Learning Lessons from TMI to Fukushima and Other Industrial Accidents: Keys for Assessing Safety Management Practices

International Nuclear Information System (INIS)

Dechy, N.; Rousseau, J.-M.; Dien, Y.; Montmayeul, R.; Llory, M.

2016-01-01

The main objective of the paper is to discuss and to argue about transfer, from an industrial sector to another industrial sector, of lessons learnt from accidents. It will be achieved through the discussion of some theoretical foundations and through the illustration of examples of application cases in assessment of safety management practices in Nuclear Power Plant (NPP). The nuclear energy production industry has faced three big ones in 30 years (TMI, Chernobyl, Fukushima) involving three different reactor technologies operated in three quite different cultural, organizational and regulatory contexts. Each of those accident has been the origin of questions, but also generator of lessons, some changing the worldview (see Wilpert and Fahlbruch, 1998) of what does cause an accident in addition to the engineering view about the importance of technical failures (human error, safety culture, sociotechnical interactions). Some of their main lessons were implemented such as improvements of human-machine interfaces ergonomics, recast of some emergency operating procedures, severe accident mitigation strategies and crisis management. Some lessons did not really provide deep changes. It is the case for organizational lessons such as, organizational complexity, management of production pressures, regulatory capture, and failure to learn, etc.

Main lessons based on the Chernobyl nuclear power plant accident liquidation experience

International Nuclear Information System (INIS)

Vasil'chenko, V.N.; Nosovskij, A.V.

2006-01-01

The authors review the main lessons of the Chernobyl nuclear power plant accident and the liquidation of its consequences in the area of the nuclear reactors safety operation, any major accident management, liquidation accident consequences criteria, emergency procedures, preventative measures and treatment irradiated victims, the monitoring methods etc. The special emphasis is put on the questions of the emergency response and the antiaccidental measures planning in frame of international cooperation program

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)

Risk communication in the case of the Fukushima accident: Impact of communication and lessons to be learned.

Science.gov (United States)

Perko, Tanja

2016-10-01

Risk communication about the Fukushima Daiichi nuclear power plant accident in 2011 was often not transparent, timely, clear, nor factually correct. However, lessons related to risk communication have been identified and some of them are already addressed in national and international communication programmes and strategies. The Fukushima accident may be seen as a practice scenario for risk communication with important lessons to be learned. As a result of risk communication failures during the accident, the world is now better prepared for communication related to nuclear emergencies than it was 5 years ago The present study discusses the impact of communication, as applied during the Fukushima accident, and the main lessons learned. It then identifies pathways for transparent, timely, clear and factually correct communication to be developed, practiced and applied in nuclear emergency communication before, during, and after nuclear accidents. Integr Environ Assess Manag 2016;12:683-686. © 2016 SETAC. © 2016 SETAC.

Radiological accident and incident in Thailand: Lesson to be learned

International Nuclear Information System (INIS)

Ya-anant, N.; Tiyapun, K.; Saiyut, K.

2011-01-01

Radioactive materials in Thailand have been used in medicine, research and industry for more than 50 y. Several radiological accident and incidents happened in the past 10 y. A serious one was the radiological accident that occurred in Samut Prakan (Thailand) in 2000. The serious radiological accident occurred when the 60 Co head was partially dismantled, taken from that storage to sell as scrap metal. Three victims died and 10 people received high dose from the source. The lesson learned from the radiological accident in Samut Prakan was to improve in many subjects, such as efficiency in Ministerial Regulations and Atomic Energy Act, emergency response and etc. In addition to the serious accident, there are also some small incidents that occurred, such as detection of contaminated scrap metals from the re-cycling of scrap metals from steel factories. Therefore, the radiation protection infrastructure was established after the accident. Laws and regulations of radiation safety and the relevant regulatory procedures must be revised. (authors)

Emergency operating procedures improvement based on the lesson learned from the Fukushima Daiichi accident

Energy Technology Data Exchange (ETDEWEB)

Wu, Wen-Hsiung, E-mail: whwu1127@aec.gov.tw [Atomic Energy Council, 2F., No. 80, Sec.1, Chenggong Rd., Yonghe Dist., New Taipei City 234, Taiwan (China); Institute of Nuclear Engineering and Science, National Tsing Hua University, No. 101, Sec. 2, Guangfu Rd., Hsinchu City 300, Taiwan (China); Liao, Lih-Yih, E-mail: lyliao@iner.gov.tw [Institute of Nuclear Energy Research, Atomic Energy Council, No. 1000, Wenhua Rd., Jiaan Village, Longtan Township, Taoyuan County 325, Taiwan (China)

2016-12-01

Highlights: • Discuss the problem of EOPs at the time of Fukushima accident to deal with the prolonged SBO. • Elaborate the potential risk accompanied with the emergency depressurization in the SBO. • Describe a special guideline to cope with Fukushima-like accidents and provide its technical basis. • Point out that Fukushima accident might have been prevented if improved EOPs had been used. • Propose key points and suggestions for improving the EOPs. - Abstract: One of the lessons learned from the Fukushima Daiichi accident is the emergency operating procedures (EOPs) have to be improved. The BWR Owners’ Group revised the emergency procedure guidelines and addressed the lesson learned from the Fukushima Daiichi accident in revision 3 in order to avoid loss of turbine-driven makeup water systems during reactor depressurization. However, the improvement deserves much more attention. The existing EOPs at the time of the accident may not be adequate enough for the prolonged station blackout condition, because resources required for performing the EOPs are vastly unavailable or gradually exhausted. The improved EOPs must not only permit early reactor pressure vessel depressurization, but also address the risk accompanied with the emergency depressurization. For this reason, Taiwan Power Company proposed the Ultimate Response Guideline (URG) to cope with Fukushima-like accidents. The main content of the URG is a two-stage depressurization strategy, namely the controlled depressurization and the emergency depressurization. The technical basis of the two-stage depressurization strategy was discussed in this paper. The effectiveness of the URG was verified by using TRAC/RELAP Advanced Computational Engine (TRACE). Besides, the emergency responses performed by Fukushima Daini nuclear power plant (Fukushima Daini NPP) were found to be very similar to the URG. The consequences of Fukushima Daini NPP somehow demonstrate that the URG is effective for Fukushima

Emergency operating procedures improvement based on the lesson learned from the Fukushima Daiichi accident

International Nuclear Information System (INIS)

Wu, Wen-Hsiung; Liao, Lih-Yih

2016-01-01

Highlights: • Discuss the problem of EOPs at the time of Fukushima accident to deal with the prolonged SBO. • Elaborate the potential risk accompanied with the emergency depressurization in the SBO. • Describe a special guideline to cope with Fukushima-like accidents and provide its technical basis. • Point out that Fukushima accident might have been prevented if improved EOPs had been used. • Propose key points and suggestions for improving the EOPs. - Abstract: One of the lessons learned from the Fukushima Daiichi accident is the emergency operating procedures (EOPs) have to be improved. The BWR Owners’ Group revised the emergency procedure guidelines and addressed the lesson learned from the Fukushima Daiichi accident in revision 3 in order to avoid loss of turbine-driven makeup water systems during reactor depressurization. However, the improvement deserves much more attention. The existing EOPs at the time of the accident may not be adequate enough for the prolonged station blackout condition, because resources required for performing the EOPs are vastly unavailable or gradually exhausted. The improved EOPs must not only permit early reactor pressure vessel depressurization, but also address the risk accompanied with the emergency depressurization. For this reason, Taiwan Power Company proposed the Ultimate Response Guideline (URG) to cope with Fukushima-like accidents. The main content of the URG is a two-stage depressurization strategy, namely the controlled depressurization and the emergency depressurization. The technical basis of the two-stage depressurization strategy was discussed in this paper. The effectiveness of the URG was verified by using TRAC/RELAP Advanced Computational Engine (TRACE). Besides, the emergency responses performed by Fukushima Daini nuclear power plant (Fukushima Daini NPP) were found to be very similar to the URG. The consequences of Fukushima Daini NPP somehow demonstrate that the URG is effective for Fukushima

Key regulatory and safety issues emerging NEA activities. Lessons Learned from Fukushima Dai-ichi NPS Accident - Key Regulatory and Safety Issues

International Nuclear Information System (INIS)

Nakoski, John

2013-01-01

A presentation was provided on the key safety and regulatory issues and an update of activities undertaken by the NEA and its members in response to the accident at the Fukushima Daiichi nuclear power stations (NPS) on 11 March 2011. An overview of the accident sequence and the consequences was provided that identified the safety functions that were lost (electrical power, core cooling, and primary containment) that lead to units 1, 2, and 3 being in severe accident conditions with large off-site releases. Key areas identified for which activities of the NEA and member countries are in progress include accident management; defence-in-depth; crisis communication; initiating events; operating experience; deterministic and probabilistic assessments; regulatory infrastructure; radiological protection and public health; and decontamination and recovery. For each of these areas, a brief description of the on-going and planned NEA activities was provided within the three standing technical committees of the NEA with safety and regulatory mandates (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). On-going activities of CNRA include a review of enhancement being made to the regulatory aspects for the oversight of on-site accident management strategies and processes in light of the lessons learned from the accident; providing guidance to regulators on crisis communication; and supporting the peer review of the safety assessments of risk-significant research reactor facilities in light of the accident. Within the scope of the CSNI mandate, activities are being undertaken to better understand accident progression; characteristics of new fuel designs; and a benchmarking study of fast-running software for estimating source term under severe accident conditions to support protective measure recommendations. CSNI also has ongoing work in human

Safety Requirements / Design Criteria for SFR. Lessons Learned from the Fukushima Dai-ichi Accident

International Nuclear Information System (INIS)

Yllera, Javier

2013-01-01

After the Fukushima event (March 2011) the IAEA has started an action to review and revise, if necessary, all Safety Standards to take into consideration the lessons learned from the accident. The Safety Standards that need to be revised have been identified. A Prioritization Approach has been established: The first priority is to review safety guides applicable for NPPs and spent fuel storage with focus on the measures for the prevention and mitigation of severe accident due to external hazards - ● Regulatory framework, Safety assessment, Management system, Radiation protection and Emergency Preparedness and response; ● Sitting, Design, Operation of NPPs ● Decommissioning and Waste Management. Original sources for lessons learned: IAE fact Finding Mission, Japan´s report to the Ministerial Conference, INSAG Report, etc. Later, other lesson sources considered

Goiania radiation accident: activities carried out and lessons learned based on personal experience

International Nuclear Information System (INIS)

Silva, F.C.A. da

2017-01-01

Goiânia Radiological Accident, on September 13, 1987, with a radioactive source of cesium-137 with 50.9 TBq, used in radiotherapy, is one of the most important accidents in the scientific area, representing a milestone for all workers in the areas of radiation protection and radiological emergency that worked during the event. A personal view of the Goiânia Radiological Accident is presented, showing some activities carried out in contaminated areas and lessons learned based on own experience during the event

Lessons learned from accidents in industrial irradiation facilities

International Nuclear Information System (INIS)

1996-01-01

Use of ionizing radiation in medicine, industry and research for technical development continues to increase throughout the world. One application with a high growth rate is irradiation suing high energy gamma photons and electron beams. There are currently more than 160 gamma irradiation facilities and over 600 electron beam facilities in operation in almost all IAEA Member States. The most common uses of these facilities are to sterilize medical and pharmaceutical products, to preserve foodstuffs, to synthesize polymers and to eradicate insects. Although this industry has a good safety record, there is a potential for accidents with serious consequences to human health because of the high dose rates produced by these sources. Fatal accidents have occurred at installations in both developed and developing countries. Such accidents have prompted a review of several accidents, including five with fatalities, by a team of manufacturers, regulatory authorities and operating organizations. Having looked closely at the circumstances of each accident and the apparent deficiencies in design, safety and regulatory systems and personnel performance, the team made a number of recommendations on the ways in which the safety of irradiators can be improved. The findings of extensive research pertaining to the lessons that can be learned from irradiator accidents are presented. This publication is intended for manufacturers, regulatory authorities and operating organizations dealing with industrial irradiators. It was drafted by J.E. Glen, United States Nuclear Regulatory Commission, United States of America, and P. Zuniga-Bello, Consejo Nacional de Ciencia y Technologia, Mexico

The Fukushima accident: radiological consequences and first lessons. Proceedings; L'accident de Fukushima: consequences radiologiques et premiers enseignements. Recueil des presentations

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-02-15

This document brings together the available presentations given at the conference organised by the French society of radiation protection about the Fukushima accident, its radiological consequences and the first lessons learnt. Sixteen presentations (slides) are compiled in this document and deal with: 1 - Accident progress and first actions (Thierry Charles, IRSN); 2 - Conditions and health monitoring of the Japanese intervention teams (Bernard Le Guen, EDF); 3 - The Intra Group action after the Fukushima accident (Michel Chevallier, Groupe Intra; Frederic Mariotte, CEA); 4 - Processing of effluents (Georges Pagis, Areva); 5 - Fukushima accident: impact on the terrestrial environment in Japan (Didier Champion, IRSN); 6 - Consequences of the Fukushima accident on the marine environment (Dominique Boust, IRSN); 7 - Territories decontamination perspectives (Pierre Chagvardieff, CEA); 8 - Actions undertaken by Japanese authorities (Florence Gallay, ASN); 9 - Japanese population monitoring and health stakes (Philippe Pirard, InVS); 10 - Citizen oversight actions implemented in Japan (David Boilley, ACRO); 11 - Implementation of ICRP's (International Commission on Radiological Protection) recommendations by Japanese authorities: first analysis (Jacques Lochard, CIPR); 12 - Control of Japan imported food stuff (David Brouque, DGAL); 13 - Questions asked by populations in France and in Germany (Florence-Nathalie Sentuc, GRS; Pascale Monti, IRSN); 14 - Labour law applicable to French workers working abroad (Thierry Lahaye, DGT); 15 - Protection of French workers working in Japan, Areva's experience (Patrick Devin, Areva); 16 - Fukushima accident experience feedback and post-accident nuclear doctrine (Jean-Luc Godet, ASN)

Learning non-technical skill lessons from testimony given in the investigation of the nuclear accident at the Fukushima Nuclear Power Stations

International Nuclear Information System (INIS)

Hikono, Masaru; Sakuda, Hiroshi; Matsui, Yuko; Goto, Manabu; Kanayama, Masaki

2016-01-01

The Government Investigation Committee on the Accident at the Fukushima Nuclear Power Stations interviewed individuals concerned. The hearing records, published in 2014, are considered to have valuable lessons for power station managers who encounter severe accidents. In this study, descriptions from the hearing records were extracted as lessons for managers. The extractions were classified by the subject (for whom the lessons are intended), and the category of the non-technical skills. The results showed the possibility of pointing out the lessons in accordance with responsibilities. (author)

Nuclear Security Summit and Workshop 2015: Preventing, Understanding and Recovering from Nuclear Accidents lessons learned from Chernobyl and Fukushima

Science.gov (United States)

2016-09-01

Workshop 2015 "Preventing, Understanding and Recovering from Nuclear Accidents"--lessons learned from Chernobyl and Fukushima Distribution Statement...by the factor to get the U.S. customary unit. “Preventing, Understanding and Recovering from Nuclear Accidents” – lessons learned from Chernobyl ...and Fukushima NUCLEAR SECURITY SUMMIT & WORKSHOP 2015 2 Background The 1986 Chernobyl and the 2011 Fukushima accidents provoked world-wide concern

Outline of the Fukushima Daiichi Accident. Lessons Learned and Safety Enhancements

Directory of Open Access Journals (Sweden)

Hirano Masashi

2017-01-01

This paper briefly presents the outline of the Fukushima Daiichi accident and summarizes the major lessons learned having been drawn and safety enhancements having been done in Japan for the purpose of giving inputs to the discussions to be taken place in the Special Invited Session “Fukushima, 5 years after”.

Lessons learned from the Fukushima Dai-ichi accident and responses in NRA regulatory requirements

International Nuclear Information System (INIS)

Fuketa, Toyoshi

2014-01-01

The author would like to present significant lessons learned from the TEPCO’s Fukushima Dai-ichi accident and responses in regulatory requirements developed by the Nuclear Regulation Authority for power-producing light water reactors. The presentation will cover prevention of structures, systems and components failures, measures to prevent common cause failures, prevention of core damage, mitigation of severe accidents, emergency preparedness, continuous improvement of safety, use of probabilistic risk assessment, and post-accident regulation on the Fukushima Dai-ichi. (author)

Comparative analysis of the countermeasures taken to mitigate exposure of the public to radioiodine following the Chernobyl and Fukushima accidents: lessons from both accidents.

Science.gov (United States)

Uyba, Vladimir; Samoylov, Alexander; Shinkarev, Sergey

2018-04-01

In the case of a severe radiation accident at a nuclear power station, the most important radiation hazard for the public is internal exposure of the thyroid to radioiodine. The purposes of this paper were (i) to compare countermeasures conducted (following the Chernobyl and Fukushima accidents) aimed at mitigation of exposure to the thyroid for the public, (ii) to present comparative estimates of doses to the thyroid and (iii) to derive lessons from the two accidents. The scale and time of countermeasures applied in the early phase of the accidents (sheltering, evacuation, and intake of stable iodine to block the thyroid) and at a later time (control of 131I concentration in foodstuffs) have been described. After the Chernobyl accident, the estimation of the thyroid doses for the public was mainly based on direct thyroid measurements of ~400 000 residents carried out within the first 2 months. The highest estimates of thyroid doses to children reached 50 Gy. After the Fukushima accident, the estimation of thyroid doses was based on radioecological models due to a lack of direct thyroid measurements (only slightly more than 1000 residents were measured). The highest estimates of thyroid doses to children were a few hundred mGy. Following the Chernobyl accident, ingestion of 131I through cows' milk was the dominant pathway. Following the Fukushima accident, it appears that inhalation of contaminated air was the dominant pathway. Some lessons learned following the Chernobyl and Fukushima accidents have been presented in this paper.

Applicability of health physics lessons learned from the Three Mile Island Unit 2 accident to the Fukushima Daiichi accident.

Science.gov (United States)

Bevelacqua, J J

2012-02-01

The TMI-2 and Fukushima Daiichi accidents appear to be dissimilar because they involve different reactor types. However, the health physics related lessons learned from TMI-2 are applicable, and can enhance the Fukushima Daiichi recovery effort. Copyright © 2011 Elsevier Ltd. All rights reserved.

Lessons learned from accident simulation exercises and their implications for operation of the IPSN Centre Technique de Crise

International Nuclear Information System (INIS)

Manesse, D.; Ney, J.; Crabol, B.; Ginot, P.

1990-01-01

The Centre Technique de Crise (CTC) of the Institut de Protection et de Surete Nucleaire (IPSN) has an important role to play in the event of an accident at a nuclear installation of Electricite de France (EdF) concerning diagnosis of the situation and forecasting its evolution. For this purpose the CTS is organized into various groups; only that responsible for the evaluation of the radiological consequences is considered in the present paper. Since the beginning of the eighties numerous simulations of nuclear accidents have been organized both by the public authorities and by the nuclear operators. These exercises, of growing complexity, are distinguished according to the type of installation concerned, the scenario (with and without a simulator), the equipment involved, the participants (local and national officials), the accident phase used (at the time of the accident or post-accident), the use of actual or pre-determined meteorological conditions etc.. Different combinations are imposed as a function of the specific aims of each exercise. Numerous lessons have been drawn progressively from these very varied exercises for the operation of the CTC and, in particular, of the Radiological Consequences Group. The principal Lessons concern: development of calculation and mapping tools, specific liaison with the national meteorological services, modification of the centre's facilities, composition of the team and definition of the role of each of its members, improved liaison with the Site Evaluation Group and the provision of appropriate documentation. The need for continuous training of duty teams in the form of presentations and exercises has also been confirmed

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

OpenAIRE

TANAKA, Shun-ichi

2012-01-01

The severe accident that broke out at Fukushima Dai-ichi nuclear power stations on March 11, 2011, caused seemingly infinite damage to the daily life of residents. Serious and wide-spread contamination of the environment occurred due to radioactive materials discharged from nuclear power stations (NPSs). At the same time, many issues were highlighted concerning countermeasures to severe nuclear accidents. The accident is outlined, and lessons learned are extracted with respect to the safety o...

Lessons learnt from Fukushima Accident - What did McMaster Undergraduate Students learn?

Energy Technology Data Exchange (ETDEWEB)

Nagasaki, S., E-mail: nagasas@mcmaster.ca [McMaster University, Hamilton, ON, (Canada)

2015-07-01

Nuclear communities not only in Japan but also around the world learnt a lot of lessons from the Fukushima accident. The direct cause of the accident from the viewpoint of traditional engineering is clear, and as a result various measures have been implemented around the world. The accident also provides many insights into the relationship between traditional engineering and Japanese society. In this paper, the root causes of the accident were studied by applying a psychological model for evocation of an individual's anxiety related to social affairs [1] to the discussions in an undergraduate course at McMaster University. In the last section, the challenges, which McMaster students considered Japanese nuclear community is now facing and Canadian nuclear community can contribute to in future, are summarized. (author)

Lessons learnt from Fukushima Accident - What did McMaster Undergraduate Students learn?

International Nuclear Information System (INIS)

Nagasaki, S.

2015-01-01

Nuclear communities not only in Japan but also around the world learnt a lot of lessons from the Fukushima accident. The direct cause of the accident from the viewpoint of traditional engineering is clear, and as a result various measures have been implemented around the world. The accident also provides many insights into the relationship between traditional engineering and Japanese society. In this paper, the root causes of the accident were studied by applying a psychological model for evocation of an individual's anxiety related to social affairs [1] to the discussions in an undergraduate course at McMaster University. In the last section, the challenges, which McMaster students considered Japanese nuclear community is now facing and Canadian nuclear community can contribute to in future, are summarized. (author)

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

International Nuclear Information System (INIS)

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

1989-01-01

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

Lessons learned in the accident of contamination with Pu-239

International Nuclear Information System (INIS)

Molina, G.; Ruiz C, M.; Angeles C, A.; Benitez S, J.A.

2004-01-01

This work describes the lessons learned during the accident by transuranic contamination in the National Institute of Nuclear Research happened between 1998 and 2003. The origin of the same one is the not authorized transfer of 0.51 g of plutonium metallic used as pattern source in the Department of Metrology to a laboratory which lacked of physical infrastructure, training and team to manipulate this source. (Author)

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

Lessons drawn from the accidents occurred in the framework of conventional external radiotherapy;Lecons tirees des accidents survenus dans le cadre de la radiotherapie externe conventionnelle

Energy Technology Data Exchange (ETDEWEB)

Holmberg, O. [Agence Internationale de l' Energie Atomique, Unite de Radioprotection des Patients, Section Securite et Controle, Vienna (Austria); Czarwinski, R. [Agence Internationale de l' Energie Atomique, Unite de Radioprotection des Patients, Vienna (Austria)

2009-12-15

This study examines some radiation accidents occurred in the past. This information has been systematically assessed to get global lessons. The experience feedback shows that the most of accidents happened in certain conditions. These conditions can be distributed in four categories: 1- perception and vigilance in occupation: accidental exposure happened by lack of vigilance in details and lack of vigilance and perception; 2- procedures: accidental exposure happened following a lack of procedures or control that were not enough complete, not enough documented or not completely implemented; 3- training and understanding: accidental exposures happened because the personnel was not enough qualified and educated, did not get the general training nor the the necessary specialized training; 4- liabilities: accidental exposures happened following lacks and ambiguity in the definition of functions of the personnel and in the hierarchy liabilities. In these precise cases the safety tasks have not been enough covered. (N.C.)

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

International Nuclear Information System (INIS)

Dechy, N.; Rousseau, J.M.; Jeffroy, F.

2012-01-01

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

Twenty years' application of agricultural countermeasures following the Chernobyl accident: lessons learned

International Nuclear Information System (INIS)

Fesenko, S V; Alexakhin, R M; Balonov, M I; Bogdevich, I M; Howard, B J; Kashparov, V A; Sanzharova, N I; Panov, A V; Voigt, G; Zhuchenka, Yu M

2006-01-01

The accident at the Chernobyl NPP (nuclear power plant) was the most serious ever to have occurred in the history of nuclear energy. The consumption of contaminated foodstuffs in affected areas was a significant source of irradiation for the population. A wide range of different countermeasures have been used to reduce exposure of people and to mitigate the consequences of the Chernobyl accident for agriculture in affected regions in Belarus, Russia and Ukraine. This paper for the first time summarises key data on countermeasure application over twenty years for all three countries and describes key lessons learnt from this experience. (review)

Should evacuation conditions after a nuclear accident be revised?; Faut-il revoir les conditions d'evacuation a la suite d'un accident nucleaire?

Energy Technology Data Exchange (ETDEWEB)

Nifenecker, H.

2011-07-01

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

Lessons learned from accidents in radiotherapy. An IAEA Safety Report

International Nuclear Information System (INIS)

Ortiz, P.

1998-01-01

Radiotherapy is a very special application from the view point of protection because humans are deliberately exposed to high doses of radiation, and no physical barrier can be placed between the source and the patient. It deserves, therefore, special considerations from the point of view of potential exposure. An IAEA's Safety Report (in preparation) reviews a large collection of accident information, their initiating events and contributing factors, followed by a set of lessons learned and measures for prevention. The most important causes were: deficiencies in education and training, lack of procedures and protocols for essential tasks (such as commissioning, calibration, commissioning and treatment delivery), deficient communication and information transfer, absence of defence in depth and deficiencies in design, manufacture, testing and maintenance of equipment. Often a combination of more than one of these causes was present in an accident, thus pointing to a problem of management. Arrangements for a comprehensive quality assurance and accident prevention should be required by regulations and compliance be monitored by a Regulatory Authority. (author)

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

Science.gov (United States)

TANAKA, Shun-ichi

2012-01-01

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

Accident at the Fukushima Dai-ichi nuclear power stations of TEPCO. Outline and lessons learned

International Nuclear Information System (INIS)

Tanaka, Shun-ichi

2012-01-01

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

Lessons of the Fukushima Dai-ichi accident for PSA

International Nuclear Information System (INIS)

Kumar, M.; Klug, J.; Alzbutas, R.; Burgazzi, L.; Farcasiu, M.; Nitoi, M.; Ivanov, I.; Bogdanov, D.; Hashimoto, K.; Hirata, K.; La Rovere, S.; Sevbo, O.; Vitazkova, J.; Hustak, S.; Wielenberg, A.; Raimond, E.

2016-01-01

The objective of this document is to identify some lessons learned from the Fukushima Dai-ichi accident for PSA. Based on the public information on the causes that have led to major radioactive release during the Fukushima Dai-ichi accident (initiating events, material and human response), the authors, ASAMPSA-E WP30 members have performed a review to examine the gaps/insufficiencies/incompleteness in the existing Level 1 and Level 2 PSAs. This is the aim of this report which is one of WP30 deliverables i.e. D30.2. The consideration of external initiating events for the different levels of defense-in-depth is one of the focal points in this review. Recommendations in the way of developing the different elements of PSAs have been proposed by the authors and were completed later during the ASAMPSA-E project. Moreover, first recommendations on the use of PSA information in decision making have been included as well. (authors)

Overview of Fukushima accident and the lessons learned from it

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 Dacha 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 1a resulted in the loss of cooling function and ultimate heat sink for a long time period. TEPC 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 equipment 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 proposed 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

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)

Introduction of the Amendment of IAEA Safety Requirements Reflected Lessons Learned from Fukushima Nuclear Accident

Energy Technology Data Exchange (ETDEWEB)

Ahn, Sang-Kyu; Ahn, Hyung-Joon; Kim, Sun-Hae; Cheong, Jae-Hak [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

2015-10-15

The following five Safety Requirements publications were amended: Governmental, Legal and Regulatory Framework for Safety (GSR Part 1, 2010), Site Evaluation for Nuclear Installations (NS-R-3, 2003), Safety of Nuclear Power Plants: Design (SSR-2/1, 2012), Safety of Nuclear Power Plants: Commissioning and Operation (SSR-2/2, 2011), and Safety Assessment for Facilities and Activities (GSR Part 4, 2009). Figure 1 shows IAEA Safety Standards Categories Major amendments of five Safety Requirements publications were introduced and analyzed in this study. The five IAEA safety requirements publications which are GSR Part 1 and 4, NS-R-3 and SSR-2/1 and 2, were amended to reflect the lesson learned from the Fukushima accident and other operating experiences. Specially, 36 provisions were modified and the new 29 provision with 1 requirement (No. 67: Emergency response facilities on the site) of the SSR-2/1 were established. Since the Fukushima accident happened, a new word, design extension conditions (DECs) which cover substantially the beyond design basis accidents (BDBA), including severe accident conditions, was created and more elaborated by the world nuclear experts. Design extension conditions could include conditions in events without significant fuel degradation and conditions with core melting. Figure 2 shows the range of the DECs. The amendment of the five IAEA safety requirements publications are focused at the prevention of initiating events, which would lead to the DECs, and mitigation of the consequences of DECs by the enhanced defense in depth principle. The following examples of the IAEA requirements to prevent the initiating events are: margins for withstanding external events; margins for avoiding cliff edge effects; safety assessment for multiple facilities or activities at a single site; safety assessment in cases where resources at a facility are shared; consideration of the potential occurrence of events in combination; establishing levels of hazard

Outline of the Fukushima Daiichi Accident. Lessons Learned and Safety Enhancements

Science.gov (United States)

Hirano, Masashi

2017-09-01

Abstract. On March 11, 2011, an earthquake and subsequent tsunamis off the Pacific coastline of Japan's Tohoku region caused widespread devastation in Japan. As of June 10, 2016, it is reported that a total of 15,894 people lost their lives and 2,558 people are still unaccounted for. In Fukushima Prefecture, approximately 100,000 people are still obliged to live away from their homes due to the earthquake and tsunami as well as the Fukushima Daiichi accident. On the day, the earthquake and tsunami caused severe damages to the Tokyo Electric Power Company (TEPCO)'s Fukushima Daiichi Nuclear Power Station (NPS). All the units in operation, namely Units 1 to 3, were automatically shut down on seismic reactor protection system trips but the earthquake led to the loss of all off-site electrical power supplies to that site. The subsequent tsunami inundated the site up to 4 to 5 m above its ground level and caused, in the end, the loss of core cooling function in Units 1 to 3, resulting in severe core damages and containment vessel failures in these three units. Hydrogen was released from the containment vessels, leading to explosions in the reactor buildings of Units 1, 3 and 4. Radioactive materials were released to the atmosphere and were deposited on the land and in the ocean. One of the most important lessons learned is an importance to prevent such large scale common cause failures due to extreme natural events. This leads to a conclusion that application of the defense-in-depth philosophy be enhanced because the defense-in-depth philosophy has been and continues to be an effective way to account for uncertainties associated with risks. From the human and organizational viewpoints, the final report from the Investigation Committee of the Government pointed out so-called "safety myth" that existed among nuclear operators including TEPCO as well as the government, that serious severe accidents could never occur in nuclear power plants in Japan. After the accident, the

Strengthening Regulatory Effectiveness in India – Lessons Learnt from Fukushima Accident

International Nuclear Information System (INIS)

Solanki, R.

2016-01-01

Following the Fukushima Daiichi accident in Japan, one of the most important lessons learnt, among other things, was the issue of strengthening the effectiveness of the regulatory bodies. Immediately after the Fukushima accident, National level safety audits were conducted on all operating NPPs in India to review safety of NPPs in India. A national action plan has been prepared to implement the identified short term, midterm and long term measures. The assessment indicates that national response to the Fukushima Accident for safety assessment of NPPs and subsequent actions and initiatives taken for safety enhancement of the NPPs in India are in-line with the objectives of the IAEA Action plan. This paper highlights the actions taken by India in the light of Fukushima Daiichi accident in order to strengthen the regulatory effectiveness through improvements in the existing core processes, challenges faced, Insights gained from the recent initiatives on safety performance indicators and assessment of safety culture, relevant observations of IRRS mission report and Indian perspectives on the further cooperation among the member states for enhancing the regulatory effectiveness for nuclear oversight of regulated organizations. (author)

Twenty years' application of agricultural countermeasures following the Chernobyl accident: lessons learned

Energy Technology Data Exchange (ETDEWEB)

Fesenko, S V [International Atomic Energy Agency, 1400 Vienna (Austria); Alexakhin, R M [Russian Institute of Agricultural Radiology and Agroecology, 249020 Obninsk (Russian Federation); Balonov, M I [International Atomic Energy Agency, 1400 Vienna (Austria); Bogdevich, I M [Research Institute for Soil Science and Agrochemistry, Minsk (Belarus); Howard, B J [Centre for Ecology and Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster LAI 4AP (United Kingdom); Kashparov, V A [Ukrainian Institute of Agricultural Radiology (UIAR), Mashinostroiteley Street 7, Chabany, Kiev Region 08162 (Ukraine); Sanzharova, N I [Russian Institute of Agricultural Radiology and Agroecology, 249020 Obninsk (Russian Federation); Panov, A V [Russian Institute of Agricultural Radiology and Agroecology, 249020 Obninsk (Russian Federation); Voigt, G [International Atomic Energy Agency, 1400 Vienna (Austria); Zhuchenka, Yu M [Research Institute of Radiology, 246000 Gomel (Belarus)

2006-12-15

The accident at the Chernobyl NPP (nuclear power plant) was the most serious ever to have occurred in the history of nuclear energy. The consumption of contaminated foodstuffs in affected areas was a significant source of irradiation for the population. A wide range of different countermeasures have been used to reduce exposure of people and to mitigate the consequences of the Chernobyl accident for agriculture in affected regions in Belarus, Russia and Ukraine. This paper for the first time summarises key data on countermeasure application over twenty years for all three countries and describes key lessons learnt from this experience. (review)

Analysis of emergency response after the Chernobyl accident in Belarus: observed and prevented medical consequences, lessons learned

International Nuclear Information System (INIS)

Buglova, E.; Kenigsberg, J.

1997-01-01

Belarus is one of the most contaminated Republic due to the Chernobyl accident. 23% of the entire area of Belarus was contaminated with radionuclides. To protect the population after the accident different types of protective actions were performed during all phases, based on various temporary dose limits. An analysis of conducted protective actions and lessons obtained during the emergency response is briefly presented

Lessons learned from the CEOG generic accident management guidelines confirmation (validation) exercise

International Nuclear Information System (INIS)

Khalil, Y.F.; Schneider, R.E.; Greene, M.A.

1996-01-01

In July 1995, the CE Owner's Group completed and issued Revision 0 of the Generic Accident Management Guidelines (AMG's) to the owners group task participants. This guidance provides a structured mechanism for the plant staff at CE utilities to respond to accidents that beyond the plant design basis and, possibly, the Emergency Operating Procedures. Prior to final issue of the generic AMGs, the CEOG conducted an AMG Confirmation Exercise to establish the ability of the AMGs to fulfill this important role. The specific objectives of the AMG Confirmation Exercise were to (1) clarify the interactions and transitions between the AMG/Technical Support Center (TSC) and the EOPS/Operations Personnel (2) validate the adequacy of the AMG data collection and plant condition diagnostic evaluation process and (3) assess the feasibility of the mechanical material and recommendations contained in the AMG's. The purpose of paper is to provide a detailed description of the AMG Confirmation Exercise as well as important lessons learned during the planning and implementation of the exercise. In addition, a discussion will be presented pertaining to the relationship between the AMG's (incumbent to the Technical Support Center) and the plants Emergency Operating Procedures (incumbent to the Control Room Operations Staff)

Lessons Learnt from Past Incidents and Accidents in Radiation Oncology.

Science.gov (United States)

Knöös, T

2017-09-01

The purpose of this report is to review and compile what have been and can be learnt from incidents and accidents in radiation oncology, especially in external beam and brachytherapy. Some major accidents from the last 20 years will be discussed. The relationship between major events and minor or so-called near misses is mentioned, leading to the next topic of exploring the knowledge hidden among them. The main lessons learnt from the discussion here and elsewhere are that a well-functioning and safe radiotherapy department should help staff to work with awareness and alertness and that documentation and procedures should be in place and known by everyone. It also requires that trained and educated staff with the required competences are in place and, finally, functions and responsibilities are defined and well known. Copyright © 2017 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Analysis of emergency response after the Chernobyl accident in Belarus: observed and prevented medical consequences, lessons learned

Energy Technology Data Exchange (ETDEWEB)

Buglova, E.; Kenigsberg, J. [Research Clinical Inst. of Radiation Medicine and Endocrinology, Minsk (Belarus)

1997-12-31

Belarus is one of the most contaminated Republic due to the Chernobyl accident. 23% of the entire area of Belarus was contaminated with radionuclides. To protect the population after the accident different types of protective actions were performed during all phases, based on various temporary dose limits. An analysis of conducted protective actions and lessons obtained during the emergency response is briefly presented 9 refs.

Introduction of new terms and lessons for radiological protection after Fukushima Dai-Ichi accident

International Nuclear Information System (INIS)

Singh, Vishwanath P.; Managanvi, S.S.; Bhat, H.R.

2012-01-01

The nuclear accidents in the world are very few among various types of operating facilities. However when an accident happened, we have learnt a lot to improve the philosophy, term, definitions, document preparation, equipment's requirement, supporting systems, awareness program and restriction etc. After Fukushima Dai-ichi we have learnt a lot, in this view this paper has been prepared to discuss for radiological protection aspects. Discussion: The probability of nuclear accidents is negligible but when happens, it opens new doors of lessons for radiological protection practices for occupational workers, emergency workers for damage control to prevent catastrophic situation/rescue to life saving actions and the member of the public. The Chernobyl and Three Mile Island accidents have provided a lot experiences for management of emergency situations, documentation, radiation emergency preparedness, emergency equipment's, concept of defense-in-depth, emergency planning zone (EPZ), accidental dose limits, estimation of source term and public dose, intervention levels, decision supporting system, remedial actions in public domain; decontamination of person, houses/building and land and etc. Recent Fukushima Dai-ichi accident in Japan was managed in appreciable manner but still new definitions and lessons for radiological protection have been emerged out. The present paper discusses difficulties w. r. t. the radiological aspects observed/faced by Japanese during nuclear crises. The accident introduced new terms as Natural Dose Rate Unit (NDRU), voluntary evacuation, deliberate evacuation area, restricted area and difference between evacuation zone and EPZ. The Fukushima accident has enforced worldwide regulators and operators to review the individual dose limit and amendment for raise in the dose limit during accident, availability of efficient/adequate quantities of personal dosimeter in public domain, collection arrangement of bulk amount of radioactive wastes

Accidents in industrial radiography and lessons to be learned. A review of IAEA Safety Report

International Nuclear Information System (INIS)

Modupe, M.S.; Oresegun, O.

1998-01-01

This IAEA Safety Report Series publication is the result of a review of a large selection of accidents in industrial radiography which Regulatory Authorities, professional associations and scientific journals have reported. The review's objective was to draw lessons from the initiating events of the accidents, contributing factors and the consequences. A small, representative selection of accident descriptions is used to illustrate the primary causes of radiography accidents and a set of recommendations to prevent recurrence of such accidents or to mitigate the consequences of those that do occur is provided. By far the most common primary cause of over-exposure was 'Failure to follow operational procedures' and specifically failure to perform radiation monitoring to locate the position of the source. The information in the Safety Report is intended for use by Regulatory Authorities, operating organizations, workers manufacturers and client organizations having responsibilities for radiation protection and safety in industrial radiography. (author)

Use of accident experience in developing criteria for teleoperator equipment

International Nuclear Information System (INIS)

Vallario, E.J.; Selby, J.M.

1985-10-01

The 1961 SL-1 reactor accident in Idaho and the Recuplex accident at Hanford are reviewed to identify problems common to emergency situations, lessons learned from accidents, criteria for emergency equipment, and recommendations for using robotics to solve problems during emergencies. Teleoperator equipment could be used to assess the extent of the damage and the condition of the reactor, retrieve dosimeters, evacuate and treat accident victims, clean up debris and decontaminate accident areas. 2 refs., 9 figs

Lessons learned from post-accident management at Chernobyl: the P.a.r.e.x. project

International Nuclear Information System (INIS)

Heriard Dubreuil, G.; Lochard, J.; Bataille, C.; Ollagnon, H.; Baude, St.

2008-01-01

Return of experience on Chernobyl post-accident management: the PAREX study Belarus is the country the most affected by the Chernobyl fallouts and is among the most significant experiences in the nuclear post-accident field. Despite specificities inherent to the political and social situation in Belarus, the experience of post-accidental management in this country holds a wealth of lessons in the perspective of preparation to a post-accidental situation in the French and European context. Through the PAREX project (2005-2006), the French Nuclear Safety Authority analysed the return of experience of Chernobyl post-accident management from 1986 to 2005 in order to draw its lessons in the perspective of a preparation policy. The study was led by a group of experts and involved the participation of a pluralistic group of about thirty participants (public authorities, local governments, NGOs, experts, operators). PAREX highlighted the complexity of a situation of long-lasting radioactive contamination (diversity of stakeholders and of dimensions at stake: health, environment, economy, society...). Beyond traditional public crisis management tools and frameworks, post-accident strategies also involves in the longer term a territorial and social response, which relies on local capacities of initiative. Preparation to such process requires experimenting new modes of operation that allow a diversity of local actors to take part to the response to a situation of contamination and to the surveillance system, with the support of public authorities. The conclusions of PAREX include a set of recommendations in this perspective. (authors)

The accident at TEPCO's Fukushima-Daiichi Nuclear Power Station: What went wrong and what lessons are universal?

Science.gov (United States)

Omoto, Akira

2013-12-01

After a short summary of the nuclear accident at the Fukushima Daiichi Nuclear Power Station, this paper discusses “what went wrong” by illustrating the problems of the specific layers of defense-in-depth (basic strategy for assuring nuclear safety) and “what lessons are universal.” Breaches in the multiple layers of defense were particularly significant in respective protection (a) against natural disasters (first layer of defense) as well as (b) against severe conditions, specifically in this case, a complete loss of AC/DC power and isolation from the primary heat sink (fourth layer of defense). Confusion in crisis management by the government and insufficient implementation of offsite emergency plans revealed problems in the fifth layer of defense. By taking into consideration managerial and safety culture that might have relevance to this accident, in the author's view, universal lessons are as follows: Resilience: the need to enhance organizational capabilities to respond, monitor, anticipate, and learn in changing conditions, especially to prepare for the unexpected. This includes increasing distance to cliff edge by knowing where it exists and how to increase safety margin. Responsibility: the operator is primarily responsible for safety, and the government is responsible for protecting public health and environment. For both, their right decisions are supported by competence, knowledge, and an understanding of the technology, as well as humble attitudes toward the limitations of what we know and what we can learn from others. Social license to operate: the need to avoid, as much as possible regardless of its probability of occurrence, the reasonably anticipated environmental impact (such as land contamination), as well as to build public confidence/trust and a renewed liability scheme.

Lessons Learned from the Fukushima Daiichi Accident, Actions Taken and Challenges Ahead

International Nuclear Information System (INIS)

Shimizu, Y.

2016-01-01

On 19 September, 2012, the Nuclear Regulation Authority (NRA) was established in light of lessons learned from the Fukushima Daiichi accident of 11 March 2011, to ensure that such accidents never happen again, to restore public trust in regulator both in Japan and abroad and to rebuild and foster a genuine safety culture by placing the highest priority on public safety. The NRA, an independent administrative commission of the Ministry of the Environment, is organized to separate the regulatory functions from the promotional functions of the use of nuclear energy within the government, and to independently implement its duties from the perspectives of neutrality and fairness based on its expertise. Having learned the lessons from the Fukushima Daiichi accident and with reference to IAEA safety standards, since its establishment, the NRA has endeavored to strengthen the regulatory requirements, in particular, for hazards such as tsunamis and earthquakes which may lead to common cause failures, and countermeasures against severe accidents. Under the new regulatory scheme, a back-fitting system was introduced. Emergency preparedness and response measures for nuclear facilities were also enhanced. As of end of March 2016, five reactors received NRA’s permission for changing their reactor installations based on the new regulatory requirements, and two nuclear power reactors have restarted their operations. In January 2016, at the request of Japan, the IAEA sent the IRRS mission team to Japan to assess the regulatory framework for nuclear and radiation safety. Through the self-assessment prior to the mission, the NRA has developed 22 action plans, including a) improvement of regulatory inspection, b) capacity building, and c) strengthening of safety research capability. The mission team has found that Japan’s nuclear regulator has demonstrated independence and transparency since it was set up in 2012. The team also noted that the NRA needs to improve the inspection

Evaluation of severe accident environmental conditions taking accident management strategy into account for equipment survivability assessments

International Nuclear Information System (INIS)

Lee, Byung Chul; Jeong, Ji Hwan; Na, Man Gyun; Kim, Soong Pyung

2003-01-01

This paper presents a methodology utilizing accident management strategy in order to determine accident environmental conditions in equipment survivability assessments. In case that there is well-established accident management strategy for specific nuclear power plant, an application of this tool can provide a technical rationale on equipment survivability assessment so that plant-specific and time-dependent accident environmental conditions could be practically and realistically defined in accordance with the equipment and instrumentation required for accident management strategy or action appropriately taken. For this work, three different tools are introduced; Probabilistic Safety Assessment (PSA) outcomes, major accident management strategy actions, and Accident Environmental Stages (AESs). In order to quantitatively investigate an applicability of accident management strategy to equipment survivability, the accident simulation for a most likely scenario in Korean Standard Nuclear Power Plants (KSNPs) is performed with MAAP4 code. The Accident Management Guidance (AMG) actions such as the Reactor Control System (RCS) depressurization, water injection into the RCS, the containment pressure and temperature control, and hydrogen concentration control in containment are applied. The effects of these AMG actions on the accident environmental conditions are investigated by comparing with those from previous normal accident simulation, especially focused on equipment survivability assessment. As a result, the AMG-involved case shows the higher accident consequences along the accident environmental stages

Accident management insights after the Fukushima Daiichi NPP accident

International Nuclear Information System (INIS)

Degueldre, Didier; Viktorov, Alexandre; Tuomainen, Minna; Ducamp, Francois; Chevalier, Sophie; Guigueno, Yves; Tasset, Daniel; Heinrich, Marcus; Schneider, Matthias; Funahashi, Toshihiro; Hotta, Akitoshi; Kajimoto, Mitsuhiro; Chung, Dae-Wook; Kuriene, Laima; Kozlova, Nadezhda; Zivko, Tomi; Aleza, Santiago; Jones, John; McHale, Jack; Nieh, Ho; Pascal, Ghislain; ); Nakoski, John; Neretin, Victor; Nezuka, Takayoshi; )

2014-01-01

The Fukushima Daiichi nuclear power plant (NPP) accident, that took place on 11 March 2011, initiated a significant number of activities at the national and international levels to reassess the safety of existing NPPs, evaluate the sufficiency of technical means and administrative measures available for emergency response, and develop recommendations for increasing the robustness of NPPs to withstand extreme external events and beyond design basis accidents. The OECD Nuclear Energy Agency (NEA) is working closely with its member and partner countries to examine the causes of the accident and to identify lessons learnt with a view to the appropriate follow-up actions to be taken by the nuclear safety community. Accident management is a priority area of work for the NEA to address lessons being learnt from the accident at the Fukushima Daiichi NPP following the recommendations of Committee on Nuclear Regulatory Activities (CNRA), Committee on the Safety of Nuclear Installations (CSNI), and Committee on Radiation Protection and Public Health (CRPPH). Considering the importance of these issues, the CNRA authorised the formation of a task group on accident management (TGAM) in June 2012 to review the regulatory framework for accident management following the Fukushima Daiichi NPP accident. The task group was requested to assess the NEA member countries needs and challenges in light of the accident from a regulatory point of view. The general objectives of the TGAM review were to consider: - enhancements of on-site accident management procedures and guidelines based on lessons learnt from the Fukushima Daiichi NPP accident; - decision-making and guiding principles in emergency situations; - guidance for instrumentation, equipment and supplies for addressing long-term aspects of accident management; - guidance and implementation when taking extreme measures for accident management. The report is built on the existing bases for capabilities to respond to design basis

Our consistent countermeasure following up with lesson from Fukushima NPPs accident

Energy Technology Data Exchange (ETDEWEB)

Kim, Jae Rok [Korea Academy of Nuclear Safety, Seoul (Korea, Republic of); Ro, Seung Gy [Sung woo E and T, Kyeonggi (Korea, Republic of); Kim, Si Hwan [UNIST, Ulsan (Korea, Republic of); Nam, Jang Soo [Korean Nuclear Society, Daejeon (Korea, Republic of); Yoo, Guk Hee [Nuclear Safety and Security Commission, Seoul (Korea, Republic of); Kim, Soong Pyung [Chosun Univ., Gwangju (Korea, Republic of)

2012-10-15

Fukushima NPPs accident has not only resulted in driving out the nuclear Renaissance which is about to revive after several lean years, but also given humankind a very rigorous lessons in nuclear safety. Recently administrative systems were reorganized for stepping up further nuclear safety. Nuclear Safety and Security Commission(NSSC) as a governmental organization, directly under the jurisdiction of the president, which is responsible for a nuclear safety mission separated from Ministry of Education, Science and Technology. A beef up work of 50 safety related items for Korean NPPs identified after Fukushima NPPs accident has been implemented under the supervision of the commission. It has also been emphasized that sincere communications between the nuclear society and the people at large are essential for obtaining public acceptance of nuclear energy by ensuring the credibility of nuclear safety. The main points of lecture materials presented in the nuclear senior members' forum have been reviewed to derive invaluable guidelines.

The accident at TEPCO's Fukushima-Daiichi Nuclear Power Station: What went wrong and what lessons are universal?

