ML15149A143

North Anna, Units 1 and 2 - Compliance Letter and Final Integrated Plan in Response to the March 12, 2012, Commission Order Modifying Licenses with Regard to Requirements for Mitigating Strategies for Beyond-Design-Basis External Events (Or

ML15149A143
Person / Time
Site:	North Anna
Issue date:	05/19/2015
From:	Mark D. Sartain Virginia Electric & Power Co (VEPCO)
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
14-394C, EA-12-049
Download: ML15149A143 (119)

Text

VIRGINIA ELECTRIC AND POWER COMPANYRICHMOND, VIRGINIA 23261May 19, 2015U. S. Nuclear Regulatory Commission Serial No.: 14-394CAttention:

Document Control Desk NLOS/DEA:

R1Washington, DC 20555-0001 Docket Nos.: 50-338/339 License Nos.: NPF-4/7VIRGINIA ELECTRIC AND POWER COMPANYNORTH ANNA POWER STATION UNITS 1 AND 2COMPLIANCE LETTER AND FINAL INTEGRATED PLAN IN RESPONSE TOTHE MARCH 12, 2012 COMMISSION ORDER MODIFYING LICENSES WITHREGARD TO REQUIREMENTS FOR MITIGATING STRATEGIES FORBEYOND-DESIGN-BASIS EXTERNAL EVENTS (ORDER NUMBER EA-12-049)

On March 28, 2012 the Nuclear Regulatory Commission (NRC) issuedOrder EA-12-049, "Order to Modify Licenses with Regard to Requirements forMitigation Strategies for Beyond-Design-Basis External Events" [the Order]. TheOrder requires a three-phase approach for mitigating beyond-design-basis external events. The initial phase requires the use of installed equipment andresources to maintain or restore core cooling, containment, and spent fuel pool(SFP) cooling capabilities.

The transition phase requires providing sufficient,

portable, onsite equipment and consumables to maintain or restore functions untilthey can be accomplished with resources brought from offsite.

The final phaserequires obtaining sufficient offsite resources to sustain these functions indefinitely.

Condition C.3 of the Order requires all Licensees to notify theCommission when full compliance with the requirements of the Order isachieved.

This letter provides notification that Virginia Electric and Power Company(Dominion) has completed the requirements of the Order and is in full compliance with the Order for North Anna Power Station Unit 1. Attachment 1 to this letterprovides a summary of how the requirements of the Order were met for NorthAnna Unit 1. Dominion provided notification that the requirements of the Orderwere met for North Anna Power Station Unit 2 by Letter Serial No. 14-394A datedDecember 8, 2014. Accordingly, with both units in compliance with the Order,Attachment 2 provides the Final Integrated Plan (FIP) for North Anna PowerStation Units 1 and 2.

Serial No. 14-394CDocket Nos. 50-338/339 Compliance with EA-12-049 Page 2 of 3Should you have any questions or require additional information, please contactMargaret Earle at (804)273-2768.

Respectfully, Mark Sartaini " Vicki L. MullVice President-Nuclear Engineering NOTARY HUBLICCommonwealth of VirginiaReg. # 140542My Commission Expires May 31,.2018COMMONWEALTH OF VIRGINIA

) .140542COUNTY OF HENRICO)The foregoing document was acknowledged before me, in and for the County and Commonwealth aforesaid, today by Mr.Mark D. Sartain, who is Vice President

-Nuclear Engineering, of Virginia Electric and Power Company.

He has affirmedbefore me that he is duly authorized to execute and file the foregoing document in behalf of that company, and that thestatements in the document are true to the best of his knowledge and belief.Acknowledged before me this /. 7-rday of L 2015.My Commission Expires:

5L3 , LNotary PublicAttachments:

1. Order EA-12-049 Compliance Requirements Summary2. Final Integrated Plan (FIP) for North Anna Power Station Units 1 and 2Commitments contained in this letter:Nonecc: U.S. Nuclear Regulatory Commission

-Region IIMarquis One Tower245 Peachtree Center Avenue, NE Suite 1200Atlanta, GA 30303-1257 Dr. V. Sreenivas NRC Project Manager North AnnaU.S. Nuclear Regulatory Commission One White Flint NorthMail Stop 08 G-9A11555 Rockville PikeRockville, MD 20852-2738 Serial No. 14-394CDocket Nos. 50-338/339 Compliance with EA-12-049 Page 3 of 3Mrs. Lisa M. RegnerU.S. Nuclear Regulatory Commission One White Flint NorthMail Stop 011 F111555 Rockville PikeRockville, MD 20852-2738 Mr. Blake A. PurnellU.S. Nuclear Regulatory Commission One White Flint NorthMail Stop 012 D2011555 Rockville PikeRockville, MD 20852-2738 Mr. Steven R. JonesU.S. Nuclear Regulatory Commission One White Flint NorthMail Stop 010 Al11555 Rockville PikeRockville, MD 20852-2738 NRC Senior Resident Inspector North Anna Power StationMr. J. E. Reasor, Jr.Old Dominion Electric Cooperative Innsbrook Corporate Center, Suite 3004201 Dominion Blvd.Glen Allen, Virginia 23060 Serial No. 14-394CDocket Nos. 50-338/339 Compliance with EA-12-049 Attachment 1Order EA-12-049 Compliance Requirements SummaryVirginia Electric and Power CompanyNorth Anna Power Station, Units I and 2 Serial No. 14-394CDocket Nos. 50-338/339 Compliance with EA-12-049 Attachment 1Page 1 of 7North Anna Power Station, Unit IOrder EA-12-049 Compliance Requirements SummaryNorth Anna Power Station developed an Overall Integrated Plan (OIP) (Reference 1), documenting diverse and flexible strategies (FLEX) in response to Order EA-12-049, "Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events,"

(Reference 2). The OIP forNorth Anna Power Station, Units 1 and 2 was submitted to the NRC on February28, 2013 and was supplemented by Six-Month Status Reports (References 3, 4,5 and 15), in accordance with Order EA-12-049, along with an additional supplemental letter that was submitted on April 30, 2013 (Reference 6). Fullcompliance with Order EA-12-049 for Unit 2 was completed on October 8, 2014and documented in letter Serial No. 14-394A (Reference 14), dated December 8,2014.Full compliance with Order EA-12-049 for Unit 1 was completed on March 27,2015. This date corresponds to the end of the second refueling outage aftersubmittal of the OIP as required by Reference

2. The information provided hereindocuments full compliance with Order EA-12-049 for North Anna Power StationUnit 1.Completion of the elements identified below, as well as References 1, 3, 4, 5, 6 and15 document full compliance with Order EA-12-049 for North Anna Power Station,Unit 1.NRC ISE AND AUDIT ITEMS COMPLETEDuring the ongoing audit process (Reference 7), Dominion provided responses forthe following items for North Anna:" Interim Staff Evaluation (ISE) Open and Confirmatory Items (Reference 13)* Licensee Identified Open Items (Reference 1)" Audit Questions

" Safety Evaluation Review ItemsThe report "NRC North Anna Power Station, Units 1 and 2 -Report for the OnsiteAudit Regarding Implementation of Mitigating Strategies and Reliable Spent FuelInstrumentation Related to Orders EA-12-049 and EA-12-051" (Reference 8)delineated the items reviewed during the North Anna Power Station onsite audit.The report also identified additional audit items, specified as Safety Evaluation Serial No. 14-394CDocket Nos. 50-338/339 Compliance with EA-12-049 Attachment 1Page 2 of 7Review Items, which were added following the audit and required supplemental information to address.Dominion's responses, or references to the source document for responses, toInterim Staff Evaluation (ISE) Open and Confirmatory Items, Audit Questions, Safety Evaluation Review Items, and with the exception of Item 12, LicenseeIdentified Open Items, have been documented in References 8 and 14. LicenseeIdentified Open Item 12, "Plant modifications will be completed for permanent changes required for implementation of FLEX strategies" is addressed for Unit 1 inthe section titled "Modifications,"

of this attachment.

It is Dominion's position that nofurther actions are required related to the above items.MILESTONE SCHEDULE

-ITEMS COMPLETEUnit 1 Milestone Completion DateSubmit Integrated Plan February 2013Develop Strategies October 2013Develop Modifications July 2014Implement Unit 1 Modifications March 2015Develop Training Plan April 2014Implement Training September 2014Issue FSGs and Associated Procedure Revisions September 2014Develop Strategies/Contract with NSRC August 2014Purchase Equipment February 2014Receive Equipment August 2014Validation Walk-Throughs or Demonstrations of FLEXStrategies and Procedures August 2014Create Maintenance Strategies August 2014Unit 1 Outage Implementation March 2015 Serial No. 14-394CDocket Nos. 50-338/339 Compliance with EA-12-049 Attachment 1Page 3 of 7STRATEGIES

-COMPLETEStrategy related Interim Staff Evaluation (ISE) Open and Confirmatory Items, AuditQuestions, Safety Evaluation Review Items, and with the exception of Item 12,Licensee Identified Open Items, have been addressed as documented in References 8 and 14. Licensee Identified Open Item 12, "Plant modifications will be completed forpermanent changes required for implementation of FLEX strategies,"

is addressed inthe following section titled "Modifications".

The North Anna Power Station, Unit 1strategies are in compliance with Order EA-12-049.

MODIFICATIONS

-COMPLETEThe modifications required to support the FLEX strategies for North Anna PowerStation, Unit 1 have been completed in accordance with the station design controlprocess.

The plant modification design changes (DCs) implemented in support of theFLEX strategies for Unit 1 compliance are as follows:Unit 1 Modifications:

FLEX Mechanical Connections (NA-12-01217),

FLEXElectrical Connections (NA-13-01017),

Quench Spray (QS) Piping Connection (NA-13-00104),

Primary Grade Water Tank Mechanical Connection (NA-13-00086), and Power Feeds to Support Pre-Stage 120VAC Generators (NA-13-00089). Also, the DC for Reactor Coolant Pump Seal Replacement (NA-12-01110) has completed the replacement of two of the three seals for Unit 1.Modifications common to both Units 1 and 2: Spent Fuel Pool Mechanical Connections (NA-12-01218),

Alternate RCS Injection Connection (NA-13-00085),

Alternate Auxiliary Feedwater (AFW) Connection (NA-13-00083),

Service WaterMechanical Connection (NA-13-00090),

Concrete Pads and Grounding Connection for Pump Draft Locations (NA-14-00027),

BDB Storage Building (NA-13-00061),

BDB Offsite Communications (NA-14-01077),

Spent Fuel Pool LevelInstrumentation (NA-13-01043) and Condenser Hotwell Connections (NA-14-00035).Copies of these DCs have previously been provided to the NRC staff and are available for their review.EQUIPMENT

-PROCURED AND MAINTENANCE

& TESTING -COMPLETEThe equipment required to implement the FLEX strategies for North Anna PowerStation, Unit 1 has been procured in accordance with NEI 12-06, Section 11.1 and11.2, received onsite, initially tested, performance verified as identified in NEI 12-06,Section 11.5, and is available for use.

Serial No. 14-394CDocket Nos. 50-338/339 Compliance with EA-12-049 Attachment 1Page 4 of 7Maintenance and testing will be conducted through the use of the North Anna PowerStation Preventative Maintenance Program such that equipment reliability is maintained and is in compliance with EPRI guidelines where applicable to the FLEX equipment.

PROTECTED STORAGE -COMPLETEThe storage facility required to protect BDB equipment has been completed for NorthAnna Power Station.

The BDB equipment is protected from the applicable site hazardsand will remain deployable to assure implementation of the FLEX strategies for NorthAnna Power Station, Unit 1.PROCEDURES

-COMPLETEFLEX Support Guidelines (FSGs) for North Anna Power Station, Unit 1, have beendeveloped and integrated with existing procedures.

The FSGs and affected existingprocedures have been approved and are available for use in accordance with the siteprocedure control program.TRAINING

-COMPLETETraining of personnel responsible for the mitigation of beyond-design-basis events atNorth Anna Power Station, Unit 1 has been completed in accordance with an acceptedtraining process as recommended in NEI 12-06, Section 11.6.STAFFING

-COMPLETEThe staffing study for North Anna Power Station has been completed in accordance with "Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f)

Regarding Recommendations 2.1, 2.3, and 9.3, of the Near-Term Task ForceReview of Insights from the Fukushima Dai-ichi Accident,"

Enclosure 5 pertaining toRecommendation 9.3, dated March 12, 2012 (Reference 9). The staffing assessment was submitted by letter dated May 7, 2014, "North Anna Power Station Units I and 2,March 12, 2012 Information

Request, Phase 2 Staffing Assessment Report,"(Reference 10), and in the response to a Request for Additional Information (RAI)(Reference

11) regarding the Phase 2 Staffing Assessment Report, Recommendation 9.3, dated September 22, 2014. As indicated in the RAI response, FSG strategies canbe successfully implemented using the current minimum on-shift staffing.

Revision 1 tothe North Anna Phase 2 Staffing Assessment Report documenting this additional information was transmitted to the NRC in letter Serial No.15-025 (Reference 16),dated January 30, 2015.

Serial No. 14-394CDocket Nos. 50-338/339 Compliance with EA-12-049 Attachment 1Page 5 of 7NATIONAL SAFER RESPONSE CENTERS -COMPLETEDominion has established a contract with Pooled Equipment Inventory Company(PEICo) and has joined the Strategic Alliance for FLEX Emergency Response (SAFER)Team Equipment Committee for off-site facility coordination.

It has been confirmed thatPEICo is ready to support North Anna Power Station with Phase 3 equipment stored inthe National SAFER Response Centers in accordance with the site-specific SAFERResponse Plan (Reference 12).VALIDATION

-COMPLETEDominion has completed validation testing of the FLEX strategies for North Anna PowerStation, Unit 1 in accordance with industry developed guidance.

The validations assurethat required tasks, manual actions, and decisions for FLEX strategies may beexecuted within the constraints identified in the Overall Integrated Plan (OIP)/Final Integrated Plan (FIP) for Order EA-12-049.

FLEX PROGRAM DOCUMENT

-ESTABLISHED The Dominion FLEX Program has been developed and documented in accordance withthe requirements of NEI 12-06 and is in effect for North Anna Power Station.REFERENCES The following references support the North Anna Power Station, Unit 1 FLEXCompliance Summary:1. North Anna Power Station Units 1 and 2, "Overall Integrated Plan in Response toMarch 12, 2012 Commission Order Modifying Licenses with Regard toRequirements for Mitigation Strategies for Beyond-Design-Basis External Events(Order Number EA 049)," February 28, 2013 (ML1 3063A1 82).2. NRC Order Number EA-12-049, "Order Modifying Licenses with Regard toRequirements for Mitigation Strategies for Beyond-Design-Basis ExternalEvents,"

dated March 12, 2012 (ML12229A174).

3. Letter from Dominion to NRC, "North Anna Power Station Units 1 and 2 Six-Month Status Report 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),"

datedAugust 23, 2013 (ML13242A012).

Serial No. 14-394CDocket Nos. 50-338/339 Compliance with EA-12-049 Attachment 1Page 6 of 74. Letter from Dominion to NRC, "North Anna Power Station Units 1 and 2 Six-Month Status Report 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),"

datedFebruary 27, 2014 (ML14069A012).

5. Letter from Dominion to NRC, "North Anna Power Station Units 1 and 2 Six-Month Status Report 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),"

dated August28, 2014 (ML14251A024).

6. Letter from Dominion to NRC, "Supplement to Overall Integrated Plan inResponse to March 12, 2012 Commission Order Modifying Licenses withRegard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order Number EA-12-049),"

dated April 30, 2013(ML1 3126A207).

7. NRC letter to All Operating Reactor Licensees and Holders of Construction

Permits, "Nuclear Regulatory Commission Audits of Licensee Responses toMitigation Strategies Order EA-12-049,"

dated August 28, 2013 (ML13234A503).

8. NRC letter from John Boska, Senior Project Manager, JLD, Office of NRR, toDavid A. Heacock, President and Chief Nuclear Officer, Virginia Electric andPower Company, "NRC North Anna Power Station, Units 1 and 2 -Report forthe Onsite Audit Regarding Implementation of Mitigating Strategies and ReliableSpend Fuel Instrumentation Related to Orders EA-12-049 and EA-12-051,"

dated September 24, 2014 (ML14259A458).

9. 10CFR50.54(f),

"Request for Information Pursuant to Title 10 of the Code ofFederal Recommendations 2.1, 2.3, and 9.3, of the Near-Term Task ForceReview of Insights from the Fukushima Dai-ichi Accident,"

Recommendation 9.3,dated March 12, 2012 (ML2073A348).

10. Letter from Dominion to NRC, "North Anna Power Station Units 1 and 2, March12, 2012 Information Request Phase 2 Staffing Assessment Report,"

May 7,2014 (ML14133A011).

11. Letter from Dominion to NRC, "North Anna Power Station Units 1 and 2, March12, 2012 Response to Request for Additional Information Regarding Phase 2Staffing Assessment Report Recommendation 9.3," dated September 22, 2014.

Serial No. 14-394CDocket Nos. 50-338/339 Compliance with EA-12-049 Attachment 1Page 7 of 712. NRC letter from Jack Davis, JLD, Office of NRA, to Joseph E. Pollock, VicePresident, Nuclear Operations, NEI, "Staff Assessment of National SaferResponse Centers Established in Response to Order EA-12-049,"

September 26, 2014 (ML14265A1 07).13. NRC letter from Jeremy S. Bowen, Chief, Mitigating Strategies Branch Office ofNRR, to David A. Heacock, President and Chief Nuclear Officer, Virginia Electricand Power Company, "North Anna Power Station, Units 1 and 2 -Interim StaffEvaluation Related to Overall Integrated Plan in Response to Order EA-12-049 (Mitigating Strategies),"

dated January 29, 2014 (ML13338A445).

14. Letter from Dominion to NRC, "North Anna Power Station Unit 2, Status ofRequired Actions for EA-12-049 Issuance of Order to Modify Licenses withRegard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events,"

Serial No. 14-394A, dated December 8, 2014.15. Letter from Dominion to NRC, "North Anna Power Station Unit 1 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 EA-12-049),"

Serial No. 14-394B,dated March 2, 2015.16. Letter from Dominion to NRC, "North Anna Power Station Units 1 and 2, March12, 2012 Information

Request, Revision to Phase 2 Staffing Assessment Report,"

Serial No.15-025, dated January 30, 2015.

Serial No. 14-394CDocket Nos. 50-338/339 Order EA-12-049 Attachment 2FINAL INTEGRATED PLANBeyond Design BasisFLEX Mitigation Strategies Virginia Electric and Power CompanyNorth Anna Power Station BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 2Table of Contents1. Background

.......................................................................................................

12. NRC Order EA-12-049

-Diverse and Flexible Mitigation Capability (FLEX) ...... 22.1 G eneral Elem ents -Assum ptions ............................................................................

22.2 Strategies

.....................................................................................................................

52.3 Reactor Core Cooling Strategy

................................................................................

62.3.1 Phase 1 Strategy

................................................................................................

72.3.2 Phase 2 Strategy

................................................................................................

92.3.3 Phase 3 Strategy

..............................................................................................

112.3.4 System s, Structures, Com ponents ...................................................................

122.3.5 FLEX Strategy Connections

............................................................................

142.3.6 Key Reactor Param eters ..................................................................................

172.3.7 Therm al Hydraulic Analyses

............................................................................

192.3.8 Reactor Coolant Pum p Seals ..........................................................................

202.3.9 Shutdown M argin Analysis

..............................................................................

202.3.10 FLEX Pum ps and W ater Supplies

...................................................................

222.3.11 Electrical Analysis

...........................................................................................

252.4 Spent Fuel Pool Cooling/Inventory

.........................................................................

262.4.1 Phase 1 Strategy

..............................................................................................

262.4.2 Phase 2 Strategy

..............................................................................................

262.4.3 Phase 3 Strategy

.............................................................................................

262.4.4 Structures, System s, and Com ponents ..........................................................

272.4.5 Key Reactor Param eters ...................................................................................

282.4.6 Therm al-Hydraulic Analyses

...........................................................................

292.4.7 FLEX Pum p and W ater Supplies

......................................................................

292.4.8 Electrical Analysis

...........................................................................................

302.5 Containm ent Integrity

..............................................................................................

302.5.1 Phase I .................................................................................................................

30Page i BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 22.5.2 Phase 2 ...................................................................

302.5.3 Phase 3 ...........................................................

312.5.4 Structures,

Systems, Components...................................................................

332.5.5 Key Containment Parameters

.........................................................................

342.5.6 Thermal-Hydraulic Analyses

............................................................................

342.5.7 FLEX Pump and Water Supplies

......................................

352.5.8 Electrical Analysis

............................................

352.6 Characterization of External Hazards ...................................................

352 .6 .1 S e is m ic ..........................................................

....................................................

3 52.6.2 External Flooding

...............................

...... ......................................................

372.6.3 Severe Storms with High Wind ........................................................................

382.6.4 Ice, Snow and Extreme Cold.............................................

392.6.5 H igh Tem peratures

.........................................................................................

402.7 Protection of FLEX Equipment...............................................

402.8 Planned Deployment of FLEX Equipment

..............................

.....................

412.8.1 Haul Paths .................................................

412 .8 .2 A ccessibility

.....................................................................................................

..4 22.9 Deploym ent of Strategies

......................................................................................

432.9.1 AFW Makeup Strategy

.........................................

432.9.2 RC S M akeup Strategy

....................................................................................

442.9.3 Spent Fuel Pool Makeup Strategy

...... ..............................

442.9.4 Electrical Strategy

...................................................................................

........

452.9.5 Fueling of Equipm ent ................................

....................................................

462.10 O ffsite R esources

..............................................

.................................................

482.10.1 National SAFER Response Center...................................

482.10.2 Equipment List ...................................................

482.11 Equipment Operating Conditions

............................................................................

482.11.1 Ventilation

..........................................................

482 .11.2 H eat T racing ..................................................................................................

..50Page ii BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-1 2-049Attachment 22.12 Habitability

..................................................................................................................

502.13 Lighting

.......................................................................................................................

502.14 Com m unications

....................................................................................................

512.15 W ater Sources ............................................................................................................

522.15.1 W ater Sources -Secondary Side ...................................................................

522.15.2 W ater Sources -Prim ary Side ..........................................................................

542.15.3 Spent Fuel Pool (SFP) ....................................................................................

542.16 Shutdown and Refueling Modes Analysis

...............................................................

542.17 Sequence of Events ................................................................................................

562.18 Program m atic Elem ents .........................................................................................

562.18.1 Overall Program Document

..............................................................................

562.18.2 Procedural Guidance

......................................................................................

572.18.3 Staffing

.................................................................................................................

582.18.4 Training

................................................................................................................

602.18.5 Equipm ent List .................................................................................................

612.18.6 N+1 Equipm ent Requirem ent ..........................................................................

612.18.7 Equipm ent Maintenance and Testing ...............................................................

623. References

..............................................................................................................

63Page iii BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-1 2-049Attachment 2List of TablesTable 1 -PW R Portable Equipment Stored Onsite ............................................................

67Table 2 -PW R Portable Equipment From NSRC ...............................................................

71Table 3 -W ater Sources ....................................................................................................

73Table 4 -Sequence of Events Tim eline ..............................................................................

75List of FiguresFigure 1: BDB FLEX Strategy Equipment and Hose Layout ...............................................

