ML14073A458

South Texas Project, Units 1 & 2, Second 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 Number E

ML14073A458
Person / Time
Site:	South Texas
Issue date:	02/27/2014
From:	Powell G T South Texas
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
EA-12-049, NOC-AE-14003089
Download: ML14073A458 (26)

Text

Nuclear Operating CompanySouth Teas Project Electric Generat/ne Station PO. Box 289 Wadsworth.

Texas 77483 _AAAA-February 27, 2014NOC-AE-14003089 10 CFR 2.202U. S. Nuclear Regulatory Commission Attention:

Document Control DeskWashington, DC 20555-0001 South Texas ProjectUnits 1 & 2Docket Nos. STN 50-498, STN 50-499STPNOC Second Six-Month Status Report in Response to March 12, 2012 Commission OrderModifying Licenses with Regard to Requirements for Mitigation Strategies For Beyond-Design-Basis External Events (Order Number EA-12-049)

References:

1. NRC Order Number EA-1 2-049, "Issuance of Order to Modify Licenses withRegard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events",

March 12, 2012 (ML12073A1 95)2. Letter from D.W. Rencurrel, STPNOC, to NRC Document Control Desk, "InitialStatus 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 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 Commission Order Modifying Licenses with Regard to Requirements for Mitigating Strategies for Beyond-Design-Basis External Events (Order Number EA-12-049)", August 26, 2013 (ML13249A060)

(NOC-AE-1 3003027)6. Nuclear Energy Institute (NEI) Guidance 12-06, "Diverse and Flexible CopingStrategies (FLEX) Implementation Guide," Revision 0, August 21, 2012(ML12242A378)

STI 33829922 NOC-AE-14003089 Page 2 of 3On March 12, 2012, the Nuclear Regulatory Commission (NRC) issued Order EA-12-049 (Reference

1) to STP Nuclear Operating Company (STPNOC) to develop, implement, andmaintain guidance and strategies to maintain or restore core cooling, containment, and spentfuel pool cooling capabilities in the event of a beyond-design-basis external event. The purposeof this letter is to provide the second six-month status report pursuant to Section IV, Condition C.2, of EA-12-049 (Reference 1), delineating progress made in implementing the requirements of EA-12-049.

The Attachments included with this letter provide updates of milestone accomplishments since the last status report, including any changes to the compliance method,schedule, or need for relief and the basis, if any.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).Direction regarding the content of the status reports is provided in NEI 12-06 (Reference 7).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: o i, "go%-G. T. PowellSite Vice President webAttachments:

1. STP Nuclear Operating Company (STPNOC)

Second Six-Month Status Reportfor the Implementation of Order EA-1 2-049, Order Modifying Licenses withRegard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events2. Conceptual Drawings3. Updated Phase 3 Equipment Table NOC-AE-14003089 Page 3 of 3cc:(paper copy)(electronic copy)Regional Administrator, Region IVU. S. Nuclear Regulatory Commission 1600 East Lamar Boulevard Arlington, TX 76011-4511 Balwant K. SingalSenior Project ManagerU.S. Nuclear Regulatory Commission One White Flint North (MS 8 B1)11555 Rockville PikeRockville, MD 20852Senior Resident Inspector U. S. Nuclear Regulatory Commission P. O. Box 289, Mail Code: MN116Wadsworth, TX 77483Jim CollinsCity of AustinElectric Utility Department 721 Barton Springs RoadAustin, TX 78704Eric LeedsDirector, Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission One White Flint North (MS 13 H 16M)11555 Rockville PikeRockville, MD 20852A. H. Gutterman, EsquireMorgan, Lewis & Bockius LLPBalwant K. SingalU. S. Nuclear Regulatory Commission John RaganChris O'HaraJim von SuskilNRG South Texas LPKevin PolioRichard PehaL.D. BlaylockCity Public ServicePeter NemethCrain Caton & James, P.C.C. MeleCity of AustinRichard A. RatliffRobert FreeTexas Department of State HealthServices Attachment 1NOC-AE-14003089 Attachment 1STP Nuclear Operating Company (STPNOC)

