ML110660079

March 3, 2011 Meeting Handouts - Revise Footnote in TS 3.8.1, Prairie Island Nuclear Generating Plant

ML110660079
Person / Time
Site:	Prairie Island
Issue date:	03/03/2011
From:	Xcel Energy
To:	Plant Licensing Branch III
Wengert, Thomas
References
TAC ME5426
Download: ML110660079 (29)

Text

NRC MeetingRevise Footnote in TS 3.8.1March 3, 2011 Xcel Energy ParticipantsJon Anderson Regulatory Affairs ManagerCorey Hessen General Manager -EngineeringThomas Roddey Prairie Island Site Engineering DirectorMarcia Thompson Project SponsorBob Flaaen Plant Engineering Interface Dale Vincent Licensing Engineer AgendaIntroductions-Jon AndersonMeeting purpose-Jon AndersonScope of LAR-Jon AndersonLAR Background-Dale VincentProposed TS and Bases changes -Dale VincentBattery Charger Modification -Marcia ThompsonBasis for Alternative Modification-Marcia ThompsonRequested Schedule Basis-Thomas RoddeyRAI discussion-Dale VincentSummary -Thomas Roddey Meeting GoalsDiscuss LAR to revise SR 3.8.1.10.c footnoteProvide technical basis for battery charger modificationSchedule basis Scope of LARRevise footnoteBattery charger modification under 10 CFR 50.59 LAR Background -112 Battery Charger manual actions identifiedD2 operability question Exigent LAR October 14, 2010SR 3.8.1.10.c footnote added LAR Background -2October 2010 LAR stated:NSPM is planning a modification to the 12 Battery Charger that will automatically shed the battery charger during an undervoltage event (e.g. LOOP, SI with LOOP or other undervoltage condition) and then repower the battery charger back on the bus within the 60 seconds required by the current TS.

LAR Background -3Current SR 3.8.1.10.c footnote:A modification will be installed during or prior to the Unit 1 2011 refueling outage to automatically shed the 12 Battery Charger from its normal bus and then automatically repower the charger from the bus within 60 seconds. Compliance with this SR will be demonstrated after implementation of the modification.

Proposed TS and Bases Changes -1Revise SR 3.8.1.10.c footnote to read:A modification will be installed during or prior to the Unit 1 2011 refueling outage to assure the 12 Battery Charger is automatically powered from its normal bus within 60 seconds. Compliance with this SR will be demonstrated after implementation of the modification.

Proposed TS and Bases Changes -2Revise SR 3.8.1.10 Bases:Note 3 is provided to allow D2 DG to be OPERABLE without requiring the 12 Battery Charger to be energized until completion of the Unit 1 2011 refueling outage.

Battery Charger Modification -1 Battery Charger Study options (October 2010):1.SI contact2.New chargers3.C&D Technologies, Inc. battery charger control modification4.Low voltage relay control modification5.Charger output based control modification Battery Charger Modification -2 Selected modifications 1 and 4Most viable Equipment external to chargersOpening/closing power supply breaker to charger based on charger input voltageAutomatic shedding and repowering of the chargers NSPM approved modification concept Early December 2010 Battery Charger Modification -3 PBNP Ametek SCI chargerNot susceptible to the C&D charger lockupIdentified late December 2010Could meet PINGP performance requirements Would not meet PINGP seismic and physical dimension requirements Battery Charger Modification -4 VEGP Ametek SCI chargerIdentified during reviews with AmetekMeets PINGP design and performance requirementsProcure on expedited schedule Battery Charger Modification -5 Internal control features of the Ametek SCI chargers Not susceptible to conditions which cause PINGP charger lockupInternal control relay Prevent back feeding control circuit board Relay senses incoming AC line voltageShut off charger -AC voltage below relay dropout setpointRestart charger -voltage returns above pickup setpointInstantaneous shutoff Time delay on reset -a few seconds Battery Charger Modification -6 PBNP prototype Ametek battery charger testingPINGP has known voltage variations outside nameplate ratingInformational testing January 2011Confirm engineering design review of the control circuit operationEquipped with internal control function Demonstrate charger capabilities, operation, shutdown, and automatic restart during anticipated voltage transients outside the nameplate rating of the chargers.

