Study of LERF and AFPCS Update Analysis for Chin-shan Nuclear Power Plant in Taiwan

• Main Authors: Wu-pin Lo, 羅武斌
• Other Authors: Yuan-ching Chou
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/55678125460154065232

碩士 === 龍華科技大學 === 工程技術研究所 === 100 === U.S. NRC (Nuclear Regulatory Commission) adopts LERF (Large Early Release Frequency) to estimate the probability of early fatalities due to radiological release in nuclear power plant accident, and also made CDF (Core Damage Frequency) and LERF as oversight indicators for the nuclear power plant risk. NUREG/CR-6595 provided a simple LERF assessment method. It applies the PRA Level-1 results with a standard CET to conduct the LERF assessment. Chin-Shan Nuclear Power Plant adopted similar approach but using CSET (Containment System Event Tree) to reflect the effects of containment safety systems on LERF. However, the LERF assessment for Chin-Shan Nuclear Power Plant did not take CPET (Containment Phenomenological Event Tree) into consideration. To make the effects of containment physical phenomena on LERF more clear, this study integrates CPET into the existing LERF assessment for Chin-Shan Nuclear Power Plant, and compared the results with the existing analysis results. The results of comparisons show that, after integrating the effects of CPET, the new LERFs reduced by 74.36 %, 26.01% and 78.47% for internal, typhoons, and earthquake initiated events respectively. And the total LERF is reduced by 38.62%. It is clear that the original LERF analysis is more conservative, and the LERF obtained in this study can further reflect the effects of containment physical phenomena on large early release accidents. This study also investigates the effects of the “specific strengthening measure and improving program” on Chin-Shan CPET. The program was implemented by Taiwan Power Company after Japanese Fukushima accidents. In this program, although the improvement of spent fuel pool cooling capability did not affect CPET very much, but it plays an important role in the improvement activities after the Fukushima nuclear disaster. For this concern, three strengthened AFPCS (Advance Fuel Pool Cooling System) designs are analyzed by using Fault Tree technology in this study. The relative cost, construction complexity, and failure probabilities of the three designs are compared and can be used as reference information for relevant decision making.