HIGH-TEMPERATURE COMPATIBILITY OF A1203-, BeO-, AND METAL-COATED UO2 PARTICLES WITH GRAPHITE AND COKE

摘要

The compatibility of carbon and graphite matrices with UO2 particles coated with Al2O3, BeO, nickel, niobium, and nickel-chromium alloy has been investigated at several temperatures up to 3000 F in flowing helium. Two different carbonaceous fillers and binders were used. As expected, the 2 to 8-μ metal coatings were badly damaged by reaction with carbon at temperatures as low as 1700 F. Both oxide coatings were completely destroyed after 6 hr at 3000 F. Considerable reaction between the matrices and Al2O3 and BeO coatings occurred during 1000 hr at 2500 F. Coating damage was more severe in surface particles than in particles located inside the specimens. The graphite filler and pitch binder combination used in this study was less reactive than combinations containing coke filler or resin binder.