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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)
	ML16057A007
Person / Time
Site:	Nine Mile Point
Issue date:	02/26/2016
From:	David Helker; Exelon Generation Co
To:	; Document Control Desk, Office of Nuclear Reactor Regulation
References
	EA-12-049, RS-16-029, TAC MF1129, TAC MF1130, TAC MF1131, TAC MF1132
	Download: ML16057A007 (38)
	v • d • e

Exelon Generation (.,

Order No. EA-12-049 RS-16-029 February 26, 2016 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Nine Mile Point Nuclear Station, Unit 2 Renewed Facility Operating License No. NPF-69 NRG Docket No. 50-410

Subject:

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)

References:

1. NRG 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. NRG 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. Letter from M. G. Korsnick (GENG) to Document Control Desk (NRG), 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 26, 2012

5. Letter from M. G. Korsnick (GENG) to Document Control Desk (NRG), 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

6. Letter from M. G. Korsnick (GENG) to Document Control Desk (NRG), Supplement to 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 March 8, 2013

7. Letter from E. D. Dean (GENG) to Document Control Desk (NRG), Nine Mile Point Nuclear Station, Units 1 and 2 - 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 27, 2013

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

8. Letter from M. G. Korsnick (GENG) to Document Control Desk (NRC) - February 2014 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, 2014 (Nine Mile Point Nuclear Station, Units 1 and 2)

9. Letter from M. G. Korsnick (GENG) to Document Control Desk (NRC) - August 2014 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, 2014 (Nine Mile Point Nuclear Station, Units 1 and 2)

10. Letter from M. G. Korsnick (GENG) to Document Control Desk (NRC) - February 2015 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 19, 2015 (RS 057) (Nine Mile Point Nuclear Station, Units 1 and 2)

11. 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-15-219) (Nine Mile Point Nuclear Station, Unit 2)

12. Letter from J. S. Bowen (NRC) to J. A. Spina (GENG), Nine Mile Point Nuclear Station, Units 1 and 2 - Interim Staff Evaluation Relating to Overall Integrated Plan in Response to Order EA-12-049, (Mitigation Strategies) (TAC Nos. MF1129 and MF1130), dated December 19, 2013

13. Letter from J. Paige (NRC) to P. M. Orphanos (EGC), Nine Mile Point Nuclear 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 051 (TAC Nos. MF1129, MF1130, MF1131, and MF1132), dated April 28, 2015 On March 12, 2012, the Nuclear Regulatory Commission ("NRC" or "Commission") issued an order (Reference 1) to Exelon Generation Company, LLC (EGC), previously Constellation Energy Nuclear Group, LLC (Exelon, the licensee). 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 0 (Reference 3) with clarifications and exceptions identified in Reference 2. Reference 4 provided the EGC initial status report regarding mitigation strategies. References 5 and 6 provided the Nine Mile Point Nuclear Station, Unit 2 Overall Integrated Plan.

Reference 1 requires submission of a status report at six-month intervals following submittal of the Overall Integrated Plan. Reference 3 provides direction regarding the content of the status reports. References 7, 8, 9, 10, and 11 provided the first, second, third, fourth, and fifth six-month status reports, respectively, pursuant to Section IV, Condition C.2, of Reference 1 for Nine Mile Point Nuclear Station, Unit 2. The purpose of this letter is to provide the sixth six-month status report pursuant to Section IV, Condition C.2, of Reference 1, that delineates

U.S. Nuclear Regulatory Commission Integrated Plan Report to EA-12-049 February 26, 2016 Page 3 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 12, and the NRG 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.

I declare under penalty of perjury that the foregoing is true and correct. Executed on the 261h day of February 2016.

Respectfully submitted, David P. Helker Manager - Licensing & Regulatory Affairs Exelon Generation Company, LLC

Enclosure:

Nine Mile Point Nuclear Station, Unit 2 Sixth 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 - Nine Mile Point Nuclear Station NRG Project Manager, NRR - Nine Mile Point Nuclear Station Mr. Jason C. Paige, NRR/JLD/JOMB, NRC

Enclosure Nine Mile Point Nuclear Station, Unit 2 Sixth 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 (34 pages)

ENCLOSURE NMP2 SIXTH SIX MONTH STATUS REPORT {FEBRUARY 2016)

FOR MITIGATION STRATEGIES FOR BEYOND-DESIGN-BASIS EXTERNAL EVENTS 1 Introduction The Nine Mile Point Unit 2 (NMP2) Overall Integrated Plan (OIP) was submitted to the Nuclear Regulatory Commission (NRC) in February 2013 (Reference 1), documenting the diverse and flexible strategies (FLEX), in response to NRG Order Number EA-12-049 (Reference 2).

Subsequently, a supplement to the NMP2 OIP for FLEX was submitted to the NRC in March 2013 (Reference 3). This attachment 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 applicable).

Since the submittal of the last status report in August 2015 (Reference 14), NMP2 has progressed with engineering analysis, calculations, procedures and other activities that support the mitigating strategies.

By letter dated December 19, 2013, the NRC issued to Exelon Generation Company, LLC (previously Constellation Energy Nuclear Group, LLC) the Nine Mile Point Nuclear Station, Units 1 and 2 - Interim Staff Evaluation Relating to Overall Integrated Plan in Response to Order EA-12-049 (Mitigation Strategies) (TAC Nos. MF1129 and MF1130) (Reference 7). The Interim Staff Evaluation (ISE) contains open and confirmatory items for which NMP will provide clarifying or additional information in Six Month Status Reports in order for the NRC to determine that the issues are satisfactorily resolved.

2 Milestone Accomplishments The following Milestones have been completed since the development of the OIP (Reference 3),

and are current as of January 15, 2016.

Six Month Integrated Plan Progress Report submitted (8/2013)

Six Month Integrated Plan Progress Report submitted (2/2014)

Refueling Outage (RFO), including walk downs in support of pending modifications for installation for FLEX strategies (8/2014)

Six Month Integrated Plan Progress Report submitted (8/2014)

Six Month Integrated Plan Progress Report submitted (2/2015)

Six Month Integrated Plan Progress Report submitted (8/2015)

Engineering and Design Completion - Equipment Storage Facility (3/2015)

Equipment Storage Facility Installation (4/2015) 3 Milestone Schedule Status Table 1 provides an update to Attachment 3 of the NMP2 OIP (References 1 and 3). 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. Any changes to the following target completion dates will be reflected in the Report of Full Compliance with Order EA-12-049.

The revised milestone target completion dates do not impact the Order implementation date.

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ENCLOSURE NMP2 SIXTH SIX MONTH STATUS REPORT (FEBRUARY 2016)

FOR MITIGATION STRATEGIES FOR BEYOND-DESIGN-BASIS EXTERNAL EVENTS Table 1 Status of NMP2 FLEX OIP Milestones Revised Target Activity Target Milestone Completion Status Completion Date Date Submit 60 Day Status Report October 2012 Complete Submit Overall Integrated February 2013 Complete Implementation Plan Six Month Integrated Plan Progress August 2013 Complete Report Engineering and Design Completion - November Complete March 2015 Equipment Storage Facility 2014 Six Month Integrated Plan Progress February 2014 Complete Report Refueling Outage April 2014 Complete Six Month Integrated Plan Progress August 2014 Complete Report Engineering and Design Completion - November Complete Portable Equipment Connections 2014 Six Month Integrated Plan Progress February 2015 Complete Report Equipment Storage Facility installation May 2015 Complete Six Month Integrated Plan Progress August 2015 Complete Report Non-Outage Installation - Portable January 2016 Started March 2016 1 Equipment Connection Complete upon Six Month Integrated Plan Progress February 2016 submittal of Report this report Validation Walkdowns Complete February 2016 Started Portable Equipment Procedures March 2016 Started Changes FLEX Training March 2016 Started Page 2 of 34

ENCLOSURE NMP2 SIXTH SIX MONTH STATUS REPORT (FEBRUARY 2016)

FOR MITIGATION STRATEGIES FOR BEYOND-DESIGN-BASIS EXTERNAL EVENTS Table 1 Status of NMP2 FLEX OIP Milestones (cont'd)

Revised Target Activity Target Milestone Completion Status Completion Date Date Refueling Outage April 2016 Not Started May 2016 1 Outage Installation - Portable May 2016 Not Started Equipment Connections Final Implementation Notification to July 2016 Not Started USN RC Note 1.. Change since submittal of last six month integrated plan status report in August 2015.

4 Changes to Compliance Method Changes were made to the information provided in the 01 P that do not change the compliance method with Nuclear Energy Institute (NEI) 12-06 (Reference 5) and were provided in previous Six Month Status Reports. NMP has incorporated the supplemental guidance provided in the NEI position paper entitled "Shutdown I Refueling Modes" to enhance the shutdown risk process and procedures (References 9 and 10).

No significant strategy changes have occurred since the previous Six Month Status Update provided on August 28, 2015 (Reference 14).

Remaining design specifications and requirements and strategy revisions will be determined upon completion of the final design and installation.

5 Need for Relief/Relaxation and Basis for the Relief/Relaxation NMP2 expects to comply with the Order implementation date and no relief/relaxation is required at this time.

6 Open Items from Overall Integrated Plan and Draft Safety Evaluation Table 2 below provides a summary of the open items documented in the OIP and those added in any subsequent Six Month Status Reports and the status of each item.

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ENCLOSURE NMP2 SIXTH SIX MONTH STATUS REPORT (FEBRUARY 2016)

FOR MITIGATION STRATEGIES FOR BEYOND-DESIGN-BASIS EXTERNAL EVENTS The following is a list of the open items from the 01 P that have been added, deleted or completed since the last Six Month Status Report with an explanation of the changes:

1. General Integrated Plan Elements - BWR Open Item # 4: Exceptions for the site security plan or other (license/site specific - 10 CFR 50.54x) requirements of a nature requiring NRC approval will be communicated in a future Six Month Update following identification This item is complete.

