RS-17-096, Ninth 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 No. EA-12-049)

Ninth 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 No. EA-12-049)

ML17240A029
Person / Time
Site:	Peach Bottom
Issue date:	08/28/2017
From:	Jim Barstow Exelon Generation Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
EA-12-049, RS-17-096
Download: ML17240A029 (35)

Text

Exelon Generation , RS-17-096 August28,2017 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Peach Bottom Atomic Power Station, Unit 3 Renewed Facility Operating License No. DPR-56 NRC Docket No. 50-278 Order No. EA-12-049

Subject:

Ninth Six-Month Status Report in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for 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-13-024)

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-12-049), dated August 28, 2013 (RS-13-127)

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-12-049), dated February 28, 2014 (RS-14-014)

U.S. Nuclear Regulatory Commission Integrated Plan Report to EA-12-049 August28,2017 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-12-049), dated August 28, 2014 (RS-14-212)

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-12-049), dated February 27, 2015 (RS-15-023)

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-12-049), dated August 28, 2015 (RS-15-214)

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-12-049), dated February 26, 2016 (RS-16-026)

12. Exelon Generation Company, LLC 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), dated August 26, 2016 (RS-16-149)

13. Exelon Generation Company, LLC Eighth 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), dated February 28, 2017 (RS-17-021)

14. NRC letter to Exelon Generation Company, LLC, Peach Bottom Atomic Power Station, Units 2 and 3 -Interim Staff Evaluation Relating to Overall Integrated Plan in Response to Order EA-12-049 (Mitigation Strategies) (TAC Nos.

MF0845 and MF0846), dated November 22, 2013 15. NRC letter to Exelon Generation Company, LLC, Peach Bottom Atomic Power Station, Units 2 and 3 -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. MF0845, MF0846, MF0849 and MF0850), dated September 23, 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 Attachment 2 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 O (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 Peach Bottom Atomic Power Station, Units 2 and 3 Overall Integrated Plan.

U.S. Nuclear Regulatory Commission Integrated Plan Report to EA-12-049 August28,2017 Page 3 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, 11, 12, and 13 provided the first, second, third, fourth, fifth, sixth, seventh, and eighth six-month status reports, respectively, pursuant to Section IV, Condition C.2, of Reference 1 for Peach Bottom Atomic Power Station. The purpose of this letter is to provide the ninth 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 14, and the NRC Audit Report open items contained in Reference

15. This letter contains no new regulatory commitments.

If you have any questions regarding this report, please contact David J. Distel at 610-765-5517.

I declare under penalty of perjury that the foregoing is true and correct. Executed on the 28 1 h day of August 2017. James Barstow Director -Licensing

& Regulatory Affairs Exelon Generation Company, LLC

Enclosure:

Peach Bottom Atomic Power Station, Unit 3 Ninth 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 I NRC Senior Resident Inspector-Peach Bottom Atomic Power Station NRC Project Manager, NRR -Peach Bottom Atomic Power Station Mr. Peter J. Bamford, NRR/JLD/PPSD/JOMB, NRC Director, Bureau of Radiation Protection

-Pennsylvania Department of Environmental Resources S. T. Gray, State of Maryland R. R. Janati, Chief, Division of Nuclear Safety, Pennsylvania Department of Environmental Protection, Bureau of Radiation Protection Enclosure Peach Bottom Atomic Power Station, Unit 3 Ninth Six-Month Status Report for the Implementation of Order EA-12-049, Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Design-Basis External Events (31 pages)

Peach Bottom Atomic Power Station, Unit 3 Ninth Six Month Report for the Implementation of FLEX August 28, 2017 Enclosure Peach Bottom Atomic Power Station Unit 3 Ninth 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 Peach Bottom Atomic Power Station, Units 2 and 3 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 Overall Integrated Plan, including any changes to the compliance method, schedule, or need for relief/relaxation and the basis, if any. 2 Milestone Accomplishments

• Peach Bottom Unit 3 completed full implementation of FLEX strategies, except for Phase l Hardened Vents, before startup from P3R20 Refuel Outage on October 21, 2015.

• Peach Bottom Unit 2 completed full implementation of FLEX strategies, inclusive of Phase 1 Hardened Vents, before startup from P2R21 Refuel Outage on November 10, 2016. 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.

Milestone Target Activity Status Revised Target Completion Completion Date Date Submit 60 Day Status Report Oct 2012 Complete Submit Overall Integrated Plan Feb 2013 Complete Contract with RRC Complete Submit 6 Month Updates: Update 1 Aug 2013 Complete Update 2 Feb 2014 Complete Update 3 Aug 20 14 Complete Update 4 Feb 2015 Complete Update 5 Aug 2015 Complete Update 6 Feb 2016 Complete Update 7 Aug 2016 Complete Update 8 Feb 2017 Complete Update 9 Aug 2017 Complete with this submittal Perform Staffing Analysis May 2015 Complete Peach Bottom Atomic Power Station, Unit 3 Ninth Six Month Report for the Implementation of FLEX August 28, 2017 Milestone Target Activity Status Revised Target Completion Completion Date Date Modifications:

Unit 2 Design Engineering May 2015 Complete Unit 2 Im p lementation Outage Nov 2016 Com p lete Unit 3 Design Engineering Se p t2015 Com p lete Unit 3 Im p lementation Outage Oct 2015 Com p lete Stora g e: Storage Design En g ineerin g I Oct 2015 I Com p lete I Storage Implementation I Oct 2015 I Com p lete I FLEX Eq ui p ment: Procure On-Site Eq ui p ment Sept 2015 Com p lete Develo p Strate g ies with RR C Dec 2014 Com p lete Procedures:

Create Site-Specific Procedu res Sept 2015 (U3) Complete (U3) Oct 2016 (U2) Com p lete (U2) Validat e Pro ce dures (NEI-1 2.06, Sept 2015 (U3) Complete (U3) Section 11.4.3) Oct 2016 (U2) Com p lete (U2) Create Maintenance Procedu res Oct 2016 Com p lete Training: Develop Training Plan March 2015 Complete Training Com p lete Oct 2015 Com p lete FLEX Im p lementation:

Unit 2 FLEX Im p lementation Nov 10, 2016 Com p lete Submit Unit 2 Completion Jan 6, 2017 Complete Re p ort Unit 3 FLEX Im p lementation Nov 12, 2017 Started Submit Unit 3 Completion Jan 2018 Not Started Re p ort Full Site FLEX Implementation Jan 2018 Started 4 Changes to Compliance Method 4.1 Storage, Maintenance and Testing Alternate Approach for Peach Bottom Atomic Power Station Storage Exelon proposes an alternate approach to NEI 12-06, Revision 0 for protection of FLEX equipment as stated in Section 5 (seismic), Section 7 (severe storms with high winds) and Section 8 (impact of snow, ice and extreme cold). This alternate approach will be to store "N" sets of equipment in a fully robust building and the + 1 set of equipment in a commercial building.

Peach Bottom may also elect 2 Peach Bottom Atomic Power Station, Unit 3 Ninth Six Month Report for the Implementation of FLEX August 28, 2017 to store the + 1 set of equipment in the robust building with the N sets of equipment.

If the + 1 set of FLEX equipment is stored in the robust storage building, Peach Bottom will not be using the alternative approach.

For all hazards scoped in for the site, the FLEX equipment will be stored in a configuration such that no one external event can reasonably fail the site FLEX capability (N). To ensure that no one external event will reasonably fail the site FLEX capability (N), Exelon will ensure that N equipment is protected in the robust building.

