Nuclear Regulatory Commission.
Draft regulatory guide; request for comment.
The U.S. Nuclear Regulatory Commission (NRC) is issuing for public comment draft regulatory guide (DG), DG–1362, “Acceptability of Probabilistic Risk Assessment Results for Risk-Informed Activities.” This proposed guide, which is Revision 3 to Regulatory Guide (RG) 1.200, describes one acceptable approach for determining whether a base probabilistic risk assessment (PRA), in total or the portions that are used to support an application, is acceptable to provide confidence in the results, such that the PRA can be used in regulatory decision-making for light-water reactors. When used in support of an application, the use of this RG will obviate the need for an in-depth review of the base PRA by NRC reviewers, allowing them to focus their review on key assumptions and areas identified by peer reviewers.
Submit comments by July 31, 2020. Comments received after this date will be considered if it is practical to do so, but the NRC is able to ensure consideration only for comments received on or before this date. Although a time limit is given, comments and suggestions in connection with items for inclusion in guides currently being developed or improvements in all published guides are encouraged at any time.
This public review and comment period is 30 days. The staff has discussed the content of this draft RG in several public meetings and the staff has addressed multiple comments from the public and industry representatives.
You may submit comments by any of the following methods:
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For additional direction on obtaining information and submitting comments, see “Obtaining Information and Submitting Comments” in the
Anders Gilbertson, telephone: 301–415–1541, email:
Please refer to Docket ID NRC–2012–0110 when contacting the NRC about the availability of information regarding this action. You may obtain publicly-available information related to this action, by any of the following methods:
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Please include Docket ID NRC–2012–0110 in your comment submission.
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The NRC is issuing for public comment a draft guide in the NRC's “Regulatory Guide” series. This series was developed to describe methods that are acceptable to the NRC staff for implementing specific parts of the agency's regulations, to explain techniques that the staff uses in evaluating specific issues or postulated events, and to describe information that the staff needs in its review of applications for permits and licenses.
The DG, titled, “Acceptability of Probabilistic Risk Assessment Results for Risk-Informed Activities,” is proposed Revision 3 of RG 1.200 and is temporarily identified by its task number, DG–1362 (ADAMS Accession No. ML19308B636).
DG–1362 describes one acceptable approach for determining whether the acceptability of the base probabilistic risk assessment (PRA), in total or the portions that are used to support an application, is sufficient to provide confidence in the results, such that the PRA can be used in regulatory decision-making for light-water reactors (LWRs). Also, it addresses new industry guidance and enhancements identified since the last revision was issued in March 2009. Specifically, this revision endorses, with staff clarifications and exceptions, the American Society of Mechanical Engineers (ASME) and American Nuclear Society (ANS) Standard ASME/ANS RA-Sa-2009, “Standard for Level 1/Large Early Release Frequency Probabilistic Risk Assessment for Nuclear Power Plant Applications,” the ASME/ANS standard ASME/ANS RA–S Case 1 for seismic PRA, “Case for ASME/ANS RA-Sb-2013 Standard for Level 1/Large Early Release Frequency Probabilistic Risk Assessment of Nuclear Power Plant Applications,” Nuclear Energy Institute (NEI) 17–07, Revision 2, “Performance of PRA Peer Reviews Using the ASME/ANS PRA Standard” (ADAMS Accession No. ML19241A615) and Pressurized-Reactor Owners Group (PWROG) report PWROG–19027–NP, Revision 1, “Newly Developed Method Requirements and Peer Review” (ADAMS Accession No. ML20010F274). This revision further provides for a peer review of newly developed methods, clarifies the process for determining how to classify changes to a PRA,
The staff is also issuing for public comment a draft regulatory analysis (ADAMS Accession No. ML20052C809). The staff develops a regulatory analysis to assess the value of issuing or revising a regulatory guide as well as alternative courses of action.
This DG, if finalized, would provide one acceptable approach for determining whether the acceptability of the base PRA, in total or the portions that are used to support an application, is sufficient to provide confidence in the results, such that the PRA can be used in regulatory decision-making for LWRs. Issuance of this DG, if finalized, would not constitute backfitting as defined in section 50.109 of title 10 of
In addition to the general request for comments on DG–1362, the NRC is also seeking specific comments that address the following questions:
1. Prolonged retention of peer review exceptions and deficiencies, which are more commonly referred to as Facts and Observations (F&Os), has the potential to reduce confidence in the implementation of risk-informed programs and increase licensing and potential inspection review resources. As part of a licensee's base PRA model configuration control process, should licensees periodically close all F&Os using one of the two relevant processes (
2. What should be the periodicity for completion of these closure processes?
For the Nuclear Regulatory Commission.