Abstract

Molten-salt reactors will likely require some level of irradiation testing as part of their licensing basis. An ideal experiment would consider the integrated effect of neutron flux and fission product generation in addition to circulating flow conditions. The feasibility of a natural-circulation irradiation salt loop in the Advanced Test Reactor (ATR) is assessed here. The flow is induced by the innovative combination of gas gaps and fin gaps along the capsule wall to fine-tune radial heat conductance, and therefore drive an axial temperature gradient across the experiment height. Following multiple design optimizations, a promising configuration has been identified. The 45-kW experiment would generate a 0.15 m/s flow velocity with 6 kg of fuel-bearing salt. This demonstrates the possibility of generating appreciable flow rates within manageable experimental conditions (e.g., total size and heat generation). An initial assessment of species mass tracking inside the experiment was also performed to gain an understanding of radionuclide behavior within the system. Results showed that significant quantities of Xe can be extracted in the off-gas (1.7 kCi) for an 8% bubble removal efficiency rate. These results highlight the potential value of such experiments. Further work will involve detailed engineering drawings and analyses of the loop, as well as more computationally expensive modeling of species mass tracking.

摘要

熔盐反应堆可能需要一定程度的辐照测试，作为其许可基础的一部分。除了循环流动条件外，理想的实验还应考虑中子通量和裂变产物产生的综合影响。此处评估了高级测试反应堆 (ATR) 中自然循环辐照盐回路的可行性。气流是由沿胶囊壁的气隙和翅片间隙的创新组合引起的，以微调径向热导，从而驱动整个实验高度的轴向温度梯度。经过多次设计优化，确定了一种有前途的配置。45 千瓦的实验将产生 0.15 m/s 的流速，含 6 kg 燃料盐。这证明了在可管理的实验条件（例如，总尺寸和热量产生）内产生可观的流速的可能性。还对实验内的物种质量跟踪进行了初步评估，以了解系统内的放射性核素行为。结果表明，对于 8% 的气泡去除效率，可以在尾气 (1.7 kCi) 中提取大量 Xe。这些结果突出了此类实验的潜在价值。进一步的工作将涉及详细的工程图纸和回路分析，以及对物种质量跟踪进行更昂贵的计算建模。还对实验内的物种质量跟踪进行了初步评估，以了解系统内的放射性核素行为。结果表明，对于 8% 的气泡去除效率，可以在尾气 (1.7 kCi) 中提取大量 Xe。这些结果突出了此类实验的潜在价值。进一步的工作将涉及详细的工程图纸和回路分析，以及对物种质量跟踪进行更昂贵的计算建模。还对实验内的物种质量跟踪进行了初步评估，以了解系统内的放射性核素行为。结果表明，对于 8% 的气泡去除效率，可以在尾气 (1.7 kCi) 中提取大量 Xe。这些结果突出了此类实验的潜在价值。进一步的工作将涉及详细的工程图纸和回路分析，以及对物种质量跟踪进行更昂贵的计算建模。