ML14069A013

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)

ML14069A013
Person / Time
Site:	Millstone
Issue date:	02/28/2014
From:	Mark D. Sartain Dominion, Dominion Nuclear Connecticut
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
EA-12-049
Download: ML14069A013 (54)

Text

7A Dominion Nuclear Connecticut, Inc. .

5000 Dominion Boulevard, Glen Allen, VA 23060 -'J hoEmlnlOW Web Address: www.dom.com February 28, 2014 10 CFR 2.202 EA-12-049 Attention: Document Control Desk Serial No.: 12-161E U.S. Nuclear Regulatory Commission NL&OS/MAE: R1 Washington, D.C. 20555-0001 Docket Nos.: 50-336 License Nos.: DPR-65 DOMINION NUCLEAR CONNECTICUT. INC.

MILLSTONE POWER STATION UNIT 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)

References:

1. 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

2. Dominion Nuclear Connecticut, Inc.'s 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 (Serial No. 12-161B)

3. Dominion Nuclear Connecticut, Inc's 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 23, 2013 (Serial No. 12-161D)

4. NRC letter, "Nuclear Regulatory Audits of Licensee Responses to Mitigating Strategies Order EA-12-049," dated August 28, 2013 (ADAMS Accession No. ML13234A503)

On March 12, 2012, the Nuclear Regulatory Commission (NRC) issued an order (Reference 1) to Dominion Nuclear Connecticut (DNC). Reference 1 was immediately effective and directed DNC to develop, implement, and maintain guidance and strategies to maintain core cooling, containment, and spent fuel pool cooling capabilities in the event of a beyond-design-basis external event.

Reference 1 required submission of an Overall Integrated Plan (OIP) (Reference 2) pursuant to Section IV, Condition C. Reference 1 also required submission of a status report at six-month intervals following submittal of the OIP. of this letter provides the second six-month status report and an update of milestone accomplishments since the submittal of the first six-month status report

Serial No. 12-161E Docket Nos. 50-336 Order EA-12-049 Page 2 of 3 (Reference 3), including any changes to the compliance method, schedule, or need for relief and the basis. provides the Phase 3 containment strategy, identified as Open Item 14 for the OIP. This information is provided in the template format used for the originally submitted OIP. The pages provided in Attachment 2 for Section D, "Maintain Containment" supersede Section D in the originally submitted OIP. formally documents responses provided to several Audit Questions received for Millstone Power Station Unit 2 during the Audit of Licensee Responses to Mitigating Strategies Order EA-1 2-049 (Reference 4).

If you have any questions, please contact Ms. Margaret Earle at (804) 273-2768.

Sincerely, Mark D. Sartain Vice President - Nuclear Engineering Dominion Nuclear Connecticut, Inc.

Attachments (3)

Commitments made by this letter: No new Regulatory Commitments COMMONWEALTH OF VIRGINIA

)

COUNTY OF HENRICO The foregoing document was acknowledged before me, in and for the County and Commonwealth aforesaid, today by Mark D. Sartain who is Vice President Nuclear Engineering of Dominion Nuclear Connecticut, Inc. He has affirmed before me that he is duly authorized to execute and file the foregoing document in behalf of the Company, and that the statements in the document are true to the best of his knowledge and belief.

Acknowledged before me this 4bay of '2014.

My Commission Expires: 5-31-/i. 6 VICK! L. HULL Notary Public Notary Public Commonwealth of Virginia (SEAL) ( 140542 My Cnmmissinn FEnirae Mnu 41 9M11A

Serial No. 12-161E Docket Nos. 50-336 Order EA-12-049 Page 3 of 3 cc: Director of Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission One White Flint North Mail Stop 13H16M 11555 Rockville Pike Rockville, MD 20852-2738 U. S. Nuclear Regulatory Commission, Region I Regional Administrator 2100 Renaissance Blvd.

Suite 100 King of Prussia, PA 19406-2713 Mr. M. C. Thadani NRC Project Manager Millstone Units 2 and 3 U. S. Nuclear Regulatory Commission One White Flint North Mail Stop 08 B-1 11555 Rockville Pike Rockville, MD 20852-2738 Ms. J. A. Kratchman U. S. Nuclear Regulatory Commission One White Flint North Mail Stop 09 D2 11555 Rockville Pike Rockville, MD 20852-2738 NRC Senior Resident Inspector Millstone Power Station

Serial No.12-161 E Docket No. 50-336 Order EA-1 2-049 Attachment 1 Six-Month Status Report for the Implementation of Order EA-1 2-049, Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events Millstone Power Station Unit 2 Dominion Nuclear Connecticut, Inc. (DNC)

Serial No. 12-161E Docket No. 50-336 Order EA-12-049 Attachment 1 Page 1 of 30 Six-Month Status Report for the Implementation of Order EA-12-049, Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events 1 Introduction Dominion Nuclear Connecticut (DNC) developed an Overall Integrated Plan (OIP) (Reference 1), documenting the diverse and flexible strategies (FLEX) for Millstone Power Station Unit 2 (MPS2), in response to NRC Order Number EA-12-049 (Reference 2). This attachment provides an update of milestone accomplishments and open items since the last status report (Reference 14), including any changes to the compliance method, schedule, or need for relief/relaxation and the basis, if any.

2 Milestone Accomplishments The following milestones have been completed since the development of the OIP, and are current as of January 31, 2014.

• Submit Integrated Plan 3 Milestone Schedule Status The following table provides an update to Attachment 2A of the OIP. It provides the activity status of each item as of January 31, 2014, and whether the expected completion date has changed. The dates are planning dates subject to change as design and implementation details are developed.

The revised milestone target completion dates for 'Develop Strategies,' 'Develop Modifications' and 'Develop Strategies/Contract with the RRC' do not impact the Order implementation date.

Target Activity Revised Target Milestone Completion Status Completion Date Date Submit Integrated Plan February 2013 Complete Develop Strategies December 2013 Started April 2014

• Develop Modifications February 2014 Started July 2014

• Implement Modifications August 2014 Started Develop Training Plan April 2014 Started Implement Training August 2014 Started Issue FSGs and Associated September Started Procedure Revisions 2014 Develop Strategies/Contract with April 2014 Started August 2014

• RRC I I

Serial No. 12-161E Docket No. 50-336 Order EA-12-049 Attachment 1 Page 2 of 30 Target Activity Revised Target Milestone Completion Status Completion Date Date Purchase Equipment February 2014 Started Receive Equipment August 2014 Started Validation Walk-throughs or Demonstrations of FLEX Strategies December 2014 Not Started and Procedures Create Maintenance Procedures August 2014 Not Started Outage Implementation October 2015 Not Started

• Refer to Section 8, Supplemental Information, for an explanation of the change to this Milestone.

4 Changes to Compliance Method By letter dated February 28, 2013, Serial No.12-161 B, DNC provided an OIP to address Beyond-Design-Basis (BDB) events at MPS2 and MPS3 as required by Order Number EA 049, dated March 12, 2012. The first Six-Month Status Update of the OIP for MPS2 and Millstone Power Station Unit 3 (MPS3) was provided by letter dated August 23, 2013. The following are changes to the compliance method information provided in the MPS2 OIP; which continue to meet NEI 12-06 (Reference 3):

a) Details of the deployment locations and connections have changed for the portable 120/240VAC and the 480VAC diesel generators (DGs) used to re-power the vital bus circuits as described below. However, the electrical re-powering strategy, as described in Section F1.2 - PWR Portable Equipment Phase 2 of the OIP, as modified in the August 2013 Six-Month Status Update, have not changed.

The deployment location of the single 120/240VAC DG shown in OIP Figure 6 has not changed. However, the cable routing and location of the connection receptacles has been revised. The attached revised OIP Figure 7 shows the updated configuration with the cable being routed through the "A" and "B" DC Switchgear rooms and connected to local receptacle boxes near the VA20 and VA40 Distribution Panels.

The deployment location of the 480VAC DG has changed. The attached revised OIP Figure 6 shows the new location in the courtyard east of the MPS2 DC Switchgear rooms.

The attached revised OIP Figure 8 shows that the cable is now routed through the Millstone Power Station Unit 1 Cable Vault to a receptacle box permanently connected to Bus 22F.

b) Details of the deployment locations and connections have changed for the portable 4160VAC Diesel Generators (DGs) used to re-power the vital bus circuits as described below. However, the electrical re-powering strategy, as described in Section F1.3 - PWR Portable Equipment Phase 3 of the original OIP, has not changed for MPS2.

Serial No. 12-161E Docket No. 50-336 Order EA-12-049 Attachment 1 Page 3 of 30 The deployment location and cable routing for the 4160VAC DG have changed and now reflect a simpler tie-in into the 4160 Vital Bus 24D. This new configuration eliminated the need to tie into the non-vital 24A bus as previously presented. (This simplification is reflected in the revised response to Audit Question No. 42 in Attachment 3 to this letter.)

The new tie-in is to a panel in the Emergency Diesel Generator (EDG) room. The leads from an existing (and non-operational) "B" EDG connection to Panel C39 will be lifted and the cables from the BDB 4160VAC DG will be connected in their place. The attached revised Figures 6 and 9 reflect the new deployment and cable tie-in locations.

c) The location and type of alternate connection for the BDB Auxiliary Feedwater (AFW) pump has changed. The discharge connection will no longer use the steam generator feedwater regulating bypass valves. Instead, the discharge connection will utilize a 2" flanged connection on the Steam Generator (SG) pump down skid. The connection is not seismically designed, but is at a location in the lower level of the Auxiliary Building which is a seismic, flood, and missile protected structure. The attached revised OIP Figure 3 shows this new AFW connection.

d) In response to OIP Open Item No. 10, a strategy has been developed for use of the BDB AFW Pump to provide SG injection in the unlikely event of loss of the TDAFW pump due to hurricane related storm surge flooding of the Turbine Building. Procedure AOP 2560, Storms, High Winds and High Tides, will be revised to pre-deploy one BDB AFW pump in theMPS2 Turbine Building Truck Bay as part of storm preparations. In the event of failure of the TDAFW pump, located in the lower levels of the Turbine Building (Elevation 4 feet 8 inches), the early-deployed BDB AFW Pump will be available without waiting for flood waters to recede in order to obtain a portable pump from the BDB Storage Building. SG level will be controlled using the Auxiliary Feedwater Regulating Valves or the Auxiliary Feedwater Bypass valves. The diesel driven BDB AFW pump exhaust will be directed outdoors.