To accomplish this, Exelon will develop procedures to address the unavailability allowance as stated in NEI 12-06, Revision 0, Section 11.5.3, (see Maintenance and Testing section below for further details).

This section allows for a 90-day period of unavailability.

If a piece of FLEX equipment stored in the robust building were to become or found to be unavailable, Exelon will impose a shorter allowed outage time of 45 days. For portable equipment that is expected to be unavailable for more than 45 days, actions will be initiated within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of this determination to restore the site FLEX capability (N) in the robust storage location and implement compensatory measures (e.g., move the+ 1 piece of equipment into the robust building) within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> where the total unavailability time is not to exceed 45 days. Once the site FLEX capability (N) is restored in the robust storage location, Exelon will enter the 90-day allowed out of service time for the unavailable piece of equipment with an entry date and time from discovery date and time. Maintenance and Testing The unavailability of equipment and applicable connections that directly performs a FLEX mitigation strategy for core, containment, and SFP should be managed such that risk to mitigating strategy capability is minimized.

I. The unavailability of plant equipment is controlled by existing plant processes such as the Technical Specifications.

When plant equipment which supports FLEX strategies becomes unavailable, then the FLEX strategy affected by this unavailability does not need to be maintained during the unavailability.

2. The required FLEX equipment may be unavailable for 90 days provided that the site FLEX capability (N) is met. If the site FLEX (N) capability is met but not protected for all of the site's applicable hazards, then the allowed unavailability is reduced to 45 days 1* 3. If FLEX equipment is likely to be unavailable during forecast site specific external events (e.g., hurricane), appropriate compensatory measures should be taken to restore equivalent capability in advance of the event. 4. The duration of FLEX equipment unavailability, discussed above, does not constitute a loss of reasonable protection from a diverse storage location protection strategy perspective.

5. If FLEX equipment or connections become unavailable such that the site FLEX capability (N) is not maintained, initiate actions within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to restore the site FLEX capability (N) and implement compensatory measures (e.g., use of alternate suitable equipment or supplemental personnel) within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. 1 The spare FLEX equipment is not required for the FLEX capability to be met. The allowance of90-day unavailability is based on a normal plant work cycle of 12 weeks. In cases where the remaining N equipment is not fully protected for the applicable site hazards. the unavailability allowance is reduced to 45 days to match a 6-week short cycle work period. Aligning the unavailability to the site work management program is important to keep maintenance of spare FLEX equipment from inappropriately superseding other more risk-significant work activity.

3 Peach Bottom Atomic Power Station, Unit 3 Ninth Six Month Report for the Implementation of FLEX August 28, 2017 6. If FLEX equipment or connections to permanent plant equipment required for FLEX strategies are unavailable for greater than 45/90 days, restore the FLEX capability or implement compensatory measures (e.g., use of alternate suitable equipment or supplemental personnel) prior to exceedance of the 45/90 days. For Section 5, Seismic Hazard, Exelon will also incorporate these actions: I. Large portable FLEX equipment such as pumps and power supplies should be secured as appropriate to protect them during a seismic event (i.e., Safe Shutdown Earthquake (SSE) level). 2. Stored equipment and structures will be evaluated and protected from seismic interactions to ensure that unsecured and/or non-seismic components do not damage the equipment.

For Section 7, Severe Storms with High Winds, Exelon will also incorporate this action:

• For a 2-Unit site, N+ I set(s) of on-site FLEX equipment are required.

The plant screens in per Sections 5 through 9 for seismic, flooding, wind (both tornado and/or hurricane), snow, ice and extreme cold, and high temperatures.

o To meet Section 7 .3.1.1 a, either of the following are acceptable:

• All sets (N=2) in a structure(s) that meets the plant's design basis for high wind hazards, or

• Two set(s) in a structure(s) that meets the plant's design basis for high wind hazards and one set (+I) stored in a location not protected for a high wind hazard. For Section 8, Impact of Snow, Ice and Extreme Cold, Exelon will also incorporate this action:

• Storage of FLEX equipment should account for the fact that the equipment will need to function in a timely manner. The equipment should be maintained at a temperature within a range to ensure its likely function when called upon. For example, by storage in a heated enclosure or by direct heating (e.g., jacket water, battery, engine block heater, etc.). Exelon will meet all the requirements for NEI 12-06, Revision 0 for Section 6.2.3. J for external flood hazard and Section 9.3.1 for impact of high temperatures.

4.2 Alternate Approach to NEI 12-06, Rev O, Section 3.2.2 Issue An alternative is being proposed to the N+ I requirement applicable to hoses and cables as stated in Section 3.2.2 of NEI 12-06. 4 Peach Bottom Atomic Power Station, Unit 3 Ninth Six Month Report for the Implementation of FLEX August 28, 2017 Background NEI 12-06, Section 3.2.2 specifically states that a site will have FLEX equipment to meet the needs of each Unit on a site plus one additional spare. This is commonly known as N+I where N is the number of Units at a given site. The relevant text from NEI 12-06 is as follows: NE/ 12-06, Section 3.2.2 states: "In order to assure reliability and availability of the FLEX equipment required to meet these capabilities, the site should have sufficient equipment to address all functions at all Units on-site, plus one additional spare, i.e. an N+ I capability, where "N" is the number of Units on-site. Thus, a Unit site would nominally have at least three portable pumps, three sets of portable ac/dc power supplies, three sets of hoses & cables, etc." NE/ 12-06, Section 11.3.3 states: "FLEX mitigation equipment should be stored in a location or locations informed by evaluations performed per Sections 5 through 9 such that no one external event can reasonably fail the site FLEX capability (N)." Typically those hoses utilized to implement a FLEX strategy are not a single continuous hose but are composed of individual sections of a smaller length joined together to form a sufficient length. In the case of cables, multiple individual lengths are used to construct a circuit such as in the case of 3-phase power. Proposed Alternative NEI 12-06 currently requires N+ I set of hoses and cables. As an alternative, the spare quantity of hose and cable is adequate if it meets either of the two methods described be low: Method I: Provide additional hose or cable equivalent to I 0% of the total length of each type/size of hose or cable necessary for the "N" capability.

For each type/size of hose or cable needed for the "N" capability, at least I spare of the longest single section/length must be provided.

Example 1-1: An installation requiring 5,000 ft. of 5 in. diameter fire hose consisting of one hundred 50 ft. sections would require 500 ft. of 5 in. diameter spare fire hose (i.e., ten 50 ft. sections).

Example 1-2: A pump requires a single 20 ft. suction hose of 4 in. diameter, its discharge is connected to a flanged hard pipe connection.

One spare 4 in. diameter 20 ft. suction hose would be required.

Example 1-3: An electrical strategy requires 350 ft. cable runs of 410 cable to support 480 volt loads. The cable runs are made up of 50 ft. sections coupled together.

Eight cable runs (2 cables 5 Peach Bottom Atomic Power Station, Unit 3 Ninth Six Month Report for the Implementation of FLEX August 28, 2017 run per phase and 2 cables run for the neutral) totaling 2800 ft. of cable (56 sections) are required.

A minimum of 280 ft. spare cable would be required or 6 spare 50 ft. sections.

Example 1-4: An electrical strategy requires I 00 ft. of 410 cables, I 00 ft. each) to support one set of 4 kV loads and 50 ft. of 410 (4 cables, 50 ft. each) to support another section of 4 kV loads. The total length of 410 cable is 600 ft. (I 00 ft. x 4 plus 50 ft. x 4 ). One spare 100 ft. 4/0 cable would be required representing the longest single section/length.

