Document: NUREG-0800
Document ID: 4f0d611c-d3fb-43e5-ab91-e7f7b4de3511
Document Type: srp
Title: Determining the Technical Adequacy of Probabilistic Risk
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0406/ML040630300.pdf
Revision Date: 2023-06
Chapter: 19
Section ID: 19.1
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Assessment Results for Risk-Informed Activities INTRODUCTION In their March 1999 report, “Nuclear Regulation: Strategy Needed To Regulate Safety Using Information on Risk,” GAO/RCED-99-95 (Ref. 1), the General Accounting Office (GAO) identified a number of issues that it believed required resolution for the NRC to successfully implement a risk- informed regulatory approach. Among these, GAO indicated that more was needed to “develop standards on the scope and detail of risk assessments needed for utilities to determine that changes to their plants’ designs will not negatively affect safety.” Probabilistic risk assessment (PRA) standards have been developed by the American Society of Mechanical Engineers (ASME) and American Nuclear Society (ANS). On April 5, 2002, ASME issued a standard (Ref. 2) for a full-power, internal events (excluding fire) Level 1 and a limited Level 2 PRA. In the future, ANS plans to issue standards for PRAs for evaluating external events risk and risk from low power and shutdown modes of operation. In addition, reactor owners’ groups have been developing and applying a PRA peer review program for several years, NEI-00-02, “Probabilistic Risk Assessment Peer Review Process Guidance,” Revision A3) (Ref. 3). In a letter dated April 24, 2000, the Nuclear Energy Institute (NEI) submitted NEI-00-02 to the NRC for review in the context of the staff’s work to risk-inform the scope of special treatment requirements contained in 10 CFR Part 50 (discussed in SECY-99-256) (Ref. 4). 2 On December 18, 2001, NEI (Ref. 5) requested the staff to extend its review of NEI-00-02, and on August 16, 2002, NEI submitted draft industry guidance for self-assessments (Ref. 6) to address the use of industry peer review results in demonstrating conformance with the ASME PRA standard. This guidance supplements and will ultimately become part of NEI-00-02 (per NEI, Ref. 6). This additional guidance contains: 1. Self-assessment guidance document 2.