RS-16-145, Seventh 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)

Seventh 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)

ML16239A321
Person / Time
Site:	Braidwood
Issue date:	08/26/2016
From:	Kaegi G Exelon Generation Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
EA-12-049, RS-16-145
Download: ML16239A321 (18)

Text

Exelon Generation,,,,,

Order No. EA-12-049 RS-16-145 August 26, 2016 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Braidwood Station, Unit 1 Renewed Facility Operating License No. NPF-72 NRC Docket No. STN 50-456

Subject:

Seventh 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. NEI 12-06, "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. Exelon Generation Company, LLC 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 049), dated February 28, 2014 (RS-14-007)

U.S. Nuclear Regulatory Commission Integrated Plan Report to EA-12-049 August 26, 2016 Page 2

8. Exelon Generation Company, LLC Third Six-Month Status Report in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order Number EA 049), dated August 28, 2014 (RS-14-205)

9. Exelon Generation Company, LLC Fourth 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 February 27, 2015 (RS-15-016)

10. Exelon Generation Company, LLC Fifth 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, 2015 (RS-15-208)

11. Exelon Generation Company, LLC Sixth 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 February 26, 2016 (RS-16-020)

12. 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

13. NRC letter to Exelon Generation Company, LLC, Braidwood Station, Units 1 and 2 Report for the Audit Regarding Implementation of Mitigating Strategies and Reliable Spent Fuel Pool Instrumentation Related to Orders EA-12-049 and EA-12-051 (TAC Nos. MF0895 and MF0896), dated May 27, 2015 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, Unit 1 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. References 6, 7, 8, 9, 10, and 11 provided the first, second, third, fourth, fifth, and sixth six-month status reports, respectively, pursuant to Section IV, Condition C.2, of Reference 1 for Braidwood Station, Unit 1. The purpose of this letter is to provide the seventh 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

U.S. Nuclear Regulatory Commission Integrated Plan Report to EA-12-049 August 26, 2016 Page 3 addresses the NRC Interim Staff Evaluation Open and Confirmatory Items contained in Reference 12, and the NRC Audit Report open items contained in Reference 13.

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

1 declare under penalty of perjury that the foregoing is true and correct. Executed on the 26th day of August 2016.

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

Enclosure:

1. Braidwood Station, Unit 1 Seventh 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 cc: NRC Regional Administrator - Region III NRC Senior Resident Inspector - Braidwood Station NRC Project Manager, NRR - Braidwood Station Mr. John D. Hughey, NRR/JLD/JOMB, NRC Illinois Emergency Management Agency - Division of Nuclear Safety

IE in c 11 (o) s tu ire Braidwood Station, Unit 1 Seventh 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 (14 pages)

Braidwood Station, Unit 1 Seventh 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 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.

With the report of Unit 2 full compliance (Reference 38) submitted on December 16, 2015, this six-month update provides the status of Braidwood Station, Unit 1 mitigating strategies implementation.

2 Milestone Accomplishments No new milestone accomplishments since the last 6 month update on February 26, 2016 (Ref 40).

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 Strategic Alliance Complete for FLEX Emergency Response National SAFER Response Center Submit Six (6) month updates Aug 2013 Update 1 Complete Feb 2014 Update 2 Complete Aug 2014 Update 3 Complete Feb 2015 Update 4 Complete Aug 2015 Update 5 Complete Page Iof14

Braidwood Station, Unit 1 Seventh 6 Month Status Report for the Implementation of FLEX August 26, 2016 Original Target Activity Status Revised Target Completion Date Completion Date Feb 2016 Update 6 Complete Aug 2016 Update 7 Complete with this submittal Unit 1 Unit 2 Modification Development Unit 1 Unit 2 Unit 1 Unit 2 Feb Sept Phase 1 modifications Started Complete Oct Oct 2014 2014 2016 2015 Feb Sept

• Phase 2 modifications Complete Complete Dec Dec 2014 2014 2014 2014 Feb Sept

• Phase 3 modifications Complete Complete 2014 2014 Unit 1 Unit 2 Modification Implementation Unit 1 Unit 2 Unit 1 Apr Oct

• Phase 1 modifications Started Complete Oct Y 2015 2015 2016 Apr Oct

• Phase 2 modifications Complete Complete A 2015 2015 Apr Oct

• Phase 3 modifications Complete Complete 2015 2015 Unit 1 Unit 2 Procedure Development Unit 1 Unit 2 Unit 1 Apr Oct