AOP 2560 provides procedure guidance to shutdown the unit prior to severe hurricane conditions on site. Guidelines will be provided for operations to start the BDB AFW Pump and initiate flow following failure of the TDAFW pump. The BDB AFW pump takes suction from the Condensate Storage Tank (CST) through a connection which is located inside the Turbine Building Truck Bay. With a pre-emptive shutdown occurring 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> before an Extended Loss of AC Power (ELAP) event, the CST will supply the SGs for approximately 13.4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> beyond the loss of power. This is adequate time for the worst case storm surge to recede.

e) The calculation to determine the battery life of the Class 1E battery banks for MPS2 has been revised. The resulting re-calculation supports the extension of the Class 1 E battery duty cycle to 29 hours3.356481e-4 days <br />0.00806 hours <br />4.794974e-5 weeks <br />1.10345e-5 months <br /> based on the implementation of load stripping within 45 minutes of the onset of an ELAP event and completion of the load stripping action within 75 minutes of the onset of the ELAP event.

Serial No. 12-161E Docket No. 50-336 Order EA-12-049 Attachment 1 Page 4 of 30 DNC confirms that the Class 1 E battery duty cycle MPS2 was calculated in accordance with the IEEE-485 methodology using manufacturer discharge test data applicable to the licensee's FLEX strategy as outlined in the NEI white paper on Extended Battery Duty Cycles. The detailed licensee calculations, supporting vendor discharge test data, FLEX strategy battery load profile, and other inputs/initial conditions required by IEEE-485 are available on DNC's web portal for documents and calculations. The time margin between the calculated battery depletion for the FLEX strategy and the expected deployment time for FLEX equipment to supply the DC loads is approximately 17 hours1.967593e-4 days <br />0.00472 hours <br />2.810847e-5 weeks <br />6.4685e-6 months <br /> for Millstone Unit 2.

f) The BDB and Regional Response Center (RRC) equipment details in OIP Table 1, PWR Portable Equipment Phase 2, and OIP Table 2, PWR Portable Equipment Phase 3, respectively, have changed. Updates to the 'List Portable Equipment', 'Performance Criteria,' and usage categories are included as well as associated changes/deletions in footnotes. Minor changes to the number of components have been included for some of the support equipment categories, but no changes are made to the quantities of any of the major FLEX components. Revised OIP Tables 1 and 2 are attached.

g) The strategy has been revised regarding the flowpath for supplying water to the SGs following depletion of the contents of the CST. The CST has been removed from the flowpath once it is depleted. Attached is the revised OIP Figure 2 showing the updated connection strategy and flowpaths.

h) The OIP submitted on February 28, 2013 contained an open item for the development of the coping strategy to maintain Containment integrity following an ELAP event, if required.

OIP Section A.4 (Action Item 17) and Attachment 1A, Sequence of Events, Item 17, discussed the timeframe for which action was required to address Containment temperature and pressure. Conservative analysis has concluded that Containment temperature and pressure response will remain below design limits following an ELAP event and that key parameter instrumentation subject to the Containment environment will remain functional for at least seven days (Reference 10).

The strategy for coping with Containment temperature and pressure increases has been developed. By maintaining these parameters below their design limits, Containment structural integrity is ensured. To remain within analyzed limits for equipment qualification temperature, the Containment temperature will be procedurally monitored and, if necessary, the temperature will be reduced. This will require the implementation of the Phase 3 Containment cooling strategy such that heat removal from Containment is initiated in a timely manner.

The Phase 3 Containment coping strategy was not provided in the initial submittal of the 0IP. It is provided in Attachment 2 of this submittal. The Containment coping strategy is provided in the original OIP template format as Section D and is intended to supersede the previous Section D in its entirety. Attachment 2 also contains 2 new OIP figures (Figures 10 and 11) in support of the Section D Containment strategy.

Serial No. 12-161E Docket No. 50-336 Order EA-12-049 Attachment 1 Page 5 of 30 i) In response to the NRC staff concern that sufficient time and core flow conditions are available for adequate boron mixing, the , Pressurized Water Reactor Owners Group (PWROG), in conjunction with Westinghouse, developed a boron mixing position paper.

This position paper has been endorsed by the NRC with clarifications as stated in a letter from Jack Davis, Director Mitigating Strategies, USNRC to Jack Stringfellow, PWROG, Endorsing PWROG Position Paper, January 8, 2014. The MPS2 ELAP analyses verify that the conditions set forth in the NRC's endorsement of the boron mixing position paper with clarifications are met. Accordingly, the endorsed boron mixing methodology has been applied to the final FLEX RCS inventory and reactivity management strategies.

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

6 Open Items 6.1. Open Items from Overall Integrated Plan The following table provides a summary of the status of open items documented in Attachment 2B of the MPS2 Overall Integrated Plan submitted on February 28, 2013 and the status of each item.

Overall Integrated Plan Open Item 01 # Description Status Verify response times listed in timeline and perform staffing Not started assessment.

1 aScheduled completion date: December, 2014 Preliminary analyses have been performed to determine the time Complete.

to steam generator (SG) overfill without operator action to reduce 2 Auxiliary Feedwater (AFW) flow, time to SG dryout without AFW (Provided in Reference flow, and time to depletion of the Condensate Storage Tank 4)

(CST). Final durations will be provided when the analyses are completed.

Analyses will be performed to develop fluid components Started.

performance requirements and confirm fluid hydraulic-related strategy objectives can be met. Phase 2: The hydraulic calculation for the FLEX pumps deployed using their associated hose 3 networks have confirmed that the primary connections for core cooling/decay heat removal, RCS Inventory, and Reactivity Control (RCS Injection), and

Serial No. 12-161E Docket No. 50-336 Order EA-12-049 Attachment 1 Page 6 of 30 Overall Integrated Plan Open Item I 01 # I Description I Status Spent Fuel Pool (SFP)

Make-up strategies can be satisfactorily accomplished in response to an ELAP/Loss of Ultimate Heat Sink (LUHS) event.

(Reference 8)

The hydraulic calculations for the Phase 2 FLEX strategies for core cooling/decay heat removal, Reactor Coolant System RCS)

Inventory, and Reactivity Control (RCS Injection),

and SFP Make-up using the alternate connections will be fully completed by June 2014.

Phase 3: Thermal and hydraulic calculations confirming that the Containment strategies are adequate will be completed by June 2014.

Scheduled completion date is revised from September, 2013 to June, 2014 **

A study is in progress to determine the design features, site Complete.

location(s), and number of equipment storage facilities. The final design for BDB equipment storage will be based on the guidance A single 10,000 sq. ft.

contained in NEI 12-06, Section 11.3, Equipment Storage. A Type 1 building will be supplement to this submittal will be provided with the results of the constructed at Millstone 4 equipment storage study. Power Station for storage of BDB equipment. The building will be designed to meet the plant's design basis for the Safe Shutdown

Serial No. 12-161E Docket No. 50-336 Order EA-12-049 Attachment 1 Page 7 of 30 Overall Intearated Plan ODen Item I #I Description I Status Earthquake, high wind hazards, snow, ice and cold conditions, and located above the flood elevation from the most recent site flood analysis.

The BDB Storage Building will be sited south of the railroad bridge, on the west side of the MPS access road, adjacent to the existing northeast contractor Darkina lot. **

FLEX Support Guidelines (FSGs) will be developed in accordance Started.

with PWROG guidance. Existing procedures will be revised as necessary to implement FSGs. Scheduled completion date: September 2014 Electric Power Research Institute (EPRI) guidance documents will Not started.

be used to develop periodic testing and preventative maintenance 6 procedures for BDB equipment. Procedures will be developed to Scheduled completion manage unavailability of equipment such that risk to mitigating date: December 2014 strategy capability is minimized.

An overall program document will be developed to maintain the Started.

FLEX strategies and their bases, and provide configuration control and change management for the FLEX Program. Scheduled completion date: December 2014 The DNC Nuclear Training Program will be revised to assure Started.

personnel proficiency in the mitigation of BDB events is developed 8 and maintained. These programs and controls will be developed Scheduled completion and implemented in accordance with the Systematic Approach to date: December 2014 Training (SAT).

Complete.

The Combustion Engineering (CE)

Owners Group has Confirm consistency of the FLEX strategies with the PWROG issued generic 9 evaluation of post-loss of all AC power plant response for guidelines to address Combustion Engineering plants. plant response for post-loss of all AC power for Combustion Engineering plants. Based on these guidelines, DNC will develop plant specific

Serial No. 12-161E Docket No. 50-336 Order EA-12-049 Attachment 1 Page 8 of 30 Overall Integrated Plan Open Item 01 # Description Status FSGs for MPS2 to address plant response for post-loss of all AC power. Specifically, depressurization of SGs to a plant specific value of either a target SG pressure to prevent Safety Injection Tank (SIT) nitrogen injection OR a minimum steam pressure to support continuous operation of the turbine driven (TD)

AFW pump will be specified.

(Reference 7)

Develop strategy for use of the BDB AFW Pump to provide SG Complete.

injection in the unlikely event of loss of TDAFW pump due to hurricane related storm surge flooding of the Turbine Building. In accordance with storm preparation procedures, one BDB AFW pump will be early 10 deployed in the MPS2 Turbine Building Truck Bay.

