Three-dimensional full-scale neutronics/thermal-hydraulics/mechanics coupling analysis-based structural assessment of helium-cooled ceramic breeder blanket for fusion reactor

To accelerate the development and utilization of fusion energy, the China Fusion Engineering Test Reactor (CFETR) has been proposed as a bridge between the International Thermonuclear Experimental Reactor and demonstration fusion reactors. The primary objective of the CFETR is to achieve fusion energy transformation and tritium self-sufficiency, which is realized through the function of the blanket. In this study, a neutronics/thermal-hydraulics/mechanics coupling method is developed and applied to a helium-cooled ceramic breeder (HCCB) blanket, which is one of the two blanket candidates for the CFETR. A three-dimensional full-scale model is utilized in the coupling analysis to obtain the distributions of the neutronic, thermal-hydraulic, and mechanical parameters. A structural assessment of the CFETR HCCB blanket is then conducted considering steady-state conditions and two transient scenarios. The results demonstrate that following optimization of the blanket structure, the maximum temperatures of the different components remain below the safety limit of the corresponding materials. The structural assessment indicates that the blanket maintains its structural integrity under steady-state conditions. However, immediately after an in-box loss-of-coolant accident, structural failure owing to stress concentration may occur. Additionally, in the early stage of a loss-of-flow accident, the stress at the joint point between the cooling plate and cap exceeds the allowable stress of the material, potentially leading to structural failure within 17 s if no protective response is implemented. These findings provide comprehensive insights into the performance and safety of the CFETR HCCB blanket design.