A new reactor concept is described that directly couples a supercritical CO₂ (sCO₂) power cycle with a CO₂-cooled, heavy water moderated pressure tube core. This configuration attains the simplification and economic potential of past direct-cycle sCO₂ concepts, while also providing safety and power density benefits by using the moderator as a heat sink for decay heat removal. A 200 MWe design is described that heavily leverages existing commercial nuclear technologies, including reactor and moderator systems from Canadian CANDU reactors and fuels and materials from UK Advanced Gas-cooled Reactors (AGRs). Descriptions are provided of the power cycle, nuclear island systems, reactor core, and safety systems, and the results of safety analyses are shown illustrating the ability of the design to withstand large-break loss of coolant accidents. The resulting design attains high efficiency while employing considerably fewer systems than current light water reactors and advanced reactor technologies, illustrating its economic promise. Prospects for the design are discussed, including the ability to demonstrate its technologies in a small (∼20 MWe) initial system, and avenues for further improvement of the design using advanced technologies.

_{描述了一种将超临界 CO 2} (sCO ₂ ) 动力循环与 CO ₂冷却的重水缓压管芯直接耦合的新反应堆概念。这种配置实现了过去直接循环 sCO _{2的简化和经济潜力}概念，同时还通过使用减速器作为散热片来去除衰变热，从而提供安全性和功率密度优势。描述了一个 200 MWe 的设计，该设计大量利用了现有的商业核技术，包括来自加拿大 CANDU 反应堆的反应堆和慢化剂系统以及来自英国先进气冷反应堆 (AGR) 的燃料和材料。提供了对动力循环、核岛系统、反应堆堆芯和安全系统的描述，并显示了安全分析结果，说明了设计承受大断口冷却剂损失事故的能力。与目前的轻水反应堆和先进的反应堆技术相比，由此产生的设计获得了高效率，同时使用的系统要少得多，这说明了它的经济前景。讨论了设计的前景，