79Figure 2: RCS Makeup Primary Mechanical Connection North Anna Unit 1 .......................

82Figure 3: RCS Makeup Primary Mechanical Connection North Anna Unit 2 .......................

83Figure 4: RCS Makeup Alternate Mechanical Connection North Anna Unit 1 .....................

84Figure 5: RCS Makeup Alternate Mechanical Connection North Anna Unit 2 .....................

85Figure 6: BDB Electrical Connection 120 VAC, 480 VAC, & 4160 VAC General Layout ........

86Figure 7: 120/240 VAC Portable Generator (BDB) Electrical Connection Panel #1 -North A nna Unit 1 .............................................................................

87Figure 8: 120/240 VAC Portable Generator (BDB) Electrical Connection Panel #2 -North A nna Unit 1 .............................................................................

88Figure 9: 480 VAC Portable Generator (BDB) Electrical Connections to 480 VACMCC 1H and 1J -North Anna Unit 1 ..................................................................

89Figure 10: 480 VAC Portable Generator (BDB) Electrical Connections to 480 VACMCC 2H and 2J -North Anna Unit 2 .................................................................

90Figure 11: 4160 VAC Generator (NSRC) Electrical Connection General Layout ................

91Figure 12: Core Cooling and Decay Heat Removal AFW Primary and Alternate Mechanical Connections

-North Anna Unit 1 ....................................................

92Page iv BDB FLEX Mitigation Strategies Final Integrated PlanNorth Anna Power StationSerial No. 14-394CDocket Nos. 50-338/339 Order EA-1 2-049Attachment 2Figure 13:Figure 14:Figure 15:Figure 16:Figure 17:Figure 18:Figure 19:Figure 20:Figure 21:Figure 22:Core Cooling and Decay Heat Removal AFW Primary and Alternate Mechanical Connections

-North Anna Unit 2 ....................................................

93ECST Refill Mechanical Connections, Paths, and Sources North Anna Unit 1 ...... 94ECST Refill Mechanical Connections, Paths, and Sources North Anna Unit 2 ...... 954160 VAC Generator (NSRC) Electrical Connections to 4160 VACMCC 1H and 1J -North Anna Unit 1 ................................................................

964160 VAC Generator (NSRC) Electrical Connections to 4160 VACMCC 2H and 2J -North Anna Unit 2 .................................................................

97Spent Fuel Pool Cooling Primary and Alternate Mechanical Connections

...... 98Phase 3 Containment Cooling Connections

......................................................

99Containment Cooling Phase 3 Containment Spray Mechanical C onnections North A nna U nit 1 ............................................................................

100Containment Cooling Phase 3 Containment Spray Mechanical C onnections North A nna U nit 2 ............................................................................

101Haul Paths From BDB Storage Building and Staging Areas ................................

102Page v BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment

21. Background In 2011, an earthquake-induced tsunami caused Beyond-Design-Basis (BDB) floodingat the Fukushima Dai-ichi Nuclear Power Station in Japan. The flooding caused theemergency power supplies and electrical distribution systems to be inoperable, resulting in an extended loss of alternating current (AC) power (ELAP) in five of the sixunits on the site. The ELAP led to (1) the loss of core cooling, (2) loss of spent fuel poolcooling capabilities, and (3) a significant challenge to maintaining containment integrity.

All direct current (DC) power was lost early in the event at Units 1 and 2 and aftersome period of time at the other units. Core damage occurred in three of the unitsalong with a loss of containment integrity, resulting in a release of radioactive materialto the surrounding environment.

The US Nuclear Regulatory Commission (NRC) assembled a Near-Term Task Force(NTTF) to advise the Commission on actions the US nuclear industry should take topreclude core damage and a release of radioactive material after a natural disastersuch as that seen at Fukushima.

The NTTF report (Reference

1) contained manyrecommendations to fulfill this charter, including assessing extreme external eventhazards and strengthening station capabilities for responding to Beyond-Design-Basis external events.Based on NTTF Recommendation 4.2, the NRC issued Order EA-12-049 (Reference

2) on March 12, 2012 to implement mitigation strategies for BDB external events. TheOrder included the following requirements:

1. Licensees shall develop, implement, and maintain guidance and strategies tomaintain or restore core cooling, containment, and SFP cooling capabilities following a BDB external event.2. Licensees shall develop strategies that are capable of mitigating a simultaneous loss of all AC power and loss of normal access to the ultimate heat sink (LUHS) andhave adequate capacity to address challenges to core cooling, containment andSFP cooling capabilities at all units on a site subject to the Order.3. Licensees must provide reasonable protection for the associated equipment fromexternal events. Such protection must demonstrate that there is adequate capacityto address challenges to core cooling, containment, and SFP cooling capabilities atall units on a site subject to the Order.4. Licensees must be capable of implementing the strategies in all modes.5. Full compliance shall include procedures,

guidance, training, and acquisition, staging or installing of equipment needed for the strategies.

Page 1 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 2The Order specifies a three-phase approach for strategies to mitigate BDB externalevents:-Phase 1 -Initially cope relying on installed equipment and onsite resources.

-Phase 2 -Transition from installed plant equipment to onsite BDB equipment.

-Phase 3 -Obtain additional capability and redundancy from offsite equipment until power, water, and coolant injection systems are restored orcommissioned.

NRC Order EA-12-049 required licensees of operating reactors to submit an overallintegrated plan, including a description of how compliance with these requirements would be achieved by February 28, 2013. The Order also required licensees tocomplete implementation of the requirements no later than two refueling cycles aftersubmittal of the overall integrated plan or December 31, 2016, whichever came first.The Nuclear Energy Institute (NEI) developed NEI 12-06 (Reference 3), which providedguidelines for nuclear stations to assess extreme external event hazards andimplement the mitigation strategies specified in NRC Order EA-12-049.

The NRCissued Interim Staff Guidance JLD-ISG-2012-01 (Reference 4), dated August 29, 2012,which endorsed NEI 12-06 with clarifications on determining baseline coping capability and equipment quality.NRC Order EA-12-051 (Reference

5) required licensees to install reliable SFPinstrumentation with specific design features for monitoring SFP water level. ThisOrder was prompted by NTTF Recommendation 7.1 (Reference 1).NEI 12-02 (Reference

6) provided guidance for compliance with Order EA-12-051.

The NRC determined that, with the exceptions and clarifications provided in JLD-ISG-2012-03 (Reference7),

conformance with the guidance in NEI 12-02 was anacceptable method for satisfying the requirements in Order EA-1 2-051.2. NRC Order EA-12-049

-Diverse and Flexible Mitigation Capability (FLEX)2.1 General Elements

-Assumptions The assumptions used for the evaluations of a North Anna ELAP/LUHS event andthe development of FLEX strategies are stated below.Boundary conditions consistent with NEI 12-06, Section 3.2.1, General Criteria andBaseline Assumptions, are established to support development of FLEX strategies, as follows:Page 2 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 2-The BDB external event occurs impacting both units at the site.-Both reactors are initially operating at full power, unless there are procedural requirements to shut down due to an impending event. The reactors have beenoperating at 100% power for the past 100 days.-Each reactor is successfully shut down when required (i.e., all rods inserted, noATWS). Steam release to maintain decay heat removal upon shutdownfunctions

normally, and reactor coolant system (RCS) overpressure protection valves respond normally, if required by plant conditions, and reseat.-Onsite staff is at site administrative minimum shift staffing levels.-No independent, concurrent events, e.g., no active security threat.-All personnel onsite are available to support site response.

-The reactor and supporting plant equipment are either operating within normalranges for pressure, temperature and water level, or available to operate, at thetime of the event consistent with the design and licensing basis.The following plant initial conditions and assumptions are established for thepurpose of defining FLEX strategies and are consistent with NEI 12-06 Section3.2.1, General Criteria and Baseline Assumptions:

-No specific initiating event is used. The initial condition is assumed to be a lossof offsite power (LOOP) with installed sources of emergency onsite AC powerand station blackout (SBO) alternate AC power sources unavailable with noprospect for recovery.

-Cooling and makeup water inventories contained in systems or structures withdesigns that are robust with respect to seismic events, floods, and high windsand associated missiles are available.

Permanent plant equipment that iscontained in structures with designs that are robust with respect to seismicevents, floods, and high winds and associated

missiles, are available.

Theportion of the fire protection system that is robust with respect to seismic events,floods, and high winds and associated missiles is available as a water source.-Normal access to the ultimate heat sink is lost, but the water inventory in theultimate heat sink (UHS) remains available and robust piping connecting theUHS to plant systems remains intact. The motive force for UHS flow, i.e.,pumps, is assumed to be lost with no prospect for recovery.

Page 3 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 2-Fuel for BDB equipment stored in structures with designs that are robust withrespect to seismic events, floods and high winds and associated

missiles, remains available.

-Installed Class 1 E electrical distribution

systems, including inverters and batterychargers, remain available since they are protected.

-No additional accidents, events, or failures are assumed to occur immediately prior to or during the event, including security events.-Reactor coolant inventory loss consists of unidentified leakage at the upper limitof Technical Specifications, reactor coolant letdown flow (until isolated),

andreactor coolant pump seal leak-off at normal maximum rate.-For the spent fuel pool, the heat load is assumed to be the maximum designbasis heat load. In addition, inventory loss from sloshing during a seismic eventdoes not preclude access to the pool area.Additionally, key assumptions associated with implementation of FLEX strategies are as follows:-Exceptions for the site security plan or other requirements of 10 CFR may berequired.

-Deployment resources are assumed to begin arriving at hour 6 and unlimited resources available after 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.-This plan defines strategies capable of mitigating a simultaneous loss of allalternating current (AC) power and loss of normal access to the ultimate heatsink resulting from a BDB external event by providing adequate capability tomaintain or restore core cooling, containment, and spent fuel pool (SFP) coolingcapabilities at all units on a site. Though specific strategies have beendeveloped, due to the inability to anticipate all possible scenarios, the strategies are also diverse and flexible to encompass a wide range of possible conditions toprotect the public health and safety. Each unit's Emergency Operating Procedures (EOPs) have been revised, in accordance with established EOPchange processes, to clearly reference and identify appropriate entry and exitconditions for these pre-planned strategies.

The EOPs retain overall commandand control of the actions responding to a BDB external event. Also, the impactof these strategies on the design basis capabilities of the unit have beenevaluated under 10 CFR 50.59.Page 4 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 2-The plant Technical Specifications contain the limiting conditions for normal unitoperations to ensure that design safety features are available to respond to adesign basis accident and direct the required actions to be taken when thelimiting conditions are not met. The result of the BDB external event may placethe plant in a condition where it cannot comply with certain Technical Specifications and/or with its Security Plan, and, as such, may warrant invocation of 10 CFR 50.54(x) and/or 10 CFR 73.55(p).

This position is consistent with thepreviously documented Task Interface Agreement (TIA) 2004-04, Acceptability ofProceduralized Departures from Technical Specifications (TSs) Requirements atthe Surry Power Station, (TAC Nos. MC4331 and MC4332),

dated September 12, 2006 (Accession No. ML060590273).

2.2 Strategies

The objective of the FLEX strategies is to establish an indefinite coping capability inorder to 1) prevent damage to the fuel in the reactors,

2) maintain the containment function and 3) maintain cooling and prevent damage to fuel in the spent fuel pool(SFP) using installed equipment, onsite portable equipment, and pre-staged offsiteresources.

This indefinite coping capability will address an extended loss of allalternating current power (ELAP) (loss of offsite power, emergency dieselgenerators and any alternate AC source, but not the loss of AC power to buses fedby Class 1 E batteries through inverters) with a simultaneous loss of normal accessto the ultimate heat sink (LUHS). This condition could arise following externalevents that are within the existing design basis with additional failures andconditions that could arise from a Beyond-Design-Basis external event.The plant indefinite coping capability is attained through the implementation of pre-determined strategies (FLEX strategies) that are focused on maintaining orrestoring key plant safety functions.

The FLEX strategies are not tied to anyspecific damage state or mechanistic assessment of external events. Rather, thestrategies are developed to maintain the key plant safety functions based on theevaluation of plant response to the coincident ELAP/LUHS event. A safetyfunction-based approach provides consistency with, and allows coordination with,existing plant EOPs. FLEX strategies are implemented in support of EOPs usingFLEX Support Guidelines (FSGs).The strategies for coping with the plant conditions that result from an ELAP/LUHS event involve a three-phase approach:

• Phase 1 -Initially cope by relying on installed plant equipment and onsiteresources.

Page 5 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 2" Phase 2 -Transition from installed plant equipment to onsite BDBequipment.

" Phase 3 -Obtain additional capability and redundancy from offsiteequipment until power, water, and coolant injection systems are restored.

The duration of each phase is specific to the installed and portable equipment utilized for the particular FLEX strategy employed to mitigate the plant condition.

The FLEX strategies described below are capable of mitigating an ELAP/LUHS resulting from a BDB external event by providing adequate capability to maintain orrestore core cooling, containment, and SFP cooling capabilities at both units atNorth Anna. Though specific strategies have been developed, due to the inability toanticipate all possible scenarios the FLEX strategies are also diverse and flexible toencompass a wide range of possible conditions.

These pre-planned strategies which have been developed to protect the public health and safety are incorporated into the North Anna Emergency Operating Procedures (EOPs) in accordance withestablished EOP change processes, and their impact to the design basiscapabilities of the unit evaluated under 10 CFR 50.59.An overall diagram of the following FLEX strategies showing the staging locations of BDB equipment and general hose routing is provided in Figure 1.2.3 Reactor Core Cooling StrategyReactor core cooling involves the removal of decay heat through the secondary side of the Nuclear Steam Supply System (NSSS) and maintaining sufficient RCSinventory to ensure the continuation of natural circulation in the primary side of theNSSS. The FLEX strategy for reactor core cooling and decay heat removal is torelease steam from the Steam Generators (SG) using the SG Power OperatedRelief Valves (PORVs) and the addition of a corresponding amount of Auxiliary Feedwater (AFW) to the SGs via the turbine driven AFW (TDAFW) pump. TheAFW system includes the Emergency Condensate Storage Tank (ECST) as theinitial water supply to the TDAFW pump. Operator actions to verify, re-align, andthrottle AFW flow are required by the EOPs following an ELAP/LUHS event toprevent SG dryout and/or overfill.

RCS cooldown will be initiated within the first 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> following a BDB externalevent that initiates an ELAP/LUHS event.DC bus load stripping will be initiated within the first hour following a BDB externalevent to ensure Class 1 E battery life is extended to 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. Portable generators will be used to repower instrumentation prior to battery depletion.

Page 6 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 2RCS makeup and boron addition will be initiated within 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> following a BDBexternal event to ensure natural circulation, reactivity

control, and boron mixing ismaintained in the Reactor Coolant System (RCS).NOTE: The reactor core cooling strategy descriptions below are the same forboth of the two North Anna units. Any differences and/or unit specificinformation is included where appropriate.

2.3.1 Phase 1 StrategyFollowing the occurrence of an ELAP/LUHS event, the reactor will trip andthe plant will initially stabilize at no-load RCS temperature and pressureconditions, with reactor decay heat removal via steam release to theatmosphere through the Main Steam Safety Valves (MSSVs) and/or the SGPORVs. Natural circulation of the RCS will develop to provide core coolingand the TDAFW pump will provide flow from the Emergency Condensate Storage Tank to the SGs to makeup for steam release.Operators will respond to the ELAP/LUHS event in accordance withemergency operating procedures (EOPs) to confirm RCS, secondary system, and Containment conditions.

A transition to ECA-0.0, Loss of All ACPower, will be made upon the diagnosis of the total loss of AC power. Thisprocedure directs isolation of RCS letdown pathways, verification ofContainment isolation, reduction of DC loads on the station Class 1Ebatteries, and establishes electrical equipment alignment in preparation foreventual power restoration.

The operators re-align AFW flow to all steamgenerators, establish manual control of the SG PORVs, and initiate a rapidcooldown of the RCS to minimize inventory loss through the Reactor CoolantPump (RCP) seals. ECA-0.0 also directs local manual control of AFW flow tothe SGs and manual control of the SG PORVs to control steam release andthe RCS cooldown rate, as necessary.

Secondary Side -The Phase 1 FLEX strategy for reactor core cooling andheat removal relies on installed plant equipment and water sources forsupplying AFW flow to the SGs and steam to the atmosphere.

The TDAFWpump automatically starts on the loss of offsite power condition, and doesnot require either AC or DC electrical power to provide AFW to the SGs. Inthe event that the TDAFW pump does not start on demand or trips after start,an operator will locally reset the turbine and the pump will be restarted.

Sufficient time (approximately 50 minutes) will be available to restart theTDAFW pump to prevent SG dry-out (Reference 8). The AFW system isPage 7 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 2normally aligned for the TDAFW pump to deliver flow to one SG. Therefore, operator action is required to manually align flow to all three SGs. Manualcontrol of TDAFW pump flowrate to the SGs to establish and maintain properwater levels in the SGs will be performed locally in the AFW Pump House.Steam release from the SGs will be controlled remotely from the MainControl Room (MCR) using air-operated SG PORVs equipped with localback-up compressed air bottles.

Local manual operation of the SG PORVs,using the installed manual control handwheel, can be performed in the eventthat back-up compressed air is expended.

In accordance with the existingprocedure for response to loss of all AC power, an RCS cooldown will beinitiated at a maximum rate of 100°F/hr to a minimum SG pressure of 290psig, which corresponds to an RCS core inlet temperature of approximately 419°F. The rapid RCS cooldown minimizes the adverse effects of hightemperature RCS coolant on Reactor Coolant Pump (RCP) shaft sealperformance and reduces SG pressure to allow for eventual AFW injection from a portable pump in the event that the TDAFW pump becomesunavailable.

The minimum established SG pressure is high enough toprevent nitrogen gas from the safety injection accumulators from entering theRCS.Initially, AFW supply is provided by the installed Emergency Condensate Storage Tank (ECST). The tank has a minimum usable capacity ofapproximately 96,000 gallons and will provide a suction source to theTDAFW pump for a minimum of 4.2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> of RCS decay heat removalconcurrent with a 100°F/hr RCS cooldown to a minimum SG pressure of 290psig (Reference 8). After depletion of the usable ECST inventory, theTDAFW pump suction will be aligned to the Seismic Category I, tornadomissile protected portion of the Fire Protection (FP) system. The FP system,which is common to both units, will be pressurized by the Diesel Driven FirePump (DDFP), which provides water from the Service Water Reservoir at asufficient flowrate and pressure to support TDAFW pump operation at bothunits. The DDFP has adequate diesel fuel storage to support operation untilrefueling can be provided from the onsite BDB equipment.

The ServiceWater Reservoir provides approximately 22.5 million gallons of useablewater volume to the FP system since the Service Water (SW) system wouldnot be functional due to the ELAP/LUHS.

The water volume from theService Water Reservoir extends the AFW water supply time to depletion forseveral weeks.Page 8 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 2Potential debris at the suction screen of the DDFP would not prevent anadequate flow to the DDFP. The trash screens on the SW Reservoir IntakeBay are designed to pass the full design flow of a SW pump and the DDFPpump. The SW pumps will not be operating due to the ELAP/LUHS.

Sincethe 600 gpm required by the DDFP to provide a suction source for theTDAFW pump is a small fraction of the design flow rate of the trash screen,the calculated unblocked trash screen area required for passing the requiredflow rate is justifiable.

Primary Side (RCS) -The RCS will be cooled down and depressurized untilSG pressure reaches 290 psig, which corresponds to a core inlettemperature of approximately 4190F. RCS isolation will be verified to haveoccurred automatically, and RCS leakage will be assumed to be through theRCP seals (See Section 2.3.8). Without additional RCS inventory, naturalcirculation will continue until at least the assumed onset of reflux coolingconservatively set at 17 hours1.967593e-4 days <br />0.00472 hours <br />2.810847e-5 weeks <br />6.4685e-6 months <br /> (See Section 2.3.7.2).

Keff is calculated to beless than .99 at the described RCS conditions for approximately 37 hours4.282407e-4 days <br />0.0103 hours <br />6.117725e-5 weeks <br />1.40785e-5 months <br />(See Section 2.3.9).Electrical/Instrumentation

-Load stripping of all non-essential loads wouldbegin within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> after the occurrence of an ELAP/LUHS and completed within the next 30 minutes.

With load stripping, the useable station Class1 E battery life has been calculated to be eight (8) hours for each unit (SeeSection 2.3.11).2.3.2 Phase 2 Strategqy The Phase 2 FLEX strategy for reactor core cooling and heat removalprovides an indefinite supply of water for feeding the SGs using the installed DDFP with suction from the SW Reservoir followed by use of a portable BDBHigh Capacity pump capable of drawing water from Lake Anna. Additionally, as required by NEI 12-06, SG water injection using a portable AFW pump isavailable through both primary and alternate connection locations.

RCS makeup will be initiated within 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> of the ELAP/LUHS event usinga portable pump to replenish RCS inventory and re-establish RCS level inthe pressurizer.

Two portable diesel driven BDB RCS Injection pumps (oneper unit) will be transported from the onsite BDB Storage Building anddeployed for delivery of RCS inventory makeup and reactivity control fromthe Refueling Water Storage Tank (RWST) or from another borated suctionsource for the remainder of the event.Page 9 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 2A hose will be connected to the Quench Spray (QS) pump suction elbow toprovide borated water to the suction of the BDB RCS Injection pump fromthe RWST. A high-pressure hose will be routed from the discharge of theBDB RCS Injection pump to the primary RCS injection connection in theSafeguards Building or the alternate RCS injection connection in thebasement of the Auxiliary Building to provide RCS inventory makeup for theremainder of the ELAP event (Figures 2 and 3 for Unit 1 and Figures 4 and 5for Unit 2).The Phase 2 FLEX strategy also includes re-powering of vital 120 VACbuses within eight (8) hours using a portable 120/240 VAC Diesel Generator (DG) stored onsite for each unit. Prior to depletion of the Class 1 E batteries on each unit, selected vital 120 VAC circuits will be re-powered to continueto provide key parameter monitoring instrumentation.

Portable 480 VACDGs are available as alternates to the 120/240 VAC DGs.The primary strategy for re-powering 120 VAC vital bus circuits is to use one120/240 VAC DG per unit connected to the 120 VAC vital buses through pre-installed BDB receptacle panels, cabling, connections, and distribution panels. The portable 120/240 VAC DGs will be deployed to the alleyways east of the Auxiliary Building for Unit 1 and west of the Auxiliary Building forUnit 2 (Figure 6). The generators will be connected via cables to receptacle panels located in the Rod Drive Room of each unit. The 120/240 VACcables for both units will be stored in the Hydrogen Recombiner ControlPanel Vault on the Unit 2 side of the station.

The BDB receptacle in eachRod Drive Room is connected to a BDB distribution panel via pre-installed cable and conduit.

Each 120/240 VAC DG powers two BDB distribution panels which provide power to the vital 120 VAC buses and selected lightingcircuits for that unit (Figure 7 and 8).Preparation of the 120/240 VAC DGs for service will commence immediately after the declaration of an ELAP event. Placing the 120/240 VAC DGs intoservice can be completed within 5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> (this includes an estimated two (2)hour time allotment for debris removal, two (2) hours transport and setup,and one (1) hour for Vital Bus switching).

