[2A09-11] Severe Accident 2

[2A09] Reactor Core Degradation and Relocation at Severe Accident

(5)Temperature and Porosity Evaluation on SFD1-4 test

*Koji Nishida¹, Naoki Sano¹, Takayoshi Kusunoki¹, Mishio Murase¹ (1. INSS)

Keywords:Severe Accident, Fuel Degradation, Relocation, Porosity

In this study, the steam oxidation reaction models were examined, and the temperatures and porosity of the fuel bundle at the Severe Fuel Damage Test 1-4 were evaluated using the latest nuclear fuel/nuclear material thermodynamic database. MAAP5 was used for the computing. The porosity was evaluated after optimizing the fuel bundle temperatures. The measured porosity becomes smaller in the lower region due to melting and relocation of the fuel material. The computed values of porosity based on the fuel material thermodynamics DB and e based on the phase diagram of Hofmann et al. were compared. Both evaluation values become smaller in the lower region, and the difference between the two computed values is small.