Engineered barrier research in Canada

Recent advances in scientific and engineering research in Canada to design, test and evaluate the performance of engineered barriers for a nuclear fuel waste disposal vault are described. The characteristics of used fuel and reprocessing waste forms and models to describe radionuclide release are reviewed. Several design prototypes for waste containers have been fabricated and structurally tested; studies of container materials are concentrating on assessing their susceptibility to localized forms of corrosion in the saline groundwaters typically found in plutonic rock in Canada. Research on methods for the final closure and inspection of containers is described. Vault sealing research has developed reference materials and specifications for buffer and backfill, and defined ranges of parameters of importance to their performance. Preliminary designs and material requirements for shaft and borehole seals are discussed. (author)