ML13063A065

Submittal of Overall Integrated Plan, in Accordance with the March 12, 2012, Commission Order to Modify Licenses with Regard to Requirements for Mitigation Strategies for Beyond Design Basis External Events, EA-12-049

ML13063A065
Person / Time
Site:	Oconee
Issue date:	02/28/2013
From:	Gillespie T Duke Energy Carolinas
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
EA-12-049
Download: ML13063A065 (61)

Text

T. PRESTON GILLESPIE, Jr.

A Duke Vice President

[4'Energy Oconee Nuclear Station Duke Energy ONOl VP I 7800 Rochester Hwy.

Seneca, SC 29672 864-873-4478 864-873-4208 fax T. Gil/espie@duke-energy.com February 28, 2013 10 CFR 50.4 U. S. Nuclear Re9ulatory Commission Attn: Document Control Desk 11555 Rockville Pike Rockville, MD 20852

SUBJECT:

Duke Energy Carolinas, LLC (Duke Energy)

Oconee Nuclear Station (ONS), Units 1, 2, and 3 Docket Nos. 50-269, 50-270, and 50-287 Renewed License Nos. DPR-38, DPR-47, and DPR-55 Submittal of the ONS Overall Integrated Plan, in accordance with the March 12, 2012, Commission Order to Modify Licenses With Regard To Requirements for Mitigation Strategies for Beyond Design Basis External Events, EA-12-049

REFERENCE:

1. NRC Letter, E.J. Leeds (NRC) to All Power Reactor Licensees and Holders of Construction Permits in Active or Deferred Status, Order to Modify Licenses With Regard To Requirements for Mitigation Strategies for Beyond Design Basis External Events, EA-12-049, dated March 12, 2012, Accession No. ML12054A736

2. NRC Interim Staff Guidance JLD-ISG-2012-01, Compliance with Order EA-12-049, Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events, Revision 0, dated August 29, 2012, Accession No. ML12229A174

3. Nuclear Energy Institute document NEI 12-06, "Diverse and Flexible Coping Strategies (FLEX) Implementation Guide," Revision 0, August 21, 2012 (ADAMS Accession No.ML12242A378)

On March 12, 2012, the Nuclear Regulatory Commission (NRC) issued an Order (Reference 1) to Duke Energy. Reference 1 was immediately effective and directs Duke Energy to develop, implement, and maintain guidance and strategies to maintain or restore core cooling, containment, and spent fuel pool capabilities in the event of a beyond-design-basis external event. Specific requirements are outlined in Attachment 2 of Reference 1.

Reference 1 requires submission of an overall integrated plan, including a description of how compliance with the requirements described in Attachment 2 are to be achieved, to the Commission for review by February 28, 2013, and subsequent submission of interim status reports at six-month intervals following submittal of the overall integrated plan. Pursuant to Section IV, Condition C.1 of Reference 1, Duke Energy hereby submits to the Commission for its review the enclosed overall integrated plan for Oconee Nuclear Station.

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United States Nuclear Regulatory Commission February 28, 2013 Page 2 The Enclosure contains the current design information as of the writing of this letter, much of which is still preliminary, pending completion of on-going evaluations and analyses. As further design details and associated procedure guidance are finalized, supplemental information will be communicated to the Staff in the six-month status reports required by Reference 1.

This letter contains no new regulatory commitments.

If you have any questions or require additional information, please contact David Haile of ONS Regulatory Affairs, at (864) 873-4742.

I declare under the penalty of perjury that the foregoing is true and correct. Executed on February 28, 2013.

Sincerely, "i"fu-L~f~

T. P. Gillespie Jr., Vice President, Oconee Nuclear Station

Enclosure:

Oconee Nuclear Station (ONS}, Units 1, 2, and 3, Mitigating Strategies (FLEX) Overall Integrated Plan Contains Security Sensitive Information -

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United States Nuclear Regulatory Commission February 28, 2013 Page 3 xc:

Mr. Victor M. McCree, Administrator, Region II U.S. Nuclear Regulatory Commission Marquis One Tower 245 Peachtree Center Ave., NE, Suite 1200 Atlanta, GA 30303-1257 Mr. Eric J. Leeds, Director, Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission One White Flint North, Mailstop 13-H16M 11555 Rockville Pike Rockville, MD 20852-2738 Mr. John P. Boska, Project Manager (ONS)

(By electronic mail only)

U. S. Nuclear Regulatory Commission One White Flint North, MIS 0-8G9A 11555 Rockville Pike Rockville, MD 20852 Mr. Ed Crowe NRC Senior Resident Inspector Oconee Nuclear Station Contains Security Sensitive Information -

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ENCLOSURE OCONEE NUCLEAR STATION (ONS)

UNITS 1, 2, AND 3 DOCKET NOS. 50-269, 50-270, and 50-287 MITIGATING STRATEGIES (FLEX) OVERALL INTEGRATED PLAN

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ONS Mitigating Strategies (FLEX) Integrated Plan General Integrated Plan Elements (PWR & BWR)

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Determine Applicable Seismic Hazard Assessment:

Extreme External Hazard The seismic criteria for Oconee Nuclear Station (ONS) include two design response spectra: Maximum Hypothetical Earthquake (MHE) and Input the hazards applicable Design Basis Earthquake (DBE), also referred to as Safe Shutdown to the site; seismic, external Earthquake (SSE) and Operating Basis Earthquake (OBE) respectively.

flood. high winds. snow. ice. The Peak Ground Acceleration for the MHE and the DBE are 0.1 Og and cold, high temps. Describe 0.05g, respectively for structures founded on rock. For structures how NE/ 12-06 Sections 5 - 9 founded on overburden, the Peak Ground Acceleration for the MHE for were applied and the basis for Class 1 Structures is 0.15g (Reference 61 ). These values constitute the why the plant screened out for design basis of ONS. Per NEI 12-06, Section 5.2, all sites will consider certain hazards seismic hazard in their FLEX strategies.