See additional discussion in Section 4, Item d.

Plant modifications will be completed for permanent plant changes Started.

required for implementation of FLEX strategies.

11 Scheduled completion date: See Milestone Schedule above.

Started.

Complete the engineering evaluation of the main steam 12 atmospheric dump valve (MS ADV) outlet lines. ** Scheduled completion date is revised from December 2013 to July 2014 **

Complete.

13 Complete the evaluation of TDAFW pump long term operation with

< 120 psig inlet steam pressure. TDAFW pump operation I____and adequate AFW flow

Serial No. 12-161E Docket No. 50-336 Order EA-12-049 Attachment 1 Page 9 of 30 Overall Intecqrated Plan Open Item 01 # Description Status to the SGs at SG pressures < 120 psig has been confirmed.

(References 5 and 6)

The Phase 3 coping strategy to maintain Containment integrity is Complete.

under development. Methods to monitor and evaluate Containment conditions and depressurize/cool Containment, if See Attachment 2, OIP necessary, will be provided in a future update. Section D.

14 See Open Item 3 for confirmation of the effectiveness of Phase 3 Containment strategies.

Analyses will be performed to develop electrical components Started.

performance requirements and confirm electrical loading-related strategy objectives can be met. Phase 2: Calculations have been completed for the sizing and loading analysis of the 120VAC and 480VAC generators and confirm the electrical loading-related strategy objectives can be met (Reference 11).

Phase 3: Calculations 15 identifying the Phase 3 4160VAC generator load requirements and power cable ampacity rating along with breaker coordination between the RRC equipment and DNC equipment will be completed by June 2014.

Scheduled completion date is revised from December 2013 to June 2014 **

Started.

16 An evaluation of all BDB equipment fuel consumption and required re-fill strategies will be developed. Scheduled completion date: June 2014 17 A lighting study will be performed to validate the adequacy of Started.

Serial No. 12-161E Docket No. 50-336 Order EA-1 2-049 Attachment 1 Page 10 of 30 Overall Intecirated Plan Open Item 01 # Description Status supplemental lighting and the adequacy and practicality of using portable lighting to perform FLEX strategy actions. Scheduled completion date: June 2014 A comprehensive study of communication capabilities is being Complete.

performed in accordance with the commitments made in DNC letter S/N 12-205F dated October 29, 2012 in response to A study documenting Recommendation 9.3 of the 10 CFR 50.54(f) letter dated March the communications 12, 2012. The results of this study will identify the communication strategy has been means available or needed to implement command and control of completed. The study the FLEX strategies at Millstone. Validation of communications concludes that effective required to implement FLEX strategies will be performed as part of implementation of the Open Item No. 1. FLEX strategies will include the use of satellite phones and hand-held radios. The study acknowledges that MPS2 does not have a 18 sound-powered phone system or equivalent and that radio usage is limited (Reference 9).

Accordingly, the tabletop assessment of the FLEX strategies performed as part of the Phase 2 Staffing study has identified that the coordination of command and control of the FLEX strategies will require the use of dispatched personnel.

Details of the ventilation strategy are under development and will Started.

conform to the guidance given in NEI 12-06. The details of this 19 strategy will be provided at a later date. Scheduled completion date is revised from October, 2013 to April 2014 **

Preferred travel pathways will be determined using the guidance Started.

contained in NEI 12-06. The pathways will attempt to avoid areas with trees, power lines, and other potential obstructions and will The soil liquefaction consider the potential for soil liquefaction, study has been 20 completed (Reference 12), which supports the location of the storage building and the haul routes. The results will

Serial No. 12-161E Docket No. 50-336 Order EA-12-049 Attachment 1 Page 11 of 30 Overall Integrated Plan Open Item 01 # Description Status be included with the final design package for the storage building (Reference 13).

Scheduled completion date: June 2014 The equipment listed in Table 1 will be received on site. Started.

21 Scheduled completion date: August 2014

• • Refer to Section 8, Supplemental Information, for an explanation of the change to this Open Item.

6.2. Open Items from Interim Staff Evaluation The following table provides a summary of the open items from the MPS2 Interim Staff Evaluation (Reference 15) and the status of each item.

Interim Staff Evaluation Open Items 01 # Description Status 3.2.1.8.A Core Subcriticality and Boron Mixing: The PWROG The discussion provided submitted to NRC a position paper, dated August 15, 2013, above in Section 4, Item which provides test data regarding boric acid mixing under i, addresses this Open single-phase natural circulation conditions and outlined Item.

applicability conditions intended to ensure that boric acid addition and mixing would occur under conditions similar to Additional supporting those for which boric acid mixing data is available. documentation will be provided during the During the audit process, the licensee informed the NRC ongoing audit process.

staff of its intent to abide by the generic approach discussed above. The licensee should address the clarifications in the NRC endorsement letter dated January

_8, 2014.

Serial No. 12-161E Docket No. 50-336 Order EA-12-049 Attachment 1 Page 12 of 30 Interim Staff Evaluation Open Items 01 # Description Status 3.2.4.1 .A The licensee did not provide sufficient information This Open Item has regarding cooling functions provided by such systems as been addressed as auxiliary building cooling water, service water, or follows:

component cooling water cooling when ac power is lost during the ELAP for Phase 1 and 2. For example, the Permanently installed potential need for cooling water for the TDAFW pump plant equipment used to bearings was not discussed. Additional analysis by the support FLEX strategies licensee is required to determine the acceptability of the do not require cooling licensee's plans to provide supplemental cooling to the support systems, such subject components when normal cooling will not be as component cooling available during the ELAP. water and service water, to perform their required functions. Therefore, no additional analysis is required to confirm the acceptability of supplemental cooling to plant equipment supporting Phase 1 or 2 strategies.

6.3. Confirmatory Items from Interim Staff Evaluation The following table provides a summary of the confirmatory items from the MPS2 Interim Staff Evaluation and the status of each item.

Interim Staff Evaluation Confirmatory Items Cl # Description Status 3.1.1.2.A Confirm that the preferred travel pathways are determined This Confirmatory Item using the guidance contained in NEI 12-06. The pathways will be addressed during will attempt to avoid areas with trees, power lines, and the ongoing audit other potential obstructions and will consider the potential process.

for soil liquefaction. This is scheduled to be completed in June 2014.

3.1.1.3.A Confirm that a review is completed to determine impacts This Confirmatory Item from large internal flooding sources that are not seismically will be addressed during robust and do not require ac power. the ongoing audit process.

3.1.1.4.A The licensee's plan for implementing the use of off-site This Confirmatory Item resources is not complete. The local assembly areas have will be addressed during not been identified. The licensee is also evaluating the the ongoing audit possibility of boat transport for personnel. process.

Serial No. 12-161E Docket No. 50-336 Order EA-12-049 Attachment 1 Page 13 of 30 Interim Staff Evaluation Confirmatory Items Cl # Description Status 3.1.2.2.A The licensee has identified open items related to deployment This Confirmatory Item of equipment during flooding conditions resulting from a will be addressed during hurricane; to verify response times listed in the timeline and the ongoing audit perform staffing assessment, and to perform an evaluation of process.

all BDB equipment fuel consumption and required re-fill strategies, and to determine preferred travel pathways using the guidance contained in NEI 12- 06. The pathways will attempt to avoid areas with trees, power lines, and other potential obstructions.

3.2.1.A Confirm that Combustion Engineering Case 21 in WCAP- This Confirmatory Item 17601-P, as evaluated in MPS2 document ETE-NAF-2012- will be addressed during 0150, Section 6.1, is representative for MPS2 and the ongoing audit appropriate for simulating the ELAP transient. process.

3.2.1.1.A Confirm that Westinghouse letter LTR-TDA-13-31, Rev. 0- This Confirmatory Item B, Attachment 1, shows that the CENTS code used in the will be addressed during ELAP analysis for Combustion Engineering (CE) plants is the ongoing audit limited to analyzing the flow conditions before reflux boiling process.

initiates. This review should confirm an acceptable definition for the initiation of reflux boiling.

3.2.1.2.A The RCP seal initial maximum leakage rate should be This Confirmatory Item greater than or equal to the upper bound expectation for will be addressed during the seal leakage rate for the ELAP event discussed in the the ongoing audit PWROG position paper addressing the RCP seal leakage process.

for CE plants (ADAMS Accession No. ML13235A151 (Non-Publicly Available)) or justification should be provided for use of a lower value.

3.2.1.6.A Sequence of Event (SOE) action Item 5 indicates that the This item has been ELAP is declared at 45 minutes, and Action Item 6 addressed in Attachment indicates that at 50 minutes (5 minutes after the declaration 3, Audit Question 21.

of the ELAP), the operator controls SG atmospheric dump valves (ADVs) and AFW flow locally as an on-going action 50 minutes has been for cooldown and decay heat removal. On page 105 of the corrected to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> to integrated plan in Attachment 1 B NSSS Significant be consistent with Reference Analysis Deviation Table, the licensee notes in WCAP-17601.

item 6 that cooldown starts at 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> at 75 degrees F/hr.

to a SG pressure of 135 psia. Clarification is needed to correct this apparent inconsistency.

3.2.1.6.B The licensee did not provide a discussion regarding the This Confirmatory Item operator actions required to control SG ADVs and AFW will be addressed during flow and justification is needed to determine that all the the ongoing audit required operator actions are reasonably achievable within process.

the required time constraint of 50 minutes during the ELAP conditions, or a discussion regarding the required cooldown completion time that is supportable by analysis.

Serial No. 12-161E Docket No. 50-336 Order EA-1 2-049 Attachment 1 Page 14 of 30 Interim Staff Evaluation Confirmatory Items Cl # Description Status 3.2.1.6.C Confirm that response times listed in the SOE timeline are This Confirmatory Item verified and that staffing assessment has been performed. will be addressed during the ongoing audit process.