Method 2: Provide spare cabling and hose of sufficient length and sizing to replace the single longest run needed to support any single FLEX Strategy.

Example 2-1: A FLEX strategy for a two Unit site requires 8 runs each of 500 ft. of 5 in. diameter hose (4000 ft. per Unit). The total length of 5 in. diameter hose required for the site is 8000 ft. with the longest run of 500 ft. Using this method, 500 ft. of 5 in. diameter spare hose would be required.

Basis for an alternative approach:

The NRC has endorsed (ML 15 l 25A442) the NEI position paper (ML I 5126A 135) for the above stated alternate approach.

If using Method 2, per the endorsement letter, Exelon will ensure that the FLEX pumps and portable generators are confirmed to have sufficient capability to meet flow and electrical requirements when a longer spare hose/cable is substituted for a shorter length. Exelon acknowledges that the NRC staff has not reviewed and is not endorsing the specific examples included in the NEI endorsement request dated May 1, 2015. If necessary, Exelon will provide additional justification regarding the acceptability of various cable and hose lengths with respect to voltage drops, and fluid flow resistance, rather than merely relying on the additional, longest length cable/hose as implied by Example 1-4 in the subject letter. Hoses and cables are passive devices unlikely to fail provided they are appropriately inspected and maintained. The most likely cause of failure is mechanical damage during handling provided that the hoses and cables are stored in areas with suitable environmental conditions (e.g., cables stored in a dry condition and not subject to chemical or petroleum products). The hoses and cables for the FLEX strategies will be stored and maintained in accordance with manufacturers' recommendations including any shelf life requirements.

Initial inspections and periodic inspections or testing will be incorporated into the site's maintenance and testing program implemented in accordance with Section 11.5 of NEI 12-06. Therefore, the probability of a failure occurring during storage is minimal, resulting in the only likely failure occurring during implementation.

Mechanical damage will likely occur in a single section versus a complete set of hose or cable. Therefore, the N+ I alternative addresses the longest individual section/length of hose or cable. 6 Peach Bottom Atomic Power Station, Unit 3 Ninth Six Month Report for the Implementation of FLEX August 28, 2017 Providing either a spare cable or hose of a length of 10% of the total length necessary for the "N" capability or alternatively providing spare cabling or hose of sufficient length and sizing to replace the single longest run needed to support any single FLEX strategy is sufficient to ensure a strategy can be implemented.

Mechanical damage during implementation can be compensated for by having enough spares to replace any damaged sections with margin. It is reasonable to expect that an entire set of hoses or cables would not be damaged provided they have been reasonably protected.

5 Need for Relief/Relaxation and Basis for the Relief/Relaxation No need for relief or relaxation of requirements is expected.

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 Overall Integrated Status Reference Plan Op en Item Multiple Sections Item I) Transportation routes wi II Complete be developed from the equipment storage area to the FLEX staging Completion support information is areas. An administrative contained in the sixth six month update program will be developed to dated February 26, 2016. ensure pathways remain clear or compensatory actions will be implemented to ensure all strategies can be deployed during all modes of operation. The location of the storage areas, identification of the travel paths and creation of the administrative p ro g ram are op en items. Programmatic Item 2) An administrative Complete Controls (p. 7) program for FLEX to establish responsibilities, testing and Completion support information is contained maintenance requirements will be in the sixth six month update dated February implemented.

26, 2016. Describe Training Item 3) Training materials for C omplete Plan (p. 8) FLEX will be developed for all station staff involved in C ompletion support information is contained implementing FLEX strategies.

in the fifth six month update dated August 28, 2015. Maintain Spent Item 4) Complete an evaluation C omplete Fuel Pool Coolin g of the sp ent fuel p ool area for 7 Peach Bottom Atomic Power Station, Unit 3 Ninth Six Month Report for the Implementation of FLEX August 28, 2017 (p. 30) steam and condensation to Completion support information is contained determine vent path strategy in the fifth six month update dated August requirements.

28, 2015. Safety Function Item 5) RCIC room temperature Complete Support (p. 38) analysis is still in progress.

Completion support information is contained in the sixth six month update dated February 26, 2016. Safety Function Item 6) Evaluate the habitability Complete Support (p.38) of the Main Control Room and develop a strategy to maintain Completion support information is conta ined habitability.

in the fifth six month update dated Augu st 28, 2015. Safety Function Item 7) Develop a procedure to Complete Support (p. 38) prop open battery room doors and utilize portable fans or utilize Completion support information is contained installed room supply and in the fifth six month update dated August exhaust fans upon energizing the 28, 2015. battery chargers to prevent a buildup of hydrogen in the battery rooms. Sequence of Item 8) Timeline walk through Complete Events (p. 4) will be completed for the FLEX generator installations when the Completion support information is contained detailed design and site strategy is in the sixth six month update dated February finalized. The final timeline will 26, 2016. be validated once the detailed desi g ns are develo p ed. Sequence of Item 9) Timeline walk through Complete Events (p.4) will be completed for the FLEX pump installations when the Completion support information is contained detailed design and site strategy in the fifth six month update dated August is finalized.

The final timeline 28, 2015. will be validated once the detailed designs are developed.

The results will be provided in a future 6-month up date. 8 Peach Bottom Atomic Power Station, Unit 3 Ninth Six Month Report for the Implementation of FLEX August 28, 2017 Sequence of Item IO) Additional analysis will Complete Events (p. 5) be performed during detailed design development to ensure Completion support information is Suppression Pool temperature contained in the sixth six month update will support RCIC operation, in dated February 26, 2016. accordance with approved BWROG analysis, throughout the event. Sequence of Item 11) Analysis of deviations Complete Events (p. 5) between Exelon's engineering analyses and the analyses Completion support information is contained contained in BWROG Document in the fifth six month update dated August NEDC-33771P, "GEH 28 , 2015. Evaluation of FLEX Implementation Guidelines and documentation of results on Att. I B, "NSSS Significant Reference Analysis Deviation Table." Planned to be completed and s ubmitted w ith August 2013 Si x Month Update. Safety Function Item 12) Evaluate the effect of Complete Support (p. 38) additional load shed on the battery coping time. Completion support information is contained in the sixth six month update dated February 26, 2016. Draft Safet Evaluation 0 en Item Status See Attachments I, 2, 3, and 4 See Attachments I, 2, 3, and 4 7 Potential Draft Safety Evaluation Impacts There are no potential impacts to the Draft Safety Evaluation identified at this time. 9 Peach Bottom Atomic Power Station, Unit 3 Ninth Six Month Report for the Implementation of FLEX August 28, 2017 8 References The following references support the updates to the Overall Integrated Plan described in this enclosure.