The NMP2 Technical Specifications contain the limiting conditions for normal unit operations to ensure that design safety features are available to respond to a design basis accident and direct the required actions to be taken when the limiting conditions are not met. The result of the Beyond-Design-Basis External Event (BDBEE) may place the plant in a condition where it cannot comply with certain Technical Specifications and/or with its Security Plan, and, as such, may warrant invocation of 10CFR 50.54(x) and/or 10CFR 73.55(p). This position is consistent with the previously documented Task Interface Agreement (TIA) 2004-04, "Acceptability of Proceduralized Departures from Technical Specification (TSs) Requirements at the Surry Power Station", (TAC Nos. MC42331 and MC4332), dated September 12, 2006 (ADAMS Accession No. ML060590273).

The NMP2 FLEX mitigation strategies and procedures as developed do not require specific exceptions to the site Security Plan or other license/site specific requirements of a nature requiring NRC approval.

Open Item # 20: Develop preventive maintenance and testing procedures with frequencies based on Original Equipment Manufacturer (OEM) recommendation and Electric Power Research Institute (EPRI) guidelines for FLEX equipment This item is complete.

Periodic testing and Preventive Maintenance (PM) of the BOB/FLEX equipment conforms to the guidance provided in INPO AP-913. A fleet procedure has been developed to address Preventive Maintenance using EPRI templates or manufacturer provided information/recommendations, equipment testing and the unavailability of equipment. EPRI has completed and has issued "Preventive Maintenance Basis for FLEX Equipment - Project Overview Report" (Report 3002000623). Preventive Maintenance Templates for the major FLEX equipment including the portable diesel pumps and generators have also been issued. The PM Templates include activities such as:

Periodic Static Inspections

Fluid analysis

Periodic operational verifications Page 4 of 34

ENCLOSURE NMP2 SIXTH SIX MONTH STATUS REPORT {FEBRUARY 2016)

FOR MITIGATION STRATEGIES FOR BEYOND-DESIGN-BASIS EXTERNAL EVENTS

Periodic functional verifications with performance tests The EPRI PM Templates for FLEX equipment conform to the guidance of NEI 12-06 providing assurance that stored or pre-staged FLEX equipment are being properly maintained and tested. EPRI Templates are used for equipment where applicable.

However, in those cases where EPRI templates were not available, Preventive Maintenance actions were developed based on manufacturer provided information/

recommendations and Exelon fleet procedure ER-AA-200, Preventive Maintenance Program. FLEX equipment testing procedures contain the inspection and test criteria for functional and performance tests.

Exelon has contracted vendors to perform periodic maintenance of FLEX equipment at Nine Mile Point. Procedures S-PM-001, FLEX 3419MX WATER PUMP TEST, and S-PM-005, FLEX 3419MX WATER PUMP Performance Test, were developed to provide instructions for performing periodic testing on the FLEX portable water pumps. S-PM-003, 450 KW PORTABLE DIESEL GENERATOR TEST, provides instructions for performing periodic testing on the 450 KW FLEX generators. S-PM-002, FLEX Diesel Air Compressor Test procedure was developed for performing periodic testing of the FLEX air compressors. All of these procedures have been issued for use and contain the requirements described above.

Open Item # 27: Perform an analysis of long term RCIC Room temperatures {for equipment qualification and habitability) under ELAP conditions considering elevated Suppression Pool and Secondary Containment temperatures This item is complete.

In order to ensure RCIC survivability under ELAP conditions, a NMP specific evaluation was performed for RCIC and documented in Report 2015-01099, RCIC Equipment Survivability Review. The review contains an analysis for long term RCIC Pump Room temperatures (for equipment qualification and habitability) under ELAP conditions considering elevated Suppression Pool and Secondary Containment temperatures using GOTHIC computer code to support the ELAP coping strategies.

The analysis includes the effects of blocking open the RCIC Room door within the first two hours to mitigate RCIC Room heatup. In addition, it evaluates the effect of Reactor Building ventilation actions within the first eight hours to block open designated doors from outside at ground level through the building to the Reactor Building roof in order to provide passive convective cooling to the Reactor Building.

The GOTHIC model results indicate that the temperature in the RCIC pump room does not exceed its 10-hour qualified life temperature of 175 °F based on existing SBO Calculation ES-268. With anticipatory Primary Containment venting to control Suppression Pool water temperature rise, RCIC has been evaluated to support operation for up to 15 hours1.736111e-4 days 0.00417 hours 2.480159e-5 weeks 5.7075e-6 months with Suppression Pool temperature of less than 250°F.

Personnel access to the RCIC Room is possible for up to eight hours from RCIC start using personal protective equipment as room temperature approaches and Page 5 of 34

ENCLOSURE NMP2 SIXTH SIX MONTH STATUS REPORT (FEBRUARY 2016)

FOR MITIGATION STRATEGIES FOR BEYOND-DESIGN-BASIS EXTERNAL EVENTS subsequently exceeds 120°F and hot water starts to accumulate on the floor from RCIC seal leakage.

2. Maintain Core Cooling- BWR Portable Equipment Phase 2 Open Item # 6: Perform an analysis to validate the FLEX equipment ability to deliver sufficient flow under all expected conditions. Flow requirements from the dry hydrants will consider Phase 2 requirements.

This item is complete.

A hydraulic analysis was completed as part of the design process under ECP 001035 and documented in Calculation A 10.1-A-016 to verify the capability of the pumps and piping/hose system to deliver the required amount of water to each required location in the plant. The hydraulic analysis included primary and alternate injection locations for the Reactor Pressure Vessel and Spent Fuel Pool (SFP), and accounted for the Net Positive Suction Head (NPSH) and for conservative lengths of hoses and installed piping in any combination of primary and alternate connection points.

NMP2 mitigation strategies identify use of portable diesel driven centrifugal pumps.

The hydraulic analysis concluded that these pumps are sufficient to provide required flow rates to all required makeup points simultaneously at the expected pressures and with the required potential deployment configurations in the event of an ELAP.

One pump is capable of supplying the makeup requirements. A second pump is necessary and available if the maximum spent fuel pool spray flow of 250 gpm is required while the first pump is supplying maximum makeup to the Reactor Pressure Vessel.

NMP2 FLEX Hydraulic calculation has been completed. The key design input used and the results are summarized as follows:

1. Required Flow Rates 1.1 Core Cooling: 180 gpm Basis: Calculation N2-2014-004 which documents a MAAP analysis of the beyond design basis conditions during an ELAP event. The calculation results indicate that an alternate injection flow of 180 gpm is necessary to maintain the coolant level above the top of active fuel (TAF) after approximately 9 hours1.041667e-4 days 0.0025 hours 1.488095e-5 weeks 3.4245e-6 months of RCIC operation and followed by emergency depressurization of the RPV to 100 PSIG.

1.2 Spent Fuel Pool Cooling: 73 gpm or 250 gpm for spray Basis: Calculation A 10.1-J-045 documents the maximum boil off rate of the SPF as 73 gpm. Additionally, in accordance with Table C-3 of NEI 12-Page 6 of 34

ENCLOSURE NMP2 SIXTH SIX MONTH STATUS REPORT (FEBRUARY 2016)

FOR MITIGATION STRATEGIES FOR BEYOND-DESIGN-BASIS EXTERNAL EVENTS 06 a higher SFP makeup rate of 250 GPM is considered to accommodate for excess leakage and overspray.

2. Portable/FLEX Pump Characteristics The pump is a Cornell Pump Company Model 3419MX. The pump's operating characteristics are provided in Section 2.3 and Attachments 5 and 6 of Calculation A 10.1-A-016.

Open Item # 38: Perform an analysis to verify the capability of the portable diesel generator (DG) to power all expected loads This item is complete.

Calculation EC-206, 600 VAC FLEX Phase 2 Portable 450kW Diesel Generator Sizing ensures the FLEX generator is adequate to satisfy NMP2 electrical load requirements for implementation of FLEX Phase 2 strategies, and has been issued.

The calculation confirms that the FLEX 450 KW generator is sufficiently sized to power critical loads of the FLEX Phase 2 strategies and maintain a minimum of 530 VAC at the switchgear. In addition, the calculation determined that the FLEX portable cables and Bus Connection Devices (BCD) that are being used to connect the FLEX generator to the 600 VAC switchgear have sufficient ampacity to accommodate the worst loading conditions including short circuit currents.

Open Item # 61: Implement a design change to install permanent dry hydrants in the intake structure for FLEX portable pump suctions This item is complete.

A design change has been implemented which permanently installed two six-inch dry hydrants for FLEX pump water supply under Engineering Change Package ECP 001035. The two new six-inch dry hydrants are located along the north side of the Screenwell Building at NMP2 and will provide a water source from the service water intake structure via the tempering line, such that a nearly infinite source of make-up water to the reactor vessel and the spent fuel pool is available during Phase 2 of the FLEX strategy. A new concrete barrier has been installed to protect the hydrants from tornado generated missiles. A hinged plate across the north face of the barrier will provide access to the hydrant heads. The elevation of the hydrant heads is above the reevaluated flood level. One pump can be attached to each hydrant via a suction hose with cam and groove type end connections. Installation and post maintenance testing of the dry hydrants is complete.

3. Maintain Containment Integrity - BWR Installed Equipment Phase 1 Open Item # 28: Perform an evaluation of containment structures to identify necessary actions to enable implementation of the strategy with running RCIC with elevated temperatures This item is complete.

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ENCLOSURE NMP2 SIXTH SIX MONTH STATUS REPORT (FEBRUARY 2016)

FOR MITIGATION STRATEGIES FOR BEYOND-DESIGN-BASIS EXTERNAL EVENTS In order to ensure RCIC survivability under ELAP conditions, a NMP specific evaluation was performed for RCIC and documented in Report 2015-01099, RCIC Equipment Survivability Review. As part of the evaluation of the survivability of RCIC, the ability of the containment boundary to survive the conditions expected after a postulated ELAP with running RCIC with elevated temperature is also evaluated in Appendix D of the report.

The peak suppression pool water level, temperature, and pressure calculated based on MAAP analysis in Appendix A of the report for any of the scenarios postulated (bounding scenario for Primary Containment is RCIC suction from CST) is 33.2',

280.4 °F, and 45.1 psig, respectively. Based on these results, a qualitative assessment of the effect of the revised containment conditions on the containment structures is performed by comparing the results with the established EOP and IPE evaluation limits. However, the FLEX mitigating strategy will start venting the containment prior to reaching the maximum temperature and pressure. Therefore, although the evaluation is qualitative, it is conservative. The qualitative assessment concludes as follows:

(1) The following structures within the suppression chamber are judged to be adequate based on comparison to results of the evaluation of EOP conditions:

Liner embedment plates within the suppression chamber

Containment penetrations with the exceptions of the electrical penetration header plates and the expansion bellow assemblies attached to the outboard ends of five penetrations

The Base Ring T-joint of the Liner (2) For all other structures within the suppression chamber, the IPE provides significant evidence of the capacity of the containment structures beyond design basis conditions, and the structures will be acceptable for FLEX conditions with extremely low probabilities of failure.

