Molten salt nuclear reactors (MSRs) are a type of Generation IV nuclear reactor which use molten fluoride or chloride salts as their primary coolant. At over 800ºC, these molten salts are extremely corrosive and limit the feasibility of using conventional steel or nickel alloys. However, molten salts corrode oxidation-resistant alloys by depleting their protective films of chromium, making it very difficult to develop a nickel-based alloy capable of withstanding the conditions in a MSR. Lawrence Livermore National Laboratory (LLNL) has identified WC272, a proprietary tungsten carbide ceramic composite, as a promising structural material candidate for resisting molten halide salt corrosion. The goal of this project is to characterize additively manufactured (AM) WC272 and validate its use for a MSR heat exchanger using nanoindentation and modulus of rupture (MOR) mechanical testing. Indentation testing will be used to quantify a difference in hardness from before and after ion irradiation, as well as to correlate a change in hardness to a change in strength. Preliminary microindentation tests show that AM WC272 is significantly softer than conventionally manufactured WC272, which could be attributed to porosity and/or grain size. This study will inform the scientific community of the performance of AM WC materials when subjected to the conditions found in a simulated MSR primary coolant loop.
2025-04-09 09:00:00
