Study on the Framework of Fission Product Source Term for Nuclear Power Plants

2014 ◽  
Vol 986-987 ◽  
pp. 564-571
Author(s):  
Xin Hua Liu ◽  
Lan Fang ◽  
Zhao Wen Zhu
Keyword(s):  
Fission Product ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Source Term ◽  
Source Terms ◽  
Reactor Types

The problems occurring in the fission product source term calculations for M310/CPR1000, EPR and AP1000 are briefly analyzed, based on the related regulations and standards, as well as operational feedback, review experiences and recent research achievements for nuclear power plants in China. The framework of fission product source term proper to China has been first studied and proposed in perspective of the purpose of source terms. The calculation processes of fission product source term are rearranged and the requirements for deferent reactor types are specified. The proposed framework can be taken as a foundation for solution of the long-standing problems in the calculation of fission product source term and provide reference for source term calculation.

Management of Ultimate Risk of Nuclear Power Plants by Source Terms: Lessons Learned from the Chernobyl Accident

2006 ◽  
Author(s):  
Genn Saji
Keyword(s):  
Chernobyl Accident ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Source Term ◽  
Current Source ◽  
Lessons Learned ◽  
Final Report ◽  
Source Terms ◽  
Fission Fragments

The term ‘ultimate risk’ is used here to describe the probabilities and radiological consequences that should be incorporated in siting, containment design and accident management of nuclear power plants for hypothetical accidents. It is closely related with the source terms specified in siting criteria which assures an adequate separation of radioactive inventories of the plants from the public, in the event of a hypothetical and severe accident situation. The author would like to point out that current source terms which are based on the information from the Windscale accident (1957) through TID-14844 are very outdated and do not incorporate lessons learned from either the Three Miles Island (TMI, 1979) nor Chernobyl accident (1986), two of the most severe accidents ever experienced. As a result of the observations of benign radionuclides released at TMI, the technical community in the US felt that a more realistic evaluation of severe reactor accident source terms was necessary. In this background, the “source term research project” was organized in 1984 to respond to these challenges. Unfortunately, soon after the time of the final report from this project was released, the Chernobyl accident occurred. Due to the enormous consequences induced by then accident, the one time optimistic perspectives in establishing a more realistic source term were completely shattered. The Chernobyl accident, with its human death toll and dispersion of a large part of the fission fragments inventories into the environment, created a significant degradation in the public’s acceptance of nuclear energy throughout the world. In spite of this, nuclear communities have been prudent in responding to the public’s anxiety towards the ultimate safety of nuclear plants, since there still remained many unknown points revolving around the mechanism of the Chernobyl accident. In order to resolve some of these mysteries, the author has performed a scoping study of the dispersion and deposition mechanisms of fuel particles and fission fragments during the initial phase of the Chernobyl accident. Through this study, it is now possible to generally reconstruct the radiological consequences by using a dispersion calculation technique, combined with the meteorological data at the time of the accident and land contamination densities of 137Cs measured and reported around the Chernobyl area. Although it is challenging to incorporate lessons learned from the Chernobyl accident into the source term issues, the author has already developed an example of safety goals by incorporating the radiological consequences of the accident. The example provides safety goals by specifying source term releases in a graded approach in combination with probabilities, i.e. risks. The author believes that the future source term specification should be directly linked with safety goals.

Evaluation on Radiological Consequence Induced by MSLB Accident With Alternative Source Term

2010 ◽  
Author(s):  
Jingxi Li ◽  
Gaofeng Huang ◽  
Lili Tong
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Source Term ◽  
Control Room ◽  
Power Station ◽  
Alternative Source ◽  
Radiological Consequence

