RS-14-007, Second Six-Month Status Report in Response to March 12,2012 Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order Number EA-12-049)

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Second Six-Month Status Report in Response to March 12,2012 Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order Number EA-12-049)
ML14059A353
Person / Time
Site: Braidwood  Constellation icon.png
Issue date: 02/28/2014
From: Kaegi G
Exelon Generation Co
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
EA-12-049, RS-14-007
Download: ML14059A353 (32)
v • d • e


Text

1 ti Order No. EA-12-049 RS-14-007 February 28, 2014 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Braidwood Station, Units 1 and 2 Facility Operating License Nos. NPF-72 and NPF-77 NRC Docket Nos. STN 50-456 and STN 50-457

Subject:

Second Six-Month Status Report in Response to March 12,2012 Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order Number EA-12-049)

References:

1. NRC Order Number EA-12-049, " Issuance of Order to Modify Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events," dated March 12, 2012
2. NRC Interim Staff Guidance JLD-ISG-2012-01, "Compliance with Order EA-12-049, Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events," Revision 0, dated August 29, 2012
3. NEI12-06, "Diverse and Flexible Coping Strategies (FLEX) Implementation Guide,"

Revision 0, dated August 2012

4. Exelon Generation Company, LLC's Initial 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), dated October 25,2012
5. Exelon Generation Company, LLC Overall Integrated Plan 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), dated February 28, 2013 (RS-13-017)
6. Exelon Generation Company, LLC First 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 049), dated August 28,2013 (RS-13-113)
7. NRC letter to Exelon Generation Company, LLC, Braidwood Station, Units 1 and 2-Interim Staff Evaluation Relating to Overall Integrated Plan in Response to Order EA 049 (Mitigation Strategies) (TAC Nos. MF0895 and MF0896), dated December 17, 2013

u.s. Nuclear Regulatory Commission Integrated Plan Report to EA-12-049 February 28, 2014 Page 2 On March 12,2012, the Nuclear Regulatory Commission ("NRC" or "Commission") issued an order (Reference 1) to Exelon Generation Company, LLC (EGC). Reference 1 was immediately effective and directs EGC to develop, implement, and maintain guidance and strategies to maintain or restore core cooling, containment, and spent fuel pool cooling capabilities in the event of a beyond-design-basis external event. Specific requirements are outlined in of Reference 1.

Reference 1 required submission of an initial status report 60 days following issuance of the final interim staff guidance (Reference 2) and an overall integrated plan pursuant to Section IV, Condition C. Reference 2 endorses industry guidance document NEI 12-06, Revision 0 (Reference 3) with clarifications and exceptions identified in Reference 2. Reference 4 provided the EGC initial status report regarding mitigation strategies. Reference 5 provided the Braidwood Station, Units 1 and 2 overall integrated plan.

Reference 1 requires submission of a status report at six-month intervals following submittal of the overall integrated plan. Reference 3 provides direction regarding the content of the status reports. Reference 6 provides the first six-month status report pursuant to Section IV, Condition C.2, of Reference 1 for Braidwood Station. The purpose of this letter is to provide the second six-month status report pursuant to Section IV, Condition C.2, of Reference 1, that delineates progress made in implementing the requirements of Reference 1. The enclosed report provides an update of milestone accomplishments since the last status report, including any changes to the compliance method, schedule, or need for relief and the basis, if any. The enclosed report also addresses the NRC Interim Staff Evaluation Open and Confirmatory Items contained in Reference 7.

This letter contains no new regulatory commitments. If you have any questions regarding this report, please contact David P. Helker at 610-765-5525.

I declare under penalty of perjury that the foregoing is true and correct. Executed on the 28th day of February 2014.

Respectfully submitted,

~r~

Glen T. Kaegi Director - Licensing & Regulatory Affairs Exelon Generation Company, LLC

Enclosure:

1. Braidwood Station, Units 1 and 2 Second Six-Month Status Report for the Implementation of Order EA-12-049, Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events

U.S. Nuclear Regulatory Commission Integrated Plan Report to EA-12-049 February 28, 2014 Page 3 cc: Director, Office of Nuclear Reactor Regulation NRC Regional Administrator - Region III NRC Senior Resident Inspector - Braidwood Station, Units 1 and 2 NRC Project Manager, NRR - Braidwood Station, Units 1 and 2 Ms. Jessica A. Kratchman, NRR/JLD/PMB, NRC Mr. Jack R. Davis, NRR/DPR/MSD, NRC Mr. Eric E. Bowman, NRR/DPR/MSD, NRC Mr. Jeremy S. Bowen, NRR/DPR/MSD/MSPB, NRC Mr. Robert L. Dennig, NRR/DSS/SCVB, NRC Mr. Peter Bamford, NRRlDPR/MSD/MSPB, NRC Illinois Emergency Management Agency - Division of Nuclear Safety

Enclosure Braidwood Station, Units 1 and 2 Second Six-Month Status Report for the Implementation of Order EA-12-049, Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (28 pages)

Braidwood Station, Units 1 and 2 Second Six-Month Status Report for the Implementation of Order EA-12-049, Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events 1 Introduction Braidwood Station developed an Overall Integrated Plan (Reference 1 in Section 8),

documenting the diverse and flexible strategies (FLEX), in response to Reference 2. This enclosure provides an update of milestone accomplishments since submittal of the last status report, including any changes to the compliance method, schedule, or need for relief/relaxation and the basis, if any.

2 Milestone Accomplishments None.

3 Milestone Schedule Status The following provides an update to Attachment 2 of the Overall Integrated Plan. It provides the activity status of each item, and whether the expected completion date has changed. The dates are planning dates subject to change as design and implementation details are developed.

Site: Braidwood Original Target Activity Status Revised Target Completion Date Completion Date Submit 60 Day Status Report Complete Submit Overall Integrated Complete Implementation Plan Contract with Regional Response Complete Center (RRC)

Submit Six (6) month Updates ci' .. -

Aug 2013 Update 1 Complete ..

Feb 2014 Update 2 Complete with > c this submittal Aug 2014 Update 3 Not Started Feb 2015 Update 4 Not Started -- .... ***

Page 1 of 28

Braidwood Station, Units 1 and 2- Second Six Month Status Report for the Implementation of FLEX February 28 , 2014 Aug 2015 Update 5 Not Started <'..: "':i;c;,. . >:'

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  • Phase 1 modifications Detailed  !;.\, i:.

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Feb Sept Phase 2 modifications Detailed 2014 2014 Designs Started.

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  • Phase 3 modifications Not Started 1:",,,7<;::;

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  • Phase 1 modifications Not Started .:. _.:.'e. '\;;~

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Apr Oct

  • Phase 2 modifications Not Started 2015 2015 .: .

