ML13219A110

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...

ML13219A110
Person / Time
Site:	Oconee
Issue date:	07/31/2013
From:	Batson S L Duke Energy Carolinas
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
GL-04-002, GSI-191
Download: ML13219A110 (3)

Text

DUKE Scott L. Batson ENERGYVice Preside Oconee Nuclear Station Duke Energy ON0IVP 1 7800 Rochester Hwy Seneca, SC 29672 July 31, 2013 o: 864.873.3274 f 864.873.4208 U. S. Nuclear Regulatory Commission Scott.Batson@duke-energy.com 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 Pressurizer-Water Reactors" By letter dated May 15, 2013, Duke Energy provided an update to the NRC of the on-going efforts at Oconee to close out GSI-1 91. As noted in this letter, Duke Energy evaluated the two methods allowed under Option 1 of SECY-12-0093.

One method was to evaluate against the'Clean Plant Criteria' while the other method was to evaluate Oconee against WCAP-16793-NP, Revision 2 and associated NRC Safety Evaluation (ML 13084A154).

The May 15, 2013 letter also stated: "Duke Energy is currently evaluating both methods and will clarify the method utilized to closeout GSI-1 91 in the follow-up letter noted in Attachment 1." The purpose of this letter is to notify the NRC of Oconee's intent to utilize the WCAP-16793-NP, Revision 2 methodology, as endorsed by the NRC in its Safety Evaluation (ML 13084A1 54) to close GSI-191. This letter is also to provide a schedule for the response back to the NRC on the results of this analysis.

Preliminary results from the LOCADM calculation show that the deposition thickness criteria and peak cladding temperature meet the acceptance criteria established in WCAP-16793-NP, Revision 2.The Safety Evaluation for WCAP-1 6793-NP, Revision 2 includes 14 Limitations and Conditions that must be addressed to meet the requirements to close GSI-191. A review of these Limitations and Conditions has revealed that the size distribution of the fiber debris used in the Oconee emergency sump strainer bypass testing does not meet the fiber size distribution noted in Appendix G of WCAP-1 6793-NP, Revision 2. Oconee's strainer testing occurred in 2006, while the strainer bypass testing requirements were established later. Oconee's emergency sump strainers were designed and manufactured by Control Components Incorporated (CCI).As such, Oconee is evaluating testing conducted by other nuclear sites that utilize CCI emergency sump strainers.

The intent is to evaluate their testing and apply it to Oconee where applicable.

www.duke-energy.com U. S. Nuclear Regulatory Commission July'31, 2013 Page 2 The evaluation of CCI testing by other sites is on-going and there are test cases that align with Oconee's fiber load. Upon completion of the above evaluations, Oconee will document and submit the results of its closure option evaluation to the NRC by December 15, 2013.There are no regulatory commitments made herein.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 July 31, 2013 Very truly yours, Scott L. Batson Vice President Oconee Nuclear Station U. S. Nuclear Regulatory Commission July 31, 2013 Page 3 xc (with Attachment):

Mr. Victor McCree U.S. Nuclear Regulatory Commission, Region II Marquis One Tower 245 Peachtree Center Ave., 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