information, focusing on the event sequence, the consequence of accident, and the cause of accident. The observations from the reviews are summarized as follows: Twenty of the 21 accidents occurred with the fissile material in a liquid. Twenty of the 21 accidents occurred in vessels/tanks with unfavorable geometry but one occurred in the vessel with favorable geometry. There were seven fatalities that were involved in five accidents. Three accidents involved a re-criticality condition caused by inadequate operator actions and two of them led to the death of the operators. One accident reached a re-criticality condition several hours after the first excursion was terminated by injecting borated water into the affected vessel. This accident implies the possibility that the borated water injection might not be effective to the criticality termination due to solubility of boric acid. Mechanisms of the criticality termination vary as follows: ejection or splashing of the solution at the time of power excursion, boiling or evaporation, addition of neutron poisons, or manual draining of solutions. (author)

  12. Review and compilation of criticality accidents in nuclear fuel processing facilities outside of Japan

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Norio [Planning and Analysis Division, Nuclear Safety Research Center, Tokai Research Establishment, Japan Atomic Energy Research Institute, Tokai, Ibaraki (Japan); Tamaki, Hitoshi [Department of Safety Research Technical Support, Tokai Research Establishment, Japan Atomic Energy Research Institute, Tokai, Ibaraki (Japan)

    2000-04-01

    On September 30, 1999, a criticality accident occurred at the Tokai-mura uranium processing plant operated by JCO Co., Ltd., which resulted in the first nuclear accident involving a fatality, in Japan, and forced the residents in the vicinity of the site to be evacuated and be sheltered indoors. There have now been 21 criticality accidents reported in nuclear fuel processing facilities in foreign countries: seven in the United States, one in the United Kingdom and thirteen in Russia. Most of them occurred during the period from mid-1950's to mid-1960's, but one criticality accident tool place in Russian in 1997. This report reviews and compiles the published information on these accidents, including the latest information, focusing on the event sequence, the consequence of accident, and the cause of accident. The observations from the reviews are summarized as follows: Twenty of the 21 accidents occurred with the fissile material in a liquid. Twenty of the 21 accidents occurred in vessels/tanks with unfavorable geometry but one occurred in the vessel with favorable geometry. There were seven fatalities that were involved in five accidents. Three accidents involved a re-criticality condition caused by inadequate operator actions and two of them led to the death of the operators. One accident reached a re-criticality condition several hours after the first excursion was terminated by injecting borated water into the affected vessel. This accident implies the possibility that the borated water injection might not be effective to the criticality termination due to solubility of boric acid. Mechanisms of the criticality termination vary as follows: ejection or splashing of the solution at the time of power excursion, boiling or evaporation, addition of neutron poisons, or manual draining of solutions. (author)

  13. Critical examination of emergency plans for nuclear accidents

    International Nuclear Information System (INIS)

    Catsaros, Nicolas.

    1986-08-01

    An analysis of emergency plans of various countries for nuclear installations on- and off-site emergency preparedness is presented. The analysis is focused on the off-site organization and countermeasures to protect public health and safety. A critical examination of the different approaches is performed and recommendations for effectiveness improvement and optimization are formulated. (author)

  14. Analysis and evaluation of the nuclear criticality accident in JCO CO. LTD in Japan

    International Nuclear Information System (INIS)

    Liu Hua; Liu Xinhua; Li Bing

    2001-01-01

    The author describes JCO criticality accident situation including the background, process chronology and emergency countermeasures taken of the accident and its radiation consequence. The analysis about the direct and root causes of the accident and some conclusions are also showed. The direct cause of the accident is the use of geometrically unsafe process equipment and personnel violation. However, the root cause is lack of efficient technical management. Therefore, it is necessary to emphasize the criticality safety in nuclear fuel cycle installations and enhance safety culture of regulatory and operational personnel

  15. Nuclear accidents

    International Nuclear Information System (INIS)

    1987-01-01

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

  16. Nuclear accident dosimetry

    International Nuclear Information System (INIS)

    1982-01-01

    The film presents statistical data on criticality accidents. It outlines past IAEA activities on criticality accident dosimetry and the technical documents that resulted from this work. The film furthermore illustrates an international comparison study on nuclear accident dosimetry conducted at the Atomic Energy Research Establishment, Harwell, United Kingdom

  17. Nuclear accident dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1983-12-31

    The film presents statistical data on criticality accidents. It outlines past IAEA activities on criticality accident dosimetry and the technical documents that resulted from this work. The film furthermore illustrates an international comparison study on nuclear accident dosimetry conducted at the Atomic Energy Research Establishment, Harwell, United Kingdom

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

    International Nuclear Information System (INIS)

    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

  19. Instructions on the nuclear critical accident and how to correspond to future

    International Nuclear Information System (INIS)

    Kimura, Itsuro

    2000-01-01

    The nuclear accident occurred at Tokai Works of the JCO Co., Ltd. is a simple but disallowable one formed by neglecting possibility of nuclear fission chain reaction, one of three dangers specific to nuclear power facilities and by feeding middle concentrated uranium solution with more than critical mass into a precipitation tank. As a man consumed most of his life to nuclear power, it is to occur a critical accident forming about 50 previous examples in the world and about 10 victims at Tokai-mura the most earnestly promoting its experiment and analysis and to generate new victims, what was thought to be the most regrettable in this accident. How the previous experiences and results in Tokai-mura could be transmitted to the JCO Co., Ltd. ? This was a large alarm-bell for persons engaging to R and D on nuclear power. As this accident was much deplorable and apological for the common public, it must be carried out to thoroughly analyze its causes, to establish its future responses, and to promote its essential countermeasures. As it is important to open informations on its contents, it is hopeful not to over-exaggerate and over-differentiate the accident, to calmly and scientifically analyze the risk as well as in the other accidents, and to construct actually effective countermeasures. (G.K.)

  20. Crisis, criticism, change: Regulatory reform in the wake of nuclear accidents

    International Nuclear Information System (INIS)

    Sexton, Kimberly A.; )

    2015-01-01

    Accidents are a forcing function for change in the nuclear industry. While these events can shed light on needed technical safety reforms, they can also shine a light on needed regulatory system reforms. The TEPCO Fukushima Daiichi nuclear power plant (NPP) accident in Japan is the most recent example of this phenomenon, but it is not the only one. In the wake of the three major accidents that have occurred in the nuclear power industry - Three Mile Island (TMI) in the United States; Chernobyl in Ukraine, in the former Soviet Union; and the Fukushima Daiichi NPP accident in Japan - a commission or committee of experts issued a report (or reports) with harsh criticism of the countries' regulatory system. And each of these accidents prompted changes in the respective regulatory systems. In looking at these responses, however, one must ask if this crisis, criticism, change approach is working and whether regulatory bodies around the world should instead undertake their own systematic reviews, un-prompted by crisis, to better ensure safety. This article will attempt to analyse the issue of regulatory reform in the wake of nuclear accidents by first providing a background in nuclear regulatory systems, looking to international and national legal frameworks. Next, the article will detail a cross-section of current regulatory systems around the world. Following that, the article will analyse the before and after of the regulatory systems in the United States, the Soviet Union and Japan in relation to the TMI, Chernobyl and Fukushima accidents. Finally, taking all this together, the article will address some of the international and national efforts to define exactly what makes a good regulator and provide conclusions on regulatory reform in the wake of nuclear accidents. (author)

  1. Organizational factors and reoccurrence protection on the JCO nuclear critical accident

    International Nuclear Information System (INIS)

    Takano, Kenichi

    2000-01-01

    A nuclear critical accident formed at a nuclear fuel conversion factory in Tokai-mura on September, 1999 became gradually clear not to be a simple human error formed at a level of workmen but to be an organizational error or accident relating to various organizational factors. As a nuclear power facility adopts a depth protection system fundamentally, a large accident with serious danger would not form only by a single trouble and a human error and unless some factors overlaps. By reviewing recent serious accidents and troubles, all of them seem to have a keyword of 'organizational factor'. In the JCO accident, there are some organizational factors such as a climate deviating from a manual, insufficient and loose check against change of procedure, reduction of operators from a reason of profit priority, attitude on priority of working efficiency, and so forth, which are partially common to the Chernobyl accident. Recently, accidents and troubles impossible to make them a cause of simple human error by a person but to have to say an organizational error, have increased. This trend seems to depend upon not only complication and scale-up of technology system but also graduate change of social and management systems operating them. Therefore, it seems to be necessary to introduce a concept of depth protection (multiple protection) in order to keep its reliability and safety when complicating and scaling-up of system. (G.K.)

  2. Questionnaire survey report about the criticality accident at a nuclear fuel processing facility

    International Nuclear Information System (INIS)

    2000-01-01

    The Radiation Protection Section of the Japanese Society of Radiological Technology conducted a questionnaire survey on the criticality accident at the nuclear fuel processing facility in Tokai village on September 30, 1999 in order to identify factors related to the accident and consider countermeasures to deal with such accidents. The questionnaire was distributed to 347 members (122 facilities) of the Japanese Society of Radiological Technology who were working or living in Ibaraki Prefecture, and replies were obtained from 104 members (75 facilities). Questions to elicit the opinions of individuals were as following: method of obtaining information about the accident, knowledge about radiation, opinions about the accident, and requests directed to the Society. Questions regarding facilities concerned the following: communication after the accident, requests for dispatch to the accident site, and possession of radiometry devices. In regard to acquisition of information, 91 of the 104 members (87.5%) answered 'television or radios' followed by newspapers. Forty-five of 101 members were questioned about radiation exposure and radiation effects by the public. There were many opinions that accurate news should be provided rapidly, by the mass media. Many members (75%) felt that they lacked knowledge about radiation, reconfirming the importance of education and instruction concerning radiation. Dispatch was requested of 36 of the 75 facilities (48%), and 44 of 83 facilities (53%) owned radiometry instruments. (K.H.)

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

    International Nuclear Information System (INIS)

    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

  4. First Responders and Criticality Accidents

    Energy Technology Data Exchange (ETDEWEB)

    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. Criticality accident in uranium fuel processing plant. Questionnaires from Research Committee of Nuclear Safety

    International Nuclear Information System (INIS)

    Kataoka, Isao; Sekimoto, Hiroshi

    2000-01-01

    The Research Committee of Nuclear Safety carried out a research on criticality accident at the JCO plant according to statement of president of the Japan Atomic Energy Society on October 8, 1999, of which results are planned to be summarized by the constitutions shown as follows, for a report on the 'Questionnaires of criticality accident in the Uranium Fuel Processing Plant of the JCO, Inc.': general criticality safety, fuel cycle and the JCO, Inc.; elucidation on progress and fact of accident; cause analysis and problem picking-up; proposals on improvement; and duty of the Society. Among them, on last two items, because of a conclusion to be required for members of the Society at discussions of the Committee, some questionnaires were send to more than 1800 of them on April 5, 2000 with name of chairman of the Committee. As results of the questionnaires contained proposals and opinions on a great numbers of fields, some key-words like words were found on a shape of repeating in most questionnaires. As they were thought to be very important nuclei in these two items, they were further largely classified to use for summarizing proposals and opinions on the questionnaires. This questionnaire had a big characteristic on the duty of the Society in comparison with those in the other organizations. (G.K.)

  6. Nuclear criticality safety: general. 3. Tokaimura Criticality Accident: Point Model Stochastic Neutronic Interpretation

    International Nuclear Information System (INIS)

    Mechitoua, Boukhmes

    2001-01-01

    This paper shows what can be the stochastic neutronic contribution for the interpretation of criticality accidents. Stochastic neutronic comprehensive texts may be found in refs.1 through 4. We limit our study to the use of initiation probability, which is an important stochastic neutronic tally. Initiation probability P may be defined as the probability for one neutron to initiate an infinite neutron fission chain. The complement probability of P is the extinction probability Q. The probability that the neutron fission chain produced by one neutron will quench is equal to the multiplication of the probability of production of i neutrons g i by the probability of extinction of these i neutrons. We can estimate P by a Newton or by a dichotomic method. We suppose that P S (t) is the probability that an infinite neutron fission chain has been initiated before time t by a neutron produced by the source S(t). P S (t + dt) is the sum of two probabilities: 1. the probability that an infinite neutron fission chain has been initiated before time t by a neutron produced by the source S(t): P S (t); 2. The second probability is a multiplication of two probabilities: the probability that there was no initiation before t that is 1-P S (t), and the probability that a neutron emitted by the source with the probability S dt initiates an infinite neutron fission chain with the probability P(t). This last relation gives the link between P and the source density. The aim of this paper is to show how one can apply the foregoing derivations. We have simplified the Tokaimura criticality accident for this application. We have mono-energetic neutrons with infinite and homogeneous media; we have two reactions: capture and fission. In this section, we show how one can estimate the initiation probability with a source density as a function of time. This estimation makes use of three steps: 1. Reactivity insertion: Estimation of the multiplication coefficient as a function of time K(t). This

  7. JCO criticality accident termination operation

    International Nuclear Information System (INIS)

    Kanamori, Masashi

    2001-12-01

    On September 30 at around 10:35 AM, criticality accident occurred at the JCO's conversion building in Tokai-mura. Since criticality accident had not been anticipated, neither devices for termination of criticality accident nor neutron detectors were available. Immediately after the information of the accident, our emergency staff (Japan Nuclear Cycle development institute staff) went to JCO site, to measure the intensity of neutrons and gammas. There were four main tasks, first one was to measure the radiation intensity, second one was to terminate the criticality accident, third one is to alert the residents surrounding the JCO site, fourth one is to evacuate the employees in the site. These tasks were successfully performed until October 1. This paper describes about how these operations were performed by the relevant staffs. (author)

  8. JCO criticality accident termination operation

    OpenAIRE

    金盛 正至

    2010-01-01

    In 2001, we summarized the circumstances surrounding termination of the JCO criticality accident based on testimony in the Mito District Court on December 17, 2001. JCO was the company for uranium fuels production in Japan. That document was assembled based on actual testimony in the belief that a description of the work involved in termination of the accident would be useful in some way for preventing nuclear disasters in the future. This year is the tenth year of the JCO criticality acciden...

  9. Criticality accident in Argentina

    International Nuclear Information System (INIS)

    Oliveira, A.R. de.

    1984-01-01

    A recent criticality type accident, ocurred in Argetina, is commented. Considerations about the nature of the facility where this accident took place, its genesis, type of operation carried out on the day of the event, and the medical aspects involved are done. (Author) [pt

  10. Safety demonstration analyses on criticality for severe accident during overland transport of fresh nuclear fuel

    International Nuclear Information System (INIS)

    Takahashi, Satoshi; Okuno, Hiroshi; Yamada, Kenji; Watanabe, Kouji; Nomura, Yasushi; Miyoshi, Yoshinori

    2005-01-01

    Criticality safety analysis was performed for transport packages of uranium dioxide powder or of fresh PWR fuel involved in a severe accident during overland transportation, and as a result, sub-criticality was confirmed against impact accident conditions such as loaded by a drop from high position to a concrete or asphalt surface, and fire accident conditions such as caused by collisions with an oil tank trailer carrying lots of inflammable material in open air, or with a commonly used two-ton-truck inside an unventilated tunnel. (author)

  11. Effects of the criticality accident at Tokai-mura on the public's attitude to nuclear power generation

    Energy Technology Data Exchange (ETDEWEB)

    Kitada, Atsuko [Institute of Social Research, Institute of Nuclear Safety System Inc., Mihama, Fukui (Japan); Hayashi, Chikio [The Institute of Statistical Mathematics, Tokyo (Japan)

    2000-09-01

    The objective of our study was to clarify the effects on the public's attitude of nuclear power and the criticality accident that occurred at the JCO plant in Tokai-mura, Ibaraki Prefecture. For this purpose, we conducted an awareness survey in the Kansai and Kanto areas two months after the accident. Analysis was made on the basis of the comparison of the survey results with the data that the Institute of Nuclear Safety System had accumulated through continuous awareness surveys on nuclear power generation (regular surveys) since 1993. The public's reactions were twofold. On one hand, there were emotional reactions about accidents in nuclear facilities and a reduction in the sense of security. On the other hand, there were reactions concerning the image of nuclear power plant workers and demand on electricity utilities for enhanced employee education and training. The latter reactions correspond to the problems pointed out after the JCO accident. Regarding the utilization of nuclear power generation, the opinion that 'the utilization of nuclear power generation is unavoidable' accounts for 60% of those surveyed. With the opinion that 'nuclear power generation should be utilized' added, 70% of those surveyed take an affirmative attitude to nuclear power utilization. This situation has remained about the same since 1998, the year before the JCO accident. Using the quantification method III to analyze a number of questionnaires about nuclear power generation such as the anxiety about it, we determined overall attitude indexes regarding nuclear power to perform a time sequence comparison. The comparison shows that the attitude after the JCO accident tended to be more negative than in 1998. However, no significant difference in the overall indexes is seen between 1993 and 1998. Judging the comparison results on the basis of the time span starting in 1993 allows us to conclude that the JCO accident has not greatly contributed to worsening

  12. Effects of the criticality accident at Tokai-mura on the public's attitude to nuclear power generation

    International Nuclear Information System (INIS)

    Kitada, Atsuko; Hayashi, Chikio

    2000-01-01

    The objective of our study was to clarify the effects on the public's attitude of nuclear power and the criticality accident that occurred at the JCO plant in Tokai-mura, Ibaraki Prefecture. For this purpose, we conducted an awareness survey in the Kansai and Kanto areas two months after the accident. Analysis was made on the basis of the comparison of the survey results with the data that the Institute of Nuclear Safety System had accumulated through continuous awareness surveys on nuclear power generation (regular surveys) since 1993. The public's reactions were twofold. On one hand, there were emotional reactions about accidents in nuclear facilities and a reduction in the sense of security. On the other hand, there were reactions concerning the image of nuclear power plant workers and demand on electricity utilities for enhanced employee education and training. The latter reactions correspond to the problems pointed out after the JCO accident. Regarding the utilization of nuclear power generation, the opinion that 'the utilization of nuclear power generation is unavoidable' accounts for 60% of those surveyed. With the opinion that 'nuclear power generation should be utilized' added, 70% of those surveyed take an affirmative attitude to nuclear power utilization. This situation has remained about the same since 1998, the year before the JCO accident. Using the quantification method III to analyze a number of questionnaires about nuclear power generation such as the anxiety about it, we determined overall attitude indexes regarding nuclear power to perform a time sequence comparison. The comparison shows that the attitude after the JCO accident tended to be more negative than in 1998. However, no significant difference in the overall indexes is seen between 1993 and 1998. Judging the comparison results on the basis of the time span starting in 1993 allows us to conclude that the JCO accident has not greatly contributed to worsening the attitude towards nuclear

  13. Prevention of criticality accidents

    International Nuclear Information System (INIS)

    Canavese, S.I.

    1982-01-01

    These notes used in the postgraduate course on Radiological Protection and Nuclear Safety discuss macro-and microscopic nuclear constants for fissile materials systems. Critical systems: their definition; criteria to analyze the critical state; determination of the critical size; analysis of practical problems about prevention of criticality. Safety of isolated units and of sets of units. Application of standards. Conception of facilities from the criticality control view point. (author) [es

  14. Criticality accident alarm system

    International Nuclear Information System (INIS)

    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% 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

  15. Theoretical Derivation of Simplified Evaluation Models for the First Peak of a Criticality Accident in Nuclear Fuel Solution

    International Nuclear Information System (INIS)

    Nomura, Yasushi

    2000-01-01

    In a reprocessing facility where nuclear fuel solutions are processed, one could observe a series of power peaks, with the highest peak right after a criticality accident. The criticality alarm system (CAS) is designed to detect the first power peak and warn workers near the reacting material by sounding alarms immediately. Consequently, exposure of the workers would be minimized by an immediate and effective evacuation. Therefore, in the design and installation of a CAS, it is necessary to estimate the magnitude of the first power peak and to set up the threshold point where the CAS initiates the alarm. Furthermore, it is necessary to estimate the level of potential exposure of workers in the case of accidents so as to decide the appropriateness of installing a CAS for a given compartment.A simplified evaluation model to estimate the minimum scale of the first power peak during a criticality accident is derived by theoretical considerations only for use in the design of a CAS to set up the threshold point triggering the alarm signal. Another simplified evaluation model is derived in the same way to estimate the maximum scale of the first power peak for use in judging the appropriateness for installing a CAS. Both models are shown to have adequate margin in predicting the minimum and maximum scale of criticality accidents by comparing their results with French CRiticality occurring ACcidentally (CRAC) experimental data

  16. JCO criticality accident termination operation

    International Nuclear Information System (INIS)

    Kanamori, Masashi

    2010-07-01

    In 2001, we summarized the circumstances surrounding termination of the JCO criticality accident based on testimony in the Mito District Court on December 17, 2001. JCO was the company for uranium fuels production in Japan. That document was assembled based on actual testimony in the belief that a description of the work involved in termination of the accident would be useful in some way for preventing nuclear disasters in the future. The description focuses on the witness' own behavior, and what he saw and heard, and thus is written from the perspective of action by one individual. This was done simply because it was easier for the witness to write down his memories as he remembers them. Description of the activities of other organizations and people is provided only as necessary, to ensure that consistency in the descriptive approach is not lost. The essentials of this report were rewritten as a third-person objective description in the summary of the report by the Atomic Energy Society of Japan (AESJ). Since then, comments have been received from sources such as former members of the Nuclear Safety Commission (Dr. Kenji Sumita and Dr. Akira Kanagawa), concerned parties from the former Science and Technology Agency, and reports from the JCO Criticality Accident Investigation Committee of the AESJ, and thus this report was rewritten to correct incorrect information, and add material where that was felt to be necessary. This year is the tenth year of the JCO criticality accident. To mark this occasion we have decided to translate the record of what occurred at the accident site into English so that more people can draw lessons from this accident. This report is an English version of JAEA-Technology 2009-073. (author)

  17. NARCISS critical stand experiments for studying the nuclear safety in accident water immersion of highly enriched uranium dioxide fuel elements

    International Nuclear Information System (INIS)

    Ponomarev-Stepnoj, N.N.; Glushkov, E.S.; Bubelev, V.G.

    2005-01-01

    A brief description of the Topaz-2 SNPS designed under scientific supervision of RRC KI in Russia, and of the NARCISS critical facility, is given. At the NARCISS critical facility, neutronic peculiarities and nuclear safety issues of the Topaz-2 system reactor were studied experimentally. This work is devoted to a detailed description of experiments on investigation of criticality safety in accident water immersion og highly enriched uranium dioxide fuel elements, performed at the NARCISS facility. The experiments were carried out at water-moderated critical assemblies with varying height, number, and spacing of fuel elements. The results obtained in the critical experiments, computational models of the investigated critical configurations, and comparison of the computational and experimental results are given [ru

  18. Nuclear accidents and epidemiology

    International Nuclear Information System (INIS)

    1987-01-01

    A consultation on epidemiology related to the Chernobyl accident was held in Copenhagen in May 1987 as a basis for concerted action. This was followed by a joint IAEA/WHO workshop in Vienna, which reviewed appropriate methodologies for possible long-term effects of radiation following nuclear accidents. The reports of these two meetings are included in this volume, and cover the subjects: 1) Epidemiology related to the Chernobyl nuclear accident. 2) Appropriate methodologies for studying possible long-term effects of radiation on individuals exposed in a nuclear accident. Figs and tabs

  19. Big nuclear accidents

    International Nuclear Information System (INIS)

    Marshall, W.; Billingon, D.E.; Cameron, R.F.; Curl, S.J.

    1983-09-01

    Much of the debate on the safety of nuclear power focuses on the large number of fatalities that could, in theory, be caused by extremely unlikely but just imaginable reactor accidents. This, along with the nuclear industry's inappropriate use of vocabulary during public debate, has given the general public a distorted impression of the risks of nuclear power. The paper reviews the way in which the probability and consequences of big nuclear accidents have been presented in the past and makes recommendations for the future, including the presentation of the long-term consequences of such accidents in terms of 'loss of life expectancy', 'increased chance of fatal cancer' and 'equivalent pattern of compulsory cigarette smoking'. The paper presents mathematical arguments, which show the derivation and validity of the proposed methods of presenting the consequences of imaginable big nuclear accidents. (author)

  20. Four years after the JCO criticality accident

    International Nuclear Information System (INIS)

    Sumita, Kenji

    2003-01-01

    It has been about four years since the first criticality accident in Japan. The JCO accident site was not so far from this auditorium. I have been asked to give a short review of important results from the various technical investigations on the accident that have been performed during the past four years. I will also give a short introduction to the changes that have been made in the nuclear safety regulation systems of the Japanese Government. (author)

  1. Some issues on the Law for the Regulations of Nuclear Source Material, Nuclear Fuel Material and Reactors Amendment after JCO criticality accident

    International Nuclear Information System (INIS)

    Tanabe, Tomoyuki

    2001-01-01

    As the Amendment of the Law for the Regulation of Nuclear Material, Nuclear Fuel Material and Reactors on an opportunity of the JCO criticality accident can be almost evaluated at a viewpoint of upgrading on effectiveness of safety regulation, it is thought to remain a large problem to rely on only enforcement of regulation due to amendment of the Law at future accident. In future, it can be also said to be important subjects to further expand a philosophy on the regulation (material regulation) focussed to hazards of nuclear material itself, not only to secure effectiveness on the multi-complementary safety regulation due to the administrative agency and the Nuclear Safety Commission but also to prepare a mechanism reflexible of a new information to the safety regulation, and to prepare a mechanism to assist adequate business execution and so forth of enterprises. (G.K.)

  2. Study of source term evaluation from fuel solution under simulated nuclear criticality accident in TRACY

    International Nuclear Information System (INIS)

    Abe, Hitoshi; Tashiro, Shinsuke; Nagai, Hitoshi; Koike, Tadao; Okagawa, Seigo; Murata, Mikio

    1999-01-01

    In a accident at the dissolver in a reprocessing plant, various fission products and radiolysis gases will be produced in the fuel solution and volatile radioactive nuclides and radiolysis gases and nitrogen oxide will be released into vent-gas spontaneously. Moreover other on-volatile nuclide will be releases as radioactive aerosol (mist) with bursting bubbles at surface of the solution. Therefore quantitative estimation of release and transport behavior of the radioactive material from solution as source term is very important. TRACY is a transient criticality experimental facility for studying the transient criticality characteristics of low enriched uranium. In this paper, experiment methods and results about the release behavior of the hydrogen, radioactive aerosol and iodine species from the fuel solutions are reported. As the results of the experiments, release patterns of H 2 , 140 Ba and 131 I could be grasped. Concentrations of H 2 in the vent-gas and 140 Ba in the gas phase in the core tank attained to the peak just after the transient criticality and decreased exponentially with time. On the other hand, concentrations of 131 I in the gas phase of the tank began to increase with a time lag of several minutes from the transient criticality and attained approximately constant values. (J.P.N.)

  3. The ultimate nuclear accident

    International Nuclear Information System (INIS)

    Abdus Salam, A.

    1988-01-01

    The estimated energy equivalent of Chernobyl explosion was the 1/150 th of the explosive energy equivalent of atomic bomb dropped on Hiroshima; while the devastation that could be caused by the world's stock pile of nuclear weapons, could be equivalent to 160 millions of Chernobyl-like incidents. As known, the number of nuclear weapons is over 50,000 and 2000 nuclear weapons are sufficient to destroy the world. The Three Mile Island and Chernobyl accidents have been blamed on human factors but also the human element, particularly in the form of psychological stresses on those operating the nuclear weapons, could accidentally bring the world to a nuclear catastrophe. This opinion is encouraged by the London's Sunday Times magazine which gave a graphic description of life inside a nuclear submarine. So, to speak of nuclear reactor accidents and not of nuclear weapons is false security. (author)

  4. Big nuclear accidents

    International Nuclear Information System (INIS)

    Marshall, W.

    1983-01-01

    Much of the debate on the safety of nuclear power focuses on the large number of fatalities that could, in theory, be caused by extremely unlikely but imaginable reactor accidents. This, along with the nuclear industry's inappropriate use of vocabulary during public debate, has given the general public a distorted impression of the safety of nuclear power. The way in which the probability and consequences of big nuclear accidents have been presented in the past is reviewed and recommendations for the future are made including the presentation of the long-term consequences of such accidents in terms of 'reduction in life expectancy', 'increased chance of fatal cancer' and the equivalent pattern of compulsory cigarette smoking. (author)

  5. Nuclear accidents and protection

    International Nuclear Information System (INIS)

    Biocanin, R.; Amidzic, B.

    2005-01-01

    The numerous threats are our cruel reality. There is a great arsenal of nuclear weapons. Nuclear terrorism and nuclear accidents are always possible, especially during the transport and handling different nuclear material. Terrorist organisation also goes for coming into the possession of the nuclear means. Specific and important problem is human radioactive contamination in using nuclear energy for peaceful and military purpose. So, realisation of the universal and united system of NBCD gives us a possibility by using the modern communication equipment and very effective mobile units to react in a real time and successfully perform monitoring, alarming, protection and decontamination. (author) [sr

  6. Potential criticality accident at the General Electric Nuclear Fuel and Component Manufacturing Facility, May 29, 1991

    International Nuclear Information System (INIS)

    1991-08-01

    At the General Electric Nuclear Fuel and Component Manufacturing facility, located near Wilmington, North Carolina, on May 28 and 29, 1991, approximately 150 kilograms of uranium were inadvertently transferred from safe process tanks to an unsafe tank located at the waste treatment facility, thus creating the potential for a localized criticality safety problem. The excess uranium was ultimately safely recovered when the tank contents were centrifuged to remove the uranium-bearing material. Subsequently, the US Nuclear Regulatory Commission dispatched an Incident Investigation Team to determine what happened, to identify probable causes, and to make appropriate findings and conclusions. This report describes the incident, the methodology used by the team in its investigation, and presents the team's findings and conclusions. 48 figs., 8 tabs

  7. Nuclear fuel cycle facility accident analysis handbook

    International Nuclear Information System (INIS)

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

    1988-05-01

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

  8. The sensitivity of calculated doses to critical assumptions for the offsite consequences of nuclear power reactor accidents

    International Nuclear Information System (INIS)

    Moeller, M.P.; Scherpelz, R.I.; Desrosiers, A.E.

    1982-01-01

    This work analyzes the sensitivity of calculated doses to critical assumptions for offsite consequences following a PWR-2 accident at a nuclear power reactor. The calculations include three radiation dose pathways: internal dose resulting from inhalation, external doses from exposure to the plume, and external doses from exposure to contaminated ground. The critical parameters are the time period of integration for internal dose commitment and the duration of residence on contaminated ground. The data indicate the calculated offsite whole body dose will vary by as much as 600% depending upon the parameters assumed. When offsite radiation doses determine the size of emergency planning zones, this uncertainty has significant effect upon the resources allocated to emergency preparedness

  9. Accidents in nuclear ships

    Energy Technology Data Exchange (ETDEWEB)

    Oelgaard, P L [Risoe National Lab., Roskilde (Denmark); [Technical Univ. of Denmark, Lyngby (Denmark)

    1996-12-01

    This report starts with a discussion of the types of nuclear vessels accidents, in particular accidents which involve the nuclear propulsion systems. Next available information on 61 reported nuclear ship events in considered. Of these 6 deals with U.S. ships, 54 with USSR ships and 1 with a French ship. The ships are in almost all cases nuclear submarines. Only events that involve the sinking of vessels, the nuclear propulsion plants, radiation exposures, fires/explosions, sea-water leaks into the submarines and sinking of vessels are considered. For each event a summary of available information is presented, and comments are added. In some cases the available information is not credible, and these events are neglected. This reduces the number of events to 5 U.S. events, 35 USSR/Russian events and 1 French event. A comparison is made between the reported Soviet accidents and information available on dumped and damaged Soviet naval reactors. It seems possible to obtain good correlation between the two types of events. An analysis is made of the accident and estimates are made of the accident probabilities which are found to be of the order of 10{sup -3} per ship reactor years. It if finally pointed out that the consequences of nuclear ship accidents are fairly local and does in no way not approach the magnitude of the Chernobyl accident. It is emphasized that some of the information on which this report is based, may not be correct. Consequently some of the results of the assessments made may not be correct. (au).

  10. Accidents in nuclear ships

    International Nuclear Information System (INIS)

    Oelgaard, P.L.

    1996-12-01

    This report starts with a discussion of the types of nuclear vessels accidents, in particular accidents which involve the nuclear propulsion systems. Next available information on 61 reported nuclear ship events in considered. Of these 6 deals with U.S. ships, 54 with USSR ships and 1 with a French ship. The ships are in almost all cases nuclear submarines. Only events that involve the sinking of vessels, the nuclear propulsion plants, radiation exposures, fires/explosions, sea-water leaks into the submarines and sinking of vessels are considered. For each event a summary of available information is presented, and comments are added. In some cases the available information is not credible, and these events are neglected. This reduces the number of events to 5 U.S. events, 35 USSR/Russian events and 1 French event. A comparison is made between the reported Soviet accidents and information available on dumped and damaged Soviet naval reactors. It seems possible to obtain good correlation between the two types of events. An analysis is made of the accident and estimates are made of the accident probabilities which are found to be of the order of 10 -3 per ship reactor years. It if finally pointed out that the consequences of nuclear ship accidents are fairly local and does in no way not approach the magnitude of the Chernobyl accident. It is emphasized that some of the information on which this report is based, may not be correct. Consequently some of the results of the assessments made may not be correct. (au)

  11. Socioeconomic consequences of nuclear reactor accidents

    International Nuclear Information System (INIS)

    Tawil, J.J.; Callaway, J.W.; Coles, B.L.; Cronin, F.J.; Currie, J.W.; Imhoff, K.L.; Lewis, P.M.; Nesse, R.J.; Strenge, D.L.

    1984-06-01

    This report identifies and characterizes the off-site socioeconomic consequences that would likely result from a severe radiological accident at a nuclear power plant. The types of impacts that are addressed include economic impacts, health impacts, social/psychological impacts and institutional impacts. These impacts are identified for each of several phases of a reactor accident - from the warning phase through the post-resettlement phase. The relative importance of the impact during each accident phase and the degree to which the impact can be predicted are indicated. The report also examines the methods that are currently used for assessing nuclear reactor accidents, including development of accident scenarios and the estimating of socioeconomic accident consequences with various models. Finally, a critical evaluation is made regarding the use of impact analyses in estimating the contribution of socioeconomic consequences to nuclear accident reactor accident risk. 116 references, 7 figures, 15 tables

  12. Lessons learned from early criticality accidents

    International Nuclear Information System (INIS)

    Malenfant, R.E.

    1996-01-01

    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

  13. Note nuclear accidents combat

    International Nuclear Information System (INIS)

    1989-01-01

    In this document the starting points are described which underlie the new framework for the nuclear-accident combat in the Netherlands. All the elaboration of this is indicated in main lines. The juridical consequences of the proposed structure are enlightened and the sequel activities are indicated. (H.W.). 6 figs.; 8 tabs

  14. Nuclear ship accidents

    International Nuclear Information System (INIS)

    Oelgaard, P.L.

    1993-05-01

    In this report available information on 28 nuclear ship accident and incidents is considered. Of these 5 deals with U.S. ships and 23 with USSR ships. The ships are in almost all cases nuclear submarines. Only events that involve the nuclear propulsion plants, radiation exposures, fires/explosions and sea water leaks into the submarines are considered. Comments are made on each of the events, and at the end of the report an attempt is made to point out the weaknesses of the submarine designs which have resulted in the accidents. It is emphasized that much of the available information is of a rather dubious nature. consequently some of the assessments made may not be correct. (au)

  15. A review of criticality accidents

    International Nuclear Information System (INIS)

    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

  16. Nuclear laws and radiologic accidents

    International Nuclear Information System (INIS)

    Frois, Fernanda

    1997-01-01

    Some aspects of the nuclear activities in Brazil, specially concerning the Goiania s accident are demonstrated using concepts from environmental and nuclear law. Nuclear and environmental competence, the impossibility of the states of making regional laws, as the lack of regulation about the nuclear waste, are discussed. The situation of Goiania when the accident happened, the present situation of the victims and the nuclear waste provisionally stored in Abadia de Goias is reported

  17. An emergent proposal on the Committee of Uranium Processing Factory Criticality Accident Survey of the Nuclear Safety Commission. A meantime report dated on November 5, 1999

    International Nuclear Information System (INIS)

    2000-01-01

    The Nuclear Safety Commission was received a decision on thorough investigations of accident reason on criticality accident at the Tokai-mura uranium processing factory of the JCO Incorporation occurred on September 30, 1999, to establish the Committee of Uranium Processing Factory Criticality Accident Survey to elucidate its reason thoroughly and contribute to set up a sufficient reforming prevention countermeasure. This Committee judged that it was important to propose a countermeasure directly obtainable by grasping some fact relations clarified before now as soon as possible and intended to conduct this meantime report of 'emergent proposal' by arrangement of such fact relations. Here were described on accidental conditions and their effects, response to the accident (on prevention of the accident), its reasons and their relating conditions, and some emergent proposals. In the last items, safety security at accidental site, health countermeasures to residents and others, establishment of safety security for nuclear business workers and others, and reconstruction on safety regulation in national government. (G.K.)

  18. Design parameters and testing techniques for criticality accident detection systems used in various nuclear establishments - a review

    International Nuclear Information System (INIS)

    Janardhanan, S.; Krishnamony, S.; Krishnamurthi, T.N.; Gopalan, C.S.

    1981-01-01

    Accidental criticality excursion is a potential hazard in operations involving fissile material. In this review paper, design criteria for criticality detection systems, associated requirements for reliable functioning of the instrument and recent advances in the field are discussed. Systems based on integrated dose and rate of change of dose rate concepts are explained. A criticality accident simulator using a pneumatically driven 60 Co source for testing the detector is described. The paper also discusses the relative advantages of gamma and neutron sensing devices. (author)

  19. Design parameters and testing techniques for criticality accident detection systems used in various nuclear establishments - a review

    Energy Technology Data Exchange (ETDEWEB)

    Janardhanan, S.; Krishnamony, S.; Krishnamurthi, T.N.; Gopalan, C.S. (Bhabha Atomic Research Centre, Bombay (India). Health Physics Div.)

    Accidental criticality excursion is a potential hazard in operations involving fissile material. In this review paper, design criteria for criticality detection systems, associated requirements for reliable functioning of the instrument and recent advances in the field are discussed. Systems based on integrated dose and rate of change of dose rate concepts are explained. A criticality accident simulator using a pneumatically driven /sup 60/Co source for testing the detector is described. The paper also discusses the relative advantages of gamma and neutron sensing devices.

  20. Preparedness against nuclear power accidents

    International Nuclear Information System (INIS)

    1985-01-01

    This booklet contains information about the organization against nuclear power accidents, which exist in the four Swedish counties with nuclear power plants. It is aimed at classes 7-9 of the Swedish schools. (L.E.)

  1. The detection of criticality accidents

    International Nuclear Information System (INIS)

    Prigent, R.; Renard, C.

    It is necessary to shield the personnel from the radiological consequences of a criticality accident. In the past ten years the study programmes have highlighted fresh data which have led to new thinking on the detection philosophy and as a consequence the design of detection equipment. Concurrently, new recommendations have been drawn up by the Safety Criticality Committee. The new detection equipment was developed by the CEA on the basis of the CRAC and SILENE experiments. Its industrialization was entrusted to the Intertechnique Company and the first network installed dates back to 1976. An examination is made of the problem of accident detection, dealing in turn with detection, the characteristics of the equipment and the installation rules. To clarify the various points discussed, a parallel has been drawn between the equipment existing up to 1975 and the new generation developed since then [fr

  2. Recommendations about criticality accident dosimetry

    International Nuclear Information System (INIS)

    1975-07-01

    The aims of criticality accident dosimetry and the characteristics peculiar to a critical burst being defined, the requirements to be fulfilled by a dosimetric system applied to this type of measurements are presented. The devices chosen by the C.E.A. Radiation Survey Divisions, simple and cheap, are described along with the main processes to be carried out in order to evaluate doses after an accident. The apparatus necessary for detector counting and the directions for use are presented in detail, allowing standardization of measurements. A set of linear formula enables to obtain, from these measurements, all required informations about neutron fluences and spectra, along with the suitable components of the dose at the irradiated people locations [fr

  3. Plant safety review from mass criticality accident

    International Nuclear Information System (INIS)

    Susanto, B.G.

    2000-01-01

    The review has been done to understand the resent status of the plant in facing postulated mass criticality accident. From the design concept of the plant all the components in the system including functional groups have been designed based on favorable mass/geometry safety principle. The criticality safety for each component is guaranteed because all the dimensions relevant to criticality of the components are smaller than dimensions of 'favorable mass/geometry'. The procedures covering all aspects affecting quality including the safety related are developed and adhered to at all times. Staff are indoctrinated periodically in short training session to warn the important of the safety in process of production. The plant is fully equipped with 6 (six) criticality detectors in strategic places to alert employees whenever the postulated mass criticality accident occur. In the event of Nuclear Emergency Preparedness, PT BATAN TEKNOLOGI has also proposed the organization structure how promptly to report the crisis to Nuclear Energy Control Board (BAPETEN) Indonesia. (author)

  4. Research on consequence analysis method for probabilistic safety assessment of nuclear fuel facilities (5). Evaluation method and trial evaluation of criticality accident

    International Nuclear Information System (INIS)

    Yamane, Yuichi; Abe, Hitoshi; Nakajima, Ken; Hayashi, Yoshiaki; Arisawa, Jun; Hayami, Satoru

    2010-01-01

    A special committee of 'Research on the analysis methods for accident consequence of nuclear fuel facilities (NFFs)' was organized by the Atomic Energy Society of Japan (AESJ) under the entrustment of Japan Atomic Energy Agency (JAEA). The committee aims to research on the state-of-the-art consequence analysis method for the Probabilistic Safety Assessment (PSA) of NFFs, such as fuel reprocessing and fuel fabrication facilities. The objectives of this research are to obtain information useful for establishing quantitative performance objectives and to demonstrate risk-informed regulation through qualifying issues needed to be resolved for applying PSA to NFFs. The research activities of the committee were mainly focused on the consequence analysis method for postulated accidents with potentially large consequences in NFFs, e.g., events of criticality, spill of molten glass, hydrogen explosion, boiling of radioactive solution and fire (including the rapid decomposition of TBP complexes), resulting in the release of radioactive materials to the environment. The results of the research were summarized in a series of six reports, which consist of a review report and five technical ones. In this report, the evaluation methods of criticality accident, such as simplified methods, one-point reactor kinetics codes and quasi-static method, were investigated and their features were summarized to provide information useful for the safety evaluation of NFFs. In addition, several trial evaluations were performed for a hypothetical scenario of criticality accident using the investigated methods, and their results were compared. The release fraction of volatile fission products in a criticality accident was also investigated. (author)

  5. Nuclear law and radiological accidents

    International Nuclear Information System (INIS)

    Frois, F.

    1998-01-01

    Nuclear activities in Brazil, and particularly the radiological accident of Goiania, are examined in the light of the environmental and nuclear laws of Brazil and the issue of responsibility. The absence of legislation covering radioactive wastes as well as the restrictions on Brazilian States to issue regulations covering nuclear activities are reviewed. The radiological accident and its consequences, including the protection and compensation of the victims, the responsibility of the shareholders of the Instituto Goiano de Radioterapia, operator of the radioactive source, the provisional storage and the final disposal at Abadia de Goias of the radioactive waste generated by the accident are reviewed. Finally, nuclear responsibility, the inapplicability of the Law 6453/77 which deals with nuclear damages, and the state liability regime are analysed in accordance with the principles of the Brazilian Federal Constitution. (author)

  6. International aspects of nuclear accidents

    International Nuclear Information System (INIS)

    Uematsu, K.

    1989-09-01

    The accident at Chernobyl revealed that there were shortcomings and gaps in the existing international mechanisms and brought home to governments the need for stronger measures to provide better protection against the risks of severe accidents. The main thrust of international co-operation with regard to nuclear safety issues is aimed at achieving a uniformly high level of safety in nuclear power plants through continuous exchanges of research findings and feedback from reactor operating experience. The second type of problem posed in the event of an accident resulting in radioactive contamination of several countries relates to the obligation to notify details of the circumstances and nature of the accident speedily so that the countries affected can take appropriate protective measures and, if necessary, organize mutual assistance. Giving the public accurate information is also an important aspect of managing an emergency situation arising from a severe accident. Finally, the confusion resulting from the unwarranted variety of protective measures implemented after the Chernobyl accident has highlighted the need for international harmonization of the principles and scientific criteria applicable to the protection of the public in the event of an accident and for a more consistent approach to emergency plans. The international conventions on third party liability in the nuclear energy sector (Paris/Brussels Conventions and the Vienna Convention) provide for compensation for damage caused by nuclear accidents in accordance with the rules and jurisdiction that they lay down. These provisions impose obligations on the operator responsible for an accident, and the State where the nuclear facility is located, towards the victims of damage caused in another country

  7. Civil liability concerning nuclear accidents

    International Nuclear Information System (INIS)

    Anon.

    2013-01-01

    France and the USA wish to cooperate in order to promote an international regime of civil liability in order to give a fair compensation to victims of nuclear accidents as it is recommended by IAEA. On the other hand the European Commission has launched a consultation to see the necessity or not to harmonize all the civil liability regimes valid throughout Europe. According to the Commission the potential victims of nuclear accidents would not receive equal treatment at the European scale in terms of insurance cover and compensation which might distort competition in the nuclear sector. (A.C.)

  8. Severe accidents in nuclear reactors

    International Nuclear Information System (INIS)

    Ohai, Dumitru; Dumitrescu, Iulia; Tunaru, Mariana

    2004-01-01

    The likelihood of accidents leading to core meltdown in nuclear reactors is low. The consequences of such an event are but so severe that developing and implementing of adequate measures for preventing or diminishing the consequences of such events are of paramount importance. The analysis of major accidents requires sophisticated computation codes but necessary are also relevant experiments for checking the accuracy of the predictions and capability of these codes. In this paper an overview of the severe accidents worldwide with definitions, computation codes and relating experiments is presented. The experimental research activity of severe accidents was conducted in INR Pitesti since 2003, when the Institute jointed the SARNET Excellence Network. The INR activity within SARNET consists in studying scenarios of severe accidents by means of ASTEC and RELAP/SCDAP codes and conducting bench-scale experiments

  9. The cost of nuclear accidents

    International Nuclear Information System (INIS)

    2015-01-01

    Proposed by a technical section of the SFEN, and based on a meeting with representatives of different organisations (OECD-NEA, IRSN, EDF, and European Nuclear Energy Forum), this publication addresses the economic consequences of a severe accident (level 6 or 7) within an electricity producing nuclear power plant. Such an assessment essentially relies on three pillars: release of radio-elements outside the reactor, the scenario of induced consequences, and the method of economic quantification. After a recall and a comment of safety arrangements, and of the generally admitted probability of such an accident, this document notices that several actors are concerned by nuclear energy and are trying to assess accident costs. The issue of how to assess a cost (or costs) of a nuclear accident is discussed: there are in fact several types of costs and consequences. Thus, some costs can be rather precisely quantified when some others can be difficult to assess or with uncertainty. The relevance of some cost categories appears to be a matter of discussion and one must not forget that consequences can occur on a long term. The need for methodological advances is outlined and three categories of technical objectives are identified for the assessment (efficiency of safety measures to be put forward to mitigate the risk via a better accident management, compensation of victims and nuclear civil responsibility, and comparison of electricity production sectors and assessment of externalisation to guide public choices). It is outlined that the impact of accidents depend on several factors, that the most efficient mean to limit consequences of accidents is of course to limit radioactive emissions

  10. Measures against nuclear accidents

    International Nuclear Information System (INIS)

    1992-01-01

    A select committee appointed by the Norwegian Ministry of Social Affairs put forward proposals concerning measures for the improvement of radiation protection preparedness in Norway. On the basis on an assessment of the potential radiation accident threat, the report examines the process of response, and identifies the organizational and management factors that influence that process

  11. Personal nuclear accident dosimetry at Sandia National Laboratories

    International Nuclear Information System (INIS)

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

    1996-09-01

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

  12. Radiation monitoring using imaging plate technology: A case study of leaves affected by the Chernobyl nuclear power plant and JCO criticality accidents

    Directory of Open Access Journals (Sweden)

    Kimura Shinzo

    2006-01-01

    Full Text Available This paper describes the use of a photostimulable phosphor screen imaging technique to detect radioactive contamination in the leaves of wormwood (Artemisia vulgaris L and fern (Dryopteris filix-max CL. Schoff plants affected by the Chernobyl nuclear power plant accident. The imaging plate technology is well known for many striking performances in two-dimensional radiation detection. Since imaging plate comprises an integrated detection system, it has been extensively applied to surface contamination distribution studies. In this study, plant samples were collected from high- and low-contaminated areas of Ukraine and Belarus, which were affected due to the Chernobyl accident and exposed to imaging technique. Samples from the highly contaminated areas revealed the highest photo-stimulated luminescence on the imaging plate. Moreover, the radio nuclides detected in the leaves by gamma and beta ray spectroscopy were 137Cs and 90Sr, respectively. Additionally, in order to assess contamination, a comparison was also made with leaves of plants affected during the JCO criticality accident in Japan. Based on the results obtained, the importance of imaging plate technology in environmental radiation monitoring has been suggested.

  13. Regulatory aspects of nuclear accidents

    International Nuclear Information System (INIS)

    Caoui, A.

    1988-01-01

    The legislative systems used in different countries insist on requiring the license of the nuclear installations exploitation and on providing a nuclear safety report. For obtaining this license, the operators have to consider all situations of functioning (normal, incidental and accidental) to make workers and the public secure. The licensing procedures depend on the juridical and administrative systems of the country. Usually, protection of people against ionzing radiation is the responsibility of the ministry of health and the ministry of industry. In general, the regulations avoid to fix a definite technical standards by reason of technological development. An emergency plan is normally designed in the stage of the installation project planification. This plan contains the instructions and advices to give to populations in case of accident. The main lesson learnt from the nuclear accidents that happened is to enlarge the international cooperation in the nuclear safety field. 4 refs. (author)

  14. Tank farm nuclear criticality review

    International Nuclear Information System (INIS)

    Bratzel, D.R.

