Alpha self-irradiation of waste glasses: State of the knowledge
A key issue for the permanent disposal of high level waste is the development of predictive models for long-term performance. These models have to be based on a reliable database and a sound scientific understanding of the phenomena of importance for long term storage. Radiation effects from alpha-decay could change physical and chemical properties of the waste glass. The heavy recoil atom of the alpha-decay produces a dense collision cascade, and the alpha-particle, at the end of its range of about 25 µm, is transformed into a He-atom by electron capture. The present paper therefore deals predominantly with the effects of displacement damage and of He-accumulation due to alpha-decay. The work performed deals with property measurements on three waste glasses doped with either 0.5 wt% or 1.5 wt% (244)Cm and stored for up to 10 years. The properties, measured as a function of time (damage level), were volume changes (swelling), leaching behaviour, hardness, Young's modulus and fracture toughness, and He release. Emphasis is given to the French glass R7T7. The results are compared with literature data on other waste glasses and with results from ion implantation. It is shown that, within the parameter range investigated, no significant negative effects of alpha-decay were observed.
Bibliographic Reference: Paper presented: CEA-Valrho Summer Workshop on Scientific Research for High Performance Containment, Valrho (FR), 31 August - 7 September 1997
Availability: Available from (1) as Paper EN 41192 ORA
Record Number: 199810340 / Last updated on: 1998-03-09
Original language: en
Available languages: en