ML17037B598

Nine Mile Point Unit 1 - Letter Regarding Mark I Containment Short Term Program Safety Evaluation Report and a Sample Federal Register Notice

ML17037B598
Person / Time
Site:	Nine Mile Point
Issue date:	02/28/1978
From:	Stello V Office of Nuclear Reactor Regulation
To:	Niagara Mohawk Power Corp
References
NUREG-0408
Download: ML17037B598 (14)

Text

8REGOg~oCyAO+~O~+*+<<IUNITEDSTATESNUCLEARREGULATORY COMMlsslON WASHINGTON, D.C.20555February28,1978AllOperating BWRLicensees (ExceptforHumboldt)

Gentlemen:

TheNRCstaffhascompleted itsreviewofthegenericMarkIContainment ShortTermProgramconducted bytheMarkIOwnersGroup'ndtheassociated plant-unique information whichyouprovidedwithrespecttoyourfacility'scontainment system.Theresultsofourreviewaredocumented inthestaff's"MarkIContainment ShortTermProgramSafetyEvaluation Report,"NUREG-0408,December1977.Acopy.ofthisdocumentisenclosedforyourinformation.Baseduponourreview,wehaveconcluded thatlicensedMarkIBWRfacilities cancontinuetooperatesafely,withoutunduerisktothehealthandsafetyofthepublic,duringaninterimperiodofapproximately twoyearswhileamethodical, comprehensive LonqTermProgram(LTP)isconducted.

Thisconclu-sionhasbeenmadebasedonourdetermination (1)thatthemagnitude andcharacter ofeachofthehydrodynamic loadsresulting fromapostulated de-signbasislossofcoolantaccident(LOCA)havebeenadequately definedforuseintheShortTermProgram(STP)structural assessment oftheMarkIcontainment system;and(2)that,forthemostprobableloadsinducedbyapostulated designbasisLOCA,asafetyfactortofailureofatleasttwoexistsfortheweakeststructural ormechanical component inthecontain-mentsystemforeachoperating MarkIBWRfacility.

Asdescribed inSectionIVofNUREG-0408, ourevaluation ofthecapability ofyourfaci'lity's MarkIcontainment systemtowithstand therecentlyidentified'OCA-related hydrodynamic suppression poolloadsindicates that,althougheachofthestructural andmechanical components ofyourcontain-mentsystemmeettheSTPstructural acceptance criteria(i.e.,asafetyfactortofailureofatleasttwo),thedemonstrated safetymarginsofcertaincomponents undertheseloadingconditions islessthan.thatwhichisnecessary tosatisfytherequirements ofSectionIIIoftheASMEBoilerandPressureVesselCode.Consequently, wehaveconcluded thatthe

demonstrated safetymarginofyourfacility's containment systemwithrespecttosuchloadingconditions doesnotcomplywithourcurrentinterpretation of"sufficient margin"asprescribed inGeneralDesignCriterion (GDC)50,"Containment DesignBasis",ofAppendixAto10CFRPart50.Forlongtermoperation ofyourfacility, wewillrequirethatthestructural andmechanical components

-ofyourfacility's con-tainmentsystemmeettheacceptance criteriaoftheASMEBoilerandPressureVesselCodetothemaximumextentpracticable fortheloadsandloadingcombinations identifieg jntheMarkIContainment LongTermProgramandapprovedbytheNRCstaff.However,wefindthat:(1)yourfacility's containment systemdesignstillretainssufficient marginunderpresentconditions toprecludefailureandthusprovidesreasonable assurance ofnounduerisktothehealthandsafetyofthepublic,(2)theobjective oftheHarkICon-tainmentLTP,i.e.,torestoretheoriginally intendeddesignsafetymarginsforeachHarkIcontainment system,isacceptable, and(3)theHarkIOwner'sProgramActionPlanfortheLTPisreasonably designedtosatisfytheLTPobjectives.

Therefore, wefindthatoperation ofyourfacility, inconformance withtheconditions specified inNUREG-0408, willnotendangerlifeorpropertyorthecommondefenseandsecurity.

Intheabsenceofanysafetyproblemassociated withoperation ofyourfacilityuntiltheLTPiscompleted, thereappearstobenopublicinterestconsiderationfavoringrestriction oftheoperation ofyourfacility.

Accordingly, pursuantto10CFRPart50,Section50.12,you'rehereby.grantedanexemption fromGDC-50,withrespecttoLOCA-relatedhydrodynamic suppression poolloads,foraninterimperioduntilcompletion oftheLTP(approximately twoyears),providedthattheconditions specified inNUREG-0408 andanyresulting Technical Specification requirements aremaintained.