    1996-01-01

    The technical basis for the nuclear criticality safety of stored wastes at the Hanford Site Tank Farm Complex was reviewed by a team of senior technical personnel whose expertise covered all appropriate aspects of fissile materials chemistry and physics. The team concluded that the detailed and documented nucleonics-related studies underlying the waste tanks criticality safety basis were sound. The team concluded that, under current plutonium inventories and operating conditions, a nuclear criticality accident is incredible in any of the Hanford single-shell tanks (SST), double-shell tanks (DST), or double-contained receiver tanks (DCRTS) on the Hanford Site

  15. Nuclear criticality safety: 2-day training course

    Energy Technology Data Exchange (ETDEWEB)

    Schlesser, J.A. [ed.] [comp.

    1997-02-01

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

  16. Nuclear criticality safety: 2-day training course

    International Nuclear Information System (INIS)

    Schlesser, J.A.

    1997-02-01

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

  17. Review of the CRAC and SILENE Criticality Accident Studies

    International Nuclear Information System (INIS)

    Barbry, F.; Fouillaud, P.; Grivot, P.; Reverdy, L.

    2009-01-01

    In 1967, the Commissariat et l'Energie Atomique (French Atomic Energy Agency) performed its first research on criticality accidents for the purpose of limiting their impact on people, the environment, and nuclear facilities themselves. A criticality accident is accompanied by intense neutron and gamma emissions and release of radioactive fission products-gases and aerosols-gene rating risk of irradiation and contamination. This work has supplemented earlier work in criticality safety, which concentrated on critical mass measurements and computations. Understanding of the consequences of criticality accidents was limited. Emergency planning was hampered by lack of data. Information became available from pulsed reactor experiments, but the experiments were restricted to the established reactor configurations. The objectives of research performed at the Valduc criticality laboratory, mainly on aqueous fissile media, using the CRAC and SILENE facilities, by multidisciplinary teams of physicists, dosimetry specialists, and radio-biologists, were to model criticality accident physics, estimate irradiation risks and radioactive releases, detect excursions, and organize emergency response. The results of the Valduc experiments have contributed toward improved understanding of criticality accident phenomenology and better evaluation of the risks associated with such accidents. (authors)

  18. Review of the CRAC and SILENE Criticality Accident Studies

    Energy Technology Data Exchange (ETDEWEB)

    Barbry, F.; Fouillaud, P.; Grivot, P.; Reverdy, L. [CEA Valduc, Serv Rech Neutron and Critcite, 21 - Is-sur-Tille (France)

    2009-02-15

    In 1967, the Commissariat et l'Energie Atomique (French Atomic Energy Agency) performed its first research on criticality accidents for the purpose of limiting their impact on people, the environment, and nuclear facilities themselves. A criticality accident is accompanied by intense neutron and gamma emissions and release of radioactive fission products-gases and aerosols-gene rating risk of irradiation and contamination. This work has supplemented earlier work in criticality safety, which concentrated on critical mass measurements and computations. Understanding of the consequences of criticality accidents was limited. Emergency planning was hampered by lack of data. Information became available from pulsed reactor experiments, but the experiments were restricted to the established reactor configurations. The objectives of research performed at the Valduc criticality laboratory, mainly on aqueous fissile media, using the CRAC and SILENE facilities, by multidisciplinary teams of physicists, dosimetry specialists, and radio-biologists, were to model criticality accident physics, estimate irradiation risks and radioactive releases, detect excursions, and organize emergency response. The results of the Valduc experiments have contributed toward improved understanding of criticality accident phenomenology and better evaluation of the risks associated with such accidents. (authors)

  19. Workplace Accidents and Self-Organized Criticality

    OpenAIRE

    Mauro, John C.; Diehl, Brett; Marcellin, Richard F.; Vaughn, Daniel J.

    2018-01-01

    The occurrence of workplace accidents is described within the context of self-organized criticality, a theory from statistical physics that governs a wide range of phenomena across physics, biology, geosciences, economics, and the social sciences. Workplace accident data from the U.S. Bureau of Labor Statistics reveal a power-law relationship between the number of accidents and their severity as measured by the number of days lost from work. This power-law scaling is indicative of workplace a...

  20. Learning from nuclear accident experience

    International Nuclear Information System (INIS)

    Vaurio, J.K.

    1984-01-01

    Statistical procedures are developed to estimate accident occurrence rates from historical event records, to predict future rates and trends, and to estimate the accuracy of the rate estimates and predictions. Maximum likelihood estimation is applied to several learning models, and results are compared to earlier graphical and analytical estimates. The models are based on (1) the cumulative number of operating years, (2) the cumulative number of plants built, and (3) accidents (explicitly), with the accident rate distinctly different before and after an accident. The statistical accuracies of the parameters estimated are obtained in analytical form using the Fisher information matrix. Using data on core damage accidents in electricity producing plants, it is estimated that the probability for a plant to have a serious flaw has decreased from 0.1 to 0.01 during the developmental phase of the nuclear industry. At the same time the equivalent frequency of accidents has decreased from 0.04 per reactor year to 0.0004 per reactor year, partly due to the increasing population of plants. 10 references, 7 figures, 2 tables

  1. Process criticality accident likelihoods, magnitudes and emergency planning. A focus on solution accidents

    International Nuclear Information System (INIS)

    McLaughlin, Thomas P.

    2003-01-01

    This paper presents analyses and applications of data from reactor and critical experiment research on the dynamics of nuclear excursions in solution media. Available criticality accident information is also discussed and shown to provide strong evidence of the overwhelming likelihood of accidents in liquid media over other forms and to support the measured data. These analyses are shown to provide valuable insights into key parameters important to understanding solution excursion dynamics in general and in evaluating practical upper bounds on criticality accident magnitudes. This understanding and these upper bounds are directly applicable to the evaluation of the consequences of postulated criticality accidents. These bounds are also essential in order to comply with national and international consensus standards and regulatory requirements for emergency planning. (author)

  2. Monitoring of nuclear accidents

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, J.; Camps, J.

    2010-07-01

    No matter how extensive the safety measures might be in and around nuclear sites, an incident can never be entirely ruled out. SCK-CEN is a specialist in radiological evaluations, in order to determine the impact of ionising radiation or a discharge of radionuclides on man and the environment. In August 2008, a team of SCK-CEN researchers participated in the radiological monitoring of the environment after an incident at the National Institute of Radio Elements (IRE) in Fleurus. SCK-CEN also conducted thyroid gland measurements in the population. The incident provided useful lessons on dealing with nuclear emergency situations.

  3. Nuclear criticality safety guide

    International Nuclear Information System (INIS)

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

    1996-09-01

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

  4. Nuclear criticality safety guide

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-09-01

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

  5. Dosimetric management during a criticality accident

    International Nuclear Information System (INIS)

    Lebaron-Jacobs, L.; Fottorino, R.; Racine, Y.; Miele, A.; Barbry, F.; Briot, F.; Distinguin, S.; Le Goff, J.P.; Berard, P.; Boisson, P.; Cavadore, D.; Lecoix, G.; Persico, M.H.; Rongier, E.; Challeton-De Vathaire, C.; Medioni, R.; Voisin, P.; Exmelin, L.; Flury-Herard, A.; Gaillard-Lecanu, E.; Lemaire, G.; Gonin, M.; Riasse, C.

    2008-01-01

    A working group from health occupational and clinical biochemistry services on French sites has issued essential data sheets on the guidelines to follow in managing the victims of a criticality accident. Since the priority of the medical management after a criticality accident is to assess the dose and the distribution of dose, some dosimetric investigations have been selected in order to provide a prompt response and to anticipate the final dose reconstruction. Comparison exercises between clinical biochemistry laboratories on French sites were carried out to confirm that each laboratory maintained the required operational methods for hair treatment and the appropriate equipment for 32 P activity in hair and 24 Na activity in blood measurements, and to demonstrate its ability to rapidly provide neutron dose estimates after a criticality accident. As a result, a relation has been assessed to estimate the dose and the distribution of dose according to the neutron spectrum following a criticality accident. (authors)

  6. Management of foodstuffs after nuclear accidents

    International Nuclear Information System (INIS)

    1991-01-01

    A model for the management of foodstuffs after nuclear accidents is presented. The model is a synthesis of traditions and principles taken from both radioactive protection and management of food. It is based on cooperation between the Nordic countries and on practical experience gained from the Chernobyl accident. The aim of the model is to produce a basis for common plans for critical situations based on criteria for decision making. In the case of radioactive accidents it is important that the protection of the public and of the society is handled in a positive way. The model concerns production, marketing and consumption of food and beverage. The overall aim is that the radiation doses should be as low and harmless to health for individual members of the public. (CLS) 35 refs

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

    International Nuclear Information System (INIS)

    Hill, Robin L.; Conrady, Matthew M.

    2011-01-01

    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.

  8. Development of the criticality accident analysis code, AGNES

    International Nuclear Information System (INIS)

    Nakajima, Ken

    1989-01-01

    In the design works for the facilities which handle nuclear fuel, the evaluation of criticality accidents cannot be avoided even if their possibility is as small as negligible. In particular in the system using solution fuel like uranyl nitrate, solution has the property easily becoming dangerous form, and all the past criticality accidents occurred in the case of solution, therefore, the evaluation of criticality accidents becomes the most important item of safety analysis. When a criticality accident occurred in a solution fuel system, due to the generation and movement of radiolysis gas voids, the oscillation of power output and pressure pulses are observed. In order to evaluate the effect of criticality accidents, these output oscillation and pressure pulses must be calculated accurately. For this purpose, the development of the dynamic characteristic code AGNES (Accidentally Generated Nuclear Excursion Simulation code) was carried out. The AGNES is the reactor dynamic characteristic code having two independent void models. Modified energy model and pressure model, and as the benchmark calculation of the AGNES code, the results of the experimental analysis on the CRAC experiment are reported. (K.I.)

  9. Cognitive systems engineering analysis of the JCO criticality accident

    International Nuclear Information System (INIS)

    Tanabe, Fumiya; Yamaguchi, Yukichi

    2000-01-01

    The JCO Criticality Accident is analyzed with a framework based on cognitive systems engineering. With the framework, analysis is conducted integrally both from the system viewpoint and actors viewpoint. The occupational chemical risk was important as safety constraint for the actors as well as the nuclear risk, which is due to criticality accident, to the public and to actors. The inappropriate actor's mental model of the work system played a critical role and several factors (e.g. poor training and education, lack of information on criticality safety control in the procedures and instructions, and lack of warning signs at workplace) contributed to form and shape the mental model. Based on the analysis, several countermeasures, such as warning signs, information system for supporting actors and improved training and education, are derived to prevent such an accident. (author)

  10. Nuclear criticality safety: 2-day training course

    International Nuclear Information System (INIS)

    Schlesser, J.A.

    1992-11-01

    This compilation of notes is presented as a source reference for the criticality safety course. At the completion of this training course, the attendee will: (1) be able to define terms commonly used in nuclear criticality safety; (2) be able to appreciate the fundamentals of nuclear criticality safety; (3) be able to identify factors which affect nuclear criticality safety; (4) be able to identify examples of criticality controls as used at Los Alamos; (5) be able to identify examples of circumstances present during criticality accidents; (6) have participated in conducting two critical experiments

  11. Nuclear criticality safety guide

    International Nuclear Information System (INIS)

    Ro, Seong Ki; Shin, Hee Seong; Park, Seong Won; Shin, Young Joon.

    1997-06-01

    Nuclear criticality safety guide was described for handling, transportation and storage of nuclear fissile materials in this report. The major part of the report was excerpted frp, TID-7016(revision 2) and nuclear criticality safety written by Knief. (author). 16 tabs., 44 figs., 5 refs

  12. Comparison of the dose evaluation methods for criticality accident

    International Nuclear Information System (INIS)

    Shimizu, Yoshio; Oka, Tsutomu

    2004-01-01

    The improvement of the dose evaluation method for criticality accidents is important to rationalize design of the nuclear fuel cycle facilities. The source spectrums of neutron and gamma ray of a criticality accident depend on the condition of the source, its materials, moderation, density and so on. The comparison of the dose evaluation methods for a criticality accident is made. Some methods, which are combination of criticality calculation and shielding calculation, are proposed. Prompt neutron and gamma ray doses from nuclear criticality of some uranium systems have been evaluated as the Nuclear Criticality Slide Rule. The uranium metal source (unmoderated system) and the uranyl nitrate solution source (moderated system) in the rule are evaluated by some calculation methods, which are combinations of code and cross section library, as follows: (a) SAS1X (ENDF/B-IV), (b) MCNP4C (ENDF/B-VI)-ANISN (DLC23E or JSD120), (c) MCNP4C-MCNP4C (ENDF/B-VI). They have consisted of criticality calculation and shielding calculation. These calculation methods are compared about the tissue absorbed dose and the spectrums at 2 m from the source. (author)

  13. Reactor accidents and nuclear catastrophes

    International Nuclear Information System (INIS)

    Kirchhoff, R.; Linde, H.J.

    1979-01-01

    Assuming some preliminary knowledge of the fundamentals of atomic physics, the book describes the effects of ionizing radiation on the human organism. In order to assess the potential hazards of reactor accidents and the extent of a nuclear catastrophe, the technology of power generation in nuclear power stations is presented together with its potential dangers as well as the physical and medical processes occurring during a nuclear weapons explosion. The special medical aspects are presented which range from first aid in the case of a catastrophe to the accute radiation syndrome, the treatment of burns to the therapy of late radiolesions. Finally, it is confirmed that the treatment of radiation injured persons does not give rise to basically new medical problems. (orig./HP) [de

  14. Criticality accident studies and research performed in the Valduc criticality laboratory, France

    International Nuclear Information System (INIS)

    Barbry, F.; Fouillaud, P.

    2001-01-01

    In 1967, the IPSN (Institut de Protection et de Surete Nucleaire - Nuclear Protection and Safety Institute) started studies and research in France on criticality accidents, with the objective of improving knowledge and modelling of accidents in order to limit consequences to the public, the environment and installations. The criticality accident is accompanied by an intense emission of neutronic and gamma radiation and releases of radioactive products in the form of gas and aerosols, generating irradiation and contamination risks. The main objectives of the studies carried out, particularly using the CRAC installation and the SILENE reactor at Valduc (France), were to model the physics of criticality accidents, to estimate the risks of irradiation and radioactive releases, to elaborate an accident detection system and to provide information for intervention plans. This document summarizes the state of knowledge in the various fields mentioned above. The results of experiments carried out in the Valduc criticality laboratory are used internationally as reference data for the qualification of calculation codes and the assessment of the consequences of a criticality accident. The SILENE installation, that reproduces the various conditions encountered during a criticality accident, is also a unique international research tool for studies and training on those matters. (author)

  15. Thyroid blocking after nuclear accidents

    International Nuclear Information System (INIS)

    Rendl, J.; Reiners, C.

    1999-01-01

    Following the Chernobyl accident a marked increase in thyroid cancer incidence among the children in Belarus, the Ukraine and Russia has been detected, strongly suggesting a causal relationship to the large amounts of radioactive iodine isotopes in the resulting fallout. Taking into account the Chernobyl experience the German Committee on Radiation Protection decided to reduce the intervention levels on the basis of the 1989 WHO recommendations and adopted a new concept concerning thyroid blocking in response to nuclear power plant accidents. Experimental animal studies and theoretical considerations show that thyroid blocking with potassium iodide (KI) in a dose of about 1.4 mg per kg body weight is most effective in reducing irradiation to the thyroid from the intake of radioiodine nuclides, provided KI is given within 2 hours after exposure. According to the new concept, persons over 45 years of age should not take iodine tablets because the drug could cause a greater health risk due to prevalent functional thyroid autonomy in this age group than the radioactive iodine averted by KI. On the basis of accident analysis and the new philosophy suitable distribution strategies and logistics are proposed and discussed. (orig.) [de

  16. Realism in nuclear criticality safety

    International Nuclear Information System (INIS)

    McLaughlin, T. P.

    2009-01-01

    Commercial nuclear power plant operation and regulation have made remarkable progress since the Three Mile Island Accident. This is attributed largely to a heavy dose of introspection and self-regulation by the industry and to a significant infusion of risk-informed and performance-based regulation by the Nuclear Regulatory Commission. This truly represents reality in action both by the plant operators and the regulators. On the other hand, the implementation of nuclear criticality safety in ex-reactor operations involving significant quantities of fissile material has not progressed, but, tragically, it has regressed. Not only is the practice of the discipline in excess of a factor of ten more expensive than decades ago; the trend continues. This unfortunate reality is attributed to a lack of coordination within the industry (as contrasted to what occurred in the reactor operations sector), and to a lack of implementation of risk-informed and performance-based regulation by the NRC While the criticality safety discipline is orders of magnitude smaller than the reactor safety discipline, both operators and regulators must learn from the progress made in reactor safety and apply it to the former to reduce the waste, inefficiency and potentially increased accident risks associated with current practices. Only when these changes are made will there be progress made toward putting realism back into nuclear criticality safety. (authors)

  17. Third IAEA nuclear accident intercomparison experiment

    Energy Technology Data Exchange (ETDEWEB)

    Miric, I; Ubovic, Z

    1974-05-15

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

  18. Third IAEA nuclear accident intercomparison experiment

    International Nuclear Information System (INIS)

    Miric, I.; Ubovic, Z.

    1974-05-01

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

  19. ANS-8.23: Criticality accident emergency planning and response

    International Nuclear Information System (INIS)

    Pruvost, N.L.

    1991-01-01

    A study group has been formed under the auspices of ANS-8 to examine the need for a standard on nuclear criticality accident emergency planning and response. This standard would be ANS-8.23. ANSI/ANS-8.19-1984, Administrative Practices for Nuclear Criticality Safety, provides some guidance on the subject in Section 10 titled -- Planned Response to Nuclear Criticality Accidents. However, the study group has formed a consensus that Section 10 is inadequate in that technical guidance in addition to administrative guidance is needed. The group believes that a new standard which specifically addresses emergency planning and response to a perceived criticality accident is needed. Plans for underway to request the study group be designated a writing group to create a draft of such a new standard. The proposed standard will divide responsibility between management and technical staff. Generally, management will be charged with providing the necessary elements of emergency planning such as a criticality detection and alarm system, training, safe evacuation routes and assembly areas, a system for timely accountability of personnel, and an effective emergency response organization. The technical staff, on the other hand, will be made responsible for establishing specific items such as safe and clearly posted evacuation evacuation routes and dose criteria for personnel assembly areas. The key to the question of responsibilities is that management must provide the resources for the technical staff to establish the elements of an emergency response effort

  20. An introduction to serious nuclear accident chemistry

    Directory of Open Access Journals (Sweden)

    Mark Russell St. John Foreman

    2015-12-01

    Full Text Available A review of the chemistry occurring inside a nuclear power plant during a serious reactor accident is presented. This includes some aspects of the behavior of nuclear fuel, its cladding, cesium and iodine. This review concentrates on the chemistry of an accident in a water-cooled reactor loaded with uranium dioxide or mixed metal oxide fuel.

  1. Medical consequences of a nuclear plant accident

    International Nuclear Information System (INIS)

    Olsson, S.E.; Reizenstein, P.; Stenke, L.

    1987-01-01

    The report gives background information concerning radiation and the biological medical effects and damages caused by radiation. The report also discusses nuclear power plant accidents and efforts from the medical service in the case of a nuclear power plant accident. (L.F.)

  2. An updated nuclear criticality slide rule

    International Nuclear Information System (INIS)

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

    1998-04-01

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

  3. Iodine Prophylaxis and Nuclear Accidents

    International Nuclear Information System (INIS)

    Franic, Z.

    1998-01-01

    Iodine is a highly volatile element therefore being very mobile in the environment. It enters the metabolism of living organisms and is selectively taken up and concentrated in the thyroid gland. The plume (cloud-like formation) of radioactive material that might be released in the environment in the case of a serious nuclear accident, primarily consists of the radioactive isotopes of iodine. Among those, due to its decay properties, is the most important 131 I. The effective means of protecting the thyroid gland against exposure to radioactive iodine is an intake of stable iodine. Therefore, one of the central issues in the emergency planning is to determine whether and at which projected thyroid radiation dose stable iodine should be given to the population. The International Atomic Energy Agency (IAEA) set the generic optimized intervention value for iodine prophylaxis to 100 mGy of avertable committed dose to a thyroid.The prophylaxis is implemented by utilizing the pills of pills of potassium iodine (KI). The efficacy of KI in protecting the thyroid gland depends upon the time of intake relative to the start of exposure to radioactive iodine. The best results are obtained if KI is taken 1-2 hours before or immediately after the start of exposure. The recommended dosage, based upon the study performed by Il'in et.al. is 130 mg/day. KI should be taken at least three days after the acute exposure to radioiodine, to prevent accumulation in a thyroid gland of radioiodine excreted from the other compartments of the body. The largest epidemiological study on the effects of KI prophylaxis ever performed was the one in Poland after the Chernobyl accident. Stable iodine was given as single dose of KI solution to 10.5 million of children and 7 millions of adults. Among children no serious side effects were seen while only two adults (with previously recorded iodine sensitivity) had severe respiratory distresses. Polish experiences showed that rapid response to such

  4. JCO criticality accident as POST-LOCA: Poor structure induced loss of organizational control accident

    International Nuclear Information System (INIS)

    Furuhama, Yutaka

    2000-01-01

    Some problems in operation and business management of JCO (Japan Nuclear Fuel Conversion Co.) have been studied as background factors of the criticality accident. Open information about business conditions of JCO suggests that the cause of the accident is not so simple as to be attributed only to economic pressure, but includes immanent problems in JCO. We investigate the problems from five viewpoints, organization of safety management, system of operation management, activities for business improvement, risk awareness, and restructuring of business, and discuss the effects and causality of background factors as well as remedies for them. (author)

  5. A Review of Criticality Accidents 2000 Revision

    Energy Technology Data Exchange (ETDEWEB)

    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.

  6. A Review of Criticality Accidents 2000 Revision

    International Nuclear Information System (INIS)

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

    2000-01-01

    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

  7. Elements of a nuclear criticality safety program

    International Nuclear Information System (INIS)

    Hopper, C.M.

    1995-01-01

    Nuclear criticality safety programs throughout the United States are quite successful, as compared with other safety disciplines, at protecting life and property, especially when regarded as a developing safety function with no historical perspective for the cause and effect of process nuclear criticality accidents before 1943. The programs evolved through self-imposed and regulatory-imposed incentives. They are the products of conscientious individuals, supportive corporations, obliged regulators, and intervenors (political, public, and private). The maturing of nuclear criticality safety programs throughout the United States has been spasmodic, with stability provided by the volunteer standards efforts within the American Nuclear Society. This presentation provides the status, relative to current needs, for nuclear criticality safety program elements that address organization of and assignments for nuclear criticality safety program responsibilities; personnel qualifications; and analytical capabilities for the technical definition of critical, subcritical, safety and operating limits, and program quality assurance

  8. Return on experience on nuclear accidents

    International Nuclear Information System (INIS)

    Barre, Bertrand

    2015-09-01

    After a presentation of the International Nuclear and radiological Events Scale (INES scale), of its levels and criteria, this article proposes brief recalls of some nuclear accidents which occurred in nuclear reactors: Chalk River in Canada (1952), Windscale in England (1957), the universal Canadian reactor (NRU in 1958), the SL1 reactor of the Idaho National Laboratory in the USA (1961), the Swiss Lucens reactor (1969), Saint-Laurent des Eaux in France (1969 and 1980). More detailed descriptions are then given for the Three Mile Island accident in 1979, the Chernobyl accident in 1986, and the Fukushima accident in 2011. The main causes of these accidents are identified: loss of control of chain reaction, cooling defect on a stopped reactor, cooling defect on an operated reactor. Some lessons are drawn from these facts, and some characteristics of the EPR are outlined with respect with problems encountered in these accidents

  9. Review of nuclear reactor accidents

    International Nuclear Information System (INIS)

    Connelly, J.W.; Storr, G.J.

    1989-01-01

    Two types of severe reactor accidents - loss of coolant or coolant flow and transient overpower (TOP) accidents - are described and compared. Accidents in research reactors are discussed. The 1961 SL1 accident in the US is used as an illustration as it incorporates the three features usually combined in a severe accident - a design flaw or flaws in the system, a circumvention of safety circuits or procedures, and gross operator error. The SL1 reactor, the reactivity accident and the following fuel-coolant interaction and steam explosion are reviewed. 3 figs

  10. Accidents in nuclear facilities: classification, incidence and impact

    International Nuclear Information System (INIS)

    Galicia A, J.; Paredes G, L. C.

    2012-10-01

    A general analysis of the 146 accidents reported officially in nuclear facilities from 1945 to 2012 is presented, among them some took place in: power or research nuclear reactors, critical and subcritical nuclear assemblies, handling of nuclear materials inside laboratories belonging to institutes or universities, in radiochemistry industrial plants and nuclear fuel factories. In form graph the incidence of these accidents is illustrated classified for; category, decades, geographical localization, country classification before the OECD, failure type, and the immediate or later victims. On the other hand, the main learned lessons of the nuclear accidents of Three Mile Island, Chernobyl and Fukushima are stood out, among those that highlight; the human factors, the necessity of designs more innovative and major technology for the operation, control and surveillance of the nuclear facilities, to increase the criterions of nuclear, radiological and physics safety applied to these facilities, the necessity to carry out probabilistic analysis of safety more detailed for cases of not very probable accidents and their impact, to revalue the selection criterions of the sites for nuclear locations, the methodology of post-accident sites recovery and major instrumentation for parameters evaluation and the radiological monitoring among others. (Author)

  11. Severe accidents: in nuclear power plants

    International Nuclear Information System (INIS)

    1986-01-01

    A ''severe'' nuclear accident refers to a reactor accident that could exceed reactor design specifications to such a degree as to prevent cooling of the reactor's core by normal means. This report summarizes the work of a NEA Senior Group of Experts who have studied the potential response of existing light-water reactors to severe accidents and have found that current designs of reactors are far more capable of coping with severe accidents than design specifications would suggest. The report emphasises the specific knowledge and means that can be used for diagnosing a severe accident and for managing its progression in order to prevent or mitigate its consequences

  12. Workbench experiments on interaction of nuclear fuel with channel reactor materials: the LFCM congestions criticality and accident scenario in both re-examinations

    International Nuclear Information System (INIS)

    Baryakhtar, V.; Gonchar, V.; Zhidkov, A.

    2002-01-01

    The heavy radioecological consequences of 1986 accident were mainly stipulated by destruction of both a significant part of fuel envelopes and fuel matrix due to high-temperature interaction with silicates, when nuclear fuel has lost an important property to keep the fission products inside its volume. In this respect the silicate material application in thermal-insulating filling is a crucial fault had been made when Chornobyl NPP channel reactor designing

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

    Science.gov (United States)

    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.

  14. Modeling of criticality accidents and their environmental consequences

    International Nuclear Information System (INIS)

    Thomas, W.; Gmal, B.

    1987-01-01

    In the Federal Republic of Germany, potential radiological consequences of accidental nuclear criticality have to be evaluated in the licensing procedure for fuel cycle facilities. A prerequisite to this evaluation is to establish conceivable accident scenarios. First, possibilities for a criticality exceeding the generally applied double contingency principle of safety are identified by screening the equipment and operation of the facility. Identification of undetected accumulations of fissile material or incorrect transfer of fissile solution to unfavorable geometry normally are most important. Second, relevant and credible scenarios causing the most severe consequences are derived from these possibilities. For the identified relevant scenarios, time-dependent fission rates and reasonable numbers for peak power and total fissions must be determined. Experience from real accidents and experiments (KEWB, SPERT, CRAC, SILENE) has been evaluated using empirical formulas. To model the time-dependent behavior of criticality excursions in fissile solutions, a computer program FELIX has been developed

  15. Development of INCTAC code for analyzing criticality accident phenomena

    International Nuclear Information System (INIS)

    Mitake, Susumu; Hayashi, Yamato; Sakurai, Shungo

    2003-01-01

    Aiming at understanding nuclear transients and thermal- and hydraulic-phenomena of the criticality accident, a code named INCTAC has been newly developed at the Institute of Nuclear Safety. The code is applicable to the analysis of criticality accident transients of aqueous homogenous fuel solution system. Neutronic transient model is composed of equations for the kinetics and for the spatial distributions, which are deduced from the time dependent multi-group transport equations with the quasi steady state assumption. Thermal-hydraulic transient model is composed of a complete set of the mass, momentum and energy equations together with the two-phase flow assumptions. Validation tests of INCTAC were made using the data obtained at TRACY, a transient experiment criticality facility of JAERI. The calculated results with INCTAC showed a very good agreement with the experiment data, except a slight discrepancy of the time when the peak of reactor power was attained. But, the discrepancy was resolved with the use of an adequate model for movement and transfer of the void in the fuel solution mostly generated by radiolysis. With a simulation model for the transport of radioactive materials through ventilation systems to the environment, INCTAC will be used as an overall safety evaluation code of the criticality accident. (author)

  16. Nuclear accidents and safety measures of domestic nuclear power plants

    International Nuclear Information System (INIS)

    Song Zurong; Che Shuwei; Pan Xiang

    2012-01-01

    Based on the design standards for the safety of nuclear and radiation in nuclear power plants, the three accidents in the history of nuclear power are analyzed. And the main factors for these accidents are found out, that is, human factors and unpredicted natural calamity. By combining the design and operation parameters of domestic nuclear plants, the same accidents are studied and some necessary preventive schemes are put forward. In the security operation technology of domestic nuclear power plants nowadays, accidents caused by human factors can by prevented completely. But the safety standards have to be reconsidered for the unpredicted neutral disasters. How to reduce the hazard of nuclear radiation and leakage to the level that can be accepted by the government and public when accidents occur under extreme conditions during construction and operation of nuclear power plants must be considered adequately. (authors)

  17. Legal aspects of nuclear and radiological accidents

    International Nuclear Information System (INIS)

    El-baroudy, M.M.

    2005-01-01

    Aiming at preventing nuclear and radiological accidents and maintaining safety and security, the State extends its jurisdiction over nuclear and radiological activities through the promulgation of regulatory legislations and providing criminal protection to these activities. The State, in its legislation, defines an authority responsible for the planning of preparedness for emergency situations. That Authority cooperates with other competent authorities in the State as well as with other relevant international organizations and other States in a coordinated way aiming at dealing effectively with and mitigating the consequences of nuclear and radiological accidents through promulgating relevant international conventions and plans for reinforcement of international cooperation in accidents situations. Moreover, the International Atomic Energy Authority (IAEA) can provide specialized consultations and offer assistance in case of accidents. The present study is divided into an introduction and two chapters. In the introduction, the nature of nuclear or radiological accidents is defined. The first chapter deals with the national legal system for preventing the occurrence of nuclear and radiological accidents and mitigating their consequences. The second chapter deals with the international cooperation for facing nuclear or radiological accidents and mitigating their consequences

  18. Triage and medical management of criticality accident victims

    International Nuclear Information System (INIS)

    Lebaron-Jacobs, L.; Flury-Herard, A.; Cavadore, D.

    2002-01-01

    The criticality accident is the result of an uncontrolled chain fission reaction initiated when the quantities of nuclear materials (uranium or plutonium)present accidentally exceed a given limit called the c ritical mass . As soon as the critical state is exceeded, the chain reaction increases exponentially. The result is a fast increase in the number of fission events which occur within the fissile medium. This phenomenon results in a release of energy mainly in the form of heat, accompanied by the intense emission of neutron and gamma radiation and the release of fission gases (Barby, 1983)

  19. Dutch National Plan combat nuclear accidents

    International Nuclear Information System (INIS)

    1988-01-01

    This document presents the Dutch National Plan combat nuclear accidents (NPK). Ch. 2 discusses some important starting points which are determining for the framework and the performance of the NPK, in particular the accident typology which underlies the plan. Also the new accident-classification system for the Dutch nuclear power plants, the standardization for the measures to be taken and the staging around nuclear power plants are pursued. In ch. 3 the legal framework of the combat nuclear accidents is described. In particular the Nuclear-power law, the Accident law and the Municipality law are pursued. Also the role of province and municipality are described. Ch. 4 deals with the role of the owner/licensee of the object where the accident occurs, in the combat of accident. In ch. 5 the structure of the nuclear-accident combat at national level is outlined, subdivided in alarm phase, combat phase and the winding-up phase. In ch.'s 6-12 these phases are elaborated more in detail. In ch.'s 10-13 the measures to be taken in nuclear accidents, are described. These measures are distinguished with regard to: protection of the population and medical aspects, water economy, drinking-water supply, agriculture and food supply. Ch. 14 describes the responsibility of the burgomaster. Ch.'s 15 and 16 present an overview of the personnel, material, procedural and juridical modifications and supplements of existing structures which are necessary with regard to the new and modified parts of the structure. Ch. 17 indicates how by means of the appropriate education and exercise it can be achieved that all personnel, services and institutes concerned possess the knowledge and experience necessary for the activities from the NKP to be executed as has been described. Ch. 18 contains a survey of activities to be performed and a proposal how these can be realized. (H.W.). figs.; tabs

  20. Nuclear accident evacuee bullying and structural violence

    International Nuclear Information System (INIS)

    Tsujiuchi, Takuya

    2018-01-01

    Nuclear accident sufferers should be now referred to as nuclear accident victims. The authors discuss why nuclear accident victims receive not only psychological bullying where no peculiar causes exist, but also corporal and physical bullying and mental suffering, based on the results of questionnaire survey conducted by the authors from January to February 2017, the 'survey on bullying problems related to evacuation from the nuclear accident.' The reasons why the nuclear power evacuation bullying has become a problem at present can be largely classified to the following three categories: (1) opinion that 'bullying' that originally existed just after the nuclear accident became surfaced recently, (2) opinion that latent problems exist as background, and (3) opinion that socially underlying issues are involved in the generation of bullying. Thus, various factors existing under nuclear power evacuation bullying were structurally clarified. In the background of children's nuclear evacuation bullying, adult nuclear power evacuation bullying exists, and there are 'lack of understanding, prejudice, and discrimination against nuclear power and Fukushima' under that. The author thought that 'structural violence' to create the disparity, discrimination, inequality, and injustice of society exists as the basis of such lack of understanding, prejudice, and discrimination, and discussed the 'structural violence' as the basis of bullying. As the upper structure of structural violence associated with nuclear accidents, there are two big phenomena: (1) setting of evacuation/return area not based on reasonable radiation dose standards and (2) fabricated safety and carefreeness myth. The Ministry of Education, Culture, Sports, Science and Technology's report on nuclear bullying could give an impression that 'nuclear power evacuation bullying' is 'not so big problem'. (A.O.)

  1. Criticality accident dosimetry with ESR spectroscopy.

    Science.gov (United States)

    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.

  2. Nuclear criticality predictability

    International Nuclear Information System (INIS)

    Briggs, J.B.

    1999-01-01

    As a result of lots of efforts, a large portion of the tedious and redundant research and processing of critical experiment data has been eliminated. The necessary step in criticality safety analyses of validating computer codes with benchmark critical data is greatly streamlined, and valuable criticality safety experimental data is preserved. Criticality safety personnel in 31 different countries are now using the 'International Handbook of Evaluated Criticality Safety Benchmark Experiments'. Much has been accomplished by the work of the ICSBEP. However, evaluation and documentation represents only one element of a successful Nuclear Criticality Safety Predictability Program and this element only exists as a separate entity, because this work was not completed in conjunction with the experimentation process. I believe; however, that the work of the ICSBEP has also served to unify the other elements of nuclear criticality predictability. All elements are interrelated, but for a time it seemed that communications between these elements was not adequate. The ICSBEP has highlighted gaps in data, has retrieved lost data, has helped to identify errors in cross section processing codes, and has helped bring the international criticality safety community together in a common cause as true friends and colleagues. It has been a privilege to associate with those who work so diligently to make the project a success. (J.P.N.)

  3. Nuclear multifragmentation critical exponents

    International Nuclear Information System (INIS)

    Bauer, W.; Friedman, W.A.; Univ. of Wisconsin, Madison, WI

    1995-01-01

    In a recent Letter, cited in a reference, the EoS collaboration presented data of fragmentation of 1 A GeV gold nuclei incident on carbon. By analyzing moments of the fragment charge distribution, the authors claim to determine the values of the critical exponents γ, β, and τ for finite nuclei. These data represent a crucial step forward in the understanding of the physics of nuclear fragmentation. However, as shown in this paper, the analysis presented in the cited reference is not sufficient to support the claim that the critical exponents for nuclear fragmentation have been unambiguously determined

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

    International Nuclear Information System (INIS)

    Tayloe, R.W. Jr.; D'Aquila, D.M.; McGinnis, R.B.

    1991-01-01

    The nuclear criticality accident radiation alarm system installed at the Portsmouth Gaseous Diffusion Plant was tested extensively at critical facilities located at the Los Alamos National Laboratory. The ability of the neutron scintillator radiation detection units to respond to a minimum accident of concern as defined in Standard ANSI/ANS-83.-1986 was demonstrated. Detector placement and the established trip point are based on shielding calculations performed by the Oak Ridge National Laboratory and criticality specialists at the Portsmouth plant. Based on these experiments and calculations, a detector trip point of 5 mrad/h in air is used. Any credible criticality accident is expected to produce neutron radiation fields >5 mrad/h in air at one or more radiation alarm locations. Each radiation alarm location has a cluster of three detectors that employs a two-out-of-three alarm logic. Earlier work focused on testing the alarm logic latching circuitry. This work was directed toward measurements involving the actual audible alarm signal delivered

  5. Radioactive release during nuclear accidents in Chernobyl and Fukushima

    Science.gov (United States)

    Nur Ain Sulaiman, Siti; Mohamed, Faizal; Rahim, Ahmad Nabil Ab

    2018-01-01

    Nuclear accidents that occurred in Chernobyl and Fukushima have initiated many research interests to understand the cause and mechanism of radioactive release within reactor compound and to the environment. Common types of radionuclide release are the fission products from the irradiated fuel rod itself. In case of nuclear accident, the focus of monitoring will be mostly on the release of noble gases, I-131 and Cs-137. As these are the only accidents have been rated within International Nuclear Events Scale (INES) Level 7, the radioactive release to the environment was one of the critical insights to be monitored. It was estimated that the release of radioactive material to the atmosphere due to Fukushima accident was approximately 10% of the Chernobyl accident. By referring to the previous reports using computational code systems to model the release rate, the release activity of I-131 and Cs-137 in Chernobyl was significantly higher compare to Fukushima. The simulation code also showed that Chernobyl had higher release rate of both radionuclides on the day of accident. Other factors affecting the radioactive release for Fukushima and Chernobyl accidents such as the current reactor technology and safety measures are also compared for discussion.

  6. Radiocontamination of agricultural workers due to nuclear accidents

    International Nuclear Information System (INIS)

    Petrovic, B.; Smelcerovic, M.; Djuric, G.; Popovic, D.

    1989-01-01

    In the radiocontamination of the environment due to nuclear accidents, agricultural workers should be considered as a critical group of population. The presented paper discusses this problem from the aspects of folder production. The values of the effective dose equivalent are estimated for different phases of the production process and certain procedures aimed to reduce the radiation risk are proposed (author)

  7. Radiocontamination of agricultural workers due to nuclear accidents

    Energy Technology Data Exchange (ETDEWEB)

    Petrovic, B [Faculty of Veterinary Medicine, Beograd, (Serbia and Montenegro); Smelcerovic, M; Djuric, G; Popovic, D [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1989-07-01

    In the radiocontamination of the environment due to nuclear accidents, agricultural workers should be considered as a critical group of population. The presented paper discusses this problem from the aspects of folder production. The values of the effective dose equivalent are estimated for different phases of the production process and certain procedures aimed to reduce the radiation risk are proposed (author)

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

    International Nuclear Information System (INIS)

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

    2014-01-01

    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. (paper)

  9. Accidents at nuclear power plants

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    The accidents which accurred at Wuergassen, Browns Ferry and Three Mile Island are each briefly described and discussed. The last is naturally treated in much more detail than the first two. Damage to the fuel elements is briefly considered and the release of fission products, radiation doses to the population and their expected consequences are discussed. The accidents are evaluated and related to risk evaluations, especially in WASH-1400. (JIW)

  10. Process criticality accident likelihoods, consequences and emergency planning

    International Nuclear Information System (INIS)

    McLaughlin, T.P.

    1992-01-01

    Evaluation of criticality accident risks in the processing of significant quantities of fissile materials is both complex and subjective, largely due to the lack of accident statistics. Thus, complying with national and international standards and regulations which require an evaluation of the net benefit of a criticality accident alarm system, is also subjective. A review of guidance found in the literature on potential accident magnitudes is presented for different material forms and arrangements. Reasoned arguments are also presented concerning accident prevention and accident likelihoods for these material forms and arrangements. (Author)

  11. The nuclear accident risk: a territorial approach

    International Nuclear Information System (INIS)

    Ambroise, Pascal

    2011-01-01

    How many people live in the vicinity of French nuclear power stations? Recent events - notably in Japan, but also in France - highlight the urgent need to be able to predict the possible effects of a nuclear accident on surrounding territories. Here, Ambroise Pascal identifies two key criteria for such an estimation: residential density and land use. (author)

  12. Accidents with nuclear power plants, ch. 11

    International Nuclear Information System (INIS)

    Anon.

    1976-01-01

    A recalculation of the consequences of nuclear power plant accidents is presented taking into account different parameters or different quantities than those usually accepted. A case study of a nuclear power plant planned for the Eems-river estuary in the Netherlands is presented

  13. Nuclear accidents, consumers' perspectives and demands

    International Nuclear Information System (INIS)

    Alevritou-Goulielmou, H.

    2005-01-01

    The public's reaction to life threatening situations is determined by a variety of factors. In the case of nuclear accidents, the panic experienced by citizens may be reasonably justified. This paper briefly describes the parameters that cause panic reactions from a consumer's point of view and summarizes citizen's demands concerning nuclear crisis management

  14. The Fukushima nuclear accident: insights on the safety aspects

    International Nuclear Information System (INIS)

    Thome, Zieli D.; Vellozo, Sergio O.; Silva, Fernando C.

    2013-01-01

    The Fukushima nuclear accident has generated doubts and questions which need to be properly understood and addressed. This scientific attitude became necessary to allow the use of the nuclear technology for electricity generation around the world. The nuclear stakeholders are working to obtain these technical answers for the Fukushima questions. We believe that, such challenges will be, certainly, implemented in the next reactor generation, following the technological evolution. The purpose of this work is to perform a critical analysis of the Fukushima nuclear accident, focusing at the common cause failures produced by tsunami, as well as an analysis of the main redundant systems. This work also assesses the mitigative procedures and the subsequent consequences of such actions, which gave results below expectations to avoid the progression of the accident, discussing the concept of sharing of structures, systems and components at multi-unit nuclear power plants, and its eventual inappropriate use in safety-related devices which can compromise the nuclear safety, as well as its consequent impact on the Fukushima accident scenario. The lessons from Fukushima must be better learned, aiming the development of new procedures and new safety systems. Thus, the nuclear technology could reach a higher evolution level in its safety requirements. This knowledge will establish a conceptual milestone in the safety system design, becoming necessary the review of the current acceptance criteria of safety-related systems. (author)

  15. The Fukushima nuclear accident: insights on the safety aspects

    Energy Technology Data Exchange (ETDEWEB)

    Thome, Zieli D.; Vellozo, Sergio O., E-mail: zielithome@gmail.com, E-mail: vellozo@cbpf.br [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil). Secao de Engenharia Nuclear; Gomes, Rogerio S., E-mail: rogeriog@cnen.gov.br [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil); Silva, Fernando C., E-mail: fernando@con.ufrj.br [Coordenacao do Programas de Pos-Graduacao em Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil)

    2013-07-01

    The Fukushima nuclear accident has generated doubts and questions which need to be properly understood and addressed. This scientific attitude became necessary to allow the use of the nuclear technology for electricity generation around the world. The nuclear stakeholders are working to obtain these technical answers for the Fukushima questions. We believe that, such challenges will be, certainly, implemented in the next reactor generation, following the technological evolution. The purpose of this work is to perform a critical analysis of the Fukushima nuclear accident, focusing at the common cause failures produced by tsunami, as well as an analysis of the main redundant systems. This work also assesses the mitigative procedures and the subsequent consequences of such actions, which gave results below expectations to avoid the progression of the accident, discussing the concept of sharing of structures, systems and components at multi-unit nuclear power plants, and its eventual inappropriate use in safety-related devices which can compromise the nuclear safety, as well as its consequent impact on the Fukushima accident scenario. The lessons from Fukushima must be better learned, aiming the development of new procedures and new safety systems. Thus, the nuclear technology could reach a higher evolution level in its safety requirements. This knowledge will establish a conceptual milestone in the safety system design, becoming necessary the review of the current acceptance criteria of safety-related systems. (author)

  16. Fukushima nuclear power plant accident was preventable

    Science.gov (United States)

    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

  17. Severe accidents in Nuclear Power Plants

    International Nuclear Information System (INIS)

    Valle Cepero, R.; Castillo Alvarez, J.; Ramon Fuente, J.

    1996-01-01

    For the assessment of the safety of nuclear power plants it is of great importance the analyses of severe accidents since they allow to estimate the possible failure models of the containment, and also permit knowing the magnitude and composition of the radioactive material that would be released to the environment in case of an accident upon population and the environment. This paper presents in general terms the basic principles for conducting the analysis of severe accidents, the fundamental sources in the generation of radionuclides and aerosols, the transportation and deposition processes, and also makes reference to de main codes used in the modulation of severe accidents. The final part of the paper contents information on how severe accidents are dialed with the regulatory point view in different countries

  18. National emergency plan for nuclear accidents

    International Nuclear Information System (INIS)

    1992-10-01

    The national emergency plan for nuclear accidents is a plan of action designed to provide a response to accidents involving the release or potential release of radioactive substances into the environment, which could give rise to radiation exposure to the public. The plan outlines the measures which are in place to assess and mitigate the effects of nuclear accidents which might pose a radiological hazard in ireland. It shows how accident management will operate, how technical information and monitoring data will be collected, how public information will be provided and what measures may be taken for the protection of the public in the short and long term. The plan can be integrated with the Department of Defence arrangements for wartime emergencies

  19. Lessons from the Fukushima nuclear power accident

    International Nuclear Information System (INIS)

    Hatamura, Yotaro

    2013-01-01

    Through the investigation of the Fukushima Nuclear Power Accident as the chairman of the related Government's Committee, many things had been considered. Essence of the accident could be not only what occurred in the Fukushima nuclear power station, but also dispersed radioactive materials forced many residents to move and not to be returned. Such events as indication errors of water level meter occurring in severe accident could no be thought and remote mechanical operation of valves under high radiation environment were not prepared. Contamination by radioactive clouds caused the evacuation of residents for a long period. Lessons learned from the accident were described such as; (1) the verification of the road to failure connecting selected accident sequence and road to success with another supposed choice, (2) considering what might occur and then what should be needed on the contrary, (3) nuclear power, if should be continued, should be used with the premise of its hazards, and (4) advise to nuclear engineer for adequate information dissemination and technical explanation to the public and keeping nuclear technologies alive. (T. Tanaka)

  20. NCIS: a nuclear criticality information system

    International Nuclear Information System (INIS)

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

    1984-01-01

    The NCIS is one of the developments carried out to meet the requirements in the field of criticality safety information. Its primary goal is to enhance nuclear criticality safety by dissemination of data, standards, and training material. This paper presents the ''NCIS'' progess since 1950: computer-searching, database management, nuclear critical experiments bibliography. American Nuclear Society transactions criticality safety publications compilation, edition of a personnel directory representing over 140 organizations located in 16 countries and showing a wide range of specialists involved in the field of nuclear criticality safety. The NCIS uses the information management and communication resources of TIS (Technology Information System): automated access procedures; creation of program-dependent information systems; communications. The NCIS is still in a growing, formative stage; it has concentrated first on collecting and organizing the nuclear criticality literature; nuclear critical data, calculational tools, standards, and training materials will follow. Finally the planned and contemplated resources are dealt with: expansion of bibliographic compilations; news database; fundamental criticality safety reference; criticality benchmarck database; user community; training resources; related resources; criticality accident database; dynamic databook; dynamic textbook; expert knowledge system; and, extraction of intelligence

  1. Nuclear criticality information system

    International Nuclear Information System (INIS)

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

    1981-01-01

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

  2. Criticality accident studies and methodology implemented at the CEA

    International Nuclear Information System (INIS)

    Barbry, Francis; Fouillaud, Patrick; Reverdy, Ludovic; Mijuin, Dominique

    2003-01-01

    Based on the studies and results of experimental programs performed since 1967 in the CRAC, then SILENE facilities, the CEA has devised a methodology for criticality accident studies. This methodology integrates all the main focuses of its approach, from criticality accident phenomenology to emergency planning and response, and thus includes aspects such as criticality alarm detector triggering, airborne releases, and irradiation risk assessment. (author)

  3. The nuclear accidents: Causes and consequences

    International Nuclear Information System (INIS)

    Rochd, M.

    1988-01-01

    The author discussed and compared the real causes of T.M.I. and Chernobyl accidents and cited their consequences. To better understand how these accidents occurred, a brief description of PWR type (reactor type of T.M.I.) and of RBMK type (reactor type of Chernobyl) has been presented. The author has also set out briefly the safety analysis objectives and the three barriers established to protect the public against the radiological consequences. To distinguish failures that cause severe accidents and to analyze them in details, it is necessary to classify the accidents. There are many ways to do it according to their initiator event, or to their frequency, or to their degree of gravity. The safety criteria adopted by nuclear industry have been explained. These criteria specify the limits of certain physical parameters that should not be exceeded in case of incidents or accidents. To compare the real causes of T.M.I. and Chernobyl accidents, the events that led to both have been presented. As observed the main common contributing factors in both cases are that the operators did not pay attention to warnings and signals that were available to them and that they were not trained to handle these accident sequences. The essential conclusions derived from these severe accidents are: -The improvement of operators competence contribute to reduce the accident risks; -The rapid and correct diagnosis of real conditions at each point of the accidents permits an appropriate behavior that would bring the plant to a stable state; -Competent technical teams have to intervene and to assist the operators in case of emergency; -Emergency plans and an international collaboration are necessary to limit the accident risks. 11 figs. (author)

  4. Nuclear fuel in a reactor accident.

    Science.gov (United States)

    Burns, Peter C; Ewing, Rodney C; Navrotsky, Alexandra

    2012-03-09

    Nuclear accidents that lead to melting of a reactor core create heterogeneous materials containing hundreds of radionuclides, many with short half-lives. The long-lived fission products and transuranium elements within damaged fuel remain a concern for millennia. Currently, accurate fundamental models for the prediction of release rates of radionuclides from fuel, especially in contact with water, after an accident remain limited. Relatively little is known about fuel corrosion and radionuclide release under the extreme chemical, radiation, and thermal conditions during and subsequent to a nuclear accident. We review the current understanding of nuclear fuel interactions with the environment, including studies over the relatively narrow range of geochemical, hydrological, and radiation environments relevant to geological repository performance, and discuss priorities for research needed to develop future predictive models.

