Mechanistic modeling of water radiolysis in supercritical water-cooled small modular reactors.

超临界水冷小型模块化反应堆中水辐射分解的机理建模。

• 批准号: 580463-2022
• 负责人: JayGerin, JeanPaulJP
• 金额: $ 8.74万
• 依托单位: Université de Sherbrooke
• 依托单位国家: 加拿大
• 项目类别: Alliance Grants
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=760616
• 关键词: Mechanistic; modeling; water; radiolysis; supercritical

Together with hydropower, nuclear is the only low-carbon source of energy that can replace fossil fuels. The use of supercritical water (SCW) as the coolant in a nuclear reactor is the logical evolution of the current generation of subcritical water-cooled reactors (WCRs). The radiation-induced chemistry of water under the operating conditions of both current WCRs (~250-330 oC, 10 MPa) and small modular SCW-cooled reactor (SCW-SMR) concepts now under development (~280-500 oC, 25 MPa) remains poorly understood. One of the most significant water chemistry challenges for all SCW-SMR concepts is to predict the effects of water radiolysis on materials performance and develop a chemistry control strategy to mitigate these effects. This is because chemical species formed during radiolysis are highly reactive with most metal alloys at the elevated temperatures proposed for SCW reactors, increasing the rates of corrosion and stress corrosion cracking (SCC) and leading to fuel cladding failure. Direct measurements of the water chemistry are difficult (if not impossible) to perform due to the fact that this water is subjected to an intense mixed radiation field as it passes through the reactor core. As a result, theoretical modeling and computer simulations provide an important route of investigation to help elucidate mechanisms by which radiation interacts with SCW and the consequences for materials. Of a theoretical nature, our long-term goal is to develop a computer-based SCW-SMR radiolysis model using coupled molecular dynamics and Monte Carlo multi-track chemistry simulations, based on a detailed knowledge of radiolytic yields and their dependence on temperature, density, SCW structure and other parameters such as LET and pH of the solution. Our research activities are expected to generate exploitable results that will provide new insights into water chemistry in SCW-SMRs and thus provide benefits to Canada by supporting the program objectives. In addition, they will provide recommendations to nuclear regulatory agencies on key chemistry parameters that must be monitored to ensure that an SCW-SMR is operated safely.

与水电一起，核能是唯一可以替代化石燃料的低碳源。 超临界水（SCW）用作核反应堆中的冷却剂是当前产生亚临界水冷反应堆（WCR）的逻辑演化。 在当前WCR（〜250-330 OC，10 MPA）和小型模块化SCW冷却反应器（SCW-SMR）概念（〜280-500 oC，25 MPA）的辐射诱导的水化学条件下，辐射诱导的化学条件均保持不佳。 所有SCW-SMR概念最重要的水化学挑战之一是预测辐射分解对材料性能的影响并制定化学控制策略以减轻这些作用。 这是因为在辐射溶解过程中形成的化学物种在提出的SCW反应器的高温下与大多数金属合金具有高反应性，从而增加了腐蚀和应力腐蚀裂纹（SCC）的速率，并导致燃油包层失败。 由于水通过反应堆芯时，水化学的直接测量很难（如果不是不可能）进行（如果不是不可能）。 结果，理论建模和计算机模拟提供了重要的研究途径，以帮助阐明辐射与SCW相互作用的机制以及对材料的后果。 在理论性质中，我们的长期目标是基于对放射性，密度，密度，SCW结构和其他参数（例如溶液的LET和PH）的详细知识，使用耦合分子动力学和Monte Carlo多轨化学模拟开发基于计算机的SCW-SMR辐射模型。 预计我们的研究活动将产生可剥削的结果，从而为SCW-SMR中的水化学提供新的见解，从而通过支持计划目标来为加拿大带来好处。 此外，他们将向必须对关键化学参数的核监管机构提供建议，以确保安全操作SCW-SMR。