3.2.2.A Following a BOB event, a vent pathway would be required This Confirmatory Item in the event of SFP bulk boiling and can be established by will be addressed during opening the Fuel Building roll-up doors for inlet and outlet the ongoing audit air flow. However the licensee's strategy for providing air process.

flow to remove steam generated from pool boiling is not clear. The path for inlet and exhaust air is apparently the same i.e., the fuel building rollup doors. It is not clear from the discussion provided how this will enable a flow path to vent the steam and condensate from the Fuel Building.

3.2.3.A During the audit process the licensee stated that the details Details of the Phase 3 of the long term Containment cooldown and depressurization long term Containment strategies for MPS2 are still under development. Upon cooldown and selection of the preferred strategy, detailed GOTHIC analysis depressurization will be performed to document and validate the strategy and strategies for MPS2 are also to provide operators with timelines and guidelines for provided in Attachment actions to ensure the long term integrity of the Containment 2.

throughout the Phase 3 of the postulated ELAP/LUHS scenario. Confirm that the revised analyses and the selected Confirmation of the strategy are acceptable. detailed Containment analysis will be addressed during the ongoing audit process.

3.2.4.2.A The ventilation evaluation will be completed later this year This Confirmatory Item and the results will be provided in the February 2014 6-Month will be addressed during update. Confirm that the evaluation and results are the ongoing audit acceptable. process and the August 2014 6-month status update.

3.2.4.4.A Confirm the adequacy of existing lighting and the adequacy This Confirmatory Item of portable lighting to perform FLEX strategy actions. will be addressed during the ongoing audit process and the August 2014 6-month status update.

3.2.4.4.B Confirm that upgrades to the site's communications systems This Confirmatory Item have been completed. will be addressed during the ongoing audit

_process.

Serial No. 12-161E Docket No. 50-336 Order EA-1 2-049 Attachment 1 Page 15 of 30 Interim Staff Evaluation Confirmatory Items CI # Description Status 3.2.4.6.A Additional information is needed to confirm habitability of the This Confirmatory Item Main Control Room during the ELAP. will be addressed during the ongoing audit process.

3.2.4.7.A Westinghouse is currently performing an analysis to This Confirmatory Item determine the consequences of usage of impure water will be addressed during sources in the steam generators. The results of the analysis the ongoing audit are expected to provide the allowed time limits on usage of process.

these sources. The RRC will provide equipment to initiate residual heat removal and water treatment equipment such that heat removal can be ensured for extended durations.

Confirm that the analysis results and resultant strategies are acceptable.

3.2.4.9.A A secondary source for fuel oil will be the MPS3 Diesel Fuel This Confirmatory Item Oil Storage Tanks. These underground tanks contain a will be addressed during minimum of 32,670 gallons of fuel oil. They are seismic and the ongoing audit missile protected. Confirm the ability to transfer this fuel, and process and the August complete an evaluation of all BDB equipment fuel 2014 6-month status consumption and required re-fill strategies, including any update.

gasoline required for small miscellaneous equipment.

3.2.4.10.A The licensee has completed an analysis of the battery This Confirmatory Item capability regarding expected time available with ac power. will be addressed during Site specific procedural guidance governing load stripping will the ongoing audit be developed. Confirm electrical components performance process and the August requirements and electrical loading-related strategy 2014 6-month status objectives can be met. update.

3.4.A The licensee's plans for the use of off-site resources conform This Confirmatory Item to the minimum capabilities specified in NEI12-06 Section will be addressed during 12.2, with regard to the capability to obtain equipment and the ongoing audit commodities to sustain and backup the site's coping process.

strategies (item 1). Confirm the licensee addresses the remaining items (2 through 10), or provides an appropriate alternative.

7 Potential Safety Evaluation Impacts DNC is participating in the ongoing industry effort to develop guidance for the Overall Program Document that will support the NRCs preparation of the Safety Evaluation documenting MPSU2 compliance with Order EA-12-049. As this Overall Program Document is developed, potential challenges and impacts will be identified in this section of future Six-Month Status Reports.

Serial No. 12-161E Docket No. 50-336 Order EA-12-049 Attachment 1 Page 16 of 30 8 Supplemental Information This supplemental information provides details of the changes identified in the status updates above and addresses the following topics: a) a revision to Milestone Task 'Develop Strategies',

b) a revision to Milestone Task 'Develop Modifications', c) a revision to Milestone Task

'Develop Strategies/ Contract with RRC', d) a revision to Open Item No. 3, e) a revision to Open Item No. 4, f) a revision to Open Item No. 12, g) a revision to Open Item No.15, and h) a revision to Open Item No.19.

a) MPS2. Milestone Task 'Develop Strategies': The revision to the scheduled milestone target completion date allows for completion of calculations needed to finalize the ventilation strategies for the Spent Fuel Pool General Area at Elevation 38' 6" of the Auxiliary Building and the CRACS Mechanical Equipment Room at Elevation 38' 6" of the Auxiliary Building.

b) MPS2, Milestone Task 'Develop Modifications': The revision to the scheduled milestone target completion date is needed to complete minor modifications supporting FLEX strategies (e.g., standpipe, hose adapters, etc.).

c) MPS2. Milestone Task 'Develop Strategies/Contract with RRC': The revision to the scheduled milestone target completion date is consistent with the date the RRC will be fully operational.

d) MPS2, Open Item 3: The Open Item completion date is revised to June 2014.

Additional time is required to complete the hydraulic calculations for the Phase 2 strategies using alternate connections and to confirm the fluid-hydraulic-related strategy objectives can be met utilizing the Phase 3 RRC pumps.

e) MPS2, Open Item 4: The location for the MPS BDB Storage Building has changed.

The BDB storage Building will be sited south of the railroad bridge, on the west side of the MPS access road, adjacent to the existing northeast contractor parking lot instead of north of the bridge near the salt shed as previously reported in the August 2013 Six-Month Status Report.

f) MPS2, Open Item 12: The revision to the wording more accurately reflects the actual evaluation being performed on the ADV pipe supports for seismic loading and the ADV vent piping for tornado missile protection. The updated completion schedule accurately reflects the current project schedule for completion of the engineering evaluation. The revised Open Item and revised completion schedule are as follows:

Open Item 12: Complete the engineering evaluation of the main steam atmospheric dump valve (MS ADV) outlet lines.

Completion Schedule: July 2014

Serial No. 12-161E Docket No. 50-336 Order EA-12-049 Attachment 1 Page 17 of 30 g) MPS2, Open Item 15: The Open Item completion date is revised to June 2014.

Additional time is required to obtain design specification information on the Phase 3 RRC electrical components and complete the calculations needed to confirm the electrical loading-related strategy objectives can be met with this equipment.

h) MPS2, Open Item 19: The Open Item completion date is revised to April, 2014.

Additional time is required to complete the ventilation calculations needed to finalize the MPS2 ventilation strategies for the Spent Fuel Pool General Area at Elevation 38' 6" of the Auxiliary Building and the CRACS Mechanical Equipment Room at Elevation 38' 6" of the Auxiliary Building.

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

1. DNC's 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 29, 2013 (Serial No. 12-161B).

2. NRC Order Number EA-1 2-049, "Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events," dated March 12, 2012.

3. NEI 12-06, "Diverse and Flexible Coping Strategies (FLEX) Implementation Guide,"

Revision 0, dated August 2012.

4. DNC's Supplement to Overall Integrated Plan in Response to March 21, 2012 Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis Events (Order Number EA-12-049), dated April 30, 2013 (Serial No. 12-161C).

5. Calculation 13-024, "Turbine Driven Auxiliary Feedwater (TDAFW) Pump Delivered Flow at Reduced Steam Generator Pressure," April 22, 2013.

6. Engineering Technical Evaluation ETE-MP-2013-1034, "MP2 Turbine Driven Aux Feedwater Pump Minimum Continuous Operating Speed," dated March 12, 2013.

7. PWROG letter, OG-13-197, Transmittal of PA-PSC-0965 Final CE-NSSS Specific ELAP Response (FLEX) Guidelines, May 17, 2013.

8. Calculation 13-015, "MP2 & MP3 FLEX Strategy Hydraulic Calculations," Rev. 0.

9. ETE-CPR-2013-0003, "Beyond Design Basis Communications Strategy/Plan," Rev. 0

10. Dominion Calculation MISC-1 1793, "Evaluation of Long-Term Containment Pressure and Temperature Profiles Following and Extended Loss of AC Power (ELAP)," Rev. 0.

11. Calculation 2013-ENG-04383E2, "Millstone Power Station Unit 2 Beyond Design Basis -

FLEX Electrical 4160V, 4840V and 120VAC System Loading Analysis," Rev. 0.

Serial No. 12-161E Docket No. 50-336 Order EA-12-049 Attachment 1 Page 18 of 30

12. URS Geotechnical Investigation and Engineering Report, FLEX Storage Building Project, Millstone Power Station, Waterford, Connecticut, dated January 27, 2014.

13. Design Change MPG-1 3-00010, "BDB Storage Building/Millstone Power Station/Units 2&3."

14. DNC's 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 23, 2013 (Serial No. 12-161D).

15. Millstone Power Station, Units 2 and 3 - Interim Staff Evaluation Relating to Overall Integrated Plan in Response to Order EA-1 2-049 (Mitigating Strategies), dated January 31,2014.

Serial No. 12-161E Docket No. 50-336 Order EA-12-049-Attachment 1 Page 19 of 30 Table 1 - PWR Portable Equipment Phase 21 [Open Item 21]

Use and (Potential / Flexibility) Diverse Uses Performance Maintenance Criteria Maintenance!

