Study on the application of risk-informed methods in the safety design of gas-cooled reactor

The Gas-cooled Reactor (GCR) represents an advanced nuclear reactor type with significant market potential, characterized by its high safety, reliability, operational simplicity, and ease of maintenance. To address the challenge of achieving an optimal balance between safety and economic efficiency, and to provide direction for GCR safety design, this study is grounded in reactor safety design principles. It explores the application of risk-informed methodologies within the context of GCR safety design and incorporates prior experience in probabilistic safety analysis to develop a systematic framework of risk-informed safety design methods and procedures. These procedures encompass potential event scenario identification, risk a ssessment, and the determination of safety design requirements. By integrating comprehensive GCR design information, the study conducts applied research that includes the classification of operational states and accident conditions, frequency-consequence analysis, and cumulative risk assessment. The investigation identifies essential safety functions such as reactivity control, residual core heat removal, and chemical reaction control, while also defining performance and reliability requirements for the systems, structures, and components (SSCs) responsible for these functions. Recommendations are made to revise the principles governing accident condition classification, thereby informing the design of safety-related SSCs and supporting the establishment of an effective SSC classification and safety design framework. The methodologies and findings presented in this study offer a structured and practical approach to GCR safety design, contributing to enhancements in economic performance and strengthening the market competitiveness of GCR technology.