Ref: NEI 12-06, S.ection 4.0 -9.0 External Flood Assessment:

JLD-ISG-2012-01, Section 1.0 ONS has extensive licensing consideration, analysis, correspondence and pending actions with respect to flooding. There are two separate external flooding events that potentially put water in the ONS yard. One of the current licensing basis external floods is a local intense precipitation event defined by the UFSAR Section 2.4.2.2. The other flooding event is defined in the June 22, 2010 Confirmatory Action Letter (CAL) as a postulated upstream dam failure (Reference 14). Both of these modeled scenarios produce flooding in the ONS yard.

Maximum external flood levels in the yard are bounded by a postulated upstream dam failure. Since the CAL was submitted, ONS has taken defense in depth steps by constructing two flood protection features.

These two features keep portions of the site dry and limit water heights in the yard. These features are not credited in ONS current licensing basi~. However, additional analysis has been performed to prove these added features lower the modeled w~ter heights (Reference 48).

Separate an.alysis is currently underway to define new flooding hazards for both the local intense precipitation event (Open Item I) and the sunny day upstream dam failure event (Open Item 2). These analyses are driven by the NRC 10 CFR 50.54(f) Recommendation 2.1, Flood Hazard Reevaluation. Therefore, ONS will consider a flood event in its FLEX strategies.

High Wind Hazard Assessment:

Using Figures 7-1 and 7-2 from NEI 12-06, it was determined the ONS site is in Region 3 which indicates tornado winds should not exceed 179 mph. However, hurricane winds could produce 140 mph peak gusts.

Therefore, ONS will consider a high wind hazard.

Extreme Cold Assessment:

Per NEI 12-06 Section 8, ONS will consider between 8 and 10 inches of snow and is considered a Level 5 (most severe) in ice storm severity:

meaning there is potential for catastrophic destruction to power lines and/or existence of extreme amounts of ice.

Extreme High Temperature Assessment:

Per NEI 12-06 Section 9, all sites will consider temperatures in excess of 110 °f.

The applicable extreme external hazards at ONS are Seismic, Flood, High Wind, Extreme Cold, and Extreme High Temperatures.

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ONS Mitigating Strategies (FLEX) Integrated Plan General Integrated Plan Elements (PWR & BWR)

Key Site assumptions to 1. Any future Station Blackout (SBO) or Extended Loss of Alternating implement NEI 12-06 Current Power (ELAP) Rule is assumed to be consistent with Order strategies. EA-12-049 (Reference 3) and JLD-ISG-2012-01(Reference4).

Different or additional requirements in the Rule may necessitate a Provide key assumptions change in the plans made in the ONS response to Order EA-12-049.

associated with implementation of FLEX 2. The NRC 10 CFR 50.54(f) Recommendation 2.1, Seismic Strategies. Reevaluation does not result in changes to the current design basis. In other words, it is assumed that the seismic re-evaluation does not Ref: NEI 12-06, Section 3.2.l adversely impact the equipment that forms a part of the ONS FLEX strategy. Any changes to the seismic design basis may require a change to the plans in the ONS response to Order EA-12-049.

3. Systems, structures, and components (SSC) will be considered seismically robust if they:

• Are constructed to ONS QA- I or Category I criteria,

• Meet the requirements to be robust relative to the SSE using Seismic Qualification Utility Group (SQUG) procedures,

• Meet the requirements to be robust relative to the SSE using EPRI 1012023, Experience Based Seismic Verification Guidelines for Piping Systems,

• Meet the requirements to be robust relative to the SSE using EPRI I 019199, Experience Based Seismic Verification Guidelines for Piping and Tubing Systems,

• Meet the requirements to be robust relative to the SSE using other industry recognized codes like A WW A D 100, or

• Are demonstrated via a shake table.

4. Personnel access to and qualification of equipment that forms a part of the FLEX strategy assumes no core damage.

5. For events with no advance warning, per NEI 12-06 Section 12 .1, on-site resources will be used to cope with the first two phases of the event and for a minimum of the first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of the event.

Emergency Response Organization (ERO) personnel are assumed to begin arriving at 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and the site ERO will be staffed at 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after the event.

6. Phase 3 resources (personnel and equipment) are assumed to start arriving within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> in accordance with the Regional Resource Center (RRC) playbook (Open Item 9). All resources from the RRC are assumed to be available within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

7. This plan defines strategies capable of mitigating a simultaneous loss of all alternating current (AC) power and loss of normal access to the ultimate heat sink resulting from a beyond-design-basis external event (BDBEE) by providing adequate capability to maintain or restore core cooling, containment, and Spent Fuel Pool (SFP) cooling capabilities at all units on a site. Though specific strategies are being developed, due to the inability to anticipate all possible scenarios, the strategies are also diverse and flexible to encompass a wide range of possible conditions. These pre-planned strategies developed to Page 3 of 58

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ONS Mitigating Strategies (FLEX) Integrated Plan General Integrated Plan Elements (PWR & BWR) protect the public health and safety will be incorporated into the unit emergency operating procedures in accordance with established Emergency Operating Procedure (EOP) change processes, and their impact to the design basis capabilities of the unit evaluated under 10 CFR 50.59. The plant 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 event 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 10 CFR 50.54(x) and/or 10 CFR 73.55(p).

8. The flood re-evaluation pursuant to the 10 CFR 50.54(t) letter of March 12, 2012 is not completed, and therefore not assumed in this submittal. Defense in depth measures have been put in place to minimize flood levels onsite in response to the CAL for upstream dam failure. Based on analysis of the effects of the defense in depth measures, flood levels onsite are estimated to peak at 4.9 feet (Reference 48). For conservatism, a maximum flood level of 10 feet (Elevation 806') will be utilized in the development of mitigating strategies (Open Item 2).

9. The ONS "FLEX Strategy" is based on A) events with pre-warning (External Flood) and B) events with no warning (Seismic) .

