High-level radioactive waste from light-water reactors

Abstract

The production of radioactive nuclei during the operation of a light-water reactor is traced, and their decay history is followed. The potential environmental impacts of this waste are calculated and shown to be comparable to those of other materials we produce. Assuming deep burial, it is shown that there are important time delays which prevent the waste from reaching the biosphere in the first few hundred years while its toxicity is decreasing by several orders of magnitude. In the long term, the most important pathway to man was found to be through groundwater into food and water supplies, with consequences calculated to be 0.4 fatalities in 10 years from each year of all-nuclear power in U.S. Other pathways considered and found to be less important include meteorites, volcanism, release through ground water to airborne particulate, and human intrusion by drilling and mining for unspecified materials and for salt. For time scales longer than 10 years, nuclear power is shown to reduce man's exposure to radiation by consuming uranium. A cost-benefit analysis is developed for surveillance of buried waste. It is shown that buried high-level waste is environmentally much less dangerous than uranium mill tailings. CONTENTS

Sorption and desorption kinetics of Np(V) on magnetite and hematite

“…Neptunium-237 is present in high-level radioactive wastes, although in smaller amounts in comparison to other radionuclides [2]. However, because of its long half-life and its mobile nature under aerobic conditions due to the high chemical stability of its pentavalent state, Np-237 is considered a possible long-term pollutant of the ecosystem.…”

Extreme Scenarios for Nuclear Waste Repositories

“…Methods and other assumptions are outlined below. Cohen (1977) estimates that the number of deaths resulting from spreading gamma emitters evenly over the U.S. is 0.016 per watt per…”

“…The overestimate in hazard resulting from using this value is diminished somewhat by the preferential attachment of radioactivity to smaller particles (Fr80) and wind, turbulence, and updrafts near the ground. The assumptions of Cohen (1977) are adopted to estimate dust resuspension, increasing the total dust inhalation by 60%. Figure 1 shows the number of cancer doses received by various pathways as a function of the delay between reprocessing and the eruption which releases 1 km2 of the repository.…”

“…We suggest that they are a starting point for elucidating some important issues. Cohen (1977) has calculated probable numbers of fatalities from nuclear waste disposal on various assumptions. The expected number of people with radiation injuries from a nuclear waste repository is less than 50 over 50,000 yr.…”

Sorption of Np(V) onto hybrid clay-based materials: Montmorillonite-melanoidin

“…After years of investigations, the deep geological disposal appears to be the best choice and the most internationally accepted solution for the storage of radioactive waste, since the geosphere is stable and secure on a long time scale [1,2]. The separation and transmutation of the radionuclides may be of interest in order to reduce the amount of nuclear waste, but there will be still high-level waste (HLW) which has to be considered.…”