Thermo-Hydro-Mechanical Processes in Evolving Multi-Phasic Geomaterials, Interfaces and Geoenvironmental Endeavours

演化的多相岩土材料、界面和地质环境努力中的热水力机械过程

• 批准号: RGPIN-2021-02650
• 负责人: Selvadurai, Antony
• 金额: $ 3.79万
• 依托单位: McGill University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=742132
• 关键词: Thermo; Hydro; Mechanical; Processes; Evolving

Developing feasible techniques for disposal of hazardous, heat emitting nuclear fuel waste is a critical environmental concern to many countries that store their waste at reactor sites, which, as they age, become increasingly unsuitable for safely storing the waste. Events in Fukushima have emphasized the vulnerability of temporary storage sites; safe disposal strategies must address the cradle-to-grave cycle and restore nuclear energy as a viable option to reduce reliance on fossil fuels. Many countries favour the creation of a Deep Geologic Repository (DGR) in stable geologic formations to contain the stored waste and prevent release to the geosphere and the biosphere. The favoured geologic media varies by country; clay deposits in Belgium, argillaceous rocks in France, granitic rock masses in Canada, Finland, Japan, Sweden and Switzerland, salt formations in Germany, arid geologic media in China, sedimentary rock formations in the UK and Spain and porous tuff in the USA. Since the 1960's Canada has considered locating a DGR for high-level nuclear waste in the Canadian Shield and possibly a DGR for short-lived low- to intermediate-level nuclear waste in the argillaceous rock formations of southern Ontario. Developing a DGR is not routine; strict environmental controls must be in place with a series of engineered barriers to minimize both short- and long-term release of radionuclides to the environment. Any rock mass that houses a DGR is a key element in a disposal concept and should act as a natural geologic barrier to retard radionuclide migration in the long term. The Thermo-Hydro-Mechanical (THM) behaviour of intact rocks and defects such as fractures are critical factors that will decide the efficacy of a DGR concept. The mechanical, fluid flow and thermal properties of rocks can be altered by the creation of a storage vault and by the thermal loading by the stored waste. The long-term impacts on the DGR, ranging from groundwater flow alterations due to climate change, glacial advance and other processes such as induced earthquakes, need to be accounted for in the safety assessment. Most importantly, the performance of the DGR needs to be investigated for time scales that transcend conventional engineering endeavours. Suitable mathematical models of THM processes and experimental techniques, have to be developed to evaluate the parameters characterizing the multi-physics processes. The mathematical models have to be implemented in computational procedures to predict the performance of a DGR at time scales of interest to long-lived radioactive wastes. These important research components will lead to the implementation of a successful deep geologic disposal strategy in Canada. The over-arching findings related to THM research examined in this proposal can also enhance our understanding of both leakage of sequestered greenhouse gases and methane from defective interfaces and ground subsidence due to water and resource extraction.

对于许多国家来说，开发可处置有害的危险，排放核燃料浪费的可行技术对于许多国家来说是一个至关重要的环境问题，这些国家将其废物存储在反应堆地点上，随着年龄的增长，它们变得越来越不适合安全地存储废物。福岛的事件强调了临时存储站点的脆弱性。安全处置策略必须解决摇篮到宽度周期，并恢复核能，作为减少对化石燃料的依赖的可行选择。许多国家赞成在稳定的地质地层中创建深层地质储存库（DGR），以包含储存的废物并防止向地质和生物圈释放。受欢迎的地质媒体因国家而异。比利时的粘土沉积物，法国的泥土岩石，加拿大，芬兰，日本，瑞典和瑞士的花岗岩岩石块，德国的盐层，中国的干旱地质媒体，英国的沉积岩层以及西班牙和美国的多孔塔夫。自1960年代加拿大以来，加拿大考虑在加拿大盾牌中找到高级核废料的DGR，并可能是安大略省南部的泥质岩层中短期低至中间核废料的DGR。开发DGR不是常规的；必须具有一系列工程障碍，以最大程度地减少放射性核素向环境的短期释放和长期释放。任何容纳DGR的岩石块都是处置概念的关键要素，从长远来看，应该充当延迟放射性核素迁移的自然地质障碍。完整岩石和缺陷（例如裂缝）的热杂种力学（THM）行为是决定DGR概念功效的关键因素。岩石的机械，流体流量和热性能可以通过存储库的产生以及存储的废物的热负载来改变。长期对DGR的影响，从气候变化，冰川进展以及其他过程（例如诱导地震）引起的地下水流动的变化范围都需要在安全评估中考虑。最重要的是，需要研究超越常规工程努力的时间尺度的DGR的性能。必须开发出适当的THM过程和实验技术的数学模型，以评估表征多物理过程的参数。数学模型必须在计算过程中实现，以预测DGR在感兴趣的时间尺度上的性能到长期寿命的放射性废物。这些重要的研究组件将导致在加拿大成功实施一项成功的深层处置战略。与本提案中研究的THM研究相关的总体发现也可​​以增强我们对由于水和资源提取引起的缺陷界面和地面沉降的隔离温室气体泄漏和甲烷的理解。