1. Peach Bottom Atomic Power Station Units 2 and 3, 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 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. NRC Order Number EA-13-109, "Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation Under Severe Accident Conditions," dated June 6, 2013 4. NRC Order Number EA-12-050, "Order Modifying Licenses with Regard to Reliable Hardened Containment Vents," dated March 12, 2012 5. First Six-Month Status Report in Response to March 12, 2012 Commission "Order Modifying Licenses with Regard to Requirements for Mitigating Strategies for Design Basis External Events (Order Number EA-12-049)," dated August 28, 2013 6. NRC Interim Staff Evaluation Relating to Overall Integrated Plan in Response to Order EA-12-049 (Mitigating Strategies)," dated November 22, 2013 7. Second Six-Month Status Report in Response to March 12, 2012 Commission "Order Modifying Licenses with Regard to Requirements for Mitigating Strategies for Beyond-Design Basis External Events (Order Number EA-12-049)," dated February 28,2014 8. Relaxation of Certain Schedule Requirements for Order EA-12-049 "Issuance of Order to Modify Licenses with regard to Requirements for Mitigation Strategies for Beyond Design Basis External Events," dated April 15, 2014 9. Third Six-Month Status Report in Response to March 12, 2012 Commission "Order Modifying Licenses with Regard to Requirements for Mitigating Strategies for Beyond-Design Basis External Events (Order Number EA-12-049)," dated August 28,2014 10. Fourth Six-Month Status Report in Response to March 12, 2012 Commission "Order Modifying Licenses with Regard to Requirements for Mitigating Strategies for Beyond-Design Basis External Events (Order Number EA-12-049)," dated February 28,2015 11. Fifth Six-Month Status Report in Response to March 12, 2012 Commission "Order Modifying Licenses with Regard to Requirements for Mitigating Strategies for Beyond-Design Basis External Events (Order Number EA-12-049)," dated August 28,2015 12. Sixth Six-Month Status Report in Response to March 12, 2012 Commission "Order Modifying Licenses with Regard to Requirements for Mitigating Strategies for Beyond-Design Basis External Events (Order Number EA-12-049)," dated February 26,2016 13. Seventh Six-Month Status Report in Response to March 12, 2012 Commission "Order Modifying Licenses with Regard to Requirements for Mitigating Strategies for Beyond-Design Basis External Events (Order Number EA-12-049)," dated August 26, 2016 10 Peach Bottom Atomic Power Station, Unit 3 Ninth Six Month Report for the Implementation of FLEX August 28, 2017 14. Eighth Six-Month Status Report in Response to March 12, 2012 Commission "Order Modifying Licenses with Regard to Requirements for Mitigating Strategies for Beyond-Design Basis External Events (Order Number EA-12-049)," dated February 28,2017 15. Letter to NRC, Report of Full Compliance with March 12, 2012 Commission Order Modifying Licenses with Regard to Requirements for Mitigating Strategies for Beyond-Design-Basis External Events (Order Number EA-12-049), dated January 6, 2017 (RS-17-001) for PBAPS Unit 2 9 Attachments

1. Attachment 1 -Interim Safety Evaluation 4.1 Open Items 2. Attachment 2 -Interim Safety Evaluation 4.2 Confirmatory Items 3. Attachment 3 -Confirmatory Item 3.1. l. l.A Response 4. Attachment 4 -NRC Audit Report Open Items 11 Peach Bottom Atomic Power Station, Unit 3 Ninth Six Month Report for the Implementation of FLEX August 28, 2017 Attachment 1 -Interim Safety Evaluation 4.1 Open Items 4.1 NRC ISE Op en Items Op en Item Status 3.2.3.A-Revision 3 to the BWROG Complete EPG/SAG is a Generic Concern because the BWROG has not addressed the Completion support information is contained in the potential for the revised venting strategy fifth six month update dated August 28, 2015. to increase the likelihood of detrimental effects on containment response for events in which the venting strategy is invoked. 3.2.4.3.A

-Freeze protection has not been Complete discussed in the Integrated Plan or during the audit process. Completion support information is contained in the fifth six month update dated August 28, 2015. 3.2.4.4.A

-Portable and emergency Complete lighting during an ELAP has not been Completion support information is co nt ained in the discussed in the integrated plan or during fifth six month update dated August 28, 2015. the Audit process. 3.2.4.5.A

-Access to protected and Complete.

internal locked plant areas during an ELAP has not been discussed in the Completion support information is contained in the Integrated Plan or during the audit fifth six month update dated August 28, 2015. process. 12 Peach Bottom Atomic Power Station, Unit 3 Ninth Six Month Report for the Implementation of FLEX August 28, 2017 Attachment 2 -Interim Safety Evaluation 4.2 Confirmatory Items 4.2 NRC ISE Op en Items Confirmator y Item Status 3.1.1.1.A

-The method selected for protection of Complete equipment during a BDBEE was not discussed in the Integrated Plan or during the audit process. Close to NRC Audit Report Open Items: CI There was no discussion of the specifications 3.1.1.1.A (Completed) stated in NEI 12-06, Sections 5.3.1, 6.2.3.1, 7.3.1, 8.3.1, and 9.3.1. Also, there was no discussion of securing large portable equipment for p rotection during a seismic hazard. 3.1.1.2.A

-Deployment routes have not yet been Complete finalized or reviewed for possible impacts due to debris and potential soil liquefaction. Completion support information is contained in the sixth six month update dated February 26, 2016. 3.1.1.2.C

-Protection of vehicles used to deploy Complete and re-fuel portable/FLEX equipment during a BDBEE was not discussed in the Integrated Plan or Completion support information is contained in the during the audit process. fifth six month update dated August 28, 2015. 3.1.1.3.A

-Seismic procedural interface Complete consideration NEI 12-06, Section 5.3.3, consideration I, which considers the possible Completion support information is contained in the failure of seismically qualified electrical equipment fifth six month update dated August 28, 2015. by beyond-design basis seismic events, was not discussed in the Integrated Plan or during the audit process. 3.1.1.3.B

-Seismic procedural interface Complete considerations NEI 12-06, Section 5.3.3, 2 and 3, which considers flooding from large internal Completion support information is contained in the sources and also mitigation of ground water was fifth six month update dated August 28, 2015. not discussed in the Integrated Plan or during the audit process. 3.1.1.4.A

-Utilization of off site resources

-the Complete local staging area was not discussed in the Integrated Plan or during the audit process. Completion support information is contained in the sixth six month update dated February 26, 2016. 3.1.2.A -Characterization of the external flooding Compl ete hazard in terms of warnin g time and p ersistence 13 Peach Bottom Atomic Power Station, Unit 3 Ninth Six Month Report for the Implementation of FLEX August 28, 2017 Attachment 2 -Interim Safety Evaluation 4.2 Confirmatory Items was not discussed in the Integrated Plan or during Close to NRC Audit Report Open Items: CI audit process. 3.1.2.A (Completed) 3.1.2.1 A -Protection of portable/FLEX equipment Complete during a flooding BDBEE was not discussed in the Integrated Plan or during the audit process. Completion support information is contained in the sixth six month update dated February 26, 2016. 3.1.2.2.A

-Movement of equipment and restocking Complete of supplies in the context of a flood with long persistence during a BDBEE was not discussed in Completion support information is contained in the the Integrated Plan or during the audit process. fifth six month update dated August 28, 2015. 3.1.3.2.A

-Availability of debris clearing Complete equipment during a BDBEE was not discussed in the Integrated Plan or during the audit process. Completion support information is contained in the fifth six month update dated August 28, 2015. 3.1.4.2.A

-Snow or ice removal during a BDBEE Complete was not discussed in the Integrated Plan or during the audit process. Additionally, there was no Completion support information is contained in discussion of ice blocking the FLEX pump the sixth six month update dated February 26, suctions. 2016. 3.2.1.1.A -MAAP benchmarks should be Complete identified and discussed which demonstrate that MAAP4 is an appropriate code for the simulation Completion support information is contained in the of an ELAP event. fifth six month update dated August 28, 2015. 14 Peach Bottom Atomic Power Station, Unit 3 Ninth Six Month Report for the Implementation of FLEX August 28, 2017 Attachment 2 -Interim Safety Evaluation 4.2 Confirmatory Items 3.2.1.1.B

-MAAP Analysis -collapsed level Complete should remain above Top of Active Fuel (T AF) and the cool down rate should be within technical Completion support information is contained in the specification limits. fifth six month update dated August 28, 2015. 3.2.1.1.C

-MAAP4 should be used in accordance Complete with Sections 4.1, 4.2, 4.3, 4.4, and 4.5 of the June 2013 position paper. Completion support information is contained in the fifth six month update dated August 28, 2015. 3.2.1.1.D -MAAP modeling parameters.

