Comparative Studies on Plutonium and Minor Actinides Utilization in Small Molten Salt Reactors with Various Powers and Core Sizes

Molten salt reactor (MSR) has many advantages such as safety improvement and ability for waste burning. In the present study, the use of plutonium and minor actinides (MA) in small MSRs with various powers and core sizes has been investigated. For the small MSRs with 50 MWth, 100 MWth, 150 MWth, 200 MWth, and 250 MWth of power output, the criticality condition can be achieved if the reactor grade plutonium and MA content in loaded fuel are 7.56%, 6.76%, 6.56%, 6.56%, and 6.56%, respectively. The plutonium and MA utilization in small MSR results in the hardening of neutron spectrum compared to that of the standard 25 MWth miniFUJI MSR with Th-²³³U fuel. Furthermore, the neutron spectra become harder with the augmenting of Pu and MA contents in loaded fuel as well as the increasing of the output power.