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.

尽管在过去几十年中取得了重大进展，但高放废物和乏核燃料的地质储存库的设计仍然是核燃料循环中一个尚未完全解决的问题。当前设计的一个关键主题是多屏障概念，即从罐子到EBS再到低渗透性寄主岩石的几层屏障材料，确保废物的隔离。工程屏障系统(EBS)发挥着重要的作用，它必须在废料罐周围保持足够的密封能力(即低水力渗透性和机械完整性)数千年，同时暴露在以下环境中：(I)废物释放的热引起的大温度梯度；(Ii)罐-EBS和EBS-围岩界面上的腐蚀和离子交换反应引起的大的地球化学梯度；以及(Iii)由毛细压力驱动的大地质力学梯度，这些压力与最初的EBS再水化、水蒸发以及后来可能通过腐蚀和水解反应在罐-EBS界面产生气体有关。本项目的目的是开发一种新的多尺度模拟方法来预测高放废物和固体核地质储存库近场工程粘土屏障的热-水文-力学-化学耦合演化。