(FT/P2-8) Thermal-hydraulic Safety Study of Chinese Helium Cooled Solid Breeder Test Blanket Module for ITER

H. Liu1), K.M. Feng1)
1) Southwestern Institute of Physics, Chengdu Sichuan, China

Abstract.  This paper introduces the transient accidents analysis for Chinese Helium Cooled Solid Breeder Test Blanket Module (CN-HCSB TBM) and its cooling system using RELAP5 code. The sub-modules bypass is used to control the first wall (FW) coolant temperature increase. The In-Vessel Loss of Coolant Accident (LOCA) results indicate that the induced over-pressurization of the vacuum vessel is within the ITER design limit pressure 200kPa. The Ex-Vessel LOCA will induce the melting of FW beryllium armor after 86s of this LOCA beginning. The In-Box LOCA will induce the pressure increase of the purge gas to about 7.3MPa within one second. Installing the fast isolation valve for tritium extraction system (TES) and pressure relief valve to TBM box are very important. The maximum temperature of FW beryllium armor induced by Loss of Flow Accident reaches 764oC and the final pressure of vacuum vessel is 28kPa. The Loss of Heat Sink accident induces the FW beryllium armor maximum temperature of 877 oC, and then the armor temperature decreases. The coolant water of heat exchanger (HX) secondary side begins to evaporate after 415s accident beginning.

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