水が混入した RCIC タービン内の二相流挙動に関する数値予測

抄録

A reactor core isolation cooling (RCIC) system of the Fukushima Daiichi Nuclear Power Plant Unit 2 is continued to operate even after the loss of power supply. As a result, the water injection to the reactor core has been carried out for more than 70 hours from the earthquake. Even though the control power is lost, the factors that water injection by the RCIC is continued is still unknown. On the other hand, from the results with the MAAP analysis, the RCIC is speculated that had been driven by two-phase flow of water and vapor. Therefore, in order to contribute to the clarification of the unexplained events related to the RCIC of 1F2, void fraction distributions based on water and vapor volumetric rates in the RCIC turbine has been evaluated analytically. From the present study, it was found that the torque applied to the turbine increases with the increase of accumulated water and prevents the rotation.