Radiological Aspects of Public Protection at Early Release Stage of NPP Severe Accident

2020 ◽  
pp. 62-73
Author(s):  
V. Bogorad ◽  
O. Slepchenko ◽  
T. Lytvynska ◽  
D. Bielykh ◽  
I. Kalyta ◽  
...  
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Emergency Preparedness ◽  
Nuclear Power ◽  
Severe Accident ◽  
Modern World ◽  
Plant Design ◽  
Early Release ◽  
Safety Standards ◽  
General Physical

In the modern world, nuclear energy is one of the most economically feasible sources of energy. Although related risks are of a great public interest, they are quite obvious and predictable. The steady risk reduction trend is based on two main areas: improvement of nuclear power plant design basis and enhancement of emergency preparedness at all levels. Such a trend is maintained by more strict requirements for licensees from states and international competent authorities. Recently, practical elimination of an early radioactive release at a nuclear power plant is one of the most significant requirements for NPP safety. The paper covers issues focusing on how this requirement will be implemented within national radiation safety standards, namely within the regulations of the third group on intervention in the case of a radiological emergency, and whether Ukraine is ready to implement this standard for operating NPPs. The paper addresses the following issues: determination of an early release, available interval, theoretical grounds applied to assess an early release and public exposure doses. All the results presented in the paper are of an evaluative nature. The attention is focused not on specific features of a particular power unit or settlement, but on general physical principles of modeling the source term and protective properties of the premises.

Requirement and Discussion of Design Extension Conditions

2017 ◽  
Author(s):  
Yan Jinquan ◽  
Chen Song ◽  
Tian Lin ◽  
Wang Minglu
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Nuclear Safety ◽  
Severe Accident ◽  
Plant Design ◽  
Plant Safety ◽  
Severe Accidents ◽  
Safety Code ◽  
Nuclear Power Plant Safety

Nuclear safety especially severe accidents risks are of great concerns of nuclear power plant. Design consideration of severe accident prevention and mitigation is generally required by various nuclear safety authorities worldwide. However, those requirements related to severe accidents consideration are somewhat different from country to country. Recently, the International Atomic Energy Agency (IAEA) updated and published a safety code on Specific Safety Requirement of Nuclear Power Plant Safety: Design (SSR-2/1). Meanwhile, the Chinese National Nuclear Safety Administration (NNSA) also revised and updated the safety code on Requirement of Nuclear Power Plant Safety in Design (HAF102). In these two codes, both IAEA and NNSA established some new requirements, among which two are of great concern. One is Design Extension Conditions (DEC) for consideration of those conditions traditionally called Beyond Design Basis Accidents (BDBA) in design of nuclear power plant, another is requirement of practically eliminating large release of radionuclide. These two new requirements are internally related, somewhat different and more restrict from those related to severe accident requirements set forth by Nuclear Regulatory Committee of United States (USNRC). Up to date, there are no specific guidelines about engineering implementation of those new safety codes. This paper present an overview of those requirements from IAEA, WENRA, NRC and China NNSA, followed by discussion of engineering approach for the implementation of the DEC requirement set forth by safety authorities.

scholarly journals Estimation of Dietary Intake of Radionuclides and Effectiveness of Regulation after the Fukushima Accident and in Virtual Nuclear Power Plant Accident Scenarios

2018 ◽  
Vol 15 (8) ◽  
pp. 1589 ◽  
Author(s):  
Michio Murakami ◽  
Takao Nirasawa ◽  
Takao Yoshikane ◽  
Keisuke Sueki ◽  
Kimikazu Sasa ◽  
...  
Keyword(s):  
Cost Effectiveness ◽  
Power Plant ◽  
Nuclear Power Plant ◽  
Dietary Intake ◽  
Emergency Preparedness ◽  
Nuclear Power ◽  
Food Distribution ◽  
Fukushima Accident ◽  
Accident Scenarios ◽  
Effectiveness Of Regulation

Evaluation of radiation exposure from diet is necessary under the assumption of a virtual accident as a part of emergency preparedness. Here, we developed a model with complete consideration of the regional food trade using deposition data simulated by a transport model, and estimated the dietary intake of radionuclides and the effectiveness of regulation (e.g., restrictions on the distribution of foods) after the Fukushima accident and in virtual accident scenarios. We also evaluated the dilution factors (i.e., ratios of contaminated foods to consumed foods) and cost-effectiveness of regulation as basic information for setting regulatory values. The doses estimated under actual emission conditions were generally consistent with those observed in food-duplicate and market-basket surveys within a factor of three. Regulation of restricted food distribution resulted in reductions in the doses of 54–65% in the nearest large city to the nuclear power plant. The dilution factors under actual emission conditions were 4.4% for radioiodine and 2.7% for radiocesium, which are ~20 times lower than those used in the Japanese provisional regulation values after the Fukushima accident. Strict regulation worsened the cost-effectiveness for both radionuclides. This study highlights the significance and utility of the developed model for a risk analysis of emergency preparedness and regulation.

Memories from the Abyss

2017 ◽  
Author(s):  
Naoto Kan ◽  
Jeffrey S. Irish
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Emergency Preparedness ◽  
Disaster Response ◽  
Nuclear Power ◽  
Industrial Safety ◽  
Response Team ◽  
Japanese Prime Minister ◽  
Fukushima Daiichi ◽  
Nuclear Emergency

This chapter presents Japanese Prime Minister Naoto Kan's recollections about the week immediately following the Great East Japan earthquake. Topics discussed include the response team meeting at the Emergency Disaster Response Headquarters; the Act on Special Measures Concerning Nuclear Emergency Preparedness; the declaration of a nuclear emergency; whether the state has authority over TEPCO's Fukushima Daiichi Nuclear Power Plant; the responsibilities of the Nuclear Safety Commission and Nuclear and Industrial Safety Agency; TEPCO's inability to resolve problems on their own; the evacuation of residents with within a three-kilometer [1.9 mile] radius of the nuclear power plant; and Kan's decision to address the Japanese people a day and a half after the earthquake.

Valves Maintainability Study on Nuclear Power Plant Design Stage

2017 ◽  
pp. 307-313
Author(s):  
Xiaohu Yang ◽  
Jiao Deng ◽  
Hong Jiang ◽  
Lifei Yang ◽  
Wen Chen
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Design Stage ◽  
Plant Design
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