[2K12-19] Severe Accident

[2K12] Evaluation on Reactor Core Degradation and Relocation at Severe Accident

(4) MAAP5 Analysis of LOFT Experiment LP-FP-2

*Koji Nishida¹, Naoki Sano¹, Seitaro Sakurai¹, Michio Murase¹ (1. INSS)

Keywords:Severe Accident, Fuel Degradation, Relocation, MAAP5

The boiling transition time, cladding temperature from boiling transition to re-flooding and relocation in the LOFT experiment LP-FP-2, which simulated core damage and relocation in the early stages of a severe accident, were studied in MAAP5. In the LOFT experiment LP-FP-2, coolant was drained from the reactor vessel to reduce primary system pressure and core water level. The cladding temperatures from the boiling transition to re-flooding and relocation after the experiment were investigated. It was confirmed that MAAP5 could approximately predict the time of boiling transition, cladding temperature from the boiling transition to the time of re-flooding and relocation in the LOFT experiment LP-FP-2.