Regulatory Perspectives and Lessons Learned from USNRC New Reactor Instrumentation and Control Licensing Reviews

摘要

The United States Nuclear Regulatory Commission (USNRC) staff has been challenged with the licensing review of the instrumentation and control (I&C) systems for various new large light-water reactor designs. The reactor designs include the Advanced Boiling-Water Reactor (ABWR), Advanced Passive 1000 (AP1000), Economic Simplified Boiling Water Reactor (ESBWR), United States Evolutionary Power Reactor (U.S. EPR), and United States Advanced Pressurized-Water Reactor (US-APWR). These designs include the predominant use of digital technology which provides significant benefits as well as challenges in demonstrating safety and conformancc to the applicable regulatory requirements. Understanding the challenges, the industry requested the USNRC staff for additional staff guidance on several key areas, such as cyber security, communication independence, human factors engineering, and diversity and defense-in-depth, to reduce the project risk for deploying new reactors in the United States on schedule. The USNRC staff has subsequently developed and issued interim staff guidance documents and used them for the review of the new reactor I&C systems. Along with the interim staff guidance, the USNRC staff has used the Standard Review Plan (NUREG-0800) and applicable Regulatory Guides and industry standards in the reviews of the design certification applications, a design certification amendment, and combined license applications. For about last five years, the USNRC staff's tremendous efforts have resulted in significant successes and progress in new reactor I&C licensing by performing effective and efficient reviews that ensures safety. The efforts also generated insights and lessons that can provide valuable opportunities for both the USNRC staff and the industry to learn and apply. This paper describes these insights and lessons learned and perspectives on potential ways to apply them in future licensing reviews for I&C