• Strategy procedures *Complete Complete Oct 2015 2015 2016 Apr Oct

• Validate procedures (NEI *Complete Complete Oct 2015 2015 12-06, Sect. 11.4.3) 2016 Apr Oct

• Maintenance procedures *Complete Complete Oct 2015 2015 2016 Nov 2014 Staffing analysis Complete Apr 2015 Storage plan and construction Complete Apr 2015 FLEX equipment acquisition Complete Apr 2015 Training completion Complete Sept 2015 Dec 2014 National SAFER Response Complete Feb 2015 Center operational Apr 2015 Unit 1 Implementation date Started October 2016 Oct 2015 Unit 2 Implementation date Complete Page 2 of 14

Braidwood Station, Unit 1 Seventh 6 Month Status Report for the Implementation of FLEX August 26, 2016 Notes:

• Procedures completed. Awaiting implementation during Refueling Outage Al R19 (Fall 2016) due to the RCP Seals.

4 Changes to Compliance Method No new changes to compliance method since the last 6 month update on February 26, 2016.

5 Need for Relief/Relaxation and Basis for the Relief/Relaxation Braidwood Station, Unit 1 has received an 18-month extension of the Order due to Pressurized-Water Reactor Owners Group (PWROG) refining RCP Seal Leakage rate projections and is scheduled to be in compliance by October 2016 in accordance with NRC letter, dated April 15, 2015 (ADAMS Accession No. ML15068A215) (Ref 41) stating: "Accordingly, based upon the authority granted to the Director, Office of Nuclear Reactor Regulation, the requirement of the order for full order implementation for Braidwood Station, Unit 1, is relaxed until the completion of the fall 2016 refueling outage. This additional time will allow Exelon to complete the engineering analysis associated with the additional information provided by the PWROG regarding the analytical basis for RCP seal leakage".

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.

NOTE: The "Status" indicated in this document is as of August 3, 2016. This date was chosen to support the development, review, approval and submittal of this report by the required August 26, 2016 due date.

Section Reference Overall Integrated Plan Open Item Status Key Site assumptions Primary and secondary storage Item Closed During Onsite NRC Audit (p.4) locations have not been selected yet; (Ref. 31).

once locations are finalized implementation strategies and routes Complete Closure supplied as part of will be assessed for hazard impact. fifth 6-month update (Ref. 36).

Sequence of events The final timeline will be time validated Item Closed During Onsite NRC Audit (p.5) once detailed designs are completed (Ref. 31).

and procedures are developed.

Complete Closure supplied as part of sixth 6-month update (Ref. 40).

Page 3 of 14

Braidwood Station, Unit 1 Seventh 6 Month Status Report for the Implementation of FLEX August 26, 2016 Identify how strategies Identification of storage area and Item Closed During Onsite NRC Audit will be deployed (p.7) creation of the administrative program. (Ref. 31).

Complete Closure supplied as part of fifth 6-month update (Ref. 36).

Programmatic controls Develop an administrative program for Item Closed During Onsite NRC Audit (p.8) FLEX responsibilities, and testing & (Ref. 31).

maintenance.

Complete Closure supplied as part of fifth 6-month update (Ref. 36).

National SAFER Development of Braidwood Station's Item Closed During Onsite NRC Audit Response Center plan playbook. (Ref. 31).

(p'9) Complete Closure supplied as part of fifth 6-month update (Ref. 36).

Key Reactor Identify additional parameters that are Item Closed During Onsite NRC Audit Parameters (p. multiple) needed in order to support key actions (Ref. 31).

identified in the plant Complete Closure supplied as part of procedures/guidance or to indicate third 6-month update (Ref. 25).

imminent or actual core damage.

Deployment Conceptual Develop the storage structure Item Closed During Onsite NRC Audit Design (p. multiple) conceptual design. (Ref. 31).

Complete Closure supplied as part of fourth 6-month update (Ref. 29).

Maintain RCS Inventory A calculation will be required for the Item Closed During Onsite NRC Audit Control, Phase 2 (p.23) timing of the boration and quantity (Ref. 31).

required.

Complete Closure supplied as part of sixth 6-month update (Ref. 40).