In using Complete MAAP4, the licensee should identify and justify the subset of key modeling parameters cited from Completion support information is contained in the Tables 4-1 through 4-6 of the "MAAP4 fifth six month update dated August 28, 2015. Application Guidance, Desktop Reference for Using MAAP4 Software, Revision 2" (Electric Power Research Institute Report I 020236). 3.2.1.1.E

-The specific MAAP4 analysis case that Compl ete was used to validate the timing of mitigating strategies in the Integrated Plan should be Completion support information is contained in the identified and available for review. fifth six month update dated August 28, 2015. 3.2.1.2.A -There was no discussion of the assumed Complete recirculation system leakage rates including the recirculation pump seal leakage rates that were Completion support information is contained in the used in the ELAP analysis. Questions still remain fifth six month update dated August 28, 2015. unanswered regarding pressure dependence of the assumed leakage rates, assumed leakage phase, i.e. single phase liquid, two phase, or steam, and other q uestions p resented in the audit. 3 .2.1.4.A -Required flow rates and portable/FLEX Complete pump characteristics were not discussed in the Integrated Plan or during the audit process. Close to NRC Audit Report Open Items: CI Likewise, there was no discussion of the required 3.2.1.4.A (Completed) flow for mitigation strategies and no discussion of the calculations that verif y ade q uate flow. 15 Peach Bottom Atomic Power Station, Unit 3 Ninth Six Month Report for the Implementation of FLEX August 28, 2017 Attachment 2 -Interim Safety Evaluation 4.2 Confirmatory Items 3.2.1.4.B

-There was no discussion of the Complete assumptions used in the calculations for battery coping time and to evaluate the effectiveness of de Completion support information is contained in the load reduction including the basis for the assumed sixth six month update dated February 26, 2016. minimum battery voltage. 3.2.1.4.C

-The operability of the RCIC pump at Complete elevated suction temperature was not discussed in the Integrated Plan or during the audit process. Completion support information is contained in the sixth six month update dated February 26, 2016. 3.2.1.4.D

-Water quality issues and guidance on Complete priority of water source usage were not fully addressed in the Integrated Plan or during the audit Completion support information is contained in the process and requires further analysis by licensee fifth six month update dated August 28, 2015. 3.2.2.A -Evaluation of the refueling floor SFP area Complete for steam and condensation was not yet completed.

Mitigating strategies for a vent pathway were not Completion support information is contained in the discussed in the Integrated Plan or during the audit fifth six month update dated August 28, 2015. p rocess. 3.2.4.2.A

-The impact of high temperature on the Complete operability of RCIC Room electrical and mechanical equipment, including the RCIC turbine Completion support information is contained in speed controller, was not discussed in the the sixth six month update dated February 26, Integrated Plan or during the audit process. 2016. 3.2.4.2.B

-Evaluation of high and low battery Complete temperatures is to be provided during a future six-month-update.

Completion support information is contained in the fifth six month update dated August 28, 2015. 3.2.4.4.B

-Plant communications during an ELAP Complete were not discussed in the Integrated Plan or the audit process. Follow-up of commitments made in Close to NRC Audit Report Open Items: CI the communications assessment (ADAMS 3.2.4.4.B (Completed)

Accession No. ML12306A199) is necessary.

16 Peach Bottom Atomic Power Station, Unit 3 Ninth Six Month Report for the Implementation of FLEX August 28, 2017 Attachment 2 -Interim Safety Evaluation 4.2 Confirmatory Items 3.2.4.6.A -Initial analysis for accessibility and Complete habitability of critical plant locations as the RCIC Room showed relatively high temperatures.

There Completion support information is contained in was no discussion of the effectiveness of the sixth six month update dated February 26, ventilation with portable fans. There was no 2016. discussion of long term habitability in critical plant locations durin g an ELAP. 3.2.4.7.A-Emergency Cooling Tower water Complete volume and replenishment was not discussed in the Integrated Plan or during the audit process. Completion support information is contained in the fifth six month update dated August 28, 2015. 3.2.4.8.A

-The licensee did not provide sufficient Complete information regarding loading/sizing calculations of portable diesel generator(s) and strategy for Completion support information is contained in the electrical isolation for FLEX electrical generators fifth six month update dated August 28, 2015. from installed plant equipment.

3.2.4.9.A

-Details of portable equipment fuel Complete storage transfer were provided during the audit process. However, the method to ensure fuel quality Completion support information is contained in the was not discussed in the Integrated Plan or during fifth six month update dated August 28, 2015. the audit process. 3.4.A -The program or process to request RRC Complete equipment was not discussed in the Integrated Plan or during the audit process. Completion support information is contained in the fifth six month update dated August 28, 2015. 3.4.B -Sizing calculations of RRC FLEX Complete equipment and the compatibility of RRC equipment to plant connection points were not Completion support information is contained in the discussed in the Integrated Plan or during the audit fifth six month update dated August 28, 2015. process. 17 Peach Bottom Atomic Power Station, Unit 3 Ninth Six Month Report for the Implementation of FLEX August 28, 2017 Attachment 3 -Confirmatory Item 3.1.1.1.A Response 5.3.1 Protection of FLEX Equipment (Seismic)

Complete I. FLEX equipment should be stored in one or more of following three configurations:

a. In a structure that meets the plant's design basis for the FLEX pumps, generators and other Safe Shutdown Earthquake (SSE) (e.g., existing safety-equipment are stored in a robust related structure).

structure designed to survive a SSE. b. In a structure designed to or evaluated equivalent to NA ASCE 7-IO, Minimum Design Loads for Buildings and Other. c. Outside a structure and evaluated for seismic interactions NA to ensure equipment is not damaged by non-seismically robust components or structures.

2. Large portable FLEX equipment such as pumps and power FLEX pumps, generators and other supplies should be secured as appropriate to protect them large equipment will be secured to during a seismic event (i.e., Safe Shutdown Earthquake prevent damage during a SSE. (SSE) level). 3. Stored equipment and s tructure s should be evaluated and The robust FLEX storage structure protected from seismic interactions to ensure that unsecured has been constructed to protect the and/or non-se ismic components do not damage the FLEX equipment from unsecured or equipment.

non-sei s mic components during a SSE. 6.2.3.1 Protection of FLEX Equipment (Floodin2)

Complete The se considerations apply to the protection of FLEX equipment from external flood hazard s: I. The equipment should be stored in one or more of the following configurations: a. Stored above the flood elevation from the most recent site NA flood analysis.

The evaluation to determine the elevation for storage s hould be informed by flood analysis applicable to the site from early site permits, combined license applications, and/or contiguous licensed sites. b. Stored in a structure designed to protect the equipment NA from the flood. c. FLEX equipment can be stored below flood level if time FLEX pumps , generators and other is available and plant procedures/guidance address the equipment are stored below the needed actions to relocate the equipment.

Based on the PMF elevation.

