Development of a multiscale multiphysics simulation toolset with uncertainty for nuclear safety assessment, design, and licensing of SMRs

本提案的目标是开发一套用于核安全评估的集成软件工具集，该工具集将基于物理的计算机建模和先进小型模块化反应堆（smr）的模拟与建模中出现的所有不确定性的全面量化相结合。这将实现端到端的不确定性量化（UQ）和原则性安全（事故）分析、预测和决策框架，适用于小型反应堆（更广泛地说，适用于基于熔盐、液态金属和气体等非轻水冷却剂的下一代先进核反应堆技术，这些技术需要在其整个生命周期内进行评估、监测和控制）。将UQ整合到本提案中开发的大型科学模拟器中，包括计算流体动力学模型与系统代码的耦合，是关键的启用技术，将为可能涉及灾难性后果的环境中的安全/关键任务评估提供可靠性、弹性和信任。纳入关于小型反应堆安全性评估中使用的各种优点数字是可信的还是不确定的信息，将允许决策者就加拿大先进小型反应堆的认证和许可做出更明智的（基于科学的）决策。因此，这对加拿大的清洁能源未来尤其有利，因为smr可以生产大量的清洁能源，因此这种潜在的颠覆性技术必须成为加拿大未来无碳道路的解决方案之一。此外，小型反应堆占地面积小，这意味着它们可以安装在偏远地区，可以安装在现有电网系统中，也可以安装在远离电网的地方（例如，在偏远的土著社区），因此是加拿大清洁能源未来的一项使能技术。

The objective of this proposal is to develop an integrated software tool set for nuclear safety assessment that combines a physics-based computer modelling and simulation of advanced small modular reactors (SMRs) with a comprehensive quantification of all uncertainties that arise in the modelling. This will enable an end-to-end uncertainty quantification (UQ) and principled safety (accident) analysis, prediction, and decision-making framework for SMRs (and, more broadly, for the next-generation advanced nuclear reactor technologies based on non-light water coolants such as molten salt, liquid metal and gas that will need to be assessed, monitored and controlled throughout their life cycle). Incorporation of UQ in the large-scale scientific simulator developed in this proposal, consisting of the coupling of a computational fluid dynamics model with a systems code, is the key-enabling technology that will provide the reliability, resilience, and trust for safety/mission-critical assessments in those settings that can potentially involve catastrophic consequences. Inclusion of information with respect to whether various figures of merit used in the safety evaluation of SMRs are confident or uncertain will permit more informed (science-based) decisions to be made by decision makers concerning the certification and licensing of advanced SMRs in Canada. As a consequence, this is especially beneficial for Canada's clean energy future as SMRs can produce a large amount of clean energy so this potentially disruptive technology must be one of the solutions to a carbon-free future path for Canada. Moreover, the small footprint of SMRs implies that they can be sited at remote locations and can be installed into the existing grid system or remotely off grid (e.g., in remotely indigenous communities) and, as a result, is an enabling technology for a clean energy future in Canada.