  5. Contribution to evaluating nuclear power plant accidents

    International Nuclear Information System (INIS)

    Razga, J.; Horacek, P.

    1990-01-01

    Large-scale accidents pose the highest risk in the use of nuclear power. They are the major factor that has to be taken into account when assessing the effect of nuclear power plants on human health and on the environment. In Czechoslovak conditions, the effectiveness of provisions made to reduce the hazard of large-scale nuclear power plant accidents must be considered from the following aspects: effect on human health, consequences of long-term disabling of the infrastructure, potential of human and material reserves in coping with the accident, consequences of power failure for the electricity system, effect on agricultural production and catering, risk of ground and surface water contamination in the Labe or Danube river basin, and international political aspects. (Z.M.). 3 tabs., 18 refs

  6. Alternative evacuation strategies for nuclear power accidents

    International Nuclear Information System (INIS)

    Hammond, Gregory D.; Bier, Vicki M.

    2015-01-01

    In the U.S., current protective-action strategies to safeguard the public following a nuclear power accident have remained largely unchanged since their implementation in the early 1980s. In the past thirty years, new technologies have been introduced, allowing faster computations, better modeling of predicted radiological consequences, and improved accident mapping using geographic information systems (GIS). Utilizing these new technologies, we evaluate the efficacy of alternative strategies, called adaptive protective action zones (APAZs), that use site-specific and event-specific data to dynamically determine evacuation boundaries with simple heuristics in order to better inform protective action decisions (rather than relying on pre-event regulatory bright lines). Several candidate APAZs were developed and then compared to the Nuclear Regulatory Commission’s keyhole evacuation strategy (and full evacuation of the emergency planning zone). Two of the APAZs were better on average than existing NRC strategies at reducing either the radiological exposure, the population evacuated, or both. These APAZs are especially effective for larger radioactive plumes and at high population sites; one of them is better at reducing radiation exposure, while the other is better at reducing the size of the population evacuated. - Highlights: • Developed framework to compare nuclear power accident evacuation strategies. • Evacuation strategies were compared on basis of radiological and evacuation risk. • Current strategies are adequate for smaller scale nuclear power accidents. • New strategies reduced radiation exposure and evacuation size for larger accidents

  7. Nuclear criticality safety handbook. Version 2

    International Nuclear Information System (INIS)

    1999-03-01

    The Nuclear Criticality Safety Handbook, Version 2 essentially includes the description of the Supplement Report to the Nuclear Criticality Safety Handbook, released in 1995, into the first version of Nuclear Criticality Safety Handbook, published in 1988. The following two points are new: (1) exemplifying safety margins related to modelled dissolution and extraction processes, (2) describing evaluation methods and alarm system for criticality accidents. Revision is made based on previous studies for the chapter that treats modelling the fuel system: e.g., the fuel grain size that the system can be regarded as homogeneous, non-uniformity effect of fuel solution, and burnup credit. This revision solves the inconsistencies found in the first version between the evaluation of errors found in JACS code system and criticality condition data that were calculated based on the evaluation. (author)

  8. Noticeable aspects of selecting intervention measures for nuclear accidents

    International Nuclear Information System (INIS)

    Guo Yong; Shi Yuanming

    1993-01-01

    Referring to the experience of intervention measures taken for protecting the public after Chernobyl accident and to recent knowledge of source terms of reactor accidents, the noticeable aspects of selecting of intervention measures for nuclear accidents is discussed

  9. Dose evaluation on the basis of {sup 24}Na activity in the human body for the criticality accident at JCO Tokai nuclear fuel processing plant

    Energy Technology Data Exchange (ETDEWEB)

    Momose, T.; Tsujimura, N.; Tasaki, T.; Kanai, K.; Hayashi, N.; Shinohara, K. [Japan Nuclear Cycle Development Inst., Tokai, Ibaraki (Japan)

    2001-11-01

    {sup 24}Na 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 {sup 24}Na activity in the body was 7.7 kBq (83 Bq({sup 24}Na)/g({sup 23}Na)) and the relevant effective dose equivalent was 47 mSv. (author)

  10. Dose evaluation on the basis of 24Na activity in the human body for the criticality accident at JCO Tokai nuclear fuel processing plant

    International Nuclear Information System (INIS)

    Momose, T.; Tsujimura, N.; Tasaki, T.; Kanai, K.; Hayashi, N.; Shinohara, K.

    2001-01-01

    24 Na 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 24 Na activity in the body was 7.7 kBq (83 Bq( 24 Na)/g( 23 Na)) and the relevant effective dose equivalent was 47 mSv. (author)

  11. The victim of the nuclear accident

    International Nuclear Information System (INIS)

    Carvalho, A.B. de.

    1990-01-01

    This paper shows the effects of the nuclear accident in the victims, in their lives, changes in the behaviour, neurosis including all the psychological aspects. The author compare the victims with nuclear accident like AIDS patients, in terms of people's discrimination. There is another kind of victims. They are the people who gave helpness, for example physicians, firemen and everybody involved with the first aids that suffer together with the victims trying to safe them and to diminish their suffering, combating the danger, the discrimination and the no information. (L.M.J.)

  12. The Chernobyl nuclear accident and its consequences

    International Nuclear Information System (INIS)

    1986-01-01

    An AAEC Task Group was set up shortly after the accident at the Chernobyl Nuclear Power Plant to monitor and evaluate initial reports and to assess the implications for Australia. The Task Group issued a preliminary report on 9 May 1986. On 25-29 August 1986, the USSR released details of the accident and its consequences and further information has become available from the Nuclear Energy Agency of OECD and the World Health Organisation. The Task Group now presents a revised report summarising this information and commenting on the consequences from the Australian viewpoint

  13. Accident analysis for nuclear power plants

    International Nuclear Information System (INIS)

    2002-01-01

    Deterministic safety analysis (frequently referred to as accident analysis) is an important tool for confirming the adequacy and efficiency of provisions within the defence in depth concept for the safety of nuclear power plants (NPPs). Owing to the close interrelation between accident analysis and safety, an analysis that lacks consistency, is incomplete or is of poor quality is considered a safety issue for a given NPP. Developing IAEA guidance documents for accident analysis is thus an important step towards resolving this issue. Requirements and guidelines pertaining to the scope and content of accident analysis have, in the past, been partially described in various IAEA documents. Several guidelines relevant to WWER and RBMK type reactors have been developed within the IAEA Extrabudgetary Programme on the Safety of WWER and RBMK NPPs. To a certain extent, accident analysis is also covered in several documents of the revised NUSS series, for example, in the Safety Requirements on Safety of Nuclear Power Plants: Design (NS-R-1) and in the Safety Guide on Safety Assessment and Verification for Nuclear Power Plants (NS-G-1.2). Consistent with these documents, the IAEA has developed the present Safety Report on Accident Analysis for Nuclear Power Plants. Many experts have contributed to the development of this Safety Report. Besides several consultants meetings, comments were collected from more than fifty selected organizations. The report was also reviewed at the IAEA Technical Committee Meeting on Accident Analysis held in Vienna from 30 August to 3 September 1999. The present IAEA Safety Report is aimed at providing practical guidance for performing accident analyses. The guidance is based on present good practice worldwide. The report covers all the steps required to perform accident analyses, i.e. selection of initiating events and acceptance criteria, selection of computer codes and modelling assumptions, preparation of input data and presentation of the

  14. Chemical dosimetry system for criticality accidents.

    Science.gov (United States)

    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.

  15. A critical assessment of energy accident studies

    International Nuclear Information System (INIS)

    Felder, Frank A.

    2009-01-01

    A comparison of two studies conducted ten years apart on energy accidents provides important insights into methodological issues and policy implications. Recommendations for further improvements in energy accident studies are developed including accounting for differences between average and incremental accident damages, testing for appropriate levels of aggregation of accidents, making references and databases publicly available, more precisely defining and reporting different types of economic damages, accounting for involuntary and voluntary risks, reporting normalized damages, raising broader public policy and planning implications and updating existing accident databases.

  16. A critical assessment of energy accident studies

    Energy Technology Data Exchange (ETDEWEB)

    Felder, Frank A. [Edward J. Bloustein School of Planning and Public Policy, Rutgers, The State University of New Jersey, 33 Livingston Avenue, New Brunswick, NJ 08901 (United States)

    2009-12-15

    A comparison of two studies conducted ten years apart on energy accidents provides important insights into methodological issues and policy implications. Recommendations for further improvements in energy accident studies are developed including accounting for differences between average and incremental accident damages, testing for appropriate levels of aggregation of accidents, making references and databases publicly available, more precisely defining and reporting different types of economic damages, accounting for involuntary and voluntary risks, reporting normalized damages, raising broader public policy and planning implications and updating existing accident databases. (author)

  17. Nuclear accident dosimetry. Revision of emergency data sheets

    International Nuclear Information System (INIS)

    Delafield, H.J.

    1976-09-01

    The Emergency Data Sheets on Nuclear Accident Dosimetry have been revealed following the publication of a three part manual on this subject (Delafield, Dennis and Gibson, AERE-R 7485/6/7, 1973). This memo provides an explanation of the action levels adopted for the initial segregation of irradiated persons following a criticality accident, by monitoring the activity of indium foils contained in personnel dosimeters and the induced body sodium activity. The data sheets are given as an Appendix. They provide basic information on; the segregation of irradiated persons, the estimation of radiation exposure, and the assessment of personnel γ-ray and neutron doses. (author)

  18. Agricultural implications of the Fukushima nuclear accident

    International Nuclear Information System (INIS)

    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

  19. DOZIM - evaluation dose code for nuclear accident

    International Nuclear Information System (INIS)

    Oprea, I.; Musat, D.; Ionita, I.

    2008-01-01

    During a nuclear accident an environmentally significant fission products release can happen. In that case it is not possible to determine precisely the air fission products concentration and, consequently, the estimated doses will be affected by certain errors. The stringent requirement to cope with a nuclear accident, even minor, imposes creation of a computation method for emergency dosimetric evaluations needed to compare the measurement data to certain reference levels, previously established. These comparisons will allow a qualified option regarding the necessary actions to diminish the accident effects. DOZIM code estimates the soil contamination and the irradiation doses produced either by radioactive plume or by soil contamination. Irradiations either on whole body or on certain organs, as well as internal contamination doses produced by isotope inhalation during radioactive plume crossing are taken into account. The calculus does not consider neither the internal contamination produced by contaminated food consumption, or that produced by radioactive deposits resuspension. The code is recommended for dose computation on the wind direction, at distances from 10 2 to 2 x 10 4 m. The DOZIM code was utilized for three different cases: - In air TRIGA-SSR fuel bundle destruction with different input data for fission products fractions released into the environment; - Chernobyl-like accident doses estimation; - Intervention areas determination for a hypothetical severe accident at Cernavoda Nuclear Power Plant. For the first case input data and results (for a 60 m emission height without iodine retention on active coal filters) are presented. To summarize, the DOZIM code conception allows the dose estimation for any nuclear accident. Fission products inventory, released fractions, emission conditions, atmospherical and geographical parameters are the input data. Dosimetric factors are included in the program. The program is in FORTRAN IV language and was run on

  20. The application of the assessment of nuclear accident status in emergency decision-making during nuclear accident

    International Nuclear Information System (INIS)

    Yang Ling

    2011-01-01

    Nuclear accident assessment is one of the bases for emergency decision-making in the situation of nuclear accident in NPP. Usually, the assessment includes accident status and consequence assessment. It is accident status assessment, and its application in emergency decision-making is introduced here. (author)

  1. Program of nuclear criticality safety experiment at JAERI

    International Nuclear Information System (INIS)

    Kobayashi, Iwao; Tachimori, Shoichi; Takeshita, Isao; Suzaki, Takenori; Ohnishi, Nobuaki

    1983-11-01

    JAERI is promoting the nuclear criticality safety research program, in which a new facility for criticality safety experiments (Criticality Safety Experimental Facility : CSEF) is to be built for the experiments with solution fuel. One of the experimental researches is to measure, collect and evaluate the experimental data needed for evaluation of criticality safety of the nuclear fuel cycle facilities. Another research area is a study of the phenomena themselves which are incidental to postulated critical accidents. Investigation of the scale and characteristics of the influences caused by the accident is also included in this research. The result of the conceptual design of CSEF is summarized in this report. (author)

  2. Six Decades of Nuclear Accidents, Nuclear Compensation, and Issues of Radioactive Waste Management

    International Nuclear Information System (INIS)

    Boonsuwan, P.; Songjakkeaw, A.

    2011-11-01

    Thailand has made a serious aim to employ nuclear power by adopting five 1,000 MWt in the 2010 national Power Development Plan (PDP 2010) with the first NPP coming online in 2020. However, after the Fukushima nuclear disaster in March 2011, the National Energy Policy Committee had made the resolution to postpone the plan by 3 years. The post-Fukushima atmosphere does not bode well for the public sentiment towards the proposed programme, especially with regards to safety of an NPP. Nonetheless, during the six decades that NPPs have been in operation in 32 countries worldwide, there are only 19 serious accidents involving fatalities and/or damage to properties in excess of 100 million USD. Out of the three significant accidents - Fukushima nuclear accident (2011), Chernobyl nuclear accident (1986), and Three Miles Island nuclear accident (1979) - only the accident at Three Miles Island occurs during normal operation. Such can be implied that the operation of NPPs does maintain a high level of safety. The current technology on nuclear safety has been advancing greatly to the point that the new NPP design claims to render the possibility of a severe accident resulting in core melting insignificant. Along with the technical improvements, laws and regulations have also be progressing in parallel to adequately compensate and limit the liability of operators in case of a nuclear accident. The international agreements such as the Vienna Convention on Civil Liability for Nuclear Damage and the Convention of the Third Party Liability in the Field of Nuclear Energy had also been established and also the national laws of countries such as the United States and Japan have been implemented to address such issues to the point that victims of a nuclear accidents are adequately and justly compensated. In addition to the issues of nuclear accident, the dilemma in nuclear waste management, especially with regards to the High Level Waste which is highly radioactive while having very

  3. Truck accident involving unirradiated nuclear fuel

    International Nuclear Information System (INIS)

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

    1992-07-01

    In the early morning of Dec. 16, 1991, a severe accident occurred when a passenger vehicle traveling in the wrong direction collided with a tractor trailer carrying 24 nuclear fuel assemblies in 12 containers on Interstate 1-91 in Springfield, Massachusetts. This paper documents the mechanical circumstances of the accident and the physical environment to which the containers were exposed and the response of the containers and their contents. The accident involved four impacts where the truck was struck by the car, impacted on the center guardrail, impacted on the outer concrete barrier and came to rest against the center guardrail. The impacts were followed by a fire that began in the engine compartment, spread to the.tractor and cab, and eventually spread to the trailer and payload. The fire lasted for about three hours and the packages were involved in the fire for about two hours. As a result of the fire, the tractor-trailer was completely destroyed and the packages were exposed to flames with temperatures between 1300 degrees F and 1800 degrees F. The fuel assemblies remained intact during the accident and there was no release of any radioactive material during the accident. This was a very severe accident; however, the injuries were minor and at no time was the public health and safety at risk

  4. Truck accident involving unirradiated nuclear fuel

    International Nuclear Information System (INIS)

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

    1993-01-01

    In the early morning of Dec. 16, 1991, a severe accident occurred when a passenger vehicle traveling in the wrong direction collided with a tractor trailer carrying 24 unirradiated nuclear fuel assemblies in 12 containers on Interstate I-91 in Springfield, Massachusetts. This paper documents the mechanical circumstances of the accident and assesses the physical environment to which the containers were exposed and the response of the containers and their contents. The accident involved four impacts where the truck was struck by the car, impacted on the center guardrail, impacted on the outer concrete barrier and came to rest against the center guardrail. The impacts were followed by a fire that began in the engine compartment, spread to the tractor and cab, and eventually spread to the trailer and payload. The fire lasted for about three hours and the packages were involved in the fire for about two hours. As a result of the fire, the tractor-trailer was completely destroyed and the packages were exposed to flames with temperatures between 1,300 F and 1,800 F. The fuel assemblies remained intact during the accident and there was no release of any radioactive material during the accident. This was a very severe accident; however, the injuries were minor and at no time was the public health and safety at risk

  5. 10 CFR 835.1304 - Nuclear accident dosimetry.

    Science.gov (United States)

    2010-01-01

    ...) Methods and equipment for analysis of biological materials; (3) A system of fixed nuclear accident... Nuclear accident dosimetry. (a) Installations possessing sufficient quantities of fissile material to... 10 Energy 4 2010-01-01 2010-01-01 false Nuclear accident dosimetry. 835.1304 Section 835.1304...

  6. Nuclear accident: dosimetric and medical aspects

    International Nuclear Information System (INIS)

    Oliveira, A.R. de.

    The conservation aspect of the treatment of patients who received whole-body exposure is presented. Such treatment to be started during the first hours after the accident (prodomal phase), as well as the nonconventional measures to be adopted when the critical phase of acute irradiation syndrome is reached. (E.G.) [pt

  7. An analysis on human factor issues in criticality accident at a uranium processing plant. Investigation on human behavior contributing to the criticality accident. Interim report

    International Nuclear Information System (INIS)

    Sasou, Kuonihide; Goda, Hideki; Hirotsu, Yuko

    1999-01-01

    At 10:30 am, September 30th, 1999, a criticality accident occurred in a conversion building of a uranium processing plant in Tokai, Ibaraki prefecture. 69 people including 3 workers who then worked at the building, 3 fire fighters who dispatched to rescue them were exposed to the radiation. People with a 350 m-radius of the site were recommended to evacuate themselves from the region to a temporarily prepared evacuation center. And about one hundred thousand people within a 10 km-radius were also advised to stay inside of their home. Nuclear Safety Commission's Accident Investigation Committee is investigating causes of this accident and have been revealing that deviation from government-authorized processing method and negligence of its illegal procedure had contributed to the accident. The influence of this accident is expanding not only to the plant operating company, local people but also to Japanese nuclear power policy, the whole nuclear industry in Japan. Especially pervasion of 'Safety Culture' is strongly being required. This report analyses latent factors of some human behavior directly contributing to the criticality accident. It also mentions that 4 critical points on the poor climate for safety in the work place, the inadequate safety management, the unsuitable equipment and the production-biased company's policy are the latent factors of this accident. It also finds that the poor climate and the production-biased policy are the most important factors. It can be said that some people directly or indirectly having caused the accident are the victims of them. (author)

  8. Process criticality accident likelihoods, consequences, and emergency planning

    Energy Technology Data Exchange (ETDEWEB)

    McLaughlin, T.P.

    1991-01-01

    Evaluation of criticality accident risks in the processing of significant quantities of fissile materials is both complex and subjective, largely due to the lack of accident statistics. Thus, complying with standards such as ISO 7753 which mandates that the need for an alarm system be evaluated, is also subjective. A review of guidance found in the literature on potential accident magnitudes is presented for different material forms and arrangements. Reasoned arguments are also presented concerning accident prevention and accident likelihoods for these material forms and arrangements. 13 refs., 1 fig., 1 tab.

  9. Nuclear accidents and bone marrow graft

    International Nuclear Information System (INIS)

    Bernard, J.

    1988-01-01

    In case of serious contamination, the only efficacious treatment is the bone marrow grafts. The graft types and conditions have been explained. To restrict the nuclear accidents consequences, it is recommended to: - take osseous medulla of the personnel exposed to radiations and preserve it , that permits to carry out rapidly the auto-graft in case of accidents; - determine, beforehand, the HLA group of the personnel; - to register the voluntary donors names and addresses, and their HLA group, that permits to find easily a compatible donar in case of allo-graft. (author)

  10. Engineering design guidelines for nuclear criticality safety

    International Nuclear Information System (INIS)

    Waltz, W.R.

    1988-08-01

    This document provides general engineering design guidelines specific to nuclear criticality safety for a facility where the potential for a criticality accident exists. The guide is applicable to the design of new SRP/SRL facilities and to major modifications Of existing facilities. The document is intended an: A guide for persons actively engaged in the design process. A resource document for persons charged with design review for adequacy relative to criticality safety. A resource document for facility operating personnel. The guide defines six basic criticality safety design objectives and provides information to assist in accomplishing each objective. The guide in intended to supplement the design requirements relating to criticality safety contained in applicable Department of Energy (DOE) documents. The scope of the guide is limited to engineering design guidelines associated with criticality safety and does not include other areas of the design process, such as: criticality safety analytical methods and modeling, nor requirements for control of the design process

  11. Applications of PRA in nuclear criticality safety

    International Nuclear Information System (INIS)

    McLaughlin, T.P.

    1992-01-01

    Traditionally, criticality accident prevention at Los Alamos National Laboratory (LANL) has been based on a thorough review and understanding of proposed operations or changes to operations involving both process supervision and criticality safety staff. The outcome of this communication was usually an agreement, based on professional judgment, that certain accident sequences were credible and had to be precluded by design; others were incredible and thus did not warrant expenditures to further reduce their likelihood. The extent of documentation was generally in proportion to the complexity of the operation but never as detailed as that associated with quantified risk assessments. During the last 3 yr, nuclear criticality safety-related probabilistic risk assessments (PRAs) have been performed on operations in two LANL facilities. Both of these were conducted in order to better understand the cost/benefit aspects of PRAs as they apply to largely hands-on operations with fissile material

  12. Installation places of criticality accident detectors in the plutonium conversion development facility

    International Nuclear Information System (INIS)

    Sanada, Yukihisa; Tsujimura, Norio; Shimizu, Yoshio; Izaki, Kenji; Furuta, Sadaaki

    2008-01-01

    At the Plutonium Conversion Development Facility (PCDF) in the Nuclear Fuel Cycle Engineering Laboratories, the co-conversion technologies to purify the mixed plutonium and uranium nitrate solution discharged from a reprocessing plant have been developed. The probability of a criticality accident in PCDF is extremely low. However, the criticality accident alarm system (CAAS) has been in place since 1982 to reduce the radiation dose to workers in case of such a rare criticality accident. The CAAS contains criticality accident detector units (CADs), one unit consisting of three plastic scintillation detectors, and using the 2 out of 3 voting system for the purpose of high reliability. Currently, eight CADs are installed in PCDF evaluating the dose using a simple equation allowing for a safety margin. The purpose of this study is to show the determination procedures for the adequate relocation of the CADs which adequately ensures safety in PCDF. (author)

  13. The role of chemistry in nuclear accidents

    International Nuclear Information System (INIS)

    Johnson, C.E.; Johnson, I.

    1986-01-01

    An accurate description of the chemical state of fission products is required for quick response in assessing the impact of nuclide release during a nuclear accident. The chemical state of the fission products is certain to change in response to their local environment. More specifically, fission products released from fuel will change their composition on contact with high-temperature steam, and these changes will determine their behavior with regard to either transport, deposition, aerosol formation, or reaction with structural components. The local oxygen potential is a key parameter in establishing the chemical state of the fission products and their release and transport mechanisms. Knowledge of the relationship of this parameter and thermal hydraulics is needed for prediction of fission product behavior in degraded core accidents. The behavior of key fission products in various stages of an accident, based on experimental results and appropriate calculations founded on fundamental thermodynamic information, will be discussed

  14. State of reaction on news media for JCO criticality accident on abroad

    International Nuclear Information System (INIS)

    Itoh, Takeshi

    1999-01-01

    The criticality accident, which occurred in JCO Tokai on September 30th 1999, was the first accident accompanied with serious radiation exposure to persons at Japanese nuclear facilities. As an evacuation order for local residents was issued, it caused uneasiness to the public. It also gave great impact to the foreign countries. In this report we have investigated the reactions in such countries, as U.S., France, Germany and U.K. by means of news media like TV, newspapers and magazines. Finding are as follows: They were all surprised to know the cause of the accident, which was by improper procedure of JCO workers. Because they couldn't imagine that such an accident might happen in such a high-tech country as Japan. The Japanese regulator was criticized for their insufficient criticality facility surveillance. There arose some questions for Japanese nuclear reliabilities. Because of the delayed announcement of the accident by Japanese public sector, anti-nuclear groups, like Greenpeace, NCI, etc., have a chance to carry on their campaign. The information from Japanese public sector was not enough to satisfy the foreign news media. We concluded that it is also necessary to develop effective information dissemination to overseas in case of a nuclear accident. (author)

  15. Martin Marietta Energy Systems Nuclear Criticality Safety Improvement Program

    International Nuclear Information System (INIS)

    Speas, I.G.

    1987-01-01

    This report addresses questions raised by criticality safety violation at several DOE plants. Two charts are included that define the severity and reporting requirements for the six levels of accidents. A summary is given of all reported criticality incident at the DOE plants involved. The report concludes with Martin Marietta's Nuclear Criticality Safety Policy Statement

  16. Human Factors in Nuclear Reactor Accidents

    International Nuclear Information System (INIS)

    Mustafa, M.E.

    2016-01-01

    While many people would blame nature for the disaster of the “Fukushima Daiichi” accident, experts considered this accident to be also a human-induced disaster. This confirmed the importance of human errors which have been getting a growing interest in the nuclear field after the Three Mile Island accident. Personnel play an important role in design, operation, maintenance, planning, and management. The interface between machine and man is known as a human factor. In the present work, the human factors that have to be considered were discussed. The effect of the control room configuration and equipment design effect on the human behavior was also discussed. Precise reviewing of person’s qualifications and experience was focused. Insufficient training has been a major cause of human error in the nuclear field. The effective training issues were introduced. Avoiding complicated operational processes and non responsive management systems was stressed. Distinguishing between the procedures for normal and emergency operations was emphasised. It was stated that human error during maintenance and testing activities could cause a serious accident. This is because safety systems do not cover much more risk probabilities in the maintenance and testing activities like they do in the normal operation. In nuclear industry, the need for a classification and identification of human errors has been well recognised. As a result of this, human reliability must be assessed. These errors are analyzed by a probabilistic safety assessment which deals with errors in reading, listening and implementing procedures but not with cognitive errors. Much efforts must be accomplished to consider cognitive errors in the probabilistic safety assessment. The ways of collecting human factor data were surveyed. The methods for identifying safe designs, helping decision makers to predict how proposed or current policies will affect safety, and comprehensive understanding of the relationship

  17. Biological and medical consequences of nuclear accidents

    International Nuclear Information System (INIS)

    Latarjet, R.

    1988-01-01

    The study of the medical and biological consequences of the nuclear accidents is a vast program. The Chernobyl accident has caused some thirty deceases: Some of them were rapid and the others occurred after a certain time. The particularity of these deaths was that the irradiation has been associated to burns and traumatisms. The lesson learnt from the Chernobyl accident is to treat the burn and the traumatism before treating the irradiation. Contrary to what the research workers believe, the first wave of deaths has passed between 15 and 35 days and it has not been followed by any others. But the therapeutic lesson drawn from the accident confirm the research workers results; for example: the radioactive doses band that determines where the therapy could be efficacious or not. the medical cares dispensed to the irradiated people in the hospital of Moscow has confirmed that the biochemical equilibrium of proteinic elements of blood has to be maintained, and the transfusion of the purified elements are very important to restore a patient to health, and the sterilization of the medium (room, food, bedding,etc...) of the patient is indispensable. Therefore, it is necessary to establish an international cooperation for providing enough sterilized rooms and specialists in the irradiation treatment. The genetic consequences and cancers from the Chernobyl accident have been discussed. It is impossible to detect these consequences because of their negligible percentages. (author)

  18. Prevention of the causes and consequences of a criticality accident - measures adopted in France

    International Nuclear Information System (INIS)

    Fruchard, Y.; Lavie, J.M.

    1966-01-01

    The question of safety in regard to criticality accident risks has two aspects: prevention of the cause and limitation of the consequences. These two aspects are closely connected. The effort devoted to prevention of the causes depends on the seriousness of the possible human psychologic and economic consequences of the accident. The criticality accidents which have occurred in the nuclear industry, though few in number, do reveal the imperfect nature of the techniques adopted to prevent the causes, and also constitute the only available realistic basis for evaluating the consequences and developing measures to limit them. The authors give a analysis of the known causes and consequences of past criticality accidents and on this basis make a number of comments concerning: the validity of traditional safety criteria, the probability of accidents for different types of operations, characteristic accidents which can serve as models, and the extent of possible radiological consequences. The measures adopted in France to limit the consequences of a possible criticality accident under the headings: location, design and lay-out of the installations, accident detection, and dosimetry for the exposed personnel, are briefly described after a short account of the criteria used in deciding on them. (author) [fr

  19. Environmental consequences of releases from nuclear accidents

    International Nuclear Information System (INIS)

    Tveten, U.

    1990-01-01

    The primary purpose of this report is to present the results of a four-year Nordic cooperation program in the area of consequence assessment of nuclear accidents with large releases to the environment. This program was completed in 1989. Related information from other research programs has also been described, so that many chapters of the report reflect the current status in the respective areas, in addition to containing the results of the Nordic program. (author) 179 refs

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

    International Nuclear Information System (INIS)

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

    1990-01-01

    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

  1. Applicability of simplified methods to evaluate consequences of criticality accident using past accident data

    International Nuclear Information System (INIS)

    Nakajima, Ken

    2003-01-01

    Applicability of four simplified methods to evaluate the consequences of criticality accident was investigated. Fissions in the initial burst and total fissions were evaluated using the simplified methods and those results were compared with the past accident data. The simplified methods give the number of fissions in the initial burst as a function of solution volume; however the accident data did not show such tendency. This would be caused by the lack of accident data for the initial burst with high accuracy. For total fissions, simplified almost reproduced the upper envelope of the accidents. However several accidents, which were beyond the applicable conditions, resulted in the larger total fissions than the evaluations. In particular, the Tokai-mura accident in 1999 gave in the largest total specific fissions, because the activation of cooling system brought the relatively high power for a long time. (author)

  2. Applications of PRA in nuclear criticality safety

    International Nuclear Information System (INIS)

    McLaughlin, T.P.

    1992-01-01

    Traditionally, criticality accident prevention at Los Alamos has been based on a thorough review and understanding of proposed operations of changes to operations, involving both process supervision and criticality safety staff. The outcome of this communication was usually an agreement, based on professional judgement, that certain accident sequences were credible and had to be reduced in likelihood either by administrative controls or by equipment design and others were not credible, and thus did not warrant expenditures to further reduce their likelihood. The extent of analysis and documentation was generally in proportion to the complexity of the operation but did not include quantified risk assessments. During the last three years nuclear criticality safety related Probabilistic Risk Assessments (PRAs) have been preformed on operations in two Los Alamos facilities. Both of these were conducted in order to better understand the cost/benefit aspects of PRA's as they apply to largely ''hands-on'' operations with fissile material for which human errors or equipment failures significant to criticality safety are both rare and unique. Based on these two applications and an appreciation of the historical criticality accident record (frequency and consequences) it is apparent that quantified risk assessments should be performed very selectively

  3. Agricultural implications of the Fukushima nuclear accident

    International Nuclear Information System (INIS)

    Nakanishi, Tomoko M.; Tanoi, Keitaro

    2013-01-01

    Since the Fukushima Daiichi nuclear power plant accident in March 2011, contamination of places and foods has been a matter of concern. Unfortunately, agricultural producers have few sources of information and have had to rely on the lessons from the Chernobyl accident in 1986 or on information obtained from the International Atomic Energy Agency. However, as of this writing, data on the specific consequences of the Fukushima accident on Japanese agriculture remain limited. More than 80% of the land that suffered from the accident was related to agriculture or was in forests and meadows. The in fluence of the accident on agriculture was the most difficult to study because the activity in nature had to be dealt with. For example, when contaminated rice is harvested, scientists working on rice plants and soils and the study of watercourses or mountains have to collaborate to analyze or determine the vehicle by which the radioactivity accumulated and through which it spread in nature. At the request of agriculturists in Fukushima, we at the Graduate School of Agricultural and Life Sciences at The University of Tokyo have been urgently collecting reliable data on the contamination of soil, plants, milk, and crops. Based on our data, we would like to comment on or propose an effective way of resuming agricultural activity. Because obtaining research results based on in situ experiments is time-consuming, we have been periodically holding research report meetings at our university every 3-4 months for lay people, showing them how the contamination situation has changed or what type of effect can be estimated. Although our research is still ongoing, we would like to summarize in this book our observations made during the one and a half years after the accident. (author)

  4. Criticality Calculations for a Typical Nuclear Fuel Fabrication Plant with Low Enriched Uranium

    International Nuclear Information System (INIS)

    Elsayed, Hade; Nagy, Mohamed; Agamy, Said; Shaat, Mohmaed

    2013-01-01

    The operations with the fissile materials such as U 235 introduce the risk of a criticality accident that may be lethal to nearby personnel and can lead the facility to shutdown. Therefore, the prevention of a nuclear criticality accident should play a major role in the design of a nuclear facility. The objectives of criticality safety are to prevent a self-sustained nuclear chain reaction and to minimize the consequences. Sixty criticality accidents were occurred in the world. These are accidents divided into two categories, 22 accidents occurred in process facilities and 38 accidents occurred during critical experiments or operations with research reactor. About 21 criticality accidents including Japan Nuclear Fuel Conversion Co. (JCO) accident took place with fuel solution or slurry and only one accident occurred with metal fuel. In this study the nuclear criticality calculations have been performed for a typical nuclear fuel fabrication plant producing nuclear fuel elements for nuclear research reactors with low enriched uranium up to 20%. The calculations were performed for both normal and abnormal operation conditions. The effective multiplication factor (k eff ) during the nuclear fuel fabrication process (Uranium hexafluoride - Ammonium Diuranate conversion process) was determined. Several accident scenarios were postulated and the criticalities of these accidents were evaluated. The computer code MCNP-4B which based on Monte Carlo method was used to calculate neutron multiplication factor. The criticality calculations Monte Carlo method was used to calculate neutron multiplication factor. The criticality calculations were performed for the cases of, change of moderator to fuel ratio, solution density and concentration of the solute in order to prevent or mitigate criticality accidents during the nuclear fuel fabrication process. The calculation results are analyzed and discussed

  5. Bayesian methods for chromosome dosimetry following a criticality accident

    International Nuclear Information System (INIS)

    Brame, R.S.; Groer, P.G.

    2003-01-01

    Radiation doses received during a criticality accident will be from a combination of fission spectrum neutrons and gamma rays. It is desirable to estimate the total dose, as well as the neutron and gamma doses. Present methods for dose estimation with chromosome aberrations after a criticality accident use point estimates of the neutron to gamma dose ratio obtained from personnel dosemeters and/or accident reconstruction calculations. In this paper a Bayesian approach to dose estimation with chromosome aberrations is developed that allows the uncertainty of the dose ratio to be considered. Posterior probability densities for the total and the neutron and gamma doses were derived. (author)

  6. Detection of criticality accidents. The Intertechnique EDAC II system

    International Nuclear Information System (INIS)

    Prigent, R.

    1991-01-01

    The chief aim of the new generation of EDAC II criticality accidents detection system is to reduce the risks associated to the handling of fissile material by providing a swift and safe warning of the development of any criticality accident. To this function already devolving on the EDAC system of the previous generation, the EDAC II adds the possibility of storing in memory the characteristics of the accident, providing a daily follow-up of the striking events in the system through the print-out of a log book and providing assistance to the operators during the periodical tests. (Author)

  7. Research investigation report on Fukushima Daiichi nuclear accident

    International Nuclear Information System (INIS)

    2012-03-01

    This report was issued in February 2012 by Rebuild Japan Initiative Foundation's Independent Investigation Commission on the Fukushima Daiichi Nuclear Accident, which consisted of six members from the private sector in independent positions and with no direct interest in the business of promoting nuclear power. Commission aimed to determine the truth behind the accident by clarifying the various problems and reveal systematic problems behind these issues so as to create a new starting point by identifying clear lessons learned. Report composed of four chapters; (1) progression of Fukushima accident and resulting damage (accident management after Fukushima accident, and effects and countermeasure of radioactive materials discharged into the environment), (2) response against Fukushima accident (emergency response of cabinet office against nuclear disaster, risk communication and on-site response against nuclear disaster), (3) analysis of historical and structural factors (technical philosophy of nuclear safety, problems of nuclear safety regulation of Fukushima accident, safety regulatory governance and social background of 'Safety Myth'), (4) Global Context (implication in nuclear security, Japan in nuclear safety regime, U.S.-Japan relations for response against Fukushima accident, lessons learned from Fukushima accident - aiming at creation of resilience). Report could identify causes of Fukushima accident and factors related to resulting damages, show the realities behind failure to prevent the spread of damage, and analyze the overall structural and historical background behind the accidents. (T. Tanaka)

  8. A description of nuclear reactor accidents and their consequences

    International Nuclear Information System (INIS)

    Murray, A.

    1989-01-01

    Nuclear reactor accidents which have caused core damage, released a significant amount of radioactivity, or caused death or serious injury are described. The reactor accidents discussed in detail include Chernobyl, Three Mile Island, SL-1 and Windscale, although information on other less consequential accidents is also provided. The consequences of these accidents are examined in terms of the amounts of radioactivity released, the radiation doses received, and remedial actions and interventions taken following the accident. 10 refs., 1 fig., 2 tabs

  9. Nuclear ship accidents, description and analysis

    International Nuclear Information System (INIS)

    Oelgaard, P.L.

    1993-03-01

    In this report available information on 44 reported nuclear ship events is considered. Of these 6 deals with U.S. ships and 38 with USSR ships. The ships are in almost all cases nuclear submarines. Only events that involve the sinking of vessels, the nuclear propulsion plants, radiation exposures, fires/ explosions, sea-water leaks into the submarines and sinking of vessels are considered. Comments are made on each of the events, and at the end of the report an attempt is made to point out the weaknesses of the submarine designs which have resulted in the accidents. It is emphasized that some of the information of which this report is based, may be of dubious nature. Consequently some of the results of the assessments made may not be correct. (au)

  10. Consequences of severe nuclear accidents in Europe

    Science.gov (United States)

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

    2013-04-01

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

  11. Neutron personal dosimetry in criticality accidents

    International Nuclear Information System (INIS)

    Fonseca, E.S. da; Mauricio, C.L.P.

    1996-01-01

    In the present work an innovating method is proposed to estimate the absorbed dose received by individuals irradiated with neutrons in an accident, even in the case that the victim is not using any kind of neutron dosemeter. The method combines direct measurements of 24 Na and 32 P activated in the human body. The calculation method was developed using data taken from previously published papers and experimental measurements. Other irradiations results in different neutron spectra prove the validity of the method here proposed. Using a whole body counter to measure 24 Na activity, it is possible to evaluate neutron absorbed doses in the order of 140 μ Gy of very soft (thermal) spectra. For fast neutron fields, the lower limit for neutron dose detection increases, but the present method continues to be very useful in accidents, with higher neutron doses. (author)

  12. Nuclear industry after the Fukushima accident

    International Nuclear Information System (INIS)

    Branche, Thomas; Billes-Garabedian, Laurent; Salha, Bernard; Behar, Christophe; Dupuis, Marie-Claude; Labalette, Thibaud; Lagarde, Dominique; Planchais, Bernard; West, Jean-Pierre; Stubler, Jerome; Lancia, Bruno; Machenaud, Herve; Einaudi, Andre; Anglaret, Philippe; Brachet, Yves; Bonnave, Philippe; Knoche, Philippe; Gasquet, Denis

    2013-01-01

    This special dossier about the situation of nuclear industry two years after the Fukushima accident comprises 15 contributions dealing with: the nuclear industry two years after the Fukushima accident (Bernard Salha); a low-carbon electricity at a reasonable cost (Christophe Behar); nuclear engineering has to gain even more efficiency (Thomas Branche); how to dispose off the most radioactive wastes (Marie-Claude Dupuis, Thibaud Labalette); ensuring the continuation for more than 40 years onward (Denis Gasquet); developing and investing in the future (Philippe Knoche); more than just signing contracts (Dominique Lagarde); immersed power plants, an innovative concept (Bernard Planchais); R and D as a source of innovation for safety and performances (Jean-Pierre West); dismantlement, a very long term market (Jerome Stubler, Bruno Lancia); a reference industrial model (Herve Machenaud); recruiting and training (Andre Einaudi); a diversity of modern reactors and a world market in rebirth (Philippe Anglaret); an industrial revolution is necessary (Yves Brachet); contracts adapted to sensible works (Philippe Bonnave)

  13. Calculation code used in criticality analyses for the accident of JCO precipitation tank

    International Nuclear Information System (INIS)

    Miyoshi, Yoshinori

    2000-01-01

    In order to evaluate nuclear features on criticality accident formed at the nuclear fuel processing facility in Tokai Works of the JCO, Ltd. (JCO), in Tokai-mura, Ibaraki prefecture, dynamic analyses to calculate output change after occurring the accident as well as criticality analyses to calculate reactivity added to precipitation tank, were carried out according to scenario on accident formation. For the criticality analyses, a continuous energy Monte Carlo code MCNP was used to carry out calculation of reactivity fed into the precipitation tank as correctly as possible. And, SRAC code system was used for calculation on temperature and void reactivity coefficients, effective delayed neutron ratio beta eff , and instantaneous neutron generation time required for parameters controlling transition features at criticality accident. In addition, for the dynamic analyses, because of necessity of considering on volume expansion of solution fuels used as exothermic body and radiation decomposition gas forming into solution, output behavior, numbers of nuclear fission, and so forth at initial burst portion were calculated by using TRACE and quasi-regular code, at a center of AGNES-2 promoting on its development in JAERI. Here were reported on outlines and an analysis example on calculation code using for the nuclear features evaluation. (G.K.)

  14. Chernobyl and the problem of international obligations regarding nuclear accidents

    International Nuclear Information System (INIS)

    Strohl, P.

    1988-01-01

    This paper analyses the way nuclear law was put to the test by the Chernobyl accident - in particular international nuclear law - so as to propose a train of thought which might contribute to adopting and revising the legal system presently in force or even new orientations. It deals only with that part of nuclear law which concerns accidents and their consequences (NEA) [fr

  15. Risks of potential accidents of nuclear power plants in Europe

    NARCIS (Netherlands)

    Slaper H; Eggink GJ; Blaauboer RO

    1993-01-01

    Over 200 nuclear power plants for commercial electricity production are presently operational in Europe. The 1986 accident with the nuclear power plant in Chernobyl has shown that severe accidents with a nuclear power plant can lead to a large scale contamination of Europe. This report is focussed

  16. Study of Iodine Prophylaxis Following Nuclear Accidents

    International Nuclear Information System (INIS)

    Sri Widayati; Tedjasari, R. S.; Elfida

    2007-01-01

    Study of iodine prophylaxis following nuclear accidents has been done. Giving stable iodine to a population exposed by I-131 is one of preventive action from internal radiation to the thyroid gland. Stable iodine could be given as Kl tablet in a range of dose of 30 mg/day to 130 mg/day. Improper giving of stable iodine could cause side effect to health, so then some factors should be considered i. e. dose estimation, age, dose of stable iodine to be given, duration of stable iodine prophylaxis and risk of health. (author)

  17. NIRS report of the criticality accident in a uranium conversion test plant in Tokai-mura

    International Nuclear Information System (INIS)

    2001-01-01

    This report is a detailed account of the roles that National Institute of Radiological Sciences (NIRS) played at the criticality accident in the title, which occurred at around 10:35, on Sep. 30, 1999 and resulted in death of two workers after all, and is published to discharge NIRS responsibilities in regards to the accident. The accident caused many residents concern on their health and rumors had both social and economic consequences. The report involves chapters of detailed outline of the accident; demand for acceptance of the victims and communications until the identification of the criticality'' accident; the acceptance and initial treatment; the exposure dose estimation (based on acute symptoms, on physics, on chromosomal analyses and on neutron-activated dental metals, and detailed analyses for dose distribution); decision made for therapeutic strategies; cooperation with the Network Council for Radiation Emergency and with other medical facilities; the urgent import of medicine; treatment and processes (patients, nursing system and radiation injuries); radiation protection in medical facilities; response to nearby residents of the Plant; international response; press release; Uranium Processing Plant Criticality Accident Investigation Committee and the Health Management Committee organized by the Nuclear Safety Commission; handling of information; and radiation emergency medical preparedness at the NIRS (future issues and prospect). The report is hopefully useful in preventing the occurrence of future accidents. (N.I.)

  18. Nuclear power plant Severe Accident Research Plan

    International Nuclear Information System (INIS)

    Larkins, J.T.; Cunningham, M.A.

    1983-01-01

    The Severe Accident Research Plan (SARP) will provide technical information necessary to support regulatory decisions in the severe accident area for existing or planned nuclear power plants, and covers research for the time period of January 1982 through January 1986. SARP will develop generic bases to determine how safe the plants are and where and how their level of safety ought to be improved. The analysis to address these issues will be performed using improved probabilistic risk assessment methodology, as benchmarked to more exact data and analysis. There are thirteen program elements in the plan and the work is phased in two parts, with the first phase being completed in early 1984, at which time an assessment will be made whether or not any major changes will be recommended to the Commission for operating plants to handle severe accidents. Additionally at this time, all of the thirteen program elements in Chapter 5 will be reviewed and assessed in terms of how much additional work is necessary and where major impacts in probabilistic risk assessment might be achieved. Confirmatory research will be carried out in phase II to provide additional assurance on the appropriateness of phase I decisions. Most of this work will be concluded by early 1986

  19. Proposal optimization in nuclear accident emergency decision based on IAHP

    International Nuclear Information System (INIS)

    Xin Jing

    2007-01-01

    On the basis of establishing the multi-layer structure of nuclear accident emergency decision, several decision objectives are synthetically analyzed, and an optimization model of decision proposals for nuclear accident emergency based on interval analytic hierarchy process is proposed in the paper. The model makes comparisons among several emergency decision proposals quantified, and the optimum proposal is selected out, which solved the uncertain and fuzzy decision problem of judgments by experts' experiences in nuclear accidents emergency decision. Case study shows that the optimization result is much more reasonable, objective and reliable than subjective judgments, and it could be decision references for nuclear accident emergency. (authors)

  20. International nuclear accident dosimetry intercomparison: results of Czech participation

    International Nuclear Information System (INIS)

    Spurny, F.; Votockova, I.

    1996-01-01

    An international intercomparison scheme for criticality accident dosimetry systems took place at the SILENE reactor, Valduc, France in June 1993. The dosemeters were exposed both on phantoms and in free air to radiation from the reactor, both shielded by lead and bare. The results obtained during this event by Czech participants are presented and compared with the average values obtained by the complete group of participants and with the reference values. The systems used consisted mostly of Si-diodes and thermoluminescent detectors, some supporting measurements were performed with solid state nuclear track detectors and using the albedo principle. The agreement between the data sets is very good. 7 tabs., 13 refs

  1. Economic risks of nuclear power reactor accidents

    International Nuclear Information System (INIS)

    Burke, R.P.; Aldrich, D.C.

    1984-04-01

    Models to be used for analyses of economic risks from events which occur during US LWR plant operation are developed in this study. The models include capabilities to estimate both onsite and offsite costs of LWR events ranging from routine plant forced outages to severe core-melt accidents resulting in large releases of radioactive material to the environment. The models have been developed for potential use by both the nuclear power industry and regulatory agencies in cost/benefit analyses for decision-making purposes. The new onsite cost models estimate societal losses from power production cost increases, plant capital losses, plant decontamination costs, and plant repair costs which may be incurred after LWR operational events. Early decommissioning costs, plant worker health impact costs, electric utility business costs, nuclear power industry costs, and litigation costs are also addressed. The newly developed offsite economic consequence models estimate The costs of post-accident population protective measures and public health impacts. The costs of population evacuation and temporary relocation, agricultural product disposal, land and property decontamination, and land interdiction are included in the economic models for population protective measures. Costs of health impacts and medical care costs are also included in the models

  2. Severe accidents at nuclear power plants. Their risk assessment and accident management

    International Nuclear Information System (INIS)

    Abe, Kiyoharu.

    1995-05-01

    This document is to explain the severe accident issues. Severe Accidents are defined as accidents which are far beyond the design basis and result in severe damage of the core. Accidents at Three Mild Island in USA and at Chernobyl in former Soviet Union are examples of severe accidents. The causes and progressions of the accidents as well as the actions taken are described. Probabilistic Safety Assessment (PSA) is a method to estimate the risk of severe accidents at nuclear reactors. The methodology for PSA is briefly described and current status on its application to safety related issues is introduced. The acceptability of the risks which inherently accompany every technology is then discussed. Finally, provision of accident management in Japan is introduced, including the description of accident management measures proposed for BWRs and PWRs. (author)

  3. Accident at the Three Mile Island Nuclear Power Plant

    International Nuclear Information System (INIS)

    Bajusz, J.; Vamos, G.