Procedure s timing of the limiting flood scenario(s), the FLEX governing actual or predicted high equipment can be relocated to a position that is protected river level or flow s include guidance from the flood, either by barriers or by elevation, prior to for relocating the equipment to an the arrival of the potentially damaging flood levels. This elevation above the PMF level and s hould also consider the conditions on-si te during the prior to a river level that would 18 Peach Bottom Atomic Power Station, Unit 3 Ninth Six Month Report for the Implementation of FLEX August 28, 2017 Attachment 3 -Confirmatory Item 3.1.1.1.A Response increasing flood levels and whether movement of the prevent transport.

FLEX equipment will be possible before potential inundation occurs, not j ust the ultimate flood hei g ht. 2. Storage areas that are potentially impacted by a rapid rise of Events causing a river level water should be avoided. exceeding 116 ft. elevation that would prevent transport of FLEX equipment are precipitation events, which would have advanced warn mg. 7.3.1 Protection of FLEX Eq ui p ment (Wind) Com p lete These considerations apply to the protection of FLEX equipment from high wind hazards: I. For plants exposed to high wind hazards, FLEX equipment should be stored in one of the followin g confi g urations: a. In a structure that meets the plant's design basis for high FLEX pumps, generators and ot her wind hazards (e.g., existing safety-related structure).

equipment are stored in a robust structure that will survive the de sign basis wind. b. In storage locations designed to or evaluated equivalent NA to ASCE 7-10, Minimum Design Loads for Buildings and Other Structures given the limiting tornado wind speeds from Regulatory Guide 1.76 or design basis hurricane wind speeds for the site. Given the FLEX b asis limiting tornado or hurricane wind speeds, building l oads would be computed in accordance with requirements of ASCE 7-10. Acceptance criteria would be based on building serviceability requirements not strict compli ance with stress or capacity limits. This would allow for so me minor plastic deformation, yet assure that the buildin g would remain functional.

• Tornado missiles and hurricane missiles will be NA accounted for in that the FLEX equipment will be stored in diverse locations to provide reasonable assurance that N sets of FLEX equipment will rem ain deployable following the high wind event. This w ill consider locations adjacent to existing robust structures or in lower sections of buildings that minimizes the probability that missiles will dama ge all mitigation equipment required from a single e vent by protection from adjacent buildings and limitin g p athways for missiles to damage eq ui p ment.

• The axis of separation should consider the NA p redominant p ath of tomados in the g eo g ra p hical 19 Peach Bottom Atomic Power Station, Unit 3 Ninth Six Month Report for the Implementation of FLEX August 28, 2017 Attachment 3 -Confirmatory Item 3.1.1.1.A Response location.

In general, tornadoes travel from the W est or West Southwesterly direction, diverse locations should be aligned in the North-South arrangeme nt, where possible.

Additionally, in selecting diverse FLEX storage locations, consideration should be given to the location of the diesel generators and switch yard such that the path of a single tornado would not im p act all locations.

• Stored mitigation equipment exposed to the wind NA should be adequately tied down. Loose equipment should be in protective boxes that are adequately tied down to foundations or slabs to prevent protected equipment from being damaged or becoming airborne. (During a tornado, high winds may blow away metal siding and metal deck roof, subjecting the eq ui p ment to high wind forces.) c. In evaluated storage locations separated by a sufficient NA distance that minimizes the probability that a single event would damage all FLEX mitigation equipment such that at least N sets of FLEX equipment would remain deployable following the high wind event. (This option is not a pp licable for hurricane conditions).

• Consistent with configuration b., the axis of NA separation should consider the predominant path of tornados in the g eo g ra p hical location.

• Consistent with configuration b., stored NA mitigation equipment should be adequately tied down. 8.3.1 Protection of FLEX Eq ui p ment (Snow. Ice. Cold) Com p lete These considerations apply to the protection of FLEX equipment from snow, ice, and extreme cold hazards: I. For sites subject to significant snowfall and ice storms, portable FLEX equipment should be stored in one of two confi g urations:

a. In a structure that meets the plant's design basis for the FLEX pumps, generators and other snow, ice and cold conditions (e.g., existing safety-equipment are stored in a robust related structure).

structure that will survive the design basis for snow, ice, and cold. b. In a structure designed to or evaluated equivalent to NA ASCE 7-10, Minimum Design Loads for Buildings and Other Structures for the snow, ice, and cold conditions from the site's design basis. c. Provided the N FLEX equipment is located as described NA in a. orb. above, the N+ I equipment may be stored in an evaluated storage location ca p able of withstandin g 20

2. Peach Bottom Atomic Power Station, Unit 3 Ninth Six Month Report for the Implementation of FLEX August 28, 20 I 7 Attachment 3 -Confirmatory Item 3.1.1.1.A Response historical extreme weather conditions and the equipment is deployable. Storage of FLEX equipment should account for the fact that FLEX pumps, generators and/or the equipment will need to function in a timely manner. The their storage location include equipment should be maintained at a temperature within a appropriate heating. range to ensure its likely function when called upon. For example, by storage in a heated enclosure or by direct heating (e.g., jacket water, battery, engine block heater, etc.). 9.3.1 Protection of FLEX Equipment (Hi2h Temperature)

Complete The equipment sh ould be maintained at a temperature within a FLEX pumps, generators and/or range to ensure its likely function when called upon. their storage location include appropriate ventilation such that the equipment is maintained within operating limits. 21 Peach Bottom Atomic Power Station, Unit 3 Ninth Six Month Report for the Implementation of FLEX August 28, 2017 Attachment 4 -NRC Audit Report Open Items Audit Item Item Description Reference CI 3.1.2.A Flood Warning Time and Persistence CI 3.2.1.4.A Portable/FLEX pump characteristics, required flow rates, and supporting calculations 22 Response Complete The Conowingo TAMS Report information has been entered into site records to fully address the issue. Complete Exelon has approved Calculation PM-1173, FLEX Makeup Analysis.

The purpose of this analysis is to evaluate the ability of the various proposed PBAPS FLEX Mitigation Strategies to provide flow of water from the Emergency Cooling Tower (ECT) basin or the Intake Canal (Ultimate Heat Sink) to the following locations:

a) Spent Fuel Pool (SFP): 1) Injection

-via existing Residual Heat Removal (RHR) I Fuel Pool Cooling (FPC) piping and I or hose routed through I up stair towers to the Refueling Floor. 2) Over-Spray

-via existing RHR I Fuel Pool Cooling piping and I or hose routed through I up stair towers to the Refueling Floor. b) Reactor Pressure Vessel (RPV) -via existing RHR piping. c) Suppression Pool (torus) 1) Injection

-via existing RHR piping 2) Spray -via existing RHR piping PM-1173 was performed with computer program Pipe-Flow 2009 to model incompressible flow in the applicable portions of the RHR, FPC, and High Pressure Service Water (HPSW) systems. Godwin Ori-Prime (model HLl30M) pumps are the drivers for the PBAPS FLEX strategies.

The Godwin model HL I 30M diesel engine driven pumps can be operated at variable speeds to obtain flow rates from 0 to 1,400 go m at p ressures ran g in g from 0 AQ40 Peach Bottom Atomic Power Station, Unit 3 Ninth Six Month Report for the Implementation of FLEX August 28, 2017 Attachment 4 -NRC Audit Report Open Items to 300 psig. PM-1173 confirmed that the proposed Mechanical FLEX Strategies can supply the required make-up flow to the various plant demands, while not exceeding the system piping pressure limitations or the capacity of the diesel engine driven FLEX pumps. Performance Attributes are included in the calculation.

