ML12250A622

McGuire, Units 1 and 2, Response to Request for Additional Information Regarding License Amendment Request Related to Measurement Uncertainty Recapture Power Uprate

ML12250A622
Person / Time
Site:	Mcguire, McGuire
Issue date:	08/15/2012
From:	Capps S D Duke Energy Carolinas
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
TAC ME8213, TAC ME8214
Download: ML12250A622 (10)

Text

")O ,D u k e ST EVEN DCA PPSM Energy Vice PresideontMcGuire Nuclear StationDuke EnergyMG0O VP / 12700 Hagers Ferry Rd.Huntersville, NC 28078980-875-4805980-875-4809 faxSteven. Capps@duke-energy. cornAugust 15, 2012 10 CFR 50.90U. S. Nuclear Regulatory CommissionWashington, D.C. 20555ATTENTION: Document Control DeskSubject: Duke Energy Carolinas, LLC (Duke Energy)McGuire Nuclear Station, Units 1 and 2Docket Nos. 50-369 and 50-370Response to Request for Additional Information Regarding LicenseAmendment Request Related to Measurement Uncertainty RecapturePower Uprate (TAC Nos. ME8213 and ME8214)This letter provides the responses to a August 1, 2012 Nuclear Regulatory Commission (NRC)request for additional information (RAI) and a August 6, 2012 NRC RAI related to a March 5,2012 McGuire Nuclear Station (MNS) Units 1 and 2 License Amendment Request (LAR)submitted pursuant to 10 CFR 50.90 in support of a measurement uncertainty recapture (MUR)power uprate.NRC MUR LAR RAI questions 41 and 42 provided in the August 1, 2012 RAI and DukeEnergy's responses are provided in Enclosure 1. NRC MUR LAR RAI questions 43 and 44provided in the August 6, 2012 RAI and Duke Energy's responses are provided in Enclosure 2.Duke Energy regulatory commitments related to NRC RAI questions 42 and 43 are provided inEnclosure 3.Responses to MNS MUR LAR RAI questions 1 through 3 and questions 5 through 19 wereprovided to the NRC via correspondence dated May 29, 2012 and June 21, 2012 respectively.Responses to MNS MUR LAR RAI question 4 and questions 20 through 31 were provided to theNRC via correspondence dated July 6, 2012. Responses to MNS MUR LAR RAI question 32through 40 were provided to the NRC via correspondence dated July 16, 2012.The conclusions reached in the original determination that this LAR contains No SignificantHazards Considerations and the basis for the categorical exclusion from performing anEnvironmental/Impact Statement have not changed as a result of the RAI responses provided inthis submittal.w duke -energycorn August 15, 2012Nuclear Regulatory CommissionPage 2Please contact Kenneth L. Ashe at 980-875-4535 if additional questions arise regarding thisLAR.Sincerely,S. D. CappsEnclosurescc: w/enclosuresV. M. McCreeRegional Administrator, Region IIU.S. Nuclear Regulatory CommissionMarquis One Tower245 Peachtree Center Ave., NE, Suite 1200Atlanta, GA 30303-1257J. H. Thompson (addressee only)Project Manager (MNS)U.S. Nuclear Regulatory Commission11555 Rockville PikeMail Stop 0-8 G9ARockville, MD, 20852-2738J. ZeilerNRC Senior Resident InspectorMcGuire Nuclear StationW. L. Cox IlI, Section ChiefNorth Carolina Department of Environment and Natural ResourcesDivision of Environmental HealthRadiation Protection Section1645 Mail Service CenterRaleigh, NC 27699-1645 August 15, 2012Nuclear Regulatory CommissionPage 3OATH AND AFFIRMATIONSteven D. Capps affirms that he is the person who subscribed his name to the foregoingstatement, and that all the matters and facts set forth herein are true and correct to the best ofhis knowledge.SZeven D Capps, Vice " rAet, McGuire Nuclear StationSubscribed and sworn to me: ID, 2- 2-DateNotary PublicMy commission expires: 25, 2oiqDate RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION BY THE OFFICE OFNUCLEAR REGULATION REGARDING A MCGUIRE LICENSE AMENDMENT TO SUPPORTA MEASUREMENT UNCERTAINTY RECAPTURE (MUR) POWER UPRATEEnclosure 1McGuire Nuclear Station'sResponses to MUR LAR RAI Questions 41 and 42 In TheAugust 1, 2012 NRC Request for Additional InformationBy letter dated March 5, 2012 (Agencywide Documents Access and Management System(ADAMS), Accession No. ML12082A210), Duke Energy Carolinas, LLC (Duke Energy, thelicensee), submitted a license amendment request (LAR) to change the McGuire NuclearStation, Units 1 and 2 (McGuire 1 and 2), Technical Specifications (TSs). The proposed changerevises the TSs to implement a measurement