[en] As part of the Nuclear Regulatory Commission's requirement to assess the Department of Energy's application to construct geologic repositories for high-level radioactive waste, Battelle's Columbus Laboratories is investigating the long-term performance of materials used for high-level waste packages. The effects on glass waste-form dissolution of temperature, pressure, solution chemistry, and ratio of glass surface area to solution volume have been studied. The glass-dissolution correlation is ready to be evaluated by comparison with experiments. The devitrification correlation has been completed. In canister-corrosion studies, CF8 alloy was found less susceptible to glass attack than Type 304L stainless steel. Limited experiments revealed no corrosion mechanism which would indicate that cast steel could not be used as a corrosion-allowance container material; additional tests with cracking agents are planned. In hydrogen-uptake studies, cast steel was found to absorb more hydrogen than wrought steel. Parts of the general-corrosion correlation have been tested, and work continues on obtaining realistic experimental data as input for it. Gamma fluxes and dose rates in and near the waste package were calculated for CHLW and spent-fuel waste forms. The current water-radiolysis model was found adequate when tested against existing data, and preliminary calculations were performed with the current water-chemistry model; in both cases, additional chemical species are being incorporated. This report documents investigations performed during the period April, 1983 to April, 1984