The PM-1173 conclusions are: a) SFP: The FLEX pump has the capability to provide the recommended makeup flow to the SFP alone, and concurrently to the RPV and the SFP. b) RPV: The FLEX pump has the capability to provide the recommended makeup flow to the RPV alone, and concurrently to the RPV and the SFP. Suppression Pool (torus): The FLEX pump has the capability to provide makeup flow to the Su pp ression Pool. Battery Room Temperature Complete Based on Battery Room ELAP Temperature Profile calculation PM-I I 86, the battery room temperature during the summer case peaks at approximately I 18 degrees F, prior to doors being opened. This is the highest temperature in the battery rooms prior to connecting the FLEX generator and entering Phase II of the FLEX Strategy.

The negative impact of any prolonged elevated temperature is a shorter overall battery life (battery ages quicker) and a corresponding faster replacement cycle. However, these are long-term impacts, and are not a concern during Phase I of an ELAP. In Phase II of the ELAP, the FLEX diesel generators are connected and provide required power, making battery power unessential.

In PM-I I 86 the starting temperature of the battery room is conservatively assumed to be JOO degrees F, which is the set-point of the Main Control Room high tem p erature 23 OIP.9 Peach Bottom Atomic Power Station, Unit 3 Ninth Six Month Report for the Implementation of FLEX August 28, 2017 Attachment 4 -NRC Audit Report Open Items alarm. However , the Battery Room HV AC system is sized for a maximum temperature of 122 degrees F. Therefore, the calculated ELAP Phase I maximum temperature is less than the Battery Room HV AC system sizing maximum temperature , and heightened temperature has a negligible adverse impact on the battery's capability to perform its function during an ELAP. For lowered temperatures, the battery room temperature during the winter case is greater than 64 degrees F, which will have a slight reduction in battery capacity during discharge during an ELAP. As calculated in PE-0140, the station batteries during an ELAP can cope for 7.25 hours2.893519e-4 days <br />0.00694 hours <br />4.133598e-5 weeks <br />9.5125e-6 months <br /> (435 min.) at a minimum temperature of 60 degrees F. Therefore, the assumed low temperature in PE-0140 is less than the calculated low temperature of the battery rooms; and lowered temperatures have no adverse impact on the battery's capability to perform it s function during an ELAP. Calculations PM-I I 86, Revision 0 and PE-0 I 40, Revision I 2, and the FLEX strategy, are available on the Exelon web portal. The time margin between calculated sta tion battery run-time for the FLEX strategy and expected deployment time for FLEX equipment to supply the de loads is approximately one hour, forty-five minutes (7.25 hours2.893519e-4 days <br />0.00694 hours <br />4.133598e-5 weeks <br />9.5125e-6 months <br /> -5.50 hours5.787037e-4 days <br />0.0139 hours <br />8.267196e-5 weeks <br />1.9025e-5 months <br />). Timeline walk through will be Complete completed for the FLEX pump installations when the detailed design The updated timeline was added to the and site strategy is finalized.

Fifth Six-Month Status Report in Response to March I 2, 20 I 2 Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond Design-Basis External Events (Order Number EA-12-049)

RS-15-214. 24 OIP.11 Peach Bottom Atomic Power Station, Unit 3 Ninth Six Month Report for the Implementation of FLEX August 28, 2017 Attachment 4 -NRC Audit Report Open Items The 6-month update dated August 28, Complete 2013, indicates the core thermal power used in the Exelon analysis was 3517 Analy s is of deviations between Exelon's MWT (megawatts thermal)(maximum engineering analyses and the analyses power prior to plant extended power contained in BWROG Document NEDC-uprate). 33771 P, "GEH Evaluation of FLEX Implementation Guidelines" was completed and documented in the OIP August 2013 Six-Month Update. The information is found as Attachment 3 (page 16 of 17 in the OIP August 2013 Six-Month Update). The OIP August 2013 Six-Month Update compared the NEDC-33771 P with the engineering analysis (MAAP) performed under PB-MISC-010 Revi s ion 0 (approved February 13, 2013). Subsequently PB-MISC-010 was revised to Revision 1 (approved March 11 , 2015).

• Post-EPU core power level is 3951 MWt In addition to the MAAP Analysis described above , the four FLEX calculations to which core power level is an input, have been verified to have post-EPU core power level. Those calculation s are: PM-1173, PBAPS FLEX Makeup Hydraulic Analysi s; and PM-1174 Spent Fuel Pool Air Space Temperature Profile following an ELAP , Calculation PM-1171 , RCIC Room Heat-up Analysis for ELAP (does not use core power level as a direct input -but uses PB-MISC-010-determined torus temperature, which is ba s ed on the post-EPU core power level), and Calculation PM-1184, PBAPS FLEX Alternate Hydraulic Analysis (doe s not use core power level as a direct input -but uses PM-1173-determined flow rate, which is based on the post-EPU core power level). 25 SE.10 SE.12 Peach Bottom Atomic Power Station, Unit 3 Ninth Six Month Report for the Implementation of FLEX August 28, 2017 Attachment 4 -NRC Audit Report Open Items Provide a detailed discussion on the Complete capability of equipment in primary containment (the SRV locations in Tech Eval No. 2530982-02

-Evaluation of particular), the reactor building (RCIC Certain Drywell Electrical Equipment for pump room), the main control room, Survivability during an ELAP Event at and the electrical switchgear rooms, to PBAPS, Units 2 and 3. perform their expected functions under ELAP conditions (i.e. temperature, pressure , radiation, humidity, etc.) for an indefinite p eriod. The PBAPS strategy for RPV makeup Complete contains flow paths that do not have the flexibility inherent in NEI 12-06 as Diverse Makeup "B" RHR Addition specified in Table 3-1 and Appendix C, Table C-1. Specifically, the two Additional flexibility is required to meet identified flow paths are mutually the requirements of NRC EA-12-049.

The independent in terms of FLEX pump present response timeline requiring suction source and FLEX pump injection is based on MAAP Case 16, discharge connections to their which includes anticipatory venting. RCIC respective plant systems. In addition, is capable of providing makeup in excess the flow paths share a common section of 70 hours8.101852e-4 days <br />0.0194 hours <br />1.157407e-4 weeks <br />2.6635e-5 months <br /> based on limiting NPSH, of piping , as well as a single RPV temperature, pressure, and operational injection point. parameters which are controlled procedurally.

The spent fuel pool inventory is assum ed to begin to decrease as a result of boili ng in 2.3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />, as identified in hydraulic calculation PM-I I 73. The pool boil off rate has been calculated to be I 37 gpm with irradiated fuel uncovered at 30.3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> (also from PM-1173). Torus level for NPSH is adequate for the entire 70-hour period with operators maintaining torus pressure as directed by curves in the EOPs. The operators may elect to increase torus inventory due to loss from saturated steam venting. The in v entory addition would provide additional margin to NPSH limits while allowing further torus depressurization if desired. The timeline indicates that the portable pumps will be lined up and available for injection in 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> which allows adequate margin to the 30.3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> until sp ent fuel is uncovered. 26 CI 3.1.1.1.A Peach Bottom Atomic Power Station, Unit 3 Ninth Six Month Report for the Implementation of FLEX August 28, 2017 Attachment 4 -NRC Audit Report Open Items MAAP Case 16 indicates the reactor vessel inventory makeup requirement at T-12 to be 200 gpm. As described above, the makeup to the spent fuel pool is 137 gpm for a total makeup of 337 gpm if both RPV and SFP were supplied simultaneously (200 gpm and 137 gpm respectively if addressed in a batch makeup manner). The flow path for additional flexibility is as follows: the pumps will take suction from the ECT and discharge through a hose, where it will split. One hose will go to supply the spent fuel pool and the other will go to the B.5.B connection in the RBCCW room and enter the "B" RHR train independently.

