ML21140A299

Response to Request for Additional Information for Proposed License Amendment Request to Add an Analytical Methodology to the Core Operating Limits Report for a Large Break Loss of Coolant Accident

ML21140A299
Person / Time
Site:	Millstone
Issue date:	05/20/2021
From:	Mark D. Sartain Dominion Energy Nuclear Connecticut
To:	Document Control Desk, Office of Nuclear Reactor Regulation
Shared Package
ML21140A298	List: ML21140A299
References
21-154
Download: ML21140A299 (17)

Text

PROPRIETARY INFORMATION-WITHHOLD UNDER 10CFR2.390 Energy Nuclear Inc.

Connecticut, Dominion 5000 Dominion Boulevard, Glen VA23060 Allen, @

DominionEnergy,com

@QQ May20,2021 U.S. Nuclear Regulatory Commission Serial No.21-154 Attention: Document ControlDesk NRA/SS RO Washington, DC 20555 Docket No. 50-423 License No. NPF-49 I

MILLSTONE POWER STATION UNIT 3  !

RESPONSE TO REQUESTFOR ADDITIONAL INFORMATION FORPROPOSED I LICENSE AMENDMENT REQUEST TO ADDANANALYTICAL METHODOLOGY TO THE COREOPERATING LIMITS REPORT FORA LARGEBREAKLOSSOF COOLANT ACCIDENT j t

Byletter dated November 5,2020(Agencywide Documents Access andManagement System (ADAMS) Accession No. ML20310A324), Dominion Energy Nuclear Connecticut, l

Inc. (DENC), submitted a license amendment request (LAR) to the Nuclear Regulatory '

Commission (NRC) forMillstone Power Station, Unit No. 3 (MPS3).Theproposed  !

amendment would revise Technical Specification (TS)6.9.1.6.b byadding WCAP-16996-P-A,Revision 1,"Realistic LOCAEvaluation Methodology Applied tothe FullSpectrum ofBreak Sizes (Full Spectrum LOCAMethodology)," tothe list of methodologies approved forreference intheCore Operating LimitsReport (COLR) for MPS3. Theadded reference identifies theanalytical methods used todetermine thecore operating limits forthe large j break Analysis loss of Report.

coolant accident (LBLOCA) described MPS3 Final event in the Safety [

Inan email dated March31,2021,theNRCissued a draft request for additional j information conducted (RAI) related a conference totheproposed call with DENCstaff LAR. On April toclarify 13,2021, therequest.

theNRC staff Inanemail dated E

April 15,2021, theNRCtransmitted thefinal version ofthe (ADAMS R AI Accession No. ML21105A115). DENCagreed torespond totheRAlwithin 45days ofissuance, orno later than May31,2021.

Theproprietary information inAttachment 3 issupported byanaffidavit (Attachment 2) signed byWestinghouse Electric Company LLC., theowner oftheinformation. The ,

attached affidavit sets forth thebasis onwhich theinformation maybewithheld from public disclosure bytheNRCandaddresses, with specificity, theconsiderations listed in paragraph (b)(4) of10 CFR 2.390. Accordingly, itis respectfully requested that the information that isproprietary toWestinghouse bewithheld frompublic disclosure in accordance with 10CFR2.390. 3 i

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Attachment 3contains proprietaryinformation that isbeing withheld frompublic disclosure under 10CFR2.390. UponseparationofAttachment 3,this letter isdecontrolled. g l

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Serial No.21-154 '

Docket No.50-423 Page2 of3 Correspondence with respect tothecopyright orproprietary aspects oftheitems listed above, or thesupporting Westinghouse should affidavit, reference CAW-21-5177 j (Attachment 2) andshould beaddressed toCamille T.zozula, Manager, Regulatory l Compliance & Corporate Licensing, Westinghouse Electric Company,1000 I Westinghouse Drive, Cranberry Township, Pennsylvania 16066.

l DENC'sresponse to theRAIisprovided (proprietary). Westinghouse's inAttachment affidavit 1 (non-proprietary) forwithholding and proprietary j

information isprovidedin Attachment 2.

Ifyouhaveanyquestions orrequire additional information,please contact Shayan Sinha at(804) 273-4687.

