Optimization and Thermal Safety Analysis of CFETR Advanced Small Sample Irradiation Capsule

The capsule structure of the advanced material irradiation test sample in China Fusion Engineering Experimental Reactor (CFETR) is relatively complicated, and the capsule is filled with helium. The size and location of the capsule rib and the material of the filling inside the capsule have great influence on the sample temperature. Based on the STAR-CCM+ code, a full-scale capsule model was established in the CFETR advanced small sample irradiation device, and the rib and filler materials of the capsule were adjusted according to the target temperature of the sample. For the problem that the heat release rate of the whole sample in the capsule is low, using tungsten material with higher heat release rate as filling material can significantly increase the overall sample temperature. For the case that the heat release rate of local samples is quite different, the temperature between samples can be well controlled by adjusting the size and position of the local rib, so that the calculated temperature of the sample can meet the target temperature range. The results show that after optimization with the above method, the sample center temperature can meet the target temperature range and meet the thermal safety of irradiation in the High Flux Engineering Test Reactor (HFETR), ensuring the smooth development of the entire irradiation task.