Additional reactor makeup beyond the required flow rates can be provided through the SBLC system via a hose connection.

Calculation PM-1184 (uploaded to the eportal) provides basis for the flow capability assumptions of the lineups. FSGs have been approved and issued to support this additional approach.

FLEX Building Storage Configuration Complete NEJ 12-06 addresses FLEX Equipment protection against Seismic Hazards (5.3. l ), Flood Hazards (6.2.3.1), High Wind Hazards (7 .3.1 ), Extreme Low Temperature Hazards (8.3.1), and Extreme High Temperature Hazards (9.3.1 ). The Peach Bottom Integrated Plan protects FLEX Equipment from external events in accordance with NEI Guidance such that no one external event can reasonably fail the site FLEX capability (N). The PBAPS strategy is to store and protect N sets of FLEX Equipment in a seismically-protected, temperature controlled, wind-protected structure. The structure is as close to the FLEX Equipment deployment areas as reasonable.

Although the structure is not above the flood plain, the PBAPS strate gy is to de p lo y the 27 Peach Bottom Atomic Power Station, Unit 3 Ninth Six Month Report for the Implementation of FLEX August 28, 20 I 7 Attachment 4 -NRC Audit Report Open Items equipment well before the arrival of any flood that has potential to be of magnitude that could obstruct deployment.

The PBAPS strategy is to store and protect +I sets of FLEX Equipment in a commercial structure located farther from the deployment areas. On a periodic interval, equipment will be rotated and transferred from one structure to the other, such that all N+ I sets of equipment are fully maintained and in ready status. Peach Bottom may also elect to store the +I set of equipment in the robust building with the N sets of equipment.

If the +I set of FLEX equipment is stored in the robust storage building, Peach Bottom will not be using the alternative approach. 5.3. I Seismic Hazards The Peach Bottom Integrated Plan protects FLEX equipment from seismic hazards. The FLEX equipment seismic storage building, which protects N sets of equipment, is designed to meet the plant's design basis for the Safe Shutdown Earthquake (SSE). The commercial structure, which protects +I sets of equipment, is designed to or evaluated equivalent to ASCE 7-I 0, Minimum Design Loads for Buildings and Other Structures.

The FLEX equipment seismic storage building will have equipment tie-down straps to secure major equipment such as generators, pumps, and trailers. These straps will be secured to the concrete floor with Hilti-bolts or equivalent.

Other infrastructure in the FLEX equipment seismic storage building, such as fire system (sprinkler) piping is designed to seismic 2-over-l criteria, such that it cannot fall in a seismic event or otherwise damage FLEX Equipment.

6.2.3. I External Flood Hazards Although the structure is not above the flood plain, the PBAPS strategy is to de p lo y the eq ui p ment well before the 28 Peach Bottom Atomic Power Station, Unit 3 Ninth Six Month Report for the Implementation of FLEX August 28, 2017 Attachment 4 -NRC Audit Report Open Items 29 arrival of any flood that has potential to be of magnitude that could obstruct deployment.

The FLEX equipment seismic storage building, which protects N sets of equipment, is not above the flood plain. The PBAPS strategy is to deploy the equipment well before the arrival of any flood that has potential to be of magnitude that could obstruct deployment.

The commercial structure is well above the flood plain. The PBAPS strategy is to deploy the+ 1 equipment at same time as N sets, well before the arrival of any flood that has potential to be of magnitude that could obstruct deployment.

At the designated deployment locations, FLEX equipment will be protected from ultimate flood height and wind generated waves. The FLEX equipment storage location and deployment paths are not subject to rapid rise of water. 7.3.1 High Wind Hazard The FLEX equipment seismic storage building, which protects N sets of equipment, is designed to meet the plant's design basis for the high winds and tornado missiles.

The structure, built to protect+ I sets of equipment, is designed to or evaluated equivalent to ASCE 7-10, Minimum Design Loads for Buildings and Other Structures, in accordance with the limiting tornado wind speeds from Regulatory Guide 1.76 or design basis hurricane wind speeds for the site. At PBAPS, there is no FLEX equipment that will be exposed to the wind. 8.3.1 Extreme Low Temperature Hazard The FLEX equipment seismic storage building, which protects N sets of equipment, is designed to meet the plant's design basis for snow, ice, and cold conditions.

The structure, built to p rotect CI 3.2.4.4.B Peach Bottom Atomic Power Station, Unit 3 Ninth Six Month Report for the Implementation of FLEX August 28, 2017 Attachment 4 -NRC Audit Report Open Items + 1 sets of equipment, is designed to or evaluated equivalent to ASCE 7-10, Minimum Design Loads for Buildings and Other Structures for the snow, ice and cold conditions from the site's design basis. The PBAPS UFSAR Section 2.3.4.1 characterizes site temperature conditions as a few winter temperatures in the 5 degree to I 0 degree F range. The FLEX equipment seismic storage is a heated enclosure.

The FLEX Pump Engine manufacturer documents the limiting pump component is the controller designed for -40 degrees F to 185 degrees F, which bounds Peach Bottom conditions. The FLEX Generator design specification is for I 00% full load operation at -25 degrees F, which bounds the Peach Bottom conditions.

9.3.1 Extreme High Temperature Hazard The FLEX equipment high temperature operating capability exceeds the plant's design basis for (high temperature) environmental conditions.

PBAPS UFSAR Section 2.3.4.1 states there are occasional readings above 90 degrees F in the summer. The FLEX Pump Engine manufacturer documents the limiting pump component is the controller designed for -40 degrees F to 185 degrees F, which bounds Peach Bottom conditions.

The FLEX Generator manufacturer documents the radiator design is based on a I 04 degrees F ambient temperature, which bounds Peach Bottom conditions. The alternate strategies for the FLEX building and the + 1 equipment have been included in the fifth 6 month update transmitted to the NRC on 8-28-15. Communications System Upgrades Complete The PBAPS plan provides for the installation and connection of EMNet Voice over IP (VoIP) phones and new network switches (Power over Ethernet 30 Peach Bottom Atomic Power Station, Unit 3 Ninth Six Month Report for the Implementation of FLEX August 28, 2017 Attachment 4 -NRC Audit Report Open Items 31 (PoE) capable) for the MCR to an existing Level 2 network. Four EMNet phone connections have been installed to replace Emergency Response Organization (ERO) hotlines, Nuclear Accident Reporting System (NARS) or dedicated ring downs in the MCR. These phones are located on the Control Room Supervisor's desk , the Plant Reactor Operator's desk with one each on the Unit 2 and Unit 3 Reactor Operators' desks. A network cable has been run to the MCR north office area that can be the location of the temporary TSC when the current TSC, Unit I control room, is unavailable.

The satellite system uses a fixed mount dish that is installed on the Radwaste building roof. This dish is reasonably protected from winds with mounting designed for 150 mph. The dish can survive winds up to 125 mph. If the permanently mounted dish is damaged during the event, a portable satellite dish is available for setup and use which is stored in the FLEX storage building which is protected.

In-plant communications utilizes a duplicate radio repeater system located inside of the Unit 3 reactor building with a deployable antenna to allow operators to use their radios for communication after a BDBEE. The plant radio "Talk Around" is adequate for line of sight communications and extra batteries and chargers are available and stored in the FLEX Robust Building.

Three portable satellite phones are available for offsite communications.