Preliminary neutron study of a thorium-based molten salt energy amplifier

Present designs for molten salt thermal reactors require complex online processing systems, which are technologically challenging, while an accelerator-driven subcritical molten salt system can operate without an online processing system, simplifying the design. Previous designs of accelerator-driven subcritical systems usually required very high-power proton accelerators (> 10 MW). In this research, a proton accelerator is used to drive a thorium-based molten salt fast energy amplifier (TMSFEA) that improves the neutron efficiency of the system. The research results show that TMSFEA can achieve a long-term stable state for more than 30 years with a rated power of 300 MW and a stabilizing effective multiplication factor (k(eff)) without any online processing. In this study, a physical design of an integrated molten salt energy amplifier with an initial energy gain of 117 was accomplished. According to the burn-up calculation, a molten salt energy amplifier with the rated power of 300 MWth should be able to operate continuously for nearly 40 years using a 1 GeV proton beam below 4 mA during the lifetime. By the end of the life cycle, the energy gain can still reach 76, and U-233 contributes 70.9% of the total fission rate, which indicates the efficient utilization of the thorium fuel.