How Thick Should Cover Layer be for Radioactive Waste Disposal Facility? The Case of the Yamin Plain, Israel

Abstract

Two main natural processes which control the migration of radioactive contaminants to the biosphere were studied in the Yamin Plain in order to evaluate the thickness of a cover layer needed for near-surface radioactive waste disposal facility. The first is the natural erosion of the cover layer, and the second is the infiltration during rain and runoff events. The erosion rate of the soil surface was studied by optical stimulation luminescence technique. It was found that during the last 14,000 years, the erosion rate was 0.3 mm/y which are 3 m for 10,000 years. The infiltration depth assessment was based on water content measurements and numerical modeling. It shows that under the most extreme rain event having an equivalent rain of 84 mm, infiltration depth was limited to 4.5 m. Taking into account the two processes, the effective cover layer thickness over 10,000 years should be at least 7.5 m thick.