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%的电力是由核反应堆提供的，这种核反应堆提供的电力没有温室气体排放。核能发电的一个不幸的副产品是，它导致以长寿命放射性核素的形式产生废物，这些放射性核素如果被释放到环境中，可能对生物圈的所有组成部分造成重大损害。因此，这种废物必须以一种使其免受生物圈逸出的方式储存。放射性废物的处理是目前国际上所有依靠核能来满足其部分需求的国家正在解决的一个问题。选择的解决方案涉及开发一个深层地质储存库（DGR），该储存库由一个在地表以下数百米处建造的拱顶组成，其中废物储存在旨在防止泄漏的罐中。为加拿大开发这样一个储存库必须面对这样一个问题，即这样一个储存库对重新冰期的影响有多大。由于整个国家在过去90万年中大约经历了9次冰期和冰期消退，而且由于构成核废料的许多放射性核素的半衰期可能超过10万年，因此，一旦发生这种再冰期事件，核废料储存库的脆弱性问题可能会很严重。本建议的目的是分析与以前对边界条件的分析有关的不确定性，如果再发生一次这样的冰期，这种储存库将受到边界条件的限制。造成这种不确定性的最重要因素预计是与导致再冰期的气候强迫的性质有关的因素，本建议的重点就是这个问题。为此目的，本文采用了最近一次此类冰川事件模拟的最新进展，其中相关的表面边界条件与现代耦合的大气-海洋气候模式完全耦合，以便评估以前在冰川边界条件分析中用于推断冰厚变化的强迫条件的有效性。

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.