Uranium deposits: Natural analogues for radioactive waste repositories

点击翻译按钮获取中文摘要

Worldwide, there will be ~500 nuclear reactors operating by 2030, which will result in a 66% increase in global nuclear power generation. To remain at the forefront of an ever-competitive mining and energy exploration market, Canada and its industries need to adopt a leadership position in the development of strategies for nuclear waste disposal. Most countries with used nuclear fuel (UNF) agree that the safest way is to dispose of this waste in a deep geological repository (DGR) and that safe disposal of high-level nuclear waste (HLNW) requires containment in the DGR for at least 1 million years. One of the more difficult concepts involved in the disposal of UNF in DGRs are the very long time frames (e.g., 1 million years) required by the long-term safety assessment models. This is well beyond anything that can be considered in an experimental setting. Uranium deposits can provide important information on the performance of radioactive waste forms and radioactive waste repositories because uraninite (UO2+X), the most abundant uranium-bearing mineral in most uranium deposits, is similar in many ways to the UO2 in UNF. We propose to study the geological environments that host specific deposits, which can serve as important natural laboratories in which to study uranium and other radionuclides over very large spatial (nanometers to kilometers) and temporal scales (thousands to millions of years). The proposed research brings together geoscientists from the University of Manitoba, the Canadian Nuclear Safety Commission (CNSC) and Cameco Corp. This work will provide training for three PhD students and several undergraduate research assistants. The major potential outcome and impact of this partnership will be to show that natural analogues (e.g., uranium deposits) can complement numerical modeling data for DGR performance. We will use quantitative data from systems that formed over geological time-scales, and that have remained stable for millions to billions of years, thus providing more confidence in the safety case for the DGR concept.