uncertainty recapture (MUR) power uprate forMcGuire 1 and 2.The U.S. Nuclear Regulatory Commission (NRC) staff has reviewed the licensee's submittaland determined that the following additional information is needed in order to complete ourreview:NRC Question 41Pressure-Temperature (P-T) limit curvesThe regulation at 10 CFR Part 50, Appendix G, Paragraph IV.A states that, "the pressure-retaining components of the reactor coolant pressure boundary [RCPB] that are made of ferriticmaterials must meet the requirements of the American Society of Mechanical Engineers Boilerand Pressure Vessel Code [ASME Code, Section III], supplemented by the additionalrequirements set forth in [paragraph IV.A.2, "Pressure-Temperature (P-T) Limits and MinimumTemperature Requirements"]..." Therefore, 10 CFR Part 50, Appendix G requires that P-Tlimits be developed for the ferritic materials in the reactor vessel (RV) beltline (neutron fluence> 1 x 1017 n/cm2, E > 1 MeV), as well as ferritic materials not in the RV beltline (neutron fluence< 1 x 1017 n/cm2, E > 1 MeV). Further, 10 CFR Part 50, Appendix G, requires that all RCPBcomponents must meet the ASME Code,Section III, requirements. The relevant ASME Code,Section III, requirement that will affect the P-T limits is the lowest service temperaturerequirement for all RCPB components specified in Section III, NB-2332(b).The P-T limit calculations for ferritic RCPB components that are not RV beltline shell materialsmay define P-T curves that are more limiting than those calculated for the RV beltline shellmaterials due to the following factors:Page 1 of 3 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION BY THE OFFICE OFNUCLEAR REGULATION REGARDING A MCGUIRE LICENSE AMENDMENT TO SUPPORTA MEASUREMENT UNCERTAINTY RECAPTURE (MUR) POWER UPRATE1. RV nozzles, penetrations, and other discontinuities have complex geometriesthat may exhibit significantly higher stresses than those for the RV beltline shellregion. These higher stresses can potentially result in more restrictive P-T limits,even if the reference temperature (RTNDT) for these components is not as highas that of RV beltline shell materials that have simpler geometries.2. Ferritic RCPB components that are not part of the RV may have initial RTNDTvalues, which may define a more restrictive lowest operating temperature in theP -T limits than those for the RV beltline shell materials.Consequently, please describe how the current P-T limit curves at 34 EFPY for McGuireUnits 1 and 2 and the methodology used to develop these curves considered all RV materials(beltline and non-beltline) and the lowest service temperature of all ferritic RCPB materials,consistent with the requirements of 10 CFR Part 50, Appendix G, in the MUR power uprateLAR.McGuire Response to NRC Question 41Consideration of RV materials (beltline and non-beltline) and the lowest service temperature ofall ferritic RCPB materials consistent with the requirements of 10 CFR Part 50, Appendix G, isthe subject of ongoing discussions between the industry and the NRC. During discussion of thisRAI question with the NRC, the NRC Staff indicated they would require this issue be addressedas part of their MUR LAR review rather than waiting for resolution of the ongoing industrydiscussions. To this end, the NRC proposed issuance of a new MNS License Conditionrequiring submittal of a site-specific analysis or a topical report addressing RAI Question 41within approximately one year after NRC approval of the MNS MUR LAR. MNS agrees that aLicense Condition would address the issue raised in the RAI.NRC Question 42RV InternalsMcGuire 1 and 2 participated in the industry effort for providing inspection and evaluationguidelines for plants to ensure integrity of RV internals. The product of this industry effort is theMRP-227-A report "Materials Reliability Program: Pressurized Water Reactor InternalsInspection and Evaluation Guidelines." Sections 7.2 and 7.3 of the MRP-227-A report havespecified requirements related to RV internals to be executed during the current 40-year license:(1) Aging management program development Section 7.2 requires, "Eachcommercial U.S. PWR unit shall develop and document a program forPage 2 of 3 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION BY THE OFFICE OFNUCLEAR REGULATION REGARDING A MCGUIRE LICENSE AMENDMENT TO SUPPORTA MEASUREMENT UNCERTAINTY RECAPTURE (MUR) POWER UPRATEmanagement of aging of reactor internal components within thirty-six monthsfollowing issuance of MRP-227-Rev. 0 (that is, no later than December 31,2011)."