Analytical solution on temperature evolution in three-layer barrier high-level radioactive waste repository and required pre-cooling time determination

• Published in: International journal of thermal sciences 2024-02, Vol.196, p.108688, Article 108688
• Main Authors: He, Luqiang, Sun, De'an, Zhou, Xiangyun, Xu, Xun
• Format: Article
• Language: English
• Subjects: Analytical model; Deep geological disposal; Fully analytical solution; High-level radioactive waste; Thermal analysis
• ISSN: 1290-0729
• DOI: 10.1016/j.ijthermalsci.2023.108688

An analytical model of the temperature field in a high-level radioactive waste (HLW) disposal repository containing three-layer barrier of bentonite blocks, bentonite pellets and surrounding rock was established, and a series of mathematical methods were used to obtain a fully analytical solution for the model, which can visually represent the relationships between temperature and various parameters and provide a reference for designing repository. Through comparisons to other existing analytical and numerical simulation results, the validity of our solution was verified. Subsequently, temperature evolution analyses of one-canister and one-panel conditions were performed using the derived solution. Additionally, the temperature evolution at the point where peak temperatures are expected (i.e., mid-height of central canister's side surface in one disposal panel) was investigated with different geometric design dimensions, and it was observed that temperature remains virtually unchanged when the tunnel spacing exceeds 40 m. The required pre-cooling times for four types of HLW under different geometric and thermal parameters were analyzed using the obtained solution, with all canisters considered in one disposal panel.