A Simple Probabilistic Risk Analysis for High-Level Waste Repositories

A method is developed for estimating, on a generic basis, the probability per year for an atom of average rock at a given depth to be transferred into a river. For a 600-m depth, it is 0.9 × 10⁻⁹/yr. The transfer probability from shallow aquifers or rivers into human stomachs is dominated by our use of well water with additional contributions from direct use of river water, irrigation, and fish; the total probability is 4 × 10⁻⁴. The product of these, corrected for the greater leach-ability of waste glass than of average rock, gives a total transfer rate for an atom of buried waste into human stomachs of 10⁻¹²/yr. When combined with health risk information, it is concluded that we may eventually expect 0.017 deaths/GW(electric).yr from high-level waste, and 0.068 deaths/GW(electric) .yr from unreprocessed spent fuel.