Extent to which the Conformance with NEI 12-06 is expected with the following exception:

guidance, JLD-ISG-2012- The exception that the Standby Shutdown Facility (SSF) Diesel 01 and NEI 12-06, are Generator will be considered available for Phase 1 coping until being followed. Identify Phase 2 FLEX equipment has been deployed and is capable of any deviations to JLD- being placed into operation, was presented to the NRC on November 8, 2012 (Reference 50).

ISG-2012-01 and NEI 12-

06. NEI 12-06, 3.2.1.3: (2) "All sources of emergency on-site AC power and Include a description of any Station Blackout (SBO) alternate AC power sources are assumed to be alternatives to the guidance, not available and not imminently recoverable" and (6) "Permanent plant and provide a milestone equipment that is contained in structures with designs that are robust schedule ofplanned action. with respect to seismic events, floods, and high winds, and associated missiles, are available" Ref: JLD-ISG-2012-01 NEI 12-06 13.1 Justification: The SSF is robust as described in (6) above. The SSF is credited for:

• The safe shutdown requirements for fire protection

• A seismic event resulting in a circulating water pipe break which floods the Turbine Building (internal flood)

• Physical Security concerns

• SBO when Turbine Driven Emergency Feedwater (TDEFW) is unavailable The SSF diesels are provided solely for operation of SSF equipment and are disconnected from normal/emergency electrical distribution system (similar to a diesel/turbine driven pump). The SSF Reactor Coolant (RC) makeup system provides Reactor Coolant Pump (RCP) seal Page 4 of 58

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ONS Mitigating Strategies (FLEX) Integrated Plan General Integrated Plan Elements (PWR & BWR) injection and seal cooling independent of the High Pressure Injection (HPI) system. The SSF Auxiliary Service Water (ASW) system provides auxiliary feedwater flow independent of the main feedwater, emergency feedwater, and station auxiliary feedwater systems.

The SSF system:

• Normally aligned to 4160V switchgear for house loads from the unit 2 main feeder bus.

• During emergency operation the SSF electrical equipment is independent of plant electrical equipment.

• SSF pumps are independent of plant equipment.

• Oconee's Phase I Coping Strategy assumes, during a complete loss of AC power event, that all three Units' Turbine Driven Emergency Feedwater (TDEFW) Pumps are also instantly unavailable at T=O. (Any one TDEFW Pump can be aligned to any or all three Units).

In an SSF mitigated event, the SSF is not connected to the offsite or onsite emergency AC power systems. Procedures, protective relaying, and interlocks ensure SSF systems are only supplied from the SSF (Reference 30, 11_, and 42).

The full capability of Phase 2 using portable equipment/strategies will be deployed with the time critical aspects beginning upon recognition of an ELAP event.

Provide a sequence of See Attachment IA-I and Attachment lA-2 events and identify any Note: This section involves Open Items which are not explicitly time constraint required id~ntified or referenced in this section, but are addressed within the key for success including the plant safety and support functions sections of the integrated plan.

technical basis for the Discussion of ELAP New Time Constraints Identified in Attachment IA:

time constraint.

Seismic:

Strategies that hm e a time 1

I. 45 min - 2 hrs - Crew determines event is ELAP and enters FLEX constraint to be successfi1l Support Guidelines (FSG). Crew exhausts all efforts to regain power should be identified with a in the EOP Blackout tab. Input from Charlotte SOC (System technical basis and a Operating Center) confirms that return of grid is not possible. FSGs justification provided that the will be developed.

time can reasonab~v be met (for example. a walkthrough 2. 2 - 3 hrs - Perfom1 additional Vital Battery deep load shedding.

of deployment). Extension in battery life to be determined based upon load shed analysis. Provides Main Control Room (MCR) indication of key Describe in detail in this variables to gain margin with respect to Phase 2 FLEX deployment section the technical basis for time.

the time constraint identified 011 the sequence of events 3. 2 - 12 hrs - Crew begins cool down of Reactor Coolant System (RCS) timeline Attachment IA using SSF and Atmospheric Dump Valves (ADVs), limited only by the ability to maintain pressurizer level. FSGs to direct a cool down See attached sequence of using the ADV while feeding from the SSF will have to be developed.

events timeline (Attachment This cool down using the SSF will utilize both steam generators JA).

(SGs). Current licensing for the SSF does not permit cool down Technical Basis Support below 525°F. ONS site specific analysis will be perfonned to support information. see attached this action.

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ONS Mitigating Strategies {FLEX) Integrated Plan General Integrated Plan Elements (PWR & BWR)

NSSS Significant Reference 4. 2 - 72 hrs - FLEX equipment deployed:

Analysis Deviation Table Portable diesel-driven pump with suction from intake canal feeding 1 (Attachment 1B) SG per unit.

Ref: NEI 12-06, Section 3.2.1.7 Establish Reactor Coolant System Makeup (RCMU)

JLD-ISG-2012-01, Section 2.1 using one of the following:

• Repowered SSF RCMU pump with suction from SFP

• Portable low capacity, high head pump taking suction from missile protected portion of borated water storage tank (BWST)

Open core flood tank (CFT) vent valves or close CFT isolation valves using power from portable generators. Repower required electrical loads, install portable lighting and ventilation fans for the vital battery rooms, electrical equipment rooms, and control rooms.

FSGs will be developed that will direct deploying FLEX Equipment and strategies. Strategies to deploy SG Makeup pumps exist, time will have to be determined. Repower of the SSF RCMUP will require new analysis to determine time. Installation of portable makeup pump supplying makeup from the BWST will require new analysis.

Venting the CFTs or isolating CFTs will require new analysis.

Repower of all electrical loads will require new analysis. New analysis required for time to install portable lighting and ventilation fans for the vital battery rooms, electrical equipment rooms, and control rooms. Deployment must be completed before end of Phase I coping.