Apr Oct

  • Phase 3 modifications Not Started 2015 2015 ..,

Procedure Development Apr 2015

  • Strategy procedures Started Apr 2015
  • Validate Procedures (NEI Started 12-06, Sect. 11.4.3t Apr 2015
  • Maintenance procedures Not Started Nov 2014 Staffing analysis Not Started Apr 2015 Storage Plan and construction Started Apr 2015 FLEX equipment acquisition Started Apr 2015 Training completion Started Dec 2014 Regional Response Center Started Operational Apr 2015 Unit 1 Implementation date Not Started Oct 2015 Unit 2 Implementation date Not Started Page 2 of 28

Braidwood Station, Units 1 and 2- Second Six Month Status Report for the Implementation of FLEX February 28, 2014 4 Changes to Compliance Method Change 1 Section: Multiple Sections Reason for Change: For consistency throughout this project we have chosen to utilize the calculations of the WCAP-17601-P for our reference calculations.

Reason for Change: With engineering review and judgment the values from the WCAP are bounding.

Change 2 Section: General Integrated Plan Elements PWR - Provide a sequence of events and identify any time constraint required for success including the technical basis for the time constraint.

Reason for Change: Modification design details were refined as parts of the standardized modification design process and manual actions have been added and verified to accomplish these tasks.

Change:

1. Added new step to close the 2 S/G PORVs that have battery backup when it is verified that there is no Auxiliary Feedwater. This will conserve S/G inventory and provide symmetric cooling as required in the WCAP-17601-P.
2. Added new step to shed DC Loads as recommended by WCAP-17601-P along with procedure reference 1/2BwFSG-4, ELAP DC Load Shed/Management.
3. Added new step to align the AF pump SX cooling water FLEX supply within two (2) hours of pump start to prevent overheating from the short cycle of the cooling water along with the procedure reference of 1/2BwFSG-2, Alternate AFW/EFW Suction Source.
4. Added new step to deploy all hoses and connections in the FHB for alternate SFP fill and RCS inventory/boration strategies, before the FHB becomes uninhabitable due to SFP boiling. This is expected to occur within six (6) hours of the event initiation and will be governed by procedures OBwFSG-S, Initial Assessment and FLEX Equipment Staging Unit 0, and OBwFSG-11, Alternate SFP Make-Up and Cooling.

Change 3 Section: Maintain Core Cooling & Heat Removal - PWR Installed Equipment Phase 1 and Maintain RCS Inventory Control- PWR Installed Equipment Phase 1.

Reason for Change: Site alignment with Nuclear Energy Institute (NEI) position paper dated September 18, 2013, entitled "Position Paper: Shutdown/ Refueling Modes" .

Change: Change last paragraph to the following:

Cold Shutdown and Refueling: When in Cold Shutdown and Refueling, many variables exist, which impact the ability to cool the core. In the event of an ELAP during these Modes, installed plant systems cannot be relied upon to cool the core, thus transition to Phase 2 will be required Page 3 of 28

Braidwood Station, Units 1 and 2- Second Six Month Status Report for the Implementation of FLEX February 28, 2014 sooner. All efforts will be made to expeditiously provide core cooling and minimize heat-up and repressurization. Exelon has a program in place (Ref. 3) to determine the time to boil for all conditions during shutdown periods.

To accommodate the activities of vessel disassembly and refueling, water levels in the reactor vessel and the reactor cavity are often changed. The most limiting condition is the case in which the reactor head is removed and water level in the vessel is at or below the reactor vessel flange. If an ELAP/LUHS occurs during this condition then (depending on the time after shutdown) boiling in the core may occur quite rapidly. Deploying and implementation of portable FLEX pumps to supply injection flow must commence immediately from the time of the event.

This should be plausible because more personnel are on site during outages to provide the necessary resources. Strategies for makeup water include deploying a FLEX pump to take suction from the RWST and lor UHS as described in the Phase 2 Core Cooling section.

Guidance will be provided to ensure that sufficient area is available for deployment and that haul paths remain accessible without interference from outage equipment during refueling outages.

Change 4 Section: Maintain Core Cooling & Heat Removal - PWR Installed Equipment Phase 1 - Identify Modifications.

Reason for Change: Modification design details have been refined as parts of the standardized modification design process.

Change: (replace section with the following)

The following gaps have been identified that prevent operation of the DDAF pump:

1. DDAF pump suction flow path is not available due to CST unavailability and failure of the CST isolation valve to close and the SX suction valve to open on loss of AC power.
2. DDAF batteries are drained due to repetitive engine starts with automatic reset of low-low suction pressure trip.
3. DDAF pump overheating due to cooling water recirculation flow paths within SX system cycling and overheating the pump within two (2) hours.

Gap 1 will be resolved with manual operator actions. Operators will be procedurally directed to open the SX suction valves (1/2AF006 and 1/2AF017) and close the CST isolation valves (1/2AF002) prior to starting the DDAF pump.

Gap 2 will be resolved by modifying the DDAF pump logic to lock-out the pump after unsuccessful starting attempts prior to draining the battery. This lockout will be manually reset after the DDAF pump suction is realigned.

Gap 3 will be resolved by modifying the DDAF pump SX cooling water flow path. The modification consists of installing a piping tee on the discharge of both Unit 1 and Unit 2 "B" SX pump discharge lines on the 330' elevation in the AB. These tees will be connected by a header and routed vertically through the AB to the 383' elevation. On the 383' elevation, the line will tee into two lines feeding the 1/2 DDAF pump SX booster pump. This new line will be isolated during normal operation. In the event of an ELAP, this new line will be unisolated and the normal SX cooling supply to the DDAF pump SX booster pump will be isolated.

Page 4 of 28

Braidwood Station, Units 1 and 2- Second Six Month Status Report for the Implementation of FLEX February 28, 2014 Change 5 Section: Maintain Core Cooling & Heat Removal - PWR Portable Equipment Phase 1, 2 and 3 -

Key Reactor parameters and Maintain RCS Inventory Control - PWR Portable Equipment Phase 1 , 2 and 3 - Key Reactor parameters.

Reason for Change: FLEX strategy has been refined and draft site FSG procedures have been developed.

Change: RWST level channel LT-931 has been identified as a required instrument for the FLEX strategy.

In addition, Core Exit Thermocouple (CET) temperature TI-IT002, Reactor Vessel Level indicating System (RVLlS) LI-RC020, and Post Accident Neutron monitor NI-NR006 AlB will be re-energized per the site strategy.

Change 6 Section: Maintain Core Cooling & Heat Removal - PWR Portable Equipment Phase 2 - Identify Modifications.

Reason for Change: Modification design details have been refined as parts of the standardized modification design process.

Change: (replace section with the following)

The following modifications will be installed to support FLEX pump water injection into the SGs:

Primary: A pipe flange connection will be attached to the Band C Auxiliary Feedwater (AF) SG injection lines at the existing test flanges within the 377' Main Steam Safety Valve (MSSV) rooms. The pipe flanges will be connected to a header and routed vertically to the 401' elevation in the BIC MSSV room. The header will be terminated with a standard FLEX connection inside the robust MSSV room above the 401' elevation. This will allow a FLEX pump to provide cooling water to the BIC SGs.

Alternate: This modification is identical to the primary except it is within the AID MSSV room. It will allow a FLEX pump to supply cooling water to the AID SGs.