    1979-01-01

    A short description of the TMI power plant is given. The course of events leading to the reactor accident and that of the first two weeks is described. The effect on the environment is estimated. The reasons and consequences of the accident are analysed. The probability of such an accident at the Paks Nuclear Power Plant is estimated. (R.J.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-01-15

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

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

    Science.gov (United States)

    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. Evaluation of coverage of enriched UF6 cylinder storage lots by existing criticality accident alarms

    International Nuclear Information System (INIS)

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

    1995-03-01

    The Portsmouth Gaseous Diffusion Plant (PORTS) is leased from the US Department of Energy (DOE) by the United States Enrichment Corporation (USEC), a government corporation formed in 1993. PORTS is in transition from regulation by DOE to regulation by the Nuclear Regulatory Commission (NRC). One regulation is 10 CFR Part 76.89, which requires that criticality alarm systems be provided for the site. PORTS originally installed criticality accident alarm systems in all building for which nuclear criticality accidents were credible. Currently, however, alarm systems are not installed in the enriched uranium hexafluoride (UF 6 ) cylinder storage lots. This report analyzes and documents the extent to which enriched UF 6 cylinder storage lots at PORTS are covered by criticality detectors and alarms currently installed in adjacent buildings. Monte Carlo calculations are performed on simplified models of the cylinder storage lots and adjacent buildings. The storage lots modelled are X-745B, X-745C, X745D, X-745E, and X-745F. The criticality detectors modelled are located in building X-343, the building X-344A/X-342A complex, and portions of building X-330 (see Figures 1 and 2). These criticality detectors are those located closest to the cylinder storage lots. Results of this analysis indicate that the existing criticality detectors currently installed at PORTS are largely ineffective in detecting neutron radiation from criticality accidents in most of the cylinder storage lots at PORTS, except sometimes along portions of their peripheries

  7. Program for rapid dose assessment in criticality accident, RADAPAS

    International Nuclear Information System (INIS)

    Takahashi, Fumiaki

    2006-09-01

    In a criticality accident, a person near fissile material can receive extremely high dose which can cause acute health effect. For such a case, medical treatment should be carried out for the exposed person, according to severity of the exposure. Then, radiation dose should be rapidly assessed soon after an outbreak of an accident. Dose assessment based upon the quantity of induced 24 Na in human body through neutron exposure is expected as one of useful dosimetry techniques in a criticality accident. A dose assessment program, called RADAPAS (RApid Dose Assessment Program from Activated Sodium in Criticality Accidents), was therefore developed to assess rapidly radiation dose to exposed persons from activity of induced 24 Na. RADAPAS consists of two parts; one is a database part and the other is a part for execution of dose calculation. The database contains data compendiums of energy spectra and dose conversion coefficients from specific activity of 24 Na induced in human body, which had been derived in a previous analysis using Monte Carlo calculation code. Information for criticality configuration or characteristics of radiation in the accident field is to be interactively given with interface displays in the dose calculation. RADAPAS can rapidly derive radiation dose to the exposed person from the given information and measured 24 Na specific activity by using the conversion coefficient in database. This report describes data for dose conversions and dose calculation in RADAPAS and explains how to use the program. (author)

  8. Study Of Severe Accident Phenomena In Nuclear Power Plant

    International Nuclear Information System (INIS)

    Sugiyanto; Antariksawan; Anhar, R.; Arifal

    2001-01-01

    Several phenomena that occurred in the light water reactor type of nuclear power plant during severe accident were studied. The study was carried out based on the results of severe accident researches in various countries. In general, severe accident phenomena can be classified into in-vessel phenomena, retention in the reactor coolant system, and ex-vessel phenomena. In-vessel retention has been recommended as a severe accident management strategy

  9. Dose evaluation on the basis of {sup 24}Na activity in the human body for the criticality accident at JCO Tokai nuclear fuel processing plant

    Energy Technology Data Exchange (ETDEWEB)

    Momose, T.; Tsujimura, N.; Tasaki, T.; Kanai, K.; Hayashi, N.; Shinohara, K. [Japan Nuclear Cycle Development Inst., Tokai, Ibaraki (Japan)

    2000-07-01

    Sodium-24({sup 24}Na) generated in human body due to neutron activation was measured by whole body counter (WBC) in JNC Tokai works. Total 148 persons (JCO employees and contractor, public member, fire fighters, etc.) were measured and {sup 24}Na was detected in the 62 persons. Neutron energy spectrum around the facility was calculated using ANISN and MCNP code and estimated mean capture probability {xi} of neutron for human body at this accident was around 0.25-0.28 at any distance from the center of the precipitation tank. Effective dose equivalent for the 62 persons were estimated based on the calculated conversion factors from {sup 24}Na specific activity to neutron dose. Maximum {sup 24}Na activity was 7.7 kBq (83 Bq({sup 24}Na)/g({sup 23}Na)) in total body and the evaluated effective dose equivalent was 47 mSv. (author)

  10. Compensation for damages in case of a nuclear accident

    International Nuclear Information System (INIS)

    Leger, M.

    2011-01-01

    This article presents the system of compensation for damages in case of a nuclear accident. This system of civil liability for nuclear damage, as a specific regime, departs on several points from the common rules of civil liability, in order to provide an adequate and equitable compensation for the damages suffered by the victims of nuclear accidents. The French system of civil liability for nuclear damage results from two International Conventions integrated in French law (Paris convention 1960 and Brussels convention 1963) and the French law of 1968, October 30 on civil liability in the area of nuclear energy. These texts define the conditions under which a nuclear operator could be held liable in case of a nuclear accident. The protocols to amend the Paris and Brussels Conventions of 2004, not yet come into force, are also presented. They ensure that increased resources are available to compensate a greater number of victims of a nuclear accident. (author)

  11. Nuclear data for criticality safety

    International Nuclear Information System (INIS)

    Westfall, R.M.

    1994-01-01

    A brief overview is presented on emerging requirements for new criticality safety analyses arising from applications involving nuclear waste management, facility remediation, and the storage of nuclear weapons components. A derivation of criticality analyses from the specifications of national consensus standards is given. These analyses, both static and dynamic, define the needs for nuclear data. Integral data, used primarily for analytical validation, and differential data, used in performing the analyses, are listed, along with desirable margins of uncertainty. Examples are given of needs for additional data to address systems having intermediate neutron energy spectra and/or containing nuclides of intermediate mass number

  12. Community response against the nuclear accident. Confusion in Sweden after the Chernobyl nuclear accident and its features

    International Nuclear Information System (INIS)

    Sato, Yoshihiro

    2014-01-01

    The Chernobyl nuclear accident, which occurred in April 1986, became popular in Sweden after two days, and Sweden was hit by a big mess immediately after that. This paper introduces various actions taken in Sweden at that time. The authors analyzed the situation based on the following materials to tell the situation at that time: (1) materials summarized by researchers upon request of the administrative organs of the country, (2) two diaries that were written by Sven Aner, who was a former reporter of a major daily newspaper published after the accident and an activist of antinuclear groups, and Sven Lofvegerg, who handled the accident as a technical officer at Radiation Protection Agency, and (3) newspaper articles at that time. The situations that was revealed after the accident were summarized from the following viewpoints: (1) governmental remarks toward safety standards and effects on residents, and the anxiety of residents, (2) grazing ban on livestock as an important industry and its lifting, (3) correspondence of antinuclear activists, (4) anxiety against the effects of radiation on humans, and counseling on the safety addressed to the Headquarters for Disaster Control, (5) roles of regional radio stations, (6) defects of bureaucracy, (7) criticism against the actions of the Headquarters for Disaster Control, and (8) influence of extreme experts. (A.O.)

  13. Evaluation of the influences of nuclear accident by hedonic approach

    International Nuclear Information System (INIS)

    Takai, Toru

    2005-01-01

    The purpose of this sturdy is to examine the influences on residential land prices of criticality accident in Tokai-mura. To clarify the influences, three types of hedonic model are used to estimate land prices around JCO before and after the accident. The result of estimation indicates that land prices decreased according to proximity to JCO after the accident. (author)

  14. Prevention of criticality accidents in a fuel cycle plant

    International Nuclear Information System (INIS)

    Gatti, A.M.; Canavese, S.I.; Capadona, N.M.

    1990-01-01

    This work reports the basic considerations on criticality accidents applied to an uranium dioxide fuel cycle production plant. The different fabrication stages are briefly described, with the identification of the neutronically isolated areas. Once the areas have been defined, an evaluation is made, setting up the control parameters to be used in each of them and their variation ranges; normal operation limitations based on experimental data or validating calculations, applied specifically to 5% enriched uranium, are established. Afterwards, defined parameters deviations are analyzed due to incidental conditions in order to prevent criticality accidents under normal conditions and maintenance operations. (Author) [es

  15. New approach to managing nuclear criticality risk at Nuclear Fuel Services, Inc

    International Nuclear Information System (INIS)

    Green, R.; Droke, R.; Paine, D.

    1992-01-01

    The negative aspects of having a nuclear criticality accident at a fuel fabrication facility have substantially increased in recent years. Although ensuring that the facility is designed and operating in a critically safe manner is a high management priority, practices of managing the risk of a criticality accident have not significantly changed. The method of evaluating risk based on quantitative analysis can enable management to adapt to the increased consequences of a nuclear criticality accident. Additional controls may be placed on high-risk areas within a facility to ensure safe operation of the plant. Areas where controls are in place that impede the productivity of the facility and have negligible impact on criticality safety may be removed or replaced. Management can also streamline the safety analysis efforts applied to facility upgrades by demonstrating that proposed design changes do not compromise criticality safety. Future expansion of quantitative analysis techniques will also allow risk-based management decisions on industrial, radiological, and environmental safety

  16. 25 years since Chernobyl nuclear accident

    International Nuclear Information System (INIS)

    Chiosila, Ion; Gheorghe, Raluca; Simion, Elena

    2011-01-01

    Environmental and food radioactivity surveillance in Romania, begun since the early 60's, with 47 laboratories from National Environment Radioactivity Surveillance Network (NERSN) in the framework of Ministry of Environmental and the network of 21 Radiation Hygiene Laboratories (RHL) from centers and institutes of the Ministry of Public Health. The surveillance was conducted by global beta and alpha measurements, necessary to make some quick decisions as well as gamma spectrometry to detect high and low resolution profile accident. Thus the two networks together and some departmental labs recorded from the first moments (since April 30, 1986) the presence of the contaminated radioactive cloud originated from Ukraine, after the nuclear accident on 26 April 1986 at Chernobyl NPP, on the Romanian territory. NERSN followed up the radioactive contamination of air (gamma dose rate, atmospheric aerosols and total deposition), surface water, uncultivated soil, and spontaneous vegetation while the RHL monitored the drinking water and food. Early notification of this event allowed local and central authorities to take protective measures like: administration of stable iodine, advertisements in media on avoiding consumption of heavily contaminated food, prohibition of certain events that took place outdoors, interdiction of drinking milk and eating milk products for one month long. Most radionuclides, fission and activation products (22 radionuclides), released during the accident, have been determined in the environmental factors. A special attention was paid to radionuclides like Sr-90, I-131, Cs-134 and Cs-137, especially in aerosol samples, where the maximum values were recorded on Toaca Peak (Ceahlau Mountain) on May, the first, 1986: 103 Bq/m 3 , I-131, 63 Bq/m 3 , Cs-137. The highest value of I-131 in drinking water, 21 Bq/l, was achieved on May, the third, 1986 in Bucharest and in cow milk exceeded the value of 3000 Bq/l. For sheep milk some sporadic values exceeding

  17. The report of the criticality accident in a uranium conversion test plant in Tokai-mura

    International Nuclear Information System (INIS)

    Murata, Hajime; Akashi, Makoto

    2002-03-01

    The criticality accident in the title occurred at around 10:35, on Sep. 30, 1999, cost the lives of two workers and caused many residents concern on their health. Moreover, rumors had both social and economic consequences. This report is a detailed account of the roles that many individuals and groups in the National Institute of Radiological Sciences (NIRS) performed in a range of the areas, and is published to discharge NIRS responsibilities in regards to the accident. The report involves chapters of detailed outline of the accident; acceptance of the victims and communications until the identification of the ''criticality'' accident; initial treatment; dose estimation (medical, hematological, physical and biological ones and that by dental metals activated by the neutron); decision making for therapeutic strategies; cooperation with the Network Council for Radiation Emergency Medicine and other medical facilities; emergency importation of medical supplies; treatment and progress (nursing system and radiation injuries); protection from radiation in medical facilities; response to nearby residents of the Plant; international response; press release; Uranium Processing Plant Criticality Accident Investigation Committee and the Health Management Committee organized by the Nuclear Safety Commission; handling of information; and radiation emergency medical preparedness at the NIRS (future issues and prospect). The report is hoped to be useful in preventing the occurrence of future accidents. (K.H.)

  18. Severe accidents and nuclear containment integrity (SANCY). SANCY summary report

    Energy Technology Data Exchange (ETDEWEB)

    Lindholm, I. [VTT Processes, Espoo (Finland)

    2004-07-01

    SANCY project investigates physical phenomena related to severe nuclear accidents with importance to Finnish nuclear power plants. Currently the major topics are the ex-vessel coolability issues, long-term severe accident management and containment leak tightness and adoption and development of new calculation tools considering also the needs of the future Olkiluoto 3 plant. SANCY employs both experimental and analytical methods. (orig.)

  19. STACY and TRACY: nuclear criticality experimental facilities under construction

    International Nuclear Information System (INIS)

    Kobayashi, I.; Takeshita, I.; Yanagisawa, H.; Tsujino, T.

    1992-01-01

    Japan Atomic Energy Research Institute is constructing a Nuclear Fuel Cycle Safety Engineering Research Facility, NUCEF, where the following research themes essential for evaluating safety problems relating to back-end technology in nuclear fuel cycle facilities will be studied: nuclear criticality safety research; research on advanced reprocessing processes and partitioning; and research on transuranic waste treatment and disposal. To perform nuclear criticality safety research related to the reprocessing of light water reactor spent fuels, two criticality experimental facilities, STACY and TRACY, are under construction. STACY (Static Criticality Facility) will be used for the study of criticality conditions of solution fuels, uranium, plutonium and their mixtures. TRACY (Transient Criticality Facility) will be used to investigate criticality accident phenomena with uranium solutions. The construction progress and experimental programmes are described in this Paper. (author)

  20. A second simulated criticality accident dosimetry experiment

    CERN Document Server

    Adams, N

    1973-01-01

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

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

    International Nuclear Information System (INIS)

    Miljanic, S.; Zorko, B.; Gregori, B.; Knezevic, Z.

    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 Boskovic Inst. (RBI), Croatia, Jozef Stefan Inst. (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: 7 LiF (TLD-700), CaF 2 :Mn and Al2 O3 :Mg,Y - all from RBI; CaF 2 :Mn from JSI and 7 LiF (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. (authors)

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

    Science.gov (United States)

    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.

  3. Are the French authorities beginning to prepare for nuclear accident?

    International Nuclear Information System (INIS)

    Autret, J.C.

    2008-01-01

    This article, published in issue 80 of 'l'ACROnique du nucleaire', aims to retrace the early steps in the consideration of the possibility of a nuclear accident in France, with the inclusion of 'non-institutional' participants and applying the lessons learned in Belarus in the contaminated territories around the Chernobyl nuclear power plant. After a review of the origin of the involvement of the Association pour le Controle de la Radioactivite dans l'Ouest (ACRO) in addressing post-accident issues alongside the populations living in an environment polluted by radioactivity, it discusses, from the critical viewpoint of an NGO, the context and the working method adopted for this examination. This is followed by some key elements of the programme and unresolved questions about the available body of knowledge which motivates research and about the method adopted for the work. The conclusion, moderately optimistic, highlights some advances and limits arising during this exercise in a French nuclear scene which remains characterised by a centralized mode of management. (author)

  4. USNRC licensing process as related to nuclear criticality safety

    International Nuclear Information System (INIS)

    Ketzlach, N.

    1987-01-01

    The U.S. Code of Federal Regulations establishes procedures and criteria for the issuance of licenses to receive title to, own, acquire, deliver, receive, possess, use, and initially transfer special nuclear material; and establishes and provides for the terms and conditions upon which the Nuclear Regulatory Commission (NRC) will issue such licenses. Section 70.22 of the regulations, ''Contents of Applications'', requires that applications for licenses contain proposed procedures to avoid accidental conditions of criticality. These procedures are elements of a nuclear criticality safety program for operations with fissionable materials at fuels and materials facilities (i.e., fuel cycle facilities other than nuclear reactors) in which there exists a potential for criticality accidents. To assist the applicant in providing specific information needed for a nuclear criticality safety program in a license application, the NRC has issued regulatory guides. The NRC requirements for nuclear criticality safety include organizational, administrative, and technical requirements. For purely technical matters on nuclear criticality safety these guides endorse national standards. Others provide guidance on the standard format and content of license applications, guidance on evaluating radiological consequences of criticality accidents, or guidance for dealing with other radiation safety issues. (author)

  5. Nuclear criticality safety in Canada

    International Nuclear Information System (INIS)

    Shultz, K.R.

    1980-04-01

    The approach taken to nuclear criticality safety in Canada has been influenced by the historical development of participants. The roles played by governmental agencies and private industry since the Atomic Energy Control Act was passed into Canadian Law in 1946 are outlined to set the scene for the current situation and directions that may be taken in the future. Nuclear criticality safety puts emphasis on the control of materials called special fissionable material in Canada. A brief account is given of the historical development and philosophy underlying the existing regulations governing special fissionable material. Subsequent events have led to a change in emphasis in the regulatory process that has not yet been fully integrated into Canadian legislation and regulations. Current efforts towards further development of regulations governing the practice of nuclear criticality safety are described. (auth)

  6. Nuclear Criticality Safety Handbook, Version 2. English translation

    International Nuclear Information System (INIS)

    2001-08-01

    The Nuclear Criticality Safety Handbook, Version 2 essentially includes the description of the Supplement Report to the Nuclear Criticality Safety Handbook, released in 1995, into the first version of the Nuclear Criticality Safety Handbook, published in 1988. The following two points are new: (1) exemplifying safety margins related to modeled dissolution and extraction processes, (2) describing evaluation methods and alarm system for criticality accidents. Revision has been made based on previous studies for the chapter that treats modeling the fuel system: e.g., the fuel grain size that the system can be regarded as homogeneous, non-uniformity effect of fuel solution, an burnup credit. This revision has solved the inconsistencies found in the first version between the evaluation of errors found in JACS code system and the criticality condition data that were calculated based on the evaluation. This report is an English translation of the Nuclear Criticality Safety Handbook, Version 2, originally published in Japanese as JAERI 1340 in 1999. (author)

  7. Severe accident management program at Cofrentes Nuclear Power Plant

    International Nuclear Information System (INIS)

    Borondo, L.; Serrano, C.; Fiol, M.J.; Sanchez, A.

    2000-01-01

    Cofrentes Nuclear Power Plant (GE BWR/6) has implemented its specific Severe Accident Management Program within this year 2000. New organization and guides have been developed to successfully undertake the management of a severe accident. In particular, the Technical Support Center will count on a new ''Severe Accident Management Team'' (SAMT) which will be in charge of the Severe Accident Guides (SAG) when Control Room Crew reaches the Emergency Operation Procedures (EOP) step that requires containment flooding. Specific tools and training have also been developed to help the SAMT to mitigate the accident. (author)

  8. Severe accident sequences simulated at the Grand Gulf Nuclear Station

    International Nuclear Information System (INIS)

    Carbajo, J.J.

    1999-01-01

    Different severe accident sequences employing the MELCOR code, version 1.8.4 QK, have been simulated at the Grand Gulf Nuclear Station (Grand Gulf). The postulated severe accidents simulated are two low-pressure, short-term, station blackouts; two unmitigated small-break (SB) loss-of-coolant accidents (LOCAs) (SBLOCAs); and one unmitigated large LOCA (LLOCA). The purpose of this study was to calculate best-estimate timings of events and source terms for a wide range of severe accidents and to compare the plant response to these accidents

  9. Statistical evaluation of design-error related nuclear reactor accidents

    International Nuclear Information System (INIS)

    Ott, K.O.; Marchaterre, J.F.

    1981-01-01

    In this paper, general methodology for the statistical evaluation of design-error related accidents is proposed that can be applied to a variety of systems that evolves during the development of large-scale technologies. The evaluation aims at an estimate of the combined ''residual'' frequency of yet unknown types of accidents ''lurking'' in a certain technological system. A special categorization in incidents and accidents is introduced to define the events that should be jointly analyzed. The resulting formalism is applied to the development of U.S. nuclear power reactor technology, considering serious accidents (category 2 events) that involved, in the accident progression, a particular design inadequacy. 9 refs

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

    International Nuclear Information System (INIS)

    Gale, R.P.

    1987-01-01

    The immediate medical response to the nuclear accident at the Chernobyl nuclear power station involved containment of the radioactivity and evacuation of the nearby population. The next step consisted of assessment of the radiation dose received by individuals, based on biological dosimetry, and treatment of those exposed. Medical care involved treatment of skin burns; measures to support bone marrow failure, gastrointestinal tract injury, and other organ damage (i.e., infection prophylaxis and transfusions) for those with lower radiation dose exposure; and bone marrow transplantation for those exposed to a high dose of radiation. At Chernobyl, two victims died immediately and 29 died of radiation or thermal injuries in the next three months. The remaining victims of the accident are currently well. A nuclear accident anywhere is a nuclear accident everywhere. Prevention and cooperation in response to these accidents are essential goals

  11. Improvements in the nuclear accident response system in Brazil

    International Nuclear Information System (INIS)

    Estrada, J.J.S.; Azevedo, E.M.; Knofel, T.M.J.; Recio, J.C.A.; Alves, R.N.

    1998-01-01

    The National Commission on Nuclear Energy has been making outstanding effort to improve its nuclear and radiological accident response systems since the tragic accident in Goiania. Most of this effort is related to nuclear area although the radiological accident has been also considered. This paper describes the improvements in the CNEN response system structure, discusses several topics involving those related to emergency planning and preparedness, and points out some deficiencies that need to be corrected also. The situation during the Goiania accident was more disadvantageous than nowadays, so it is believed that none of the actual deficiencies are sufficient to guess that the population and the environment will not be protected in case of a nuclear or radiological accident

  12. Radiation doses from contaminated food after a nuclear accident

    International Nuclear Information System (INIS)

    Nielsen, S.P.; Oehlenschlaeger, M.

    1991-03-01

    This report presents estimates of radiation doses from contaminated food after a hypothetical accident at a nuclear power plant. The calculations are made from assumptions intended to represent Swedish conditions. The accident scenario is based on a hypothetical core melt in a nuclear power reactor followed by a release to the atmosphere of iodine and caesium corresponding to 0.6% of the Forsmark unit 3 core inventory. The results are expressed in terms of average effective doses from contaminated food to individuals in the critical group living near the power plant, 2 km from the point of release, and living from locally produced foodstuffs. The calculations are made for a winter release and a summer release, and for dry and rainy conditions. Dynamic radioecological models are used, which have been developed from Danish experience with readioactive fallout from nuclear weapons testing and with fallout from the Chernobyl accident. The accidental release is estimated to cause doses in the summer season from 131 I of circa 200 mSv to children and circa 30 mSv to adults based on a deposition during dry conditions of 11 MBq 131 I m -2 . The dosed from 134 Cs and 137 Cs are estimated at circa 20 mSv to children and adults in case of winter release and circa 160 mSv in case of summer release based on a deposition during dry conditions of 0.5 MBQ 134 Cs and 0.4 MBq 137 Cs m -2 . The main reason for the large difference between the winter and the summer releases is the high sensitivity of cerals to direct contamination on month prior to harvest. In case of precipitation the doses are estimated at twice those for dry conditons. (author) 8 tabs., 16 ills., 13 refs

  13. Autoclave nuclear criticality safety analysis

    Energy Technology Data Exchange (ETDEWEB)

    D`Aquila, D.M. [Martin Marietta Energy Systems, Inc., Piketon, OH (United States); Tayloe, R.W. Jr. [Battelle, Columbus, OH (United States)

    1991-12-31

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

  14. Aerosol measurements and nuclear accidents: a reconsideration

    International Nuclear Information System (INIS)

    Raes, F.

    1988-01-01

    Within its radioactivity environmental monitoring programme, the Commission of the European Communities and in particular its Joint Research Centre wants to encourage the qualitative improvement of radioactivity monitoring. On 3 and 4 December 1987 an experts' meeting has been organized by the Ispra Joint Research Centre in collaboration with the Gesellschaft fuer Aerosolforschung, in order to discuss measuring techniques for radioactive aerosols in the environment in case of a nuclear accident. During the workshop, current practices in routine monitoring programmes in the near and far field of nuclear power plants were confronted with the latest developments in the metrology of aerosols and radioactivity. The need and feasibility of implementing advanced aerosol and radioactivity techniques in routine monitoring networks have been discussed. This publication gives the full text of 12 presentations and a report of the roundtable discussion being held afterwards. It does not intend to give a complete picture of all activities going on in the field of radioactive aerosol metrology; it rather collects a number of common statements of people who approach the problem from quite different directions

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

    Science.gov (United States)

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

    2015-06-01

    In 2005, at the request of the French Government, the Nuclear Safety Authority (ASN) established a Steering Committee for the Management of the Post-Accident Phase of a Nuclear Accident or a Radiological Emergency, with the objective of establishing a policy framework. Under the supervision of ASN, this Committee, involving several tens of experts from different backgrounds (e.g. relevant ministerial offices, expert agencies, local information commissions around nuclear installations, non-governmental organisations, elected officials, licensees, and international experts), developed a number of recommendations over a 7-year period. First published in November 2012, these recommendations cover the immediate post-emergency situation, and the transition and longer-term periods of the post-accident phase in the case of medium-scale nuclear accidents causing short-term radioactive release (less than 24 h) that might occur at French nuclear facilities. They also apply to actions to be undertaken in the event of accidents during the transportation of radioactive materials. These recommendations are an important first step in preparation for the management of a post-accident situation in France in the case of a nuclear accident. © The Chartered Institution of Building Services Engineers 2014.

  16. Analysis of the criticality safety of a nuclear fuel deposit

    International Nuclear Information System (INIS)

    Landeyro, P.A.; Mincarini, M.

    1987-01-01

    In the present work a safety analysis from criticality accidents of nuclear fuel deposits is performed. The analysis is performed utilizing two methods derived from different physical principes: 1) superficial density method, obtained from experimental research; 2) solid angle method, derived from transport theory

  17. Outline of Fukushima nuclear accident and future action. Lessons learned from accident and countermeasure plan

    International Nuclear Information System (INIS)

    Fukuda, Toshihiko

    2012-01-01

    Fukushima nuclear accident was caused by loss of all AC power sources (SBO) and loss of ultimate heat sink (LUHS) at Fukushima Daiichi Nuclear Power Plants (NPPs) hit by the Great East Japan Earthquake. This article reviewed outline of Fukushima nuclear accident progression when on year had passed since and referred to lessons learned from accident and countermeasure plan to prevent severe accident in SBO and LUHS events by earthquake and tsunami as future action. This countermeasure would be taken to (1) prevent serious flooding in case a tsunami overwhelms the breakwater, with improving water tightness of rooms for emergency diesel generator, batteries and power centers, (2) enhance emergency power supply and cooling function with mobile electricity generator, high pressure fire pump car and alternate water supply source, (3) mitigate environmental effects caused by core damage with installing containment filtered venting, and (4) enforce emergency preparedness in case of severe accident. Definite countermeasure plan for Kashiwazaki-Kariwa NPPs was enumerated. (T. Tanaka)

  18. Nuclear accidents. Three mile Island (United States)

    International Nuclear Information System (INIS)

    Duco, J.

    2004-01-01

    This paper describes the accident of Three Miles Island power plant which occurred the 28 march 1979 in the United States. The accident scenario, the consequences and the reactor core and vessel, after the accident, are analyzed. (A.L.B.)

  19. Simple estimate of fission rate during JCO criticality accident

    Energy Technology Data Exchange (ETDEWEB)

    Oyamatsu, Kazuhiro [Faculty of Studies on Contemporary Society, Aichi Shukutoku Univ., Nagakute, Aichi (Japan)

    2000-03-01

    The fission rate during JCO criticality accident is estimated from fission-product (FP) radioactivities in a uranium solution sample taken from the preparation basin 20 days after the accident. The FP radioactivity data are taken from a report by JAERI released in the Accident Investigation Committee. The total fission number is found quite dependent on the FP radioactivities and estimated to be about 4x10{sup 16} per liter, or 2x10{sup 18} per 16 kgU (assuming uranium concentration 278.9 g/liter). On the contrary, the time dependence of the fission rate is rather insensitive to the FP radioactivities. Hence, it is difficult to determine the fission number in the initial burst from the radioactivity data. (author)

  20. Simple estimate of fission rate during JCO criticality accident

    International Nuclear Information System (INIS)

    Oyamatsu, Kazuhiro

    2000-01-01

    The fission rate during JCO criticality accident is estimated from fission-product (FP) radioactivities in a uranium solution sample taken from the preparation basin 20 days after the accident. The FP radioactivity data are taken from a report by JAERI released in the Accident Investigation Committee. The total fission number is found quite dependent on the FP radioactivities and estimated to be about 4x10 16 per liter, or 2x10 18 per 16 kgU (assuming uranium concentration 278.9 g/liter). On the contrary, the time dependence of the fission rate is rather insensitive to the FP radioactivities. Hence, it is difficult to determine the fission number in the initial burst from the radioactivity data. (author)

  1. CARNAC, Neutron Flux and Neutron Spectra in Criticality Accident

    International Nuclear Information System (INIS)

    Bessis, J.

    1976-01-01

    Nature of physical problem solved: Calculation of flux and neutron spectra in the case of a criticality accident. The method is unsophisticated but fast. The program is divided into two parts: (1) The code CRITIC is based on the Fermi age equation and evaluates the neutron number per fission emitted from a moderate critical system and its energy spectrum. (2) The code NARCISSE uses concrete current albedo, evaluates the product of neutron reflection on walls of the source containment and calculates the resulting flux at any point, and its energy distribution into 21 groups. The results obtained seem satisfactory, if compared with a Monte Carlo program

  2. The Tokai-mura JCO criticality accident and the activities of the accident countermeasure support team of Electric Power Companies, Japan

    International Nuclear Information System (INIS)

    Ogawa, Junko

    2000-01-01

    A criticality accident occurred at the JCO Tokai-mura nuclear fuel processing plant on September 30, 1999. This accident brought the damages which were unrivaled in the history of atomic energy development in Japan, seriously influencing the citizen life to such an extent as requesting for 320,000 inhabitants within 10 kilometers radius to stay indoors for as long as 18 hours. However, it could be said that though three workers suffered fatal injuries, no substantial hazards were made upon the regional inhabitants due to little release of radioactive substances. This video recorded the activities of the Accident Countermeasure Support Team of the Electric Power Companies immediately after the accident occurred, showing the chronological overview of the particulars of the accident. (author)

  3. The role of nuclear reactor containment in severe accidents

    International Nuclear Information System (INIS)

    1989-04-01

    The containment is a structural envelope which completely surrounds the nuclear reactor system and is designed to confine the radioactive releases in case of an accident. This report summarises the work of an NEA Senior Group of Experts who have studied the potential role of containment in accidents exceeding design specifications (so-called severe accidents). Some possibilities for enhancing the ability of plants to reduce the risk of significant off-site consequences by appropriate management of the acident have been examined

  4. Impact of accidents on organizational aspects of nuclear utilities

    OpenAIRE

    Spurgin, A. J.; Stupples, D.

    2012-01-01

    This paper applies the Beer Viable Systems Model (VSM) approach to the study of nuclear accidents. It relates how organizational structures and rules are affected by accidents in the attempt to improve safety and reduce risk. The paper illustrates this process with reference to a number of accidents. The dynamic cybernetic aspect of the VSM approach to organizations yields a better understanding of the need for good decision-making to minimize risk and how organizations really operate.

  5. The consequences of the Chernobyl nuclear accident in Greece

    International Nuclear Information System (INIS)

    1986-07-01

    In this report the radioactive fallout on Greece from the Chernobyl nuclear accident is described. The flow pattern to Greece of the radioactive materials released, the measurements performed on environmental samples and samples of the food chain, as well as some estimations of the population doses and of the expected consequences of the accident are presented. The analysis has shown that the radiological impact of the accident in Greece can be considered minor. (J.K.)

  6. Report on the accident at the Chernobyl Nuclear Power Station

    International Nuclear Information System (INIS)

    1987-01-01

    This report presents the compilation of information obtained by various organizations regarding the accident (and the consequences of the accident) that occurred at Unit 4 of the nuclear power station at Chernobyl in the USSR on April 26, 1986. The various authors are identified in a footnote to each chapter. An overview of the report is provided. Very briefly the other chapters cover: the design of the Chernobyl nuclear station Unit 4; safety analyses for Unit 4; the accident scenario; the role of the operator; an assessment of the radioactive release, dispersion, and transport; the activities associated with emergency actions; and information on the health and environmental consequences from the accident. These subjects cover the major aspects of the accident that have the potential to present new information and lessons for the nuclear industry in general

  7. Management of Radioactive Waste after a Nuclear Power Plant Accident

    International Nuclear Information System (INIS)

    Strand, Per; Laurent, Gerard; Rindo, Hiroshi; Georges, Christine; Ito, Eiichiro; Yamada, Norikazu; Iablokov, Iuri; Kilochytska, Tatiana; Jefferies, Nick; Byrne, Jim; Siemann, Michael; Koganeya, Toshiyuki; Aoki, Hiroomi

    2016-01-01

    The NEA Expert Group on Fukushima Waste Management and Decommissioning R and D (EGFWMD) was established in 2014 to offer advice to the authorities in Japan on the management of large quantities of on-site waste with complex properties and to share experiences with the international community and NEA member countries on ongoing work at the Fukushima Daiichi site. The group was formed with specialists from around the world who had gained experience in waste management, radiological contamination or decommissioning and waste management R and D after the Three Mile Island and Chernobyl accidents. This report provides technical opinions and ideas from these experts on post-accident waste management and R and D at the Fukushima Daiichi site, as well as information on decommissioning challenges. Chapter 1 provides general descriptions and a short introduction to nuclear accidents or radiological contaminations; for instance the Chernobyl NPP accident, the Three Mile Island Unit 2 accident and the Windscale fire accident. Chapter 2 provides experiences on regulator-implementer interaction in both normal and abnormal situations, including after a nuclear accident. Chapter 3 provides experiences on stakeholder involvement after accidents. These two chapters focus on human aspects after an accident and provide recommendations on how to improve communication between stakeholders so as to resolve issues arising after unexpected nuclear accidents. Chapters 4, 5 and 6 provide information on technical issues related to waste management after accidents. Chapter 4 focuses on the physical and chemical nature of the waste, Chapter 5 on radiological characterisation, and Chapter 6 on waste classification and categorisation. The persons involved in waste management after an accident should address these issues as soon as possible after the accident. Chapters 7 and 8 also focus on technical issues but with a long-term perspective of the waste direction in the future. Chapter 7 relates

  8. Our reflections and lessons from the Fukushima Nuclear Accident

    International Nuclear Information System (INIS)

    Matsuoka, Takeshi; Sawada, Takashi; Yagawa, Genki

    2017-01-01

    In order to investigate the cause of the accident that began on March 11, 2011 at the Tokyo Electric Power Company Fukushima Daiichi Nuclear Power Station, the Science Council of Japan set an investigation committee, the 'Sub-Committee on Fukushima Nuclear Accident (SCFNA)' under the Comprehensive Synthetic Engineering Committee. The committee has published a record entitled 'Reflections and Lessons from the Fukushima Nuclear Accident, (1st report)'. There are still many items about the accident for which the details are not clear. It is important to discuss the reasons why the severe accident could not be prevented and the possibilities that there might have been other proper operations and accident management to prevent or lessen the severity of the accident than those adopted at the time. SCFNA decided to continue its investigation by setting up our working group called the 'Working Group on Fukushima Nuclear Accident'. Our working group have published 'Reflection and Lessons from the Fukushima Nuclear Accident (2nd Report)'. We investigated the issues of specific units. Unit 1 were validity of the operation of the isolation condenser, whether or not a loss of coolant accident occurred due to a failure of the cooling piping system by the seismic ground motion, and the cause of the loss of the emergency AC power supply, Unit 2 was the reason why a large amount of radioactive materials was emitted to the environment although the reactor building did not explode, Unit 3 was the reasons why the operator stopped running the high pressure coolant injection system, and Units 1 to 3 was validity of the venting operation. These items were considered to be the key issues in these units that would have prevented progression to the severe accident. (author)

  9. Iodine tablets and a nuclear accident

    International Nuclear Information System (INIS)

    Paile, W.

    1992-01-01

    Radioactive iodine is one of the major substances released during severe nuclear accidents. Radioactive iodine is easily gasified, and if present in fallout it can enter the lungs, and thereby the circulatory system, with the inhalation of air. Once in a body, radioactive iodine accumulates in the thyroid and may result in tumours in the thyroid and, in extreme cases, impaired thyroid function. Accumulation of radioactive iodine can be prevented by taking non-radioactive, 'cold' iodine as tablets. Iodine tablets dilute the radioactive iodine that has entered the body. A dose of iodine also paralyses the thyroid temporarily by saturating its iodine-carrying capacity. To be useful iodine tablets should be taken immediately when a radioactive emission has occurred. If the tablets are taken too early or too late, they give little protection. Iodine tablets should not be taken just to be on the safe side, since their use may involve harmful side effects. Dosing instructions should also be followed with care. (orig.)

  10. Severe accident analysis and management in nuclear fuel cycle facilities

    International Nuclear Information System (INIS)

    Golshan, Mina

    2013-01-01

    Within the UK regulatory regime, assessment of risks arising from licensee's activities are expected to cover both normal operations and fault conditions. In order to establish the safety case for fault conditions, fault analysis is expected to cover three forms of analysis: design basis analysis (DBA), probabilistic safety assessment (PSA) and severe accident analysis (SAA). DBA should provide a robust demonstration of the fault tolerance of the engineering design and the effectiveness of the safety measures on a conservative basis. PSA looks at a wider range of fault sequences (on a best estimate basis) including those excluded from the DBA. SAA considers significant but unlikely accidents and provides information on their progression and consequences, within the facility, on the site and off site. The assessment of severe accidents is not limited to nuclear power plants and is expected to be carried out for all plant states where the identified dose targets could be exceeded. This paper sets out the UK nuclear regulatory expectation on what constitutes a severe accident, irrespective of the type of facility, and describes characteristics of severe accidents focusing on nuclear fuel cycle facilities. Key rules in assessment of severe accidents as well as the relationship to other fault analysis techniques are discussed. The role of SAA in informing accident management strategies and offsite emergency plans is covered. The paper also presents generic examples of scenarios that could lead to severe accidents in a range of nuclear fuel cycle facilities. (authors)

  11. Radioactive fallout from the Chernobyl nuclear reactor accident

    International Nuclear Information System (INIS)

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

    1987-08-01

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

  12. Emergency preparedness and response: compensating victims of a nuclear accident

    International Nuclear Information System (INIS)

    Schwartz, Julia

    2004-01-01

    The 1986 tragedy at the Chernobyl Nuclear Power Plant in Ukraine motivated the entire international nuclear community to ensure that countries would, in the future, be well prepared to manage the physical, psychological and financial consequences of a serious nuclear accident. Since that event, numerous nuclear emergency preparedness and post-emergency management programmes have been established at national and international levels to ensure that appropriate mechanisms will respond to the threat, and the aftermath, of a nuclear accident. The INEX 2000 Workshop on the Indemnification of Nuclear Damage, jointly organised by the OECD/Nuclear Energy Agency and the French Government, was the first ever international programme to address the manner in which victims of a nuclear accident with trans-boundary consequences would be compensated for damage suffered before, during and after the accident. The Workshop results revealed striking differences in the compensation principles and practices implemented in the 30 participating countries, in the co-ordination measures between different public authorities within an affected state, and in the co-operative procedures between the accident state and its neighbours. All participants agreed on the need for improvement in these areas, particularly for maintaining public confidence in governments' ability to properly manage nuclear emergencies

  13. International Intercomparison Exercise for Nuclear Accident Dosimetry at the DAF Using GODIVA-IV

    Energy Technology Data Exchange (ETDEWEB)

    Hickman, David [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hudson, Becka [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-12-15

    The Nuclear Criticality Safety Program operated under the direction of Dr. Jerry McKamy completed the first NNSA Nuclear Accident Dosimetry exercise on May 27, 2016. Participants in the exercise were from Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), Sandia National Laboratory (SNL), Savanah River Site (SRS), Pacific Northwest National Laboratory (PNNL), US Navy, the Atomic Weapons Establishment (United Kingdom) under the auspices of JOWOG 30, and the Institute for Radiological Protection and Nuclear Safety (France) by special invitation and NCSP memorandum of understanding. This exercise was the culmination of a series of Integral Experiment Requests (IER) that included the establishment of the Nuclear Criticality Experimental Research Center, (NCERC) the startup of the Godiva Reactor (IER-194), the establishment of a the Nuclear Accident Dosimetry Laboratory (NAD LAB) in Mercury, NV, and the determination of reference dosimetry values for the mixed neutron and photon radiation field of Godiva within NCERC.

  14. Nuclear criticality safety. Chapter 0530 of AEC manual

    International Nuclear Information System (INIS)

    2006-01-01

    The programme objectives of this chapter of the U.S. Atomic Energy Commission manual on nuclear criticality safety are to protect the health and safety of the public and of the government and contractor personnel working in plants that handle fissionable material and to protect public and private property from the consequences of a criticality accident occurring in AEC-owned plants and other AEC-contracted activities involving fissionable materials

  15. Severe accident management guidance for third Qinshan Nuclear Power Plant

    International Nuclear Information System (INIS)

    Su Changsong

    2010-01-01

    The paper describes the background, document structure and the summaries of Severe Accident Management Guidance (SAMG) for Third Qinshan Nuclear Power Plant (TQNPP), and also introduces briefly some design features and their impacts on SAMG. (authors)

  16. Managing Nuclear Reactor Accidents: Issues Raised by Three Mile Island

    OpenAIRE

    Hamilton, G.W.

    1980-01-01

    This paper provides a descriptive account of significant events in the accident at the Three Mile Island nuclear power plant in March, 1979. It is based upon documents collected as background materials for the IIASA workshop: Procedural and Organizational Measures for Accident Management: Nuclear Reactors. In addition to the references listed, information was supplied by John Lathrop, who conducted interviews with government and industry officials involved in the crisis. There have been ...

  17. Nuclear. Convention on early notification of a nuclear accident. Treaty series 1990 no.21

    International Nuclear Information System (INIS)

    1991-01-01

    The States present at this convention are aware that comprehensive measures have been are being taken to ensure a high level of safety in nuclear activities, aimed at preventing nuclear accidents and minimizing the consequences of any such accident should it occur. The States are convinced of the need to provide relevant information about nuclear accidents as early as possible in order that transboundary radiological consequences can be minimized. In the event of an accident the State involved will notify, through the International Energy Agency the other States which may be physically affected, as to the nature of the accident, the time of occurrence and its exact location

  18. Nuclear. Convention on early notification of a nuclear accident. Treaty series 1990 no.21

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1992-12-31

    The States present at this convention are aware that comprehensive measures have been are being taken to ensure a high level of safety in nuclear activities, aimed at preventing nuclear accidents and minimizing the consequences of any such accident should it occur. The States are convinced of the need to provide relevant information about nuclear accidents as early as possible in order that transboundary radiological consequences can be minimized. In the event of an accident the State involved will notify, through the International Energy Agency the other States which may be physically affected, as to the nature of the accident, the time of occurrence and its exact location.

  19. Nuclear Criticality Safety Data Book

    Energy Technology Data Exchange (ETDEWEB)

    Hollenbach, D. F. [Y-12 National Security Complex, Oak Ridge, TN (United States)

    2016-11-14

    The objective of this document is to support the revision of criticality safety process studies (CSPSs) for the Uranium Processing Facility (UPF) at the Y-12 National Security Complex (Y-12). This design analysis and calculation (DAC) document contains development and justification for generic inputs typically used in Nuclear Criticality Safety (NCS) DACs to model both normal and abnormal conditions of processes at UPF to support CSPSs. This will provide consistency between NCS DACs and efficiency in preparation and review of DACs, as frequently used data are provided in one reference source.

  20. Nuclear Criticality Safety Data Book

    International Nuclear Information System (INIS)

    Hollenbach, D. F.

    2016-01-01

    The objective of this document is to support the revision of criticality safety process studies (CSPSs) for the Uranium Processing Facility (UPF) at the Y-12 National Security Complex (Y-12). This design analysis and calculation (DAC) document contains development and justification for generic inputs typically used in Nuclear Criticality Safety (NCS) DACs to model both normal and abnormal conditions of processes at UPF to support CSPSs. This will provide consistency between NCS DACs and efficiency in preparation and review of DACs, as frequently used data are provided in one reference source.

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

    International Nuclear Information System (INIS)

    Xu Xiegu; Zhen Bei; Yang Xiaoming; Chen Xiaohua

    2012-01-01

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

  2. The Fukushima nuclear accident and its effect on global energy security

    International Nuclear Information System (INIS)

    Hayashi, Masatsugu; Hughes, Larry

    2013-01-01

    The March 2011 nuclear accident at the Fukushima Daiichi nuclear power station affected both short- and long-term energy-security in Japan, resulting in crisis-driven, ad hoc energy policy and, because of the decision to shutter all nuclear reactors, increased the country’s demand for fossil fuels, primarily natural gas. However, the effects of the accident on energy security were not restricted to Japan; for example, the worldwide availability and affordability of liquefied natural gas were affected by Japan’s increased demand; while the accident itself resulted in the loss of public acceptability of nuclear power and led countries, such as Germany and Italy, to immediately shut down some of the nuclear reactors or abandon plans to build new ones. This paper examines some of the short-term effects on global energy security following the accident at Fukushima, focusing on the main replacement fuel, liquefied natural gas. It shows, amongst other things, that the accident increased investment in liquefied natural gas projects around the world. The paper shows that despite Fukushima contributing to nuclear power’s loss of acceptability in most developed countries, it is still seen as an essential way of improving energy security in many countries and, despite what its critics may say, will probably continue to be used as a significant source of low-carbon electricity. - Highlights: ► Japan’s demands for fossil fuels raised the price of LNG and low-sulfur crudes. ► The accident affected the global price of uranium and producer share prices. ► The accident accelerated foreign-direct investment in LNG projects worldwide. ► The change in public perception toward nuclear power was relatively limited. ► A radical shift in global nuclear policy seems to be unrealistic after Fukushima

  3. Nuclear safety in light water reactors severe accident phenomenology

    CERN Document Server

    Sehgal, Bal Raj

    2011-01-01

    This vital reference is the only one-stop resource on how to assess, prevent, and manage severe nuclear accidents in the light water reactors (LWRs) that pose the most risk to the public. LWRs are the predominant nuclear reactor in use around the world today, and they will continue to be the most frequently utilized in the near future. Therefore, accurate determination of the safety issues associated with such reactors is central to a consideration of the risks and benefits of nuclear power. This book emphasizes the prevention and management of severe accidents to teach nuclear professionals

  4. Relative evaluation on decommissioning accident scenarios of nuclear facilities

    International Nuclear Information System (INIS)

    Jeong, Kwan-Seong; Choi, Byung-Seon; Moon, Jei-Kwon; Hyun, Dong-Jun; Kim, Geun-Ho; Kim, Tae-Hyoung; Jo, Kyung-Hwa; Seo, Jae-Seok; Jeong, Seong-Young; Lee, Jung-Jun

    2012-01-01

    Highlights: ► This paper suggests relative importance on accident scenarios during decommissioning of nuclear facilities. ► The importance of scenarios can be performed by using AHP and Sugeno fuzzy method. ► The AHP and Sugeno fuzzy method guarantee reliability of the importance evaluation. -- Abstract: This paper suggests the evaluation method of relative importance on accident scenarios during decommissioning of nuclear facilities. The evaluation method consists of AHP method and Sugeno fuzzy integral method. This method will guarantee the reliability of relative importance evaluation for decommissioning accident scenarios.

  5. Fukushima nuclear accident and the social responsibility of science

    International Nuclear Information System (INIS)

    Yoshioka, Hitoshi

    2011-01-01

    Five months had passed since Fukushima Daiichi Nuclear Power Plant (NPP) accident occurred but still there was no knowing when the accident ended. Released radioactivity seemed to be greater than one million terra Bq and if there occurred an explosive rupture of containment vessel due to the failure of containment vent or occurrence of steam explosion, the amount of released radioactivity might amount to be at least equivalent to or surpass that of Chernobyl NPP accident. There existed still a risk that overheating and meltdown of nuclear fuels might reoccur with loss of cooling due to a possible giant aftershock. This article described total views on significant disaster that the accident brought about on many neighboring residents or wide range of people. After a general discussion about what was social responsibility of scientists, social responsibility of scientists for Fukushima Daiichi NPP accident was discussed. Responsibility of omission was also argued. (T. Tanaka)

  6. Developing and assessing accident management plans for nuclear power plants

    International Nuclear Information System (INIS)

    Hanson, D.J.; Johnson, S.P.; Blackman, H.S.; Stewart, M.A.

    1992-07-01

    This document is the second of a two-volume NUREG/CR that discusses development of accident management plans for nuclear power plants. The first volume (a) describes a four-phase approach for developing criteria that could be used for assessing the adequacy of accident management plans, (b) identifies the general attributes of accident management plans (Phase 1), (c) presents a prototype process for developing and implementing severe accident management plans (Phase 2), and (d) presents criteria that can be used to assess the adequacy of accident management plans. This volume (a) describes results from an evaluation of the capabilities of the prototype process to produce an accident management plan (Phase 3) and (b), based on these results and preliminary criteria included in NUREG/CR-5543, presents modifications to the criteria where appropriate

  7. Residents call for greater openness, accountability and involvement: Lessons learned from the JCO criticality accident

    International Nuclear Information System (INIS)

    Taniguchi, Taketoshi; Tsuchiya, Tomoko; Kosugi, Motoko

    2000-01-01

    This paper discusses the JCO (Japan Nuclear Fuel Conversion Co.) criticality accident from social viewpoints based on the detailed examination of the survey data and experience of participation into Tokai village office's surveys. We focus the mechanisms of amplifying anxieties of the local residents and clarify the key factors affected in the social amplification process. And we discuss the importance of communicating and deliberating among the lay people, public officials and professionals about health, safety and environmental risks associated with nuclear energy, referring to the public opinions about what kinds of information and actions are needed. (J.P.N.)

