NL-11-0692, Discrepancies Identified Between Alternative ISI-ALT-08-02 and the NRC Safety Evaluation

Discrepancies Identified Between Alternative ISI-ALT-08-02 and the NRC Safety Evaluation

ML111250064
Person / Time
Site:	Hatch
Issue date:	04/27/2011
From:	Ajluni M Southern Nuclear Operating Co
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
NL-11-0692
Download: ML111250064 (4)

Text

Mark J. Ajluni, P.E. Southern Nuclear Nuclear Licensing Director Operating Company, Inc.

40 Inverness Center Parkway Post Off Ice Box 1295 Birmingham, Alabama 35201 rei 205.992.7673 Fax 205.992.7885 April 27, 2011 SOUTHERN'\'

Docket Nos.: 50-321 NL_11_069~OMPANY 50-366 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555-0001 Edwin I. Hatch Nuclear Plant, Units 1 and 2 Discrepancies Identified Between Alternative ISI-ALT-08-02 and the NRC Safety Evaluation Ladies and Gentlemen:

By letters to the Nuclear Regulatory Commission (NRC) dated June 11, 2008 and October 8,2008, Southern Nuclear Operating Company (SNC) submitted a request for alternative ISI-ALT-08-02, Version 1.0, to use weld overlay repairs as an alternative to the ASME Code repair requirements for the specified dissimilar metal welds. The NRC approved this request by Safety Evaluation dated June 24,2009 (ML090340017).

During preparation for an overlay to be applied during the 2R21 Spring 2011 outage, discrepancies were noted between the wording in submitted alternative ISI-ALT-08-02, Version 1.0 and the NRC's Safety Evaluation. The submitted alternative ISI-ALT 02, Version 1.0, defines that the test coupon be equal to or less than the thickness of the item to be welded, while the NRC Safety Evaluation defines that the test coupon will be equal to or greater than the thickness of the item to be welded.

SNC has determined that the wording for the previously submitted alternative ISI AL T-08-02, Version 1.0 is correct. This alternative will be used for an overlay to be applied during the ongoing Hatch Unit 2 outage. SNC requests that the NRC generate a correction letter confirming the error in the previously issued NRC Safety Evaluation and provide revised pages as applicable.

This letter contains no NRC commitments. If you have any questions, please contact Jack Stringfellow at (205) 992-7037.

Respectfully submitted,

~~+.

M. J. Ajluni Nuclear Licensing Director MJAlLPHllac

U. S. Nuclear Regulatory Commission NL-11-0692 Page 2

Enclosure:

Hatch Nuclear Plant - Units 1 and 2, ISI-ALT-08-02, Version 1.0, Discrepancies cc: Southern Nuclear Operating Company Mr. J. T. Gasser, Executive Vice President Mr. D. R Madison, Vice President - Hatch Ms. P. M. Marino, Vice President - Engineering RTYPE: CHA02.004 U. S. Nuclear Regulatory Commission Mr. V.M. McCree, Regional Administrator Mr. P. G. Boyle, NRR Project Manager Mr. E. D. Morris, Senior Resident Inspector - Hatch

Edwin I. Hatch Nuclear Plant, Units 1 and 2 Discrepancies Identified Between Alternative ISI-ALT-08-02 and the NRC Safety Evaluation Enclosure Hatch Nuclear Plant - Units 1 and 2, ISI-ALT-08-02, Version 1.0, Discrepancies

Enclosure Hatch Nuclear Plant - Units 1 and 2, ISI-ALT-08-02, Version 1.0, Discrepancies Plant Site-Unit: Hatch Nuclear Plant Units 1 and 2 (HNP-1 and 2).

Interval Dates: 4th lSI Interval extending from January 1,2006 through December 31,2015.

By letters to the Nuclear Regulatory Commission (NRC) dated June 11, 2008 and October 8,2008, Southern Nuclear Operating Company (SNC) submitted a request for alternative ISI-ALT 02, Version 1.0 to use weld overlay repairs as an alternative to the ASME Code repair requirements for the specified dissimilar metal welds. The NRC approved this request by Safety Evaluation dated June 24, 2009 (ML090340017).

Reason for this During preparation for an overlay to be applied during the 2R21 Spring 2011 Request: outage, discrepancies were noted between the wording in the submitted alternative ISI-ALT-08-02 and the wording in the NRC's Safety Evaluation.

As shown below, ISI-ALT 02 defines that the test coupon be equal to or less than the thickness of the item to be welded, while the NRC Safety Evaluation defines that the test coupon will be equal to or greater than the thickness of the item to be welded.

Discrepancies: SNC's alternative ISI-ALT-08-02, Appendix I, Section 3.0(e)(3) states, "Measurement of the maximum interpass temperature on a test coupon that is equal to or less than the thickness of the item to be welded."

NRC Safety Evaluation, Section 3.6.3, 3rd paragraph, last sentence, states, "The test coupon will be made using maximum heat input of the welding procedure to be used in production and the thickness of the test coupon will be equal to or greaterJhan the thickness of the item to be welded."

NRC Safety Evaluation, Section 3.7.3, 4th paragraph, 6th sentence states, "The test coupon will be made using maximum heat input of the welding procedure to be used in production and the thickness of the test coupon shall be equal to or greater than the thickness of the item to be welded."

Supporting ISI-ALT-08-02 was based on Code Case N-638-1 which was the latest NRC Documentation: approved version at the time SNC submitted the request. Code Case N-638-1 did not address test coupon thickness. Additionally, guidance from later versions of Code Case N-638 was used to develop the submittal, since temper bead welding techniques were in an evolutionary state. The first of these later versions approved by the NRC was Code Case N-638-4, which is listed in Regulatory Guide 1.147, Revision 16, dated October 2010. SNC has reviewed Code Case N-638-4 to determine the current approved requirements regarding the test coupon thickness. Code Case N-638-4 determined that a test coupon is to be equal to or less than the thickness of the item to be welded, which agrees with the SNC submittals dated June 11, 2008 and October 8, 2008.

Request: SNC requests that the NRC generate a correction letter confirming the error in the previously issued NRC Safety Evaluation and provide revised pages as applicable.

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