Open Item # 29: Perform additional plant specific analysis to verify acceptable Suppression Pool levels during a long term operation of RCIC beginning with suction from the Condensate Storage Tanks (CSTs). Verify containment limitations are not exceeded This item is complete.

In order to ensure RCIC survivability under ELAP conditions, a NMP specific evaluation was performed for RCIC and documented in Report 2015-01099, RCIC Equipment Survivability Review. As part of the evaluation of the survivability of RCIC, the ability of the containment boundary to survive the conditions expected after a postulated ELAP with elevated suppression pool level is also evaluated in Appendix D of the report. The NMP2 FLEX strategy does not assume RCIC suction from the CST because the CST is not considered hardened per the NEI 12-06 guidelines.

Long term operation using RCIC will draw from the suppression pool. For the purposes of the RCIC and containment evaluations, RCIC suction from CSTs was analyzed to assess its impact on containment limits.

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ENCLOSURE NMP2 SIXTH SIX MONTH STATUS REPORT (FEBRUARY 2016)

FOR MITIGATION STRATEGIES FOR BEYOND-DESIGN-BASIS EXTERNAL EVENTS The peak suppression pool water level, temperature, and pressure calculated based on MAAP analysis in Appendix A of the report for all of the scenarios postulated (bounding scenario for Primary Containment is RCIC suction from CST) is 33.2',

280.4 °F, and 45.1 psig, respectively. Based on these results, a qualitative assessment of the effect of the revised containment conditions on the containment structures was performed by comparing the Appendix A results with the established EOP and IPE evaluation limits. The IPE report determined that the probability of failure was low for a containment pressure of 120 psi and a temperature of 400°F, which significantly envelopes the peak containment conditions of 45.1 psi and 280.4°F identified in the MAAP analysis in Appendix A of report 2015-01099.

Therefore, the IPE provides significant evidence of the capacity of the containment structures beyond design basis conditions, and the structures will be acceptable for FLEX scenario conditions with small probabilities of failure.

Open Item# 30: Perform an analysis to verify acceptable parameters (e.g., Net Positive Suction Head (NPSH) requirements) for RCIC operation with the higher temperatures and anticipated changes in Suppression Pool level This item is complete.

In order to ensure RCIC survivability under ELAP conditions, a NMP specific evaluation was performed for RCIC and documented in Report 2015-01099, RCIC Equipment Survivability Review. As part of the evaluation of the survivability of RCIC, evaluation of NPSH for the RCIC pump following a postulated ELAP is evaluated in Appendix A of the report.

Appendix A provides an evaluation of NPSH for the RCIC equipment and shows that the EOP RCIC NPSH limit curve is exceeded in 13 hours1.50463e-4 days 0.00361 hours 2.149471e-5 weeks 4.9465e-6 months without RCIC CST suction and 22 hours2.546296e-4 days 0.00611 hours 3.637566e-5 weeks 8.371e-6 months with suction first from the CST. If the containment is vented at a suppression pool pressure of 1O psig (anticipatory venting) the time of exceedance is reduced to 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months without the CST suction and remains at 22 hours2.546296e-4 days 0.00611 hours 3.637566e-5 weeks 8.371e-6 months with the CST suction. However, the EOP RCIC NPSH curve is conservatively based on maximum RCIC speed and flow conditions. Review of the RCIC flow curves in Appendix A indicates that at about 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months the RCIC flow required would be about 200 gpm average rather than 600 gpm and the Reactor pressure would be below 200 psia instead of the EOP value of 1215 psia which results in a reduction in RCIC NPSH required. Twenty four hours was chosen since the available NPSH at that point in Appendix A, Case 9 (RCIC suction from suppression pool) with anticipatory containment venting, is about 4 ft, which is the required head at low RCIC speed (2000 RPM) and 200 gpm flow rate.

The MAAP results show that the available NPSH remains above required for at least 27 hours3.125e-4 days 0.0075 hours 4.464286e-5 weeks 1.02735e-5 months without RCIC suction from CST and containment venting at 10 psig, or 60 hours6.944444e-4 days 0.0167 hours 9.920635e-5 weeks 2.283e-5 months with CST inventory in addition to containment venting at 10 psig.

Open Item # 31: Perform an analysis to validate containment vent sizing to maintain Suppression Pool parameters to support RCIC capability This item is complete.

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ENCLOSURE NMP2 SIXTH SIX MONTH STATUS REPORT (FEBRUARY 2016)

FOR MITIGATION STRATEGIES FOR BEYOND-DESIGN-BASIS EXTERNAL EVENTS In accordance with NRC Order EA-13-109, the Hardened Containment Vent System (HCVS) is required to be designed to have the capacity to vent the steam equivalent of a decay heat rate of 1% of rated thermal power at a pressure equivalent to the lessor of containment design pressure or the PCPL which is 45 psig at NMP2. This is equivalent to a flow rate of approximately 148,600 lbm/hr. The current HCVS design has been evaluated considering pipe diameter, length, and geometry, as well as valve flow coefficients, and the losses associated with a burst rupture disc. Hardened Containment Vent capacity Calculation A 10.1-P-050 concludes that the NMP2 HCVS design provides margin to the minimum required flow rate.

Additional analysis was performed to validate containment vent size is adequate to maintain acceptable parameters for RCIC operations and is documented in the RCIC Equipment Survivability Review Report # 2015-01099. Appendix A (MAAP analysis) in Report 2015-01099 provides an evaluation of containment parameters to support the RCIC pump for various containment venting cases. The MAAP model reflects the NMP2 HCVS vent size. Under all cases evaluated which model early venting of the containment at 1O psig, the evaluation determined the HCVS vent size is adequate to support RCIC operation for a minimum of 15 hours1.736111e-4 days 0.00417 hours 2.480159e-5 weeks 5.7075e-6 months , which supports NMP2 FLEX strategies.

Open Item # 37: Perform an analysis to verify assumptions related to an adequate nitrogen supply during ELAP conditions and revise or provide ELAP procedures that optimize Safety Relief Valve (SRV) control during an ELAP condition This item is complete.

The NMP2 FLEX strategy utilizes Safety Relief Valves (SRV) during ELAP conditions to initially control and subsequently reduce RPV pressure to target bands. An analysis (A 10.1-P-054) was performed to verify the adequacy of the nitrogen pneumatic supply which is used to operate the SRVs. The conclusion is that the seven (7) ADS-SRV accumulators used for SRV operation have sufficient pneumatic capacity to provide a total of 42 actuations which exceeds the maximum expected number of actuations of twelve (12) during the first 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months of the ELAP to achieve the RPV target pressure band of 150 - 200 psig. To optimize the SRV pneumatic supply, per NMP Transient Mitigation Guidelines (OP-NM-101-111-1001 ), when SRV operation is required and no makeup nitrogen is available for recharge of SRV accumulators, sustained SRV opening is utilized to establish and maintain the target RPV pressure band.

For ADS-SRV accumulators, the analysis has verified pneumatic supplies to the SRVs can be subsequently re-charged from safety related pneumatic supply tanks 21AS*TK4 and 21AS*TK5 located in the Reactor Building during Phase 1 when safety related battery power is available to both trains. The minimum times that ADS-SRV accumulators can be re-charged is 1 time for the four DIV II accumulators from tank 21AS*TK5 and 2 times for the three DIV I accumulators from tank 21AS*TK4. Without recharging, the accumulator can maintain an ADS-SRV open for 6.6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months after one actuation for the bounding Phase 2 conditions.

Page 10 of 34

ENCLOSURE NMP2 SIXTH SIX MONTH STATUS REPORT (FEBRUARY 2016)

FOR MITIGATION STRATEGIES FOR BEYOND-DESIGN-BASIS EXTERNAL EVENTS For ADS-SRV accumulators located in the division where power is available during the Phase 2 and 3 periods, the plant installed N2 capacity is sufficient to maintain corresponding divisional ADS-SRVs open for the entire ELAP. Procedure N2-SOP-02 has been revised to provide the necessary actions for recharging of ADS-SRV accumulators.

For indefinite coping, an onsite portable FLEX diesel driven air compressor will be utilized to provide pneumatic recharge capability of safety related pneumatic supply tanks 21AS*TK4 and 21AS*TK5. The FLEX compressor is stored in the robust FLEX Storage Building. A portable diesel driven air compressor is also being delivered to NMP by the National SAFER Response Center after 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months per the NMP SAFER Response Plan.

4. Safety Functions Support - BWR Portable Equipment Phase 2 Open Item # 12: Perform an analysis for feasibility of utilizing the sound powered communications for onsite communications for FLEX strategies This item is complete.

For NMP2, Sound Powered Phones will be the backup communication method to hand-held radios for implementation of FLEX strategies. The Sound Powered Phone system is a function of the NMP2 Maintenance and Calibration Communication System and is described in USAR section 9.5.2. Operations Procedure N2-0P-76, Section H.4.0 describes how to use the Sound Powered Phones.

Testing of the Sound Powered phone circuits was completed the week of 11/30/15 under Work Order C93170992. This test demonstrated that Sound Powered Phone equipment may be used to effectively communicate between personnel in the Control Room and personnel in other areas of the plant to support FLEX equipment deployment for maintaining Core, Containment, and Spent Fuel Pool cooling when normal in-plant communication methods are not available. Each communication circuit needed to support a FLEX implementation strategy has been verified to be functional by testing two-way communication from the designated field location to the Control Room or another location as recorded.

Open Item # 13: Evaluate required consumables and options for storage and availability during an ELAP and implement programmatic controls to ensure required inventory is maintained This item is complete.

Exelon fleet Procedure HR-AA-4003 Employee and Family Disaster Support has been implemented at NMP and communicated to site personnel. This procedure describes the support that personnel unable to leave the site and their families will receive during disaster events.