Sincerely,

/ '

y j ,

Mark D.Sartain Vice President -

Nuclear Engineering & Fleet Support COMMONWEALTH OFVIRGINIA )

)

COUNTY OF HENRICO ) ,

Theforegoing document wasacknowledged before me,inandfor theCounty and Commonwealth aforesaid, today byMr.MarkD.Sartain, whoisVice President Nuclear Engineering andFleet Support ofDominion Energy Nuclear Connecticut, Inc. Hehasaffirmed before me that heis duly authorized toexecute andfile theforegoing document inbehalfofthat company, and thatthe statements inthe document aretrue tothe best ofhis knowledgeandbelief.

Acknowledged before methis 204dayof , 2021.

MyCommission Expires:

CRAIGD SLY Notary Public Commonwealth ofVirginia Reg. # 7518653 Notary ublic MyCommission Expires December 31,2D Attachments:  !

1.Response toRequest forAdditional Information Regarding LAR toAdd an Analytical Methodology tothe COLRfor a LBLOCA (Non-Proprietary) 2.Westinghouse Affidavit for Withholding Information Proprietary (Non-Proprietary) 1 3.Response toRequest forAdditional Information Regarding LAR toAdd an j Analytical Methodology totheCOLRfor a LBLOCA (Proprietary) j Commitments madeinthis letter: None  !

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No.21-154 Serial No.50-423 Docket Page3of3 cc: U.S. NuclearRegulatory Commission Region I 2100 Renaissance Blvd, Suite 100 King of Prussia, PA19406-2713 l l

R.V.Guzman l Senior U.S.

Project Manager NuclearRegulatory Commission l

I OneWhite FlintNorth, Mail Stop08-C 2 11555 Rockville Pike Rockville, MD20852-2738 NRCSenior Resident Inspector Millstone Power Station Director, Radiation Division Department ofEnergy andEnvironmental Protection 79ElmStreet Hartford, CT 06106-5127 j

Serial No.21-154 Docket No.50-423 ATTACHMENT 1 INon-PmpffetgyJ b

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l MILLSTONEPOWER STATIONUNIT3 DOMINION ENERGY NUCLEAR CONNECTICUT, INC.

Serial No.21-154 Docket No.50-423 Attachment 1,Page1of9 By letter datedNovember 5,2020(Agencywide Documents Access andManagement System (ADAMS) Accession No.ML20310A324), Dominion Energy Nuclear Connecticut, Inc. (DENC), submitted a license amendment request (LAR) totheNuclear Regulatory Commission (NRC) for Millstone Power Station, Unit N o. 3 (MPS3).proposed The amendmentwould revise Technical Specification (TS) 6.9.1.6.b byadding WCAP-16996-P-A,Revision1, "Realistic LOCAEvaluation Methodology Applied totheFull Spectrum ofBreak Sizes(Full Spectrum LOCA Methodology)," tothe listof methodologies approved for reference inthe Core Operating Limits Report (COLR) for M PS3. The added r eference identifies theanalyticalmethods used todetermine the core operating limits forthelarge break loss ofcoolant accident (LBLOCA) event d escribed in the MPS3 Final Safety Analysis Report. i Inan email dated March 31,2021, theNRCissued a draft request foradditional l information (RAI) related to the proposed LAR. On April 13, 2021, the NRCstaff conducted a conference call withDENC staff toclarify therequest. Inanemail dated April 15,2021, theNRCtransmitted thefinal version oftheRAl(ADAMS Accession No. l l

ML21105A115). DENC agreed to respond to the RAl within 45 days o fissuance, or no j later than May 2021 31, )

Thenon-proprietary version ofDENC's response tothe RAI isprovided in this attachment.  ;

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Theaddedreference identifies theanalytical methods used to determine thecore l operating limits for the large break loss ofcoolant accident (LBLOCA) event describedin [

f theMPS3Final Safety Analysis Report (FSAR), Section 15.6.5, "Loss-of-Coolant Accidents Resulting from a Spectrum ofPostulated Piping Breakswithin theReactor j Coolant Pressure Boundary." Theamendment also proposes toremove an obsolete COLRreference that isnolonger used tosupport MPS3core reload analysis.

l TheNRCstaff hasdetermined that additional information isneeded tocomplete its j review, asdescribed inthe request for additional information (RAI) shown below. (

Regulatory Basis:

Theregulations in10CFR50.46(b) require during LOCAevents, the following criteria are met:

(1) Peakcladding temperature. Thecalculated maximumfuel element cladding temperature shall not exceed 2200" F.

