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

从一开始，核电就是一个两极分化的话题，引发了强烈的观点和情感。即使加拿大的所有核电站立即关闭，仍将有200多万捆用过的核燃料。除了人们对核能未来的看法外，它的遗产留下了大量的旧燃料，这些燃料在数十万年的时间里保持活跃。目前，用过的燃料储存在地面上。然而，由于靠近潜在的自然灾害和可能的恐怖主义威胁，这不可能是一个长期的解决办法。加拿大的集体核废料产生者，以及所有其他正在探索各种选择的国家，已经确定了长期解决方案是建立一个深层地质库。200多万捆用过的核燃料将被放置在集装箱中，并被地面下约500米处的膨润土基屏障包围。在储存库中，膨润土屏障将支撑废物容器，将热能从最初热的容器转移出去，限制地下水渗透，并吸附放射性副产品。核废物管理组织(NWMO)是加拿大政府创建的一个公共机构，目的是协调该国所有用过燃料生产商努力实现核废物管理的共同解决方案。NWMO目前正在解决许多实际的设计、制造和施工问题。然而，从储存库的环境中产生了一些基本的工程科学问题，这些问题仍然需要解决：首先，膨润土在与咸水地下水饱和后是否会自我修复以起到合格的屏障作用？其次，内部气体压力是否会导致膨润土屏障破裂，从而将废物容器与环境直接联系起来？这项提议将为6名博士生提供资金，以研究该储存库的这些关键方面，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.