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ENCLOSURE NMP2 SIXTH SIX MONTH STATUS REPORT (FEBRUARY 2016)

FOR MITIGATION STRATEGIES FOR BEYOND-DESIGN-BASIS EXTERNAL EVENTS The procedure defines the responsibility for each site to maintain food, water, sleeping arrangements, sanitation and emergency supplies to support the needs of personnel sequestered on-site for a 24-hour period based on minimum staffing levels.

Additionally, the procedure assigns the Emergency Operations Facility (EOF)

Logistics Coordinator responsibility to contact off-site support for the delivery of food and water for on-site personnel and to arrange for sleeping areas to be established.

The procedure directs the human resources crisis team to contact employees and families to provide assistance during the disaster recovery activities.

Adequate water, food, sleeping cots, and portable sanitation equipment are available for at least a 24-hour period onsite from the NMP Warehouse where they are reasonably protected. Minimum inventories are maintained that support the 24-hour requirement and are also maintained within the required shelf life, in accordance with Procedure SM-AA-102 Warehouse Operations.

NMP maintains an inventory inside the robust FLEX Storage Building of bottled water, foul weather clothing, and personal protective equipment for use by onsite personnel during a BDBEE. These items are inventoried annually in accordance with Procedure S-PM-FLEX, FLEX Equipment Inventories and Checklists.

Open Item # 25: Evaluate requirements and options and develop strategies related to the storage and transport of the on-site FLEX portable equipment This item is complete.

The FLEX Storage Building is designed and constructed to protect the contents of the building from all screened-in hazards identified in NEI 12-06. For NMP, all N and +1 equipment required to satisfy both NMP1 and NMP2 mitigation strategies is stored in the FLEX Storage Building, built to meet the design requirements specified in NEI 12-06 for the protection of FLEX portable equipment for the site.

Transport of the mitigation strategy portable equipment during deployment will be accomplished utilizing a large four-wheel drive tractor for the portable diesel generators and an adequately sized truck for the portable diesel driven pumps. One of the trucks is also sized to tow the portable generators. These deployment vehicles are stored in the FLEX building with the portable equipment attached to the tow vehicle and ready to immediately deploy out of the building for deployment.

Open Item # 47: Evaluate the strategy for repower of select Emergency Lighting loads when the FLEX portable Diesel Generator reenergizes the 600 VAC bus This item is complete.

The emergency lighting system provides adequate illumination in areas required for operating the safety-related equipment during emergency conditions. The emergency lighting system normally receives power from Division I, II and Ill 600VAC emergency busses. Emergency busses feed Class 1E main lighting distribution panels. These Page 12 of 34

ENCLOSURE NMP2 SIXTH SIX MONTH STATUS REPORT (FEBRUARY 2016)

FOR MITIGATION STRATEGIES FOR BEYOND-DESIGN-BASIS EXTERNAL EVENTS lighting loads are shed to extend safety related battery conservation and reduce Control Room and Relay Room heat loading. Once the FLEX portable generators are deployed, portions of this lighting can be restored when 2EJS*US1 (Div I) or 2EJS*US3 (Div II) is repowered. The emergency lighting available that may be re-energized from the safety related 600VAC switchgear, 2EJS*US1 or 3 will supply a portion of the lighting in the Control Building El 306' (Control Room), El 288' (Relay Room), El 261' (Divisional Switchgear and Remote Shutdown Rooms) and the Divisional Diesel Rooms.

FLEX generator sizing calculation (EC-206) has the lighting panels supplied from switchgear 2EJS*US1 or 3 evaluated as loads to restore. Calculation EC-206 Attachments 11.1 and 11.2 for Div I loads or Div 2 loads respectively, lists electrical loads, both required and optional for FLEX Phase 2, and includes these lighting panels which power lighting in the areas described above. The sum of all the identified loads on Attachment 11.1 (or 11.2) was determined to be 489.6 kVA which is less than the 563 kVA continuous rating of the FLEX generator. The FLEX generator worst case loading scenario is a start of the largest motor with the most demanding locked rotor current while all other loads identified in Attachment 11.1 (or 11.2) are energized and in service. The calculated instantaneous power required was determined to be 752.3 kVA which is within the FLEX generator maximum rating of 1749 kVA.

Therefore, restoration of lighting loads in the safety related areas is well within the capability of the FLEX generator and will be restored utilizing FLEX Procedure N2-DRP-FLEX-ELEC.

Page 13 of 34

ENCLOSURE NMP2 SIXTH SIX MONTH STATUS REPORT (FEBRUARY 2016)

FOR MITIGATION STRATEGIES FOR BEYOND-DESIGN-BASIS EXTERNAL EVENTS Table 2 Status of NMP2 FLEX OIP Open Items NMP2 OIP Open Items Status

1. Define criteria for the local (25 mile) staging area. Complete (2/2014)

2. Evaluate deployment strategies and deployment routes for hazard Complete impact. (2/2015)

3. Evaluate requirements and options and develop strategies related to the storage on-site of the FLEX portable equipment (including lighting Complete tools such as flashlights and batteries) in accordance with the (8/2015) requirements of NEI 12-06.

4. Exceptions for the site security plan or other (license/site specific - 1O Complete CFR 50.54x) requirements of a nature requiring NRC approval will be (2/2016) communicated in a future Six Month Update following identification.

5. Determine schedule for when Regional Response Centers (RRCs) will Complete be fully operational. (8/2013)

6. Perform an analysis to validate the FLEX equipment ability to deliver Complete sufficient flow under all expected conditions. Flow requirements from (2/2016) the dry hydrants will consider Phase 2 requirements.

7. Perform an analysis to validate the FLEX equipment ability to deliver sufficient flow under all expected conditions. Flow requirements from Deleted (8/2014) the dry hydrants will consider Phase 3 requirements.

8. Perform calculations and validate assumptions of fuel consumption Complete and replenishment rate to ascertain the time before off-site (2/2015) replenishment is required.

9. Perform an evaluation of the Uninterruptible Power Supply (UPS) strategy and design and implement as required or formalize the use of Started (2/2014) the small portable gas generators (communication strategies).

10. Perform an evaluation of the redundant power strategy for radio repeaters and design and implement modifications or programmatic Started (2/2014) changes as required.

Page 14 of 34

ENCLOSURE NMP2 SIXTH SIX MONTH STATUS REPORT (FEBRUARY 2016)

FOR MITIGATION STRATEGIES FOR BEYOND-DESIGN-BASIS EXTERNAL EVENTS Table 2 Status of NMP2 FLEX OIP Open Items (cont'd)

NMP2 OIP Open Items Status

11. Verify plans for the FLEX storage facilities in accordance with NEI 12-Complete 06 requirements also accommodate the storage and availability of fuel (8/2014) for the small gas generators.

12. Perform an analysis for feasibility of utilizing the sound powered Complete communications for onsite communications for FLEX strategies. {2/2016)

13. Evaluate required consumables and options for storage and Complete availability during an ELAP and implement programmatic controls to (2/2016) ensure required inventory is maintained.

14. Establish deployment routes from FLEX equipment storage location to Complete connection points (including hazards impacts). {2/2015)

15. Establish a suitable local staging area for portable FLEX equipment to Complete be delivered from the RRC to the site SAFER Staging Area 11 C 11 * (2/2015)

16. Establish a suitable local staging area for Phase 3 portable FLEX Complete equipment to be deployed on site SAFER Staging Area 11 8 11 * (2/2015)

17. Provide the necessary storage facilities in order to provide fuel to the Complete transfer pumps during an ELAP event. (2/2015)

18. Develop site specific SAFER Response Plan (playbook) for delivery of Complete portable FLEX equipment from the RRC to the site. (8/2015)

19. Develop and implement a program and/or procedures to keep FLEX Complete equipment deployment pathways clear or identify actions to clear the (8/2015) pathways.

20. Develop preventive maintenance and testing procedures with frequencies based on Original Equipment Manufacturer (OEM) Complete recommendation and Electric Power Research Institute (EPRI) (2/2016) guidelines for FLEX equipment.

21. Evaluate and implement procedures that direct immediate deployment Complete of Phase 2 equipment during Refueling conditions. (8/2015)

22. Purchase and maintain the required equipment to ensure debris Complete removal capability to re-establish deployment routes and transport (2/2015)

FLEX portable equipment during all modes of operation.

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ENCLOSURE NMP2 SIXTH SIX MONTH STATUS REPORT (FEBRUARY 2016)

FOR MITIGATION STRATEGIES FOR BEYOND-DESIGN-BASIS EXTERNAL EVENTS Table 2 Status of NMP2 FLEX OIP Open Items (cont'd)

NMP2 OIP Open Items Status

23. Develop procedures/guidelines to address the criteria in NEI 12-06 to support existing symptom based strategies in the Emergency Started (2/2014)

Operating Procedures (EOPs).

24. Evaluate potential soil liquefaction for Nine Mile Point site considering Complete final storage location of FLEX portable equipment and deployment (2/2015) routes established for this equipment.

25. Evaluate requirements and options and develop strategies related to Complete the storage and transport of the on-site FLEX portable equipment. (2/2016)

26. Implement a design change to Reactor Core Isolation Cooling (RCIC) that will support operation of the system at elevated Suppression Pool Deleted (8/2015) temperatures as identified in GEH 000-0155-1545 (BWROG RCIC Pump and Turbine Durability Evaluation - Pinch Point Study).

27. Perform an analysis of long term RCIC Room temperatures (for equipment qualification and habitability) under ELAP conditions Complete considering elevated Suppression Pool and Secondary Containment (2/2016) temperatures.

28. Perform an evaluation of containment structures to identify necessary Complete actions to enable implementation of the strategy with running RCIC (2/2016) with elevated temperatures.

29. Perform additional plant specific analysis to verify acceptable Suppression Pool levels during a long term operation of RCIC Complete beginning with suction from the Condensate Storage Tanks (CSTs). (2/2016)

Verify containment limitations are not exceeded.

30. Perform an analysis to verify acceptable parameters (e.g., Net Positive Suction Head (NPSH) requirements) for RCIC operation with Complete the higher temperatures and anticipated changes in Suppression Pool (2/2016) level.

