Molten salt reactor metals can last 3x longer using high purity salt

Researchers from the University of Liverpool and Copenhagen Atomics have demonstrated that using high-purity molten salts significantly reduces corrosion in molten salt reactors (MSRs), allowing metals like 316L stainless steel to last up to three times longer. Their study, published in the Journal of Nuclear Materials, showed that untreated salts containing moisture and oxides cause severe corrosion, metal loss, and surface degradation within 1,000 hours at temperatures up to 700°C. In contrast, purified salts resulted in negligible corrosion even after 3,000 hours, highlighting the critical role of salt purity in maintaining material integrity by preserving the protective chromium oxide layer on the steel surface. Molten salt reactors, a promising fourth-generation nuclear technology, use molten salt as both coolant and fuel, offering advantages such as a high boiling point that reduces explosion risk and eliminates the need for expensive pressure vessels. Historically, corrosion issues in molten fluoride salts limited MSR viability, often necessitating costly high-nickel alloys. This research suggests that controlling