Study of thorium–uranium based molten salt blanket in a fusion–fission hybrid reactor

Not only solid fuels, but also liquid fuels can be used for the fusion–fission symbiotic reactor blanket. The operational record of the molten salt reactor with F–Li–Be was very successful, so the F–Li–Be blanket was chosen for research. The molten salt has several features which are suited for the fusion–fission applications.The fuel material uranium and thorium were dissolved in the F–Li–Be molten salt. A combined program, COUPLE, was used for neutronics analysis of the molten salt blanket. Several cases have been calculated and compared. Not only the influence of the different fuels have been studied, but also the thickness of the molten salt, and the concentration of the 6Li in the molten salt.Preliminary studies indicate that when thorium–uranium–plutonium fuels were added into a F–Li–Be molten salt blanket and with a component of 71% LiF–2% BeF2–13.5% ThF4–8.5% UF4–5% PuF3, and also with the molten salt thickness of 40 cm and natural concentration of 6Li, the appropriate blanket energy multiplication factor and TBR can be obtained.The result shows that thorium–uranium molten salt can be used in the blanket of a fusion–fission symbiotic reactor. The research on the molten salt blanket must be valuable for the design of fusion–fission symbiotic reactor.

► A molten salt blanket has been designed for the fusion–fission hybrid reactor.
► The use of Thorium in the molten salt fuels has been studied.
► The molten salt was consisted of F–Li–Be and with the thickness of 40 cm.
► The concentration of 6Li was chosen to be the natural enrichment ratio.
► The result shows that TBR is greater than 1, M is about 15–16.