ML15132A064

Presentation for Pre-Submittal Call on 5-13-15

ML15132A064
Person / Time
Site:	Mcguire, McGuire
Issue date:	05/11/2015
From:	Ed Miller Plant Licensing Branch II
To:	Casto G, Robert Elliott, Matthew Hamm, Caroline Tilton, Larry Wheeler, John Zeiler Office of Nuclear Reactor Regulation
References
Download: ML15132A064 (27)

Text

1 NRR-PMDAPEm Resource From: Miller, Ed Sent: Monday, May 11, 2015 12:25 PM To: Wheeler, Larry; Tilton, Caroline; Elliott, Rober t; Casto, Greg; Hamm, Matthew; Zeiler, John

Subject:

McGuire Presentation for Pre-Submittal Call on 5-13-15 Attachments:

5-11-15 A RN SNSWP Supply LAR presentation Final .pptx All, Here is the presentation information that the licensee intends to use at the meeting on Wednesday.

Ed x-2481 Hearing Identifier: NRR_PMDA Email Number: 2056 Mail Envelope Properties (9C2386A0C0BC584684916F7A0482B6CA018F6CB56484)

Subject:

McGuire Presentation for Pre-Submittal Call on 5-13-15 Sent Date: 5/11/2015 12:24:30 PM Received Date: 5/11/2015 12:24:00 PM From: Miller, Ed Created By: Ed.Miller@nrc.gov Recipients: "Wheeler, Larry" <Larry.Wheeler@nrc.gov>

Tracking Status:: Response: None : 4/28/2015 10:44:00 AM "Tilton, Caroline" <Caroline.Tilton@nrc.gov>

Tracking Status:: Response: None : 4/28/2015 10:41:00 AM "Elliott, Robert" <Robert.Elliott@nrc.gov> Tracking Status:: Response: None : 10/22/1602 5:18:00 PM "Casto, Greg" <Greg.Casto@nrc.gov> Tracking Status:: Response: None : 4/28/2015 11:41:00 AM "Hamm, Matthew" <Matthew.Hamm@nrc.gov>

Tracking Status:: Response: None : 4/28/2015 10:37:00 AM "Zeiler, John" <John.Zeiler@nrc.gov> Tracking Status: None

Post Office: HQCLSTR02.nrc.gov Files Size Date & Time MESSAGE 132 5/11/2015 12:24:00 PM 5-11-15 A RN SNSWP Supply LAR presentation Final .pptx 3472931 Options Priority: Standard Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date: Recipients Received:

McGuire Nuclear Station 'A' NSWS Supply LAR LAR BackgroundThe proposed LAR would revise the McGuire TS 3.7.7, "Nuclear Service Water System (NSWS)," and other supported TSs to allow time to correct a degraded condition in the common Unit 1 and 2 'A' Train supply piping from the Standby Nuclear Service Water Pond (SNSWP)(SNSWP). The proposed change would introduce the following note into each affected TS:'A' Train to be inoperable for a total of 14 days from [The date of NRC Safety Evaluation issuance] until December 31, 2016 to allow for the correction of a degraded condition on the 'A' Train supply piping from the Standby Nuclear Service Water Pond (SNSWP). The 14 da y s ma y be taken consecutivel y or in parts durin g this period of time. Durin g the p eriod in ()yyypgpgpwhich the 'A' Train NSWS suppl y piping from the SNSWP is not available, the 'A' Train NSWS will remain aligned to Lake Norman. Any maintenance that is performed on the remaining portions of A' NSWS train during the period in which the 'A' NSWS from the SNSWP supply piping is not available will be limited to a 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> completion time. The latter will not count against the 14 day completion time.

2 LAR BackgroundOther affected TSs are:3.5.2, Emergency Core Cooling System (ECCS) -Operating3.6.6, Containment Spray System (CSS)3.7.5, Auxiliary Feedwater (AFW) System3.7.6, Component Cooling Water (CCW) System3.7.9, Control Room Area Ventilation System (CRAVS)3.7.11, Auxiliary Building Filtered Ventilation Exhaust System (ABFVES)3.8.1, AC Sources -OperatingProposed LAR is deterministic with risk insights 3

LAR BackgroundThe NSWS is designed for operation during and after seismic conditions and supplies cooling water to thefollowing coolers:

CtCliPMtC omponen t C oo li n g P ump M o t orsCentrifugal Charging Pump MotorsSafety Injection Pump MotorsResidual Heat Removal Pum p Motors pContainment Spray Pump MotorsNuclear Service Water Pump MotorsAuxiliary Feedwater Pump MotorsFlPlCliPMtF ue l P oo l C oo li n g P ump M o t ors 4 LAR BackgroundThe NSWS also supplies cooling water to the following heat exchangers:Containment Spray Heat ExchangersDiesel Generator Heat Exchan g ersComponent Cooling Heat ExchangersCentrifugal Charging Pump Bearing Oil CoolersCentrifugalChargingPumpGearOilCoolers Centrifugal Charging Pump Gear Oil CoolersAssured Auxiliary Feedwater SuppliesAssured Diesel Generator Cooling SuppliesAssured Fuel Pool Makeup SuppliesAssured Component Coolin g SuppliesSafety Injection Pump Bearing Oil CoolersControl Room Area Chilled Water System Chiller Condensers 5

