ML11238A072
| ML11238A072 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 08/23/2011 |
| From: | Powell G T South Texas |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NOC-AE-11002714 | |
| Download: ML11238A072 (9) | |
Text
Nuclear Operating CompanySouth Texas Prolect Electric Generating' Station P.. Box 289 Wadsworth, Texas 77483 AAugust 23, 2011NOC-AE-1 100271410CFR54STI: 32913936File: G25U. S. Nuclear Regulatory CommissionAttention: Document Control DeskOne White Flint North11555 Rockville PikeRockville, MD 20852-2746South Texas ProjectUnits 1 and 2Docket Nos. STN 50-498, STN 50-499Response to Requests for Additional Information for theSouth Texas Proiect License Renewal Application (TAC Nos. ME4936 and ME4937)References: 1. STPNOC Letter dated October 25, 2010, from G. T. Powell to NRC DocumentControl Desk, "License Renewal Application" (NOC-AE-10002607) (ML103010257)2. NRC letter dated July 28, 2011, "Requests for Additional Information for the Reviewof the South Texas Project, License Renewal Application -Scoping and ScreeningAudit" (ML1 1201A055)By Reference 1, STP Nuclear Operating Company (STPNOC) submitted a License RenewalApplication (LRA) for South Texas Project (STP) Units 1 and 2. By Reference 2, the NRC staffrequested additional information for review of the STP LRA. STPNOC's response to the requestfor additional information is provided in the Enclosure to this letter.There are no regulatory commitments in this letter.Should you have any questions regarding this letter, please contact either Arden Aldridge, STPLicense Renewal Project Lead, at (361) 972-8243 or Ken Taplett, STP License Renewal Projectregulatory point-of-contact, at (361) 972-8416.I declare under penalty of perjury that the foregoing is true and correct.Executed on &.t$'+ 2'3: ZO//DateG. T. PowellVice President,Technical Support & OversightKJTEnclosure: STPNOC Response to Requests for Additional Information A NOC-AE-1 1002714Page 2cc:(paper copy)(electronic copy)Regional Administrator, Region IVU. S. Nuclear Regulatory Commission612 East Lamar Blvd, Suite 400Arlington, Texas 76011-4125Balwant K. SingalSenior Project ManagerU.S. Nuclear Regulatory CommissionOne White Flint North (MS 8B1)11555 Rockville PikeRockville, MD 20852Senior Resident InspectorU. S. Nuclear Regulatory CommissionP. 0. Box 289, Mail Code: MN1 16Wadsworth, TX 77483C. M. CanadyCity of AustinElectric Utility Department721 Barton Springs RoadAustin, TX 78704John W. DailyLicense Renewal Project Manager (Safety)U.S. Nuclear Regulatory CommissionOne White Flint North (MS 011-Fl)Washington, DC 20555-0001Tam TranLicense Renewal Project Manager(Environmental)U. S. Nuclear Regulatory CommissionOne White Flint North (MS O11F01)Washington, DC 20555-0001A. H. Gutterman, EsquireKathryn M. Sutton, EsquireMorgan, Lewis & Bockius, LLPJohn RaganCatherine CallawayJim von SuskilNRG South Texas LPEd AlarconKevin PolioRichard PenaCity Public ServicePeter NemethCrain Caton & James, P.C.C. MeleCity of AustinRichard A. RatliffAlice RogersTexas Department of State Health ServicesBalwant K. SingalJohn W. DailyTam TranU. S. Nuclear Regulatory Commission
Enclosure
NOC-AE-1 1002714Page 1 of 7STPNOC Response to Requests for Additional InformationSOUTH TEXAS PROJECTLICENSE RENEWAL APPLICATIONREQUESTS FOR ADDITIONAL INFORMATIONRAI 2.1-1Background:Title 10 of the Code of Federal Regulations (10 CFR) 54.4, "Scope," states, in part,(a) Plant systems, structures and components within the scope of this part are:(1) Safety-related systems, structures, and components which are those relied upon toremain functional during and following design-basis events (as defined in 10 CFR 50.49(b)(1)) to ensure the following functions:(i) The integrity of the reactor coolant pressure boundary;(ii) The capability to shut down the reactor and maintain it in a safe shutdown condition;or(iii) The capability to prevent or mitigate the consequences of accidents which couldresult in potential offsite exposures comparable to those referred to in10 CFR 50.34(a)(1), 10 CFR 50.67(b)(2), or 10 CFR 100.11, as applicable.Issue:During the scoping