ML13137A047

Closure Options for Generic Safety Issue (GSI) -191, Assessment of Debris Accumulation on Pressurized-Water Reactor Sump Performance in Resolution of Final Issue Related to Generic Letter (GL) 2004-02, Potential Impact Of.

ML13137A047
Person / Time
Site:	Oconee
Issue date:	05/15/2013
From:	Batson S L Duke Energy Carolinas
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
GL-04-002, GSI-191
Download: ML13137A047 (5)

Text

Scott L. Batson DUKEG Vice President ENERGY. Oconee Nuclear Station Duke Energy ON01VP I 7800 Rochester Hwy.Seneca, SC 29672 o: 864.873.3274 f: 864.873.4208 Scott. Batson@duke-energy.com May 15, 2013 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001

SUBJECT:

Duke Energy Carolinas, LLC (Duke Energy)Oconee Nuclear Station (Oconee), Units 1, 2 and 3 Docket Nos. 50-269, 50-270 and 50-287 Closure Options for Generic Safety Issue (GSI)-191, "Assessment of Debris Accumulation on Pressurized-Water Reactor Sump Performance" in resolution of final Issues related to Generic Letter (GL) 2004-02, "Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors" By letter dated February 29, 2008, Duke Energy submitted a supplemental response to NRC Generic Letter 2004-02 regarding the status of GL 04-02 Requests for Additional Information (RAIs) and inspection questions.

Included in this letter was a commitment to "Evaluate and Respond to NRC Conditions and Limitations of WCAP 16793-NP, rev. 0, 90 days after receipt of final NRC Conditions and Limitations." By letter dated July 1, 2008, the NRC issued a response to Duke Energy's February 29, 2008 summary of the GL 04-02 program. In this letter, the NRC stated: "We have no further questions at this time regarding your completion of corrective actions for Generic Letter (GL) 2004-02. In large part this conclusion is based on the very low potential debris loading at Oconee, as discussed in your supplemental response." In a subsequent paragraph, the July 1, 2008, letter from the NRC stated the following: "As you may be aware, we have not yet issued a final safety evaluation (SE) on WCAP 16793 NP. "Evaluation of Long-Term Cooling Considering Particulate, Fibrous, and Chemical Debris in the Recirculating Fluid." We believe that the likelihood of unacceptable in-vessel debris impact for Oconee is very low because of the low debris loading. However, because your GL 2004-02 response refers to and relies on this topical report, we plan to defer issuance of a closure letter to Oconee for the GL until uncertainties regarding the remaining issues with WCAP-1 6793 are reduced. You may wait for the issue to be resolved through the WCAP process or may demonstrate that in-vessel downstream effects issues are resolved for Oconee by demonstrating without reference to WCAP-16793 or the NRC staff SE that in-vessel downstream effects have been addressed at Oconee." aLt www.duke-energy.corn U. S. Nuclear Regulatory Commission May 15, 2013 Page 2 Based on the above statement, Duke Energy has chosen to wait until issues associated with WCAP-16793-NP were resolved through the WCAP process to address in-vessel downstream effects evaluation commitment for Oconee.Duke Energy has selected GSI-191 Closure Option 1 from SECY-12-0093 because it has determined that Oconee Nuclear Station, Units 1, 2, and 3, meets the requirements of 10 CFR 50.46, "Acceptance Criteria for Emergency Core Cooling Systems for Light-Water Nuclear Power Reactors," based on approved models for analysis and strainer head loss testing. In addition, Duke Energy expects to demonstrate compliance with recently approved models for analysis of in-vessel downstream effects.Based on the aforementioned statement from the July 1, 2008, letter concerning WCAP-16793-NP and telephone discussions between Duke Energy personnel and NRC staff on April 30, 2013, Duke Energy's understanding is that there are two methods available to Duke Energy to address Closure Option 1 and close-out GSI-191 for Oconee. Duke Energy can;1) evaluate Oconee against WCAP-1 6793-NP, revision 2 and associated Safety Evaluation (ML1 3084A1 54) limits and restrictions, or 2) demonstrate compliance with 'Clean Plant Criteria'(with additional NRC considerations and clarifications) as reviewed by the NRC in a letter to the Nuclear Energy Institute (NEI) dated May 2, 2012 (ML120730181).

Duke Energy is currently evaluating both methods and will clarify the method utilized to closeout GSI-191 in the follow-up letter noted in Attachment 1.There are no new commitments made herein; however, the completion date for the outstanding commitment to address WCAP 16973-NP and associated NRC SE is revised to July 31, 2013, to allow time for the appropriate documentation of the in-vessel downstream effects analysis.If any questions arise or additional information is needed, please contact Bob Meixell of the Oconee Regulatory Affairs Group at (864) 873-3279.I declare under penalty of perjury that the foregoing is true and correct.Executed on May 15, 2013 Very truly yours, Scott L. Batson Vice President Oconee Nuclear Station

Attachment:

1. Oconee Nuclear Station -Generic Letter 2004-02 Supplemental Response, Commitments U. S. Nuclear Regulatory Commission May 15, 2013 Page 3 xc (with Attachment):

Mr. Victor McCree U.S. Nuclear Regulatory Commission, Region II Marquis One Tower 245 Peachtree CenterAve., NE, Suite 1200 Atlanta, GA 30303-1257 Mr. John P. Boska (electronic copy only)Oconee Project Manager, NRR/DORL U.S. Nuclear Regulatory Commission 11555 Rockville Pike Mail Stop O-8G9A Rockville, MD 20852-2746 Ed Crowe NRC Senior Resident Inspector Oconee Nuclear Station Ms. Susan E, Jenkins Manager, Infectious and Radioactive Waste Management Bureau of Land and Waste Management Department of Health & Environmental Control 2600 Bull Street, Columbia, SC 29201 Attachment 1 Oconee Nuclear Station Generic Letter 2004-02 Supplemental Response Commitments May 15, 2013 Attachment 1 Generic Letter 2004-02 Supplemental Response May 15, 2013 Commit. Commitment Due Date 1 Oconee will address the in-vessel downstream July 31, 2013 effects issue in subsequent correspondence.

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