Climate forcing impacts upon uncertainties in boundary conditions of a repository for spent nuclear fuel caused by a re-glaciation of the Canadian shield

在安大略省，50%的电力由核反应堆提供，这些核反应堆提供的电力没有伴随的温室气体排放。核能发电的一个不幸的副产品是，它导致产生长寿命放射性核素形式的废物，如果这些废物被释放到环境中，可能对生物圈的所有组成部分造成重大损害。因此，这种废物的储存方式必须使其免受生物圈逃逸的影响。放射性废物处置是国际上所有国家目前正在处理的一个问题，这些国家依赖核能为其部分需求提供动力。选择的解决方案涉及开发一个深层地质储存库（DGR），该储存库由一个建造在地球表面以下数百米处的拱顶组成，其中废物储存在旨在防止泄漏的罐中。为加拿大建立这样一个储存库必须面对这样一个问题，即这样一个储存库在冰川再消融时有多脆弱。由于在过去90万年中，整个国家经历了约9次冰川化和冰川消退，而且构成废物的许多放射性核素的半衰期可能超过10万年，因此，一旦发生这种冰川再消融事件，处置库的脆弱性问题可能是严重的。本提案的目的是分析与先前对边界条件的分析有关的不确定性，如果再发生这种冰川作用，这种处置库将受到边界条件的影响。预计造成这种不确定性的最重要因素是与造成冰川再消融事件的气候强迫的性质有关的因素，本提案的重点正是这个问题。为此，最近的进展，在模拟的最后一次这样的冰川事件中，相关的表面边界条件完全耦合到一个现代的耦合大气-海洋气候模式，以评估以前采用的强迫条件的有效性，以推断在以前的冰川边界条件分析冰厚度的变化。

In the Province of Ontario fully 50% of electrical power is provided by nuclear reactors which provide power that is free of accompanying greenhouse gas emissions. An unfortunate byproduct of nuclear power generation is that it leads to the production of waste in the form of long lived radio nucleides which, if they were to be released into the environment, could cause substantial harm to all components of the biosphere. It is therefore imperative that this waste be stored in a way that insolates it from biospheric escape. Radioactive waste disposal is a problem that is currently being addressed by all countries internationally which depend upon nuclear energy to power some fraction of their requirements. The solution of choice involves the development of a Deep Geological Repository (DGR) consisting of a vault constructed many hundreds of meters below Earth's surface in which the waste is stored in canisters designed to prevent escape. The development of such a repository for Canada must face the question as to how vulnerable such a repository might be to an episode of re-glaciation. Since the entire country has been glaciated and deglaciated approximately 9 times during the past 900,000 years, and since the half lives of many of the radio-nucleides of which the waste is composed may exceed 100,000 years, the issue of repository vulnerability in the event of such a re-glaciation event is potentially serious. The goal of this proposal is to provide an analysis of the uncertainties associated with previous analyses of the boundary conditions to which such a repository would be subject if a further such episode of glaciation were to occur. The most significant contributor to this uncertainty is expected to be that associated with the nature of the climate forcing that is responsible for the re-glaciation episode and it is upon this issue that this proposal is focused. To this end very recent advances in the modeling of the last such glaciation event are employed in which the associated surface boundary conditions are fully coupled to a modern coupled atmosphere-ocean climate model in order to assess the validity of the forcing conditions previously employed to infer the ice thickness variations in previous glaciation boundary condition analyses.