and screening methodology audit, performed on-site May 16-19, 2011, theU.S. Nuclear Regulatory Commission (NRC or the staff) determined, through a review of thelicense renewal implementing documents and discussions with STP Nuclear OperatingCompany (STPNOC or the applicant), that a quality class, "QC-4," had been used in identifyingstructures, systems, and components (SSCs) to be included within the scopeof license renewalin accordance with 10 CFR 54.4(a)(1) that was not addressed in the license renewal application.Request:The staff requests that the applicant provide a description of the process used to evaluatecomponents identified as QC-4 in the plant equipment database or other documents, to identifySSCs to be included within the scope of license renewal in accordance with 10 CFR 54.4(a)(1).The staff requests that the applicant perform a review of this issue and indicate if the reviewconcludes that use of the scoping methodology precluded the identification of SSCs whichshould have been included within the scope of license renewal in accordance with 10 CFR54.4{a).. Describe any additional scoping evaluations performed to address the 10 CFR 54.4(a)criteria. List any additional SSCs included within the scope as a result of your efforts, and listthose structures and components for which aging management reviews were conducted or anyadditional information related to material and environment combinations. For each structure and
Enclosure
NOC-AE-1 1002714Page 2 of 7component, describe the aging management programs, as applicable, to be credited formanaging the identified aging effects.STPNOC Response:South Texas Project (STP) systems, structures and components (SSCs) classified as QualityClass 4 (QC-4) are identified as safety-related and are included within the scope of licenserenewal under the requirements of 10 CFR 54.4(a)(1). In accordance with the requirements of10 CFR 54.4(a)(2), nonsafety-related SSCs whose failure could impact any of the functionsidentified for 10 CFR 54.4(a)(1) SSCs including SSCs classified as QC-4, are included within thescope of license renewal. Therefore, this review concludes that use of this scoping methodologydoes not preclude the identification of SSCs which should have been included within the scopeof license renewal in accordance with 10 CFR 54.4(a). No additional scoping evaluationsregarding this issue are required to be performed to address the 10 CFR 54.4(a) criteria.Section 2.1.2.1, 10 CFR54.4(a)(1) Safety Related, of the STP License Renewal Application(LRA) will be revised to include Quality Class 4 (QC-4) SSCs and will state that Quality Class 4SSCs are within the scope of license renewal for 10 CFR 50.54(a)(1).RAI 2.1-2Backgqround:Title 10 of the Code of Federal Regulations (10 CFR) 54.4, "Scope," states, in part,(a) Plant systems, structures and components within the scope of this part are:(1) Safety-related systems, structures, and components which are those relied upon toremain functional during and following design-basis events (as defined in 10 CFR 50.49(b)(1)) to ensure the following functions:(i) The integrity of the reactor coolant pressure boundary;(ii) The capability to shut down the reactor and maintain it in a safe shutdown condition;or(iii) The capability to prevent or mitigate the consequences of accidents which couldresult in potential offsite exposures comparable to those referred to in 10 CFR50.34(a)(1), 10 CFR 50.67(b)(2), or 10 CFR 100.11, as applicable.(2) All nonsafety-related systems, structures and components whose failure could preventsatisfactory accomplishment of any of the functions identified in (a)(1)(i), (ii), or (iii) of thissection.Issue:During the scoping and screening methodology audit, performed on-site May 16-19, 2011, thestaff reviewed the license renewal application, license renewal implementing documents and haddiscussions with the applicant, to determine the applicant's approach for identifyingnonsafety-related SSCs, with the potential to impact safety-related SSCs, and to include thenonsafety-related SSCs within the scope of license renewal in accordance with 10 CFR 54.4