(2) Maximum cladding oxidation. Thecalculated totaloxidation ofthe cladding shall nowhere exceed 0.17 times the total cladding thickness before oxidation. l l

Serial No.21-154 DocketNo.50-423 Attachment 1,Page2 of9 (3) Maximum hydrogen generation. Thecalculated total amountofhydrogen generated from thechemical reaction ofthecladding with water orsteam shall not exceed 0.01times the hypothetical amount that would begenerated ifall of the metal inthecladding cylinders surrounding thefuel, excluding thecladding surrounding theplenum volume, were toreact.

(4) Coolablegeometry. Calculated changes incore geometry shall besuch that the core remains amendable tocooling R.Aj1 InReference 1,Attachment 3,Limitation andCondition 2,under "Compliance" -

(a) Thelicensee refers to LTR-NRC-18-30 describe (Reference 3)andLTR-NRC-19-6 Westinghouse small-break loss-of-(Reference 4)which changes tothe coolant accident (LOCA) and LBLOCA emergency core c ooling system (ECCS) )

evaluation models andtheimpactof these changes. These references provide )

generically Reference estimated 1,Attachment effect on the peak cladding temperature 3,Section 5.0, the FSLOCA Evaluation (PCT).

Model (EM)

In l l

referred toisRevision 1,dated November 2016 which isnotupdated by incorporating theerrors reported inReferences 3 and 4.Confirm the that MPS3 .

LBLOCA analysiswasperformed with theupdated code after removing allerrors reported inReferences 3 and4.Ifthe codewasnot updated, provide reasons, andjustify quantitativelythat theMPS3LBLOCAanalysis performed (without updating thecode) has no impact onPCT,maximum local oxidation (MLO), core wide oxidation (CWO), andminimum containment back pressure.

(b) References 3 and4 donot report the error identified inReference 5 that impacts thegammaenergy redistribution multiplier.Ifapplicable toMPS3, provide an evaluation ofitsimpact on theMPS3LBLOCA analysis PCTresult and its thermal-hydraulic response. Incaseitis not applicable toMPS3,provide reasons.

i TheMPS3analysis usingtheFSLOCA EMutilized aversion ofthe WCOBRA/TRAC-TF2 code which incorporated the changes anderror corrections described inLTR-NRC-18-30 i (Reference 3) andLTR-NRC-19-6 (Reference 4). Itisconfirmed that theanalysis was performed with theupdated codewhich removed theerrors applicable totheFSLOCA EM,asreported inReferences 3 and4.

No.21-154 Serial DocketNo.50-423 Attachment 1,Page3 of9 Theerror related togammaenergy redistributiondiscussed therein wasnotanerror in theFSLOCA EM ortheWCOBRA/TRAC-TF2 code, butratheranerror intheplant-specificimplementation ofthemethodology forNorth AnnaUnits 1 and2.Assuch, the wasnotreported inthe error Westinghouse communications asa methodology error for theFSLOCA EM.The implementation error didnotoccur intheexecutionoftheMPS3 analysis using theFSLOCA EM,andasa result theas-approved methodology related to gammaenergy redistribution wascorrectlyapplied. Therefore,theerrorisnotapplicable totheMPS3FSLOCA EM analysis.

RAl-2 InReference 1,Attachment 3,Section3.0, thedescriptionof RegionIIanalysisdoes not provide theLBLOCAbreak spectrum scenarios thatwereanalyzed. Provide thebreak spectrum, i.e.,the PCTsversus break areasand MLOs versus PCTsthat wereanalyzed fromwhich the limiting resultsreported inTable 5 were obtained.