Second Six-Month Status Report for the Implementation of Order EA-12-049, OrderModifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events Attachment 1NOC-AE-1 4003089Page 1 of 11STP Nuclear Operating Company (STPNOC)

Second Six-Month Status Report forthe Implementation of Order EA-12-049, Order ModifVing Licenses with Regard toRequirements for Mitigation Strategies for Beyond-Design-Basis External Events1. Introduction STPNOC developed an Overall Integrated Plan (OIP) (Reference 1 in Section 8), documenting the diverse and flexible strategies (FLEX), in response to Reference

2. This attachment provides the second update of milestone accomplishments since submittal of the OIP, including any changes to the compliance method, schedule, or need for relief/relaxation and the basis, ifany. Because several changes have occurred to the OIP, the following is a brief overview ofSTP's current basic strategies to meet the Order. Changes to the OIP specific to this updateare emphasized with italics.NOTE: All flow rates and pressures are approximate Overview of how the strategies work together:

If the Extended Loss of AC Power (ELAP) occurs while the Steam Generators (SGs) are beingused 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, ensuring acooldown will not result in a return to criticality event and the cooldown will not allow nitrogeninto the Reactor Coolant System (RCS) from the Safety Injection (SI) accumulators.

Once the cooldown begins, site personnel will begin to focus on starting the FLEX dieselgenerators and mechanically and electrically lining up FLEX equipment to be placed in service.Cooldown and depressurization should start during the first hour following initial event. Afterapproximately ten hours, one of the FLEX DGs will be running and providing power to an RCSmakeup pump permitting boric acid to be added to the RCS to maintain shutdown margin. Oncethe SI accumulators are isolated or vented, then the RCS will be further depressurized andcooled down. This subsequent cooldown and depressurization is to 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 hours1.736111e-4 days <br />0.00417 hours <br />2.480159e-5 weeks <br />5.7075e-6 months <br /> 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 hours2.546296e-4 days <br />0.00611 hours <br />3.637566e-5 weeks <br />8.371e-6 months <br /> following event start.Most of STP's strategies now involve the use of a primary and alternate means to meet thesafety functions for the Order instead of only using an N and +1 pump. Having diversestrategies make the response more robust and the station is more likely to survive any event.The revised sequence of events timelines are based conservatively on starting the FLEX dieselgenerator and associated pumps and equipment at hour 10 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.

Attachment 1NOC-AE-14003089 Page 2 of 11REACTOR 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) at 3100 psig taking suction on either theBoric Acid Tanks (BATs) or the Refueling Water Storage Tank (RWST) and discharging into the CVCS charging line. The alternate means of filling the RCS is a pre-staged 40gpm FLEX RCS Makeup pump at 700 psi installed in one of the SI pump bays located inthe Fuel Handling Building (FHB). Suction is from the RWST, discharging into the SI linedownstream of High Head SI discharge motor-operated valve (MOV). The pump sizehas changed from 1600 psig discharge pressure to 700 psig to reduce the physical sizeof the pump. STP has the ability to vent the reactor head thus allowing the use of thissmaller head pump.* CORE COOLING (Modes 1-4) -Initial core cooling is accomplished using the TurbineDriven Auxiliary Feedwater (TDAFW) pump. In the event the TDAFW pump is lost, theprimary strategy for cooling the core is a new 300 gpm at 500 psig pre-staged motor-driven FLEX SG Makeup pump located in the Isolation Valve Cubicle (IVC) that will takesuction from the Auxiliary Feedwater Storage Tank (AFWST) and discharge into thecross-connect header that feeds all four SGs. The alternate means of feeding the SGsuses a trailer mounted diesel driven high capacity pump that will feed the SGs using thenormal Feedwater lines. This alternate strategy provides flexibility and diversity to meetthis safety function.