Enclosure
NOC-AE-1 1002714Page 3 of 7(a)(2). The staff determined that the method used to address the potential for nonsafety-relatedSSCs to impact safety-related SSCs located in the turbine building as provided duringdiscussions with the applicant, was different than the method provided in the license renewalapplication (LRA) and the applicant's implementing documents. The staff performed a plantwalkdown of the safety-related SSCs located in the turbine building (feedwater regulating controlvalves' associated air solenoid valves and limit switches) and determined that there werenonsafety-related SSCs located within the vicinity of the safety-related SSCs. The LRA and theapplicant's implementing documents stated that nonsafety-related piping and structures thatcould potentially interact with the safety-related solenoid valves and limit switches were includedwithin the scope of license renewal in accordance with 10 CFR 54.4 (a)(2). However, duringaudit discussions with the staff, the applicant stated that the safety-related solenoid valves andlimit switches were qualified to withstand the effects of the failure of nonsafety-related SSCswithin the vicinity of the safety-related SSCs and, therefore, the nonsafety-related SSCs werenot included within the scope of license renewal in accordance with 10 CFR 54.4 (a){2).Request:The staff requests that the applicant perform a review of this issue and provide a discussion andbasis for the position, as stated by the applicant during the scoping and screening methodologyaudit, that nonsafety-related SSCs within the vicinity of the safety-related solenoid valves andlimit switches located in the turbine building are not required to be included within the scope oflicense renewal in accordance with 10 CFR 54.4(a)(2). Indicate if the review concludes that useof the scoping methodology precluded the identification of systems, structures, and components(SSCs) which should have been included within the scope of license renewal in accordance with10 CFR 54.4(a)(2). Describe any additional scoping evaluations performed to address the10 CFR 54.4(a)(2) criteria. List any additional SSCs included within the scope as a result of yourefforts, and list those structures and components for which aging management reviews wereconducted or any additional information related to material and environment combinations. Foreach structure and component, describe the aging management programs, as applicable, to becredited for managing the identified aging effects.STPNOC Response:Prior to submittal of the STP LRA, the feedwater regulating valves and associated safety-relatedsolenoid valves and limit switches were walked down to identify nonsafety-related componentswhose failure could affect these safety-related components. Components in immediate vicinityof the solenoid valves and limit switches that were judged to have the potential for spatialinteraction with the solenoid valves and limit switches to prevent satisfactory performance oftheir Intended function were included in the scope of license renewal under the requirements of10 CFR 54.4(a)(2). The feedwater regulating valves and lines are within the scope of licenserenewal and subject to periodic external surfaces monitoring per LRA Section B2.1.20; thereby,ensuring that any external aging effects will be managed.The solenoid valves, limit switches and associated circuits are environmentally qualified forsteam line break, water spray and harsh temperature environments. High energynonsafety-related components not in immediate vicinity that can not impact the safety-relatedcomponents are not included within the scope of license renewal because the safety-relatedcomponents are qualified for the environment resulting from failure of those nonsafety-relatedcomponents. This is consistent with Section 5.2.3.2 of NEI 95-10, Rev. 6, Appendix F whichstates that "If a component is qualified/designed to maintain its function in an environment thatcould be caused by failure of a nearby non-safety SSC, that non-safety SSC would NOT need tobe within the scope of 54.4(a)(2)."
