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Aging Management Associated With Wall Thinning Due to Erosion Mechanisms

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Draft interim staff guidance; request for public comment.


The U.S. Nuclear Regulatory Commission (NRC or the Commission) requests public comment on Draft License Renewal Interim Staff Guidance (LR-ISG), LR-ISG-2012-01, “Wall Thinning Due to Erosion Mechanisms.” The draft LR-ISG proposes to revise an NRC staff-recommended aging management program (AMP) in NUREG-1801, Revision 2, “Generic Aging Lessons Learned (GALL) Report,” and the NRC staff's aging management review procedure and acceptance criteria contained in NUREG-1800, Revision 2, “Standard Review Plan for Review of License Renewal Applications for Nuclear Power Plants” (SRP-LR) to address wall thinning due to various erosion mechanisms for piping and components within the scope of the Requirements for Renewal of Operating Licenses for Nuclear Power Plants. This LR-ISG provides changes to the recommendations in GALL Report, Revision 2, AMP XI.M17, “Flow-Accelerated Corrosion,” based on the staff's review of several license renewal applications' flow-accelerated corrosion AMPs and stakeholder input.


Submit comments by August 27, 2012. Comments received after this date will be considered, if it is practical to do so, but the NRC staff is able to ensure consideration only for comments received on or before this date.


You may access information and comment submissions related to this document, which the NRC possesses and are publicly available, by searching on under Docket ID NRC-2012-0170. You may submit comments by any of the following methods:

  • Federal Rulemaking Web site: Go to and search for Docket ID NRC-2012-0170. Address questions about NRC dockets to Carol Gallagher; telephone: 301-492-3668; email:
  • Mail comments to: Cindy Bladey, Chief, Rules, Announcements, and Directives Branch (RADB), Office of Administration, Mail Stop: TWB-05-B01M, U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001.
  • Fax comments to: RADB at 301-492-3446.

For additional direction on accessing information and submitting comments, see “Accessing Information and Submitting Comments” in the SUPPLEMENTARY INFORMATION section of this document.


Mr. James Gavula, Division of License Renewal, Office of Nuclear Reactor Regulation, U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001; telephone: 630-829-9755; email:


I. Accessing Information and Submitting Comments

A. Accessing Information

Please refer to Docket ID NRC-2012-0170 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 are publicly available, by any of the following methods:

  • Federal Rulemaking Web Site: Go to and search for Docket ID NRC-2012-0170.
  • NRC's Agencywide Documents Access and Management System (ADAMS): You may access publicly available documents online in the NRC Library at 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 draft LR-ISG-2012-01 is available electronically under ADAMS Accession No. ML12114A211. The GALL Report and SRP-LR are available under ADAMS Accession Nos. ML103490041 and ML103490036, respectively.
  • 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 Interim Staff Guidance Web Site: The LR-ISG documents are also available online under the “License Renewal” heading at

B. Submitting Comments

Please include Docket ID NRC-2012-0170 in the subject line of your comment submission, in order to ensure that the NRC is able to make your comment submission available to the public in this docket.

The NRC cautions you not to include identifying or contact information that you do not want to be publicly disclosed in your comment submission. The NRC will post all comment submissions at as well as enter the comment submissions into ADAMS. The NRC does not routinely edit comment submissions to remove identifying or contact information.

If you are requesting or aggregating comments from other persons for submission to the NRC, then you should inform those persons not to include identifying or contact information that they do not want to be publicly disclosed in their comment submission. Your request should state that the NRC does not routinely edit comment submissions to remove such information before making the comment submissions available to the public or entering the comment submissions into ADAMS.

II. Background

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 has developed draft LR-ISG-2012-01 to: (a) Revise the definition of “wall thinning” to include erosion mechanisms; (b) revise the definition of “flow-accelerated corrosion” and “erosion” to align them with the definitions commonly used in industry; (c) allow applicants that have identified wall thinning due to erosion mechanisms to monitor wall thinning caused by erosion mechanisms to be included in the aging management program for flow-accelerated corrosion by (i) ensuring extent of condition reviews determine if other components are susceptible to similar degradation, and (ii) verifying that corrective actions have either eliminated the erosion mechanism precluding the need for ongoing aging management activities or included periodic wall thickness measurements in an aging management program; and (d) make miscellaneous and editorial changes.

III. Proposed Action

By this action, the NRC is requesting public comments on draft LR-ISG-2012-01. This LR-ISG proposes certain revisions to NRC guidance on implementation of the requirements in 10 CFR Part 54. The NRC staff will make a final determination regarding issuance of the LR-ISG after it considers any public comments received in response to this request.

Dated at Rockville, Maryland, this 5th day of July 2012.

For the Nuclear Regulatory Commission.

Melanie A. Galloway,

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

[FR Doc. 2012-17117 Filed 7-12-12; 8:45 am]