ONS-2013-023, Response to Request for Additional Information (RAI) Regarding License Amendment Request to Update Pressure-Temperature Limit Curves License Amendment Request (LAR) No. 2012-10, Supplement 3

Response to Request for Additional Information (RAI) Regarding License Amendment Request to Update Pressure-Temperature Limit Curves License Amendment Request (LAR) No. 2012-10, Supplement 3

ML13337A169
Person / Time
Site:	Oconee
Issue date:	11/29/2013
From:	Batson S Duke Energy Carolinas
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
LAR 2012-10, Suppl 3, ONS-2013-023
Download: ML13337A169 (5)

Text

ENERGY.

DUKE

~ENERGY ViceL.

Scott President Batson Oconee Nuclear Station Duke Energy ONO IVP 17800 RochesterHwy Seneca, SC 29672 ONS-2013-023 o: 864.873.3274 f 864.873.4208 Scott.Batson@duke-energy.com 10 CFR 50.90 November 29, 2013 ATTN: Document Control Desk U. S. Nuclear Regulatory Commission 11555 Rockville Pike Rockville, MD 20852-2746

Subject:

Duke Energy Carolinas, LLC Oconee Nuclear Station (ONS), Units 1, 2, and 3 Docket Numbers 50-269, 50-270, and 50-287 Renewed Operating License Numbers DPR-38, DPR-47, and DPR-55 Response to Request for Additional Information (RAI) regarding License Amendment Request to Update Pressure-Temperature Limit Curves License Amendment Request (LAR) No. 2012-10, Supplement 3 On February 22, 2013, Duke Energy Carolinas, LLC (Duke Energy) submitted a License Amendment Request (LAR) requesting the Nuclear Regulatory Commission (NRC) approve new pressure-temperature (P-T) limit curves applicable to 54 effective full power years (EFPY) to replace the 33 EFPY P-T limit curves in Technical Specification (TS) 3.4.3 and approve changes to the operational requirements for unit heatup and cooldown in TS Tables 3.4.3-1 and 3.4.3-2. By letter dated June 21, 2013, the NRC requested Duke Energy to provide additional information associated with the LAR. By letter dated September 10, 2013, Duke Energy responded to the June 21, 2013, RAI and advised the NRC that the potential deficiency did not impact the RAI responses but did result in the need to revise the existing 33 EFPY P-T curves and the proposed 54 EFPY P-T curves for ONS Unit 3.

By letter dated October 25, 2013, Duke Energy addressed the potential deficiency and provided revised proposed TSs that included the corrected 54 EFPY P-T curves for Unit 3 and submitted a plant specific Appendix G analysis requested by the NRC during a Duke Energy/NRC conference call conducted on September 19, 2013.

By electronic mail dated November 4, 2013, NRC Staff requested Duke Energy to submit additional information associated with the adjusted reference temperature values for the lower head components. The Enclosure provides the requested information.

If there are any additional questions, please contact Boyd Shingleton, ONS Regulatory Affairs, at (864) 873-4716.

www.duke-energy.com S[D(D

Nuclear Regulatory Commission November 29, 2013 Page 2 I declare under penalty of perjury that the foregoing is true and correct. Executed on November 29, 2013.

Sincerely, Scott L. Batson Vice President Oconee Nuclear Station Enclosure - Response to NRC Request for Additional Information

Nuclear Regulatory Commission November 29, 2013 Page 3 cc w/

Enclosure:

Mr. Victor McCree, Regional Administrator U. S. Nuclear Regulatory Commission - Region II Marquis One Tower 245 Peachtree Center Ave., NE, Suite 1200 Atlanta, GA 30303-1257 Mr. Richard Guzman, Senior Project Manager (by electronic mail only)

Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission 11555 Rockville Pike Mail Stop 0-8 C2 Rockville, MD 20852 Mr. Eddy Crowe Senior Resident Inspector Oconee Nuclear Site Ms. Susan E. Jenkins, Manager Radioactive & Infectious Waste Management Division of Waste Management South Carolina Department of Health and Environmental Control 2600 Bull St.

Columbia, SC 29201

License Amendment Request No. 2012-10, Supplement 3 November 29, 2013 ENCLOSURE Response to NRC Request for Additional Information (2 pages including this page)

License Amendment Request No. 2012-10, Supplement 3 November 29, 2013 Response to NRC Request for Additional Information RAI-I Section 2.1.2.1.4 of the RAI response dated September 10, 2013, states, "the predicted 54 2 EFPY fluences at the lower shell forging to Dutchman forging welds are greater than 1017 n/cm (E>1 MeV) for all three Oconee RPVs. Therefore, adjusted reference temperature values for the lower head components (transition ring forging, lower head, and their associated welds) were calculated in accordance with Regulatory Guide 1.99, Revision 2 using the lower shell forging to Dutchman forging weld fluences." Please address the upper-shelf energy requirement for the lower head components.

Response to RAI-1 The Oconee Nuclear Station (ONS) Units 1, 2, and 3 lower head non-traditional beltline reactor pressure vessel (RPV) materials that could have fluences greater than 1017 n/cm 2 (E>1.0 MeV) include: 1) the RPV lower shell to Dutchman circumferential welds, 2) the Dutchman forgings, 3)

Dutchman forging to lower head circumferential welds, and 4) the RPV lower head plates.

The predicted Charpy upper-shelf energy (CvUSE) decreases for the ONS RPV lower head components were calculated in accordance with Regulatory Guide 1.99, Revision 2. For conservatism the inner wetted surface 54 EFPY fluences were used instead of the attenuated

%-thickness (1/4AT) fluences for all the ONS-1, -2, and -3 lower head non-traditional beltline RPV materials. For additional conservatism, the inner wetted surface fluence at the ONS-1, -2, and -3 RPV lower shell to Dutchman forging circumferential weld is used for the Dutchman forgings, the Dutchman forging to lower head circumferential welds and RPV lower head plates. These components and welds are located below the RPV lower shell to Dutchman forging circumferential weld and are at a greater distance from the active core.

Based on the 54 EFPY fluence and the predicted CvUSE decreases per Regulatory Guide 1.99, Revision 2, the CvUSE values for the ONS-1, -2, and -3 RPV lower head non-traditional beltline materials remain above 50 ft-lbs and remain in compliance with 10 CFR 50, Appendix G.