31. Perform an analysis to validate containment vent sizing to maintain Complete Suppression Pool parameters to support RCIC capability. (2/2016)

32. Perform an analysis to identify necessary actions, (e.g., modifications Complete or programmatic changes) to maximize battery coping time to at least (2/2015) 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months .

Page 16 of 34

ENCLOSURE NMP2 SIXTH SIX MONTH STATUS REPORT (FEBRUARY 2016)

FOR MITIGATION STRATEGIES FOR BEYOND-DESIGN-BASIS EXTERNAL EVENTS Table 2 Status of NMP2 FLEX OIP Open Items (cont'd)

NMP2 OIP Open Items Status

33. Evaluate NMP2 containment integrity for Phases 1 through 3 and Complete update calculations. (8/2015)

34. Implement an alternative Containment Cooling strategy, if required, Deleted (8/2015) when the analysis of structural temperatures are complete.

35. Perform an analysis to determine the containment pr.essure profile during an ELAP I Loss of Ultimate Heat Sink (LUHS) event and verify Complete the instrumentation and controls in containment which are relied upon (8/2015) by the operators are sufficient to perform their intended function.

36. Perform an analysis to determine when ambient heat losses will be low enough such that with Residual Heat Removal (RHR) in a Phase Deleted (2/2015) 3 mode of shutdown cooling, venting of the primary containment will no longer be required.

37. Perform an analysis to verify assumptions related to an adequate nitrogen supply during ELAP conditions and revise or provide ELAP Complete procedures that optimize Safety Relief Valve (SRV) control during an (2/2016)

ELAP condition.

38. Perform an analysis to verify the capability of the portable diesel Complete generator (DG) to power all expected loads. (2/2016)

39. Perform an analysis to determine the limiting conditions for an RHR loop to be restarted (e.g., RHR Room, seals and fluid temperatures)

Deleted (8/2014) and adjust the strategy to start in Shutdown Cooling (SOC) based on the results of the analysis.

40. Perform a load distribution analysis for safety related equipment restoration utilizing either two RRC Diesel Generators paralleled on Deleted (8/2013) one 4160 VAC bus or one RRC Diesel Generator on each safety related bus (i.e., one on Division 1 and one on Division 2).

41. Perform an analysis to determine the service water cooling water flow needed to accommodate all expected cooling loads and resulting Deleted (8/2013)

RRC pump size requirement.

42. Evaluate a strategy to provide a vent pathway for steam and Complete condensate from the SFP or justify why it is not needed. (8/2015)

Page 17 of 34

ENCLOSURE NMP2 SIXTH SIX MONTH STATUS REPORT (FEBRUARY 2016)

FOR MITIGATION STRATEGIES FOR BEYOND-DESIGN-BASIS EXTERNAL EVENTS Table 2 Status of NMP2 FLEX OIP Open Items (cont'd)

NMP2 OIP Open Items Status

43. Perform an evaluation to determine the effects and required actions Complete for Spent Fuel Pool temperatures expected above design of 150°F (2/2015) during an ELAP.

44. Perform analysis to verify SFP temperature and level after an ELAP Complete event and adequate level for maintaining radiological access to the (8/2015) refuel floor.

45. Perform an analysis to evaluate long term temperature profiles in the Deleted (8/2013)

NMP2 Main Control Room (MCR) under ELAP condition (Phase 1).

46. Perform an analysis for long term environmental conditions in the Completed NMP2 Battery Rooms during an ELAP and evaluate any actions to (8/2015) mitigate the impact of this hydrogen production as required.

47. Evaluate the strategy for repower of select Emergency Lighting loads Complete when the FLEX portable Diesel Generator reenergizes the 600 VAC (2/2016) bus.

48. Perform an analysis of the light coverage during ELAP conditions and Complete determine if the lighting loads should be re-energized from the non-(2/2015) safety related buses by the RRC FLEX generator.

49. Perform an analysis of the need for dewatering based on leak rates Deleted (8/2014) and flood response capabilities.

50. Implement a design change to install permanent 4160 VAC bus connection points to be able to connect to the RRC supplied Diesel Deleted (8/2014)

Generator, including paralleling capability, as required to connect more than one Diesel Generator to an electrical bus.

51. Implement a design change to receive large capacity RRC pumps to Deleted (8/2014) supply the service water distribution header.

52. Design and implement a modification that provides for connection of a Started (8/2014)

FLEX portable pump to makeup to the SFP.

53. Implement a design change to install connections for FLEX portable Started (8/2014) pumps to RHR for both RHR 'A' and 'B'.

54. Implement a design change to install portable generator connections Started (8/2014) for 600 VAC primary (2EJS*US1) and alternate (2EJS*US3) busses.

Page 18 of 34

ENCLOSURE NMP2 SIXTH SIX MONTH STATUS REPORT (FEBRUARY 2016)

FOR MITIGATION STRATEGIES FOR BEYOND-DESIGN-BASIS EXTERNAL EVENTS Table 2 Status of NMP2 FLEX OIP Open Items (cont'd)

NMP2 OIP Open Items Status

55. Revise procedures to provide reactor pressure control direction during Started (8/2015) an ELAP event.

56. Develop and implement procedure direction to ensure that the Main Started (8/2015)

Turbine Hydrogen is vented prior to battery depletion.

57. Revise current EOPs to implement EOP actions necessary to support the strategy to terminate emergency depressurization to preserve Started (2/2014)

RCIC operation.

58. Develop and implement procedures to provide direction for re-energizing the Solenoid Operated Valves (SOVs) and ensuring long Started (8/2015}

term pneumatic supply during an ELAP.

59. Develop procedures to implement the connection of a FLEX portable pump to makeup water to the SFP during an ELAP event to include Started (8/2014) both primary and alternate strategies.

60. Develop and implement procedures that provide direction for Deleted (8/2013) restoration of SFP cooling during ELAP conditions (Phase 3).

61. Implement a design change to install permanent dry hydrants in the Complete intake structure for FLEX portable pump suctions. (2/2016)

Page 19 of 34

ENCLOSURE NMP2 SIXTH SIX MONTH STATUS REPORT (FEBRUARY 2016)

FOR MITIGATION STRATEGIES FOR BEYOND-DESIGN-BASIS EXTERNAL EVENTS Table 3 below provides a summary of the open and confirmatory items documented in the NRC's NMP2 ISE (Reference 7) and the status of each item.

ISE Open Item # 1: ISE Open Item 3.1.1.3.A - Seismic procedural interface consideration NEI 12-06, Section 5.3.3, Consideration 1, which considers the possible failure of seismically qualified electrical equipment by beyond-design-basis seismic events, was not discussed in the Integrated Plan or during the audit process ISE Open Item # 1 is submitted for closure.

Nine Mile Point Unit 2 has existing Procedure N2-SOP-78A, EOP Key Parameter -

Alternate Instrumentation, which was developed and implemented to provide operators with alternate instrumentation to utilize in the event the primary instrumentation used for implementing EOPs malfunctions. The specified alternate instrumentation can then be used to obtain key EOP parameter readings to support successful EOP implementation.

In response to the requirement contained in NEI 12-06, Section 5.3.3, Consideration 1, a reference source document (VENRPT-15-000012) was developed for NMP2 critical instrumentation which provides guidance on how and where to measure key instrument readings at local instrument sources (i.e., transmitter, penetration, panel connection, connector, etc.). This reference source document also includes critical actions to perform until alternate indications can be connected and how to control critical equipment without associated control power. The reference source document was completed and issued June 2015. Operations Procedure N2-SOP-78A, EOP Key Parameter - Alternate Instrumentation, has been revised to incorporate the content of the reference source document. Training of personnel on the revised N2-SOP-78A procedure has been completed and the procedure will be issued prior to startup from the Spring 2016 Refueling Outage.

ISE Open Item # 2: ISE Open Item 3.2.3.B - The licensee has not performed finalized calculations to demonstrate that the assumed timeline is appropriate and that containment functions will be restored and maintained following an ELAP event.

ISE Open Item# 2 is submitted for closure.

NMP2 MAAP Evaluation N2-2014-004, Revision 3 contains three additional MAAP runs that were performed to evaluate the reactor pressure vessel (RPV) level as well as primary containment pressure and temperature response to an extended SBO event. A series of scoping analyses had been performed previously to assess NMP2 response to an extended station blackout condition. The primary emphasis of those analyses was to study overall containment thermal response and to support decision-making regarding a strategy to cope with extended SBO.

Page 20 of 34

ENCLOSURE NMP2 SIXTH SIX MONTH STATUS REPORT (FEBRUARY 2016)

FOR MITIGATION STRATEGIES FOR BEYOND-DESIGN-BASIS EXTERNAL EVENTS In MAAP Vent Cases 1F19a and 1F23a of Evaluation N2-2014-004, whereby RCIC suction is initially from the suppression pool, it was demonstrated that when assuming RCIC failed at about 240°F in the suppression pool (reached at approximately 11 hours1.273148e-4 days 0.00306 hours 1.818783e-5 weeks 4.1855e-6 months into the event), emergency depressurization combined with a nominal 180 gpm of alternate injection flow to the RPV is adequate to prevent RPV level from dropping to the TAF.

NMP2 Phase 2 staffing assessment results conclude that the FLEX portable pump will be ready for injection by 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months into the event and the FLEX portable generator will be ready to reenergize a Class 1E 600 VAC load bus by 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months into the event. This will ensure transition to Phase 2 support equipment will be ready with significant margin when the pump will be needed for RPV injection (at approximately 11 hours1.273148e-4 days 0.00306 hours 1.818783e-5 weeks 4.1855e-6 months ) and for the generator to provide backup power to the Hardened Containment Vent System (at 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months ).

These results demonstrate that the assumed timeline is appropriate to maintain both RPV and primary containment functions during an ELAP event at NMP2.

ISE Confirmatory Item # 12: ISE Confirmatory Item 3.2.1.2.A - There was no discussion of the applicability of the assumed recirculation system leakage rates and the recirculation pump seal leakage rates to the ELAP event; the pressure dependence of the leak rates; whether the leakage was determined to be single-phase, two-phase, or steam at the donor cell; and how mixing of the leakage flow with the drywell atmosphere was modeled ISE Confirmatory Item # 12 is submitted for closure.

