AGR Technologies for Enabling Molten Salt-cooled Reactor Designs

高温反应堆通常使用氦气作为冷却剂。然而，气体的主要缺点是，与液体冷却剂相比，气体的体积热容量较低，这最终导致反应堆功率密度较低，因此经济性较差。熔盐是高温反应堆中替代氦气冷却剂的主要候选者，因为它具有优异的换热性能，可以显著提高堆芯功率密度。此外，在高温(约700摄氏度)下运行将导致高功率转换效率，并允许将反应堆热用于各种工业过程。此外，熔盐的高沸点(&gt；1,200℃)将允许在低压下运行的设计，这应该会降低反应堆容器的成本，进一步促进这一概念的经济吸引力。熔盐冷却高温反应堆设计的另一个共同特点是使用高度坚固的涂层颗粒TRISO燃料和石墨慢化剂。结合盐冷却剂的化学惰性和高热容，这些特点构成了极好的安全案例。最近提出的此类系统的变种之一是氟化盐冷却高温反应堆(FHR)。执行这一概念有许多选择，它们依赖于结合不同的燃料形式、冷却剂盐和关键部件的配置。到目前为止，这个巨大的设计空间只有一小部分被探索过。具有特定燃料设计的FHR可能会采用先进气体冷却反应堆(AGR)的许多特点，这些反应堆在英国设计并成功运行了多年。利用现有的AGR技术和运行经验，将大大降低FHR的开发成本，提高其经济吸引力。本项目将利用和适应AGR的现有技术，如加油策略、部件布局和维护方法，以及调整使用高温气冷堆的Triso颗粒燃料，开发出高热力商业规模的FHR。该项目将确定燃料、盐冷却剂和堆芯配置在经济效益和安全性方面最具吸引力的组合。该项目将由马萨诸塞大学洛厄尔分校领导，与麻省理工学院、英国剑桥大学和作为工业合作伙伴的阿海珐合作。美国大学将进行核心设计空间探索和基线设计的燃料循环战略，而剑桥大学将专注于AGR类型燃料配置的替代方案。工业伙伴将领导经济分析工作，并为制定加油和维护战略以及安全分析任务做出贡献。

High temperature reactors most commonly use He gas as a coolant. The main disadvantage of gases however is their low, compared to liquid coolants, volumetric heat capacity, which ultimately leads to low reactor power density and hence inferior economics. Molten salts are leading candidates to replace the helium coolant in high temperature reactors due to superior heat transfer properties that would allow substantial increase in the core power density. In addition, operation at high temperature (around 700 C) would lead to high power conversion efficiency and allow the use of the reactor heat for various industrial processes. Moreover, high boiling point of molten salts (>1,200 C) would allow designs that operate at low pressure, which should reduce the cost of the reactor vessel, further contributing to economic attractiveness of the concept. Another common feature of molten salt-cooled high temperature reactor designs is the use of highly robust coated-particle TRISO fuel and a graphite moderator. In combination with chemical inertness and high heat capacity of the salt coolant, these features make excellent safety case.One of the recently proposed variants of such system is Fluoride salt-cooled High temperature Reactor (FHR). Many options exist for the implementation of the concept which rely on combining different fuel forms, coolant salts and configurations of key components. Only a small fraction of this vast design space has been explored so far. FHRs with certain fuel designs can potentially adopt many features from the Advanced Gas cooled Reactors (AGRs) designed and being successfully operated in the UK for many years. Taking advantage of the existing AGR technology and operating experience would substantially reduce the development costs of FHRs and improve their economic attractiveness.This project will develop a high thermal power commercial-scale FHR leveraging and adapting existing technology from the AGR, such as refuelling strategy, layout of components and maintenance approaches, as well as adapting the use TRISO particles fuel from the High Temperature Gas-cooled Reactors. The project will identify the most attractive combination of fuel, salt coolant and core configuration with respect to economic performance and safety.The project will be led by the University of Massachusetts at Lowell in collaboration with Massachusetts Institute of Technology, University of Cambridge, UK and AREVA as an industrial partner. The US Universities will perform the design space exploration for core and fuel cycle strategies for the base line design, while the University of Cambridge will focus on alternative options with AGR-type fuel configurations. The industrial partner will lead the economic analysis effort and contribute to the development of refuelling and maintenance strategies as well as the safety analysis tasks.