• CORE COOLING/RCS INVENTORY (Modes 5 and 6 without SGs when naturalcirculation is not available)

-The primary strategy uses a 170 gpm at 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 alternate means of filling the RCS will be a Boric Acid (BA) Transfer pump and CVCS piping. TheBA Transfer pump can deliver 140 gpm at 180 psi.* 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) pumpand opening FC-0048, which is the valve used to fill the SFP.o The hose to the pool method will be a 250 gpm at 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 BA Storage tanks will be the primary tanks used tomakeup to the RCS. The tanks will not deplete because of the new strategy ofdepressurizing the RCS to the point that the loss of coolant via the RCP sealreturn pressurized safety valve (PSV) will stop. Thus, not more than 70,000gallons 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-filled Attachment 1NOC-AE-14003089 Page 3 of 11using 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 levelaround the AFWST at about 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br /> (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 the trailer mounted diesel driven pumpand entering the south side of the MAB near the Waste Monitor tanks and goinginto the RMW tank room.o SFP makeup and spray -" For normal makeup, the source is the RMW Storage Tank (RMWST)." 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 aid in understanding the pumps and protection forthe strategies:

Attachment 1NOC-AE-14003089 Page 4 of 11SAFETY FUNCTIONRCS RCS Inventory/

Core Cooling (SG Makeup) SFP MakeupInventory Core Cooling(Modes 1-4) (shutdown modes)Primary Installed Pre-staged Installed TDAFW pump Installed Reactorstrategy CVCS PDP FLEX RCS (Phase 1) and pre-staged Makeup Water pumpat 35 gpm Makeup at 170 FLEX SG Makeup motor at 300 gpmgpm driven pump at 300 gpm(Phase 2)Alternate Pre-staged Installed BA Trailer mounted diesel driven Pre-staged FLEXstrategy FLEX RCS Transfer pump pump SFP makeup pumpMakeup at at 140 gpm See Note below at 250 gpm40 gpmProtection Yes, both Yes, both inside Yes, primary strategy is inside Yes, both insidein inside Class Class 1E Class 1E building, fully class 1E buildings.

accordance 1 E buildings.

buildings.

protected.

Alternate strategywith NEI will meet 12-06, separated 12-06? sufficiently that a tornadomissile should only affect one.Note: The two trailer mounted pumps will be stored in structures that meet NEI 12-06protection guidelines with the exception of a tornado missile.

The buildings will beseparated sufficiently to provide reasonable assurance that a tornado missile should notdestroy both pumps. Deployment following an incredible design basis flood from theMCR embankment breach cannot take place until about 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> following event. This isan Interim Staff Evaluation open item.2. Milestone Accomplishments STP has no milestone accomplishments to discuss at this time.

Attachment 1NOC-AE-1 4003089Page 5 of 113. Milestone Schedule StatusThe following provides an update to Attachment 2 of the OIP. It provides the activity status ofeach item, and whether the expected completion date has changed.

The dates are planningdates subject to change as design and implementation details are developed.

The revised milestone target completion dates do not impact the Order implementation date.Milestone Submit 60 Day Status ReportSubmit Overall Integrated PlanSubmit 6 Month Updates:Update 1Update 2Update 3Update 4Update 5Update 6Update 7FLEX Strategy Evaluation Walk-throughs or Demonstrations Perform Staffing AnalysisModifications:

Modifications Evaluation Unit 1 Design Engineering Unit 1 Implementation OutageUnit 2 Design Engineering Unit 2 Implementation OutageTargetCompletion DateOct 2012Feb 2013Aug 2013Feb 2014Aug 2014Feb 2015Aug 2015Feb 2016Aug 2016Sept 2013Dec 2014Dec 2013Sept 2013Jan 2014Oct 2015Jan 2014Apr 2015Activity StatusCompleteCompleteCompleteCompleteNot StartedNot StartedNot StartedNot StartedNot StartedStartedNot startedNot startedStartedStartedNot startedStartedNot startedRevisedTargetCompletion DateNoneNoneNoneNoneNov 2014April 2015Dec 2014June 2014Aug 2014June 2014 Attachment 1NOC-AE-14003089 Page 6 of 11Storage:Storage Design Engineering Sept 2013Storage Implementation Apr 2015FLEX Equipment:

