Development of Subchannel Analysis Program for He-Xe Mixed Gas Cooled Reactor

In order to facilitate the thermohydraulic analysis of gas-cooled fast reactors, a sub-channel analysis program specifically designed for this purpose has been developed. This program employs a helium-xenon mixed gas as the coolant to simulate the PCFD-474 design scheme within the Prometheus program of the United States. Benchmarking calculations were performed to validate the accuracy of the model. The findings indicate that the center temperature of the hot rod, the maximum temperature of the cladding, and the relative errors associated with the design scheme in the sub-channel analysis program for gas-cooled fast reactors are all below 2%. This demonstrates the program's strong applicability to the thermohydraulic design of gas-cooled fast reactors utilizing helium and xenon as coolants. Furthermore, an analysis was conducted to assess the impact of introducing a 3mm center hole on the thermal hydraulic performance of the fuel. The results of this analysis revealed a reduction of 36.9K in the center temperature of the fuel following the creation of the center hole, thereby enhancing the safety margin for the thermal design of gas-cooled fast reactors..