It is therefore reasonable to expectthe 120/240 VAC generators to be supplying power to the keyinstrumentation within six (6) hours of a BDB external event which initiates an ELAP.The alternate FLEX strategy for re-powering 120 VAC vital bus circuits is thedeployment of one 480 VAC DG per unit connected to the Class 1 E 480Page 10 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 2VAC bus through pre-installed BDB cabling and connections.

The 480 VACDG allows for recharging the Class 1 E batteries and restoring other AC loadsin addition to the key parameter monitoring instrumentation.

The portable480 VAC DGs and the required color-coded power cables will be transported from the BDB Storage Building to their deployed positions in the alleyways on the west and east sides of the Auxiliary Building (Figure 6). The powercables will be connected to seismically-designed, tornado missile protected, BDB connection receptacles in the respective unit's Rod Drive Room.The BDB connection receptacles in the Rod Drive Rooms are connected tothe Class 1 E 480 VAC bus via pre-installed cable and conduit to Class 1 E480 VAC MCC breakers (Figures 9 and 10).Deployment of the 480 VAC DGs from the BDB Storage Building and placingthe 480 VAC generators into service can be completed within four (4) hoursafter deployment has been initiated.

However, this time does not include theestimated two (2) hour time allotment for debris removal, but does includeadditional time for transport from the BDB Storage Building due to the DG'slarger size and the fact that a cable trailer must also be deployed to thestaging location.

2.3.3 Phase 3 StrategyThe Phase 3 strategy for core cooling and decay heat removal includesadditional equipment available from the National SAFER Response Center(NSRC) to provide backup to the BDB High Capacity pumps, BDB RCSInjection pumps, BDB AFW pumps, Boric Acid Mixing Tanks, and the 480VAC DGs. Additionally, a Reverse Osmosis/Ion Exchanger waterprocessing system will be provided from the NSRC to provide a method toremove impurities from alternate fresh water supplies to the TDAFW pump,the BDB AFW pumps, or the BDB RCS Injection pumps.Use of the SGs for core cooling and decay heat removal is dependent onadequate reactor core decay heat generation if using the TDAFW pump andan available supply of clean water from onsite sources or from waterprocessing units provided from the NSRC. The Phase 3 strategy for restoring RHR provides an alternate method for removing decay heat and/or RCScooldown to Cold Shutdown.

Restoration of RHR requires the restoration of 4160 VAC power and portionsof the Component

Cooling, Service Water, and Containment Instrument Airsystems.Page 11 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 2Portable 4160 VAC generators will be provided from the NSRC for each unitin order to supply power to either of the two Class 1 E 4160 VAC buses oneach unit. Additionally, by restoring the Class 1 E 4160 VAC bus, power canbe restored to the Class 1 E 480 VAC via the 4160/480 VAC transformers topower selected 480 VAC loads.Two 1MW 4160 VAC generators will be connected to a distribution panel(also provided from the NSRC) in order to meet the required 4160 VAC loadrequirements for each unit. Due to the size of the equipment, the DGs will bedeployed to areas either near the existing Emergency Diesel Generator (EDG) rooms (Figure 6) or by the large openings in the Unit 1 and 2 TurbineBuildings (Figure 11). The area near the existing EDG rooms affords thebest configuration to connect to one of the two Class 1 E 4160 VAC buses foreach unit, but space is limited.

Depending on the debris situation, theTurbine Building openings may be the more viable option for deployment.

Inthis case, either the Emergency Switchgear Room or the normal Switchgear Room would be used to tie the 4160 VAC generators to one of the two Class1E 4160 VAC buses for each unit. Necessary cable for any of the aboveconnections are also provided from the NSRC.2.3.4 Systems, Structures, Components 2.3.4.1 Turbine Driven Auxiliary Feedwater PumpThe TDAFW pump will automatically start and deliver AFW flow to the"A" SG following an ELAP/LUHS event. Two air-operated steamsupply trip valves (TVs) supply steam to the TDAFW pump turbine.These TVs are normally closed. The TVs are actuated by DCsolenoids in the air supply line. If the solenoids de-energize, air isvented to open the valves and admit steam to the turbine.

During anELAP, procedures ensure that the TVs are open by removing powerfrom the solenoids to vent the actuators, and the TDAFW pumpturbine steam flow will be controlled automatically by the governorvalve or manually with the overspeed trip/throttle valve. In the eventthe TDAFW pump fails to start, procedures direct the operators tomanually reset and start the pump (which does not require electrical power for motive force or control).

Approximately 50 minutes areavailable to manually start the pump and initiate flow prior to steamgenerator dryout (Reference 8). The TDAFW pump is sized to providemore than the design basis AFW flow requirements and is located in aPage 12 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 2structure designed for protection from applicable design basis externalhazards.2.3.4.2 Steam Generator Power Operated Relief Valves (PORVs)During an ELAP/LUHS event with the loss of all AC power andinstrument air, reactor core cooling and decay heat will be removedfrom the SGs for an indefinite time period by manuallyopening/throttling the SG PORVs, which are equipped with backup airbottles.

The SG PORVs are safety-related, missile protected, seismically qualified valves. Power to the SG PORV controllers in theMCR will be provided by the Class 1 E batteries in Phase 1 and by theportable 120/240 VAC or 480 VAC diesel generators in Phases 2 and3. Controlling the SG PORVs from the MCR will aid in minimizing fieldaction and maximizing SG PORV control response.

Operation of theSG PORVs from the MCR will continue until air supply from therespective back-up air receivers is depleted, at which time manualcontrol will be initiated via local manual hand wheel control, or thebackup air receivers will be recharged by a portable diesel driven aircompressor stored in the BDB Storage Building.

2.3.4.3 Batteries The safety-related Class 1 E batteries and associated DC distribution systems are located within safety-related structures designed to meetapplicable design basis external hazards and will be used to initially power required key instrumentation and applicable DC components.

Load stripping of non-essential equipment has been conservatively calculated to provide a total service time of 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> of operations.

2.3.4.4 Diesel Driven Fire Pump and Fire Protection PipingThe Diesel Driven Fire Pump (DDFP) is located within a safety-related structure and is, therefore, protected against applicable design basisexternal hazards.

The FP piping from the pump to the suction of theTDAFW pump is also Seismic Category I, tornado missile protected and therefore determined to be robust as defined in NEI 12-06. TheFP system will be pressurized by the DDFP, which provides waterfrom the SW Reservoir at sufficient flowrate and pressure to supportTDAFW pump operation.

Page 13 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 22.3.4.5 Emergency Condensate Storage TankThe Emergency Condensate Storage Tank (ECST) provides an AFWwater source at the initial onset of the event. The tank is a safety-related,

seismic, tornado missile protected structure and is, therefore, designed to withstand the applicable design basis external hazardsstated in NEI 12-06 (Reference 3). ECST volume is maintained greater than or equal to 110,000 gallons per Surveillance Requirement 3.7.6.1 of the North Anna Technical Specification (Reference

9) and is normally aligned to provide emergency makeupto the SGs. The ECST minimum usable volume is approximately 96,000 gallons.2.3.4.6 Service Water Reservoir The SW Reservoir has approximately 22.5 million gallons of storagecapacity (Reference 15). Since the SW pumps are not available during a BDB ELAP event, the full volume of the SW Reservoir isavailable as a water source for the AFW system. Refer to Section2.15 for discussion of water quality.2.3.5 FLEX Strategy Connections 2.3.5.1 Primary AFW Pump Connection The primary connection to supply AFW to the SGs is located on theTDAFW pump discharge line in the AFW Pump House (Figures 12and 13). A flexible hose will be routed from the BDB AFW pumpdischarge to the primary connection inside the AFW Pump House.Hydraulic analysis of the flowpath from the BDB ECST refillconnection to the primary BDB AFW pump discharge connection hasconfirmed that applicable performance requirements are met.2.3.5.2 Alternate AFW Connection In the event that the primary AFW connection is not available, analternate connection location is provided.

The alternate AFWconnection for SG injection is located in the main feedwater system inthe Mechanical Equipment Room located in the Service Building, which is separate from the AFW Pump House. The connection consists of a hose adapter that replaces the valve bottom flangeconnection on one of three main feedwater regulating bypass valvesPage 14 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 2(Figures 12 and 13). A flexible hose will be routed from the BDB AFWpump discharge to the alternate connection hose adapter.

The mainfeedwater header will be pressurized.

The flow to the SGs will bemanually controlled by operating the main feedwater regulating bypass valve for each SG. Hydraulic analysis of the flowpath from theBDB ECST Refill connection to the alternate AFW Pump discharge connection confirmed that applicable performance requirements aremet.2.3.5.3 ECST Connection (AFW Pump Suction)A suction and/or refill connection to the ECST is installed to provide asuction source to portable equipment or to facilitate refill of the ECST.The connection is seismically designed and located inside the AFWPump House. The connection includes a hose coupling suitable foreasy connection of a fire hose supplying water from the BDB HighCapacity pump or one of the other sources of water to refill the ECST(Figures 14 and 15).2.3.5.4 Primary RCS Connection The primary connection for RCS makeup is a connection locateddownstream of the Low Head Safety Injection (LHSI) pump discharge motor operated valves to the RCS hot legs (Figures 2 and 3).2.3.5.5 Alternate RCS Connection The alternate RCS connection utilizes a connection to a standpipe located in the Auxiliary Building basement that extends to anaccessible area in the Hydrogen Recombiner Vault (Figures 4 and 5).The BDB RCS Injection pump discharge

connects, via a highpressure hose, to the inlet (upper end) of the standpipe connection.

Aspectacle flange is attached to the standpipe outlet (lower end) to aconnection located on the Unit 2 normal charging header. The BDBRCS Injection pump can deliver borated water from the RWST or theportable boric acid mixing tank to the RCS via the normal chargingheader. This connection's location in the Auxiliary

Building, along withthe charging system flowpath utilized by the connection, provide thephysical and train separation required per NEI 12-06 from the primaryconnection.

The cross-ties in the normal charging system provide thecapability to inject borated water into either unit from this location.

InPage 15 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 2the event that only one RCS Injection pump is available, this alternate connection would be used to alternate RCS injection/makeup betweenthe units.2.3.5.6 RWST Suction Connection The primary supply of water to the BDB RCS Injection pump isthrough a suction connection from the RWST via a permanent hoseconnection.

The connection is installed in one of two quench spraypump's suction elbows for each unit, allowing borated water from theRWST to be supplied to a portable BDB RCS Injection Pump (Figures2 and 3).In the event that one unit's RWST is damaged, the suction hose tothat unit's BDB RCS Injection pump can be routed from the oppositeunits RWST to provide a borated water source to the BDB RCSInjection pump.Each hose connection is capable of providing flow to the suction ofboth BDB RCS Injection pumps through either RWST.Alternately, if neither RWST is available, portable Boric Acid MixingTanks are available to batch borated water and provide borated waterto the suction of the BDB RCS Injection pumps.2.3.5.7 Primary Electrical Connection A receptacle panel for the 120/240 VAC DG cable connections islocated in the Cable Vault Rod Drive Room which provides connection to repower essential instrumentation from a portable 120/240 VAC DG(Figure 6). From the receptacle panel, cables are installed inseismically mounted raceways to two distribution panels, one for eachof the 120/240 VAC DG output circuits.

Each BDB distribution panelhas branch circuit breakers sized to feed the required loads.The cables required to connect the 120/240 VAC DG to the receptacle panel are stored in the Hydrogen Recombiner Control Panel Vault andare protected from seismic interactions,

missiles, flood, snow and ice;and are operable within the outside temperature ranges applicable tothe site.Page 16 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 22.3.5.8 Alternate Electrical Connection The receptacle panel for the 120/240 VAC DG connections located inthe Cable Vault Rod Drive Room also contains the 480 VAC DG cableconnections to repower 480 VAC loads including battery chargers(Figure 6). From the receptacle panel, cables are installed inseismically mounted raceways to the Class 1 E 480 VAC bus via pre-installed cable and conduit to Class 1 E 480 VAC MCC breakers.

2.3.5.9 4160 VAC Electrical Connection Two (2) 1-MW 4160 VAC generators delivered to the site from theNSRC will be connected to a distribution panel (also delivered fromthe NSRC) in order to meet the required Phase 3 4160 VAC loadrequirements for each unit. Due to the size of the equipment, the 4160VAC generators will be deployed to areas either near the existingEmergency Diesel Generator (EDG) Rooms (Figure 6) or by the largeopenings in the Unit 1 and 2 Turbine Buildings (Figure 11). The areanear the existing EDG rooms affords the simplest configuration toconnect to one of the two Class 1 E 4160 VAC buses for each unit, butspace outside of these rooms is limited.

Depending on the debrissituation, the Turbine Building openings may be the more viableoption for deployment.

In this case, either the Emergency Switchgear Room or the normal Switchgear Room would be used to tie the 4160VAC generators to one of the two Class 1 E 4160 VAC buses for eachunit (Figures 16 and 17).2.3.6 Key Reactor Parameters Instrumentation providing the following key parameters is credited for allphases of the reactor core cooling and decay heat removal strategy:

-FW Flowrate

-AFW flowrate indication will be available in the MainControl Room (MCR). AFW flowrate indication will be available for SG A,B, and C throughout the event.-SG Water Level -SG wide range (WR) water level indication will beavailable from the MCR, Auxiliary Shutdown (ASD) Panel, and locallywithin the AFW Pump House. SG narrow-range (NR) level indication willbe available from the MCR and ASD Panel. SG WR and NR levelindication will be available for SG A, B, and C throughout the event.Page 17 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 2-SG Pressure

-SG pressure indication will be available from the MCR, theASD Panel, and locally in the Main Steam Valve House (MSVH). SGpressure indication will be available for SG A, B, and C throughout theevent.-RCS Temperature

-RCS hot-leg and cold-leg temperature indication willbe available from the MCR (recorder only), the ASD panel, and the FuelBuilding.

RCS hot-leg and cold-leg temperature indication will beavailable throughout the event, but only "A" and "B" loop temperatures will be indicated in the Fuel Building.

-RCS Pressure

-RCS wide range pressure indication will be available forthe MCR, the ASD panel, and the Fuel Building.

RCS pressure indication will be available throughout the event.-Core Exit Thermocouple Temperature

-Core exit thermocouple temperature indication will be available in the MCR. This temperature indication will be available throughout the event.-ECST Level -ECST water level indication will be available from the MCR,the ASD Panel, locally using pressure indication installed on the ECSTrefill connection, and locally using pump suction gauges.-Pressurizer Level: Pressurizer level indication will be available from theMCR, ASD panel, and Fuel Building.

Pressurizer level indication will beavailable throughout the event.-Reactor Vessel Level Indication System (RVLIS):

RCS level indication from the RVLIS will be available from the MCR. Train "A" of RVLIS willbe also available on a recorder in the post accident monitoring (PAM)panel. RVLIS will be available throughout the event.-Excore Nuclear Instruments:

Indication of nuclear source range activitywill be available from the MCR and in the Fuel Building.

Indication will beavailable throughout the event.Portable BDB equipment is supplied with the local instrumentation needed tooperate the equipment.

The use of these instruments is detailed in theassociated FSGs for use of the equipment.

These procedures are based oninputs from the equipment suppliers, operating experience, and expectedequipment function in an ELAP.Page 18 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-1 2-049Attachment 2In the unlikely event that 125 VDC and 120 VAC Vital Bus infrastructure isdamaged, FLEX strategy guidelines for alternately obtaining the criticalparameters locally is provided in FSG-7, Loss of Vital Instrumentation orControl Power.2.3.7 Thermal Hydraulic Analyses2.3.7.1 Secondary Makeup Water Requirements Calculations were performed to determine the inventory required forcore decay heat removal, RCS cooldown, and to maintain steamgenerator levels and dryout times associated with the volumes ofvarious onsite AFW water sources.

The conclusions from thisanalysis showed that the existing Emergency Condensate Storagetank usable volume of approximately 96,000 gallons would bedepleted in approximately 4.2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> at which time another source ofwater would be required..

The additional source at North Anna is theexisting fire protection system with the Diesel Driven Fire Pump(DDFP) taking suction from the approximately 22.5 million gallon SWReservoir.

The additional 22.5 million gallons of water will besufficient for several weeks of decay heat removal.

Lake Annaprovides an additional source of water to extend decay heat removalcapability indefinitely, if required.

2.3.7.2 RCS ResponseThe model used for the determination of RCS response was the samemodel used in the generic analysis in Section 5.2.1 of WCAP-17601 (Reference 10), and updated for Westinghouse 3-loop plants inWCAP-17792 (Reference 11). Section 5.2.1 of WCAP-17601 provides a Reference Case which assumes standard Westinghouse OEM RCP seal packages to determine the minimum adequate corecooling time with respect to RCS inventory (i.e., core uncovery).

TheReference Case models a Westinghouse 4-loop plant with a coreheight of 12 feet (i.e., a 412 plant), a Tcold upper head, at 3723 MWt,with Model F Steam Generators and Model 93A/A-1 Reactor CoolantPumps.PWROG-14064 (Reference

12) indicates that the initiation time forreflux cooling will be set to 17.0 hours0 days <br />0 hours <br />0 weeks <br />0 months <br /> for the WCAP-17601, Section5.2.1, Westinghouse 4-loop Tcold Reference Case. PWROG-14064 Page 19 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 2also indicates that 17.0 hours0 days <br />0 hours <br />0 weeks <br />0 months <br /> can be used, as a conservative basis,for Westinghouse 3-loop Thot plants (i.e., for North Anna Units 1 and2).RCS inventory makeup will begin within 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> following the onsetof the ELAP condition.

Based on information from WCAP-17601 andWCAP-17792, reflux cooling is conservatively set at 17.0 hours0 days <br />0 hours <br />0 weeks <br />0 months <br /> withassumed leakage rates for Westinghouse OEM equivalent seals.North Anna has replaced the OEM equivalent seals on 2 of 3 RCPswith Flowserve N-9000 seals. An evaluation demonstrated that theintegrated RCS leakage, with at least 2 of 3 Westinghouse OEMequivalent seals replaced with Flowserve N-9000 seals, is less thanthe value used in WCAP-17792; therefore additional margin to refluxcooling is available for North Anna units.Since RCS inventory makeup will begin within 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> following theonset of the ELAP condition at 45 gpm makeup capacity, the refluxcooling condition will be avoided.2.3.8 Reactor Coolant Pump SealsNorth Anna Units 1 and 2 are Westinghouse 3-loop plants withWestinghouse RCP pumps and originally with Westinghouse OEM RCPseals. The original seals were replaced with an equivalent seal supplied byAREVA. North Anna intends to replace all the RCP seals with Flowserve N-9000 seals and has completed 2 of the 3 seal replacements on each unit asof the required FLEX implementation date. As stated in Section 2.3.7, anevaluation was performed comparing the integrated leakage for the NorthAnna configuration with the analyzed values used in WCAP-17792.

Leakagefrom the Flowserve seals is based on the Flowserve White Paper (Reference 13). Leakage from the Westinghouse OEM equivalent seals is based oninformation provided in PWROG-14015, Revision 1 (Reference 14). Basedon the comparative evaluation, the integrated leakage for the post-implementation North Anna RCP seal configuration (i.e., 2 of 3 sealsreplaced on each unit) is bounded by the analyzed values used in WCAP-17601 and WCAP-17792.

2.3.9 Shutdown Margin AnalysisA Shutdown Margin (SDM) Analysis was performed for the reactor core fromNorth Anna Unit 1, Cycle 23 (which was determined to be representative of aPage 20 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 2typical North Anna unit reload core) and determined that at least 1% SDM(Keff <0.99) is available up to 37 hours4.282407e-4 days <br />0.0103 hours <br />6.117725e-5 weeks <br />1.40785e-5 months <br /> following a reactor trip from fullpower. However, due to xenon decay, additional core boron is needed after37 hours in order to continue at the target (290 psig) SG pressure.

Calculations show that injection of approximately 4600 gallons of 2600 ppmborated water from the RWST will be adequate to meet shutdown reactivity requirements at the limiting End-of-Cycle condition and the core inlettemperature as low as 3660F. This additional boron requirement is met atless than 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> of RCS inventory makeup at 45 gpm. This makeup volumecan easily be accommodated by RCS volume shrink without venting theRCS.Since the RCS inventory makeup is initiated no later than 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> following an ELAP/LUHS event, the borated water injected into the RCS for inventory makeup is adequate to maintain core reactivity shutdown margin of 1 %following an ELAP/LUHS.

Dominion's Nuclear Analysis and Fuel Department performs checks for everyreload core to verify that the FLEX inventory management and reactivity control strategy remains adequate to maintain k-eff < 0.99 throughout theELAP event.The SDM calculation assumes a uniform boron mixing model. Boron mixingwas identified as a generic concern by the NRC and was addressed by thePressurized Water Reactor Owner's Group (PWROG).

The NRC endorsedthe PWROG boron mixing position paper (Reference

15) with the clarification that a one hour mixing time was adequate provided that the flow in all loopsis greater than or equal to the corresponding single-phase natural circulation flow rate (Reference 16). For 3-loop plants, such as North Anna, the time toreach this condition (two-phase natural circulation flow is less than single-phase natural circulation flow) is conservatively set at 17.0 hours0 days <br />0 hours <br />0 weeks <br />0 months <br /> (SeeSection 2.3.7.2).

Since RCS makeup will be initiated within 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br />, andthe pump capacity of 45 gpm is greater than the maximum RCS leakage at16 hours, the NRC clarification regarding single-phase flow has beenaddressed and a one hour mixing time is acceptable.

Since additional boronis not required until 37 hours4.282407e-4 days <br />0.0103 hours <br />6.117725e-5 weeks <br />1.40785e-5 months <br /> after the ELAP event, the SDM of at least 1% ismaintained.

If one of the two BDB RCS Injection pumps stored in the onsite BDB StorageBuilding is unavailable, the available BDB RCS Injection pump may be usedPage 21 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 2to supply RCS inventory makeup to both units by alternating RCS injection between the units. RCS injection would begin with the BDB RCS Injection pump supplying one of the two units for 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. Then the pump would bealigned to the opposite unit for the next 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> period. This would be doneusing the normal charging header cross-tie lines so the BDB RCS Injection pump would not need to be repositioned.

The alternating RCS injection process would be repeated until RCS level is indicated in the pressurizer(s),

or until such time as a RCS Injection pump could be received from the NSRCand deployed for RCS makeup to one of the two units. Since the BDB RCSInjection pump flow rate is more than double the RCP seal leak rateassociated with the North Anna RCP seal configuration (two Flowserve andone Westinghouse OEM equivalent seals), the approach of sharing the RCSInjection pump ensures adequate boron mixing which, therefore, maintains the required SDM previously discussed.

2.3.10 FLEX Pumps and Water Supplies2.3.10.1 Beyond-Design-Basis (BDB) High Capacity PumpThe BDB High Capacity pump is a nominal 150 psid at 1200 gpmpump that is shared between several functions.

The pump is sized toprovide AFW water supply of 300 gpm to each unit and 500 gpmSpent Fuel Pool makeup simultaneously.

Hydraulic analysis of theflowpath from each water source to the SFP and to the ECST or to theBDB AFW pump suction for both units has confirmed that applicable performance requirements are met.The BDB High Capacity pump is a trailer-mounted, diesel drivencentrifugal pump that is stored in the BDB Storage Building.

