Preliminary transient thermal analysis for safety of the dual-cooled waste transmutation blanket for the FDS-I

The dual-cooled waste transmutation (DWT) blanket is one of the key components of the fusion-driven subcritical system (FDS-I). Because of the large energy gain, the heat removal in accidents remains a major safety concern. In this contribution, several representative transients such as unprotected loss of flow accident in helium gas and LiPb (ULOFA), protected loss of flow accident in helium gas and LiPb (LOFA) and loss of power accident (LOPA) are calculated and analyzed. The blanket will not melt until several hours if the plasma core is shut down in time when the accidents occur. It has enough time to start additional action to keep the system safety. The results show that passive solution to shut down the plasma shall be given due to the little scale of responding time. Also, the results show an effective active heat removal solution such as liquid metal (LM) drain system and emergency blanket cooling system is needed.