Experimental investigation of the high-temperature interaction of steel with a lead coolant

This article presents the results of a study of the high-temperature interaction of a lead coolant with the material of the fuel element cladding of the promising BREST-$300$-OD reactor. The threshold temperature $(1425^{\circ}$C$)$ above which, when held for $30$ min, there is an active intergranular diffusion of lead into steel and entrainment of steel droplets into the coolant melt is experimentally determined. The spatial position of liquid phases based on lead and steel at a high temperature close to the boiling point of lead, as well as the solubility limits of steel in lead and lead in steel during the liquid-phase separation of the steel-heat carrier system at $1660^{\circ}$C, are determined.