List Portable Preventive Equipment Core Containment SFP Instrumentation Accessibility Maintenance Requirements BDB High Capacity Will follow EPRI diesel-driven pump (2) X X X 1200 gpm @ template and assoc. hoses and 150 psid templte fittings requirements BDB AFW pump (3) and 300 gpm @ Will follow EPRI assoc. hoses and X gpm template fittings 500 psid requirements BDB RCS Injection Will follow EPRI pump (2) and assoc. 45 gpm @

hoses and fittings X3000 psid template requirements 120/240VAC generators Will follow EPRI (3) and associated X 23.3 kW template cables, connectors and switchgear requirements

Serial No. 12-161E Docket No. 50-336 Order EA-12-049-Attachment 1 Page 20 of 30 Table 1 - PWR Portable Equipment Phase 21 [Open Item 21]

Use and (Potential / Flexibility) Diverse Uses Performance CriteriaManenc Maintenance!

List Portable C Ctm Preventive Equipment Core Containment SFP Instrumentation Accessibility Maintenance Requirements 120/240VAC generators (8)2 and associated Will follow EPRI cables, connectors and X 5-6.5 kW template switchgear (to power requirements support equipment) 480VAC generators (3) and associated cables, connectors and Will follow EPRI switchgear (to re-power X X X 500 kW template requirements battery chargers, inverters, and Vital Buses)

Portable boric acid Will follow EPRI batching tank (2) X 1000 gal template requirements Light plants (2) Will follow EPRI

+ Light strings (15)2 X template requirements

Serial No. 12-161E Docket No. 50-336 Order EA-12-049.

Attachment 1 Page 21 of 30 Table 1 - PWR Portable Equipment Phase 21 [Open Item 21]

Use and (Potential / Flexibility) Diverse Uses Performance CriteriaManenc Maintenance/

List Portable Preventive Equipment Core Containment SFP Instrumentation Accessibility Maintenance Requirements Front end loader (1) 2 X Will follow EPRI template requirements Tow vehicles (2) 2 X X X X Will follow EPRI template requirements Hose trailer (2) and Will follow EPRI Utility vehicle (1)2 X X X X template requirements Fans / blowers (10) 2 X Will follow EPRI template requirements Air compressors (6) 2 X X Will follow EPRI template requirements Fuel truck (1) with 1,100 X X X X X Will follow EPRI gal. tank and pumps template requirements Fuel carts with transfer Will follow EPRI pumps (2) 2 X X X X X template requirements Communications Will follow EPRI equipment 3 X X X X X template requirements

Serial No. 12-161E Docket No. 50-336 Order EA-12-049.

Attachment 1 Page 22 of 30 Table 1 - PWR Portable Equipment Phase 21 [Open Item 21]

Use and (Potential / Flexibility) Diverse Uses Performance Criteria Maintenance Maintenance!

List Portable Preventive LqistPortalen Core Containment SFP Instrumentation Accessibility Mainte Equipment Maintenance Requirements Misc. debris removal Will follow EPRI equipment 2 template requirements Misc. Support Will follow EPRI Equipment 2 X template requirements Cables for 4160VAC Will follow EPRI generator connections template requirements NOTES:

1. This table is based on one BDB Storage Building containing equipment for both MPS2 and MPS3.

2. Support equipment. Not required to meet N+1.

3. Quantities are identified in ETE-CPR-2013-0003 that was developed in response to the results of the study performed for Recommendation 9.3 of the 10 CFR 50.54(f) letter dated March 12, 2012.

Serial No. 12-161E Docket No. 50-336 Order EA-1 2-049-Attachment 1 Page 23 of 30 Table 2 - PWR Portable Equipment Phase 3 Use and (Potential / Flexibility) Diverse Uses Performance Criteria Maintenance Notes List Portable Quantity Quantity Power Core Cont. Access Instrumentation RCS Preventative Equipment Req'd Provided Cooling Cooling/ Inventory Maintenance

/Unit I Unit Integrity Required Medium 'J4"6t 'V.Performed by Voltage 1 1 Tu.

eTurb. X 4.16 KV 2MW RRC (1)

Generators Low Voltage 0 1 Jet "Performed by (2)

Generators Turb.  : X X X 48VAC 1100KW 2RC High Prssre0 1 Diesel K4 .X 3000# 60 GPM Pefre y (2)

Injection  :*"""*:':;":

i;Q.[:=::*';'.*:"li

.RRC 'i~~iiPerformed I ;1* by Pump__ _ __ __ _

S/G RPV Makeup 0 1 Diesel X X 500# 500 GPM PRorme b (2)

PumpRRC Low Pressure 0 1 Diesel X 300# 2500 GPM Performed by (2)

Medium RRG Flow Pump _ _ . :___ ___ __

Low Pressure 1 Diesel X X 150# 5000 GPM Performed by High Flow *." .. RRC Pum p TihFowe"rs1":'* :__. . ._..

• i . . "**",*.. RRC(3 Lighting 0.1"Diesel 40,000.Lu'Performed by er 0 4,00 RRDiesel CX (4)

Serial No. 12-161E Docket No. 50-336 Order EA-12-049.

Attachment 1 Page 24 of 30 Table 2 - PWR Portable Equipment Phase 3 Use and (Potential / Flexibility) Diverse Uses Performance Criteria Maintenance Notes List Portable Quantity Quantity Power Core Cont. Access Instrumentation RCS Preventative Equipment Req'd Provided Cooling Cooling/ Inventory Maintenance

/Unit IUnit Integrity Required Diesel Fuel 0 AR N/A X X X X X 500 Gal Performed by (2)

Transfer RIRC Mobile Performed by Water 0 2 Diesel X X 150 GPM RRC (2)(5)

Mobile "" ' ".. .' . . .:: " *"

Treatment i. ,........*

• ":* *:::::.Performed

": :" " by Mobile 0 1 N/A

• X 1000 Gal Performedby (2)

Skid Note 1 - RRC 4KV generator supplied in support of Phase 3 for Core Cooling, Containment Cooling, and Instrumentation FLEX Strategies.

Note 2 - RRC Generic Equipment - Not required for FLEX Strategy - Provided as Defense-in-Depth.

Note 3 - RRC Low Pressure / High Flow pump supplied in support of Phase 3 for Core Cooling and Containment Cooling FLEX Strategies.

Note 4 - RRC components provided for low light response plans.

Note 5 - Usage dependent on Westinghouse Water Quality Study results.

Serial No. 12-161E Docket No. 50-336 Order EA-12-049 Attachment 1 Page 25 of 30 FIGURE 2 (FEBRUARY 2014 UPDATE)

BDB FLEX STRATEGY MECHANICAL CONNECTIONS FLOW DIAGRAM MILLSTONE UNIT 2

Serial No. 12-161E Docket No. 50-336 Order EA-1 2-049 Attachment 1 Page 26 of 30 TO STEAM GENERATOR No. 2 r CST REFILL TURBINE BUILDING LEGENOo PRIMARY BOB AFW CONNECTIONS OD H OOIFICATIOe SUCTION SAME AS PRIMARY BOB ANFW PUMP SUCTION CONNECTION SHOWN ABOVE BOB AFW ALTERNATE 2-MS-229A SG INJECTION GASSED OPEN CONNECTION FLANGE AD* TER --

BODAFW PU4P I I 2-MS-411 ALTERNATE BOB AFW CONNECTION 5'-6 AUX BLDG EAST PEN ROOM FIGURE 3 (FEBRUARY 2014 UPDATE)

CORE COOLING AND DECAY HEAT REMOVAL MILLSTONE UNIT 2

Serial No.12-161 E Docket No. 50-336 Order EA-1 2-049 Attachment 1 Page 27 of 30 FIGURE 6 (FEBRUARY 2014 UPDATE)

ELECTRICAL GENERATOR DEPLOYMENT MILLSTONE UNIT 2

Serial No. 12-161E Docket No. 50-336 Order EA-12-049 Attachment 1 Page 28 of 30 NOTEx 120/240V PORTA BLE 1. CABLES TO THE GENERATOR FROM THE LOCAL DIESEL GENERAT OR CONNECTION BOXES ARE ROUTED THROUGH THE "B" AND "Aq DC SWITCHGEAR ROOMS AND THEN THROUGH THE EXTERION DOOR TO THE COURTYARD I BKR. BKR I NOTE I COURTYARD. EAST OF OF DC SWITCHGEAR ROOMS A DC SWGR ROOM

~* 8G"R" , RGR ROOM 120V VITAL BUS DISTRIBUTION PANEL 12OV VITAL BUS DISTRIBUTION PANEL VIAC-2 (VA20) FACILITY Z2 VIAC-4 (VA40) FACILITY Z4 18 2P CKT BKR PANEL SINGLE PHASE 1I 2P CKT BKR PANEL SINGLtE PHASE KEY:

SBDOB MODIFICATION FIGURE 7 (FEBRUARY 2014 UPDATE) 120/240VAC GENERATOR ELECTRICAL CONNECTIONS MILLSTONE UNIT 2

Serial No. 12-161E Docket No. 50-336 Order EA-12-049 Attachment 1 Page 29 of 30 22F FEEDER 2407-IX3-2 52-B2611 480V LOAD CENTER BUS 22F (B06) EMERGENCY 2000A 3000A (4042) (B@I) (403C) (4038) (403A) (4040) 2484A) 80603 80604 00605 6M0G 80607 B0608 OWq L) N I ,

713-x XoL LJD &&=U-~

ý 1- *CC) 04 'SIC (

NI (801) 1402C) 80604 BMse0 0A BREAKER 22FI-2 WILL BE MADE AVAILABLE FOR USE HYDROGEN RECOMBINER IS ABANDONED IN PLACE.