  8. The relationship of JNC and JCO in the uranium processing plant criticality accident

    International Nuclear Information System (INIS)

    Kanamori, Masashi; Yanagibashi, Katsumi; Okamoto, Naritoshi

    2002-12-01

    On September 30th 1999, the criticality accident occurred at JCO's uranium conversion building in Tokai. The accident occurred during reconversion from U 3 O 8 to uranium nitrate solution (UNH) with uranium enriched 18.8% and about 60 kgU. JCO contacted with JNC to supply UNH that is fuel material for the experimental fast breeder reactor 'JOYO'. JNC has contracted with JCO that had started nuclear fuel material processing business following a definite policy of Japanese government and developed SUMITOMO ADU PROCESS'. JNC made the first contract with JCO in 1985 and has made a contact every year. There had never been a problem in their products. JNC inspected products based on contract. JNC discharge our duty as customer inspecting products based on contract. As for safety control, JCO had taken licensing safety review and had been permitted to be 'a processing facility'. Therefore JNC understood that JCO produced following this license. 'The Uranium Processing Plant Criticality Accident Investigation' showed that JCO had been taking a different method from the permit and violating the license. However JNC had never been explained about that and JCO's operation procedures had never described about that. Therefore the Criticality Accident couldn't be avoided. This report describes the relationship of JNC and JCO in the uranium reconversion contract for JOYO, atomic development policy of Japanese government, process to the order and the contents of contract. (author)

  9. Energy and angular responses of the criticality accident detector using a plastic scintillator

    International Nuclear Information System (INIS)

    Tsujimura, Norio; Yoshida, Tadayoshi

    2006-01-01

    The Japan Atomic Energy Agency (JAEA), Nuclear Fuel Cycle Engineering Laboratories, operates a spent fuel reprocessing plant and MOX (Plutonium-Uranium Mixed Oxide) fuel fabrication plants. Criticality accident detectors have been installed in these facilities. The detector, the Toshiba RD120, is composed of a plastic scintillator coupled to a photomultiplier tube, and an operational amplifier. The alarm triggering point is set to 1.0-3.6 mGy·h -1 in photon dose rate to detect the minimum accident of concern. However, a plastic scintillator is principally sensitive not only to primary photons but also to neutrons by secondary photons and heavy charged particles produced in the detector itself. The authors calculated energy and angular responses of the RD120 criticality accident detector to photons and neutrons using Monte Carlo computer codes. The response to primary photons was evaluated with the MCNP-4B and EGS4 calculations, and photon and X-ray irradiation experiments. The response to neutrons that produce secondary photons and heavy charged particles from neutron interactions was computed using the MCNP-4B and SCINFUL, respectively. As a result, reliable response functions were obtained. These results will be a great help in reassessing the coverage area and in determining the appropriate triggering dose rate level in criticality accidents. (author)

  10. Nuclear installations abroad the accident risks and their potential consequences

    International Nuclear Information System (INIS)

    Turvey, F.J.

    1996-01-01

    This paper endeavors to assess the threat to Ireland from severe accidents at civil nuclear installations. Among the various types of nuclear installations worldwide, reactors and reprocessing plants are considered to be the most threatening and so the paper focuses on these. The threat is assumed to be a function of the risk of severe accidents at the above types of installations and the probability of unfavourable weather conditions carrying the radioactive releases to Ireland. Although nuclear installations designed in eastern Europe and Asia are less safe than others, the greatest threat to Ireland arises from nearby installations in the UK. The difficulty of measuring the probabilities and consequences of severe nuclear accidents at nuclear installations in general is explained. In the case of the UK installations, this difficulty is overcome to some degree by using values of 'tolerable' risk adopted by the national nuclear regulator to define the radiotoxic releases from nuclear accidents. These are used as input to atmospheric dispersion models in which unfavourable weather conditions for Ireland are assumed and radiation doses are calculated to members of the Irish public. No countermeasures, such as sheltering, are assumed. In the worst cast scenario no deaths would be expected in Ireland in the immediate aftermath of the accident however, an increase in cancers over a period of 25 years or so would be expected assuming present-day models for the effect of low level radiation are valid

  11. Nuclear installations abroad the accident risks and their potential consequences

    Energy Technology Data Exchange (ETDEWEB)

    Turvey, F J [Radiological Protection Inst. of Ireland (Ireland)

    1996-10-01

    This paper endeavors to assess the threat to Ireland from severe accidents at civil nuclear installations. Among the various types of nuclear installations worldwide, reactors and reprocessing plants are considered to be the most threatening and so the paper focuses on these. The threat is assumed to be a function of the risk of severe accidents at the above types of installations and the probability of unfavourable weather conditions carrying the radioactive releases to Ireland. Although nuclear installations designed in eastern Europe and Asia are less safe than others, the greatest threat to Ireland arises from nearby installations in the UK. The difficulty of measuring the probabilities and consequences of severe nuclear accidents at nuclear installations in general is explained. In the case of the UK installations, this difficulty is overcome to some degree by using values of `tolerable` risk adopted by the national nuclear regulator to define the radiotoxic releases from nuclear accidents. These are used as input to atmospheric dispersion models in which unfavourable weather conditions for Ireland are assumed and radiation doses are calculated to members of the Irish public. No countermeasures, such as sheltering, are assumed. In the worst cast scenario no deaths would be expected in Ireland in the immediate aftermath of the accident however, an increase in cancers over a period of 25 years or so would be expected assuming present-day models for the effect of low level radiation are valid.

  12. Supplement report to the Nuclear Criticality Safety Handbook of Japan

    International Nuclear Information System (INIS)

    Okuno, Hiroshi; Komuro, Yuichi; Nakajima, Ken

    1995-10-01

    Supplementing works to 'The Nuclear Criticality Safety Handbook' of Japan have been continued since 1988, the year the handbook edited by the Science and Technology Agency first appeared. This report publishes the fruits obtained in the supplementing works. Substantial improvements are made in the chapters of 'Modelling the evaluation object' and 'Methodology for analytical safety assessment', and newly added are chapters of 'Criticality safety of chemical processes', 'Criticality accidents and their evaluation methods' and 'Basic principles on design and installation of criticality alarm system'. (author)

  13. The accident at the Harrisburg nuclear reactor - Interim conclusions

    International Nuclear Information System (INIS)

    Yiftah, S.

    1979-07-01

    This work describes the first minutes, first day and first week following the Three Mile Island accident. It shows the failures that occurred and the lessons which should be derived. It is pointed out that the doses of radiation that escaped from the TMI plant were at no time large enough to have had any effect on the 2 million people living on a radius of 80 km from the plant. Although no casualties occurred the Harrisburg accident will create an impulse for a new study and understanding of the nuclear plant safety and might serve as a live safety laboratory. After the TMI accident nuclear plants are already safer, one of the conclusions being that a new planning of the operation room is required, with the operators acquiring a better understanding of what is going on during a nuclear reactor accident. (B.G.)

  14. Nuclear fuel cycle facility accident analysis handbook

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

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

  15. Nuclear fuel cycle facility accident analysis handbook

    International Nuclear Information System (INIS)

    1998-03-01

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

  16. Agricultural implications for Fukushima nuclear accident

    International Nuclear Information System (INIS)

    Nakanishi, Tomoko M.

    2013-01-01

    The overview of our research projects for Fukushima is presented including how they were derived. Then, where the fallout was found, right after the accident, is briefly summarized for soil, plants, trees, etc. The time of the accident was late winter, there were hardly any plants growing except for the wheat in the farming field. Most of the fallout was found at the surface of soil, tree barks, etc., which were exposed to the air at the time of the accident. The fallout found was firmly adsorbed to anything and did not move for months from the site when they first touched. Therefore, the newly emerged tissue after the accident showed very low radioactivity. The fallout contamination was not uniform, therefore, when radiograph of contaminated soil or leaves were taken, fallout was shown as spots. Generally, plants could not absorb radiocesium adsorbed to soil. Some of the results we obtained will be presented. (author)

  17. Accident analysis in nuclear power plants

    International Nuclear Information System (INIS)

    Silva, D.E. da

    1981-01-01

    The way the philosophy of Safety in Depth can be verified through the analysis of simulated accidents is shown. This can be achieved by verifying that the integrity of the protection barriers against the release of radioactivity to the environment is preserved even during accident conditions. The simulation of LOCA is focalized as an example, including a study about the associated environmental radiological consequences. (Author) [pt

  18. Criticality accident in uranium fuel processing plant. The estimation of the total number of fissions with related reactor physics parameters

    International Nuclear Information System (INIS)

    Nishina, Kojiro; Oyamatsu, Kazuhiro; Kondo, Shunsuke; Sekimoto, Hiroshi; Ishitani, Kazuki; Yamane, Yoshihiro; Miyoshi, Yoshinori

    2000-01-01

    This accident occurred when workers were pouring a uranium solution into a precipitation tank with handy operation against the established procedure and both the cylindrical diameter and the total mass exceeded the limited values. As a result, nuclear fission chain reactor in the solution reached not only a 'criticality' state continuing it independently but also an instantly forming criticality state exceed the criticality and increasing further nuclear fission number. The place occurring the accident at this time was not reactor but a place having not to form 'criticality' called by a processing process of uranium fuel. In such place, as because of relating to mechanism of chain reaction, it is required naturally for knowledge on the reactor physics, it is also necessary to understand chemical reaction in chemical process, and functions of tanks, valves and pumps mounted at the processes. For this purpose, some information on uranium concentration ratio, atomic density of nuclides largely affecting to chain reaction such as uranium, hydrogen, and so forth in the solution, shape, inner structure and size of container for the solution, and its temperature and total volume, were necessary for determining criticality volume of the accident uranium solution by using nuclear physics procedures. Here were described on estimation of energy emission in the JCO accident, estimation from analytical results on neutron and solution, calculation of various nuclear physics property estimation on the JCO precipitation tank at JAERI. (G.K.)

  19. Effects of the Chernobyl accident on public perceptions of nuclear plant accident risks

    International Nuclear Information System (INIS)

    Lindell, M.K.; Perry, R.W.

    1990-01-01

    Assessments of public perceptions of the characteristics of a nuclear power plant accident and affective responses to its likelihood were conducted 5 months before and 1 month after the Chernobyl accident. Analyses of data from 69 residents of southwestern Washington showed significant test-retest correlations for only 10 of 18 variables--accident likelihood, three measures of impact characteristics, three measures of affective reactions, and hazard knowledge by governmental sources. Of these variables, only two had significant changes in mean ratings; frequency of thought and frequency of discussion about a nearby nuclear power plant both increased. While there were significant changes only for two personal consequences (expectations of cancer and genetic effects), both of these decreased. The results of this study indicate that more attention should be given to assessing the stability of risk perceptions over time. Moreover, the data demonstrate that experience with a major accident can actually decrease rather than increase perceptions of threat

  20. Emergency planning and preparedness for a nuclear accident

    International Nuclear Information System (INIS)

    Rahe, E.P.

    1985-01-01

    Based on current regulations, FEMA approves each site-specific plan of state and local governments for each power reactor site after 1) formal review offsite preparedness, 2) holding a public meeting at which the preparedness status has been reviewed, and 3) a satisfactory joint exercise has been conducted with both utility and local participation. Annually, each state, within any position of the 10-mile emergency planning zone, must conduct a joint exercise with the utility to demonstrate its preparedness for a nuclear accident. While it is unlikely that these extreme measures will be needed as a result of an accident at a nuclear power station, the fact that these plans have been well thought out and implemented have already proven their benefit to society. The preparedness for a nuclear accident can be of great advantage in other types of emergencies. For example, on December 11, 1982, a non-nuclear chemical storage tank exploded at a Union Carbide plant in Louisiana shortly after midnight. More than 20,000 people were evacuated from their homes. They were evacuated under the emergency response plan formulated for use in the event of a nuclear accident at the nearby Waterford Nuclear plants. Clearly, this illustrates how a plan conceived for one purpose is appropriate to handle other types of accidents that occur in a modern industrial society

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

    International Nuclear Information System (INIS)

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

    1983-07-01

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

  2. Fifteenth nuclear accident dosimetry intercomparison study: August 14--22, 1978

    International Nuclear Information System (INIS)

    Sims, C.S.

    1979-05-01

    The fifteenth in the continuing series of Nuclear Accident Dosimetry Intercomparison Studies was held August 14--22, 1978 at the Oak Ridge National Laboratory. The Health Physics Research Reactor, operated in the pulse mode, served as the radiation source. Using different shielding configurations, nuclear accidents with three different neutron and gamma spectra were simulated. Participants from 19 organizations, the most in the history of the studies, exposed dosimeters set up as area monitors as well as dosimeters mounted on phantoms for personnel monitoring. Although many participants performed accurate measurements, the composite dose results, in the majority of cases, failed to meet established nuclear criticality accident dosimetry guidelines which suggest accuracies of +- 25% for neutron dose and +- 20% for gamma dose. This indicates that many participants need to improve their dosimetry systems, their analytical techniques, or both

  3. Indemnification of damage in the event of a nuclear accident

    International Nuclear Information System (INIS)

    2003-01-01

    The Workshop on the Indemnification of Damage in the Event of a Nuclear Accident, organised by the OECD Nuclear Energy Agency in close co-operation with the French authorities, was held in Paris from 26 to 28 November 2001. This event was an integral part of the International Nuclear Emergency Exercise INEX 2000. It attracted wide participation from national nuclear authorities, regulators, operators of nuclear installations, nuclear insurers and international organisations. The objective was to test the capacity of the existing nuclear liability and compensation mechanisms in the 29 countries represented at the workshop to manage the consequences of a nuclear emergency. This workshop was based upon the scenario used for the INEX 2000 Exercise, i.e. an accident simulated at the Gravelines nuclear power plant in the north of France in May 2001. These proceedings contain a comparative analysis of legislative and regulatory provisions governing emergency response and nuclear third party liability, based upon country replies to a questionnaire. This publication also includes the full responses provided to that questionnaire, as well as the texts of presentations made by special guests from Germany and Japan describing the manner in which the public authorities in their respective countries responded to two nuclear accidents of a very different nature and scale. (authors)

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

    International Nuclear Information System (INIS)

    Schwebel, M.; Schwebel, B.

    1981-01-01

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

  5. Soviet medical response to the Chernobyl nuclear accident

    International Nuclear Information System (INIS)

    Linnemann, R.E.

    1987-01-01

    The nuclear accident at Chernobyl was the worst in the history of nuclear power. It tested the organized medical response to mass radiation casualties. This article reviews the Soviet response as reported at the 1986 postaccident review meeting in Vienna and as determined from interviews. The Soviets used three levels of care: rescue and first aid at the plant site; emergency treatment at regional hospitals; and definitive evaluation and treatment in Moscow. Diagnosis, triage, patient disposition, attendant exposure, and preventive actions are detailed. The United States would be well advised to organize its resources definitively to cope with future nonmilitary nuclear accidents

  6. Severe accident management: radiation dose control, Fukushima Daiichi and TMI-2 nuclear plant accidents

    International Nuclear Information System (INIS)

    Shaw, Roger

    2014-01-01

    This presentation presents valuable dose information related to the Fukushima Daiichi and Three Mile Island Unit 2 (TMI-2) Nuclear Plant accidents. Dose information is provided for what is well known for TMI-2, and what is available for Fukushima Daiichi. Particular emphasis is placed on the difference between the type of reactors involved, overarching plant damage issues, and radiation worker dose outcomes. For TMI-2, more in depth dose data is available for the accident and the subsequent recovery efforts. The comparisons demonstrate the need to understand the wide variation in potential dose management measures and outcomes for severe reactor accidents. (author)

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

    Science.gov (United States)

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

    2017-06-15

    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. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  8. Nuclear Power Reactor Core Melt Accidents. Current State of Knowledge

    International Nuclear Information System (INIS)

    Bentaib, Ahmed; Bonneville, Herve; Clement, Bernard; Cranga, Michel; Fichot, Florian; Koundy, Vincent; Meignen, Renaud; Corenwinder, Francois; Leteinturier, Denis; Monroig, Frederique; Nahas, Georges; Pichereau, Frederique; Van-Dorsselaere, Jean-Pierre; Cenerino, Gerard; Jacquemain, Didier; Raimond, Emmanuel; Ducros, Gerard; Journeau, Christophe; Magallon, Daniel; Seiler, Jean-Marie; Tourniaire, Bruno

    2013-01-01

    For over thirty years, IPSN and subsequently IRSN has played a major international role in the field of nuclear power reactor core melt accidents through the undertaking of important experimental programmes (the most significant being the Phebus- FP programme), the development of validated simulation tools (the ASTEC code that is today the leading European tool for modelling severe accidents), and the coordination of the SARNET (Severe Accident Research Network) international network of excellence. These accidents are described as 'severe accidents' because they can lead to radioactive releases outside the plant concerned, with serious consequences for the general public and for the environment. This book compiles the sum of the knowledge acquired on this subject and summarises the lessons that have been learnt from severe accidents around the world for the prevention and reduction of the consequences of such accidents, without addressing those from the Fukushima accident, where knowledge of events is still evolving. The knowledge accumulated by the Institute on these subjects enabled it to play an active role in informing public authorities, the media and the public when this accident occurred, and continues to do so to this day

  9. The assessment of environmental consequences of nuclear reactor accidents

    International Nuclear Information System (INIS)

    Beattie, J.R.

    1981-01-01

    Thorough measures are taken throughout all stages of design, construction and operation of nuclear power reactors, and therefore no accident producing any significant environmental impact is likely to occur. Nevertheless as a precaution, such accidents have been the subject of intensive scientific predictive studies. After a historical review of theoretical papers on reactor accidents and their imagined environmental impacts and of those accidents that have indeed occurred, this paper gives an outline of fission products or other radioactive substances that may or may not be released by an accident, and of their possible effects after dispersion in the atmosphere. This general introduction is followed by sections describing what are sometimes called 'design basis accidents' for four of the main reactor types (magnox, AGR, PWR and CDFR), the precautions against these accidents and the probable degree of environmental impact likely. The paper concludes with a reference to those very low probability accidents which might have more serious environmental impacts, and proceeds from there to show that both the individual and community risks from such accidents are numerically moderate compared to other risks apparently accepted by society. A brief reflection on the relevance of numerical values and perceived risk concludes the paper. (author)

  10. Core fusion accidents in nuclear power reactors. Knowledge review

    International Nuclear Information System (INIS)

    Bentaib, Ahmed; Bonneville, Herve; Clement, Bernard; Cranga, Michel; Fichot, Florian; Koundy, Vincent; Meignen, Renaud; Corenwinder, Francois; Leteinturier, Denis; Monroig, Frederique; Nahas, Georges; Pichereau, Frederique; Van-Dorsselaere, Jean-Pierre; Cenerino, Gerard; Jacquemain, Didier; Raimond, Emmanuel; Ducros, Gerard; Journeau, Christophe; Magallon, Daniel; Seiler, Jean-Marie; Tourniaire, Bruno

    2013-01-01

    This reference document proposes a large and detailed review of severe core fusion accidents occurring in nuclear power reactors. It aims at presenting the scientific aspects of these accidents, a review of knowledge and research perspectives on this issue. After having recalled design and operation principles and safety principles for reactors operating in France, and the main studied and envisaged accident scenarios for the management of severe accidents in French PWRs, the authors describe the physical phenomena occurring during a core fusion accident, in the reactor vessel and in the containment building, their sequence and means to mitigate their effects: development of the accident within the reactor vessel, phenomena able to result in an early failure of the containment building, phenomena able to result in a delayed failure with the corium-concrete interaction, corium retention and cooling in and out of the vessel, release of fission products. They address the behaviour of containment buildings during such an accident (sizing situations, mechanical behaviour, bypasses). They review and discuss lessons learned from accidents (Three Mile Island and Chernobyl) and simulation tests (Phebus-PF). A last chapter gives an overview of software and approaches for the numerical simulation of a core fusion accident

  11. Enlightenment on international cooperation for nuclear safety in China in light of Fukushima nuclear accident

    International Nuclear Information System (INIS)

    Fu Jie; Feng Yi; Luan Haiyan; Meng Yue; Zhang Ou

    2013-01-01

    This thesis elaborates on the impact of Fukushima nuclear accident on global nuclear power development and subsequent international activities carried out by major countries. It analyses significance of international cooperation in ensuring nuclear safety and promoting nuclear power development and makes some suggestions to further strengthen the international cooperation on nuclear safety in China. (authors)

  12. PNNL Measurement Results for the 2016 Criticality Accident Dosimetry Exercise at the Nevada National Security Stite (IER-148)

    Energy Technology Data Exchange (ETDEWEB)

    Rathbone, Bruce A.; Morley, Shannon M.; Stephens, John A.

    2017-05-01

    The Pacific Northwest National Laboratory (PNNL) participated in a criticality accident dosimetry intercomparison exercise held at the Nevada National Security Site (NNSS) May 24-27, 2016. The exercise was administered by Lawrence Livermore National Laboratory (LLNL) and consisted of three exposures performed using the Godiva-IV critical assembly housed in the Device Assembly Facility (DAF) located on the NNSS site. The exercise allowed participants to test the ability of their nuclear accident dosimeters to meet the performance criteria in ANSI/HPS N13.3-2013, Dosimetry for Criticality Accidents and to obtain new measurement data for use in revising dose calculation methods and quick sort screening methods where appropriate. PNNL participated with new prototype Personal Nuclear Accident Dosimeter (PNAD) and Fixed Nuclear Accident Dosimeter (FNAD) designs as well as the existing historical PNAD design. The new prototype designs incorporate optically stimulated luminescence (OSL) dosimeters in place of thermoluminescence dosimeters (TLDs), among other design changes, while retaining the same set of activation foils historically used. The default dose calculation methodology established decades ago for use with activation foils in PNNL PNADs and FNADs was used to calculate neutron dose results for both the existing and prototype dosimeters tested in the exercise. The results indicate that the effective cross sections and/or dose conversion factors used historically need to be updated to accurately measure the operational quantities recommended for nuclear accident dosimetry in ANSI/HPS N13.3-2013 and to ensure PNAD and FNAD performance meets the ANSI/HPS N13.3-2013 performance criteria. The operational quantities recommended for nuclear accident dosimetry are personal absorbed dose, Dp(10), and ambient absorbed dose, D*(10).

  13. Accident analysis device for nuclear power plants

    International Nuclear Information System (INIS)

    Ito, Masayuki.

    1982-01-01

    Purpose: To enable rapid recognition of and countermeasure required for accidents upon scram, by identifying the first contact point of causes for resulting the scram and displaying the contact point of causes. Constitution: When a scram signal is inputted by way of process input device, the time of the input is determined by a timer and the contact point of causes generated just before is taken as the point whose changes occurred prior to but most closely to the generation of the signal while referring to the data memory section for the time of change of the contact point of the cause, and sent to the accident analyzing display. The accident analyzing display extracts, based on the contact point of cause, a list for the forecast accidents corresponding thereto from the data memory section and also extracts the list for the corresponding confirmation items of the accident detection and displays them together with the system from which the scram signal has been generated, the time of generation, the name of the contact point of causes operated at first, and the value of the state quantity contained in the data memory section for the store of contact point of cause at the change. (Kawakami, Y.)

  14. The role of post accident chemistry data in nuclear safety

    International Nuclear Information System (INIS)

    Bradshaw, R.W.; Caruthers, G.F.

    1982-01-01

    The NRC instituted the NUREG-0737 requirements as implementation of the Post-TMI Action Plan in October, 1980. Among these requirements was the capability to obtain chemistry samples of the reactor coolant and containment building atmosphere under post accident conditions. The quantitative criteria were, in general, beyond the capabilities of existing plant systems. As a consequence the nuclear industry expended substantial efforts to design and install the post-accident sampling systems necessary to comply with these criteria. With such efforts essentially complete, the task remains to establish the role that data provided by these systems would play in mitigating the consequences of a nuclear plant accident. This role definition must include a characterization of the timing and priority for the post accident chemistry data. This paper defines that role using the Safety Level and Safety Function concepts as a matrix

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

    Science.gov (United States)

    Koketsu, Kazuki

    2016-04-01

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

  16. Analytical measurements of fission products during a severe nuclear accident

    Science.gov (United States)

    Doizi, D.; Reymond la Ruinaz, S.; Haykal, I.; Manceron, L.; Perrin, A.; Boudon, V.; Vander Auwera, J.; tchana, F. Kwabia; Faye, M.

    2018-01-01

    The Fukushima accident emphasized the fact that ways to monitor in real time the evolution of a nuclear reactor during a severe accident remain to be developed. No fission products were monitored during twelve days; only dose rates were measured, which is not sufficient to carry out an online diagnosis of the event. The first measurements were announced with little reliability for low volatile fission products. In order to improve the safety of nuclear plants and minimize the industrial, ecological and health consequences of a severe accident, it is necessary to develop new reliable measurement systems, operating at the earliest and closest to the emission source of fission products. Through the French program ANR « Projet d'Investissement d'Avenir », the aim of the DECA-PF project (diagnosis of core degradation from fission products measurements) is to monitor in real time the release of the major fission products (krypton, xenon, gaseous forms of iodine and ruthenium) outside the nuclear reactor containment. These products are released at different times during a nuclear accident and at different states of the nuclear core degradation. Thus, monitoring these fission products gives information on the situation inside the containment and helps to apply the Severe Accident Management procedures. Analytical techniques have been proposed and evaluated. The results are discussed here.

  17. Analytical measurements of fission products during a severe nuclear accident

    Directory of Open Access Journals (Sweden)

    Doizi D.

    2018-01-01

    Full Text Available The Fukushima accident emphasized the fact that ways to monitor in real time the evolution of a nuclear reactor during a severe accident remain to be developed. No fission products were monitored during twelve days; only dose rates were measured, which is not sufficient to carry out an online diagnosis of the event. The first measurements were announced with little reliability for low volatile fission products. In order to improve the safety of nuclear plants and minimize the industrial, ecological and health consequences of a severe accident, it is necessary to develop new reliable measurement systems, operating at the earliest and closest to the emission source of fission products. Through the French program ANR « Projet d’Investissement d’Avenir », the aim of the DECA-PF project (diagnosis of core degradation from fission products measurements is to monitor in real time the release of the major fission products (krypton, xenon, gaseous forms of iodine and ruthenium outside the nuclear reactor containment. These products are released at different times during a nuclear accident and at different states of the nuclear core degradation. Thus, monitoring these fission products gives information on the situation inside the containment and helps to apply the Severe Accident Management procedures. Analytical techniques have been proposed and evaluated. The results are discussed here.

  18. A review on liability in case of nuclear accident

    International Nuclear Information System (INIS)

    Gallage-Alwis, Sylvie; Faron, Pauline

    2013-01-01

    After having evoked assessments of the cost of a nuclear accident in France and of that of damages caused by the Fukushima accident, the authors propose an overview of the issue of liability of companies involved in the operation of a nuclear power plant. They outline that this regime is mainly governed by two international conventions: the Paris Convention on third party liability in the field of nuclear energy, and the Brussels Convention. The first one bears on the liability of nuclear installation operators, while the second one aims at ensuring an additional compensation of casualties on public funds. They also evoke the Vienna Convention which aims at defining a world regime for nuclear liability. They outline the limited scope of application of the Paris Convention, and the limitation of compensations. They discuss the liability of companies others than those operating nuclear installations

  19. On the Perspective of Nuclear Energy Following the Fukushima Accident

    International Nuclear Information System (INIS)

    Cavlina, N.; Knapp, V.; Pevec, D.

    2011-01-01

    Future of nuclear energy after accidents on the nuclear power station Daichi at Fukushima has been questioned and discussed. At present 433 nuclear power plants are contributing with about 14% to the world production of electricity. Looking at regional distribution of nuclear power plants, the largest number of nuclear power plants (143) is operating in European Union (EU) producing around one third of its electric energy. EU leads the world in the use of nuclear energy, with very good geopolitical and strategic reasons. Without its own oil and gas resources and with high dependence on external supplier EU has a problem in conducting independent foreign policy. As industrially and technologically developed region of the world EU intends to play a leading role in efforts to reduce C0 2 emission and limit the global temperature increase to below 2 degrees of C. Also, nuclear energy is important for international competitiveness of European industry. After the Fukushima accident, and in the light of that event, many expert groups have revaluated the safety of operating nuclear power plants. Whilst they do not find faults with basic conceptions, some safety related improvements will be recommended. As regards to nuclear energy in EU, irrespectively of short or medium term political decisions, long term geopolitical and strategic reasons that stimulated strong nuclear development in the past, continue to exist. Thus, we may expect continuation of nuclear development in EU without essential delays. As it appears, pending post-Fukushima nuclear safety analysis and applying safety improvements where needed, Fukushima accident will not stop nuclear development in industrially and technologically developed regions of the world. In view of frequently expressed claims that nuclear fuel resources are insufficient for the long term large scale production of nuclear energy we also give a short comment on the sustainability of nuclear energy. (author)

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

    International Nuclear Information System (INIS)

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

    2011-01-01

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

  1. Nuclear Accidents Intervention Levels for Protection of the Public

    International Nuclear Information System (INIS)

    1989-01-01

    The impact of the 1986 Chernobyl accident called attention to the need to improve international harmonization of the principles and criteria for the protection of the public in the event of a nuclear accident. This report provides observations and guidance related to the harmonization of radiological protection criteria, and is intended to be of use to national authorities and international organizations examining the issue of emergency response planning and intervention levels

  2. The accident of the Three Mile Island nuclear power plant

    International Nuclear Information System (INIS)

    Llory, M.

    1999-01-01

    This book questions which statement can be made twenty years after the accident of the Three Mile Island reactor (USA) on the performances of complex reactor safety systems and on their evolutions and improvements. It questions also todays limits of reactors security and how such a reactor accident can be possible today. It presents also an analysis of the organizations which propose new perspectives in nuclear safety. (J.S.)

  3. Japanese Nuclear Accident and U.S. Response

    International Nuclear Information System (INIS)

    Douet, Randy

    2011-01-01

    U.S. Government response to the Fukushima accident: • Multi-agency task force (Nuclear Regulatory Commission, Department of Energy, Department of Defense) supporting Japan recovery efforts; • President Obama directed the NRC to perform a comprehensive review of U.S. reactors; • NRC established agency task force to develop lessons learned from Fukushima Daiichi accident to provide short-term and long-term analysis of the events

  4. External Cost Assessment of Nuclear Power Plant Accident considering Public Risk Aversion Behavior: the Korean Case

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Hun; Kang, Hyun Gook [KAIST, Daejeon (Korea, Republic of)

    2016-05-15

    The conventional approach for monetary valuation of NPP accident consequence consists of calculating the expected value of various accident scenarios. However, the main criticism of the conventional approach is that there is a discrepancy between the social acceptability of the risk and the estimated expected value of NPP accident. Therefore, an integrated framework for the estimation of the external cost associated with an NPP accident considering the public risk aversion behavior was proposed in this study based on the constructed theoretical framework for estimating both the value of statistical life (VSL) and the risk aversion coefficient associated with an NPP accident to take account of the accident cost into the unit electricity generation cost of NPP. To estimate both parameters, an individual-level survey was conducted on a sample of 1,364 participants in Korea. Based on the collected survey responses, both parameters were estimated based on the proposed framework and the external cost of NPP accident was estimated based on the consequence analysis and considering the direct cost factors for NPP accident. Internalization of external costs into the comprehensive energy production cost has been considered as a potentially efficient policy instrument for a more sustainable energy supply and use. However, the internalization of externalities, such as public health damage, have raised a number of generic policy issues in a nuclear energy sector, with specific challenges resulting from the distinct characteristics of external cost estimation. Especially, the major challenge remained to address the public safety concerns regarding a nuclear accident, which can be specified as low-probability high-consequence accident, driven by the aspects of public risk aversion.

  5. External Cost Assessment of Nuclear Power Plant Accident considering Public Risk Aversion Behavior: the Korean Case

    International Nuclear Information System (INIS)

    Lee, Sang Hun; Kang, Hyun Gook

    2016-01-01

    The conventional approach for monetary valuation of NPP accident consequence consists of calculating the expected value of various accident scenarios. However, the main criticism of the conventional approach is that there is a discrepancy between the social acceptability of the risk and the estimated expected value of NPP accident. Therefore, an integrated framework for the estimation of the external cost associated with an NPP accident considering the public risk aversion behavior was proposed in this study based on the constructed theoretical framework for estimating both the value of statistical life (VSL) and the risk aversion coefficient associated with an NPP accident to take account of the accident cost into the unit electricity generation cost of NPP. To estimate both parameters, an individual-level survey was conducted on a sample of 1,364 participants in Korea. Based on the collected survey responses, both parameters were estimated based on the proposed framework and the external cost of NPP accident was estimated based on the consequence analysis and considering the direct cost factors for NPP accident. Internalization of external costs into the comprehensive energy production cost has been considered as a potentially efficient policy instrument for a more sustainable energy supply and use. However, the internalization of externalities, such as public health damage, have raised a number of generic policy issues in a nuclear energy sector, with specific challenges resulting from the distinct characteristics of external cost estimation. Especially, the major challenge remained to address the public safety concerns regarding a nuclear accident, which can be specified as low-probability high-consequence accident, driven by the aspects of public risk aversion

  6. Methodology used in IRSN nuclear accident cost estimates in France

    International Nuclear Information System (INIS)

    2015-01-01

    This report describes the methodology used by IRSN to estimate the cost of potential nuclear accidents in France. It concerns possible accidents involving pressurized water reactors leading to radioactive releases in the environment. These accidents have been grouped in two accident families called: severe accidents and major accidents. Two model scenarios have been selected to represent each of these families. The report discusses the general methodology of nuclear accident cost estimation. The crucial point is that all cost should be considered: if not, the cost is underestimated which can lead to negative consequences for the value attributed to safety and for crisis preparation. As a result, the overall cost comprises many components: the most well-known is offsite radiological costs, but there are many others. The proposed estimates have thus required using a diversity of methods which are described in this report. Figures are presented at the end of this report. Among other things, they show that purely radiological costs only represent a non-dominant part of foreseeable economic consequences. (authors)

  7. Emergency response and nuclear risk governance. Nuclear safety at nuclear power plant accidents

    International Nuclear Information System (INIS)

    Kuhlen, Johannes

    2014-01-01

    The present study entitled ''Emergency Response and Nuclear Risk Governance: nuclear safety at nuclear power plant accidents'' deals with issues of the protection of the population and the environment against hazardous radiation (the hazards of nuclear energy) and the harmful effects of radioactivity during nuclear power plant accidents. The aim of this study is to contribute to both the identification and remediation of shortcomings and deficits in the management of severe nuclear accidents like those that occurred at Chernobyl in 1986 and at Fukushima in 2011 as well as to the improvement and harmonization of plans and measures taken on an international level in nuclear emergency management. This thesis is divided into a theoretical part and an empirical part. The theoretical part focuses on embedding the subject in a specifically global governance concept, which includes, as far as Nuclear Risk Governance is concerned, the global governance of nuclear risks. Due to their characteristic features the following governance concepts can be assigned to these risks: Nuclear Safety Governance is related to safety, Nuclear Security Governance to security and NonProliferation Governance to safeguards. The subject of investigation of the present study is as a special case of the Nuclear Safety Governance, the Nuclear Emergency governance, which refers to off-site emergency response. The global impact of nuclear accidents and the concepts of security, safety culture and residual risk are contemplated in this context. The findings (accident sequences, their consequences and implications) from the analyses of two reactor accidents prior to Fukushima (Three Mile Iceland in 1979, Chernobyl in 1986) are examined from a historical analytical perspective and the state of the Nuclear Emergency governance and international cooperation aimed at improving nuclear safety after Chernobyl is portrayed by discussing, among other topics, examples of &apos

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

    Science.gov (United States)

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

    2015-01-01

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

  9. The medical implications of nuclear power plant accidents

    International Nuclear Information System (INIS)

    Tyror, J.G.; Pearson, G.W.

    1989-11-01

    This paper examines the UK position regarding the potential for an accident at a nuclear power plant, the safeguards in place to prevent such an accident occurring and the emergency procedures designed to cope with the consequences should one occur. It focuses on the role of the medical services and examines previous accidents to suggest the nature and likely scale of response that may need to be provided. It is apparent that designs of UK nuclear power stations are robust and that the likelihood of a significant accident occurring is extremely remote. Emergency arrangements are, however, in place to deal with the eventuality should it arise and these incorporate sufficient flexibility to accommodate a wide range of accidents. Analysis of previous nuclear accidents at Windscale, Three Mile Island and Chernobyl provide a limited but valuable insight into the diversity and potential scale of response that may be required. It is concluded that above all, the response must be flexible to enable medical services to deal with the wide range of effects that may arise. (author)

  10. Integration of risk aversion in the evaluation of the external cost of a nuclear accident

    International Nuclear Information System (INIS)

    Eeckhoudt, L.; Schieber, C.; Schneider, Th.

    1998-01-01

    Full text of publication follows: the external costs of fuel cycles used in the production of electricity are those imposed on society and environment that are not accounted for by the producers and consumers of energy. Within the evaluation of the external cost of the nuclear fuel cycle, the evaluation of a nuclear accident has to be addressed. For this purpose, the basic approach consists in calculating the expected value of various occident scenarios. the main criticism of this approach is that there is a discrepancy between the social acceptability of the risk and the average monetary value which corresponds in principle to the compensation of the consequences for each individual of the population affected by the accident. The aim of this paper is to propose a methodology for the integration of risk aversion, relying on the expected utility approach, as well as a numerical application based on the French data for the external cost of a nuclear accident. Although a huge range of values has been published for the relative risk aversion coefficient, it seems reasonable to adopt a value of 2 for the specific case of nuclear accident. This leads to an estimated multiplying coefficient approximately equal to 20 to be applied to the expected external cost of a nuclear accident corresponding to a release of about 1% of the core. In this case, the external cost of the nuclear accident is estimated to 0.046 mECU/kWh (i.e. about 50% of the total external costs of the nuclear fuel cycle estimated at 0.1 mECU/kWh with a 3% discount rate), instead of 0.0023 mECU/kWh without taking into account risk aversion. (authors)

  11. A Review of Accident Modelling Approaches for Complex Critical Sociotechnical Systems

    National Research Council Canada - National Science Library

    Qureshi, Zahid H

    2008-01-01

    .... This report provides a review of key traditional accident modelling approaches and their limitations, and describes new system-theoretic approaches to the modelling and analysis of accidents in safety-critical systems...

  12. Preparation for the second edition of nuclear criticality safety handbook

    International Nuclear Information System (INIS)

    Okuno, Hiroshi; Nomura, Yasushi

    1997-01-01

    The making of the second edition of Nuclear Criticality Safety Handbook entered the final stage of investigation by the working group. In the second edition, the newest results of the researches in Japan were taken. In this report, among the subjects which were examined continuously from the first edition published in 1988, the size of fuel particles which can be regarded as homogeneous even in a heterogeneous system, the reactivity effect when fuel concentration distribution became not uniform in a homogeneous fuel system, the method of evaluating criticality safety in which submersion is not assumed, and the criticality data when fuel burning is considered are explained. Further, about the matters related to the criticality in chemical processes and the matters related to criticality accident, the outlines are introduced. Finally, the state of preparation for aiming at the third edition is mentioned. Criticality safety control is important for overall nuclear fuel cycle including the transportation and storage of fuel. The course of the publication of this Handbook is outlined. The matters which have been successively examined from the first edition, the results of criticality safety analysis for the dissolving tanks of fuel reprocessing, and the analysis code and the simplified evaluation method for criticality accident are reported. (K.I.)

  13. The biotic sample bank of Chernobyl nuclear accident

    International Nuclear Information System (INIS)

    Li Yu; Min Rui; Cai Jianming

    2006-01-01

    Objective: To built a simple and easy biologic sample bank from irradiated people in nuclear accident, for the long time research of biological effect of low dose ionization radiation on people. Methods: The blood sample is fixed on a piece of filter paper rand sealed up in plastic bottle for keeping, blood sample scribble on glass lice, fixed and dyed as routine clinic examination, and still, reserve a slice of hair of the examined people. Results: Having built a biologic sample bank which from 1162 human body. The samples are come from 958 liquidators of Chernobyl nuclear accident, 46 people in other nuclear accident and 158 people as control groups. It is also having much information details. Conclusions: If the biologic sample bank is combined with the modern bimolecular technique, maybe have much meaningful for the theory and practice of radiobiology. (authors)

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

    Science.gov (United States)

    Perko, Tanja

    2011-07-01

    Past nuclear accidents highlight communication as one of the most important challenges in emergency management. In the early phase, communication increases awareness and understanding of protective actions and improves the population response. In the medium and long term, risk communication can facilitate the remediation process and the return to normal life. Mass media play a central role in risk communication. The recent nuclear accident in Japan, as expected, induced massive media coverage. Media were employed to communicate with the public during the contamination phase, and they will play the same important role in the clean-up and recovery phases. However, media also have to fulfill the economic aspects of publishing or broadcasting, with the "bad news is good news" slogan that is a well-known phenomenon in journalism. This article addresses the main communication challenges and suggests possible risk communication approaches to adopt in the case of a nuclear accident. Copyright © 2011 SETAC.

  15. The compensation of losses in case of a nuclear accident

    International Nuclear Information System (INIS)

    Leger, M.

    2010-01-01

    After having recalled that the elaboration of a special regime of liability for nuclear damages due to a nuclear accident aimed at conciliating two distinct objectives (to protect population and workers, and to provide a judicial security to the nuclear industry), this document comments the present regime of nuclear civil liability, its legal framework and its evolution. It comments its scope of application (geographical field of application, concerned activities, covered damages), and the principles of nuclear civil liability regime (a specific regime has been introduced by the Paris Convention for the operators). The content of Paris and Brussels Conventions review protocols which have been signed in 2004 is described

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

    Science.gov (United States)

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

    2012-09-01

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

  17. EPRI nuclear fuel-cycle accident risk assessment

    International Nuclear Information System (INIS)

    Anon.

    1981-01-01

    The present results of the nuclear fuel-cycle accident risk assessment conducted by the Electric Power Research Institute show that the total risk contribution of the nuclear fuel cycle is only approx. 1% of the accident risk of the power plant; hence, with little error, the accident risk of nuclear electric power is essentially that of the power plant itself. The power-plant risk, assuming a very large usage of nuclear power by the year 2005 is only approx. 0.5% of the radiological risk of natural background. The smallness of the fuel-cycle risk relative to the power-plant risk may be attributed to the lack of internal energy to drive an accident and the small amount of dispersible material. This work aims at a realistic assessment of the process hazards, the effectiveness of confinement and mitigation systems and procedures, and the associated likelihood of errors and the estimated size of errors. The primary probabilistic estimation tool is fault-tree analysis, with the release source terms calculated using physicochemical processes. Doses and health effects are calculated with CRAC (Consequences of Reactor Accident Code). No evacuation or mitigation is considered; source terms may be conservative through the assumption of high fuel burnup (40,000 MWd/t) and short cooling period (90 to 150 d); high-efficiency particulate air filter efficiencies are derived from experiments

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

    Science.gov (United States)

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

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

    International Nuclear Information System (INIS)

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

    1983-11-01

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

  20. Impacts of the Fukushima Daiichi Accident on Nuclear Development Policies

    International Nuclear Information System (INIS)

    Vance, Robert; Henderson, David; ); Moore, Laurie

    2017-01-01

    The Fukushima Daiichi nuclear power plant accident has had an impact on the development of nuclear power around the world. While the accident was followed by thorough technical assessments of the safety of all operating nuclear power plants, and a general increase in safety requirements has been observed worldwide, national policy responses have been more varied. These responses have ranged from countries phasing out or accelerating decisions to phase out nuclear energy to countries reducing their reliance on nuclear power or on the contrary continuing to pursue or expand their nuclear power programs. This study examines changes to policies, and plans and attempts to distinguish the impact of the Fukushima Daiichi accident from other factors that have affected policy-making in relation to nuclear energy, in particular electricity market economics, financing challenges and competition from other sources (gas, coal and renewables). It also examines changes over time to long-term, quantitative country projections, which reveal interesting trends on the possible role of nuclear energy in future energy systems. (authors)

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

    Science.gov (United States)

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

    2005-01-01

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

  2. Policy on stable iodine prophylaxis following nuclear reactor accidents (1989)

    International Nuclear Information System (INIS)

    1989-09-01

    This policy considers the alleviation of possible hazards that may arise from any radioiodines inhaled from a plume of fission products emanating from a nuclear reactor accident. Such a nuclear reactor may be land or ship-based. In any accident that releases radioiodines to the environment, one countermeasure that may need to be considered to reduce the effect of inhalation of radioiodines by persons downwind of the point of release is to provide those persons with tablets containing stable iodine. Both potassium iodide (KI) and potassium iodate (KIO 3 ) are recommended as effective prophylactics tablets for this purpose in Australia. Action levels, doses and contraindicatories are briefly outlined

  3. Safety demonstration analyses at JAERI for severe accident during overland transport of fresh nuclear fuel

    International Nuclear Information System (INIS)

    Nomura, Yasushi; Kitao, Kohichi; Karasawa, Kiyonori; Yamada, Kenji; Takahashi, Satoshi; Watanabe, Kohji; Okuno, Hiroshi; Miyoshi, Yoshinori

    2005-01-01

    structure was found to be intact to maintain leak tightness even in the severe fire accidents. In addition, criticality safety was assessed by using the continuous energy Monte Carlo code MVP and the nuclear data library JENDL-3.2 for the cask in consideration of the mechanical damages and thermal failure resulted from the above analyses. As a conclusion, integrity of the packages of fresh nuclear fuel materials can be maintained even in the case of the severe accident, and criticality safety can also be secured to prevent radioactive material from releasing into environment. (author)

  4. Consequences of nuclear accidents for human beings and the environment; Auswirkungen nuklearer Unfaelle auf den Menschen und die Umwelt

    Energy Technology Data Exchange (ETDEWEB)

    Huebner, Felix; Jung, Jennifer Jana; Schultmann, Frank

    2017-03-15

    In the 1950s and 1960s many countries believed that they could become energy self-efficient with the help of nuclear power plants. For this reason, nuclear energy experienced internationally an enormous upswing during these years. In the following decades, many nuclear power plants were planned and built. Despite a few critics, who drew attention to the dangers of nuclear power use, an end to the upturn was not foreseeable. But in 1979, the nuclear accident in Three Mile Island in Harrisburg (USA) caused international attention and the critics of the nuclear power became stronger. However, many Europeans only were aware of the danger by nuclear power plants when in 1986 the nuclear disaster occurred in the Ukrainian nuclear power plant in Chernobyl. The effects of this nuclear disaster were also felt in Central Europe. Recently, the nuclear disaster at the Fukushima nuclear power plant has prompted a nuclear phase-out in Germany and the rest of the world. This work focuses not on the political implications of these nuclear accidents, but rather on the impacts of nuclear accidents on human beings, animals and the environment. In particular, reports on the incidents in Chernobyl and Fukushima as well as studies on their effects are analysed and summarised.

  5. Anomalies of Nuclear Criticality, Revision 6

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-02-19

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

  6. Nuclear power reactor core melt accidents. Current State of Knowledge

    International Nuclear Information System (INIS)

    Jacquemain, Didier; Cenerino, Gerard; Corenwinder, Francois; Raimond, Emmanuel IRSN; Bentaib, Ahmed; Bonneville, Herve; Clement, Bernard; Cranga, Michel; Fichot, Florian; Koundy, Vincent; Meignen, Renaud; Corenwinder, Francois; Leteinturier, Denis; Monroig, Frederique; Nahas, Georges; Pichereau, Frederique; Van-Dorsselaere, Jean-Pierre; Couturier, Jean; Debaudringhien, Cecile; Duprat, Anna; Dupuy, Patricia; Evrard, Jean-Michel; Nicaise, Gregory; Berthoud, Georges; Studer, Etienne; Boulaud, Denis; Chaumont, Bernard; Clement, Bernard; Gonzalez, Richard; Queniart, Daniel; Peltier, Jean; Goue, Georges; Lefevre, Odile; Marano, Sandrine; Gobin, Jean-Dominique; Schwarz, Michel; Repussard, Jacques; Haste, Tim; Ducros, Gerard; Journeau, Christophe; Magallon, Daniel; Seiler, Jean-Marie; Tourniaire, Bruno; Durin, Michel; Andreo, Francois; Atkhen, Kresna; Daguse, Thierry; Dubreuil-Chambardel, Alain; Kappler, Francois; Labadie, Gerard; Schumm, Andreas; Gauntt, Randall O.; Birchley, Jonathan

    2015-11-01

    For over thirty years, IPSN and subsequently IRSN has played a major international role in the field of nuclear power reactor core melt accidents through the undertaking of important experimental programmes (the most significant being the Phebus-FP programme), the development of validated simulation tools (the ASTEC code that is today the leading European tool for modelling severe accidents), and the coordination of the SARNET (Severe Accident Research Network) international network of excellence. These accidents are described as 'severe accidents' because they can lead to radioactive releases outside the plant concerned, with serious consequences for the general public and for the environment. This book compiles the sum of the knowledge acquired on this subject and summarises the lessons that have been learnt from severe accidents around the world for the prevention and reduction of the consequences of such accidents, without addressing those from the Fukushima accident, where knowledge of events is still evolving. The knowledge accumulated by the Institute on these subjects enabled it to play an active role in informing public authorities, the media and the public when this accident occurred, and continues to do so to this day. Following the introduction, which describes the structure of this book and highlights the objectives of R and D on core melt accidents, this book briefly presents the design and operating principles (Chapter 2) and safety principles (Chapter 3) of the reactors currently in operation in France, as well as the main accident scenarios envisaged and studied (Chapter 4). The objective of these chapters is not to provide exhaustive information on these subjects (the reader should refer to the general reference documents listed in the corresponding chapters), but instead to provide the information needed in order to understand, firstly, the general approach adopted in France for preventing and mitigating the consequences of core melt

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

    International Nuclear Information System (INIS)

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

    2012-01-01

    Major reactor accidents of nuclear power plants are rare, yet the consequences are catastrophic. But what is meant by ''rare''? And what can be learned from the Chernobyl and Fukushima incidents? Here we assess the cumulative, global risk of exposure to radioactivity due to atmospheric dispersion of gases and particles following severe nuclear accidents (the most severe ones on the International Nuclear Event Scale, INES 7), using particulate "1"3"7Cs and gaseous "1"3"1I as proxies for the fallout. Our results indicate that previously the occurrence of INES 7 major accidents and the risks of radioactive contamination have been underestimated. Using a global model of the atmosphere we compute that on average, in the event of a major reactor accident of any nuclear power plant worldwide, more than 90% of emitted "1"3"7Cs would be transported beyond 50 km and about 50% beyond 1000 km distance before being deposited. This corroborates that such accidents have large-scale and trans-boundary impacts. Although the emission strengths and atmospheric removal processes of "1"3"7Cs and "1"3"1I are quite different, the radioactive contamination patterns over land and the human exposure due to deposition are computed to be similar. High human exposure risks occur around reactors in densely populated regions, notably in West Europe and South Asia, where a major reactor accident can subject around 30 million people to radioactive contamination. The recent decision by Germany to phase out its nuclear reactors will reduce the national risk, though a large risk will still remain from the reactors in neighbouring countries.