The NMP2 MAAP analysis documented in Evaluation N2-2014-004 utilizes a Reactor Coolant System leakage rate of 61 gpm total based on the 18 gpm leakage rate per seal for each of the two Reactor Recirculation Pumps as recommended by NUMARC 87-00, Page J-2, for BWR SBO design basis, plus 25 gpm technical specification maximum leakage. The seal leakage is defined in the containment analysis as a small line break located at the vessel bottom head. The break size (parameter ALOCA in the MAAP) is defined based on rated pressure conditions and single-phase liquid at time = O using the Henry-Fauske leakage expression for liquid. With defined break size, the leakage is therefore calculated as a function of the vessel pressure transient. The mass flow rates are based on a simplified version of the Henry-Fauske two-phase critical flow model

[Henry and Fauske, 1971 ]. In the general form of the expression for the mass flow rate, the mass flow rate is proportional to the square root of the absolute pressure of the upstream compartment, P1, and the square root of the 1-r factor, where r is the pressure ratio. The model checks for critical flow condition and the pressure ratio r takes on the value of:

P2/P1 for unchoked flow, where P2 is the downstream pressure, or Page 21 of 34

ENCLOSURE NMP2 SIXTH SIX MONTH STATUS REPORT (FEBRUARY 2016)

FOR MITIGATION STRATEGIES FOR BEYOND-DESIGN-BASIS EXTERNAL EVENTS

PsatfP1 or a complex dimensionless value eta, fl, which depends on the quality of the two-phase mixture and the ratio of the specific heats of steam, for choked flow.

There is also a secondary dependence on upstream pressure since the mass flow rate is proportional to the square root of the density of the fluid.

Leakage flow in terms of mass and energy is into one lumped drywell atmosphere volume, assuming homogeneous mixing.

ISE Confirmatory Item# 14: ISE Confirmatory Item 3.2.3.A - Perform an evaluation of containment structures to identify necessary actions to enable implementation of the strategy with running RCIC with elevated temperatures ISE Confirmatory Item # 14 is submitted for closure.

As part of the evaluation of the survivability of Reactor Core Isolation Coolant (RCIC) equipment in the event of an Extended Loss of AC Power (ELAP) and documented in NMP2 Report 2015-01099, the ability of the containment boundary to survive the conditions expected after a postulated ELAP with running RCIC with elevated temperature is also evaluated as documented in Appendix D of Report 2015-01099.

The peak suppression pool water level, temperature, and pressure calculated based on MAAP analysis for any of the scenarios (bounding scenario for Primary Containment is RCIC suction from CST) is 33.2', 280.4 °F, and 45.1 psig, respectively (Appendix A of Report 2015-01099). Based on these results, a qualitative assessment of the effect of the revised containment conditions on the containment structures is performed by comparing the results with the established EOP and IPE evaluation limits. However, the FLEX Mitigating Strategy will start venting the containment prior to reaching the maximum temperature and pressure. Therefore, although the evaluation is qualitative, it is conservative. The qualitative assessment concludes as follows that:

(1) The following structures within the suppression chamber are judged to be adequate based on comparison to results of the evaluation of EOP conditions:

Liner embedment plates within the suppression chamber

Containment penetrations with the exceptions of the electrical penetration header plates and the expansion bellow assemblies attached to the outboard ends of five penetrations

The Base Ring T-joint of the Liner (2) For all other structures within the suppression chamber, the IPE provides significant evidence of the capacity of the containment structures beyond design basis conditions, and the structures will be acceptable for FLEX conditions with extremely low probabilities of failure.

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ENCLOSURE NMP2 SIXTH SIX MONTH STATUS REPORT (FEBRUARY 2016)

FOR MITIGATION STRATEGIES FOR BEYOND-DESIGN-BASIS EXTERNAL EVENTS ISE Confirmatory Item # 15: ISE Confirmatory Item 3.2.4.2.A - The completion and determination of acceptable results for all of the calculations associated with the proposed strategies for ventilation and critical equipment cooling (e.g., RCIC and Battery Rooms) are required SE Confirmatory Item # 15 is submitted for closure.

The effects of loss of HVAC in an extended loss of AC power event are being addressed for both equipment operability and habitability and have been incorporated into the ELAP strategies. The environmental conditions in the areas where the critical equipment exists, which is relied upon by the operators, and in the areas where operators will require access, have been evaluated via review of existing calculations and/or development of new calculations (by hand calculation or computer model). These areas include: Primary Containment, Secondary Containment, Control Building (Control Room and Battery Rooms), and RCIC Pump Rooms. Equipment operability and habitability are confirmed for all the concerned areas as described below.

1. Primary Containment A. Equipment operability A MAAP computer model (NMP2 Report N2-2014-004) has been developed to determine the primary containment environmental conditions following an extended loss of AC power. The peak pressure and temperature during the ELAP with containment venting are as follows:

Drywell: peak pressure: 45 psig and peak temperature: approximately 272 °F; Wetwell Pool: peak pressure: 45 psig and peak temperature:

approximately 280 °F.

The critical equipment that operators will rely on during an ELAP that is located in the primary containment are the RPV Safety Relief Valves. (SRV).

The SRVs are operated via pneumatics supplied via solenoid operated valves. The SRV solenoid valves are solenoid coils (Eugen Seitz Model Type 6A39) mounted on the Eugen Seitz Model 1133 control valve assembly on the Dikkers Main Steam SRVs. Environmental Qualification Document Package 2EQDP-SOV011 establishes environmental qualification of the Eugen Seitz, A. G. Model Type 6A39 Solenoid Coil in accordance with the

NMP EQ Program. The SRV solenoid coil qualifications contained in 2EQDP-SOV011 were compared to the results contained in MAAP Report N2-2014-004. The highest Containment temperature modeled by MAAP Report N2-2014-004 was approximately 272° F. SRV solenoid coil qualifications documented in Report 2EQDP-SOV011 indicate that the solenoid coils would Page 23 of 34

ENCLOSURE NMP2 SIXTH SIX MONTH STATUS REPORT (FEBRUARY 2016)

FOR MITIGATION STRATEGIES FOR BEYOND-DESIGN-BASIS EXTERNAL EVENTS operate at above 325° F for up to 2400 hrs (100 days) providing sufficient margin to the temperatures projected in the MAAP report.

There are no critical monitoring instruments required for the ELAP that are located in the primary containment.

2. Secondary Containment - Reactor Building There are three major sources of heat in the Reactor Building following event onset: 1) RCIC operation, 2) Spent Fuel Pool decay heat, 3) Hardened Containment Vent System operation. The Spent Fuel Pool decay heat affects the upper elevations of the Reactor Building while RCIC and HCVS heat influences lower elevations. Actions have been proceduralized to mitigate Reactor Building heatup as a result of the ELAP. Per SBO/ELAP Procedure N2-SOP-01, the RCIC Room door is blocked open within the first two hours to mitigate RCIC Room heatup. Reactor Building ventilation actions directed by N2-SOP-01 within the first eight hours, block open designated doors from outside at ground level to allow outside air flow through the Reactor Building to the roof to provide passive natural convective cooling. Both actions reduce challenges to equipment and improve environmental conditions for habitability from heat produced by the three sources. Supporting Calculation ES-289, Reactor Building Therrnal Response Following ELAP, is being revised to include the effects of Hardened Containment Vent System (HCVS) operation on Reactor Building heatup.

A. Equipment operability A Reactor Building heatup calculation using a GOTHIC model has been performed to evaluate the environmental conditions in the Reactor Building, including pressurization of the refueling floor following an ELAP event. The peak temperature at EL 328', where the reliable wide range SFP water level instrumentation in accordance with the requirements of NRC Order EA 051 is located, is determined to be 150 °F, which is below the 176 °F limiting temperature for the level sensing devices. The humidity is predicted to be 100%, which is also within the capability of level sensing device. The existing FLEX strategy (including opening the door to release air/steam mixture) has incorporated these environmental conditions.

A list of critical instruments located in the Reactor Building that are relied on during the ELAP has been reviewed and found acceptable under the ELAP environmental condition. These instruments are located in the Reactor Building on elevations 328', 261', 215', and 175'. With the exception of the wide range SFP water level instruments discussed above, all transmitters located in the Reactor Building are qualified to at least 203 °F for 25 days per Page 24 of 34

ENCLOSURE NMP2 SIXTH SIX MONTH STATUS REPORT (FEBRUARY 2016)

FOR MITIGATION STRATEGIES FOR BEYOND-DESIGN-BASIS EXTERNAL EVENTS the respective instrument Environmental Qualification Document Package in accordance with the NMP EQ Program. Suppression Pool instruments are qualified to 340 °F per Environmental Qualification Document Package.

Implementation of Reactor Building natural convection ventilation actions directed by N2-SOP-01 will limit Reactor Building temperatures below the refueling floor (elevation 353') to well below the qualification limits of the instruments.

B. Habitability The temperature at the refueling floor is predicted to be below 120 °F during the first 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months into the ELAP event. Access to the refueling floor to deploy FLEX equipment will be limited to the first 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months of the ELAP event due to the Spent Fuel heatup. Procedure N2-SOP-01 directs Spent Fuel Pool makeup and overspray hoses deployed within the seven hours following event onset as a backup measure to ensure makeup hoses are ready to support Spent Fuel Pool makeup prior to environmental conditions on the refueling floor precluding access.

3. Control Building A. Equipment operability Existing SBO Calculation ES-198 was reviewed and determined to bound the ELAP event. Therefore, the operability of the components in the Main Control Room and Computer and Relay Room are not impacted. When selected electrical loads in the Control Room are restored following the deployment of the FLEX Generator, one of the Control Room air conditioning fans (2HVC*ACU1A or 2HVC*ACU1 B) may be restored. Outside air (1500 CFM) will also be available through either the Division I or Division II Special Filter Train (2HVC*FN2A or 2HVC*FN2B) to provide air circulation and makeup air from outside. These fan loads are within the FLEX generator load capability.