EAST 480V SWITCHGEAR UN IT 2 CABLE VAULTi UNIT 1 CABLE VAULT KEY:

4860V PORTABLE GENERATOR SKID

-m DBD8 MODIFICATION FIGURE 8 (FEBRUARY 2014 UPDATE) 480VAC GENERATOR ELECTRICAL CONNECTIONS MILLSTONE UNIT 2

Serial No. 12-161E Docket No. 50-336 Order EA-1 2-049 Attachment 1 Page 30 of 30 4160V BUS 240 2000A 15G- 13U-2 (52-A4G1)

PANEL C39 "B" EDG ROOM 4160V PORTABLE DISTRIBUTION PANEL BKR I BKR I~w 4160V PORTABLE, 4160V PORTABLE

. GE NERATOR . I GENERATOR L Aft A A A A A A A A £ A A KEYs NOTE:

cT=3BOB MODIFICATION THE TWO IMW 4168V GENERATORS PROVIDED BY THE REGIONAL CENIER AND CON1NECTED TO PANEL C39 VIA A 4160V PORTABLE DISTRIBUTION PANEL FIGURE 9 (FEBRUARY 2014 UPDATE) 4160VAC GENERATOR ELECTRICAL CONNECTIONS MILLSTONE UNIT 2

Serial No. 12-161E Docket No. 50-336 Order EA-12-049 Attachment 2 Overall Integrated Plan Section D Maintain Containment Millstone Power Station Unit 2 Dominion Nuclear Connecticut, Inc. (DNC)

Serial No. 12-161E Docket No. 50-336 Order EA-1 2-049 Attachment 2 Page 1 of 10 D. Maintain Containment Determine Baseline coping capability with installed coping' modifications not including FLEX modifications, utilizing methods described in Table 3-2 of NEI 12-06:

• Containment Spray

• Hydrogen igniters (ice condenser containments only)

D.1 - PWR Installed Equipment Phase 1:

Provide a generaldescription of the coping strategies using installedequipment including modifications that are proposed to maintain Containment. Identify methods (Containment spray/Hydrogen igniter)and strategy(ies) utilized to achieve this coping time.

The Phase 1 coping strategy for Containment involves verifying Containment isolation per EOP-2530, Station Blackout, and monitoring Containment temperature and pressure.

Evaluations have been performed and conclude that Containment temperature and pressure will remain below design limits and key parameter instruments subject to Containment environment will remain functional for at least 7 days. Therefore, actions to reduce Containment temperature and pressure and to ensure continued functionality of the key parameters will not be required immediately and will utilize off-site equipment and resources during Phase 3.

Details:

D.1.1 - Provide a brief Confirm that procedure/guidanceexists or will be developed to description of Procedures support implementation I Strategies / Guidelines Procedural guidance for monitoring Containment pressure is provided by EOP-2530, Station Blackout.

Procedural guidance for monitoring Containment temperature will be provided by FSGs. [Open Item 5]

D.1.2 - Identify List modifications modifications No plant modifications are required to support implementation of this Phase 1 strategy.

D.1.3 - Key Containment List instrumentationcredited for this coping evaluation.

Parameters Containment Pressure - Containment pressure indication is available in the MCR throughout the event.

Containment Temp~erature - Containment temperature indication is available locally by handheld meter at Containment penetrations associated with the temperature elements TE-8108, TE-8109, and TE-81 10. [Open Item 5]

Coping modifications consist of modifications installed to increase initial coping time, i.e. generators to preserve vital instruments or increase operating time on battery powered equipment.

Serial No. 12-161E Docket No. 50-336 Order EA-12-049 Attachment 2 Page 2 of 10 D. Maintain Containment Notes:

The information provided in this section is based on the following reference(s):

Dominion Nuclear Engineering ETE-CPR-2012-0009, "Beyond Design Basis - FLEX Strategy Overall Integrated Plan Basis Document," Revision 2.

Dominion Nuclear Engineering Calculation MISC-1 1793, "Evaluation of Long Term Containment Pressure and Temperature Profiles Following Loss of Extended AC Power (ELAP), Revision 0."

Serial No. 12-161E Docket No. 50-336 Order EA-12-049 Attachment 2 Page 3 of 10 D. Maintain Containment D.2 - PWR Portable Equipment Phase 2:

Provide a generaldescription of the coping strategies using on-site portable equipment including modifications that are proposed to maintain Containment. Identify methods (Containment spray/hydrogenigniters) and strategy(ies) utilized to achieve this coping time.

Evaluations have been performed and conclude that Containment temperature and pressure will remain below design limits and key parameter instruments subject to Containment environment will remain functional for at least 7 days. Therefore, actions to reduce Containment temperature and pressure and to ensure continued functionality of the key parameters will not be required immediately and will utilize off-site equipment and resources during Phase 3. There is no separate Phase 2 strategy.

Details:

D.2.1 - Provide a brief Confirm that procedure/guidanceexists or will be developed to description of Procedures support implementation

/ Strategies / Guidelines None required for Phase 2.

D.2.2 - Identify List modifications modifications None required for Phase 2.

D.2.3 - Key Containment List instrumentationcredited or recovered for this coping evaluation.

Parameters Although a Phase 2 strategy is not required, the Phase 1 Containment monitoring instrumentation will continue to be utilized during Phase 2.

D.2.4 - Storage / Protection of Equipment:

Describe storage I protection plan or schedule to determine storage requirements Seismic List how equipment is protected or schedule to protect None required for Phase 2.

Flooding List how equipment is protected or schedule to protect None required for Phase 2.

Severe Storms with High List how equipment is protectedor schedule to protect Winds None required for Phase 2.

Snow, Ice, and Extreme List how equipment is protectedor schedule to protect Cold None required for Phase 2.

Serial No. 12-161E Docket No. 50-336 Order EA-1 2-049 Attachment 2 Page 4 of 10 D. Maintain Containment High Temperatures List how equipment is protectedor schedule to protect None required for Phase 2.

D.2.5 - Deployment Conceptual Modification (Attachment 3 contains Conceptual Sketches)

Strategy Modifications Protection of connections

a. Identify Strategy including Identify modifications Identify how the connection is how the equipment will be protected deployed to the point of use.

None required for Phase 2. None required for Phase 2. None required for Phase 2.

Notes:

The information provided in this section is based on the following reference(s):

Dominion Nuclear Engineering ETE-CPR-2012-0009, "Beyond Design Basis - FLEX Strategy Overall Integrated Plan Basis Document," Revision 2.

Dominion Nuclear Engineering Calculation MISC-1 1793, "Evaluation of Long Term Containment Pressure and Temperature Profiles Following Loss of Extended AC Power (ELAP), Revision 0."

Serial No. 12-161E Docket No. 50-336 Order EA-12-049 Attachment 2 Page 5 of 10 D. Maintain Containment D.3 - PWR Portable Equipment Phase 3:

Provide a general description of the coping strategies using Phase 3 equipment including modifications that are proposedto maintain Containment. Identify methods (Containment spray/hydrogen igniters)and strategy(ies) utilized to achieve this coping time.

An evaluation has been performed and concludes that Containment temperature and pressure will remain below design limits and key parameter instruments subject to Containment environment will remain functional for at least 7 days. To remain within analyzed limits for equipment qualification temperature, the Containment temperature will be procedurally monitored and, if necessary, the temperature will be reduced. This will require the implementation of the Phase 3 Containment cooling strategy such that heat removal from Containment is initiated in a timely manner.

The strategy to reduce Containment temperature is to provide for Containment heat removal through water spray into the Containment atmosphere using the installed Containment Spray (CS) pumps and spray rings. This strategy requires repowering a Class 1E 4160VAC bus using a 4160VAC DG from the Regional Response Center (RRC) and restoration of cooling water flow to the CS heat exchanger. An alternate strategy is also available which will provide Containment ventilation cooling using the safety-related Containment Air Recirculation Fans.

Primary Containment Cooling Strategy - Containment Recirculation Spray The 4160VAC DG from the RRC will be aligned to power a Class 1E 4160VAC bus as described in Section F1.3, which will provide power to CS, Reactor Building Closed Cooling Water (RBCCW), and Service Water (SW) pumps 4kV motors. Flow will be initially established from the RWST to the Containment through the normal CS flowpath through the spray ring header nozzles. This initial flow will provide heat removal from the Containment atmosphere and fill the Containment sump in preparation for initiation of Containment recirculation flow. When the Containment sump level is adequate to support swap over to sump suction, the CS pumps will be aligned to draw water from the sump and recirculate flow through the CS heat exchangers and the spray nozzles. SW flow will be established through the RBCCW heat exchangers to provide a heat sink, and RBCCW flow will be established through the CS heat exchangers and the RBCCW heat exchangers to transfer heat to the SW system. In this manner, Containment atmosphere heat will be rejected to the ultimate heat sink via the sump water recirculation spray flowpath.

In the event that the Service Water system pumps are unavailable, portable 5,000 gpm (low pressure/high flow) diesel driven pumps from the RRC will be utilized to provide water flow from the Niantic Bay to the RBCCW heat exchangers via connection of the pump discharge to existing inspection port flanged openings in the Service Water pumps discharge header located in the Intake Structure. The seismic Category 1 Intake Structure is designed to withstand missiles and high wind. The system connection points are located inside the Intake Structure and are protected from extreme cold, ice and snow, and extreme high temperature.

Thermal/hydraulic and Containment analyses will be performed to confirm this Containment coolinq strateqy [Open Item 3].

Serial No. 12-161E Docket No. 50-336 Order EA-12-049 Attachment 2 Page 6 of 10 D. Maintain Containment Alternate Containment Cooling Strategy - Containment Ventilation Cooling The 4160VAC DG from the RRC will be aligned to power a Class 1 E 4160VAC bus as described in Section F1.3, which will provide power to Reactor Building Closed Cooling Water (RBCCW) and Service Water (SW) pumps 4kV motors. A portable 480VAC DG from the BDB Storage Facility will be aligned to power a Class 1 E 480VAC bus as described in Section F1.2, which will provide power to a Containment Air Recirculation Fan (CARF) motor. Containment ventilation flow will be established by starting the CARF fan with air flow through the CARF heat exchanger and recirculating within the Containment. SW flow will be established through the RBCCW heat exchanger to provide a heat sink, and RBCCW flow will be established through the CARF heat exchanger and the RBCCW heat exchanger to transfer heat to the SW system. In this manner, Containment atmosphere heat will be rejected to the ultimate heat sink via the recirculation of Containment atmosphere through the CARF heat exchanger.

