Abstract Tritium management is a vital factor that needs to be considered before a molten salt reactor (MSR) or fluoride-salt-cooled high-temperature reactor (FHR) is constructed. The analysis of tritium transport characteristics under steady and transient conditions is essential in the conceptual design of MSRs and FHRs. In this study, tritium transport characteristics analysis is conducted for a fluoride-salt-cooled pebble bed reactor, i.e., thorium molten salt reactor with solid fuel (TMSR-SF) under accident conditions. The tritium transport characteristics analysis (TAPAS) code is improved with a power model and heat-and-mass transfer model to adapt to TMSR-SF. The transient responses of the tritium transport characteristics of TMSR-SF under the unprotected reactivity insertion accident (URIA) and unprotected overcooling accident (UOC) are determined. It is found that the amount of tritium fluoride (TF) adsorbed on graphite varies, indicating the dynamic equilibrium between the TF adsorption and desorption on graphite. Due to the nuclear density variations of Li-6 and Be-9 in the fluoride salt under the accident conditions, the tritium production rate increases and decreases under the UOC and URIA conditions, respectively. Generally, under these two accident conditions, the tritium permeation rates are lower than that of the normal operation condition. In these cases, it is unnecessary to develop extra safety facilities for tritium control. This study contributes to the tritium management of TMSR-SF.

中文翻译：

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固体燃料钍熔盐堆氚输运特性瞬态分析

摘要 氚管理是熔盐堆（MSR）或氟盐冷却高温堆（FHR）建设前需要考虑的重要因素。在 MSR 和 FHR 的概念设计中，分析稳态和瞬态条件下的氚传输特性是必不可少的。本研究对氟化物-盐冷却球床反应堆，即事故工况下的固体燃料钍熔盐反应堆（TMSR-SF）进行氚输运特性分析。氚输运特性分析 (TAPAS) 代码通过功率模型和传热传质模型进行了改进，以适应 TMSR-SF。确定了无保护反应插入事故（URIA）和无保护过冷事故（UOC）下TMSR-SF氚输运特性的瞬态响应。发现吸附在石墨上的氟化氚（TF）的量不同，表明TF在石墨上的吸附和解吸之间存在动态平衡。由于事故工况下氟化盐中Li-6和Be-9的核密度变化，UOC和URIA工况下氚产率分别增加和减少。一般来说，在这两种事故工况下，氚渗透率低于正常运行工况。在这些情况下，没有必要为氚控制开发额外的安全设施。该研究有助于 TMSR-SF 的氚管理。