Small modular reactors (SMRs) are an alternative for clean energy solutions in Canada's remote northern communities, owing to their safety, flexibility, and reduced capital requirements. Currently, these communities are heavily reliant on fossil fuels, and the transition to cleaner energy sources, such as SMRs, becomes imperative for Canada to achieve its ambitious net-zero emissions target by 2050. However, applying SMR technology in permafrost regions affected by climate change presents unique challenges. The degradation of permafrost can lead to significant deformations and settlements, which can result in increased maintenance expenses and reduced structural resilience of SMR infrastructure. In this paper, we studied the combined effect of climate nonstationarity in terms of ground surface temperature and heat dissipation from SMR reactor cores for the first time in two distinct locations in Canada's North: Salluit in Quebec and Inuvik in the Northwest Territories. It was shown that these combined effects can make significant changes to the ground thermal conditions within a radius of 15-20 m around the reactor core. The change in the ground thermal conditions poses a threat to the integrity of the permafrost table. The implementation of mitigation strategies is imperative to maintain the structural integrity of the nuclear infrastructure in permafrost regions. The thermal modeling presented in this study paves the way for the development of advanced coupled thermo-hydromechanical models to examine the impact of SMRs and climate nonstationarity on permafrost degradation.

A novel indirect solar receiver/volatile extractor concept was considered for thermally extracting H2O(s) from lunar regolith in the permanently shadowed regions on the Moon. The modeled indirect solar receiver/H2O(s) extractor consisted of a rigid, highly conductive chamber that was partially embedded in the lunar surface. Solar selective and non-selective absorbers were examined to efficiently capture concentrated solar irradiation and effectively transfer heat to icy regolith to drive H2O sublimation. A detailed heat and mass transfer model was developed in ANSYS Fluent to assess the feasibility of thermal extraction from permanently shadowed regions near the lunar poles with 5 wt% of H2O(s). The maximum H2O(v) collected after 10 terrestrial h of simulation time was 2789 g for the solar selective coated receiver and 1035 g for the non-selective receiver. The addition of a solar selective coating was observed to significantly enhance H2O(s) thermal extraction. The low lunar regolith thermal conductivity was shown as the major bottleneck for thermal extraction.