5. 12 -72 hrs - Feed SGs with high capacity low head diesel driven portable pump taking suction from the Lake Keowee intake. Make up to RCS using one of two options in action item 4 above. Cool down and maintain RCS temp 240 - 250 °F.

FSGs will be developed directing the cool down using I SIG per unit and making up from one of the two options in 4 above. ONS site specific analysis to support cool down will be developed.

Flood:

1. 8 - 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> - When the flood recedes, Establish FLEX RCS makeup Makeup to RCS using one of the following:

• Repowered SSF RCMUP with suction from SFP.

• Portable low capacity, high head pump taking suction from missile protected portion of BWST.

• Connect the portable instrumentation in Electrical Penetration Rooms.

Install portable lighting and ventilation fans for the Electrical Penetration Rooms.

FSGs will be developed that will direct deploying FLEX Equipment and strategies. Repower of the SSF RCMUP will require new analysis to determine time. Installation of portable makeup pump supplying makeup from the BWST will require new analysis. Time to deploy and connect the portable instrumentation panel will be determined as well as portable lighting and ventilation fans.

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ONS Mitigating Strategies (FLEX) Integrated Plan General Integrated Plan Elements (PWR & BWR)

2. 24 hrs - Provide alternate source offeed using embedded condenser circulation water (CCW) water to replenish Chemical Treatment Pond I (CTP-1) for next 5.75 days. CTP-1 contains at least 1E6 gallons of water which will supply inventory for 3 units for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

Water in CCW lines could add approximately 5.75 days. FSGs to access this water and transfer to CTP-1 will be developed along with determination of time to align the equipment.

For technical basis support information, see "NSSS Significant Reference Analysis Deviation Table" (Attachment 1-B)

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Identify how strategies Deployment routes shown in attached sketches will be utilized to will be deployed in all transport FLEX equipment to the deployment areas. The identified paths modes. and deployment areas will be accessible during all modes of operation.

This deployment strategy will be included within an administrative Describe how the strategies program in order to keep pathways clear or actions to clear the pathways will be deployed in all modes. (Open Item 3). Connections for portable equipment will be sized for all modes. Portable FLEX equipment will have the capacity for all modes.

Ref: NEI 12-06, Section 13.1.6 Deployment routes are shown in the following figures:

Figure I, Figure 2, Figure 3, Figure 4, Figure 5, Figure 6, Figure 7, Figure 8, figure 9

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Provide a milestone The dates specifically required by the order are obligated or committed schedule. This schedule dates. Other dates are planned dates subject to change. Updates will be should include: provided in the periodic (six month) status reports.

• Modifications timeline o Phase 1 Modifications See attached milestone schedule in Attachment 2.

o Phase 2 Modifications o Phase 3 Modifications

• Procedure guidance development complete o Strategies o Maintenance

• Storage plan (reasonable protection)

• Staffing analysis completion

• FLEX equipment acquisition timeline

• Training completion for the strategies

• Regional Response Centers operational Ref: NEI 12-06, Section 13.1

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Identify how the ONS will implement programmatic controls in accordance with programmatic controls NEI 12-06 as defined below (Open Item 4). Procedures and guidelines will be met. will be reviewed and revised and/or generated as required to address additional programmatic controls as a result of FLEX requirements.

Ref: NEI 12-06, Section 11 Equipment associated with these strategies will be procured as JLD-ISG-2012-01, Section 6.0 commercial equipment with design, storage, maintenance, testing, and Provide a description of the configuration control in accordance with NEI 12-06 Section 11.1.

prowammatic controls Page 7 of 58

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ONS Mitigating Strategies (FLEX) Integrated Plan General Integrated Plan Elements (PWR & BWR) equipment protection. storage Installed structures, systems and components pursuant to and deployment and 10 CFR 50.63(a) will continue to meet augmented guidelines ofRG equipment quality. See 1.155 Station Blackout. The unavailability of equipment and applicable section 11 in NE! 12-06. connections that directly performs a FLEX mitigation strategy will be Storage of equipment, 11.3, managed using plant equipment control guidelines developed in will be documented in later accordance with NEI 12-06 Section 11.5 (Open Item 5).

sections of this template and Programs and processes will be established to assure personnel need not be included in this proficiency in the mitigation of beyond design basis external events is section. See section 6. 0 of developed and maintained in accordance with NEI 12-06 Section 11.6 JLD-JSG-2012-01.

(Open Item 6).

The FLEX strategies and basis will be maintained in overall FLEX basis documents (Open Item 7). Existing plant configuration control procedures will be modified (Open Item 8) to ensure that changes to the plant design, physical plant layout, roads, buildings, and miscellaneous structures will not adversely impact the approved FLEX strategies in accordance with NEI 12-06, Section 11.8.

Describe training plan Training will be initiated through the Systematic Approach to Training List training plans for (SAT) process. Training will be developed and provided to all involved affected organizations or plant personnel based on any procedural changes or new procedures describe the plan for training developed to address and identify FLEX activities. Applicable training development. will be completed prior to the implementation of FLEX (Open Item 6).