Note: Both the BIC and AID headers in the 377' MSSV rooms will have flanges allowing a temporary hose to connect the headers and allow one FLEX pump to feed all four (4) SGs. This temporary hose will be stored within the robust Main Steam Tunnel for easy deployment.

FLEX pump suction: A tee will be installed on the A SI pump suction line (in the B SI pump room). A header will be routed from the tee to the robust RWST tunnel area and terminated with a standard FLEX connection. Temporary hoses will be routed through the RWST tunnel hatch to connect this line to the FLEX pump suction located outside.

Note: The SG cooling water source is prioritized from cleanest to dirtiest. The priority is the CST (not Robust) and then the UHS (Lake water). The RWST (Boration source) will also be available, if needed, to the FLEX medium pressure diesel pumps until the UHS FLEX pump and hoses are in place.

Page 5 of 28

Braidwood Station, Units 1 and 2- Second Six Month Status Report for the Implementation of FLEX February 28, 2014 Additionally, a water filtration unit will be requested from the RRC and installed to provide purification of the UHS water source as staffing permits.

Change 7 Section: Maintain Core Cooling and Heat Removal, - PWR Portable Equipment Phase 2 -

Deployment Conceptual Design - Strategy, Maintain RCS Inventory Control- PWR Portable Equipment Phase 2 - Deployment Conceptual Modifications - Strategy, Maintain Spent Fuel Pool Cooling - PWR Portable Equipment Phase 2 - Deployment Conceptual Design - Strategy, and Safety Function Support - PWR Portable Equipment Phase 2 - Deployment Conceptual Design - Strategy.

Reason for Change: The site storage building will consist of one robust building housing ION" FLEX equipment and a commercial building housing "+1" FLEX equipment. The site strategy will have several strategic temporary hoses and electrical cables staged within robust structures in the plant.

Change: (replace section with the following).

The required FLEX equipment needed for Core Cooling, RCS Inventory Control, Spent Fuel Pool Cooling and Safety Function Support will be stored in a FLEX building and transported to a pre-identified staging location. Hoses and electrical cables to support the site coping strategy will be stored within the FLEX building or staged in the plant. The equipment deployment strategy will be validated and reported in a future six (6) month update.

Change 8 Section: Maintain Core Cooling & Heat Removal - PWR Portable Equipment Phase 3, Maintain RCS Inventory Control- PWR Portable Equipment Phase 3, Maintain Spent Fuel Pool Cooling

- PWR Portable Equipment Phase 3, and Safety Functions Support - PWR Portable Equipment Phase 3.

Reason for Change: Site FLEX strategy has been refined as parts of the standardized modification design process and through detailed reviews.

Change: (replace section with the following)

Phase 3 equipment for Braidwood includes backup portable pumps and generators. The portable pumps will be capable of providing the necessary flow and pressure as outlined in Phase 2 response for Core Cooling & Heat Removal, RCS Inventory Control and Spent Fuel Pool Cooling. The portable generators will be capable of providing the necessary 480 volt power requirements as outlined in Phase 2 response for Safety Functions Support.

In addition, a water purification skid and a boration skid will be requested from the RRC to support Phase 3 strategy.

Page 6 of 28

Braidwood Station, Units 1 and 2- Second Six Month Status Report for the Implementation of FLEX February 28, 2014 Change 9 Section: Maintain Core Cooling & Heat Removal- PWR Portable Equipment Phase 3-Strategy, Maintain RCS Inventory Control- PWR Portable Equipment Phase 3 - Strategy, Maintain Spent Fuel Pool Cooling - PWR Portable Equipment Phase 3 - Strategy, and Safety Functions Support - PWR Portable Equipment Phase 3 - Strategy.

Reason for Change: RRC will provide operating instructions for the equipment delivered to the site.

Change: (replace section with the following)

Equipment will be delivered from the RRC to the staging area. From there, the equipment will be transported to the site and hooked up by both RRC and plant personnel per the playbook.

Equipment will then be operated per industry developed operating instructions.

Change 10 Section: Maintain RCS Inventory Control - PWR Portable Equipment Phase 2.

Reason for Change: Draft calculations have been prepared which show the RCS accumulators inject a portion of their concentrated boric acid inventory maintaining the reactor subcritical.

Change: (replace section with the following)

Phase 2 RCS inventory control and boration will be achieved within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> via a portable pump. The pump suction will be from the RWST. The discharge will be into the CV/SI pump discharge line downstream of the CV/SI pump. A calculation is in progress to validate the timeframe and any change to this will be provided in a future six (6) month update.

Electrical power to support the FLEX strategy is described in the Safety Function Support section.

Change 11 Section: Maintain RCS Inventory Control- PWR Portable Equipment Phase 2 - Identify modifications.

Reason for Change: Modification design details have been refined as parts of the standardized modification design process.

Change: (replace section with the following)

The following FLEX modifications will be installed to support inventory and boration of the RCS:

FLEX pump discharge: The B CV pump discharge header, downstream of check valve CV8481 B, will be modified with a tee and a standard FLEX connection (Alternate). The flow path goes through a normally closed MOV SI8801 AlB which can be manually opened or the B train MOV can be electrically opened after the FLEX DG energizes the associated Div 2 ESF Bus.

Page 7 of 28

Braidwood Station, Units 1 and 2- Second Six Month Status Report for the Implementation of FLEX February 28, 2014 FLEX pump suction: The B SI pump discharge header, downstream of SI8921 B, will be modified with a tee. A header will be routed from a tee to the RWST tunnel and terminated with a standard FLEX connection (Primary). Deployment of this flow path will be contingent on primary pressure conditions less than 1750 psig due to the SI discharge header relief valves.

FLEX pump Suction: A tee will be installed on the A SI pump suction line (In the B SI pump room). A header will be routed from the tee to the robust RWST tunnel area and terminated with a standard FLEX connection. Temporary hoses will be routed through the RWST tunnel hatch to connect this line to the FLEX pump suction located outside.

Note: The RCS Inventory water source priority is the respective Unit's RWST. A Boration skid will be requested from the RRC to provide a borated make-up source as needed.

Change 12 Section: Maintain Spent Fuel Pool Cooling - PWR Installed Equipment Phase 1 Reason for Change: The spent fuel pool area vent path strategy has been developed.

Change: Delete - Initial Spent fuel pool make-up will be accomplished with gravity drain from the RWST. Procedure development will be documented in a future six (6) month update.

And Replace - Evaluation of the spent fuel pool area for steam and condensation has not yet been performed. The results of this evaluation and the vent path strategy, if needed, will be provided in a future six (6) month update.

With the following: A Spent Fuel Pool Vent path will be provided by opening the Fuel Handling building track way roll-up door. The site does have manual actions within the Fuel Handling building. The actions include setting up SFP make-up temporary hoses and the RCS inventory control alternate injection path hoses. The site plans to perform these manual actions prior to the onset of SFP boiling. The actions will be directed by the FSGs being developed.