(2) Reactor internals Guidelines Implementation Section 7.3 requires,"Implementation of these guidelines [MRP-227-A Tables 4-1 through 4-9 andTables 5-1 through 5-3] is to take effect 24 months following issuance ofMRP-227-A (that is, no later than December 31, 2013). Implementation meansperformance of inspections of applicable components within the time framespecified in the guidance provided in the applicable tables."Please confirm that you will meet the above MRP-227-A requirements by the dates specified inthe parentheses to support the MUR power uprate application.McGuire Response to NRC Question 42(1) As required by Section 7.2 of MRP-227-A, the Aging Management Programs forMcGuire Units 1 and 2 reactor internal components were developed anddocumented by December 31, 2011. These programs were documented inWCAP-17466-NP, Revision 0, December 2011 (Unit 1) and WCAP-17467-NP,Revision 0, December 2011 (Unit 2).(2) McGuire commits to implement the guidelines of Section 7.3 of MRP 227-A nolater than December 31, 2013, including the performance of inspections ofapplicable components within the time frame specified in Tables 4-3, 4-6, 4-9,and 5-3 of MRP-227-A. This commitment is documented in Enclosure 3 of thisRAI response.Page 3 of 3 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION BY THE OFFICE OFNUCLEAR REGULATION REGARDING A MCGUIRE LICENSE AMENDMENT TO SUPPORTA MEASUREMENT UNCERTAINTY RECAPTURE (MUR) POWER UPRATEEnclosure 2McGuire Nuclear Station'sResponses to MUR LAR RAI Questions 43 and 44 In TheAugust 6, 2012 NRC Request for Additional InformationBy letter dated March 5, 2012 (Agencywide Documents Access and Management System(ADAMS), Accession No. ML1 2082A21 0), Duke Energy Carolinas, LLC (Duke Energy, thelicensee), submitted a license amendment request (LAR) to change the McGuire NuclearStation, Units 1 and 2 (McGuire 1 and 2), Technical Specifications (TSs). The proposed changerevises the TSs to implement a measurement uncertainty recapture (MUR) power uprate forMcGuire 1 and 2.By letter July 6, 2012, (ADAMS Package No. ML121990025) the licensee responded to theNRC's request for additional information (RAI) question 20.c, dated June 6, 2012 (ADAMSAccession No. ML12158A481). RAI question 20.c requested the following: (1) engineeringevaluation on how the bounding uncertainty of 0.045% rated thermal power (RTP) wasestablished in calculating secondary calorimetric uncertainty (SCU) and (2) justifications forselection of a 7-day period upon loss of the leading edge flow meter (LEFM). In its response,the licensee stated that these numbers were established using a drift analysis of the operatoraid computer calorimetric data, which is then compared to the turbine first stage pressure forone year of full operation. Based on this drift analysis, a bounding value of 0.0451%, RTP wasestimated. This analysis was performed by Cameron and inspected and run independently bythe licensee.The NRC staff has reviewed the licensee's response and determined that following additionalinformation are needed to complete the safety evaluation:NRC Question 43The licensee indicated that bounding value of 0.045% RTP SCU was established by a one yearstudy of the SCU data. Provide information how this bounding SCU data will be updated basedon future plant performance data.Page 1 of 3 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION BY THE OFFICE OFNUCLEAR REGULATION REGARDING A MCGUIRE LICENSE AMENDMENT TO SUPPORTA MEASUREMENT UNCERTAINTY RECAPTURE (MUR) POWER UPRATEMcGuire Response to NRC Question 43As described in Section 3 of Enclosure I and Attachment 1 of Enclosure 2 of the McGuireNuclear Station (MNS) March 5, 2012 LAR for a MUR Power Uprate, MNS committed to add aSelected Licensee Commitment (SLC) to address functional requirements for the LEFMs andappropriate Required Actions and Completion Times when an LEFM is not functional.This RAI response provides the following additional regulatory commitment related to the SLCdiscussed above. This commitment is documented in Enclosure 3 of