In the event that the Service Water system pumps are unavailable, cooling water flow to the RBCCW heat exchanger will be established as described for the primary Containment cooling strategy.

Thermal/hydraulic and Containment analyses will be performed to confirm this Containment cooling strategy [Open Item 3].

Details:

D.3.1 - Provide a brief Confirm that procedure/guidanceexists or will be developed to description of Procedures support implementation I Strategies / Guidelines Site specific procedural guidance governing the Containment cooling strategy will be developed using industry guidance, and will address the necessary steps to align and operate permanent plant equipment, deploy portable pumps and hoses, establish connections, and operate the portable equipment to perform the required function.

[Open Item 5]

D.3.2 - Identify List modifications modifications None required.

D.3.3 - Key Containment List instrumentationcredited for this coping evaluation.

Parameters Containment Pressure - Containment pressure indication is available in the MCR throughout the event.

Containment Temperature - Containment temperature indication is available locally by handheld meter at Containment penetrations associated with the temperature elements TE-8108, TE-8109, and TE-81 10. [Open Item 5]

Serial No. 12-161E Docket No. 50-336 Order EA-12-049 Attachment 2 Page 7 of 10 D. Maintain Containment Following 120VAC bus re-powering described in Section F1.2, the following instrumentation will be available in the MCR:

- CS Flow Rate

- CS Temperature

- CS Discharge Pressure

- Containment Sump Level

- RBCCW Flow Rate

- RBCCW Temperature

- RWST Level

- CAR Fan Discharge Temperature D.3.4 - Deployment Conceptual Modification (Attachment 3 contains Conceptual Sketches)

Strategy Modifications Protection of connections

a. Identify Strategy including Identify modifications Identify how the connection is how the equipment will be protected deployed to the point of use.

The primary strategy for None The SW system connection Containment cooling is to to provide flow from the provide Containment portable low pressure/ high recirculation spray flow using flow (5,000 gpm) diesel installed plant equipment. driven pumps from the RRC Therefore, no deployment of to the Service Water pumps equipment is required. discharge header is located In the event that SW pumps in the Intake Structure. The are unavailable, the cooling Intake Structure is a seismic water will be provided by a Category 1 structure portable low pressure/high flow designed to withstand (5,000 gpm) diesel driven missiles and high wind. The pump deployed from the RRC. system connection points are The pump will be staged near protected from extreme cold, the Intake Structure with a ice and snow, and extreme suction hose routed to the high temperature.

Niantic Bay and the discharge hose routed inside the Intake Structure to the 12" flanged inspection port connection point in the SW pump discharge header. See Figure 10.

The alternate strategy for Containment cooling is to

Serial No. 12-161E Docket No. 50-336 Order EA-12-049 Attachment 2 Page 8 of 10 D. Maintain Containment provide Containment ventilation cooling using installed plant equipment. Therefore, no deployment of equipment is required. See Figure 11.

Notes:

The information provided in this section is based on the following reference(s):

Dominion Nuclear Engineering ETE-CPR-2012-0009, "Beyond Design Basis - FLEX Strategy Overall InteQrated Plan Basis Document," Revision 2.

Serial No. 12-161E Docket No. 50-336 Order EA-1 2-049 Attachment 2 Page 9 of 10 2-6,W2.2 LOWPRESM/HMIW FL1l. LOW sISL LEGENO, C D BOB MODIFICATION FIGURE 10 CONTAINMENT COOLING BDB FLEX PRIMARY MECHANICAL CONNECTIONS MILLSTONE UNIT 2

Serial No. 12-161E Docket No. 50-336 Order EA-12-049 Attachment 2 Page 10 of 10 ImIT 2 CONTAINMXT FO "SW- 12C ý SURGE TAW A8C,*d p- IsC 2-S- 38 LEGENDs QZ ;4MtFICATION BOB FIGURE 11 CONTAINMENT COOLING BDB FLEX ALTERNATE MECHANICAL CONNECTIONS MILLSTONE UNIT 2

Serial No. 12-161E Docket No. 50-336 Order EA-12-049 Attachment 3 I

Attachment 3 Formal Responses to September 2013 Audit Questions Millstone Power Station Unit 2 Dominion Nuclear Connecticut, Inc. (DNC)

Serial No. 12-161E Docket No. 50-336 Order EA-12-049 Attachment 3 Page 1 of 8 Response to September 2013 Audit Questions Millstone Power Station Unit 2

Background

By letter dated February 28, 2013 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML13064A265), Dominion Nuclear Connecticut, Inc.,

(DNC) submitted an Overall Integrated Plan (OIP) in response to the March 12, 2012, U.S. Nuclear Regulatory Commission (NRC) Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order Number EA-12-049; ADAMS Accession No. ML12056A045) for Millstone Power Station Units 2 and 3 (MPS2 and MPS3), which is consistent with NEI 12-06.

The NRC staff reviewed the February 28, 2013 OIP submittal for MPS2 and conducted an audit of the OIP in September 2013. Some of the information provided during that audit is provided below.

NRC Audit Question No. 21 Dominion provided apparently conflicting information regarding the start of cooldown.

Action Item 5 in the SOE notes that the initiation of cooldown (5 minutes following ELAP) at 50 minutes. This information appears inconsistent with the information in Item 6 of Attachment 1B (page 105) that indicates that based on the analysis of Case 21 in WCAP-17601, plant cooldown begins 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> following declarationof the ELAP with cooldown rate of 75 oF/hr until the SG pressure reaches 135 psia. Clarification is needed to correct this apparent inconsistency. Specify the required operatoractions prior to the initiation of cooldown at 50 minutes. Also, specify the required cooldown completion time that is supportable by adequate analysis and identify the required operatoractions for completing the cooldown. Discuss how all the requiredactions can be reasonably achievable within the required time constraint during the ELAP conditions. (Reference Item 3.2.1.6.A)

DNC Response:

The initiation time of 50 minutes that is listed in Sequence of Event (SOE) Action Item 6 is being revised to a time of 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> to provide consistency with the reference plant case 21 of WCAP-17601. That reference case is applicable for MPS2. The correct time for initiation of cooldown is listed in Attachment 1B of the Overall Integrated Plan for MPS2. As stated in the sixth line of Attachment 1B, the initiating time for cooldown is at 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> with a rate <75 0F/hr to a steam generator pressure of 120 psig.

2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> is considered more than adequate time to dispatch operators to the Enclosure Building (EB) for Atmospheric Steam Dump local operation, establish communication

Serial No. 12-161E Docket No. 50-336 Order EA-12-049 Attachment 3 Page 2 of 8 with the Control Room and initiate the cooldown. Personnel will be able to access the EB and initiate cooldown prior to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />. Steam release from the SGs will be controlled locally within the EB using the handwheels installed on the atmospheric dump valves.

Initiation of the cooldown at a time earlier than 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> would not invalidate the conclusions of the generic analysis. This would result in more rapid depressurization of the RCS and less leakage through the RCP seals. Review of the analysis (Calculation No. MISC-1 1790) results show that there is more than adequate shutdown reactivity throughout the event to offset this effect.

NRC Audit Question No. 35 In the integrated plan Dominion did not discuss the effects of loss of power to heat tracing. Provide a discussion and analysis of the effects of the loss of heat tracing for equipment required to cope with an ELAP. (Reference Item 3.2.4.3.A)

DNC Response:

Heat trace is used to provide two protection functions:

- Heat trace is used to maintain highly concentrated soluble boron solutions above the temperature where the soluble boron will precipitate out of solution.

- Heat trace is also used to protect piping systems and components from freezing in extreme cold weather conditions.

The FLEX strategies that have been developed do not depend on highly concentrated soluble boron solutions. The FLEX strategies will use borated water sources with boron concentrations below 4000 PPM; therefore, boron precipitation is not expected to occur.

Additionally, the FLEX strategies have been developed to protect piping systems and components from freezing. Commercially available Heat Tape and insulation rolls will be maintained in the BDB Storage Building for use on piping systems and components that will be used during an ELAP event where freezing is a concern in extreme cold weather conditions. In addition, major components being procured for FLEX strategies are being provided with cold weather packages and small electrical generators to power the heat tape circuits as well as protect the equipment from damage due to extreme cold weather and help assure equipment reliability.

Equipment used for the mixing of borated water in the portable Boric Acid Batch Tanks will include components such as an agitator and a tank heater to facilitate complete dissolution of the boric acid crystals. FLEX Strategies will provide guidance for mixing

Serial No. 12-161E Docket No. 50-336 Order EA-1 2-049 Attachment 3 Page 3 of 8 to maintain concentrations below the solubility limit corresponding to freezing temperatures. This will ensure that boron precipitation during an extreme cold weather event is not challenged.

NRC Audit Question No. 37 The licensee's plan for electrical isolation and interactions did not provide reasonable assurance that the plan conforms to the guidance in NEI 12-06, Section 3.2.2, Paragraph (13) because there is insufficient information on electrical isolations and interactions to determine how the portable FLEX generatorand the Safeguards Buses are isolated to prevent simultaneously supplying power to the same bus from different sources. Pleaseprovide information on how Dominion addresses electricalisolation to prevent simultaneouslysupplying power to the same bus from different sources.