The SFP environment has the potential to communicate with the Aux Building via the FHB supply ducting, due to the FHB Supply dampers failing open on a loss of AC. It is reasonable to assume this flow path will be isolated by fire damper OVA413Y. The fire damper will close when its fusible link melts shortly after reaching a set point of 165F. Due to this damper arrangement and lack of motive force, minimal FHB atmosphere should be dispersed into the AB.

Change 13 Section: Maintain Spent Fuel Pool Cooling - PWR Portable Equipment Phase 1, 2 and 3 - Key SFP parameters.

Reason for Change: SFP design has identified the EPNs for the SFP level instrumentation.

Change: Replace SFP Level: (component # TBD) with Spent Fuel pool level: OLl-FC001 Band OLl-FC002B.

Page 8 of 28

Braidwood Station, Units 1 and 2- Second Six Month Status Report for the Implementation of FLEX February 28, 2014 Change 14 Section: Maintain Spent Fuel Pool Cooling - PWR Installed Equipment Phase 2.

Reason for Change: The spent fuel pool cooling and area vent path strategy has been developed.

Change: (replace section with the following)

The SFP cooling will be achieved with one of the following methods:

The primary method will be repowering the installed OA refueling water purification pump OFC03PA utilizing the 480V Flex generator connection described in the Safety Functions Support section. The RWST with the installed piping will be used as the suction source. The discharge will use the existing OA refueling water purification pump discharge piping directly to the SFP.

The secondary method will be achieved with a portable FLEX diesel pump and temporary hoses routed to the SFP via the FHB track way. The FLEX pump suction will be the UHS and/or RWST.

A Spent Fuel Pool Vent path will be provided by opening the FHB track way roll-up door. The site does have manual actions within the spent fuel pool building to setup pool make-up temporary hoses and route the RCS inventory alternate connection hoses. The site plans to perform these manual actions prior to the onset of SFP boiling. The actions will be directed by the FSGs being developed.

The SFP environment has the potential to communicate with the Aux Building via the FHB supply ducting, because the FHB Supply dampers fail open on a loss of AC. It is reasonable to assume this flow path will be isolated by fire damper OVA413Y. The fire damper will close when its fusible link melts shortly after reaching a set point of 165F. Due to this damper arrangement and lack of motive force, minimal FHB atmosphere should be dispersed in to the AB.

Change 15 Section: Maintain Spent Fuel Pool Cooling - PWR Portable Equipment Phase 2 - Identify modifications.

Reason for Change: The Spent fuel pool make-up strategy has changed. No modifications will be required for Phase 2 Spent Fuel Pool Cooling.

Change: (replace section with the following)

The primary make-up strategy will use the installed refueling water purification pump OFC03PA and associated piping as directed by OBwFSG-11 , Alternate SFP Make Up and Cooling. The pump will be repowered as part of the site plan to re-energize safety related 480V buses with a FLEX generator. The pump's suction source is the RWST. Its discharge piping provides flow directly to the SFP. Make-up to the RWST can be performed by completing EDMG-1, Extensive Damage Mitigation Guideline, Attachment J.

Page 9 of 28

Braidwood Station, Units 1 and 2- Second Six Month Status Report for the Implementation of FLEX February 28, 2014 The alternate make-up strategy will be via temporary hoses routed from a FLEX pump to a spray nozzle located in the vicinity of the SFP. The temporary hose / spray nozzle required to be routed within the FHB will be stored in that building and deployed prior to the onset of SFP boiling.

FHB vent path will be established by opening the FHB track way rollup door.

Change 16 Section: Safety Support Function - PWR Portable Equipment Phase 1,2 and 3 - Key Parameters.

Reason for Change: FLEX strategy has been refined and draft site FSG procedures have been developed.

Change: DC Bus Voltage _EI-DC002, has been identified as a required instrument for the FLEX strategy.

Change 17 Section: Safety Function Support - PWR Portable Equipment Phase 2 Reason for Change: Site FLEX strategy has been refined through industry reviews and site challenges.

Change: (replace section with the following)

A portable diesel generator will provide power to one (1) division of the 480V ESF busses.

Repowering at this level will permit the recovery of one division of station battery chargers, DDAFP battery chargers, MCCs powering critical equipment such as Diesel fuel oil transfer pumps, and other ESF equipment beneficial in mitigating the event.

Exelon Generation Company, LLC (Exelon) intends to maintain Operational command and control within the Main Control Room (MCR). Habitability conditions within the MCR and other areas of the plant will be maintained with a tool box approach limiting the impact of high temperatures with methods such as supplemental cooling, personnel rotation and/or availability of fluids.

The fuel handling building habitability should be maintained until the SFP begins to boil. The site does have manual actions within the Fuel Handling Building. The actions include setting up SFP make-up temporary hoses and the RCS inventory control alternate injection path hoses.

The site plans to perform these manual actions prior to the onset of SFP boiling. The actions will be directed by the FSGs being developed.

Critical ventilation assets may be required to support DDAF pumps, the OA refueling water purification pump, the station battery rooms and the miscellaneous electric equipment room component survivability. Specific analyses of these rooms are open items and will be addressed as part of the detailed engineering design phase. Closure of these items will be documented in a future six (6) month update.

Page 10 of 28

Braidwood Station, Units 1 and 2- Second Six Month Status Report for the Implementation of FLEX February 28, 2014 Additionally, a backup water source for core cooling, inventory, and SFP make-up will be established with a portable FLEX diesel driven pump and temporary hoses from the UHS. The FLEX pump suction hose will be routed from its deployment location into the UHS. A Dry Hydrant will be installed at the UHS to support testing.

Change 18 Section: Safety Function Support - PWR Portable Equipment Phase 2 -Indentify Modifications Reason for Change: Modification design details have been refined as parts of the standardized modification design process.

Change:

The primary FLEX connection will be installed adjacent to MCC 132X and MCC 232X. An existing spare breaker within these MCCs will be modified such that its load side feed is connected to a new disconnect switch and patch panel. Temporary cables will be routed from the patch panel to the associated Unit's FLEX generator at the 401' TB track way entrance.

Once the MCC is energized, appropriate breakers will be closed to provide power to the safety related batteries.

The Alternate strategy is to provide a connection via the existing Site DC crosstie. In the event either Unit's primary FLEX strategy is unable to be implemented, DC busses 112 and 212 will be crosstied to provide power to the site B train safety related batteries. In addition, the other required 480V critical loads will be powered up via a patch panel and TPU in the Aux building which is powered from either Unit's FLEX DG.

The discharge of the existing diesel fuel oil transfer pumps is being modified with a tee and isolation valve within the B main diesel generator rooms. This connection, along with temporary hoses and reenergizing the diesel fuel oil transfer pumps, will provide a fuel source for the FLEX equipment.

A Dry Hydrant will be installed at the UHS to support testing.

Change 19 Section: PWR Portable Equipment Phase 2.

Reason for Change: Modification design details have been refined as parts of the standardized modification design process.

Change: The three (3) 480 VAC Generators will be 350 KW instead of the listed 500 KW.

Change 20 Section: Phase 3 Response Equipment/Commodities - Heavy Equipment.

Reason for Change: Site strategy details have been refined as a result of strategy reviews.