International Nuclear Information System (INIS)

Omoto, Akira

2013-01-01

After a short summary of the nuclear accident at the Fukushima Daiichi Nuclear Power Station, this paper discusses “what went wrong” by illustrating the problems of the specific layers of defense-in-depth (basic strategy for assuring nuclear safety) and “what lessons are universal.” Breaches in the multiple layers of defense were particularly significant in respective protection (a) against natural disasters (first layer of defense) as well as (b) against severe conditions, specifically in this case, a complete loss of AC/DC power and isolation from the primary heat sink (fourth layer of defense). Confusion in crisis management by the government and insufficient implementation of offsite emergency plans revealed problems in the fifth layer of defense. By taking into consideration managerial and safety culture that might have relevance to this accident, in the author's view, universal lessons are as follows: a)Resilience: the need to enhance organizational capabilities to respond, monitor, anticipate, and learn in changing conditions, especially to prepare for the unexpected. This includes increasing distance to cliff edge by knowing where it exists and how to increase safety margin. b)Responsibility: the operator is primarily responsible for safety, and the government is responsible for protecting public health and environment. For both, their right decisions are supported by competence, knowledge, and an understanding of the technology, as well as humble attitudes toward the limitations of what we know and what we can learn from others. c)Social license to operate: the need to avoid, as much as possible regardless of its probability of occurrence, the reasonably anticipated environmental impact (such as land contamination), as well as to build public confidence/trust and a renewed liability scheme

Case examples of chemical plant accidents. What we learn from them?

International Nuclear Information System (INIS)

Nakamura, Masayoshi

2009-01-01

Lessons learned from the JCO Nuclear Criticality Accident of 30 September 1999 in a uranium conversion test plant in Tokai-mura, Japan, are reviewed by referring some pertinent matters from the official report of this accident to remind of the universal characteristics among possible accidents of chemical plants. The paper discusses the responsibility of the establishment or institution to the demand alternation or request change from the client, how to respond to the proposal arising from the factory floor, and the safety control system of every-day maintenance of the factory which are important to prevent accidents in chemical plants. After explaining a background leading to the JCO accident, the author summarizes the lessons as follows: (1) changeable control system, (2) perfect provision of the manual considering the actual condition, and (3) clarification of the roles each played by the managers and the workers are most necessary and important. (S. Ohno)

Lessons learned from radiological accidents at medical exposures in radiotherapy; Lições aprendidas com acidentes radiológicos nas exposições médicas em radioterapia

Energy Technology Data Exchange (ETDEWEB)

Fagundes, J.S.; Ferreira, A.F. [Faculdade Casa Branca, SP (Brazil); Lima, C.M.A. [MAXIM Cursos, Rio de Janeiro, RJ (Brazil); Silva, F.C.A. da, E-mail: franciscodasilva13uk@gmail.com [Instituto de Radioproteção e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

2017-07-01

An exposure is considered accidental in radiotherapy when there is a substantial deviation in the prescription of treatment. In this work, an analysis of published radiological accidents, both in Brazil and internationally, was performed during medical exposures in radiotherapy treatments, removing the main lessons learned. Of the research carried out, we highlight Brazil with four radiological accidents and one death in the period between 2011 and 2014; the United States of America with 169 accidents with two deaths from 2000 to 2010 and France from 2001 to 2014 had 569 deaths without patients. Lessons learned have been described, for example, that maintenance personnel training should specify limitations or restrictions on the handling or adjustment of critical parts on the accelerator. It is recommended to apply the 10 main lessons learned due to radiological accidents during medical exposures in radiotherapy treatments to avoid future events.

Lessons learned from the Fukushima accident to improve the performance of the national nuclear preparedness system

International Nuclear Information System (INIS)

Dewi Apriliani

2013-01-01

A study of emergency response failure in the early phase of a nuclear accident in Fukushima, Japan has conducted. This study aimed to obtain lesson learned from the problems and constraints that exist at the time of the Fukushima emergency response. This lesson learned will be adjusted to the situation, conditions and problems in nuclear preparedness systems in Indonesia, so that it can obtain the necessary recommendations to improve the performance of SKNN (National Nuclear Emergency Preparedness System). Recommendations include: improvements in coordination and information systems, including early warning systems and dissemination of information; improvements in the preparation of emergency plans/contingency plan, which includes an integrated disaster management; improvement in the development of disaster management practice/field exercise, by extending the scenario and integrate it with nuclear disaster, chemical, biological, and acts of terrorism; and improvement in public education of nuclear emergency preparedness and also improvement in management for dissemination of information to the public and the mass media. These improvements need to be done as part of efforts in preparing a reliable nuclear emergency preparedness in order to support nuclear power plant development plan. (author)

Radiation protection issues raised in Korea since Fukushima accident

International Nuclear Information System (INIS)

Kim, Byeongsoo

2014-01-01

For the past 3 years since Fukushima accident, various issues related to nuclear safety and radiation safety were raised in Korea. This presentation focuses radiation protection (RP) issues among the various issues and has the purpose to share experiences and lessons-learned related to the RP issues. Special safety inspections on NPPs in Korea were performed immediately after Fukushima accident and 50 follow-up measures were established in May, 2011 to improve the nuclear safety. Some of them were related to radiation protection and emergency responses. Recently, in March, 2014, additional follow-up measures were decided to be taken in additionally strengthening safety-related equipment and emergency response organization. The 50 Fukushima-accident-follow-up measures include radiation protection for members of the public in emergency responses. Based on the follow-up measures, expansion of emergency planning zone (EPZ) is to be made according to the approval of legislation by National Assembly on May 2, 2014. For the past 3 years, the degree of the public concerns on radiation risk has been the highest. Spontaneous activities for radiation monitoring happened in the public. Some members of the public found some contaminated paved roads in November, 2011 and a contaminated kitchen ware in January, 2012. These findings suggest the importance of the management of recycled metal scraps imported from other countries. Fukushima accident gave much impact on Korean society all. The public gets very sensitive to issues about nuclear safety and radiation safety. Most parts of RP issues raised are related to the public. The lessons-learned are that as an issue is raised, it has a chance to be solved. However, RP issues related to radiation workers in accident conditions in NPPs are difficult to be raised enough to confirm and improve the robustness of radiation protection programs in accident conditions. It is necessary to share RP issues raised in each country as well as

Lessons learned and implications of the Fukushima NPP accidents

International Nuclear Information System (INIS)

Tokuhiro, A.

2014-01-01

The global nuclear 'enterprise' is now 3-1/2 years (March 11, 2011) beyond the historic Tohoku earthquake (M9.0), subsequent tsunami (~14-15m waves), and unfortunately, the continuing consequences of the 'Fukushima nuclear power plant (NPP) accident. We now live in the post-Fukushima nuclear era. First let us pay our respects to this tragic loss-of-life (~16,000 fatalities) as a result of the earthquake and tsunami; also 10-years earlier in 2004, centered further south in the Indian Ocean (230,000+ fatalities). The movie, 'The Impossible', was a reminder that indeed, energy provides sustenance and socio-economic development for humankind. Energy will determine the state of AsiaPacific (AP) in years to come. Over the past 15-years, AP has clearly had increasing means to lead global economic growth, relative to stagnating economies of scale in Europe and U.S. AP also has both existing and emerging larger-scale industrial ambitions and capital to construct new nuclear power plants (NPPs). China has some 25-28 units under construction at 11 sites; the near-term goal is to establish 40GW of generating capacity by 2020 and to reach some 70-75GW approximately 10 years later. Although some investments are also being made in renewable energy, the demand for capacity clearly dictates further growth in nuclear power. However, unless high expectations for safety, safety culture are concurrently encouraged, we may face the next nuclear accident again in Asia. This work looks at the technical and non-technical lessons learned from the Fukushima Daiichi accident and the implications that we cannot afford to ignore. (author)

Lessons learned and implications of the Fukushima NPP accidents

Energy Technology Data Exchange (ETDEWEB)

Tokuhiro, A., E-mail: tokuhio@uidaho.edu [Univ. of Idaho, Idaho Falls, ID (United States)

2014-07-01

The global nuclear 'enterprise' is now 3-1/2 years (March 11, 2011) beyond the historic Tohoku earthquake (M9.0), subsequent tsunami (~14-15m waves), and unfortunately, the continuing consequences of the 'Fukushima nuclear power plant (NPP) accident. We now live in the post-Fukushima nuclear era. First let us pay our respects to this tragic loss-of-life (~16,000 fatalities) as a result of the earthquake and tsunami; also 10-years earlier in 2004, centered further south in the Indian Ocean (230,000+ fatalities). The movie, 'The Impossible', was a reminder that indeed, energy provides sustenance and socio-economic development for humankind. Energy will determine the state of AsiaPacific (AP) in years to come. Over the past 15-years, AP has clearly had increasing means to lead global economic growth, relative to stagnating economies of scale in Europe and U.S. AP also has both existing and emerging larger-scale industrial ambitions and capital to construct new nuclear power plants (NPPs). China has some 25-28 units under construction at 11 sites; the near-term goal is to establish 40GW of generating capacity by 2020 and to reach some 70-75GW approximately 10 years later. Although some investments are also being made in renewable energy, the demand for capacity clearly dictates further growth in nuclear power. However, unless high expectations for safety, safety culture are concurrently encouraged, we may face the next nuclear accident again in Asia. This work looks at the technical and non-technical lessons learned from the Fukushima Daiichi accident and the implications that we cannot afford to ignore. (author)

Response of HEPA filters to simulated-accident conditions

International Nuclear Information System (INIS)

Gregory, W.S.; Martin, R.A.; Smith, P.R.; Fenton, D.E.

1982-01-01

High-efficiency particulate air (HEPA) filters have been subjected to simulated accident conditions to determine their response to abnormal operating events. Both domestic and European standard and high-capacity filters have been evaluated to determine their response to simulated fire, explosion, and tornado conditions. The HEPA filter structural limitations for tornado and explosive loadings are discussed. In addition, filtration efficiencies during these accident conditions are reported for the first time. Our data indicate efficiencies between 80% and 90% for shock loadings below the structural limit level. We describe two types of testing for ineffective filtration - clean filters exposed to pulse-entrained aerosol and dirty filters exposed to tornado and shock pulses. Efficiency and material loss data are described. Also, the resonse of standard HEPA filters to simulated fire conditions is presented. We describe a unique method of measuring accumulated combustion products on the filter. Additionally, data relating to pressure drop vs accumulated mass during plugging are reported for simulated combustion aerosols. The effects of concentration and moisture levels on filter plugging were evaluated. We are obtaining all of the above data so that mathematical models can be developed for fire, explosion, and tornado accident analysis computer codes. These computer codes can be used to assess the response of nuclear air cleaning systems to accident conditions

Five Years after the Fukushima Daiichi Accident: Nuclear Safety Improvements and Lessons Learnt

International Nuclear Information System (INIS)

Magwood, William D. IV; Niel, Jean-Christophe; Fuketa, Toyoshi; Sheron, Brian; Boyd, Michael; McGarry, Ann; Dussart-Desart, Roland; Reig, Javier; Hah, Yeonhee; Nieh, Ho; Vasquez-Maignan, Ximena; Salgado, Nancy; White, Andrew; Lazo, Edward; Creswell, Len; Leeds, Eric; Gannon-Picot, Cynthia; Griffiths, Janice

2016-01-01

Countries around the world continue to implement safety improvements and corrective actions based on lessons learnt from the 11 March 2011 accident at the Fukushima Daiichi nuclear power plant. This report provides a high-level summary and update on these activities, and outlines further lessons learnt and challenges identified for future consideration. It focuses on actions taken by NEA committees and NEA member countries, and as such is complementary to reports produced by other international organisations. It is in a spirit of openness and transparency that NEA member countries share this information to illustrate that appropriate actions are being taken to maintain and enhance the level of safety at their nuclear facilities. Nuclear power plants are safer today because of these actions. High-priority follow-on items identified by NEA committees are provided to assist countries in continuously benchmarking and improving their nuclear safety practices. (authors)

The accidents during shutdown conditions Temelin NPP

International Nuclear Information System (INIS)

Sykora, M.; Mlady, O.

1996-01-01

Two parallel activities oriented for the accidents during shutdown conditions are performed at Temelin NPP: Development of symptom based emergency operating procedures (EOPs) applicable for the accidents which could occur during operational modes 1 through 4; independent evaluation of plant safety as part of the Temelin Shutdown probabilistic assessment to define the accidents which could occur during mode 5 and 6 for which the EOPs must be extended. Both these activities are in progress now because Temelin plant is still in the construction phase

Shipping container response to severe highway and railway accident conditions: Main report

International Nuclear Information System (INIS)

Fischer, L.E.; Chou, C.K.; Gerhard, M.A.; Kimura, C.Y.; Martin, R.W.; Mensing, R.W.; Mount, M.E.; Witte, M.C.

1987-02-01

This report describes a study performed by the Lawrence Livermore National Laboratory to evaluate the level of safety provided under severe accident conditions during the shipment of spent fuel from nuclear power reactors. The evaluation is performed using data from real accident histories and using representative truck and rail cask models that likely meet 10 CFR 71 regulations. The responses of the representative casks are calculated for structural and thermal loads generated by severe highway and railway accident conditions. The cask responses are compared with those responses calculated for the 10 CFR 71 hypothetical accident conditions. By comparing the responses it is determined that most highway and railway accident conditions fall within the 10 CFR 71 hypothetical accident conditions. For those accidents that have higher responses, the probabilities anf potential radiation exposures of the accidents are compared with those identified by the assessments made in the ''Final Environmental Statement on the Transportation of Radioactive Material by Air and other Modes,'' NUREG-0170. Based on this comparison, it is concluded that the radiological risks from spent fuel under severe highway and railway accident conditions as derived in this study are less than risks previously estimated in the NUREG-0170 document

The accident at TEPCO's Fukushima-Daiichi Nuclear Power Station: What went wrong and what lessons are universal?

Energy Technology Data Exchange (ETDEWEB)

Omoto, Akira, E-mail: akira.omoto@mac.com

2013-12-11

After a short summary of the nuclear accident at the Fukushima Daiichi Nuclear Power Station, this paper discusses “what went wrong” by illustrating the problems of the specific layers of defense-in-depth (basic strategy for assuring nuclear safety) and “what lessons are universal.” Breaches in the multiple layers of defense were particularly significant in respective protection (a) against natural disasters (first layer of defense) as well as (b) against severe conditions, specifically in this case, a complete loss of AC/DC power and isolation from the primary heat sink (fourth layer of defense). Confusion in crisis management by the government and insufficient implementation of offsite emergency plans revealed problems in the fifth layer of defense. By taking into consideration managerial and safety culture that might have relevance to this accident, in the author's view, universal lessons are as follows: a)Resilience: the need to enhance organizational capabilities to respond, monitor, anticipate, and learn in changing conditions, especially to prepare for the unexpected. This includes increasing distance to cliff edge by knowing where it exists and how to increase safety margin. b)Responsibility: the operator is primarily responsible for safety, and the government is responsible for protecting public health and environment. For both, their right decisions are supported by competence, knowledge, and an understanding of the technology, as well as humble attitudes toward the limitations of what we know and what we can learn from others. c)Social license to operate: the need to avoid, as much as possible regardless of its probability of occurrence, the reasonably anticipated environmental impact (such as land contamination), as well as to build public confidence/trust and a renewed liability scheme.

Lessons of nuclear robot history

International Nuclear Information System (INIS)

Oomichi, Takeo

2014-01-01

Severe accidents occurred at Fukushima Daiichi Nuclear Power Station stirred up people's great expectation of nuclear robot's deployment. However unexpected nuclear disaster, especially rupture of reactor building caused by core meltdown and hydrogen explosion, made it quite difficult to introduce nuclear robot under high radiation environment to cease accidents and dispose damaged reactor. Robotics Society of Japan (RSJ) set up committee to look back upon lessons learned from 50 year's past experience of nuclear robot development and summarized 'Lessons of nuclear robot history', which was shown on the home page website of RSJ. This article outlined it with personal comment. History of nuclear robot developed for inspection and maintenance at normal operation and for specific required response at nuclear accidents was reviewed with many examples at home and abroad for TMI, Chernobyl and JCO accidents. Present state of Fukushima accident response robot's introduction and development was also described with some comments on nuclear robot development from academia based on lessons. (T. Tanaka)

ACCOUNT OF ROAD CONDITIONS WHILE INVESTIGATING TRAFFIC ACCIDENTS

Directory of Open Access Journals (Sweden)

D. D. Selioukov

2010-01-01

Full Text Available The paper considers problems on better traffic safety at government, authority, engineering and driver activity levels, account of road conditions while investigating traffic accidents. The paper also provides road defects mentioned in forensic transport examinations of traffic accidents.

Cesium-137 accident lessons in Goiania, Goias State, Brazil

International Nuclear Information System (INIS)

1990-11-01

This document relates the experience obtained by several professionals which had an important role in the cesium-137 accident occurred in Goiania, Goias State, Brazil in September, 1987. It's divided into chapters, according to the action area - medical, nursing, social assistance, odontological and psychological. At first, some notions of radioprotection are explained, followed by the accident history and by the doctors and nurses action during the emergency phase and the medical, odontological, social and psychological assistance to the victims. The social assistance report shows some statistical data about the economic, occupational and social conditions of the accident victims. It is shown some information about the health institutions and the sanitary care in the ionizing radiation and about the occupational radiological protection in Goiania

Lessons from Goiania

International Nuclear Information System (INIS)

Nazari Alves, R.

2000-01-01

The lessons learned from the radiological accident of Goiania in 1987 derived from the observations from the Regulatory Agency which was in charge of the decontamination tasks may be consolidated into four classes: Preventive Actions, characterised as those that aim to minimise the probability of occurrence of a radiological accident; Minimisation of time between the moment of the accident occurrence and the beginning of intervention, in case a radiological accident does occur, despite all preventive measures; Intervention, which is correlated to the type of installation, its geographical location, the social classes involved and their contamination vectors; and Follow up, for which well established rules to allow continuing monitoring of the victims and rebuilding of homes are necessary. The greatest lesson of all was the need for integration of the professionals involved, from all organizations. (author)

SEVERE ACCIDENT ISSUES RAISED BY THE FUKUSHIMA ACCIDENT AND IMPROVEMENTS SUGGESTED

OpenAIRE

SONG, JIN HO; KIM, TAE WOON

2014-01-01

This paper revisits the Fukushima accident to draw lessons in the aspect of nuclear safety considering the fact that the Fukushima accident resulted in core damage for three nuclear power plants simultaneously and that there is a high possibility of a failure of the integrity of reactor vessel and primary containment vessel. A brief review on the accident progression at Fukushima nuclear power plants is discussed to highlight the nature and characteristic of the event. As the severe accide...

Analysis of flammability in the attached buildings to containment under severe accident conditions

Energy Technology Data Exchange (ETDEWEB)

Rosa, J.C. de la, E-mail: juan-carlos.de-la-rosa-blul@ec.europa.eu [European Commission Joint Research Centre (Netherlands); Fornós, Joan, E-mail: jfornosh@anacnv.com [Asociación Nuclear Ascó-Vandellós (Spain)

2016-11-15

Highlights: • Analysis of flammability conditions in buildings outside containment. • Stepwise approach easily applicable for any kind of containment and attached buildings layout. • Detailed application for real plant conditions has been included. - Abstract: Right after the events unfolded in Fukushima Daiichi, the European Union countries agreed in subjecting Nuclear Power Plants to Stress Tests as developed by WENRA and ENSREG organizations. One of the results as implemented in many European countries derived from such tests consisted of mandatory technical instructions issued by nuclear regulatory bodies on the analysis of potential risk of flammable gases in attached buildings to containment. The current study addresses the key aspects of the analysis of flammable gases leaking to auxiliary buildings attached to Westinghouse large-dry PWR containment for the specific situation where mitigating systems to prevent flammable gases to grow up inside containment are available, and containment integrity is preserved – hence avoiding isolation system failure. It also provides a full practical exercise where lessons learned derived from the current study – hence limited to the imposed boundary conditions – are applied. The leakage of gas from the containment to the support buildings is based on separate calculations using the EPRI-owned Modular Accident Analysis Program, MAAP4.07. The FATE™ code (facility Flow, Aerosol, Thermal, and Explosion) was used to model the transport and distribution of leaked flammable gas (H{sub 2} and CO) in the penetration buildings. FATE models the significant mixing (dilution) which occurs as the released buoyant gas rises and entrains air. Also, FATE accounts for the condensation of steam on room surfaces, an effect which acts to concentrate flammable gas. The results of the analysis show that during a severe accident, flammable conditions are unlikely to occur in compartmentalized buildings such as the one used in the

Analysis of flammability in the attached buildings to containment under severe accident conditions

International Nuclear Information System (INIS)

Rosa, J.C. de la; Fornós, Joan

2016-01-01

Highlights: • Analysis of flammability conditions in buildings outside containment. • Stepwise approach easily applicable for any kind of containment and attached buildings layout. • Detailed application for real plant conditions has been included. - Abstract: Right after the events unfolded in Fukushima Daiichi, the European Union countries agreed in subjecting Nuclear Power Plants to Stress Tests as developed by WENRA and ENSREG organizations. One of the results as implemented in many European countries derived from such tests consisted of mandatory technical instructions issued by nuclear regulatory bodies on the analysis of potential risk of flammable gases in attached buildings to containment. The current study addresses the key aspects of the analysis of flammable gases leaking to auxiliary buildings attached to Westinghouse large-dry PWR containment for the specific situation where mitigating systems to prevent flammable gases to grow up inside containment are available, and containment integrity is preserved – hence avoiding isolation system failure. It also provides a full practical exercise where lessons learned derived from the current study – hence limited to the imposed boundary conditions – are applied. The leakage of gas from the containment to the support buildings is based on separate calculations using the EPRI-owned Modular Accident Analysis Program, MAAP4.07. The FATE™ code (facility Flow, Aerosol, Thermal, and Explosion) was used to model the transport and distribution of leaked flammable gas (H_2 and CO) in the penetration buildings. FATE models the significant mixing (dilution) which occurs as the released buoyant gas rises and entrains air. Also, FATE accounts for the condensation of steam on room surfaces, an effect which acts to concentrate flammable gas. The results of the analysis show that during a severe accident, flammable conditions are unlikely to occur in compartmentalized buildings such as the one used in the

Radiation protection lessons learned from the TEPCO Fukushima No.1 NPS accident

International Nuclear Information System (INIS)

Urabe, Itsumasa; Hattori, Takatoshi; Iimoto, Takeshi; Yokoyama, Sumi

2014-01-01

Lessons learned from the TEPCO Fukushima No.1 NPS accident are discussed from the viewpoint of radiation protection in the situation of nuclear emergency. It became clear from the discussion that the protective measures should be practiced by taking into account the time profiles of the radiological disaster after the nuclear accident and that the land and coastal sea areas monitoring had to be practiced immediately after the nuclear accident and the communication methods to tell the public about the radiation information and the meaning of protective measures should be developed for mitigation of the sociological aspects of disaster impacts. And it was pointed out from the view point of practicing countermeasures that application of the reference levels, above which it was judged to be inappropriate to plan to allow exposure to occur, played an important role for practicing protective measures in an optimized way and that the quantities and units used for quantifying radiation exposure of individuals in terms of radiation doses have caused considerable communication problems. Finally, the occupational exposures and the public exposures that have been reported so far are shown, and it is concluded that there is no conclusive evidence on low dose exposures that would justify a modification of the radiation risk recommended by the International Commission on Radiological Protection. (author)

Chernobyl accident: Causes, consequences and problems of radiation measurements

International Nuclear Information System (INIS)

Kortov, V.; Ustyantsev, Yu.

2013-01-01

General description of Chernobyl accident is given in the review. The accident causes are briefly described. Special attention is paid to radiation situation after the accident and radiation measurements problems. Some data on Chernobyl disaster are compared with the corresponding data on Fukushima accident. It is noted that Chernobyl and Fukushima lessons should be taken into account while developing further measures on raising nuclear industry safety. -- Highlights: ► The short comparative analysis of accidents at Chernobyl and Fukushima is given. ► We note the great effect of β-radiation on the radiation situation at Chernobyl. ► We discuss the problems of radiation measurements under these conditions. ► The impact of shelter on the radiation situation near Chernobyl NPS is described

Advances in global development and deployment of small modular reactors and incorporating lessons learned from the Fukushima Daiichi accident into the designs of engineered safety features of advanced reactors

International Nuclear Information System (INIS)

Hadid Subki, M.; )

2014-01-01

The IAEA has been facilitating the Member States in incorporating the lessons-learned from the Fukushima Dai-ichi Accident into the designs of engineered safety features of advanced reactors, including small modular reactors. An extended assessment is required to address challenges for advancing reactor safety in the new evolving generation of SMR plants to preserve the historic lessons in safety, through: assuring the diversity in emergency core cooling systems following loss of onsite AC power; ensuring diversity in reactor depressurization following a transient or accident; confirming independence in reactor trip and safety systems for sensors, power supplies and actuation systems, and finally diversity in maintaining containment integrity following a severe accident

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

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

Science.gov (United States)

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

2013-09-01

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

Lessons from Fukushima for Improving the Safety of Nuclear Reactors

Science.gov (United States)

Lyman, Edwin

2012-02-01

The March 2011 accident at the Fukushima Daiichi nuclear power plant has revealed serious vulnerabilities in the design, operation and regulation of nuclear power plants. While some aspects of the accident were plant- and site-specific, others have implications that are broadly applicable to the current generation of nuclear plants in operation around the world. Although many of the details of the accident progression and public health consequences are still unclear, there are a number of lessons that can already be drawn. The accident demonstrated the need at nuclear plants for robust, highly reliable backup power sources capable of functioning for many days in the event of a complete loss of primary off-site and on-site electrical power. It highlighted the importance of detailed planning for severe accident management that realistically evaluates the capabilities of personnel to carry out mitigation operations under extremely hazardous conditions. It showed how emergency plans rooted in the assumption that only one reactor at a multi-unit site would be likely to experience a crisis fail miserably in the event of an accident affecting multiple reactor units simultaneously. It revealed that alternate water injection following a severe accident could be needed for weeks or months, generating large volumes of contaminated water that must be contained. And it reinforced the grim lesson of Chernobyl: that a nuclear reactor accident could lead to widespread radioactive contamination with profound implications for public health, the economy and the environment. While many nations have re-examined their policies regarding nuclear power safety in the months following the accident, it remains to be seen to what extent the world will take the lessons of Fukushima seriously and make meaningful changes in time to avert another, and potentially even worse, nuclear catastrophe.

Generation IV reactors and the ASTRID prototype: lessons from the Fukushima accident

International Nuclear Information System (INIS)

Gauche, F.

2012-01-01

In France, the ASTRID prototype is an industrial demonstrator of a sodium-cooled fast neutron reactor (SFR), fulfilling the criteria for Generation IV reactors. ASTRID will meet safety requirements as stringent as for third generation reactors, and it takes into account lessons from the Fukushima accident. The objectives are to reinforce the robustness of the safety demonstration for all safety functions. ASTRID will feature an innovative core with a negative sodium void coefficient, it will take advantage of the large thermal inertia of SFR for decay heat removal, and will provide for a design either eliminating the sodium-water reaction, or guaranteeing no consequences for safety in case such reaction would take place. (author)

Risk Communication Strategies: Lessons Learned from Previous Disasters with a Focus on the Fukushima Radiation Accident.

Science.gov (United States)

Svendsen, Erik R; Yamaguchi, Ichiro; Tsuda, Toshihide; Guimaraes, Jean Remy Davee; Tondel, Martin

2016-12-01

It has been difficult to both mitigate the health consequences and effectively provide health risk information to the public affected by the Fukushima radiological disaster. Often, there are contrasting public health ethics within these activities which complicate risk communication. Although no risk communication strategy is perfect in such disasters, the ethical principles of risk communication provide good practical guidance. These discussions will be made in the context of similar lessons learned after radiation exposures in Goiania, Brazil, in 1987; the Chernobyl nuclear power plant accident, Ukraine, in 1986; and the attack at the World Trade Center, New York, USA, in 2001. Neither of the two strategies is perfect nor fatally flawed. Yet, this discussion and lessons from prior events should assist decision makers with navigating difficult risk communication strategies in similar environmental health disasters.

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

International Nuclear Information System (INIS)

Obu, Etsuji; Hamada, Jun; Fukano, Takuya

2011-01-01

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

Behaviour of molten reactor fuels under accident conditions

International Nuclear Information System (INIS)

Xavier Swamikannu, A.; Mathews, C.K.

1980-01-01

The behaviour of molten reactor fuels under accident conditions has received considerable importance in recent times. The chemical processes that occur in the molten state among the fuel, the clad components and the concrete of the containment building under the conditions of a core melt down accident in oxide fuelled reactors have been reviewed with the purpose of identifying areas of developmental work required to be performed to assess and minimize the consequences of such an accident. This includes the computation and estimation of vapour pressure of various gaseous species over the fuel, the clad and the coolant, providing of sacrificial materials in the concrete in order to protect the containment building in order to prevent release of radioactive gases into the atmosphere and understanding the distribution and chemical state of fission products in the molten fuel in order to provide for the effective removal of their decay heats. (auth.)

OCCUPATIONAL ACCIDENTS AS INDICATORS OF INADEQUATE WORK CONDITIONS AND WORK ENVIRONMENT

OpenAIRE

Petar Babović

2009-01-01

Occupational accidents due to inadequate working conditions and work environment present a major problem in highly industrialised countries, as well as in developing ones. Occupational accidents are a regular and accompanying phenomenon in all human activities and one of the main health related and economic problems in modern societies.The aim of this study is the analysis of the connections of unfavourable working conditions and working environment on occupational accidents. Occurrence of oc...

Radionuclides release possibility analysis of MSR at various accident conditions

Energy Technology Data Exchange (ETDEWEB)

Lee, Choong Wie; Kim, Hee Reyoung [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2015-10-15

There are some accidents which go beyond our expectation such as Fukushima Daiichi nuclear disaster and amounts of radionuclides release to environment, so more effort and research are conducted to prevent it. MSR (Molten Salt Reactor) is one of GEN-IV reactor types, and its coolant and fuel are mixtures of molten salt. MSR has a schematic like figure 1 and it has different features with the solid fuel reactor, but most important and interesting feature of MSR is its many safety systems. For example, MSR has a large negative void coefficient. Even though power increases, the reactor slows down soon. Radionuclides release possibility of MSR was analyzed at various accident conditions including Chernobyl and Fukushima ones. The MSR was understood to prevent the severe accident by the negative reactivity coefficient and the absence of explosive material such as water at the Chernobyl disaster condition. It was expected to contain fuel salts in the reactor building and not to release radionuclides into environment even if the primary system could be ruptured or broken and fuel salts would be leaked at the Fukushima Daiichi nuclear disaster condition of earthquake and tsunami. The MSR, which would not lead to the severe accident and therefore prevents the fuel release to the environment at many expected scenarios, was thought to have priority in the aspect of accidents. A quantitative analysis and a further research are needed to evaluate the possibility of radionuclide release to the environment at the various accident conditions based on the simple comparison of the safety feature between MSR and solid fuel reactor.

IRSN-Ancli seminar on the post-accident context

International Nuclear Information System (INIS)

Didier, Damien; Leroyer, Veronique; Gariel, Jean-Christophe; Meier, Christine; Petitfrere, Michael; Meraux-Netillard, Isabelle; Lerouxel, Roland; Gandouen, Gael; Boutin, Dominique; Charre, Jean-Pierre; Noe, Maite; Quenneville, Celine; Farandeau, Sebastien; Mouchet, Chantal; Pineau, Coralie; Rollinger, Francois; GARIEL, Jean-Christophe; Ando, Ryoko; Nishida, Shoshi; Miazaki, Makoto; Hayano, Ryugo; Lheureux, Yves; Lochard, Jacques; Boilley, David; Godet, Jean-Luc

2014-10-01

The first session addressed the context of post-accident management: main challenges of radiation protection in case of nuclear accident, management of energy situations (specific intervention plans of nuclear plants), elements of doctrine for the post-accident management of an accident. The second session addressed the preparedness of territories to post-accident management: preparation to post-accident management in the Montbeliard district, emergency and post-accidental situation (preparedness at the district scale, example of Loiret), and return on experience from the post-accident exercise in Cattenom. The third session addressed the action undertaken by the ANCCLI and IRSN for the awareness of post-accidental problematic (experiments in Saclay, Marcoule, Gravelines and Golfech, lessons learned from the pilot phase and perspectives). The last session addressed the post-accidental management of the Fukushima accident: approach of the IRSN to learn lessons from the dialogue initiative in Fukushima, round table on challenges on the long term of post-accidental management, Japanese witnesses

Basic safety principles: Lessons learned

International Nuclear Information System (INIS)

Erp, J.B. van

1997-01-01

The presentation reviews the following issues: basic safety principles and lessons learned; some conclusions from the Kemeny report on the accident at TMI; some recommendations from the Kemeny report on the accident at TMI; conclusions and recommendations from the Rogovin report on the accident on TMI; instrumentation deficiencies (from Rogovin report)

Basic safety principles: Lessons learned

Energy Technology Data Exchange (ETDEWEB)

Erp, J.B. van [Argonne National Lab., IL (United States)

1997-09-01

The presentation reviews the following issues: basic safety principles and lessons learned; some conclusions from the Kemeny report on the accident at TMI; some recommendations from the Kemeny report on the accident at TMI; conclusions and recommendations from the Rogovin report on the accident on TMI; instrumentation deficiencies (from Rogovin report).

10 CFR 71.74 - Accident conditions for air transport of plutonium.

Science.gov (United States)

2010-01-01

... 10 Energy 2 2010-01-01 2010-01-01 false Accident conditions for air transport of plutonium. 71.74 Section 71.74 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) PACKAGING AND TRANSPORTATION OF RADIOACTIVE MATERIAL Package, Special Form, and LSA-III Tests 2 § 71.74 Accident conditions for air transport of...

Some lessons on radiological protection learnt from the accident at the Fukushima Dai-ichi nuclear power plant

International Nuclear Information System (INIS)

Kai, M

2012-01-01

The accident at the Fukushima Dai-ichi nuclear power plant released a large quantity of radioactive iodine and caesium into the environment. In terms of radiological protection, the evacuation and food restrictions that were adopted in a timely manner by the authorities effectively reduced the dose received by people living in the affected area. Since late March, the transition from an emergency to an existing exposure situation has been in progress. In selecting the reference exposure levels in some areas under an existing exposure situation, the authorities tried to follow the situation-based approach recommended by the ICRP. However, a mixture of emergency and post-emergency approaches confused the people living in the contaminated areas because the reactor conditions continued to be not completely stable. In deriving the criteria in an existing exposure situation, the regulatory authority selected 20 mSv y −1 . The mothers in the affected area believed that a dose of 20 mSv y −1 was unacceptably high for children since 1 mSv y −1 is the dose limit for the public under normal conditions. Internet information accelerated concern about the internal exposure to children and the related health effects. From some experiences after the accident the following lessons could be learned. The selection of reference doses in existing exposure situations after an accident must be openly communicated with the public using a risk-informed approach. The detriment-adjusted nominal risk coefficient was misused for calculating the hypothetical number of cancer deaths by some non-radiation experts. It would not be possible to resolve this problem unless the ICRP addressed an alternative risk assessment to convey the meaning and associated uncertainty of the risk to an exposed population. A situation-based approach in addition to a risk-informed approach needs to be disseminated properly in order to select the level of protection that would be the best possible under the

Full-length fuel rod behavior under severe accident conditions

International Nuclear Information System (INIS)

Lombardo, N.J.; Lanning, D.D.; Panisko, F.E.

1992-12-01

This document presents an assessment of the severe accident phenomena observed from four Full-Length High-Temperature (FLHT) tests that were performed by the Pacific Northwest Laboratory (PNL) in the National Research Universal (NRU) reactor at Chalk River, Ontario, Canada. These tests were conducted for the US Nuclear Regulatory Commission (NRC) as part of the Severe Accident Research Program. The objectives of the test were to simulate conditions and provide information on the behavior of full-length fuel rods during hypothetical, small-break, loss-of-coolant severe accidents, in commercial light water reactors

Accidents in chemical industry: are they foreseeable?

NARCIS (Netherlands)

Sonnemans, P.J.M.; Körvers, P.M.W.

2006-01-01

‘Accidents recur,’ which is what Kletz [Kletz T. (1993). Lessons from disasters, how organisations have no memory and accidents recur. UK: Institution of Chemical Engineers] wrote in 1993. Indeed, despite all measures taken accidents may re-occur, but ‘disruptions’ in a process reoccur much more

Study of containment air cooler capacity in steam air environment during accident conditions

International Nuclear Information System (INIS)

Kansal, M.; Mohan, N.; Bhawal, R.N.; Bajaj, S.S.

2002-01-01

Full text: The air coolers are provided for controlling the temperature in the reactor building during normal operation. These air coolers also serve as the main heat sink for the removal of energy from high enthalpy air-steam mixture expected in reactor building under accident conditions. A subroutine COOLER has been developed to estimate the heat removal rate of the air coolers at high temperature and steam conditions. The subroutine COOLER has been attached with the code PACSR (post accident containment system response) used for containment pressure temperature calculation. The subroutine was validated using design parameters at normal operating condition. A study was done to estimate the heat removal rate for some postulated accident conditions. The study reveals that, under accident conditions, the heat removal rate of air coolers increases several times compared with normal operating conditions

Biomass accident investigations – missed opportunities for learning and accident prevention

DEFF Research Database (Denmark)

Hedlund, Frank Huess

2017-01-01

The past decade has seen a major increase in the production of energy from biomass. The growth has been mirrored in an increase of serious biomass related accidents involving fires, gas explosions, combustible dust explosions and the release of toxic gasses. There are indications that the number...... of bioenergy related accidents is growing faster than the energy production. This paper argues that biomass accidents, if properly investigated and lessons shared widely, provide ample opportunities for improving general hazard awareness and safety performance of the biomass industry. The paper examines...... selected serious accidents involving biogas and wood pellets in Denmark and argues that such opportunities for learning were missed because accident investigations were superficial, follow-up incomplete and information sharing absent. In one particularly distressing case, a facility saw a repeat accident...

Analysis of Fukushima unit 2 accident considering the operating conditions of RCIC system

Energy Technology Data Exchange (ETDEWEB)

Kim, Sung Il, E-mail: sikim@kaeri.re.kr; Park, Jong Hwa; Ha, Kwang Soon; Cho, Song-Won; Song, JinHo

2016-03-15

Highlights: • Fukushima unit 2 accident was analyzed using MELCOR 1.8.6. • RCIC operating conditions were assumed and best case was selected. • Effect of RCIC operating condition on accident scenario was found. - Abstract: A severe accident in Fukushima occurred on March 11, 2011 and units 1, 2 and 3 were damaged severely. A tsunami following an earthquake made the supply of electricity power stop, and the safety systems, which use AC or DC power in plants could not operate properly. It is supposed that the degree of core degradation of unit 2 is less serious than in the other plants, and it was estimated that the operation of reactor core isolation cooling (RCIC) system at the initial stage of the accident minimized the core damage through decay heat removal. Although the operating conditions of the RCIC system are not known clearly, it can be important to analyze the accident scenario of unit 2. In this study, best case of the Fukushima unit 2 accident was presented considering the operating conditions of the RCIC system. The effects of operating condition on core degradation and fission product release rate to environment were also examined. In addition, importance of torus room flooding level in the accident analysis was discussed. MELCOR 1.8.6 was used in this research, and the geometries of plant and operating conditions of safety system were obtained from TEPCO through OECD/NEA BSAF Project.

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

Energy Technology Data Exchange (ETDEWEB)

Clayton, Dwight A [ORNL; Poore III, Willis P [ORNL

2015-01-01

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

Post-processing activities after Chernobyl accident in Ukraine and lesson learned to the response Fukushima Dai-ichi accident

International Nuclear Information System (INIS)

Fujii, Yuzo

2012-01-01

After the accident of Chernobyl NPP no.4 1986, various activities including the construction of the shelter, prevention of the release of radioactive dust and liquid from the shelter, monitoring the condition of the damaged core, and disposal of radioactive waste have been implemented in the Chernobyl site for mitigating the nuclear and radioactive risks of damaged nuclear facilities, and the reducing radiation dose of working personnel. The construction of new shelter started for the decommissioning of the damaged unit no.4. facility. For reducing the radiation dose to the inhabitants from the contaminated land and feedstuff, the countermeasures including the set of the exclusive zone and permissible level of radionuclide in the foodstuff have been conducted for the countrywide. These activities include many valuable information about how to recover the condition of the site and maintain the social activities after the severe accident of NPP, and it would be important to learn the above activities in conducting the post-processing activities on the Fukushima-Daiichi accident successfully. (author)

NPP Krsko containment environmental conditions during postulated accident

International Nuclear Information System (INIS)

Kozaric, M.; Cavlina, N.; Spalj, S.

1989-01-01

This paper presents NPP Krsko containment pressure and temperature increase during Loss of Coolant Accident (LOCA) and Main Steam Line Break (MSLB). Containment environmental condition calculation was performed by CONTEMPT4/MOD4 computer code. Design accident calculations were performed by RELAP4/MOD6 and RELAP5/MOD1 computer codes. Calculational abilities and application methodology of these codes are presented. The CONTEMPT code is described in more detail. The containment pressure and temperature time distribution are presented as well. (author)

Safety regulations regarding to accident monitoring and accident sampling at Russian NPPs with VVER type reactors

International Nuclear Information System (INIS)

Sharafutdinov, Rachet; Lankin, Michail; Kharitonova, Nataliya

2014-01-01

The paper describes a tendency by development of regulatory document requirements related to accident monitoring and accident sampling at Russia's NPPs. Lessons learned from the Fukushima Daiichi accident pointed at the importance and necessary to carry out an additional safety check at Russia's nuclear power plants in the preparedness for management of severe accidents at NPPs. Planned measures for improvement of severe accidents management include development and implementation of the accident instrumentation systems, providing, monitoring, management and storage of information in a severe accident conditions. The draft of Safety Guidelines <accident monitoring system of nuclear power plants with VVER reactors' prepared by Scientific and Engineering Centre for Nuclear and Radiation Safety (SEC NRS) established the main criteria for accident monitoring instrumentation that can monitor relevant plant parameters in the reactor and inside containment during and after a severe accident in nuclear power plants. Development of these safety guidelines is in line with the recommendations of IAEA Action Plan on Nuclear Safety in response to the Fukushima Daiichi event and recommendations of the IAEA Nuclear Energy series Report <<Accident Monitoring Systems for Nuclear Power Plants' (Draft V 2.7). The paper presents the principles, which are used as the basis for selection of plant parameters for accident monitoring and for establishing of accident monitoring instrumentation. The recommendations to the accident sampling system capable to obtain the representative reactor coolant and containment air and fluid samples that support accurate analytical results for the parameters of interest are considered. The radiological and chemistry parameters to be monitored for primary coolant and sump and for containment air are specified. (author)

Assessment of Equipment Capability to Perform Reliably under Severe Accident Conditions

International Nuclear Information System (INIS)

2017-07-01

The experience from the last 40 years has shown that severe accidents can subject electrical and instrumentation and control (I&C) equipment to environmental conditions exceeding the equipment’s original design basis assumptions. Severe accident conditions can then cause rapid degradation or damage to various degrees up to complete failure of such equipment. This publication provides the technical basis to consider when assessing the capability of electrical and I&C equipment to perform reliably during a severe accident. It provides examples of calculation tools to determine the environmental parameters as well as examples and methods that Member States can apply to assess equipment reliability.

OSSA - An optimized approach to severe accident management: EPR application

International Nuclear Information System (INIS)

Sauvage, E. C.; Prior, R.; Coffey, K.; Mazurkiewicz, S. M.

2006-01-01

There is a recognized need to provide nuclear power plant technical staff with structured guidance for response to a potential severe accident condition involving core damage and potential release of fission products to the environment. Over the past ten years, many plants worldwide have implemented such guidance for their emergency technical support center teams either by following one of the generic approaches, or by developing fully independent approaches. There are many lessons to be learned from the experience of the past decade, in developing, implementing, and validating severe accident management guidance. Also, though numerous basic approaches exist which share common principles, there are differences in the methodology and application of the guidelines. AREVA/Framatome-ANP is developing an optimized approach to severe accident management guidance in a project called OSSA ('Operating Strategies for Severe Accidents'). There are still numerous operating power plants which have yet to implement severe accident management programs. For these, the option to use an updated approach which makes full use of lessons learned and experience, is seen as a major advantage. Very few of the current approaches covers all operating plant states, including shutdown states with the primary system closed and open. Although it is not necessary to develop an entirely new approach in order to add this capability, the opportunity has been taken to develop revised full scope guidance covering all plant states in addition to the fuel in the fuel building. The EPR includes at the design phase systems and measures to minimize the risk of severe accident and to mitigate such potential scenarios. This presents a difference in comparison with existing plant, for which severe accidents where not considered in the design. Thought developed for all type of plants, OSSA will also be applied on the EPR, with adaptations designed to take into account its favourable situation in that field

Lessons learned in the accident of contamination with Pu-239; Lecciones aprendidas en el accidente de contaminacion con Pu-239

Energy Technology Data Exchange (ETDEWEB)

Molina, G.; Ruiz C, M.; Angeles C, A.; Benitez S, J.A. [ININ, 52045 Estado de Mexico (Mexico)]. e-mail: gm@nuclear.inin.mx

2004-07-01

This work describes the lessons learned during the accident by transuranic contamination in the National Institute of Nuclear Research happened between 1998 and 2003. The origin of the same one is the not authorized transfer of 0.51 g of plutonium metallic used as pattern source in the Department of Metrology to a laboratory which lacked of physical infrastructure, training and team to manipulate this source. (Author)

Lessons from Chernobyl post-accident management

International Nuclear Information System (INIS)

Schneider, T.

2012-01-01

The Chernobyl accident has shown that the long-term management of its consequences is not straightforward. The management of the consequences has revealed the complexity of the situation to deal with. The long-term contamination of the environment has affected all the dimensions of the daily life of the inhabitants living in affected territories: health, environment, social life, education, work, distribution of foodstuffs and commodities... The experience from the Chernobyl accident shows 4 key issues that may be beneficial for the populations living in territories affected by the Fukushima accident: 1) the direct involvement of the inhabitants in their own protection, 2) the radiation monitoring system and health surveillance at the local level, 3) to develop a practical radiation protection culture among the population, and 4) the setting up of economic measures to favour the local development. (A.C.)

Reliability analysis of emergency decay heat removal system of nuclear ship under various accident conditions

International Nuclear Information System (INIS)

Matsuoka, Takeshi

1984-01-01

A reliability analysis is given for the emergency decay heat removal system of the Nuclear Ship ''Mutsu'' and the emergency sea water cooling system of the Nuclear Ship ''Savannah'', under ten typical nuclear ship accident conditions. Basic event probabilities under these accident conditions are estimated from literature survey. These systems of Mutsu and Savannah have almost the same reliability under the normal condition. The dispersive arrangement of a system is useful to prevent the reduction of the system reliability under the condition of an accident restricted in one room. As for the reliability of these two systems under various accident conditions, it is seen that the configuration and the environmental condition of a system are two main factors which determine the reliability of the system. Furthermore, it was found that, for the evaluation of the effectiveness of safety system of a nuclear ship, it is necessary to evaluate its reliability under various accident conditions. (author)

Inherent safety features of the HTTR revealed in the accident condition

International Nuclear Information System (INIS)

Kunitomi, K.; Shinozaki, M.; Baba, O.; Saito, S.

1992-01-01

The High Temperature Engineering Test Reactor (HTTR) being constructed by JAERI (Japan Atomic Energy Research Institute) is a graphite-moderated and helium-cooled reactor with an outlet gas temperature of 950degC. The inherent safety characteristics in the HTTR prevent temperature increase of reactor fuels and fission product release from the reactor core in postulated accident conditions. The reactor core can be cooled by a Vessel Cooling System (VCS) indirectly, even in the case that no forced cooling is expected during the accident such as primary pipe break. The VCS consists of independent water cooling loop and cooling panel around the reactor pressure vessel. The cooling panel whose temperature of 60-90degC cools the reactor pressure vessel by radiation and removes the decay heat from the core indirectly. Furthermore, even if failure of VCS is assumed during this accident as a severe accident, the reactor core is remained safe despite the temperature increase of biological concrete shield around the reactor pressure vessel. This paper describes the inherent safety features of the HTTR specially focused on the accident condition without forced cooling. The detailed analytical results of such an accident are described together with clarifying the role of the VCS. (author)

Effect of RCIC Operating Conditions on the Accident Scenario in Fukushima Unit 2

International Nuclear Information System (INIS)

Kim, Sung Il; Park, Jong Hwa; Ha, Kwang Soon

2015-01-01

This study was conducted by using MELCOR 1.8.6. Fukushima unit 2 accident was analyzed using MELCOR in this study, and best estimate scenario with considering RCIC operating conditions was presented. Researches on the boiling water reactor (BWR) plant with reactor core isolation cooling (RCIC) system have been conducted. Research on the RCIC operation in Fukushima unit 2 was also conducted by Sandia National Laboratory. MELCOR analysis of the Fukushima unit 2 accident was conducted in the report and energy balance in wetwell was described by considering RCIC operation. However, the effect of RCIC operation condition on the accident scenario has not been studied. The operating conditions of RCIC system affect the pressures in wetwell and drywell, and the high pressure can make leakage path of fission product from PCV to reactor building. Thus it can be directly related with the amount of fission product which released to environment. In this study, severe accident on Fukushima unit 2 was analyzed considering the operating condition of RCIC system, and best estimated scenario was presented. In addition, the effect of RCIC turbine efficiency on the accident progression was examined. Energy balance in suppression chamber was also considered with discussion on the effect of torus room flooding level. It was found that the operating condition of RCIC turbine not only affects the variation of drywell pressure but also the amount of released fission products to environment. It was also confirmed that the RCIC turbine efficiency in the accident would be less than normal operating condition

Fukushima Accident: Was it preventable or unavoidable? - A sociological perspective

International Nuclear Information System (INIS)

Choi, Young Sung; Choi, Kwang Sik; Kam, Seong Cheon

2012-01-01

Global renaissance of nuclear energy was widely predicted and accepted before the Fukushima accident of March 11, 2011. The prospects for nuclear energy now appear to face a turn-around point. Serious debates about the adequacy of nuclear power utilization and safety regulation are underway in many national and/or international settings. Many investigations and analyses have been and will be conducted to identify the causes and consequences and to seek lessons to be taken into account in their own nuclear power programs. These efforts evidently will contribute to preventing accidents caused by such extreme damage conditions as Fukushima desperately encountered. But, in order to discuss the future of nuclear energy, new approach to the nature of the accident needs to be sought rather than the usual and conventional way of viewing the accidents with the benefit of hindsight. This paper examines institutional and sociological aspects of Fukushima accident to get some clues as to whether it was preventable or unavoidable

Computer code calculations of the TMI-2 accident: initial and boundary conditions

International Nuclear Information System (INIS)

Behling, S.R.

