The Korean Society of Surface Science and Engineering

Gadolinium oxide (Gd₂O₃) and boron carbide (B₄C) composites layers on 304-stainless steels were plasma thermal spray coated to make a high thermal neutron absorption and shielding layers for a nuclear spent fuel transportation and storage container and a high-level nuclear wastes canisters. The coating layers contained Gd₂O₃, B₄C and binder Ni alloy. More than 100㎛ thick coating layers with a 1:1 ratio of the neutron absorber material and the binder nickel alloy were able to shield 100% neutron against the neutron beam with the 48.4 meV energy and 0.13 nm wavelength that was higher the neutron energy of domestic spent nuclear fuels undergone 30 years of cooling in a spent fuel pool. The corrosion current density and potential of the coating layers in an artificial sea water were less than 10^-6 A/cm² and lower than -835 mV_SHE, respectively. These results support that the plasma coating layers can be well applicable as the thermal neutron shielding materials for a domestic spent nuclear fuel transportation and storage containers.

키워드 thermal plasma spray coating; gadolinium oxide; boron carbide; spent nuclear fuel; corrosion; neutron shielding efficiency.