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Final Interim Staff Guidance LR-ISG-2011-04; Updated Aging Management Criteria for Reactor Vessel Internal Components for Pressurized Water Reactors

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Nuclear Regulatory Commission.


Interim staff guidance; issuance.


The U.S. Nuclear Regulatory Commission (NRC) is issuing the final License Renewal Interim Staff Guidance (LR-ISG), LR-ISG-2011-04, “Updated Aging Management Criteria for Reactor Vessel Internal Components for Pressurized Water Reactors.” This final LR-ISG revises the guidance in NUREG-1800, Revision 2, “Standard Review Plan for Review of License Renewal Applications for Nuclear Power Plants” (SRP-LR) and NUREG-1801, Revision 2, “Generic Aging Lessons Learned Report” (GALL Report), for the aging management of Pressurized Water Reactors (PWR) reactor vessel internals components exposed to reactor coolant environments.


Please refer to Docket ID NRC-2012-0070 when contacting the NRC about the availability of information regarding this document. You may access information related to this document, which the NRC possesses and is publicly available, using any of the following methods:

  • Federal Rulemaking Web site: Go to and search for Docket ID NRC-2012-0070. Address questions about NRC dockets to Carol Gallagher; telephone: 301-492-3668; email: For technical questions, contact the individual(s) listed in the FOR FURTHER INFORMATION CONTACT section of this document.
  • NRC's Agencywide Documents Access and Management System (ADAMS): You may access publicly available documents online in the NRC Library at​reading-rm/​adams.html. To begin the search, select “ADAMS Public Documents” and then select “Begin Web-based ADAMS Search.” For problems with ADAMS, please contact the NRC's Public Document Room (PDR) reference staff at 1-800-397-4209, 301-415-4737, or by email to The LR-ISG-2011-04 is available in ADAMS under Accession No. ML12270A436.
  • NRC's PDR: You may examine and purchase copies of public documents at the NRC's PDR, Room O1-F21, One White Flint North, 11555 Rockville Pike, Rockville, Maryland 20852.
  • NRC's License Renewal Interim Staff Guidance Web site: LR-ISG documents are available online, for a limited time, at​reading-rm/​doc-collections/​isg/​license-renewal.html.
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Mr. On Yee, Office of Nuclear Reactor Regulation, U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001; telephone: 301-415-1905; email:

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Background Information

The NRC issues LR-ISGs to communicate insights and lessons learned and to address emergent issues not covered in license renewal guidance documents, such as the GALL Report and SRP-LR. In this way, the NRC staff and stakeholders may use the guidance in an LR-ISG document before it is incorporated into a formal license renewal guidance document revision. The NRC staff issues LR-ISGs in accordance with the LR-ISG Process, Revision 2 (ADAMS Accession No. ML100920158), for which a notice of availability was published in the Federal Register on June 22, 2010 (75 FR 35510).

The NRC staff developed LR-ISG-2011-04 to update its guidance in SRP-LR and GALL Report based on the conclusions of the NRC's revised safety evaluation on Electric Power Research Institute (EPRI) Technical Report No. 1022863, Materials Reliability Program: Pressurized Water Reactor Internals Inspection and Evaluation Guidelines (MRP-227-A), dated December 2011 (ADAMS Accession No. ML12017A193 [Transmittal letter from the EPRI-MRP] and ADAMS Accession Nos. ML12017A194, ML12017A196, ML12017A197, ML12017A191, ML12017A192, ML12017A195 and ML12017A199 [Final Report]). The NRC's revised safety evaluation of EPRI Technical Report No. 1022863 may be accessed in ADAMS under Accession No. ML11308A770. The LR-ISG-2011-04 revises the recommendations in the GALL Report and the NRC staff's acceptance criteria and review procedures in the SRP-LR to ensure consistency with MRP-227-A and provides a framework to ensure that PWR license renewal applicants will adequately address age-related degradation and aging management of reactor vessel internal components during the term of the renewed license.

On March 20, 2012, (77 FR 16270), the NRC requested public comments on draft LR-ISG-2011-04. Subsequently, as published on April 19, 2012, (77 FR 23513), the NRC issued an editorial correction to the original notice to specifically identify the ADAMS Accession No. for additional documents associated with draft LR-ISG-2011-04.

The NRC received comments from the Nuclear Energy Institute by letter dated May 21, 2012 (ADAMS Accession No. ML12144A147), and from the Electric Power Research Institute and the Pressurized Water Reactor Owners Group Materials Subcommittee by letter dated May, 21, 2012 (ADAMS Accession No. ML12146A267). No other comments were submitted. The NRC considered these comments in developing the final LR-ISG. Detailed responses to the comments can be found in Appendix C of the final LR-ISG.

The final LR-ISG-2011-04 is approved for NRC staff and stakeholder Start Printed Page 33121use and will be incorporated into NRC's next license renewal guidance document revision.

Backfitting and Issue Finality

Issuance of this final LR-ISG does not constitute backfitting as defined in 10 CFR 50.109 (the Backfit Rule) and is not otherwise inconsistent with the issue finality provisions in Part 52, “Licenses, Certifications, and Approvals for Nuclear Power Plants” of 10 CFR. The basis for this determination is set forth in the “Backfitting and Issue Finality” section of the final LR-ISG.

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Dated at Rockville, Maryland, this Tuesday, May 28, 2013.

For the Nuclear Regulatory Commission.

John Lubinski,

Director, Division of License Renewal, Office of Nuclear Reactor Regulation.

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[FR Doc. 2013-13088 Filed 5-31-13; 8:45 am]