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#REDIRECT [[NOC-AE-14003162, Third Six-Month Status Report in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order EA-12-049)]]
| number = ML14251A029
| issue date = 08/27/2014
| title = South Texas Project, Units 1 and 2 - Third Six-Month Status Report in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order EA-12-
| author name = Powell G T
| author affiliation = South Texas Project Nuclear Operating Co
| addressee name =
| addressee affiliation = NRC/Document Control Desk, NRC/NRR
| docket = 05000498, 05000499
| license number =
| contact person =
| case reference number = EA-12-049, NOC-AE-14003162, STI: 33906061, TAC MF0825, TAC MF0826
| document type = Letter
| page count = 10
| project = TAC:MF0826, TAC:MF0825
| stage = Other
}}
 
=Text=
{{#Wiki_filter:Nuclear Operating CompanySouth Tews Pro/ect Electric Generating Station P.O Batr 289 Wadsworth Tesas 77483 ,August 27, 2014NOC-AE-1400316210 CFR 2.202U. S. Nuclear Regulatory CommissionAttention: Document Control DeskWashington, DC 20555-0001South Texas ProjectUnits 1 & 2Docket Nos. STN 50-498, STN 50-499STPNOC Third Six-Month Status Report in Response to March 12, 2012 Commission OrderModifying Licenses with Regard to Requirements for Mitigation StrategiesFor Beyond-Desiq n-Basis External Events (Order EA-12-049)(TAC Nos. MF0825 and MF0826)
 
==References:==
: 1. NRC Order Number EA-1 2-049, "Issuance of Order to Modify Licenses withRegard to Requirements for Mitigation Strategies for Beyond-Design-BasisExternal Events", March 12, 2012 (ML12073A195)2. Letter from D.W. Rencurrel, STPNOC, to NRC Document Control Desk, "InitialStatus Report in Response to March 12, 2012 Commission Order ModifyingLicenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order Number EA-12-049)", October 24, 2012(ML12310A389) (NOC-AE-13002909)3. NRC Interim Staff Guidance JLD-ISG-2012-01, "Compliance with OrderEA-12-049, Order Modifying Licenses with Regard to Requirements forMitigation Strategies for Beyond-Design-Basis External Events," August 29,2012 (ML12233A042)4. Letter from D.L. Koehl, STPNOC, to NRC Document Control Desk, "STPNOCOverall Integrated Plan in Response to March 12, 2012 Commission OrderModifying Licenses with Regard to Requirements for Mitigation Strategies forBeyond-Design-Basis External Events (Order Number EA-12-049)", February28, 2013 (ML1307OA011) (NOC-AE-13002963)5. Letter from G.T. Powell, STPNOC, to NRC Document Control Desk, "STPNOCFirst Six-Month Status Report in Response to March 12, 2012 CommissionOrder Modifying Licenses with Regard to Requirements for MitigatingStrategies for Beyond-Design-Basis External Events (Order Number EA-12-049)", August 26, 2013 (ML13249A060) (NOC-AE-1 3003027)6. Letter from G.T. Powell, STPNOC, to NRC Document Control Desk, "STPNOCSecond Six-Month Status Report in Response to March 12, 2012 CommissionOrder Modifying Licenses with Regard to Requirements for MitigatingStrategies for Beyond-Design-Basis External Events (Order Number EA-12-049)", February 27, 2014 (ML14073A458) (NOC-AE-14003089)STI: 33906061 NOC-AE-14003162Page 2 of 3On March 12, 2012, the Nuclear Regulatory Commission (NRC) issued Order EA-12-049(Reference 1) to South Texas Project Nuclear Operating Company (STPNOC) to develop,implement, and maintain guidance and strategies to maintain or restore core cooling,containment, and spent fuel pool cooling capabilities in the event of a beyond-design-basisexternal event. The purpose of this letter is to provide the third six-month status report pursuantto Section IV, Condition C.2, of EA-12-049 delineating progress made in implementing therequirements of EA-12-049. The Attachment included with this letter provides updates ofmilestone accomplishments since the last status report including any changes to the compliancemethod, schedule, or need for relief and the associated basis.Per the requirements of Reference 1, STPNOC submitted an initial status report (Reference 2)60-days following issuance of the final Interim Staff Guidance (Reference 3) and an OverallIntegrated Plan pursuant to Section IV, Condition C of the Order (Reference 4). STPNOCsubmitted the first six-month status report on August 26, 2013 (Reference 5) and the secondsix-month status report on February 27, 2014 (Reference 6).Changes made since the issuance of the second status report are summarized below anddescribed in further detail in the
 