Thepump is deployed by towing the trailer to a designated draft locationnear the selected water source. One BDB High Capacity pump isrequired to implement the reactor core cooling and heat removalstrategy for both units. Two high capacity pumps are available tosatisfy the N+1 requirement.

The station's 50.54(hh)(2) high capacity pump can meet the flowrequirements for both the FLEX core cooling and SFP coolingstrategies that credit the BDB High Capacity pump. Therefore, the50.54(hh)(2) high capacity pump will meet the N+1 requirement.

The50.54(hh)(2) high capacity pump will be stored in Warehouse 10,Page 22 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 2which is reasonably protected from flooding, extreme heat, andextreme cold hazards.2.3.10.2 BDB AFW PumpConsistent with NEI 12-06, Appendix D, SG water injection capability is provided using a portable AFW pump through a primary andalternate connection.

The BDB AFW pump is a nominal 450 psid 300gpm pump. The BDB AFW pump is a trailer-mounted, diesel enginedriven centrifugal pump that is stored in the BDB Storage Building.

The portable, diesel-driven BDB AFW pump will provide a back-upmethod for SG injection in the event that the TDAFW pump can nolonger perform its function due to insufficient turbine inlet steam flowfrom the SGs. Hydraulic analyses has confirmed that the BDB AFWpump is sized to provide the minimum required SG injection flowrateto support reactor core cooling and decay heat removal.

Three BDBAFW pumps are available to satisfy the N+1 requirement.

2.3.10.3 BDB RCS Iniection PumpThe PWROG Core Cooling Position Paper (issued in conjunction withWCAP-17601) recommends that the RCS Injection pump requireddelivery pressure be established at the saturation pressure of thereactor vessel head +100 psi driving head to allow RCS injection.

Following the formula in the position paper, the required deliverypressure for the RCS Injection pump at North Anna is approximately 1886 psia. Accordingly, the BDB RCS Injection pump is capable ofdelivering a minimum flow of 45 gpm at a discharge pressure ofgreater than 2000 psig. Hydraulic analysis of the BDB RCS Injection pump with the associated hoses and installed piping systems confirmthat the BDB RCS Injection pump minimum flow rate and headcapabilities exceed the FLEX strategy requirements for maintaining RCS inventory.

One BDB RCS Injection pump is available for each North Anna unit.However, in the event of a failure of one of the pumps, the pumpdesign capacity is such that a single pump can be shared between theunits, thus meeting the N+1 requirement with two pumps.2.3.10.4 AFW Water SuppliesEmergency Condensate Storage Tank (ECST)Page 23 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 2The ECST provides the source of AFW at the onset of the event. Thetank is a safety-related, seismically

designed, tornado missileprotected structure and is, therefore, designed to withstand applicable design basis external hazards.

ECST volume is maintained withgreater than or equal to 110,000 gallons per Surveillance Requirement 3.7.6.1 of the Technical Specification (Reference

9) andaligned to provide emergency makeup to the SGs. The minimumusable volume is approximately 96,000 gallons.Service Water Reservoir The SW Reservoir has approximately 22.5 million gallons of storagecapacity of which 600,000 gallons is allocated in the design basis ofthe SW Reservoir volume for fire protection using the DDFP.However, since the SW pumps are not available during a BDB ELAPevent, the full volume of the SW Reservoir (22.5 million gallons ofwater) would be available to the Fire Protection system as a watersource for the AFW system. Refer to Section 2.15 for discussion ofwater quality.Lake AnnaLake Anna is a source of water for the ultimate heat sink. Refer toSection 2.15 for a discussion of water quality.2.3.10.5 Borated Water SuppliesTwo sources of borated water have been evaluated for use during aBeyond-Design-Basis event. Each borated water source is discussed below, in order of usage preference.

-Refueling Water Storage Tank: Each unit is equipped with oneRWST located at grade level just outside of its respective Safeguards Building.

The tanks are stainless steel, safety-related, seismically qualified storage tanks, but are not protected frommissiles.

During "at power" operations each operating unit's RWSTborated volume is maintained greater than 466,200 gallons at aboron concentration between 2600 and 2800 ppm. The RWST isthe preferred borated water source for the RCS Injection strategies.

-Portable Boric Acid Mixing Tank: In the event that both RWSTsare unavailable or become depleted, portable Boric Acid MixingPage 24 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 2Tanks are available to provide a suction source for the BDB RCSInjection pumps. These mixing tanks will be transported from theonsite BDB Storage Building and positioned near the respective BDB RCS Injection pump. Dilution water will be added to themixing tank by either a portable transfer pump, the BDB AFWpump, or from the BDB High Capacity pump header taking suctionfrom a clean water source. Bags of powdered boric acid will bemixed with dilution water to achieve the proper concentration formaintaining adequate shutdown margin while making up RCSinventory.

Each tank is equipped with an agitator to facilitate mixing of the boric acid although complete dissolution of thepowdered boric acid is not required since agitation will becontinued throughout the injection process.

The maximum boronconcentration that will be mixed is below the level at whichprecipitation concerns occur, even at temperatures down to 320F;however, a heater is also available to prevent tank freezing, ifnecessary.

2.3.11 Electrical AnalysisThe Class 1E battery duty cycle of eight (8) hours for North Anna wascalculated in accordance with the IEEE-485 methodology usingmanufacturer discharge test data applicable to the FLEX strategy as outlinedin the NEI white paper on Extended Battery Duty Cycles (Reference 17).The time margin between the calculated battery duration for the FLEXstrategy and the expected deployment time for FLEX equipment to supplythe DC loads is approximately two (2) hours for North Anna.The strategy to re-power the stations vital AC/DC buses requires the use ofdiesel powered generators.

For this purpose, each unit requires one120/240 VAC portable diesel generator.

One 480 VAC portable dieselgenerator per unit is available as an alternate re-powering option.The 120/240 VAC DGs are 40 KW, single phase, 60Hz, generators that aretrailer-mounted with a 100 gallon double-walled diesel fuel tank built into thetrailer.The 480 VAC diesel generators are 350 KW generators that are trailer-mounted with a 500 gallon double-walled diesel fuel tank built into the trailer.Additional replacement 480 VAC generators and 4160 VAC diesel poweredgenerators are available from the National SAFER Response Center (NSRC)Page 25 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 2for the Phase 3 strategy.

The specifications and ratings for this equipment are listed in Table 2.2.4 Spent Fuel Pool Cooling/Inventory The North Anna Spent Fuel Pool (SFP) is a common pool designed for both Unit 1and Unit 2. The basic FLEX strategy for maintaining SFP cooling is to monitor SFPlevel and provide sufficient makeup water to the SFP to maintain the normal SFPlevel.2.4.1 Phase 1 StrateqyEvaluations estimate that with no operator action following a loss of SFPcooling at the maximum design heat load, the SFP will reach 212'F inapproximately 9 hours1.041667e-4 days <br />0.0025 hours <br />1.488095e-5 weeks <br />3.4245e-6 months <br /> and boil off to a level 10 feet above the top of fuel in43 hours from initiation of the event. The Phase 1 coping strategy for spentfuel pool cooling is to monitor spent fuel pool level using instrumentation installed as required by NRC Order EA-12-051 (Reference 5).2.4.2 Phase 2 StrategyThe Phase 2 strategy is to initiate SFP makeup using either the BDB HighCapacity pump or the existing fire protection (FP) system through the BDBSFP makeup connection.

The BDB High Capacity pump would be deployedfrom the BDB Storage Building to an area near one of several available draftpoints (Figure 1). The discharge of the pump would be connected to theBDB SFP makeup hose connection outside of the Fuel building (Figure 18).Required hose lengths and fittings are also located in the BDB StorageBuilding.

The BDB High Capacity pump is trailer mounted and will be towedto the draft point, along with the necessary hoses and fittings, by towvehicles also located within the protected BDB Storage Building.

No deployment is required for use of the FP system as a SFP makeupsource.Additionally, as required by NEI 12-06, spray monitors and sufficient hoselength required for the SFP spray option are located in the BDB StorageBuilding.

2.4.3 Phase 3 StrategyAdditional Low Pressure/High Flow pumps will be available from the NSRCas a backup to the onsite BDB High Capacity pumps.Page 26 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 22.4.4 Structures,

Systems, and Components 2.4.4.1 Primary Connection The hose connection for the permanent, seismically designed primaryBDB SFP makeup connection is located on the outside wall of theFuel Building.

The BDB SFP makeup connection is sufficiently sizedto restore SFP level long-term after the loss of SFP cooling at amakeup rate of 500 gpm for SFP boil off.The new BDB SFP makeup connection line is a 4-inch line that teesinto the existing 6-inch emergency SFP makeup line (Figure 18). Theexisting line runs vertically along the south inside (concrete) wall ofthe Fuel Building between the 265-foot and the 270-foot elevations.

The new seismically supported 4-inch line is routed from the new teealong and through the south inside wall to the exterior connection location.

The new connection is supported from the outside wall ofthe Fuel Building at the 274-foot elevation near the Unit 1Containment above the vicinity where the buried emergency SFPmakeup header from the FP system enters the Fuel Building atelevation 265-foot.

A new check valve is installed inside the FuelBuilding in the 6-inch line upstream of the tee to prevent back flowthrough the FP piping from the connection.

A check valve in the new4-inch line inside the Fuel Building will prevent flow out of the newconnection line in the event that the existing emergency SFP makeupconnection is in use (supplied from the FP header).

The newconnection is a standard fire hose connection and is located outsidethe Fuel Building at approximately the 274-foot elevation.

Use of the primary BDB SFP makeup connection will not require entryinto the Fuel Building.

2.4.4.2 Alternate Connection The alternate Phase 2 strategy for providing makeup water to the SFPis to use the SFP refill equipment that is already in place. The FPsystem feeds the emergency SFP makeup line from the yard fire mainloop. The emergency SFP makeup line extends above the SFP sothat water can be discharged directly into the pool (Figure 18).The water source for the alternate strategy is the pressurized firemain, which can be pressurized by the Diesel Driven Fire PumpPage 27 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-1 2-049Attachment 2(DDFP) or the BDB High Capacity pump. The yard fire main is buriedand seismically qualified, and is expected to be able to provide waterduring a flooding event.2.4.4.3 Spray Option Connection An additional alternate strategy utilizes a spray option to achieve SFPmakeup. The spray strategy (as required by NEI 12-06 Table D-3 forproviding spray at 250 gpm/unit) is to provide 500 gpm flow throughportable spray monitors set up on the deck next to the SFP (Figure18). A hose will be run from the fire main or the discharge of the BDBHigh Capacity pump, through the Fuel Building door, and up to theSFP operating deck. From there, the hose may be run directly overthe side of the pool or to portable spray monitors.

When deployed, thetwo spray monitors will be connected via a wye that splits the pumpdischarge into two hoses. The two spray monitor hoses will be routedfrom the new fuel storage area to the SFP. The oscillating spraymonitors will be set up approximately 30 feet apart and 16 feet backfrom the SFP. These spray monitors will spray water into the SFP tomaintain water level.2.4.4.4 Fuel Building Ventilation Ventilation requirements to prevent excessive steam accumulation inthe Fuel Building are included in an existing site Abnormal Procedure (AP). The AP directs operators to open several rollup doors in theFuel Building to establish a natural circulation flowpath.

Airflowthrough these doors provides adequate vent pathways through whichsteam generated by SFP boiling can exit the Fuel Building.

BDBFLEX Support Guidelines (FSGs) implement this method of ventilation for the Fuel Building.

2.4.5 Key Reactor Parameters The key parameter for the SFP makeup strategy is the SFP water level. TheSFP water level is monitored by the instrumentation that was installed inresponse to Order EA-12-051, Reliable Spent Fuel Pool LevelInstrumentation (Reference 5).Page 28 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 22.4.6 Thermal-Hydraulic AnalysesAn analyses was performed that determined, with the maximum expectedSFP heat load immediately following a core offload, that the SFP will reach abulk boiling temperature of 212°F in approximately 9 hours1.041667e-4 days <br />0.0025 hours <br />1.488095e-5 weeks <br />3.4245e-6 months <br /> and boil off to alevel 10 feet above the top of fuel in 43 hours4.976852e-4 days <br />0.0119 hours <br />7.109788e-5 weeks <br />1.63615e-5 months <br /> unless additional water issupplied to the SFP. A flow of 101 gpm will replenish the water lost due toboiling.

Deployment of the SFP hose connection from the BDB HighCapacity pump within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> with a design flow of 500 gpm for the SFPwill provide for adequate makeup to restore the SFP level and maintain anacceptable level of water for shielding purposes.

2.4.7 FLEX Pump and Water Supplies2.4.7.1 BDB High Capacity Pump (Refer to 2.3.10.1)

The BDB High Capacity pump is a nominal 150 psid at 1200 gpmpump that is shared between several functions.

The BDB HighCapacity pump is a trailer-mounted, diesel driven centrifugal pumpthat is stored in the BDB Storage Building.

The pump is deployed bytowing the trailer to a designated draft location near the selectedwater source. One BDB High Capacity pump is sized to provide anAFW water supply of 300 gpm each to Unit 1 and Unit 2 and 500 togpm Spent Fuel Pool makeup simultaneously.

2.4.7.2 Service Water Reservoir The SW Reservoir has approximately 22.5 million gallon of storagecapacity of which 600,000 gallons is allocated in the design basis ofthe SW Reservoir volume for fire protection using the DDFP.However, since the SW pumps are not available during a BDB ELAPevent, the full volume of the SW Reservoir (22.5 million gallons ofwater) would be available to the Fire Protection system as a watersource for emergency SFP makeup. Refer to Section 2.15 fordiscussion of water quality.2.4.7.3 Lake AnnaLake Anna is a source of water for the ultimate heat sink. Refer toSection 2.15 for discussion of water quality.Page 29 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-1 2-049Attachment 22.4.8 Electrical AnalysisThe SFP will be monitored by instrumentation installed in response to OrderEA-1 2-051. The power for this equipment has backup battery capacity for 72hours. Alternative power will be provided within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> using onsiteportable generators, if necessary, to provide power to the instrumentation and display panels and to recharge the backup battery.2.5 Containment Integrity With an extended loss of all alternating current power (ELAP) initiated while eitherNorth Anna unit is in Modes 1-4, Containment cooling for that unit is also lost for anextended period of time. Therefore, Containment temperature and pressure willslowly increase.

Structural integrity of the reactor containment building due toincreasing Containment pressure will not be challenged during the first severalweeks of a BDB ELAP event. However, with no cooling in the Containment, temperatures in the Containment are expected to rise and could reach a pointwhere continued reliable operation of key instrumentation might be challenged.

Conservative evaluations have concluded that Containment temperature andpressure will remain below Containment design limits and that key parameter instruments subject to the Containment environment will remain functional for aminimum of seven days. Therefore, actions to reduce Containment temperature and pressure and to ensure continued functionality of the key parameters will not berequired immediately and will utilize offsite equipment during Phase 3.NOTE: The containment integrity strategy descriptions below are the same forboth of the two North Anna units. Any differences and/or unit specificinformation is included where appropriate.

2.5.1 Phase IThe Phase 1 coping strategy for Containment involves verifying Containment isolation per ECA-0.0, Loss of All AC Power, and monitoring Containment temperature and pressure using installed instrumentation.

Control roomindication for "A" and "B" train Containment wide range pressure and "A"train Containment temperature will be available for the duration of the ELAP.2.5.2 Phase 2The Phase 2 coping strategy is to continue monitoring Containment temperature and pressure using installed instrumentation.

Phase 2 activities Page 30 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 2to repower key instrumentation (Section 2.9.3) are required to continueContainment monitoring.

Containment temperature will be procedurally monitored and, if necessary, Containment temperature will be reduced to ensure that key instruments inside Containment will remain within analyzed limits for equipment qualification.

The choice of equipment qualification as a temperature limit isconservative.

Containment temperature reduction will require theimplementation of a Containment cooling strategy utilizing equipment provided in Phase 3. The various Containment cooling strategy options arediscussed in Section 2.5.3.2.5.3 Phase 3Necessary actions to reduce Containment temperature and ensurecontinued functionality of the key parameters will utilize existing plantsystems powered by offsite equipment during Phase 3. 4160 VAC power willbe needed to operate various station pumps. This capability will be providedby two 1 MW 4160 VAC portable generators per unit provided from theNSRC. The portable 4160 VAC generators and a distribution panel for eachunit will be brought in from the National SAFER Response Center (NSRC) inorder to supply power to either of the two Class 1 E 4160 VAC buses on eachunit. Additionally, by restoring the Class 1 E 4160 VAC bus, power can berestored to the Class 1 E 480 VAC buses via the 4160/480 VAC transformers to power selected 480 VAC loads.If the Service Water (SW) pumps are not available, then Low Pressure/High Flow diesel driven pumps (up to 5,000 gpm) from the NSRC will be available to provide flow to existing site heat exchangers to facilitate heat removalfrom the Containment atmosphere.

Several options were evaluated to provide operators with the ability toreduce the Containment temperature.

Each of these options require therestoration of multiple support systems to effectively remove heat from theContainment and reduce Containment temperature and pressure.

Ventilation Cooling Option (Preferred)

The ventilation option for Phase 3 Containment cooling is to establish Containment ventilation by either:0 Establishing Containment Air Recirculation Fan (CARF) coolingPage 31 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 2OREstablishing Control Rod Drive Mechanism (CRDM) coolingTo implement this option, the 4160 VAC generators from the NSRC will bealigned to power a Class 1 E 4160 VAC bus and a 480 VAC bus as described in Section 2.3.3. The 4160 VAC generators will provide power to the existingComponent Cooling (CC) Water system and the SW pumps (if available),

anInstrument Air (IA) system compressor, and either the CARF or the CRDMfan motors. Containment ventilation flow would be established by startingthe CARF, cooling with air flow through the CARF cooling coil unit, andrecirculating within the Containment.

IA system pressure will be restored toremotely operate valves inside Containment, as required.

SW system flowwill be established through a CC heat exchanger to provide a heat sink, andCC flow will be established through the CARF cooling coil unit and the CCheat exchanger to transfer heat to the SW system. In this manner, heat fromthe Containment atmosphere will be rejected to the ultimate heat sink via therecirculation of Containment air through the CARF cooling coil unit.Restoration of the CRDM fan cooling involves essentially the same stepsinvolved in the restoration of the CARF cooling capability.

The CRDM fansand the Containment Air Recirculation fans are both 480 VAC motors.In the event that the SW system pumps are unavailable, the SW system canbe pressurized by the site Diesel Driven Fire Pump (DDFP) drawing from theSW Reservoir.

Alternately, a portable NSRC Low Pressure

/ High Flow pump(or two NSRC Low Pressure/Medium Flow pumps) will be located near theSW pumphouse to draw from the SW Reservoir and discharge to the SWsystem via a flanged opening in the 36" piping in the Service Water PumpHouse Expansion Joint Vault using a hose adapter (Figure 19).Spray OptionA spray option is available to spray water into the Containment using theContainment Recirculation Spray (RS) system utilizing clean water fromthe Casing Cooling Tank (CCT) and the RWST (Figures 20 and 21).To utilize this option, the 4160 VAC generators from the NSRC will bealigned to power one of the Class 1 E 4160 VAC and 480 VAC buses oneach unit as described in Section 2.3.3, which will provide power to the RSpump 480 VAC (or 4160 VAC, depending upon the selected pump) motor.The Containment sump must be filled to provide a suction water source forthe RS pump. The CCT would be gravity drained to the Containment sump.Page 32 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 2Since the volume of water from the CCT is not sufficient to adequately fill theContainment sump, water from the RWST can be pumped through theQuench Spray (QS) ring header nozzles into Containment using either theNSRC Low Pressure

/ Medium Flow pump (up to 2500 gpm) or the BDBHigh Capacity pump connected to the BDB RCS Quench Spray (QS) pumpsuction connection, located in the Quench Spray Pump House (QSPH), anddischarging to the pre-fabricated BDB QS blind flange hose adapterconnection located in the Safeguards Building.

The CCT and RWST are not high wind and associated missile protected, and if unavailable as water sources to fill the Containment sump, adequatesump inventory can be provided from the Service Water Reservoir or LakeAnna. Suction strainers are provided for this use to prevent clogging of theQS ring header nozzles (Figure 22).This initial spray flow will fill the Containment sump in preparation forinitiation of RS flow. When the sump level is adequate, either an inside oroutside RS pump will be started to draw water from the sump and recirculate flow through the RS heat exchangers and the spray nozzles.

SW systemflow will be established through the RS heat exchangers to provide a heatsink. In this manner, Containment atmosphere heat will be rejected to theultimate heat sink via the sump water recirculation spray flowpath.

In the event that the SW system pumps are unavailable, cooling water flowto the RS heat exchanger will be established by pressurizing the SW systemas described for the Containment cooling ventilation option.2.5.4 Structures,

Systems, Components 2.5.4.1 Ventilation Cooling StrategyNo mechanical equipment connections are required for theContainment ventilation cooling option if the SW pumps are available.

If the SW pumps are not available, a Low Pressure/High Flow pumpfrom the NSRC will be connected to a flanged opening in the 36"piping in the Service Water Pump House Expansion Joint Vault usinga pre-fabricated hose adapter.2.5.4.2 Spray StrategyThe Containment spray option requires connections of BDBequipment to transfer water from the RWST (or Lake Anna) into thePage 33 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 2Containment sump. The RWST suction connection for a LowPressure/Medium Flow NSRC pump is located in the QSPH. Thedischarge connection is to the pre-fabricated BDB QS blind flangehose adapter connection located in the Safeguards Building.

The existing site equipment required to implement the Containment cooling options discussed above are components of safety-related systems and are both seismic category I structures and are alsoprotected from high wind generated

missiles, floods, and extreme highand low temperatures.

The Seismic Category 1 SW Pump House Expansion Joint Vault isdesigned to withstand missiles and high wind. The system connection points are located inside the structure and are protected from flooding, extreme cold, ice and snow, and extreme high temperature.

The remaining equipment required to implement the Containment cooling options discussed above is delivered to the site from theNSRC and is not subject to the site BDB hazards initiating the ELAP.2.5.5 Key Containment Parameters Instrumentation providing the following key parameters is credited for allphases of the Containment Integrity strategy:

-Containment Pressure:

Containment pressure indication is available inthe main control room (MCR) throughout the event (Trains A and B).-Containment Wide Range Temperature:

Containment wide rangetemperature indication is available in the MCR throughout the event(Train A only).-Containment Sump Level: Containment sump level indication is available in the MCR throughout the event (Train B only). Although this keyparameter is available for all phases of the Containment cooling strategy, it is only credited in Phase 3, specifically for the Containment coolingspray option.2.5.6 Thermal-Hydraulic AnalysesConservative evaluations have concluded that Containment temperature andpressure will remain below Containment design limits and that key parameter instruments subject to the Containment environment will remain functional for a minimum of seven days. The Containment temperature will bePage 34 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 2procedurally monitored and, if necessary, the Containment temperature willbe reduced using the options available to ensure that key Containment instruments will remain within their analyzed limits for equipment qualification.

2.5.7 FLEX Pump and Water SuppliesThe NSRC is providing a Low Pressure/High Flow pump (nominal 5,000gpm) which will be used if required to provide cooling loads to the SWsystem. A Low Pressure/Medium Flow (nominal 2,500 gpm) pump is alsoavailable from the NSRC, if needed. Water supplies are as described inSection 2.3.10 (i.e. SW Reservoir and Lake Anna).2.5.8 Electrical AnalysisOne (1) of the two (2) Class 1 E 4160 VAC buses is required for each unit torepower the Containment cooling options described above. The 4160 VACequipment being supplied from the NSRC will provide adequate power toperform the Phase 3 Containment cooling strategies.