Maintain Containment, Additional calculations will be performed Item Closed During Onsite NRC Audit Phase 1 (p.31) to evaluate containment response. (Ref. 31).

Complete Closure supplied as part of fifth 6-month update (Ref. 36).

Maintain Spent Fuel Procedure development for Initial Spent Item Closed During Onsite NRC Audit Pool Cooling, Phase 1 fuel pool make-up with gravity drain (Ref. 31).

(p.39) from the RWST.

Complete Closure supplied as part of third 6-month update (Ref. 25).

Maintain Spent Fuel Initial calculations were used to Item Closed During Onsite NRC Audit Pool Cooling, Phase 1 determine the fuel pool timelines. (Ref. 31).

(p.39) Formal calculations will be performed to Complete -Closure supplied as part of validate this information during third 6-month update (Ref. 25).

development of the spent fuel pool cooling strategy detailed design.

Page 4 of 14

Braidwood Station, Unit 1 Seventh 6 Month Status Report for the Implementation of FLEX August 26, 2016 Maintain Spent Fuel Evaluation of the spent fuel pool area Item Closed During Onsite NRC Audit Pool Cooling, Phase 1, for steam and condensation will be (Ref. 31).

(p.39 and p.42) performed and used to determine if vent Complete -Closure supplied as part of path strategy is needed.

third 6-month update (Ref. 25).

Safety Functions Habitability conditions will be evaluated Item Closed During Onsite NRC Audit Support, Phase 2 (p.51) and a strategy will be developed to (Ref. 31).

maintain Main Control Room.

Complete - Closure supplied as part of third 6-month update (Ref. 25).

Safety Functions Critical ventilation assets may be Item Closed During Onsite NRC Audit Support, Phase 2 (p.51) required to support DDAF pumps, (Ref. 31).

station battery rooms, miscellaneous Complete Closure supplied as part of electric equipment rooms, and fuel fourth 6-month update (Ref. 29).

handling building personnel habitability and/or component survivability. Specific analyses of these rooms will be performed.

Interim Safety Evaluation Open Item Status Rraidwood's ISE Response Line Item Description Answer Number Number 1 Open Item Core Subcriticality- The NRC staff Item Closed During Onsite NRC Audit 3.2.1.8.A has not endorsed the industry- (Ref. 31).

proposed position paper regarding boron mixing. The licensee has Complete Closure supplied as part indicated that Braidwood is planning of sixth 6-month update (Ref. 40).

on following this methodology. Thus, further resolution of this issue will be necessary in the next phase of the audit process.

Confirmatory Items 2 3.1.1.1.A Storage & Protection of FLEX Complete Closure supplied as part equipment - Confirm final design of of fifth 6-month update (Ref. 36).

FLEX storage structure conforms to N EI 12-06, Sections 5.3.1, 7.3.1, and 8.3.1 for storage considerations for the hazards applicable to Braidwood.

3 3.1.1.3.A Procedural Interface Considerations Item Closed During Onsite NRC Audit (Seismic) Confirm procedure for (Ref. 31).

measuring key instruments at Complete Closure supplied as part containment penetrations using of fourth 6-month update (Ref. 29).

portable instrument.

Page 5 of 14

Braidwood Station, Unit 1 Seventh 6 Month Status Report for the Implementation of FLEX August 26, 2016 4 3.1.1.4.A Off-Site Resources Confirm Item Closed During Onsite NRC Audit National SAFER Response Center (Ref. 31).

local staging area and method of Complete Closure supplied as part transportation to the site in future 6-of fifth 6-month update (Ref. 36).

month update 5 3.1.5.1 .A Protection of Equipment (High Item Closed During Onsite NRC Audit Temperature) - Confirm FLEX (Ref. 31).

storage structure will maintain FLEX Complete Closure supplied as part equipment at a temperature range to of fourth 6-month update (Ref. 29).

ensure its likely function when called upon.

6 3.1.5.3.A Deployment of Equipment (High Item Closed During Onsite NRC Audit Temperature) - Confirm that the (Ref. 31).

effects of high temperature on FLEX Complete Closure supplied as part equipment have been evaluated in of fourth 6-month update (Ref. 29).

the locations they are intended to operate.

7 3.2.1.A RCS cooling & RCS inventory control Item Closed During Onsite NRC Audit

- Specify which analysis performed in (Ref. 31).

