ML21133A421

Response to NRC Request for Additional Information Regarding Proposed License Amendment Request Update of LOCA Alternative Source Term Dose Analysis

ML21133A421
Person / Time
Site:	Surry
Issue date:	05/13/2021
From:	Mark D. Sartain Virginia Electric & Power Co (VEPCO)
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
21-156
Download: ML21133A421 (6)

Text

VIRGINIAELECTRIC ANDPOWER COMPANY 23261 RICHMOND,VIRGINIA

[

May13,2021 10CFR50.90 p U.S.Nuclear Regulatory Commission Serial No.: 21-156 Attention:

Document Control Desk NRA/GDM:R1 E DC20555-0001 Washington, DocketNos.: 50-280 ,

50-281 I LicenseNos.: DPR-32 DPR-37 i

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IEBM.DOSLANALY.Sis I I

r By letter dated December 3,2020(Serial No.20381),Virginia ElectricandPower i Company (Surry)

(Dominion Units Energy 1 and2 Facility Virginia) amendments to Surry PowerStation requested Operating License NumbersDPR-32 andDPR-37, j

I respectively.

The proposed License Amendment Request(LAR) (Agencywide j Documents Access andManagement System (ADAMS) Accession No. ML20338A542) j updates theAlternate Source Term(AST) analysisforSurryUnits 1 and 2 following a j LossofCoolantAccident hasbeenrevisedtoincrease (LOCA).

theassumed theLOCAdoseconsequence analysis Specifically, containmentdepressurizationprofile and to l

theRefueling reduce Water Storage Tankbackleakage limit.

During their review oftheproposed tocomplete information theirreview.

LAR,theNRCstaff Specifically, identified theneedfor theNRCrequested additional a discussion of l

I theproposed whether electrical equipment change hadany incontainment impact subject on theenvironmental totherequirements qualification of10 CFR50.49.

of j 1

Energy Dominion Virginia's response totherequest foradditionalinformation (RAI) is j intheattachment.

provided  !

l Thenosignificant hazards considerationdeterminationandthe environmental evaluation j provided intheL AR are n otaffectedbythe RAlresponse.

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Serial No.21-156 Docket 50-280/281 Nos.

Page2 of3 Should you have anyquestions orrequire additional information, please contact Gary D.

Miller at (804) 273-2771.

Respectfully, D

MarkD.Sartain Vice President -

Nuclear Engineering andFleet Support Commitments contained inthisletter: None

Attachment:

Response toNRCRequest for Additional information, LossofCoolant Accident (LOCA) Updated Alternate Source Term Dose Analysis COMMONWEALTH OFVIRGINIA )

)

COUNTY OFHENRICO )

Theforegoing document wasacknowledged before me, inand for theCountyandCommonwealth aforesaid, today byMr.MarkD.Sartain, who isVicePresident Nuclear Engineering andFleet Support, ofVirginia andPowerCompany.

Electric He hasaffirmed before me that he isduly authorized toexecute andfiletheforegoing document inbehalf of that company, andthat the statements inthe document aretrue tothe bestofhis knowledge andbelief.

Acknowledged before methis /3 dayof , 2021.

MyCommission Expires: U 2o21 A

GARYDONMILLER No y Public Notary Public Comrnonwealth ofVirginia Reg.# 7629412 MyCommission ExpiresAugust31,20E3-

No.21-156 Serial Docket 50-280/281 Nos.

Page3 of3 cc: U.S. Nuclear Regulatory Commission -

Region II Marquis OneTower 245 Peachtree Center Avenue, NESuite 1200 Atlanta, GA 30303-1257 State Health Commissioner Virginia Department ofHealth JamesMadison Building -

7thfloor 109Governor Street, Suite 730 Richmond, VA23219 Mr.Vaughn Thomas NRCProject ManagerSurry U.S. Nuclear Regulatory Commission OneWhite Flint North Mail Stop 04F-1211555 Rockville Pike Rockville, MD20852-2738 Mr.G.Edward Miller NRCSenior Project ManagerNorth Anna U.S. Nuclear Regulatory Commission OneWhite Flint North Mail Stop 09E-311555 Rockville Pike Rockville, MD20852-2738 NRCSenior Resident Inspector Surry PowerStation

Serial No.21-156 Docket 50-280/281 Nos.