Describe Regional The industry will establish two (2) Regional Response Centers (RRC) to Response Center plan support utilities during a BDBEE. Each RRC will hold five (5) sets of Discussion in this section may equipment, four (4) of which will be able to be fully deployed when include the following requested, the fifth set will have equipment in a maintenance cycle.

information and will be further Equipment will be moved from an RRC to a local assembly area, developed as the Regional established by the Strategic Alliance of FLEX Emergency Response Response Center development is (SAFER) team and the utility. Communications will be established completed. between the affected nuclear site and the SAFER team and required

• Site-specific RRC plan equipment moved to the site as needed. First arriving equipment, as

• Identification of the primaty established during development of the nuclear site's playbook, will be and secondat)' RRC sites delivered to the site within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> from the initial request. A contract

• Identification of any alternate has been signed between the site and the Pooled Equipment Inventory equipment sites (i.e. another Company to provide Phase 3 services and equipment (Open Item 9).

nearby site with compatible equipment that can be deployed)

• Describe how delivery to the site is acceptable

• Describe how all requirements in NE/ 12-06 are identified Page 8 of 58

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ONS Mitigating Strategies (FLEX) Integrated Plan Maintain Core Cooling & Heat Removal PWR Installed Equipment (Phase 1)

Determine Baseline coping capability with installed coping 1 modifications not including FLEX modifications, utilizing methods described in Table 3-2 of NEI 12-06:

• AFW/EFW

• Depressurize SG for Makeup with Portable Injection Source

• Sustained Source of Water Ref: JLD-ISG-2012-01, Section 2 and 3 Provide a general description of the coping strategies using installed equipment including station modifications that are proposed to maintain core cooling. Identify methods (AFWIEFW) and strategies utilized to achieve this coping time.

Seismic:

At the initiation of the event, operators will enter the Emergency Operating Procedure (EOP)

(Reference 51 ). During the performance of immediate manual actions, an operator on each affected unit will be dispatched to the SSF. The control room supervisor (CRS) will transfer to the station blackout tab of the EOP and attempt to regain power by running the restoration of power enclosure. The FLEX support guidelines (FSGs) will be implemented (Open Item 4) when the enclosure actions fail to restore power and it becomes apparent that power restoration is not achievable in the near term.

The SSF is designed to operate for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> (UFSAR 9.6.3.2 RCS Makeup System). The Phase 1 reliance on the SSF will only be as long as needed to deploy the Phase 2 FLEX equipment. However, while Phase 1 coping capabilities remain viable; they will continue to be utilized. The operator at.the SSF will align SSF ASW within 14 minutes. This is a Time Critical Action (TCA) that has been validated using licensed operators (Reference 65). The SSF ASW pump will take suction from the CCW intake crossover line and discharge to both steam generators on each unit. RCS pressure will be maintained between 1950 and 2250 psig with an RCS temperature of 550 to 555°F (Reference 30). When the determination is made to enter FSGs due to an ELAP, the SSF operator will isolate letdown and begin an RCS cool down using SSF ASW and plant ADV s (Open Item 10). The atmospheric dump. valves are manual valves located in the turbine building on the 5th floor. An assessment will be completed to verify the seismic robustness of the ADV s and adequate accessibility after an event (Open Item 11 ).

Pressurizer level will be maintained and cool down rate will be established, limited only by the ability to maintain pressurizer level on scale (Open Item 10).

Flood:

At the initiation of the event, operators will enter the approved abnormal procedure for flood mitigation.

All three units will begin shutdown. Operations will run three enclosures simultaneously. (Reference 25)

The CRS enclosure: trips unit, borates RCS to Cold Shutdown (CSD) conditions, closes Core Flood Tank (CFT) isolation valves, increases levels in Pzr and SGs, and begins plant cool down to 240 - 250°F.

The Operations Shift Manager (OSM) enclosure: activates operational support center/ technical support center (OSC/TSC), classifies event, conducts site assembly, requests increased staffing, and directs SFP monitoring.

The Work Control Center Senior Reactor Operator (WCC SRO) enclosure: dispatches operators and maintenance to align portable pump and notifies Security. A change will be made to the WCC SRO enclosure to notify Maintenance, Single Point of Contact (SPOC) to pre-stage the FLEX portable instrumentation in the Penetration Rooms (Open Item 4).

1 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.

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ONS Mitigating Strategies (FLEX) Integrated Plan Maintain Core Cooling & Heat Removal PWR Installed Equipment (Phase 1)

The ;:::;3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> before SSF function is lost as flood waters in the ONS yard begin overtopping the SSF flood wall allows time to perform all the above actions as well as begin the cool down (Reference 18).

Details:

Provide a brief

• Guidance to align and operate the SSF is contained in approved description of abnormal operating procedure (Reference 30),

Procedures I Strategies I

• Guidance to perform flood actions is contained in an approved Guidelines abnormal operating procedure (Reference 25), and approved Confirm that engineering manual directive (Reference 18).

procedure/guidance exists or

• FSGs will be developed to implement FLEX strategies in accordance will be developed to support with PWROG generic FLEX support guidelines (Open Item 4).

implementation.

Identify modifications No modifications are required to support Phase 1 coping actions.

List modifications and describe how they support copinK time.

Key Reactor Parameters SEISMIC EVENT List instrumentation credited SSF: For a seismic event, Phase 1 coping will utilize the SSF to provide for this coping evaluation steam generator feed. While operating from the SSF, the following SSF phase. dedicated instrumentation with indications located in the SSF control room will be used (Reference 41, 42, and 55, and UFSAR Section 7.5.2.2.1 and Table 9-16).

1. RCS Pressure 4. Steam Generator Level

2. RCS Thot & RCS Tcold 5.ASWFlow

3. Pressurizer Level 6. Five (5) Core Exit T/Cs Note that Reactor coolant system heat removal can be direct~v monitored by RCS parameters and controlled by SG level without SG pressure indication (Reference 42 and UFSAR Section 9.6.4.6.2).

Main Control Room: The following Main Control Room instrumentation powered from 120 V AC battery backed vital panelboards remains available to support core cooling and heat removal (Reference 33, 43, and 56). A load shedding analysis will be performed to determine the length of time this instrumentation will be available. (Open Item 12)

I.RCS Wide Range Pressure 5.Steam Generator Pressure 2.RCS Thot 6.Core Exit T/Cs 3.Pressurizer Level 7.RVLIS

4. Steam Generator Level FLOOD EVENT As previously discussed, based on the advanced warning of a flood, instrumentation normally used to support core cooling and heat removal will be available for Phase 1 coping.

Notes: None.

