Radiation damage in nuclear waste glasses following ion implantation at different temperatures
The German nuclear waste glass GP 98/12 was implanted with Kr-ions at different temperatures up to 350 C, thus covering and extending the temperature range expected in a repository for fully radioactive nuclear waste glasses. Vickers indentations were used to measure the fracture toughness, K; leaching was done at different temperatures up to 200 C in deionised water, and the leached surfaces were analyzed by RBS and ERDA in order to determine the changes in composition with the formation of hydrated layers. For implantation at room temperature, K increased with the ion dose with a maximum at approximately 5 x 1.0 E15 ions/cm2. Such a dose corresponds to damage levels that will not be surpassed in real waste glasses. This technologically positive feature of damage was largely absent for implantation at T >= 250 C, indicating that damage-induced stresses are significantly decreased for these conditions. In contrast, damage-induced enhanced leaching and hydration were observed also at higher implantation temperatures showing that the damage features responsible for increased leaching recover at much higher temperatures than those responsible for increased fracture toughness. This previously unknown difference is discussed in the context of related work on glasses using other damage sources (e.g. alpha-decay of incorporated short-lived actinides).
Bibliographic Reference: Paper presented: Radiation Effects in Insulators REI-89, Hamilton (CN), June 1989
Availability: Available from (1) as Paper EN 34840 ORA
Record Number: 198910893 / Last updated on: 1994-12-01
Original language: en
Available languages: en