The necessary components to implement the various Containment cooling options havebeen included in the calculations to support the sizing of the 4160 VACgenerators being provided by the NSRC. Accordingly, two (2) 1-MW 4160VAC generators and a distribution panel (including cable and connectors) are provided from the NSRC per unit.2.6 Characterization of External Hazards2.6.1 SeismicPer NEI 12-06 (Reference 2), seismic hazards must be considered for allnuclear sites. As a result, the credited FLEX equipment has been assessedbased on the current NAPS seismic licensing basis to ensure that at aminimum, N sets of credited BDB equipment remains accessible andfunctional after a Beyond Design Basis external event. The North Annaseismic hazard is considered to be the earthquake magnitude associated with the design-basis seismic event. Per Section 2.5.2.6 of the North AnnaUFSAR (Reference 18), the design-basis earthquake for structures foundedon rock is 0.12g for horizontal ground motion and .08g for vertical groundmotion. For structures founded on soil, the design-basis earthquake is 0.18gfor horizontal motion and 0.12g for vertical motion.Page 35 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 2As described in UFSAR Section 2.5.2.5.1, a magnitude

5.8 earthquake

occurred on August 23, 2011, with an epicenter approximately 11 miles fromthe site. The Peak Ground Acceleration (PGA) values developed fromrecorded motions as a result of this earthquake exceeded the horizontal andvertical design basis PGA values. However, evaluations performed following the earthquake have concluded that there was no significant physical orfunctional damage to seismically designed Structures,

Systems, andComponents (SSCs) and only limited effects on non-seismic plant structures and equipment.

In addition to the NEI 12-06 guidance, Near-Term Task Force (NTTF)Recommendation 2.1, Seismic, required that facilities re-evaluate the site'sseismic hazard. NAPS subsequently re-evaluated the seismic hazard anddeveloped a Ground Motion Response Spectra (GMRS) for the site basedupon the most recent seismic data and methodologies, and has found thatthe existing SSE does not envelop the new GMRS over the entire frequency range. This reevaluated seismic hazard is being addressed in the industryinitiative referred to as the Augmented Approach (EPRI Report3002000704).

The Augmented Approach requires plants to address theGMRS by performing the Expedited Seismic Evaluation Process (ESEP) asan interim measure while completing the long-term seismic risk evaluation.

The Augmented Approach evaluates the seismic capability of a subset ofFLEX-credited installed plant equipment to provide confidence that theequipment would retain function during and after a beyond design basisseismic event using seismic margins assessment to a Review Level GroundMotion (RLGM) capped at 2 x SSE from 1 to 10 Hz. NRC endorsement ofuse of the EPRI Augmented Approach was provided in Reference 32.For FLEX strategies, the earthquake is assumed to occur without warningand result in damage to non-seismically designed structures and equipment.

Non-seismic structures and equipment may fail in a manner that wouldprevent accomplishment of FLEX-related activities (normal access to plantequipment, functionality of non-seismic plant equipment, deployment ofBeyond-Design-Basis (BDB) equipment, restoration of normal plant services, etc.). The diverse nature of the FLEX strategies has been discussed.

Theability to clear haul routes from seismic debris to facilitate the deployment ofthe BDB Phase 2 equipment is addressed in Section 2.8.Page 36 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 22.6.2 External FloodingNorth Anna Power Station is located on Lake Anna, which has a nominalwater level at the 250 foot MSL elevation.

The watershed for Lake Anna is343 square miles. The release of any upstream body of impounded water,due to a seismic event or dam failure, would not have a significant impact onlake level and thus would not cause flooding at the site (UFSAR Section2.4.4). A potential cause of flooding at the site would be from high lake leveldue to runoff from an extreme precipitation event in the watershed.

An evaluation was performed to determine the highest potential lake leveldue to runoff of precipitation in the watershed.

The probable maximum floodwas generated using the unit hydrograph of April 1973 and the 48-hourprobable maximum precipitation (PMP) of 27.04 inches. The standardproject storm of 13.54 inches in 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> (approximately one-half of thePMP), is used for antecedent precipitation.

The antecedent precipitation isassumed to occur 5 days before the main storm, with 3 rainless daysbetween the storms. The resultant probable maximum flood still-water levelis elevation 264.2 feet. When wind surge and wave run-up, due to a 40 mphwind blowing in the most critical direction, are added to this height, there isan increase of 2.9 feet, plus a backwater allowance of 0.2 foot. The resultant upper-bound flood stage is at elevation 267.3, which is 3.7 feet below typicalplant grade (UFSAR Section 2A.2.1).A potential source of flooding is the local accumulation of water due toprecipitation.

UFSAR Section 2.4.2.2 states: "The site is relatively flat, andno concentration of runoff is expected on the flat areas. The drainage areathat will contribute to runoff on the site is not much larger than the site. Thearea west of the site will receive runoff from approximately 35 acres;however, the drainage facilities in this area have been designed for a 50-year storm." In this discussion, the site refers to the area around the TurbineBuildings and reactor Containments.

Since the site is not located on an estuary or open coast, surge flooding isnot a concern.

Tsunami flooding is not a concern for the site because of itsinland location.

Per NEI 12-06 (Reference 3), North Anna is considered a "wet" sitebecause the site is maintained "dry" by a permanently installed dike.The design-basis flood level is based on the maximum potential lakelevel of 267.3 feet MSL resulting from a PMP event over the Lake AnnaPage 37 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 2watershed causing a significant rise in lake level. Although the majorityof the site grade is above the design base flood level, the westernportion of the Unit 2 Turbine Building is protected by a dike to preventflooding during the design-basis flood. There is no deployment of FLEXequipment in the area west of the Unit 2 Turbine Building; therefore, there are no deployment limitations due to flooding from the design-basis flood.Since the original submittal of the Overall Integrated Plan, Dominion hascompleted and submitted the Flood Hazard Reevaluation Report(FHRR) (Reference

19) for North Anna as requested by the 10 CFR50.54(f) letter dated March 12, 2012. The reevaluation represents themost current flooding analysis for North Anna Units 1 and 2. Thereevaluation results were mostly bounded by the original North AnnaUFSAR site flooding vulnerabilities and characteristics, in that the non-events such as seiche and dam failures continued to be non-events.

The maximum flood level due to elevated lake levels resulting from aPMP event over the Lake Anna watershed exceeded the UFSAR valueby 0.1 foot. This difference is insignificant since the plant grade is nearly4 feet above this flood level. The only significant difference identified from the UFSAR was the local intense precipitation (LIP) event. Usingconservative drainage assumptions and current-day PMP rates, someareas of the site were subject to short term flooding which requiredminimal protective actions.

Details of the LIP event are provided inSection 2.1 of the FHRR (Reference 19). Consistent with Enclosure 2 ofthe March 12, 2012, letter, North Anna has implemented interim actions toaddress the higher LIP event levels relative to the current licensing basis.Additionally, North Anna will complete an Integrated Assessment and willprepare a report for the NRC. Submittal of the report is currently scheduled for September 2015 but is subject to extension by the NRC.2.6.3 Severe Storms with High WindThe current plant design basis addresses the storm hazards of hurricanes, high winds and tornados.

For hurricanes, a total of 51 tropical storms or hurricane centers wererecorded between 1871 and 1987 as passing within 100 nautical miles of theNorth Anna site. North Anna UFSAR Section 2.3.1 stated that an average ofapproximately two tropical storms or hurricanes pass within 100 nauticalPage 38 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 2miles of the North Anna plant site every 5 years. With the site beingapproximately 100 miles from the Atlantic Ocean, hurricanes and tropicalstorms tend to weaken before reaching the site.For extreme straight winds -the extreme 1-mile wind speed is defined as the1-mile passage of wind with the highest speed for the day. The extreme 1-mile wind speed at 30 feet above the ground, which is predicted to occuronce in 100 years, is 80 mph. The fastest wind speed recorded atRichmond, based on the 1951-1987 period, was 68 mph from the southeast in October 1954.For tornados and tornado missiles, the North Anna UFSAR indicates thatbetween January 1916 and December 1987, there were a total of 65tornadoes reported within a 50-mile radius of the site (UFSAR Section 2.3.1).The tornado model used for design purposes has a 300 mph rotational velocity and a 60 mph translational velocity (UFSAR Section 3.3.2).2.6.4 Ice, Snow and Extreme ColdSnowfalls of 4 inches or more occur, on average, once a year, and snowusually only remains on the ground from 1 to 4 days at a time. Richmondaverages about 14.6 inches of snow a year. The UFSAR states that anexamination of the period between 1977 and 1987, indicates that there wereonly six documented cases of ice storms in Louisa and the immediately surrounding counties.

Of these, two were reported to have caused seriousdamage (including damage to power lines and trees).Temperatures in the site region rarely fall below 10°F (UFSAR Section2.3.1). The lowest temperature recorded in Richmond was minus 120F inJanuary 1940 and the lowest recorded in Charlottesville was minus 90F inJanuary 1985 (UFSAR Table 2.3-2). Such low temperatures could adversely affect access to and the flowpath from Lake Anna or the Service WaterReservoir.

Ice could form on the surface of Lake Anna or the Service WaterReservoir and impact FLEX strategies.

However, capabilities are available to break through the ice, if needed, to provide access and a flowpath.

The UFSAR information is limited to data prior to 1987. Therefore, the highand low temperature data presented above has been confirmed to beaccurate based on published data for the southeast region of the UnitedStates through 2012.Page 39 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 22.6.5 High Temperatures Temperatures in the site region rarely exceed 95 OF (UFSAR Section 2.3.1).The peak temperature recorded in Richmond was 1050F in July 1977 and thepeak temperature recorded in Charlottesville was 1070F in September 1954(UFSAR Table 2.3-2).The UFSAR information is limited to data prior to 1987. Therefore, the highand low temperature data presented above has been confirmed to beaccurate based on published data for the southeast region of the UnitedStates through 2012.2.7 Protection of FLEX Equipment BDB equipment is stored in a single 10,000 sq. ft. concrete building that meets theplant's design-basis for both seismic and tornado-missile protection.

The BDBStorage Building was evaluated for the effect of local seismic ground motionsconsistent with the NAPS Ground Motion Response Spectrum (GMRS) developed for the site as a result of the seismic hazard reevaluation (See Section 2.6.1) andfound to have adequate structural margin to remain functional (i.e., collapse is notexpected and access to the interior retained).

The BDB Storage Building is located in the parking lot west of Warehouse

1. 5(Figure 22). This location is above the flood elevation from the most recent siteflood analysis.

The BDB Storage Building was designed and constructed to preventwater intrusion and designed to protect the equipment from the other hazardsidentified in Section 2.6.Analysis of component stored in the BDB Storage Building have been performed todetermine appropriate measures to prevent seismic interaction.

The fire protection and HVAC systems in the BDB Storage Building are seismically installed.

Thelighting,

conduits, electrical, and fire detection components are not seismically installed, but are considered insignificant and not able to damage BDB equipment.

The debris removal equipment required to support the implementation of the FLEXstrategies is also stored inside the BDB Storage Building in order to protect themfrom the applicable external hazards.

Therefore, the equipment will remainfunctional and deployable to clear obstructions from the pathway between the BDBequipment's storage location and its deployment location(s).

This debris removalequipment includes mobile equipment such as a front end loader and tow vehicles(tractors).

Page 40 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 2Deployment of the debris removal equipment and the Phase 2 BDB equipment fromthe BDB Storage Building is not dependent on offsite power. The buildingequipment doors are hydraulically operated with a battery backup and can also beopened manually.

The 50.54(hh)(2) high capacity pump can meet the flow requirements for both theFLEX core cooling and SFP cooling strategies cooling strategies that credit theBDB High Capacity pump and serves to meet the N+1 requirement.

The50.54(hh)(2) high capacity pump is stored in Warehouse 10, which is reasonably protected from flooding, extreme heat, and extreme cold hazards.2.8 Planned Deployment of FLEX Equipment 2.8.1 Haul PathsPre-determined, preferred haul paths have been identified and documented in the FLEX Support Guidelines (FSGs). Figure 22 shows the haul pathsfrom the BDB Storage Building to the various deployment locations.

Thesehaul paths have been reviewed for potential soil liquefaction and have beendetermined to be stable following a seismic event. Additionally, the preferred haul paths minimize travel through areas with trees, power lines, narrowpassages, etc. to the extent practical.

However, high winds can causedebris from distant sources to interfere with planned haul paths. Debrisremoval equipment is stored inside the BDB Storage Building and isprotected from the severe storm and high wind hazards such that theequipment remains functional and deployable to clear obstructions from thepathway between the BDB Storage Building and its deployment location(s).

The deployment of onsite BDB equipment in Phase 2 requires.that pathwaysbetween the BDB Storage Building(s) and various deployment locations beclear of debris resulting from BDB seismic, high wind (tornado),

or floodingevents. The stored BDB debris removal equipment includes tow vehicles(tractors) equipped with front end buckets and rear tow connections in orderto move or remove debris from the needed travel paths. A front end loaderwill also be available to deal with more significant debris conditions.

Phase 3 of the FLEX strategies involves the receipt of equipment from offsitesources including the NSRC and various commodities such as fuel andsupplies.

Delivery of this equipment can be through airlift or via groundtransportation.

Debris removal for the pathway between the site and thePage 41 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 2NSRC receiving "Staging Areas" locations and from the various plant accessroutes may be required.

The same debris removal equipment used foronsite pathways may also be used to support debris removal to facilitate road access to the site once necessary haul routes and transport pathwaysonsite are clear.2.8.2 Accessibility The potential impairments to required access are: 1) doors and gates, and 2)site debris blocking personnel or equipment access. The coping strategy tomaintain site accessibility through doors and gates is applicable to all phasesof the FLEX coping strategies, but is essential as part of the immediate activities required during Phase 1.Doors and gates serve a variety of barrier functions on the site. One primaryfunction,

security, is discussed below. However, other barrier functions include fire, flood, radiation, ventilation,

tornado, and HELB. These doorsand gates are typically administratively controlled to maintain their functionas barriers during normal operations.

Following a BDB external event andsubsequent ELAP event, FLEX coping strategies require the routing of hosesand cables through various barriers in order to connect portable BDBequipment to station fluid and electric systems.

For this reason, certainbarriers (gates and doors) will be opened and remain open. This departure from normal administrative controls is acknowledged and is acceptable during the implementation of FLEX coping strategies.

The ability to open doors for ingress and egress, ventilation, or temporary cables/hoses routing is necessary to implement the FLEX coping strategies.

Security doors and gates that rely on electric power to operate openingand/or locking mechanisms are barriers of concern.

The Security force willinitiate an access contingency upon loss of the Security Diesel and allAC/DC power as part of the Security Plan. Access to the Owner Controlled Area, site Protected Area, and areas within the plant structures will becontrolled under this access contingency as implemented by Securitypersonnel.

Access authorization lists are prepared daily and copies areprotected from the various BDB external events for use post-ELAP event.The plant MCR contains a duplicate set of security keys for use by plantOperations personnel in implementing the FLEX strategies.

Vehicle access to the Protected Area is via the double gated sally-port at theSecurity Building.

As part of the Security access contingency, the sally-port Page 42 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-1 2-049Attachment 2gates will be manually controlled to allow delivery of BDB equipment (e.g.,generators, pumps) and other vehicles such as debris removal equipment into the Protected Area.2.9 Deployment of Strategies 2.9.1 AFW Makeup StrategyLake Anna provides an indefinite supply of water, as makeup to theEmergency Condensate Storage Tank (ECST) for supply to the TurbineDriven Auxiliary Feedwater (TDAFW) pump or directly to the suction of theportable diesel driven BDB AFW pump. Lake Anna will remain available forany of the external hazards listed in Section 2.6. Additionally, the ServiceWater (SW) Reservoir is a safety-related, seismic Category I earthenstructure and will also remain available for any of the external hazards listedin Section 2.6.The portable, diesel driven BDB High Capacity pump will be transported fromthe BDB Storage Building to a draft location near the selected water source.A flexible hose will be routed from the pump suction to the water sourcewhere water will be drawn through a suction strainer and discharged througha strainer sized to limit solid debris size and prevent damage to the TDAFWor the BDB AFW pump. A flexible hose will be routed from the BDB HighCapacity pump discharge to the BDB ECST Refill connection or to thesuction of the portable BDB AFW pump. Water from the selected watersource can also be pumped to the Spent Fuel Pool.Both the primary BDB AFW pump discharge connection and the BDB ECSTRefill connection are located within the seismic Category I, tornado missileprotected AFW Pump House above the 272 foot floor elevation.

Portableheating will be provided in the event of an ELAP and extended extreme coldhazard to protect the connection from freezing.

The connection is protected from the external hazards described in Section 2.6.The alternate BDB AFW pump discharge connection is located within thenon-seismic Category I, non-missile protected portion of the ServiceBuilding.

As such, this connection point may not be available following aseismic event or extreme high wind condition.

The connection is protected from the other external hazards described in Section 2.6Figure 1 provides a diagram of the flowpath and equipment utilized tofacilitate this FLEX strategy.

Page 43 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-1 2-049Attachment 22.9.2 RCS Makeup StrategyThe RCS Injection pumps are stored in the BDB Storage Building and areprotected against all external hazards described in Section 2.6.The primary RCS Injection pump discharge connection is located inside ofthe Safeguards Building of each unit and provides a path to the RCS hot legsof that unit. Accordingly, these connections are protected against all BDBexternal hazards.The alternate RCS Injection pump discharge connection for both units islocated inside of the Hydrogen Recombiner Vault and provides a path to theRCS hot legs and cold legs of both units. Accordingly, these connections are protected against all BDB external hazards.The primary supply connection from the RWST for the RCS Injection pump islocated in the Quench Spray Pump House of each unit. Accordingly, theseconnections are protected against all BDB hazards.

Should the RWSTbecome unavailable, an alternate supply of borated water is available fromthe portable Boric Acid Mixing tanks stored in the BDB Storage Building.

Figure 1 provides a diagram of the flowpath and equipment utilized tofacilitate this strategy.

2.9.3 Spent Fuel Pool Makeup StrategyThe SFP makeup strategy will initiate makeup by deploying the BDB HighCapacity pump from the BDB Storage Building or by using the existing FPsystem installed emergency SFP makeup piping. The discharge of the BDBHigh Capacity pump will be connected to a hose connection outside of theFuel Building.

No deployment is required for use of the FP systememergency SFP makeup piping as a SFP makeup source.The BDB SFP makeup hose connection is located on the outside wall of theFuel Building and is seismically designed and missile protected.

The BDBSFP makeup connection is sufficiently sized to restore SFP level long termfollowing the loss of SFP cooling with a makeup rate of 500 gpm.Figure 1 provides a diagram of the flowpath and equipment utilized tofacilitate this strategy.

Page 44 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-1 2-049Attachment 22.9.4 Electrical StrateqyThe 120/240 VAC diesel generators (DGs) are stored in the BDB StorageBuilding and are, therefore, protected from the BDB external hazardsidentified in Section 2.6.One (1) 120/240 VAC DG for each unit will be deployed to the east or westalleyway (depending on the unit) adjacent to the Auxiliary Building.

The120/240 VAC DGs each have two output circuits.

Each circuit on the120/240 VAC DG includes an adjustable output breaker, weatherproof receptacle, flexible and weatherproof cable with weatherproof connectors atboth ends which connects to a receptacle panel located in the associated unit's Rod Drive Room. The connecting cables for both units are pre-staged in the Hydrogen Recombiner Control Panel Vault and are, therefore, protected from the BDB external event hazards identified in Section 2.6.The receptacle panel for the 120/240 VAC DG cables is seismically

mounted, protected from missiles, flood, snow and ice, and operable withinthe outside temperature ranges specified for the site. From the receptacle panel, cables in seismically mounted raceways have been installed to twonew BDB distribution panels, one for each output circuit.

Each BDBdistribution panel has branch circuit breakers sized to feed the requiredloads.The 480 VAC DGs are stored in the BDB Storage Building and are,therefore, protected from the BDB external event hazards identified inSection 2.6.The 480 VAC DGs will be deployed to the east or west alleyway (depending on the unit) adjacent to the locations of the 120/240 VAC DG deployment.

The 480 VAC DGs each have a set of color coded cables which connectfrom the deployed generators to a receptacle panel located in the associated unit's Rod Drive Room. The color coded cables from each generator outputcircuit will be connected with proper phase rotation to the color coded matingreceptacles in the receptacle panel located in the Rod Drive Room. Inaddition to color coding, a phase rotation meter is provided in the receptacle panel for each 480 VAC circuit.The protection for the 480 VAC DG connections is the same as for theprimary connections with the exception that the 480 VAC DG cables arestored in the BDB Storage Building with the generator and are, therefore, protected from the BDB external event hazards identified in Section 2.6.Page 45 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 22.9.5 Fueling of Equipment FLEX equipment is stored in the fueled condition.

Fuel tanks are typically sized to hold 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of fuel. Once deployed during a BDB external event, afuel transfer truck will refuel this equipment in the first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> or sooner asrequired.

The general coping strategy for supplying fuel oil to diesel drivenportable equipment being utilized to cope with an ELAP/LUHS is to draw fueloil out of any available existing diesel fuel oil tanks on the North Anna site.The following onsite fuel sources will be used to refuel the FLEX equipment via the fuel transfer truck (or portable containers) as required.

The primary source of diesel fuel for portable equipment is the emergency diesel generator (EDG) Fuel Oil Day Tanks. These four tanks contain 800gallons of diesel fuel each (a total of 3200 gallons) and are seismically mounted and housed in the tornado protected EDG rooms. Fuel can beobtained using the tank drain valve and a flexible hose. Fuel can be gravityfed to suitable fuel containers for transport to BDB equipment.

No pumps arenecessary.

A second source for diesel fuel is the two EDG underground Diesel Fuel OilStorage Tanks. Each tank has a 45,000 gallon capacity.

These tanks areprotected from high wind tornado missiles by virtue of the underground location and are also protected from seismic and flooding events. Fuel canbe obtained using a fuel pump and attaching the pump suction to any of theeight (8) EDG fuel transfer pump suction strainer drain valves and pumpingthe diesel fuel to suitable fuel containers for transport.

A third source is the EDG above ground Diesel Fuel Oil Storage Tank thathas a 275,000 gallon capacity.

This tank is protected from flooding, but is notseismic or tornado protected.

Fuel can be obtained using the tank drainvalve located inside the flood wall. Fuel can be gravity fed to containers fortransport to BDB equipment or pumped from the tank fill.Diesel fuel in the fuel oil storage tanks is routinely sampled and tested toassure fuel oil quality is maintained to ASTM standards.

This sampling andtesting surveillance program also assures the fuel oil quality is maintained foroperation of the station Emergency Diesel Generators (EDGs).Portable equipment powered by diesel fuel are designed to use the samelow sulfur diesel fuel oil as the installed EDGs.Page 46 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-1 2-049Attachment 2The above fuel oil sources will be used to fill the fuel transfer truck that isstored in the BDB Storage Building.