  8. Environment radiological monitoring by JNC related to the JCO criticality accident

    International Nuclear Information System (INIS)

    Watanabe, Hitoshi

    2001-01-01

    Concerning the criticality accident at JCO Co., Ltd. (JCO) which occurred at 10:35 on 30th Sep. 1999, Japan Nuclear Cycle Development Institute (JNC) established ''JNC's task force'' at 12:35 on the same data in conjunction with Head Office and Tokai Works. JNC's task force had collaborated on environmental radiological monitoring with the government of Japan and the local governments. This report compiles the results of the environmental monitoring performed by JNC's task force based on the request from the government of Japan and the local governments. (author)

  9. Safety of Ikata Nuclear Power Station from the accident of Three Mile Island

    International Nuclear Information System (INIS)

    Nonaka, Hiroshi

    1979-01-01

    The leak of radioactive substances occurred on March 28, 1979, in the No. 2 plant of Three Mile Island Nuclear Power Station, and this accident must be put to use to prevent similar accidents and to secure safety hereafter in the nuclear power stations being operated in Japan. In the TMI accident, too many problems concerning the operation management seemed to exist in a series of events. In this paper, a few matters related to the TMI accident among the aspects of the operation management in Ikata Nuclear Power Station are reported. As the problems of operation management, it is considered that the operation of the TMI plant was continued as the exit valve of auxiliary feed line was closed, that it took long time to close the root valve for a pressurizer relief valve manually, and that the ECCS was stopped manually. In TMI, the abnormal phenomenon of losing main feed water has occurred 6 times since the attainment of criticality in March, 1978, and the opening and sticking of pressurizer relief valves occurred at least twice in about 150 times of their actuation in the nuclear reactors designed by Babcock and Wilcox Co. In Ikata Nuclear Power Station, these problems are detected early and the suitable measures are taken immediately, therefore it never happens to continue the operation as the problems are left as they are. It is not conceivable that similar troubles occur many times. (Kako, I.)

  10. Severe accidents and terrorist threats at nuclear reactors

    International Nuclear Information System (INIS)

    Pollack, G.L.

    1987-01-01

    Some of the key areas of uncertainty are the nature of the physical and chemical interactions of released fission products and of the interactions between a molten core and concrete, the completeness and validity of the computer codes used to predict accidents, and the behavior of the containment. Because of these and other uncertainties, it is not yet possible to reliably predict the consequences of reactor accidents. It is known that for many accident scenarios, especially less severe ones or where the containment is not seriously compromised, the amount of radioactive material expected to escape the reactor is less, even much less, than was previously calculated. For such accidents, the predictions are easier and more reliable. With severe accidents, however, there is considerable uncertainty as to the predicted results. For accidents of the type that terrorists might cause - for example, where the sequence of failure would be unexpected or where redundant safety features are caused to fail together - the uncertainties are still larger. The conclusion, then, is that there are potential dangers to the public from terrorist actions at a nuclear reactor; however, because of the variety of potential terrorist threats and the incompleteness of the knowledge about the behavior of reactor components and fission products during accidents, the consequences cannot yet be assessed quantitatively

  11. Report on the accident at the Chernobyl Nuclear Power Station

    International Nuclear Information System (INIS)

    1987-12-01

    This report presents the compilation of information obtained by various organizations regarding the accident (and the consequences of the accident) that occurred at Unit 4 of the nuclear power station at Chernobyl in the USSR on April 26, 1986. Each organization has independently accepted responsibility for one or more chapters. The specific responsibility of each organization is indicated. The various authors are identified in a footnote to each chapter. Very briefly the other chapters cover: the design of the Chernobyl nuclear station Unit 4; safety analyses for Unit 4; the accident scenario; the role of the operator; an assessment of the radioactive release, dispersion, and transport; the activities associated with emergency actions; and information on the health and environmental consequences from the accident. These subjects cover the major aspects of the accident that have the potential to present new information and lessons for the nuclear industry in general. The task of evaluating the information obtained in these various areas and the assessment of the potential implications has been left to each organization to pursue according to the relevance of the subject to their organization. Those findings will be issued separately by the cognizant organizations. The basic purpose of this report is to provide the information upon which such assessments can be made

  12. Accident sequences simulated at the Juragua nuclear power plant

    International Nuclear Information System (INIS)

    Carbajo, J.J.

    1998-01-01

    Different hypothetical accident sequences have been simulated at Unit 1 of the Juragua nuclear power plant in Cuba, a plant with two VVER-440 V213 units under construction. The computer code MELCOR was employed for these simulations. The sequences simulated are: (1) a design-basis accident (DBA) large loss of coolant accident (LOCA) with the emergency core coolant system (ECCS) on, (2) a station blackout (SBO), (3) a small LOCA (SLOCA) concurrent with SBO, (4) a large LOCA (LLOCA) concurrent with SBO, and (5) a LLOCA concurrent with SBO and with the containment breached at time zero. Timings of important events and source term releases have been calculated for the different sequences analyzed. Under certain weather conditions, the fission products released from the severe accident sequences may travel to southern Florida

  13. Applying Functional Modeling for Accident Management of Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Lind, Morten; Zhang Xinxin [Harbin Engineering University, Harbin (China)

    2014-08-15

    The paper investigate applications of functional modeling for accident management in complex industrial plant with special reference to nuclear power production. Main applications for information sharing among decision makers and decision support are identified. An overview of Multilevel Flow Modeling is given and a detailed presentation of the foundational means-end concepts is presented and the conditions for proper use in modelling accidents are identified. It is shown that Multilevel Flow Modeling can be used for modelling and reasoning about design basis accidents. Its possible role for information sharing and decision support in accidents beyond design basis is also indicated. A modelling example demonstrating the application of Multilevel Flow Modelling and reasoning for a PWR LOCA is presented.

  14. Preliminary report about nuclear accident of Chernobylsk reactor

    International Nuclear Information System (INIS)

    Oliveira, A.R. de.

    1986-07-01

    The preliminary report of nuclear accident at Chernobyl, in URSS is presented. The Chernobyl site is located geographically and the RBMK type reactors - initials of russian words which mean high power pressure tube reactors are described. The conditions of reactor operation in beginning of accident, the events which lead to reactor destruction, the means to finish the fire, the measurements adopted by Russian in the accident location, the estimative of radioactive wastes, the meteorological conditions during the accident, the victims and medical assistence, the sanitary aspects and consequences for population, the evaluation of radiation doses received at small and medium distance and the estimative of reffered doses by population attained are presented. The official communication of Russian Minister Council and the declaration of IAEA general manager during a collective interview in Moscou are annexed. (M.C.K.) [pt

  15. Should evacuation conditions after a nuclear accident be revised?

    International Nuclear Information System (INIS)

    Nifenecker, H.

    2011-01-01

    The author proposes to draw lessons from the Fukushima accident, notably in the field of post-accident management. He discusses the definition of an as widely understandable as possible method of description of risks related to irradiations after a nuclear accident. As these irradiations are mainly low dose ones which have a carcinogenic effect, he proposes to assess the average life expectancy loss due to an irradiation. Then, this risk can be easily compared with other risks like air pollution, smoking and passive smoking, and so on. Then, once this risk assessment method is well defined, it is possible to associate the inhabitants of contaminated areas to the post-accident management. They could then decide to go back to their homes or not with full knowledge of the facts

  16. Concerning the structure of occupational accidents involving construction workers in the erection of nuclear power plants

    International Nuclear Information System (INIS)

    Nowak, B.; Roebenack, K.D.

    1991-01-01

    An investigation of 561 occupational accidents involving construction workers which took place during the construction of nuclear power plants failed to show any significant deviation in comparison with general construction as regards process classification, classification of accidents according to occupation and situation, and accidents severity. Occupational accidents which are typial for nuclear power plant construction are a rare exception. (orig.) [de

  17. Catastrophes and nuclear accidents in the former USSR

    International Nuclear Information System (INIS)

    Robeau, D.

    2001-01-01

    In the former USSR, the nuclear safety, the environment protection and the preservation of workers and population health were not the first priority for the Soviet Union authorities. The fabrication of nuclear weapons, the construction of nuclear submarines and the production of an abundant energy source were the only goals at that time. This book describes and explains the circumstances of the nuclear catastrophes and accidents that have occurred during this era. It tries to estimate their impacts on populations and environment and their possible consequences in a near or far future. (J.S.)

  18. A cost effective approach for criticality accident analysis of a DOE SNF storage facility

    International Nuclear Information System (INIS)

    Garrett, R.L.; Couture, G.F.; Gough, S.T.

    1997-01-01

    This paper presents the methodologies used to derive criticality accident analyses for a spent nuclear fuel receipt, storage, handling, and shipping facility. Two criticality events are considered: process-induced and Natural Phenomena Hazards (NPH)-induced. The criticality analyses required the development of: (1) the frequency at which each sceanario occurred, (2) the estimated number of fissions for each scenario, and (3) the consequences associated with each criticality scenario. A fault tree analysis was performed to quantify the frequency of criticality due to process-induced events. For the frequency analysis of NPH-induced criticality, a probabilistic approach was employed. To estimate the consequences of a criticality event, the resulting fission yield was determined using a probabilistic approach. For estimating the source term, a 95% amount of overall conservatism was targeted. This methodology applied to the facility criticality scenarios indicated that: (1) the 95th percentile yield levels from the historical yield distributions are approximately 5 x 10 17 fissions and 5 x 10 18 fissions for internal event and NPH-induced criticality event, respectively; and (2) using probabilistic Latin Hypercube Sampling, the downwind 95th percentile dose to a receptor at the US DOE reservation boundary is 2.2 mrem. This estimate is compared to the bounding dose of 1.4 rem. 4 refs., 1 fig

  19. Review of Ontario Hydro Pickering 'A' and Bruce 'A' nuclear generating stations' accident analyses

    International Nuclear Information System (INIS)

    Serdula, K.J.

    1988-01-01

    Deterministic safety analysis for the Pickering 'A' and Bruce 'A' nuclear generating stations were reviewed. The methodology used in the evaluation and assessment was based on the concept of 'N' critical parameters defining an N-dimensional safety parameter space. The reviewed accident analyses were evaluated and assessed based on their demonstrated safety coverage for credible values and trajectories of the critical parameters within this N-dimensional safety parameter space. The reported assessment did not consider probability of occurrence of event. The reviewed analyses were extensive for potential occurrence of accidents under normal steady-state operating conditions. These analyses demonstrated an adequate assurance of safety for the analyzed conditions. However, even for these reactor conditions, items have been identified for consideration of review and/or further study, which would provide a greater assurance of safety in the event of an accident. Accident analyses based on a plant in a normal transient operating state or in an off-normal condition but within the allowable operating envelope are not as extensive. Improvements in demonstrations and/or justifications of safety upon potential occurrence of accidents would provide further assurance of adequacy of safety under these conditions. Some events under these conditions have not been analyzed because of their judged low probability; however, accident analyses in this area should be considered. Recommendations are presented relating to these items; it is also recommended that further study is needed of the Pickering 'A' special safety systems

  20. Legal contamination of food products in case of nuclear accident. The CRIIRAD criticizes the outrageous work performed by Euratom experts, and calls for a massive mobilisation against the project of the European Commission

    International Nuclear Information System (INIS)

    Castanier, Corinne

    2015-01-01

    After having recalled the content of the project of the European Commission on the definition of maximum permissible levels of radioactive contamination of food products which will be applied in case of nuclear accident, this report first outlines that the associated risk levels are unacceptable (the maximum dose limit would not be respected by far). The authors outline numerous extremely severe anomalies and errors which occurred in the process of elaboration of the project. They try to identify responsibilities for these errors, and wander whether they are due to incompetence, or made on purpose as they always go in the same direction. The CRIIRAD therefore calls for a European mobilisation to sign a petition for a complete review of the applicable regulation. Letters written to or by members of European institutions are provided

  1. Local governments' roles of the compensation for damage by the Tokai JCO criticality accident

    Energy Technology Data Exchange (ETDEWEB)

    Tanabe, Tomoyuki [Central Research Inst. of Electric Power Industry, Tokyo (Japan). Socio-Economic Research Center

    2003-03-01

    The Tokai JCO criticality accident on September 30, 1999 was the first case to which The Law on Compensation for Nuclear Damage was applied. Although the Law on Compensation for Nuclear Damage formulates the outline of the institutional framework for nuclear third party liability together with operator's insurance scheme, details of actual compensation procedure are not specified. By this reason, the compensation procedure in the Tokai accident had been executed without a concrete legal specification and a precedent. In spite of this situation, the compensation procedure with the accident led to an unexpectedly successful result. We observe the several reasons why the compensation procedure was implemented successfully despite the lack of concrete legal specification and a precedent. One of the reasons is that the local governments, Tokai Village and Ibaraki Prefecture, immediately took the leadership in implementing a temporary regime of compensation procedure without wasting time for waiting national government's directives. Upon practicing this compensation procedure, the local governments implemented the following steps. (1) Initial estimation of the amount and scope of damage. (2) Providing the criteria and heads of damage subject to compensation. (3) Unitary compensation procedure at the local levels. (4) Distribution of emergency payments for the victims. (5) Facilitating compensatory negotiation between the victims and JCO as arbitrator. However, some concerns are also pointed out about the fact that the local government directed the whole procedure without sufficient adjustment with the national government for compensation policy. Among all, in the compensation led by the local governments, it was difficult to guarantee fairness of compensation because victims who are influential on the local government such as industrial associations would have unfairly strong negotiation power in the compensatory negotiation, while the operator being

  2. Local governments' roles of the compensation for damage by the Tokai JCO criticality accident

    International Nuclear Information System (INIS)

    Tanabe, Tomoyuki

    2003-01-01

    The Tokai JCO criticality accident on September 30, 1999 was the first case to which The Law on Compensation for Nuclear Damage was applied. Although the Law on Compensation for Nuclear Damage formulates the outline of the institutional framework for nuclear third party liability together with operator's insurance scheme, details of actual compensation procedure are not specified. By this reason, the compensation procedure in the Tokai accident had been executed without a concrete legal specification and a precedent. In spite of this situation, the compensation procedure with the accident led to an unexpectedly successful result. We observe the several reasons why the compensation procedure was implemented successfully despite the lack of concrete legal specification and a precedent. One of the reasons is that the local governments, Tokai Village and Ibaraki Prefecture, immediately took the leadership in implementing a temporary regime of compensation procedure without wasting time for waiting national government's directives. Upon practicing this compensation procedure, the local governments implemented the following steps. (1) Initial estimation of the amount and scope of damage. (2) Providing the criteria and heads of damage subject to compensation. (3) Unitary compensation procedure at the local levels. (4) Distribution of emergency payments for the victims. (5) Facilitating compensatory negotiation between the victims and JCO as arbitrator. However, some concerns are also pointed out about the fact that the local government directed the whole procedure without sufficient adjustment with the national government for compensation policy. Among all, in the compensation led by the local governments, it was difficult to guarantee fairness of compensation because victims who are influential on the local government such as industrial associations would have unfairly strong negotiation power in the compensatory negotiation, while the operator being responsible for the

  3. Nuclear accident dosimetry, Report on the Third IAEA intercomparison experiment at Vinca, Yugoslavia

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1977-03-15

    The objective of this report is to present the results of the third IAEA intercomparison experiment held at the Boris Kidric Institute, Vinca, in May 1973. These experiments were a part of multi laboratory intercomparison programme sponsored by the IAEA for evaluation of nuclear accident dosimetry systems that ought to provide adequate information in the event of criticality accidents. This report deals with the data concerning the Third intercomparison experiments in which the RB reactor at Vinca was used as a source of mixed radiation.

  4. Economic damage caused by a nuclear reactor accident

    International Nuclear Information System (INIS)

    Goemans, T.; Schwarz, J.J.

    1988-01-01

    This study is directed towards the estimation of the economic damage which arises from a severe possible accident with a newly built 1000 MWE nuclear power plant in the Netherlands. A number of cases have been considered which are specified by the weather conditions during and the severity of the accident and the location of the nuclear power plant. For each accident case the economic damage has been estimated for the following impact categories: loss of the power plant, public health, evacuation and relocation of population, export of agricultural products, working and living in contaminated regions, decontamination, costs of transportation and incoming foreign tourism. The consequences for drinking water could not be quantified adequately. The total economic damage could reach 30 billion guilders. Besides the power plant itself, loss of export and decreasing incoming foreign tourism determine an important part of the total damage. 12 figs.; 52 tabs

  5. Nuclear aerosol behavior during reactor accidents

    International Nuclear Information System (INIS)

    Williams, M.M.R.

    1990-01-01

    Some early reactor accidents are recalled together with their associated environmental consequences. One such consequence is the generation of radioactive aerosol. We described the various physical processes that such an aerosol cloud undergoes within the secondary containment building. These physical processes are then brought together quantitatively in a balance equation for the aerosol size spectrum as a function of position and time. Methods for solving this equation are discussed and illustrated by the method of moments based upon log-normal and modified gamma distributions. Current problems are outlined and directions for future work into aerosol behavior are suggested. (author)

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

    Science.gov (United States)

    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. © World Health Organisation 2016. All rights reserved. The World Health Organization has granted Oxford University Press permission for the reproduction of this article.

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

    International Nuclear Information System (INIS)

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

    2016-01-01

    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. (authors)

  8. Operational behaviour of WWER nuclear power units after Chernobyl accident

    International Nuclear Information System (INIS)

    Milivojevic, S.; Spasojevic, D.

    2000-01-01

    The indicators of effectiveness of WWER operation, in 1987-1998 were analyzed. For three groups of nuclear units (WWER, NPP Kozloduy, NPP Paks), the trends of Indicators flow were established. The comparative analysis of forced outage rate, and load factor of WWERs and nuclear units all in the world was carried out; it gives the general picture of accident influence on the states and the relations of these indicators in considered period (author)

  9. Considerations on radiation protection and accidents in nuclear medicine

    International Nuclear Information System (INIS)

    Lima, Carla Flavia de; Avelar, Artur Canella; Campos, Tarcisio P.R.

    2001-01-01

    The present study presents the radiation protection in the services of nuclear medicine in relation to the design of the services, manipulation of sources, cares with the patient, accomplishment of procedures and definition of accidents and incidents; besides approaching the CNEN requirements

  10. Chernobyl accident consequences in Germany: Nuclear safety and radiation protection

    International Nuclear Information System (INIS)

    Edelhauser, H.; Wendling, R.D.; Weiss, W.; Klonk, H.; Weil, L.

    1997-01-01

    A working Programme of the Federal Government was initiated on 26 May 1986 to cover all aspects of nuclear safety and public health, including research and public affairs in the light of the European and international activities resulting from the accident

  11. Preparedness and planning for nuclear accidents at national level

    International Nuclear Information System (INIS)

    Shiukshta, A.

    1998-01-01

    National plan for the protection of population in the case in nuclear accident at Ignalina NPP is presented. The plan was elaborated and approved in 1995, tested in a number of training and practical operations and positively evaluated by experts. The plan provides for measures of protection, their scope, schedule, executive officers and organizations and procedure of implementation

  12. Organisation and tasks concerning population protection in nuclear accident

    International Nuclear Information System (INIS)

    Nikolov, N.

    1995-01-01

    The structure and the scope of activities of Civil Defense Administration of Bulgaria are briefly outlined. Protection of general public in the case of nuclear accident will be provided according to a special off-site emergency plan. The plan is based on results of research and development approved by the permanent commission for public protection. 3 refs

  13. Report from the Special Committee on Fukushima Nuclear Accident

    International Nuclear Information System (INIS)

    Ozawa, Mamoru

    2012-01-01

    The Special Committee on Fukushima Nuclear Accident was established in April 2011 under the Heat Transfer Society of Japan (HTSJ) and discussed (1) how had evolved heat transfer research in progress of nuclear technology, (2) role of expert group in the area of heat transfer academy and technology and (3) energy prospect in Japan after the Fukushima nuclear accident. This report was described by the chairman of the special committee summarizing one year discussions as (1) background of heat transfer research progress, (2) progression of Fukushima Daiichi Nuclear Power Plant accident, (3) energy problem in Japan after the Fukushima accident and (4) social role of the HTSJ. This HTSJ was a unique, nonprofit association in Japan of the people engaged in heat transfers research or in various engineering aspects related to heat transfer, which meant interdisciplinary or common platform of heat transfer as elementary technologies. Such actual complex problems could be discussed in the HTSJ from an overlooking viewpoint in order for the HTSJ to play a social role. (T. Tanaka)

  14. Organisation and tasks concerning population protection in nuclear accident

    Energy Technology Data Exchange (ETDEWEB)

    Nikolov, N [Civil Defence Administration, Sofia (Bulgaria)

    1996-12-31

    The structure and the scope of activities of Civil Defense Administration of Bulgaria are briefly outlined. Protection of general public in the case of nuclear accident will be provided according to a special off-site emergency plan. The plan is based on results of research and development approved by the permanent commission for public protection. 3 refs.

  15. Necessity of international cooperation for the prevention from nuclear accidents

    International Nuclear Information System (INIS)

    Hidayatullah, M.

    1988-01-01

    The lessons learnt from nuclear accidents (Chernobyl and T.M.I.) and atomic bombs effects (Hiroshima, Nakasaki) have served to establish international conventions that insist on regional and international cooperation and on protection of workers and the public against the radiological effects. (author)

  16. Criticality accident in uranium fuel processing plant. Cause analysis and teachings from a viewpoint of a human factor

    International Nuclear Information System (INIS)

    Furuta, Kazuo

    2000-01-01

    On the JCO criticality accident occurred on September 30, 1999, from relatively earlier time since its occurrence it was elucidated that it was formed not by accident and error operation of apparatus and instruments but by unsafe actions of operators beyond regular manual as its direct cause, and that an organizational factor on business managers and safety administration unable to control such unsafe actions of operators at its background. Then, it was judged to be essential to carry out an accident research from a viewpoint of the human factor (HF) for elucidation on essence of the accident, to establish a 'special workshop on the JCO accident research' to investigate elucidation of the accident cause and countermeasure of reoccurrence at a standpoint of HF. As a result, the essential cause of this accident was summarized that safety information such as ideals, information, teachings and so forth necessary for safety management were failed to share among different organizations. As a teaching of this accident, nuclear energy participants must recognize that safety culture is not finished only in specific organization and range but produced by protecting weathering of danger consciousness and effort of mutually exciting and learning by sharing a safety information beyond different organization, range and time. (G.K.)

  17. Environmental consequences of releases from nuclear accidents

    International Nuclear Information System (INIS)

    Tveten, U.

    1990-03-01

    The report presents the results of a four-year Nordic cooperation project (AKTU-200). The results have impact upon many facets of accident consequence assessment, ranging from new computational tools to recommendations concerning food preparation methods to be utilized in a fallout situation. Some of the subprojects have approached areas where little or no research has been performed previously, like the project on winter conditions, the project on the physico/chemical form of radionuclides in the Chernobyl fallout, and the project on resuspension. The conclusion from the first of these projects is that the impact of an accident or fallout situation occuring during winter may be considerable smaller than in a similar situation during summer conditions. The most important conclusion from the second of these projects is that bioavailability of radiocesium in soil is significantly lower than that of radiocesium in plant material taken up via the roots. In the third project is was found that the resuspension factor is several orders of magnitude lower than the values traditionally cited, and that resuspension is a local phenomenon in a majority of weather conditions. The development of large-scale testing of mitigating actions to prevent uptake of radiocesium in animals in a fallout situation is also one of the projects where new ground has been sucessfully broken. 189 refs., 89 figs., 55 tabs

  18. Nuclear accidents and policy. Notes on public perception

    Energy Technology Data Exchange (ETDEWEB)

    Richter, Felix; Steenbeck, Malte; Wilhelm, Markus [Hamburg Univ. (Germany). Lehrstuhl fuer Wirtschaftspolitik

    2013-07-01

    Major nuclear accidents as recently in Fukushima set nuclear power plant security at the top of the public agenda. Using data of the German Socio-Economic Panel we analyze the effects of the Fukushima accident and a subsequent government decision on nuclear power phase-out on several measures of subjective perception in Germany. In the light of current political debates about the strategic orientation of this energy turnaround, such an analysis is of particular interest since non-pecuniary gains in measures of subjective perception might provide further aspects to be taken into consideration when evaluating the economic costs of the policy. We find that the Fukushima accident increases the probability to report greater worries about the environment. Furthermore, we find evidence for a decrease in the probability to be very worried about the security of nuclear power plants as well as for an increase in reported levels of subjective well-being following the government's resolution on nuclear phase-out. Finally we find that the probabilities of reporting very high concerns are related to the distance between the respondents' place of residence and the nearest nuclear power station.

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

    International Nuclear Information System (INIS)

    Fabrikant, J.I.

    1980-05-01

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

  20. Nuclear accidents and policy. Notes on public perception

    Energy Technology Data Exchange (ETDEWEB)

    Richter, Felix; Steenbeck, Malte; Wilhelm, Markus [Hamburg Univ. (Germany). Lehrstuhl fuer Wirtschaftspolitik

    2013-07-01

    Major nuclear accidents as recently in Fukushima set nuclear power plant security at the top of the public agenda. Using data of the German Socio-Economic Panel we analyze the effects of the Fukushima accident and a subsequent government decision on nuclear power phase-out on several measures of subjective perception in Germany. In the light of current political debates about the strategic orientation of this energy turnaround, such an analysis is of particular interest since non-pecuniary gains in measures of subjective perception might provide further aspects to be taken into consideration when evaluating the economic costs of the policy. We find that the Fukushima accident increases the probability to report greater worries about the environment. Furthermore, we find evidence for a decrease in the probability to be very worried about the security of nuclear power plants as well as for an increase in reported levels of subjective well-being following the government's resolution on nuclear phase-out. Finally we find that the probabilities of reporting very high concerns are related to the distance between the respondents' place of residence and the nearest nuclear power station.

  1. Medical assistance in case of nuclear accident

    International Nuclear Information System (INIS)

    Dodig, D.; Tezak, S.; Kasal, B.; Huic, D.; Medvedec, M.; Loncaric, S.; Grosev, D.; Rozman, B.; Popovic, S.

    1996-01-01

    Medical service is a prerequisite for work license of nuclear installation. Every nuclear installation incorporate in their safety procedure also medical emergency plan. Usually the medical emergency plan consists of several degrees of action: 1. First aid, 2. First medical treatment, 3. Treatment in regional hospital, 4. Treatment in special institution (centre for radiation medicine). This paper discusses organization and activities of Centre for Radiation Medicine and Protection - Clinical Hospital Centre Zagreb

  2. Critical management system for nuclear fuels

    International Nuclear Information System (INIS)

    Tai, Ichiro; Seki, Eiji.

    1981-01-01

    Purpose: To enable to provide display for the scale of accidents and critical state by detecting gamma-rays issued from nuclear fuels by gamma-ray level indicators to obtain outputs in proportion to the input level of the gamma-rays based on the detected pulse signals. Constitution: The gamma-ray level indicators comprises a plastic scintillator that emits light upon input of gamma-rays and a photomultiplier that amplifies weak fluorescence obtained from the scintillator. The photomultiplier is applied with a high voltage from a power source. A pre-amplifier amplifies pulse signals corresponding to individual gamma-rays at a high amplification factor and send them to a pulse counter circuit if the detected signal level from the gamma-ray level indicators is low, or amplifies the pulse detection signals at a low amplification factor and sends them to a voltage pulse averaging circuit if the detection signal level is high. A signal procession circuit selects the output from the pulse counter circuit or the voltage pulse averaging circuit. Thus, the system has a linear characteristic over a wide range equivalent to a wide range of incident gamma-rays. (Horiuchi, T.)

  3. Nuclear laws and radiologic accidents; Direito nuclear e os acidentes radiologicos

    Energy Technology Data Exchange (ETDEWEB)

    Frois, Fernanda [Pontificia Univ. Catolica de Sao Paulo, SP (Brazil)

    1997-12-31

    Some aspects of the nuclear activities in Brazil, specially concerning the Goiania s accident are demonstrated using concepts from environmental and nuclear law. Nuclear and environmental competence, the impossibility of the states of making regional laws, as the lack of regulation about the nuclear waste, are discussed. The situation of Goiania when the accident happened, the present situation of the victims and the nuclear waste provisionally stored in Abadia de Goias is reported 7 refs.; e-mail: froes at sti.com.br

  4. Analysis of articles in weekly magazines on scientific issues related to Fukushima nuclear power plant accident

    International Nuclear Information System (INIS)

    Sano, Kazumi; Kikuchi, Macoto

    2012-01-01

    The large area was polluted by the radioactive fallout released after the nuclear fuel meltdown of Fukushima first nuclear plant of Tokyo electric power company. The news media that reported the accident were required to have scientific knowledge on the structure of the nuclear reactor and the physics and health issues of the radioactivity. In this paper, we focus on how the weekly magazines reported this critical accident. The weekly magazines are not regarded as a neutral news media. Rather, their articles in general strongly reflect the editorial opinions. In this sense, the weekly magazines are 'biased media'. So, there are many points to discuss from the view point of the science communication. We analyze the articles appeared in the seven major weekly magazines published during the first half year after the earthquake. We found that the differences in the scientific literacy between magazines are reflected, for example, in selection of the experts who made comments in articles. (author)

  5. Indemnification of Damage in the Event of a Nuclear Accident

    International Nuclear Information System (INIS)

    2006-01-01

    The Second International Workshop on the Indemnification of Nuclear Damage was held in Bratislava, Slovak Republic, from 18 to 20 May 2005. The workshop was co-organised by the OECD Nuclear Energy Agency and the Nuclear Regulatory Authority of the Slovak Republic. It attracted wide participation from national nuclear authorities, regulators, operators of nuclear installations, nuclear insurers and international organisations. The purpose of the workshop was to assess the third party liability and compensation mechanisms that would be implemented by participating countries in the event of a nuclear accident taking place within or near their borders. To accommodate this objective, two fictitious accident scenarios were developed: one involving a fire in a nuclear installation located in the Slovak Republic and resulting in the release of significant amounts of radioactive materials off-site, and the other a fire on board a ship transporting enriched uranium hexafluoride along the Danube River. The first scenario was designed to involve the greatest possible number of countries, with the second being restricted to countries with a geographical proximity to the Danube. These proceedings contain the papers presented at the workshop, as well as reports on the discussion sessions held. (author)

  6. Nuclear energy. Danger only in case of accidents?

    Energy Technology Data Exchange (ETDEWEB)

    Scherb, Hagen; Voigt, Kristina; Kusmierz, Ralf [Helmholtz Zentrum Muenchen, Neuherberg (Germany). Inst. of Computational Biology

    2014-07-01

    The environmental impacts of nuclear energy are highly underestimated. Nuclear weapons, atomic bomb tests, and nuclear accidents are considered a danger for the environment and a human cancer risk. However, childhood leukemia is consistently elevated near nuclear power plants and the Chernobyl accident entailed elevated human birth sex ratios across Europe. We studied the annual sex ratio near nuclear facilities in Germany, France, and Switzerland at the municipality level. We will demonstrate that low doses of ionizing radiation cause effects in human beings. This is shown by strongly consistent spatial-temporal shifts in the human sex ratio trends in the vicinity of nuclear facilities. In the chosen countries complete official data on over 70 million gender specific annual births at the municipality level are available. By Lambert-93 coordinates (France) and GK3 coordinates (Germany, Switzerland) we determined the minimum distances of municipalities from major nuclear facilities. Spatial-temporal trend analyses of the annual sex ratio depending on municipalities' minimum distances from nuclear facilities were carried out. Applying ordinary linear logistic regression (jump or broken-stick functions) and non-linear logistic regression (Rayleigh functions) we demonstrate that the sex ratio at birth shows the influence of mutagenic ionizing radiation on human health. As important environmental chemical contaminants are also mutagenic, the usefulness of the sex ratio at birth as a genetic health indicator can be inferred by analogy.

  7. Nuclear energy. Danger only in case of accidents?

    International Nuclear Information System (INIS)

    Scherb, Hagen; Voigt, Kristina; Kusmierz, Ralf

    2014-01-01

    The environmental impacts of nuclear energy are highly underestimated. Nuclear weapons, atomic bomb tests, and nuclear accidents are considered a danger for the environment and a human cancer risk. However, childhood leukemia is consistently elevated near nuclear power plants and the Chernobyl accident entailed elevated human birth sex ratios across Europe. We studied the annual sex ratio near nuclear facilities in Germany, France, and Switzerland at the municipality level. We will demonstrate that low doses of ionizing radiation cause effects in human beings. This is shown by strongly consistent spatial-temporal shifts in the human sex ratio trends in the vicinity of nuclear facilities. In the chosen countries complete official data on over 70 million gender specific annual births at the municipality level are available. By Lambert-93 coordinates (France) and GK3 coordinates (Germany, Switzerland) we determined the minimum distances of municipalities from major nuclear facilities. Spatial-temporal trend analyses of the annual sex ratio depending on municipalities' minimum distances from nuclear facilities were carried out. Applying ordinary linear logistic regression (jump or broken-stick functions) and non-linear logistic regression (Rayleigh functions) we demonstrate that the sex ratio at birth shows the influence of mutagenic ionizing radiation on human health. As important environmental chemical contaminants are also mutagenic, the usefulness of the sex ratio at birth as a genetic health indicator can be inferred by analogy.

  8. Absorbed dose by thyroid in case of nuclear accidents

    International Nuclear Information System (INIS)

    Campos, Laelia; Attie, Marcia Regina Pereira; Amaral, Ademir

    2011-01-01

    Radioisotopes of iodine are produced in abundance in nuclear fission reactions, and great amounts of radioiodine may be released into the environment in case of a nuclear reactor accident. Thyroid gland is among the most radiosensitive organs due to its capacity to concentrate iodine. The aim of this work was to evaluate the importance of contributions of internally deposited iodines ( 131 I, 132 I, 133 I, 134 I and 135 I) to the dose absorbed to thyroid follicle and to the whole organ, after internal contamination by those isotopes. For internal dose calculation, the code of particles transport MCNP4C was employed. The results showed that, in case of nuclear accidents, the contribution of short-lived iodines for total dose is about 45% for thyroid of newborn and about 40% for thyroid of adult. Thus, these contributions should not be neglected in a prospective evaluation of risks associated to internal contamination by radioactive iodine. (author)

  9. Current state of the communications program concerning nuclear energy following the JCO accident

    International Nuclear Information System (INIS)

    Mitsui, Rie

    2001-01-01

    Full text: Public trust in nuclear energy was significantly affected by a criticality accident that occurred in September 1999 at JCO's uranium re-conversion plant in Tokai-mura Village, Ibaraki Prefecture, some 120 kilometres north-east of Tokyo. An opinion survey was taken with local citizens in December that year, asking them how their views on nuclear energy changed after the accident. The survey findings indicate a grave fact that the citizens, who had lived in harmony with nuclear energy for the past 40 years, lost their confidence in this energy source because of the accident. The mishap also led to severer public opinion on nuclear energy at the nation-wide level, bringing forth a serious impediment to such projects as the siting of new nuclear power plants, the use of plutonium in light water reactors, intermediate storage of spent nuclear fuel, and the promotion of high-level radioactive waste disposal. Japan Atomic Energy Relations Organisation analysed the critical situation surrounding nuclear energy development in the country. Based on the analysis results, JAERO is now actively promoting an interactive, participatory program that meets people's needs, in an effort to regain public trust in nuclear energy. We, at JAERO, believe that greater importance should be attached to the offer of relevant information to the rising generation that will play a leading role in future society. The most typical of JAERO activities for junior and senior high school students include an Essay Content launched in 1968 in commemoration of Atomic Energy Day on October 26 every year and a Radiation Workshop established in 1978. Through more than 11,000 essays collected from junior and senior high school students across the county, this report discusses how these young people think of the JCO criticality accident and what they expect of nuclear energy development in the years ahead. Amid growing public concern with radiation following the JCO accident, the report also

  10. Radiological consequence of Chernobyl nuclear power accident in Japan

    International Nuclear Information System (INIS)

    Uchiyama, Masafumi; Nakamura, Yuji; Kankura, Takako; Iwasaki, Tamiko; Fujimoto, Kenzo; Kobayashi, Sadayoshi.

    1988-03-01

    Two years have elapsed since the accident in Chernobyl nuclear power station shocked those concerned with nuclear power generation. The effect that this accident exerted on human environment has still continued directly and indirectly, and the reports on the effect have been made in various countries and by international organizations. In Japan, about the exposure dose of Japanese people due to this accident, the Nuclear Safety Commission and Japan Atomic Energy Research Institute issued the reports. In this report, the available data concerning the envrionmental radioactivity level in Japan due to the Chernobyl accident are collected, and the evaluation of exposure dose which seems most appropriate from the present day scientific viewpoint was attempted by the detailed analysis in the National Institute of Radiological Sciences. The enormous number of the data observed in various parts of Japan were different in sampling, locality, time and measuring method, so difficulty arose frequently. The maximum concentration of I-131 in floating dust was 2.5 Bq/m 3 observed in Fukui, and the same kinds of radioactive nuclides as those in Europe were detected. (Kako, I.)

  11. A study into the consequences of a nuclear accident

    International Nuclear Information System (INIS)

    Arnott, D.G.

    1987-07-01

    The nuclear industry in Britain would like to believe, and would like the general public to believe, that major accidents such as that at Chernobyl in 1986, could no happen in Britain, because the design and operating procedure have been made as safe as possible. However, because the designers and operators are human, they can make mistakes. Some of these are mentioned; errors of design, errors of maintenance or inspection and errors of judgement. In spite of protestations to the contrary, a major accident could occur at Sizewell-B reactor. Given that this a real possibility, plans should be drawn up to prepare for the situation. The study considers the possible consequences of a nuclear accident under the headings, human error, how nuclear fission works, radioactivity, the truth about Chernobyl, what patterns of reactor accident are possible, what can be done (this includes meteorological information, the issuing of potassium iodate tables, radiation monitoring and evacuation). Practical issues which should concern the local authorities, especially Wrekin Council, are discussed and a recommendation made for an environmental protection officer to be appointed to keep the matter under continuing review. (U.K.)

  12. Severe accident considerations in Canadian nuclear power reactors

    International Nuclear Information System (INIS)

    Omar, A.M.; Measures, M.P.; Scott, C.K.; Lewis, M.J.

    1990-08-01

    This paper describes a current study on severe accidents being sponsored by the Atomic Energy Control Board (AECB) and provides background on other related Canadian work. Scoping calculations are performed in Phase I of the AECB study to establish the relative consequences of several permutations resulting from six postulated initiating events, nine containment states, and a selection of meteorological conditions and health effects mitigating criteria. In Phase II of the study, selected accidents sequences would be analyzed in detail using models suitable for the design features of the Canadian nuclear power reactors

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

    International Nuclear Information System (INIS)

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

    1986-01-01

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

  14. Nuclear Fuel Behaviour during Reactivity Initiated Accidents. Workshop Proceedings

    International Nuclear Information System (INIS)

    2010-01-01

    A reactivity initiated accident (RIA) is a nuclear reactor accident that involves an unwanted increase in fission rate and reactor power. The power increase may damage the reactor core. The main objective of the workshop was to review the current status of the experimental and analytical studies of the fuel behavior during the RIA transients in PWR and BWR reactors and the acceptance criteria for RIA in use and under consideration. The workshop was organized in an opening session and 5 technical sessions: 1) Recent experimental results and experimental techniques used; 2) Modelling and Data Interpretation; 3) Code Assessment; 4) RIA Core Analysis and 5) Revision and application of safety criteria

  15. Mitigation of severe accidents in Swedish nuclear power plants

    International Nuclear Information System (INIS)

    Soederman, E.

    1987-01-01

    Sweden is the first country to build filtered venting systems, the first one became operable at Barsebaeck nuclear power plant in 1985. In new concepts, now being installed in Sweden, an enhanced containment spray system is the basic element and the filtered venting is only the secondary mitigating system. The filter is a new design, a submerged multi venturi scrubber. The Swedish strategy has been built on three basics: improved knowledge through research; containment integrity through mitigating systems; and accident management to prevent severe accidents. 2 figs

  16. The Impact of Severe Nuclear Accidents on National Decision for Nuclear Decommissioning

    Energy Technology Data Exchange (ETDEWEB)

    Suh, Young A; Hornibrook, Carol; Yim, Man Sung [KAIST, Daejeon (Korea, Republic of)

    2016-05-15

    Many researchers have tried to identify the impact of severe nuclear accidents on a country's or international nuclear energy policy [2-3]. However, there is little research on the influence of nuclear accidents and historical events on a country's decision to permanently shutdown an NPP versus international nuclear decommissioning trends. To demonstrate the correlation between a nuclear severe accident and the impact on world nuclear decommissioning, this research reviewed case studies of individual historical events, such as the St. Lucens, TMI, Chernobyl, Fukushima accidents and the series of events leading up to the collapse of the Soviet Union. For validation of the results of these case studies, a statistical analysis was conducted using the R code. This will be useful in explaining how international and national decommissioning strategies are affected by shutdown reasons, i.e. world historical events. The number of permanently shutdown NPPs was selected as an indicator because any relationship between the number of permanently In conclusion, nuclear severe accidents and historical events have an impact on the number of international NPPs that shutdown permanently and cancelled NPP construction. This directly impacts international nuclear decommissioning policy and nuclear energy policy trends. The number of permanently shutdown NPPs was selected as an indicator because any relationship between the number of permanently.

  17. The Impact of Severe Nuclear Accidents on National Decision for Nuclear Decommissioning

    International Nuclear Information System (INIS)

    Suh, Young A; Hornibrook, Carol; Yim, Man Sung

    2016-01-01

    Many researchers have tried to identify the impact of severe nuclear accidents on a country's or international nuclear energy policy [2-3]. However, there is little research on the influence of nuclear accidents and historical events on a country's decision to permanently shutdown an NPP versus international nuclear decommissioning trends. To demonstrate the correlation between a nuclear severe accident and the impact on world nuclear decommissioning, this research reviewed case studies of individual historical events, such as the St. Lucens, TMI, Chernobyl, Fukushima accidents and the series of events leading up to the collapse of the Soviet Union. For validation of the results of these case studies, a statistical analysis was conducted using the R code. This will be useful in explaining how international and national decommissioning strategies are affected by shutdown reasons, i.e. world historical events. The number of permanently shutdown NPPs was selected as an indicator because any relationship between the number of permanently In conclusion, nuclear severe accidents and historical events have an impact on the number of international NPPs that shutdown permanently and cancelled NPP construction. This directly impacts international nuclear decommissioning policy and nuclear energy policy trends. The number of permanently shutdown NPPs was selected as an indicator because any relationship between the number of permanently

  18. Public attitudes toward nuclear power and the TMI accident

    International Nuclear Information System (INIS)

    Kanga, B.K.

    1983-01-01

    This paper which examines the Three Mile Island accident in the context of public reactions to the plant in the surrounding area emphasises that public attitudes to nuclear power should be discussed according to two time frames - short and long range. Public perception of safety, reliability and economy may be different in the future and the role of the nuclear industry is to operate plants safely and ensure that the public gains a clearer understanding of the essential part played by nuclear reactors in generating electricity. (NEA) [fr

  19. Japanese authorities inform IAEA about accident at nuclear plant

    International Nuclear Information System (INIS)

    2004-01-01

    Full text: The IAEA today received information from Japanese nuclear regulatory authorities about an accident in the steam generator turbine circuit of the Mihama Nuclear Power Plant (unit 3). According to the Japanese nuclear authorities this is a non-radioactive part of the plant. The regulatory body has reported that four contract employees died and 7 were injured, and stated that there was no release of radioactivity. The IAEA continues to be in contact with Japanese authorities and expects to receive updates on a continuous basis. No request for IAEA assistance has been received at this time. (IAEA)

  20. Nuclear power: accident probabilities, risks, and benefits. A bibliography

    International Nuclear Information System (INIS)

    1976-02-01

    This report is a selected listing of 396 documents pertaining to nuclear accident probability and nuclear risk. Because of the attention focused on these concepts by the recent (August 1974) publication of the draft of WASH-1400, ''Reactor Safety Study,'' it is intended that this bibliography make conveniently available the existence of relevant literature on these concepts. Such an awareness will enhance an understanding of probability and risk as applied to nuclear power plants and is essential to their further development and/or application. This bibliography includes first a listing of the selected documents with abstracts and keywords, followed by three indexes: (1) keyword, (2) author, and (3) permuted title

  1. Nuclear Accidents: Consequences for Human, Society and Energy Sector

    Directory of Open Access Journals (Sweden)

    L. A. Bolshov

    2016-01-01

    Full Text Available The article examines radiation and hygienic regulations with regard to the elimination of consequences of the Chernobyl NPP accident in the context of relationships with other aspects, primarily socio-economic and political factors. This experience is reasonable to take into account when defining criteria in other regulatory fields, for example, in radioactive waste classification and remediation of areas. The article presents an analysis of joint features and peculiarities of nuclear accidents in the industry and energy sectors. It is noted that the scale of global consequences of the Chernobyl NPP accident is defined by the large-scale release of radioactivity into the environment, as well as an affiliation of the nuclear installation with the energy sector. Large-scale radiation accidents affect the most diverse spheres of human activities, what, in its turn, evokes the reverse reaction from the society and its institutions, including involvement of political means of settlement. If the latter is seeing for criteria that are scientifically justified and feasible, then the preconditions for minimizing socio-economic impacts are created. In other cases, political decisions, such as nuclear units’ shutdown and phasing out of nuclear energy, appear to be an economic price which society, as a whole and a single industry sector, pay to compensate the negative public response. The article describes fundamental changes in approaches to ensure nuclear and radiation safety that occurred after the Chernobyl NPP accident. Multiple and negative consequences of the Chernobyl accident for human and society are balanced to some extent by a higher level of operational safety, emergency preparedness, and life-cycle safety. The article indicates that harmonization and ensuring consistency of regulations that involve different aspects of nuclear and radiation safety are important to implement practical solutions to the nuclear legacy problems. The

  2. Review of Cytogenetic analysis of restoration workers for Fukushima Daiichi nuclear power station accident

    International Nuclear Information System (INIS)

    Suto, Yumiko

    2016-01-01

    Japan faced with the nuclear accident of the Fukushima Daiichi Nuclear Power Station (NPS) caused by the combined disaster of the Great East Japan Earthquake and the subsequent tsunamis on 11 March 2011. National Institute of Radiological Sciences received all nuclear workers who were engaged in emergency response tasks at the NPS and suspected of being overexposed to acute radiation. Biological dosimetry by dicentric chromosome assay was helpful for medical triage and management of the workers. When an unplanned radiation exposure occurs, biological dosimetry based on cytogenetic assays has been used to estimate the absorbed dose in the exposed individual to get useful information for the medical management of radiological casualties with suspected acute radiation syndrome (ARS). Nowadays, more cytogenetic assays to measure chromosomal aberrations, such as micronuclei in bi-nucleated cells, prematurely condensed chromosomes (PCCs) and inter-chromosomal exchanges detected by fluorescence in situ hybridization (FISH) techniques, are available. However, the dicentric chromosome assay (DCA) using peripheral blood lymphocytes is still considered to be the 'gold standard' of biological dosimetry for the radiation emergency medicine. Experimental protocols of DCA has been standardized and shared among laboratories all over the world. In fact, DCA was useful in previous radiation accidents, e.g. the Chernobyl accident in 1986, the Goiania accident in 1987, the JCO criticality accident in 1999 and the Tokyo electric power company (TEPCO) Fukushima Daiichi Nuclear Power Station (NPS) accident in 2011. The recent development of microscopic image analysis system with automatic metaphase finding and capturing functions was helpful for rapid detection of dicentric chromosomes to perform DCA for the Fukushima NPS restoration workers. (author)

  3. Organization and methods of radiation monitoring while working at nuclear critical assemblies

    International Nuclear Information System (INIS)

    Shishkin, G.V.; Komissarov, L.A.

    1980-01-01

    The organization and methods of environmental radiation monitoring while working at nuclear critical assemblies, are described. Necessary equipment for critical assemblies (signal and Ventilation systems, devices for recording accidental radiation levels of and for measuring radiation field distribution) and the personnel program of actions in case of nuclear accident. The dosimetric control at critical assemblies is usually ensured by telesystems. 8004-01 multi-channel dosimetric device is described as an example of such-system [ru

  4. Nuclear power plant safety - the risk of accidents

    International Nuclear Information System (INIS)

    Higson, D.; Crancher, D.W.

    1975-08-01

    Although it is physically impossible for any nuclear plant to explode like an atom bomb, an accidental release of radioactive material into the environment is conceivable. Three factors reduce the probability of such releases, in dangerous quantities, to an extremely low level. Firstly, there are many safety features built into the plant including a leaktight containment building to prevent the escape of such material. Secondly, the quality of engineering and standards used are far more demanding than in conventional power engineering. Thirdly, strict government licensing and regulatory control is enforced at all phases from design through construction to operation. No member of the general public is known to have been injured or died as a result of any accident to a commercial nuclear power plant. Ten workers have died as a result of over-exposure to radiation from experimental reactors and laboratory work connected with the development of nuclear plant since 1945. Because of this excellent safety record the risk of serious accidents can only be estimated. On the basis of such estimates, the chance of an accident in a nuclear power reactor which could cause a detectable increase in the incidence of radiation-induced illnesses would be less than one chance in a million per year. In a typical highly industrialised society, such as the USA, the estimated risk of an individual being killed by such accidents, from one hundred operating reactors, is no greater than one chance in sixteen million per year. There are undoubtedly risks from reactor accidents but estimates of these risks show that they are considerably less than from other activities which are accepted by society. (author)

  5. Minimum qualifications for nuclear criticality safety professionals

    International Nuclear Information System (INIS)

    Ketzlach, N.

