University of Illinois, Urbana-Champaign (UIUC)

The University of Illinois, Urbana-Champaign (UIUC) will develop a fuel processing system that enables load-following in molten salt reactors (MSRs), an important ability that allows nuclear power plants to ramp electricity production up or down to meet changing electricity demand. Nuclear reactions in MSRs produce unwanted byproducts (such as xenon and krypton) that can adversely affect power production. In steady, baseload operation, these byproducts form and decay at the same rate. When electricity production is ramped down, however, the byproducts start to be produced at a greater rate than they decay, leading to a buildup within the reactor. When power production must be once again increased, the response rate is slowed by the time needed for the byproducts to reach their equilibrium level (determined by the radioactive decay half-life, which is on the order of hours). Thus, buildup of these unwanted byproducts resulting from ramping down inhibit proper load following for molten salt reactors. Fortunately, MSRs transport fuel in a flowing molten salt fuel loop, which means that a section of the reactor, outside the core, can be leveraged for fuel processing and “cleanup.” The team will determine the feasibility of removal of these unwanted byproducts and design a fuel reprocessing system, removing a major barrier to commercialization for molten salt reactors.