Procure On-Site Equipment Jan 2014Develop Strategies with RRC Oct 2013Procedures:

PWROG1 issues NSSS2-specific Apr 2015guidelines Create Site-Specific FSGs3 Apr 2015Create Maintenance Procedures May 2014Training:

Develop Training Plan May 2014Training Complete Sept 2014Unit 1 FLEX Implementation Oct 2015Unit 2 FLEX Implementation Apr 2015Submit Completion Report1 PWROG -Pressurized Water Reactor Owner's Group2 NSSS -Nuclear Steam Supply System3 FSG -Functional Safety Guidelines StartedStartedStartedStartedStartedStartedNot startedStartedNot startedStartedStartedNot startedJuly 2014Nov 2014Oct 2014Jan 2015April 2015Oct 2015 Attachment 1NOC-AE-14003089 Page 7 of 114. Changes to Compliance MethodSPECIFIC CHANGES TO THE OIP AND THE FIRST 6 MONTH UPDATE:A. STP originally planned to recirculate the water from the containment floor back into theRCS; however, the elevated temperature of the water inside containment prevents thisdue to inadequate net positive suction head. RMWST and RWST water sources providewell beyond 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> of inventory for both the RCS and SFP.B. The capacity of the diesel generators has been increased to 1000 kW at 480V toaccommodate running more equipment.

C. For Modes 1-4 Core Cooling, STP's strategy has been updated to:a. Use the Turbine Driven Auxiliary Feedwater (TDAFW) pump in Phase 1.b. Use the new 300 gpm at 500 psig FLEX SG fill pump as the primary strategy toback up the TDAFW pump during Phase 2.c. Use the trailer mounted portable diesel driven pump feeding the Main Feedwater lines as the alternate strategy.

This strategy cannot be used for about 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />sfollowing a Main Reservoir embankment breach flood but can be usedimmediately for all other external events.D. The FLEX RCS Makeup pump was originally rated at 1500 psi but has been updated to arating of 700 psi. STP can open the Reactor Head Vents as necessary during this event.E. The trailer mounted diesel driven pumps will be used as a backup for SFP spray. Bothwill be stored separately and protected from design basis hurricane winds.F. The FLEX power diesel generator enclosures on top of the MAB will be made of steelvice concrete.

G. For Modes 5 and 6 Core Cooling, a new FLEX pump rated at 170 gpm at 100 psig will beused as the primary strategy and a Boric Acid Transfer pump will be used as the alternate strategy.

H. The new FLEX SFP makeup pump has been updated to a rating of 250 gpm at 150 psig.This pump will be used both for makeup using hoses and for spray.I. The strategy for draining the FW Deaerator (DA) into the AFWST has changed.

STPplans to modify a drain from the DA and install a valve and blind flange on the deck of theTurbine Generator Building (TGB) to support this effort.J. Most drawings have changed during the design process.

Final drawings will be providedin the basis document.

K. Phase 3 Strategies

-When the OIP was written, the Phase 3 strategies had not beenthoroughly addressed.

The Phase 2 strategies will enable STP to cope indefinitely; however Phase 3 equipment will arrive from the RRC and will be used on an "as needed"basis. For example, a medium voltage generator (4160 VAC) will be supplied to eachunit from the RRC -Although this generator is not required for indefinite coping, it willprovide for the restoration of a Class 1 E switchgear thereby restoring additional plant Attachment 1NOC-AE-14003089 Page 8 of 11support equipment.

This generator also permits the plant to start 4160 VAC pumps thatcan be used as a method for meeting the required safety functions.

See Attachment 2 for conceptual drawings and drawing changes planned for FLEX powerdistribution, SFP Makeup, RCS Makeup, and SG Makeup.5. Need for Relief/Relaxation and Basis for the Relief/Relaxation The 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.See Section 6 for further information and justifications.