this RAI response:Add a SLC requirement to perform an analysis of a MNS Unit's LEFM system on anevery other refueling outage frequency.This analysis will include updating the bounding SCU data used to establish the bounding valueof RTP SCU. The update of the bounding SCU data will utilize applicable plant performancedata from the period after the previous LEFM System calibration. The bounding value of RTPSCU over a 7 day period would then be established by performance of a drift analysis using theupdated bounding SCU data. Since the LEFM system will be in service, this drift analysis willbe performed using LEFM data in lieu of Turbine First Stage pressure. This bounding value ofRTP SCU, which would be restricted to values greater than or equal to 0.045 percent, would beapplied as a bias to the ASME Flow Nozzle reading used as an input to the SecondaryCalorimetric when the LEFM System is not functional.The SLC changes described above are not provided as part of the MNS MUR LAR or this RAIresponse but will be controlled using the 10 CFR 50.59 process.NRC Question 44The MUR LAR is asking for 7 days plant operation with the above bounding SCU when theLEFM is inoperative. For previous measurement uncertainty recapture (MUR) power uprateapplications, the NRC approved similar allowed outage time (AOT) with LEFM inoperable formaximum of 3 days, which is consistent with Cameron's analysis and recommendations tooperate with a failed LEFM. AOT of 3 days for repair or replacement of inoperableinstrumentation and controls systems is an established practice in the nuclear power industry.Please explain why 7-days AOT at the higher power level is needed for McGuire, when theLEFM equipment that justifies operation at the higher power level is inoperable.Page 2 of 3 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION BY THE OFFICE OFNUCLEAR REGULATION REGARDING A MCGUIRE LICENSE AMENDMENT TO SUPPORTA MEASUREMENT UNCERTAINTY RECAPTURE (MUR) POWER UPRATEMcGuire Response to NRC Question 44MNS evaluation of Criterion 1 from ER-157P, Rev 8, described in Enclosure 2 of the MUR LARdated March 5, 2012 and the MNS response to MUR LAR RAI Question 20c provided incorrespondence dated July 6, 2012 provided the basis for selection of the AOT when an LEFMsystem is not functional. Analysis demonstrated the instrumentation which will be used toprovide variables to the RTP calculation while a LEFM System is non-functional is stable anddrifts very little over a 10-day interval, which supports a 10-day AOT. However, MNS elected torestrict the AOT to 7-days for conservatism. Analysis confirmed, without applying correctionfactors, the MNS Units can be operated for 7-days with a non-functional LEFM System withoutexceeding the licensed RTP limit. Additional conservatism is added by applying a correctionfactor based upon the bias described in the above response to NRC Question 43. Thiscorrection factor will ensure that plant operation based on the secondary calorimetric powercalculation incorporates additional uncertainty while the LEFM is not functional.It is anticipated that, compared with a 3-day AOT, more issues rendering an LEFM system non-functional could be resolved within a 7-day AOT which would likely result in fewer powertransients directed by SLC Required Actions associated with a failure to restore the LEFM to afunctional status within the AOT. Note, by correspondence dated August 18, 2010, the NRCapproved a MUR LAR for Prairie Island Nuclear Generating Plant which incorporated a 7-day.AOT for a failed LEFM (reference Accession Number ML1 02030573, TAC NOS ME3015 andME3016).Page 3 of 3 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION BY THE OFFICE OFNUCLEAR REGULATION REGARDING A MCGUIRE LICENSE AMENDMENT TO SUPPORTA MEASUREMENT UNCERTAINTY RECAPTURE (MUR) POWER UPRATEEnclosure 3List of CommitmentsCommitment Commitment DateMcGuire commits to implement the guidelines No later than December 31, 2013.of Section 7.3 of MRP 227-A, including theperformance of inspections of applicablecomponents within the time frame specified inTables 4-3, 4-6, 4-9, and 5-3 of MRP227-A.Add a SLC requirement to perform an analysis Prior to implementation of the MUR Powerof a MNS Unit's LEFM system on an every Uprate on the first McGuire Unit.other refueling outage frequency.