[2J09-13] Passive Safety System

[2J12] Development of a passive safety shutdown device to prevent core damage accidents in fast reactors

(9) Basic evaluations of fuel migration behavior in the device by visualization experiments

*Yoshihiro Sekio¹, Isamu Sato², Masatoshi Kawashima³, Koji Morita⁴ (1. JAEA, 2. TCU, 3. Tokyo Tech, 4. Kyushu Univ.)

Keywords:fast reactor, core damage accident, passive safety, prevention of severe accidents

The proposed passive reactor shutdown device contains pins with fuels that are kept in the solid state during normal operation but melt into the liquid when its temperature exceeds a prescribed value under severe accidents. The device leads the reactor to the subcritical state by the migration of the liquid fuel to low positions in the pins. In this study, in order to obtain basic findings for evaluating the engineering feasibility of the proposed device structure, a simulated device pin sample which contains a simulated fuel (low melting point metal) and a thin tube was made. And, the behaviors of both the melting with heating and migration of the molten fuel were evaluated through the visualization experiments.