Change:

Page 11 of 28

Braidwood Station, Units 1 and 2- Second Six Month Status Report for the Implementation of FLEX February 28, 2014 The F750 Truck has been purchased with a snow plow for debris removal. The truck will be used initially for debris removal. The F-750 will also be used for equipment deployment and FLEX equipment refueling.

In addition, Braidwood will be acquiring 2 F-250, or equivalent, trucks with snow plows. They will tow the first needed Phase 2 equipment: the Flex DG for each unit.

All three trucks will then be utilized to transport additional equipment as required by the event and the Phase 2 plans.

Change 21 Section: Attachment 1A, Sequence of Events time line.

Reason for Change: Modification design details were refined as parts of the standardized modification design process and manual actions have been added and verified to accomplish these tasks.

Change: Added new steps and rearranged to reorder based on strategy updates, (see attachment 1A at end of this submittal).

1. Added new step 4 to close UPS powered SG PORVs to conserve inventory until _B AF Pp can be started.
2. Added new step 8 to perform DC load shed to extend life of 125v DC Batteries.

Performed to align with WCAP-17601-P and in accordance with new 1/2BwFSG-4.

3. Added new step 9 for the short cycle cooling mod for the _B AF Pumps.
4. Added new step 13 for layout of alternate strategy hoses for RCS make-up and SFP make-up in the FHB before it is not inhabitable.
5. Added new step 14 for SI Accumulator isolation.
6. Added new step 15 for new primary strategy for SFP make up.
7. Changed time on step 16 to 12-14 hrs.
8. Changed time on step 17 to 16-18 hrs to ensure boron is available when required.

Change 22 Section: Attachment 3 Conceptual Sketches.

Reason for Change: Modification design details were refined as part of the standardized modification design process resulting in changes to the mechanical conceptual sketches.

Change: Current mechanical conceptual sketches are attached to this document. See Attachment 3.

Change 23 Section: General Integrated Plan Elements PWR - Determine Applicable Extreme External Hazard.

Reason for Change: The site area is susceptible and will be evaluated for soil liquefaction.

Page 12 of 28

Braidwood Station, Units 1 and 2- Second Six Month Status Report for the Implementation of FLEX February 28, 2014 Change: Remove the words "except soil liquefaction" from first paragraph.

Seismic events, flooding from local/intense precipitation; severe storms with high winds; snow, ice and extreme cold; and high temperatures were determined to be applicable Extreme External Hazards for Braidwood Station per the guidance of NEI 12-06 Rev. 0 and are as follows:

5 Need for Relief/Relaxation and Basis for the Relief/Relaxation Braidwood Station, Units 1 and 2 expects to comply with the order implementation date and no relief/relaxation is required at this time.

6 Open Items from Overall Integrated Plan and Draft Safety Evaluation The following tables provide a summary of the open items documented in the Overall Integrated Plan or the Draft Safety Evaluation (SE) and the status of each item.

Section Reference Overall Integrated Plan Open Item Status Key Site assumptions (pA) Primary and secondary storage Started locations have not been selected yet; once locations are finalized implementation strategies and routes will be assessed for hazard impact.

Sequence of events (p.5) The final timeline will be time Not Started validated once detailed designs are completed and procedures are developed.

Identify how strategies will Identification of storage area and Started be deployed (p.?) creation of the administrative program.

Programmatic controls (p.8) Develop an administrative program Started for FLEX responsibilities, and testing

& maintenance.

Regional Response Center Development of Braidwood Station's Not Started plan (p.9) playbook.

Key Reactor Parameters Identify additional parameters that Started are needed in order to support key (p. multiple) actions identified in the plant procedures/guidance or to indicate imminent or actual core damage.

Deployment Conceptual Develop the storage structure Started Design (p. multiple) conceptual design.

Page 13 of 28

Braidwood Station, Units 1 and 2- Second Six Month Status Report for the Implementation of FLEX February 28, 2014 Maintain RCS Inventory A calculation will be required for the Started Control, Phase 2 (p.23) timing of the boration and quantity required.

Maintain Containment, Additional calculations will be Started Phase 1 (p.31) performed to evaluate containment response.

Maintain Spent Fuel Pool Procedure development for Initial Complete - Procedures will Cooling, Phase 1 (p.39) Spent fuel pool make-up with gravity not be developed for SFP drain from the RWST. make-up with gravity drain.

The primary method for SFP make-up will be repowering the installed OA refueling water purification pump utilizing the 480V Flex generator connection described in the Safety Functions Support section.

The RWST with the installed piping will be used as the suction source. The discharge will use the existing OA refueling water purification pump discharge piping directly to the SFP.

Maintain Spent Fuel Pool Initial calculations were used to Started Cooling, Phase 1 (p.39) determine the fuel pool timelines.

Formal calculations will be performed to validate this information during development of the spent fuel pool cooling strategy detailed design.

Maintain Spent Fuel Pool Evaluation of the spent fuel pool area Complete - A Spent Fuel Pool Cooling, Phase 1, (p.39 for steam and condensation will be Vent path will be provided by and p.42) performed and used to determine if opening the Fuel Handling vent path strategy is needed. building track way roll-up door.

The site plans to perform required manual actions within the FH building prior to the onset of SFP boiling. A formal calculation will not be performed.

Safety Functions Support, Habitability conditions will be Complete - Habitability Phase 2 (p.51) evaluated and a strategy will be conditions within the MCR will developed to maintain Main Control be maintained with a tool box Page 14 of 28

Braidwood Station, Units 1 and 2- Second Six Month Status Report for the Implementation of FLEX F e b ruary 28 ,2014 Room. approach limiting the impact of high temperatures with methods such as supplemental cooling, personnel rotation and/or availability of fluids.

Safety Functions Support, Critical ventilation assets may be Started - Habitability Phase 2 (p.51) required to support DDAF pumps, conditions within the Plant will station battery rooms, miscellaneous be maintained with a tool box electric equipment rooms, and fuel approach limiting the impact of handling building personnel high temperatures with habitability and/or component methods such as survivability. Specific analyses of supplemental cooling, these rooms will be performed. personnel rotation and/or availability of fluids. Analysis is in progress to ensure component survivability post event.

Interim Safety Evaluation Open Item Status Braidwood's ISE Response Line Item Description Answer Number Number 1 Open Item Core Subcriticality- The NRC staff Started- Braidwood will abide by 3.2.1.8.A has not endorsed the industry- the position expressed by the NRC proposed position paper regarding staff in the letter dated January 8, boron mixing. The licensee has 2014 regarding the boron mixing indicated that Braidwood is planning issue for PWRs (Adams Accession on following this methodology. Thus, No. ML13276A183). The NRC further resolution of this issue will be letter states that the NRC staff has necessary in the next phase of the reviewed the information submitted audit process. to date and concluded that use of the industry approach dated August 15, 2013, entitled 'Westinghouse Response to NRC Generic Request for Additional Information (RAI) on Boron Mixing in Support of the Pressurized Water Reactor Owners Group (PWROG)," ML13235A135, is acceptable with clarifications listed in the letter.

