The assessment of shutdown dose rate and radioactive waste of HCSB during its replacement in CFETR

Highlights: • A cell-counting R2S method is carried out by coupling MCNP and FISPACT. • The updated design of HCSB during the CFETR operations is applied in this study. • Not only SDR assessment but also radioactive waste evaluation is being considered. • Corresponding suggestions are put forward respectively after the assessment. - Abstract: Chinese Fusion Engineering Testing Reactor (CFETR) is a new test superconducting tokamak in China aimed to obtain the state-of-the-art technologies and bridge the gaps between ITER and DEMO. The helium cooled solid breeder blanket (HCSB) is one of three main blanket candidates for CFETR. During reactor operations, the highly radioactive nuclides will be produced by the blanket components which are located in the high-energy neutron radiation field. In order to protect the workers from too high radiation and ensure the normal operation of machinery, the Shutdown Dose Rate (SDR) of HCSB during its replacement is evaluated based on the rigorous two-step (R2S) method. Besides, according to the recommended standards provided by Safety and Environmental Assessment of Fusion Power (SEAFP) of the EU fusion program, the initial evaluation of the high level radioactive waste of the blanket is carried out as well. The results show that, based on current design of HCSB, the maximum SDR of the blanket is decreased to 4728 Sv/h after the reactor shutdown one day. And after 50 years of cooling, most of the structural materials can be recycled by simple remote operation.