Battery Charger Modification -7 Factory Acceptance Testing (April 2011)Per Ametek quality assurance program Specified in NSPM purchase orderFormal documentation of charger capabilitiesshut off and reset setpointstime delaysother operating requirements Battery Charger Modification -8 Ametek SCI battery charger controls accommodate AC input voltage variations SR 3.8.1.10 footnote specifically statesmodification will be installed to automatically its busSR 3.8.1.10 footnote requires revision to allow installation of the Ametek SCI battery charger Battery Charger Modification -9 Schedule MilestonesIssue Ametek contract for Unit 1 chargers Unit 1 30% EC Design Review meetingUnit 1 90% EC Design Review meetingBattery charger shipped to PINGP Start Unit 1 2011 outageUnit 1 outage installation and post-modification testingUnit 1 integrated SI test Basis for Alternative Modification -1Battery charger considerations:Required logic internal to chargerModification performed in controlled shop environment Testing performed in advance of installation Basis for Alternative Modification -2Plant design considerations:Simpler design Spare breaker on Bus 16 preservedMaintenance sources at the 480V level preservedRelay setting or logic design coordination not required Basis for Alternative Modification -3Plant modification considerations:Simpler installationFocus Engineering and procurement resourcesReduces procurement riskAvoid: new power cable installationfire penetration work when routing new cablesadditions to the load sequencer cabinets Reduces outage work time and outage testing time Requested Schedule Basis -1Refueling outage scheduleRequest review and approval by May 6, 2011 Current footnote specifies resolution by end of Unit 1 2011 refueling outageTesting performed after modification Requested Schedule Basis -2Battery charger replacement decision January 2011 LAR submitted approximately one week after decision RAI discussion -11.Provide a comparison of the major electrical parameters including the minimum voltage requirement of the alternating current (AC) input breaker, drop out, reset for the existing and proposed new battery chargers. Discuss in detail the electrical parameters for the proposed new charger that are different than the existing 12 charger and how these parameters were determined to be acceptable. 2.Discuss whether the description of existing and new battery chargers will be provided in a future revision of the PINGP Updated Final Safety Analysis Report (UFSAR). 3.Confirm that the proposed new battery charger can recharge its associated battery to the fully charged state within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> while supplying its normal loads after a battery discharge to the bounding design basis event discharge state in accordance with PINGP UFSAR Section 8.5.3 and Technical Specification Surveillance Requirement 3.8.4.2.

RAI discussion -24.Industry operating experience has shown that momentary overvoltage or undervoltage transients experienced during switching, fault or lightning-related perturbations can trigger a self-protecting lockout feature in battery chargers resulting in disabling the chargers. Provide details on the magnitude and duration of transient and sustained overvoltage/undervoltage conditions resulting from grid perturbations (or the emergency diesel generator system) that have been evaluated for operation of the proposed battery charger. 5.Technical Specification SR 3.8.1.10 NOTE 3 states that the 12 Battery Charger is not required to be energized during performance of SR 3.8.1.10(c) until the completion of Unit 1 2011 refueling outage. The license amendment request proposes a footnote stating that the battery charger equipment will be modified during or prior to the Unit 1 2011 refueling outage. State why NOTE 3 was not modified to apply only until the new equipment has been installed and tested.

RAI discussion -3Proposed response scheduleTwo weeks from receipt of letter SummaryTS require 12 Battery Charger modification during Unit 1 2011 refueling outage Battery charger replacement modification assures battery charger function performed This LAR proposes to revise footnote to allow battery charger replacement modificationExpedited review and approval requested