WCAP-17601 is being applied to Complete Closure supplied as part Braidwood. Additionally, justify the of fifth 6-month update (Ref. 36).

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 Item Closed During Onsite NRC Audit NOTRUMP in the ELAP analysis is (Ref. 31).

limited to the flow conditions before Complete Closure supplied as part reflux condensation initiates. This of fifth 6-month update (Ref. 36).

includes specifying an acceptable definition for reflux condensation cooling.

9 3.2.1.1.B ELAP Analysis - Confirm calculations Item Closed During Onsite NRC Audit to verify no nitrogen injection into (Ref. 31).

RCS during depressurization.

Complete Closure supplied as part of fourth 6-month update (Ref. 29).

10 3.2.1.1.0 Confirm analysis for secondary side Item Closed During Onsite NRC Audit SG fouling due to the use of (Ref. 31).

abnormal water sources (RWST, well Complete Closure supplied as part water, SX water) of fourth 6-month update (Ref. 29).

Page 6 of 14

Braidwood Station, Unit 1 Seventh 6 Month Status Report for the Implementation of FLEX August 26, 2016 11 3.2.1.1.D Complete analysis for length of time Item Closed During Onsite NRC Audit prior to depletion of the RWST and (Ref. 31).

determine whether additional Complete Closure supplied as part boration equipment is needed for of fourth 6-month update (Ref. 29).

Phase 3 coping strategy.

12 3.2.1.2.B Reactor Coolant Pump (RCP) Seal Item Closed During Onsite NRC Audit Leakage - In some plant designs, the (Ref. 31).

cold legs could experience temperatures as high as 580 OF Complete Closure supplied as part before cooldown commences. This is of sixth 6-month update (Ref. 40).

beyond the qualification temperature (550°F) of the 0-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 FLAP is adequate and acceptable.

13 3.2.1.2.E RCP Seal Leakage Rates - The Item Closed During Onsite NRC Audit licensee is requested to provide the (Ref. 31).

manufacturer and model number of Complete Closure supplied as part the RCP seals and discuss whether of fifth 6-month update (Ref. 36).

or not the RCP and seal combination complies with a seal leakage model described in WCAP-17601.

14 3.2.1.3.A Decay Heat- Verify that the Item Closed During Onsite NRC Audit Integrated Plan update provides the (Ref. 31).

details of the WCAP 17601-P Complete Closure supplied as part methodology to include the values of of fifth 6-month update (Ref. 36).

certain key parameters used to determine the decay heat levels.

Address the adequacy of the values used.

15 3.2.1.4.A Initial Values for Key Plant Item Closed During Onsite NRC Audit Parameters and Assumptions- (Ref. 31).

Confirm WCAP-17601-P analyses Page 7 of 14

Braidwood Station, Unit 1 Seventh 6 Month Status Report for the Implementation of FLEX August 26, 2016 are bounding for Braidwood for Complete Closure supplied as part strategy response or verify plant- of fifth 6-month update (Ref. 36).

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 Item Closed During Onsite NRC Audit Parameters and Assumptions- (Ref. 31).

Confirm calculations to validate 8 Complete Closure supplied as part hours run time limit on DDAF pump of fourth 6-month update (Ref. 29).

batteries and DDAF room temp for pump operation and human occupancy. Also, confirm site phase 2 staffing study confirms the required time can be met for refilling diesel day tank.

17 3.2.1.5.A Monitoring Instruments and Control- Item Closed During Onsite NRC Audit Confirm additional parameters (Ref. 31).

evaluated for use in plant Complete - Closure supplied as part procedures/guidance or to indicate of third 6-month update (Ref. 25).

imminent or actual core damage.

18 3.2.1.6.A Sequence of Events - Confirm that Complete Closure supplied as part the final timeline has been time of sixth 6-month update (Ref. 40).

validated after detailed designs are completed and procedures are developed. The results may be provided in a future 6-month update.

19 3.2.1.6.B Sequence of Events - Confirm Item Closed During Onsite NRC Audit analysis to validate Phase 2 pump (Ref. 31).

capacities.

Complete Closure supplied as part of fourth 6-month update (Ref. 29).

20 3.2.1.9.A Use of portable pumps - Confirm Item Closed During Onsite NRC Audit final design of strategies meets "use (Ref. 31).

of portable pumps" guideline in NEI Complete Closure supplied as part 12-06, Section 3.2.2, Guideline 13.

of fourth 6 month update (Ref. 29).