1985-05-01

Initial and boundary conditions during the Three Mile Island Unit 2 (TMI-2) accident are described and detailed. A brief description of the TMI-2 plant configuration is given. Important contributions to the progression of the accident in the reactor coolant system are discussed. Sufficient information is provided to allow calculation of the TMI-2 accident with computer codes

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)

TMI-2 lessons have been learned

International Nuclear Information System (INIS)

Long, R.L.

1994-01-01

This paper is an introduction to the more detailed papers which are presented in this session titled ''Advanced Light Water Reactors -- 15 Years After TMI.'' Many of the advances in the design, operation and maintenance of nuclear power plants are the direct result of applying lessons learned from the 1979 TMI-2 accident. The authors believe the ''reality awakening'' which occurred following the accident should never be forgotten. Thus, this paper briefly reviews the TMI-2 accident and identifies the broad lessons learned following the accident. Then it describes briefly some indicators which show the very impressive improvements in nuclear power plant performance that have occurred over the past 10-15 years. This sets the stage for Dr. Ransom's paper which shows the continuing need for nuclear power, Dr. Beckjord's paper which describes the ''final'' TMI-2 research project and the subsequent papers which focus on advanced light water reactor developments

Hydrogen formation and control under postulated LMFBR accident conditions

International Nuclear Information System (INIS)

Armstrong, G.R.; Wierman, R.W.

1976-09-01

The objective of this study is to experimentally investigate the potential for autoignition and combustion of hydrogen-sodium mixtures which may be produced in LMFBR accidents. The purpose and ultimate usefulness of this work is to provide data that will establish the validity and acceptability of mechanisms inherent to the LMFBR that could either prevent or delay the accumulation of hydrogen gas to less than 4 percent (V) in the Reactor Containment Building (RCB) under accident conditions. The results to date indicate that sodium and sodium-hydrogen mixtures such as may be expected during LMFBR postulated accidents will ignite upon entering an air atmosphere and that the hydrogen present will be essentially all consumed until such time that the oxygen concentration is depleted

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.

Chapter 6: Accidents; Capitulo 6: Acidentes

Energy Technology Data Exchange (ETDEWEB)

NONE

2014-06-01

The chapter 6 talks about the accidents with radiators all over the world, specifically, the Stimos, in Italy, 1975, San Salvador, in El Salvador, 1989, Soreq, in Israel, 1990, Nesvizh, in Byelorussian, 1991, in Illinois, US, 1965, in Maryland, US, 1991, Hanoi, Vietnam, 1992, Fleurus, in Belgium, 2006. Comments on the accidents and mainly the learned lessons.

Development of Parameter Network for Accident Management Applications

Energy Technology Data Exchange (ETDEWEB)

Pak, Sukyoung; Ahemd, Rizwan; Heo, Gyunyoung [Kyung Hee Univ., Yongin (Korea, Republic of); Kim, Jung Taek; Park, Soo Yong; Ahn, Kwang Il [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2013-10-15

When a severe accident happens, it is hard to obtain the necessary information to understand of internal status because of the failure or damage of instrumentation and control systems. We learned the lessons from Fukushima accident that internal instrumentation system should be secured and must have ability to react in serious conditions. While there might be a number of methods to reinforce the integrity of instrumentation systems, we focused on the use of redundant behavior of plant parameters without additional hardware installation. Specifically, the objective of this study is to estimate the replaced value which is able to identify internal status by using set of available signals when it is impossible to use instrumentation information in a severe accident, which is the continuation of the paper which was submitted at the last KNS meeting. The concept of the VPN was suggested to improve the quality of parameters particularly to be logged during severe accidents in NPPs using a software based approach, and quantize the importance of each parameter for further maintenance. In the future, we will continue to perform the same analysis to other accident scenarios and extend the spectrum of initial conditions so that we are able to get more sets of VPNs and ANN models to predict the behavior of accident scenarios. The suggested method has the uncertainty underlain in the analysis code for severe accidents. However, In case of failure to the safety critical instrumentation, the information from the VPN would be available to carry out safety management operation.

Chernobyl NPP accident. Overcoming experience. Acquired lessons

International Nuclear Information System (INIS)

Nosovskij, A.V.; Vasil'chenko, V.N.; Klyuchnikov, A.A.; Prister, B.S.

2006-01-01

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

Two decades of radiological accidents direct causes, roots causes and consequences

Directory of Open Access Journals (Sweden)

Rozental Jose de Julio

2002-01-01

Full Text Available Practically all Countries utilize radioisotopes in medicine, industry, agriculture and research. The extent to which ionizing radiation practices are employed varies considerably, depending largely upon social and economic conditions and the level of technical skills available in the country. An overview of the majority of practices and the associated hazards will be found in the Table IV to VII of this document. The practices in normal and abnormal operating conditions should follow the basic principles of radiation protection and the Safety of Radiation Sources, considering the IAEA Radiation Protection and the Safety of Radiation Sources, Safety Series 120 and the IAEA Recommendation of the Basic Safety Standards for Radiation Protection, Safety Series Nº 115. The Standards themselves underline the necessity to be able to predict the radiological consequences of emergency conditions and the investigations that should need to be done. This paper describes the major accidents that had happened in the last two decades, provides a methodology for analyses and gives a collection of lessons learned. This will help the Regulatory Authority to review the reasons of vulnerabilities, and to start a Radiation safety and Security Programme to introduce measurescapable to avoid the recurrence of similar events. Although a number of accidents with fatalities have caught the attention of the public in recent year, a safety record has accompanied the widespread use of radiation sources. However, the fact that accidents are uncommon should not give grounds for complacency. No radiological accident is acceptable. From a radiation safety and security of the sources standpoint, accident investigation is necessary to determine what happened, why, when, where and how it occurred and who was (were involved and responsible. The investigation conclusion is an important process toward alertness and feedback to avoid careless attitudes by improving the comprehension

Analysis of simulation results of damaged nuclear fuel accidents at NPPs with shell-type nuclear reactors

Directory of Open Access Journals (Sweden)

Igor L. Kozlov

2015-03-01

Full Text Available Lessons from the accident at the Fukushima Daiichi NPP made it necessary to reevaluate and intensificate the work on modeling and analyzing various scenarios of severe accidents with damage to the nuclear fuel in the reactor, containment and spent nuclear fuel storage pool with the expansion of the primary initiating event causes group listing. Further development of computational tools for modeling the explosion prevention criteria as to steam and gas mixtures, considering the specific thermal-hydrodynamic conditions and mechanisms of explosive situations arrival at different stages of a severe accident development, is substantiated. Based on the analysis of the known shell-type nuclear reactors accidents results the explosion safety thermodynamic criteria are presented, the parameters defining the steam and gas explosions conditions are found, the need to perform the further verification and validation of deterministic codes serving to simulate general accident processes behavior as well as phase-to-phase interaction calculated dependencies is established. The main parameters controlling and defining the criteria explosion safety effective regulation areas and their optimization conditions are found.

Noble gas control room accident filtration system for severe accident conditions (N-CRAFT)

International Nuclear Information System (INIS)

Hill, Axel; Stiepani, Cristoph; Drechsler, Michael

2015-01-01

Severe accidents might cause the release of airborne radioactive substances to the environment of the NPP either due to containment leakages or due to intentional filtered containment venting. In the latter case aerosols and iodine are retained, however noble gases are not retainable by the FCVS or by conventional air filtration systems like HEPA filters and iodine absorbers. Radioactive noble gases nevertheless dominate the activity release depending on the venting procedure and the weather conditions. To prevent unacceptable contamination of the control room atmosphere by noble gases, AREVA GmbH has developed a noble gas control room accident filtration system (CRAFT) which can supply purified fresh air to the control room without time limitation. The retention process is based on dynamic adsorption of noble gases on activated carbon. The system consists of delay lines (carbon columns) which are operated by a continuous and simultaneous adsorption and desorption process. CRAFT allows minimization of the dose rate inside the control room and ensures low radiation exposure to the staff by maintaining the control room environment suitable for prolonged occupancy throughout the duration of the accident. CRAFT consists of a proven modular design either transportable or permanently installed. (author)

Implementation of Defence in Depth at Nuclear Power Plants. Lessons Learnt from the Fukushima Daiichi Accident

International Nuclear Information System (INIS)

Lachaume, Jean-Luc; Miller, Douglass; Rzentkowski, Greg; Lahtinen, Nina; Valtonen, Keijo; Foucher, Laurent; Harikumar, Shri S.; Yamada, Tomoho; Sharafutdinov, Rashet; Kuznetsov, Mark; Carlsson, Lennart; Hanberg, Jan; Theiss, Klaus; Holahan, Gary; Williams, Donna; Nuenighoff, Kay; Wattelle, Emmanuel; Lazo, Edward; White, Andrew; Reig, Javier; Salgado, Nancy; Weightman, Mike

2016-01-01

Defence in depth (DiD) is a concept that has been used for many years alongside tools to optimise nuclear safety in reactor design, assessment and regulation. The 2011 Fukushima Daiichi nuclear power plant accident raised many questions and gave unique insight into nuclear safety issues, including DiD. In June 2013, the NEA held a Joint Workshop on Challenges and Enhancements to DiD in Light of the Fukushima Daiichi Accident (NEA, 2014), organised by the NEA Committee on the Safety of Nuclear Installations (CSNI) and the NEA Committee on Nuclear Regulatory Activities (CNRA). It was noted at the time that further work would be beneficial to enhance nuclear safety worldwide, especially with regard to the implementation of DiD. Accordingly, a senior-level task group (STG) was set up to produce a regulatory guidance booklet that would assist member countries in the use of DiD, taking into account lessons learnt from the 2011 accident. This regulatory guidance booklet builds on the work of this NEA workshop, of the International Atomic Energy Agency (IAEA), the Western European Nuclear Regulators Association (WENRA) and of other members of the STG. It uses as its basis the International Nuclear Safety Advisory Group's Defence in Depth in Nuclear Safety study (INSAG-10) (IAEA, 1996). The booklet provides insights into the implementation of DiD by regulators and emergency management authorities after the Fukushima Daiichi accident, aiming to enhance global harmonisation by providing guidance on: - the background to the DiD concept; - the need for independent effectiveness among the safety provisions for the various DiD levels, to the extent practicable; - the need for greater attention to reinforce prevention and mitigation at the various levels; - the vital importance of ensuring that common cause and common mode failures, especially external events acting in combination, do not lead to breaches of safety provisions at several DiD levels, taking note of the

Computational analysis of the behaviour of nuclear fuel under steady state, transient and accident conditions

International Nuclear Information System (INIS)

2007-12-01

Accident analysis is an important tool for ensuring the adequacy and efficiency of the provision in the defence in depth concept to cope with challenges to plant safety. Accident analysis is the milestone of the demonstration that the plant is capable of meeting any prescribed limits for radioactive releases and any other acceptable limits for the safe operation of the plant. It is used, by designers, utilities and regulators, in a number of applications such as: (a) licensing of new plants, (b) modification of existing plants, (c) analysis of operational events, (d) development, improvement or justification of the plant operational limits and conditions, and (e) safety cases. According to the defence in depth concept, the fuel rod cladding constitutes the first containment barrier of the fission products. Therefore, related safety objectives and associated criteria are defined, in order to ensure, at least for normal operation and anticipated transients, the integrity of the cladding, and for accident conditions, acceptable radiological consequences with regard to the postulated frequency of the accident, as usually identified in the safety analysis reports. Therefore, computational analysis of fuel behaviour under steady state, transient and accident conditions constitutes a major link of the safety case in order to justify the design and the safety of the fuel assemblies, as far as all relevant phenomena are correctly addressed and modelled. This publication complements the IAEA Safety Report on Accident Analysis for Nuclear Power Plants (Safety Report Series No. 23) that provides practical guidance for establishing a set of conceptual and formal methods and practices for performing accident analysis. Computational analysis of the behaviour of nuclear fuel under transient and accident conditions, including normal operation (e.g. power ramp rates) is developed in this publication. For design basis accidents, depending on the type of influence on a fuel element

Programmatic changes due to TMI-2 [Three Mile Island Unit 2]: Accident planning

International Nuclear Information System (INIS)

Wingert, V.L.

1988-01-01

The focus of the paper is lessons learned for emergency planning and preparedness form the Three Mile Island Unit 2 (TMI-2) accident. The lessons learned are examined from two perspectives: (a) lessons learned that have resulted in programmatic changes, and (b) lessons learned that have not been adequately addressed. There is no doubt that the TMI-2 accident is the pivotal event that caused a major rethinking of the pre-TMI emergency preparedness posture and led to a fundamentally different approach to emergency preparedness for commercial nuclear power plant accidents. While this new approach has evolved into a comprehensive, systematic, and even prototypical national program, it has also generated new problems: escalating costs for state and local governments and leveraging of the federal licensing process by state and local governments who do not want specific nuclear power plants to operate. A discussion of the primary lessons learned on emergency preparedness is presented under the following topics: beyond defense-in-depth, predetermined action, mandatory emergency planning and preparedness, and federal coordination

Radiological accidents/incidents with caesium-137 in Estonia

International Nuclear Information System (INIS)

Sinisoo, M.

1998-01-01

A report is provided of an accident and an incident involving radioactive sources in Estonia. In the 1994 occurrence, looters of a depository of radioactive waste manipulated a source containing 137 Cs and received dangerous doses of radiation. One of the persons involved died, others suffered minor burns. Another event, which occurred in early 1995, did not have a tragic outcome: an abandoned 137 Cs source was found in the vicinity of the highway linking Tallinn and Narva and was disposed of safely. Both these accidents draw attention to the potential dangers caused by the insufficient survey of the territory, radiation protection structures not yet fully operable, and the lack of equipment and know-how. The lessons to be drawn from these events are considered on the basis of the chronologies and factual data. The report contains concise descriptions of the accidents, a medical overview of the fate of the injured persons and the lessons learned from these accidents. (author)

Researches of WWER fuel rods behaviour under RIA accident conditions

International Nuclear Information System (INIS)

Nechaeva, O.; Medvedev, A.; Novikov, V.; Salatov, A.

2003-01-01

Unirradiated fuel rod and refabricated fuel rod tests in the BIGR as well as acceptance criteria proving absence of fragmentation and the settlement modeling of refabricated fuel rods thermomechanical behavior in the BIGR-tests using RAPTA-5 code are discussed in this paper. The behaviour of WWER type simulators with E110 and E635 cladding was researched at the BIGR reactor under power pulse conditions simulating reactivity initiated accident. The results of the tests in four variants of experimental conditions are submitted. The behaviour of 12 WWER type refabricated fuel rods was researched in the BIGR reactor under power pulse conditions simulating reactivity initiated accident: burnup 48 and 60 MWd/kgU, pulse width 3 ms, peak fuel enthalpy 115-190 cal/g. The program of future tests in the research reactor MIR with high burnup fuel rod (up to 70 MWd/kgU) under conditions simulating design RIA in WWER-1000 is presented

On the removal of airborne particulate radioactivity under accident conditions

International Nuclear Information System (INIS)

Ruedinger, V.; Wilhelm, J.G.

1985-03-01

In the case of an accident, the filter elements in the ventilation systems of a nuclear facility may become a part of the remaining fission product barrier. Within the framework of the Project Nuclear Safety of the Karlsruhe Nuclear Research Center, contributions are made to an increase in reliability of the air cleaning systems under accident conditions. These include the development and verification of computer programs for the estimation of those conditions prevailing inside the air cleaning systems in the case of an accident. Experimental investigations into the response of HEPA filters to differential pressures involving both dry and moist air have demonstrated the occurence of structural failures with subsequent loss of efficiency at relatively low values of differential pressures. With regard to further investigations, a new test facility was put into operation for the realization of superimposed challenges. A new method for testing particulate removal efficiency under high temperature or high humidity was developed. Finally, first results of code development work and of the corresponding verification experiments are reported on. (orig.) [de

Behaviour of LWR core materials under accident conditions. Proceedings of a technical committee meeting

International Nuclear Information System (INIS)

1996-12-01

At the invitation of the Government of the Russian Federation, following a proposal of the International Working Group on Water Reactor Fuel Performance and Technology, the IAEA convened a Technical Committee Meeting on Behaviour of LWR Core Materials Under Accident Conditions from 9 to 13 October 1995 in Dimitrovgrad to analyze and evaluate the behaviour of LWR core materials under accident conditions with special emphasis on severe accidents. In-vessel severe accidents phenomena were considered in detail, but specialized thermal hydraulic aspects as well as ex-vessel phenomena were outside the scope of the meeting. Forty participants representing eight countries attended the meeting. Twenty-three papers were presented and discussed during five sessions. Refs, figs, tabs

Analysis of Fukushima Daiichi Accident Using HFACS

International Nuclear Information System (INIS)

Mohamed, Saeed Almheiri

2013-01-01

The shadow of Fukushima Daiichi nuclear power plant (NPP) accident is still too big and will last long. On the other hand, it could still teach us lots of lessons to better design and operate nuclear power plants. In this paper, we will be focusing on the Fukushima Daiichi accident, especially on human organizational factors. We will analyze the accident using Human Factors Analysis and Classification System (HFACS) in order to better understand the organizational climate of TEPCO 1 and NISA 2 that led to Fukushima Daiichi Accident. HFACS was developed for the U. S. aviation industry and has been used at many industries like the rail and mining industries. We found that the HFACS to be greatly beneficial in investigating the latent and organizational causes for the accident. The application results show that the causes of Fukushima Daiichi accident were spread out from sharp end (i.e. Unsafe Act) to blunt end (i. e. Organizational Influences). This means that the corresponding countermeasures should cover from front line staff to management. Thus, we managed to develop a better understanding on how to prevent similar errors or violations. The incident and near-miss have a lot of helpful information because it may show the actual and latent deficiencies of complex systems. We applied the HFACS into Fukushima Daiichi accident to better locate the causes related to both sharp and blunt ends of operation of NPP. In order to derive useful lessons from the accident analysis, the analyst should try to find the similarities not differences from the incident. It is imperative that whatever accident/incident analysis systems we use, we should fully utilize the disastrous Fukushima accident

Analysis of Fukushima Daiichi Accident Using HFACS

Energy Technology Data Exchange (ETDEWEB)

Mohamed, Saeed Almheiri [Korea Advanced Institue of Science and Technology, Daejeon (Korea, Republic of)

2013-10-15

The shadow of Fukushima Daiichi nuclear power plant (NPP) accident is still too big and will last long. On the other hand, it could still teach us lots of lessons to better design and operate nuclear power plants. In this paper, we will be focusing on the Fukushima Daiichi accident, especially on human organizational factors. We will analyze the accident using Human Factors Analysis and Classification System (HFACS) in order to better understand the organizational climate of TEPCO{sup 1} and NISA{sup 2} that led to Fukushima Daiichi Accident. HFACS was developed for the U. S. aviation industry and has been used at many industries like the rail and mining industries. We found that the HFACS to be greatly beneficial in investigating the latent and organizational causes for the accident. The application results show that the causes of Fukushima Daiichi accident were spread out from sharp end (i.e. Unsafe Act) to blunt end (i. e. Organizational Influences). This means that the corresponding countermeasures should cover from front line staff to management. Thus, we managed to develop a better understanding on how to prevent similar errors or violations. The incident and near-miss have a lot of helpful information because it may show the actual and latent deficiencies of complex systems. We applied the HFACS into Fukushima Daiichi accident to better locate the causes related to both sharp and blunt ends of operation of NPP. In order to derive useful lessons from the accident analysis, the analyst should try to find the similarities not differences from the incident. It is imperative that whatever accident/incident analysis systems we use, we should fully utilize the disastrous Fukushima accident.

Using modular neural networks to monitor accident conditions in nuclear power plants

International Nuclear Information System (INIS)

Guo, Z.

1992-01-01

Nuclear power plants are very complex systems. The diagnoses of transients or accident conditions is very difficult because a large amount of information, which is often noisy, or intermittent, or even incomplete, need to be processed in real time. To demonstrate their potential application to nuclear power plants, neural networks axe used to monitor the accident scenarios simulated by the training simulator of TVA's Watts Bar Nuclear Power Plant. A self-organization network is used to compress original data to reduce the total number of training patterns. Different accident scenarios are closely related to different key parameters which distinguish one accident scenario from another. Therefore, the accident scenarios can be monitored by a set of small size neural networks, called modular networks, each one of which monitors only one assigned accident scenario, to obtain fast training and recall. Sensitivity analysis is applied to select proper input variables for modular networks

Chemical phenomena under severe accident conditions

International Nuclear Information System (INIS)

Powers, D.A.

1988-01-01

A severe nuclear reactor accident is expected to involve a vast number of chemical processes. The chemical processes of major safety significance begin with the production of hydrogen during steam oxidation of fuel cladding. Physico-chemical changes in the fuel and the vaporization of radionuclides during reactor accidents have captured much of the attention of the safety community in recent years. Protracted chemical interactions of core debris with structural concrete mark the conclusion of dynamic events in a severe accident. An overview of the current understanding of chemical processes in severe reactor accident is provided in this paper. It is shown that most of this understanding has come from application of findings from other fields though a few areas have in the past been subject to in-depth study of a fundamental nature. Challenges in the study of severe accident chemistry are delineated

Summary of the foreign countries reports on the Fukushima Daiichi Nuclear Power Plants accident, on the lessons learnt and recommendation

International Nuclear Information System (INIS)

Nariai, Hideki

2017-01-01

This paper focused on the lessons and recommendations from the accident investigation reports prepared by the National Academy of Sciences (NAS), IAEA, and OECD/NEA on the accident of Fukushima Daiichi Nuclear Power Station associated with the Great East Japan Earthquake. (1) As for the causes of the accident, the IAEA report pointed out as a technical factor that Japan's scientists did not think that the earthquake occurrence probability of the magnitude 9 as an external event was high. As for tsunami countermeasures, it reported that accident countermeasures would have been easier if only seawater pump flood protection and the high-elevation positioning of emergency power supply etc. were prepared. As for human organizational factor, it pointed out that nuclear regulations were performed by many divided organizations, and responsibility and authority were not clear. The NAS report pointed out that the regulatory agency and nuclear promotion agency were not functionally separated, and that the regulatory agency was not independent as a result of the relationship between the Japanese government agency and companies, and the agency became a captive of regulations. The following items were also reported; (2) safety measures and emergency preparedness, (3) off-site response during emergency, (4) radiation effects, (5) restoration after the accident, (6) international issues, and (7) issues of the spent fuel storage pool of NAS. Japan established the Nuclear Regulation Authority by integrating related organizations, but how to create a regulatory agency with advanced expertise is the future task. (A.O.)

Behavior of LWR fuel elements under accident conditions

International Nuclear Information System (INIS)

Albrecht, H.; Bocek, M.; Erbacher, F.; Fiege, A.; Fischer, M.; Hagen, S.; Hofmann, P.; Holleck, H.; Karb, E.; Leistikow, S.; Melang, S.; Ondracek, G.; Thuemmler, F.; Wiehr, K.

1977-01-01

In the frame of the German reactor safety research program, the Kernforschungszentrum Karlsruhe is carrying out a comprehensive program on the behavior of LWR fuel elements under a variety of power cooling mismatch conditions in particular during loss-of-coolant accidents. The major objectives are to establish a detailed quantitative understanding of fuel rod failures mechanisms and their thresholds, to evaluate the safety margins of power reactor cores under accident conditions and to investigate the feedback of fuel rod failures on the efficiency of emergency core cooling systems. This detailed quantitative understanding is achieved through extensive basic and integral experiments and is incorporated in a fuel behavior code. On the basis of these results the design of power reactor fuel elements and of safety devices can be further improved. The results of investigations on the inelastic deformation (ballooning) behavior of Zircaloy 4 cladding at LOCA temperatures in oxidizing atmosphere are presented. Depending upon strain rate and temperature superplastic deformation behavior was observed. In the equation of state of Zry 4 the strain rate sensitivity index depends strongly upon strain and in the superplastic region upon sample anisotropy. Oxidation kinetics experiments with Zry-tubes at 900-1300 0 C showed that the Baker-Just correlation describes the reality quite conservative. Therefore a reduction of the amount of Zry oxidation can be assumed in the course of a LOCA. The external oxidation of Zry-cladding by steam as well as internal oxidation by the oxygen in oxide fuel and fission products (Cs, I, Te) have an influence on the strain and rupture behavior of Zry-cladding at LOCA temperatures. In out-of-pile and inpile experiments the mechanical and thermal behavior of fuel rods during the blowdown, the heatup and the reflood phases of a LOCA are investigated under representative and controlled thermohydraulic conditions. The task of the inpile experiments is

Safety design criteria for the next generation Sodium-cooled fast reactors based on lessons learned from the Fukushima NPS accident

International Nuclear Information System (INIS)

Sakai, Takaaki

2012-01-01

In this presentation, architecture of the safety design criteria as requirements for SFR system and the activities on safety research works to establish safety evaluation methods for the next generation SFRs are summarized with the basis on lessons learned from the Fukushima NPS accident. Nuclear safety is a grovel issue which should be achieved by the international cooperation. In respect of the development for the next generation reactor, it is necessary to build the harmonized safety criteria and evaluation methods to establish the next level of safety

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

Occupational Radiation Protection in Severe Accident Management

International Nuclear Information System (INIS)

2015-01-01

protection job coverage during severe accident response. The IAEA defines a 'Severe Accident' as a beyond design basis accident comprising of accident conditions more severe than a design basis accident, involving significant core degradation. Preparation of the report The expert group met several times to share their experience and develop an interim (preliminary) report by the end of 2013. The content of the report is thus based on current reflections and action plans undertaken by the ISOE participating utilities and regulatory authorities to improve the emergency response plans in the event of a severe nuclear accident from the point of view of occupational radiation protection. A specific attention has been given to the analysis of past nuclear accidents (TMI-2, USA-1979; Chernobyl, USSR-1986 and Fukushima Daiichi, Japan-2011) and to the integration of the occupational radiation protection (ORP) lessons learned from these accidents into the various chapters of the report (See synthesis of these lessons learned in Appendix-1). To finalize the report, an international workshop was organized in 2014 to present and discuss the content of the interim version and share national experiences on best occupational RP management practices and protocols for optimum RP job coverage during severe accident, initial response and recovery efforts (see Appendix-2). The workshop notably allowed to improve and complete the report which has then be submitted to the ISOE Management Board for approval. This report comprises five main chapters. Chapter 2 provides essential information on radiation protection management and organisation. Chapter 3 establishes the goal of radiation protection training and exercises related to severe accident management. Chapter 4 discusses facility characteristics that must be considered when planning actions in response to a severe accident. Chapter 5 introduces an overall approach for the protection of workers / responders with its interpretation and

Numerical Study of Severe Accidents on Containment Venting Conditions

Energy Technology Data Exchange (ETDEWEB)

Lee, Na Rae; Bang, Young Suk; Park, Tong Kyu; Lee, Doo Yong [FNC Technology Co., Yongin (Korea, Republic of); Choi, Yu Jung; Lee, Sang Won; Kim, Hyeong Taek [KHNP-CRI, Daejeon (Korea, Republic of)

2014-10-15

Under severe accident, the containment integrity can be challenged due to over-pressurization by steam and non-condensable gas generation. According to Seismic Probabilistic Safety Assessment (PSA) result, the late containment failure by over-pressurization has been identified as the most probable containment failure mode. In addition, the analyses of Fukushima nuclear power plant accident reveal the necessity of the proper containment depressurization to prevent the large release of the radionuclide to environment. Containment venting has been considered as an effective approach to maintain the containment integrity from over-pressurization. Basic idea of containment venting is to relieve the pressure inside of the containment by establishing a flow path to the external environment. To ensure the containment integrity under over-pressure conditions, it is crucial to conduct the containment vent in a timely manner with a sufficient discharge flow rate. It is also important to optimize the vent line size to prevent additional risk of leakage and to install at the site with limited space availability. The purpose of this study is to identify the effective venting conditions for preventing the containment over-pressurization and investigate the vent flow characteristics to minimize the consequence of the containment ventilation.. In order that, thermodynamic behavior of the containment and the discharged flow depending on different vent strategies are analyzed and compared. The representative accident scenarios are identified by reviewing the Level 2 PSA result and the sensitivity analyses with varying conditions (i.e. vent line size and vent initiation pressure) are conducted. MAAP5 model for the OPR1000 Korea nuclear power plant has been used for severe accident simulations. Containment venting can be an effective strategy to prevent the significant failure of the containment due to over-pressurization. However, it should be carefully conducted because the vented

Numerical Study of Severe Accidents on Containment Venting Conditions

International Nuclear Information System (INIS)

Lee, Na Rae; Bang, Young Suk; Park, Tong Kyu; Lee, Doo Yong; Choi, Yu Jung; Lee, Sang Won; Kim, Hyeong Taek

2014-01-01

Under severe accident, the containment integrity can be challenged due to over-pressurization by steam and non-condensable gas generation. According to Seismic Probabilistic Safety Assessment (PSA) result, the late containment failure by over-pressurization has been identified as the most probable containment failure mode. In addition, the analyses of Fukushima nuclear power plant accident reveal the necessity of the proper containment depressurization to prevent the large release of the radionuclide to environment. Containment venting has been considered as an effective approach to maintain the containment integrity from over-pressurization. Basic idea of containment venting is to relieve the pressure inside of the containment by establishing a flow path to the external environment. To ensure the containment integrity under over-pressure conditions, it is crucial to conduct the containment vent in a timely manner with a sufficient discharge flow rate. It is also important to optimize the vent line size to prevent additional risk of leakage and to install at the site with limited space availability. The purpose of this study is to identify the effective venting conditions for preventing the containment over-pressurization and investigate the vent flow characteristics to minimize the consequence of the containment ventilation.. In order that, thermodynamic behavior of the containment and the discharged flow depending on different vent strategies are analyzed and compared. The representative accident scenarios are identified by reviewing the Level 2 PSA result and the sensitivity analyses with varying conditions (i.e. vent line size and vent initiation pressure) are conducted. MAAP5 model for the OPR1000 Korea nuclear power plant has been used for severe accident simulations. Containment venting can be an effective strategy to prevent the significant failure of the containment due to over-pressurization. However, it should be carefully conducted because the vented

The TMI-2 accident

International Nuclear Information System (INIS)

Loureiro, L.A.

1986-01-01

A critical study about the technical and man-related facts in order to establish what is considered the worst commercial nuclear power accident until 1986. Radiological consequences and stress to the public are considered in contrast to antinuclear groups. This descriptive and technical study has the purpose to document written and oral opinions obtained abroad and then explain to the public in an easy language terminology. Preliminary study describing safety related systems fails and the accident itself with minute to minute description, conduct to the consequences and then, to learned lessons

Thermalydraulic processes in the reactor coolant system of a BWR under severe accident conditions

International Nuclear Information System (INIS)

Hodge, S.A.

1990-01-01

Boiling water reactors (BWRs) incorporate many unique structural features that make their expected response under severe accident conditions very different from that predicted in the case of pressurized water reactor accident sequences. Automatic main steam isolation valve (MIV) closure as the vessel water level approaches the top of the core would cause reactor vessel isolation while automatic recirculation pump trip would limit the in-vessel flows to those characteristic of natural circulation (as disturbed by vessel relief valve actuation). This paper provides a discussion of the BWR control blade, channel box, core plate, control rod guide tube, and reactor vessel safety relief valve (SRV) configuration and the effects of these structural components upon thermal hydraulic processes within the reactor vessel under severe accident conditions. The dominant BWR severe accident sequences as determined by probabilistic risk assessment are described and the expected timing of events for the unmitigated short-term station blackout severe accident sequence at the Peach Bottom atomic power station is presented

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

International Nuclear Information System (INIS)

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

1986-09-01

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

Predictions of structural integrity of steam generator tubes under normal operating, accident, and severe accident conditions

International Nuclear Information System (INIS)

Majumdar, S.

1996-09-01

Available models for predicting failure of flawed and unflawed steam generator tubes under normal operating, accident, and severe accident conditions are reviewed. Tests conducted in the past, though limited, tended to show that the earlier flow-stress model for part-through-wall axial cracks overestimated the damaging influence of deep cracks. This observation is confirmed by further tests at high temperatures as well as by finite element analysis. A modified correlation for deep cracks can correct this shortcoming of the model. Recent tests have shown that lateral restraint can significantly increase the failure pressure of tubes with unsymmetrical circumferential cracks. This observation is confirmed by finite element analysis. The rate-independent flow stress models that are successful at low temperatures cannot predict the rate sensitive failure behavior of steam generator tubes at high temperatures. Therefore, a creep rupture model for predicting failure is developed and validated by tests under varying temperature and pressure loading expected during severe accidents

Response to the accident at TEPCO's Fukushima Daiichi Nuclear Power Plants

International Nuclear Information System (INIS)

Nei, Hisanori

2012-01-01

This article was reading from the author's plenary lecture at the thermal and nuclear power generation convention 2011, which was summary of the author edited report of Japanese government to IAEA ministerial conference on nuclear safety. The article consisted of (1) outlines of occurrence and development of the accident at TEPCO's Fukushima Daiichi Nuclear Power Plants (NPPs), (2) comparison of Fukushima Daiichi NPPs with other NPPs (Fukushima Daini, Onagawa and Tokai Daini NPPs), (3) major countermeasures to settle the situation regarding the accident, (4) comprehensive safety evaluation of other NPPs as response to the accident and (5) lessons learned from the accident so far. It was highly important to ensure power supplies and robust cooling functions of reactors, pressure containment vessels and spent fuel pools. 28 lessons were categorized into five groups such as (1) strengthen preventive measures against a severe accident, (2) enhancement of response measures against severe accidents, (3) enhancement of nuclear emergency responses, (4) reinforcement of safety infrastructure and (5) thoroughness of safety culture. (T. Tanaka)

A brief review of the accident at Three Mile Island

International Nuclear Information System (INIS)

Corey, G.R.

1979-01-01

A question-and-answer format is used to discuss the Three Mile Reactor accident and the lessons learned. The aspects touched upon include the hydrogen bubble, the radiation levels the public was exposed to, and the consequences of the accident to the nuclear power program

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

Evaluation of major polluting accidents in China-Results and perspectives

International Nuclear Information System (INIS)

Hou Yu; Zhang Tianzhu

2009-01-01

Lessons learnt from accidents are essential sources for updating state-of-the-art requirements in pollution accident prevention. To improve this input in the People's Republic of China in a systematic way, a database for collecting and evaluating major pollution accidents is being established. This is being done in co-operation with Chinese Society for Environment Sciences and other national Institutions. At the time of writing over 80 major events from 2002-2006 have been collected. In this paper, a summary evaluation on the major polluting events in China from 2002 to 2006 is presented and some basic lessons drawn shown. There is no a systematic pollution accident notification system currently in China. The results from root cause analysis underline the importance of emergency measures, maintenance, human factor issues and the role of safety organization. Chronic pollution, especially water pollution and air pollution should be paid the same attention as the sudden pollution. It is important to keep in mind that collecting information from major accidents represents a small percentage of the actual number of events taking place.

Review of the international forum on peaceful use of nuclear energy and nuclear security. Taking the lessons learned from Fukushima Daiichi Nuclear Power Plant accident to the 2012 Seoul nuclear security summit

International Nuclear Information System (INIS)

Tazaki, Makiko; Suda, Kazunori; Suzuki, Mitsutoshi; Kuno, Yusuke; Mochiji, Toshiro

2012-06-01

The Japan Atomic Energy Agency (JAEA) held '2011 International Forum on the Peaceful Use of Nuclear Energy and Nuclear Security - Taking the lessons learned from Fukushima Daiichi Nuclear Power Plant Accident to the 2012 Seoul Nuclear Security Summit-' on 8 and 9 December, 2011. It intended to articulate effective strategies and measures for strengthening nuclear security using lessons learned from the Fukushima Nuclear Accident. Moreover, it was expected to explore comprehensive approaches which could contribute to enhancing both nuclear safety and security in order to support sustainable and appropriate development of the peaceful use of nuclear energy. This report includes abstracts of keynote speeches, summary of panel discussions and materials of the presentations in the forum. The editors take full responsibility for the wording and content of this report, excepts presentation materials. (author)

Review of the international forum on peaceful use of nuclear energy and nuclear security. Taking the lessons learned from Fukushima Daiichi Nuclear Power Plant accident to the 2012 Seoul nuclear security summit

Energy Technology Data Exchange (ETDEWEB)

Tazaki, Makiko; Suda, Kazunori; Suzuki, Mitsutoshi; Kuno, Yusuke; Mochiji, Toshiro [Japan Atomic Energy Agency, Department of Science and Technology for Nuclear Material Management, Tokai, Ibaraki (Japan)

2012-06-15

The Japan Atomic Energy Agency (JAEA) held '2011 International Forum on the Peaceful Use of Nuclear Energy and Nuclear Security - Taking the lessons learned from Fukushima Daiichi Nuclear Power Plant Accident to the 2012 Seoul Nuclear Security Summit-' on 8 and 9 December, 2011. It intended to articulate effective strategies and measures for strengthening nuclear security using lessons learned from the Fukushima Nuclear Accident. Moreover, it was expected to explore comprehensive approaches which could contribute to enhancing both nuclear safety and security in order to support sustainable and appropriate development of the peaceful use of nuclear energy. This report includes abstracts of keynote speeches, summary of panel discussions and materials of the presentations in the forum. The editors take full responsibility for the wording and content of this report, excepts presentation materials. (author)

Accidents in radiotherapy: Lack of quality assurance?

International Nuclear Information System (INIS)

Novotny, J.

1997-01-01

About 150 radiological accidents, involving more than 3000 patients with adverse effects, 15 patient's fatalities and about 5000 staff and public exposures have been collected and analysed. Out of 67 analysed accidents in external beam therapy 22% has been caused by wrong calculation of the exposure time or monitor units, 13% by inadequate review of patient's chart, 12% by mistakes in the anatomical area to be treated. The remaining 35% can be attributed to 17 different causes. The most common mistakes in brachytherapy were wrong activities of sources used for treatment (20%), inadequate procedures for placement of sources applicators (14%), mistakes in calculating the treatment time (12%), etc. The direct and contributing causes of radiological accidents have been deduced from each event, when it was possible and categorized into 9 categories: mistakes in procedures (30%), professional mistakes (17%), communication mistakes (15%), lack of training (8.5%), interpretation mistakes (7%), lack of supervision (6%), mistakes in judgement (6%), hardware failures (5%), software and other mistakes (5.5%). Three types of direct and contributing causes responsible for almost 62% of all accidents are directly connected to the quality assurance of treatment. The lessons learnt from the accidents are related to frequencies of direct and contributing factors and show that most of the accident are caused by lack, non-application of quality assurance (QA) procedures or by underestimating of QA procedures. The international system for collection of accidents and dissemination of lessons learnt from the different accidents, proposed by IAEA, can contribute to better practice in many radiotherapy departments. Most of the accidents could have been avoided, had a comprehensive QA programme been established and properly applied in all radiotherapy departments, whatever the size. (author)

Emergency preparedness lessons from Chernobyl

International Nuclear Information System (INIS)

Martin, J.B.

1987-09-01

Emergency preparedness at nuclear power plants in the US has been considerably enhanced since the Three Mile Island accident. The Chernobyl accident has provided valuable data that can be used to evaluate the merit of some of these enhancements and to determine the need for additional improvements. For example, the USSR intervention levels of 25 rem and 75 rem for evacuation are contrasted with US Environmental Protection Agency protective action guides. The manner in which 135,000 persons were evacuated from the 30-km zone around Chernobyl is constrasted with typical US evacuation plans. Meteorological conditions and particulate deposition patterns were studied to infer characteristics of the radioactive plume from Chernobyl. Typical plume monitoring techniques are examined in light of lessons learned by the Soviets about plume behavior. This review has indicated a need for additional improvements in utility and government emergency plans, procedures, equipment, and training. 12 refs., 1 fig., 2 tabs

Lessons learned from accidents in radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Ortiz-Lopez, P [International Atomic Energy Agency, Vienna (Austria). Div. of Nuclear Safety; Novotny, J [University Hospital St. Rafael, Leuven (Belgium); Haywood, J [South Cleveland Hospital (United Kingdom). Cleveland Medical Physics Unit

1996-08-01

Radiotherapy is the only application of radiation which intentionally delivers very high doses to humans. A gross deviation from the prescribed dose or dose distribution can have severe, or even fatal consequences. Since the patient is placed directly in the beam or sources are inserted in the body, any mistake made with the beam or the sources leads almost certainly to an accidental exposure. Lessons learned from previous incidents can be used to test the vulnerability of a given facility, provided that these are adequately disseminated. The purpose of this paper is to present a summary of the lessons learned from a relatively large sample of events. The analysis has been presented as a short description followed by an identification of the triggering event and the contributing factors. These have been grouped as follows: errors in commissioning or calibration machines and sources affecting many patients; mistakes affecting individual patients such as irradiating the wrong patient, the wrong, field or site, and mistakes when entering data into or reading from the patient`s chart; error due to unusual treatments or situations; equipment failure and human machine problems, including maintenance. (author). 1 ref.

Lessons learned from accidents in radiotherapy

International Nuclear Information System (INIS)

Ortiz-Lopez, P.; Haywood, J.

1996-01-01

Radiotherapy is the only application of radiation which intentionally delivers very high doses to humans. A gross deviation from the prescribed dose or dose distribution can have severe, or even fatal consequences. Since the patient is placed directly in the beam or sources are inserted in the body, any mistake made with the beam or the sources leads almost certainly to an accidental exposure. Lessons learned from previous incidents can be used to test the vulnerability of a given facility, provided that these are adequately disseminated. The purpose of this paper is to present a summary of the lessons learned from a relatively large sample of events. The analysis has been presented as a short description followed by an identification of the triggering event and the contributing factors. These have been grouped as follows: errors in commissioning or calibration machines and sources affecting many patients; mistakes affecting individual patients such as irradiating the wrong patient, the wrong, field or site, and mistakes when entering data into or reading from the patient's chart; error due to unusual treatments or situations; equipment failure and human machine problems, including maintenance. (author). 1 ref

Proceedings of the workshop on operator training for severe accident management and instrumentation capabilities during severe accidents

International Nuclear Information System (INIS)

2001-01-01

This Workshop was organised in collaboration with Electricite de France (Service Etudes et Projets Thermiques et Nucleaires). There were 34 participants, representing thirteen OECD Member countries, the Russian Federation and the OECD/NEA. Almost half the participants represented utilities. The second largest group was regulatory authorities and their technical support organisations. Basically, the Workshop was a follow-up to the 1997 Second Specialist Meeting on Operator Aids for Severe Accident Management (SAMOA-2) [Reports NEA/CSNI/R(97)10 and 27] and to the 1992 Specialist Meeting on Instrumentation to Manage Severe Accidents [Reports NEA/CSNI/R(92)11 and (93)3]. It was aimed at sharing and comparing progress made and experience gained from these two meetings, emphasizing practical lessons learnt during training or incidents as well as feedback from instrumentation capability assessment. The objectives of the Workshop were therefore: - to exchange information on recent and current activities in the area of operator training for SAM, and lessons learnt during the management of real incidents ('operator' is defined hear as all personnel involved in SAM); - to compare capabilities and use of instrumentation available during severe accidents; - to monitor progress made; - to identify and discuss differences between approaches relevant to reactor safety; - and to make recommendations to the Working Group on the Analysis and Management of Accidents and the CSNI (GAMA). The meeting confirmed that only limited information is needed for making required decisions for SAM. In most cases existing instrumentation should be able to provide usable information. Additional instrumentation requirements may arise from particular accident management measures implemented in some plants. In any case, depending on the time frame where the instrumentation should be relied upon, it should be assessed whether it is likely to survive the harsh environmental conditions it will be exposed

Accident information needs

International Nuclear Information System (INIS)

Hanson, D.J.; Arcieri, W.C.; Ward, L.W.

1992-01-01

A Five-step methodology has been developed to evaluate information needs for nuclear power plants under accident conditions and the availability of plant instrumentation during severe accidents. Step 1 examines the credible accidents and their relationships to plant safety functions. Step 2 determines the information personnel involved in accident management will need to understand plant behavior. Step 3 determines the capability of the instrumentation to function properly under severe accident conditions. Step 4 determines the conditions expected during the identified severe accidents. Step 5 compares the instrument capabilities and the severe accident conditions to evaluate the availability of the instrumentation to supply needed plant information

Accident information needs

Energy Technology Data Exchange (ETDEWEB)

Hanson, D.J.; Arcieri, W.C.; Ward, L.W.

1992-12-31

A Five-step methodology has been developed to evaluate information needs for nuclear power plants under accident conditions and the availability of plant instrumentation during severe accidents. Step 1 examines the credible accidents and their relationships to plant safety functions. Step 2 determines the information personnel involved in accident management will need to understand plant behavior. Step 3 determines the capability of the instrumentation to function properly under severe accident conditions. Step 4 determines the conditions expected during the identified severe accidents. Step 5 compares the instrument capabilities and the severe accident conditions to evaluate the availability of the instrumentation to supply needed plant information.

Accident information needs

Energy Technology Data Exchange (ETDEWEB)

Hanson, D.J.; Arcieri, W.C.; Ward, L.W.

1992-01-01

A Five-step methodology has been developed to evaluate information needs for nuclear power plants under accident conditions and the availability of plant instrumentation during severe accidents. Step 1 examines the credible accidents and their relationships to plant safety functions. Step 2 determines the information personnel involved in accident management will need to understand plant behavior. Step 3 determines the capability of the instrumentation to function properly under severe accident conditions. Step 4 determines the conditions expected during the identified severe accidents. Step 5 compares the instrument capabilities and the severe accident conditions to evaluate the availability of the instrumentation to supply needed plant information.

Analysis of some accident conditions in confirmation of the HTGR safety

Energy Technology Data Exchange (ETDEWEB)

Grebennik, V. N.; Grishanin, E. I.; Kukharkin, N. E.; Mikhailov, P. V.; Pinchuk, V. V.; Ponomarev-Stepnoy, N. N.; Fedin, G. I.; Shilov, V. N.; Yanushevich, I. V. [Gosudarstvennyj Komitet po Ispol' zovaniyu Atomnoj Ehnergii SSSR, Moscow. Inst. Atomnoj Ehnergii

1981-01-15

This report concerns some accident conditions for the HTGR-50 demonstrational reactor which along with the safety features common to the typical HTGR differs in design. The analyses carried out on the accident situations showed that due to the high heat capacity of the graphite core and negative temperature effect of the reactivity the HTGR-50 reactor is effectively selfcontrolled at different perturbations of the reactivity and has low sensitivity to the failure of the core cooling. The primary circuit depressurization accident should be thoroughly studied because of the dangerous consequences i.e. the core overheating and the reactivity release into the environment. As a whole, the studies now in progress show that the problem of the HTGR safety can be successfully solved.

Analysis of some accident conditions in confirmation of the HTGR safety

International Nuclear Information System (INIS)

Grebennik, V.N.; Grishanin, E.I.; Kukharkin, N.E.; Mikhailov, P.V.; Pinchuk, V.V.; Ponomarev-Stepnoy, N.N.; Fedin, G.I.; Shilov, V.N.; Yanushevich, I.V.

1981-01-01

This report concerns some accident conditions for the HTGR-50 demonstrational reactor which along with the safety features common to the typical HTGR differs in design. The analyses carried out on the accident situations showed that due to the high heat capacity of the graphite core and negative temperature effect of the reactivity the HTGR-50 reactor is effectively selfcontrolled at different perturbations of the reactivity and has low sensitivity to the failure of the core cooling. The primary circuit depressurization accident should be thoroughly studied because of the dangerous consequences i.e. the core overheating and the reactivity release into the environment. As a whole, the studies now in progress show that the problem of the HTGR safety can be successfully solved

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

Chernobyl accident: lessons learned for radiation protection

International Nuclear Information System (INIS)

Kenigsberg, Jacov

2008-01-01

Full text: The long-term nature of the consequences of the accident at the Chernobyl nuclear power plant, which was a major technological catastrophe in terms of its scope and complexity and created humanitarian, environmental, social, economic and health consequences. After more than twenty years we can conclude that Chernobyl accident was requested the big efforts of the national governments and international organisations for improvement new approaches to radiation safety, radiation protection, health care, emergency preparedness and response. During first years after accident some response actions did more harm than good because not based on international radiation protection principles, based on criteria developed during emergency and associated with mistrust, emotions, political pressure. As a result was inappropriate government reaction: unjustified relocation and decontamination - loss jobs, homes, billions of $ cost; unjustified compensation (high portion of annual national budgets). Non-radiological (e.g. detrimental economic, social and psychological) consequences was worse than direct radiological consequences. Psychological effects do not correlate with real exposure but with perception of risk. The affected people believe in threat to their health, doubt what has been reported about accident and resulted doses, got modification in life style, have somatic complains, got substance abuse (alcohol, tranquilizers, sleeping pills). The lack of accurate information and misperception of real radiation risk is believed also to have lead to change in behavior of some affected people. Possible long-term health effect due to the accidental exposure remains an issue. There is no doubt that excess thyroid cancer incidence results from exposure to radioactive iodines, mainly by iodine-131. Radiation induced thyroid cancer could easily be prevented by timely warning, effective thyroid blocking, timely restriction of consumption for contaminated food. The

Chernobyl: lessons of the decade

International Nuclear Information System (INIS)

Tsaregorodtsev, A.D.

