Post-irradiation examination of the Molten Salt Reactor Experiment from the 1970s revealed intergranular cracking of the salt-facing material, Hastelloy-N, from the penetration of fission products, specifically tellurium (Te), into the components. Stainless steel 316H is a candidate salt-facing structural material for future molten salt reactors due to its excellent corrosion, oxidation, and neutron irradiation resistance. Thus, studies are needed to verify if Te may lead to material degradation of salt-facing components made from 316H.

This work examined the behavior of stainless steel 316H in three conditions: as received, heat treated to 800°C for 100 h without Te, and with a highly concentrated Te environment. After exposure, mechanical testing was performed on all samples to reveal the loss of strength and ductility in the Te-exposed samples. Additional analysis of the Te-exposed 316H samples using scanning electron microscopy displayed intergranular embrittlement and energy-dispersive X-ray spectroscopy maps highlighted the infiltration of Te within grain boundary cracks. These results present the need for additional experiments to understand how Te weakens the structural material, especially in molten salt, and to eventually identify the driving mechanism for this observed behavior.