Using one hybrid 3D-1D-3D approach for the conceptual design of WCCB blanket for CFETR

A Two-Way Neutronics/Thermal-Hydraulics Coupling Analysis Method for Fusion Blankets and Its Application to CFETR

The China Fusion Engineering Test Reactor (CFETR) is a tokamak device to validate and demonstrate fusion engineering technology. In CFETR, the breeding blanket is a vital important component that is closely related to the performance and safety of the fusion reactor. Neutronics/thermal-hydraulics (N/TH) coupling effect is significant in the numerical analysis of the fission reactor. However, in the numerical analysis of the fusion reactor, the existing coupling code system mostly adopts the one-way coupling method. The ignorance of the two-way N/TH coupling effect would lead to inaccurate results. In this paper, the MCNP/FLUENT code system is developed based on the 3D-1D-2D hybrid coupling method. The one-way and two-way N/TH coupling calculations for two typical blanket concepts, the helium-cooled solid breeder (HCSB) blanket and the water-cooled ceramic breeder (WCCB) blanket, are carried out to study the two-way N/TH coupling effect in CFETR. The numerical results show that, compared with the results from the one-way N/TH coupling calculation, the tritium breeding ration (TBR) calculated with the two-way N/TH calculation decreases by −0.11% and increases by 4.45% for the HCSB and WCCB blankets, respectively. The maximum temperature increases by 1 °C and 29 °C for the HCSB and WCCB blankets, respectively.

Neutronic and Thermo-Hydraulic Analyses of Water-Cooled Blanket Based on Pressurized/Supercritical Water Conditions for CFETR

China Fusion Engineering Test Reactor (CFETR) is a test tokamak reactor being designed in China to bridge the gap between International Thermonuclear Experimental Reactor (ITER) and future fusion power plant. As one of the candidates, a water-cooled solid breeder blanket based on pressurized water and supercritical water conditions were proposed. In the concept, multiplying layers separated by three breeding layers were designed and optimized for higher tritium breeding ratio (TBR) and uniform heat distribution. This blanket adopts the Li2TiO3 lithium ceramic pebbles as the breeder, while beryllium pebbles as the neutron multiplier. In this paper, the thermal and fluid dynamic analyses of the optimized blanket on both water conditions were performed by numerical simulation, to discuss thermo-hydraulic performance of the blanket using pressurized water/supercritical water as its coolant. At first, the neutronic analysis was performed and based on the typical outboard equatorial blanket. Then, thermal and fluid dynamic analysis of the 3D model was carried out by CFX with fluid–solid coupling approach. It was found that the blanket can be effectively cooled on both water conditions, certified the feasibility of the blanket design with pressurized/supercritical water conditions. It indicated that supercritical water blanket had smaller safety margin than pressurized water blanket, but supercritical water blanket would lead to higher outlet temperature, thermal conductivity, and heat exchange efficiency also. In addition, the beryllium fraction was considered as one of the dominant factor, which leading a higher TBR in our simulations.