B. Habitability Since the maximum temperature in the Main Control Room is 100 °F, per existing SBO Calculation ES-198, the Control Room habitability is not a concern. If necessary following the deployment of the FLEX Generator and re-energization of a 600 VAC loads, one of the Control Room air conditioning fans (2HVC*ACU1A or 2HVC*ACU1B) may be restored. Outside air (1500 CFM) will also be available through either the Division I or Division II Special Filter Train (2HVC*FN2A or 2HVC*FN2B) to provide air circulation and makeup air from outside. All of the fans described above are identified as Page 25 of 34

ENCLOSURE NMP2 SIXTH SIX MONTH STATUS REPORT (FEBRUARY 2016)

FOR MITIGATION STRATEGIES FOR BEYOND-DESIGN-BASIS EXTERNAL EVENTS supported equipment in Calculation EC-206, 600VAC FLEX Phase II Portable 450kW Diesel Generator Sizing Calculation, and are within the generator load capability.

4. Control Building Battery Rooms A. Equipment operability To prevent unacceptable hydrogen gas concentrations in the Battery Room during charging operations, power required to restore Battery Room exhaust fan 2HVC*FN4A or 2HVC*FN4B has been included in the FLEX Generator Sizing Calculation EC-206. Existing Calculation HVC-064 provides the basis for the Battery Room ventilation requirement for hydrogen removal.

With restoration of power to the Battery Room exhaust fan (2HVC*FN4A or 2HVC*FN4B) during the ELAP, the temperature in the Battery Rooms will be maintained below the 104 °F design limit since the general area temperature (corridor of Control Building) is expected to be less than summer design outdoor ambient temperature of 93 °F during the ELAP.

5. RCIC Pump Room A. Equipment Operability/Habitability An analysis for long term RCIC Pump Room temperatures (for equipment qualification and habitability) under ELAP conditions considering elevated Suppression Pool and Secondary Containment temperatures using GOTHIC computer code was performed to support the ELAP coping strategies (NMP2 Report 2015-01099, RCIC Survivability Review). The analysis includes the effects of blocking open the RCIC Room door within the first two hours to mitigate RCIC Room heatup. In addition, it evaluates the effect of Reactor Building ventilation actions within the first eight hours to block open designated doors from outside at ground level through the building to the Reactor Building roof in order to provide passive convective cooling to the Reactor Building.

The results indicate that the temperature in the RCIC pump room does not exceed its 10-hour qualified life temperature of 175 °F based on existing SBO Calculation ES-268. With anticipatory Primary Containment venting to control Suppression Pool water temperature rise, RCIC has been evaluated to support operation for up to 15 hours1.736111e-4 days 0.00417 hours 2.480159e-5 weeks 5.7075e-6 months with Suppression Pool temperature of less than 250°F.

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ENCLOSURE NMP2 SIXTH SIX MONTH STATUS REPORT (FEBRUARY 2016)

FOR MITIGATION STRATEGIES FOR BEYOND-DESIGN-BASIS EXTERNAL EVENTS The RCIC room will become uninhabitable at 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months without anticipatory venting and 11 hours1.273148e-4 days 0.00306 hours 1.818783e-5 weeks 4.1855e-6 months with anticipatory venting due to hot water on the floor.

Personnel access to the RCIC Room is possible for up to 9 hours1.041667e-4 days 0.0025 hours 1.488095e-5 weeks 3.4245e-6 months from RCIC start using personal protective equipment as room temperature approaches and subsequently exceeds 120°F.

ISE Confirmatory Item # 16: ISE Confirmatory Item 3.2.4.4.A - The potential restoration of a portion of the Emergency Lighting System when Division I 600 VAC Unit Substation 2EJS*US1 (or alternatively Division II 2EJS*US3) is repowered is currently under evaluation. NMP2 will provide a summary of the restoration of Emergency Lighting expected to be restored in a future update SE Confirmatory Item # 16 is submitted for closure.

The emergency lighting system provides adequate illumination in areas required for operating the safety-related equipment during emergency conditions. The emergency lighting system normally receives power from Division I, II and 111 600VAC emergency busses. Emergency busses feed Class 1E main lighting distribution panels. These lighting loads are shed to extend safety related battery conservation and reduce Control Room and Relay Room heat loading. Once the FLEX portable generators are deployed, portions of this lighting can be restored when 2EJS*US1 (Div I) or 2EJS*US3 (Div II) is repowered. The emergency lighting available that may be re-energized from the safety related 600VAC switchgear, 2EJS*US1 or 3 will supply a portion of the lighting in the Control Building El 306' (Control Room), El 288' (Relay Room), El 261' (Divisional Switchgear and Remote Shutdown Rooms) and the Divisional Diesel Rooms.

FLEX generator sizing calculation (EC-206) has the lighting panels supplied from switchgear 2EJS*US1 or 3 evaluated as loads to restore. Calculation EC-206, Attachments 11.1 and 11.2 for Div I loads or Div 2 loads respectively, lists electrical loads, both required and optional for FLEX Phase 2, and includes these lighting panels which power lighting in the areas described above. The sum of all the identified loads on Attachment 11.1 (or 11.2) was determined to be 489.6 kVA which is less than the 563 kVA continuous rating of the FLEX generator. The FLEX generator worst case loading scenario is a start of the largest motor with the most demanding locked rotor current while all other loads identified in Attachment 11.1 (or 11.2) are energized and in service.

The calculated instantaneous power required was determined to be 752.3 kVA which is within the FLEX generator maximum rating of 1749 kVA.

Therefore, restoration of lighting loads in the safety related areas is well within the capability of the FLEX generator and will be restored utilizing FLEX Procedure N2-DRP-FLEX-ELEC.

ISE Confirmatory Item # 19: ISE Confirmatory Item 3.2.4.8.A - The licensee stated that when the design review of the portable generator protection is completed, the Page 27 of 34

ENCLOSURE NMP2 SIXTH SIX MONTH STATUS REPORT (FEBRUARY 2016)

FOR MITIGATION STRATEGIES FOR BEYOND-DESIGN-BASIS EXTERNAL EVENTS specific details on the protection schemes to protect Class 1E equipment from faults from the portable FLEX equipment will be provided in a future update SE Confirmatory Item # 19 is submitted for closure.

The FLEX Generator(s) will be initially connected to a Dead Bus. Other sources of power to that bus will be verified to be unavailable, de-energized, and isolated. This will preclude the possibility that the other potential power sources will also attempt to repower the same equipment.

Design change ECP-13-1068 installs Bus Connection Devices (BCDs) in the unused Cubicle 5C located in each of the Emergency Load Centers 2EJS*US1 and 2EJS*US3.

They are seismically qualified to meet the emergency load centers' requirements such that they remain functional following a seismic event. The BCDs are normally racked out and will not be racked into the bus unless it has been verified that the bus is dead and isolated from its normal source of power by the FLEX implementing Procedure N2-DRP-FLEX-ELEC.

A combination of two (2) single conductor #4/0 AWG cables per phase and one (1) single conductor 500 MCM are required for making connection between the FLEX generator and either 2EJS*US1 or 2EJS*US3. A cable splitter is constructed with a single conductor 500 MCM cable joining two (2) parallel single conductor #4/0 cables.

Each #4/0 cable can carry up to 362.3 Amps in free air at 40°C ambient for a total of 724.6 Amps, which is greater than the available DG output current of 541.8 Amps. The 500 MCM cable adjusted ampacity of 626.1 Amps is also greater than the DG output current. The potential short circuit current from the portable DG is 5,472.7 Amps. Per industry standard (ICEA P-32-382-2007), #4/0 cable can withstand a short circuit current of 30,000 Amps for approximately 16 cycles and 500 MCM cable can withstand the short circuit current for approximately 100 cycles. This duration is longer than the typical 1-2 cycles needed for breakers to actuate. The BCDs and the existing ITE/Gould K-600 series breakers at 600VAC load centers 2EJS*US1 and 2EJS*US3 are rated for a minimum of 22,000 amps and are adequate to withstand the available short circuit rating of the FLEX DG.

The 450kW DG output circuit breaker is an electronic trip molded case circuit breaker rated at 18,000 Amps at 600V AC. The circuit breaker long time pickup setting will be limited to approximately 540 amps. This long time pickup setting will provide sufficient overload protection to the cable splitters and BCD downstream of the portable DG. The setting of "3X" will fix the instantaneous trip of the portable DG at approximately 1,800 amps, sufficient to isolate the 450 kW portable DG to protect its loads against the available short circuit.

The total amperage of the required and optional loads to be powered by the portable DG is approximately 471.2 amps. The worst case loading scenario is determined to be starting the motor with the most demanding locked rotor current while all other identified Page 28 of 34

ENCLOSURE NMP2 SIXTH SIX MONTH STATUS REPORT (FEBRUARY 2016)

FOR MITIGATION STRATEGIES FOR BEYOND-DESIGN-BASIS EXTERNAL EVENTS loads have been energized and operating. Per FLEX generator sizing calculation EC-206, the total FLEX DG load at the start of the largest load is 752.34 kV A, well within the DG alternator's maximum motor starting rating of 1, 7 49 kVA. The loads connected to the Division II load center 2EJS*US3 have redundant loads with the same loading demand as 2EJS*US1. Therefore, the loading analysis performed on Division I bounds both Divisions I and II and was used for the NMP2 FLEX Phase 2 electrical strategies.

Following the connection and start-up of the FLEX DG, manual restoration of loads on the affected bus will be administratively controlled per Procedure N2-DRP-FLEX-ELEC.

The protective schemes for the control circuits for the individual loads that may be re-energized remain unaffected when the FLEX DG is aligned with the associated unit substation.

Based on the above, the design and applicable procedures are sufficient to protect the Class 1E equipment from faults in the portable FLEX Generator, and ensure that multiple sources do not attempt to power the unit substations during FLEX deployment.

Page 29 of 34

ENCLOSURE NMP2 SIXTH SIX MONTH STATUS REPORT (FEBRUARY 2016)

FOR MITIGATION STRATEGIES FOR BEYOND-DESIGN-BASIS EXTERNAL EVENTS Table 3 Status of NMP2 Interim Staff Evaluation (ISE) Open and Confirmatory Items ISE Open Items Status

1. ISE Open Item 3.1.1.3.A - Seismic procedural interface consideration NEI 12-06, Section 5.3.3, Consideration 1, which considers the possible Submitted failure of seismically qualified electrical equipment by beyond-design- for Closure basis seismic events, was not discussed in the Integrated Plan or (2/2016) during the audit process.

2. ISE Open Item 3.2.3.B - The licensee has not performed finalized Submitted calculations to demonstrate that the assumed timeline is appropriate for Closure and that containment functions will be restored and maintained (2/2016) following an ELAP event.