1996-01-01

The Chernobyl accident led to a drastic increase the incidents of thyroid cancer in children living at territories contaminated with radionuclides. The incidents of hemoblastoses which are etiologically closely related to radiation did not change after the incident. The lessons of the decade that passed since the accident necessitate measures aimed at alleviation of the medical consequences of the accident which are to be implemented for many years. The program of such measures should be based on a strictly scientific evaluation of each factor, that will be conductive to a most adequate state financing of this work [ru

Lessons learned from post-accident management at Chernobyl: the P.a.r.e.x. project; Retour d'experience sur la gestion post-accidentelle de Tchernobyl: le projet Parex

Energy Technology Data Exchange (ETDEWEB)

Heriard Dubreuil, G. [Mutadis Consultants, 75 - Paris (France); Lochard, J.; Bataille, C. [CEPN, 92 - Fontenay aux Roses (France); Ollagnon, H. [AgroParisTech, 75 - Paris (France); Baude, St. [Mutadis, 75 - Paris (France)

2008-07-15

Return of experience on Chernobyl post-accident management: the PAREX study Belarus is the country the most affected by the Chernobyl fallouts and is among the most significant experiences in the nuclear post-accident field. Despite specificities inherent to the political and social situation in Belarus, the experience of post-accidental management in this country holds a wealth of lessons in the perspective of preparation to a post-accidental situation in the French and European context. Through the PAREX project (2005-2006), the French Nuclear Safety Authority analysed the return of experience of Chernobyl post-accident management from 1986 to 2005 in order to draw its lessons in the perspective of a preparation policy. The study was led by a group of experts and involved the participation of a pluralistic group of about thirty participants (public authorities, local governments, NGOs, experts, operators). PAREX highlighted the complexity of a situation of long-lasting radioactive contamination (diversity of stakeholders and of dimensions at stake: health, environment, economy, society...). Beyond traditional public crisis management tools and frameworks, post-accident strategies also involves in the longer term a territorial and social response, which relies on local capacities of initiative. Preparation to such process requires experimenting new modes of operation that allow a diversity of local actors to take part to the response to a situation of contamination and to the surveillance system, with the support of public authorities. The conclusions of PAREX include a set of recommendations in this perspective. (authors)

Off-gas and air cleaning systems for accident conditions in nuclear power plants

International Nuclear Information System (INIS)

1993-01-01

This report surveys the design principles and strategies for mitigating the consequences of abnormal events in nuclear power plants by the use of air cleaning systems. Equipment intended for use in design basis accident and severe accident conditions is reviewed, with reference to designs used in IAEA Member States. 93 refs, 48 figs, 23 tabs

Lessons for PHWRs learned from the Chernobyl accident

International Nuclear Information System (INIS)

Waddington, J.G.; Molloy, T.J.

1996-01-01

The Atomic Energy Control Board of Canada examined its criteria for licensing nuclear power plants following the accident to the Chernobyl reactor in 1986. The causes of the accident were studied to ascertain whether they revealed any deficiencies in the safety of CANDU PHWRs. A report published in 1987 contained nine recommendations, and this paper revisits these to indicate how they were dealt with the plant owners and the regulatory authority

Lessons learned from EU stress tests evaluations with regard to external hazards

International Nuclear Information System (INIS)

Misak, J.

2014-01-01

The presentation was oriented to critical review of the lessons learned from the European Union (EU) Stress Test focusing on NPP robustness against external hazards. These lessons addressed: - organization of the stress tests, - scope and objectives of the stress tests, - peer review findings, recommendations and implications on the design in the area of external hazards, - further studies recommended in the area of external hazards and PSA, - relevant research areas identified by the SNETP Task Group in response to Fukushima accident. Some important conclusions were made in the final part of the presentation: - Vulnerability to the Fukushima Dai-ichi reactor accidents caused by external hazards and including their secondary effects was underestimated, - Lessons learned from Fukushima Dai-ichi reactor accidents, from the EU Stress Test and from peer reviews are to be reflected in safety improvements of operating plants and considered in new designs, - while no completely new phenomena were revealed from the Fukushima Dai-ichi reactor accidents, improvements in specific research areas (including external hazards and use of PSA) should be considered with high priority

Lessons learnt from clean-up of urban area after Chernobyl accident

International Nuclear Information System (INIS)

Zlobenko, Borys

2008-01-01

principles and criteria need detailed clarification. The specific aspect of this phase is the problem of social protection and social rehabilitation. The rehabilitation of the contaminated territories has been considered as a combination of measures directed at improvement of environmental conditions and the quality of life. While planning decontamination for the long term, it is important to take into account the contribution of external dose to the total (external and internal) dose. The materialization of the social aspect is a very important characteristic of this phase. Unfortunately, in spite of all the efforts, the negative consequences of the accident have not been completely overcome. Nevertheless, the data array that has been accumulated since the accident allows unbiased assessment of not only the errors but also the achievements of the stupendous work on minimization of the consequences of the accident and drawing conclusions important for the future. (author)

Retention of elemental 131I by activated carbons under accident conditions

International Nuclear Information System (INIS)

Deuber, H.

1984-09-01

Under simulated accident conditions (maximum temperature: 130 0 C) no significant difference was found in the retention of I-131 loaded as elemental iodine, by various fresh and aged commercial activated carbons. In all the cases, the I-131 passing through deep beds of activated carbon was in a non-elemental form. It is concluded that a minimum retention of 99.99% for elemental radioiodine, as required by the RSK guidelines for PWR accident filters, can be equally well achieved with various commercial activated carbons. (orig.) [de

Most likely failure location during severe accident conditions

International Nuclear Information System (INIS)

Rempe, J.L.; Allison, C.M.

1991-01-01

This paper describes preliminary results from which finite element calculation results are used in conjunction with analytical calculation results to predict failure in different LWR vessel designs during a severe accident. Detailed analyses are being performed to investigate the relative likelihood of a BWR vessel and drain line penetration to fail during a wide range of severe accident conditions. Analytically developed failure maps, which were developed in terms of dimensionless groups, are applied to consider geometries and materials occurring in other LWR vessel designs. Preliminary numerical analysis results indicate that if ceramic debris relocates within the BWR drain line to a distance below the lower head, the drain line will reach failure temperatures before the vessel fails. Application of failure maps for these debris conditions to other LWR geometries indicate that in-vessel tube melting will occur in either BWR or PWR vessel designs. Furthermore, if this melt is assumed to fill the entire penetration flow area, the melt is predicted to travel well below the lower head in any of the reference LWR penetrations. However, failure maps suggest the result that ex-vessel tube temperatures exceed the penetration's ultimate strength is specific to the BWR drain line because of its material composition and relatively large effective diameter for melt flow

Heat transport and afterheat removal for gas cooled reactors under accident conditions

International Nuclear Information System (INIS)

2001-01-01

The Co-ordinated Research Project (CRP) on Heat Transport and Afterheat Removal for Gas Cooled Reactors Under Accident Conditions was organized within the framework of the International Working Group on Gas Cooled Reactors (IWGGCR). This International Working Group serves as a forum for exchange of information on national programmes, provides advice to the IAEA on international co-operative activities in advanced technologies of gas cooled reactors (GCRs) and supports the conduct of these activities. Advanced GCR designs currently being developed are predicted to achieve a high degree of safety through reliance on inherent safety features. Such design features should permit the technical demonstration of exceptional public protection with significantly reduced emergency planning requirements. For advanced GCRs, this predicted high degree of safety largely derives from the ability of the ceramic coated fuel particles to retain the fission products under normal and accident conditions, the safe neutron physics behaviour of the core, the chemical stability of the core and the ability of the design to dissipate decay heat by natural heat transport mechanisms without reaching excessive temperatures. Prior to licensing and commercial deployment of advanced GCRs, these features must first be demonstrated under experimental conditions representing realistic reactor conditions, and the methods used to predict the performance of the fuel and reactor must be validated against these experimental data. Within this CRP, the participants addressed the inherent mechanisms for removal of decay heat from GCRs under accident conditions. The objective of this CRP was to establish sufficient experimental data at realistic conditions and validated analytical tools to confirm the predicted safe thermal response of advance gas cooled reactors during accidents. The scope includes experimental and analytical investigations of heat transport by natural convection conduction and thermal

Iodine behaviour under LWR accident conditions: Lessons learnt from analyses of the first two Phebus FP tests

International Nuclear Information System (INIS)

Girault, N.; Dickinson, S.; Funke, F.; Auvinen, A.; Herranz, L.; Krausmann, E.

2006-01-01

The International Phebus Fission Product programme, initiated in 1988 and performed by the French 'Institut de Radioprotection et de Surete Nucleaire' (IRSN), investigates through a series of in-pile integral experiments, key phenomena involved in light water reactor (LWR) severe accidents. The tests cover fuel rod degradation and the behaviour of fission products released via the primary coolant circuit into the containment building. The results of the first two tests, called FPT0 and Ftp, carried out under low pressure, in a steam rich atmosphere and using fresh fuel for Ftp and fuel burned in a reactor at 23 GWdt -1 for Ftp, were immensely challenging, especially with regard to the iodine radiochemistry. Some of the most important observed phenomena with regard to the chemistry of iodine were indeed neither predicted nor pre-calculated, which clearly shows the interest and the need for carrying out integral experiments to study the complex phenomena governing fission product behaviour in a PWR in accident conditions. The three most unexpected results in the iodine behaviour related to early detection during fuel degradation of a weak but significant fraction of volatile iodine in the containment, the key role played by silver rapidly binding iodine to form insoluble AgI in the containment sump and the importance of painted surfaces in the containment atmosphere for the formation of a large quantity of volatile organic iodides. To support the Phebus test interpretation small-scale analytical experiments and computer code analyses were carried out. The former, helping towards a better understanding of overall iodine behaviour, were used to develop or improve models while the latter mainly aimed at identifying relevant key phenomena and at modelling weaknesses. Specific efforts were devoted to exploring the potential origins of the early-detected volatile iodine in the containment building. If a clear explanation has not yet been found, the non-equilibrium chemical

Key risk indicators for accident assessment conditioned on pre-crash vehicle trajectory.

Science.gov (United States)

Shi, X; Wong, Y D; Li, M Z F; Chai, C

2018-08-01

Accident events are generally unexpected and occur rarely. Pre-accident risk assessment by surrogate indicators is an effective way to identify risk levels and thus boost accident prediction. Herein, the concept of Key Risk Indicator (KRI) is proposed, which assesses risk exposures using hybrid indicators. Seven metrics are shortlisted as the basic indicators in KRI, with evaluation in terms of risk behaviour, risk avoidance, and risk margin. A typical real-world chain-collision accident and its antecedent (pre-crash) road traffic movements are retrieved from surveillance video footage, and a grid remapping method is proposed for data extraction and coordinates transformation. To investigate the feasibility of each indicator in risk assessment, a temporal-spatial case-control is designed. By comparison, Time Integrated Time-to-collision (TIT) performs better in identifying pre-accident risk conditions; while Crash Potential Index (CPI) is helpful in further picking out the severest ones (the near-accident). Based on TIT and CPI, the expressions of KRIs are developed, which enable us to evaluate risk severity with three levels, as well as the likelihood. KRI-based risk assessment also reveals predictive insights about a potential accident, including at-risk vehicles, locations and time. Furthermore, straightforward thresholds are defined flexibly in KRIs, since the impact of different threshold values is found not to be very critical. For better validation, another independent real-world accident sample is examined, and the two results are in close agreement. Hierarchical indicators such as KRIs offer new insights about pre-accident risk exposures, which is helpful for accident assessment and prediction. Copyright © 2018 Elsevier Ltd. All rights reserved.

A radioactive waste transportation package monitoring system for normal transport and accident emergency response conditions

International Nuclear Information System (INIS)

Brown, G.S.; Cashwell, J.W.; Apple, M.L.

1993-01-01

This paper addresses spent fuel and high level waste transportation history and prospects, discusses accident histories of radioactive material transport, discusses emergency responder needs and provides a general description of the Transportation Intelligent Monitoring System (TRANSIMS) design. The key objectives of the monitoring system are twofold: (1) to facilitate effective emergency response to accidents involving a radioactive waste transportation package, while minimizing risk to the public and emergency first-response personnel, and (2) to allow remote monitoring of transportation vehicle and payload conditions to enable research into radioactive material transportation for normal and accident conditions. (J.P.N.)

Lessons for PHWRs learned from the Chernobyl accident

International Nuclear Information System (INIS)

Waddington, J.G.; Molloy, T.J.

1996-04-01

The Atomic Energy Control Board of Canada examined its criteria for licensing nuclear power plants following the accident to the Chernobyl reactor in 1986. The causes of the accident were studied to ascertain whether they revealed any deficiencies in the safety of CANDU PHWRs. A report published in 1987 contained nine recommendations, and this paper revisits these to indicate how they were dealt with by plant owners and the regulatory authority. (author)

The accident in Fukushima. Preliminary report on the accident progress in the nuclear power plants as a consequence of the earth quake on 11th March 2011; Der Unfall in Fukushima. Zwischenbericht zu den Ablaeufen in den Kernkraftwerken nach dem Erdbeben vom 11. Maerz 2011

Energy Technology Data Exchange (ETDEWEB)

Borghoff, Stefan; Brueck, Benjamin; Kilian-Huelsmeyer, Yvonne; Maqua, Michael; Mildenberger, Oliver; Quester, Claudia; Stahl, Thorsten; Thuma, Gernot; Wetzel, Norbert; Wild, Volker

2011-08-15

The preliminary report on the accident progress in the nuclear power plants as a consequence of the earth quake on 11th March 2011 describes the chronologic sequence of the accident in the different units of the power plant. The measures for mitigation of the accident impact at the site of Fukushima Daiichi and Fukushima Daini included the efforts to reach and maintain stable plant conditions. The issue radiological situation includes an estimation of the air-borne radionuclide release, the contamination of the environment and the sea water, measures for protection of the public. The lessons learned following the NISA and IAEA fact finding missions and the open questions are summarized.

Lessons learned from on-site safety assessments performed by DOE in response to the Tomsk accident

International Nuclear Information System (INIS)

Witmer, F.E.

1995-01-01

In response to the accident, in April 1993, at the nuclear fuel reprocessing plant of the Siberian chemical Combine, Tomsk, Russia, the U.S. Department of Energy (DOE) initiated concurrent efforts to understand the causes for the accident and to review potential vulnerabilities for similar occurrences across the DOE radiochemical complex. Because the accident occurred in the feed adjustment stage of a Purex type process, US facilities which contained significant inventories of TBP, organic diluent and nitric acid were evaluated by expert teams. From accident conditions, prior experience, modeling and experimental programs and confirmatory dialogue with the Russians, enhanced understanding was achieved and vulnerabilities (e.g., lack of safety analysis, organic layering, inadvertent acid addition, use of aromatic diluents, uncertain venting capability, no mitigative/emergency procedures, etc.) were identified and corrected

Introduction of the Space Shuttle Columbia Accident, Investigation Details, Findings and Crew Survival Investigation Report

Science.gov (United States)

Chandler, Michael

2010-01-01

As the Space Shuttle Program comes to an end, it is important that the lessons learned from the Columbia accident be captured and understood by those who will be developing future aerospace programs and supporting current programs. Aeromedical lessons learned from the Accident were presented at AsMA in 2005. This Panel will update that information, closeout the lessons learned, provide additional information on the accident and provide suggestions for the future. To set the stage, an overview of the accident is required. The Space Shuttle Columbia was returning to Earth with a crew of seven astronauts on 1Feb, 2003. It disintegrated along a track extending from California to Louisiana and observers along part of the track filmed the breakup of Columbia. Debris was recovered from Littlefield, Texas to Fort Polk, Louisiana, along a 567 statute mile track; the largest ever recorded debris field. The Columbia Accident Investigation Board (CAIB) concluded its investigation in August 2003, and released their findings in a report published in February 2004. NASA recognized the importance of capturing the lessons learned from the loss of Columbia and her crew and the Space Shuttle Program managers commissioned the Spacecraft Crew Survival Integrated Investigation Team (SCSIIT) to accomplish this. Their task was to perform a comprehensive analysis of the accident, focusing on factors and events affecting crew survival, and to develop recommendations for improving crew survival, including the design features, equipment, training and procedures intended to protect the crew. NASA released the Columbia Crew Survival Investigation Report in December 2008. Key personnel have been assembled to give you an overview of the Space Shuttle Columbia accident, the medical response, the medico-legal issues, the SCSIIT findings and recommendations and future NASA flight surgeon spacecraft accident response training. Educational Objectives: Set the stage for the Panel to address the

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)

MCCI study for Pressurized Heavy Water Reactor under hypothetical accident condition

International Nuclear Information System (INIS)

Verma, Vishnu; Mukhopadhyay, Deb; Chatterjee, B.; Singh, R.K.; Vaze, K.K.

2011-01-01

In case of severe core damage accident in Pressurized Heavy Water Reactor (PHWR), large amount of molten corium is expected to come out into the calandria vault due to failure of calandria vessel. Molten corium at high temperature is sufficient to decompose and ablate concrete. Such attack could fail CV by basement penetration. Since containment is ultimate barrier for activity release. The Molten Core Concrete Interaction (MCCI) of the resulting pool of debris with the concrete has been identified as an important part of the accident sequence. MCCI Analysis has been carried out for PHWR for a hypothetical accident condition where total core material is considered to be relocated in calandria vault. Concrete ablation rate in vertical and radial direction is evaluated for rectangular geometry using MEDICIS module of ASTEC Code. Amount of gases released during MCCI is also evaluated. (author)

Overview of Brazilian industrial radiography accidents with cutaneous radiation syndrome

International Nuclear Information System (INIS)

Lima, C.M.A.; Silva, F.C.A. da

2017-01-01

It is well documented that industrial radiography is related to radiological accidents, which makes it the highest potential risk for human health. More than 80 radiological accidents happened in the world that includes 6 Brazilian accidents with Cutaneous Radiation Syndrome. Five of them happened with 192 Ir and one with 60 Co radioactive sources. Nineteen members of the public and 8 radiographers were involved. All of them suffered severe hands and fingers injuries. The Brazilian radiological accident happened in 1985 with 16 persons is analyzed showing causes, consequences, radiation doses and lessons learned. (author)

Design Safety Considerations for Water Cooled Small Modular Reactors Incorporating Lessons Learned from the Fukushima Daiichi Accident

International Nuclear Information System (INIS)

2016-03-01

The global future deployment of advanced nuclear reactors for electricity generation depends primarily on the ability of nuclear industries, utilities and regulatory authorities to further enhance their reliability and economic competitiveness while satisfying stringent safety requirements. The IAEA has a project to help coordinate Member States efforts in the development and deployment of small and medium sized or small modular reactor (SMR) technology. This project aims simultaneously to facilitate SMR technology developers and potential SMR uses, particularly States embarking on a nuclear power programme, in identifying key enabling technologies and enhancing capacity building by resolving issues relevant to deployment, including nuclear reactor safety. The objective of this publication is to explore common practices for Member States, which will be an essential resource for future development and deployment of SMR technology. The accident at the Fukushima Daiichi nuclear power plant was caused by an unprecedented combination of natural events: a strong earthquake, beyond the design basis, followed by a series of tsunamis of heights exceeding the design basis tsunami considered in the flood analysis for the site. Consequently, all the operating nuclear power plants and advanced reactors under development, including SMRs, have been incorporating lessons learned from the accident to assure and enhance the performance of the engineered safety features in coping with such external events

Aging, condition monitoring, and loss-of-coolant accident (LOCA) tests of class 1E electrical cables

International Nuclear Information System (INIS)

Jacobus, M.J.

1992-11-01

This report describes the results of aging, condition monitoring, and accident testing of miscellaneous cable types. Three sets of cables were aged for up to 9 months under simultaneous thermal (≅100 degrees C) and radiation (≅0.10 kGy/hr) conditions. A sequential accident consisting of high dose rate irradiation (≅6 kGy/hr) and high temperature steam followed the aging. Also exposed to the accident conditions was a fourth set of cables, which were unaged. The test results indicate that, properly installed, most of the various miscellaneous cable products tested should be able to survive an accident after 60 years for total aging doses of at least 150 kGy or higher (depending on the material) and for moderate ambient temperatures on the order of 45--55 degrees C (potentially higher or lower, depending on material specific activtion energies and total radiation doses). Mechanical measurements (primarily elongation, modulus, and density) were more effective than electrical measurements for monitoring age-related degradation

Beyond Design Basis Severe Accident Management as an Element of DiD Concept Strengthening

Energy Technology Data Exchange (ETDEWEB)

Kuznetsov, M., E-mail: kuznetsov_mv@vosafety.ru [FSUE VO “Safety”, Moscow (Russian Federation)

2014-10-15

The 4{sup th} Level of DiD is ensured by management of beyond design basis accidents which is achieved by implementation of the Beyond Design Basis Accidents Management Guidance (BDBAMG) and, if necessary, by additional technical devices and organizational measures at NPP Unit. BDBAMG is located between Levels 3 and 5 in DiD and is related to them. It is connected with Level 3 by means of conditions generated at this Level and according to which BDBAM should be initiated (Level 4). It is associated with Level 5 by conditions which necessitate implementation of Emergency planning. Both types of conditions should be identified in BDBAMG. BDBAs including the phase of severe damage of fuel and protective barriers (severe accidents) in accordance with Russian regulatory framework are a subset of all BDBAs set. In this connection, such accident scenarios meet the representativeness criterion for further analysis and development of Guidance for their management. BDBAMG availability, as it provides robustness of DiD as a whole, is an obligatory condition for obtaining a NPP operational license. In the process of BDBAMG development and implementation a feedback with technical and organizational measures, comprising Level 1 and, to a less extent, Level 2, comes up. BDBAMG verification is an important final stage of its development. Addressing severe accidents, it is a challenging issue for a full scope simulator and may require its software modernization to make it responsive to severe accident phenomena. The existing BDBAMGs should be updated due to NPP Unit modernizations and in conjunction with the latest knowledge on severe accident phenomenology and lessons learnt from known events (e.g. NPP Fukushima). Thus, improvements incorporated in BDBAMG, enhance the strength of DiD. (author)

The lessons drawn from accident simulation, consequences for the operation of the Crisis Technical Center of the Nuclear Safety and Protection Institut

International Nuclear Information System (INIS)

Manesse, D.; Ney, J.; Crabol, B.; Ginot, P.

1989-07-01

The aim of the work is to summarize the lessons drawn from planning and performing the nuclear accident simulation exercises. The analysis is focused on the simulation and foresight of the radiation effects. The simulation exercises allowed a progressive improvement of the technical survey organization, leading to an improvement of its availability to the authorities. The subjects which need to be taken into account are those related to the intervention actions, in order to obtain realistic situations, the actions related to public organizations, people and communication networks [fr

Failure Mode Estimation of Wolsong Unit 1 Containment Building with respect to Severe Accident Condition

International Nuclear Information System (INIS)

Hahm, Dae Gi; Choi, In Kil

2009-01-01

The containment buildings in a nuclear power plant (NPP) are final barriers against the exposure of harmful radiation materials at severe accident condition. Since the accident at Three Mile Island nuclear plant in 1979, it has become necessary to evaluate the internal pressure capacity of the containment buildings for the assessment of the safety of nuclear power plants. According to this necessity, many researchers including Yonezawa et al. and Hu and Lin analyzed the ultimate capacity of prestressed concrete containments subjected to internal pressure which can be occurred at sever accident condition. Especially in Wolsong nuclear power plant, the Unit 1 containment structures were constructed in the late 1970 to early 1980, so that the end of its service life will be reached in near future. Since that the complete decommission and reconstruction of the NPP may cause a huge expenses, an extension of the service time can be a cost-effective alternative. To extend the service time of NPP, an overall safety evaluation of the containment building under severe accident condition should be performed. In this study, we assessed the pressure capacity of Wolsong Unit 1 containment building under severe accident, and estimated the responses at all of the probable critical areas. Based on those results, we found the significant failure modes of Wolsong Unit 1 containment building with respect to the severe accident condition. On the other hand, for the aged NPP, the degradation of their structural performance must also be explained in the procedure of the internal pressure capacity evaluation. Therefore, in this study, we performed a parametric study on the degradation effects and evaluated the internal pressure capacity of Wolsong Unit 1 containment building with considering aging and degradation effects

Some conditions affecting the definition of design basis accidents relating to sodium/water reactions

International Nuclear Information System (INIS)

Bolt, P.R.

1984-01-01

The possible damaging effects of large sodium/water reactions on the steam generator, IHX and secondary circuit are considered. The conditions to be considered in defining the design basis accidents for these components are discussed, together with some of the assumptions that may be associated with design assessments of the scale of the accidents. (author)

Post-Fukushima lessons and safety orientations for ASTRID

International Nuclear Information System (INIS)

Carluec, B.; Sauvage, J.F.; Pariteau, Patrick; Lo Pinto, P.

2013-01-01

Lessons learned from the Fukushima accident: → Reinforcement of demonstrations of “practical elimination” of situations leading to important radiological releases in the environment. → Reinforcement of consideration of loss of some supplies, the objective is to prevent severe accident: • Loss of all AC power; • Loss of I&C; • Failure of operator action. → Reinforcement of the capability to prevent severe accident by natural behavior: • Favorable neutronic feedback effects; • Natural circulation capability to remove the decay heat

Potential behavior of depleted uranium penetrators under shipping and bulk storage accident conditions

Energy Technology Data Exchange (ETDEWEB)

Mishima, J.; Parkhurst, M.A.; Scherpelz, R.I.

1985-03-01

An investigation of the potential hazard from airborne releases of depleted uranium (DU) from the Army's M829 munitions was conducted at the Pacific Northwest Laboratory. The study included: (1) assessing the characteristics of DU oxide from an April 1983 burn test, (2) postulating conditions of specific accident situations, and (3) reviewing laboratory and theoretical studies of oxidation and airborne transport of DU from accidents. Results of the experimental measurements of the DU oxides were combined with atmospheric transport models and lung and kidney exposure data to help establish reasonable exclusion boundaries to protect personnel and the public at an accident site. 121 references, 44 figures, 30 tables.

Accident Prevention: A Workers' Education Manual.

Science.gov (United States)

International Labour Office, Geneva (Switzerland).

Devoted to providing industrial workers with a greater knowledge of precautionary measures undertaken and enforced by industries for the protection of workers, this safety education manual contains 14 lessons ranging from "The Problems of Accidents during Work" to "Trade Unions and Workers and Industrial Safety." Fire protection, safety equipment…

The radiological accident in Cochabamba

International Nuclear Information System (INIS)

2004-07-01

In April 2002 an accident involving an industrial radiography source containing 192 Ir occurred in Cochabamba, Bolivia, some 400 km from the capital, La Paz. A faulty radiography source container had been sent back to the headquarters of the company concerned in La Paz together with other equipment as cargo on a passenger bus. This gave rise to a potential for serious exposure for the bus passengers as well as for the company employees who were using and transporting the source. The Government of Bolivia requested the assistance of the IAEA under the terms of the Convention on Assistance in the Case of a Nuclear Accident or Radiological Emergency. The IAEA in response assembled and sent to Bolivia a team composed of senior radiation safety experts and radiation pathology experts from Brazil, the United Kingdom and the IAEA to investigate the accident. The IAEA is grateful to the Government of Bolivia for the opportunity to report on this accident in order to disseminate the valuable lessons learned and help prevent similar accidents in the future

Preliminary safety analysis of the PWR with accident-tolerant fuels during severe accident conditions

International Nuclear Information System (INIS)

Wu, Xiaoli; Li, Wei; Wang, Yang; Zhang, Yapei; Tian, Wenxi; Su, Guanghui; Qiu, Suizheng; Liu, Tong; Deng, Yongjun; Huang, Heng

2015-01-01

Highlights: • Analysis of severe accident scenarios for a PWR fueled with ATF system is performed. • A large-break LOCA without ECCS is analyzed for the PWR fueled with ATF system. • Extended SBO cases are discussed for the PWR fueled with ATF system. • The accident-tolerance of ATF system for application in PWR is illustrated. - Abstract: Experience gained in decades of nuclear safety research and previous nuclear accidents direct to the investigation of passive safety system design and accident-tolerant fuel (ATF) system which is now becoming a hot research point in the nuclear energy field. The ATF system is aimed at upgrading safety characteristics of the nuclear fuel and cladding in a reactor core where active cooling has been lost, and is preferable or comparable to the current UO 2 –Zr system when the reactor is in normal operation. By virtue of advanced materials with improved properties, the ATF system will obviously slow down the progression of accidents, allowing wider margin of time for the mitigation measures to work. Specifically, the simulation and analysis of a large break loss of coolant accident (LBLOCA) without ECCS and extended station blackout (SBO) severe accident are performed for a pressurized water reactor (PWR) loaded with ATF candidates, to reflect the accident-tolerance of ATF

Societal and ethical aspects of the Fukushima accident.

Science.gov (United States)

Oughton, Deborah

2016-10-01

The Fukushima Nuclear Power Station accident in Japan in 2011 was a poignant reminder that radioactive contamination of the environment has consequences that encompass far more than health risks from exposure to radiation. Both the accident and remediation measures have resulted in serious societal impacts and raise questions about the ethical aspects of risk management. This article presents a brief review of some of these issues and compares similarities and differences with the lessons learned from the 1986 Chernobyl Nuclear Power Plant accident in Ukraine. Integr Environ Assess Manag 2016;12:651-653. © 2016 SETAC. © 2016 SETAC.

Dynamics Modeling and Simulation of Large Transport Airplanes in Upset Conditions

Science.gov (United States)

Foster, John V.; Cunningham, Kevin; Fremaux, Charles M.; Shah, Gautam H.; Stewart, Eric C.; Rivers, Robert A.; Wilborn, James E.; Gato, William

2005-01-01

As part of NASA's Aviation Safety and Security Program, research has been in progress to develop aerodynamic modeling methods for simulations that accurately predict the flight dynamics characteristics of large transport airplanes in upset conditions. The motivation for this research stems from the recognition that simulation is a vital tool for addressing loss-of-control accidents, including applications to pilot training, accident reconstruction, and advanced control system analysis. The ultimate goal of this effort is to contribute to the reduction of the fatal accident rate due to loss-of-control. Research activities have involved accident analyses, wind tunnel testing, and piloted simulation. Results have shown that significant improvements in simulation fidelity for upset conditions, compared to current training simulations, can be achieved using state-of-the-art wind tunnel testing and aerodynamic modeling methods. This paper provides a summary of research completed to date and includes discussion on key technical results, lessons learned, and future research needs.

Spent fuel transport cask thermal evaluation under normal and accident conditions

Energy Technology Data Exchange (ETDEWEB)

Pugliese, G. [Department of Mechanical, Nuclear and Production Engineering, University of Pisa, Via Diotisalvi, no 2-56126 Pisa (Italy); Lo Frano, R., E-mail: rosa.lofrano@ing.unipi.i [Department of Mechanical, Nuclear and Production Engineering, University of Pisa, Via Diotisalvi, no 2-56126 Pisa (Italy); Forasassi, G. [Department of Mechanical, Nuclear and Production Engineering, University of Pisa, Via Diotisalvi, no 2-56126 Pisa (Italy)

2010-06-15

The casks used for transport of nuclear materials, especially the spent fuel element (SPE), must be designed according to rigorous acceptance criteria and standards requirements, e.g. the International Atomic Energy Agency ones, in order to provide protection to people and environment against radiation exposure particularly in a severe accident scenario. The aim of this work was the evaluation of the integrity of a spent fuel cask under both normal and accident scenarios transport conditions, such as impact and rigorous fire events, in according to the IAEA accident test requirements. The thermal behaviour and the temperatures distribution of a Light Water Reactor (LWR) spent fuel transport cask are presented in this paper, especially with reference to the Italian cask designed by AGN, which was characterized by a cylindrical body, with water or air inside the internal cavity, and two lateral shock absorbers. Using the finite element code ANSYS a series of thermal analyses (steady-state and transient thermal analyses) were carried out in order to obtain the maximum fuel temperature and the temperatures field in the body of the cask, both in normal and in accidents scenario, considering all the heat transfer modes between the cask and the external environment (fire in the test or air in the normal conditions) as well as inside the cask itself. In order to follow the standards requirements, the thermal analyses in accidents scenarios were also performed adopting a deformed shape of the shock absorbers to simulate the mechanical effects of a previous IAEA 9 m drop test event. Impact tests on scale models of the shock absorbers have already been conducted in the past at the Department of Mechanical, Nuclear and Production Engineering, University of Pisa, in the '80s. The obtained results, used for possible new licensing approval purposes by the Italian competent Authority of the cask for PWR spent fuel cask transport by the Italian competent Authority, are

Severe accident tests and development of domestic severe accident system codes

Energy Technology Data Exchange (ETDEWEB)

NONE

2013-08-15

According to lessons learned from Fukushima-Daiichi NPS accidents, the safety evaluation will be started based on the NRA's New Safety Standards. In parallel with this movement, reinforcement of Severe Accident (SA) Measures and Accident Managements (AMs) has been undertaken and establishments of relevant regulations and standards are recognized as urgent subjects. Strengthening responses against nuclear plant hazards, as well as realistic protection measures and their standardization is also recognized as urgent subjects. Furthermore, decommissioning of Fukushima-Daiichi Unit1 through Unit4 is promoted diligently. Taking into account JNES's mission with regard to these SA Measures, AMs and decommissioning, movement of improving SA evaluation methodologies inside and outside Japan, and prioritization of subjects based on analyses of sequences of Fukushima-Daiichi NPS accidents, three viewpoints was extracted. These viewpoints were substantiated as the following three groups of R and D subjects: (1) Obtaining near term experimental subjects: Containment venting, Seawater injection, Iodine behaviors. (2) Obtaining mid and long experimental subjects: Fuel damage behavior at early phase of core degradation, Core melting and debris formation. (3) Development of a macroscopic level SA code for plant system behaviors and a mechanistic level code for core melting and debris formation. (author)

Severe accident tests and development of domestic severe accident system codes

International Nuclear Information System (INIS)

2013-01-01

According to lessons learned from Fukushima-Daiichi NPS accidents, the safety evaluation will be started based on the NRA's New Safety Standards. In parallel with this movement, reinforcement of Severe Accident (SA) Measures and Accident Managements (AMs) has been undertaken and establishments of relevant regulations and standards are recognized as urgent subjects. Strengthening responses against nuclear plant hazards, as well as realistic protection measures and their standardization is also recognized as urgent subjects. Furthermore, decommissioning of Fukushima-Daiichi Unit1 through Unit4 is promoted diligently. Taking into account JNES's mission with regard to these SA Measures, AMs and decommissioning, movement of improving SA evaluation methodologies inside and outside Japan, and prioritization of subjects based on analyses of sequences of Fukushima-Daiichi NPS accidents, three viewpoints was extracted. These viewpoints were substantiated as the following three groups of R and D subjects: (1) Obtaining near term experimental subjects: Containment venting, Seawater injection, Iodine behaviors. (2) Obtaining mid and long experimental subjects: Fuel damage behavior at early phase of core degradation, Core melting and debris formation. (3) Development of a macroscopic level SA code for plant system behaviors and a mechanistic level code for core melting and debris formation. (author)

Lessons learned from major accidents relating to ageing of chemical plants

OpenAIRE

GYENES ZSUZSANNA; WOOD Maureen

2016-01-01

Major industrial accidents that occurred in the past and even recently, such as the Flixborough, UK in 1974, the ConocoPhillips, UK in 2001 and the Chevron, US in 2012 show that ageing is still a disturbing phenomenon present in chemical process industries. Further to these cases, it is estimated that 30 % of the major accidents reported in the eMARS accident database run by the Major Accident Hazards Bureau of the European Commission are connected to at least one ageing phenomenon. It is som...

Overview of Brazilian industrial radiography accidents with cutaneous radiation syndrome

Energy Technology Data Exchange (ETDEWEB)

Lima, C.M.A.; Silva, F.C.A. da, E-mail: dasilva@ird.gov.br [Instituto de Radioproteção e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

2017-07-01

It is well documented that industrial radiography is related to radiological accidents, which makes it the highest potential risk for human health. More than 80 radiological accidents happened in the world that includes 6 Brazilian accidents with Cutaneous Radiation Syndrome. Five of them happened with {sup 192}Ir and one with {sup 60}Co radioactive sources. Nineteen members of the public and 8 radiographers were involved. All of them suffered severe hands and fingers injuries. The Brazilian radiological accident happened in 1985 with 16 persons is analyzed showing causes, consequences, radiation doses and lessons learned. (author)

Behaviour of organic iodides under pwr accident conditions

International Nuclear Information System (INIS)

Alm, M.

1982-01-01

Laboratory experiments were performed to study the behaviour of radioactive methyl iodide under PWR loss-of-coolant conditions. The pressure relief equipment consisted of an autoclave for simulating the primary circuit and of an expansion vessel for simulating the conditions after a rupture in the reactor coolant system. After pressure relief, the composition of the CH 3 sup(127/131)I-containing steam-air mixture within the expansion vessel was analysed at 80 0 C over a period of 42 days. On the basis of the values measured and of data taken from the literature, both qualitative and quantitative assessments have been made as to the behaviour of radioactive methyl iodide in the event of loss-of-coolant accidents. (author)

Lessons learned and evaluation of the impact from the Chernobyl accident

International Nuclear Information System (INIS)

Cigna, A.

1990-07-01

The impact on society of the Chernobyl accident is assessed. The situation prior to Chernobyl with respect to regulations of radiation protection against the consequences of a major accident is considered. The development of the recommendations and regulations issued by the CEC for the Maximum Permitted Levels of different reactions to the accident are examined and some data on the average individual effective dose equivalents estimated in a number of countries are reported. Finally some main problems concerning the information of the public and the preparedness for possible future accidents are also summarized. (author)

Lessons learned and evaluation of the impact from the Chernobyl accident

Energy Technology Data Exchange (ETDEWEB)

Cigna, A [ENEA - Area Energia, Ambiente e Salute, Centro Ricerche Energia, Saluggia, Vercelli (Italy)

1990-07-15

The impact on society of the Chernobyl accident is assessed. The situation prior to Chernobyl with respect to regulations of radiation protection against the consequences of a major accident is considered. The development of the recommendations and regulations issued by the CEC for the Maximum Permitted Levels of different reactions to the accident are examined and some data on the average individual effective dose equivalents estimated in a number of countries are reported. Finally some main problems concerning the information of the public and the preparedness for possible future accidents are also summarized. (author)

U. S. Department of energy actions to ensure nuclear safety at its nuclear facilities in response to lessons being learned from the Fukushima dacha accident

Energy Technology Data Exchange (ETDEWEB)

Chung, Dae; O' Brien, James [U. S. Department of Energy, Washington (United States)

2012-03-15

The U. S. Department of Energy (DOE) has established a rigorous nuclear safety regulatory infrastructure for the protection of workers, the public, and the environment. An essential part of this infrastructure is a safety culture that promotes organizational learning and includes a commitment to safety by senior leaders that is demonstrated through their actions and behaviors. The tragic Fukushima Dacha accident presented an important challenge for DOE leaders to demonstrate a robust safety culture by critically examining the Department' s regulatory infrastructure and its implementation to ensure that appropriate safety provisions were in place. This paper discusses the actions DOE has taken to date in this regard and further planned action to ensure safety at DOE facilities in light of lessons being learned from the Fukushima Dacha accident.

U. S. Department of energy actions to ensure nuclear safety at its nuclear facilities in response to lessons being learned from the Fukushima dacha accident

International Nuclear Information System (INIS)

Chung, Dae; O'Brien, James

2012-01-01

The U. S. Department of Energy (DOE) has established a rigorous nuclear safety regulatory infrastructure for the protection of workers, the public, and the environment. An essential part of this infrastructure is a safety culture that promotes organizational learning and includes a commitment to safety by senior leaders that is demonstrated through their actions and behaviors. The tragic Fukushima Dacha accident presented an important challenge for DOE leaders to demonstrate a robust safety culture by critically examining the Department' s regulatory infrastructure and its implementation to ensure that appropriate safety provisions were in place. This paper discusses the actions DOE has taken to date in this regard and further planned action to ensure safety at DOE facilities in light of lessons being learned from the Fukushima Dacha accident

Sharing Lessons Learned Between Industries in EU

International Nuclear Information System (INIS)

Muehleisen, A.; Strucic, M.

2012-01-01

Recent events in nuclear industry remind us on importance of continuous sharing of the knowledge and experience gained through evaluations of incidents and accidents. We frequently use experience from our daily life activities to improve our performance and avoid some mistakes or unwanted events. In the similar way we can use other industries experience. These experiences can be applied to improve nuclear safety. For example, Safety Culture, which has a great influence on the level of nuclear power plants safety, is similarly presented in other industries. Mechanisms which led to accidents from weak safety culture in one branch of other industry could be comparable to those in nuclear industry. Some other industries have many more cumulative years of experience than nuclear industry. Aviation and Oil industries are typical representatives. Part of their experience can be used in nuclear industry too. Number of reports from nuclear power plants showed us that not only specific equipment related causes lay behind accidents; there are also other causes and contributors which are more common for all industries. Hence lessons learned in other industry should be assessed and used in nuclear industry too. In the European Union, a regional initiative has been set up in 2008 in support of EU Member State nuclear safety authorities, but also EU technical support organizations, international organizations and the broader nuclear community, to enhance nuclear safety through improvement of the use of lessons learned from operational experience of nuclear power plants (NPPs). The initiative, called ''the EU Clearinghouse on Operational Experience Feedback for NPP'', is organized as a network operated by a centralized office located at the Joint Research Centre of the European Commission. The reduction of occurrence and significance of events in NPPs and their safe operation is its ultimate goal. Among others EU Clearinghouse provides services such as technical and scientific

Structural aspects of the Chernobyl accident

International Nuclear Information System (INIS)

Murray, R.C.; Cummings, G.E.

1988-01-01

On April 26, 1986 the world's worst nuclear power plant accident occurred at the Unit 4 of the Chernobyl Nuclear Power Station in the USSR. This paper presents a discussion of the design of the Chernobyl Power Plant, the sequence of events that led to the accident and the damage caused by the resulting explosion. The structural design features that contributed to the accident and resulting damage will be highlighted. Photographs and sketches obtained from various worldwide news agencies will be shown to try and gain a perspective of the extent of the damage. The aftermath, clean-up, and current situation will be discussed and the important lessons learned for the structural engineer will be presented. 15 refs., 10 figs

Reperes, the information magazine of the Institute for Radiation Protection and Nuclear Safety - IRSN, No. 12 - January 2012, Special issue Fukushima - First lessons from the accident

International Nuclear Information System (INIS)

2012-01-01

A first set of articles addresses the nuclear crisis in Japan (description of the accident, information mission sent by France, and support actions undertaken by France in Japan in the fields of education, civilian security, culture, sailing, media, dosimeters, robotics). A second set discusses lessons learned in terms of nuclear safety (complementary safety assessments, stress test in Gravelines), radiological consequences (impact on Japanese population, the Symbiose software, the Teleray network), crisis management, and research

Interaction of radionuclides in severe accident conditions

International Nuclear Information System (INIS)

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

2015-01-01

Nuclear power plants are designed with inherent engineering safety systems and associated operational procedures that provide an in-depth defence against accidents. Radionuclides such as Iodine, Cesium, Tellurium, Barium, Strontium, Rubidium, Molybdenum and many others may get released during a severe accident. Among these, Iodine, one of the fission products, behaviour is significant for the analysis of severe accident consequences because iodine is a chemically more active to the potential components released to the environment. During severe accident, Iodine is released and transported in aqueous, organic and inorganic forms. Iodine release from fuel, iodine transport in primary coolant system, containment, and reaction with control rods are some of the important phases in a severe accident scenario. The behaviour of iodine is governed by aerosol physics, depletion mechanisms gravitational settling, diffusiophoresis and thermophoresis. The presence of gaseous organic compounds and oxidizing compounds on iodine, reactions of aerosol iodine with boron and formation of cesium iodide which results in more volatile iodine release in containment play significant roles. Water radiolysis products due to presence of dissolved impurities, chloride ions, organic impurities should be considered while calculating iodine release. Containment filtered venting system (CFVS) consists of venturi scrubber and a scrubber tank which is dosed with NaOH and NaS_2O_3 in water where iodine will react with the chemicals and convert into NaI and Na_2SO_4. This paper elaborates the issues with respect to interaction of radionuclides and its consideration in modeling of severe accident. (author)

Determination of Optimal Flow Paths for Safety Injection According to Accident Conditions

Energy Technology Data Exchange (ETDEWEB)

Yoo, Kwae Hwan; Kim, Ju Hyun; Kim, Dong Yeong; Na, Man Gyun [Chosun Univ., Gwangju (Korea, Republic of); Hur, Seop; Kim, Changhwoi [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2014-05-15

In case severe accidents happen, major safety parameters of nuclear reactors are rapidly changed. Therefore, operators are unable to respond appropriately. This situation causes the human error of operators that led to serious accidents at Chernobyl. In this study, we aimed to develop an algorithm that can be used to select the optimal flow path for cold shutdown in serious accidents, and to recover an NPP quickly and efficiently from the severe accidents. In order to select the optimal flow path, we applied a Dijkstra algorithm. The Dijkstra algorithm is used to find the path of minimum total length between two given nodes and needs a weight (or length) matrix. In this study, the weight between nodes was calculated from frictional and minor losses inside pipes. That is, the optimal flow path is found so that the pressure drop between a starting node (water source) and a destination node (position that cooling water is injected) is minimized. In case a severe accident has happened, if we inject cooling water through the optimized flow path, then the nuclear reactor will be safely and effectively returned into the cold shutdown state. In this study, we have analyzed the optimal flow paths for safety injection as a preliminary study for developing an accident recovery system. After analyzing the optimal flow path using the Dijkstra algorithm, and the optimal flow paths were selected by calculating the head loss according to path conditions.

Introduction of the U.S. Nuclear Regulatory Commission's Activities to Reflect Lessons Learned from Fukushima Nuclear Accident

Energy Technology Data Exchange (ETDEWEB)

Kim, Jongtae; Hong, Seong-Wan [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Kim, Gun Hong [Kyungwon E-C Co., Seongnam (Korea, Republic of)

2014-10-15

The Charter requires the staff to highlight potential policy issues for the Commission and provide the Commission every 6 months an update on the review work conducted under the Charter. The recent status of NRC's activities and related program to reflect the lesson-learned from the Fukushima Daiichi nuclear power plant's severe accident are introduced in this paper. A wide variety of the U.S. NRC's activities to reflect lessons learned from the Fukushima nuclear accidents was investigated. From the investigation, it was found that most of NRC's activities, based on the Fukushima Near-Term Task Force (NTTF) recommendations, are being implemented in a comprehensive and systematic manner. The NRC staff initially prioritized the NTTF recommendations based on its judgment of the potential and relative safety enhancement which could be realized by each. As a result of the staff's prioritization and assessment process, the NTTF recommendations were prioritized into three tiers (i.e., Tier 1, 2 and 3). Tier 1 recommendations are which the staff determined should be started without unnecessary delay and for which sufficient resource flexibility, including availability of critical skill sets, exists. Tier 2 recommendations are which could not be initiated in the near term due to factors that include the need for further technical assessment and alignment, dependence on Tier 1 issues, or availability of critical skill sets. Tier 3 recommendations are that require further staff study to support a regulatory action, have an associated shorter term action that needs to be completed to inform the longer-term action, are dependent on the availability of critical skill sets, or are dependent on the resolution of NTTF Recommendation 1. Through the implementation of each tier activities, existing layers of defense in depth are expected to be gradually bolstered, and such a regulatory approach is much similar in the other countries. It was also found that

Introduction of the U.S. Nuclear Regulatory Commission's Activities to Reflect Lessons Learned from Fukushima Nuclear Accident

International Nuclear Information System (INIS)

Kim, Jongtae; Hong, Seong-Wan; Kim, Gun Hong

2014-01-01

The Charter requires the staff to highlight potential policy issues for the Commission and provide the Commission every 6 months an update on the review work conducted under the Charter. The recent status of NRC's activities and related program to reflect the lesson-learned from the Fukushima Daiichi nuclear power plant's severe accident are introduced in this paper. A wide variety of the U.S. NRC's activities to reflect lessons learned from the Fukushima nuclear accidents was investigated. From the investigation, it was found that most of NRC's activities, based on the Fukushima Near-Term Task Force (NTTF) recommendations, are being implemented in a comprehensive and systematic manner. The NRC staff initially prioritized the NTTF recommendations based on its judgment of the potential and relative safety enhancement which could be realized by each. As a result of the staff's prioritization and assessment process, the NTTF recommendations were prioritized into three tiers (i.e., Tier 1, 2 and 3). Tier 1 recommendations are which the staff determined should be started without unnecessary delay and for which sufficient resource flexibility, including availability of critical skill sets, exists. Tier 2 recommendations are which could not be initiated in the near term due to factors that include the need for further technical assessment and alignment, dependence on Tier 1 issues, or availability of critical skill sets. Tier 3 recommendations are that require further staff study to support a regulatory action, have an associated shorter term action that needs to be completed to inform the longer-term action, are dependent on the availability of critical skill sets, or are dependent on the resolution of NTTF Recommendation 1. Through the implementation of each tier activities, existing layers of defense in depth are expected to be gradually bolstered, and such a regulatory approach is much similar in the other countries. It was also found that

Safety Enhancements for PHWRs Based on Macroscopic Losses of the Fukushima Accident

Directory of Open Access Journals (Sweden)

Sang Ho Kim

2015-01-01

Full Text Available The role of nuclear energy is to supply electric power on a stable basis to meet increasing demands, reduce carbon dioxide emissions, and maintain stable electric power costs while ensuring safety. The Fukushima accident taught us many lessons for creating safer nuclear power plants. Considering the design of systems, the areas of weakness at the Fukushima nuclear power plants can be divided into three categories: plant protection, electricity supply, and cooling of the nuclear fuel. In this paper, focusing on these three areas, the lessons learned are proposed and applied for pressurized heavy water reactors. Firstly, hard protection against external risks ensures the integrity of components and systems such that they can perform their original functions. Secondly, additional emergency power supply systems for electrical redundancy and diversity can improve the response capabilities for an accident by increasing the availability of active components. Thirdly, cooling for removing decay heat can be augmented by adopting diverse safety systems derived from other types of reactors. This study is expected to contribute to the safety enhancement of pressurized heavy water reactors by applying design changes based on the lessons learned from the Fukushima accident.

