[3F09-14] Severe Accident Analysis

[3F10] Severe accident analysis of 2 loop PWR by MAAP 5.01

Part 2: Discretization effect of containment vessel model on the TMLB 'and ADCB' sequences

*Masaaki Satake¹, Satoshi Nishimura¹, Yoshihisa Nishi¹, Genta Aoki², Taku Shibata² (1. CRIEPI, 2. HEPCO)

Keywords:Severe Accident, MAAP, SBO, LOCA

Using the two input data decks of PWR 2 loop, two severe accident sequences are analyzed by MAAP 5.01. In both sequences, it was confirmed that dividing the containment vessel (CV) is effective in order to grasp the temperature change of each section. In addition, it was confirmed that the number of divisions of CV affects the event progression of the primary system. Because these are an irreversible process, this can lead to surprisingly large variations in the calculated results as the sequence progression. From this, uncertainty analysis also needs to consider dividing the CV because the discretization of divisions of CV affects the event progression of the primary system.