The analyses and evaluations Page 15 of 28

Braidwood Station, Units 1 and 2- Second Six Month Status Report for the Implementation of FLEX 2014 supporting the OIP will demonstrate that the FLEX RCS makeup pump is being implemented one-hour prior to the loop flow rate decreasing below the loop flow rate corresponding to single-phase natural circulation for the assumed highest applicable leakage rate at normal operating pressure and temperature for the reactor coolant pump seals and unidentified reactor coolant system leakage.

Confirmatory Items 2 3.1.1.1.A Storage & Protection of FLEX Started - The site FLEX equipment equipment - Confirm final design of storage structure is under FLEX storage structure conforms to development and will comply with NEI 12-06, Sections 5.3.1, 7.3.1, the requirements of 12-06, Sections and 8.3.1 for storage considerations 5.3.1, 7.3.1, and 8.3.1 for storage for the hazards applicable to considerations for the hazards Braidwood. applicable to Braidwood.

The FLEX storage buildings will consist of one robust building housing UN" FLEX equipment and one commercial building housing the "+ 1" FLEX equipment.

3 3.1.1.3.A Procedural Interface Considerations Started - 1/2 BwFSG-7, Loss of (Seismic) -Confirm procedure for Vital Instrument or Control Power, measuring key instruments at is being developed. It will provide containment penetrations using guidance to measure key portable instrument. instruments at appropriate locations within the plant.

4 3.1.1.4.A Off-Site Resources - Confirm RRC Started.

local staging area and method of transportation to the site in future 6-month update.

5 3.1.5.1.A Protection of Equipment (High Started - The FLEX storage Temperature) - Confirm FLEX buildings ventilation systems will be storage structure will maintain FLEX designed as required by code and equipment at a temperature range to to maintain the FLEX equipment in ensure its likely function when called a ready state. The minimum upon. temperature will be maintained at or above 32°F and the maximum Page 16 of 28

Braidwood Station, Units 1 and 2- Second Six Month Status Report for the Implementation of FLEX F e b ruary 28 , 2014 building temperature will be maintained by natural air ventilation utilizing vents. Temperature information from Braidwood's UFSAR indicates the site extreme temperatures range is from a maximum of 102°F to a minimum of

-20°F.

6 3.1.5.3.A Deployment of Equipment (High Started - Temperature information Temperature) - Confirm that the from Braidwwod's UFSAR indicates effects of high temperature on FLEX the extreme Temperatures up to a equipment have been evaluated in maximum of 102°F.

the locations they are intended to FLEX equipment is being ordered operate.

with temperature limits to ensure it will function in the extreme temperature conditions applicable to the site.

7 3.2.1.A RCS cooling & RCS inventory Started - WCAP 17601-P will be control - Specify which analysis evaluated to ensure it is bounding performed in WCAP-17601 is being for Braidwood.

applied to Braidwood. Additionally, justify the use of that analysis by identifying and evaluating the important parameters and assumptions demonstrating that they are representative of Braidwood and appropriate for simulating the ELAP transient.

8 3.2.1.1.A NOTRUMP - Confirm that the use of Started - Braidwood will use NOTRUMP in the ELAP analysis is generic ELAP analyses performed limited to the flow conditions before with the NOTRUMP computer code reflux condensation initiates. This to support the mitigating strategy in includes specifying an acceptable its Overall Integrated Plan (OIP).

definition for reflux condensation The use of NOTRUMP was limited cooling. to the thermal-hydraulic conditions before reflux condensation initiates.

The initiation of reflux condensation cooling is defined when the one hour centered moving average (CMA) of the flow quality at the top of the SG U-tube bend exceeds 0.1 in anyone loop.

9 3.2.1.1.B ELAP Analysis - Confirm Started - Engineering calculations Page 17 of 28

Braidwood Station, Units 1 and 2- Second Six Month Status Report for the Implementation of FLEX F e b ruarv 28 , 2014 calculations to verify no nitrogen are being performed to verify RCS injection into RCS during Pressure will be held above the depressurization. point of accumulator N2 injection until the accumulator isolation valves CS18808s) are closed.

10 3.2.1.1.C Confirm analysis for secondary side Complete - A water analysis is not SG fouling due to the use of planned for Braidwood Station.

abnormal water sources (RWST, Procedural guidance will be well water, SX water) developed utilizing the cleanest to dirtiest water.

The SG cooling water source is prioritized from cleanest to dirtiest.

The priority is the CST (not robust) and then the UHS (Lake water).

The RWST (boration source) will also be available, if needed, to the FLEX medium pressure diesel pumps until the UHS FLEX pump and hoses are in place.

Additionally, a water filtration unit will be requested from the RRC and installed to provide purification of the UHS water source as staffing permits.

11 3.2.1.1.0 Complete analysis for length of time Started - The RWST volume of prior to depletion of the RWST and 450,000 gallons with maximum determine whether additional output of 470 gpm will last -14 boration equipment is needed for hours once this flow is initiated.

Phase 3 coping strategy. The 470 gpm flow rate will not be initiated at the beginning of the event. The RCS inventory and Boration of 40 gpm will not be required for - 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br />. The 130 gpm required for SFP make-up will not be required for - 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. The SG make-up of 300 gpm should not be required.

The site has 2 RWSTs that can be used for FLEX on either unit.

A boration skid will be requested from the RRC.

12 3.2.1.2.B Reactor Coolant Pump (RCP) Seal Started Leakage - In some plant designs, Page 18 of 28

Braidwood Station, Units 1 and 2- Second Six Month Status Report for the Implementation of FLEX Fe bruary 2 8 , 20 14 the cold legs could experience temperatures as high as 580 of before cool down commences. This is beyond the qualification temperature (550°F) of the O-rings used in the RCP seals. For those Westinghouse designs, a discussion should be provided to justify that (1) the integrity of the associated 0-rings will be maintained at the temperature conditions experienced during the ELAP event, and (2) the seal leakage rate of 21 gpm/seal used in the ELAP is adequate and acceptable.

13 3.2.1.2.E RCP Seal Leakage Rates - The Complete - The Braidwood RCPs licensee is requested to provide the are model 93A. This aligns with the manufacturer and model number of seal leakage model listed in WCAP the RCP seals and discuss whether 17601-P analysis as shown in or not the RCP and seal Table 5.3.1.7-1.

combination complies with a seal leakage model described in WCAP-17601.

14 3.2.1.3.A Decay Heat- Verify that the Started - From the WCAP-17601-P Integrated Plan update provides the page 4-13 and the NE112-06 details of the WCAP 17601-P section 3.2.1.3 the methodology of methodology to include the values of decay heat values of ANS 5.1-certain key parameters used to 1979+2 sigma is being evaluated to determine the decay heat levels. ensure it bounds NEI 12-063.2.1.2 Address the adequacy of the values assumption of 100 days at 100%

used. power.

