Clay Hydration, Drying, and Cracking in Nuclear Waste Repositories

核废料处置库中的粘土水合、干燥和裂解

• 批准号: EP/X011615/1
• 负责人: Jon Harrington
• 金额: $ 41.99万
• 依托单位: British Geological Survey
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FX011615%2F1
• 关键词: Clay; Hydration; Drying; Cracking; Nuclear

The design of geologic repositories for high-level waste (HLW) and spent nuclear fuel (SNF) remains an incompletely resolved question in the nuclear fuel cycle despite significant advances over the last several decades. A key theme in current designs is the multibarrier concept, whereby several layers of barrier materials, from canisters to EBS to low-permeability host rock, ensure the isolation of the waste. An important role is played by the Engineered Barrier System (EBS), which must maintain adequate sealing capacity (i.e., low hydraulic permeability, mechanical integrity) around the waste canisters for durations of thousands of years while exposed to (i) large thermal gradients caused by heat released by the waste; (ii) large geochemical gradients due to corrosion and ion-exchange reactions at the canister-EBS and EBS-host rock interfaces; and (iii) large geomechanical gradients driven by capillary stresses associated with the initial EBS rehydration, water evaporation and, later, with the possible generation of gases at the canister-EBS interface through corrosion and hydrolysis reactions. The objective of this project is to develop a new multi-scale simulation approach to predict the coupled thermal-hydrologic-mechanical-chemical (THMC) evolution of an engineered clay barrier in the near field of a geological repository for HLW and SNF.

尽管在过去的几十年中，但在核燃料周期中，核燃料（SNF）的地质存储库（HLW）和花费的核燃料（SNF）仍然是一个无法完全解决的问题。当前设计中的一个关键主题是多载体概念，从罐头到EBS到低渗透性主机岩石，几层屏障材料确保了废物的隔离。工程屏障系统（EBS）扮演着一个重要的角色，该系统必须保持足够的密封能力（即，在浪费罐中围绕数千年，在浪费罐中围绕着足够的密封能力（即，低液压渗透性，机械完整性），而暴露于（i）由废物释放的热量引起的（i）大型热梯度； （ii）由于罐和EBS-Host岩石界面的腐蚀和离子 - 交换反应引起的大量地球化学梯度； （iii）与初始EBS补液，水蒸发相关的毛细应力驱动的大地质力学梯度，以及随后通过腐蚀和水解反应在罐EBS界面上可能产生的气体。该项目的目的是开发一种新的多尺度仿真方法，以预测工程粘土屏障在HLW和SNF的地质存储库的近场中的耦合热流程学机械化学化学（THMC）演变。