==Attachment:==
* The alternate Reactor Coolant System (RCS) Inventory (Modes 1-4) pump will be ratedat 70 gpm instead of the original 40 gpm.* The alternate RCS Inventory/Core Cooling strategy for shutdown modes is beingreevaluated. The Boric Acid pump will not work for this strategy as previously thought.* The alternate Core Cooling Steam Generator (SG) Makeup pump will be pre-staged inthe same building as the FLEX pump for the primary strategy in a separate bay/ train.This second pump will provide the same flow and pressure as the first.* Three Open Items have been updated. One Open Item has been closed.Direction regarding the content of the status reports is provided in NEI 12-06.This letter contains no new regulatory commitments.If there are any questions regarding this letter, please contact Wendy Brost at (361) 972-8516 orme at (361) 972-7566.I declare under penalty of perjury that the foregoing is true and correct.Executed on: AU-,tAA al) 9,O4G. T. PowellSite Vice Presidentweb
 
==Attachment:==
South Texas Project Nuclear Operating Company (STPNOC) Third Six-MonthStatus Report for the Implementation of Order EA-12-049, Order ModifyingLicenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events NOC-AE-14003162Page 3 of 3cc:(paper copy)(electronic copy)Regional Administrator, Region IVU. S. Nuclear Regulatory Commission1600 East Lamar BoulevardArlington, TX 76011-4511Balwant K. SingalSenior Project ManagerU.S. Nuclear Regulatory CommissionOne White Flint North (MS 8 B1)11555 Rockville PikeRockville, MD 20852NRC Resident InspectorU. S. Nuclear Regulatory CommissionP. 0. Box 289, Mail Code: MN1 16Wadsworth, TX 77483Eric LeedsDirector, Office of Nuclear Reactor RegulationU.S. Nuclear Regulatory CommissionOne White Flint North (MS 13 H 16M)11555 Rockville PikeRockville, MD 20852Steve Frantz, EsquireMorgan, Lewis & Bockius LLPBalwant K. SingalU. S. Nuclear Regulatory CommissionJohn RaganChris O'HaraJim von SuskilNRG South Texas LPKevin PolioCris EugsterL.D. BlaylockCPS EnergyPeter NemethCrain Caton & James, P.C.C. MeleJohn WesterCity of AustinRichard A. RatliffRobert FreeTexas Department of State Health Services AttachmentNOC-AE-14003162Page 1 of 7STP Nuclear Operating Company (STPNOC) Third Six-Month Status Report for theImplementation of Order EA-12-049, Order Modifying Licenses with Regard toRequirements for Mitigation Strategies for Beyond-Design-Basis External Events1. IntroductionSTPNOC developed an Overall Integrated Plan (OIP) (Reference 1) documenting the diverseand flexible strategies (FLEX), in response to Order EA 12-049 (Reference 2). This Attachmentprovides the third update of milestone accomplishments since submittal of the OIP, includingany changes to the compliance method, schedule, or need for relief or relaxation and theassociated basis. Several changes have been made to the OIP and the following is a briefoverview of STP's current strategies to meet the requirements of the Order. Note that all flowrates and pressures listed are approximate values.The overall strategic plan is as follows:If the Extended Loss of AC Power (ELAP) occurs while the Steam Generators (SGs) are beingutilized as the heat sink, the Turbine Driven Auxiliary Feedwater (TDAFW) pump will startautomatically and feed one SG. Operators will then manually line up feedwater to all SGs.Operators will cooldown and depressurize the plant to a predetermined SG pressure, ensuringthat the cooldown will not result in a return to criticality event nor allow nitrogen into the ReactorCoolant System (RCS) from the Safety Injection (SI) accumulators. Cooldown anddepressurization should start during the first hour following the initial event.Once the cooldown begins, site personnel will begin to focus on starting the FLEX dieselgenerators and mechanically and electrically aligning the FLEX equipment to be placed inservice. After approximately eight hours, one of the FLEX diesel generators will be providingpower to an RCS makeup pump permitting boric acid to be added to the RCS to maintainshutdown margin. During this time two battery chargers will be powered to begin recharging twoof the Class 1 E batteries.The RCS will be further depressurized and cooled once Operators isolate or vent the SIaccumulators. This subsequent cooldown and depressurization will seat the pressure reliefvalve (PRV) on the Reactor Coolant Pump (RCP) seal return line that should have opened dueto the increased RCP seal leakage early in the event. At about 15 hours into the event, thePRV should be re-seated. Pressurizer level will be restored and makeup to the RCS will nolonger be necessary at approximately 22 hours following event start.The revised sequence of events timelines are based conservatively on starting the FLEX dieselgenerator and associated pumps and equipment eight hours following event initiation.