ML15247A066

McGuire, Units 1 and 2 - Response to Request for Additional Information Regarding License Amendment Request (LAR) for Temporary Changes to Technical Specifications for Correction of an 'A' Train Nuclear Service Water System (Nsws) Degraded

ML15247A066
Person / Time
Site:	Mcguire, McGuire
Issue date:	08/11/2015
From:	Capps S D Duke Energy Carolinas
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
MNS-15-062, TAC MF6409, TAC MF6410
Download: ML15247A066 (5)

Text

.DUKEsteven D. CappsivJ~DUKEVice President',., -ENERGYMoGuire Nucl ear StationDuke EnergyMG01VP I112700 Hagers Ferry RoadHuntersville, NC 28078o: 980.875.4805f: 980.875.4809Steven.Capps@duke-energy.com10 CFR 50.90August 11, 2015Serial: MNS-1 5-062U.S. Nuclear Regulatory CommissionWashington, DC 20555-00 1ATTENTION: Document Control DeskDuke Energy Carolinas, LLC (Duke Energy)McGuire Nuclear Station, Units 1 and 2Docket Nos. 50-369 and 50-370Renewed License Nos. NPF-9 and NPF-17Subject: Response to Request for Additional Information Regarding License AmendmentRequest (LAR) for Temporary Changes to Technical Specifications for Correctionof an 'A' Train Nuclear Service Water System (NSWS) Degraded Condition (TACNOS. MF6409 AND MF6410)By letter dated June 30, 2015, Duke Energy requested a license amendment for the RenewedFacility Operating Licenses (FOL) and Technical Specifications (TS) for the McGuire NuclearStation, Units 1 and 2, to allow temporary changes to TS 3.5.2, Emergency Core CoolingSystem (ECCS) -Operating; TS 3.6.6, Containment Spray System (CSS); TS 3.7.5, AuxiliaryFeedwater (AFW) System; TS 3.7.6, Component Cooling Water (CCW) System; TS 3.7.7,Nuclear Service Water System (NSWS); TS 3.7.9, Control Room Area Ventilation System(CRAVS); TS 3.7.11, Auxiliary Building Filtered Ventilation Exhaust System (ABFVES), and TS3.8.1, AC Sources- Operating.By letter dated July 27, 2015, Nuclear RegulatorY Commission (NRC) Staff requested additionalinformation (RAI) needed to complete their review of the proposed LAR. The enclosure providesDuke Energy's responses to the RAI questions and contains no additional regulatorycommitments.Pursuant to 10CFR50.91, 'a copy of this LAR has been forwarded to the appropriate NorthCarolina state officials.Please direct any comments or questions regarding this submittal to George Murphy at(980) 875-5715.

J. JS Nuclear Regulatory Commission-.YAugust 11, 2015Page 2I declare under penalty of perjury that the foregoing is true and correct. Executed onAugust 11, 2015.Sincerely,Steven D. CappsEnclosure:Response to Request for Additional Information 4.UtS Nuclear Regulatory CommissionAugust 11, 2015Page 3cc wI/Attachments:V. M. McCreeAdministrator, Region IlU.S. Nuclear Regulatory CommissionMarquis One Tower245 Peachtree Center Ave., NE, Suite 1200Atlanta, GA 30303-1257J. ZeilerNRC Senior Resident InspectorMcGuire Nuclear StationG. E. Miller, Project ManagerU.S. Nuclear Regulatory Commission11555 Rockville PikeMail Stop 0-8 G9ARockville, MD 20852-2738W. L. Cox, Ill, Section ChiefNorth Carolina Department of Environment and Natural ResourcesDivision of Environmental HealthRadiation Protection Section1645 Mail Service CenterRaleigh, NC 27699-1 645 AEnclosureResponse to Request for Additional InformationNRC Request for Additional Information:1.The proposed footnotes allow partial usage of the extra 14-day completion time over thecourse of multiple entries into the action statement. Multiple entries into the actionstatement seems inconsistent with the planned diagnostic and corrective work evolutiondescribed in the submittal.Please iustify why it is necessary to allow partial usage of the extra 14 days.Duke Energy Response:MNS expects to inspect the obstruction within the normal TS 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> completion time andgain additional information that can be used to remove the obstruction at a later date. Theinformation acquired will be used to compile the best equipment and resources to removethe obstruction to minimize total system unavailability. However, there is a possibility thatthe inspection may determine that some type of margin enhancement action is prudent. Inthis case, MoGuire will take the action using some portion of the 14 day extension.Additionally, the inspection may also indicate that the.obstruction can be easily removedwith available equipment and resources, in which case, McGuire will use the 14 dayextension as needed to remove the obstruction. Finally, the 14 day extension will not addadditional time to the unavailability time managed by the maintenance rule.2. The submittal does not address why this maintenance evolution cannot be performed whenone unit is in a refueling outage and, as such, would potentially represent a lower riskconfiguration and could afford additional time to respond to an event on the shutdown unit.Please justify why this maintenance evolution is not more appropriately performedcoincident with a refueling outage of one of the units.Duke Energy Response:Incorporation of the 'A' NSWS SNSWP piping work scope into the refueling outage of oneunit would unnecessarily increase the risk of the evolution. The inlet and outlet isolationvalves for both units have shared power supplies that would be at greater risk during anoutage. The compensatory measures to protect an array of redundant system trains andshared systems would also be at greater risk during an outage. Additionally, the outagewould reduce station focus on the A NSWS SNSWP piping work scope due to the numberof activities in the outage.The pre-activity defense in depth actions for aligning 'B' Train NSWS to its ESFAS suctionsource and maintaining the 'A' NSWS Train aligned to Lake Norman make the system fullyfunctional on both Units 1 and 2 for all operating design basis events and analyzedaccidents except an earthquake that damages the Lake Norman dam or associated LowPage 1 of 2

.pA ALevel Intake (LLI). The dam and LLI were originally designed for an Operating BasisEarthquake (OBE).The probability and risk from an OBE during the 14 day extended completion time windowis very low as discussed in the LAR. In addition, more recent analysis demonstrates thatthe Cowan's Ford Dam and LLI supply to the 'A' Train NSWS would survive an OBE and isrugged enough to withstand a Safe Shutdown Earthquake (SSE).The 'B' Train NSWS remains operable and defense in depth guidance is available for abeyond design basis total loss of NSWS flow.Again, the 14 day extension will not add additional time to the unavailability time managedby the maintenance rule.3. The submittal indicates that requested need date is October 31, 2015; however, theproposed expiration date for the TS footnote is December 31, 2016.Given the implied urgency of the requested need date, the NRC staff requests thatDuke provide additional iustification for allowing the temporary completion timeextension to remain valid until December 31, 2016.Duke Energy Response:As indicated in the response to question 1 above, MNS expects to inspect the obstructionwithin the normal TS 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> completion time and gain additional information that can beused to remove the obstruction at a later date. The information acquired will be used tocompile the best equipment and resources to remove the obstruction to minimize totalsystem unavailability.Equipment and resources identified during the inspection may not be immediately availabledue to long lead times. The final removal work schedule will be defined based on theassociated lead times. However, equipment and resources will be identified and acquiredas necessary to support the December 31, 2016, expiration date.Page 2 of 2