Attachment i

TONRCREQUEST RESPONSE FORADDITIONAL INFORMATION

- DOSEANALYSIS LICENSEAMENDMENT REQUEST

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l Virginia andPowerCompany Electric (Dominion EnergyVirginia)

PowerStation Surry Units1 and2

Serial No.21-156 DocketNos. 50-280/281 Attachment Back.groun.st dated By letter December 3, 2020 (Serial No.20-381), Electric Virginia andPower Company (Dominion Energy Virginia) requested amendments to Surry Power Station (Surry)

Units 1 and2 Facility Operating License Numbers DPR-32andDPR-37, respectively.The proposed License Amendment Request (LAR) (Agencywide DocumentsAccess andManagement System (ADAMS) Accession No.ML20338A542) updates theAlternate Source Term(AST) analysis for Surry Units1 and2 following a LossofCoolant (LOCA).

Accident Specifically, theLOCAdoseconsequence analysis hasbeenrevised toincreasetheassumedcontainment depressurization profileandto reduce the Refueling Storage backleakage Water Tank limit.

Subsequenttothesubmittal oftheproposed LAR,the NRC staff requested additional information tocomplete their review. TheNRC'srequest and Dominion Energy Virginia's response areprovided below.

N.

R.CRegges) 2,"Proposed InSection Licensing Basis Changes," ofthelicenseamendment request (LAR),

thelicenseestated:

Theproposed changes fora LOCAradiological eventare: 1)an increase ofthe depressurization containment profile, and2)a reduction oftheRWSTback leakage limit.

Fudhermore,inSection2.1, "Increased Containment Depressurization Profile,"ofthe LAR,thelicenseestated:

Thecurrentlicensingbasisstates that thecontainment will depressurize to1.0psig within 1 hourandless than0.0psig within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. Theproposed change would require thecontainment todepressurize to2.0psig within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> andlessthan 0.0psig within6 This hours. change bereflected will intheLOCAdoseconsequence analysis through anincreased containmentleak rate aspresented inTable 2-1andSection 3.5.1.

Theproposed amendment would increase thecontainment depressurizationprofile as described insection2.1.However, the proposed LARdoesnotdiscuss theimpact to theenvironmental ofelectrical qualification equipment subjecttotherequirements of Page1of2

Serial No.21-156 Docket Nos.

50-280/281 Attachment 10CFR 50.49. Therefore, theNRCstaff requests the licensee todiscuss theimpact of theproposed change onthe environmental qualification ofelectrical equipment.

M Asdescribed inthe proposed LAR,Dominion Energy Virginia hasrequested a change tothecontainment depressurization profile that isused asaninput totheLOCAdose consequence analysis. The proposed bounding profile sets a newacceptance criterion for the safety analyses containment pressure response.

Separate from theprofile used inthe LOCAdoseconsequence analysis, Dominion Energy maintains a bounding containment pressure profile for Equipment the Qualification (EQ) program. The proposed LAR does notchange orimpact theEQ containment pressure profile, which will continue to boundthesafety analyses containment pressure response. As such, thecontainment pressure response acceptance criterion forthe EQprogram will remain the same. t Thebounding containment pressure profilesused for theLOCAdoseconsequence analysis andEQ program areestablished independently fromoneanother. Both profilesconstitute acceptance criteria forthesafety analyses containment pressure response. Themethods used togenerate eachprofile are governed byseparate rules and/or regulations, butinall cases, thecontainment safety analyses demonstrate that theprofiles arenotexceeded.

Asdescribed above, theEQcontainment pressure profile isunchanged andcontinues tobound thesafety analyses containment pressure response. Therefore, theproposed  ;

LARhasnoimpact onthe EQprogram atSurry Power Station.

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