The major threat that nuclear power plants (NPPs) pose to the safety of the public comes from the large amount radioactive material released during design-basis accidents (DBAs). Additionally, many aspects of Control Room Habitability, Environmental Reports, Facility Siting and Operation derive from the design analyses that incorporated the earlier accident source term and radiological consequence of NPPs. Depending on current applications, majority of Chinese NPPs adopt the method of TID-14844, which uses the whole body and thyroid dose criteria. However, alternative Source Term (AST) are commonly used in AP1000 and some LWRs (such as Beaver Valley Power Station, Units No. 1 and No. 2, Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 And 2, Kewaunee Power Station and so on), so it is attempted to adopt AST in radiological consequence analysis of other nuclear power plants. By introducing and implementing the method of AST defined in RG 1.183 and using integral safety analysis code, a pressurized water reactor (PWR) of 900 MW nuclear power plant analysis model is constructed and the radiological consequence induced by Main Steam Line Break (MSLB) accident is evaluated. For DBA MSLB, the fractions of core inventory are assumed to be in the gap for various radionuclides and then the release from the fuel gap is assumed to occur instantaneously with the onset of assumed damage. According to the assumptions for evaluating the radiological consequences of PWR MSLB, dose calculation methodology is performed with total effective dose equivalent (TEDE) which is the criteria of dose evaluation. Compared with dose criteria of RG 1.183, the dose of control room, exclusion area boundary and outer boundary of low population zone are acceptable.

Wall Thinning Analyses for Secondary Side Piping of Korean NPPS Using CHECWORKS Code

2002 ◽  
Author(s):  
K. M. Hwang ◽  
T. E. Jin ◽  
S. H. Lee ◽  
S. C. Jeon
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Operating Time ◽  
Accelerated Corrosion ◽  
Wear Rates ◽  
Wall Thinning ◽  
Management Technology ◽  
Reactor Types ◽  
Secondary Side

Since the mid-1990s, nuclear power plants in Korea have experienced wall thinning, leaks, and ruptures of secondary side piping caused by flow-accelerated corrosion (FAC). The pipe failures have increased as operating time progresses. In order to prevent FAC-induced pipe failures and to develop an effective FAC management strategy, KEPRI and KOPEC, along with KHNP’s support, have conducted a study for developing a systematic FAC management technology for all domestic nuclear power plants. As part of the study, FAC analyses were performed using CHECWORKS code. The analysis results were used to select components for inspection on each nuclear power plant. The site application feasibility of the analysis results was proven by comparisons of predicted and measured wear rates. This paper focuses on the introduction of the FAC analysis results for secondary side piping associated with three types of domestic nuclear power plants and the comparisons of predicted and measured wear rates. This paper also represents the comparisons of analysis results according to reactor types, power rates, and systems to facilitate the development of FAC management technology.

scholarly journals Accident source terms for Light-Water Nuclear Power Plants. Final report

10.2172/29438 ◽  
1995 ◽  
Author(s):  
L. Soffer ◽  
S.B. Burson ◽  
C.M. Ferrell ◽  
R.Y. Lee ◽  
J.N. Ridgely
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Final Report ◽  
Source Terms ◽  
Light Water

scholarly journals Fire Protection Regulations for Ensuring Fire Safety during Decommissioning Nuclear Power Plants in Korea

2020 ◽  
Vol 34 (3) ◽  
pp. 134-140
Author(s):  
Jung-Wun Kim ◽  
Chan-Geun Park
Keyword(s):  
Fire Protection ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Nuclear Reactor ◽  
The United States ◽  
Regulatory Body ◽  
Basic Technology ◽  
Reactor Types ◽  
First Time

Nuclear power plants (NPPs) in Korea are required to be maintained using a defense in-depth approach to prevent leakage of radioactive substances outside the plant and allow safe shutdown in the event of a fire. Periodic testing must be conducted to ensure that the fire protection facilities perform as required by the laws for various nuclear reactor types. In June 2017, for the first time in Korea, a nuclear plant, Kori Unit 1, was permanently shut down. It was prepared for decommissioning in accordance with the fire protection regulations imposed by the regulatory body. However, a standard protocol is necessary for systematically establishing the fire protection program for decommissioning of NPPs in the future. Therefore, the nuclear legal systems of countries with many operating nuclear power plants, such as the United States, Japan, Canada, and various European countries, were reviewed and guidelines for establishing a fire protection program for decommissioning NPPs was suggested; the fire protection requirements stated by Reg Guide 1.191 (Decommissioning fire protection program for NPPs during decommissioning and permanent shutdown) were used as a model. Suggestions for establishing legal regulations to optimize fire protection programs and secure basic technology for decommissioning NPPs were also made.

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