* FLEX POWER -Two 480V AC, 1000 kW diesel generators (N and +1) will be staged onthe Mechanical Auxiliary Building (MAB) roof of each unit in an enclosure that protectsthem from external hazards.* REACTOR COOLANT SYSTEM (RCS) INVENTORY (Modes 1-4)- The primarystrategy for filling the RCS will use a 35 gpm Chemical and Volume Control System(CVCS) Positive Displacement pump (PDP) @ 3100 psig taking suction on either the AttachmentNOC-AE-14003162Page 2 of 7Boric Acid Tanks (BATs) or the Refueling Water Storage Tank (RWST) and discharginginto the CVCS charging line. The alternate means of filling the RCS (or +1) is a pre-staged 70 gpm FLEX RCS Makeup pump @ 700 psi installed in one of the SI pumpbays located in the Fuel Handling Building (FHB). Suction is from the RWST,discharging into the SI line downstream of High Head SI discharge motor-operated valve(MOV). The pump size has changed from 1600 psig discharge pressure to 700 psig toreduce the physical size of the pump. STP has the ability to vent the reactor head thusallowing the use of this smaller head pump.* CORE COOLING (Modes 1-4) -Initial core cooling is accomplished using the TDAFWpump. In the event the TDAFW pump is lost, the primary strategy for cooling the core isa new 300 gpm @ 500 psig pre-staged motor-driven FLEX SG Makeup pump located inthe Isolation Valve Cubicle (IVC) that will take suction from the Auxiliary FeedwaterStorage Tank (AFWST) and discharge into the cross-connect header that feeds all fourSGs. The +1 for this function is provided by an additional FLEX pump staged in adifferent IVC bay/train than the N pump. Both pumps are sized the same and take theirsuction from the same AFWST and discharge into the same Auxiliary Feedwater (AFW)header at different locations.CORE COOLING/RCS INVENTORY (Modes 5 and 6 without SGs when naturalcirculation is not available) -The primary strategy uses a 170 gpm @ 100 psi FLEXpump that will be located in the FHB SI pump bays. It will use the identical suction anddischarge path as the Modes 1-4 RCS Inventory (Makeup) FLEX pump. The alternatemeans of filling the RCS is still being evaluated.SPENT FUEL POOL (SFP) MAKEUP AND SPRAY -There are 3 different makeupmeans required in the guidance:o The normal makeup mode will be using a Reactor Makeup Water (RMW) pumpthrough valve FC-0048 to fill the SFP.o The hose to the pool method will be a 250 gpm @ 150 psi pre-staged FLEX SFPMakeup pump in the FHB. Hose fittings will be installed on the end of the pipeand temporary hoses will be staged in the area. Hoses will be routed from thislocation to the SFP. This FLEX pump suction is from the RWST.o The spray method uses this same above mentioned pump but hoses are routedto the monitors on the south end of the SFP deck.WATER SUPPLIESo RCS Inventory -RWST and Boric Acid Storage tanks will be the primary tanksused to makeup to the RCS. The tanks will not deplete because of the newstrategy of depressurizing the RCS to the point that the loss of coolant via theRCP seal return pressurized safety valve (PSV) will stop. Thus, not more than70,000 gallons should be needed to refill the RCS following seating the PSV.O Core Cooling (Modes 1-4) -For external events other than the Design Basis(DB) flood from a Reservoir embankment breach, the AFWST will be re-filledusing a diesel driven pump from the Regional Response Center (RRC) or usingone of STP's trailer mounted diesel driven pumps. The suction source can beany one of a number of tanks, basins or the Ultimate Heat Sink, whichever isavailable. For the DB flood from a Reservoir embankment breach, water level AttachmentNOC-AE-14003162Page 3 of 7around the AFWST at about 30 hours (fill start time) into the event will still beapproximately five feet deep. A modification to the Feedwater
 