Page 10 of 58

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ONS Mitigating Strategies (FLEX} Integrated Plan Maintain Core Cooling & Heat Removal PWR Portable Equipment (Phase 2)

Provide a general description of the coping strategies using on-site portable equipment including station modifications that are proposed to maintain core cooling. ldentijj; methods and strategies utilized to achieve this coping time.

Seismic:

Phase 2 Core cooling will be achieved with a high capacity low head portable diesel driven pump. The pump suction will come from the plant intake canal at a location separate from the intake pump structure (Figure 1). The discharge will be into one of two SG feed options.

Primary Strategy: Station ASW feed lines through the existing tap upstream of the units manual throttle valves (Figure 3). This single tap feeds a header that supplies all three units (Open Item 13 ).

Note: When the new Protected Service Water (PSW) modification is completed the Station ASW line will be replaced with a PSW line that will perform the same function (Open Item 17).

Alternate Strategy: Three individual unit connections to the SSF ASW, upstream of the SSF ASW control valves (Open Item 13) (Figure 4).

Flood:

Phase 2 Core cooling will be achieved with a high capacity low head portable diesel driven pump. The pump suction will come from Chemical Treatment Pond 1 (CTP-1 ). The discharge will be into one of two SG feed options (Figure 2).

Primary Strategy: Station ASW feed lines through the existing tap upstream of the units manual throttle valves (Figure 3). When the new Protected Service Water (PSW) modification is completed, the Station ASW line will be replaced with a PSW line that will perform the same function (Open Item 15).

Alternate Strategy: Connection to the SSF ASW lines, upstream of the SSF ASW control valves (Open Item 15) (Figure 4).

Administrative controls ensure there is always enough water in CTP-1 to supply cooling for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> (Reference 52 and 62). Phase 2 core cooling will be sustained beyond the initial capability of CTP-1, by using the water volume retained in the embedded CCW piping. Operator action to break siphon is required to maximize CCW water retention. These actions must be taken during the 2.86 hours9.953704e-4 days <br />0.0239 hours <br />1.421958e-4 weeks <br />3.2723e-5 months <br /> prior to inundation (Reference 25). Modifications are required to enable the siphon break actions. Access to the CCW inventory is achieved by opening CCW manway 1A4 or 1B4 inserting a diesel driven submersible pump, and discharging to CTP-1(Figure9). The CCW inventory coupled with the water in CTP-1 provides cooling for approximately 6.75 days (Open Item 16).

Details:

Provide a brief Site-specific procedures and/or FSGs will be developed using industry description of Procedures guidance to address th'e criteria in NEI 12-06, Section 11.4 (Open I Strategies I Guidelines Item 4).

Confirm that Flood: Guidance to perform actions is contained in approved abnormal procedure/guidance exists or operation procedure (External Flood Mitigation). New guidance must be will be developed to support developed to perform preemptive siphon break actions within 2.86 hours9.953704e-4 days <br />0.0239 hours <br />1.421958e-4 weeks <br />3.2723e-5 months <br /> implementation with a and to establish transfer flow from CCW to CTP-1 within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after des~ription of the procedure I CTP-1 feed begins (Open Item 16).

straterzv I guideline.

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ONS Mitigating Strategies (FLEX) Integrated Plan Maintain Core Cooling & Heat Removal PWR Portable Equipment (Phase 2)

Identify modifications

• PSW Feed line will replace Station ASW line. This existing List modifications necessary modification is in progress (Open Item 17).

for Phase 2

• Taps to the SSF ASW lines will be installed (Open Item 18).

• Portable pumps, portable submersible pump drive unit, and hose pathway strategies to be shown on design drawings, equipment database, design basis documents, etc (Open Item 8).

• Valves for breaking siphons in embedded CCW piping (Open Item 19).

Key Reactor Parameters SEISMIC EVENT List instrumentation Main Control Room: (Reference 33, 43, 56, and 59) credited or recovered for 1. RCS Wide Range Pressure*

this coping evaluation. 2. RCS Th 01 & RCS Tcold (Tcold will need separate re-power)

3. Pressurizer Level

4. Steam Generator Level*

5. Steam Generator Pressure

6. Core Exit T/Cs*

7. RVLIS FLOOD EVENT Indication for the same variables listed in a seismic event will be available using portable instrumentation in the East Penetration Room.

(Open Item 20)

• Indications currently required by Reference 18 and 25, and will be first priority to restore.

Storage I Protection of Equipment :

Describe storage I protection plan or schedule to determine storage requirements Seismic Structures to provide protection of the FLEX equipment will be constructed to List Protection or meet the requirements identified in NEI 12-06, Section 11. The structures will schedule to protect be built prior to the FLEX implementation date (Open Item 21 ).

The ONS procedures and programs are being developed to address storage structure requirements, deployment path requirements, and FLEX equipment requirements relative to the hazards applicable to ONS (Open Item 4 ).

Flooding Oconee intends to locate the FLEX storage facility above flood levels currently List Protection or identified in the NRC's January 28, 2011, Safety Evaluation regarding the schedule to protect CAL (Reference 63 ), unless better informed by ongoing flood hazard re-analysis and flooding mitigation modification plans (Open Item 21 ).

Note: If stored below current flood level, then ensure procedures exist to move equipment prior to exceeding flood level.

Severe Storms with Structures to provide protection of the FLEX equipment will be constructed to High Winds meet the requirements identified in NEI 12-06, section 11. The structures will List Protection or be built prior to the FLEX implementation date (Open Item 21 ).

schedule to protect The ONS procedures and programs are being developed to address storage structure requirements, deployment path requirements, and FLEX equipment requirements relative to the hazards applicable to ONS (Open Item 4).

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ONS Mitigating Strategies (FLEX) Integrated Plan Maintain Core Cooling & Heat Removal PWR Portable Equipment (Phase 2)

Snow, Ice, and Structures to provide protection of the FLEX equipment will be constructed to Extreme Cold meet the requirements identified in NEI 12-06, Section 11. The structures will List Protection or be built prior to the FLEX implementation date (Open Item 21 ).

schedule to protect The ONS procedures and programs are being developed to address storage structure requirements, deployment path requirements, and FLEX equipment requirements relative to the hazards applicable to ONS (Open Item 4).