DNC Response:

Electrical isolation to prevent simultaneously supplying power to a Class 1E Emergency Bus from different sources will be administratively controlled. The FLEX Support Guidelines will be written to ensure the breakers from other potential supply sources are racked out and tagged before power is supplied to any of the Class 1 E Emergency Busses by the BDB portable diesel generators which are to be back fed through the "B" heater drain pumps for the 4160VAC Emergency Bus tie-in and the "B" retired Hydrogen Recombiner for the 480VAC Emergency Bus tie-in.

MPS2 FSAR Figure 8.2-1 provides a Single Line Diagram for the unit. A copy of Figure 8.2-1, with notations highlighting the 4160VAC and 480VAC BDB diesel generator tie-in locations was provided during the audit process.

NRC Audit Question No. 42 Systems and Equipment for Mitigation Strategies: List the non-safety related installed systems or equipment that are credited in the ELAP analysis supporting the FLEX mitigation strategies. Specify the functions of each system or equipment credited in the ELAP analysis. For all the systems or equipment listed, justify that they are available and reliable to provide the desired functions on demand during the ELAP conditions.

DNC Response:

The response to Audit Question No. 42 has been revised. There are no non-safety related installed systems or equipment credited in the ELAP analysis supporting the FLEX mitigation strategies.

Serial No. 12-161E Docket No. 50-336 Order EA-12-049 Attachment 3 Page 4 of 8 NRC Audit Question No. 48 Reference Item 3.1.1.2.A: Describe the fuel oil supply system and flow paths for the fuel oil (i.e., fuel oil storage tank volume, supply pathway, etc.). In addition, explain how fuel quality will be assuredif stored for extended periods of time.

DNC Response:

Fuel sources for the BDB portable pumps and generators used for the FLEX strategies during Phase II and Phase III of an ELAP event are provided from the following on-site fuel oil sources:

1. Two 12,000 gallon (TS Minimum) seismically installed, missile protected fuel oil storage tanks located on the 38'6" elevation in the MPS2 Auxiliary Building.

These two tanks are located well above the maximum postulated flood elevation so they can reasonably be expected to survive following a BDB external event (BDBEE).

2. Two below-ground fuel oil storage tanks, each containing 32,670 gallons (TS Minimum), are located outside the MPS3 Emergency Diesel Generator facility.

These tanks are seismically installed, missile protected, and located above the maximum postulated flood elevation. Therefore, these fuel oil storage tanks can be reasonably expected to survive following a BDBEE.

Diesel fuel in the fuel oil storage tanks is routinely sampled and tested to assure fuel oil quality is maintained to ASTM standards. This sampling and testing surveillance program also assures the fuel oil quality is maintained for operation of the station Emergency Diesel generators.

The fuel sources will be used to fill a fuel oil truck with a self-powered pump that will be procured and stored in the BDB Storage Building. The truck will be deployed from the BDB Storage Building facility to the east side of the MPS2 Auxiliary Building and will be gravity filled from the 12,000 gallon MPS2 fuel oil storage tanks.

As an alternate fuel source, the fuel oil truck can be dispatched to the west side of the MPS3 EDG facility where it can be filled from underground fuel sources using the trucks' self-powered pump.

To facilitate deployment of the BDB portable pumps and generators the equipment will be stored in a fueled condition. As a part of the Preventative Maintenance (PM) templates being created by EPRI, the fuel oil tanks for this FLEX equipment will also be routinely sampled and tested to assure proper fuel oil quality is maintained.

The proposed BDB Storage Building where the fuel truck will be stored, will be located south of the railroad bridge, and on the west side of the MPS access road, adjacent to

i Serial No. 12-161E Docket No. 50-336 Order EA-12-049 Attachment 3 Page 5 of 8 the existing northeast contractor parking lot. This location was shown in a figure provided during the audit process.

NRC Audit Question No. 49 Reference Item 3.2.4.2.D: Ventilation. There are insufficient details regarding the effects of loss of ventilation in the TDAFW pump room, such that the staff is unable to conclude that the equipment in the TDAFW pump room will perform its function and assist in core cooling throughout all Phases of an ELAP. Please provide information on the adequacy of the ventilation provided in the TDAFW pump room to support equipment operation throughout all phases of an ELAP. Specifically, provide a discussion on the impact of elevated temperatures, as a result of loss of ventilation and/or cooling, on electrical equipment being credited as part of the ELAP strategies (e.g., electrical equipment in the turbine driven emergency feedwater pump room). In your response, specify whether the initial temperature condition assumed the worst-case outside temperature with the plant operating at full power. Provide the list of electrical components that are located in the pump rooms that are necessary to ensure successful operation of required pumps. Also provide the qualification level for temperature and pressure for these electrical components for the duration that the pumps are assumed to perform its mitigating strategies function.

DNC Response:

As documented in the MPS2 SBO safe shutdown evaluation, the TDAFW Pump room temperature during SBO is bounded by the steady state normal room operating temperature of the pump. The room has a water tight door that is not assumed to be open and the heat up analysis for the room does not take credit for ventilation. The room temperature has been calculated to not exceed 130'F. This temperature is less than the room design temperature of 135°F specified in the MPS2 Specification for Environmental Conditions for Equipment Qualification.

Since this room is not expected to experience a heat load during the ELAP/LUHS scenario that is any greater than the heat load during normal TDAFW pump operation, no compensatory cooling measures are required for this room.

NRC Audit Question No. 53 Reference Item 3.2.4.8.F. Section F1.2 states that the BDB electrical receptacles 53 will be connected to a new breaker on the 120VAC vital bus panels. However, this new breaker is not identified in Section A.4, Action item 12 (page 11), nor in F1.2.2.

Please clarify if this is a breaker will be installed as part of the FLEX and if it is part of the modifications necessary for Phase2

• Q Serial No. 12-161E Docket No. 50-336 Order EA-12-049 Attachment 3 Page 6 of 8 DNC Response:

The receptacles identified in Section F1.2 are to be installed and connected to new breakers within the 120VAC distribution panels. Regarding F1.2.2, the new breakers were considered part of the receptacle modification. OIP Section A.4 (Action Item 12) addressed the complete action to provide 120VAC to the distribution panels. However, the discussion only stated the actions to deploy the portable DGs and connect the DGs to the receptacles. Starting the DGs and closing the breakers to power the panels was an implied action necessary to complete the re-powering of the distribution panels.

These additional actions were included in the stated approximate completion time and do not impact the margin available to meet the depletion of battery life.

NRC Audit Question No. 64 The Order requires mitigating beyond-design-basisexternal events. On page 3 of 109, as part of the discussion of external flooding, the licensee states that seiche-related flooding is not addressedin the FSAR.

The licensee is requested to discuss why a beyond-design-basis external event such as a seiche cannot occur on Long Island Sound. If a seiche is possible, please discuss why the licensee does not consider a seiche as a beyond-design-basis external event applicable to MPS2.

DNC Response:

As stated, the MPS2 FSAR does not address seiche-related flooding. However, the MPS3 FSAR does include seiche conditions, but states that the Probable Maximum Hurricane (PMH) surge is the more significant flooding event at the MPS site. Although this statement is made for MPS3, it is applicable to both units at the MPS site.

Based on the above, DNC does not consider a seiche as a beyond-design-basis external event applicable to MPS2.

NRC Audit Question No. 80 Generic Open Item: The licensees' plans for equipment maintenance and testing which endorses the EPRI industry program for maintenance which is currently under development does not provide reasonable assurance that guidance and strategies developed and implemented under them will conform to the guidance of NEI 12-06, Section 11.5 with respect to maintenance and testing. Please provide details of the EPRI industry program for maintenance and testing of FLEX electricalequipment such as batteries, cables, and diesel generators.

Serial No. 12-161E Docket No. 50-336 Order EA-1 2-049 Attachment 3 Page 7 of 8 DNC Response:

NEI 12-06 "Diverse and Flexible Coping Strategies (FLEX) Implementation Guide" section 11.5 requires in part:

"Portable equipment that directly performs a FLEX mitigation strategy for the core, Containment, or SFP should be subject to maintenance and testing guidance provided in INPO AP 913, Equipment Reliability Process, to verify proper function.

The maintenance program should ensure that the FLEX equipment reliability is being achieved. Standard industry templates (e.g., EPRI) and associated bases will be developed to define specific maintenance and testing .....

EPRI has completed and has issued "Preventive Maintenance Basis for FLEX Equipment-Project Overview Report" (Report 3002000623). Preventative Maintenance Templates for several of the FLEX Portable diesel pumps and generators have been issued. Additional PM templates are under development for the remaining FLEX equipment. PM Templates include activities such as those listed below:

- Periodic Static Inspections - Monthly walkdown

- Fluid analysis (Yearly)

- Periodic operational verifications - Quarterly starts

- Periodic functional verifications with performance tests - Annual 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> run with pump flow and head verifications The EPRI PM templates for FLEX equipment will conform to the guidance of NEI 12-06 providing assurance that the FLEX equipment is being properly maintained and tested.

EPRI templates will be used for most equipment. However, in the event EPRI templates are not available, Preventative Maintenance (PM) actions will be developed based on manufacturer provided information / recommendations. Additionally, EPRI Templates will be adopted for new pieces of FLEX equipment as they are purchased /

received on site.

NRC Audit Question No. 82 Please clarify whether you plan to abide by the Nuclear Energy Institute position paper addressing mitigating strategies in shutdown and refueling modes that is dated September 18, 2013 (ADAMS Accession No. ML13273A514), and which has been endorsed by the NRC staff (ADAMS Accession No. ML13267A382). If not, please clarify how mitigating strategies for shutdown and refueling modes will be addressed and provide justification for the plannedapproach.

Serial No. 12-161E Docket No. 50-336 Order EA-12-049 Attachment 3 Page 8 of 8 DNC Response:

MPS2 will abide by the Nuclear Energy Institute position paper entitled "Shutdown /

Refueling Modes" addressing mitigating strategies in shutdown and refueling modes that is dated September 18, 2013 and has been endorsed by the NRC staff.