21 3.2.2.A SFP cooling -Verify procedure for Item Closed During Onsite NRC Audit SFP makeup via gravity drain; (Ref. 31).

confirm verification of timeline for Complete Closure supplied as part performing the strategy; and confirm of fourth 6-month update (Ref. 29).

evaluation of SFP area for steam and condensation affects.

22 3.2.3.A Containment - Confirm containment Complete Closure supplied as part reanalysis supports no Phase 1, 2, i of fifth 6-month update (Ref. 36).

and 3 mitigation strategies are required because containment pressure and temperature are Page 8 of 14

Braidwood Station, Unit 1 Seventh 6 Month Status Report for the Implementation of FLEX August 26, 2016 maintained within acceptable limits.

23 3.2.3.B Containment - Confirm evaluation Item Closed During Onsite NRC Audit performed for the need to monitor (Ref. 31).

containment temperature.

Complete Closure supplied as part of fifth 6-month update (Ref. 36).

24 3.2.4.1.A Equipment cooling - Confirm Item Closed During Onsite NRC Audit modification has been performed to (Ref. 31).

prevent DDAF pump from Complete Closure supplied as part overheating due to cooling water of fourth 6-month update (Ref. 29).

recirculation flow paths within the SX system cycling and overheating 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 - Item Closed During Onsite NRC Audit Review licensee's evaluation of loss (Ref. 31).

of ventilation effects on equipment in Complete Closure supplied as part various rooms (DDAF pump room, of fourth 6-month update (Ref. 29).

battery rooms, control room, miscellaneous electrical equipment rooms) 26 3.2.4.2.B A discussion is needed on the Item Closed During Onsite NRC Audit extreme high/low temperatures (Ref. 31).

effects of the battery's capability to Complete Closure supplied as part perform its function for the duration of fourth 6-month update (Ref. 29).

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 Item Closed During Onsite NRC Audit adverse impacts from a loss of heat (Ref. 31).

tracing and normal heating on any Complete Closure supplied as part equipment credited for ELAP of fourth 6-month update (Ref. 29).

mitigation are adequately addressed.

In particular, ensure an RCS inventory and source of borated water is available for a BDBEE associated with extreme cold, ice, and snow.

28 3.2.4.4.A Communications - Confirm that Item Closed During Onsite NRC Audit upgrades to the site's (Ref. 31).

communications systems have been Complete Closure supplied as part completed.

of fifth 6-month update (Ref. 36).

29 3.2.4.6.A Personnel Habitability - Review Item Closed During Onsite NRC Audit licensee's evaluation of loss of (Ref. 31).

ventilation effects on personnel Complete - Closure supplied as part habitability and accessibility.

of third 6-month update (Ref. 25).

Page 9 of 14

Braidwood Station, Unit 1 Seventh 6 Month Status Report for the Implementation of FLEX August 26, 2016 30 3.2.4.7.A Water Sources - Justify the time at Item Closed During Onsite NRC Audit which SG dryout will occur. (Ref. 31).

Complete Closure supplied as part of sixth 6-month update (Ref. 40).

31 3.2.4.8.A Electrical Power Sources / Isolation Item Closed During Onsite NRC Audit and interactions- confirm class 1 E (Ref. 31).

equipment is protected from faults in Complete Closure supplied as part portable/FLEX equipment and of fourth 6-month update (Ref. 29).

multiple sources do not attempt to power electrical buses.

32 3.2.4.9.A Portable Equipment Fuel - Confirm Item Closed During Onsite NRC Audit that complete analysis of fuel usage (Ref. 31).

requirements has been developed Complete Closure supplied as part after the specific FLEX equipment is of fifth 6-month update (Ref. 36).

identified and the fuel usage is determined. A discussion is needed on maintaining the quality of fuel stored in the tanks for extended periods of time 33 3.2.4.10.A Load reduction to conserve DC Item Closed During Onsite NRC Audit power- Confirm sizing calculations (Ref. 31).

for FLEX generators and details of Complete Closure supplied as part load shedding.

of fourth 6-month update (Ref. 29).