Noble gas control room accident filtration system for severe accident conditions N-CRAFT. System design

International Nuclear Information System (INIS)

Hill, Axel

2014-01-01

Severe accidents might cause the release of airborne radioactive substances to the environment of the NPP. This can either be due to leakages of the containment or due to a filtered containment venting in order to ensure the overall integrity of the containment. During the containment venting process aerosols and iodine can be retained by the FCVS which prevents long term ground contamination. Noble gases are not retainable by the FCVS. From this it follows that a large amount of radioactive noble gases (e.g. xenon, krypton) might be present in the nearby environment of the plant dominating the activity release, depending on the venting procedure and the weather conditions. Accident management measures are necessary in case of severe accidents and the prolonged stay of staff inside the main control room (MCR) or emergency response center (ERC) is essential. Therefore, the in leakage and contamination of the MRC and ERC with airborne activity has to be prevented. The radiation exposure of the crises team needs to be minimized. The entrance of noble gases cannot be sufficiently prevented by the conventional air filtration systems such as HEPA filters and iodine absorbers. With the objective to prevent an unacceptable contamination of the MCR/ERC atmosphere by noble gases AREVA GmbH has developed a noble gas retention system. The noble gas control room accident filtration system CRAFT is designed for this case and provides supply of fresh air to the MCR/ERC without time limitation. The retention process of the system is based on the dynamic adsorption of noble gases on activated carbon. The system consists of delay lines (carbon columns) which are operated by a continuous and simultaneous adsorption and desorption process. These cycles ensure a periodic load and flushing of the delay lines retaining the noble gases from entering the MCR. CRAFT allows a minimization of the dose rate inside MCR/ERC and ensures a low radiation exposure to the staff on shift maintaining

Development of stable walking robot for accident condition monitoring on uneven floors in a nuclear power plant

Energy Technology Data Exchange (ETDEWEB)

Kim, Jong Seog; Jang, You Hyun [Central Research Institute of Korea Hydro and Nuclear Power Company, Daejeon (Korea, Republic of)

2017-04-15

Even though the potential for an accident in nuclear power plants is very low, multiple emergency plans are necessary because the impact of such an accident to the public is enormous. One of these emergency plans involves a robotic system for investigating accidents under conditions of high radiation and contaminated air. To develop a robot suitable for operation in a nuclear power plant, we focused on eliminating the three major obstacles that challenge robots in such conditions: the disconnection of radio communication, falling on uneven floors, and loss of localization. To solve the radio problem, a Wi-Fi extender was used in radio shadow areas. To reinforce the walking, we developed two- and four-leg convertible walking, a floor adaptive foot, a roly-poly defensive falling design, and automatic standing recovery after falling methods were developed. To allow the robot to determine its location in the containment building, a bar code landmark reading method was chosen. When a severe accident occurs, this robot will be useful for accident condition monitoring. We also anticipate the robot can serve as a workman aid in a high radiation area during normal operations.

Thirty years after the Chernobyl accident: What lessons have we learnt?

International Nuclear Information System (INIS)

Beresford, N.A.; Fesenko, S.; Konoplev, A.; Skuterud, L.; Smith, J.T.; Voigt, G.

2016-01-01

April 2016 sees the 30 th anniversary of the accident at the Chernobyl nuclear power plant. As a consequence of the accident populations were relocated in Belarus, Russia and Ukraine and remedial measures were put in place to reduce the entry of contaminants (primarily 134+137 Cs) into the human food chain in a number of countries throughout Europe. Remedial measures are still today in place in a number of countries, and areas of the former Soviet Union remain abandoned. The Chernobyl accident led to a large resurgence in radioecological studies both to aid remediation and to be able to make future predictions on the post-accident situation, but, also in recognition that more knowledge was required to cope with future accidents. In this paper we discuss, what in the authors' opinions, were the advances made in radioecology as a consequence of the Chernobyl accident. The areas we identified as being significantly advanced following Chernobyl were: the importance of semi-natural ecosystems in human dose formation; the characterisation and environmental behaviour of ‘hot particles'; the development and application of countermeasures; the “fixation” and long term bioavailability of radiocaesium and; the effects of radiation on plants and animals. - Highlights: • A review of 30 years of radioecological studies following the 1986 Chernobyl accident. • Key contributions to radioecology from post-Chernobyl research are discussed.

Primary pump vibration under accident conditions

International Nuclear Information System (INIS)

Guthrie, B.M.; Currie, T.C.

1984-06-01

This report presents the results of an international survey on the subject of vibration in nuclear primary coolant pumps due to two-phase flow, accident conditions. The literature search also revealed few Canadian references other than those of Ontario Hydro. Ontario Hydro's work has been extensive. Confidence in the mechanical integrity of the pumpsets is good, given the extent of the testing. However, conclusions with respect to piping integrity and thermal-hydraulic performance are difficult to determine due to the inexact geometry of the piping and the difficulties in estimating fluid conditions at the pump. The tests help to understand the phenomena and provide background information for analysis, but should be applied with caution to plant analyses. Much of the discussion in the report relates to pump head instability. This is perceived to be the most important flow regime causing vibration, as attested by the emphasis of the reviewed literature. A method for quantitative assessment of the forcing functions acting on the pump-piping system due to void generation and collapse is recommended. A relatively fundamental analytical approach is proposed, supplemented by reduced scale testing in the latter stages. 151 refs

BWR severe accident sequence analyses at ORNL - some lessons learned

International Nuclear Information System (INIS)

Hodge, S.A.

1983-01-01

Boiling water reactor severe accident sequence studies are being carried out using Browns Ferry Unit 1 as the model plant. Four accident studies were completed, resulting in recommendations for improvements in system design, emergency procedures, and operator training. Computer code improvements were an important by-product

Impact of the accident at TMI-2 on new safety regulations

International Nuclear Information System (INIS)

Collins, J.T.

1981-01-01

The Nuclear Regulatory Commission (NRC) has been very busy, since the accident, looking into the causes surrounding the events that occurred on the morning of March 28, 1979. To date, the Commission has implemented the Short-Term Lessons Learned and has provided a schedule for implementing the Long-Term Lessons Learned. Some of these requirements have resulted in delays in licensing of new plants and the temporary shutdown of some operating plants. However, the NRC believes these new requirements are essential to increase the safety of nuclear power plants and to protect the health and safety of the public. Although the accident occurred almost 19 months ago, the cleanup of TMI-2 continues and will continue for the next 5 to 7 years. As the cleanup progresses and ultimately the fuel removed, the Commission will continue to learn from the information generated by this program. This information will be factored into the licensing process. If nuclear power is to remain a viable option as a source of electrical power in the United States, then NRC must continue to assure the general public that these plants can be operated safely from the lessons learned at TMI and that systems required to mitigate the consequences of accidents will indeed perform their intended functions

Lessons learned and evaluation of the impact from the Chernobyl accident

International Nuclear Information System (INIS)

Cigna, A.A.

1990-01-01

The impact on society of the Chernobyl accidents is assessed. The situation prior to Chernobyl with respect to regulations of radiation protection against the consequences of a major accident is considered. The development of the recommendations and regulations issued by the Commission of the European Communities for the Maximum Permitted Levels of different groups of radionuclides in foodstuffs is reviewed. The different reactions to the accident are examined and some data on the average individual effective dose equivalents estimated in a number of countries are also reported. Finally some main problems concerning the information of the public and the preparedness for possible future accidents are also summarized

Qualitative analysis of the man-organization system in accident conditions for nuclear installations

International Nuclear Information System (INIS)

Farcasiu, Mita; Prisecaru, Ilie

2010-01-01

In this paper a model of the human performance investigation of accident conditions in the operation of the nuclear installation is developed. A framework for analyses of the human action in the man-organization system context is achieved. The goal of this model is to identify the possible roots causing human errors which could occur during the evolution of the accident by the qualitative analysis of the interfaces in man-organization system. These interfaces represent the main elements which characterize the implication of the organization in human performance. The results of this paper are the interfaces of the man-organization and their circumstances in which human performance could fail. Also, another result is a pre-designed framework which could help in the investigation of an accident. (authors)

Lessons Learned in Protection of the Public for the Accident at the Fukushima Daiichi Nuclear Power Plant.

Science.gov (United States)

Callen, Jessica; Homma, Toshimitsu

2017-06-01

What insights can the accident at the Fukushima Daiichi nuclear power plant provide in the reality of decision making on actions to protect the public during a severe reactor and spent fuel pool emergency? In order to answer this question, and with the goal of limiting the consequences of any future emergencies at a nuclear power plant due to severe conditions, this paper presents the main actions taken in response to the emergency in the form of a timeline. The focus of this paper is those insights concerning the progression of an accident due to severe conditions at a light water reactor nuclear power plant that must be understood in order to protect the public.

Application of uncertainty analysis method for calculations of accident conditions for RP AES-2006

International Nuclear Information System (INIS)

Zajtsev, S.I.; Bykov, M.A.; Zakutaev, M.O.; Siryapin, V.N.; Petkevich, I.G.; Siryapin, N.V.; Borisov, S.L.; Kozlachkov, A.N.

2015-01-01

An analysis of some accidents using the uncertainly assessment methods is given. The list of the variable parameters incorporated the model parameters of the computer codes, initial and boundary conditions of reactor plant, neutronics. On the basis of the performed calculations of the accident conditions using the statistical method, errors assessment is presented in the determination of the main parameters comparable with the acceptance criteria. It was shown that in the investigated accidents the values of the calculated parameters with account for their error obtained from TRAP-KS and KORSAR/GP Codes do not exceed the established acceptance criteria. Besides, these values do not exceed the values obtained in the conservative calculations. A possibility in principle of the actual application of the method of estimation of uncertainty was shown to justify the safety of WWER AES-2006 using the thermal-physical codes KORSAR/GP and TRAP-KS, PANDA and SUSA programs [ru

Postulated accident conditions for air cleaning systems and radiological dose assessments for containment options

International Nuclear Information System (INIS)

Hilliard, R.K.; Postma, A.K.

1975-01-01

Ambient conditions and performance requirements for emergency air cleaning systems applicable to commercial LMFBR plants were studied. The focus of this study centered on aerosol removal under hypothetical core disruptive accident conditions. Effort completed includes a review of air cleaning systems related to LMFBR plants, selection of three reference containment system designs, postulation of the EACS design basis accident (EACS-DBA), analysis of thermal conditions resulting from the DBA, analysis of aerosol transport behavior following the DBA, and an estimate of bone dose at the site boundary for each of the reference plant designs. Reference plant concepts were a single containment system (e.g., FFTF), a double containment system (e.g., CRBRP with closed head compartment), and a containment-confinement design in which an inerted, sealed primary volume was located within a ventilated building whose exhaust was filtered. The reference design basis accident selected here involved release to the inner containment system of 1 percent of non-volatile solids and plutonium, 25 percent of core halogens, 25 percent of core volatile solids, 100 percent of core noble gases, 68 lbs of sodium vapor and 5000 lbs of liquid sodium. 13 references. (U.S.)

Behaviour of gas cooled reactor fuel under accident conditions

International Nuclear Information System (INIS)

1991-11-01

The Specialists Meeting on Behaviour of Gas Cooled Reactor Fuel under Accident Conditions was convened by the International Atomic Energy Agency on the recommendation of the International Working Group on Gas Cooled Reactors. The purpose of the meeting was to provide an international forum for the review of the development status and for the discussion on the behaviour of gas cooled reactor fuel under accident conditions and to identify areas in which additional research and development are still needed and where international co-operation would be beneficial for all involved parties. The meeting was attended by 45 participants from France, Germany, Japan, Switzerland, the Union of Soviet Socialists Republics, the United Kingdom, the United States of America, CEC and the IAEA. The meeting was subdivided into five technical sessions: Summary of Current Research and Development Programmes for Fuel; Fuel Manufacture and Quality Control; Safety Requirements; Modelling of Fission Product Release - Part I and Part II; Irradiation Testing/Operational Experience with Fuel Elements; Behaviour at Depressurization, Core Heat-up, Power Transients; Water/Steam Ingress - Part I and Part II. 22 papers were presented. A separate abstract was prepared for each of these papers. At the end of the meeting a round table discussion was held on Directions for Future R and D Work and International Co-operation. Refs, figs and tabs

Summary of lessons learned in Japan from severe accidents: R&D programme for SA-Keisou in Japan. Annex I

International Nuclear Information System (INIS)

2015-01-01

Instrumentation systems in a nuclear power plant are very important for monitoring plant conditions for safe operation and shutdown. The severe accident at the Fukushima Daiichi nuclear power plant in March 2011 caused several severe situations such as failure of the plant power supply for many monitoring instruments, core damage and hydrogen explosion, among other things. Many of the functions of the instrumentation systems were lost. Monitoring the plant’s conditions then became harder to perform. In the event that an accident similar to the one at the Fukushima Daiichi nuclear power plant were to occur in the future, measurements of the important variables, such as reactor water level or reactor pressure, are to be ensured. The development of SA-Keisou1 is needed to monitor these important variables, which contribute to preventing the escalation of an event into a severe accident, mitigating the consequences of a severe accident, achieving a safe state for the plant and confirming that the plant continues to be in a safe state over the long term

Status of USNRC research on fuel behavior under accident conditions

International Nuclear Information System (INIS)

Johnston, W.V.

1976-01-01

The program of the Fuel Behaviour Research is directed at providing a detailed understanding of the response of nuclear fuel assemblies to off-normal or accident conditions. This understanding is expressed in physical and analytical correlations which are incorporated into computer codes. The results of these experiments and the resulting codes are available to the licensing authorities for use in evaluating utility submissions. (orig.) [de

Thirty years after the Chernobyl accident: What lessons have we learnt?

Science.gov (United States)

Beresford, N A; Fesenko, S; Konoplev, A; Skuterud, L; Smith, J T; Voigt, G

2016-06-01

April 2016 sees the 30(th) anniversary of the accident at the Chernobyl nuclear power plant. As a consequence of the accident populations were relocated in Belarus, Russia and Ukraine and remedial measures were put in place to reduce the entry of contaminants (primarily (134+137)Cs) into the human food chain in a number of countries throughout Europe. Remedial measures are still today in place in a number of countries, and areas of the former Soviet Union remain abandoned. The Chernobyl accident led to a large resurgence in radioecological studies both to aid remediation and to be able to make future predictions on the post-accident situation, but, also in recognition that more knowledge was required to cope with future accidents. In this paper we discuss, what in the authors' opinions, were the advances made in radioecology as a consequence of the Chernobyl accident. The areas we identified as being significantly advanced following Chernobyl were: the importance of semi-natural ecosystems in human dose formation; the characterisation and environmental behaviour of 'hot particles'; the development and application of countermeasures; the "fixation" and long term bioavailability of radiocaesium and; the effects of radiation on plants and animals. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Extending the application range of a fuel performance code from normal operating to design basis accident conditions

International Nuclear Information System (INIS)

Van Uffelen, P.; Gyori, C.; Schubert, A.; Laar, J. van de; Hozer, Z.; Spykman, G.

2008-01-01

Two types of fuel performance codes are generally being applied, corresponding to the normal operating conditions and the design basis accident conditions, respectively. In order to simplify the code management and the interface between the codes, and to take advantage of the hardware progress it is favourable to generate a code that can cope with both conditions. In the first part of the present paper, we discuss the needs for creating such a code. The second part of the paper describes an example of model developments carried out by various members of the TRANSURANUS user group for coping with a loss of coolant accident (LOCA). In the third part, the validation of the extended fuel performance code is presented for LOCA conditions, whereas the last section summarises the present status and indicates needs for further developments to enable the code to deal with reactivity initiated accident (RIA) events

Causal Factors and Adverse Conditions of Aviation Accidents and Incidents Related to Integrated Resilient Aircraft Control

Science.gov (United States)

Reveley, Mary S.; Briggs, Jeffrey L.; Evans, Joni K.; Sandifer, Carl E.; Jones, Sharon Monica

2010-01-01

The causal factors of accidents from the National Transportation Safety Board (NTSB) database and incidents from the Federal Aviation Administration (FAA) database associated with loss of control (LOC) were examined for four types of operations (i.e., Federal Aviation Regulation Part 121, Part 135 Scheduled, Part 135 Nonscheduled, and Part 91) for the years 1988 to 2004. In-flight LOC is a serious aviation problem. Well over half of the LOC accidents included at least one fatality (80 percent in Part 121), and roughly half of all aviation fatalities in the studied time period occurred in conjunction with LOC. An adverse events table was updated to provide focus to the technology validation strategy of the Integrated Resilient Aircraft Control (IRAC) Project. The table contains three types of adverse conditions: failure, damage, and upset. Thirteen different adverse condition subtypes were gleaned from the Aviation Safety Reporting System (ASRS), the FAA Accident and Incident database, and the NTSB database. The severity and frequency of the damage conditions, initial test conditions, and milestones references are also provided.

Learned lessons of the radiological accident occurred in La Ciudadela of El Cementerio, Gran Caracas. September 2005

International Nuclear Information System (INIS)

Lea, D.; Cubillan, Y.; Figuera, J.L.; Mora, G.; Pacheco, J.; Yanez, H.; Carrizales, L.

2006-01-01

On September 20, 2005 when a mission conformed by five (05) officials: two (02) belonging to the Ministry of Energy and Mines (MEP) and three (03) of the Ministry of Health (MS) it was prepared to carry out a routine inspection in the one temporary warehouse of sources in disuse located in La Ciudadela of El Cementerio, identified administratively as Warehouse Number 5 (MS) Area X, noticed that those armor-plating that kept the radioactive sources of Cs-137 had been violated. Those people that entered to the warehouse were able to extract the armor-plating in whose interior its were found an important number of sources of Cs-137 in disuse, used in the decade of 70 and 80 in treatment of cancer of the uterine neck, by means of the Brachytherapy technique of Differed charge manual, low dose rate, as well as, lead sheets with the apparent intention of selling them as junk. The intruders extracted a total of 58 radioactive sources of Cs-137 of its armor-plating for then to disperse them inside warehouse and in the external areas to this. An important number of the dispersed sources its had lost it integrity what gave place to a combined scenario of exposed dispersed sources in a public area with the danger of radioactive contamination by Cs-137. A task force conformed by the following institutions: Ministry of Health (MS), Ministry of Energy and Petroleum (MENPET), Venezuelan Institute of Scientific Investigations (IVIC), Unit of Dangerous Materials of the Metropolitan Firemen under the coordination of Civil Protection (PC) it was the one in charge of responding to the radiological accident, of conformity to the National Plan for the Answer to Radiological Accidents. All the radioactive sources dispersed in La Ciudadela achieved to be recovered. The experience of the accident and as learned lesson it was the importance of harmonizing the Generic Procedures for the Evaluation and Answer during Radiological Emergencies, IAEA-TECDOC-1162 technical document, Vienna, August

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.

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

Assessment of PASS Effectiveness under Severe Accidents in Nuclear Power Plants

International Nuclear Information System (INIS)

Choi, Yu Jung; Lee, Sung Bok; Kim, Hyeong Taek; Lee, Jin Yong

2008-01-01

Following the accident at Three Mile Island Unit 2 (TMI-2) on March 28, 1979, the USNRC formed a lessons-learned Task Force to identify and evaluate safety concerns originating with the TMI-2 accident. NUREG-0578 documented the results of the task force effort. One of the recommendations of the task force was for licensees to upgrade the capability to obtain samples from the reactor coolant system and containment atmosphere under high radioactivity conditions and to provide the capability for chemical and spectral analyses of high-level samples on site. NUREG-0737 contained the details of the TMI recommendations that were to be implemented by the licensees. Additional criteria for post accident sampling system(PASS) were issued by Regulatory Guide 1.97. As the results, PASS has been installed on nuclear power plants(NPPs) in Korea as well as United States. However, significant improvements have been achieved since the TMI-2 accident in the areas of understanding risks associated with nuclear plant operations and developing better strategies for managing the response to potential severe accidents at NPPs. Thus, the requirements for PASS have been re-evaluated in some reports. According to the reports, the samples and measurements from PASS do not contribute significantly to emergency management response to severe accidents due to the long analyzing time, 3 hours. Hence, this paper focused on the development of the quantitative analysis methodology to analyze the sequence of the severe accident in Yonggwang nuclear power plants (YGN) and presented the results of the analysis according to the developed methodology

Hydrogen-control systems for severe LWR accident conditions - a state-of-technology report

International Nuclear Information System (INIS)

Hilliard, R.K.; Postma, A.K.; Jeppson, D.W.

1983-03-01

This report reviews the current state of technology regarding hydrogen safety issues in light water reactor plants. Topics considered in this report relate to control systems and include combustion prevention, controlled combustion, minimization of combustion effects, combination of control concepts, and post-accident disposal. A companion report addresses hydrogen generation, distribution, and combustion. The objectives of the study were to identify the key safety issues related to hydrogen produced under severe accident conditions, to describe the state of technology for each issue, and to point out ongoing programs aimed at resolving the open issues

Comparative study of heterogeneous and homogeneous LMFBR cores in some accident conditions

International Nuclear Information System (INIS)

Renard, A.; Evrard, G.

1978-01-01

An heterogeneous design and a homogeneous one of a LMFBR core with the same power and similar dimensions are compared from the safety point-of-view. The comparison is performed for several accident conditions, such as Loss-of-Flow and Transient Overpower, with the same failure criteria and model assumptions for both cores. Qualitative trends are deduced from the behaviour of the core designs in the investigated transient conditions. (author)

Potential for containment leak paths through electrical penetration assemblies under severe accident conditions

International Nuclear Information System (INIS)

Sebrell, W.

1983-07-01

The leakage behavior of containments beyond design conditions and knowledge of failure modes is required for evaluation of mitigation strategies for severe accidents, risk studies, emergency preparedness planning, and siting. These studies are directed towards assessing the risk and consequences of severe accidents. An accident sequence analysis conducted on a Boiling Water Reactor (BWR), Mark I (MK I), indicated very high temperatures in the dry-well region, which is the location of the majority of electrical penetration assemblies. Because of the high temperatures, it was postulated in the ORNL study that the sealants would fail and all the electrical penetration assemblies would leak before structural failure would occur. Since other containments had similar electrical penetration assemblies, it was concluded that all containments would experience the same type of failure. The results of this study, however, show that this conclusion does not hold for PWRs because in the worst accident sequence, the long time containment gases stabilize to 350 0 F. BWRs, on the other hand, do experience high dry-well temperatures and have a higher potential for leakage

Multi-phase model development to assess RCIC system capabilities under severe accident conditions

Energy Technology Data Exchange (ETDEWEB)

Kirkland, Karen Vierow [Texas A & M Univ., College Station, TX (United States); Ross, Kyle [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Beeny, Bradley [Texas A & M Univ., College Station, TX (United States); Luthman, Nicholas [Texas A& M Engineering Experiment Station, College Station, TX (United States); Strater, Zachary [Texas A & M Univ., College Station, TX (United States)

2017-12-23

The Reactor Core Isolation Cooling (RCIC) System is a safety-related system that provides makeup water for core cooling of some Boiling Water Reactors (BWRs) with a Mark I containment. The RCIC System consists of a steam-driven Terry turbine that powers a centrifugal, multi-stage pump for providing water to the reactor pressure vessel. The Fukushima Dai-ichi accidents demonstrated that the RCIC System can play an important role under accident conditions in removing core decay heat. The unexpectedly sustained, good performance of the RCIC System in the Fukushima reactor demonstrates, firstly, that its capabilities are not well understood, and secondly, that the system has high potential for extended core cooling in accident scenarios. Better understanding and analysis tools would allow for more options to cope with a severe accident situation and to reduce the consequences. The objectives of this project were to develop physics-based models of the RCIC System, incorporate them into a multi-phase code and validate the models. This Final Technical Report details the progress throughout the project duration and the accomplishments.

Network conditioning under conflicting goals: Accident causation

International Nuclear Information System (INIS)

Jouse, W.C.

1992-01-01

Networks based on the Barto-Sutton architecture (BSA) of neural-like elements have an information-processing structure that is analogous to the cognitive structure of a human. Given a set of explicitly stated rules of conduct, such networks develop a set of skills that is capable of satisfying the rules. In this sense, the network acts as a translator of rules into skill-based behavior. The BSA acquires its skills through casual, correlation-based scheduling. Stated briefly, it first constructs an internal representation, or model, of the rules of conduct, and then uses the model to correct deficiencies in its skill. It learns in a manner that closely resembles classical conditioning, shifting the onset of signals associated with unconditioned stimuli forward in time to coincide with the onset of conditioning stimuli. The low-level positive reinforcement the network receives from enhancing its operational efficiency is immediate and direct. In the absence of countervailing influences, this continuous pressure is sufficient to discount the recollection of past failures and leads to accidents with a predictable regularity

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.

Accident identification system with automatic detection of abnormal condition using quantum computation

International Nuclear Information System (INIS)

Nicolau, Andressa dos Santos; Schirru, Roberto; Lima, Alan Miranda Monteiro de

2011-01-01

Transient identification systems have been proposed in order to maintain the plant operating in safe conditions and help operators in make decisions in emergency short time interval with maximum certainty associated. This article presents a system, time independent and without the use of an event that can be used as a starting point for t = 0 (reactor scram, for instance), for transient/accident identification of a pressurized water nuclear reactor (PWR). The model was developed in order to be able to recognize the normal condition and three accidents of the design basis list of the Nuclear Power Plant Angra 2, postulated in the Final Safety Analysis Report (FSAR). Were used several sets of process variables in order to establish a minimum set of variables considered necessary and sufficient. The optimization step of the identification algorithm is based upon the paradigm of Quantum Computing. In this case, the optimization metaheuristic Quantum Inspired Evolutionary Algorithm (QEA) was implemented and works as a data mining tool. The results obtained with the QEA without the time variable are compatible to the techniques in the reference literature, for the transient identification problem, with less computational effort (number of evaluations). This system allows a solution that approximates the ideal solution, the Voronoi Vectors with only one partition for the classes of accidents with robustness. (author)

The implementation of the IAEA accident response plan in Yugoslav practice

International Nuclear Information System (INIS)

Orlic, M.; Pavlovic, R.; Markovic, S.; Pavlovic, S.

1996-01-01

One of the important lessons from the Chernobyl accident is the necessity of existence of operational national emergency response plan. Summarizing consequences and experiences after Chernobyl accident, expert groups from IAEA, ICRP and other international scientific organizations, have been extensively worked on reviewing old ones, and preparing new radiation protection and nuclear safety principals and codes. One of the important issue is national emergency response plan for radiological accident. The nuclear accident response plan in Yugoslavia is presented in this paper. It is essentially based on IAEA model national response plan for radiological accident. This model has to be adjusted to the specificity of member states. The optimum society organization for emergency management in the case of accidents in ionizing radiation sources practices is suggested in this paper. Specific characteriztics of Yugoslav state organization relating to accident response are emphasised. (author)

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)

Structural Evaluation on HIC Transport Packaging under Accident Conditions

International Nuclear Information System (INIS)

Chung, Sung Hwan; Kim, Duck Hoi; Jung, Jin Se; Yang, Ke Hyung; Lee, Heung Young

2005-01-01

HIC transport packaging to transport a high integrity container(HIC) containing dry spent resin generated from nuclear power plants is to comply with the regulatory requirements of Korea and IAEA for Type B packaging due to the high radioactivity of the content, and to maintain the structural integrity under normal and accident conditions. It must withstand 9 m free drop impact onto an unyielding surface and 1 m drop impact onto a mild steel bar in a position causing maximum damage. For the conceptual design of a cylindrical HIC transport package, three dimensional dynamic structural analysis to ensure that the integrity of the package is maintained under all credible loads for 9 m free drop and 1 m puncture conditions were carried out using ABAQUS code.

Development of advanced claddings for suppressing the hydrogen emission in accident conditions. Development of advanced claddings for suppressing the hydrogen emission in the accident condition

International Nuclear Information System (INIS)

Park, Jeong-Yong; KIM, Hyun-Gil; JUNG, Yang-Il; PARK, Dong-Jun; KOO, Yang-Hyun

2013-01-01

The development of accident-tolerant fuels can be a breakthrough to help solve the challenge facing nuclear fuels. One of the goals to be reached with accident-tolerant fuels is to reduce the hydrogen emission in the accident condition by improving the high-temperature oxidation resistance of claddings. KAERI launched a new project to develop the accident-tolerant fuel claddings with the primary objective to suppress the hydrogen emission even in severe accident conditions. Two concepts are now being considered as hydrogen-suppressed cladding. In concept 1, the surface modification technique was used to improve the oxidation resistance of Zr claddings. Like in concept 2, the metal-ceramic hybrid cladding which has a ceramic composite layer between the Zr inner layer and the outer surface coating is being developed. The high-temperature steam oxidation behaviour was investigated for several candidate materials for the surface modification of Zr claddings. From the oxidation tests carried out in 1 200 deg. C steam, it was found that the high-temperature steam oxidation resistance of Cr and Si was much higher than that of zircaloy-4. Al 3 Ti-based alloys also showed extremely low-oxidation rate compared to zircaloy-4. One important part in the surface modification is to develop the surface coating technology where the optimum process needs to be established depending on the surface layer materials. Several candidate materials were coated on the Zr alloy specimens by a laser beam scanning (LBS), a plasma spray (PS) and a PS followed by LBS and subject to the high-temperature steam oxidation test. It was found that Cr and Si coating layers were effective in protecting Zr-alloys from the oxidation. The corrosion behaviour of the candidate materials in normal reactor operation condition such as 360 deg. C water will be investigated after the screening test in the high-temperature steam. The metal-ceramic hybrid cladding consisted of three major parts; a Zr liner, a

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.)

Role of Winter Weather Conditions and Slipperiness on Tourists’ Accidents in Finland

Directory of Open Access Journals (Sweden)

Élise Lépy

2016-08-01

Full Text Available (1 Background: In Finland, slippery snowy or icy ground surface conditions can be quite hazardous to human health during wintertime. We focused on the impacts of the variability in weather conditions on tourists’ health via documented accidents during the winter season in the Sotkamo area. We attempted to estimate the slipping hazard in a specific context of space and time focusing on the weather and other possible parameters, responsible for fluctuations in the numbers of injuries/accidents; (2 Methods: We used statistical distributions with graphical illustrations to examine the distribution of visits to Kainuu Hospital by non-local patients and their characteristics/causes; graphs to illustrate the distribution of the different characteristics of weather conditions; questionnaires and interviews conducted among health care and safety personnel in Sotkamo and Kuusamo; (3 Results: There was a clear seasonal distribution in the numbers and types of extremity injuries of non-local patients. While the risk of slipping is emphasized, other factors leading to injuries are evaluated; and (4 Conclusions: The study highlighted the clear role of wintery weather conditions as a cause of extremity injuries even though other aspects must also be considered. Future scenarios, challenges and adaptive strategies are also discussed from the viewpoint of climate change.

Severe Accident Management Guidance: Lessons Still to be Learned after Fukushima

International Nuclear Information System (INIS)

Vayssier, G.

2016-01-01

After the accidents in Three Mile Island (TMI) and Chernobyl, many countries decided to develop and implement guidelines specifically directed to mitigate accidents with core damage, so-called severe accidents. The guidelines are usually named Severe Accident Management Guidelines (SAMG). In the USA, all operating plants had these guidelines in place at the end of 1998. Most other countries followed later, but today, it can be said that many nuclear power plants in the world have such guidelines in place. Typically, however, the guidelines were constructed under the assumption that many plant systems still will be available, i.e. there will be DC to feed the instruments, AC to feed equipment and water to restore cooling to the core. Typically, this was basically the situation at TMI: most equipment was functional, only the insight of what had happened had been lost and operators did not know how to respond. At Fukushima-Daiichi, a Site Disruptive Accident (SDA) occurred and it appeared that the situation was much more complex: much of the needed supportive equipment needed was unavailable, which greatly complicated the handling of the event. In this paper, the major shortcomings of the present existing SAMG are discussed, both from a technical, and an organisational viewpoint. It is concluded that, where proper regulation still is missing, the development of an industrial standard is recommended to define adequate tools and guidelines to mitigate severe accidents, including SDAs. (author).

Impact of the Fukushima Accident on Current Fast Reactor Monju

International Nuclear Information System (INIS)

Ohira, Hiroaki

2012-01-01

Conclusions: • Based on the lessons learned from the Fukushima Dai-ichi NPS accidents, the emergency safety countermeasures and the enhanced countermeasures for the reactor, EVST and SFP have been conducted in Monju as of March 2012. • Plant dynamics analysis using possible conditions were also performed to confirm the cooling capabilities when a tsunami-induced SBO continued over a long period. • These results indicated that the decay heat produced from the core and the EVST could be removed safely by the natural circulation in the cooling systems, and that from the SFP could also removed only if water would be supplied in a few months interval

Cesium-137 accident lessons in Goiania, Goias State, Brazil; Licoes do acidente com cesio-137 em Goiania

Energy Technology Data Exchange (ETDEWEB)

NONE

1990-11-01

This document relates the experience obtained by several professionals which had an important role in the cesium-137 accident occurred in Goiania, Goias State, Brazil in September, 1987. It`s divided into chapters, according to the action area - medical, nursing, social assistance, odontological and psychological. At first, some notions of radioprotection are explained, followed by the accident history and by the doctors and nurses action during the emergency phase and the medical, odontological, social and psychological assistance to the victims. The social assistance report shows some statistical data about the economic, occupational and social conditions of the accident victims. It is shown some information about the health institutions and the sanitary care in the ionizing radiation and about the occupational radiological protection in Goiania. 38 refs., 8 tabs.

Emergency response to a highway accident in Springfield, Massachusetts, on December 16, 1991

International Nuclear Information System (INIS)

1992-06-01

On December 16, 1991, a truck carrying unirradiated (fresh) nuclear fuel was involved in an accident on US Interstate 91, in Springfield, Massachusetts. This report describes the emergency response measures undertaken by local, State, Federal, and private parties. The report also discusses ''lessons learned'' from the response to the accident and suggests areas where improvements might be made

Lessons learned? Selected public acceptance case studies since Three Mile Island

Energy Technology Data Exchange (ETDEWEB)

Blee, D. [NAC International, Atlanta Corporate Headquarters, Atlanta, GA (United States)

2001-02-01

This paper will present an overview of the present situation, some recent polling survey information, and then look at lessons learned in terms of selected case studies and some global issues over the 22 years since the Three Mile Island (TMI) accident. That is quite an ambitious topic but there are some important lessons we can learn from the post-TMI era. (author)

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

A dynamic model for the study of evacuation under accident conditions

International Nuclear Information System (INIS)

Boeri, G.C.; Caracciolo, R.; Sepede, M.; Casiroli, F.; Rodriguez, R.

1987-01-01

Information techniques and models are being used to simulate the evacuation of people living around a nuclear power plant and these methods are being increasingly used for planning purposes. In this study vehicular mobility on a complex road network following an accident has been considered and applied to the specifications of the emergency plans. Simulation tests of the mobility relevant to different combinations of time and meteorological conditions have been undertaken through use of the computer code TRIPS in order to assess the impact on the road network of an accident situation and the preparedness measures. The study has led to a description of the accessibility time curves related to the population gathering centres and has enabled identification of the best routes in order to achieve the minimum travel time. (author)

Investigation of air cleaning system response to accident conditions

International Nuclear Information System (INIS)

Andrae, R.W.; Bolstad, J.W.; Foster, R.D.; Gregory, W.S.; Horak, H.L.; Idar, E.S.; Martin, R.A.; Ricketts, C.I.; Smith, P.R.; Tang, P.K.

1980-01-01

Air cleaning system response to the stress of accident conditions are being investigated. A program overview and hghlight recent results of our investigation are presented. The program includes both analytical and experimental investigations. Computer codes for predicting effects of tornados, explosions, fires, and material transport are described. The test facilities used to obtain supportive experimental data to define structural integrity and confinement effectiveness of ventilation system components are described. Examples of experimental results for code verification, blower response to tornado transients, and filter response to tornado and explosion transients are reported

The Fukushima Daiichi Accident. Technical Volume 2/5. Safety Assessment

International Nuclear Information System (INIS)

2015-08-01

Technical Volume 1 of this report has described what happened during the accident at the Fukushima Daiichi nuclear power plant (NPP). This volume begins (Section 2.1) with a review of how the design basis of the site for external events was assessed initially and then reassessed over the life of the NPP. The section also describes the physical changes that were made to the units as a result. The remainder of the volume describes the treatment of beyond design basis events in the safety assessment of the site, the accident management provisions, the effectiveness of regulatory programmes, human and organizational factors and the safety culture, and the role of operating experience. Further background information is contained in three annexes included on the CD-ROM of this Technical Volume which describe analytical investigations of the accident along with information on topics such as system performance, defence in depth and severe accident phenomena. Section 2.2 provides an assessment of the systems that failed, resulting in a failure to maintain the fundamental safety functions in Units 1–3, which were in operation at the time of the tsunami and in which the reactor pressure vessels (RPV) and containment vessels failed. The section also describes Units 4-6, which were shut down at the time of the tsunami, and the site’s central spent fuel storage facility. Section 2.3 discusses the probabilistic and deterministic safety assessments of beyond design basis accidents (BDBAs) that had been performed for the plant and the insights from these assessments that had led to changes in the plant’s design. The section pays particular attention to the assessment of extreme natural hazards, such as the one which led to the total loss of AC power supply on the site. The additional loss of DC power supply in Units 1 and 2 played a key role in the progression of the accident because it impeded the diagnosis of plant conditions and made the operators unaware of the status of

Runaway reactions. Part 2 Causes of Accidents in selected CSB case histories Part 2

OpenAIRE

GYENES ZSUZSANNA; CARSON PHILLIP

2017-01-01

Part 1 briefly discussed the basic thermochemistry of reactive chemicals, the statistics of accidents involving runaway reactions, and general control measures to minimise risk and mitigate the consequences. The present paper highlights the main causes of major accidents from runaway reactions with illustrative case histories to link theory and practice. It also discusses lessons learned from these accidents, which are very similar in the cases studied. The main causes are management deficien...

Fuel Accident Condition Simulator (FACS) Furnace for Post-Irradiation Heating Tests of VHTR Fuel Compacts

Energy Technology Data Exchange (ETDEWEB)

Paul A Demkowicz; Paul Demkowicz; David V Laug

2010-10-01

Abstract –Fuel irradiation testing and post-irradiation examination are currently in progress as part of the Next Generation Nuclear Plant Fuels Development and Qualification Program. The PIE campaign will include extensive accident testing of irradiated very high temperature reactor fuel compacts to verify fission product retention characteristics at high temperatures. This work will be carried out at both the Idaho National Laboratory (INL) and the Oak Ridge National Laboratory, beginning with accident tests on irradiated fuel from the AGR-1 experiment in 2010. A new furnace system has been designed, built, and tested at INL to perform high temperature accident tests. The Fuel Accident Condition Simulator furnace system is designed to heat fuel specimens at temperatures up to 2000°C in helium while monitoring the release of volatile fission metals (e.g. Cs, Ag, Sr, Eu, and I) and fission gases (Kr, Xe). Fission gases released from the fuel to the sweep gas are monitored in real time using dual cryogenic traps fitted with high purity germanium detectors. Condensable fission products are collected on a plate attached to a water-cooled cold finger that can be exchanged periodically without interrupting the test. Analysis of fission products on the condensation plates involves dry gamma counting followed by chemical analysis of selected isotopes. This paper will describe design and operational details of the Fuel Accident Condition Simulator (FACS) furnace system, as well as preliminary system calibration results.

Living conditions in the contaminated territories of Bielorussia 8 years after the Chernobyl accident

International Nuclear Information System (INIS)

Heriard-Dubreuil, G.; Girard, P.

1997-01-01

Living conditions in the contaminated territories of Bielorussia after the Chernobyl accident: evaluation of the situation in the district of Chetchersk in Bielorussia. This article presents an analysis of the social and economic aspects of radiological protection in the territories contaminated by the Chernobyl accident. It is based on the results of two surveys performed in 1994 on the living conditions of the inhabitants of a territorial community located in Bielorussia, 180 km north of Chernobyl. The first part presents the radiological post-accident situation of the district, together with an analysis of this situation's demographic impact since 1986. The second part presents a description of the modes of exposure of the inhabitants of the contaminated territories and an assessment of he various countermeasures programmes initiated by the authorities in the legislative framework of 1991. The last part addresses the economic aspects of the Chetchersk district and an evaluation of the consequences of the radiological situation on the economic, and above all agricultural, activities of the district.The conclusion highlights the difficulties that face the Byelorussian authorities today. The now definitive presence of inhabitants in a durably contaminated environment poses a new category of problems. The objectives of radiological protection have to be reshaped within a set of constraints of different types, notably social and economic. The development of radiological safety cannot be dissociated from a return to quality living in these territories. This necessarily entails re-establishing a climate of social confidence. The initial legislative plan for post-accident management must be adapted to give greater autonomy to local participants in the reconstruction of satisfactory living conditions. (authors)

A digest of the Nuclear Safety Division report on the Fukushima Dai-ichi accident seminar (4). Issues identified by the accident

International Nuclear Information System (INIS)

Moriyama, Kumiaki; Abe, Kiyoharu

2013-01-01

AESJ Nuclear Safety Division published 'Report on the Fukushima Dai-ichi Accident Seminar - what was wrong and what should been down in future-' which would be published as five special articles of the AESJ journal. The Fukushima Dai-ichi accident identified issues of several activities directly related with nuclear safety in the areas of safety design, severe accident management and safety regulations. PRA, operational experiences and safety research could not always contribute safety assurance of nuclear power plant so much. This article (4) summarized technical issues based on related facts of the accident as much as possible and discussed' what was wrong and what should be down in future'. Important issues were identified from defense-in-depth philosophy and lessons learned on safety design were obtained from accident progression analysis. Activities against external events and continuous improvements of safety standards based on latest knowledge were most indispensable. Strong cooperation among experts in different areas was also needed. (T. Tanaka)

The Human Aspect of the Fukushima Daiichi Accident

International Nuclear Information System (INIS)

Anegawa, T.; Kawano, A.

2016-01-01

Recognizing itself as the main party involved in the nuclear accident triggered by the Tohoku-Chihou-Taiheiyo-Oki Earthquake on March 11, 2011, Tokyo Electric Power Company (TEPCO) has performed accident investigation from various aspects. Results of the investigation are reported mainly in two reports; (1) Fukushima Nuclear Accident Analysis Report (June 20, 2012), which identified the timeline and the proximate causes of the accident, and (2) Summary of Fukushima Nuclear Accident and Nuclear Safety Reform Plan (March 29, 2013) to set forth the results of the investigation and provide an analysis of the background factors surrounding the accident and countermeasures taken. This presentation will first provide overview of the accident response at Fukushima Daiichi and Daini Nuclear Power Stations. Voices from the first responders at the sites will be introduced in order to share thoughts of individuals involved in the emergency response. Summary of retrospective study of the accident by one of the shift supervisors at the time of the accident will be presented in order to share the facts that happened at main control rooms. The shift supervisor and his crew had to manage the situation for extended period of time that exceeded the scenarios that they had been trained, in a situation with no lightning and high radiation condition. During the accident response, shift supervisors had to decide to dispatch some of his crew members to the field to open valves, check the status of equipment etc., in the situation where the high radiation exposure is foreseen. The presentation will include conflict of shift supervisors and crew focusing on the human aspects. In addition, actions being taken at the Emergency Response Centers (ERC) set up at the seismic-isolated building on-site and the Headquarters in Tokyo will be shared focusing on the human aspects related to the accident progress. This includes difficult decisions to dispatch first responders to the field, in the

Application of the accident management information needs methodology to a severe accident sequence

International Nuclear Information System (INIS)

Ward, L.W.; Hanson, D.J.; Nelson, W.R.; Solberg, D.E.

1989-01-01

The U.S. Nuclear Regulatory Commission is conducting an accident management research program that emphasizes the use of severe accident research to enhance the ability of plant operating personnel to effectively manage severe accidents. Hence, it is necessary to ensure that the plant instrumentation and information systems adequately provide this information to the operating staff during accident conditions. A methodology to identify and assess the information needs of the operating staff of a nuclear power plant during a severe accident has been developed. The methodology identifies (a) the information needs of the plant personnel during a wide range of accident conditions, (b) the existing plant measurements capable of supplying these information needs and minor additions to instrument and display systems that would enhance management capabilities, (c) measurement capabilities and limitations during severe accident conditions, and (d) areas in which the information systems could mislead plant personnel

Application of the accident management information needs methodology to a severe accident sequence

Energy Technology Data Exchange (ETDEWEB)

Ward, L.W.; Hanson, D.J.; Nelson, W.R. (Idaho National Engineering Laboratory, Idaho Falls (USA)); Solberg, D.E. (Nuclear Regulatory Commission, Washington, DC (USA))

1989-11-01

The U.S. Nuclear Regulatory Commission is conducting an accident management research program that emphasizes the use of severe accident research to enhance the ability of plant operating personnel to effectively manage severe accidents. Hence, it is necessary to ensure that the plant instrumentation and information systems adequately provide this information to the operating staff during accident conditions. A methodology to identify and assess the information needs of the operating staff of a nuclear power plant during a severe accident has been developed. The methodology identifies (a) the information needs of the plant personnel during a wide range of accident conditions, (b) the existing plant measurements capable of supplying these information needs and minor additions to instrument and display systems that would enhance management capabilities, (c) measurement capabilities and limitations during severe accident conditions, and (d) areas in which the information systems could mislead plant personnel.

[Development and effect analysis of web-based instruction program to prevent elementary school students from safety accidents].

Science.gov (United States)

Chung, Eun-Soon; Jeong, Ihn-Sook; Song, Mi-Gyoung

2004-06-01

This study was aimed to develop a WBI(Web Based Instruction) program on safety for 3rd grade elementary school students and to test the effects of it. The WBI program was developed using Macromedia flash MX, Adobe Illustrator 10.0 and Adobe Photoshop 7.0. The web site was http://www.safeschool.co.kr. The effect of it was tested from Mar 24, to Apr 30, 2003. The subjects were 144 students enrolled in the 3rd grade of an elementary school in Gyungju. The experimental group received the WBI program lessons while each control group received textbook-based lessons with visual presenters and maps, 3 times. Data was analyzed with descriptive statistics, and chi2 test, t-test, and repeated measure ANOVA. First, the WBI group reported a longer effect on knowledge and practice of accident prevention than the textbook-based lessons, indicating that the WBI is more effective. Second, the WBI group was better motivated to learn the accident prevention lessons, showing that the WBI is effective. As a result, the WBI group had total longer effects on knowledge, practice and motivation of accident prevention than the textbook-based instruction. We recommend that this WBI program be used in each class to provide more effective safety instruction in elementary schools.

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

Covering techniques for severe burn treatment: lessons for radiological burn accidents

International Nuclear Information System (INIS)

Carsin, H.; Stephanazzi, J.; Lambert, F.; Curet, P.M.; Gourmelon, P.

2002-01-01

Covering techniques for severe burn treatment: lessons for radiological burn accidents. After a severe burn, the injured person is weakened by a risk of infection and a general inflammation. The necrotic tissues have to be removed because they are toxic for the organism. The injured person also needs to be covered by a cutaneous envelope, which has to be done by a treatment centre for burned people. The different techniques are the following: - auto grafts on limited burned areas; - cutaneous substitutes to cover temporary extended burned areas. Among them: natural substitutes like xenografts (pork skin, sheep skin,..) or allografts (human skin), - treated natural substitutes which only maintain the extracellular matrix. Artificial skins belong to this category and allow the development of high quality scars, - cell cultures in the laboratory: multiplying the individual cells and grafting them onto the patient. This technique is not common but allows one to heal severely injured patients. X-ray burns are still a problem. Their characteristics are analysed: intensive, permanent, antalgic resistant pain. They are difficult to compare with heat burns. In spite of a small number of known cases, we can give some comments and guidance on radio necrosis cures: the importance of the patients comfort, of ending the pain, of preventing infection, and nutritional balance. At the level of epidermic inflammation and phlyctena (skin blisters), the treatment may be completed by the use of growth factors. At the level of necrosis, after a temporary cover, an auto graft can be considered only if a healthy basis is guaranteed. The use of cellular cultures in order to obtain harmonious growth factors can be argued. (author)

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

International Nuclear Information System (INIS)

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

1996-01-01

This qualitative hazard evaluation systematically assessed potential doses to workers during postulated accident conditions at the U.S. Department of Energy's Waste Isolation Pilot Plant (WIPP). Postulated accidents included the spontaneous ignition of a waste drum, puncture of a waste drum by a forklift, dropping of a waste drum from a forklift, and simultaneous dropping of seven drums during a crane failure. The descriptions and estimated frequencies of occurrence for these accidents were developed by the Hazard and Operability Study for CH TRU Waste Handling System (WCAP 14312). The estimated materials at risk, damage ratios, airborne release fractions and respirable fractions for these accidents were taken from the 1995 Safety Analysis Report (SAR) update and from the DOE handbook Airborne Release Fractions/Rates and Respirable Fractions for Nonreactor Nuclear Facilities (DOE-HDBK-3010-94). A Monte Carlo simulation was used to estimate the range of worker exposures that could result from each accident. Guidelines for evaluating the adequacy of defense-in-depth for worker protection at WIPP were adopted from a scheme presented by the International Commission on Radiological Protection in its publication on Protection from Potential Exposure: A Conceptual Framework (ICRP Publication 64). Probabilities of exposures greater than 5, 50, and 300 rem were less than 10 -2 , 10 -4 , and 10 -6 per year, respectively. In conformance with the guidance of DOE standard 3009-94, Appendix A (draft), we emphasize that use of these evaluation guidelines is not intended to imply that these numbers constitute acceptable limits for worker exposure under accident conditions. However, in conjunction with the extensive safety assessment in the 1995 SAR update, these results indicate that the Carlsbad Area Office strategy for the assessment of hazards and accidents assures the protection of workers, as well as members of the public and the environment

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)

Predicting the impact of chronic health conditions on workplace productivity and accidents: results from two US Department of Energy national laboratories.

