Regulatory Analysis for Resolution of USI A-47 (Unresolved Safety Issue). Safety Implications of Control Systems in LWR (Light Water Reactor) Nuclear Power Plants.

摘要

The report presents a summary of the regulatory analysis conducted by the NRC staff to evaluate the value impact of alternatives for the resolution of Unresolved Safety Issue (USI) A-47, 'Safety Implications of Control Systems.' The NRC staff proposed resolution is based on these analyses and the technical findings and conclusions presented in NUREG-1217. The staff has concluded that certain actions should be taken to improve safety in light-water reactor (LWR) plants. The actions recommended that certain plants upgrade their control systems to preclude reactor vessel/steam generator overfill events and to prevent steam generator dryout, modify their technical specification to periodically verify operability of these systems, and modify selected emergency procedures to ensure plant safe shutdown following a small-break loss-of-coolant accident. The report was issued as a draft for public comment on May 27, 1988. As a result of the public comments received, the report was revised. The NRC staff's responses to and resolution of the public comments are included as Appendix C to the final report, NUREG-1217.