6. Open Items from Overall Integrated Plan and Draft Safety Evaluation Below are the open items from the Technical Evaluation Report issued Jan. 29, 2014(Reference 3):O # 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.No update01 # 3.2.1 .1 .A -Demonstrate the applicability of the RETRAN-3D code for analysis of the ELAPtransient.

No update01 # 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 todemonstrate 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).No update01 # 3.2.1.6.A

-Develop the final timeline(s) and sequence(s) of events for STP.No updateO # 3.2.4.8.B

-Electric Power Sources -On page 20 of the Integrated Plan, the licensee statedthe strategy for mitigating an ELAP is to use a 480 VAC air cooled dieselgenerator on top of roof of the MAB to provide power to an electric driven SGFLEX pump, a RCS FLEX pump and a spent fuel pool FLEX pump. The use ofpre-staged generators appears to be an alternative to NEI 12-06. The licensee Attachment 1NOC-AE-14003089 Page 9 of 11has not provided sufficient information to demonstrate that the approach meetsthe NEI 12-06 provisions for pre-staged portable equipment.

Additional information is needed from the licensee to determine whether the proposedapproach provides an equivalent level of flexibility for responding to anundefined event as would be provided through conformance with NEI 12-06.Update: Pre-staging the two FLEX DGs is necessary because of thepostulated flood caused by a breach of the reservoir embankment (Reference UFSAR 3.4.1.1).

Although this event is not considered

credible, another flooding scenario due to upstream dam failure has thepotential of inundating the site with several feet of water. Staging andstoring the FLEX diesels on the MAB roof would provide reasonable protection from either flooding event. NEI 12-06 Section 11.3.2 states thatthe mitigation strategy and support equipment will be reasonably protected from applicable external events such that the equipment couldbe operated in place.Use of the existing electrical distribution system also conforms to therequirements of NEI 12-06. Section 3.2.1.3, Item (8) states that installed electrical distribution

systems, including inverters and battery chargers, remain available provided they are protected consistent with currentstation design. The electrical paths for energizing the FLEX equipment will be diverse in that the currently installed equipment will be repowered via Class 1 E motor control centers (MCCs) and the new FLEX pumps willbe powered via new cabling to the new pumps. Item (9) of Section 3.2.1.3states that no additional events or failures are assumed to occurimmediately prior to or during the event. As stated in Section 8.1.4.2 ofthe STP UFSAR, the Class 1 E Electrical System is designed to withstand the effects of design basis natural phenomena, assuming single activefailure, without loss of onsite power to those safety-related electrical components required to shut down the plant and maintain it in a safecondition or to mitigate the consequences of postulated accidents.

The two pre-staged 480VAC 1000kW DGs are capable of providing theprotection called for in the Order. New cables will be run from a newFLEX distribution panel located near the new FLEX DGs either throughexisting electrical system pathways (cable trays) or through conduits thatmeet the requirements associated with initial plant construction standards.

The FLEX equipment being powered from the FLEX diesel that will beused in Phase 2 of the FLEX strategy is contained in Category I structures and protected from external events. Cabling provides power to Class 1 EMCCs so that other components can be powered to provide a variety offunctions including battery charging,

pumping, ventilation, lighting andcommunications.

The new and previously installed cables that will beused for the FLEX strategies will be protected from all external events asdescribed in NEI 12-06 as will the MCCs and the pre-staged pumps.

Attachment 1NOC-AE-14003089 Page 10 of 11Diversity for this strategy exists:* Each FLEX DG is redundant and sized for 100% capacity

-only one isrequired.

• The FLEX distribution panel feeds three completely separate

&independent "trains" of ESF electrical equipment.

These areseparated on three different elevations in the Electrical Auxiliary Building (EAB) and power like components on different trains." Specific FLEX cables go directly to the new FLEX pumps withoututilizing the "trains" of ESF electrical equipment.