Page 10 of 4.4

Braidwood Station, Unit 1 Seventh 6 Month Status Report for the Implementation of FLEX August 26, 2016 NRC Audit Open Items Status Braidwood Station Response SE#9 Please provide adequate justification for the reactor Complete Closure supplied as part coolant Pump (RCP) seal leakage rates calculated of fifth 6-month update (Ref. 36).

according to the Westinghouse seal leakage model that was revised following the issuance of NSAL-14-1. The justification should include a discussion of the following factors:

a. benchmarking of the seal leakage model against relevant data from tests or operating events,

b. discussion of the impact on the seal leakage rate due to fluid temperatures greater than 550°F resulting in increased deflection at the seal interface,

c. clarification whether the second-stage RCP seal would remain closed under ELAP conditions predicted by the revised seal leakage model and a technical basis to support the determination, and,

d. justification that the interpolation scheme used to compute the integrated leakage from the RCP seals from a limited number of computer simulations (e.g.,

three) is realistic or conservative.

SE #10 The NRC staff understands that Westinghouse has Complete Closure supplied as part recently recalculated RCP seal leakoff line pressures of fifth 6-month update (Ref. 36).

under loss of seal cooling events based on a revised seal leakage model and additional design-specific information for certain plants.

a. Please clarify whether the piping and all components (e.g., flow elements, flanges, valves, etc.) in your seal leakoff line are capable of withstanding the pressure predicted during an ELAP event according to the revised seal leakage model.

b. Please clarify whether operator actions are credited with isolating low-pressure portions of the seal leakoff line and if so, please explain how these actions will be executed under ELAP conditions.

c. If overpressurization of piping or components could occur under ELAP conditions, please discuss any tanned modifications to the seal leakoff piping and Page 11 of 14

Braidwood Station, Unit 1 Seventh 6 Month Status Report for the Implementation of FLEX August 26, 2016 component design and the associated completion timeline.

d. Alternately, please identify the seal leakoff piping or components that would be susceptible to overpressurization under ELAP conditions, clarify their locations, and provide justification that the seal leakage rate would remain in an acceptable range if the affected piping or components were to rupture.

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's Second Six Month Status Report for the Implementation of FLEX, dated February 28, 2014.

6. Braidwood Station, Units 1 and 2 NRC 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.

7. BYR99-010/BRW-99-0017-I, Rev. 2, Documentation of the Basis of the Emergency Operating Procedures (EOP) Setpoints, dated September 2014.

8. BYR14-060/BRW-14-0080-E, Rev. 0, Unit 1(2) 125 VDC Battery FLEX Coping Calculation Common Calc Beyond Design Basis, dated September 2014.

9. BYR13-240/BRW-13-0222-M, Rev. 0, Spent Fuel Pool Boil Off Analysis during an ELAP Event, dated April 2014.

10. BYR13-239/BRW-13-0221-M, Rev. 0, RCS Boration Analysis during an ELAP Event, dated August 2014.

Page 12 of 14

Braidwood Station, Unit 1 Seventh 6 Month Status Report for the Implementation of FLEX August 26, 2016

11. Exelon Structural Drawing S-183, Rev. AF, Roadway Plan Plant and Construction Laydown Area, dated May 2014.

12. BYR1 3-235/BRW-1 3-0217-M, Rev. 0, Containment Pressure and Temperature Response during an ELAP Event, dated September 2014.

13. BYR1 3-234/BRW-1 3-0216-M, Rev. 0, Auxiliary FW Pump Room Temperature Analysis during and ELAP Event, dated April 2014.

14. BYR13-237/BRW-13-0219-M, Rev. 0, MEER and Battery Room Conditions Following ELAP, dated July 2014.

15. BYR13-236/BRW-13-0218-M, Rev. 0, Control Room and Auxiliary Electric Equipment Room heat up and Ventilation during an ELAP, dated June 2014.

16. BYR1 3-026/BRW-1 3-0031 -M, Rev. 0, Transient Analysis of SX System Following Loss of A-C Power, dated August 2013.

17. BYR14-046/BRW-14-0058-M, Rev. 0, Containment Environment Following an Extended Loss of AC Power During Shutdown, dated September 2014.

18. WCAP 17601-P, Rev. 1, Reactor Coolant System Response to the Extended Loss of AC Power Event for Westinghouse, Combustion Engineering and Babcock & Wilcox NSSS Designs, dated January 2013.

19. BRW-97-0340-E, Rev. 3, Battery Duty Cycle and Sizing for the Braidwood Diesel Driven Auxiliary Feedwater Pumps, dated August 2014.

