Ceramic plasma‐spray‐coated graphite crucible for injection casting of fast reactor fuel slugs

Abstract

AbstractCeramic plasma‐spray coatings with single and multiple layers have been applied to melting crucible material substrates for the development of a reusable crucible for the fabrication of metal fuel slugs for a sodium‐cooled fast reactor (SFR). Various combinations of vacuum plasma‐spray (VPS) coated specimens have been applied to investigate the bonding effect on the crucible substrate and the interaction between the metal fuel and the VPS‐coated crucible substrate. All VPS‐coated methods maintained a sound coating state after a dipping test with U‐10 wt%Zr melt. A single coating of a Y2O3(150) layer and a double coating layer of TaC(50)‐Y2O3(100) showed some degradation or penetration, respectively, after 2 cycles of dipping test with an aggressive U‐10 wt%Zr‐5 wt%RE melt. Injection castings of U‐10 wt%Zr and U‐10 wt%Zr‐5 wt%RE fuel slugs were also conducted to investigate the feasibility of a reusable melting crucible of metal fuel slugs. The U‐10 wt%Zr fuel slugs were soundly fabricated without significant interactions of the graphite crucibles; however, the U‐10 wt%Zr‐5 wt%RE fuel slugs had some degradation or penetration, respectively, after injection casting.