Assessment of the Conservatism in the Evaluation Models of Loss of Coolant Analyses for a Pressurized Water Reactor
Emergency Core Cooling System (ECCS) of Light Water Reactor (LWR) is designed to mitigate the consequence of Loss of Coolant Accidents (LOCA). In the present study, RELAP5 series of codes are used to analyze the LOCA margin of Maanshan Nuclear Power Station of Taiwan Power Company. The codes used in the analyses are RELAP5/Mod3, RELAP5-3D and RELAP5-3DK. The first two codes are categorized as the best estimated code. RELAP5-3DK is a revised version of RELAP-3D and the related models of the code are consistent with the requirements of Appendix K. It is classified as Evaluation Model (EM) code. The input decks of all three analyses are prepared according to the specifications of Appendix K. The purpose of the study is to assess to conservatisms embedded in the EM models. The results show that the peak cladding temperatures (PCT) in the LOCA as predicted by these three codes are 1578 F, 1713 F, and 1789 F for RELAP5/Mod3, RELAP5-3D and RELAP5-3DK, correspondingly. All predicted PCT occur at the hottest rod. The end of blowdown takes place earlier in RELAP5/Mod3 (18.3 seconds after the break) than that in other two codes (27.8 seconds in 3DK and 29.6 seconds in 3D). The end of refill is also earlier in RELAP5/Mod3 (28.3 seconds) than that in other two codes (36.8 seconds in 3DK and 41.0 seconds in 3D). The impact of ECC bypass phenomenon on the PCT is investigated using RELAP5-3D code. The results show that when the ECC bypass is included in the calculations, the PCT is lowered by 20 F. The impact is not significant.
Safety Analysis LOCA ECCS
M. Lee L. Y. Li K.H. Hsu K.Y. Chiang
Department of Engineering and System Science National Tsing Hua University No. 101, Section 2, Kuang Department of Engineering and System Science National Tsing Hua University No. 101, Section 2, Kuang Institute of Nuclear Engineering and Science National Tsing Hua University No. 101, Section 2, Kuang
国际会议
上海
英文
754-766
2010-10-10（万方平台首次上网日期，不代表论文的发表时间）