Science.gov (United States)

Frey, Jodi Jacobson; Osteen, Philip J; Berglund, Patricia A; Jinnett, Kimberly; Ko, Jungyai

2015-04-01

Examine associations of chronic health conditions on workplace productivity and accidents among US Department of Energy employees. The Health and Work Performance Questionnaire-Select was administered to a random sample of two Department of Energy national laboratory employees (46% response rate; N = 1854). The majority (87.4%) reported having one or more chronic health conditions, with 43.4% reporting four or more conditions. A population-attributable risk proportions analysis suggests improvements of 4.5% in absenteeism, 5.1% in presenteeism, 8.9% in productivity, and 77% of accidents by reducing the number of conditions by one level. Depression was the only health condition associated with all four outcomes. Results suggest that chronic conditions in this workforce are prevalent and costly. Efforts to prevent or reduce condition comorbidity among employees with multiple conditions can significantly reduce costs and workplace accident rates.

Analysis on the nitrogen drilling accident of Well Qionglai 1 (II: Restoration of the accident process and lessons learned

Directory of Open Access Journals (Sweden)

Yingfeng Meng

2015-12-01

Full Text Available All the important events of the accident of nitrogen drilling of Well Qionglai 1 have been speculated and analyzed in the paper I. In this paper II, based on the investigating information, the well log data and some calculating and simulating results, according to the analysis method of the fault tree of safe engineering, the every possible compositions, their possibilities and time schedule of the events of the accident of Well Qionglai 1 have been analyzed, the implications of the logging data have been revealed, the process of the accident of Well Qionglai 1 has been restored. Some important understandings have been obtained: the objective causes of the accident is the rock burst and the induced events form rock burst, the subjective cause of the accident is that the blooie pipe could not bear the flow burden of the clasts from rock burst and was blocked by the clasts. The blocking of blooie pipe caused high pressure in wellhead, the high pressure made the blooie pipe burst, natural gas came out and flared fire. This paper also thinks that the rock burst in gas drilling in fractured tight sandstone gas zone is objective and not avoidable, but the accidents induced from rock burst can be avoidable by improving the performance of the blooie pipe, wellhead assemblies and drilling tool accessories aiming at the downhole rock burst.

Emergency planning lessons learned from a review of past major radiological accidents

International Nuclear Information System (INIS)

Stephan, J.G.; Selby, J.M.; Martin, J.B.; Moeller, D.W.; Vallario, E.J.

1988-01-01

In examining a range of nuclear accidents from the 1950s to the present that were reported in the literature, the authors have identified a number of contributing factors which affected human judgement during these events. One common thread found in a large number of accidents is the time of occurrence; a second is the adequacy of emergency training. The data show that events, whether severe accidents or operational incidents, appear to occur more frequently during off-normal hours such as the early morning shift, weekends, or holidays. Accidents seldom occur during the day shift when the full management team and senior operations personnel are present. As a result, those facility employees most expert in coping with the situation may not be available, and the normal chain of command may be disrupted. At several nuclear power plants, it was also observed that new or less experienced technicians are often assigned to night shifts. The lack of experienced human resources and the pressure of an accident situation can have an adverse impact on individuals who are faced with making important decisions

Estimate of radionuclide release characteristics into containment under severe accident conditions

International Nuclear Information System (INIS)

Nourbakhsh, H.P.

1993-11-01

A detailed review of the available light water reactor source term information is presented as a technical basis for development of updated source terms into the containment under severe accident conditions. Simplified estimates of radionuclide release and transport characteristics are specified for each unique combination of the reactor coolant and containment system combinations. A quantitative uncertainty analysis in the release to the containment using NUREG-1150 methodology is also presented

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

Analysis of effects of calandria tube uncovery under severe accident conditions in CANDU reactors

International Nuclear Information System (INIS)

Rogers, J.T.; Currie, T.C.; Atkinson, J.C.; Dick, R.

1983-01-01

A study is being undertaken for the Atomic Energy Control Board to assess the thermal and hydraulic behaviour of CANDU reactor cores under accident conditions more severe than those normally considered in the licensing process. In this paper, we consider the effects on a coolant channel of the uncovery of a calandria tube by moderator boil-off following a LOCA in a Bruce reactor unit in which emergency cooling is ineffective and the moderator heat sink is impaired by the failure of the moderator cooling system. Calandria tube uncovery and its immediate consequences, as described here, constitute only one part of the entire accident sequence. Other aspects of this sequence as well as results of the analysis of the other accident sequences studied will be described in the final report on the project and in later papers

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

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)

The lessons from the radiation accidents in China over the past 40 years

International Nuclear Information System (INIS)

Zhang, Y.; Ma, J.; Yang, J.

1998-01-01

A brief introduction and analysis of the radiological accidents in China during the past 40 years have been made in this paper. Statistical data provided by the competent authority show that a number of cases of radiological accidents and events happened in China from 1954 to 1994. Quite a few persons received abnormal exposure. Some serious accidents resulted in death of 8 victims. The reasons of these accidents are analyzed and some recommendations for reduction of potential exposure and accidents involving radiation sources and equipment generating ionization radiation have been given, such as perfecting and improving radiation safety infrastructure and system for the control of radiation sources. It is suggested that safety culture shall be fostered, each individual must be suitably trained and qualified and the management of spent sources should be strengthened. (author)

Lessons Fukushima 11032011 -- Lessons learned and points to be checked from the nuclear accidents in Fukushima; Lessons Fukushima 11032011 -- Lessons learned und Pruefpunkte aus den kerntechnischen Unfaellen in Fukushima

Energy Technology Data Exchange (ETDEWEB)

NONE

2011-10-15

Since a long time, severe accidents are one of the main areas in the surveillance activities of the Swiss Federal Nuclear Safety Inspectorate (ENSI). The analysis of events all over the world and the evaluation of their relevance for the Swiss nuclear power plants belong to the permanent obligations of the regulatory authority. In Switzerland, for more than two decades, core melting accidents are studied using probabilistic safety assessment methods. Comprehensive risk analyses were set up for external events like earthquakes, sabotages or airplane crashes. Strategies for the mitigation of the consequences of severe accidents, so-called Severe Accident Management Guidance (SAMG), were written down by the regulatory authority and made available to the Swiss plant operators. In international comparison the Swiss nuclear power plants have reached a very high standard in the field of severe accidents. Moreover, the safety of the Swiss plants is continuously reviewed by means of permanent supervision and especially through the 10-year periodic safety review. However, the Fukushima accident justifies a renewed evaluation on whether the preparation against severe reactor accidents could be improved and additional measures be taken for the protection of the population. In the present report, ENSI indicates points to be checked, which were considered as important in the course of the analysis of the Fukushima accident, for the future improvement of the nuclear safety and radiation protection in Switzerland. These points were identified from the analysis of the behaviour of the plant staff, techniques and organisation during the accident. The resulting measures concern the plant design, the emergency management, the feed-back from the encountered events, the surveillance, the radiation protection and the safety culture, with a special emphasis on the emergency management in Switzerland. The implementation of the necessary short-term measures was launched by ENSI decrees and

Evidence for the effectiveness of Alexander Technique lessons in medical and health-related conditions: a systematic review.

Science.gov (United States)

Woodman, J P; Moore, N R

2012-01-01

Complementary medicine and alternative approaches to chronic and intractable health conditions are increasingly being used, and require critical evaluation. The aim of this review was to systematically evaluate available evidence for the effectiveness and safety of instruction in the Alexander Technique in health-related conditions. PUBMED, EMBASE, PSYCHINFO, ISI Web-of-Knowledge, AMED, CINHAL-plus, Cochrane library and Evidence-based Medicine Reviews were searched to July 2011. Inclusion criteria were prospective studies evaluating Alexander Technique instruction (individual lessons or group delivery) as an intervention for any medical indication/health-related condition. Studies were categorised and data extracted on study population, randomisation method, nature of intervention and control, practitioner characteristics, validity and reliability of outcome measures, completeness of follow-up and statistical analyses.   Of 271 publications identified, 18 were selected: three randomised, controlled trials (RCTs), two controlled non-randomised studies, eight non-controlled studies, four qualitative analyses and one health economic analysis. One well-designed, well-conducted RCT demonstrated that, compared with usual GP care, Alexander Technique lessons led to significant long-term reductions in back pain and incapacity caused by chronic back pain. The results were broadly supported by a smaller, earlier RCT in chronic back pain. The third RCT, a small, well-designed, well-conducted study in individuals with Parkinson's disease, showed a sustained increased ability to carry out everyday activities following Alexander lessons, compared with usual care. The 15 non-RCT studies are also reviewed. Strong evidence exists for the effectiveness of Alexander Technique lessons for chronic back pain and moderate evidence in Parkinson's-associated disability. Preliminary evidence suggests that Alexander Technique lessons may lead to improvements in balance skills in the

Radiation accidents: occurrence, types, consequences, medical management, and the lessons to be learned

International Nuclear Information System (INIS)

Turai, I.; Veress, K.

2001-01-01

The paper reviews the frequency, causes and occurrence of radiation accidents with some significant exposure to human. More detailed information is provided in tabulated form on the health consequences of those twenty severe radiation accidents that occurred in 1986-2000, world-wide. Reference is given to the very low cumulative incidence of significant radiation accidents, as during the last 57 years there were, in average, seven registered accidents annually in all countries of the world. Thus, the chance for most of the physicians to meet a patient with symptoms of acute radiation injury during their professional career is very low

Development and application of a radioactivity evaluation technique the to obtain radiation exposure dose of radioactivity evaluation technique when a severe accident occurs in the a power station of a severe accident. Accident management guidelines of knowledge-based maintenance

International Nuclear Information System (INIS)

Kawasaki, Ikuo; Yoshida, Yoshitaka

2013-01-01

As a One of the lessons learned from the nuclear accident at the Fukushima Daiichi Nuclear Power Stations of Tokyo Electric Power Company, the was the need for improvement of accident management guidelines is required. In this report study, we developed and applied a dose evaluation technique to evaluated the radiation dose in a nuclear power plant assuming three conditions: employees were evacuation evacuated at the time of a severe accident occurrence; operators carried out the accident management operation; of the operators, and the repair work was carried out for of the trouble damaged apparatuses in a the nuclear power plant using a dose evaluation system. The following knowledge findings were obtained and should to be reflected to in the knowledge base of the guidelines was obtained. (1) By making clearly identifying an areas beforehand becoming the that would receive high radiation doses at the time of a severe accident definitely beforehand, we can employees can be moved to the evacuation places through an areas having of low dose rate and it is also known it how much we long employees can safely stay in the evacuation places. (2) When they circulate CV containment vessel recirculation sump water is recirculated by for the accident management operation and the restoration of safety in the facilities, because the plumbing piping and the apparatuses become radioactive radioactivity sources, the dose evaluation of the shortest access route and detour access routes with should be made for effective the accident management operation is effective. Because the area where a dose rate rises changes which as safety apparatuses are restored, in consideration of a plant state, it is necessary to judge the rightness or wrongness of the work continuation from the spot radioactive dose of the actual apparatus area, with based on precedence of the need to restore with precedence, and to choose a system to be used for accident management. (author)

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.)

Guidance of reactor operators and TSC personnel with the severe accident management guidance under shutdown and low power conditions

International Nuclear Information System (INIS)

Van Haesendonck, M.F.; Prior, R.P.

2000-01-01

The Westinghouse Owners Group Severe Accident Management Guidance (WOG SAMG) was developed between 1991 and 1994. The primary goals for severe accident management that form the basis of the WOG SAMG are to terminate any radioactive releases to the environment; to prevent failure of any containment fission product boundary and to return the plant to a controlled stable condition. The WOG SAMG is primarily a TSC tool for mitigation of low probability core damage events. The philosophy is that control room operators should remain focused on the prevention of core damage, whereas the TSC personnel should concentrate on the mitigation of the severe accident. The symptom based package is built up as a structured process for choosing appropriate actions based on actual plant conditions. No detailed knowledge of severe accident phenomena is required. The scope of the WOG SAMG is limited to severe accidents resulting from initiating events occurring during full power operation. However, a number of studies such as the EdF EPS 1300 Probabilistic Safety Assessment (PSA), the shutdown Probabilistic Risk Assessment (PRA) for Surry, the BERA shutdown PRA for Beznau, the EPRI/ Westinghouse ORAM methodology etc. have shown that the frequency of core damage (a severe accident) during shutdown and low power operation can be of the same order of magnitude as for full power operation. The at-power SAMG is viewed as the resolution of the severe accident issue. Similarly, it is expected that as shutdown PRAs mature, the final resolution of the severe accident issue will lie in SAMG for low power and shutdown operation. Therefore in resolution of this issue, Westinghouse has developed the Shutdown Severe Accident Management Guidance (SSAMG) which gives guidance for both control room and TSC personnel to mitigate a severe accident under shutdown or low power conditions. In the last few years, many LWR plants have been implementing SAMG. In the US, all plants have developed SAMG, and many

Severe accident management (SAM), operator training and instrumentation capabilities - Summary and conclusions

International Nuclear Information System (INIS)

2002-01-01

The Workshop on Operator Training for Severe Accident Management (SAM) and Instrumentation Capabilities During Severe Accidents was organised in collaboration with Electricite de France (Service Etudes et Projets Thermiques et Nucleaires). There were 34 participants, representing thirteen OECD Member countries, the Russian Federation and the OECD/NEA. Almost half the participants represented utilities. The second largest group was regulatory authorities and their technical support organisations. Basically, the Workshop was a follow-up to the 1997 Second Specialist Meeting on Operator Aids for Severe Accident Management (SAMOA-2) [Reports NEA/CSNI/R(97)10 and 27] and to the 1992 Specialist Meeting on Instrumentation to Manage Severe Accidents [Reports NEA/CSNI/R(92)11 and (93)3]. It was aimed at sharing and comparing progress made and experience gained from these two meetings, emphasizing practical lessons learnt during training or incidents as well as feedback from instrumentation capability assessment. The objectives of the Workshop were therefore: - to exchange information on recent and current activities in the area of operator training for SAM, and lessons learnt during the management of real incidents ('operator' is defined hear as all personnel involved in SAM); - to compare capabilities and use of instrumentation available during severe accidents; - to monitor progress made; - to identify and discuss differences between approaches relevant to reactor safety; - and to make recommendations to the Working Group on the Analysis and Management of Accidents and the CSNI (GAMA). The Workshop was organised into five sessions: - 1: Introduction; - 2: Tools and Methods; - 3: Training Programmes and Experience; - 4: SAM Organisation Efficiency; - 5: Instrumentation Capabilities. It was concluded by a Panel and General Discussion. This report presents the summary and conclusions: the meeting confirmed that only limited information is needed for making required decisions

MDEP Common Position CP-STC-02. Common Position Addressing Fukushima Daiichi Nuclear Power Accident

International Nuclear Information System (INIS)

2016-09-01

Following the nuclear accident in Japan as a consequence of the earthquake and tsunami, the MDEP Members provide the following information, based on initial information available, to ensure adequate safety of new reactor design activities being undertaken pursuant to the MDEP program of work. Due to the extensive nature of the magnitude and duration of the Fukushima Daiichi NPP accident, it is important to consider lessons learnt at an early stage of the design. In this context, the extensive work done by the IAEA, the International Atomic Energy Agency, is also acknowledged. Vendors, licensees and applicants involved in New Design activities should examine the implications of the Fukushima Daiichi NPP accident and identify relevant issues to be taken into account to strengthen defense in depth. Those lessons learnt should include, but not be limited to, plans to assess the following: - Provisions taken in the design basis concerning flooding, earthquake, other extreme natural phenomena and combinations of external event hazards appropriate to each country, - The robustness of the plant to maintain its safety functions beyond the design basis hazards, - The capability of the plant to withstand extended loss of all electrical power supplies as well as prolonged loss of ultimate heat sink and other essential supplies, and - The capability of the plant to cope with such extreme situations, including provisions to manage severe accidents (such as combustible gas management). In assessing these areas, the effect of multiple units and nuclear fuel storages should be considered. The MDEP regulators will strive to harmonize approaches to incorporate lessons learnt in their ongoing national safety reviews of new reactors. Based on the design-specific common positions, this paper identifies the approaches to address potential safety improvements for several designs as related to lessons learned from the Fukushima Daiichi NPP accident or related issues. Designs being

The radiological accident in Yanango

International Nuclear Information System (INIS)

2000-01-01

The use of nuclear technologies has fostered new, more effective and efficient medical procedures and has substantially improved diagnostic and therapeutic capabilities. However, in order that the benefits of the use of ionizing radiation outweigh the potential hazards posed by this medium, it is important that radiation protection and safety standards be established to govern every aspect of the application of ionizing radiation. Adherence to these standards needs to be maintained through effective regulatory control, safe operational procedures and a safety culture that is shared by all. Occasionally, established safety procedures are violated and serious radiological consequences ensue. The radiological accident described in this report, which took place in Lilo, Georgia, was a result of such an infraction. Sealed radiation sources had been abandoned by a previous owner at a site without following established regulatory safety procedures, for example by transferring the sources to the new owner or treating them as spent material and conditioning them as waste. As a consequence, 11 individuals at the site were exposed for a long period of time to high doses of radiation which resulted inter alia in severe radiation induced skin injuries. Although at the time of the accident Georgia was not an IAEA Member State and was not a signatory of the Convention on Assistance in the Case of a Nuclear Accident or Radiological Emergency, the IAEA still provided assistance to the Government of Georgia in assessing the radiological situation, while the World Health Organization (WHO) assisted in alleviating the medical consequences of the accident. The two organizations co-operated closely from the beginning, following the request for assistance by the Georgian Government. The IAEA conducted the radiological assessment and was responsible for preparing the report. The WHO and its collaborating centres within the Radiation Emergency Medical Preparedness and Assistance Network

Analysis of Three Mile Island Unit 2 accident

International Nuclear Information System (INIS)

Anon.

1979-01-01

NSAC is conducting a detailed review of this accident and of the lessons to be learned. So far it has concentrated primarily on events during the sixteen hours following initiation of the accident. A sequence of events has been developed and is being verified and annotated by comparing oral and written statements with instrumentation records, data logs, operator logs, and inferences which can be made from these records. This report is being developed with the expectation that, while not completed or fully verified, it may be useful at this time. Supplements may be issued later as the analyses which are still under way are completed

Comparison of US/FRG accident condition models for HTGR fuel failure and radionuclide release

International Nuclear Information System (INIS)

Verfondern, K.

1991-03-01

The objective was to compare calculation models used in safety analyses in the US and FRG which describe fission product release behavior from TRISO coated fuel particles under core heatup accident conditions. The frist step performed is the qualitative comparison of both sides' fuel failure and release models in order to identify differences and similarities in modeling assumptions and inputs. Assumptions of possible particle failure mechanisms under accident conditions (SiC degradation, pressure vessel) are principally the same on both sides though they are used in different modeling approaches. The characterization of a standard (= intact) coated particle to be of non-releasing (GA) or possibly releasing (KFA/ISF) type is one of the major qualitative differences. Similar models are used regarding radionuclide release from exposed particle kernels. In a second step, a quantitative comparison of the calculation models was made by assessing a benchmark problem predicting particle failure and radionuclide release under MHTGR conduction cooldown accident conditions. Calculations with each side's reference method have come to almost the same failure fractions after 250 hours for the core region with maximum core heatup temperature despite the different modeling approaches of SORS and PANAMA-I. The comparison of the results of particle failure obtained with the Integrated Failure and Release Model for Standard Particles and its revision provides a 'verification' of these models in this sense that the codes (SORS and PANAMA-II, and -III, respectively) which were independently developed lead to very good agreement in the predictions. (orig./HP) [de

Interrogations to Learn from the Fukushima Accident

International Nuclear Information System (INIS)

Gisquet, E.; Jeffroy, F.

2016-01-01

On March 11, 2011, an earthquake in eastern Japan caused the reactors in operation at the Fukushima Daiichi nuclear power plant (NPP) to trip. The emergency generators started and then suddenly failed following the tsunami. The cooling water injection system no longer worked. Suddenly plunged into total darkness, the operators had to manage the accident. Starting from the official reports and testimonies on the Fukushima accident, IRSN has conducted a survey “Human and Organizational Factors Perspective on the Fukushima Nuclear Accident.” Four years after the accident, however, as more witness accounts become available, IRSN feels it useful to return to the human and organizational response to the accident inside the NPP itself. To what extent can the participants act and coordinate their actions when faced with such a dramatic situation? To what degree did their actions contribute to the disaster? Rather than looking at the causes of the accident, this study examines the unfolding of the crisis, particularly in the most urgent early stages, and draws lessons for safety culture from the decisions and actions of key actors. The main results would be presented in three key areas: 1. How to make sense of the situation? People had to make sense of what happened and create new indicators. Since instruments and controls, as well as many communication technologies, were knocked out by the tsunami, all the standard means of determining the status of the reactors were impossible. Although they were under normal circumstances almost completely dependent on these indicators, and although (or because) their lives were most directly at risk, the operators managed this uncertainty through various means that will be successively presented. 2. What are the challenges for the emergency structure? The Emergency Response Center (ERC) operations team was responsible for being in contact with the operators in the control rooms and providing them technical support as needed. The ERC

Key Characteristics of Combined Accident including TLOFW accident for PSA Modeling

Energy Technology Data Exchange (ETDEWEB)

Kim, Bo Gyung; Kang, Hyun Gook [KAIST, Daejeon (Korea, Republic of); Yoon, Ho Joon [Khalifa University of Science, Technology and Research, Abu Dhabi (United Arab Emirates)

2015-05-15

The conventional PSA techniques cannot adequately evaluate all events. The conventional PSA models usually focus on single internal events such as DBAs, the external hazards such as fire, seismic. However, the Fukushima accident of Japan in 2011 reveals that very rare event is necessary to be considered in the PSA model to prevent the radioactive release to environment caused by poor treatment based on lack of the information, and to improve the emergency operation procedure. Especially, the results from PSA can be used to decision making for regulators. Moreover, designers can consider the weakness of plant safety based on the quantified results and understand accident sequence based on human actions and system availability. This study is for PSA modeling of combined accidents including total loss of feedwater (TLOFW) accident. The TLOFW accident is a representative accident involving the failure of cooling through secondary side. If the amount of heat transfer is not enough due to the failure of secondary side, the heat will be accumulated to the primary side by continuous core decay heat. Transients with loss of feedwater include total loss of feedwater accident, loss of condenser vacuum accident, and closure of all MSIVs. When residual heat removal by the secondary side is terminated, the safety injection into the RCS with direct primary depressurization would provide alternative heat removal. This operation is called feed and bleed (F and B) operation. Combined accidents including TLOFW accident are very rare event and partially considered in conventional PSA model. Since the necessity of F and B operation is related to plant conditions, the PSA modeling for combined accidents including TLOFW accident is necessary to identify the design and operational vulnerabilities.The PSA is significant to assess the risk of NPPs, and to identify the design and operational vulnerabilities. Even though the combined accident is very rare event, the consequence of combined

Potential for containment leak paths through electrical penetration assemblies under severe accident conditions. [PWR; BWR

Energy Technology Data Exchange (ETDEWEB)

Sebrell, W.

1983-07-01

The leakage behavior of containments beyond design conditions and knowledge of failure modes is required for evaluation of mitigation strategies for severe accidents, risk studies, emergency preparedness planning, and siting. These studies are directed towards assessing the risk and consequences of severe accidents. An accident sequence analysis conducted on a Boiling Water Reactor (BWR), Mark I (MK I), indicated very high temperatures in the dry-well region, which is the location of the majority of electrical penetration assemblies. Because of the high temperatures, it was postulated in the ORNL study that the sealants would fail and all the electrical penetration assemblies would leak before structural failure would occur. Since other containments had similar electrical penetration assemblies, it was concluded that all containments would experience the same type of failure. The results of this study, however, show that this conclusion does not hold for PWRs because in the worst accident sequence, the long time containment gases stabilize to 350/sup 0/F. BWRs, on the other hand, do experience high dry-well temperatures and have a higher potential for leakage.

Group unified accident reporting database (GUARD)

International Nuclear Information System (INIS)

Koene, W.; Waterfall, K.W.

1991-01-01

Significant advances have been made in recent years in enhancing the standard of safety within Shell Companies, such that safety has now been raised to a status equal to other primary business objectives. It is widely accepted that accident prevention is part of good business practice, and that a safe operation is normally an efficient operation. Safety programmes are being widely implemented which involve all employees from top management right down to the workforce including the contract staff, and the benefits are being realized. The effectiveness of any safety programme, however, must be continuously monitored, and in this respect injury and accident statistics play an important role as a prime indicator of safety performance. Statistics form part of the safety management process indicating the success of the safety programmes being implemented, and highlighting areas of weakness. Statistical information relating to the number and frequency of accidents, significant as it is, tells us little about how the accidents occur, or about how to improve the intrinsic safety of the operations. More detailed information on accident causes and lessons derived from the investigation of non-injurious accidents and near-misses is required for this, and for the setting of appropriate remedial actions. This paper concentrates on the feedback from accidents which have already occurred. This feedback plays a vital role as an indicator of safety performance upon which to judge the effectiveness of safety programmes, and also to provide important information relating to the immediate and underlying causes of accidents. To meet these requirements, however, a system for recording analyzing and communicating safety data is essential

Overview of core disruptive accidents

International Nuclear Information System (INIS)

Marchaterre, J.F.

1977-01-01

An overview of the analysis of core-disruptive accidents is given. These analyses are for the purpose of understanding and predicting fast reactor behavior in severe low probability accident conditions, to establish the consequences of such conditions and to provide a basis for evaluating consequence limiting design features. The methods are used to analyze core-disruptive accidents from initiating event to complete core disruption, the effects of the accident on reactor structures and the resulting radiological consequences are described

MDEP Common Position CP-EPRWG-04. Common position on EPR containment heat removal system in accident conditions

International Nuclear Information System (INIS)

2015-01-01

The importance of the integrity of the containment as a fundamental barrier to protect the people and environment against the effects of a nuclear accident is well established. In this regard, an essential objective is that the necessity for off-site counter-measures to reduce radiological consequences be limited or even eliminated. The design should provide engineering means to address those sequences which would otherwise lead to large or early releases, even in case of severe external hazards. The plant shall be designed so that it can be brought into a controlled and stable state and the containment function can be maintained, under accident conditions in which there is a significant amount of radioactive material in the containment, i.e. resulting from severe degradation of the reactor core. It is expected that due consideration to these requirements is to be given while tailoring long term loss of electrical power mitigation strategies. In order to reliably maintain the containment barrier, the regulators believe that: - safety features specifically designed for fulfilling safety functions required in core melt accidents shall be independent to the extent reasonably practicable from the Systems, Structures and Components (SSC) of the other levels of defense; - safety features specifically designed for fulfilling safety functions required in core melt accidents shall be safety classified and adequately qualified for the core melt accident environmental conditions for the time frame for which they are required to operate. In the light of the Fukushima Daiichi accident, the regulators believe that those safety features shall be designed with an adequate margin as compared to the levels of natural hazards considered for the site hazard evaluation; - the systems and components necessary for ensuring the containment function in a core melt accident shall have reliability commensurate with the function that they are required to fulfil. This may require redundancy of

The accidents due to ionizing radiations - the situation on a half century

International Nuclear Information System (INIS)

2007-02-01

This report takes stock updated in 2006, serious accidents occurred in the four sectors in civil, industrial, medical and military. Its goal is to provide an explanatory and critical review of the most representative accident that caused serious harm to victims. The report analyses for each accident, and whenever reliable data exist, the reasons for its occurrence, consequences for victims and possibly to the environment, remedial actions that have been made and medical treatments when they were innovative. Using a combination of accidents with common features, the report offers key lessons to be learned from these tragic events. This report is intended for practitioners of radiation protection in general and does not target particular experts in any technical or medical specialty. (N.C.)

FUKUSHIMA DAI-ICHI ACCIDENT: LESSONS LEARNED AND FUTURE ACTIONS FROM THE RISK PERSPECTIVES

Directory of Open Access Journals (Sweden)

JOON-EON YANG

2014-02-01

Full Text Available The Fukushima Dai-Ichi accident in 2011 has affected various aspects of the nuclear society worldwide. The accident revealed some problems in the conventional approaches used to ensure the safety of nuclear installations. To prevent such disastrous accidents in the future, we have to learn from them and improve the conventional approaches in a more systematic manner. In this paper, we will cover three issues. The first is to identify the key issues that affected the progress of the Fukushima Dai-Ichi accident greatly. We examine the accident from a defense-in-depth point of view to identify such issues. The second is to develop a more systematic approach to enhance the safety of nuclear installations. We reexamine nuclear safety from a risk point of view. We use the concepts of residual and unknown risks in classifying the risk space. All possible accident scenarios types are reviewed to clarify the characteristics of the identified issues. An approach is proposed to improve our conventional approaches used to ensure nuclear safety including the design of safety features and the safety assessments from a risk point of view. Finally, we address some issues to be improved in the conventional risk assessment and management framework and/or practices to enhance nuclear safety.

Fukushima Dai-Ichi accident: Lessons Learned and Future Actions from the Risk Perspectives

Energy Technology Data Exchange (ETDEWEB)

Yang, Jooneon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2014-02-15

The Fukushima Dai-Ichi accident in 2011 has affected various aspects of the nuclear society worldwide. The accident revealed some problems in the conventional approaches used to ensure the safety of nuclear installations. To prevent such disastrous accidents in the future, we have to learn from them and improve the conventional approaches in a more systematic manner. In this paper, we will cover three issues. The first is to identify the key issues that affected the progress of the Fukushima Dai-Ichi accident greatly. We examine the accident from a defense-in-depth point of view to identify such issues. The second is to develop a more systematic approach to enhance the safety of nuclear installations. We reexamine nuclear safety from a risk point of view. We use the concepts of residual and unknown risks in classifying the risk space. All possible accident scenarios types are reviewed to clarify the characteristics of the identified issues. An approach is proposed to improve our conventional approaches used to ensure nuclear safety including the design of safety features and the safety assessments from a risk point of view. Finally, we address some issues to be improved in the conventional risk assessment and management framework and/or practices to enhance nuclear safety.

The influence of simultaneous or sequential test conditions in the properties of industrial polymers, submitted to PWR accident simulations

International Nuclear Information System (INIS)

Carlin, F.; Alba, C.; Chenion, J.; Gaussens, G.; Henry, J.Y.

1986-10-01

The effect of PWR plant normal and accident operating conditions on polymers forms the basis of nuclear qualification of safety-related containment equipment. This study was carried out on the request of safety organizations. Its purpose was to check whether accident simulations carried out sequentially during equipment qualification tests would lead to the same deterioration as that caused by an accident involving simultaneous irradiation and thermodynamic effects. The IPSN, DAS and the United States NRC have collaborated in preparing this study. The work carried out by ORIS Company as well as the results obtained from measurement of the mechanical properties of 8 industrial polymers are described in this report. The results are given in the conclusion. They tend to show that, overall, the most suitable test cycle for simulating accident operating conditions would be one which included irradiation and consecutive thermodynamic shock. The results of this study and the results obtained in a previous study, which included the same test cycles, except for more severe thermo-ageing, have been compared. This comparison, which was made on three elastomers, shows that ageing after the accident has a different effect on each material [fr

analysis of reactivity accidents in MTR for various protection system parameters and core condition

International Nuclear Information System (INIS)

Mohamed, F.M.

2011-01-01

Egypt Second Research Reactor (ETRR-2) core was modified to irradiate LEU (Low Enriched Uranium) plates in two irradiation boxes for fission 99 Mo production. The old core comprising 29 fuel elements and one Co Irradiation Device (CID) and the new core comprising 27 fuel elements, CID, and two 99 Mo production boxes. The in core irradiation has the advantage of no special cooling or irradiation loop is required. The purpose of the present work is the analysis of reactivity accidents (RIA) for ETRR-2 cores. The analysis was done to evaluate the accidents from different point of view:1- Analysis of the new core for various Reactor Protection System (RPS) parameters 2- Comparison between the two cores. 3- Analysis of the 99 Mo production boxes.PARET computer code was employed to compute various parameters. Initiating events in RIA involve various modes of reactivity insertion, namely, prompt critical condition (p=1$), accidental ejection of partial and complete CID uncontrolled withdrawal of a control rod accident, and sudden cooling of the reactor core. The time histories of reactor power, energy released, and the maximum fuel, clad and coolant temperatures of fuel elements and LEU plates were calculated for each of these accidents. The results show that the maximum clad temperatures remain well below the clad melting of both fuel and uranium plates during these accidents. It is concluded that for the new core, the RIA with scram will not result in fuel or uranium plate failure.

Impact of the TMI accident on the French nuclear program and the safety analysis

International Nuclear Information System (INIS)

Fourest, B.; Boaretto, Y.; Cayol, A.; Droulers, Y.; Goudal, M.; Oury, J.M.

1980-04-01

Almost immediately after the TMI accident, Electricite de France (EdF), Framatome and the French safety authorities started a large scale program of actions designed to analyse and understand the causes of the accident, and draw lessons applicable in France. This paper discusses these actions and the main conclusions of TMI accident analysis in France, notably: the fundamental role of plant operators, and the importance of operator training, written instructions and procedures, and diagnostic aids; the importance of feeding back operating experience to design teams, and incorporating the results of accident and post-accident studies in operating procedures; the necessity to improve knowledge of core cooling modes, including during two-phase flow and natural circulation; measures to improve particular systems and components [fr

Professional experience and traffic accidents/near-miss accidents among truck drivers.

Science.gov (United States)

Girotto, Edmarlon; Andrade, Selma Maffei de; González, Alberto Durán; Mesas, Arthur Eumann

2016-10-01

To investigate the relationship between the time working as a truck driver and the report of involvement in traffic accidents or near-miss accidents. A cross-sectional study was performed with truck drivers transporting products from the Brazilian grain harvest to the Port of Paranaguá, Paraná, Brazil. The drivers were interviewed regarding sociodemographic characteristics, working conditions, behavior in traffic and involvement in accidents or near-miss accidents in the previous 12 months. Subsequently, the participants answered a self-applied questionnaire on substance use. The time of professional experience as drivers was categorized in tertiles. Statistical analyses were performed through the construction of models adjusted by multinomial regression to assess the relationship between the length of experience as a truck driver and the involvement in accidents or near-miss accidents. This study included 665 male drivers with an average age of 42.2 (±11.1) years. Among them, 7.2% and 41.7% of the drivers reported involvement in accidents and near-miss accidents, respectively. In fully adjusted analysis, the 3rd tertile of professional experience (>22years) was shown to be inversely associated with involvement in accidents (odds ratio [OR] 0.29; 95% confidence interval [CI] 0.16-0.52) and near-miss accidents (OR 0.17; 95% CI 0.05-0.53). The 2nd tertile of professional experience (11-22 years) was inversely associated with involvement in accidents (OR 0.63; 95% CI 0.40-0.98). An evident relationship was observed between longer professional experience and a reduction in reporting involvement in accidents and near-miss accidents, regardless of age, substance use, working conditions and behavior in traffic. Copyright © 2016 Elsevier Ltd. All rights reserved.

Identification of the security threshold by logistic regression applied to fuel under accident conditions

Energy Technology Data Exchange (ETDEWEB)

Gomes, Daniel de Souza; Baptista Filho, Benedito; Oliveira, Fabio Branco de, E-mail: dsgomes@ipen.br, E-mail: bdbfilho@ipen.br, E-mail: fabio@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Giovedi, Claudia, E-mail: claudia.giovedi@labrisco.usp.br [Universidade de Sao Paulo (POLI/USP), Sao Paulo, SP (Brazil). Lab. de Analise, Avaliacao e Gerenciamento de Risco

2015-07-01

A reactivity-initiated Accident (RIA) is a disastrous failure, which occurs because of an unexpected rise in the fission rate and reactor power. This sudden increase in the reactor power may activate processes that might lead to the failure of fuel cladding. In severe accidents, a disruption of fuel and core melting can occur. The purpose of the present research is to study the patterns of such accidents using exploratory data analysis techniques. A study based on applied statistics was used for simulations. Then, we chose peak enthalpy, pulse width, burnup, fission gas release, and the oxidation of zirconium as input parameters and set the safety boundary conditions. This new approach includes the logistic regression. With this, the present research aims also to develop the ability to identify the conditions and the probability of failures. Zirconium-based alloys fabricating the cladding of the fuel rod elements with niobium 1% were analyzed for high burnup limits at 65 MWd/kgU. The data based on six decades of investigations from experimental programs. In test, perform in American reactors such as the transient reactor test (TREAT), and power Burst Facility (PBF). In experiments realized in Japanese program at nuclear in the safety research reactor (NSRR), and in Kazakhstan as impulse graphite reactor (IGR). The database obtained from the tests and served as a support for our study. (author)

Identification of the security threshold by logistic regression applied to fuel under accident conditions

International Nuclear Information System (INIS)

Gomes, Daniel de Souza; Baptista Filho, Benedito; Oliveira, Fabio Branco de; Giovedi, Claudia

2015-01-01

A reactivity-initiated Accident (RIA) is a disastrous failure, which occurs because of an unexpected rise in the fission rate and reactor power. This sudden increase in the reactor power may activate processes that might lead to the failure of fuel cladding. In severe accidents, a disruption of fuel and core melting can occur. The purpose of the present research is to study the patterns of such accidents using exploratory data analysis techniques. A study based on applied statistics was used for simulations. Then, we chose peak enthalpy, pulse width, burnup, fission gas release, and the oxidation of zirconium as input parameters and set the safety boundary conditions. This new approach includes the logistic regression. With this, the present research aims also to develop the ability to identify the conditions and the probability of failures. Zirconium-based alloys fabricating the cladding of the fuel rod elements with niobium 1% were analyzed for high burnup limits at 65 MWd/kgU. The data based on six decades of investigations from experimental programs. In test, perform in American reactors such as the transient reactor test (TREAT), and power Burst Facility (PBF). In experiments realized in Japanese program at nuclear in the safety research reactor (NSRR), and in Kazakhstan as impulse graphite reactor (IGR). The database obtained from the tests and served as a support for our study. (author)

Some Lessons Learnt From the Fukushima Daiichi Accident, as Regards Defence in Depth and its Implementation in New or Existing Designs – An Industry Example

Energy Technology Data Exchange (ETDEWEB)

De L’Epinois, B.; Bouteille, F.; Nicaise, N., E-mail: bertrand.delepinois@areva.com [AREVA, Paris (France)

2014-10-15

reducing both the severe accident probability and the consequences of a severe accident, should it occur. This paper therefore analyzes, in the light of Fukushima, the DiD approach followed in the design of the EPR and ATMEA reactors in terms of accident prevention, common mode failure prevention and mitigation, protection against natural hazards and severe accident management. Insight is given, from a designer point of view, on the topics on which the Fukushima lessons learnt are implemented. The paper also exposes to what extent and in which fields the approach followed for new reactors can be applied to operating nuclear power plants. (author)

Safety upgrading activities against tsunami, earthquake, and severe accident at Hamaoka NPPs

International Nuclear Information System (INIS)

Watanabe, Tetsuya; Wakunaga, Takao; Ishida, Takahisa

2013-01-01

As the lessons learned by the Fukushima Daiichi NPPs accident, Chubu Electric Power carried out the Emergency Safety Measures at Hamaoka NPPs immediately, and announced the plan for tsunami countermeasures including the construction of 18m-height tsunami protection wall in July 2011. Furthermore, the company announced the additional severe accident and tsunami countermeasures, and etc. in December 2012 and in April 2013, such as the installation of Filtered Containment Venting System and increasing the height of the tsunami protection wall from 18m to 22m. In this paper, we present major safety upgrading activities against tsunami, earthquake and severe accident at Hamaoka NPPs. (author)

Accident analysis of Fukushima Daiichi Nuclear Power Station unit 1

International Nuclear Information System (INIS)

Kobayashi, Masahide; Narabayashi, Tadashi; Tsuji, Masashi; Chiba, Go; Nagata, Yasunori; Shimoe, Tomohiro

2015-01-01

As a result of the Great East Japan Earthquake that occurred on 11 March 2011, all AC and DC power at the Fukushima Daiichi NPP units 1 to 3 were lost soon after the tsunami. The core cooling function was lost, and the cores of units 1 to 3 were damaged. The purpose of this work is to clarify the progress of the accident in unit 1, which was damaged the earliest among the 3 units. Therefore, an original severe accident analysis code was developed, and the progress of the accident was evaluated from the analysis results and the actual data. As a result, the leakage path from a pressure vessel was clarified, and some lessons and knowledge were gained. (author)

Recriticality, a Key Phenomenon to Investigate in Core Disruptive Accident Scenarios of Current and Future Fast Reactor Designs

International Nuclear Information System (INIS)

Maschek, W.; Rineiski, A.; Flad, M.; Kriventsev, V.; Gabrielli, F.; Morita, K.

2012-01-01

Final comments and conclusions: • Modern plants, should have performed better under Fukushima type event. • In future fast reactor systems significantly higher active and passive safety features are installed, which should cope with events like Fukushima. • One important lesson: put a focus on rare initiators, accident routes and consequences that are neither expected nor have been observed, events that are categorized under ‘black swans’. • Importance of severe accident research demonstrated - both analytically and experimentally for assessing and interpreting accident scenarios and developments. Precondition for developing preventive & mitigative safety measures. Passive safety measures are in the focus of advanced design options and must work under conditions of multiple loads and aggravating events. • Fast reactor systems behavior as the SFR under severe accident conditions: – In fast spectrum systems as the SFR the core is not in its neutronically most reactive configuration and SFRs may be loaded with MAs for waste management; – Recriticalities have a high probability because of the higher enrichment levels; – Short time scales have to be envisioned for core melt-down; – Decay heat levels might be significantly higher, if MA bearing fuel is involved. • Improve design by measures for prevention and/or mitigation of recriticalities; – High reliability of simulations required for proof; • Assessment of fuel relocated on peripheral structures; • Preventive/mitigating measures should not replace containment measures

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)

Studies of severe accidents in light-water reactors

International Nuclear Information System (INIS)

1987-01-01

From 10 to 12 November 1986 some 80 delegates met under the auspices of the CEC working group on the safety of light-water reactors. The participants from EC Member States were joined by colleagues from Sweden, Finland and the USA and met to discuss the subject of severe accidents in LWRs. Although this seminar had been planned well before Chernobyl, the ''severe-accident-that-really-happened'' made its mark on the seminar. The four main seminar topics were: (i) high source-term accident sequences identified in PSAs, (ii) containment performance, (iii) mitigation of core melt consequences, (iv) severe accident management in LWRs. In addition to the final panel discussion there was also a separate panel discussion on lessons learned from the Chernobyl accident. These proceedings include the papers presented during the seminar and they are arranged following the seminar programme outline. The presentations and discussions of the two panels are not included in the proceedings. The general conclusions and directions following from these two panels were, however, considered in a seminar review paper which was published in the March 1987 issue of Nuclear Engineering International

Dynamic containment of gaseous effluents in the auxiliary buildings and reinjection of liquid effluents from these buildings back into the reactor building for 900 MWe PWRs under accident condition

International Nuclear Information System (INIS)

Demoulin, F.; Collinet, J.; Nguyen, C.

1987-04-01

Examination of the lessons to be learned from the accident of the Three Mile Island nuclear power plant on 20 March 1979 led the French Safety Authorities and EDF (Electricite de France) to adopt a series of measures intended to improve the performance of the containment of French PWRs, especially in the event of accident. Among the measures adopted, two of them contribute to the upgrading of the containment of nuclear island buildings, by reducing radioactivity constraints inside these buildings and by limiting radioactive releases into the environment. These are: (1) dynamic containment of auxiliary buildings likely to be contaminated following an accident, (2) reinjection back into the reactor building of liquid effluents arising in the auxiliary buildings. In this paper we shall discuss, for each measure, the approach to the problem and describe the arrangements made to arrive at a satisfactory solution [fr

Development of instrumentation systems for severe accidents. 4. New accident tolerant in-containment pressure transducer for containment pressure monitoring system

International Nuclear Information System (INIS)

Oba, Masato; Teruya, Kuniyuki; Yoshitsugu, Makoto; Ikeuchi, Takeshi

2015-01-01

The accident at Tokyo Electric Power Company's Fukushima Dai-ichi Nuclear Power Plant (TF-1 accident) caused severe situations and resulted in a difficulty in measuring important parameters for monitoring plant conditions. Therefore, we have studied the TF-1 accident to select the important parameters that should be monitored at the severe accident and are developing the Severe Accident Instrumentations and Monitoring Systems that could measure the parameters in severe accident conditions. Mitsubishi Heavy Industries, LTD (MHI) developed a new accident tolerant containment pressure monitoring system and demonstrated that the monitoring system could endure extremely harsh environmental conditions that envelop severe accident environmental conditions inside a containment such as maximum operating temperature of up to 300degC and total integrated dose (TID) of 1 MGy gamma. The new containment pressure monitoring system comprises of a strain gage type pressure transducer and a mineral insulated (MI) cable with ceramic connectors, which are located in the containment, and a strain measuring amplifier located outside the containment. Less thermal and radiation degradation is achieved because of minimizing use of organic materials for in-containment equipment such as the transducer and connectors. Several tests were performed to demonstrate the performance and capability of the in-containment equipment under severe accident environmental conditions and the major steps in this testing were run in the following test sequences: (1) the baseline functional tests (e.g., repeatability, non-linearity, hysteresis, and so on) under normal conditions, (2) accident radiation testing, (3) seismic testing, and (4) steam/temperature test exposed to simulated severe accident environmental conditions. The test results demonstrate that the new pressure transducer can endure the simulated severe accident conditions. (author)

Review of U.S. Army Aviation Accident Reports: Prevalence of Environmental Stressors and Medical Conditions

Science.gov (United States)

2017-10-18

terminology related to an aforementioned stressor or medical condition. Table 1 presents the identified operational stressor with the keywords extracted...USAARL Report No. 2018-02 Review of U.S. Army Aviation Accident Reports: Prevalence of Environmental Stressors and Medical Conditions By Kathryn...Environmental Stressors and Medical Conditions N/A N/A N/A N/A N/A N/A Feltman, Kathryn A. Kelley, Amanda M. Curry, Ian P. Boudreaux, David A. Milam

Shipping container response to severe highway and railway accident conditions: Appendices

International Nuclear Information System (INIS)

Fischer, L.E.; Chou, C.K.; Gerhard, M.A.; Kimura, C.Y.; Martin, R.W.; Mensing, R.W.; Mount, M.E.; Witte, M.C.

1987-02-01

Volume 2 contains the following appendices: Severe accident data; truck accident data; railroad accident data; highway survey data and bridge column properties; structural analysis; thermal analysis; probability estimation techniques; and benchmarking for computer codes used in impact analysis. (LN)

Ruthenium transport experiments in air ingress accident conditions

Energy Technology Data Exchange (ETDEWEB)

Teemu, Karkele; Ulrika, Backman; Ari, Auvinen; Unto, Tapper; Jorma, Jokiniemi [VTT Technical Research Centre of Finland, Fine Particles (Finland); Riitta, Zilliacus; Maija, Lipponen; Tommi, Kekki [VTT Technical Research Centre of Finland, Accident Management (Finland); Jorma, Jokiniemi [Kuopio Univ., Dept. of Environmental Sciences, Fine Particle and Aerosol Technology Lab. (Finland)

2007-07-01

In this study the release, transport and speciation of ruthenium in conditions simulating an air ingress accident was studied. Ruthenium dioxide was exposed to oxidising environment at high temperature (1100-1700 K) in a tubular flow furnace. At these conditions volatile ruthenium species were formed. A large fraction of the released ruthenium was deposited in the tube as RuO{sub 2}. Depending on the experimental conditions 1-26 wt% of the released ruthenium was trapped in the outlet filter as RuO{sub 2} particles. In stainless steel tube 0-8.8 wt% of the released ruthenium reached the trapping bottle as gaseous RuO{sub 4}. A few experiments were carried out, in which revaporization of ruthenium deposited on the tube walls was studied. In these experiments, oxidation of RuO{sub 2} took place at a lower temperature. During revaporization experiments 35-65 % of ruthenium was transported as gaseous RuO{sub 4}. In order to close mass balance and achieve better time resolution 4 experiments were carried out using a radioactive tracer. In these experiments ruthenium profiles were measured. These experiments showed that the most important retention mechanism was decomposition of gaseous RuO{sub 3} into RuO{sub 2} as the temperature of the furnace was decreasing. In these experiments the transport rate of gaseous ruthenium was decreasing while the release rate was constant.

Stress in accident and post-accident management at Chernobyl

International Nuclear Information System (INIS)

Girard, P.; Dubreuil, G.H.

1996-01-01

The effects of the Chernobyl nuclear accident on the psychology of the affected population have been much discussed. The psychological dimension has been advanced as a factor explaining the emergence, from 1990 onwards, of a post-accident crisis in the main CIS countries affected. This article presents the conclusions of a series of European studies, which focused on the consequences of the Chernobyl accident. These studies show that the psychological and social effects associated with the post-accident situation arise from the interdependency of a number of complex factors exerting a deleterious effect on the population. We shall first attempt to characterise the stress phenomena observed among the population affected by the accident. Secondly, we will be presenting an anlysis of the various factors that have contributed to the emerging psychological and social features of population reaction to the accident and in post-accident phases, while not neglecting the effects of the pre-accident situation on the target population. Thirdly, we shall devote some initial consideration to the conditions that might be conducive to better management of post-accident stress. In conclusion, we shall emphasise the need to restore confidence among the population generally. (Author)

Fission product release from HTGR fuel under core heatup accident conditions - HTR2008-58160

International Nuclear Information System (INIS)

Verfondern, K.; Nabielek, H.