3. ISE Open Item 3.2.3.C- Revision 3 to the [Boiling Water Reactor Owner's Group] BWROG Emergency Procedure Guidance (EPG)

Severe Accident Guidance (SAG) is a Generic Concern because the Submitted BWROG has not addressed the potential for the revised venting for Closure strategy to increase the likelihood of detrimental effects on containment (2/2015) response for events in which the venting strategy is invoked (identified as a 'Significant Concern' in the Notes for this Open Item in the ISE).

ISE Confirmatory Items Status

4. ISE Confirmatory Item 3.1.1.1.A - The design of the storage facility for FLEX equipment is under development. The method selected for Submitted protection of equipment during a Beyond-Design-Basis External Event for Closure (BDBEE) was not discussed in the Integrated Plan or during the audit (8/2015) process. Also, there was no discussion of securing large portable equipment for protection during a seismic hazard.

5. ISE Confirmatory Item 3.1.1.2.A - Deployment routes have not yet been finalized or reviewed for possible impacts due to debris and potential soil liquefaction. Movement of equipment and procedural Submitted interfaces during a BDBEE were not discussed in the Integrated Plan or for Closure during the audit process. Deployment of temporary flood barriers, (2/2015) restocking of supplies in the context of a flood with long persistence and the potential impact of surface icing were also not addressed.

6. ISE Confirmatory Item 3.1.1.4.A - Concerning utilization of offsite Submitted resources during a BDBEE, the local staging area and access routes for Closure were not discussed in the Integrated Plan or during the audit process. (2/2015)

7. ISE Confirmatory Item 3.2.1.1.A - MAAP benchmarks must be Submitted identified and discussed which demonstrate that MAAP4 is an for Closure appropriate code for the simulation of an ELAP event. (8/2015)

Page 30 of 34

ENCLOSURE NMP2 SIXTH SIX MONTH STATUS REPORT (FEBRUARY 2016)

FOR MITIGATION STRATEGIES FOR BEYOND-DESIGN-BASIS EXTERNAL EVENTS Table 3 Status of NMP2 Interim Staff Evaluation (ISE) Open and Confirmatory Items (cont'd)

ISE Confirmatory Items Status

8. ISE Confirmatory Item 3.2.1.1.B - MAAP Analysis collapsed level Submitted for must remain above Top of Active Fuel (TAF) and the cool down rate Closure must be within technical specification limits. (8/2015)

9. ISE Confirmatory Item 3.2.1.1.C - MAAP4 must be used in Submitted for accordance with Sections 4.1, 4.2, 4.3, 4.4 and 4. 5 of the June 2013 Closure position paper. (8/2015)

10. ISE Confirmatory Item 3.2.1.1.D - MAAP modeling parameters. Submitted for Closure (8/2015)

11. ISE Confirmatory Item 3.2.1.1.E - The specific MAAP4 analysis Submitted for case that was used to validate the timing of mitigating strategies in Closure the Integrated Plan must be identified and should be available for (8/2015) review.

12. ISE Confirmatory Item 3.2.1.2.A - There was no discussion of the applicability of the assumed recirculation system leakage rates and the recirculation pump seal leakage rates to the ELAP event; the Submitted for pressure dependence of the leak rates; whether the leakage was Closure determined to be single-phase, two-phase, or steam at the donor (2/2016) cell; and how mixing of the leakage flow with the drywell atmosphere was modeled.

13. ISE Confirmatory Item 3.2.2.A - Evaluation of the refueling floor Submitted for SFP area for steam and condensation was not yet completed.

Closure Mitigating strategies were not discussed in the Integrated Plan or (8/2015) during the audit process.

14. ISE Confirmatory Item 3.2.3.A- Perform an evaluation of Submitted for containment structures to identify necessary actions to enable Closure implementation of the strategy with running RCIC with elevated (2/2016) temperatures.

15. ISE Confirmatory Item 3.2.4.2.A - The completion and Submitted for determination of acceptable results for all of the calculations Closure associated with the proposed strategies for ventilation and critical (2/2016) equipment cooling (e.g., RCIC and Battery Rooms) are required.

Page 31of34

ENCLOSURE NMP2 SIXTH SIX MONTH STATUS REPORT (FEBRUARY 2016)

FOR MITIGATION STRATEGIES FOR BEYOND-DESIGN-BASIS EXTERNAL EVENTS Table 3 Status of NMP2 Interim Staff Evaluation (ISE) Open and Confirmatory Items (cont'd)

ISE Confirmatory Items Status

16. ISE Confirmatory Item 3.2.4.4.A- The potential restoration of a portion of the Emergency Lighting System when Division I 600 VAC Unit Substation 2EJS*US1 (or alternatively Division II Submitted for 2EJS*US3) is repowered is currently under evaluation. NMP2 will Closure (2/2016) provide a summary of the restoration of Emergency Lighting expected to be restored in a future update.

17. ISE Confirmatory Item 3.2.4.4.B - Follow-up of communication commitments as discussed in the staff analysis (ML 131 OOA236) Started (2/2015) is required.

18. ISE Confirmatory Item 3.2.4.6.A - Licensee to provide Submitted for calculation and basis for use of extrapolated station blackout Closure (2/2015)

(SBO) evaluation for Main Control Room habitability.

19. ISE Confirmatory Item 3.2.4.8.A - The licensee stated that when the design review of the portable generator protection is Submitted for completed, the specific details on the protection schemes to Closure (2/2016) protect Class 1E equipment from faults from the portable FLEX equipment will be provided in a future update.

20. ISE Confirmatory Item 3.2.4.8.B - The licensee will provide an Submitted for updated summary of the sizing calculations for the FLEX Closure (2/2015) generators at a future update.

21. ISE Confirmatory Item 3.2.4.9.A - The licensee stated that a Submitted for summary of the refueling strategies for FLEX equipment will be Closure (2/2015) provided when finalized at a future date.

22. ISE Confirmatory Item 3.2.4.1 O.A - The licensee stated that a finalized summary of battery coping time, DC load profile, Submitted for discussion of loads shed, and minimum DC voltage will be Closure (2/2015) provided in a future update.

23. ISE Confirmatory Item 3.4.A - The program or process to Submitted for request RRC equipment was not discussed in the Integrated Plan Closure (2/2015) or during the audit process.

24. ISE Confirmatory Item 3.4.B - Sizing calculations of RRC FLEX equipment and the compatibility of RRC equipment to plant Submitted for connection points was not discussed in the Integrated Plan or Closure (2/2015) during the audit process.

Page 32 of 34

ENCLOSURE NMP2 SIXTH SIX MONTH STATUS REPORT (FEBRUARY 2016)

FOR MITIGATION STRATEGIES FOR BEYOND-DESIGN-BASIS EXTERNAL EVENTS 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 01 P described in this enclosure.

1. Letter from M. G. Korsnick (CENG) to Document Control Desk (NRC), Overall Integrated Plan for Mitigation Strategies for Beyond-Design-Basis External Events, 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. Letter from M. G. Korsnick (CENG) to Document Control Desk (NRC), Supplement to Overall Integrated Plan for Mitigation Strategies for Beyond-Design-Basis External Events, dated March 8, 2013

4. Letter from M. G. Korsnick (CENG) to Document Control Desk (NRC), Response to NRC Letter on Technical Issues for Resolution Regarding Communication Submittals Associated with Near-Term Task Force Recommendation 9.3, dated February 22, 2013

5. NEI 12-06, Diverse and Flexible Coping Strategies (FLEX) Implementation Guide, dated August 2012

6. Letter from E. D. Dean (CENG) to Document Control Desk (NRC), 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 27, 2013

7. Letter from J. S. Bowen (NRC) to J. A. Spina, Nine Mile Point Nuclear Station, Units 1 and 2 - Interim Staff Evaluation Relating to Overall Integrated Plans in Response to Order EA-12-049 (Mitigation Strategies) (TAC Nos. MF1129 and MF1130), dated December 19, 2013

8. Letter from M. G. Korsnick (CENG) to Document Control Desk (NRC), 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, 2014

9. NEI Position Paper Shutdown and Refueling: ADAMS Accession No. ML13273A514

10. NRC Endorsement of NEI Shutdown and Refueling Paper: ADAMS Accession No. ML13267A382

11. Letter from M. G. Korsnick (CENG) to Document Control Desk (NRC), August 2014 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, 2014

12. Letter from M. G. Korsnick (CENG) to Document Control Desk (NRC), Response to March 12, 2012, Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) Regarding Recommendations of the Near-Term Task Force Review Page 33 of 34

ENCLOSURE NMP2 SIXTH SIX MONTH STATUS REPORT (FEBRUARY 2016)

FOR MITIGATION STRATEGIES FOR BEYOND-DESIGN-BASIS EXTERNAL EVENTS of Insights from the Fukushima Dai-ichi Accident, Enclosure 5, Recommendation 9.3, Emergency Preparedness - Staffing, Requested Information Items 1, 2 and 6 - Phase 2 Staffing Assessment

13. Letter from M. G. Korsnick (CENG) to Document Control Desk (NRC), February 2015 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 19, 2015

14. Letter from J. Barstow (Exelon) to Document Control Desk (NRC), August 2015 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 Page 34 of 34

v t e Letter Sequence Other
TAC:MF1129, (Approved, Closed) TAC:MF1130, (Approved, Closed) TAC:MF1131, (Approved, Closed) TAC:MF1132, (Approved, Closed)
Initiation Request Acceptance, Acceptance, Acceptance Supplement Administration Questions 5 June 2013 Answers 5 July 2013 Results Approval Other: L-14-028, August 2014 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 EA-12-049), L-14-031, August 2014 Six-Month Status Report in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation (Order Number EA-12-051), ML13254A279, ML13338A663, ML13338A664, ML14069A180, ML15289A526, RS-15-057, February 2015 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), RS-15-058, February 2015 Six-Month Status Report in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation (Order Number EA-12-051), RS-15-117, 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), RS-15-207, Fifth Six-Month Status Report in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation (Order Number EA-12-051), RS-16-029, 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), RS-16-032, Sixth Six-Month Status Report in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation (Order Number EA-12-051)
MONTHYEAR2014-02-18 [Table View]

RS-16-029, 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)

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Enclosure:

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