Progress in thorium fuel cycle technology devoted to molten salt reactor system - 15316

The Molten Salt Reactor (MSR) is one of the Gen IV reactor system, which can be very effectively operated within ^232-233U fuel cycle as thorium breeder with the breeding factor significantly higher than 1. Other uniqueness of this reactor system is based on the fact that the primary circuit of the reactor is directly connected with the on-line reprocessing technology necessary for keeping the reactor in operation for a long run. The paper describes the existing and present activities in the area of research and development of fresh thorium - uranium liquid fuel processing, experimental studies of electrochemical separation applicable for on-line reprocessing. The results obtained from measurements show that: -) in FLIBE melt, there is a good possibility for electrochemical removal of uranium, -) in FLINAK melt, only uranium can be directly separated, and -) in LiF-CaF₂ melt, uranium, thorium and most of fission products can be electrochemically separated. The theoretical studies of the mutual link between the MSR reactor physics and online reprocessing technology are also presented. It was shown that the noble gases (Xe) and volatile fission products fluorides (Rh) removal helps to prevent more than 98% of overall parasitic absorption on fission products in the core. It is also evident that the reprocessing technology must focus in the first case on lanthanides removal, predominantly on samarium, promethium and neodymium