Seismic Risk Analysis and Design of Nuclear Power Plants

核电厂地震风险分析与设计

• 批准号: RGPIN-2018-04031
• 负责人: Xie, WeiChau
• 金额: $ 4.52万
• 依托单位: University of Waterloo
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 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=748833
• 关键词: Seismic; Risk; Analysis; Design; Nuclear

Earthquakes are among the most destructive natural disasters. In response to the occurrence of several destructive earthquakes in recent decades, the nuclear industry is taking a critical look at the existing methods of assessing seismic risk of nuclear power plants (NPPs). A number of deficiencies have been recognized in the existing methods of seismic risk analysis. In an NPP, there are a large number of safety-related structures, systems, and components (SSCs). The most effective approach to ensure safe shutdown and to prevent accidents during an earthquake is to ensure adequate safety margins for these SSCs through seismic design and seismic risk assessment. The long-term objective of my research program is to establish a systematic framework for probabilistic seismic risk analysis and design of NPPs. Through continued collaboration with nuclear industrial partners, the proposed research will satisfactorily address two important issues that have challenged earthquake engineering and the nuclear industry for decades: (1) Generating drift-free, consistent, and perfectly spectra-compatible tri-directional time histories; (2) A direct method for generating Floor Response Spectra (FRS) with flexible foundation and considering soil-structure interaction (SSI).Time history analysis has been widely used in practice, for example, in nonlinear dynamic analysis and analysis of multi-supported systems. Using eigenfunction expansions and the method of influence matrix, the proposed research will develop an efficient and easy to use algorithm to generate drift-free, consistent, and perfectly spectra-compatible tri-directional ground motion time histories. The algorithms and software developed are of great practical importance in earthquake engineering.Accurate determination of FRS, used as a seismic input to SSCs, is one of the most critical tasks in seismic analysis. Overly conservative FRS increase the cost, while non-conservative FRS compromise safety. A direct spectra-to-spectra method for generating FRS that is accurate and efficient has recently been developed by my research group. It is suitable for generating FRS for fixed-base structural models and has been successfully applied in a commercial project by Candu Energy Inc. In the proposed research, the direct method will be extended to account for flexible foundation and SSI. The effect of the uncertainty of soil properties on SSI analysis will be accurately addressed and a complete probabilistic method will be developed to model the uncertainty. This research will provide advanced methodologies and modern tools to assess seismic margin and risk of existing SSCs in refurbished NPPs and to design new SSCs in new NPPs to ensure seismic safety.Close collaborations with the industry will enable HQP to gain both theoretical knowledge and practical experience and make them well qualified for advanced work placements.

地震是最具破坏性的自然灾害之一。为了应对近几十年来发生的多次破坏性地震，核工业正在重新审视现有的核电厂（NPP）地震风险评估方法。 人们已经认识到现有的地震风险分析方法存在许多缺陷。在核电厂中，存在大量与安全相关的结构、系统和组件（SSC）。确保地震期间安全关闭和预防事故的最有效方法是通过抗震设计和地震风险评估确保这些SSC有足够的安全裕度。我的研究项目的长期目标是建立核电厂概率地震风险分析和设计的系统框架。通过与核工业合作伙伴的持续合作，拟议的研究将令人满意地解决数十年来挑战地震工程和核工业的两个重要问题：（1）生成无漂移、一致且完全光谱兼容的三向时间历史； (2)一种直接生成柔性地基地面响应谱(FRS)并考虑土-结构相互作用(SSI)的方法。时程分析在实践中得到了广泛的应用，例如非线性动力分析和多支撑分析系统。利用特征函数展开和影响矩阵方法，该研究将开发一种高效且易于使用的算法来生成无漂移、一致且完全频谱兼容的三向地震动时程。所开发的算法和软件在地震工程中具有重要的实际意义。准确确定FRS作为SSC的地震输入是地震分析中最关键的任务之一。过于保守的FRS会增加成本，而不保守的FRS会损害安全性。我的研究小组最近开发了一种直接的光谱到光谱方法，用于生成准确且高效的 FRS。它适用于生成固定基础结构模型的 FRS，并已成功应用于 Candu Energy Inc 的商业项目。在拟议的研究中，直接方法将扩展到考虑柔性基础和 SSI。将准确解决土壤性质的不确定性对 SSI 分析的影响，并开发完整的概率方法来对不确定性进行建模。这项研究将提供先进的方法和现代工具来评估翻新核电厂中现有SSC的地震裕度和风险，并在新核电厂中设计新的SSC以确保地震安全。与业界的密切合作将使HQP获得理论知识和实践经验并使他们有资格获得高级工作实习。