Evaluation of Backfill Materials for a Shallow-Depth Repository

Abstract

The focus of laboratory research effort on the disposal of low- and intermediate-level radioactive waste is to determine what conditions will dominate and which engineered barriers will be most effective for the retention of radionuclides, Initial studies have concentrated on the evaluation of a flooded repository and the assessment of backfill materials suitable for the adsorption of radioactivity, yet permeable enough to allow excess water to pass through the repository and into the underlying water table. Both physical and adsorption studies have been performed. Based on these preliminary experiments, it is felt that a mixture of 10 wt% clay and the remainder sand would satisfy the above criteria, Since both are available within the Ottawa Valley, they also have the added advantage of being more cost effective to use than imported materials.