    1990-01-01

    A Nuclear Criticality Technology and Safety Training Committee has been established within the U.S. Department of Energy (DOE) Nuclear Criticality Safety and Technology Project to review and, if necessary, develop standards for the training of personnel involved in nuclear criticality safety (NCS). The committee is exploring the need for developing a standard or other mechanism for establishing minimum qualifications for NCS professionals. The development of standards and regulatory guides for nuclear power plant personnel may serve as a guide in developing the minimum qualifications for NCS professionals

  6. A criticism of ANSI/ANS-8.3-1986: Criticality accident alarm system

    International Nuclear Information System (INIS)

    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

  7. Estimation of dose distribution and neutron spectra in JCO critical accident by shielding calculations

    International Nuclear Information System (INIS)

    Sakamoto, Yukio

    2001-01-01

    The information about neutrons at the surrounding of JCO site in the critical accident is limited to survey results by neutron Rem counter in the period of accident and activation data very near the test facility measured after the shut down of accident. This caused the big uncertainty in the dose estimation by detailed shielding calculation codes. On the other hand, environmental activity data measured by radiochemical researchers included the information about fast neutrons inside of JCO site and thermal neutrons up to 1 km from test facility. It is important to grasp the actual circumstance and examine the executed evaluation of the critical accident as scientifically as possible. Therefore, it is meaningful for different field researchers to corporate and exchange the information. In the Technical Divisions of Radiation Science and Technology in Atomic Energy Society of Japan, the information about neutron spectra are released from their home page and three groups of JAERI/CRC, Sumitomo Atomic Energy Industry and Nuclear Power Engineering Corp. (NUPEC)/Mitsubishi Research Institute Inc. (MRI), tried the shielding calculation by Monte Carlo Code MCNP-4B. The procedures and main results of shielding calculations were reviewed in this report. The main difference of shielding calculation by three groups was density and water content of autoclaved light-weight concrete (ALC) as the wall and ceiling. From the result by NUPEC/MRI, it was estimated that the water content in ALC was from 0.05 g/cm 3 to 0.10 g/cm 3 . The behavior of dose equivalent attenuation obtained by shielding calculation was very similar with the measured data from 250 m to 1,700 m obtained by survey meter, TLD and monitoring post. For more exact dose estimation, more detail examination of density and water content of ALC will be needed. (author)

  8. Application of the MOLE in post-nuclear accident characterization

    International Nuclear Information System (INIS)

    Johnson, S.J.; Alvarez, J.L.

    1981-01-01

    Following a nuclear accident there is a need to determine the chemical composition of materials in liquid, solid and gaseous form, the crystalline structure of solids, the size and chemical composition of particles, and the chemical characterization of contaminants on surfaces. This analytical information is required to reconstruct the accident scenario, to select decontamination methods, and to determine future safety requirements. The MOLE (Molecular Optical Laser Examiner) is a Raman microprobe system which has proven to be a valuable analytical tool in providing this type of chemical information. It can determine the chemical species of polyatomic molecules and ions having characteristic Raman spectra. As little as 1 picogram of a component or a 1 μm particle can be analyzed. The imaging system can also provide mapping of selected components on a surface. A system description, sample handling techniques, and applications are presented. Specific applications to the Three Mile Island-Unit 2 accident are also addressed

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

    International Nuclear Information System (INIS)

    Matsumoto, Hidezo; Kida, Masanori; Kato, Hiroyuki; Hara, Shin-ichi

    1994-01-01

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

  10. 2010 Criticality Accident Alarm System Benchmark Experiments At The CEA Valduc SILENE Facility

    International Nuclear Information System (INIS)

    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.

  11. Graphical representation of nuclear incidents/accidents by associating network in nuclear technical communication

    International Nuclear Information System (INIS)

    Hibino, Aiko; Niwa, Yuji

    2008-01-01

    Nuclear Information Archives (NUCIA) is a service for information disclosure toward the public on nuclear power plants in Japan. This paper focuses on an experience of how information stored in the NUCIA database is processed for information sharing by a 'sociotechnical interface,' the interface to the general public. Information on nuclear accidents was analyzed by market basket analysis and mapped to some graphical representation in the website for comprehension. The resultant data obtained by questionnaire survey suggests that this graphical conversion is effective for letting the public understand nuclear accidents. In this sense, this attempt gives significant hints of 'how technical communication to the public' should be. (author)

  12. Analysis to the criticality the storage and containers to the Juragua Nuclear Power Plant Fuel

    International Nuclear Information System (INIS)

    Guerra Valdes, R.

    1998-01-01

    Presently analysis the criticality the warehouses and containers the nuclear fuels in Juragua nuclear power plant the property multiplicity determined in these system and it is verified that for the geometry and operation conditions defined in the design as well as in accidents situations, the arrangement the fuel stays subcritical with an appropriate margin

  13. Fuel solution criticality accident studies with the SILENE reactor: phenomenology, consequences and simulated intervention

    International Nuclear Information System (INIS)

    Barbry, F.

    1984-01-01

    After defining the content and the objectives of criticality accident studies, the SILENE reactor, a means of studying fuel solution criticality accidents, is presented. Information obtained from the CRAC and SILENE experimental programs are then presented; they concern power excursion phenomenology, radiological consequences, and finally guide-lines for current and future programs

  14. How did Fukushima-Dai-ichi core meltdown change the probability of nuclear accidents?

    International Nuclear Information System (INIS)

    Escobar Rangel, Lina; Leveque, Francois

    2012-10-01

    How to predict the probability of a nuclear accident using past observations? What increase in probability the Fukushima Dai-ichi event does entail? Many models and approaches can be used to answer these questions. Poisson regression as well as Bayesian updating are good candidates. However, they fail to address these issues properly because the independence assumption in which they are based on is violated. We propose a Poisson Exponentially Weighted Moving Average (PEWMA) based in a state-space time series approach to overcome this critical drawback. We find an increase in the risk of a core meltdown accident for the next year in the world by a factor of ten owing to the new major accident that took place in Japan in 2011. (authors)

  15. Nuclear waste management in Canada: critical issues, critical perspectives

    National Research Council Canada - National Science Library

    Johnson, Genevieve Fuji; Durant, Darrin

    2009-01-01

    ... on FSC-certified ancient-forest-free paper (100 percent post-consumer recycled) that is processed chlorineand acid-free. Library and Archives Canada Cataloguing in Publication Nuclear waste management in Canada : critical issues, critical perspectives / edited by Darrin Durant and Genevieve Fuji Johnson. Includes bibliographical references an...

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

    International Nuclear Information System (INIS)

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

    2003-01-01

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

  17. Off-site protective action selection for nuclear reactor accidents

    International Nuclear Information System (INIS)

    Weerakkody, S.D.

    1986-01-01

    A computer program based upon a model using a rational theoretical basis was developed to select appropriate off-site protective actions during nuclear reactor accidents. The special features of this program include (a) introduction of a precursor concept that uses the history of the accident progression to determine the spectrum of potential accident scenarios and estimates of the likelihoods of each accident scenario; (b) use of statistical decision theory and the concept of entropy of a spectrum to select the appropriate protective actions using either the minimax principle or the Bayes action method; and (c) introduction of methods to quantify evacuation travel risks. In order to illustrate the usefulness of the computer program, it was applied at three stages of the Three Mile Island accident scenario. Quantified non-radiological risks of evaluation have been used to establish dose thresholds below which evacuations are not justified. Using the Poisson analysis for evacuation risks and the absolute L-L BEIR model for radiation risk suggests 330 mrems as a reasonable value for this threshold. The usefulness of the program in developing a technical basis to select the size of the plume exposure pathway emergency planning zone (EPZ) is discussed. Quantified evacuation risks, cost, and the current rationale upon which the EPZ is based, justify an EPZ between 5-10 miles for WASH-1400 source-terms

  18. Influence on UK Nuclear Regulation from the Fukushima Daiichi Accident

    International Nuclear Information System (INIS)

    Savage, R.

    2016-01-01

    This paper provides an overview of the UKs response to the Fukushima Daiichi Accident and highlights the influence that this has had on UK nuclear regulation since March 2011. ONR’s Incident Suite was staffed from the first day of the accident and remained active on a 24 hours basis for over two weeks. The purpose was to provide advice to the UK government specifically prompt assurance of why this accident couldn’t take place in the UK and practical advice in relation to the 17,000 UK nationals in Japan at that time. In the early phase of the accident ONR took part in international cooperation with the US, Canadian and French regulators in order to determine the actual technical status of the Fukushima Daiichi power plant units. The UK Secretary of State requested that the ONR Chief Inspector identify any lessons to be learnt by the UK nuclear industry and in doing so cooperate and coordinate with international colleagues. The Interim report was produced (May 2011) this focused on civil NPP’s, provided background to radiation, technology and regulations. This report compared the Japan situation with the UK and identified 11 conclusions and 26 recommendations.

  19. Hazards to nuclear plants from surface traffic accidents

    International Nuclear Information System (INIS)

    Hornyik, K.

    1975-01-01

    Analytic models have been developed for evaluating hazards to nuclear plants from hazardous-materials accidents in the vicinity of the plant. In particular, these models permit the evaluation of hazards from such accidents occurring on surface traffic routes near the plant. The analysis uses statistical information on accident rates, traffic frequency, and cargo-size distribution along with parameters describing properties of the hazardous cargo, plant design, and atmospheric conditions, to arrive at a conservative estimate of the annual probability of a catastrophic event. Two of the major effects associated with hazardous-materials accidents, explosion and release of toxic vapors, are treated by a common formalism which can be readily applied to any given case by means of a graphic procedure. As an example, for a typical case it is found that railroad shipments of chlorine in 55-ton tank cars constitute a greater hazard to a nearby nuclear plant than equally frequent rail shipments of explosives in amounts of 10 tons. 11 references. (U.S.)

  20. Estimated consequences from severe spent nuclear fuel transportation accidents

    International Nuclear Information System (INIS)

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

    1996-01-01

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

  1. Legal responsibility in case of a nuclear accident

    International Nuclear Information System (INIS)

    Nabhane, M. F.

    1988-01-01

    Numerous laws have been elaborated in order to determine the legal responsibility in case of a nuclear accident. These laws were made necessary because of intervention of the factor 'error' in the nuclear accident. The legal definition of 'error' assumes that it results from non-respect or negligence of established norms on the part of the persons who manipulate the instruments of radioactive production. Nuclear research should not be undertaken in a country without the formal engagement of the central authorities to take the necessary dispositions to ensure the security and safety of the populations and their possessions. The world community should not admit a scientific activity in the nuclear field in the absence of guarantees for the safety and the security of man. The state that permits the production of nuclear energy is legally responsible for any failure that might result in radioactive spills. Considering the possibility of error and the dangers attached to the manipulation of radioactive material, the legislators have elaborated a series of laws, which take into consideration two principles: a)The inalienable right of man to life as conceived in the monotheistic religions and proclaimed by positive law; and b)The responsibility of the state for the safety and security of its citizens. Of course, error is human; but if man may make an error of judgement in ordinary normal life, he does not have the right to make the least miscalculation when this might lead to a nuclear disaster. (author)

  2. Fukushima Nuclear Accident Recorded in Tibetan Plateau Snow Pits

    Science.gov (United States)

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

    2015-01-01

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

  3. Assessment of off-site consequences of nuclear accidents (MARIA)

    International Nuclear Information System (INIS)

    Haywood, S.M.

    1985-01-01

    A brief report is given of a workshop held in Luxembourg in 1985 on methods for assessing the off-site radiological consequences of nuclear accidents (MARIA). The sessions included topics such as atmospheric dispersion; foodchain transfer; urban contamination; demographic and land use data; dosimetry, health effects, economic and countermeasures models; uncertainty analysis; and application of probabilistic risk assessment results as input to decision aids. (U.K.)

  4. Assessment of accident risks from german nuclear plants

    International Nuclear Information System (INIS)

    Heuser, F.W.

    1979-01-01

    The German risk study are presented. The main objectives can be summed up as follows: (a) An assessment of the societal risk due to accidents in nuclear power plants with reference to German conditions; (b) To get experience in the field of risk analysis and to provide a basis for estimation of uncertainties; (c) To provide guidance for future activities in the German Reactor Safety Research Program. Finally several conclusions reached by this study are discussed. (author)

  5. Historical civilian nuclear accident based Nuclear Reactor Condition Analyzer

    Science.gov (United States)

    McCoy, Kaylyn Marie

    There are significant challenges to successfully monitoring multiple processes within a nuclear reactor facility. The evidence for this observation can be seen in the historical civilian nuclear incidents that have occurred with similar initiating conditions and sequences of events. Because there is a current lack within the nuclear industry, with regards to the monitoring of internal sensors across multiple processes for patterns of failure, this study has developed a program that is directed at accomplishing that charge through an innovation that monitors these systems simultaneously. The inclusion of digital sensor technology within the nuclear industry has appreciably increased computer systems' capabilities to manipulate sensor signals, thus making the satisfaction of these monitoring challenges possible. One such manipulation to signal data has been explored in this study. The Nuclear Reactor Condition Analyzer (NRCA) program that has been developed for this research, with the assistance of the Nuclear Regulatory Commission's Graduate Fellowship, utilizes one-norm distance and kernel weighting equations to normalize all nuclear reactor parameters under the program's analysis. This normalization allows the program to set more consistent parameter value thresholds for a more simplified approach to analyzing the condition of the nuclear reactor under its scrutiny. The product of this research provides a means for the nuclear industry to implement a safety and monitoring program that can oversee the system parameters of a nuclear power reactor facility, like that of a nuclear power plant.

  6. Implications of the Fukushima accident of nuclear safety in Finland

    International Nuclear Information System (INIS)

    Valtonen, Keijo

    2012-01-01

    A severe accident took place in Japan at Fukushima Dai-ichi nuclear power plant in March 2011. The immediate cause of the accident was a tsunami caused by the earthquake and the fact that the consequences of large tsunamis were not adequately considered in the design of the plant. Although tsunamis are not considered a real threat in Europe, the European Council requested on 25 March 2011 the European Nuclear Safety Regulators' Group (ENSREG) and the European Commission to undertake a comprehensive and transparent risk and safety assessment (''stress test'') of European nuclear power plants [ENSREG 2011A]. This report is prepared to evaluate the safety provisions of Finnish Nuclear Power Plants as specified in the European ''stress tests''. The technical description is based on the Licensees' reports on the issues within these specifications [Fortum 2011; TVO 2011]. Furthermore, evaluation on the current situation carried out by Radiation and Nuclear Safety Authority (STUK) is provided, and the possibilities to further enhance safety in the Finnish NPPs are presented. According to the ENSREG specifications, earthquakes, flooding and extreme weather conditions were studied in the stress tests. In addition, consequences of losses of some safety functions and finally management of severe accidents were studied, irrespective of their probabilities. The European stress tests cover in Finland all the operating nuclear power plants (Loviisa 1 and 2, Olkiluoto 1 and 2) and the unit under construction (Olkiluoto 3). The intermediate storages of spent fuel in Loviisa and in Olkiluoto are included in the stress tests. The new NPP units to be constructed which do not yet have a construction license, (Fennovoima 1, Olkiluoto 4) are not considered in the European stress tests. (orig.)

  7. Discussion on several issues of the accidents management of nuclear power plants in operation

    International Nuclear Information System (INIS)

    Cao Xuewu; Wang Zhe; Zhang Yingzhen

    2009-01-01

    This article discusses several issues of the accident management of nuclear power plants in operation, for example: the necessity, implementation principle of accident management and accident management program etc. For conducting accident management for beyond design basis accidents, this article thinks that the accident management program should be developed and implemented to ensure that the plant and its personnel with responsibilities for accident management are adequately prepared to take effective on-site actions to prevent or mitigate the consequences of severe accident. (authors)

  8. The Fukushima major accident. Seismic, nuclear and medical considerations

    International Nuclear Information System (INIS)

    Carpentier, Alain; Friedel, Jacques; Brezin, Edouard; Baulieu, Etienne-Emile; Courtillot, Vincent; Dercourt, Jean; Jaupart, Claude; Le Pichon, Xavier; Poirier, Jean-Paul; Salencon, Jean; Tapponnier, Paul; Dautray, Robert; Taquet, Philippe; Blanchet, Rene; Le Mouel, Jean-Louis; Chapron, Jean-Yves; Fanon, Joelle; BARD, Pierre-Yves; Bernard, Pascal; Montagner, Jean-Paul; Armijo, Rolando; Shapiro, Nikolai; Tait, Steve; Cara, Michel; Madariaga, Raul; Pecker, Alain; Schindele, Francois; Douglas, John

    2011-01-01

    The first part of this voluminous report addresses mega-earthquakes and mega-tsunamis: scientific data, case of France (West Indies and metropolitan France), and socioeconomic aspects (governance, regulation, para-seismic protection). The second part deals with the nuclear accident at Fukushima: event sequence, situation of the nuclear industry in France after Fukushima, fuel cycle and future opportunities. The third part addresses health and environmental consequences. Each part is completed by a large number of documents in which some specific aspects are more precisely reported, commented and discussed

  9. The criticality accident in Tokaimura and medical aspects of radiation emergency

    International Nuclear Information System (INIS)

    Chen Xiaohua; Mao Bingzhi

    2003-01-01

    A criticality accident occurred on September 30, 1999 at the uranium processing plant in Tokaimura Japan, which is the most severe accident since Chernobyl catastrophe. 213 people were exposed to radiation, among them 2 workers were exposed to 16-23 Gy and 6-10 Gy individually, one worker was 2 Gy, 2 people was 10 mSv and 208 person was 0-5 mSv. Author was invited to attend an international symposium on 'The Criticality Accident in Tokaimura Medical Aspects of Radiation Emergency' in Chiba Japan on December 2000. An overview of the accident, dose estimation and neutron relative biological effects are discussed in this article

  10. The human elements in phenomena giving rise to nuclear accidents

    International Nuclear Information System (INIS)

    Carnino, A.; Raggenbass, A.

    1977-01-01

    In its search for a high degree of safety, the nuclear industry should take into account the human parameters, which play an important role. This role is reflected in the individual records kept on incidents and analysis of these records, as has been carried out in conventional industry, represents a first attempt to allow for this factor. The first inquiries covering the background of incidents led to a series of studies and action in respect of individual staff members: on the part of operators, education of personnel in relation to their duties (for example, simulation of reactor control) and attempts to find objective selection criteria for certain specific posts; on the part of those responsible for safety, ergonomic studies and studies on human reliability. For effective prevention of accidents it is necessary to move backwards along the causality chains and therefore to study a nuclear facility as a man-machine system in order to discover the greatest number of potential accident factors. The nuclear facility is introduced into an environment which imposes its rules, constraints and checks and a full study of the human element in safety implies that they should be taken into account. The programme of the Nuclear Safety Department of the Institute of Protection and Nuclear Safety includes not only systematic updating of incident records but also special ergonomic studies (maintenance in a radioactive environment), studies of human reliability and overall studies known as safety management studies. (author)

  11. Nuclear energy policy issues after the 3.11 Fukushima nuclear accident

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Tatsujiro [Japan Atomic Energy Commission (Japan)

    2014-07-01

    The Fukushima nuclear accident has become one of the worst accidents in nuclear history and it is not completely over yet. It will take at least 30 years or more to decontaminate and decommission the crippled nuclear reactors on site. Still, more than 140,000 people are away from home and restoring and assuring the life and welfare of those evacuated people is the top priority of Japanese government's nuclear energy policy. The government will release its new energy policy soon which will state that nuclear power is considered as an important base load electricity source, while committing to reduce its dependence as much as possible. For nuclear energy policy, there are certain important issues to be overcome regardless of future of nuclear power in Japan. They are: (1) spent fuel management and radioactive waste disposal, (2) restoring public trust (3) securing human resources and (4) plutonium stockpile management.

  12. The accident at TEPCO's Fukushima Dai-ichi Nuclear Power Station - occurrence of the accident, current situation and Future

    International Nuclear Information System (INIS)

    Hirose, K.

    2013-01-01

    In this presentation author analyse course of accident on Fukushima Dai-chi NPPs as well as consequences of this disaster. The following parts are presented: (1) Occurrence of the accident; (2) Evacuation of the residential people; (3) Deterioration and protraction of the accident; (4) Impact on society; (5) Situation of decontamination; (6) Long-term steps towards decommissioning; (7) Situation of other nuclear power stations; (8) Conclusions and lessons learned.

  13. Nuclear Criticality Safety Department Qualification Program

    International Nuclear Information System (INIS)

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

    1996-01-01

    The Nuclear Criticality Safety Department (NCSD) is committed to developing and maintaining a staff of highly qualified personnel to meet the current and anticipated needs in Nuclear Criticality Safety (NCS) at the Oak Ridge Y-12 Plant. This document defines the Qualification Program to address the NCSD technical and managerial qualification as required by the Y-1 2 Training Implementation Matrix (TIM). This Qualification Program is in compliance with DOE Order 5480.20A and applicable Lockheed Martin Energy Systems, Inc. (LMES) and Y-1 2 Plant procedures. It is implemented through a combination of WES plant-wide training courses and professional nuclear criticality safety training provided within the department. This document supersedes Y/DD-694, Revision 2, 2/27/96, Qualification Program, Nuclear Criticality Safety Department There are no backfit requirements associated with revisions to this document

  14. The Nuclear Criticality Information System: An update

    International Nuclear Information System (INIS)

    Koponen, B.L.

    1991-07-01

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

  15. Nuclear criticality safety department training implementation

    International Nuclear Information System (INIS)

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

    1996-01-01

    The Nuclear Criticality Safety Department (NCSD) is committed to developing and maintaining a staff of qualified personnel to meet the current and anticipated needs in Nuclear Criticality Safety (NCS) at the Oak Ridge Y-12 Plant. The NCSD Qualification Program is described in Y/DD-694, Qualification Program, Nuclear Criticality Safety Department This document provides a listing of the roles and responsibilities of NCSD personnel with respect to training and details of the Training Management System (TMS) programs, Mentoring Checklists and Checksheets, as well as other documentation utilized to implement the program. This document supersedes Y/DD-696, Revision 2, dated 3/27/96, Training Implementation, Nuclear Criticality Safety Department. There are no backfit requirements associated with revisions to this document

  16. Nuclear critical opalescence and electromagnetic probes

    International Nuclear Information System (INIS)

    Delorme, J.

    1980-01-01

    A description of nuclear critical opalescence is presented with emphasis on the information which can be gained from electromagnetic probes. The connection with standard nuclear physics treatments is given. Experimental possibilities are reviewed. Present information from electron scattering is shown to be unconclusive. The maximum sensitivity to critical phenomena would be attained by measurements of longitudinal spin form factors. Photopion reactions are analyzed in this spirit and found to be promising

  17. Nuclear critical opalescence and electromagnetic probes

    International Nuclear Information System (INIS)

    Delorme, J.

    1981-01-01

    A description of nuclear critical opalescence is presented with emphasis on the information which can be gained from electromagnetic probes. The connection with standard nuclear physics treatments is given. Experimental possibilities are reviewed. Present information from electron scattering is shown to be unconclusive. The maximum sensitivity to critical phenomena would be attained by measurements of longitudinal spin form factors. Photopion reactions are analyzed in this spirit and found to be promising. (orig.)

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

    Science.gov (United States)

    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.

  19. The nuclear reactor accident at Windscale - October, 1957: Environmental aspects

    International Nuclear Information System (INIS)

    Loutit, J.F.; Marley, W.G.; Russell, R.S.

    1960-01-01

    The nature and cause of the nuclear reactor accident at Windscale in October, 1957, have been described in the summary report of the Committee of Inquiry set up by the Atomic Energy Authority. This report was published in a Command Paper Atomic Energy Office, 1957). The events leading up to the accident occurred on the 8th October, during a routine release of the energy which had become stored in the graphite moderator as a result of the normal operation of the reactor. The Committee concluded that the accident had been caused by local overheating of the uranium fuel elements, the canning of which then failed exposing the uranium and allowing it to oxidize. The temperatures in the affected channels continued to rise, leading to the combustion of the graphite. The amount of radioactivity released during the accident is not known precisely, but approximate estimates were made from the measurements of the radioactive iodine deposited on the ground in this country, and from measurements on air filters obtained both in the United Kingdom and on the continent of Europe

  20. The nuclear reactor accident at Windscale - October, 1957: Environmental aspects

    Energy Technology Data Exchange (ETDEWEB)

    Loutit, J F; Marley, W G; Russell, R S

    1960-12-01

    The nature and cause of the nuclear reactor accident at Windscale in October, 1957, have been described in the summary report of the Committee of Inquiry set up by the Atomic Energy Authority. This report was published in a Command Paper Atomic Energy Office, 1957). The events leading up to the accident occurred on the 8th October, during a routine release of the energy which had become stored in the graphite moderator as a result of the normal operation of the reactor. The Committee concluded that the accident had been caused by local overheating of the uranium fuel elements, the canning of which then failed exposing the uranium and allowing it to oxidize. The temperatures in the affected channels continued to rise, leading to the combustion of the graphite. The amount of radioactivity released during the accident is not known precisely, but approximate estimates were made from the measurements of the radioactive iodine deposited on the ground in this country, and from measurements on air filters obtained both in the United Kingdom and on the continent of Europe.

  1. Operators' arrangement for handling nuclear accidents at power plants

    International Nuclear Information System (INIS)

    Bertron, L.; Meclot, B.

    1986-01-01

    Given the preventive measures adopted by Electricite de France (EDF), the probability of a nuclear accident occurring in a power plant is extremely low but cannot, even so, be considered to be zero. The operator must therefore be prepared for this possibility. Apart from dealing with the consequences of the accident, the organization he sets up must fulfil the double objective of preventing any worsening of the accident and ensuring that the social, political and economic effects remain in proportion to the seriousness of the accident. The paper describes the organization set up by EDF in co-operation with the public authorities, indicating the concepts on which it is based and the logistical resources brought into play, in particular for telecommunications. Reports on the TMI incident showed that public telecommunications services can well be saturated in the event of an emergency. EDF, relying on the combined advantages of all transmission systems which the French Postal and Telecommunications Office can place at its disposal, as well as private networks with a concession from the Government, has taken the necessary precautions to deal with this problem. The organization is also designed to respond to the requirements of the media and the population at large for correct information. These systems are naturally all tested during training exercises which ensure that the organization as a whole can cope, in terms both of manpower and equipment, with a very improbable event. (author)

  2. National response plan - Major nuclear or radiological accidents

    International Nuclear Information System (INIS)

    2014-02-01

    France has been implementing stringent radiation protection and nuclear safety and security measures for many years. However, this does not mean that the country is exempt from having to be prepared to deal with an emergency. Changes in France, Europe and other parts of the globe have made it necessary for France to reconsider how it responds to nuclear and radiological emergencies. As the potential impact of a nuclear or radiological accident can affect a wide range of activities, the plan described herein is based on a cross-sector and inter-ministerial approach to emergency response. The Chernobyl and Fukushima-Daiichi disasters are proof that the consequences of a major nuclear or radiological accident can affect all levels of society. These challenges are substantial and relate to: public health: An uncontrolled nuclear accident can have immediate consequences (death, injury, irradiation) as well as long-term consequences that can lead to increased risk of developing radiation-induced diseases (such as certain types of cancer); environmental quality: Radiation contamination can last for several decades and, in some cases, can result in an area being closed off permanently to the public; economic and social continuity: Nuclear accidents bring human activity to a halt in contaminated areas, disrupting the economic and social order of the entire country. It may therefore be necessary to adapt economic and social systems and carry out clean-up operations if people and businesses have been displaced; quality of international relations: Related to fulfillment of obligations to alert and inform European and international partners. This international dimension also covers the protection of French nationals present in countries stricken by a nuclear accident. This national plan provides reference information on how to prepare for a nuclear or radiological emergency and make the appropriate decisions in the event of an emergency. It covers the emergency phase (including

  3. 1983 international intercomparison of nuclear accident dosimetry systems at Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

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

    1985-04-01

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

  4. Lessons of the accident at Three Mile Island nuclear power plant

    International Nuclear Information System (INIS)

    Veksler, L.M.

    1983-01-01

    Measures taken in the USA for improving safety of NPPs after the accident at ''Three Mile Island'' nuclear power plant are considered. Activities, related to elimination of accident consequences are analyzed. Perspectives of resuming the NPP operation are discussed

  5. Radiological environment within an NPP after a severe nuclear accident

    Science.gov (United States)

    Andgren, Karin; Fritioff, Karin; Buhr, Anna Maria Blixt; Huutoniemi, Tommi

    2017-09-01

    The radiological environment following a severe nuclear accident can be visualised on building layouts. The direct radiation in an area (or room) can be visualized on the layout by a colouring scheme depending on the dose rate level (for example orange for high gamma dose rate level and purple for an intermediate gamma dose rate level). Following the Fukushima accident, a need for update of these layouts has been identified at the Swedish nuclear power plant of Forsmark. Shielding calculations for areas where access is desired for severe accident management have been performed. Many different sources of radiation together with different types of shielding material contribute to the dose that would be received by a person entering the area. External radiation from radioactivity within e.g. pipes and components is considered and also external radiation from radioactivity in the air (originating from diffuse leakage of the containment atmosphere). Results are presented as dose rates for relevant dose points together with a method for estimating the dose rate levels for each of the rooms of the reactor building.

  6. Iodine removal in containment filtered venting system during nuclear accident

    International Nuclear Information System (INIS)

    Bera, Subrata; Deo, Anuj Kumar; Nagrale, D.B.; Paul, U.K.; Prasad, M.; Gaikwad, A.J.

    2015-01-01

    Post Fukushima nuclear accident, containment filtered venting system is being introduced in Indian nuclear power plant to strengthen the defense in depth safety barrier by depressurizing the containment building along with minimization of radioactivity release to environment during a severe accident. Radioactive iodine is one of the major contributors to radiation dose during early release phase of a severe accident. Physical and Chemical form of iodine and iodine bearing compounds includes particulates, elemental and organic. In the most efficient design of CFVS, wet scrubbing mechanism has been employed through use of venture scrubber. The Iodine removal process in wet scrubber involves two processes: chemical reaction in highly alkaline aqueous solution and impingement of particulates with water droplets produced in the venturi nozzle. In this paper, venturi has been modeled using the Calvert model. The variation of efficiency has been estimated for the different particle sizes. The impact of the shape parameter of log-normal distribution on the amount of scrubbed iodine has also been assessed. Release phase wise the scrubbed amount of iodine in the venturi based CFVS system has been estimated for a typical BWR. (author)

  7. Millstone Unit 1 plant vulnerabilities during postulated severe nuclear accidents

    International Nuclear Information System (INIS)

    Khalil, Y.F.

    1993-01-01

    Generic Letter 88-20, Supplement No. 1 (Ref. 1), issued by the Nuclear Regulatory Commission (NRC) requested all licensees holding operating licenses and construction permits for nuclear power reactor facilities to perform Individual Plant Examinations (IPE) of their plant(s) for severe accident vulnerabilities and to submit the results to the Commission. This paper summarizes the major Front-End (Level-1 PRA) and Back-End (Level-2 PRA) insights gained from the Millstone Unit 1 (MP-1) IPE study. No major plant vulnerabilities have been identified from a Front-End perspective. The Back-End analysis, however, has identified two potential containment vulnerabilities during postulated events that progress beyond the Design Basis Accidents (DBAs), namely, (1) MP-1 is dominated by early source term releases that would occur within a six-hour time frame from time of accident initiation, or reactor trip, and (2) MP-1 containment is somewhat vulnerable to leak-type failure through the drywell head. As a result of the second finding, a recommendation currently under evaluation, has been made to increase the drywell head bolt's preload from 54 Kips to resist the containment design pressure value (62 psig)

  8. Severe Accident Simulation of the Laguna Verde Nuclear Power Plant

    Directory of Open Access Journals (Sweden)

    Gilberto Espinosa-Paredes

    2012-01-01

    Full Text Available The loss-of-coolant accident (LOCA simulation in the boiling water reactor (BWR of Laguna Verde Nuclear Power Plant (LVNPP at 105% of rated power is analyzed in this work. The LVNPP model was developed using RELAP/SCDAPSIM code. The lack of cooling water after the LOCA gets to the LVNPP to melting of the core that exceeds the design basis of the nuclear power plant (NPP sufficiently to cause failure of structures, materials, and systems that are needed to ensure proper cooling of the reactor core by normal means. Faced with a severe accident, the first response is to maintain the reactor core cooling by any means available, but in order to carry out such an attempt is necessary to understand fully the progression of core damage, since such action has effects that may be decisive in accident progression. The simulation considers a LOCA in the recirculation loop of the reactor with and without cooling water injection. During the progression of core damage, we analyze the cooling water injection at different times and the results show that there are significant differences in the level of core damage and hydrogen production, among other variables analyzed such as maximum surface temperature, fission products released, and debris bed height.

  9. Radiological environment within an NPP after a severe nuclear accident

    Directory of Open Access Journals (Sweden)

    Andgren Karin

    2017-01-01

    Full Text Available The radiological environment following a severe nuclear accident can be visualised on building layouts. The direct radiation in an area (or room can be visualized on the layout by a colouring scheme depending on the dose rate level (for example orange for high gamma dose rate level and purple for an intermediate gamma dose rate level. Following the Fukushima accident, a need for update of these layouts has been identified at the Swedish nuclear power plant of Forsmark. Shielding calculations for areas where access is desired for severe accident management have been performed. Many different sources of radiation together with different types of shielding material contribute to the dose that would be received by a person entering the area. External radiation from radioactivity within e.g. pipes and components is considered and also external radiation from radioactivity in the air (originating from diffuse leakage of the containment atmosphere. Results are presented as dose rates for relevant dose points together with a method for estimating the dose rate levels for each of the rooms of the reactor building.

  10. Report of the Fukushima nuclear accident by the National Academy of Science. Lessons learned from the Fukushima nuclear accident for improving safety of U.S. nuclear plants

    International Nuclear Information System (INIS)

    Nariai, Hideki

    2014-01-01

    U.S. National Academy of Science investigated the accident at the Fukushima Daiichi nuclear plant initiated by the Great East Japan Earthquake for two years and published a draft report in July 24, 2014. Investigation results were summarized in nine new findings and made ten recommendations in a wide horizon; (1) hardware countermeasures against severe accidents and training of operators, (2) upgrade of risk assessment capability for beyond design basis accident, (3) incorporation of new information about hazards in safety regulations, (4) needed improvement of off-site emergency preparedness, and (5) improvements of nuclear safety culture. New information about hazards related with tsunami assessment, new risk assessment for beyond design basis accident, advice of foreigner resident evacuations, regulatory capture, and safety culture and regulator's specialty were discussed as Japanese issues. (T. Tanaka)

  11. Risk informed analysis of training effectiveness for mitigating accidents of nuclear power plants

    International Nuclear Information System (INIS)

    Lee, Chang Ju

    2012-01-01

    A critical area for deriving expected benefits from training and exercise is the measurement of 'training effectiveness'-how well the training inputs are serving the intended purpose. This aspect is often neglected by nuclear organizations, saying that measurement is difficult. However, I believe that a technique in nuclear society has developed sufficiently to measure most important aspects of training by way of human reliability analysis (HRA) used in probabilistic safety assessment (PSA) of nuclear power plants (NPPs). The consequences of errors caused by lack of training can be evaluated in terms of the overall vulnerability to human error of the facility under consideration. This study presents current situation and considerations for measures of robustness on nuclear accidents and HRA technique on the training effectiveness. In view of risk informed approach with this consideration and an example case, I'd like to identify appropriate relationship between risk measures of robustness and training effectiveness

  12. Accident assessment under emergency situation in Daya Bay nuclear power station

    International Nuclear Information System (INIS)

    Yang Ling; Chen Degan; Lin Shumou; Fu Guohui

    2004-01-01

    The accident assessment under emergency situation includes the accident status evaluation and its consequence estimation. This paper introduces evaluation methods for accident status and its assistant computer system (SESAME-GNP) utilized during the emergency situation in Guangdong Daya Bay Nuclear Power Station (GNPS) in detail. At the same time, an improved accident consequence estimation system in GNPS (RACAS-GNP) is briefly described. With the improvement of the accident assessment systems, the capability of emergency response in GNPS is strengthened

  13. Framatome-ANP France UO2 fuel fabrication. Criticality safety analysis in the light of the JCO accident

    International Nuclear Information System (INIS)

    Doucet, M.; Zheng, S.; Mouton, J.; Porte, R.

    2003-01-01

    In France the 1999' Tokai Mura criticality accident in Japan had a big impact on the nuclear fuel manufacturing facility community. Moreover this accident led to a large public discussion about all the nuclear facilities. The French Safety Authorities made strong requirements to the industrials to revisit completely their safety analysis files mainly those concerning nuclear fuels treatments. The FRAMATOME-ANP production of its French low enriched (5 w/o) UO2 fuel fabrication plant (FBFC/Romans) exceeds 1000 metric tons a year. Special attention was given to the emergency evacuation plan that should be followed in case of a criticality accident. If a criticality accident happens, site internal and external radioprotection requirements need to have an emergency evacuation plan showing the different routes where the absorbed doses will be as low as possible for people. The French Safety Authorities require also an update of the old based neutron source term accounting for state of the art methodology. UO2 blenders units contain a large amount of dry powder strictly controlled by moderation; a hypothetical water leakage inside one of these apparatus is simulated by increasing the water content of the powder. The resulted reactivity insertion is performed by several static calculations. The French IRSN/CEA CRISTAL codes are used to perform these static calculations. The kinetic criticality code POWDER simulates the power excursion versus time and determines the consequent total energy source term. MNCP4B performs the source term propagation (including neutrons and gamma) used to determine the isodose curves needed to define the emergency evacuation plant. This paper deals with the approach FRAMATOME-ANP has taken to assess Safety Authorities demands using the more up to date calculation tools and methodology. (author)

  14. Nuclear fission, chain reaction and criticality

    International Nuclear Information System (INIS)

    Reuss, Paul

    2016-01-01

    Criticality is, notably for nuclear reactors, the status which separates the case of a fission chain reaction which inexorably decays, from that of a reaction which grows faster and faster until a counter-reaction occurs. If this status is an objective in nuclear reactors, it must not be reached or exceeded in any case in other types of installations in which fissile materials are handled (fabrication, transports, nuclear fuel processing). The author proposes an insight into this notion of criticality, discusses elements of neutron science which allow the multiplication factor to be assessed, analyses accidental scenarios which may happen, and presents associated experiments and computation codes

  15. Prevention of the causes and consequences of a criticality accident - measures adopted in France; Prevention des causes et des consequences d'un accident de criticite - solutions adoptees en France

    Energy Technology Data Exchange (ETDEWEB)

    Fruchard, Y.; Lavie, J.M

    1966-07-01

    The question of safety in regard to criticality accident risks has two aspects: prevention of the cause and limitation of the consequences. These two aspects are closely connected. The effort devoted to prevention of the causes depends on the seriousness of the possible human psychologic and economic consequences of the accident. The criticality accidents which have occurred in the nuclear industry, though few in number, do reveal the imperfect nature of the techniques adopted to prevent the causes, and also constitute the only available realistic basis for evaluating the consequences and developing measures to limit them. The authors give a analysis of the known causes and consequences of past criticality accidents and on this basis make a number of comments concerning: the validity of traditional safety criteria, the probability of accidents for different types of operations, characteristic accidents which can serve as models, and the extent of possible radiological consequences. The measures adopted in France to limit the consequences of a possible criticality accident under the headings: location, design and lay-out of the installations, accident detection, and dosimetry for the exposed personnel, are briefly described after a short account of the criteria used in deciding on them. (author) [French] La surete relative aux risques d'accidents de criticite presente deux aspects: la prevention des causes et les parades aux consequences. Ces deux aspects sont tres lies. L'effort consenti a la prevention des causes decoule de l'importance des consequences humaines economiques et psychologiques possibles d'un eventuel accident. Les accidents de criticite survenus dans l'industrie nucleaire, malgre leur rarete, d'une part devoilent les imperfections des techniques de prevention des causes, d'autre part constituent la seule base realiste disponible d'evaluation des consequences et de mise au point des parades a ces consequences

  16. Prevention of the causes and consequences of a criticality accident - measures adopted in France; Prevention des causes et des consequences d'un accident de criticite - solutions adoptees en France

    Energy Technology Data Exchange (ETDEWEB)

    Fruchard, Y; Lavie, J M

    1966-07-01

    The question of safety in regard to criticality accident risks has two aspects: prevention of the cause and limitation of the consequences. These two aspects are closely connected. The effort devoted to prevention of the causes depends on the seriousness of the possible human psychologic and economic consequences of the accident. The criticality accidents which have occurred in the nuclear industry, though few in number, do reveal the imperfect nature of the techniques adopted to prevent the causes, and also constitute the only available realistic basis for evaluating the consequences and developing measures to limit them. The authors give a analysis of the known causes and consequences of past criticality accidents and on this basis make a number of comments concerning: the validity of traditional safety criteria, the probability of accidents for different types of operations, characteristic accidents which can serve as models, and the extent of possible radiological consequences. The measures adopted in France to limit the consequences of a possible criticality accident under the headings: location, design and lay-out of the installations, accident detection, and dosimetry for the exposed personnel, are briefly described after a short account of the criteria used in deciding on them. (author) [French] La surete relative aux risques d'accidents de criticite presente deux aspects: la prevention des causes et les parades aux consequences. Ces deux aspects sont tres lies. L'effort consenti a la prevention des causes decoule de l'importance des consequences humaines economiques et psychologiques possibles d'un eventuel accident. Les accidents de criticite survenus dans l'industrie nucleaire, malgre leur rarete, d'une part devoilent les imperfections des techniques de prevention des causes, d'autre part constituent la seule base realiste disponible d'evaluation des consequences et de mise au point des parades a ces consequences. Les auteurs presentent une analyse des

  17. Analysis of the 1957-1958 Soviet nuclear accident

    International Nuclear Information System (INIS)

    Trabalka, J.R.; Eyman, L.D.; Auerbach, S.I.

    1980-01-01

    The presence of an extensive environmental contamination zone in Chelibinsk Province of the Soviet Union, associated with an accident in the winter of 1957 to 1958 involving the atmospheric release of fission wastes, appears to have been confirmed, primarily by an analysis of the Soviet radioecology literature. The contamination zone is estimated to contain 10(5) to 10(6) curies of strontium-90. A plausible explanation for the incident is the use of now-obsolete techniques for waste storage and cesium-137 isotope separation. Radioactive contamination appears to have resulted in resettlement of the human population from a significant area (100 to 1000 square kilometers). It therefore seems imperative to obtain a complete explanation of the cause (or causes) and consequences of the accident; Soviet experience gained in the application of corrective measures would be invaluable to the world nuclear community

  18. Evaluation of dose equivalent rate distribution in JCO critical accident by radiation transport calculation

    CERN Document Server

    Sakamoto, Y

    2002-01-01

    In the prevention of nuclear disaster, there needs the information on the dose equivalent rate distribution inside and outside the site, and energy spectra. The three dimensional radiation transport calculation code is a useful tool for the site specific detailed analysis with the consideration of facility structures. It is important in the prediction of individual doses in the future countermeasure that the reliability of the evaluation methods of dose equivalent rate distribution and energy spectra by using of Monte Carlo radiation transport calculation code, and the factors which influence the dose equivalent rate distribution outside the site are confirmed. The reliability of radiation transport calculation code and the influence factors of dose equivalent rate distribution were examined through the analyses of critical accident at JCO's uranium processing plant occurred on September 30, 1999. The radiation transport calculations including the burn-up calculations were done by using of the structural info...

  19. Transport of large particles released in a nuclear accident

    International Nuclear Information System (INIS)

    Poellaenen, R.; Toivonen, H.; Lahtinen, J.; Ilander, T.

    1995-10-01

    Highly radioactive particulate material may be released in a nuclear accident or sometimes during normal operation of a nuclear power plant. However, consequence analyses related to radioactive releases are often performed neglecting the particle nature of the release. The properties of the particles have an important role in the radiological hazard. A particle deposited on the skin may cause a large and highly non-uniform skin beta dose. Skin dose limits may be exceeded although the overall activity concentration in air is below the level of countermeasures. For sheltering purposes it is crucial to find out the transport range, i.e. the travel distance of the particles. A method for estimating the transport range of large particles (aerodynamic diameter d a > 20 μm) in simplified meteorological conditions is presented. A user-friendly computer code, known as TROP, is developed for fast range calculations in a nuclear emergency. (orig.) (23 refs., 13 figs.)

  20. JAEA's activities relating the Fukushima Nuclear Plant accident

    International Nuclear Information System (INIS)

    Tagawa, Akihiro

    2012-01-01

    JAEA started the activities relating to the Fukushima nuclear plant accident immediately after the Great East Japan Earthquake. The Office of Fukushima Partnership Operations for Environmental Remediation was opened and the JAEA staff was stationed as the base of cooperation with other organizations. It is conducting environmental radiation monitoring, environmental radioactivity analyses, resident public consulting, and demonstration of decontamination technology. Experts of JAEA are providing technical advice and supports to the Nuclear Safety Commission of Japan and the Ministry of Education, Culture and Sports. Furthermore, the water radiolysis leading to hydrogen gas evolution by Cs 137 adsorbed zeolite and the technique for radioactive waste process and its disposal of fuel debris are being studied. JAEA's Nuclear Emergency Assistance and Training Center (NEAT) is acting as a center of these supporting activities of JAEA. (S. Ohno)

  1. Transport of large particles released in a nuclear accident

    Energy Technology Data Exchange (ETDEWEB)

    Poellaenen, R; Toivonen, H; Lahtinen, J; Ilander, T

    1995-10-01

    Highly radioactive particulate material may be released in a nuclear accident or sometimes during normal operation of a nuclear power plant. However, consequence analyses related to radioactive releases are often performed neglecting the particle nature of the release. The properties of the particles have an important role in the radiological hazard. A particle deposited on the skin may cause a large and highly non-uniform skin beta dose. Skin dose limits may be exceeded although the overall activity concentration in air is below the level of countermeasures. For sheltering purposes it is crucial to find out the transport range, i.e. the travel distance of the particles. A method for estimating the transport range of large particles (aerodynamic diameter d{sub a} > 20 {mu}m) in simplified meteorological conditions is presented. A user-friendly computer code, known as TROP, is developed for fast range calculations in a nuclear emergency. (orig.) (23 refs., 13 figs.).

  2. Status of nuclear critical opalescence

    International Nuclear Information System (INIS)

    Delorme, J.

    1980-12-01

    The present information on the pion mode in nuclei is rather adverse to strong critical opalescence phenomena. Energy levels are interpretable in terms of a rather weak particle-hole force where the pion attraction is counterbalanced by short range repulsion. Form factor measurements permit more direct exploration of the longitudinal spin-isospin correlations

  3. Identification and evaluation of accident sequences in nuclear power reactors

    International Nuclear Information System (INIS)

    Amendola, A.; Capobianchi, S.; Mancini, G.; Olivi, L.; Volta, G.; Reina, G.

    1981-01-01

    Probabilistic analysis techniques are being more and more used for the evaluation of accident progression in nuclear power plants, especially after the issue of the Reactor Safety Study (Report WASH-1400). This study and subsequent discussions have indicated the necessity of better investigating some major items, namely: adequate data base for the probabilistic evaluations; completeness of the analysis with respect both to accident initiation and behaviour; adequate treatment of uncertainties on the physical and operational parameters governing the accident behaviour. Furthermore, recent occurrences have stressed the importance of the operational aspects of reactor safety, such as plant-specific identification of possible occurrences, their prompt recognition, on-line prediction of subsequent developments and actions to be taken. The paper reviews the contributions in progress at JRC-Ispra to all these aspects, and specifically reports on the following: (1) The set-up of a European Reliability Data System for the acquisition and organisation of operational data of LWRs in the European Community. (2) The development of more complete and realistic models of systems. This work includes multistate static models of components and systems with a view to automatic fault-tree construction and dynamic models for accident sequence identification. The dynamic modelling approach ESCS (Event Sequence and Consequences Spectrum), shown in detail with an example, represents a step forward with respect to event-tree technique and opens new possibilities in dealing with human factors and on-line diagnosis problems. (3) The development of RSM (Response Surface Methodology) for the analysis of uncertainty propagations in consequence and in probability of accident chains. (author)

  4. Decision conferencing on countermeasures after a large nuclear accident

    International Nuclear Information System (INIS)

    French, S.; Walmod-Larsen, O.; Sinkko, K.

    1993-01-01

    The conference addressed the following objectives. 1. To achieve a common understanding between decision makers and local government officials on the one hand and the radiation protection community on the other of the issues that arise in decisions in the aftermath of a major nuclear accident. 2. To identify issues which need to be considered in preparing guidance on intervention levels. 3. To explore the use of decision conferencing as a format for major decision making. To achieve these objectives the participants were invited to consider a scenario of a hypothetical radiation accident. The scenario assumed that appropriate early protective actions (sheltering, issuing of iodine tablets, etc.) had been taken and that the conference was meet ng some eight days into the accident to consider medium and longer term protective actions, particularly the need for relocation of certain areas. By the end of the conference, considerable consensus on the general form of the strategy had emerged. Moreover, there was a better understanding of the evaluation criteria against which such a strategy needed to be developed. Many felt that it was important to retain flexibility in the strategy of protective actions, even if this increased the uncertainty for the affected population, who would not know exactly what would be done for several months. This emphasised even more the need for good communication and understandable presentations of the adopted strategy. All felt that more research and advice is needed on the psychological effects of such accidents and the effects of protective actions. It was felt that the exercise had illustrated the problems inherent in radiation emergencies. However, a different situation with larger populations could have led to different results. It was agreed that the exercise had been useful in meeting the need to think about the issues before an accident happens. (au) (12 tabs., 5 ills., 8 refs.)

  5. Researches on nuclear criticality safety evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Okuno, Hiroshi; Suyama, Kenya; Nomura, Yasushi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2003-10-01

    For criticality safety evaluation of burnup fuel, the general-purpose burnup calculation code, SWAT, was revised, and its precision was confirmed through comparison with other results from OECD/NEA's burnup credit benchmarks. Effect by replacing the evaluated nuclear data from JENDL-3.2 to ENDF/B-VI and JEF-2.2 was also studied. Correction factors were derived for conservative evaluation of nuclide concentrations obtained with the simplified burnup code ORIGEN2.1. The critical masses of curium were calculated and evaluated for nuclear criticality safety management of minor actinides. (author)

  6. Researches on nuclear criticality safety evaluation

    International Nuclear Information System (INIS)

    Okuno, Hiroshi; Suyama, Kenya; Nomura, Yasushi

    2003-01-01

    For criticality safety evaluation of burnup fuel, the general-purpose burnup calculation code, SWAT, was revised, and its precision was confirmed through comparison with other results from OECD/NEA's burnup credit benchmarks. Effect by replacing the evaluated nuclear data from JENDL-3.2 to ENDF/B-VI and JEF-2.2 was also studied. Correction factors were derived for conservative evaluation of nuclide concentrations obtained with the simplified burnup code ORIGEN2.1. The critical masses of curium were calculated and evaluated for nuclear criticality safety management of minor actinides. (author)

  7. The international nuclear liability and compensation regime put to the test of a nuclear accident

    International Nuclear Information System (INIS)

    Reyners, P.; Tetley, M.