LAR Background Degraded conditionThe pressure drop for the 'A' train SNSWP supply piping pressure drop is significantly higherthanforthe

'B'trainSNSWPsupplypipingpressuredrop higher than for the B train SNSWP supply piping pressure dropThe piping configurations are similarHistorical records indicate that this difference has existed as early as initial plant startupThe'A'SNSWPsupplypipinghasbeenflushednumeroustimesThe A SNSWP supply piping has been flushed numerous timesMaximum anticipated flows have been usedFlushes have demonstrated the degraded condition is stable 6

LAR Background Degraded condition (cont'd)Most of the 'A' SNSWP supply piping has been inspectedOlthltfhddftfiihtbitdbbidiO n ly th e l as t f ew h un d re d f ee t o f p i p i n g h ave no t b een i nspec t e d by su b mar ines or di versThe remaining uninspected portion is largely below the Unit 1 diesel buildingA 35 ft. deep manway and wet tap was recently completed for access to inspect the remaining pipe pipePiping will be inspected using a submarine and divers will also be used if necessaryThe inspections can be performed within the existing 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> completion timeCorrectionofthedegradedconditionwillrequiremorethanthe72hourcompletiontime Correction of the degraded condition will require more than the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> completion time. 7 Correction of the Degraded ConditionWork ScopeDrain and vent supply pipingIsolate su pp l y p i p in g inside A uxiliar y Bld g.ppyppg ygFill supply piping with air and push water back into SNSWPIsolate SNSWP from supply piping by having divers install blind flange at 40 ft. deep intakeVent p i p in g to atmos p hereppgpInstall new penetration to supply piping inside Auxiliary BuildingInstall ventilation and climbing equipment, enter piping and correct degraded conditionFillandventsupplypipingFill and vent supply pipingRemove blind flange at intakeUn-isolate supply piping from system and perform flush testEtitdtitltiitl14dithtiiilddE s ti ma t e d ti me t o comp l e t e i s approx i ma t e ly 14 d a y s w ith con ti n g enc i es i nc l u d e d 8 Correction of the Degraded Condition

• Safe personnel ingress and egress andventilationwillbeprovidedby:

and ventilation will be provided by:*Recently completed manway outside Auxiliary Bldg.

• Newsupplypipepenetration

• N ew supply pipe penetration inside the Auxiliary Bldg.

• Existing station processes will be used tocontrol:

to control:*Auxiliary Building Ventilation Boundary*Unauthorizedaccess 9*U nauthorized access Manway in yard SNSWP'A'TRNfromSNSWP'B' TRN from SNSWP A TRN from SNSWP NSWS PumpsNew opening for access on 'A' TrainNSWS Pump Strainers'A' Train from Lake Norman 10'B' Train from Lake Norman Correction of the Degraded Condition In the event of an adverse weather event (tornado, probable maximum precipitation, the manway will be rapidly covered to prevent:

• Entry of rainwater into the auxiliary buildingAditftd*A n y a d verse i mpac t o f t orna do vacuum or missiles 11 LAR Technical EvaluationTechnical EvaluationNSWS is designed such that after an ESFAS actuation:'A' NSWS aligns to Lake Norman'B' NSWS aligns to SNSWPNSWS is manuall y ali gned to SNSWP in the event Lake Norman is in j eo p ard y due to ygjpy an:EarthquakeTornadoandturbinemissilesTornado and turbine missiles*The Lake Norman dam is designed to sustain an Operating Basis Earthquake (OBE) 12 LAR Technical EvaluationTechnical EvaluationDam fragility studies indicate that the seismic capability is much greater than OBE.The probability of an OBE is no greater than 5E-4 even based on the new GMRS curvesIn the unlikely event of an OBE and unavailability of the 'A' SNSWP supply for the 14 day period proposed:The 'A' train would be shutdown and preserved by abnormal operating proceduresThe 'B' train would be aligned to the SNSWPTheLakeNormandamisdesignedtosustainanOperatingBasisEarthquake(OBE

)The Lake Norman dam is designed to sustain an Operating Basis Earthquake (OBE)Probability of turbine or tornado missile damage to exposed piping is negligible 13 LAR Defense-in-Depth Defense-in-depth

• 'B' NSWS will be pre-aligned to SNSWP

• Eliminates valve swap failure modes

• Supports other defense-in-depth measure

• Procedures will be put in place to align the 'B' train SNSWP supply to the 'A' train in the unlikel y event that the 'B' train fails subsequent to dama g e to the Lake Norman dam after an earthquake