• Each safety function strategy has both a permanent plant pump and anew FLEX pump with diverse power distribution.

Flexibility for this strategy exists:The FLEX cabling being run from the FLEX DGs to power ESF motorcontrol centers for powering battery chargers, pumps, lighting, valvesand other equipment can be modified to run to multiple motor controlcenters (MCC) to power redundant equipment in the event of a fire ordisturbance to one particular "train" of ESF electrical power. An examplewould be the Boric Acid Transfer pump B is powered from the train 'A'MCC and the Boric Acid Transfer pump A is powered from train 'C'MCC. The Reactor Makeup Water pumps are powered similarly.

Thus ifsomething disturbed the 10' elevation of the EAB electrical switchgear room where the 'A' train electrical equipment is located, the 'C' trainelectrical equipment should not be affected because it is on the 60'elevation of the EAB. For this reason, there is capability to adapt todifferent scenarios.

Section 3.2.1.3(6) of NEI 12-06 states that permanent plant equipment that is contained instructures with designs that are robust with respect to seismic events, floods, highwinds and associated missiles are available.

Section 3.2.1.7 states that the priority for theplant response is to utilize systems or equipment that provides the highest probability for success.

The STP strategies that include pre-staged FLEX diesel generators and usepermanent plant equipment provide the highest probability of success.7. Potential Draft Safety Evaluation ImpactsThere are no potential impacts to the Draft Safety Evaluation identified at this time.

Attachment 1NOC-AE-14003089 Page 11 of 118. References The following references support the updates to the Overall Integrated Plan described in thisattachment.

1. STPNOC's Overall Integrated Plan in Response to March 12, 2012 Commission OrderModifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order Number EA-12-049),"

February 28, 2013(ML13070A01 1)2. NRC Order Number EA-12-049, "Order Modifying Licenses with Regard toRequirements for Mitigation Strategies for Beyond-Design-Basis External Events,"March 12, 2012 (ML12073A195)

3. Technical Evaluation Report Related to Order Modifying Licenses with Regard toRequirements for Mitigation Strategies for Beyond-Design-Basis External Events, EA-12-049 for STPNOC, December 19, 2013 (ML13339A736)

Attachment 2NOC-AE-14003089 Attachment 2Conceptual Drawings Attachment 2NOC-AE-1 4003089Page 1 of 7NEWFLEXDG #72NEW CABLE(NOTE 5)FROMTSC DIESEL GEN.NEW CABLENEW CABLENEW CABLE(NOTE g)NEW 480VAC FLEX LOAD DISTRIBUTION PANELQ)To New FLEX Enclosure Distribution (See U1-FLEX-MD-02)

NEW NEW NEWSTARTER STARTER STARTERNEWSTARTERy y y y Y yMCC ElA MCCE184 MQCCEI4 MCCE1C2 MCCEIA2 LU XlMrLEIA IBY OTHERS& ~ (NOTE 7Lt XftmrLP14UJSG MU (Prp RCS PIrp CVrDPFLEXSFP PMo Attachment 2NOC-AE-14003089 Page 2 of 7Conceptual Drawing -Spent Fuel Pool MakeupOC-)C->SEE NOTE --lp I12"CS12001UB2 cCc,--Y4* VT-CONTAI NMENT1SPRAY PUMP-282N101NPA101B (C I APCS) IN2CS0 IN2CSO Attachment 2NOC-AE-14003089 Page 3 of 7Conceptual Drawing -Spent Fuel Pool Makeup FLEX PumpFLEXIBLEHOSE -IFLEXHOSE008 3"FR-2001-UD9 SFP MAKE-UP FLEX PUMP 4 2590532NPA0005 Attachment 2NOC-AE-14003089 Page 4 of 7Conceptual Drawing -Reactor Coolant System MakeupDOC*5N129F05Q13*2 REV. 33AFTER Attachment 2NOC-AE-1 4003089Page 5 of 7Conceptual Drawing -Reactor Coolant System Makeup FLEX PumpsSEE NOTE 2 kE0SEE NOTE 2FLEXHOSE002 FLEXHOSE001 RCS MAKE-UP FLEX PUMP 4 2490532NPA0004 MODES 5 & 6V.*HOSE -1SEE NOTE 2FLEXHOSE002 FLEXHOSE001 1ý D 41RCS MAKE-UP FLEX PUMP