    2003-01-01

    Full text: It appears that nuclear emergency plans place generally more emphasis on the nuclear safety and radiation protection aspects of the management of an accident, both inside the installation concerned and off-site, than on the particular requirements of local residents who would find themselves suddenly in such an emergency situation and of possible victims of nuclear damage. In a similar vein, studies focusing on the international nuclear third party liability regime usually take a global perspective and leave little room for the treatment of individual cases. The albeit welcome dearth of practical experience in Western countries in providing compensation for accidents of nuclear origin has, however, meant that public and local authorities are not always fully conscious of the importance of this question which should be dealt with in as practical a manner as possible. In order to cover all the legal and practical questions that could arise during the management of the consequences of a nuclear accident with regard to third party liability, insurance and compensation, the OECD/NEA held in co-operation with French authorities a workshop in November 2001. It was decided to organize this workshop according to three main stages: the alert phase, the accident phase and the post-accident phase; and to examine during these three stages the various roles played by local and national authorities, the nuclear operator and his insurer, as well as the nature and form of their respective actions. These questions were addressed both from the angle of applicable domestic legislation and of the relevant international conventions. From the analysis of different national experiences and of the information exchanged during the workshop, a striking diversity may be noted of solutions adopted or envisaged to address various aspects of civil liability, insurance and indemnification of damage in a nuclear emergency situation. This lack of uniformity should not necessarily be

  8. Nuclear criticality safety: 300 Area

    International Nuclear Information System (INIS)

    1991-01-01

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

  9. The Fukushima Daiichi Nuclear Power Plant Accident: OECD/NEA Nuclear Safety Response and Lessons Learnt

    International Nuclear Information System (INIS)

    2013-01-01

    Following the March 2011 accident at the Fukushima Daiichi nuclear power plant, all NEA member countries took early action to ensure and confirm the continued safety of their nuclear power plants and the protection of the public. After these preliminary safety reviews, all countries with nuclear facilities carried out comprehensive safety reviews, often referred to as 'stress tests', which reassessed safety margins of nuclear facilities with a primary focus on challenges related to conditions experienced at the Fukushima Daiichi nuclear power plant, for example extreme external events and the loss of safety functions, or capabilities to cope with severe accidents. As appropriate, improvements are being made to safety and emergency response systems to ensure that nuclear power plants are capable of withstanding events that lead to loss of electrical power and/or cooling capability. In the weeks following the accident, the NEA immediately began establishing expert groups in the nuclear safety and radiological protection areas, as well as contributing to information exchange with the Japanese authorities and other international organisations. It promptly provided a forum for high-level decision makers and regulators within the G8-G20 frameworks. The NEA actions taken at the international level in response to the accident have been carried out primarily by the three NEA standing technical committees concerned with nuclear and radiation safety issues - the Committee on Nuclear Regulatory Activities (CNRA), the Committee on the Safety of Nuclear Installations (CSNI) and the Committee on Radiation Protection and Public Health (CRPPH) - under the leadership of the CNRA. More than two years following the accident, the NEA continues to assist the Japanese authorities in dealing with their nuclear safety and recovery efforts as well as to facilitate international co-operation on nuclear safety and radiological protection matters. It is strongly supporting the establishment of

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

    International Nuclear Information System (INIS)

    1996-01-01

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

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

    Science.gov (United States)

    Ohska, Tokio

    2014-05-01

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

  12. United Kingdom procedures in case of nuclear accidents

    International Nuclear Information System (INIS)

    Chalfont, L.

    1988-01-01

    From the United Kingdom experience, general principles for establishing emergency plans are drawn. Every country with nuclear plant should have such emergency arrangements capable of dealing with the largest scale that can be envisaged as a practical possibility. While the effects of accidents cannot be anticipated in detail these plans should form a good flexible basis for providing the resources, communications and procedures that are likely to be needed. They encompass the administrative infrastructure of the area surrounding the nuclear installation and involve co-ordination with the police, fire services and ambulance services, the local and county authorities, the authorities responsible for food, agriculture, fisheries and water, and the health authorities including hospitals and medical services. Special training and procedures have to be established for the personnel that are involved and exercises graduating from the exercising of special procedures to large scale simulated accidents need to be carried out periodically. Good communication systems have to be established between the nuclear installations, the operational support centres or equivalent, the field and headquarters units of the relevant organizations, and the central government departments so that whatever additional resources and support are needed can be marshalled quickly and efficiently. (author)

  13. Japan's compensation system for nuclear damage - As related to the TEPCO Fukushima Daiichi nuclear accidents

    International Nuclear Information System (INIS)

    Nomura, Toyohiro; Matsuura, Shigekazu; Takahashi, Yasufumi; Takenaka, Chihiro; Hokugo, Taro; Kamada, Toshihiko; Kamai, Hiroyuki

    2012-01-01

    Following the TEPCO Fukushima Daiichi nuclear power plant accident, extraordinary efforts were undertaken in Japan to implement a compensation scheme for the proper and efficient indemnification of the affected victims. This publication provides English translations of key Japanese legislative and administrative texts and other implementing guidance, as well as several commentaries by Japanese experts in the field of third party nuclear liability. The OECD Nuclear Energy Agency (NEA) has prepared this publication in co-operation with the government of Japan to share Japan's recent experience in implementing its nuclear liability and compensation regime. The material presented in the publication should provide valuable insights for those wishing to better understand the regime applied to compensate the victims of the accident and for those working on potential improvements in national regimes and the international framework for third party nuclear liability

  14. Safety study on nuclear heat utilization system - accident delineation and assessment on nuclear steelmaking pilot plant

    International Nuclear Information System (INIS)

    Yoshida, T.; Mizuno, M.; Tsuruoka, K.

    1982-01-01

    This paper presents accident delineation and assessment on a nuclear steelmaking pilot plant as an example of nuclear heat utilization systems. The reactor thermal energy from VHTR is transported to externally located chemical process plant employing helium-heated steam reformer by an intermediate heat transport loop. This paper on the nuclear steelmaking pilot plant will describe (1) system transients under accident conditions, (2) impact of explosion and fire on the nuclear reactor and the public and (3) radiation exposure on the public. The results presented in this paper will contribute considerably to understanding safety features of nuclear heat utilization system that employs the intermediate heat transport loop and the helium-heated steam reformer

  15. Lessons learned from our accident at Fukushima nuclear power stations

    International Nuclear Information System (INIS)

    Kawano, A.

    2012-01-01

    This paper is given in order to share the detailed information on the Fukushima Accident which occurred on March 11, 2011, and the lessons learned from it which worldwide nuclear experts might currently have more interest in. The paper first reflects how the facilities were damaged by a very strong earthquake and a series of beyond design-basis tsunamis. The earthquake caused loss of all off-site electric power at Fukushima Daiichi Nuclear Power Station (1F), and the following series of tsunami made all emergency diesel generators except one for Unit 6 and most of DC batteries inoperable and severely damaged most of the facilities located on the ocean side. Thus all the units at 1F resulted in the loss of cooling function and ultimate heat sink for a long time period. TEPCO focused on restoration of the instruments and lights in the Main Control Room (MCR), preparation of alternative water injection and venting of Primary Containment Vessel (PCV) in the recovery process. However, the workers faced a lot of difficulties such as total darkness, repeated aftershocks, high radiation dose, a lot of debris on the ground, loss of communication means, etc. Massive damages by the tsunami and lack of necessary equipments and resources hampered a quick recovery. It eventually resulted in the severe core damage of Unit 1, 2, and 3 and also the hydrogen explosions in the reactor buildings of Unit 1, 3, and 4. This paper finally extracts the lessons learned from the accident and proposes the countermeasures, such as flood protection for essential facilities, preparation of practical and effective tools, securing communication means and so on. These would help the people involved in the nuclear industries all over the world properly understand the accident and develop their own countermeasures appropriately. (authors)

  16. An analysis on human factor issues in criticality accident at a uranium processing plant

    International Nuclear Information System (INIS)

    Sasou, Kunihide; Goda, Hidenori; Hirotsu, Yuko

    2000-01-01

    This report analyses latent factors of a human behavior directly contributing to the criticality accident. It is pouring some 16 kg-U with an enrichment of 18.8% into the precipitation tank. It is the fact that the direct cause of this accident is the workers' unsafe act. However, the authors find lots of latent factors relating to the production-biased company's policy, the poor climate for safety in the work place, the inadequate safety management and the unsuitable equipment. This accident was caused by many organizational factors. This paper also discusses lessons learned from this accident. (author)

  17. Multiple parameter biodosimetry of exposed workers from the JCO criticality accident in Tokai-mura

    Energy Technology Data Exchange (ETDEWEB)

    Blakely, William F. [Armed Forces Radiobiology Research Institute, Bethesda, MD (United States)

    2002-03-01

    Full text: On 30 September 1999, three workers at the JCO (Japan Nuclear Fuel Conversion Corporation) uranium fuel processing facility in Tokai-mura, Ibaraki Prefecture, Japan, were severely exposed to neutrons and gamma rays. In this issue of the journal, Nishimura et al report the measurement of {sup 32}P in urine from the three victims for early estimation of neutron exposure levels. This is one of several reports that estimate doses received by the exposed workers and residents, based on biological responses, radiation monitoring/transport codes, and other opportunistic dosimetric approaches. The higher relative biological effectiveness (RBE) of neutrons for life-threatening radiation injury justifies efforts to establish a neutron biodosimetry capability. Accurate estimation of the exposure dose by cytogenetic-based chromosome aberration assays, however, requires knowledge of the neutron component in the mixed neutron and gamma radiation scenario. Dose responses for dicentric and ring type chromosome aberration yields measured in peripheral blood lymphocytes are responsive to radiation quality. Protocols for dose assessment by cytogenetic-chromosome aberration assays are internationally accepted. Analytic approaches using cytogenetic chromosome aberrations are established for dose assessment in mixed neutron and gamma radiation accidents. Use of the premature chromosome condensation, or PCC, assay now permits these measurements even at unusually high doses of gamma and neutron radiation. Hayata and colleagues measured ring-type chromosome aberrations in interphase cells by use of the PCC-ring assay to estimate dose for the three severely exposed patients in this accident. Ring-type aberrations are formed in higher yields after neutron versus gamma radiation but these ring-aberrations do not provide a unique signature response specific for neutron exposures. Intense research efforts are currently underway to identify more specific chromosome aberration and

  18. The third update of the Fukushima Daiichi Nuclear Station accident. September 1 through November 30, 2011

    International Nuclear Information System (INIS)

    Shibutani, Yu

    2011-01-01

    This article provides the third update of the Fukushima Daiichi accident that occurred on March 11, 2011. In the report of the first update of the Fukushima Daiichi accident on March 11 through May 31, the situation was reported on both on-site and off-site of the Fukushima Daiichi, including; failed cooldown of decay heat and meltdown of stricken reactors; emergency evacuation of local residents, radioactive contamination, spread of biased rumors by the information closure by government, regional cooperation with China, Taiwan and Korea, and visit of IAEA investigation team to Japan. The report of the second update on June 1 through August 31 reported the issues of, harsh public criticism against government and electric power companies, results of the public opinion poll, a sort of gentlemen's agreements between nuclear power companies and local governments which would be peculiar tradition in Japan, the first revision of the road map to cold shutdown of stricken reactors, and submission of report on Fukushima Daiichi accident to International Atomic Energy Agency (IAEA). This article provides the third update from September 1 through November 30, particularly on the issues of the second revision of the road map where the “cold shutdown” state should be reached before the end of 2011, the overview of governmental organization on the overall energy and nuclear policy, and the establishment of the nuclear disaster response headquarters (HQ) in the Prime Minister's Office. The HQ in collaboration with Tokyo Electric Power Company (TEPCO) decided the framework of road map plans, provision of various assistance and compensation for the residents affected by the nuclear incident, redefinition by the Nuclear Safety Commission for evacuation areas, recovery process of radioactive decontaminated areas, investigation and verification of the Fukushima Daiichi accident, reorganization of TEPCO management and financial system, establishment of damage compensation scheme

  19. Iodine nutrition and risk of thyroid irradiation from nuclear accidents

    International Nuclear Information System (INIS)

    Delange, F.

    1990-01-01

    The objectives of this paper are to discuss the following aspects of physiopathology of iodine nutrition related to thyroid irradiation by nuclear accidents: (1) The cycle of iodine in nature, the dietary sources of iodine and the recommended dietary allowances for iodine. (2) The anomalies of thyroid metabolism induced by iodine deficiency. The caricatural situation as seen in endemic goitre will be used as mode. (3) The specific paediatric aspects of adaptation to iodine deficiency. (4) The present status of iodine nutrition in Europe. (author)

  20. Health hazards from radiocaesium following the Chernobyl nuclear accident

    International Nuclear Information System (INIS)

    1987-01-01

    The WHO Regional Office for Europe has organized a series of meetings to assess the health impact of the Chernobyl nuclear accident. Considering the long-term importance of radiocaesium a decision was made to examine carefully the following aspects of this radionuclide in Europe: rate of deposition; environmental pathways through soil, flora and fauna to humans; absorption, distribution, metabolism, and excretion in humans; estimated doses resulting from these exposures; and some consideration of the possible adverse health effects. This is a report from a working group studying the health implications of radiocaesium. Refs, figs and tabs

  1. Fission product chemistry in severe nuclear reactor accidents

    International Nuclear Information System (INIS)

    Nichols, A.L.

    1990-09-01

    A specialist's meeting was held at JRC-Ispra from 15 to 17 January 1990 to review the current understanding of fission-product chemistry during severe accidents in light water reactors. Discussions focussed on the important chemical phenomena that could occur across the wide range of conditions of a damaged nuclear plant. Recommendations for future chemistry work were made covering the following areas: (a) fuel degradation and fission-product release, (b) transport and attenuation processes in the reactor coolant system, (c) containment chemistry (iodine behaviour and core-concrete interactions)

  2. Radioactive fallout from the Chernobyl nuclear reactor accident

    International Nuclear Information System (INIS)

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

    1987-01-01

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

  3. Economic damage caused by a nuclear reactor accident

    International Nuclear Information System (INIS)

    Baan, P.J.A.

    1988-01-01

    The impacts of a nuclear reactor accident have been estimated for: the public water supply; the use of surface water for sprinkling in agriculture, for industry water supply, recreation, etc.; and fisheries. Contamination of water sources may affect the public water supply severely. In such a situation demand of water cannot always be met. Agriculture faces production losses, if demand for uncontaminated surface water cannot be met. The impacts on recreation can also be significant. The losses to other water users are less substantial. Fisheries may lose (export) markets, as people become reluctant to buy fish and fish products. 33 refs.; 3 figs.; 35 tabs

  4. Empirical Risk Analysis of Severe Reactor Accidents in Nuclear Power Plants after Fukushima

    OpenAIRE

    Kaiser, Jan Christian

    2012-01-01

    Many countries are reexamining the risks connected with nuclear power generation after the Fukushima accidents. To provide updated information for the corresponding discussion a simple empirical approach is applied for risk quantification of severe reactor accidents with International Nuclear and Radiological Event Scale (INES) level ≥5. The analysis is based on worldwide data of commercial nuclear facilities. An empirical hazard of 21 (95% confidence intervals (CI) 4; 62) severe accidents am...

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

    International Nuclear Information System (INIS)

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

    1993-08-01

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

  6. Health effects models for nuclear power plant accident consequence analysis

    International Nuclear Information System (INIS)

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

    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 Analysisclose 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

  7. An international co-ordinated research programme on nuclear accident dosimetry

    International Nuclear Information System (INIS)

    Flakus, F.N.

    1977-01-01

    Where fissile materials are being processed in quantities exceeding the minimum critical amounts, a radiation risk to workers arises from the possibility of criticality excursions. Despite the fact that techniques for preventing the occurende of such accidental excursions have reached very high standards it is generally agreed that the availability of suitable nuclear accident dosimetry (NAD) systems is very important. Following the recommendations of an Advisory Group meeting on NAD, the IAEA had established in 1969 an international coordinated research programme on NAD systems and elaborating standarized systems. A large number of research groups from 14 Member States throughout the world participated in this co-ordinated work. Since 1970 four international multilaboratory intercomparison experiments on NAD have been organized and the response of a variety of dosimeters examined in different neutron spectra under simulated accident conditions at Valduc (France), Oak Ridge (USA), Vinca (Yugoslavia) and Harwell (UK). The results achieved in these intercomparison studies show that NAD systems have been substantially improved and that several systems are available now in a number of laboratories throughout the world that perform within the criteria laid down by the initiating advisory group in 1969. A compendium of neutron leakage spectra has also been elaborated for facilitating the determination of dose from readings of detectors exposed to various neutron fields in criticality accidents

  8. Consideration of Command and Control Performance during Accident Management Process at the Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Nisrene M. [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Kim, Sok Chul [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2015-10-15

    The accident at the Fukushima Daiichi nuclear power plants shifted the nuclear safety paradigm from risk management to on-site management capability during a severe accident. The kernel of on-site management capability during an accident at a nuclear power plant is situation awareness and agility of command and control. However, little consideration has been given to accident management. After the events of September 11, 2001 and the catastrophic Fukushima nuclear disaster, agility of command and control has emerged as a significant element for effective and efficient accident management, with many studies emphasizing accident management strategies, particularly man-machine interface, which is considered a key role in ensuring nuclear power plant safety during severe accident conditions. This paper proposes a conceptual model for evaluating command and control performance during the accident management process at a nuclear power plant. Communication and information processing while responding to an accident is one of the key issues needed to mitigate the accident. This model will give guidelines for accurate and fast communication response during accident conditions.

  9. The principles of radioiodine dosimetry following a nuclear accident

    International Nuclear Information System (INIS)

    Zvonova, I.A.

    1996-01-01

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

  10. The principles of radioiodine dosimetry following a nuclear accident

    Energy Technology Data Exchange (ETDEWEB)

    Zvonova, I A [Institute of Radiation Hygiene, St. Petersburg (Russian Federation)

    1996-08-01

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

  11. Optimization of emergency response to major nuclear accidents

    International Nuclear Information System (INIS)

    Papazoglou, I.A.; Christou, M.D.

    1991-01-01

    A methodology for the optimization of the short-term emergency response in the event of a nuclear accident has been developed. The method aims at an optimum combination of protective actions in the presence of a multitude of conflicting objectives and under uncertainty. Conflicting objectives arise when the minimization of the potential adverse effects of an accident and the simultaneous minimization of the associated socioeconomic impacts is attempted. Additional conflicting objectives appear whenever an emergency plan tends to decrease a particular health effect (e.g. acute deaths) while at the same time it increases another (e.g. latent deaths). The uncertainty is due to the multitude of the possible accident scenarios and their respective probability of occurrence, the stochastic variability in the weather conditions and in the variability and/or lack of knowledge in the parameters of the risk assessment models. A multiobjective optimization approach is adopted in a dynamic programming scheme. An emergency protective plan consists of defining a protective action (e.g. evacuation, sheltering) at each spatial cell around the plant. Three criteria (evaluators) are used as the objective functions of the problem, namely, acute fatalities, latent effects and socioeconomic cost. The optimization procedure defines the efficient frontier, i.e. all emergency plans that are not dominated by another in all three criteria. No value trade-offs are necessary up to this point

  12. Multicomponent risk inherent to nuclear or radiation accidents

    International Nuclear Information System (INIS)

    Poyarkov, V.A.

    1997-01-01

    A nuclear or radiation emergency response planning is based on expected avertable doses for a short (4 hours, 2 days, 1 week) and a long (50 or 70 years) periods of time. On calculating the doses one should take into account not only the sources of ionizing radiation with their foreseen characteristics, e.g. a half-life, but also the possibility of their probabilistic transformations. It can be illustrated by the chronicle of Chernobyl accident, where for nine days it was impossible to envisage with reliability the quantities of released radionuclides due to many uncontrolled factors related to the scope and character of the zone wreckage. Any other developments of the accident, such as destruction of the under reactor support plate, sinking of the melted zone into a highly radioactive water down at the reactor cavity or changing of the wind could have resulted in a substantial contamination of 3 mln. Kiev and other densely populated area of Ukraine. Another factor to be taken into account in the emergency response is a way of an actual risk perception by the population. The article suggests an approach to take into account the time-dependent secondary sources of exposure and the disparity in accepting the hazard of real risk of an accident by the trained workers and population. (author)

  13. Lessons drawn from serious accidents in nuclear power stations

    International Nuclear Information System (INIS)

    Kosciusko-Morizet, F.; Tanguy, P.

    1981-01-01

    Taking a number of serious accidents considered to be particularly representative (Windscale, Enrico Fermi, Lucens, Browns Ferry, Three Mile Island and Saint-Laurent-des-Eaux), the paper analyses the conclusions reached in subsequent enquiries and the lessons drawn from them by the responsible authorities. While design problems sometimes come to light, it is much more generally operational safety - problems related to instructions, the training of operators, the man/machine relationship - which appears to be inadequate. The organization of relations between the different partners - builders, operators and safety bodies - likewise gives rise to some observations. Certain measures should be pursued on a broader scale in order to improve our ability to prevent serious accidents: (i) incidents important from the standpoint of safety must be identified; (ii) these incidents must be brought to the knowledge of all partners concerned, in all interested countries; (iii) the lessons drawn from them must be exchanged and compared; and (iv) the lessons must be made generally available in a directly usable form (i.e. as design modifications, changes in instructions and so on). Particular attention must be given to the problems of countries which are embarking on nuclear programmes and which, with a small number of installations, need direct and permanent access to all the lessons drawn from the operation of a large power station park, and must be able to call upon the assistance of teams from outside in the event of an accident. (author)

  14. Explanation of procedure on site medical emergency response for nuclear accident

    International Nuclear Information System (INIS)

    Liu Yulong; Jiang Zhong

    2012-01-01

    National occupational health standard-Procedure on Site Medical Emergency Response for Nuclear Accident has been approved and issued by the Ministry of Health. This standard is formulated according to the Emergency Response Law of the People's Republic of China, Law of the People 's Republic of China on Prevention and Control of Occupational Diseases, Regulations on Emergency Measures for Nuclear Accidents at Nuclear Power Plants, and Health Emergency Plans for Nuclear and Radiological Accidents of Ministry of Health, supporting the use of On-site Medical Emergency Planning and Preparedness for Nuclear Accidents and Off-site Medical Emergency Planning and Preparedness for Nuclear Accidents. Nuclear accident on-site medical response procedure is a part of the on-site emergency plan. The standard specifies the basic content and requirements of the nuclear accident on-site medical emergency response procedures of nuclear facilities operating units to guide and regulate the work of nuclear accident on-site medical emergency response of nuclear facilities operating units. The criteria-related contents were interpreted in this article. (authors)

  15. Implementation of accident management programmes in nuclear power plants

    International Nuclear Information System (INIS)

    2004-01-01

    According to the generally established defence in depth concept in nuclear safety, consideration in plant operation is also given to highly improbable severe plant conditions that were not explicitly addressed in the original design of currently operating nuclear power plants (NPPs). Defence in depth is achieved primarily by means of four successive barriers which prevent the release of radioactive material (fuel matrix, cladding, primary coolant boundary and containment), and these barriers are primarily protected by three levels of design measures: prevention of abnormal operation and failures (level 1), control of abnormal operation and detection of failures (level 2) and control of accidents within the design basis (level 3). If these first three levels fail to ensure the structural integrity of the core, e.g. due to beyond the design basis multiple failures, or due to extremely unlikely initiating events, additional efforts are made at level 4 to further reduce the risks. The objective at the fourth level is to ensure that both the likelihood of an accident entailing significant core damage (severe accident) and the magnitude of radioactive releases following a severe accident are kept as low as reasonably achievable. Finally, level 5 includes off-site emergency response measures, with the objective of mitigating the radiological consequences of significant releases of radioactive material. The implementation of the emergency response is usually dependent upon the type and magnitude of the accident. Good co-ordination between the operator and the responding organizations is needed to ensure the appropriate response. Accident management is one of the key components of effective defence in depth. In accordance with defence in depth, each design level should be protected individually, independently of other levels. This report focuses on the fourth level of defence in depth, including the transitions from the third level and into the fifth level. It describes

  16. The second update of the Fukushima Daiichi Nuclear Station accident. June 1 through August 31, 2011

    International Nuclear Information System (INIS)

    Shibutani, Yu

    2011-01-01

    The Fukushima Daiichi accident occurred on March 11, 2011. The Japanese government and Tokyo Electric Power Company (TEPCO) encountered great deal of difficulties to stabilize the nuclear power reactor. Although the maximum radiation level has decreased, it still accounts for one-fifth of the level detected as of end of August 2011. There are currently growing concerns regarding the complexities of nuclear energy that are faced by the society of Japan. Owing to the occurrence of the Fukushima Daiichi accident, the firm belief on absolute safety of Japan's nuclear power plants has suddenly collapsed. Over the past decades, people tended to trust the government and electric power companies, which assured the safety and ensured about the necessity of nuclear power. However the recent disaster that took place in Fukushima has triggered public anger and distrusts that lead to negative campaigns against nuclear energy, in addition to oppositions against the government and nuclear power companies. The harsh public criticism has forced the government to separate the Nuclear and Industrial Safety Agency (NISA) from affiliation with the Ministry of Economy, Trade and Industry (METI). This action was taken since NISA had expressed contradictions with METI, which is the promoting agency for nuclear energy, The nation-wide opinion poll and surveys undertaken by Asahi Shimbun, a leading Japanese daily newspaper, has announced that 74% of respondents supported the policy to phase-out all nuclear power plants with the final goal to completely end the operation of nuclear plants. A mere 14% of the respondents disagree. There are approximately 100,000 or more residents that evacuated from the dangerous Fukushima Daiichi zone and were suffering from immediate threats such as radiation exposure, health problems, sanitary contamination, products shipment ban, business slump, groundless rumors, etc. These conditions have severely weakened their capability to completely recover and

  17. Individual feature identification method for nuclear accident emergency decision-making

    International Nuclear Information System (INIS)

    Chen Yingfeng; Wang Jianlong; Lin Xiaoling; Yang Yongxin; Lu Xincheng

    2014-01-01

    According to the individual feature identification method and combining with the characteristics of nuclear accident emergency decision-making, the evaluation index system of the nuclear accident emergency decision-making was determined on the basis of investigation and analysis. The effectiveness of the nuclear accident emergency decision-making was evaluated based on the individual standards by solving the individual features of the individual standard identification decisions. The case study shows that the optimization result is reasonable, objective and reliable, and it can provide an effective analysis method and decision-making support for optimization of nuclear accident emergency protective measures. (authors)

  18. Overview of domestic and foreign comments on Fukushima nuclear accident in the past half year

    International Nuclear Information System (INIS)

    Liu Yuanyuan; Chen Haiying; Zhang Chunming

    2011-01-01

    On March 11, 2011, Fukushima Dai-ichi nuclear power plant happened severity level nuclear accident, and caused great disasters. To be able to get more experience feedbacks for the safe development of nuclear technology from this accident, this paper investigated the domestic and foreign comments on Fukushima nuclear accident in the past half year, summarized and analyzed the attentions of experts a- bout this accident and improvement methods for the existing nuclear power technology. The results show that most domestic experts focus on improving nuclear power technology and management of emergency response and supervision, while foreign experts pay more attentions to how to deal with the environmental impact of accident on the biological side. All of these attentions and improvement methods will provide more useful information for developing safe nuclear power technology. (authors)

  19. Should evacuation standards be reviewed after a nuclear accident?

    International Nuclear Information System (INIS)

    Nifenecker, Herve

    2011-10-01

    The author comments the current practices of post-accident management of nuclear disasters. He outlines the peculiarities of nuclear evacuations with respect to other disasters. After referring to the use of life expectancy or of the reduction of life expectancy, for example for smokers, he suggests that irradiation could be expressed this way and then provide some intuitive information. He discusses the notion of linear no-threshold relationship which has been introduced by the ICRP after analysis of cancers noticed on survivors of Hiroshima and Nagasaki. He addresses the case of Fukushima, the issue of low doses applied to large populations. He discusses the limitations of the linear no-threshold relationship. He discusses possible improvements of evacuation procedures

  20. Agricultural countermeasures in the Nordic countries after a nuclear accident

    International Nuclear Information System (INIS)

    Brink, M.; Lauritzen, B.

    2001-12-01

    This report by the NKSBOK-1.4 project group describes agricultural countermeasures after a nuclear accident, aiming at the reduction of radiation doses to man from the ingestion of foodstuffs. The intention has been to collect information based on common understanding that can be used as a Nordic handbook and in further developments of the national preparedness systems. The report covers two areas: the gathering and dissemination of information before and during a nuclear emergency, and the development of a countermeasures strategy. A number of factors are discussed, which will affect the choice of countermeasure(s), and as a case study, a technical cost-benefit assessment of a specific countermeasure is described. (au)

  1. Fukushima Nuclear Accident, the Third International Severe Nuclear Power Plant Accident

    International Nuclear Information System (INIS)

    Rashad, S.M.

    2013-01-01

    Japan is the world's third largest power user. Japan's last remaining nuclear reactor shutdown on Saturday 4 Th of May 2012 leaving the country entirely nuclear free. All of 50 of the nation's operable reactors (not counting for the four crippled reactors at Fukushima) are now offline. Before last year's Fukushima nuclear disaster, the country obtained 30% of its energy from nuclear plants, and had planned to produce up to 50% of its power from nuclear sources by 2030. Japan declared states of emergency for five nuclear reactors at two power plants after the units lost cooling ability in the aftermath of Friday 11 March 2011 powerful earthquake. Thousands of (14000) residents were immediately evacuated as workers struggled to get the reactors under control to prevent meltdowns. On March 11 Th, 2011, Japan experienced a sever earthquake resulting in the shutdown of multiple reactors. At Fukushima Daiichi site, the earthquake caused the loss of normal Ac power. In addition it appeals that the ensuing tsunami caused the loss of emergency Ac power at the site. Subsequent events caused damage to fuel and radiological releases offsite. The spent fuel problem is a wild card in the potentially catastrophic failure of Fukushima power plant. Since the Friday's 9.0 earthquake, the plant has been wracked by repeated explosions in three different reactors. Nuclear experts emphasized there are significant differences between the unfolding nuclear crisis at Fukushima and the events leading up to the Chernobyl disaster in 1986. The Chernobyl reactor exploded during a power surge while it was in operation and released a major cloud of radiation because the reactor had no containment structure around to. At Fukushima, each reactor has shutdown and is inside a 20 cm-thick steel pressure vessel that is designed to contain a meltdown. The pressure vessels themselves are surrounded by steel-lined, reinforced concrete shells. Chernobyl disaster was classified 7 on the International

  2. Nuclear accident dosimeter designed for use with the Panasonic TLD system

    International Nuclear Information System (INIS)

    Hankins, D.E.

    1985-01-01

    A new design for the nuclear accident dosimeter (NAD) compatible with the Panasonic TLD badge has recently been adopted for use at LLNL. This NAD was tested at the 1984 Oak Ridge National Laboratory Intercomparison of Criticality Accident Dosimeters study. We describe the procedures and constants developed to evaluate the NAD components. These constants were averaged to give reasonable results from bare and moderated spectra. Other procedures to evaluate a person's neutron dose using activation of the blood sodium and hair are described. These latter procedures are used to complement the dose determined using the NAD, or to determine a dose if a NAD had not been worn during exposure. If little is known about the configuration of the fissile material or shielding between the material and the exposed person, a procedure which combines the blood and hair activations gives a good estimate of the dose. (DT) 3 refs., 2 figs., 6 tabs

  3. Characteristics of Hydrogen Monitoring Systems for Severe Accident Management at a Nuclear Power Plant

    Science.gov (United States)

    Petrosyan, V. G.; Yeghoyan, E. A.; Grigoryan, A. D.; Petrosyan, A. P.; Movsisyan, M. R.

    2018-02-01

    One of the main objectives of severe accident management at a nuclear power plant is to protect the integrity of the containment, for which the most serious threat is possible ignition of the generated hydrogen. There should be a monitoring system providing information support of NPP personnel, ensuring data on the current state of a containment gaseous environment and trends in its composition changes. Monitoring systems' requisite characteristics definition issues are considered by the example of a particular power unit. Major characteristics important for proper information support are discussed. Some features of progression of severe accident scenarios at considered power unit are described and a possible influence of the hydrogen concentration monitoring system performance on the information support reliability in a severe accident is analyzed. The analysis results show that the following technical characteristics of the combustible gas monitoring systems are important for the proper information support of NPP personnel in the event of a severe accident at a nuclear power plant: measured parameters, measuring ranges and errors, update rate, minimum detectable concentration of combustible gas, monitoring reference points, environmental qualification parameters of the system components. For NPP power units with WWER-440/270 (230) type reactors, which have a relatively small containment volume, the update period for measurement results is a critical characteristic of the containment combustible gas monitoring system, and the choice of monitoring reference points should be focused not so much on the definition of places of possible hydrogen pockets but rather on the definition of places of a possible combustible mixture formation. It may be necessary for the above-mentioned power units to include in the emergency operating procedures measures aimed at a timely heat removal reduction from the containment environment if there are signs of a severe accident phase

  4. Quantifying the social costs of nuclear energy: Perceived risk of accident at nuclear power plants

    International Nuclear Information System (INIS)

    Huhtala, Anni; Remes, Piia

    2017-01-01

    The preferences expressed in voting on nuclear reactor licenses and the risk perceptions of citizens provide insights into social costs of nuclear power and decision making in energy policy. We show analytically that these costs consist of disutility caused by unnecessary anxiety - due to misperceived risks relating to existing reactors - and where licenses for new nuclear reactors are not granted, delayed or totally lost energy production. Empirical evidence is derived from Finnish surveys eliciting explicitly the importance of risk perceptions on preferences regarding nuclear power and its environmental and economic impacts. We show that the estimated marginal impact of a high perceived risk of nuclear accident is statistically significant and that such a perception considerably decreases the probability of a person supporting nuclear power. This result holds across a number of robustness checks including an instrumental variable estimation and a model validation by observed voting behavior of the members of Parliament. The public's risk perceptions translate into a significant social cost, and are likely to affect the revenues, costs and financing conditions in the nuclear power sector in the future. - Highlights: • Survey on preferences regarding nuclear power and its environmental and economic impacts utilized. • A high perceived risk of nuclear accident decreases support for nuclear power. • The public's risk perceptions translate into a significant social cost.

  5. Neutron nuclear data measurements for criticality safety

    Directory of Open Access Journals (Sweden)

    Guber Klaus

    2017-01-01

    Full Text Available To support the US Department of Energy Nuclear Criticality Safety Program, neutron-induced cross section experiments were performed at the Geel Electron Linear Accelerator of the Joint Research Center Site Geel, European Union. Neutron capture and transmission measurements were carried out using metallic natural cerium and vanadium samples. Together with existing data, the measured data will be used for a new evaluation and will be submitted with covariances to the ENDF/B nuclear data library.

  6. Applications of probabilistic risk analysis in nuclear criticality safety design

    International Nuclear Information System (INIS)

    Chang, J.K.

    1992-01-01

    Many documents have been prepared that try to define the scope of the criticality analysis and that suggest adding probabilistic risk analysis (PRA) to the deterministic safety analysis. The report of the US Department of Energy (DOE) AL 5481.1B suggested that an accident is credible if the occurrence probability is >1 x 10 -6 /yr. The draft DOE 5480 safety analysis report suggested that safety analyses should include the application of methods such as deterministic safety analysis, risk assessment, reliability engineering, common-cause failure analysis, human reliability analysis, and human factor safety analysis techniques. The US Nuclear Regulatory Commission (NRC) report NRC SG830.110 suggested that major safety analysis methods should include but not be limited to risk assessment, reliability engineering, and human factor safety analysis. All of these suggestions have recommended including PRA in the traditional criticality analysis

  7. NMC and A and nuclear criticality safety systems integration: A prospective way for enhancement of the nuclear industry facilities safety

    International Nuclear Information System (INIS)

    Ryazanov, Boris G.; Sviridov, Victor I.; Frolov, Vladimir V.; Shvedov, Maxim O.; Mclaughlin, Thomas P.; Pruvost, Norman L.

    2003-01-01

    A considerable body of data has now been acquired about the principles, parameters and consequences of nuclear (criticality) accidents at facilities of the atomic industry in Russia, the United States, Great Britain and Japan. The total number of such accidents stands at 22. Russian and US specialists have prepared a rather extensive survey and analysis of these accidents. The final and important section of this survey is the lessons implied by the results of analysis of these 22 accidents. Among these lessons is the necessity of unconditional enforcement of control over the movement and transformations of special nuclear materials (SNM), and in particular fissile materials, (those SNMs with criticality accident concerns) during production and processing. Inadequacies in such control have been among the causes of most of the accidents that have occurred. Nuclear materials control and accounting (MC and A) for the purpose of ensuring storage reliability and nonproliferation safeguards is a major task of nuclear facilities in any nation. MC and A systems use the latest techniques and hardware for periodic control of SNM in specifically organized material balance areas. Immediate checking, periodic inventory of SNM, and measurements of the parameters of SNM at key points are the main sources of data for these systems. Data about the presence and sites of location of SNM in material balance areas that are acquired in inventories can be used for objective assessment of the status of nuclear safety. On the other hand, the inventory itself involves performance of operations that are unlike routine process engineering, and require special consideration of nuclear safety. Use of the techniques and hardware of MC and A systems not only for purposes of storage reliability, but also to ensure nuclear safety, will reduce the risk of nuclear accidents. This paper gives a concise overview of nuclear accidents that have occurred due to inadequacies in MC and A, and demonstrates

  8. Derived intervention levels in early stage of nuclear accident development

    Energy Technology Data Exchange (ETDEWEB)

    Vladar, M; Fojtik, M [Inst. of Preventive and Clinical Medicine, Bratislava (Slovakia); Stubna, M [Research Inst. of Nuclear Power Plants, Bohunuce (Slovakia)

    1996-12-31

    In this paper the measures for protection of health and property of public in the case of nuclear accident are discussed. They are based on optimal application of so called intervention levels. The actual flow of decision depends on: (1) prognosis of mathematical modelling of possible course of nuclear accident, and (2) results of monitoring of radiation situation.The aim of this contribution was to analyze their mutual cooperation and to suggest such procedure of monitoring or radiation situation which could be used for suggestion of protective measures. In this contribution the zones of protection planning in the accident place surrounding for the urgent measures were specified : (1) regulation of free movement of persons; (2) sheltering; (3) iodine prophylaxis; (4) temporary evacuation; (5) long term or permanent emigration. At the specification of zones of planned protection it is also coming out that regulation of movement of persons, sheltering and iodine prophylaxis were ordered in advance based on the evaluation of the crashed establishment state. In such situation the decision on protective measures in the time interval 6 to 12 hours after the beginning of accidental release is forwarding to: withdrawing the accepted orders on measures and transition from sheltering to temporary evacuation. The criterion for temporary evacuation is: (1) probability of exceeding the effective dose 100 mSv for children up to 10 years of age and pregnant women and 500 mSv for other population within 48 hours after beginning of accidental release; (2) probability of averting the effective dose 50 mSv up to 7 days, 100 mSv up to 15 days and 150 mSv up to 30 days for all population groups. In next part the intervention level, interpretation of values of kerma dose rate in air and determination of the size of planned protection zones are discussed. (J.K.) 3 tabs.

  9. Consequences of the nuclear power plant accident at Chernobyl

    International Nuclear Information System (INIS)

    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

  10. The development of a nuclear accident risk information system

    International Nuclear Information System (INIS)

    Jeong, J. T.; Jeong, W. D.

    2001-01-01

    The computerized system NARIS (Nuclear Accident Risk Information System) was developed in order to support the estimation of health effects and the establishment the effective risk reduction strategies. Using the system, we can analyze the distribution of health effects easily by displaying the results on the digital map of the site. Also, the thematic mapping allows the diverse analyses of the distribution of the health effects. The NARIS can be used in the emergency operation facilities in order to analyze the distribution of the health effects resulting from the severe accidents of a nuclear power plant. Also, the rapid analysis of the health effect is possible by storing the health effect results in the form of a database. Therefore, the staffs of the emergency operation facilities can establish the rapid and effective emergency response strategies. The module for the optimization of the costs and benefits and the decision making support will be added. The technical support for the establishment of the optimum and effective emergency response strategies will be possible using this system

  11. Thyroid doses for evacuees from the Fukushima nuclear accident

    Science.gov (United States)

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

    2012-07-01

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

  12. Nuclear critical safety analysis for UX-30 transport of freight package

    International Nuclear Information System (INIS)

    Quan Yanhui; Zhou Qi; Yin Shenggui

    2014-01-01

    The nuclear critical safety analysis and evaluation for UX-30 transport freight package in the natural condition and accident condition were carried out with MONK-9A code and MCNP code. Firstly, the critical benchmark experiment data of public in international were selected, and the deflection and subcritical limiting value with MONK-9A code and MCNP code in calculating same material form were validated and confirmed. Secondly, the neutron efficiency multiplication factors in the natural condition and accident condition were calculated and analyzed, and the safety in transport process was evaluated by taking conservative suppose of nuclear critical safety. The calculation results show that the max value of k eff for UX-30 transport freight package is less than the subcritical limiting value, and the UX-30 transport freight package is in the state of subcritical safety. Moreover, the critical safety index (CSI) for UX-30 package can define zero based on the definition of critical safety index. (authors)

  13. Radioecological consequences of a potential accident during transport of spent nuclear fuel along an Arctic coastline

    International Nuclear Information System (INIS)

    Iosjpe, M.; Reistad, O.; Amundsen, I.B.

    2009-01-01

    This article presents results pertaining to a risk assessment of the potential consequences of a hypothetical accident occurring during the transportation by ship of spent nuclear fuel (SNF) along an Arctic coastline. The findings are based on modelling of potential releases of radionuclides, radionuclide transport and uptake in the marine environment. Modelling work has been done using a revised box model developed at the Norwegian Radiation Protection Authority. Evaluation of the radioecological consequences of a potential accident in the southern part of the Norwegian Current has been made on the basis of calculated collective dose to man, individual doses for the critical group, concentrations of radionuclides in seafood and doses to marine organisms. The results of the calculations indicate a large variability in the investigated parameters above mentioned. On the basis of the calculated parameters the maximum total activity ('accepted accident activity') in the ship, when the parameters that describe the consequences after the examined potential accident are still in agreement with the recommendations and criterions for protection of the human population and the environment, has been evaluated

  14. Latest developments in critical nuclear opalescence

    International Nuclear Information System (INIS)

    Delorme, J.

    It is first recalled how the nuclear spin-isospin mode generated by pion exchange gives rise to critical opalescence phenomena precursor to pion condensation. Parallel descriptions are presented by the pion field renormalization method and the RPA approach. Various detection possibilities are reviewed. Though available data indicate that nuclei are rather far from the critical regime, emphasis is put on the interest of further investigation of the longitudinal spin-isospin mode [fr

  15. A NPO project for measurement of environmental neutrons in the peninsula Shimokita after the JCO criticality accident

    International Nuclear Information System (INIS)

    Aratani, Michi

    2001-01-01

    The Penin. Shimokita as a Nuclear Peninsula: Past and Present: Since 1967, the Penin. Shimokita is characterized as a Nuclear Peninsula. Then the Shimokita Wharf of Ohminato Port in Mutsu-city was appointed as a home port of the Nuclear Power Ship Mutsu. In 1984 Mutsu Ogawara Region, a southern part of the Penin. around Rokkasho, was paid attention as a target region for reprocessing facilities of burnt nuclear fuels from all the nuclear power stations in this country. At the present stage, uranium enrichment facilities, low-level radioactive waste laying center and high-level vitrified waste storage center are in operation, and the reprocessing facilities are under construction. Burnt fuels are also carried into the site before completion of the facilities mainly for the purpose of cooling in the water pool, because cooling pools of some nuclear power stations are already full of the burnt nuclear fuels. Recently, Mayor of Mutsu has announced that Mutsu City are ready to accept a 'temporary' storage facilities for burnt nuclear fuels. Constructions of two nuclear power stations are in procession. Practice and Results: After the JCO critical accident, members of the Penin. Shimokita Activation Society (SAS) have made voluntarily some chances for learning neutron, which has played a definite role in the accident. Before the time of the accident, they have ever heard nothing about a neutron. So, neutron is entirely a new face radiation for them. Members of NPO EGG (Environmental Guardian of GALA) then obtained information from Urgent Session of the 44th Annual Meeting of Radiochemistry held in Tsukuba by the Japan Society of Nuclear and Radiochemical Sciences, and attended the seminar on the JCO accident held at Institute for Environmental Sciences (IES) in Rokkasho. A title of the seminar was 'Extremely Low Background Gamma Ray Spectroscopy applied to the JCO Accident'. The lecturer was Prof. Komura of LLRL (Low Level Radioactivity Laboratory), Kanazawa University

  16. Radionuclide release rate inversion of nuclear accidents in nuclear facility based on Kalman filter

    International Nuclear Information System (INIS)

    Tang Xiuhuan; Bao Lihong; Li Hua; Wan Junsheng

    2014-01-01

    The rapidly and continually back-calculating source term is important for nuclear emergency response. The Gaussian multi-puff atmospheric dispersion model was used to produce regional environment monitoring data virtually, and then a Kalman filter was designed to inverse radionuclide release rate of nuclear accidents in nuclear facility and the release rate tracking in real time was achieved. The results show that the Kalman filter combined with Gaussian multi-puff atmospheric dispersion model can successfully track the virtually stable, linear or nonlinear release rate after being iterated about 10 times. The standard error of inversion results increases with the true value. Meanwhile extended Kalman filter cannot inverse the height parameter of accident release as interceptive error is too large to converge. Kalman filter constructed from environment monitoring data and Gaussian multi-puff atmospheric dispersion model can be applied to source inversion in nuclear accident which is characterized by static height and position, short and continual release in nuclear facility. Hence it turns out to be an alternative source inversion method in nuclear emergency response. (authors)

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

    International Nuclear Information System (INIS)

    Kouts, H.J.C.; Apostolakis, G.; Kastenberg, W.E.; Birkhofer, E.H.A.; Hoegberg, L.G.; LeSage, L.G.; Rasmussen, N.C.; Teague, H.J.; Taylor, J.J.

    1990-08-01

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

  18. Diversity of Concerns in Recovery after a Nuclear Accident: A Perspective from Fukushima.

    Science.gov (United States)

    Sato, Akiko; Lyamzina, Yuliya

    2018-02-16

    Since the 2011 Fukushima nuclear accident, tremendous resources have been devoted to recovery, and the Japanese Government is gradually lifting evacuation orders. However, public concerns remain prevalent, affecting some people's return to a normal life and threatening their well-being. This study reviews government reports, academic papers, newspaper articles and conference presentations with the aim of obtaining a better understanding of issues which relate to radiation concerns in the recovery process in the aftermath of the accident. It looks extensively at: (1) the current status of the post-accident operations and existing radiation issues in Fukushima, and (2) approaches taken to engage the public during recovery from five previous comparable nuclear and radiological events: Three Mile Island, Buenos Aires (RA-2 facility), Chernobyl, Goiânia and Tokai-mura. The findings indicate that the limitations and emerging challenges of the current recovery operations cause concerns about radiation exposure in various aspects of day-to-day life. Past experiences suggest that long-term management that take a holistic and cohesive approach is critical for restoration of sustainable livelihoods and for social re-integration. Not only actual risks but also public perceptions of risks should be carefully assessed and addressed in the process of environmental remediation.

  19. Diversity of Concerns in Recovery after a Nuclear Accident: A Perspective from Fukushima

    Directory of Open Access Journals (Sweden)

    Akiko Sato

    2018-02-01

    Full Text Available Since the 2011 Fukushima nuclear accident, tremendous resources have been devoted to recovery, and the Japanese Government is gradually lifting evacuation orders. However, public concerns remain prevalent, affecting some people’s return to a normal life and threatening their well-being. This study reviews government reports, academic papers, newspaper articles and conference presentations with the aim of obtaining a better understanding of issues which relate to radiation concerns in the recovery process in the aftermath of the accident. It looks extensively at: (1 the current status of the post-accident operations and existing radiation issues in Fukushima, and (2 approaches taken to engage the public during recovery from five previous comparable nuclear and radiological events: Three Mile Island, Buenos Aires (RA-2 facility, Chernobyl, Goiânia and Tokai-mura. The findings indicate that the limitations and emerging challenges of the current recovery operations cause concerns about radiation exposure in various aspects of day-to-day life. Past experiences suggest that long-term management that take a holistic and cohesive approach is critical for restoration of sustainable livelihoods and for social re-integration. Not only actual risks but also public perceptions of risks should be carefully assessed and addressed in the process of environmental remediation.

  20. Nuclear waste management in Canada : critical issues, critical perspectives

    International Nuclear Information System (INIS)

    Durant, D.; Fuji Johnson, G.

    2009-01-01

    As oil reserves decline and the environment takes centre stage in public policy discussions, the merits and dangers of nuclear power and nuclear waste management continue to be debated. Canada is intent on building more reactors to increase energy production without destroying the planet, but it and other nuclear energy-producing countries face not only technical problems but also social and ethical issues. This book provides a critical antidote to the favourable position of government and industry. The contributors build their case by exploring key issues and developments. What do frequently used terms such as safety, risk, and acceptability really mean? How and why did the public consultation process in Canada fail to address ethical and social issues? What is the significance and potential of a public consultation process that involves diverse interests, epistemologies, and actors, including Aboriginal peoples? And how do we ensure that our frameworks for discussion are inclusive and ethical? This timely collection defuses the uncertainty, ambiguity, and ignorance that surrounds nuclear energy. It will appeal to academics, students, and stakeholders in public policy or environmental studies who want to think critically and more broadly about how we approach energy generation and waste management.