Establishing an open, systems level technical basis in determining the SMR emergency planning zone (EPZ)

小型模块化反应堆（SMR）的应急计划区（EPZ）可以比目前在加拿大和全球运行的传统大型反应堆设计更小（尺寸）。SMR出口加工区在技术上取决于其“设计安全性”，即综合的被动和固有安全特征预计将减少意外事故的可能性，使之越来越小或通过设计消除。SMR减轻设计扩展条件后果的能力也是预期的。与现有的传统设计相比，人们期望有一个技术基础来证实出口加工区，而不是由主题专家定义的原始建议（具有足够的安全裕度）。拟议的研究调查在系统层面上，安全设计的参考SMR与被动和固有的设计功能（包括防御深度），使评估场外释放的放射性库存-所谓的源项是小的，并形成定义其场外释放机制的基础。这为出口加工区的建设奠定了技术基础。 在这样做时，需要一个参考SMR，因为许多初创设计都受到商业保护（详细）。然而，低概率事件的时间演化预计是设计依赖性的。此外，由于SMR将在非常规和/或偏远地区使用，因此非常规威胁的范围（外部、电力损失等）需要重新评估。也就是说，相对于新的应用，现有出口加工区和相关疏散计划中的保守性也需要审查。经修订的界定出口加工区的技术基础有助于加拿大和全球的核知识库，并有助于监管的统一。最后，通过传统出版物和现有的社交媒体平台，对所有包容性利益攸关方进行知识共享和培训，促进核能发展，提高对核能和辐射科学看法的接受和理解水平。

The emergency planning zone (EPZ) of a Small Modular Reactor (SMR) can be smaller (in size) than traditional larger, reactor designs that are currently operating in Canada and globally. The EPZ of SMR technically depends on its "safety-in-design"; that is, integrated passive and inherent safety features are expected to reduce the probability of unanticipated accidents to be increasingly small or eliminated by design. The SMR's ability to mitigate consequences from design extension conditions is also expected. Compared to existing legacy designs, one expects a technical basis to substantiate the EPZ, rather than original recommendations (with sufficient safety margins), defined by subject matter experts. The proposed research investigates at the system level, safety-in-design of a reference SMR with passive and inherent design features (defense in depth included) such that assessment of off-site release of its radioactive inventory - the so-called source term is small, and forms the basis of defining its off-site release mechanism. This establishes the technical basis of the EPZ. In so doing, there is a need for a reference SMR, since many start-up designs are commercially protected (in detail). Yet the time evolution of low probability events is expected to be design-dependent. Further, since SMR will be utilized in unconventional and/or remote locations, the spectrum of unconventional threats (external, loss of electrical power etc.) needs re-evaluation. That is, the conservatism embedded in existing EPZ and linked evacuation plans also need review, relative to new applications. A revised, technical basis of defining the EPZ contributes to the Canadian and global nuclear knowledge base and contributes to regulatory harmonization. Finally, knowledge sharing and training of all inclusive stakeholders, via both traditional publications and existing social media platforms, advance nuclear energy, and enhance the level of acceptance and understanding of perceptions regarding nuclear energy and radiation science.