The fuel transfer truck has a capacity ofapproximately 1,000 gallons and has a self-powered transfer pump. The fueltransfer truck will be deployed from the BDB Storage Building facility to refillthe diesel fuel tanks of BDB equipment and to the various diesel fuel tankstorage locations where it will be refueled by either gravity fill or pumped full.Based on a fuel consumption study, a conservative combined fuelconsumption rate was determined to be 120 gal/hr. The fuel transfer truckhas sufficient capacity to support continuous operation of the major BDBequipment expected to be deployed and placed into service following a BDBexternal event. At this conservative fuel consumption rate, the two 45,000gallon underground Fuel Oil Storage Tanks, which are protected from theBDB external

hazards, have adequate capacity to provide the onsite BDBequipment with diesel fuel for >30 days. The NSRC will also be able toprovide diesel fuel for diesel operated equipment, thus providing additional margin.Continuous operation of the Diesel Driven Fire Pump (DDFP) will requirereplenishment of approximately 300 gallons of diesel fuel at a minimum of 22hour intervals.

If the DDFP is not operating, then diesel fuel for the BDBHigh Capacity pump will require replenishment of approximately 500 gallonsof diesel fuel at a minimum of 30 hour3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br /> intervals.

The diesel fuel consumption information above does not include diesel fuelrequirements for the portable 4160 VAC diesel generators (DGs) to bereceived from the NSRC. More than adequate diesel fuel is available on sitefor these generators if the above ground 275,000 gallon Fuel Oil StorageTank is available.

If not, provisions for receipt of diesel fuel from offsitesources are in place to facilitate the Phase 3 re-powering strategy with theportable 4160 VAC DGs.The BDB external event response strategy includes a very limited number ofsmall support equipment that is powered by gasoline engines (chain saws,chop saws, and small electrical generator units). These components will bere-fueled using portable containers of fuel. Gasoline will be obtained fromthe station's two (2) 8,500 gal underground gasoline fuel storage tanks or, ifnecessary, from private vehicles on site. Oil for the 2-cycle engines is alsoavailable in the BDB Storage Building.

Page 47 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 22.10 Offsite Resources 2.10.1 National SAFER Response CenterThe industry has established two (2) National SAFER Response Centers(NSRCs) to support utilities during BDB events. Dominion has established contracts with the Pooled Equipment Inventory Company (PEICo) toparticipate in the process for support of the NSRCs as required.

Each NSRCwill hold five (5) sets of equipment, four (4) of which will be able to be fullydeployed when requested, the fifth set will have equipment in a maintenance cycle. In addition, onsite BDB equipment hose and cable end fittings arestandardized with the equipment supplied from the NSRC.In the event of a BDB external event and subsequent ELAP/LUHS condition, equipment will be moved from an NSRC to a local assembly areaestablished by the Strategic Alliance for FLEX Emergency Response(SAFER) team. From there, equipment can be taken to the North Anna siteand staged at the SAFER onsite Staging Area "B" near the BDB StorageBuilding by helicopter if ground transportation is unavailable.

Communications will be established between the North Anna plant site andthe SAFER team via satellite phones and required equipment moved to thesite as needed. First arriving equipment will be delivered to the site within 24hours from the initial request.

The order in which equipment is delivered isidentified in the North Anna's SAFER Response Plan (Reference 20).2.10.2 Equipment ListThe equipment stored and maintained at the NSRC for transportation to thelocal assembly area to support the response to a BDB external event atNorth Anna is listed in Table 2. Table 2 identifies the equipment that isspecifically credited in the FLEX strategies for North Anna, but also lists theequipment that will be available for backup/replacement should onsiteequipment be unavailable.

Since all the equipment will be located at thelocal assembly area, the time needed for the replacement of a failedcomponent will be minimal.2.11 Equipment Operating Conditions 2.11.1 Ventilation Following a BDB external event and subsequent ELAP/LUHS event at NorthAnna, ventilation providing cooling to occupied areas and areas containing Page 48 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 2FLEX strategy equipment will be lost. Per the guidance in NEI 12-06, FLEXstrategies must be capable of execution under the adverse conditions (unavailability of installed plant lighting, ventilation, etc.) expected following aBDB external event resulting in an ELAP/LUHS.

The primary concern withregard to ventilation is the heat buildup which occurs when forced ventilation is lost in areas that continue to have heat loads. A loss of ventilation analysis was performed to quantify the maximum steady state temperatures expected in specific areas related to FLEX implementation to ensure theenvironmental conditions remain acceptable for personnel habitability andwithin equipment qualification limits.The key areas identified for all phases of execution of the FLEX strategyactivities are the Main Control Room (MCR), Emergency Switchgear Room(ESGR), Main Steam Valve House (MSVH) (Steam Generator

-PORV area),Turbine Driven Auxiliary Feedwater (TDAFW) Pump Room, Quench SprayPump House, Auxiliary

Building, and the Mechanical Equipment Room in theTurbine Building.

These areas have been evaluated to determine thetemperature profiles following an ELAP/LUHS event. With the exception ofthe TDAFW pump room, results of the calculation have concluded thattemperatures remain within acceptable limits based on conservative inputheat load assumptions for all areas with no actions being taken to reduceheat load or to establish either active or passive ventilation (e.g., portablefans, open doors, etc.) In the case of the TDAFW Pump Room, an alternate ventilation method will be initiated within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> of the ELAP to ensure thatthe temperatures remain within the acceptable range for equipment andpersonnel habitability.

The alternate ventilation method will be required to bein effect as long as the TDAFW pump is in service.The temperatures expected in the MSVH for local operation of the SG PORV(Section 2.3.1) are similar to conditions experienced during normal stationoperations,

testing, and maintenance.

Therefore, actions performed forFLEX activities will be essentially the same as those performed for thecurrent site procedure ECA-0.0, Loss of All AC Power, which also addresses local operation of the SG PORVs.An additional ventilation concern applicable to Phase 2 is the potential buildup of hydrogen in the battery rooms. Off-gassing of hydrogen frombatteries is only a concern when the batteries are charging.

Once a 480VAC power supply is restored in Phase 2 and the station Class 1 E batteries Page 49 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 2begin re-charging, power is also restored to the battery room ventilation fansto prevent any significant hydrogen accumulation.

2.11.2 Heat TracingMajor components for FLEX strategies are provided with cold weatherpackages and small electrical generators to protect the equipment fromdamage due to extreme cold weather and help assure equipment reliability as well as to power additional heat tape circuits, if necessary.

In addition, the Emergency Condensate Storage Tank refill connection pressure gaugeinstrument tubing credited for BDB and subject to freezing conditions in anELAP event, will be protected with the use of portable heaters which can bepowered from small generators that have been procured and designated forFLEX strategies or from the small generators that are included as part of thelarge BDB pump skids.2.12 Habitability Habitability was evaluated as discussed in Section 2.11.1 in conjunction withequipment operabilty and determined to be acceptable.

2.13 LightingIn order to validate the adequacy of supplemental lighting and the adequacy andpracticality of using portable lighting to perform FLEX strategy

actions, a lightingstudy was completed.

Tasks evaluated included traveling to/from the various areasnecessary to implement the FLEX strategies, making required mechanical andelectrical connections, performing instrumentation monitoring, equipment operation, and component manipulation.

Except for the Unit 1 and Unit 2 Mechanical Equipment Rooms (MERs), the areasreviewed contain emergency lighting fixtures (Appendix "R" lighting) consisting of abattery, battery charger and associated light fixtures.

These emergency lights aredesigned and periodically tested to insure the battery pack will provide a minimumof eight (8) hours of lighting with no external AC power sources.

Therefore, thesecurrently installed emergency lighting fixtures provide adequate lighting to lightpathways and implement the BDB strategies for Phase 1 mitigation strategyactivities for 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.Prior to the depletion of the Appendix "R" lighting (and in the MERs), portablebattery powered Remote Area Lighting Systems (RALS) would be deployed toPage 50 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-1 2-049Attachment 2support the FLEX strategy tasks. These RALSs are rechargeable LED lightingsystems designed to power the LED lights for a minimum of 7 hours8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br /> at 6000 lumensor a maximum of 40 hours4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br /> at 500 lumens.There are no emergency lighting fixtures in the yard outside of the protected area toprovide necessary lighting in those areas where portable BDB equipment is to bedeployed.

Therefore, the large portable BDB pumps and diesel generators areoutfitted with light plants that are powered from either their respective dieselgenerators or batteries in order to support connection and operation.

In addition tothe lights installed on the portable BDB equipment, portable light plants areincluded in the FLEX strategies.

These portable diesel powered light plants can bedeployed from the BDB Storage Building as needed to support night timeoperations.

In addition to installed Appendix "R" lighting, the RALS, and the portable lightplants, the BDB Storage Building also includes a stock of flashlights and headbandlights to further assist the staff responding to a BDB event during low lightconditions.

2.14 Communications In the event of a BDB external event and subsequent ELAP, communications systems functionality could be significantly limited.

A standard set of assumptions for a BDB ELAP event is identified in NEI 12-01, Guideline for Assessing BeyondDesign Basis Accident Response Staffing and Communications Capabilities, May2012.Communications necessary to provide onsite command and control of the FLEXstrategies and offsite notifications at North Anna can be effectively implemented with a combination of sound powered phones, satellite phones, and hand-held radios.Onsite:Dedicated sets of sound-powered phone headsets and cords are available for theimplementation of the FLEX strategies between the control room, the Technical Support Center (TSC), and areas which implement the FLEX strategies (e.g.,TDAFW pump, SG PORVs, etc.). The operation of this sound-powered phonesubsystem is not dependent on the availability of the electric power system.Page 51 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 2Indoor and outdoor locations where temporary BDB equipment is used may also beserved with either hand-held radios, satellite phones, or sound-powered phoneheadsets connected with extension cords to nearby jacks.There are dedicated hand-held radios available for the implementation of onsiteFLEX strategies.

Sufficient batteries and chargers are also available.

Use of thehand-held radios is somewhat limited (on a point to point basis); however, aportable repeater mounted on a communications trailer will enhance theeffectiveness of the radios when the trailer is deployed.

Offsite:Satellite phones are the only reasonable means to communicate offsite when thetelecommunications infrastructure surrounding the nuclear site is non-functional.

They connect with other satellite phones as well as normal communications devices.NEI 12-01, Section 4.1 outlines the minimum communication pathways to thefederal, state, and local authorities.

Several handheld satellite phones are available for initial notifications.

These phones are distributed between the Main ControlRoom, the Technical Support Center, the Emergency Operations

Facility, Security, and Radiological Protection Office. Additionally, all of the local Offsite ResponseOrganizations (OROs) that normally receive licensee notifications of an emergency declaration or a Protective Action Recommendation are being provided with asatellite phone if they are within a 25 mile radius of the North Anna site.The MCR and TSC satellite phones are installed units. The antennae setup is adeployable system with fiber optics cable from the inside "desk sets" to an outdoor,battery powered, portable dish antennae.

This portion of the communications strategy is intended to function on batteries beyond the first 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. If necessary, the portable dish antennae can be powered by a small portable electric generator available from the BDB Storage Building.

Once augmented staff arrives on site aself-powered, mobile communications trailer designed to handle both satellite voiceand data traffic, as well as to function as a radio repeater to enhance onsitecommunications, will be deployed from the BDB Storage Building.

2.15 Water Sources2.15.1 Water Sources -Secondary SideTable 3 provides a list of potential water sources that may be used to providecooling water to the Steam Generators (SGs), their capacities, and anPage 52 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 2assessment of availability following the applicable hazards identified inSection 2.6. Descriptions of the preferred water usage sources identified inTable 3 are provided below and are in sequence in which they would beutilized, based on their availability after an ELAP/LUHS event. As noted inTable 3, at least three water sources would survive all applicable hazards forNorth Anna and are credited for use in FLEX strategies.

The water sources have a wide range of associated chemical compositions.

Therefore, extended periods of operation with the addition of these variouswater sources to the SGs were evaluated for impact on SG performance resulting from SG material (e.g., tube) degradation and potential impact onthe heat transfer capabilities of the SGs. Use of the available clean watersources, tanks and condenser, are limited only by their quantities.

The watersupply from Lake Anna and the SW reservoir/system is essentially unlimited by quantity, but is limited in quality, specifically the concentration of totalsuspended solids (TSS).The evaluation shows that the water from Lake Anna could be used forapproximately 25 days after Emergency Condensate Storage Tank (ECST)depletion before the SG design corrosion limit would be expected to bereached.

If a conservative TSS level of 500 ppm is assumed, the limiting SGprecipitation level would be expected to be reached about 10 days afterECST depletion.

Water from the Service Water Reservoir could be used forabout 11 days after ECST depletion before the SG design corrosion limitwould be expected to be reached.

If a conservative TSS level of 500 ppm isassumed, the limiting SG precipitation level would be expected to bereached about 9 days after ECST depletion.

Exceeding the expected time to reach the SG design corrosion limit wouldhave an insignificant impact on the ability of the SGs to remove core decayheat from the RCS at its reduced temperature/pressure conditions.

However, reaching the limiting SGs precipitation levels could potentially impact/reduce the SGs heat transfer capabilities.

The results of the water quality evaluation show that the credited, fullyprotected, onsite water sources provide an adequate AFW supply source fora much longer time than would be required for the delivery and deployment of the Phase 3 NSRC reverse osmosis (RO)/ion exchange equipment toremove impurities from the onsite natural water sources.

The RO units havea capacity of up to 300 gpm. Once the reverse osmosis/ion exchangePage 53 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-1 2-049Attachment 2equipment is in operation, the onsite water sources provide for an indefinite supply of purified water.2.15.2 Water Sources -Primary SideTwo credited sources for borated water are available onsite: the Refueling Water Storage Tanks (RWSTs) (one per unit) and the BDB Boric Acid MixingTanks that are stored in the BDB Storage Building.

These sources arediscussed in Section 2.3.10.5.

Borated water may also be available from thenon-credited Boric Acid Storage Tank.Clean water sources for use in batching borated water in the Boric AcidMixing Tanks would be used in the same order of preference provided inTable 3 for the AFW sources, dependent on availability.

2.15.3 Spent Fuel Pool (SFP)At North Anna, any water source available is acceptable for use as makeupto the SFP, however, the primary source would be from Lake Anna via theBDB High Capacity pump or the Service Water (SW) Reservoir via the DieselDriven Fire Pump. Water quality is not a significant concern for makeup tothe SFP. Likewise, boration is not a concern since boron is not beingremoved from the SFP when boiling.2.16 Shutdown and Refueling Modes AnalysisNorth Anna Power Station is abiding by the Nuclear Energy Institute position paperentitled "Shutdown/Refueling Modes," dated September 18, 2013, addressing mitigation strategies in shutdown and refueling modes (Reference 21). Thisposition paper has been endorsed by the NRC staff (Reference 22).The reactor core cooling and heat removal strategies previously discussed inSection 2.3 are effective as long as the Reactor Coolant System (RCS) is intact andthe steam generators (SGs) are available for use. The window between the loss ofnatural circulation availability (i.e., the SGs are isolated) and when the refueling cavity is flooded (at approximately 50-100 hours), is considered in the Modes 5 and6 core cooling strategy development.

During this window the reactor coolant loopsare isolated and the RCS is vented with the removal of at least one Pressurizer Safety Valve (PSV).Should an ELAP occur in this window, the immediate response to a loss ofshutdown cooling will be to dispatch an operator to initiate gravity feed to the RCScold legs from the outage unit's Refueling Water Storage Tank (RWST). ThisPage 54 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 2gravity feed injection path will utilize MOVs in the Safety Injection (SI) system thatcan be manually operated to initiate RCS injection by gravity feed. The SI system isseismically qualified and located in missile protected facilities; therefore, providing assurance it would survive a BDB event and be available to support gravity feedfrom the RWST. The gravity feed to the RCS cold legs strategy is expected toprovide adequate RCS cooling until forced feed can be established.

Unit shutdown procedures require the pre-deployment of a BDB AFW pump withsupply and discharge hoses to serve as a low pressure RCS Injection pump, whichwill provide a means to establish forced feed of borated water to the RCS cold legsfrom the RWST during an ELAP event with a unit in either Modes 5 or 6. Whenforced RCS injection is established by the BDB AFW pump, gravity feed to the RCScold legs will no longer be'necessary.

It is the intent of this strategy to transition from gravity feed to forced feed prior to the loss of gravity feed effectiveness.

The RWST is not protected from all hazards (i.e. tornado missiles).

In the unlikelyevent that a tornado missile damages the RWST, procedures will direct theoperators to use the opposite unit's RWST. If both RWSTs are damaged theprocedures will direct injection of available clean water sources in the orderspecified in Table 3. In this case, the flowrate will be reduced to match the boil-offrate of the RCS to minimize dilution of the RCS when adding unborated water. Thewater supply from Emergency Condensate Storage Tank (ECST) would beavailable following a tornado event, thus providing a method for restoring corecooling for all hazards during Modes 5 and 6.If an ELAP event results in a loss of RHR, the Operations staff is directed toestablish "Containment Closure."

This activity directs the evacuation of thecontainment and the closure of all open containment penetrations including thepersonnel access hatch and the equipment access hatch. Directions are alsoprovided to secure the Containment Ventilation System. The Modes 5 and 6 corecooling strategy will cause water/steam to "spill" into Containment causing theContainment pressure to slowly increase.

In order to maintain the Containment within its design pressure limits, a vent path is necessary and will be procedurally established following an ELAP event while in Modes 5 or 6.With the Containment Purge system operating (or aligned to operate),

aContainment vent path can be manually established through the "B" vent stack.The adequacy of this vent path for stopping containment pressurization anddepressurizing the containment has been confirmed by analysis.

Page 55 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 22.17 Sequence of EventsThe Table 4 presents a Sequence of Events (SOE) Timeline for an ELAP/LUHS event at North Anna. Validation of each of the FLEX time constraint actions hasbeen completed in accordance with the FLEX Validation Process document issuedby NEI and includes consideration for staffing.

Time to clear debris to allowequipment deployment is assumed to be 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />. This time is considered to bereasonable based on site reviews and the location of the BDB Storage Building.

Debris removal equipment is stored inside the BDB Storage Building and is,therefore, protected from the external hazards described in Section 2.6.2.18 Programmatic Elements2.18.1 Overall Program DocumentA Dominion nuclear fleet procedure provides a description of the Diverse andFlexible Coping Strategies (FLEX) Program for Surry, North Anna andMillstone Power Stations.

The key elements of the program include:" Maintenance of the FSGs including any impacts on the interfacing procedures (EOPs, APs, etc.)" Maintenance and testing of BDB equipment (i.e., SFP levelinstrumentation, emergency communications equipment, portableBDB equipment, BDB support equipment, and BDB support vehicles)

• Portable equipment deployment routes, staging areas, andconnections to existing mechanical and electrical systems" Validation of time sensitive operator actions" The BDB Storage Building and the National SAFER Response Center" Hazards considerations (Flooding,

Seismic, High Winds, etc.)" Supporting evaluations, calculations and BDB drawings" Tracking of commitments and equipment unavailability

" Staffing,

Training, and Emergency Drills" Configuration Management

" Program Maintenance In addition, the program description references (1) a list of the BDB FLEXbasis documents that will be kept up to date for facility and procedure Page 56 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment

2changes, (2) a historical record of previous strategies and their bases, and(3) the bases for ongoing maintenance and testing activities for the BDBequipment.

The instructions required to implement the various elements of the FLEXProgram and thereby ensure readiness in the event of a Beyond-Design-Basis External Event are contained in a nuclear fleet administrative procedure.

Existing design control procedures have been revised to ensure thatchanges to the plant design, physical plant layout, roads, buildings, andmiscellaneous structures will not adversely impact the approved FLEXstrategies.

Future changes to the FLEX strategies may be made without prior NRCapproval provided

1) the revised FLEX strategies meet the requirements ofNEI 12-06, and 2) an engineering basis is documented that ensures that thechange in FLEX strategies continues to ensure the key safety functions (Containment, core and SFP cooling) are met.2.18.2 Procedural GuidanceThe inability to predict actual plant conditions that require the use of BDBequipment makes it impossible to provide specific procedural guidance.

Assuch, the FLEX Support Guidelines (FSGs) provide guidance that can beemployed for a variety of conditions.

Clear criteria for entry into FSGsensures that FLEX strategies are used only as directed for BDB externalevent conditions, and are not used inappropriately in lieu of existingprocedures.

When BDB equipment is needed to supplement EOPs orAbnormal Procedures (APs) strategies, the EOP or AP directs the entry intoand exit from the appropriate FSG procedure.

FLEX support guidelines have been developed in accordance withPressurized Water Reactor Owner's Group (PWROG) guidelines.

The FSGsprovide instructions for implementing available, pre-planned FLEX strategies to accomplish specific tasks in the EOPs or APs. FSGs are used tosupplement (not replace) the existing procedure structure that establishes command and control for the event.Page 57 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 2Procedural Interfaces have been incorporated into 1/2-ECA-0.0, Loss of AllAC Power, to the extent necessary to include appropriate reference to FSGsand provide command and control for the ELAP. Additionally, procedural interfaces have been incorporated into the following APs to includeappropriate reference to FSGs:-0-AP-27, Malfunction of Spent Fuel Pit System-0-AP-1 0, Loss of Electrical Power-0-AP-1 1, Loss of Residual Heat Removal (RHR)Additionally, a new abnormal procedure, 0-AP-10.1, Loss of All AC PowerWhile on RHR, was prepared to provide the command and control functionfor the ELAP while on RHR since 1/2-ECA-0.0 does not apply in thisoperating mode.FSG maintenance is performed by the Station Procedures group via theProcedure Action Request in the Dominion nuclear fleet document AD-AA-100, Technical Procedure Process Control.

In accordance with siteadministrative procedures, NEI 96-07, Revision 1 (Reference 23), and NEI97-04, Revision 1 (Reference

24) are to be used to evaluate changes tocurrent procedures, including the FSGs, to determine the need for priorNRC approval.

However, per the guidance and examples provided in NEI96-07, Revision 1, changes to procedures (EOPs, APs, or FSGs) thatperform actions in response events that exceed a site's design-basis shouldscreen out. Therefore, procedure steps which recognize the BDBELAP/LUHS has occurred and which direct FLEX strategy actions to ensurecore cooling, containment, or SFP cooling should not require prior NRCapproval.

FSGs have been reviewed and validated by the involved groups to the extentnecessary to ensure that implementation of the associated FLEX strategy isfeasible.

Specific FSG validation was accomplished via table top evaluations and walk-throughs of the guidelines when appropriate.

2.18.3 StaffinqUsing the methodology of (Nuclear Energy Institute)

NEI 12-01, Guideline forAssessing Beyond Design Basis Accident Response Staffing andCommunications Capabilities (Reference 25), an assessment of thePage 58 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 2capability of the North Anna Power Station on-shift staff and augmented Emergency Response Organization (ERO) to respond to a BDB externalevent was performed.

The results were provided to the NRC in a letter datedMay 7, 2014 (Reference 26).The assumptions for the NEI 12-01 Phase 2 scenario postulate that the BDBevent involves a large-scale external event that results in:A. An extended loss of AC power (ELAP)B. An extended loss of access to ultimate heat sink (LUHS)C. Impact on both units (all units are in operation at the time of the event)D. Impeded access to the units by offsite responders as follows:-0 to 6 Hours Post Event -No site access.-6 to 24 Hours Post Event -Limited site access. Individuals mayaccess the site by walking, personal

vehicle, or via alternate transportation capabilities (e.g., private resource providers or publicsector support).