15 3.2.1.4.A Initial Values for Key Plant Started - WCAP-17601-P is being Parameters and Assumptions- evaluated to ensure it is bounding Confirm WCAP-17601-P analyses for Braidwood Station.

are bounding for Braidwood for strategy response or verify plant-specific analyses if more restrictive limits are used due to more restrictive plant specific limits.

16 3.2.1.4.B Initial Values for Key Plant Started - The Phase 2 staffing Parameters and Assumptions- study, scheduled for November Confirm calculations to validate 8 2014, results will be provided in a Page 19 of 28

Braidwood Station, Units 1 and 2- Second Six Month Status Report for the Implementation of FLEX F e b ruary 28 , 2014 hours0.0233 days <br />0.559 hours <br />0.00333 weeks <br />7.66327e-4 months <br /> run time limit on DDAF pump future six (6) month update.

batteries and DDAF room temp for Calculations for AF Battery run time pump operation and human are in progress and will be provided occupancy. Also, confirm site phase in a future six (6) month update.

2 staffing study confirms the required time can be met for refilling Room temperatures will be diesel day tank. controlled under the tool box approach limiting the impact of high temperatures with methods such as supplemental cooling, personnel rotation and/or availability of fluids.

17 3.2.1.S.A Monitoring Instruments and Control- Started - The required Confirm additional parameters instrumentation listed in the evaluated for use in plant Braidwood Station OIP is procedures/guidance or to indicate consistent with NEI 12-06. The imminent or actual core damage. RWST level channel LT-931 has been identified as a required instrument for the FLEX strategy. In addition, Core Exit Thermocouple (CETC) temperature TI-IT002, Reactor Vessel Level indicating System (RVLlS) L1-RC020, and Post Accident Neutron monitor Nl-NROO6 AlB will be re-energized, as staffing permits.

18 3.2.1.6.A Sequence of Events - Confirm that Started - The final time line will be the final timeline has been time validated after the detailed design validated after detailed designs are is completed and will be provided in completed and procedures are a future six (6) month update.

developed. The results may be provided in a future 6-month update.

19 3.2.1.6.B Sequence of Events - Confirm Started - Analysis for the Phase 2 analysis to validate Phase 2 pump pump capacity is in progress and capacities. will be provided in a future six (6) month update.

20 3.2.1.9.A Use of portable pumps - Confirm Started - The current design of our final design of strategies meets "use FLEX strategies utilizing the of portable pumps" guideline in NEI procedures being written, BwCA 12-06 Section 3.2.2 Guideline 13. 0.0 along with the BwFSG Series will insure that the plant operators will have the guidance and direction to adequately cooldown and depressurize the plant to allow the cooling flows from our specified Page 20 of 28

Braidwood Station, Units 1 and 2- Second Six Month Status Report for the Implementation of FLEX Fe b ruary 28 , 2014 Phase 2 equipment and will meet the requirements of NEI 12-06 section 3.2.2 guideline 13.

21 3.2.2.A SFP cooling -Verify procedure for Started - The Spent fuel pool make-SFP makeup via gravity drain; up via gravity drain from the RWST confirm verification of timeline for is not being developed.

performing the strategy; and confirm The final time line will be validated evaluation of SFP area for steam after the detailed deSign is and condensation affects.

completed and will be provided in a future six (6) month update.

The SFP environment has the potential to communicate with the Aux Building via the FHB supply ducting, because the FHB Supply dampers fail open on a loss of AC.

It is reasonable to assume this flow path will be isolated by fire damper OVA413Y. The fire damper will close when its fusible link melts shortly after reaching a set point of 165F. Due to this damper arrangement and lack of motive force, minimal FHB atmosphere should be dispersed in to the AB.

A Spent Fuel Pool Vent path will be provided by opening the SFP track way roll-up door. The site does have manual actions within the spent fuel pool building to setup pool make-up temporary hoses.

The site plans to perform these manual actions prior to the onset of SFP boiling. The actions will be directed by the FSGs being developed.

22 3.2.3.A Containment - Confirm containment Started - Containment calculations reanalysis supports no Phase 1 , 2, are in progress and the results will and 3 mitigation strategies are be provided in a future six (6) required because containment month update.

pressure and temperature are maintained within acceptable limits.

23 3.2.3.B Containment - Confirm evaluation Started - Containment calculations performed for the need to monitor are in progress and the results will Page 21 of 28

Braidwood Station, Units 1 and 2- Second Six Month Status Report for the Implementation of FLEX Fe b ruary 28 , 2014 containment temperature. be provided in a future six (6) month update.

24 3.2.4.1.A Equipment cooling - Confirm Started - This modification is in modification has been performed to detailed design phase and prevent DDAF pump from procedures are being drafted to overheating due to cooling water align the flowpath within the recirculation flow paths within the required two (2) hours of the pump SX system cycling and overheating start.

the pump within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />.

25 3.2.4.2.A Ventilation - Equipment Cooling - Started - Calculations are in Review licensee's evaluation of loss progress for the various rooms of ventilation effects on equipment in listed. The results will be provided various rooms (DDAF pump room, in a future six (6) month update.

battery rooms, control room, miscellaneous electrical equipment rooms) 26 3.2.4.2.B A discussion is needed on the Started - Calculations are in extreme high/low temperatures progress and the results will be effects of the battery's capability to provided in a future six (6) month perform its function for the duration update.

of the ELAP event and hydrogen gas ventilation during recharging batteries during Phase 2 and 3.

27 3.2.4.3.A Heat Tracing - Confirm that potential Started - The study of adverse adverse impacts from a loss of heat effects of cold weather conditions tracing and normal heating on any on available RCS inventory sources equipment credited for ELAP will be performed and mitigation are adequately communicated in a future six (6) addressed. In particular, ensure an month update.

RCS inventory and source of Additionally, RRC boration borated water is available for a equipment will be provided with a BDBEE associated with extreme method to ensure availability of cold, ice, and snow.

borated water.

28 3.2.4.4.A Communications - Confirm that Started upgrades to the site's communications systems have been completed.

29 3.2.4.6.A Personnel Habitability - Review Complete - Habitability conditions licensee's evaluation of loss of within the MCR and other areas of ventilation effects on personnel the plant will be maintained with a habitability and accessibility. tool box approach limiting the impact of high temperatures with Page 22 of 28

Braidwood Station, Units 1 and 2- Second Six Month Status Report for the Implementation of FLEX February 28 ,2014 methods such as supplemental cooling, personnel rotation and/or availability of fluids.

30 3.2.4.7.A Water Sources - Justify the time at Complete - Based on WCAP-which SG dryout will occur. 17601-P Table 5.4.1.1-1 Case 2A S/G dryout would occur at 3,670 seconds, (61.16 minutes).

31 3.2.4.8.A Electrical Power Sources !Isolation Started - Electrical isolation will be and interactions- confirm class 1E provided as part of the FLEX equipment is protected from faults in procedural guidance. For example, portable/FLEX equipment and feed breakers 1425X and 2425X for multiple sources do not attempt to 480V bus 132X and 232X will be power electrical buses. opened prior to re-energizing these 480 volt buses with the FLEX Generator.

