ML13072A071
| ML13072A071 | |
| Person / Time | |
|---|---|
| Site: | McGuire  |
| Issue date: | 02/27/2013 |
| From: | Capps S Duke Energy Carolinas |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML13072A071 (4) | |
Text
Duke STEVEN D. CAPPS Vice President Ar*Energy McGuire Nuclear Station Duke Energy MG01 VP / 12700 Hagers Ferry Rd.
Huntersville, NC 28078 980-875-4805 980-875-4809 fax Steven. Capps@duke-energy. corn February 27, 2013 10 CFR 50.55a U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001
Subject:
Duke Energy Carolinas, LLC (Duke Energy)
McGuire Nuclear Station, Unit 1 Docket No. 50-369 Relief Request Serial # 13-MN-001, Response to Request for Additional Information on Proposed Alternative Depth Sizing Criteria By letter dated January 9, 2013, as supplemented by letter dated January 31, 2013, Duke Energy submitted the subject relief request proposing an alternative depth sizing qualification for volumetric examinations of the Reactor Vessel hot leg and cold leg nozzle-to-safe end dissimilar metal welds.
On February 20, 2013, the Nuclear Regulatory Commission staff electronically requested additional information regarding this relief request. Please find enclosed Duke Energy's response to your request for additional information.
If you have any questions or require additional information, please contact P. T. Vu at (980) 875-4302.
Sincerely, Steven D. Capps Enclosure www. duke-energy. com
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U. S. Nuclear Regulatory commission February 27, 2013 Page 2 xc:
V. M. McCree, Region II Administrator U. S. Nuclear Regulatory Commission Marquis One Tower 245 Peachtree Center Ave., NE Suite 1200 Atlanta, GA 30303-1257 J. H. Thompson, Project Manager U. S. Nuclear Regulatory Commission 11555 Rockville Pike Mail Stop O-8G9A Rockville, MD 20852-2738 J. Zeiler NRC Senior Resident Inspector McGuire Nuclear Station
Enclosure Relief Request 13-MN-001 Response to NRC Request for Additional Information
Relief Request 1 3-MN-001, Response to NRC Request for Additional Information Enclosure, Page 1 of 1 The following information was requested by the NRC staff:
- 1. Section 5. 0 of the relief request, Item 4 states that '...If any inner diameter (ID) surface-breaking flaws are detected, or if any flaw is detected and measured as 50% through-wall depth or greater, the licensee shall repair the indications or shall perform flaw evaluations and shall submit the evaluations to the NRC for review and approval prior to reactor startup..." It appears from the above statement that if a flaw is surface connected regardless its size, the licensee would submit a flaw evaluation. It was not NRC's intent that any ID surface-connected flaw should require a flaw evaluation. The NRC position is that only those surface-connected flaws that are measured as 50% through wall or greater should submit a flaw evaluation.
Response from Duke Energy:
Duke Energy/ proposes to amend Section 5.0, Item 4 to read as follows:
- 4. If any ioner diameter (ID) surface-breaking flaws are detected and measured as 50%
through-wall depth or greater, Duke Energy shall repair the indications or shall perform flaw evaluations and shall submit the evaluations to the NRC for review and approval prior to reactor startup.
These flaw evaluations shall include the following:
- a. Information concerning the mechanism which caused the flaw.
- b. Information concerning the surface roughness/profile in the area of the pipe/weld required to perform the examination, and an estimate of the percentage of potential surface areas with UT probe "lift-off".
- 2. Section 2.0, Item 2.1 states that the Code of Record for the fourth 10-year inservice inspection interval is the ASME Code, Section X1, 1998 Edition through the 2000 Addenda.
The licensee noted that use of this Code Edition and Addenda during Period I of the 4th Inservice Inspection Interval was authorized via Relief Request Serial #10-MN-001 NRC Safety Evaluation dated March 3, 2011, (ADAMS Accession No. MLI 10550770). During Periods 2 and 3 of the 4th Inservice Inspection Interval, the applicable Section X1 Code of Record shall be determined as specified in this Relief Request.
Please clarify the code of record for the remainder of the fourth ISI interval (presumably for the 2nd and 3rd period). If the code of record for the remainder of the 4th ISI interval is the 1998 edition through the 2000 addenda, the NRC questions why the licensee did not propose to use more recent edition and addenda of the ASME Code that are approved in 10 CFR 50.55a (i.e., the 2007 edition through 2008 addenda).
Response from Duke Energy:
The ASME Section XI Code of Record for McGuire Unit 1 Periods 2 and 3 of the 4th Inservice Inspection Interval shall be the same ASME Section Xl Code of Record for the McGuire Unit 2 4th Inservice Inspection Interval (currently scheduled to start on July 15, 2014). Unless 10CFR50.55a is revised to incorporate by reference a later Code Edition and Addenda sooner than 12 months prior to the Unit 2 4th Interval start date, the latest ASME Code, Section Xl Edition and Addenda incorporated by reference (the 2007 Edition with the 2008 Addenda) shall be used for McGuire Unit 1 Periods 2 and 3 of the 4th Inservice Inspection Interval. The applicable ASME Section X1 Code of Record for use during the 4th Inservice Inspection Interval at McGuire Unit 2 will be identified when the McGuire Unit 2 4th Inservice Inspection Program is submitted to the NRC [as required by IWA-1400(c)]. This Code of Record shall be used for McGuire Unit I during Periods 2 and 3 of the 4th Inservice Inspection Program.