Analysis of Th-U breeding capability for an accelerator-driven subcritical molten salt reactor

Accelerator-driven systems based on molten salt fuel have several unique advantages and features for advanced nuclear fuel utilization.The aim of this work was to study the Th-U breeding capability in such systems,known as‘‘accelerator-driven subcritical molten salt reactors’’（ADS–MSRs）.Breeding capacities including conversion ratio and net;U production for various subcriticalities and different minor actinides（MA）loadings were analyzed for an ADS–MSR.The results show that the subcriticality of the core has a considerable effect on the Th-U breeding.A high subcriticality is favorable to improving the conversion ratio,increasing the net;U production,and reducing the doubling time.Specifically,the doubling time for k;of 0.99 is larger than 80 years,while the counterpart for k;of 0.93 is only approximately22 years.Nevertheless,in an ADS–MSR with a high initial MA loading,MA results in a non-negligible;U depletion in the first two decades,while increasing the net;U production compared to reactors without MA loading.During the 50 years of operation,for the subcritical reactor(k;0:97)with MA fraction increasing from 1 to 14%,the net;U production increases from 3.94 to 8.24 t.