2008-01-01

Various countries engaged in the development and fabrication of modern fuel for the High Temperature Gas-Cooled Reactor (HTGR) have initiated activities of modeling the fuel and fission product release behavior with the aim of predicting the fuel performance under operating and accidental conditions of future HTGRs. Within the IAEA directed Coordinated Research Project CRP6 on 'Advances in HTGR Fuel Technology Development' active since 2002, the 13 participating Member States have agreed upon benchmark studies on fuel performance during normal operation and under accident conditions. While the former has been completed in the meantime, the focus is now on the extension of the national code developments to become applicable to core heatup accident conditions. These activities are supported by the fact that core heatup simulation experiments have been resumed recently providing new, highly valuable data. Work on accident performance will be - similar to the normal operation benchmark - consisting of three essential parts comprising both code verification that establishes the correspondence of code work with the underlying physical, chemical and mathematical laws, and code validation that establishes reasonable agreement with the existing experimental data base, but including also predictive calculations for future heating tests and/or reactor concepts. The paper will describe the cases to be studied and the calculational results obtained with the German computer model FRESCO. Among the benchmark cases in consideration are tests which were most recently conducted in the new heating facility KUEFA. Therefore this study will also re-open the discussion and analysis of both the validity of diffusion models and the transport data of the principal fission product species in the HTGR fuel materials as essential input data for the codes. (authors)

Oxidation behavior of fuel cladding tube in spent fuel pool accident condition

International Nuclear Information System (INIS)

Nemoto, Yoshiyuki; Kaji, Yoshiyuki; Ogawa, Chihiro; Nakashima, Kazuo; Tojo, Masayuki

2017-01-01

In spent fuel pool (SFP) under loss-of-cooling or loss-of-coolant severe accident condition, the spent fuels will be exposed to air and heated by their own residual decay heat. Integrity of fuel cladding is crucial for SFP safety therefore study on cladding oxidation in air at high temperature is important. Zircaloy-2 (Zry2) and zircaloy-4 (Zry4) were applied for thermogravimetric analyses (TGA) in different temperatures in air at different flow rates to evaluate oxidation behavior. Oxidation rate increased with testing temperature. In a range of flow rate of air which is predictable in spent fuel lack during a hypothetical SFP accident, influence of flow rate was not clearly observed below 950degC for the Zry2, or below 1050degC for Zry4. In higher temperature, oxidation rate was higher in high rate condition, and this trend was seen clearer when temperature increased. Oxide layers were carefully examined after the TGA analyses and compared with mass gain data to investigate detail of oxidation process in air. It was revealed that the mass gain data in pre-breakaway regime reflects growth of dense oxide film on specimen surface, meanwhile in post-breakaway regime, it reflects growth of porous oxide layer beneath fracture of the dense oxide film. (author)

Study of labor accidents in the rural environment: analysis of processes and conditions of work

Directory of Open Access Journals (Sweden)

Thaís Alves Brito

2009-01-01

Full Text Available The modernization of agriculture, that broadenned the mechanization of farming and the agrotoxic use, potentially increased some risks of accidents. The agriculture workers and cattle raising are constantly exposed to several physical, chemical and biological agents, like machine, implements, handly tools, agrotoxics, ectoparaziticides, domestic animals and poisonous animals, which can to bring accidents. The aiming the importance of this working class to economic developing of country, this study was done to identify the working process and accidents that strike the rural population. This article is composed by a specialized literature review between September and December of 2007, which was made consultations to periodical and scientific articles selected through searches in the database of Scielo and Bireme. It was founded few studies related to rural workers, as well as the main articles had as setting of investigation the Southern and Southeastern, mainly in state of São Paulo and Rio Grande do Sul. In relation to work conditions was noticed a high degree of insalubrities which the workers are exposed, such as handly tools, poisonous animals, insecure attitudes because of lack of training and the no use of equipments of individual protection. There are a prevalence of accidents among men, occurring predominantly the typical accidents, the occupational disease and commute accidents. The relationships of work have been modified along the years, being the outsourcing outstanding point, however this work relationship causes legal losses to workers, which in most of the time get without social welfare right

RADIATION CONDITIONS IN KALUGA REGION 30 YEARS AFTER CHERNOBYL NPP ACCIDENT

Directory of Open Access Journals (Sweden)

A. G. Ashitko

2016-01-01

Full Text Available The article describes radiation conditions in the Kaluga region 30 years after the Chernobyl NPP accident. The Chernobyl NPP accident caused radioactive contamination of nine Kaluga region territories: Duminichsky, Zhizdrinsky, Kuibyshevsky, Kirovsky, Kozelsky, Ludinovsky, Meshchovsky, Ulyanovsky and Hvastovichsky districts. Radioactive fallout was the strongest in three southern districts: Zhizdrinsky, Ulyanovsky and Hvastovichsky, over there cesium-137 contamination density is from 1 to 15Ci/km. According to the Russian Federation Government Order in 2015 there are 300 settlements (S in the radioactive contamination zone, including 14 settlements with caesium-137 soil contamination density from 5 to 15 Ci/ km2 and 286 settlements with the contamination density ranging from 1 to 5 Ci/km2. In the first years after the Chernobyl NPP accident in Kaluga region territories, contaminated with caesium-137, there were introduced restrictive land usage, were carried out agrochemical activities (ploughing, mineral fertilizer dressing, there was toughened laboratory radiation control over the main doze-forming foodstuff. All these measures facilitated considerable decrease of caesium-137 content in local agricultural produce. Proceeding from the achieved result, in 2002 there took place the transition to more tough requirements SanPiN 2.3.2.1078-01. Analysis of investigated samples from Zhizdrinsky, Ulyanovsky and Hvastovichsky districts demonstrated that since 2005 meat samples didn’t exceed the standard values, same for milk samples since 2007. Till the present time, the use of wild-growing mushrooms, berries and wild animals meat involves radiation issues. It was demonstrated that average specific activity of caesium-137 in milk samples keeps decreasing year after year. Long after the Chernobyl NPP accident, the main products forming internal irradiation doses in population are the wild-growing mushrooms and berries. Population average annual

Simulations of the design basis accident at conditions of power increase and the o transient of MSIV at overpressure conditions of the Laguna Verde Power Station

International Nuclear Information System (INIS)

Araiza M, E.; Nunez C, A.

2001-01-01

This document presents the analysis of the simulation of the loss of coolant accident at uprate power conditions, that is 2027 MWt (105% of the current rated power of 1931MWt). This power was reached allowing an increase in the turbine steam flow rate without changing the steam dome pressure value at its rated conditions (1020 psiaJ. There are also presented the results of the simulation of the main steam isolation va/ve transient at overpressure conditions 1065 psia and 1067 MWt), for Laguna Verde Nuclear Power Station. Both simulations were performed with the best estimate computer code TRA C BF1. The results obtained in the loss of coolant accident show that the emergency core coolant systems can recover the water level in the core before fuel temperature increases excessively, and that the peak pressure reached in the drywell is always below its design pressure. Therefore it is concluded that the integrity of the containment is not challenged during a loss of coolant accident at uprate power conditions.The analysis of the main steam isolation valve transients at overpressure conditions, and the analysis of the particular cases of the failure of one to six safety relief valves to open, show that the vessel peak pressures are below the design pressure and have no significant effect on vessel integrity. (Author)

Relationships of working conditions, health problems and vehicle accidents in bus rapid transit (BRT) drivers.

Science.gov (United States)

Gómez-Ortiz, Viviola; Cendales, Boris; Useche, Sergio; Bocarejo, Juan P

2018-04-01

The aim of this study was to estimate accident risk rates and mental health of bus rapid transit (BRT) drivers based on psychosocial risk factors at work leading to increased stress and health problems. A cross-sectional research design utilized a self-report questionnaire completed by 524 BRT drivers. Some working conditions of BRT drivers (lack of social support from supervisors and perceived potential for risk) may partially explain Bogota's BRT drivers' involvement in road accidents. Drivers' mental health problems were associated with higher job strain, less support from co-workers, fewer rewards and greater signal conflict while driving. To prevent bus accidents, supervisory support may need to be increased. To prevent mental health problems, other interventions may be needed such as reducing demands, increasing job control, reducing amount of incoming information, simplifying current signals, making signals less contradictory, and revising rewards. © 2018 Wiley Periodicals, Inc.

Accident Case Study of Organizational Silence Communication Breakdown: Shuttle Columbia, Mission STS-107

Science.gov (United States)

Rocha, Rodney

2011-01-01

This report has been developed by the National Aeronautics and Space Administration (NASA) ESMD Risk and Knowledge Management team. This document provides a point-in-time, cumulative, summary of key lessons learned derived from the official Columbia Accident Investigation Board (CAIB). Lessons learned invariably address challenges and risks and the way in which these areas have been addressed. Accordingly the risk management thread is woven throughout the document. This report is accompanied by a video that will be sent at request

A new NEA expert group on accident-tolerant fuels

International Nuclear Information System (INIS)

Massara, Simone

2014-01-01

After the events at the Fukushima Daiichi nuclear power plant in March 2011, enhancing the accident tolerance of light water reactors (LWRs) became a topic of serious discussion. One outcome of those discussions has been to promote research into the development of advanced fuels and more robust reactor system technologies with improved performance, reliability and safety characteristics during normal operations and under accident conditions. The Fukushima Daiichi accident has highlighted in particular the importance of reducing hydrogen production rates and increasing fission product retention during extended loss of cooling accidents. In this context, the NEA organised two international workshops to share information and discuss technical and safety issues associated with the development of accident-tolerant fuels (ATFs) for LWRs. Presentations were given by experts from various organisations, industry and regulatory bodies of NEA member countries, as well as from representatives of international bodies. The presentations focused on lessons learnt from the Fukushima Daiichi accident, the desired characteristics of ATFs, potential design options and candidate materials, as well as the current state of the art in related modelling and simulation methods. During discussions following these workshop presentations, delegates agreed to establish a collaborative framework on ATFs within the NEA. Reporting to the Nuclear Science Committee, the Expert Group on Accident-tolerant Fuels for Light Water Reactors (EGATFL) will define and carry out a programme of work to help advance the scientific knowledge needed to provide the technical underpinning for the development of advanced LWR fuels with more enhanced accident tolerance compared to currently used zircaloy/UO 2 fuels. The group will foster information exchange on material properties and relevant phenomenological experiments, carry out state-of-the-art reviews, organise benchmark studies and foster international

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)

An overview of industrial radiography accidents in India during the period 1987-1997

International Nuclear Information System (INIS)

Kumar, A.; Subramanya, M.J.; Raghavendran, C.P.; Murthy, B.K.S.; Vishwakarma, R.R.; Kannan, R.; Sharma, A.; Bhatt, B.C.

1998-01-01

Use of gamma radiation sources for non-destructive testing of welds, castings and vital components in several industries in India has recorded a steep rise in the last three decades. There are over 1000 industrial gamma radiography exposure devices (IGRED) in over 400 institutions in the country. Most of these employ Co-60 and Ir-192 gamma sources. In spite of regulatory control and procedures there have been accidents with the IGREDs resulting in significant radiation exposures and in some cases, injuries to members of public and radiography personnel. This paper analyses the accidents which occurred in India during the ten year period of 1987-1997, management of such accidents, steps taken to avoid recurrence of these accidents based on the lessons learnt. (author)

Human error as the root cause of severe accidents at nuclear reactors

International Nuclear Information System (INIS)

Kovács Zoltán; Rýdzi, Stanislav

2017-01-01

A root cause is a factor inducing an undesirable event. It is feasible for root causes to be eliminated through technological process improvements. Human error was the root cause of all severe accidents at nuclear power plants. The TMI accident was caused by a series of human errors. The Chernobyl disaster occurred after a badly performed test of the turbogenerator at a reactor with design deficiencies, and in addition, the operators ignored the safety principles and disabled the safety systems. At Fukushima the tsunami risk was underestimated and the project failed to consider the specific issues of the site. The paper describes the severe accidents and points out the human errors that caused them. Also, provisions that might have eliminated those severe accidents are suggested. The fact that each severe accident occurred on a different type of reactor is relevant – no severe accident ever occurred twice at the same reactor type. The lessons learnt from the severe accidents and the safety measures implemented on reactor units all over the world seem to be effective. (orig.)

Analysis of Surface Water Pollution Accidents in China: Characteristics and Lessons for Risk Management.

Science.gov (United States)

Yao, Hong; Zhang, Tongzhu; Liu, Bo; Lu, Feng; Fang, Shurong; You, Zhen

2016-04-01

Understanding historical accidents is important for accident prevention and risk mitigation; however, there are no public databases of pollution accidents in China, and no detailed information regarding such incidents is readily available. Thus, 653 representative cases of surface water pollution accidents in China were identified and described as a function of time, location, materials involved, origin, and causes. The severity and other features of the accidents, frequency and quantities of chemicals involved, frequency and number of people poisoned, frequency and number of people affected, frequency and time for which pollution lasted, and frequency and length of pollution zone were effectively used to value and estimate the accumulated probabilities. The probabilities of occurrences of various types based on origin and causes were also summarized based on these observations. The following conclusions can be drawn from these analyses: (1) There was a high proportion of accidents involving multi-district boundary regions and drinking water crises, indicating that more attention should be paid to environmental risk prevention and the mitigation of such incidents. (2) A high proportion of accidents originated from small-sized chemical plants, indicating that these types of enterprises should be considered during policy making. (3) The most common cause (49.8% of the total) was intentional acts (illegal discharge); accordingly, efforts to increase environmental consciousness in China should be enhanced.

Analysis of Surface Water Pollution Accidents in China: Characteristics and Lessons for Risk Management

Science.gov (United States)

Yao, Hong; Zhang, Tongzhu; Liu, Bo; Lu, Feng; Fang, Shurong; You, Zhen

2016-04-01

Understanding historical accidents is important for accident prevention and risk mitigation; however, there are no public databases of pollution accidents in China, and no detailed information regarding such incidents is readily available. Thus, 653 representative cases of surface water pollution accidents in China were identified and described as a function of time, location, materials involved, origin, and causes. The severity and other features of the accidents, frequency and quantities of chemicals involved, frequency and number of people poisoned, frequency and number of people affected, frequency and time for which pollution lasted, and frequency and length of pollution zone were effectively used to value and estimate the accumulated probabilities. The probabilities of occurrences of various types based on origin and causes were also summarized based on these observations. The following conclusions can be drawn from these analyses: (1) There was a high proportion of accidents involving multi-district boundary regions and drinking water crises, indicating that more attention should be paid to environmental risk prevention and the mitigation of such incidents. (2) A high proportion of accidents originated from small-sized chemical plants, indicating that these types of enterprises should be considered during policy making. (3) The most common cause (49.8 % of the total) was intentional acts (illegal discharge); accordingly, efforts to increase environmental consciousness in China should be enhanced.

Hydrogen-management in beyond design accident conditions in NPP Neckar 2

International Nuclear Information System (INIS)

Zaiss, W.

1999-01-01

Neckar 2 is a 1340 MWE 4-loop pressurized water reactor (PWR) of Siemens KONVOI type, located in the south of Germany. It was first connected to the grid in January 1989. Commercial operation started in April 1989. Task assignment: In Germany it was recommended by the Reactor Safety Commission (RSK) on December 17, 1997, to reequip passive autocatalytic recombiners for the controlling of the hydrogen problem. The removal of the hydrogen is an essential part which guarantees the integrity of the containment. The implementation of the recombiners is a further step for the decrease of the nuclear rest risk. The RSK confirmed, that the implementation of the passive autocatalytic recombiners is a safety measure for the controlled removal of the hydrogen in beyond design accident conditions. Assumption : Failure of the whole residual heat removal system (RHRS) and non sufficient effect of the systems which have been installed for beyond design accident conditions. Effect on the reactor coolant system (RCS): The reactor core will be damaged by non sufficient cooling with the output of hydrogen because all the specified emergency actions have failed. The overheating of the core is responsible for the production of hydrogen by the reaction of zirconium of the fuel-rod cladding with the water vapour. In case of nuclear superheating it would be possible that the reactor vessel would start smelting. The interacting between the core and the concrete, together with the armouring of the biological shield would also produce hydrogen. The hydrogen would escape together with the water vapour out of the leak and would spread out into the whole containment. Results : the number and the position of the different sized recombiners were determined on engineering judgement. the following 4 scenarios are representatively. The 4 scenarios were analyzed for in beyond design accident conditions with the MELCOR-Code: No. 1: Loss of main feedwater supply with primary feed and bleed. No. 2

The Fukushima accident and its consequences. Facts, explanations and comments; L'accident de Fukushima et ses consequences. Faits, explications et commentaires

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-03-06

This document proposes an overview of the present situation in the different reactors of the Fukushima power station and discusses its control by the operator. It also describes what went on, the causes of the accident, and what occurred on the accident day (earthquake, tsunami, flooding). It discusses whether some mistakes regarding the design and the protection of reactors could explain the accident. It presents the various measures which have been immediately implemented to protect the populations and to confine the accident. It proposes an assessment of damages for the ground and marine environment in terms of contamination. It addresses the consequences of the released radioactivity on population health and on personnel intervening within the site. It discusses the restoration perspectives for contaminated areas and the possible return of evacuated population. Then, it describes the different phases for the station dismantling. It evokes the issue of fallouts beyond Japan and in Europe, outlines some lessons learned from the accident and new safety measures to be implemented in France. It discusses how nuclear risk management is organised in France and its efficiency. It addresses the consequences for the development of nuclear energy in the world

Response Analysis on Electrical Pulses under Severe Nuclear Accident Temperature Conditions Using an Abnormal Signal Simulation Analysis Module

Directory of Open Access Journals (Sweden)

Kil-Mo Koo

2012-01-01

Full Text Available Unlike design basis accidents, some inherent uncertainties of the reliability of instrumentations are expected while subjected to harsh environments (e.g., high temperature and pressure, high humidity, and high radioactivity occurring in severe nuclear accident conditions. Even under such conditions, an electrical signal should be within its expected range so that some mitigating actions can be taken based on the signal in the control room. For example, an industrial process control standard requires that the normal signal level for pressure, flow, and resistance temperature detector sensors be in the range of 4~20 mA for most instruments. Whereas, in the case that an abnormal signal is expected from an instrument, such a signal should be refined through a signal validation process so that the refined signal could be available in the control room. For some abnormal signals expected under severe accident conditions, to date, diagnostics and response analysis have been evaluated with an equivalent circuit model of real instruments, which is regarded as the best method. The main objective of this paper is to introduce a program designed to implement a diagnostic and response analysis for equivalent circuit modeling. The program links signal analysis tool code to abnormal signal simulation engine code not only as a one body order system, but also as a part of functions of a PC-based ASSA (abnormal signal simulation analysis module developed to obtain a varying range of the R-C circuit elements in high temperature conditions. As a result, a special function for abnormal pulse signal patterns can be obtained through the program, which in turn makes it possible to analyze the abnormal output pulse signals through a response characteristic of a 4~20 mA circuit model and a range of the elements changing with temperature under an accident condition.

Evaluation of the leakage behavior of inflatable seals subject to severe accident conditions

International Nuclear Information System (INIS)

Parks, M.B.

1989-11-01

Sandia National Laboratories, under the sponsorship of the United States Nuclear Regulatory Commission, is currently developing test validated methods to predict the pressure capacity of light water reactor containment buildings when subjected to postulated severe accident conditions. These conditions are well beyond the design basis. Scale model tests of steel and reinforced concrete containments have been conducted as well as tests of typical containment penetrations. As a part of this effort, a series of tests was recently conducted to determine the leakage behavior of inflatable seals. These seals are used to prevent leakage around personnel and escape lock doors of some containments. The results of the inflatable seals tests are the subject of this report. Inflatable seals were tested at both room temperature and at elevated temperatures representative of postulated severe accident conditions. Both aged (radiation and thermal) and unaged seals were included in the test program. The internal seal pressure at the beginning of each test was varied to cover the range of seal pressures actually used in containments. For each seal pressure level, the external (containment) pressure was increased until significant leakage past the seals was observed. Parameters that were monitored and recorded during the tests were the internal seal pressure, chamber pressure, leakage past the seals, and temperature of the test chamber and fixture to which the seals were attached. 8 refs., 34 figs., 7 tabs

Analysis of the behaviour of the Kozloduy NPP Unit 3 under severe accident conditions

International Nuclear Information System (INIS)

Velev, V.; Saraeva, V.

2004-01-01

The objective of the analysis is to study the behaviour of the Kozloduy NPP Unit 3 under severe accident conditions. The analysis is performed using computer code MELCOR 1.8.4. This report includes a brief description of Unit 3 active core as well as description and comparison of the key events

To revisit economics of nuclear technology. Lessons from the learning of a complex technology by major accidents

International Nuclear Information System (INIS)

Finon, Dominique

2012-05-01

The Fukushima accident raises again the issue of the social and economic viability of nuclear technology. To re-evaluate this viability, we analyse the past process of internalisation of external costs of nuclear energy, which present the specificities to be chanted by accidents and has had a constant effect of complexification. This process has provoked a de-organisation of the classical learning process reflected in constant cost increases and the change of social preferences, to end up by the lack of competitiveness before climate policies. Independent institutions of safety regulation have become essential elements of the social embeddedness of nuclear technology at the expense of technology stability and standardization, condition of its competitiveness. In this perspective, the paper argues that the new sequence of social costs' internalization opened by Fukushima will have limited effects on costs, because of anterior steps of safety improvements. Nuclear technology complexification reaches its asymptote: it is being to overcome the challenge of 'learning by major accidents'. On the other hand nuclear institutions must be re-designed in such a way that it could guarantee maximum safety records and minimum residual risks by going to the other root of the safety issue, the degree of independence and capabilities of the safety authorities in every country, what cannot be decreed. It is nevertheless at this price that could be preserved the global public good of the social acceptance of nuclear technology by limiting drastically chance of new accidents. (author)

Nuclear power plant accident simulations of gasket materials under simultaneous radiation plus thermal plus mechanical stress conditions

International Nuclear Information System (INIS)

Gillen, K.T.; Malone, G.M.

1997-07-01

In order to probe the response of silicone door gasket materials to a postulated severe accident in an Italian nuclear power plant, compression stress relaxation (CSR) and compression set (CS) measurements were conducted under combined radiation (approximately 6 kGy/h) and temperature (up to 230 degrees C) conditions. By making some reasonable initial assumptions, simplified constant temperature and dose rates were derived that should do a reasonable job of simulating the complex environments for worst-case severe events that combine overall aging plus accidents. Further simplification coupled with thermal-only experiments allowed us to derive thermal-only conditions that can be used to achieve CSR and CS responses similar to those expected from the combined environments that are more difficult to simulate. Although the thermal-only simulations should lead to sealing forces similar to those expected during a severe accident, modulus and density results indicate that significant differences in underlying chemistry are expected for the thermal-only and the combined environment simulations. 15 refs., 31 figs., 15 tabs

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

Science.gov (United States)

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

2016-02-01

The better knowledge of the mechanisms of nuclear incidents and lessons learned from accidents in the recent past to improve the effectiveness of measures taken following a nuclear accident exposure to fallout of radioactive iodine isotopes. Thus, immediate, passive measures, such as containment, and stopping consumption of contaminated products are paramount. The earliest possible administration of stable iodine as potassium iodide (KI) reduces significantly (up to 90% if taken at the same time of the accident) thyroid radioactive contamination. These tablets should be given in priority to children and pregnant women. The side effects are minor. KI is not recommended for persons aged over 60 years, or for adults suffering from cardiovascular disorders. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

The analysis of a condition of an accident rate on highways of Tajikistan

International Nuclear Information System (INIS)

Davlatshoev, R.A.; Tursunov, A.A.

2005-01-01

In this clause the results of the analysis of an accident rate on highways of Tajikistan, according to the official information State Automobile Inspection the Ministry of Internal affairs of Republic of Tajikistan, and research of safe movement of automobiles in mountain conditions are given. On the basis of the qualitative and quantitative analysis, the ways of safe movement on roads of Republic of Tajikistan are determined

Probabilistic Approach to Conditional Probability of Release of Hazardous Materials from Railroad Tank Cars during Accidents

Science.gov (United States)

2009-10-13

This paper describes a probabilistic approach to estimate the conditional probability of release of hazardous materials from railroad tank cars during train accidents. Monte Carlo methods are used in developing a probabilistic model to simulate head ...

Human Factors in Accidents Involving Remotely Piloted Aircraft

Science.gov (United States)

Merlin, Peter William

2013-01-01

This presentation examines human factors that contribute to RPA mishaps and provides analysis of lessons learned. RPA accident data from U.S. military and government agencies were reviewed and analyzed to identify human factors issues. Common contributors to RPA mishaps fell into several major categories: cognitive factors (pilot workload), physiological factors (fatigue and stress), environmental factors (situational awareness), staffing factors (training and crew coordination), and design factors (human machine interface).

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

International Nuclear Information System (INIS)

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

2013-01-01

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

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

Science.gov (United States)

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

2013-09-01

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

A Study on the Operation Strategy for Combined Accident including TLOFW accident

International Nuclear Information System (INIS)

Kim, Bo Gyung; Kang, Gook Young; Yoon, Ho Joon

2014-01-01

It is difficult for operators to recognize the necessity of a feed-and-bleed (F-B) operation when the loss of coolant accident and failure of secondary side occur. An F-B operation directly cools down the reactor coolant system (RCS) using the primary cooling system when residual heat removal by the secondary cooling system is not available. The plant is not always necessary the F-B operation when the secondary side is failed. It is not necessary to initiate an F-B operation in the case of a medium or large break because these cases correspond to low RCS pressure sequences when the secondary side is failed. If the break size is too small to sufficiently decrease the RCS pressure, the F-B operation is necessary. Therefore, in the case of a combined accident including a secondary cooling system failure, the provision of clear information will play a critical role in the operators' decision to initiate an F-B operation. This study focuses on the how we establish the operation strategy for combined accident including the failure of secondary side in consideration of plant and operating conditions. Previous studies have usually focused on accidents involving a TLOFW accident. The plant conditions to make the operators confused seriously are usually the combined accident because the ORP only focuses on a single accident and FRP is less familiar with operators. The relationship between CET and PCT under various plant conditions is important to decide the limitation of initiating the F-B operation to prevent core damage

TMI-2: Lessons learned by the US Department of Energy: A programmatic perspective

International Nuclear Information System (INIS)

Schmitt, R.C.; Reno, H.W.; Bentley, K.J.; Owens, D.E.

1990-03-01

This report is a summary of the lessons learned by the US Department of Energy during its decade-long participation in the research and accident cleanup project at Three Mile Island Nuclear Power Station Unit 2 near Harrisburg, Pennsylvania. It is based on a review of a wide range of project documents and interviews with personnel from the many organizations involved. The lessons are organized into major subjects with a brief background section to orient the reader to that subject. The subjects are divided into sub-topics, each with a brief discussion and a series of lessons learned. The lessons are very brief and each is preceded with a keyword phrase to highlight its specific topic. References are given so that the details of the subject and the lesson can be further investigated. 99 refs., 24 figs

Application of the accident management information needs methodology to a severe accident sequence

International Nuclear Information System (INIS)

Ward, L.W.; Hanson, D.J.; Nelson, W.R.; Solberg, D.E.

1989-01-01

The U.S. Nuclear Regulatory Commission (NRC) is conducting an Accident Management Research Program that emphasizes the application of severe accident research results to enhance the capability of plant operating personnel to effectively manage severe accidents. A methodology to identify and assess the information needs of the operating staff of a nuclear power plant during a severe accident has been developed as part of the research program designed to resolve this issue. The methodology identifies the information needs of the plant personnel during a wide range of accident conditions, the existing plant measurements capable of supplying these information needs and what, if any minor additions to instrument and display systems would enhance the capability to manage accidents, known limitations on the capability of these measurements to function properly under the conditions that will be present during a wide range of severe accidents, and areas in which the information systems could mislead plant personnel. This paper presents an application of this methodology to a severe accident sequence to demonstrate its use in identifying the information which is available for management of the event. The methodology has been applied to a severe accident sequence in a Pressurized Water Reactor with a large dry containment. An examination of the capability of the existing measurements was then performed to determine whether the information needs can be supplied

10 years from the Chernobyl nuclear reactor accident: consequences and lesson learned

International Nuclear Information System (INIS)

1996-01-01

Published jointly by the Czech State Office for Nuclear Safety and the Czech National Radiation Protection Institute, the publication gives a succinct account of the cause of the Chernobyl accident and its impact on the former Soviet Union, and concentrates on the effects of the accident on the Czech Republic. The topics dealt with in this respect include, among others: radionuclide contents of foods with particular emphasis on milk products for babies, assessment of surface contamination of the Czech Republic due to the accident, internal contamination of the population as determined by whole-body measurements, assessment of the effective dose equivalents from external irradiation and effective dose equivalent commitments from internal irradiation, cesium radioisotopes in natural ecosystems, and the use of post-Chernobyl monitoring to test radionuclide migration models within the IAEA VAMP programme. (P.A.). 12 tabs., 30 figs., 64 refs

Analysis on the Role of RSG-GAS Pool Cooling System during Partial Loss of Heat Sink Accident

Science.gov (United States)

Susyadi; Endiah, P. H.; Sukmanto, D.; Andi, S. E.; Syaiful, B.; Hendro, T.; Geni, R. S.

2018-02-01

RSG-GAS is a 30 MW reactor that is mostly used for radioisotope production and experimental activities. Recently, it is regularly operated at half of its capacity for efficiency reason. During an accident, especially loss of heat sink, the role of its pool cooling system is very important to dump decay heat. An analysis using single failure approach and partial modeling of RELAP5 performed by S. Dibyo, 2010 shows that there is no significant increase in the coolant temperature if this system is properly functioned. However lessons learned from the Fukushima accident revealed that an accident can happen due to multiple failures. Considering ageing of the reactor, in this research the role of pool cooling system is to be investigated for a partial loss of heat sink accident which is at the same time the protection system fails to scram the reactor when being operated at 15 MW. The purpose is to clarify the transient characteristics and the final state of the coolant temperature. The method used is by simulating the system in RELAP5 code. Calculation results shows the pool cooling systems reduce coolant temperature for about 1 K as compared without activating them. The result alsoreveals that when the reactor is being operated at half of its rated power, it is still in safe condition for a partial loss of heat sink accident without scram.

The Chernobyl accident is the greatest social ecological and technological catastrophe in a human history. Chapter 4

International Nuclear Information System (INIS)

Babosov, E.M.

1995-01-01

The lessons of the Chernobyl tragedy for mankind are shown. Ecological consequences of the accident are described. It is given the analysis of social and psychological consequences of the Chernobyl accident - change of a mode of life of the people on the contaminated territories, a development post-catastrophe processes, a migration moods of the population, an aggravation of a demographic situation. Problems of an administrative activity on the contaminated territories are discussed and measures for decrease of the Chernobyl accident consequences are offered. 51 refs., 7 tabs

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)

Assessment of WWER fuel condition in design basis accident

International Nuclear Information System (INIS)

Bibilashvili, Yu.; Sokolov, N.; Andreeva-Andrievskaya, L.; Vlasov, Yu.; Nechaeva, O.; Salatov, A.

1994-01-01

The fuel behaviour in design basis accidents is assessed by means of the verified code RAPTA-5. The code uses a set of high temperature physico-chemical properties of the fuel components as determined for commercially produced materials, fuel rod simulators and fuel rod bundles. The WWER fuel criteria available in Russia for design basis accidents do not generally differ from the similar criteria adopted for PWR's. 12 figs., 11 refs

Development of Educational and Training Simulator for Emergency Response to Chinese Nuclear Accidents

International Nuclear Information System (INIS)

Kim, Juyub; Kim, Juyoul; Kim, Sukhoon; Lee, Seunghee; Yoon, Taebin; Cliff, Li-Chi

2015-01-01

One of the lessons in the emergency response category is that information on the nuclear power plants of neighboring countries should be organized and the consequence can be assessed. In addition, many reactors have been constructed and are under construction on the eastern coast of China recently. Korea might be directly affected by an accident of Chinese nuclear power plant since Korea is located in the westerly belt. performed with the PCTRAN/CPR-1000 module. The result showed that normal operation and DBA conditions were simulated swiftly with the speed of 16 times faster than real time. Thus, it would be a good source term estimation module for the educational and training simulator

Accident investigation practices in Europe--main responses from a recent study of accidents in industry and transport.

Science.gov (United States)

Roed-Larsen, Sverre; Valvisto, T; Harms-Ringdahl, L; Kirchsteiger, C

2004-07-26

Europe has during recent years been shocked by disasters from natural events and technical breakdowns. The consequences have been comprehensive, measured by lost lives, injuries, and material and environmental damage. ESReDA wanted in 2000--by setting up a special expert group on accident investigation--to clarify the state of art of accident investigation practices and to map the use of thoroughly accident investigation in order to learn lessons from past disasters and prevent new ones. The scope was to cover three sectors in the society: transport, production processes and storage of hazardous materials, and energy production. The main method used was a questionnaire, which was sent in 2001 to about 150 organisations. About 50 replies were analysed. The replies showed great variations but also similarities, among others in definition of accident and incident, the objectives of the investigation team, criteria used to start an investigation, the status of the investigation organisation, the flow of information, the composition of the investigation team, and the use of internal or international procedures or rules. Several methods (in total 14 different methods were mentioned) were used for carrying out accident /incident investigations. Most of the respondents were willing to co-operate in one or another way with ESReDA. Although there are important biases in the material, the results from questionnaire are important inputs to the future work of ESReDA Expert group in this field. 3 safety approaches have been identified.

Implications of the Chernobyl accident for Protective Action Guidance

International Nuclear Information System (INIS)

Miller, Charles W.; Pepper, Andrea J.

1989-01-01

The accident that occurred at Unit 4 of the nuclear power station at Chernobyl in the Union of Soviet Socialist Republics on April 26, 1986, was the worst accident in the history of nuclear power. Thirty-one workers and emergency personnel died and more than 200 site personnel were hospitalized as a result of this event Approximately 135,000 persons within 30 km around the reactor were evacuated, and radioactive debris was spread throughout the Northern Hemisphere. There was much public concern generated around the world, and an increased risk of fatal cancel in the world's population is possible as a result of exposure to Chernobyl fallout (USNRC, 1987a). Since the time the Chernobyl accident occurred, many authoritative studies have been published, e.g. USNRC, 1987a. In these studies, differences in design between commercial U.S. reactors and the RBMK pressure-tube reactor at Chernobyl have been emphasized, e.g. USNRC, 1987b. While significant differences in design do exist between these reactors, we believe there are still significant lessons to be learned from the Chernobyl accident for U.S. reactors. The purpose of this paper is to summarize some of the major lessons to be learned related to protective action guidance. The Illinois Department of Nuclear Safety (IDNS) has identified three areas related to protective action guidance for food and water where implications can be drawn from Chernobyl for the U.S.: (1) uniformity of Protective Action Guides (PAGs), (2) incompleteness of U.S. PAGs, and (3) international communications. Following the Chernobyl accident, a variety of protective actions were undertaken by various nations. Furthermore, these actions were initiated, modified, and terminated at different times in different places and, in some instances, were applied on a local or regional basis rather than a national basis (Goldman et al., 1987). One result of this differing application of PAGs was the generation of considerable confusion among decision

Evolution of regulation related to the Chernobyl accident

International Nuclear Information System (INIS)

Anisimova, L.I.; Belyaev, S.T.; Demin, V.F.; Kutkov, V.A.

1997-01-01

The 'classical' pattern of radiological protection considers mostly the radiation factor. The choice of protective measures is governed by effective doses, both received and projected, also established and adopted intervention levels, respectively. The effectiveness of the countermeasures is measured by the value of an averted dose. The lessons learned from Chernobyl show that the above single-factor pattern of radiological protection is appropriate only at an acute post-accident phase. In that period (days and weeks after an accident) the radiation factor prevails and bas countermeasures are proceeded from prearranged intervention levels. At the next long-term phase (months, years after the accident) there is enough time for a human factor to come fully into force. This factor implies the psychological and social acceptance, by the public, of the countermeasures to be implemented. It implies the response of the public to their implementation, the reflection of the situation by mass media, the reaction of Legislative and Administrative Bodies too

Radiological Cs-137 accidents/incidents in Estonia

International Nuclear Information System (INIS)

Sinisso, Mark

1997-01-01

Two radiological accidents/incidents in Estonia are reported. The first -21 October 1994, three brothers entered the Tammiku repository and stole a radioactive Cs-137 source and received dangerous doses of radiation. The other incident (early 1995) involved an abandoned source - a discarded metal cylinder containing Cs-137. Chronologies and factual data are considered for both events. Concise descriptions of the incidents, a medical overview of the fate of injured people and lessons learned are presented

Radiological Cs-137 accidents/incidents in Estonia

Energy Technology Data Exchange (ETDEWEB)

Sinisso, Mark [Ministry of Foreign Affairs, Tallin (Estonia)

1997-12-31

Two radiological accidents/incidents in Estonia are reported. The first -21 October 1994, three brothers entered the Tammiku repository and stole a radioactive Cs-137 source and received dangerous doses of radiation. The other incident (early 1995) involved an abandoned source - a discarded metal cylinder containing Cs-137. Chronologies and factual data are considered for both events. Concise descriptions of the incidents, a medical overview of the fate of injured people and lessons learned are presented

TMI-2 Lessons Learned Task Force. Final report

International Nuclear Information System (INIS)

1979-10-01

In its final report reviewing the Three Mile Island accident, the TMI-2 Lessons Learned Task Force has suggested change in several fundamental aspects of basic safety policy for nuclear power plants. Changes in nuclear power plant design and operations and in the regulatory process are discussed in terms of general goals. The appendix sets forth specific recommendations for reaching these goals

Failure of fretted steam generator tubes under accident conditions

International Nuclear Information System (INIS)

Forrest, C.F.

1996-10-01

Tests were carried out with a bank of tubes in a water tunnel to determine the tolerance of flawed nuclear reactor steam generator tubes to accident conditions which would result in high cross-flow velocities. Fourteen specimen tubes were tested, each having one or two types of defect machined into the surface simulating fretting-wear type scars found in some operating steam generators. The tubes were tested at flow velocities sufficient to induce high fluid elastic-type vibrations. Seven of the tubes failed near the thinnest section of the defects during the one-hour tests, due to impacting and/or rubbing between the tube and the support. Strain gauges, displacement transducers, force gauges and an accelerometer were used on the target tube and/or the tube immediately downstream of it to measure their vibrational characteristics

Recovery operations in the event of a nuclear accident or radiological emergency

International Nuclear Information System (INIS)

1990-01-01

Much progress has been made over the last decade in the field of emergency planning and preparedness, including the development of guidance, criteria, training programmes, regulations and comprehensive plans in the support of nuclear facilities. To provide a forum for international review and discussion of actual experiences gained and lessons learned from the different aspects of recovery techniques and operations in response to serious accidents at nuclear facilities and accidents associated with radioactive materials, the IAEA organized the International Symposium on Recovery Operations in the Event of a Nuclear Accident or Radiological Emergency. The symposium was held from 6 to 10 November 1989 in Vienna, Austria, and was attended by over 250 experts from 35 Member State and 7 international organizations. Although the prime focus was on on-site and off-site recovery from nuclear reactor accidents and on recovery from radiological accidents unrelated to nuclear power plants, development of emergency planning and preparedness resources was covered as well. From the experiences reported, lessons learned were identified. While further work remains to be done to improve concepts, plans, materials, communications and mechanisms to assemble quickly all the special resources needed in the event of an accident, there was general agreement that worldwide preparations to handle any possible future radiological emergencies had vastly improved. A special feature of the symposium programme was the inclusion of a full session on an accident involving a chemical explosion in a high level waste tank a a plutonium extraction plant in the Southern Urals in the USSR in 1957. Information was presented on the radioactive release, its dissemination and deposition, the resultant radiation situation, dose estimates, health effects follow-up, and the rehabilitation of contaminated land. This volume contains the full text of the 49 papers presented at the symposium together with a

Robot dispatching Scenario for Accident Condition Monitoring of NPP

International Nuclear Information System (INIS)

Kim, Jongseog

2013-01-01

In March of 2011, unanticipated big size of tsunami attacks Fukushima NPP, this accident results in explosion of containment building. Tokyo electric power of Japan couldn't dispatch a robot for monitoring of containment inside. USA Packbot robot used for desert war in Iraq was supplied to Fukushima NPP for monitoring of high radiation area. Packbot also couldn't reach deep inside of Fukushima NPP due to short length of power cable. Japanese robot 'Queens' also failed to complete a mission due to communication problem between robot and operator. I think major reason of these robot failures is absence of robot dispatching scenario. If there was a scenario and a rehearsal for monitoring during or after accident, these unanticipated obstacles could be overcome. Robot dispatching scenario studied for accident of nuclear power plant was described herein. Study on scenario of robot dispatching is performed. Flying robot is regarded as good choice for accident monitoring. Walking robot with arm equipped is good for emergency valve close. Short time work and shift work by several robots can be a solution for high radiation area. Thin and soft cable with rolling reel can be a good solution for long time work and good communication

Establishment of Technical Collaboration basis between Korea and France for the development of severe accident assessment computer code under high burnup condition

International Nuclear Information System (INIS)

Kim, H. D.; Kim, D. H.; Park, S. Y.; Park, J. H.

2005-10-01

This project was performed by KAERI in the frame of construction of the international cooperative basis on the nuclear energy. This was supported from MOST under the title of 'Establishment of Technical Collaboration basis between Korea and France for the development of severe accident assessment computer code under high burn up condition'. The current operating NPP are converting the burned fuel to the wasted fuel after burn up of 40 GWD/MTU. But in Korea, burn up of more than 60 GWD/MTU will be expected because of the high fuel efficiency but also cost saving for storing the wasted fuel safely. The domestic research for the purpose of developing the fuel and the cladding that can be used under the high burn up condition up to 100 GWD/MTU is in progress now. But the current computer code adopts the model and the data that are valid only up to the 40 GWD/MTU at most. Therefore the current model could not take into account the phenomena that may cause differences in the fission product release behavior or in the core damage process due to the high burn up operation (more than 40 GWD/MTU). To evaluate the safety of the NPP with the high burn up fuel, the improvement of current severe accident code against the high burn up condition is an important research item. Also it should start without any delay. Therefore, in this study, an expert group was constructed to establish the research basis for the severe accident under high burn up conditions. From this expert group, the research items regarding the high burn up condition were selected and identified through discussion and technical seminars. Based on these selected items, the meeting between IRSN and KAERI to find out the cooperative research items on the severe accident under the high burn up condition was held in the IRSN headquater in Paris. After the meeting, KAERI and IRSN agreed to cooperate with each other on the selected items, and to co-host the international seminar, and to develop the model and to

Nuclear Fuel Behaviour in Loss-of-coolant Accident (LOCA) Conditions

International Nuclear Information System (INIS)

Pettersson, Kjell; Chung, Haijung; ); Billone, Michael; Fuketa, Toyoshi; Nagase, Fumihisa; Grandjean, Claude; Hache, George; Papin, Joelle; Heins, Lothar; Hozer, Zoltan; In de Betou, Jan; Kelppe, Seppo; Mayer, Ralph; Scott, Harold; Voglewede, John; Sonnenburg, Heinz; Sunder, Sham; Valach, Mojmir; Vrtilkova, Vera; Waeckel, Nicolas; Wiesenack, Wolfgang; Zimmermann, Martin

2009-01-01

The NEA Working Group on Fuel Safety (WGFS) is tasked with advancing the current understanding of fuel safety issues by assessing the technical basis for current safety criteria and their applicability to high burn-up and to new fuel designs and materials. The group aims at facilitating international convergence in this area, including as regards experimental approaches and interpretation and the use of experimental data relevant for safety. In 1986, a working group of the NEA Committee on the Safety of Nuclear Installations (CSNI) issued a state-of-the-art report on water reactor fuel behaviour in design-basis accident (DBA) conditions. The 1986 report was limited to the oxidation, embrittlement and deformation of pressurised water reactor (PWR) fuel in a loss-of-coolant accident (LOCA). Since then, considerable experimental and analytical work has been performed, which has led to a broader and deeper understanding of LOCA-related phenomena. Further, new cladding alloys have been produced, which might behave differently than the previously used Zircaloy-4, both under normal operating conditions and during transients. Compared with 20 years ago, fuel burn-up has been significantly increased, which requires extending the LOCA database in order to cover the high burnup range. There was also a clear need to address LOCA performance for reactor types other than PWRs. The present report has been prepared by the WGFS and covers the following technical aspects: - Description of different LOCA scenarios for major types of reactors: BWRs, PWRs, VVERs and to a lesser extent CANDUs. - LOCA phenomena: ballooning, burst, oxidation, fuel relocation and possible fracture at quench. - Details of high-temperature oxidation behaviour of various cladding materials. - Metallurgical phase change, effect of hydrogen and oxygen on residual cladding ductility. - Methods for LOCA testing, for example two-sided oxidation and ring compression for ductility, and integral quench test for

Development of a diagnostic system for identifying accident conditions in a reactor

International Nuclear Information System (INIS)

Santhosh; Gera, B.; Kumar, Mithilesh; Thangamani, I.; Prasad, Hari; Srivastava, A.; Dutta, Anu; Sharma, Pavan K.; Majumdar, P.; Verma, V.; Mukhopadhyay, D.; Ganju, Sunil; Chatterjee, B.; Sanyasi Rao, V.V.S.; Lele, H.G.; Ghosh, A.K.

2009-07-01

This report describes a methodology for identification of accident conditions in a nuclear reactor from the signals available to the operator. A large database of such signals is generated through analyses - for core, containment, environmental dispersion and radiological dose to train a computer code based on an Artificial Neural Networks (ANNs). At present, in the prediction mode, information on LOCA (location and size of break), status of availability of ECCS, and expected doses can be predicted well for a 220 MWe PHWR. (author)

Assessment of WWER fuel condition in design basis accident

Energy Technology Data Exchange (ETDEWEB)

Bibilashvili, Yu; Sokolov, N; Andreeva-Andrievskaya, L; Vlasov, Yu; Nechaeva, O; Salatov, A [Vsesoyuznyj Nauchno-Issledovatel` skij Inst. Neorganicheskikh Materialov, Moscow (Russian Federation)

1994-12-31

The fuel behaviour in design basis accidents is assessed by means of the verified code RAPTA-5. The code uses a set of high temperature physico-chemical properties of the fuel components as determined for commercially produced materials, fuel rod simulators and fuel rod bundles. The WWER fuel criteria available in Russia for design basis accidents do not generally differ from the similar criteria adopted for PWR`s. 12 figs., 11 refs.

49 CFR 195.50 - Reporting accidents.

Science.gov (United States)

2010-10-01

... 49 Transportation 3 2010-10-01 2010-10-01 false Reporting accidents. 195.50 Section 195.50 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... PIPELINE Annual, Accident, and Safety-Related Condition Reporting § 195.50 Reporting accidents. An accident...

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.

Investigation of conditions inside the reactor building annulus of a PWR plant of KONVOI type in case of severe accidents with increased containment leakages

International Nuclear Information System (INIS)

Bakalov, Ivan; Sonnenkalb, Martin

2018-01-01

Improvements of the implemented severe accident management (SAM) concepts have been done in all operating German NPPs after the Fukushima Daiichi accidents following recommendations of the German Reactor Safety Commission (RSK) and as a result of the stress test being performed. The efficiency of newly developed severe accident management guidelines (SAMG) for a PWR KONVOI reference plant related to the mitigation of challenging conditions inside the reactor building (RB) annulus due to increased containment leakages during severe accidents have been assessed. Based on two representative severe accident scenarios the releases of both hydrogen and radionuclides into the RB annulus have been predicted with different boundary conditions. The accident scenarios have been analysed without and with the impact of several SAM measures (already planned or proposed in addition), which turned out to be efficient to mitigate the consequences. The work was done within the frame of a research project financially supported by the Federal Ministry BMUB.

Investigation of conditions inside the reactor building annulus of a PWR plant of KONVOI type in case of severe accidents with increased containment leakages

Energy Technology Data Exchange (ETDEWEB)

Bakalov, Ivan [Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) gGmbH, Berlin (Germany); Sonnenkalb, Martin [Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) gGmbH, Koeln (Germany)

2018-02-15

Improvements of the implemented severe accident management (SAM) concepts have been done in all operating German NPPs after the Fukushima Daiichi accidents following recommendations of the German Reactor Safety Commission (RSK) and as a result of the stress test being performed. The efficiency of newly developed severe accident management guidelines (SAMG) for a PWR KONVOI reference plant related to the mitigation of challenging conditions inside the reactor building (RB) annulus due to increased containment leakages during severe accidents have been assessed. Based on two representative severe accident scenarios the releases of both hydrogen and radionuclides into the RB annulus have been predicted with different boundary conditions. The accident scenarios have been analysed without and with the impact of several SAM measures (already planned or proposed in addition), which turned out to be efficient to mitigate the consequences. The work was done within the frame of a research project financially supported by the Federal Ministry BMUB.