• 2390532NPA0003 MODES 1-4I TM' S PIPW' AND 1NTAWDENT DWASRADEPICTS THE SYSTEMJ CONFSE4VXTIGN DUR1N5 MITICATION OF V FLEV EVENT.2. ILEX MOSES ARE SHAES BERMEEFLEX RCS Mg(E-AR PLWS.

Attachment 2NOC-AE-14003089 Page 6 of 7Conceptual Drawing -Steam Generator Makeup (RCS Core Coolinq)ItC It Attachment 2NOC-AE-1 4003089Page 7 of 7Conceptual Drawing -Steam Generator Makeup FLEX Pump (RCS Core Cooling)V

• PI3" I-FLEXIBLEFLEX I LE H05EHOSE INCF6 X -I IFLEXHO SE~005 FLE X(H O SE006,. 'RCS CORE COOLING FLEX PUMP # 2290532MPA0002 AFW TRAIN-C1.THIS PIPING AND INSTKIENT DIAGRAM;DEPICTS THE SYSTEM CONFIGURATION DURING MITIGATION OF A FLEX EVENT.

Attachment 3NOC-AE-1 4003089Attachment 3Updated Phase 3 Equipment Table Attachment 3NOC-AE-14003089 Page 1 of 2UPDATED PHASE 3 EQUIPMENT TABLE (Per Unit)Note: Information from previous equipment table is lined-out.

Deleted information is no longer part of the Phase 3 strategy.

PWR Portable Equipment Phase 3 -although these arc listed as Phase 3 most will need to be prc. deployed in thci. useful locatioUse and (potential/

flexibility) diverse usesPerformanceNoe List portable Core Containment SFP Instrument Accessibility/

Criteriaequipment

-ation Other4160 VAC 4160 VAC generator could power atGenerator X X X X X 2 MW least one installed ESF bus from itsrespective ESF transformer (from RRC).volume For SFP spray or foil function i'dioii lilen 1 1000 gpm at 175 nccssar-y.

AISO could be used foPupPST makeup to AFWST fromn a Yaricty ot120VAG-punps X TBD These pumps would be used to filltanks, move watcr, etca.Portable light X6 4 that usetowers diesel fuelRemoteGcllular'satllimtc X2Sml500 g pumpat 150- This will be additional equipment with-GapaGW Diesel X X ...... ,',at 15 no particular function.

driven pump psi___ ________________

Diesel Driven 2500 gpm at 300 This will be additional equipment withPump psi no particular function.

Aei X 6 Xcornwersdislf Attachment 3NOC-AE-1 4003089Page 2 of 2PWR Portable Equipment Phase 3- although these arc listed as Phase 3 most wall need to be pr -deployed in their useful locatin-due to the design basis flood from the main reserVoir breach.Use and (potential/

flexibility) diverse usesPerformanceNoe List portable Core Containment SFP Instrument Accessibility/

Criteriaequipment

-ation Other480 G AC X X X -500 kW This is additional equipment that may orGenerator may not be used.4100 ps"a 2000High Pressure psi gpm and 40Pump for RCS X 60 gpm (site This is additional equipment that may orfill speCific analysis may not be used.may beSG Fee,, 400 500 psig andMedium 3W" 500 gpm This is additional equipment that may orcapacity diesel X ....s.i may not be used.driven pump analysisSFP-FilkPmpP X 75 psig and 200tratot XFuel oil transfer Support filling various diesel driventank tanke X X 264 gal equipment truGk feG 4160V e nLht st.4 g X 100'eaeh(-12) Ventilafien XXfans and trunks