Tothisextent,thisexemp-tionencompasses anyrelatedrequirements of10CFRPart50,Section50.55(a),

andGDC-l.AsampleFEDERALREGISTERNoticerelatedtothisactionisalsoenclosedTheNoticethatisfiledwiththeOfficeoftheFederalRegisterforeachindividual plantwillbeprovidedatalaterdate.Asdiscussed inSectionIII.C.ofNUREG-0408, operating andsurveillance requirements ondrywe11/wetwell differe'ntial pressureandtoruswaterlevelswillbeincorporated, bylicenseamendment, intoyourfacilityTechnical Specifications inthenearfuture

Enclosures:

SeePage3VorStell,Jr.,rectorDivisionopenReactorsOfficeofNuclearReactorRegulation

Enclosures:

l.NUREG-0408, "NarkIContainment ShortTermProgramSafetyEvaluation Report"2.FederalReisterNotice

+C SAMPLEFEDERALREGISTERNOTICEUNITEDSTATESNUCLEARREGULATORY COMMISSION DOCKETNO.LICENSEENOTICEOFGRANTINGANEXEMPTION FROMTHEREUIREMENTS OFENERALDESIGNCRIER050CONTAINMENT DESIGNBASISOFAPPENDIATO1CFRPART5TheU.S.Nuclear.Regulatory Commission (TheCommission) hasgrantedanexemption fromtherequirements ofGeneralDesiqnCriterion 50,"Contain-mentDesignBasis",ofAppendixAto10CFRPart50to(Licensee)

(theLicensee).

Thisexemption relatestothedemonstrated safetymarginoftheMarkIcontainment systemfor(FacilitName)forrecentlyidentified hydrodynamic supppression poolloadsassociated withapostulated designbasislossofcoolantacci.dent andprovidesforoperation undertheconditions specified intheNRCstaff's"MarkICon-tainmentShortTermProgramSafetyEvaluation Report"andunderanyresulting Technical Specification requirements.

Tothisextent,thisexemption encompasses anyrelatedrequirements of10CFRPart50,Sec-tion50.55(a),

andGeneralDesignCriterion 1.Thisexemption iseffective asofthedateofitsissuance.

TheCommission hasevaluated thedemonstrated safetymarginofthecontainment systemfor(FacilitName)underpresent

conditions andhasconcluded thatsufficient marginexiststoprecludeunduerisktothehealthandsafetyofthepublic.Thisevalua-tionisdocumented inthestaff's"HarkIContainment ShortTermProgram.SafetyEvaluation Report,"NUREG-0408, Pecember1977.Thisexemption isgrantedforaninterimperiodofapproximately twoyearswhileamoredetailedreviewi'sconducted.

Attheconclusion ofthisre-view,thedesignsafetymarginofthecontainment systemfor(FacilitNamewillberestoredtothatwhichwasoriginally intendedatthetime(FacilitName)waslicensedforoperation.

Thebasisforthisexemption issetforthinthelettertothelicenseegrantingtheexemption, datedFebruary, 1978.TheCommission hasdetermined thatthegrantingofthisexemption willnotresultinanysignificant environmental impactandthatpursuantto10CFRSection51.5(d)(4) anenvironmental impactstatement ornegativedeclara-tionandenvironmental impactappraisal neednotbepreparedinconnection withthisaction.Forfurtherdetailswithrespecttothisaction,see(1)theCommission's lettertothelicenseedatedFebruary,1978,and(2)theCommission'

)~H,~"1IllII "MarkIContainment ShortTermProgramSafetyEvaluation Report,"NUREG-0408,December1977.Theseitemsareavailable forpublicinspection attheCommission's PublicDocumentRoom,1717HStreet,N.W.,Washington, D.C.andatthe(LPDR)Acopyofitem(1)maybeobtaineduponrequestaddressed totheU.S.NuclearRegulatory Commission, Washinq-ton,D.C.20555,,Attention:

Director, DivisionofOperating Reactors.

Acopyofitem(2)maybeobtaineduponrequestaddressed totheNationalTechnical Information Service,Sprinqfield, Virginia22161.DatedatBethesda, MarylandthisFORTHENUCLEARREGULATORY COMMISSION

,ChiefOperatinq ReactorsBranchDivisionofOperating Reactors Cl NiagaraMohawkPowerCorporation cc:EugeneB.Thomas,Jr.,EsquireLeBoeuf,Lamb,Leiby5MacRae1757NStreet,N.W.Washington, D.C.20036AnthonyZ.RoismanNaturalResources DefenseCouncil91715thStreet,N.W.Washington, D.C.20005OswegoCountyOfficeBuilding46E.BridgeStreetOswego,NewYork13126