-24+ Hours Post Event -Improved site access. Site access isrestored to a near-normal status and/or augmented transportation resources are available to deliver equipment, supplies and largenumbers of personnel.

A team of subject matter experts from Operations, Maintenance, Radiation Protection, Chemistry,

Security, Emergency Preparedness, and IndustryConsultants performed tabletop exercises in December 2013 and January2014 to conduct the on-shift portion of the assessment.

The participants reviewed the assumptions and applied existing procedural

guidance, including applicable FLEX Support Guidelines (FSGs) for coping with a BDBexternal event using minimum on-shift staffing.

Particular attention was givento the sequence and timing of each procedural step, its duration, and the on-shift individual performing the step to account for both the task and timemotion analyses of NEI 10-05, Assessment of On-Shift Emergency Response Organization Staffing and Capabilities (Reference 27). Thestaffing analysis concluded that there were no task overlaps for the activities that were assigned to the on-shift personnel.

The expanded ERO analysis portion of the staffing assessment concluded that sufficient personnel resources exist in the current North AnnaPage 59 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 2augmenting ERO to fill positions for the expanded ERO functions.

Thus, theERO resources and capabilities necessary to implement Transition Phasecoping strategies performed after the end of the "no site access" 6-hour timeexist in the current program.The staffing assessments noted above were performed in conjunction withthe development of procedures and guidelines that address NRC Order EA-12-049. Once the FSGs were developed, a validation assessment of theFSGs was performed using communication equipment determined available post-BDB external event and the staff deemed available per the staffingstudies.

The validation process was performed and documented inaccordance with NEI Guidance (Reference 28).2.18.4 TrainingDominion's Nuclear Training Program has been revised to assure personnel proficiency in utilizing FSGs and associated BDB equipment for themitigation of BDB external events is adequate and maintained.

Theseprograms and controls were developed and have been implemented inaccordance with the Systematic Approach to Training (SAT) Process.Initial training has been provided and periodic training will be provided to siteemergency response leaders on BDB emergency response strategies andimplementing guidelines.

Personnel assigned to direct the execution of theFLEX mitigation strategies for BDB external events have received thenecessary training to ensure familiarity with the associated tasks,considering available job aids, instructions, and mitigation strategy timeconstraints.

Care has been taken to not give undue weight (in comparison with othertraining requirements) to Operator training for BDB external event accidentmitigation.

The testing/evaluation of Operator knowledge and skills in thisarea has been similarly weighted.

In accordance with Section 11.6 of NEI 12-06, ANSI/ANS 3.5, Nuclear PowerPlant Simulators for use in Operator Training (Reference 29), certification ofsimulator fidelity is considered to be sufficient for the initial stages of the BDBexternal event scenario until the current capability of the simulator model isexceeded.

Full scope simulator models will not be upgraded toaccommodate FLEX training or drills.Page 60 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 2Where appropriate, integrated FLEX drills will be organized on a team orcrew basis and conducted periodically; with all time-sensitive actions to beevaluated over a period of not more than eight years. It is not required toconnect/operate equipment during these drills.2.18.5 Equipment ListThe equipment stored and maintained at the North Anna BDB StorageBuilding necessary for the implementation of the FLEX strategies inresponse to a BDB external event is listed in Table 1. Table 1 identifies thequantity, applicable

strategy, and capacity/rating for the major BDBequipment components only, as well as various clarifying notes. Specificdetails regarding

fittings, tools, hose lengths, consumable

supplies, etc. arenot provided in Table 1.2.18.6 N+1 Equipment Requirement NEI 12-06 invokes an N+1 requirement for the major BDB FLEX equipment that directly performs a FLEX mitigation strategy for core cooling,containment, or SFP cooling in order to assure reliability and availability ofthe FLEX equipment required to meet the FLEX strategies.

Sufficient equipment has been purchased to address all functions at all units on-site,plus one additional spare, i.e., an N+1 capability, where "N" is the number ofequipment required by FLEX strategies for all units on-site.

Therefore, wherea single resource is sized to support the required function of both units asecond resource has been purchased to meet the +1 capability.

In addition, where multiple strategies to accomplish a function have been developed, (e.g., two separate means to repower instrumentation) the equipment associated with each strategy does not require N+1 capability.

The existing50.54(hh)(2) pump is counted toward the N+1, since it meets the functional and storage requirements outlined in NEI 12-06.The N+1 capability applies to the portable FLEX equipment that directlysupports maintenance of the key safety functions identified in Table 3-2 ofNEI 12-06. Other FLEX support equipment provided for mitigation of BDBexternal events, but not directly supporting a credited FLEX strategy, is notrequired to have N+1 capability.

In the case of hoses and cables associated with FLEX equipment requiredfor FLEX strategies, an alternate approach to meet the N+1 capability hasbeen selected.

These hoses and cables are passive components beingPage 61 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 2stored in a protected facility.

It is postulated the most probable cause fordegradation/damage of these components would occur during deployment ofthe equipment.

Therefore the +1 capability is accomplished by havingsufficient hoses and cables to satisfy the N capability

+ 10% spares or atleast 1 length of hose and cable. This 10% margin capability ensures thatfailure of any one of these passive components would not prevent thesuccessful deployment of a FLEX strategy.

The N+1 requirement does not apply to the BDB FLEX support equipment,

vehicles, and tools. However, these items are covered by a fleetadministrative procedure and are subject to inventory checks, requirements, and any maintenance and testing that are needed to ensure they canperform their required functions.

2.18.7 Equipment Maintenance and TestingInitial Component Level Testing, consisting of Factory Acceptance Testingand Site Acceptance

Testing, was conducted to ensure the portable FLEXequipment can perform its required FLEX strategy design functions.

FactoryAcceptance Testing verified that the portable equipment performance conformed to the manufacturers rating for the equipment as specified in thePurchase Order. Verification of the vendor test documentation wasperformed as part of the receipt inspection process for each of the affectedpieces of equipment and included in the applicable Vendor Technical Manuals.

Site Acceptance Testing confirmed Factory Acceptance Testing toensure portable FLEX equipment delivered to the site performed inaccordance with the FLEX strategy functional design requirements.

The portable BDB equipment that directly performs a FLEX mitigation strategy for the core cooling, containment, or SFP cooling is subject toperiodic maintenance and testing in accordance with NEI 12-06 (Reference

3) and INPO AP 913, Equipment Reliability

Process, (Reference 30), toverify proper function.

Additional FLEX support equipment that requiresmaintenance and testing will have Preventive Maintenance to ensure it willperform its required functions during a BDB external event.EPRI has completed and has issued Preventive Maintenance Basis for FLEXEquipment

-Project Overview Report (Reference 31). Preventative Maintenance Templates for the major FLEX equipment including the portablediesel pumps and generators have also been issued.Page 62 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 2The PM Templates include activities such as:" Periodic Static Inspections

-Monthly walkdown" Fluid analysis

-Annually" Periodic operational verifications

" Periodic performance testsPreventive maintenance (PM) procedures and test procedures are based onthe templates contained within the EPRI Preventive Maintenance BasisDatabase, or from manufacturer provided information/recommendations when templates were not available from EPRI. The corresponding maintenance strategies were developed and documented.

The performance of the PMs and test procedures are controlled through the site work orderprocess.

FLEX support equipment not falling under the scope of INPO AP913 will be maintained as necessary to ensure continued reliability.

Performance verification testing of FLEX equipment is scheduled andperformed as part of the Dominion PM process.A fleet procedure was established to ensure the unavailability of equipment and applicable connections that directly perform a FLEX mitigation strategyfor core cooling, containment, and SFP cooling will be managed such thatrisk to mitigation strategy capability is minimized.

Maintenance/risk guidanceconforms to the guidance of NEI 12-06 as follows:* Portable FLEX equipment may be unavailable for 90 days providedthat the site FLEX capability (N) is available.

" If portable equipment becomes unavailable such that the site FLEXcapability (N) is not maintained, initiate actions within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> torestore the site FLEX capability (N) and implement compensatory measures (e.g., use of alternate suitable equipment or supplemental personnel) within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.3. References

1. Letter to All Power Reactor Licensees, Request for Information Pursuant to Titleof the Code of Federal Regulations 50.54(o Regarding Recommendations 2.1,2.3, and 9.3, of the Near Term Task Force Review of Insights from the Fukushima DaiichiAccident, March 12, 2012, U.S. Nuclear Regulatory Commission.

Page 63 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment

22. NRC Order Number EA-12-049, Order Modifying Licenses with Regard toRequirements for Mitigation Strategies for Beyond-Design-Basis External Events,dated March 12, 2012.3. NEI 12-06, Diverse and Flexible Coping Strategies (FLEX) Implementation Guide,Revision 0, dated August 2012.4. NRC Interim Staff Guidance JLD-ISG-2012-01, Compliance with OrderEA-12-049, Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events, Revision 0, datedAugust 29, 2012.5. NRC Order Number EA-12-051, Order Modifying Licenses with Regard toReliable Spent Fuel Pool Instrumentation, dated March 12, 2012.6. NEI 12-02, Revision 1, Industry Guidance for Compliance with NRC Order EA-12-051, 'To Modify Licenses with Regard to Reliable Spent Fuel PoolInstrumentation',

Nuclear Energy Institute, August 2012.7. NRC Interim Staff Guidance JLD-ISG-2012-03, Compliance with OrderEA-12-051, Order Modifying Licenses with Regard to Reliable Spent Fuel PoolInstrumentation, Revision 0, dated August 29, 2012.8. Virginia Electric and Power Company's Supplement to Overall Integrated Plan inResponse to March 12, 2012 Commission Order Modifying Licenses with Regardto Requirements for Mitigation Strategies for Beyond-Design-Basis ExternalEvents (Order Number EA-12-049),

dated April 30, 2013 (Serial No. 12-162C).

9. North Anna Power Station Technical Specifications.

10. WCAP-17601, Revision 0, Reactor Coolant System Response to the ExtendedLoss of AC Power Event for Westinghouse, Combustion Engineering andBabcock & Wilcox NSSS Designs, August 2012.11. WCAP-17792-P, Revision 0, Emergency Procedure Development Strategies forthe Extended Loss of AC Power Event for all Domestic Pressurized WaterReactor Designs.12. PWROG-1 4064-P, Revision 0, Application of NOTRUMP Code Results for PWRsin Extended Loss of AC Power Circumstances, September 2014.13. White Paper on the Response for the N-Seal Reactor Coolant Pump (RCP) SealPackage to Extended Loss of AC Power (ELAP), Revision 0, dated February 11,2014 (Proprietary).

Page 64 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 214. Pressurized Water Reactor Owner's Group Report, PWROG-14015-P, Revision 1,No. 1 Seal Flow Rate for Westinghouse Reactor Coolant Pumps Following Lossof All AC Power, Task 2: Determine Seal Flow Rates, September 2014.15. "Westinghouse Response to NRC Generic Request for Additional Information (RAI) on Boron Mixing in Support of the Pressurized Water Reactor OwnersGroup (PWROG),"

dated August 16, 2013 (ML13235A135).

16. Letter to Mr. J. Stringfellow (Westinghouse) from Mr. J. R. Davis (NRC) datedJanuary 8, 2014 endorsing the Westinghouse Position Paper on Boron Mixing(ML13276A183).

17. Letter to Mr. J. E. Pollock (NEI) from Mr. J. R. Davis (NRC) endorsing NEI WhitePaper entitled "Battery Life Issue," dated September 16, 2013 (ML1 3241A1 82).18. North Anna Power Station Updated Final Safety Analysis Report (UFSAR),Revision 50.19. Virginia Electric and Power Company North Anna Power Station Units 1 and 2Flood Hazard Reevaluation Report in Response to March 12, 2012 Information request Regarding Flooding Aspects of Recommendation

2. 1, dated March 11,2014, (ML13318A090).

20. SAFER Response Plan for North Anna Power Station, Rev. 003, datedSeptember 25, 2015 (Document

1. 38-9229807-000).

21. NEI Position Paper: "Shutdown/

Refueling Modes," dated September 18, 2013(ML1 3273A514).

22. Letter to Mr. J.E. Pollock (NEI) from Mr. J. R. Davis (NRC) dated September 30,2013 endorsing NEI Shutdown/Refueling Modes Position Paper, (ML13267A382).

23. NEI Guideline 96-07, Revision 1, Guidelines for 10CFR50.59 Implementation, November 2000.24. NEI Guideline 97-04, Revision 1, Design Basis Program Guidelines, February2001.25. NEI 12-01, Rev. 0, Guidelines for Assessing Beyond Design Basis AccidentResponse Staffing and Communications.

26. Letter from D. A. Heacock to the USNRC transmitting North Anna Power StationPhase 2 Staffing Report, dated May 7, 2014, (Serial No.14-199).27. NEI 10-05, Rev. 0, Assessment of On-Shift Emergency Response Organization Staffing and Capabilities, June 2011.Page 65 of 102 BDB FLEX Mitigation Strategies Serial No. 14-394CFinal Integrated Plan Docket Nos. 50-338/339 North Anna Power Station Order EA-12-049 Attachment 228. NEI guidance document FLEX (Beyond Design Basis) Validation Process.29. ANSI/ANS 3.5-2009, Nuclear Power Plant Simulators for use in Operator Training.

30. INPO AP 913, Revision 3, Equipment Reliability Process Description, Institute ofNuclear Power Operations, March 2011.31. Preventive Maintenance Basis for FLEX Equipment

-Project Overview Report(EPRI Report 3002000623),

September 2013.32. Letter to Mr. J. E. Pollock (NEI), Electric Power Research Institute Final DraftReport XXXXXX, "Seismic Evaluation Guidance:

Augmented Approach for theResolution of Fukushima Near-Term Task Force Recommendation

2. 1: Seismic,"

As An Acceptable Alternative to the March 12, 2012, Information Request forSeismic Reevaluations, May 7, 2013, U.S. Nuclear Regulatory Commission (ML13114A949).

Page 66 of 102 BDB FLEX Mitigation Strategies Final Integrated PlanNorth Anna Power StationSerial No. 14-394CDocket Nos. 50-338/339 Order EA-12-049 Attachment 2Table 1 -PWR Portable Equipment Stored OnsiteUse and (Potential

/ Flexibility)

Diverse UsesPerformance CriteriaList Portable Equipment Core Containment SFP Instrumentation Accessibility BDB High Capacity diesel-driven pump (2)1 and X X X 150 psid at 1200 gpmassociated hoses and fittingsBDB AFW pump (3) andassociated hoses and fittings X 450 psid at 300 gpmBDB RCS Injection pump (2)2and associated hoses and X 3000 psid at 45 gpmfittings120/240 VAC generators (3)and associated cables, X 40 kWconnectors and switchgear 120/240 VAC generators (9)4and associated cables, X 5.5-6.5 kWconnectors and switchgear (topower support equipment)

Page 67 of 102 BDB FLEX Mitigation Strategies Final Integrated PlanNorth Anna Power StationSerial No. 14-394CDocket Nos. 50-338/339 Order EA-1 2-049Attachment 2Table 1 -PWR Portable Equipment Stored OnsiteUse and (Potential

/ Flexibility)

Diverse UsesPerformance CriteriaList Portable Equipment Core Containment SFP Instrumentation Accessibility 480 VAC generators (2)3 andassociated cables, connectors and switchgear (to re-power X X 350 kWbattery chargers, inverters, and Vital Buses)Portable boric acid batching X 1000 galtank (3)Light plants (2) + Light strings(15)4 XFront end loader (1)4 XTow vehicles (2)4 X X X XHose trailer (2) and Utilityvehicle (1)4Fans/blowers (10)4 XAir compressors (7)4 X X XPage 68 of 102 BDB FLEX Mitigation Strategies Final Integrated PlanNorth Anna Power StationSerial No. 14-394CDocket Nos. 50-338/339 Order EA-1 2-049Attachment 2Table 1 -PWR Portable Equipment Stored OnsiteUse and (Potential I Flexibility)

Diverse UsesPerformance CriteriaList Portable Equipment Core Containment SFP Instrumentation Accessibility Fuel transfer truck (1) with X X X X1,000 gal. tank and pumpsFuel carts with transfer pumps(2)4 X X X XCommunications equipment X X X XX(Section 2.14)Misc. debris removalequipment 4 XMisc. Support Equipment 4XPage 69 of 102 BDB FLEX Mitigation Strategies Final Integrated PlanNorth Anna Power StationSerial No. 14-394CDocket Nos. 50-338/339 Order EA-1 2-049Attachment 2Table 1 -PWR Portable Equipment Stored OnsiteUse and (Potential

/ Flexibility)

Diverse UsesPerformance CriteriaList Portable Equipment Core Containment SFP Instrumentation Accessibility NOTES:1. One BDB High Capacity pump is needed to implement both the FLEX core cooling and SFP cooling strategies.

This pump is stored inthe BDB Storage Building and protected from the hazards identified in NEI 12-06. The 50.54(hh)(2) high capacity pump is credited tomeet the N+1 requirement as a backup to the BDB High Capacity pump. This pump is stored onsite in a location other than the BDBStorage Building.

2. One BDB RCS Injection pump can be shared between units if necessary.

A BDB RCS Injection pump from the NSRC will be deployedfrom the NSRC by 28 hours3.240741e-4 days <br />0.00778 hours <br />4.62963e-5 weeks <br />1.0654e-5 months <br />, if required, to replace an unavailable onsite BDB RCS Injection pump.3. 480 VAC generators are an alternate strategy to the 120/240 VAC generators.

Therefore, only N is required.

4. Support equipment.

Not required to meet N+1.Page 70 of 102 BDB FLEX Mitigation Strategies Final Integrated PlanNorth Anna Power StationSerial No. 14-394CDocket Nos. 50-338/339 Order EA-12-049 Attachment 2Table 2 -PWR Portable Equipment From NSRCUse and (Potential

/ Flexibility)

Diverse UsesList Quantity Quantity Performance Req'd Provided Power Core Cont. RCS Criteria NotesPortable

/Unit I Unit Cooling/

Access Instrumentation rCEquipment Cooling tegrityInventory MediumVoltage 2 2 t X X X 41601 MW (1)Generators Turb. VACLow Voltage Jet 480 1100Generators Turb. ...VAC KWHighPressure 3000 600 1 Diesel X (2)Injection psig GPMpumpS/G RPV.... "==500 500Makeup 0 1 Diesel X 50 0 (2)pump.psid GPMpump ....LowPressure/

300 2500esu 0 1 Diesel X X psid GPMFlow pump,>" ': :!i", z : ...... .2Page 71 of 102 BDB FLEX Mitigation Strategies Final Integrated PlanNorth Anna Power StationSerial No. 14-394CDocket Nos. 50-338/339 Order EA-1 2-049Attachment 2Table 2 -PWR Portable Equipment From NSRCUse and (Potential

/ Flexibility)

Diverse UsesList Quantity Quantity Performance Port Req'd Provided Power Core Cont. RCS Criteria NotesPortable

/Unit / Unit Cooling/

Access Instrumentation rCEquipment Cooling tegrityInventory LowPressure/

1 150 5000High Flow iDiesel X X G (3)pumpLighting 40,000Towers 0 1 Diesel X Lu.(4).. .....i ;=..=:

uDiesel Fuel 0 As N/A X 264 (2)Transfer Requested GalMobile 1.0Water 0 2 Diesel X X (2)Treatment GPMMobile 1000* , ,.. ...: ....10 0 0Boration 0 1 N/A XGalSkidNotes:(1) -NSRC 4160 VAC generator supplied in support of Phase 3 for core cooling, containment

cooling, and instrumentation FLEX strategies.

(2) -NSRC Generic Equipment

-Not required for FLEX strategy

-Provided as Defense-in-Depth.

(3) -NSRC Low Pressure/High Flow pump supplied in support of Phase 3 for core cooling and containment cooling FLEX strategies.

(4) -NSRC components provided for low light response plans.Page 72 of 102 BDB FLEX Mitigation Strategies Final Integrated PlanNorth Anna Power StationSerial No. 14-394CDocket Nos. 50-338/339 Order EA-12-049 Attachment 2Table 3 -Water SourcesWater Sources andAssociated Piping that Fully Meet A// BDB Hazards and-Are Credited in FLEX Strategies Usable Applicable Hazard Cumulative Water Time BasedVolume on Decay Time BasedSources Satisfies Satisfies Satisfies Satisfies Satisfies Heat' on Decay(Gallons)

Seismic Flooding High Winds Low Temp High Temp Heat'ECST (Phase 1) 96,649 Y Y Y Y Y 4.2 hr. 4.2 hr.Service Water 82,000 sharedPiping between Unit 1 y y Y Y Y 4.2 hr. 8.3 hr.(Phase 1 alt.) and Unit 2Fire Main -Diesel 22.5 Millionfire pump> from shared betweenSW Reservoir Unit 1 and Unit 2 Y Y Y Y Y 46 hr.2 55 hr.(Phase 1)Lake WaterY Y Y Y Y Indef. Indef.(Phases 2 and 3)Page 73 of 102 BDB FLEX Mitigation Strategies Final Integrated PlanNorth Anna Power StationSerial No. 14-394CDocket Nos. 50-338/339 Order EA-1 2-049Attachment 2Table 3 -Water SourcesUsable Applicable Hazard Cumulative Water _____Time BasedVolume on Decay Time BasedSources Satisfies Satisfies Satisfies Satisfies Satisfies Heat' on Decay(Gallons)

Seismic Flooding High Winds Low Temp High Temp Heat'Water Sources that Partially Meet BDB Hazards and Are Not Credited in FLEX Strategies.

CST (2) 300,000 ea N Y N Y Y 66 hr. 121 hr.Primary Grade 178,238 eaWater Storage N Y N Y Y 49hr. 170 hrTanks (2)Condenser 71,000 eaN N Y Y Y 21 hr. 191 hr.Notes:1 Includes cooldown to a SG pressure of 290 psig beginning at 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />.2 Based on using 300,000 gallons/unit allotted for Fire Protection.

Page 74 of 102 BDB FLEX Mitigation Strategies Final Integrated PlanNorth Anna Power StationSerial No. 14-394CDocket Nos. 50-338/339 Order EA-1 2-049Attachment 2Table 4 -Sequence of Events TimelineTimeAction Personnel Activity Start Duration Constraint Requirement ItemY/NN/A Event Starts. 0 N Plant @ 100% powerRO -U1 TDAFW pump starts. Verify flow Original design basis for1RO -U2 to "A" SG. 15 sec. 1 min. N SBO event. 50 min to "A"SG dryout.RO -U1 ECA-0.0, Loss of All Power, 15 sec. N SBO event requiredRO -U2 procedure is entered.

response(1) 3RO -U1 Preserve inventory in the3 -U2 Verify RCS Isolation.

15 min. 5 min. N rsRO -U2 RCSAO #1 Re-Align AFW to all SGs and 50 min (to "B" and "C" SG4AO #2 control AFW flows. 20 min. 30 min. Y dryout, 1 hr to "A" SGAO # conrol FW fowsoverfill)

AO #5 Open Condenser Vacuum N Prior to shutdown of DC oil5 Breaker and vent hydrogen from 30 min. 30 min.AO #6 Main Generators.

pumps.RO -U1 Extends station Class 1 E6 Shutdown DC Oil Pumps. < 60 min. 1 min. Ybatery capity.RO -U2 battery capacity.