Enclosure
NOC-AE-1 1002714Page 4 of 7As a result of this review, no previously unidentified components are brought into the scope oflicense renewal.RAI 2.1-3Backgqround:Title 10 of the Code of Federal Regulations (10 CFR) 54.4, "Scope," states, in part,(a) Plant systems, structures and components within the scope of this part are:(1) Safety-related systems, structures, and components which are those relied upon toremain functional during and following design-basis events (as defined in 10 CFR 50.49(b)(1))to ensure the following functions:(i) The integrity of the reactor coolant pressure boundary;(ii) The capability to shut down the reactor and maintain it in a safe shutdown condition;or(iii) The capability to prevent or mitigate the consequences of accidents which couldresult in potential offsite exposures comparable to those referred to in10 CFR 50.34(a)(1), 10 CFR 50.67(b)(2), or 10 CFR 100.11, as applicable.(2) All nonsafety-related systems, structures and components whose failure could preventsatisfactory accomplishment of any of the functions identified in (a)(1)(i), (ii), or (iii) of thissection.Issue:During the scoping and screening methodology audit performed on-site May 16-19, 2011, thestaff determined that the applicant had performed a plant walkdown in April 2011, subsequent tothe submittal of the license renewal application, during which the applicant identified additionalSSCs to be included within the scope of license of renewal in accordance with10 CFR 54.4(a)(2). The applicant had not submitted this information to the NRC, which identifiedadditional non safety-related SSCs to be included within the scope of license renewal.Request:The staff requests that the applicant perform a review of this issue and indicate if the reviewconcludes that use of the scoping methodology precluded the identification of SSCs whichshould have been included within the scope of license renewal in accordance with10 CFR 54.4(a). Describe any additional scoping evaluations performed to address the10 CFR 54.4(a) criteria. List any additional SSCs included within the scope as a result of yourefforts, and list those structures and components for which aging management reviews wereconducted or any additional information related to material and environment combinations. Foreach structure and component, describe the aging management programs, as applicable, to becredited for managing the identified aging effects.
Enclosure
NOC-AE-1 1002714Page 5 of 7STPNOC Response:Section 2.1.2.2 of the LRA states that non-safety related SSCs containing fluid or steam, andlocated in the same room or area containing safety-related SSCs are included in scope forpotential leakage boundary (spatial) interaction under criterion 10 CFR 54.4(a)(2) (regardless ofthe system pressure). Identification of the rooms and areas of concern for potential spatialinteraction is based on a review of the Current Licensing Basis and design drawings andconsidered for potential communication with other rooms that may contain10 CFR 54.4(a)(1) components. The methodology used for the Reactor Containment Building(RCB), Isolation Valve Cubicle (IVC), Fuel Handling Building (FHB), and Mechanical AuxiliaryBuilding (MAB) is to include all non safety-related fluid-filled SSCs in scope of license renewalfor spatial interaction unless the components are in a closed area that does not allow spatialinteraction with SSCs in an adjacent area.Some SSCs in the MAB and FHB were not included within the scope of license renewal in thesubmitted LRA because of an incorrect usage of the information contained on a set of drawingsshowing seismic Il/I conditions. If the drawing indicated that the room did not contain seismic Il/Iconditions (non Il/I area), then the approach was to exclude the room from 10 CFR 54.4(a)(2)evaluation for spatial interaction. The approach incorrectly concluded that the non-seismic Il/Iarea did not contain safety-related components although the room could have included safety-related components above non safety-related components.Further evaluation determined that the approach for excluding non-seismic Il/I areas from 10CFR 54.4(a)(2) evaluation for spatial interaction was not a valid approach. Walkdowns wereperformed for these previously excluded areas. The walkdowns identified that potential spatialinteraction exists between seismic Il/I and non-seismic Il/I areas, and that some non-seismic Il/Iareas contain safety-related components above non safety-related components.Each room that was excluded from a 10 CFR 54.4(a)(2) evaluation based on the approachdescribed above was reviewed to determine if the room contained safety-related components.Table 1 shows the components that were identified within previously excluded rooms that couldspatially interact with SR components and are in-scope per 10 CFR 54.4(a)(2). Thesecomponents will be placed in-scope and managed by the aging management program (AMP)listed in Table 1.LRA Sections 2.3.3, 2.3.4, 3.3 and 3.4 will be revised to include the components contained inTable 1. Boundary drawings will be revised to show the components listed in Table 1 are withinthe scope of license renewal.