32 3.2.4.9.A Portable Equipment Fuel - Confirm Started - The Unit 1 and Unit 2 "B" that complete analysis of fuel usage tanks contain 100,000 gallons of requirements has been developed fuel. It is reasonable to assume the after the specific FLEX equipment is site fuel supply will last until roads identified and the fuel usage is can be reopened and local tanks determined. A discussion is needed can replenish the supply. The site on maintaining the quality of fuel has an additional 100,000 gallons stored in the tanks for extended contained in the "A" train tanks, but periods of time. it is not available to the Diesel fuel oil transfer pumps without additional modifications. The site also has 125,000 gallons and 50,000 gallons storage tanks that are not robust and must be assumed unavailable, but would be used if available.

The complete analysis of a fuel usage requirements will be developed after the specific FLEX equipment is identified and their fuel use is determined.

Replacement fuel will be ordered with the same fuel quality standards of current fuel.

33 3.2.4.10.A Load reduction to conserve DC Started - AC Power Diesel sizing power- Confirm sizing calculations calculations for the FLEX DG are for FLEX generators and details of being performed in the electrical modification package to reenergize Page 23 of 28

Braidwood Station, Units 1 and 2- Second Six Month Status Report for the Implementation of FLEX Feb ruary 28 , 2014 load shedding. the required AC Bus. DC Load shedding will be performed in accordance with BwFSG-4, ELAP DC Load Shed/Management, being developed.

7 Potential Draft Safety Evaluation Impacts There are no potential impacts to the Draft Safety Evaluation identified at this time.

8 References The following references support the updates to the Overall Integrated Plan described in this enclosure.

1. Braidwood Station, Units 1 and 2, "Overall Integrated Plan 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)," dated February 28,2013 (RS-13-017).
2. NRC Order Number EA-12-049, "Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events," dated March 12, 2012.
3. NEI 12-06 Rev. 0, Diverse and Flexible Coping Strategies (FLEX) Implementation Guide, dated August 2012.
4. Braidwood Station's First Six Month Status Report for the Implementation of FLEX, dated August 28, 2013.
5. Braidwood Station, Units 1 and 2 -Interim Staff Evaluation Relating to Overall Integrated Plan in Response to Order EA-12-049 (Mitigating Strategies) (TAC NOS. MF0895 AND MF0896), dated December 17, 2013.

9 Attachments 1A Sequence of Events Timeline 3 Updated Mechanical One Line Diagrams Page 24 of 28

Braidwood Station, Units 1 and 2- Second Six Month Status Report for the Implementation of FLEX February 28, 2014 Attachment 1A Sequence of Events Timeline Time Remarks I Action Elapsed Constraint Applicability item Time Action YIN 1 The times to complete actions in the Events Timeline are based on operating judgment, the conceptual designs, and the current supporting analyses. The final timeline will be time validated once detailed designs are completed, procedures are developed, and the results will be provided in a future six (6) month update.

1 0 Event Starts, BDBEE occurs, Unit 1 and Unit 2 reactors NA Plant @ 100% power automatically trip and all rods are inserted.

Loss of off-site power (LOOP) affecting both units occurs 2 1 min Emergency Operating Procedures, (EOPs) and Station NA _BwCA 0.0, Loss of Black Out, (SBO), Procedures are entered. All AC Power, action.

3 5-50 mins Verify DDAF Pp is operating properly. Y -1 hour _BwCA 0.0, Loss of All AC Power, action. 1/2BwFSG-2 4 5-15mins MCR closes C & D SIG PORVs to conserve inventory. Y -15 mins _BwCA 0.0, Loss of All AC Power, action. As referenced in WCAP 17601-P and operator judgment 5 10-30 mins Attempt starting Emergency DIG's NA _BwCA 0.0, Loss of AIIAC Power, action.

6 30 mins ELAP condition recognized and ELAP Procedures are NA _BwCA 0.0, Loss of entered. All AC Power, attachment B for ELAP 7 30 mins to Connect FLEX 480V AC generators to ESF bus _32X Y -3.6 hrs

Reference:

EC-3.6 hrs and verify they are supplying power to Div 2 - 125V DC EVAL # 391872 battery chargers Battery Coping Time For The 125V DC ESF Battery Banks, dated February 8, 2013 8 35 mins to Operators dispatched to perform DC Bus Load Shed 3.6 hrs Required by WCAP-Page 25 of 28

Braidwood Station, Units 1 and 2- Second Six Month Status Report for the Implementation of FLEX Fe b ruarv 28 , 2014 75 mins 17601-P and directed by 1/2BwFSG-4 9 55 mins to SX Short Cycle Cooling EC is aligned to cool the B AF Y -2 hour _BwCA 0.0, Loss of 90 mins Pp within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> after pump start. All AC Power, action

& 1/2BwFSG-2 10 1.5 hrs Start depressurization of S/Gs to 300 psi a at Y - 2 hrs _BCA 0.0, Loss of All AC Power, approximately 75°F/hr cool down with SG PORV action. As local/manual operation. SG feed is controlled with referenced in Local/Manual operation of AFW flow control valves. WCAP-17601-P 11 2.25 hrs SI Accumulator borated water begins to inject into the NA Operator Judgment RCS 12 4 hrs Maintain RCS 300 psia /-420°F with SG PORV N Operator Judgment operation. WCAP-17601-P section 5.2.1 page 5-4 Maintain SG level.

13 4-6 hrs Deploy all hoses and connections in FHB for Alternate Y-6 hrs Directed from strategies for SFP Fill and RCS Inventory make up via OBwFSG-5 and the B CV Pp discharge connections before FHB OFSG-11 becomes uninhabitable from SFP Boiling 14 5 -7 hrs Isolate SI Accumulators N 1/2BwFSG -10 15 12 hrs Initiate SFP Make up via OA FC Purification pump as NA OBwFSG-11 required for level and temperature control 16 12-14hrs Connect Phase 2 med head FLEX Pumps and ensure NA 1/2BwFSG-5 they are available to supply make-up to the SG's.

17 16-18hrs Stage and connect Phase 2 high pressure FLEX Pumps NA 1/2BwFSG-5 and ensure they are available to supply borated make-up to the RCS.

18 24 hrs Regional Response Center (RRC) resources begin NA RRC Response arriving on site. Guide 19 24 - 72 hrs Continue to maintain critical functions of Core Cooling NA End of analytical (via DDAF), RSC Inventory Control (via FLEX pump simulation injection to RCS) and SFP Cooling (via FLEX pump injection to SFP). Utilize initial RRC equipment and resources as a spare capaci!y.

Page 26 of 28

Braidwood Station, Units 1 and 2- Second Six Month Status Report for the Implementation of FLEX February 28, 2014 Attachment 3

~~~~~~~, _______________ ~ ____

Updated

,~_~,~_~~ 1 Mechanical One Line Diagrams Page 27 of 28

Braidwood Station, Units 1 and 2- Second Six Month Status Report for the Implementation of FLEX February 28,2014 r--------------------------------------------~***-**** -------- ""I Sl( "SHORT CYCLE" YOD ***

Page 28 of 28

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