Chemical and physical effects in waste matrices caused by particle impact and implantation
Radioactive waste can be stored in a suitable matrix, the stability of which must be excellent for very long times of the order of 100,000 years. Radiation damage due to radioactive decay of the incorporated waste is an important source of changes in chemical and physical properties of the matrix. Two techniques were used to study the phenomena caused by the impact of light He-ions and heavy recoil atoms. Controlled ion implantation was extensively employed simulating (and separating) the changes in chemical and physical properties caused by recoil atoms; the consequences on material behaviour due to He-ion implantation alone were briefly investigated. To investigate the synergistic effects of He-ions and recoil atoms, waste matrices were prepared with different contents of short-lived actinides to reach realistic damage levels in a time-scale acceptable for laboratory experiments. The results obtained on a variety of waste matrices (glasses, special ceramics and spent UO(2) fuel) are presented. The damage mechanisms, the possible dose rate effects due to very large differences in dose rates between laboratory simulation experiments and real storage conditions, the effects due to the differences between irradiation by external beams and internal decay events and the conclusions and consequences for long term storage are discussed.
Bibliographic Reference: Paper presented: Gordon Research Conference on Particle Solid Interactions, Holderness, July 6-10, 1992
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Record Number: 199211373 / Last updated on: 1994-11-29
Original language: en
Available languages: en