Performance of bentonite barriers in a deep geological repository for used nuclear fuel

自成立以来，核能一直是一个两极分化的话题，带来了强烈的意见和情绪。即使加拿大所有的核电站立即关闭，仍将有200多万捆用过的核燃料留下来。除了人们对核能未来的看法之外，它的遗产留下了大量的使用过的燃料，这些燃料可以保持数十万年的活性。目前，使用过的燃料储存在地面上。然而，这不是一个长期的解决办法，因为该地区非常接近潜在的自然灾害和可能的恐怖主义威胁。加拿大的核废料集体生产者以及所有其他正在探索各种备选办法的国家都已确定，长期解决办法是建立一个深层地质处置库。200多万捆用过的核燃料将被放置在集装箱中，并由地下约500米的以硅灰石为基础的屏障包围。在处置库中，膨润土屏障将支撑废物容器，将热能从最初的热容器转移出去，限制地下水渗透，并吸附放射性副产品。核废料管理组织（NWMO）是加拿大政府设立的一个公共机构，负责协调全国所有的废燃料生产商，努力寻求核废料管理的共同解决方案。西北气象组织目前正在解决许多实际的设计，制造和施工问题。然而，有一些潜在的基础工程科学问题所产生的存储库的背景下，仍然需要解决方案：首先，膨润土自我愈合功能作为一个称职的屏障饱和后，含盐地下水？第二，内部气体压力是否会发展到破坏膨润土屏障，从而使废物容器与环境直接相连？该提案将为六名博士生提供资金，研究处置库的这些关键方面，以确保加拿大人和环境的安全。

Since its inception, nuclear power has been a polarizing topic that brings forth strong opinions and emotions. Even if all nuclear power plants in Canada were shut down immediately, more than two million bundles of used nuclear fuel would remain. Aside from one's opinions regarding the future of nuclear power, its legacy has left a substantial quantity of used fuel that stays active for hundreds of thousands of years. Currently, used fuel is stored at the ground surface. This cannot be a long-term solution, however, due to the close vicinity to potential natural disasters and possible terrorism threats. The collective producers of nuclear waste in Canada, and all other countries exploring options, have determined the long-term solution to be a deep geological repository. The over two million bundles of used nuclear fuel will be placed in containers and surrounded by bentonite-based barriers approximately 500 m below ground surface. In the repository, bentonite barriers will support the waste containers, transfer thermal energy away from the initially hot containers, limit groundwater infiltration, and adsorb radioactive by-products. Nuclear Waste Management Organization (NWMO) is a public agency created by the Canadian Government to coordinate all of the nation's producers of used fuel to work towards a common solution to nuclear waste management. NWMO is currently addressing numerous practical design, manufacturing, and construction issues. There are, however, a number of underlying fundamental engineering science questions arising from the repository context that still require solutions: First, will the bentonite self-heal to function as a competent barrier following saturation with saline groundwater? Second, will internal gas pressures develop to fracture the bentonite barriers leaving a direct link between the waste containers and the environment? This proposal would provide funding for six Doctoral students to research these critical aspects of the repository to ensure the safety of Canadians and the environment.