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Theuncertainty analysis methodology used intheFSLOCAEMisdescribed inSection 30 ofWCAP-16996-P-A, Revision 1.A MonteCarlo sampling ofalluncertainty contributors leads tothe generation ofa sample ofsimulated from results which upper tolerance limitsarederived for the analysis figures ofmerit (PCT,MLO,CWO).

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InReference 1,Attachment 3,Section 4.0, under compliance with 10CFR50.46(b)(4),

second paragraph, lastsentence states, "Inboard grid deformation duetocombined LOCAandseismic loads notcalculated is tooccur for Millstone Unit This 3." statement does not explicitly state howthis conclusion wasdetermined. Provide the technical basis forthis assertion.

M Section 32.1 oftheNRC-approved FSLOCA EM(Reference 2)discusses that theeffects ofLOCAandseismic loadsonthe core geometry donotneed tobeconsidered unless fuelassembly grid deformationextends beyond the core periphery (i.e.,

deformation ina fuel assembly with nosides adjacent t o the core baffle plates). The FSLOCA E M analysis does not affect theexistinganalysisofrecord related tothecombined LOCAandseismic loads. This conclusion isretainedfrom prior calculations andiscredited inthecurrent LOCAdesign basis analysis.Asdescribedin Section 4.2.3.4.1oftheMPS3FSAR,the combined LOCAandseismic loads remain below the allowable grid strength:

"Themaximum gridimpact forces for both the seismic accidentandasymmetric ,

LOCAoccur atthe peripheralfuel assembly locations adjacent to thebaffle wall. The maximum gridimpact forcesresult from postulated LOCA andseismicloadings, and arerequired tobeless than theallowable grid crush strength. A calculation ofthe maximum sumofthe LOCAandseismic squares method grid impact inaccordance forces, with combined SRP4.2, using the Appendix square A,demonstrated root [

that themaximum valueisbelow theallowable grid strength." 7 REFERENCES 1.Dominion Energy Nuclear Connecticut, Incletter toNRC, "Dominion Energy Nuclear Connecticut,Inc. Millstone PowerStation Unit 3 Proposed License Amendment Request Addition ofAnalytical Methodology totheCoreOperating Limits Report fora LargeBreak Loss ofCoolant Accident (LBLOCA)," November 5,2020, (ADAMS Accession No. ML20310A324). l l

2. Westinghouse Topical Report WCAP-16996-P-A, Revision 1,"Realistic LOCA l Evaluation SPECTRUM Methodology Applied LOCAMethodology),"

totheFull November Spectrum 2016.

ofBreak Sizes (FULL [

l 3.Westinghouse Electric Company letter toNRC,LTR-NRC-18-30, "U.S. Nuclear [

Regulatory Commission 10 CFR50.46 Annual Notification andReporting for l 2017," July 18, 2018(ADAMS Accession No.ML19288A174). l l

Serial No.21-154 No.50-423 Docket Attachment 1,Page9 of9

4. Westinghouse Electric Company letter "U.S.

toNRC,LTR-NRC-19-6, Nuclear Regulatory Commission 10 CFR50.46 AnnualNotification andReporting for 2018," February 7,2019 (ADAMS Package Accession No.ML19042A378).

5. Virginia Electric andPower Company toNRC,"Virginia letter Electric andPower Company North AnnaPower Station Units 1and2ProposedLicense Amendment Request Addition ofAnalytical Methodology totheCoreOperating Limits Report fora Full Spectrum LossofCoolant Accident Gamma (FSLOCA) Energy RedistributionInformation," August31, 2020,(ADAMS Accession No. ML20244A336).

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No.21-154 Serial Docket No.50-423 ATTACHMENT 2  !

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fN.gjlf.tgpffetary.1 l

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I MILLSTONE POWER STATION UNIT3 DOMINION ENERGY NUCLEAR CONNECTICUT, INC.

SerialNo.21-154 Docket No.50-423 Attachrnent 2,Page1of3 Westinghouse Non-Proprietary Class 3 CAW-21-5177 Page1of3 COMMONWEALTH OFPENNSYLVANIA:

COUNTY OFBUTLER:

(1) I,Camille T.zozula, have beenspecifically delegated andauthorized toapply for andexecute this withholding Affidavit onbehalf ofWestinghouse ElectricCompany LLC (Westinghouse).