==Dearator willallow its water to be moved via hose and gravity to the AFWST via drain lines inthe AFW system. This will provide enough water for continued AFW systemrunning until the flood waters subside.o Core Cooling (shutdown) -RWST will be the primary tank used to makeup to theRCS. Following depletion of this tank STP can fill the RWST from other on sitetanks,==
basins or main reservoirs using th12516e trailer mounted diesel drivenpump.o SFP makeup and spray -* For normal makeup, the source is the RMW Storage Tank.* For makeup with hoses, the source is the RWST.* For makeup with spray, the source is the RWST with outside basins andtanks as backup.* STP can fill the RWST with non-borated water as discussed above.The following chart has been developed to aidthe strategies:in understanding the pumps and protection forFUNCTIONRCS RCS Inventory/Inventory Core Cooling Core Cooling (SG Makeup) SFP MakeupInventory) (Shutdown(Modes 1-4) Modes)Installed TDAFW pumpPrimary Installed Pre-staged FLEX (phase 1) and pre-staged Installed ReactorPraty CVCS PDP RCS Makeup @ FLEX SG Makeup motor Makeup Water pumpstrategy @ 35 gpm 170 gpm driven pump @ 300 gpm @ 300 gpm(phase 2)Pre-staged Second pre-staged FLEX Pre-staged FLEXAlternate FLEX RCS Currently being SG Makeup motor driven SFP makeup pumpstrategy Makeup @ evaluated70 gpm pump @ 300 gpm (phase 2) @ 250 gpmProtection N pump insidein Yesfboth safety related Yes, both inside safety Yes, both insideaccorda inside safety building, alternate related buildings. safety relatedwith NEI related strategy being buildings.12-06w buildings, evaluated. L I _INote: Two trailer mounted pumps will be stored in structures that meet NEI 12-06 protectionguidelines with the exception of a tornado missile. The buildings will be separated sufficiently toprovide reasonable assurance that a tornado missile should not destroy both pumps.Deployment following a design basis flood from the MCR embankment breach cannot takeplace until about 53 hours following event. These pumps will be used to move water asnecessary throughout the plant (e.g. tank to tank or basin to tank).
AttachmentNOC-AE-1 4003162Page 4 of 72. Milestone AccomplishmentsSTP has no milestone accomplishments to discuss at this time.3. Milestone Schedule StatusThe following provides an update to Attachment 2 of the OIP including the updated activitystatus of each item and whether the expected completion date has changed. The dates listedare planning dates which are subject to change as design and implementation details aredeveloped.The revised milestone target completion dates do not impact the order implementation date.Milestone Target Activity Status Revised TargetCompletion Date Completion DateSubmit 60 Day Status Report Oct 2012 Complete NoneSubmit Overall Integrated Plan Feb 2013 Complete NoneSubmit 6 Month Updates:Update 1 Aug 2013 Complete NoneUpdate 2 Feb 2014 Complete NoneUpdate 3 Aug 2014 Complete NoneUpdate 4 Feb 2015 Not StartedUpdate 5 Aug 2015 Not StartedUpdate 6 Feb 2016 Not StartedUpdate 7 Aug 2016 Not Started -FLEX Strategy Evaluation Sept 2013 Started Nov 2014Walk-throughs or Demonstrations Dec 2014 Not started April 2015Perform Staffing Analysis Dec 2013 Started Dec 2014Modifications:Modifications Evaluation Sept 2013 Started Sept 2014Unit 1 Design Engineering Jan 2014 Started Dec 2014Unit 1 Implementation Outage Oct 2015 Not started -Unit 2 Design Engineering Jan 2014 Started Oct 2014Unit 2 Implementation Outage Apr 2015 Not started AttachmentNOC-AE-14003162Page 5 of 7Milestone Target Activity Status Revised TargetCompletion Date Completion DateStorage:Storage Design Engineering Sept 2013 Complete May 2014Storage Implementation Apr 2015 StartedFLEX Equipment:Procure On-Site Equipment Jan 2014 Started June 2015Develop Strategies with RRC Oct 2013 Started Oct 2014Procedures:PWROG1 issues NSSS2-specific Apr 2015 Complete August 2013guidelinesCreate Site-Specific FSGs3  Apr 2015 StartedCreate Maintenance Procedures May 2014 Not Started Oct 2015Training:Develop Training Plan May 2014 Started Jan 2015Training Complete Sept 2014 Started April 2015Unit 1 FLEX Implementation Oct 2015 StartedUnit 2 FLEX Implementation Apr 2015 StartedSubmit Completion Report Started Oct 20151 PWROG -Pressurized Water Reactor Owner's Group2 NSSS -Nuclear Steam Supply System3 FSG -Functional