Abstract It has been shown that the Fluoride Salt-Cooled High-Temperature Reactors (FHR) can benefit from adopting some features of well-established Advanced Gas-cooled Reactors (AGR) technology pioneered in the United Kingdom. AGRs offer a number of technological advantages that can potentially speed up the development of FHRs, such as experience with operation at high temperatures, graphite moderated core, fuel design, on-line refuelling, and experience in manufacturing and construction of large concrete pressure vessels with steel liners. This paper summarises relevant information available in the open literature on AGR core operation and design, focusing on neutronic characteristics. The obtained information was used to test the capabilities of Monte Carlo code Serpent to reproduce fuel temperature coefficient of a typical AGR. Then, the paper presents a neutronic analysis of the impact of CO2 coolant substitution with molten salt (FLiBe). The results obtained from the analysis showed that Serpent accurately reproduces the value and behaviour of fuel temperature coefficient both for fresh and depleted fuel conditions. However, subsequent sensitivity and uncertainty analysis showed high uncertainties in the calculated fuel temperature coefficients. The change of the coolant results in significant variation of an AGR neutronic characteristics. The analysis suggests that the use of FLiBe salt as a coolant in AGR-type reactors introduces additional design challenges related to the uncertainties in nuclear data. This work summarises an initial stage of AGRESR project, which was aiming to review the AGR technology relevant to FHR development.

中文翻译：

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用于实现熔盐反应堆设计的先进气冷反应堆技术——冷却剂对中子性能影响的估计

摘要 研究表明，氟化盐冷却高温反应堆 (FHR) 可以受益于采用英国首创的成熟先进气冷反应堆 (AGR) 技术的某些特征。AGR 提供了许多技术优势，可以潜在地加速 FHR 的发展，例如在高温下运行的经验、石墨慢化堆芯、燃料设计、在线加油，以及制造和建造大型混凝土压力容器的经验钢衬里。本文总结了 AGR 核心操作和设计的公开文献中可用的相关信息，重点是中子特性。获得的信息用于测试 Monte Carlo 代码 Serpent 重现典型 AGR 的燃料温度系数的能力。然后，该论文对用熔盐 (FLiBe) 替代 CO2 冷却剂的影响进行了中子分析。从分析中获得的结果表明，Serpent 准确地再现了新鲜和耗尽燃料条件下燃料温度系数的值和行为。然而，随后的敏感性和不确定性分析表明，计算出的燃料温度系数存在很大的不确定性。冷却剂的变化导致 AGR 中子特性的显着变化。分析表明，在 AGR 型反应堆中使用 FLiBe 盐作为冷却剂会带来与核数据不确定性相关的额外设计挑战。这项工作总结了 AGRESR 项目的初始阶段，该项目旨在审查与 FHR 开发相关的 AGR 技术。