Preliminary Study on the Identification of DECs Without Significant Fuel Degradation in New NPP Designs

2017 ◽  
Author(s):  
Zhiyi Yang ◽  
Yimin Chong ◽  
Chun Li ◽  
Jiajia Zhang
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Nuclear Safety ◽  
Severe Accident ◽  
Concept Design ◽  
Energy Agency ◽  
Safety Level ◽  
Safety Requirements ◽  
Specific Safety

New nuclear safety objectives and principles are being studied in main nuclear power countries and organizations after Fukushima Dai-ichi nuclear accident, to further improve the safety level of nuclear power plants (NPPs). Based on International Atomic Energy Agency (IAEA) Specific Safety Requirements (No.SSR-2/1), “Safety of Nuclear Power Plants: Design” (HAF102-2016) is issued in China. The concept “design extension condition (DEC)” is put forward, which is intend to enhance the plant’s capability to withstand accidents that are more severe than Design Basis Accidents (DBA). DEC could include conditions without significant fuel degradation (DEC-A in this paper) and conditions with core melting (DEC-B in this paper), e.g. severe accident. In this paper, the DEC-A and its application was discussed preliminarily, firstly, the development and connotation was introduced, then the identification of DEC-A, and the safety analysis principles of DEC-A were mainly described. This study may play a valuable role for implementation of new nuclear safety requirements in China.

Device for Measuring Hydrogen Concentration in Containment During Severe Accident

2013 ◽  
Author(s):  
Sha Luo ◽  
Shaobo Wang ◽  
Liang Qin ◽  
Feng Pang
Keyword(s):  
Hydrogen Concentration ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Measuring Method ◽  
Nuclear Safety ◽  
Concentration Measurement ◽  
Severe Accident ◽  
Under Construction ◽  
Hydrogen Concentration Measurement

The hydrogen explosion in Fukushima nuclear accident seriously challenged the safety of nuclear power plants in the world. Therefore, strengthening hydrogen concentration measurement in containment has become very important. To raise the nuclear safety level of in-service and under construction nuclear power plants in China, based on a document which was issued by the National Nuclear Safety Administration of China (NNSA, 2012), the function requirements, components, storage, and arrangement outlines of the hydrogen monitoring system after a severe accident was thoroughly analyzed in this article. Besides, two kinds of techniques for hydrogen concentration measurement in containment, respectively for direct measuring method and gas sampling measuring method, were also discussed and compared. Notably, based on the direct measuring method, the 718th Research Institute successfully developed the CH-15 type hydrogen concentration measuring device that suitable for used in severe accident. The hydrogen sensor, with independently intellectual property rights, is based on catalytic principles and installed inside the containment. It has many unique characteristics, such as wide measurement range, high measurement accuracy, and is capable of continuous measurement with multiple points. This device has simple structure and small size, with low energy consumption, so it is very suitable for being installed in the in-service and under construction nuclear power plants in China and abroad.

scholarly journals The governance of nuclear power in China

2020 ◽  
Vol 13 (1) ◽  
pp. 23-46
Author(s):  
Philip Andrews-Speed
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Power Industry ◽  
Nuclear Safety ◽  
The Body ◽  
Nuclear Power Industry ◽  
High Rate ◽  
Energy Agency ◽  
The Government

Abstract China has the third largest fleet of nuclear power plants in the world, totalling more than 45 GWe at the end of 2019. With the current high rate of growth, its capacity will soon overtake that of France. The country’s nuclear power industry has suffered no serious accidents to date. Nevertheless, the poor safety record of some other heavy industries in China, combined with the rapid growth of civil nuclear power capacity, has raised concerns over the industry’s ability to prevent a serious accident. The organization, development and governance of China’s nuclear power industry reflects the high strategic importance that the government has placed on the industry over several decades. At the same time, it has taken steps to address domestic and international concerns over its ability to effectively govern nuclear safety and security. The country has become party to most major treaties and conventions relating to nuclear matters and has frequent interaction with the International Atomic Energy Agency. Despite many significant steps taken by the government, a number of questions remain concerning: the capacity and independence of the National Nuclear Safety Administration; the relatively incoherent nature of the body of laws, regulations and rules that govern nuclear safety and security; the absence of a clear legal basis for managing civil nuclear liability, especially in the context of an accident with transboundary consequences; and the quality of public participation, especially in the case of planned nuclear power plants.

Results of Regulatory Investigations as a Basis for Safety Improvements of Nuclear Power Plants

1996 ◽  
Vol 210 (5) ◽  
pp. 345-350
Author(s):  
H P Berg ◽  
U Volland ◽  
L Weil
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Nuclear Safety ◽  
Technical Development ◽  
Regulatory State ◽  
Safety Level ◽  
Public Issue ◽  
State Authority ◽  
The Subject

Nuclear safety is not only a matter of technical development but is also an important public issue. Therefore it is mandatory that the responsible regulatory state authority performs its own investigation programme in order to enhance the safety level. The purpose and main objectives of this German regulatory investigation programme as well as the subject of some investigations are presented.

scholarly journals Evaluation of VVER-1200/V-491 Reactor Pressure Vessel integrity during large break LOCA along with SBO using MELCOR 1.8.6

2015 ◽  
Vol 5 (4) ◽  
pp. 54-63
Author(s):  
Thi Hoa Bui ◽  
Chi Thanh Tran
Keyword(s):  
Pressure Vessel ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Reactor Pressure Vessel ◽  
Severe Accident ◽  
Worst Case ◽  
Safety Requirements ◽  
Vessel Integrity ◽  
Reactor Pressure