20. BYR1 3-144/BRW-1 3-0160-M, Rev. 2, FLEX Pump Sizing and Hydraulic Analysis, dated December 2014.

21. BRW-14-0030-M, Rev. 0, Godwin Pump Suction Line Hydraulic Analysis to Support FLEX, dated August 2014.

22. Letter to Mr. Jack Stringfellow requesting endorsement of Westinghouse position paper entitled "Westinghouse Response to NRC Generic Request for Additional Information (RAI) on Boron Mixing in support of the Pressurized Water Reactor Owners Group (PWROG)", Accession Number ML13276A183, date January 8, 2014.

23. Westinghouse Correspondence LTR-FSE-14-43, Revision 0, "Exelon Generation Company, LLC Mitigation Strategies Order (EA-12-049) Design ELAP Simulation Parameters," dated June 15, 2015.

24. Westinghouse Correspondence LTR-FSE-14-61, Rev.0 "Exelon Generation Company, LLC Mitigation Strategies Order (EA-12-049) Open and Confirmatory Item Responses,"

dated June 15, 2015.

25. Braidwood Station's Third Six Month Status Report for the Implementation of FLEX, dated August 28, 2014.

26. BRW-14-0255-M, Rev. 1, Braidwood Units 1 and 2 FLEX Steam Generator Degraded Heat Transfer Analysis through 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, dated December 2014.

27. BYR14-129/BRW-14-0212-M, Rev. 0, RWST Usage during FLEX Scenarios, dated October 2014.

28. BRW-14-0211-M, Rev.0, Evaluation of Tank and Hose Freezing during an ELAP, dated September 2014.

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Braidwood Station, Unit 1 Seventh 6 Month Status Report for the Implementation of FLEX August 26, 2016

29. Braidwood Station's Fourth Six Month Status Report for the Implementation of FLEX, dated February 27, 2015.

30. BRW-15-0002-S, Rev.0, Evaluation of FLEX Equipment Haul Paths for Soil Liquefaction Potential, dated March 2015.

31. Braidwood Station, Units 1 and 2 NRC Report for the Audit Regarding Implementation of Mitigating Strategies and Reliable Spent Fuel Pool Instrumentation Related to Orders EA-12-049 and EA-12-051 (TAC Nos. MF0895 and MF0896), dated May 27, 2015 (ADAMS Accession No. ML15134A459).

32. PWROG-14027-P, Rev. 3, No.1 Seal Flow Rate for Westinghouse Reactor Coolant Pumps Following Loss of all AC Power, dated April 2015.

33. CN-LIS-15-34, Rev. 0, Exelon Byron and Braidwood Stations Reactor Coolant System ELAP Inventory Control Analysis SHIELD Reactor Coolant Pump Seal Packages, dated July 13, 2015.

34. CN-LIS-15-40, Rev. 0, Exelon Byron and Braidwood Stations Delayed AFW FLEX Studies, dated September 2015.

35. CN-LIS-15-39, Rev. 0, Exelon Byron and Braidwood Stations Reactor Coolant System ELAP Long-Term Subcriticality Analysis with Low-Leakage Reactor Coolant Pump Seal Packages, dated September 2015.

36. Braidwood Station's Fifth Six Month Status Report for the Implementation of FLEX, dated August 28, 2015.

37. Braidwood Station, Units 1 and 2 - Response Regarding Phase 2 Staffing Submittals Associated With Near-term Task Force Recommendation 9.3 Related to the Fukushima Dal-ichi Nuclear Power Plant Accident (ADAMS Accession No.: ML151568260), dated June 2015.

38. Exelon Generation Company, LLC letter to the NRC, "Braidwood Station, Unit 2, Report of Full Compliance with 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 December 16, 2015 (RS-15-276).

39. Westinghouse Correspondence LTR-RES-13-153, "Documentation of 7228C O-Rings at ELAP Conditions," dated October 31, 2013.

40. Braidwood Station's Sixth Six Month Status Report for the Implementation of FLEX, dated February 26, 2016.

41. NRC Letter, dated April 15, 2015 (ADAMS Accession No. ML15068A215)

Braidwood Station, Unit 1 Relaxation of the Schedule Requirements for Order EA 049 "Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events" (TAC NO. MF0895)

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