7 SRO ELAP declared

< 60 min. YAO #5 AO #6 90 min (extends station8 RO #3 Load strip 120 volt DC and Vital <60 min. < 30 min. Y Class 1 E battery capacity toAC buses. 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />)RO #4Page 75 of 102 BDB FLEX Mitigation Strategies Final Integrated PlanNorth Anna Power StationSerial No. 14-394CDocket Nos. 50-338/339 Order EA-12-049 Attachment 2TimeAction Personnel Activity Start Duration Constraint Requirement ItemYIN4hrs.Security

1. 1 (2 hrs. to clearSecurity

1. 2 Transport 120 VAC diesel 60 min. haul path and 2 y8 hrs. (station Class 1Egenerators to staging area. hrs. to transport batteries depleted) and deploygenerators.)

AO #1 Verify/Start diesel driven fire 4.2 hrs (reach minimum10 pump and align to AFW pump 90 min. 60 min. Y ECST level)AO #2 suction.AO #1 Block open door to TDAFW pump Required within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> for11 90 min 5 min long term equipment AO #2 room. operation.

-2 hrs.Decay heat removal,For cooldown cooldown of RCS. Initiation 12AO #3 Initiate RCS cooldown by < r. with limited Ywti r et h12 with lmitedY within 2 hrs meets theAO #4 controlling SG PORVs. ongoing control requirements of Genericfor decay heat ELAP analysis.

removalAO #5 8 hrs. (station Class 1 E13 AO #6 Re-power 120 VAC vital buses. 5 hr. 1 hr. Ybathries d letEAO #6 batteries depleted) 14 Augmented Staff Augmented staff arrive on site. 6 hrs. On-going N 6 hrs (Ref. NEI 12-01)Transport and deploy BDB High3 people -(Aug. Capacity pump (Drafting).

2 hrs. 8.3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> of AFW suction3 people Alternate connection for AFW 6 hrs. N supply if DDFP is notStaff) suction and SFP Make-up water available source.Page 76 of 102 BDB FLEX Mitigation Strategies Final Integrated PlanNorth Anna Power StationSerial No. 14-394CDocket Nos. 50-338/339 Order EA-1 2-049Attachment 2TimeAction Personnel Activity Start Duration Constraint Requirement ItemYINBack-up to 120 volt16 4 people -(Aug. Transport and deploy 480 VAC 7 hrs. 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> N generators for re-powering Staff) diesel generators.

Vital buses17 4 people -(Aug. Transport and deploy 10 Hrs 2 hrs N Off-site communications Staff)) communication equipment.

17.0 hours0 days <br />0 hours <br />0 weeks <br />0 months <br /> -Prior to refluxcooling and ensureadequate boron mixing.18 3 people -(Aug. Transport and deploy BDB RCS 12 hrs. 3 hrs. Y Reactivity control:

NotStaff) Injection pump. required for the first 37hours if SG pressure

>290psig.3 people -(Aug. Route BDB High Capacity pump 4 hrs. 9 hours1.041667e-4 days <br />0.0025 hours <br />1.488095e-5 weeks <br />3.4245e-6 months <br /> to boiling.

43 hour4.976852e-4 days <br />0.0119 hours <br />7.109788e-5 weeks <br />1.63615e-5 months <br />s19 people (Drafting) hose and add inventory 15 hrs. Y to water level at 10 feetStaff) to SFP. On-going (Batch) above fuelBDB AFW pumps are20 3 people -(Aug. Transport and deploy BDB AFW 19 hrs. 5 hrs. N deployed in standby as aStaff) pumps. backup to the TDAFWpumpProvide higher quality water21 Augmented Staff ECST Make-up.

20 hrs. 4 hrs. N sources for SteamGenerator make-up water.Supplemental lighting as3people-(Aug.

Transport and deploy additional neemental(lighting as22 3pol-portable light plants as needed. 24 hrs. 2 hrs N needed -(lighting towersStaff) (Supplemental lighting) are installed on largeportable equipment)

Page 77 of 102 BDB FLEX Mitigation Strategies Final Integrated PlanNorth Anna Power StationSerial No. 14-394CDocket Nos. 50-338/339 Order EA-12-049 Attachment 2TimeAction Personnel Activity Start Duration Constraint Requirement Item Y/NRestore containment Initiate Containment cooling temperature to <1p20 F23 Augmented Staff strategy to reduce temperature in 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> 24 hours Yaeith e functo ke yContainment.

affecting the function of keyparameter monitoring instrumentation RO -Reactor Operator, AO -Auxiliary OperatorPage 78 of 102 BDB FLEX Mitigation Strategies Final Integrated PlanNorth Anna Power StationSerial No. 14-394CDocket Nos. 50-338/339 Order EA-12-049 Attachment 2I(Main Plant Site)Figure 1: BDB FLEX Strategy Equipment and Hose Layout(Page 1 of 3)Page 79 of 102 BDB FLEX Mitigation Strategies Final Integrated PlanNorth Anna Power StationSerial No. 14-394CDocket Nos. 50-338/339 Order EA-12-049 Attachment 2AT1WW~T *: ........ ............

TO OWT P'UNT *\,4POINT(Draft Locations)

Figure 1: BDB FLEXStrategy Equipment and Hose Layout(Page 2 of 3)Page 80 of 102 BDB FLEX Mitigation Strategies Final Integrated PlanNorth Anna Power StationLEGENDI- RWST REFILL/SUCTION CONNECTION (U-I)2- AFW TO MOV HEADER (U-I)2A- ALT.S/G FEED (U-I)3- ECST REFILL (U-I)4- LHSI INJECTION (U-I)4A- ALT. RCS INJECTION (Ul & U2)5- SFP REFILL5A- ALT. SFP FILL6- RWST REFILL/SUCTION CONNECTION (U-2)7- AFW TO MOV-HEADER (U-2)7A- ALT. S/G FEED (U-2)8- ECST REFILL (U-2)9- LHSI INJECTION (U-2)9A- ALT. RCS INJECTION (U-2)10- PORTABLE BATCH TANK (U-1)11- PORTABLE BATCH TANK (U-2)Al- U-1 BOB HIGH CAPACITY PUMPBX- U-i BOB AFW PUMPB2- U-2 BOB AFW PUMPCl- U-1 BDB RCS INJECTION PUMPC2- U-2 BOB RCS INJECTION PUMPSerial No. 14-394CDocket Nos. 50-338/339 Order EA-1 2-049Attachment 2WATER SOURCESSYMBOLSY- CONNECTION

-7) ECSTE2 CST (NOT SHOWN)(3) PG TANKF ]UI/U2 CONDENSER HOTWELL'F7- LAKE ANNA(6) SERVICE WATER RESEVOIR (NOT SHOWN)F() SERVICE WATER PIPING (NOT SHOWN)F RWSTI?ABOVE GROUND HOSE LAY..........-

ALT. ABOVE GROUND HOSE LAYI I I ABOVE GROUND HOSE0BOB HIGH CAPACITY PUMPPORTABLE BATCH TANKBOB RCS INJECTION PUMPBOB AFW PUMP PUMPD BALL VALVErM.1 BUTTERFLY VALVEFigure 1: BDB FLEX Strategy Equipment and Hose Layout (Page 3 of 3)Page 81 of 102 BDB FLEX Mitigation Strategies Final Integrated PlanNorth Anna Power StationSerial No. 14-394CDocket Nos. 50-338/339 Order EA-12-049 Attachment 2SAFETY WNJECTION W& W WISSPRAY RMNG0,;IS;A)

-Mý 1LEGENOzQCD 80 MODIFICATION H HOSE 2 TANK OPTIONFigure 2: RCS Makeup Primary Mechanical Connection North Anna Unit 1Page 82 of 102 BDB FLEX Mitigation Strategies Final Integrated PlanNorth Anna Power StationSerial No. 14-394CDocket Nos. 50-338/339 Order EA-12-049 Attachment 2SAFETY INJECTION

, WJ w* w t .we CS INJECTION PU.MPa PSIGPORTABLEBATCHTANK 1LEOGNOsC Q WO8 MIF ICAI ION.---lHOSE ROUTE 2 TAWk OPTIONFigure 3: RCS Makeup Primary Mechanical Connection North Anna Unit 2Page 83 of 102 BDB FLEX Mitigation Strategies Final Integrated PlanNorth Anna Power StationiNSIDE MISSILE BARRIER OUTSIDE MCOLD LEG INSIOE CODLOOP ICOLO LEGLOOP 2COLO LEGLOOP 3FROMLOW° HEASAFETYINJECTION N OT LEGHOT LEGLOOP I I2F" HOT LEGLOOP 3Serial No. 14-394CDocket Nos. 50-338/339 Order EA-12-049 Attachment 2ISSILE BAR ITIII , UTSD CONTAINMENT

" FROM CHARGING PUMPDISCHARGE HEADERPEN 22O -s E86.7..C....

/kBORONIINJECTION TAW(1-sI-TK-2FROM CHARGING PUMPDISCHARGE HEADERFRbm LOW HEADSAFETY INJECTION MOV-12814A UPFIG 5)TUH.0/FOTO LOOP -FILL HEADER" ý27AFROMRWSTFROMVCTFigure 4: RCS Makeup Alternate Mechanical Connection North Anna Unit 1Page 84 of 102 BDB FLEX Mitigation Strategies Final Integrated PlanNorth Anna Power StationSerial No. 14-394CDocket Nos. 50-338/339 Order EA-12-049 Attachment 2LEOEE iKI% NO mOOIFICATION FROMRWStFigure 5: RCS Makeup Alternate Mechanical Connection North Anna Unit 2Page 85 of 102 BDB FLEX Mitigation Strategies Final Integrated PlanNorth Anna Power StationEm RooSerial No. 14-394CDocket Nos. 50-338/339 Order EA-12-049 Attachment 24KVG omao mn.VOw-o.Mfl46 VAC O6-~to480 VAC OmtO,12W124o VAC Gr.,'01201240 VAC Uni 1 R-.pt9de.

PeO3 S EA. 480 VAC Co-0msU 2 EA. 120/240 VAC Co00.n10.

3 EA. 48 VAC C.00.002 EA. 120124 VAC C.001U000

',4 1Figure 6: BDB Electrical Connection 120 VAC, 480 VAC, & 4160 VAC General LayoutPage 86 of 102 BDB FLEX Mitigation Strategies Final Integrated PlanNorth Anna Power StationSerial No. 14-394CDocket Nos. 50-338/339 Order EA-1 2-049Attachment 2KEY:MCR -MAIN CONTROL ROOMQ 8DB MODIFICATION LIGHTING PANELNORMAL FEEDREQUIRES ISOLATION I Note: Unit 2 Configuration is similar.mFigure 7: 120/240 VAC Portable Generator (BDB) Electrical Connection Panel #1 -North Anna Unit 1Page 87 of 102 BDB FLEX Mitigation Strategies Final Integrated PlanNorth Anna Power StationSerial No. 14-394CDocket Nos. 50-338/339 Order EA-12-049 Attachment 2LIGHTING PANELNORMAL FEEDREQUIRES ISOLATIOKEY:MCR -MAIN CONTROL ROOMO 808 MODIFICATION I Note: Unit 2 Configuration is similar.

IFigure 8: 120/240 VAC Portable Generator (BDB) Electrical Connection Panel #2 -North Anna Unit 1Page 88 of 102 BDB FLEX Mitigation Strategies Final Integrated PlanNorth Anna Power StationSerial No. 14-394CDocket Nos. 50-338/339 Order EA-12-049 Attachment 2FROM 4160V BUS IH14H- I1H (ESGR)C z-j 0o zI- -itU U4Tco1- tBATTERY RM Zz! I EXHAUST FANF-57BRM3 <BUS ".FROM 4160V BUS IJ ý- Mtn u4: XI MW ,,14J- IRECEPTACLE (ROUNIT I ALLEYWAY(EAST SIDE OF AUX BLDG)[ -----vC; _,'IIiI1- 11[480V PORTABLE DIESEL19NERATOR SKID IO-BDB-GEN-2A OR0- BOB- GEN- 282-Iv2NWJ :n<rrx- tog~xI WLaL<-1-WLLK4-.-- 1! -11 GND CONDUCTOR I-- 3 SINGLE PHASECONDUCTOR 7KEY:BD8 MODIFICATION CT- CABLE TUNNELRDR -ROD DRIVE ROOMESGR -EMERGENCY SWGR ROOMFigure 9: 480 VAC Portable Generator (BDB) Electrical Connections to480 VAC MCC 1 H and 1J -North Anna Unit 1Page 89 of 102 BDB FLEX Mitigation Strategies Final Integrated PlanNorth Anna Power StationFROM 4160V BUS 2HSerial No. 14-394CDocket Nos. 50-338/339 Order EA-12-049 Attachment 2FROM 4160V BUS 2H7L-I GNO CONDUCTOR

-R cRf I~lF (D'.,KEY: CONDUCTOR Q BB MODIFICATION 0CT -CABLE TUNNELRDR ROD DRIVE ROOMESOR -EMERGENCY SWGR ROOMROR -ROD DRIVE ROOMFigure 10: 480 VAC Portable Generator (BDB) Electrical Connections to480 VAC MCC 2H and 2J -North Anna Unit 2Page 90 of 102 BDB FLEX Mitigation Strategies Final Integrated PlanNorth Anna Power StationSerial No. 14-394CDocket Nos. 50-338/339 Order EA-12-049 Attachment 2~4~t rOT4'-0 I'-'t pcw4 KV Generator (Optional Location) f'-Unit 2 TurbineUnit 1 TurbineFigure 11: 4160 VAC Generator (NSRC) Electrical Connection General LayoutPage 91 of 102 IBDB FLEX Mitigation Strategies Final Integrated PlanNorth Anna Power StationSerial No. 14-394CDocket Nos. 50-338/339 Order EA-12-049 Attachment 2FP SWa P510ECSTIIIFROM -- ---I-CN-TK-2 IFROM BOBHIGH CAPICITYP UMPSUCTION SOURCES.LAK<E/SW RESERVOIR I-RC-E-1A TO STEAM GEN'ERATORi NTI-RC-E-IC 1-F -76~ INTALLATION IR- 1OR B* AF PUM TOSTEAM GENERATOR

":808 ECST PiERMANENT DICHARGET I0N--I"R FLLCONNECTION INSTAL.LATION

!~~~~~~~~~~~A W. W. ! ii!lll iiii iSifLEOENO2QD 808 MODIFICATION PRIMARY BOB AFW CONNECTIONS FROM MAINFEED PUMP STOALTERNATE BOB AFW CONNECTION Figure 12: Core Cooling and Decay Heat Removal AFW Primary andAlternate Mechanical Connections

-North Anna Unit 1Page 92 of 102 BDB FLEX Mitigation Strategies Final Integrated PlanNorth Anna Power StationFP SWdS7TO FRCRES! L.Cj 2-C0 PSIG +W77 +W6"-V (-F-77 NMFROM 808HIGH lTY lECS T -PERMANENT LAKE/SW RESERVOIR PRIMARY F8 AFW CONNECTIONS Serial No. 14-394CDocket Nos. 50-338/339 Order EA-12-049 Attachment 2rK-2..W.7TO STEAM GENERATOR 2-RC-E-IA NT -TO STEAM GENERATOR W4NN 4 --RC-E-IBINSTALLATION C"88 CAR G TO GENERATOR CONNECTION

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2-RC-E-IC LEGENDSQZ : SOS MODIFICATION TOTOTOI. _l-FCV-:498j I I I 2FW-E-A.AM GENERATOR 2-FW-37jj

!-1RC-E-IC -ELCA-OSE FROM MAIN(5FEED PUMPSALTERNATE BOB AF-W CONNECTION FROM2-FW-E-1B Figure 13: Core Cooling and Decay Heat Removal AFW Primary andAlternate Mechanical Connections

-North Anna Unit 2Page 93 of 102 BDB FLEX Mitigation Strategies Final Integrated PlanNorth Anna Power StationSerial No. 14-394CDocket Nos. 50-338/339 Order EA-12-049 Attachment 2LEGENOtCD 8D9BMODIFICATION4 FOIESEL DRIVENFIRE PUMP INSERVICE WATERPUWP HOUSEL(SERV ICE WATER RESERVOIR)

[SERV ICE WATERI(GRAVITY DRAIN OFLWATER IN SW PIPING)mlISTOAF,--W PUMP HOSBOB ECST-- PERMIANENT REFILL INSTALLATION CONNECT IONTO BOB AFW PUMP 0-0lO-P-eA OR IECST REFILLAM SUPPLYBOB AFW PUMPTO STEAM GENERATOR I-RC-E-IA TO STEAM GENERATOR I-RC-E-IB TO STEAM GENERATOR i-RC-E-tC

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H-----------

BOB TRANSFER PUMP#-M"P-" SOO HIGH CAPACITY PUMPOR -,.O-P-Ib 558 PUMPLAKE OR SWRESERVOIR ACM0OITlONAL-NON CREDITED WATER SOUESPG TANK (ALT)Figure 14: ECST Refill Mechanical Connections, Paths, and SourcesNorth Anna Unit 1Page 94 of 102 BDB FLEX Mitigation Strategies Final Integrated PlanNorth Anna Power StationSerial No. 14-394CDocket Nos. 50-338/339 Order EA-12-049 Attachment 2LEGENOi~c~ ION MO0IFICA0 PSIGECSTECST REF LLANO SUPPLY800 AW PUMP .T [ONDI ESEL DRI[VENF RE PUMP INI SERVICE WATERPUMP MOUSEE(SERV CE WATER RESERVOIR)

[SERVICE WATERL (GRAVITY ORAIN OFWATER IN SW PIPING)i I1 I II iIIAFAFWt ! --808 ECST-PERM;ZET REFILL INSTALLAT IONCONNECT IONTO BOB AFW PUMP I-BCS-P-OA oR 3-US-P-S808 TRANSFER PUMPTO STEAM GENERATOR 2-RC-E-1A TO STEAM GENERATOR 2-RC-E-lS TO STEAM GENERATOR 2-RC-E-IC

'-III-I'---oil"8-00844A BOB HIGH CAPAC ITY PUMPOR -EU-P-I B58 PUMPLAKES O RSRESERVOIR

/1IIII[A iitTIONL NtO CREDITED WATER SOURCES1PG TAWN (ALT)Figure 15: ECST Refill Mechanical Connections, Paths, and SourcesNorth Anna Unit 2Page 95 of 102 BDB FLEX Mitigation Strategies Final Integrated PlanNorth Anna Power Station4160V BUS IH (ESGR)Serial No. 14-394CDocket Nos. 50-338/339 Order EA-1 2-049Attachment 24IA.W-x UCL0.(IxI{L) -ILz 0- M-Czza. _jZOW. -.000 1 uIt~L)L) WWIKEYtQ BOB MODIFICATION ESGR -EMERGENCY SWGR ROOMROR -ROD DRIVE ROOMFigure 16: 4160 VAC Generator (NSRC) Electrical Connections to4160 VAC MCC 1H and 1J -North Anna Unit 1Page 96 of 102 BDB FLEX Mitigation Strategies Final Integrated PlanNorth Anna Power Station4160V OUS 2H (ESGR)Serial No. 14-394CDocket Nos. 50-338/339 Order EA-12-049 Attachment 215KEY:Q D8D MODIFICATION ESGR -EMERGENCY SWGR ROOMROR -ROD DRIVE ROOMFigure 17: 4160 VAC Generator (NSRC) Electrical Connections to4160 VAC MCC 2H and 2J -North Anna Unit 2Page 97 of 102 BDB FLEX Mitigation Strategies Final Integrated PlanNorth Anna Power StationSerial No. 14-394CDocket Nos. 50-338/339 Order EA-12-049 Attachment 2HOSE F" BOB HIGH CAPICITYPtJW SPRAY STRATEGYFUEL BUILDING vF[F HOSEACCESS DOOR-PRIMARY STRATEGY "LAKE ANNA /CANALALT SUCTION I-FP-54*SW RESERVOIR TO YARD ---t -TO YARDIIIDIESELIIc 4TO WAREHOUSE 5DRIVENSERVIEWATERPUM HOSELEGENOiQ: BOB MOCICMATION SUCTION FROMSERVICE WATERRESEVOIRALTERNATE STRATEGYFigure 18: Spent Fuel Pool Cooling Primary and Alternate Mechanical Connections Page 98 of 102 ETE-CPR-2012-0012 Revision 6Attachment 2NAPS Final Integrated Plan-ITIIKWTcs 4 Sarg S YSE I AI COOLG COILSMEMR3 MW WM SMIA3.--4) --~ ~ ~ --- --TtzwT~~~

Tam .t -SARA~~KA ICE WATERAAAF(h Ti H ALZ-RS- 2. S 2-AS 2 ITSE- IA E-B 10 -IC E: to-~~ý N -A-I GQraw,&RECIRCULATING AIR CM ING COILS-ajI RECIRCUILAT" 1 410 COOLIK COILSI HiramIINC,IA COOLING COILSOilI0-IAiiM-'III, ~ G~i~j-I;XLIE AID E- IC E- Is tA-* W V AFigure 19: Phase 3 Containment Cooling Connections Page 99 of 102 BDB FLEX Mitigation Strategies Final Integrated PlanNorth Anna Power StationSerial No. 14-394CDocket Nos. 50-338/339 Order EA-12-049 Attachment 2CONTAINMENT SUMP FILL FROM CASING COOLING TANKNSRC LOW PRESSURE/MEDIUM FLOW PUMP%ftt0*I 9AOMV-le~ TO RiSTPERM4ANENT asI NSTALLAT ION? I-S-6BOB RCS/QS PUMP f&SUCTION CONNECTION U WSFOR CONTAINMENT SUMP FILL LEGEND:FROM RWST. FLOW IS LIMITED BYTHE 4VDIA SUCTION CONNECTIONI BOB 5MODIFICATION Figure 20: Containment Cooling Phase 3 Containment SprayMechanical Connections North Anna Unit 1Page 100 of 102 BDB FLEX Mitigation Strategies Final Integrated PlanNorth Anna Power StationSerial No. 14-394CDocket Nos. 50-338/339 Order EA-12-049 Attachment 2CONTAINMENT SUMP FILL FROM CASING COOLING TANKFDA ADA ~JTAINt4FNT SPftA~FUt(TION-OR CONTAINMENT SULMP FILL.NC~BOB OS BLINO O( FLANGE --.-i 2 -GS-5 IC LOW PRESSURE/MEORIu FLOW PLP I FLNE TM0Na PSIG IS I 2-os 2S IM -200Aj \ i ~ ~PERM,,ANENT

-<" QINSTALLATION

! 2 OS.6..Ios 808 ACS/08 P1-SUCTION CONNCT IoN -/--------------------

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EGFOR CONTAINMENT SUMP FILLFROM RVST. FLOW IS LIMITED BYTHE 4' IA SUCTION CONNECTION

( D a MODIFICATION Figure 21: Containment Cooling Phase 3 Containment SprayMechanical Connections North Anna Unit 2IPage 101 of 102 BDB FLEX Mitigation Strategies Final Integrated PlanNorth Anna Power StationSerial No. 14-394CDocket Nos. 50-338/339 Order EA-1 2-049Attachment 2-tFS....*I StagingLZ~2JFigure 22: Haul Paths From BDB Storage Building and Staging AreasPage 102 of 102