After Fukushima accident and stress test recommended by IAEA for existing reactors, higher safety requirements are enforced upon nuclear power plants during design extension and severe accident conditions. Based on those arguments, Vietnam Government requests a lot of effective safety solutions, in designs proposed for the nuclear power plants in Ninh Thuan province of Vietnam, which can prevent the accident progression toward severe accidents and mitigate severe accident consequences. One of safety requirements is related to delay time of core melt during design extension condition. Especially, if the worst case of accidents occurs, the reactor vessel integrity must be maintained at least 24 hours from the beginning of the accident. With the aim at investigation of Reactor Pressure Vessel (RPV) integrity, in this study, MELCOR 1.8.6 code is used to evaluate the integrity of RPV lower head for VVER-1200/V-491 reactor during a Large Break Loss of Coolant Accident (LBLOCA) in combination with Station Blackout (SBO) event. The study figures out several parameters related to melt down progress such as: rupture position and rupture timing, the amount of hydrogen generated. Availability of the second stage hydro-accumulators (HA2) in the VVER-1200/V-491 is assumed as an additional improvement to delay the timing of core melt as well as to maintain the vessel integrity for long-term.

scholarly journals A decision-support approach to severe accident management in nuclear power plants

2020 ◽  
pp. 1-12
Author(s):  
Marko Bohanec ◽  
Ivan Vrbanić ◽  
Ivica Bašić ◽  
Klemen Debelak ◽  
Luka Štrubelj
Keyword(s):  
Decision Support ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Severe Accident ◽  
Accident Management

Design and Analysis of a Reliable Communication System in Nuclear Safety Instrument & Control System

2021 ◽  
Author(s):  
Le Li ◽  
Zhihui Zhang ◽  
Chao Gao ◽  
Fei Zhou ◽  
Guangqiang Ma
Keyword(s):  
Communication Networks ◽  
Communication System ◽  
Communication Systems ◽  
Nuclear Power ◽  
Data Exchange ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Nuclear Safety ◽  
Safety Communication ◽  
Digital Control Systems

Abstract With the development of digital instrument and control technology for nuclear power plants in recent decades, communication networks have become an important part of safety digital control systems, which takes charge in data exchange between the various sub-systems, and extremely impact on the reliability and safety of the entire I&C system. Traditional communication systems where some special features, such as reliability, safety, real-time, certainty, and independence are not strictly required are various illustrated. However, how to implement a communication system in a safety I&C system is rarely stated in current research. In this research, a reliable safety communication system applied in nuclear power plants is designed and analyzed. The five key characteristics of nuclear safety communication networks are explained, followed by explanation of how to achieve these characteristics. The analysis and verification of the designed system are also stated in this paper, which contributes to proving that the designed nuclear safety communication system could applied in the nuclear power plants.

scholarly journals Study on Probabilistic Safety Goals for Multimodule High-Temperature Gas-Cooled Reactor Based on Chinese Societal Risks

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Jinghan Zhang ◽  
Jun Zhao ◽  
Jiejuan Tong
Keyword(s):  
High Temperature ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Regulatory Commission ◽  
Nuclear Safety ◽  
Energy Agency ◽  
Water Reactor ◽  
Regulatory Commission ◽  
High Temperature Gas ◽  
Probabilistic Safety

Nuclear safety goal is the basic standard for limiting the operational risks of nuclear power plants. The statistics of societal risks are the basis for nuclear safety goals. Core damage frequency (CDF) and large early release frequency (LERF) are typical probabilistic safety goals that are used in the regulation of water-cooled reactors currently. In fact, Chinese current probabilistic safety goals refer to the Nuclear Regulatory Commission (NRC) and the International Atomic Energy Agency (IAEA), and they are not based on Chinese societal risks. And the CDF and LERF proposed for water reactor are not suitable for high-temperature gas-cooled reactors (HTGR), because the design of HTGR is very different from that of water reactor. And current nuclear safety goals are established for single reactor rather than unit or site. Therefore, in this paper, the development of the safety goal of NRC was investigated firstly; then, the societal risks in China were investigated in order to establish the correlation between the probabilistic safety goal of multimodule HTGR and Chinese societal risks. In the end, some other matters about multireactor site were discussed in detail.

Explore the Self-Governance on Nuclear Safety Emergency - A Case Study of the 3rd Nuclear Power Plant

2012 ◽  
Vol 260-261 ◽  
pp. 103-106
Author(s):  
Yi Chun Lin ◽  
Yung Nane Yang
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Alternative Energy ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Nuclear Safety ◽  
Security Issue ◽  
Safety Issues ◽  
Plant Safety

The ripples of the tsunami crisis in Japan triggered introspections of nuclear plant safety issues in the worldwide. Many countries have claimed the suspension of nuclear power plants. However, some countries such as Taiwan, under nearly 99% energy is exported, the disasters force government and citizen to face the importance of nuclear safety, especially the neighborhoods nearby the nuclear power plants. We have to face the nuclear safety since there is no other alternative energy presently. The 3rd nuclear power plant located in the south of Taiwan, which has the same geographic features with Fukushima, Japan. Presently, there is no precedent in Taiwan of precaution and rescue team and civil supervised mechanic on nuclear security issue. This paper will review according to transparent information, public participation and cross-organization cooperation to propose the execution and work division principles, including information monitor, educational propagation, hide and evacuation, emergence aid and care, rear and refuge service. The ultimate target is to establish self-governance inside nearby neighborhood to confront nuclear disaster at the critical moment.

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