Enclosure
NOC-AE-1 1002714Page 6 of 7Table IComponents within previously excluded roomsthat could spatially interact with SR components and are in-scope per 10 CFR 54.4(a)(2).Note: Components are designated by South Texas Project Total Plant Numbering System(TPNS) nomenclature.AMP B.1.22,"Inspection ofInternalSurfaces inAMP B.1.2, "Water MiscellaneousChemistry" and AMP B.1.20, Piping andAMP B.1.16, "One-Time Comp "External Surfaces Comp Ducting CompInspection" Type Monitoring Program" Type Components" Type7Q061TED0332 Valve 7S201MSP001 Filter 7Q061TED0096 Valve7Q061TED0361 Valve 7S201TSB0230 Valve 7Q061TED0097 Valve7Q061TED0362 Valve 7S201TSB0305 Valve 7Q061TED0098 Valve7Q061 TED0363 Valve 7S201TSBO316 Valve 7Q061TED0170 Valve7Q061TED0375 Valve 7S201TSB0380 Valve 7Q061TED0265 Valve7Q061TED0378 Valve 7S201TSB0381 Valve 7Q061TED0268 Valve7Q062TED0332 Valve 7S202MSP001 Filter 7Q061TED0281 Valve7Q062TED0361 Valve 7S202TSB0305 Valve 7Q062TED0096 Valve7Q062TED0362 Valve 7S202TSB0316 Valve 7Q062TED0097 Valve7Q062TED0363 Valve 7S202TSB0380 Valve 7Q062TED0098 Valve7Q062TED0375 Valve 7S202TSB0381 Valve 7Q062TED0170 Valve7Q062TED0378 Valve N1SBFV5019 AOV-3 7Q062TED0265 Valve7R181NDM102A Vessel N2SBFV5019 AOV-3 7Q062TED0268 Valve7R181TBR0055 Valve 7Q062TED0281 Valve7R181TBR0168 Valve 7R301TWL1086 Valve7R181TBR0169 Valve 7R302TWL1 086 Valve7R181TBR0218 Valve 7R321XPA1902 Pump7R182NDM202A Vessel 7R321XWS0076 Valve7R182TBR0055 Valve 7R321XWS0077 Valve7R182TBR0168 Valve 7R321XWS0078 Valve7R182TBR0169 Valve 7R321XWS0079 Valve7R321 TWS0035 Valve 7R321XWS0080 Valve7R322TWS0035 Valve 7R321XWS0081 Valve7R322TWS0068 Valve 7R321XWS0083 Valve7S201MDM001 Vessel 7R322TWS0036 Valve7S201 MDM002 Vessel 7R322TWS0041 Valve7S201 MSP001 Filter 7R322XPA1 902 Pump7S201 TSB0230 Valve 7R322XWS0076 Valve7S201TSB0305 Valve 7R322XWS0077 Valve7S201TSB0316 Valve 7R322XWS0078 Valve7S201TSB0319 Valve 7R322XWS0079 Valve7S201 TSB0380 Valve 7R322XWS0080 Valve7S201 TSB0381 Valve 7R322XWS0081 Valve7S202MSP001 Filter 7R322XWS0082 Valve7S202TSB0305 Valve 7R322XWS0083 Valve
Enclosure
NOC-AE-1 1002714Page 7 of 7AMP B.1.22,"Inspection ofInternalSurfaces inAMP B.1.2, "Water MiscellaneousChemistry" and AMP B.1.20, Piping andAMP B.1.16, "One-Time Comp "External Surfaces Comp Ducting CompInspection" Type Monitoring Program" Type Components" Type7S202TSB0316 Valve 9QO61NPA112A Pump7S202TSB0319 Valve 9QO61NPA112B Pump7S202TSB0380 Valve 9QO61NPA112C Pump7S202TSB0381 Valve 9QO61NPA112E Pump9S191TDW0609 Valve 9QO61NPA112F Pump9S192TDW0609 Valve 9QO61NPA112G PumpNiFHLCV0027B Valve 9QO61NPA112H PumpN1FHPSV0028A PSV 9QO62NPAl 12A PumpN 1FHPSV0028B PSV 9QO62NPA112B PumpN1SBFV5019 AOV-3 9QO62NPA112C PumpN2SBFV5019 AOV-3 9QO62NPA 112E PumpOCM01FHVLVO026B Valve 9QO62NPA112F Pump9QO62NPA112G Pump9QO62NPA112H Pump9R301NPA0103A Pump9R301NPA0103B PumpNotes:AOV -air-operated valvePSV -pressure relief valve