Advances in the fundamentals of corrosion in molten chloride salts using high resolution X-Ray Diffraction and XANES in the HERFD mode

Chloride molten salts are being investigated for use as a fuel matrix in Molten Salt Reactors. However, their highly corrosive nature poses significant risks to the structural materials. Initial experiments (proposal A20-1-864) have demonstrated the dissolution of alloying elements such as Cr and Fe into the salt after a short exposure of Ni-based alloys. While most studies in literature have focused on studying the alloys composition and microstructure after exposure, there is a surprising lack of attention to the fuel salts composition, despite the evident impact on fuel thermophysical properties, and significance for the understanding of the corrosion mechanisms. The objectives of this work are (i) to gain a fundamental understanding of the effect of the salt redox potential; (ii) to broaden the materials selection; and (iii) to study the corrosion kinetics. To this end, complementary investigations will be performed using high resolution XRD and XANES in the HERFD mode at BM20.