[3D01-07] Evaluation for Accident Reactor

[3D05] Annealing effect on strength and microstructure of LWR steels during severe accident

Residual strength estimation of the reactor structure after the severe accident

*Kengo Hashimoto¹, Kohei Noguchi¹, Shiro Jitsukawa¹ (1. National Institute of Technology, Fukushima College)

Keywords:Fukushima Daiichi , Reactor decommissioning, Strength of the Containment vessel steel, Effect of temperature history

Strength of the containment vessel of Fukushima Daiichi might be reduced by heating during severe accident. Effect of temperature history,including rapid cooling and aging for several weeks to austenitizing temperature has been examined experimentally on the containment vessel steels. Reduction of elastic plastic fracture toughness after rapid cooling has been examined. Tensile strength has been reduced to 60% after aging at 700C for 1000 h. Change of microstructures has been also evaluated.