[3F09-14] Severe Accident Analysis

[3F09] Severe accident analysis of 2 loop PWR by MAAP 5.01

Part 1: Construction of analysis model and selection of accident sequence

*Genta Aoki¹, Taku Shibata¹, Masaaki Satake², Satoshi Nishimura², Yoshihisa Nishi² (1. HEPCO, 2. CRIEPI)

Keywords:Severe Accident, MAAP, SBO, LOCA

HEPCO and CRIEPI construct an input data deck of PWR 2 loop plant based on an actual plant data for MAAP ver. 5.01. Two input data are constructed in order to grasp the influence on the analysis results of the discretization of divisions of containment vessel at the time of severe accident. Next, the severe accident sequence was selected. One was an accident sequence in which water injection by the ECCS failed with the loss of all AC power, and the pressurizer relief valve was opened. The other was an accident sequence in which large LOCA occurred and water injection by ECCS failed and only the alternative containment spray was activated for a certain period of time.