Safety Guidelines AttachmentNOC-AE-1 4003162Page 6 of 74. Changes to Compliance MethodSpecific changes to the second six-month status update (Reference 4):1. The strategy for the +1 Core Cooling pump (SG Makeup) has been changed. STP willpurchase and install a pump identical to the N pump for this function. This second SGMakeup pump will be installed in a different IVC bay/train than the N pump in the sameprotected safety related building.2. The RCS Makeup pump will provide a higher flow rate than originally planned -It willprovide 70 gpm @ 700 psig.3. The Core Cooling +1 strategy for shutdown modes is being reevaluated.5. Need for Relief/Relaxation and Basis for the Relief/RelaxationThe NRC identified two open items (3.1.2.2.A and 3.2.4.8.B) in the Interim Staff Evaluation thatrequire justification for their approach to meeting the order. 3.1.2.2.A is discussed below inSection 6 and 3.2.4.8.B was discussed in the prior six-month update (Reference 4).6. Open Items from Overall Integrated Plan and Draft Safety EvaluationBelow are the open items from the Technical Evaluation Report (Reference 3):01 # 3.1.2.2.A -The licensee does not provide for transportation/deployment of the dieseldriven trailer mounted pump relied upon as a spare SG makeup pump in theevent of a design basis flood.The strategy for the +1 Core Cooling (SG Makeup) pump has beenchanged. STP plans to purchase and install a pump identical to the Npump to perform this function. This second SG Makeup pump will beinstalled in a different bay/train than the N pump in the same protectedsafety related building.With this change in strategy, STPNOC considers this deployment issueclosed.01 # 3.2.1.1 .A -Demonstrate the applicability of the RETRAN-3D code for analysis of the ELAPtransient.STP provided a white paper to the NRC on June 12, 2014 regarding this01. An updated white paper will be provided following the incorporation ofcomments received from the NRC staff.01 # 3.2.1.1..B -Provide analysis of the ELAP transient that is applicable to STP and whichdemonstrates the adequacy of the mitigating strategy proposed for STP. Thisincludes specification of an acceptable definition for the transition to refluxcondensation cooling to ensure that the analysis is not credited beyond thisjuncture. A sufficient number of cases should be included in the analysis to AttachmentNOC-AE-14003162Page 7 of 7demonstrate the acceptability of different strategies that may be necessary tomitigate an ELAP (e.g., as discussed in Section 3.2.1.6, in some cases "N" and"N+1" pumps have different capabilities, which may substantially affect thesequence of events in the integrated plan).STP has preliminary results using the RETRAN-3D code. Results will beprovided to the NRC once all comments from the white paper submittedfor 01 # 3.2.1.1.A have been incorporated.01 # 3.2.1.6.A -Develop the final timeline(s) and sequence(s) of events for STP.No update7. Potential Draft Safety Evaluation ImpactsThere are no potential impacts to the Draft Safety Evaluation identified at this time.8. ReferencesThe following references support the updates to the Overall Integrated Plan described in thisattachment.1. Letter from D.L. Koehl, STPNOC, to NRC Document Control Desk, "STPNOC OverallIntegrated Plan in Response to March 12, 2012 Commission Order Modifying Licenseswith Regard to Requirements for Mitigation Strategies for Beyond-Design-BasisExternal Events (Order Number EA-1 2-049)", February 28, 2013 (ML1 3070A01 1)(NOC-AE-1 3002963)2. NRC Order Number EA-12-049, "Order Modifying Licenses with Regard toRequirements for Mitigation Strategies for Beyond-Design-Basis External Events,"dated March 12, 2012 (ML12054A735) (AE-NOC-12002268)3. Letter from J.S. Bowen, NRC, to D.L. Koehl, STPNOC, "South Texas Project, Units 1and 2 -Iterim Staff Evaluation Relating to Overall Integrated Plan in Response toOrder EA-12-049 (Mitigation Strategies)", January 29, 2014 (ML13339A736) (AE-NOC-14002494)4. Letter from G.T. Powell, STPNOC, to NRC Document Control Desk, "STPNOCSecond Six-Month Status Report in Response to March 12, 2012 Commission OrderModifying Licenses with Regard to Requirements for Mitigating Strategies for Beyond-Design-Basis External Events (Order Number EA-12-049)", February 27, 2014(ML14073A458) (NOC-AE-14003089)
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