The Influence of atmospheric conditions to probabilistic calculation of impact of radiology accident on PWR 1000 MWe

International Nuclear Information System (INIS)

Pande Made Udiyani; Sri Kuntjoro

2015-01-01

The calculation of the radiological impact of the fission products releases due to potential accidents that may occur in the PWR (Pressurized Water Reactor) is required in a probabilistic. The atmospheric conditions greatly contribute to the dispersion of radionuclides in the environment, so that in this study will be analyzed the influence of atmospheric conditions on probabilistic calculation of the reactor accidents consequences. The objective of this study is to conduct an analysis of the influence of atmospheric conditions based on meteorological input data models on the radiological consequences of PWR 1000 MWe accidents. Simulations using PC-Cosyma code with probabilistic calculations mode, the meteorological data input executed cyclic and stratified, the meteorological input data are executed in the cyclic and stratified, and simulated in Muria Peninsula and Serang Coastal. Meteorological data were taken every hour for the duration of the year. The result showed that the cumulative frequency for the same input models for Serang coastal is higher than the Muria Peninsula. For the same site, cumulative frequency on cyclic input models is higher than stratified models. The cyclic models provide flexibility in determining the level of accuracy of calculations and do not require reference data compared to stratified models. The use of cyclic and stratified models involving large amounts of data and calculation repetition will improve the accuracy of statistical calculation values. (author)

Fission product releases at severe LWR accident conditions: ORNL/CEA measurements versus calculations

Energy Technology Data Exchange (ETDEWEB)

Andre, B.; Ducros, G.; Leveque, J.P. [CEA Centre d`Etudes de Grenoble, 38 (France). Dept. de Thermohydraulique et de Physique; Osborne, M.F.; Lorenz, R.A. [Oak Ridge National Lab., TN (United States); Maro, D. [CEA Centre d`Etudes de Fontenay-aux-Roses, 92 (France). Dept. de Protection de l`Environnement et des Installations

1995-12-31

Experimental programs in the United States and France have followed similar paths in supplying much of the data needed to analyze severe accidents. Both the HI/VI program, conducted at the Oak Ridge National Laboratory (ORNL) under the sponsorship of the U. S. Nuclear Regulatory Commission (NRC), and the HEVA/VERCORS program, supported by IPSN-Commissariat a l`Energie Atomique (CEA) and carried out at the Centre d`Etudes Nucleaires de Grenoble, have studied fission product release from light water reactor (LWR) fuel samples during test sequences representative of severe accidents. Recognizing that more accurate data, i.e., a better defined source term, could reduce the safety margins included in the rather conservative source terms originating from WASH-1400, the primary objective of these programs has been to improve the data base concerning fission product release and behavior at high temperatures. To facilitate the comparison, a model based on fission product diffusion mechanisms that was developed at ORNL and adapted with CEA experimental data is proposed. This CEA model is compared with the ORNL experimental data in a blind test. The two experimental programs used similar techniques in out-of-pile studies. Highly irradiated fuel samples were heated in radiofrequency induction furnaces to very high temperatures (up to 2700 K at ORNL and 2750 K at CEA) in oxidizing (H{sub 2}O), reducing (H{sub 2}) or mixed (H{sub 2}O+H{sub 2}) environments. The experimental parameters, which were chosen from calculated accident scenarios, did not duplicate specific accidents, but rather emphasized careful control of test conditions to facilitate extrapolation of the results to a wide variety of accident situations. This paper presents a broad and consistent database from ORNL and CEA release results obtained independently since the early 1980`S. A comparison of CORSOR and CORSOR Booth calculations, currently used in safety analysis, and the experimental results is presented and

IAEA and WANO Mark Anniversary of Fukushima Accident, Increase Cooperation, 5 March 2012, Vienna/London

International Nuclear Information System (INIS)

2012-01-01

Full text: Next Sunday, 11 March 2012, marks the first anniversary of the devastating earthquake and tsunami that struck the east coast of Japan. One year on, the International Atomic Energy Agency (IAEA) and the World Association of Nuclear Operators (WANO) are increasing their mutual cooperation to maximise nuclear safety efforts around the globe. The two organisations are revising their Memorandum of Understanding in light of the lessons learned from the Fukushima accident, and will be stepping up their efforts to share expertise and knowledge between operators and governments. There will be greater coordination between WANO peer reviews and IAEA OSART missions, in which international experts assess the safety of individual nuclear power plants, and discussions are under way to examine further areas to improve information sharing. This is in addition to the other work each organisation is doing to reinforce nuclear safety worldwide. IAEA Director General, Yukiya Amano said: 'The IAEA is delighted to strengthen its coordination and cooperation with WANO. One of the lessons of Fukushima is the need for strong and effective communication between governments, regulators and nuclear operators. The IAEA's Action Plan on Nuclear Safety underlines the need for all stakeholders to work together to put these lessons into practice as tangibly and swiftly as possible, to deliver concrete results. By working more closely together, we can help to ensure that practical experience is properly shared to reinforce nuclear safety everywhere'. Laurent Stricker, Chairman of WANO, commented: 'While the terrible events of last year had a major lasting impact on the industry, they have also served as the catalyst for huge change. WANO has shifted from primarily focusing on accident prevention, to an emphasis on both prevention and mitigation, and has redoubled its efforts to promote excellence in nuclear safety in each and every plant across the world. All nuclear plants have carefully

Safety enhancement efforts after Fukushima accident in Korea

Energy Technology Data Exchange (ETDEWEB)

Lee, U.C., E-mail: uclee@nssc.go.kr [Nuclear Safety & Security Commission, Seoul (Korea, Republic of)

2014-07-01

On March 11 of 2011, a massive earthquake and powerful tsunami hit the north-eastern region of Japan and the Fukushima Daiichi Nuclear Power Plant was massively damaged. Korea which is located closest to Japan was not directly affected, however, its people were shocked. They were concerned over the possibility of being exposed to radiation as well as for the safety of domestic nuclear power plants. The Korean government recognized the need to take prompt and immediate actions to alleviate these concerns. The Korean government immediately implemented special safety inspection and derived 50 long and short-term improvement action items to ensure safety of NPPs under extreme hazard conditions. At present, stage 3 of implementation strategy is being implemented, with completion of 22 items including ASTS (Automatic Seismic Trip System) as well as revision of 14 items including suitability review of action measures taken for investigation and research of maximum earthquake at NPP sites. The IAEA Integrated Regulatory Review Service (IRRS) mission was conducted for two weeks during July 10 and 22, 2011, which happened to be the very first review mission to be carried out since the Fukushima disaster. A module on the policy issues related to the actions taken after the Fukushima accident was newly added to the mission. The mission highlighted positive aspects of Korea's safety regulatory program, praising its technical competence and effectiveness. Additionally it concluded that Korea has been responding to the accident in a timely and an effective manner. The follow-up review mission is scheduled in December of this year, expanding the scope to include radiation safety as well. The most noteworthy change in Korea since the Fukushima accident is independence of the regulatory body. Not only to enhance effectiveness and independence of the regulatory body but to secure nuclear safety, the Nuclear Safety and Security Commission (NSSC) was established on October 26

Core-melting accidents in Chernobyl and Harrisburg

International Nuclear Information System (INIS)

Loon, A.J. van; Vonderen, A.C.M. van

1987-01-01

This publication deals with the essences of the reactor accident in Chernobylsk and the conclusions to be drawn from these with regard to reactor safety. Therein the technical differences between the reactor types in the West and the East play an important role. Also attention is spent to the now generally accepted philosophy that by simplification and making use of proven technologies, a further deminishing of the risks can be achieved step by step. In ch.'s 2 and 4 the origin and course of the accidents in respectively Chernobylsk and Harrisburg are analyzed; in the analysis of the Chernobylsk accident also date have been used which were provided by the Sovjet-Union, supplied with results of studies of the U.S. Department of Energy (DOE). In ch. 3 this information is compared with the insights which have grown at KEMA about these on the base of reactor physical and thermohydraulic considerations and of computer calculations reproducing the course of the accident. An important question is if, and if so: to which extent, an accident such as the one in Chernobylsk also can take place in the West. In order to answer that question as accurate as possible the consequences of core meltings accidents and the risk for such an accident taking place are pursued. In ch. 6 the legal frameworks are indicated by which the risk may be limited and by which eventually yet occurring damage may be arranged. Ch. 7 finally deals with the lessons which the accidents in Chernobylsk and Harrisburg have learnt us and with the possible consequences of these for the further application of nuclear power in the Netherlands. (H.W.). 105 refs.; 42 figs.; 17 refs

Occupational accidents among mototaxi drivers.

Science.gov (United States)

Amorim, Camila Rego; de Araújo, Edna Maria; de Araújo, Tânia Maria; de Oliveira, Nelson Fernandes

2012-03-01

The use of motorcycles as a means of work has contributed to the increase in traffic accidents, in particular, mototaxi accidents. The aim of this study was to estimate and characterize the incidence of occupational accidents among the mototaxis registered in Feira de Santana, BA. This is a cross-sectional study with descriptive and census data. Of the 300 professionals registered at the Municipal Transportation Service, 267 professionals were interviewed through a structured questionnaire. Then, a descriptive analysis was conducted and the incidence of accidents was estimated based on the variables studied. Relative risks were calculated and statistical significance was determined using the chi-square test and Fisher's exact test, considering p accidents were observed in 10.5% of mototaxis. There were mainly minor injuries (48.7%), 27% of them requiring leaves of absence from work. There was an association between the days of work per week, fatigue in lower limbs and musculoskeletal complaints, and accidents. Knowledge of the working conditions and accidents involved in this activity can be of great importance for the adoption of traffic education policies, and to help prevent accidents by improving the working conditions and lives of these professionals.

Accidents and emergency conditions: Legal aspects

International Nuclear Information System (INIS)

Peinsipp, N.

1985-01-01

The currently valid versions of the Federal German Atomic Energy Act, the Radiation Protection Ordinance, and the X-Ray Ordinance show differences with regard to the use of the terms 'accident' or 'emergency', respectively, preferring either one or the other term, or using both terms. The author comments on this lack of harmonization in terminology and goes into details on aspects such as legislation and application of law. (DG) [de

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

International Nuclear Information System (INIS)

Kljenak, I.; Mavko, B.

2007-01-01

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

Generic implications of the Chernobyl accident

International Nuclear Information System (INIS)

Sege, G.

1989-01-01

The US Nuclear Regulatory Commission (NRC) staff's assessment of the generic implications of the Chernobyl accident led to the conclusion that no immediate changes in the NRC's regulations regarding design or operation of US commercial reactors are needed. However, further consideration of certain issues was recommended. This paper discusses those issues and the studies being addressed to them. Although 24 tasks relating to light water reactor issues are identified in the Chernobyl follow-up research program, only four are new initiatives originating from Chernobyl implications. The remainder are limited modifications of ongoing programs designed to ensure that those programs duly reflect any lessons that may be drawn from the Chernobyl experience. The four new study tasks discussed include a study of reactivity transients, to reconfirm or bring into question the adequacy of potential reactivity accident sequences hitherto selected as a basis for design approvals; analysis of risk at low power and shutdown; a study of procedure violations; and a review of current NRC testing requirements for balance of benefits and risks. Also discussed, briefly, are adjustments to ongoing studies in the areas of operational controls, design, containment, emergency planning, and severe accident phenomena

Reperes, the information magazine of the Institute for Radiation Protection and Nuclear Safety - IRSN, No. 12 - January 2012, Special issue Fukushima - First lessons from the accident; Reperes, le magazine d'information de l'Institut de radioprotection et de surete nucleaire - IRSN, No. 12 - janvier 2012, Special Fukushima - Premieres lecons de l'accident

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-01-15

A first set of articles addresses the nuclear crisis in Japan (description of the accident, information mission sent by France, and support actions undertaken by France in Japan in the fields of education, civilian security, culture, sailing, media, dosimeters, robotics). A second set discusses lessons learned in terms of nuclear safety (complementary safety assessments, stress test in Gravelines), radiological consequences (impact on Japanese population, the Symbiose software, the Teleray network), crisis management, and research

What kind of accidents can happen in a nuclear power plant

International Nuclear Information System (INIS)

Debes, M.

1995-01-01

The lessons drawn from real reactor accidents are of great value. The safety approach in France relies on defence in depth and takes into account accidents in the plant design, completed by a probabilistic approach and experience feedback. Ultimate procedure are implemented on the basis of severe accidents studies which include core melting or partial containment defect, in order to mitigate their consequences even if they are improbable, and to enable a proper implementation of emergency planning countermeasures. The accident hypothesis and consequences are considered to draw the emergency planning procedures. Off site countermeasures, such as in house-confinement, limited evacuation or iodine distribution, are efficient in limiting the consequences for the public. Experience feedback, in association with a proactive vigilance and prevention policy, is developed in order to detect and correct in a proactive way the root causes of any deviation, even minor, so as to avoid multiple failures and ensure safety. (author). 4 refs., 2 figs., 1 tab

Helping HSE Team in Learning from Accident by Using the Management Oversight and Risk Tree Analysis Method

Directory of Open Access Journals (Sweden)

Iraj Mohammadfam

2016-09-01

Conclusion: The analysis using MORT method helped the organization with learning lessons from the accident especially at the management level. In order to prevent the similar and dissimilar accidents, the inappropriate informational network within the organization, inappropriate operational readiness, lack of proper implementation of work permit, the inappropriate and lack of updated technical information systems regarding equipments and working process, and the inappropriate barriers should be considered in a special way.

Reconstruction of the Chernobyl emergency and accident management

International Nuclear Information System (INIS)

Schinner, F.; Andreev, I.; Andreeva, I.; Fritsche, F.; Hofer, P.; Lettner, E.; Seidelberger, E.; Kromp-Kolb, H.; Kromp, W.

1998-01-01

Full text of publication follows: on April 26, 1986 the most serious civil technological accident in the history of mankind occurred of the Chernobyl Nuclear Power Plant (ChNPP) in the former Soviet Union. As a direct result of the accident, the reactor was severely destroyed and large quantities of radionuclides were released. Some 800000 persons, also called 'liquidators' - including plant operators, fire-fighters, scientists, technicians, construction workers, emergency managers, volunteers, as well as medical and military personnel - were part of emergency measurements and accident management efforts. Activities included measures to prevent the escalation of the accident, mitigation actions, help for victims as well as activities in order to provide a basic infrastructure for this unprecedented and overwhelming task. The overall goal of the 'Project Chernobyl' of the Institute of Risk Research of the University of Vienna was to preserve for mankind the experience and knowledge of the experts among the 'liquidators' before it is lost forever. One method used to reconstruct the emergency measures of Chernobyl was the direct cooperation with liquidators. Simple questionnaires were distributed among liquidators and a database of leading accident managers, engineers, medical experts etc. was established. During an initial struggle with a number of difficulties, the response was sparse. However, after an official permit had been issued, the questionnaires delivered a wealth of data. Furthermore a documentary archive was established, which provided additional information. The multidimensional problem in connection with the severe accident of Chernobyl, the clarification of the causes of the accident, as well as failures and successes and lessons to be learned from the Chernobyl emergency measures and accident management are discussed. (authors)

The Fukushima accident and its consequences. Facts, explanations and comments

International Nuclear Information System (INIS)

2012-01-01

This document proposes an overview of the present situation in the different reactors of the Fukushima power station and discusses its control by the operator. It also describes what went on, the causes of the accident, and what occurred on the accident day (earthquake, tsunami, flooding). It discusses whether some mistakes regarding the design and the protection of reactors could explain the accident. It presents the various measures which have been immediately implemented to protect the populations and to confine the accident. It proposes an assessment of damages for the ground and marine environment in terms of contamination. It addresses the consequences of the released radioactivity on population health and on personnel intervening within the site. It discusses the restoration perspectives for contaminated areas and the possible return of evacuated population. Then, it describes the different phases for the station dismantling. It evokes the issue of fallouts beyond Japan and in Europe, outlines some lessons learned from the accident and new safety measures to be implemented in France. It discusses how nuclear risk management is organised in France and its efficiency. It addresses the consequences for the development of nuclear energy in the world

Design feasibility study on corium stabilization in bottom end-fitting for AHWR under accident condition

International Nuclear Information System (INIS)

Gokhale, Onkar; Mukhopadhyay, D.; Chatterjee, B.; Singh, R.K.

2015-01-01

Advanced Heavy Water Reactor (AHWR) is being designed in a robust way to cater both Design and Beyond Design Basis Accidents to meet all the safety functions. All the functions are met by passive means with special emphasis on 'residual heat removal' which is catered by passive natural circulation mode. In context to Design Basis Accidents, several features are designed to handle worst kind of scenario like Station Black Out. For Design Extension Conditions (DEC), the means of passive natural circulation is adopted as a design means to meet the DEC-A conditions like cooling of moderator by natural circulation means with GDWP inventory. Under the DEC-B condition where large scale of fuel melting is envisaged, a core catcher is designed with active/passive cooling modes to take care of the residual heat of the core. All the mentioned features utilizes the natural mode of heat transfer to meet one of the safety function i.e. 'residual heat removal'. The analysis shows that the tube sheet as well as lattice tube temperatures remain low and are able to take out the heat from corium through sub-cooled nucleate boiling. The ES cooling is sufficient to maintain the cooling water in subcooled condition. The integrity of tube sheet and lattice tube is maintained

Basic study on BWR plant behavior under the condition of severe accident (2)

International Nuclear Information System (INIS)

Ozaki, Yoshihiko; Ueda, Masataka; Sasaki, Hajime

2016-01-01

In this paper, we report on the results using the BWR plant simulator about the plant behavior under the condition of the two types of severe accidents that LOCA occurs but ECCS fails the water irrigation into the reactor core and SBO occurs and at the same time the reclosed failure of SRV occurs. The simulation experiments were carried out for the cases that LOCA has occurred in the main feed-water piping. As for the results about the relationship between the LOCA area and the time from LOCA occurs until the fuel temperature rise start, the effect that RCIC operated was extremely big for small and middle LOCA area. In the case of main feed-water system LOCA, the core water level suddenly decreased for large LOCA of 2000 cm"2 area, however, if the irrigation into the reactor core was carried out 30 min after LOCA occurrence, the core had little damage. In addition, the H_2 concentration in the containment vessel did not exceed both limits of H_2 explosion nor detonation. The pressure of the containment vessel was around 3 kg/cm"2 of design value, so the soundness of the containment vessel was confirmed. On the other hand, for the accident of SBO with reclosed failure of SRV, it has been shown that the accidents continue to progress rapidly as compared with the case of normally operating of SRV. Because SRV has the function that keep the inside pressure of reactor core by repeating opened and closed in response of the inside pressure and prevent the decrease of water level inside reactor core. However, if the irrigation into the reactor core was carried out 30 min after SBO occurrence, the core had little damage and also the H_2 concentration in the containment vessel did not exceed limits of H_2 explosion. Further, as for the accident of reclosed failure of SRV, it has been shown that there are very good correspondence with the simulation results of main steam piping LOCA of area 180 cm"2 corresponding to the inlet cross-sectional area SRV installed on the piping

Inadequacies of Belgium nuclear emergency plans: lessons from the Fukushima catastrophe have not been learned

International Nuclear Information System (INIS)

Boilley, David; Josset, Mylene

2015-01-01

After having outlined that some Belgium regional authorities made some statements showing that they did not learn lessons neither from the Chernobyl catastrophe, nor from the Fukushima accident, this report aims at examining whether Belgium is well prepared to face a severe nuclear accident occurring within its borders or in neighbouring countries, whether all hypotheses have actually been taken into account, and whether existing emergency plans are realistic. After a presentation of Belgium's situation regarding nuclear plants (Belgium plants and neighbouring French plants), the report presents the content and organisation of the nuclear emergency plan for the Belgium territory at the national, provincial and municipal levels. While outlining inadequacies and weaknesses of the Belgium plan regarding the addressed issues, it discusses the main lessons learned from the Fukushima accident in terms of emergency planning areas, of population sheltering, of iodine-based prophylaxis, of population evacuation, of food supply, of tools (measurement instruments) and human resources, and of public information. In the next parts, the report addresses and discusses trans-border issues, and the commitment of stakeholders

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

Energy Technology Data Exchange (ETDEWEB)

Hoover, M.D.; Farrell, R.F. [DOE, Carlsbad, NM (United States); Newton, G.J.

1995-12-01

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

Analysis of emergency response to fukushima nuclear accident in Japan and suggestions for China's nuclear emergency management

International Nuclear Information System (INIS)

Li Wei; Ding Qihua; Wu Haosong

2014-01-01

On March 11, 2011, the Fukushima Dai-ichi Nuclear Power Station of the Tokyo Electric Power Company ('TEPCO') was hit and damaged by a magnitude 9 earthquake and accompanying tsunami. The accident is determined to be of the highest rating on the International Nuclear Event Scale. The Government of Japan and TEPCO have taken emergency response actions on-site and off-site at the accident. It became clear through the investigation that the accident had been initiated on the occasion of a natural disaster of an earthquake and tsunami, but there have been various complex problems behind this very serious and large scale accident. For an example, the then-available accident preventive measures and disaster preparedness of TEPCO were insufficient against tsunami and severe accidents; inadequate TEPCO emergency responses to the accident at the site were also identified. The accident rang the alarm for the nuclear safety of nuclear power plants. It also taught us a great of lessons in nuclear emergency management. (authors)

The individual teacher in lesson study collaboration

DEFF Research Database (Denmark)

Skott, Charlotte Krog; Møller, Hanne

2017-01-01

used in lesson study research. Design/methodology/approach The authors use collective case studies. By being participant observers the authors provide detailed descriptions of two selected teachers’ lived experiences of lesson study collaboration. In addition to gain first-hand insights, the authors...... in the participation of each of the two teachers during a two-year lesson study project. By comparing these shifts the authors identify significant conditions for their individual learning. Research limitations/implications Although the study is small scale, both the insights into the different ways in which teachers...... participated and the theoretical insights might be valuable for other lesson study research approaches. Practical implications This paper provides valuable insights into conditions that might influence teachers’ participation in lesson study activities, especially in cultures with little experience of lesson...

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.

Contributing factors in construction accidents.

Science.gov (United States)

Haslam, R A; Hide, S A; Gibb, A G F; Gyi, D E; Pavitt, T; Atkinson, S; Duff, A R

2005-07-01

This overview paper draws together findings from previous focus group research and studies of 100 individual construction accidents. Pursuing issues raised by the focus groups, the accident studies collected qualitative information on the circumstances of each incident and the causal influences involved. Site based data collection entailed interviews with accident-involved personnel and their supervisor or manager, inspection of the accident location, and review of appropriate documentation. Relevant issues from the site investigations were then followed up with off-site stakeholders, including designers, manufacturers and suppliers. Levels of involvement of key factors in the accidents were: problems arising from workers or the work team (70% of accidents), workplace issues (49%), shortcomings with equipment (including PPE) (56%), problems with suitability and condition of materials (27%), and deficiencies with risk management (84%). Employing an ergonomics systems approach, a model is proposed, indicating the manner in which originating managerial, design and cultural factors shape the circumstances found in the work place, giving rise to the acts and conditions which, in turn, lead to accidents. It is argued that attention to the originating influences will be necessary for sustained improvement in construction safety to be achieved.

Simulation of the transient processes of load rejection under different accident conditions in a hydroelectric generating set

Science.gov (United States)

Guo, W. C.; Yang, J. D.; Chen, J. P.; Peng, Z. Y.; Zhang, Y.; Chen, C. C.

2016-11-01

Load rejection test is one of the essential tests that carried out before the hydroelectric generating set is put into operation formally. The test aims at inspecting the rationality of the design of the water diversion and power generation system of hydropower station, reliability of the equipment of generating set and the dynamic characteristics of hydroturbine governing system. Proceeding from different accident conditions of hydroelectric generating set, this paper presents the transient processes of load rejection corresponding to different accident conditions, and elaborates the characteristics of different types of load rejection. Then the numerical simulation method of different types of load rejection is established. An engineering project is calculated to verify the validity of the method. Finally, based on the numerical simulation results, the relationship among the different types of load rejection and their functions on the design of hydropower station and the operation of load rejection test are pointed out. The results indicate that: The load rejection caused by the accident within the hydroelectric generating set is realized by emergency distributing valve, and it is the basis of the optimization for the closing law of guide vane and the calculation of regulation and guarantee. The load rejection caused by the accident outside the hydroelectric generating set is realized by the governor. It is the most efficient measure to inspect the dynamic characteristics of hydro-turbine governing system, and its closure rate of guide vane set in the governor depends on the optimization result in the former type load rejection.

Prevalence of oral health-related conditions that could trigger accidents for patients with moderate-to-severe dementia.

Science.gov (United States)

Kobayashi, Naoki; Soga, Yoshihiko; Maekawa, Kyoko; Kanda, Yuko; Kobayashi, Eiko; Inoue, Hisako; Kanao, Ayana; Himuro, Yumiko; Fujiwara, Yumi

2017-03-01

This study was performed to determine the prevalence of oral health conditions unnoticed by doctors and ward staff that may increase risk of incidents and/or accidents in hospitalised patients with moderate-severe dementia. Dementia patients may not recognise risks in the mouth, such as tooth mobility or ill-fitting dental prostheses and/or dentures. In addition to the risk of choking, injury by sharp edges of collapsed teeth or prosthodontics could pose risks. However, many previous publications were limited to case reports or series. Ninety-two consecutive hospitalised dementia patients (M: 52, F: 40, median age: 82.5 years, range: 62-99 years, from 2011 to 2014), referred for dentistry for dysphagia rehabilitation, were enrolled in this study. Participants referred for dental treatment with dental problems detected by ward staff were excluded. All participants had a Global Clinical Dementia Rating Score >2. Their dental records were evaluated retrospectively for issues that may cause incidents and/or accidents. Problems in the mouth, for example tooth stumps, dental caries, and ill-fitting dentures, were detected in 51.1% of participants (47/92). Furthermore, 23.9% (22/92) showed risk factors that could lead to incidents and/or accidents, for example falling out of teeth and/or prosthodontics or injury by sharp edges of teeth and/or prosthodontics. Hospitalised moderate-severe dementia patients had a high prevalence of oral health conditions unnoticed by doctors and ward staff that may increase risk of incidents and/or accidents. © 2016 John Wiley & Sons A/S and The Gerodontology Association. Published by John Wiley & Sons Ltd.

Fuel behaviour in the case of severe accidents and potential ATF designs. Fuel Behavior in Severe Accidents and Potential Accident Tolerance Fuel Designs

International Nuclear Information System (INIS)

Cheng, Bo

2013-01-01

This presentation reviews the conditions of fuel rods under severe loss of coolant conditions, approaches that may increase coping time for plant operators to recover, requirements of advanced fuel cladding to increase tolerance in accident conditions, potential candidate alloys for accident-tolerant fuel cladding and a novel design of molybdenum (Mo) -based fuel cladding. The current Zr-alloy fuel cladding will lose all its mechanical strength at 750-800 deg. C, and will react rapidly with high-pressure steam, producing significant hydrogen and exothermic heat at 700-1000 deg. C. The metallurgical properties of Zr make it unlikely that modifications of the Zr-alloy will improve the behaviour of Zr-alloys at temperatures relevant to severe accidents. The Mo-based fuel cladding is designed to (1) maintain fuel rod integrity, and reduce the release rate of hydrogen and exothermic heat in accident conditions at 1200-1500 deg. C. The EPRI research has thus far completed the design concepts, demonstration of feasibility of producing very thin wall (0.2 mm) Mo tubes. The feasibility of depositing a protective coating using various techniques has also been demonstrated. Demonstration of forming composite Mo-based cladding via mechanical reduction has been planned

Mitigative techniques and analysis of generic site conditions for ground-water contamination associated with severe accidents

Energy Technology Data Exchange (ETDEWEB)

Shafer, J.M.; Oberlander, P.L.; Skaggs, R.L.

1984-04-01

The purpose of this study is to evaluate the feasibility of using ground-water contaminant mitigation techniques to control radionuclide migration following a severe commercial nuclear power reactor accident. The two types of severe commercial reactor accidents investigated are: (1) containment basemat penetration of core melt debris which slowly cools and leaches radionuclides to the subsurface environment, and (2) containment basemat penetration of sump water without full penetration of the core mass. Six generic hydrogeologic site classifications are developed from an evaluation of reported data pertaining to the hydrogeologic properties of all existing and proposed commercial reactor sites. One-dimensional radionuclide transport analyses are conducted on each of the individual reactor sites to determine the generic characteristics of a radionuclide discharge to an accessible environment. Ground-water contaminant mitigation techniques that may be suitable, depending on specific site and accident conditions, for severe power plant accidents are identified and evaluated. Feasible mitigative techniques and associated constraints on feasibility are determined for each of the six hydrogeologic site classifications. The first of three case studies is conducted on a site located on the Texas Gulf Coastal Plain. Mitigative strategies are evaluated for their impact on contaminant transport and results show that the techniques evaluated significantly increased ground-water travel times. 31 references, 118 figures, 62 tables.

Mitigative techniques and analysis of generic site conditions for ground-water contamination associated with severe accidents

International Nuclear Information System (INIS)

Shafer, J.M.; Oberlander, P.L.; Skaggs, R.L.

1984-04-01

The purpose of this study is to evaluate the feasibility of using ground-water contaminant mitigation techniques to control radionuclide migration following a severe commercial nuclear power reactor accident. The two types of severe commercial reactor accidents investigated are: (1) containment basemat penetration of core melt debris which slowly cools and leaches radionuclides to the subsurface environment, and (2) containment basemat penetration of sump water without full penetration of the core mass. Six generic hydrogeologic site classifications are developed from an evaluation of reported data pertaining to the hydrogeologic properties of all existing and proposed commercial reactor sites. One-dimensional radionuclide transport analyses are conducted on each of the individual reactor sites to determine the generic characteristics of a radionuclide discharge to an accessible environment. Ground-water contaminant mitigation techniques that may be suitable, depending on specific site and accident conditions, for severe power plant accidents are identified and evaluated. Feasible mitigative techniques and associated constraints on feasibility are determined for each of the six hydrogeologic site classifications. The first of three case studies is conducted on a site located on the Texas Gulf Coastal Plain. Mitigative strategies are evaluated for their impact on contaminant transport and results show that the techniques evaluated significantly increased ground-water travel times. 31 references, 118 figures, 62 tables

Problems of probabilistic safety assessment after Fukushima Daiichi nuclear power plant accident

International Nuclear Information System (INIS)

Sugiyama, Naoki

2011-01-01

Probabilistic safety assessment (PSA) methodology to assure nuclear safety is had great expectations of lessons learned from Fukushima Daiichi nuclear power plant (NPP) accident and on the other hand this accident made actualized technical problems of PSA. Effectiveness of current PSA methodology for risk assessment was confirmed by comparing the accident development with accident scenario of PSA and equipment failure rate. From a viewpoint of nuclear safety objective and defense in depth approach of IAEA, technical problems of PSA were (1) extension of PSA for spent fuel pool and waste disposal system as well as level 3PSA for broader environmental contamination and (2) overlapping of accident scenario of plural unit site, balance of high quality plant management and preceding negation, treatment of uncertainty of external events, severe accident measure and human reliability analysis and reflection of disaster prevention capability to level 3PSA. In order to upgrade PSA technology, six proposals were described for nuclear safety and defense in depth, comprehensive evaluation scope and catch-up of latest technology, necessity of strategic preparation of PSA standard, human resources fostering and risk communication. (T. Tanaka)

Populations protection and territories management in nuclear emergency and post-accident situation

International Nuclear Information System (INIS)

Bourrel, M.; Calmon, Ph.; Calvez, M.; Chambrette, V.; Champion, D.; Devin, P.; Godino, O.; Lombard, J.; Rzepka, J.P.; Schneider, Th.; Verhaeghe, B.; Cogez, E.; Kayser, O.; Guenon, C.; Jourdain, J.R.; Bouchot, E.; Murith, Ch.; Lochard, J.; Cluchier, A.; Vandecasteele, Ch.; Pectorin, X.; Dubiau, Ph.; Gerphagnon, O.; Roche, H.; Cessac, B.; Cochard, A.; Machenaud, G.; Jourdain, J.R.; Pirard, Ph.; Leger, M.; Bouchot, E.; Demet, M.; Charre, J.P.; Poumadere, M.; Cogez, E.

2010-01-01

This document gathers the slides of the available presentations given during these conference days. Twenty seven presentations out of 29 are assembled in the document and deal with: 1 - radiological and dosimetric consequences in nuclear accident situation: impact on the safety approach and protection stakes (E. Cogez); 2 - organisation of public authorities in case of emergency and in post-event situation (in case of nuclear accident or radiological terror attack in France and abroad), (O. Kayser); 3 - ORSEC plan and 'nuclear' particular intervention plan (PPI), (C. Guenon); 4 - thyroid protection by stable iodine ingestion: European perspective (J.R. Jourdain); 5 - preventive distribution of stable iodine: presentation of the 2009/2010 public information campaign (E. Bouchot); 6 - 2009/2010 iodine campaign: presentation and status (O. Godino); 7 - populations protection in emergency and post-accident situation in Switzerland (C. Murith); 8 - CIPR's recommendations on the management of emergency and post-accident situations (J. Lochard); 9 - nuclear exercises in France - status and perspectives (B. Verhaeghe); 10 - the accidental rejection of uranium at the Socatri plant: lessons learnt from crisis management (D. Champion); 11 - IRE's radiological accident of August 22, 2008 (C. Vandecasteele); 12 - presentation of the CEA's crisis national organisation: coordination centre in case of crisis, technical teams, intervention means (X. Pectorin); 13 - coordination and realisation of environmental radioactivity measurement programs, exploitation and presentation of results: status of IRSN's actions and perspectives (P. Dubiau); 14 - M2IRAGE - measurements management in the framework of geographically-assisted radiological interventions in the environment (O. Gerphagnon and H. Roche); 15 - post-accident management of a nuclear accident - the CODIRPA works (I. Mehl-Auget); 16 - nuclear post-accident: new challenges of crisis expertise (D. Champion); 17 - aid guidebooks

Abnormal Signal Analysis for a Change of the R-C Passive Elements in a Equivalent Circuit Modeling under a High Temperature Accident Condition

International Nuclear Information System (INIS)

Koo, Kil-Mo; Song, Yong-Mann; Ahan, Kwang-Il; Ha, Jea-Joo

2007-01-01

An electrical signal should be checked to see whether it lies within its expected electrical range when there is a doubtful condition. The normal signal level for pressure, flow, level and resistance temperature detector sensors is 4 - 20mA for most instruments as an industrial process control standard. In the case of an abnormal signal level from an instrument under a severe accident condition, it is necessary to obtain a more accurate signal validation to operate a system in a control room in NPPs. Diagnostics and analysis for some abnormal signals have been performed through an important equivalent circuits modeling for passive elements under severe accident conditions. Unlike the design basis accidents, there are some inherent uncertainties for the instrumentation capabilities under severe accident conditions. In this paper, to implement a diagnostic analysis for an equivalent circuits modeling, a kind of linked LabVIEW program for each PSpice and MULTISim code is introduced as a one body order system, which can obtain some abnormal signal patterns by a special function such as an advanced simulation tool for each PSpice and Multi-SIM code as a means of a function for a PC based ASSA (abnormal signal simulation analyzer) module

Abnormal Signal Analysis for a Change of the R-C Passive Elements in a Equivalent Circuit Modeling under a High Temperature Accident Condition

Energy Technology Data Exchange (ETDEWEB)

Koo, Kil-Mo; Song, Yong-Mann; Ahan, Kwang-Il; Ha, Jea-Joo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2007-07-01

An electrical signal should be checked to see whether it lies within its expected electrical range when there is a doubtful condition. The normal signal level for pressure, flow, level and resistance temperature detector sensors is 4 - 20mA for most instruments as an industrial process control standard. In the case of an abnormal signal level from an instrument under a severe accident condition, it is necessary to obtain a more accurate signal validation to operate a system in a control room in NPPs. Diagnostics and analysis for some abnormal signals have been performed through an important equivalent circuits modeling for passive elements under severe accident conditions. Unlike the design basis accidents, there are some inherent uncertainties for the instrumentation capabilities under severe accident conditions. In this paper, to implement a diagnostic analysis for an equivalent circuits modeling, a kind of linked LabVIEW program for each PSpice and MULTISim code is introduced as a one body order system, which can obtain some abnormal signal patterns by a special function such as an advanced simulation tool for each PSpice and Multi-SIM code as a means of a function for a PC based ASSA (abnormal signal simulation analyzer) module.

Studies on the role of molybdenum on iodine transport in the RCS in nuclear severe accident conditions

International Nuclear Information System (INIS)

Grégoire, A.-C.; Kalilainen, J.; Cousin, F.; Mutelle, H.; Cantrel, L.; Auvinen, A.; Haste, T.; Sobanska, S.

2015-01-01

Highlights: • In oxidising conditions, Mo reacts with Cs and thus promotes gaseous iodine release. • In reducing conditions, CsI remains the dominant form for released iodine. • The nature of released iodine is well reproduced by the ASTEC code. - Abstract: The effect of molybdenum on iodine transport in the reactor coolant system (RCS) under PWR severe accident conditions was investigated in the framework of the EU SARNET project. Experiments were conducted at the VTT-Institute and at IRSN and simulations of the experimental results were performed with the ASTEC severe accident simulation code. As molybdenum affects caesium chemistry by formation of molybdates, it may have a significant impact on iodine transport in the RCS. Experimentally it has been shown that the formation of gaseous iodine is promoted in oxidising conditions, as caesium can be completely consumed to form caesium polymolybdates and is thus not available for reacting with gaseous iodine and leading to CsI aerosols. In reducing conditions, CsI remains the dominant form of iodine, as the amount of oxygen is not sufficient to allow formation of quantitative caesium polymolybdates. An I–Mo–Cs model has been developed and it reproduces well the experimental trends on iodine transport

Lessons to be learned from an analysis of ammonium nitrate disasters in the last 100 years

Energy Technology Data Exchange (ETDEWEB)

Pittman, William; Han, Zhe; Harding, Brian; Rosas, Camilo; Jiang, Jiaojun; Pineda, Alba; Mannan, M. Sam, E-mail: mannan@tamu.edu

2014-09-15

Highlights: • Root causes and contributing factors from ammonium nitrate incidents are categorized into 10 lessons. • The lessons learned from the past 100 years of ammonium nitrate incidents can be used to improve design, operation, and maintenance procedures. • Improving organizational memory to help improve safety performance. • Combating and changing organizational cultures. - Abstract: Process safety, as well as the safe storage and transportation of hazardous or reactive chemicals, has been a topic of increasing interest in the last few decades. The increased interest in improving the safety of operations has been driven largely by a series of recent catastrophes that have occurred in the United States and the rest of the world. A continuous review of past incidents and disasters to look for common causes and lessons is an essential component to any process safety and loss prevention program. While analyzing the causes of an accident cannot prevent that accident from occurring, learning from it can help to prevent future incidents. The objective of this article is to review a selection of major incidents involving ammonium nitrate in the last century to identify common causes and lessons that can be gleaned from these incidents in the hopes of preventing future disasters. Ammonium nitrate has been involved in dozens of major incidents in the last century, so a subset of major incidents were chosen for discussion for the sake of brevity. Twelve incidents are reviewed and ten lessons from these incidents are discussed.

Lessons to be learned from an analysis of ammonium nitrate disasters in the last 100 years

International Nuclear Information System (INIS)

Pittman, William; Han, Zhe; Harding, Brian; Rosas, Camilo; Jiang, Jiaojun; Pineda, Alba; Mannan, M. Sam

2014-01-01

Highlights: • Root causes and contributing factors from ammonium nitrate incidents are categorized into 10 lessons. • The lessons learned from the past 100 years of ammonium nitrate incidents can be used to improve design, operation, and maintenance procedures. • Improving organizational memory to help improve safety performance. • Combating and changing organizational cultures. - Abstract: Process safety, as well as the safe storage and transportation of hazardous or reactive chemicals, has been a topic of increasing interest in the last few decades. The increased interest in improving the safety of operations has been driven largely by a series of recent catastrophes that have occurred in the United States and the rest of the world. A continuous review of past incidents and disasters to look for common causes and lessons is an essential component to any process safety and loss prevention program. While analyzing the causes of an accident cannot prevent that accident from occurring, learning from it can help to prevent future incidents. The objective of this article is to review a selection of major incidents involving ammonium nitrate in the last century to identify common causes and lessons that can be gleaned from these incidents in the hopes of preventing future disasters. Ammonium nitrate has been involved in dozens of major incidents in the last century, so a subset of major incidents were chosen for discussion for the sake of brevity. Twelve incidents are reviewed and ten lessons from these incidents are discussed

The radiological accident in Goiania

International Nuclear Information System (INIS)

1988-01-01

The report is based on a meeting held in Brazil, 19-27 July 1988. It describes how the accident occurred, examines how it was managed and how its consequences were contained, and sets out observations and recommendations based upon lessons learned. Many people received large doses of radiation, due to both external and internal exposure. Four of the casualties ultimately died and 28 people suffered radiation burns. Residences and public places were contaminated. The decontamination necessitated the demolition of seven residences and various other buildings, and the removal of the topsoil from large areas. In total 3,500 m 3 of radioactive waste was generated. Refs, figs, tabs and photographs

Evaluation of High-Pressure RCS Natural Circulations Under Severe Accident Conditions

International Nuclear Information System (INIS)

Lee, Byung Chul; Bang, Young Suk; Suh, Nam Duk

2006-01-01

Since TMI-2 accident, the occurrence of severe accident natural circulations inside RCS during entire in-vessel core melt progressions before the reactor vessel breach had been emphasized and tried to clarify its thermal-hydraulic characteristics. As one of consolidated outcomes of these efforts, sophisticated models have been presented to explain the effects of a variety of engineering and phenomenological factors involved during severe accident mitigation on the integrity of RCS pressure boundaries, i.e. reactor pressure vessel(RPV), RCS coolant pipe and steam generator tubes. In general, natural circulation occurs due to density differences, which for single phase flow, is typically generated by temperature differences. Three natural circulation flows can be formed during severe accidents: in-vessel, hot leg countercurrent flow and flow through the coolant loops. Each of these flows may be present during high-pressure transients such as station blackout (SBO) and total loss of feedwater (TLOFW). As a part of research works in order to contribute on the completeness of severe accident management guidance (SAMG) in domestic plants by quantitatively assessing the RCS natural circulations on its integrity, this study presents basic approach for this work and some preliminary results of these efforts with development of appropriately detailed RCS model using MELCOR computer code

Status Report on Spent Fuel Pools under Loss-of-Cooling and Loss-of-Coolant Accident Conditions - Final Report

International Nuclear Information System (INIS)

Adorni, M.; Esmaili, H.; Grant, W.; Hollands, T.; Hozer, Z.; Jaeckel, B.; Munoz, M.; Nakajima, T.; Rocchi, F.; Strucic, M.; ); Tregoures, N.; Vokac, P.; Ahn, K.I.; Bourgue, L.; Dickson, R.; Douxchamps, P.A.; Herranz, L.E.; Jernkvist, L.O.; Amri, A.; Kissane, M.P.; )

2015-01-01

Following the 2011 accident at the Fukushima Daiichi Nuclear Power Station, the Nuclear Energy Agency Committee on the Safety of Nuclear Installations decided to launch several high-priority activities to address certain technical issues. Among other things, it was decided to prepare a status report on spent fuel pools (SFPs) under loss of cooling accident conditions. This activity was proposed jointly by the CSNI Working Group on Analysis and Management of Accidents (WGAMA) and the Working Group on Fuel Safety (WGFS). The main objectives, as defined by these working groups, were to: - Produce a brief summary of the status of SFP accident and mitigation strategies, to better contribute to the post-Fukushima accident decision making process; - Provide a brief assessment of current experimental and analytical knowledge about loss of cooling accidents in SFPs and their associated mitigation strategies; - Briefly describe the strengths and weaknesses of analytical methods used in codes to predict SFP accident evolution and assess the efficiency of different cooling mechanisms for mitigation of such accidents; - Identify and list additional research activities required to address gaps in the understanding of relevant phenomenological processes, to identify where analytical tool deficiencies exist, and to reduce the uncertainties in this understanding. The proposed activity was agreed and approved by CSNI in December 2012, and the first of four meetings of the appointed writing group was held in March 2013. The writing group consisted of members of the WGAMA and the WGFS, representing the European Commission and the following countries: Belgium, Canada, Czech Republic, France, Germany, Hungary, Italy, Japan, Korea, Spain, Sweden, Switzerland and the USA. This report mostly covers the information provided by these countries. The report is organised into 8 Chapters and 4 Appendices: Chapter 1: Introduction; Chapter 2: Spent fuel pools; Chapter 3: Possible accident

Accidents - Chernobyl accident; Accidents - accident de Tchernobyl

Energy Technology Data Exchange (ETDEWEB)

NONE

2004-07-01

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

Improvement of the severe accident practice tool

International Nuclear Information System (INIS)

Kawasaki, Ikuo; Takahashi, Shunsuke

2016-01-01

We developed the severe accident (SA) practice tool based on lessons learned in the accident at the Tokyo Electric Power Company Fukushima Daiichi Nuclear Power Station. We utilized the developed SA practice tool and carried out the SA training for some employees of Kansai Electric Power Co., Inc. Afterwards, we examined the opinions given by trainees attending the training lecture and improved the SA practice tool to achieve a better educational effect. The main changes we made were improvement of the practice scenario for EAL judgments and addition of functions to the practice tool such as the EAL explanation document indication. As a result of having carried out the SA education using this practice tool, we determined the tool users could make the right EAL judgment and report the communication vote. Finally, we confirmed that the knowledge necessary for SA correspondence could be given satisfactorily by this practice tool. (author)

Twenty years after the Chernobyl accident

International Nuclear Information System (INIS)

2006-01-01

Full text: The April 1986 accident at the Chernobyl nuclear power plant remains a painful memory in the lives of the hundreds of thousands of people who were most affected by the accident. In addition to the emergency rescue workers who died, thousands of children contracted thyroid cancer, and thousands of other individuals will eventually die of other cancers caused by the release of radiation. Vast areas of cropland, forests, rivers and urban centres were contaminated by environmental fallout. Hundreds of thousands of people were evacuated from these affected areas - forced to leave behind their homes, possessions, and livelihoods - and resettled elsewhere, in a traumatic outcome that has had long-lasting psychological and social impacts. The commemoration of the Chernobyl tragedy is taking place in many forums this month - in Minsk, in Kiev and in other locations. At the IAEA, it might be said that we have been responding to the accident and its consequences for twenty years, in a number of ways: first, through a variety of programmes designed to help mitigate the environmental and health consequences of the accident; second, by analyzing the lessons of what went wrong to allow such an accident to occur at all; and third, by working to prevent any such accident from occurring in the future. Building a strong and effective global nuclear safety regime is a central objective of our work. This requires effective international cooperation. The explosions that destroyed the Unit 4 reactor core, and discharged its contents in a cloud of radionuclides, made painfully clear that the safety risks associated with nuclear and radiological activities extend beyond national borders. International cooperation on nuclear safety matters - sharing information, setting clear safety standards, assisting with safety upgrades, and reviewing operational performance - has therefore become a hallmark of IAEA activity, particularly at a time when we are witnessing an expansion of

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)

Strengthening safety of nuclear power by learning lessons from the accident at TEPCO's Fukushima-Daiichi Nuclear Power Plant

International Nuclear Information System (INIS)

Omoto, Akira

2011-01-01

The paper first discusses ongoing onsite stabilization activities at Fukushima-Daiichi NPP and a plan for onsite and offsite remedial actions including decontamination and defueling. Four key lessons learned (LL) are raised; safety regulation and safety culture, workable/executable severe accident management procedure, crisis management and design. Global actions for strengthening safety in post-Fukushima era would be built around the IAEA action plan, under recognition of national responsibility. For specific country and plant, a combination of the following may help; a) overall assessment of safety and reflection of Fukushima LL in the light of principles in INSAG-12, b) specific plant assessment of risks from internal, external and security-related events for identifying vulnerabilities and continuous safety improvement, and c) international peer review for comprehensiveness, objectivity and confidence building. In this context, the followings could be worth receiving attention; a) to revisit defense-in-depth, while utilizing risk information, for its completeness and effectiveness (especially, strengthened defense against environmental contamination by effective combination of provisions and management as well as attentiveness and careful attitude towards uncertainties across all layers of defense-in-depth), b) to restore public confidence, c) to cooperate for safety infrastructure in newcomers, d) to build internationally harmonized and cooperative scheme for liability. (author)

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

Numerical module for debris behavior under severe accident conditions

International Nuclear Information System (INIS)

Kisselev, A.E.; Kobelev, G.V.; Strizhov, V.F.; Vasiliev, A.D.

2005-01-01

The late phase of a hypothetical severe accident in a nuclear reactor is characterized by the appearance of porous debris and liquid pools in core region and lower head of the reactor vessel. Thermal hydraulics and heat transfer in these regions are very important for adequate analysis of severe accident dynamics. The purpose of this work is to develop a universal module which is able to model above-mentioned phenomena on the basis of modern physical concepts. The original approach for debris evolution is developed from classical principles using a set of parameters including debris porosity; average particle diameter; temperatures and mass fractions of solid, liquid and gas phases; specific interface areas between different phases; effective thermal conductivity of each phase, including radiative heat conductivity; mass and energy fluxes through the interfaces. The calculation results of several tests on modeling of porous debris behavior, including the MP-1 experiment, are presented in comparison with experimental data. The results are obtained using this module implemented into the Russian best estimate code, RATEG/SVECHA/HEFEST, which was developed for modeling severe accident thermal hydraulics and late phase phenomena in VVER nuclear power plants. (author)

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

International Nuclear Information System (INIS)

Youngen, G.

1988-10-01

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

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

Energy Technology Data Exchange (ETDEWEB)

Youngen, G.

1988-10-01

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

Reinforcement of Defence-in-Depth: Modification Practice After the Fukushima Nuclear Accident

Energy Technology Data Exchange (ETDEWEB)

Wang, Y.; Tang, H.; Mao, Q., E-mail: wangyuhong@cgnpc.com.cn [China Nuclear Power Design Co., Ltd Xia Meilin, Futian District, Shenzhen, Guangdong Province (China)

2014-10-15

The Fukushima Daiichi nuclear accident revealed the importance and demand for further reinforcement of defence in- depth. CGN (China General Nuclear Power Group) has made a complete safety assessment on CPR1000 nuclear power plants under construction in China. Dozens of modifications have been implemented based on the assessment findings and lessons learned from Fukushima nuclear accident, taking into account of PSA (Probabilistic Safety Analysis) and comparison analysis of the latest regulations and standards. These modifications help to enhance nuclear safety significantly for nuclear power plants under construction in China, and provide helpful modification guidance for nuclear power plants in operation of the same type. (author)

Flood control construction of Shidao Bay nuclear power plant and safety analysis for hypothetical accident of HTR-PM

International Nuclear Information System (INIS)

Chen Yongrong; Zhang Keke; Zhu Li

2014-01-01

A series of events triggered by tsunami eventually led to the Fukushima nuclear accident. For drawing lessons from the nuclear accident and applying to Shidao Bay nuclear power plant flood control construction, we compare with the state laws and regulations, and prove the design of Shidao Bay nuclear power plant flood construction. Through introducing the history of domestic tsunamis and the national researches before and after the Fukushima nuclear accident, we expound the tsunami hazards of Shidao Bay nuclear power plant. In addition, in order to verify the safety of HTR-PM, we anticipate the contingent accidents after ''superposition event of earthquake and extreme flood'', and analyse the abilities and measures of HTR-PM to deal with these beyond design basis accidents (BDBA). (author)

JAERI's activities in JCO accident

International Nuclear Information System (INIS)