High Temperatures Structures to provide protection of the FLEX equipment will be constructed to List Protection or meet the requirements identified in NEI 12-06, Section 11. The structures will schedule to protect be built prior to the FLEX implementation date (Open Item 21 ).

The ONS procedures and programs are being developed to address storage structure requirements, deployment path requirements, and FLEX equipment requirements relative to the hazards applicable to ONS (Open Item 4 ).

Deployment Conceptual Design (Attachment 3 contains Conceptual Sketches)

Strate2V Modifications Protection of connections Identify Strategy including how the equipment will Identify Identify how the connection be deployed to the point of use. modifications is protected Phase 2 core cooling strategy Primary and

• SG Feed Connections are located Alternate: Connections inside the Aux Bldg on

• Equipment deployed outside is stored in a (Open Item 18) QA- I or seismically robust FLEX equipment storage building.

• FLEX Equipment piping.

• Some equipment to complete Primary Storage Building Strategy inside connections may be pre-staged (Open Item 21) in the Aux Bldg.

• FLEX hoses stacked in hose trailers for easy flaking.

• Towing vehicles and debris clearing machinery are deployed from the FLEX equipment storage building.

• Pumps, hoses, fittings, generators are trailer mounted for ease of deployment.

Deploy submersible pump in CCW embedded Breaking siphons on CCW embedded piping is piping via manways. CCW embedded robust.

piping (Open Item 1.2).

Notes: None.

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ONS Mitigating Strategies (FLEX) Integrated Plan Maintain Core Cooling & Heat Removal PWR Portable Equipment (Phase 3)

Provide a general description of the coping strategies using Phase 3 equipment including modifications that are proposed to maintain core cooling. Identify methods and strategies utilized to achieve this coping time.

At the end of Phase 2, based on preliminary analysis the RCS will be between 240 to 250'F (Open Item 10).

Continue to steam SGs using the diesel driven pump and ADVs while allowing RCS pressure to slowly decrease as RCS temperature decreases until a Decay Heat Removal (OHR) capability is available.

The Phase 3 capability is to sustain Phase 2 SG makeup by:

(a) Supplying spare makeup pumps and redundant capability (b) Integrate filtration and demineralization Additionally, a Phase 3 strategy [offsite resources] will have to be developed for flood to establish logistics for delivery (and purification/filtration) of raw water to the site (CTP-1) at an estimated rate of approximately 700,000 gpd within approximately 6 days (Open Item 23 ).

Details:

Provide a brief description Site-specific procedures and/or FSGs will be developed using of Procedures I Strategies I industry guidance to address the criteria in NEI 12-06, Section 11.4 Guidelines (Open Item 4).

Confirm that procedure/guidance exists or Flood will be developed to support

• Establish FSGs to continue water makeup to CTP-1 using offsite implementation with a resources (Open Item 4 ).

description of the procedure/strategy/guideline.

Identify modifications None.

List modifications necessary for Phase 3 Key Reactor Parameters Same as Phase 2.

List instrumentation credited or recovered for this coping evaluation.

Deployment Conceptual Design (Attachment 3 contains Conceptual Sketches)

Strategy Modifications Protection of connections Identify Strategy including how the equipment Identify Identify how the connection is will be deployed to the point of use. modifications protected Same as Phase 2. Same as Phase 2. Same as Phase 2.

Notes: None.

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ONS Mitigating Strategies (FLEX) Integrated Plan Maintain RCS Inventory Control PWR Installed Equipment (Phase 1)

Determine Baseline coping capability with installed coping2 modifications not including FLEX modifications, utilizing methods described in Table 3-2 of NEI 12-06:

• Low Leak RCP Seals or RCS makeup required

• All Plants Provide Means to Provide Borated RCS Makeup Provide a general description of the coping strategies using installed equipment including modifications that are proposed to maintain core cooling. Identify methods (Low Leak RCP Seals and/or borated high pressure RCS makeup) and strategies utilized to achieve this coping time.

Seismic:

The SSF is designed to operate for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> per UFSAR 9.6.3.2 RCS Makeup System. The Phase 1 reliance on the SSF will only be as long as needed to deploy the Phase 2 FLEX equipment. The operator at the SSF will align Reactor Coolant Makeup (RCMU) to supply Reactor Coolant Pump (RCP) seals within 20 minutes. This is a Time Critical Action that has been validated using licensed operators (Reference 65). Activation of the SSF within the required time maintains RCP seal function. The SSF RCMUP will take suction from the Spent Fuel Pool (SFP) and discharge to the RCP seal injection lines, to provide both boration of the RCS along with RCS make up and RCP seal cooling (Reference 41 ).

A minimum RCP Seal leakage of 8 gpm per unit will be included in the cool down analysis; which is consistent with WCAP Section 4.4.3 (Reference 5) for seals that do not experience overheating (Open Item I 0).

Flood:

Because of the advanced warning and conservative time assumed before the loss of plant components (3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />), the RCS will be fully borated using existing plant equipment before normal equipment is lost (Reference 64 ). Pressurizer level will be increased to accommodate normal RCS leakage (Reference 25).

Similarly, a minimum RCP Seal leakage of 8 gpm per unit will be included in the cool down analysis for a Flood Event; which is consistent with WCAP Section 4.4.3 (Reference 5) for seals that do not experience overheating (Open Item 10).

Details:

Provide a brief Seismic:

description of Procedures Guidance to align and operate the SSF is contained in approved I Strategies I Guidelines abnormal operating procedure (Reference 30). (SSF AOP).

Confirm that procedure/guidance exists or Flood:

will be developed to support Guidance to perform actions is contained in approved abnormal implementation operating procedure (External Flood Mitigation).

Identify modifications None required.