• Dedicated personnel will be provided to close the manway outside the 'A' NSWS lAiliBldithlikltfidtd supp ly A ux ili ar y Bldg. manwa y i n th e un lik e ly even t o f an acc id en t or a d verse weather (tornado or maximum precipitation event)

• The FLEX strategy will be implemented on both units prior to the evolution 14 LAR Defense-in-DepthNSWS pump suction cross connect 15 Manway in yard SNSWP'A'TRNfromSNSWP'B' TRN from SNSWP A TRN from SNSWP NSWS PumpsNSWS pump suction cross connectNew opening for access on 'A' TrainNSWS Pump Strainers'A' Train from Lake Norman 16'B' Train from Lake Norman LAR Defense-in-Depth Defense-in-depth Principles

• Over-reliance on programmatic activities for weaknesses in plant design

• ProceduralizedactionsareusedcrossconnecttheNSWSpumpsuctions

• Proceduralized actions are used cross connect the NSWS pump suctions *Existing security and radiation control directives are used to control the path from the Auxiliary Bldg. to the environment

• Systemredundancyindependenceanddiversityaremaintained System redundancy , independence and diversity are maintained

• The method to cross connect the NSWS pump suctions ensures the failed train is configured so as not to adversely impact the operating train 17 LAR Defense-in-Depth Defense-in-depth Principles

• Independence of barriers is not degraded

• Threeprinciplefissionproductbarriersarenotimpacted

• Three principle fission product barriers are not impacted*Existing radiation control directives are used to control the path from the Auxiliary Bldg. to the environment

• Intentofplantdesigncriteriaismaintained

• Intent of plant design criteria is maintained

• GDC-2, Design Basis Protection Against Natural Phenomena-Manway to be covered in the event of adverse weather

• GDC-5SharingofStructuresSystemsandComponents

-Defense-in-depth GDC 5 , Sharing of Structures , Systems and Components Defense in depth method to cross connect NSWS suction piping will continue to ensure only two units/trains are supplied from the same suction source.

18 LAR Defense-in-DepthDefense-in-depth Principles (Cont'd)

• Intent of plant design criteria is maintained

• GDC-20, Protection System Independence-The Defense-in-depth method to cross connect NSWS suction pipin g will ensure the failed 'B' train is placed in a configuration that does not adversely impact the 'A' train placed in service.

• GDC-29, Protection Against Anticipated Operational Occurrences-The dhdtdlitthitiESFASttif propose d c h an g e d oes no t a d verse ly i mpac t th e ex i s ti n g ESFAS ac t ua ti on o f the 'A' or 'B' NSWS trains.

19 LAR Compensatory Measures Compensatory Measures and CommitmentsDefense-in-depth measures in placePfkdiidhtdttdP er f orm wor k d ur i n g per i o d s w h en t orna does are no t expec t e dMonitor National Weather Service and Grid StabilityPerform onsite surveillances in the event of a tornado warningEliminate any discretionary maintenance on NSWSTrain personnel using Systematic Assessment ApproachReviewapplicableemergencyprocedurespriortoevolution Review applicable emergency procedures prior to evolutionUse Infrequently Performed Test or Evolution Process (IPTE) Man the Outage Control Center 20 LAR-Significant Hazards Consideration Significant Hazards ConsiderationDoes proposal involve significant increase in probability or consequences of accident?Normal and ESFAS ali gnment is unaffected gExisting directives will be used to control potential radioactive release path from Auxiliary Bldg. to environmentIncremental risk related to seismic or tornado events that require re-alignment of 'A' NSWS to the SNSWPiliiblfth14dtid SNSWP i s ne gligibl e f or th e 14 d a y ex t ens ion propose dDoes proposal create the possibility of a new or different accident ?The proposal only involves an extension of the time the 'A' NSWS supply from the SNSWP is out of service serviceNo new or different accidents from those already analyzed can be postulated as a result of the defense-in-depth or compensatory actions employed 21 LAR-Significant Hazards Consideration Significant Hazards Consideration (cont'd)Does proposal involve a significant reduction in margin to safety? The p ro posal onl y involves an extension of the time the 'A' NSWS su pp l y from the SNSWP is out of ppyppy serviceThe defense-in-depth or compensatory actions employed do not cause a design basis or safety limit (i.e., the controlling numerical value for a parameter established in the UFSAR or the license) to be exceeded or altered exceeded or altered Compliance with RegulationsRegGuide127Rev1NoimpactReg. Guide 1.27 Rev. 1 -No impact 22 Preliminary InformationThe information discussed in this presentation is preliminary in natureandhasnotyetbeenfullyvalidatedorvettedthrough nature and has not yet been fully validated or vetted through the Duke Energy License Amendment Request review process which includes review and approval by the McGuire site Plant OperatingandReviewCommittee(PORC)

Operating and Review Committee (PORC).23 Questions Questions?

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