Analysis of BWR station blackout accident: Thermal-hydraulic behavior up to severe core damage in Fukushima Daiichi power plant unit 2

Abstract

The analysis of the long-term station blackout accident of BWR has been performed using the TRACBF1 code. The actuation of RCIC was assumed, and the results were compared with the data observed at the Fukushima Daiichi power plant unit 2 reactor. BWR-5 of 1, 100 MW was analyzed, while the unit 2 reactor was BWR-4 of 780 MW. The reactor pressure and the core liquid level were, however, in good agreement with the observed data. It was confirmed that the quasi-steady state continued for a long time with the RCIC actuation. The timing of recovery action, which was composed of depressurization and coolant injection, necessary for the maximum clad temperature being less than 1, 500 K was studied and compared with that of the unit 2 reactor. © 2011 Atomic Energy Society of Japan, All Rights Reserved.