SBIR-STTR Award

The prospect of nuclear power produced with advanced molten salt-cooled reactor (MSR) designs has garnered the attention of the Department of Energy in conjunction with the private sector. Modern designs describe a chemically stable salt such as FLiNaK with a melting point below 500°C, heated by the nuclear reaction to a temperature near 700°C. Continuous operation of MSR heat-exchange loops requires monitoring of the molten salt as it ages. Normal operation of salt heat-exchanges loops over long periods of conventional use consume the loop components such as stainless steel pipes, flanges, pumps and reservoirs introduce impurities as they corrode, producing fluorides such as CrF2, FeF2 and NiF2 . More importantly, the electrical resistivity of these salts has been identified as a low-cost, realtime indicator (or health monitor) for informing reactor operates of real-time changes salt impurity. General Statement of How This Problem is Being Addressed: The innovation is to design and prototype a molten-salt conductance sensor with enough precision to differentiate a pure sample of FLiNaK from a sample containing various concentrations of impurities. Ozark IC is a leader in the development of extreme-environment electronics, making breakthroughs for high-temperature environments with recent demonstrations up to 800C° for DARPA with novel integrated circuit (IC) processes, high-density IC connectivity/packaging, and high-temperature connectors and cabling. These electronic solutions serve environments where temperature management of the electronics is not possible, such as the geothermal well (350°C), the surface of Venus (460°C), hypersonic vehicles (800°C), and now MSR research and development (700°C). What is to be done in Phase I? The University of Wisconsin-Madison Thermal Hydraulics Laboratory will advance its measurement of the conductivity profile of molten FLiNaK with a range of impurity species and concentrations. Ozark IC will migrate the low-temperature AFE prototype to a high-temperature implementation using its advanced ceramic additive manufacturing capability. This will correlate impurity levels with conductivity – essential for health monitoring. Commercial Applications and Other

Benefits:
Commercial applications include the development of molten salt heat health monitoring, exchange loops, high-temperature chemical analysis, and geothermal well logging.