(2) the Iam requesting proprietary portions ofLTR-LIS-21-115, Attachment 1bewithheld from public disclosure under 10CFR2.390.

(3) Ihave personalknowledge ofthe criteriaandprocedures utilized byWestinghouse in designating information asa trade secret,privileged, or as confidential commercial or information.

financial (4) Pursuant to10CFR2.390, the following isfurnished for consideration bythe Commission in determining whether the information sought tobewithheld from publicdisclosure should be withheld.

(i) Theinformation sought tobewithheld from public disclosure isowned andhas been heldinconfidence byWestinghouse andisnotcustomarily disclosedtothe public.

(ii)Theinformation sought tobewithheld isbeing transmitted totheCommission in confidenceand, toWestinghouse's knowledge, isnotavailable inpublic sources.

(iii) Westinghouse notes that ashowing ofsubstantial harm isnolonger anapplicable ,

criterion for analyzing whether a document should bewithheld from public I disclosure.

Nevertheless, public disclosure ofthis proprietary information islikely to causesubstantial harm tothe competitive position ofWestinghouse because itwould enhancethe ability ofcompetitors toprovide similar technical evaluation ,

justifications andlicensing defense services for commercial power reactors without commensurate expenses. Also, public disclosure ofthe information would enable This wasfinal record approvedon5/5/2021 5:30:04 PM.(Thisstatement wasadded bythePRIME system uponitsvalidation)

Serial No.21-154 Docket No.50-423 Attachment 2,Page2 of3 Westinghouse Non-Proprietary Class 3 CAW-21-5177 Page 2 of3 others touse the information tomeetNRCrequirements for licensing documentation without purchasing the righttousethe information (5) Westinghouse haspolicies inplace toidentify proprietary information. Under that system, informationisheld inconfidence if it falls inoneormoreofseveral types, the release of which might resultinthe loss of anexisting orpotential competitive advantage, asfollows:  !

(a)Theinformation reveals the distinguishing aspects ofaprocess (or component, structure, tool, method, etc.) where prevention ofits usebyany ofWestinghouse's competitors without license from Westinghouse constitutes a competitive economic advantage over other companies. >

l (b) Itconsists ofsupporting data, including test data, relative toaprocess (or component, structure,tool, method, etc.), the application ofwhich data secures a competitive economic advantage (e.g., by optimization orimproved marketability).

(c)Itsusebyacompetitor would reduce his expenditure of resources or improve [

hiscompetitive position inthe design, manufacture, shipment, installation, assurance ofquality, orlicensing asimilar product. ,

(d) Itreveals cost orprice information, production capacities, budget levels, or commercial strategiesofWestinghouse, its customers orsuppliers.

l (e)Itreveals aspects ofpast, present, orfuture Westinghouse orcustomer funded j development plans andprograms ofpotential commercial value to Westinghouse.

(f) Itcontains patentable ideas, for which patent protection maybedesirable.

This wasfinal record approvedon5/5/2021 PM.(This 5:30:04 statement wasadded bythe PRIME system uponits validation)

Serial No.21-154 DocketNo.50-423 Attachment 2,Page3 of3 Westinghouse Non-Proprietary Class 3 CAW-21-5177 Page 3 of3 (6) Theattached documents arebracketed andmarked toindicate thebasesforwithholding. The justification for withholding isindicated inboth versionsbymeans oflower-case letters(a) through (f)located asasuperscript immediately following the enclosing brackets each itemof information being identified asproprietary orin themargin opposite such information. These lower-case letters refer to the types ofinformation Westinghouse customarilyholds in confidence identified inSections (5)(a) through (f)ofthis Affidavit.

Ideclare that the averments offact setforthin this Affidavit aretrue andcorrecttothe best ofmy l j

i knowledge, information, andbelief.  !

Ideclare under penalty ofperjury that theforegoing istrueand correct.

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Executed on:04May2021 Q a fd CamilleT.zozula, Manager [

Regulatory Compliance & Corporate l Licensing 8

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i record This wasfinalapproved on5/5/2021 5:30:04PM.(This statement wasadded bythePRIMEsystemupon validation) its