List modifications 2

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.

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ONS Mitigating Strategies {FLEX) Integrated Plan Maintain RCS Inventory Control PWR Installed Equipment (Phase 1)

Key Reactor Parameters SEISMIC EVENT List instrumentation credited SSF:For a seismic event, Phase I coping will utilize the SSF to for this coping evaluation. provide RCS makeup capability. While operating from the SSF, the following SSF dedicated instrumentation with indications located in the SSF control room will be used for RCS inventory control (Reference 41, 42, 55, and UFSAR Section 7.5.2.2.1 and Table 9-16).

I. RCS Pressure I 3. Pressurizer Level I

2. RCS Tho!& RCS Tcold I 4. Five (5) Core Exit T/Cs I Main Control Room: The following Main Control Room instrumentation powered from 120 V AC battery backed vital panelboards remains available to support RCS inventory control (Reference 43 and 56). A load shedding analysis will be performed to determine the length of time this instrumentation will be available (Ogen Item 12).

I. RCS Wide Range Pressure 4. Core Exit T/Cs

2. RCS Thot 5. RVLIS

3. Pressurizer Level 6. Excore NI-1, 2

7. RB Normal and Emergency Sump Level FLOOD EVENT As previously discussed, based on the advanced warning of a flood, instrumentation normally used to support RCS inventory control remains available for Phase I coping.

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ONS Mitigating Strategies (FLEX) Integrated Plan Maintain RCS Inventory Control PWR Portable Equipment (Phase 2)

Provide a general description of the coping strategies using on-site portable equipment including modifications that are proposed to maintain core cooling. Identify methods (Low Leak RCP Seals and/or borated high pressure RCS makeup) and strategies utilized to achieve this coping time.

Seismic:

RCS boration and makeup will be accomplished using one of two makeup strategies:

With no power to the CF Tank isolation valves, CFT contents include pressurized nitrogen gas that could expand into the RCS; which could potentially block natural circulation flow. Strategies are to prevent CF gas injection as follows:

• Isolation/venting of CF Tank to prevent nitrogen injection, after FLEX makeup strategy established.

Primary Strategy:

• Repowering SSF RCMUP. Suction will be from the SFP to the RCP seal injection lines (Open Item 22).

• Repower CFT vent valves (CF-4 & CF-5) using portable equipment to allow venting nitrogen pressure off the tanks therefore preventing nitrogen injection into the RCS. (Open Item 22)

Alternate Strategy:

• Portable or prestaged high pressure low flow (40 gpm) injection pump taking a suction from the missile protected portion of the Borated Water Storage Tank (BWST) and discharging into existing vent lines on the High Pressure Injection (HPI) injection header (Open Item 25).

• Repower CFT isolation valves (CF-1 and CF-2) using portable equipment to allow isolation of the Core Flood Tanks (CFTs) to prevent nitrogen injection into the RCS (Open Item 22).

Flood:

RCS boration is accomplished during shutdown.

Makeup will be accomplished using either of the previous makeup options.

CF-1 and CF-2 are closed during Phase 1(Reference25).

Details:

Provide a brief Site-specific procedures and/or FSGs will be developed using industry description of guidance to address the criteria in NEI 12-06, Section 11.4 Procedures I Strategies I (Open Item 4 ).

Guidelines Confirm that procedure/guidance exists or will be developed to support implementation Identify modifications

• Repower the SSF RCMUP (Open Item 22).

List modifications

• Repower CFT Isolation or Vent Valves (Open Item 22).

• Provide suction tap on outlet of BWST (Open Item 25).

• Provide connection to HPI injection header (Open Item 25).

• Install portable high pressure pump (Ooen Item 22 and 25).

Page 17 of 58

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ONS Mitigating Strategies (FLEX) Integrated Plan Maintain RCS Inventory Control PWR Portable Equipment (Phase 2)

Key Reactor Parameters SEISMIC EVENT List instrumentation credited Main Control Room: (Reference 33, 43, 56, 58, and 59) or recovered for this coping 1. RCS Wide Range Pressure*

evaluation. 2. RCS T hot & RCS Tcold (Tcold will need separate repower)

3. Pressurizer Level

4. Core Exit T/Cs*

5. RVLIS

6. Excore NI-1 & 2

7. RB Normal and Emergency Sump Level

8. RCS High Point Vent Valve position indication (requires separate repower)

9. RCS Head Vent Valve position indication (requires separate repower)

FLOOD EVENT Indication for the same variables listed in a seismic event will be available using portable instrumentation in the East Electrical Penetration Room (Open Item 20).

• Indications currently required by Reference 18 and 25, will be first priority to restore.

Storage I Protection of Equipment:

Describe storae:e I protection plan or schedule to determine storae:e requirements Seismic Structures to provide protection of the FLEX equipment will be constructed to List Protection or meet the requirements identified in NEI 12-06, Section 11. The structures will schedule to protect be built prior to the FLEX implementation date (Open Item 21 ).

The ONS procedures and programs are being developed to address storage structure requirements, deployment path requirements, and FLEX equipment requirements relative to the hazards applicable to ONS (Open Item 4).

Flooding Oconee intends to locate the FLEX storage facility above the current flood List Protection or levels as identified in Reference 63 unless better informed by ongoing flood schedule to protect hazard re-analysis and flooding mitigation modification plans (Open Item 21 ).

Note: if stored below current flood level, then ensure procedures exist to move equipment prior to exceeding flood level.

Severe Storms with Structures to provide protection of the FLEX equipment will be constructed to High Winds meet the requirements identified in NEI 12-06, Section 11. The structures will List Protection or be built prior to the FLEX implementation date (Open Item 21 ).

schedule to protect The ONS procedures and programs are being developed to address storage structure requirements, deployment path requirements, and FLEX equipment requirements relative to the hazards applicable to ONS (Open Item 4).

Page 18 of 58

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ONS Mitigating Strategies (FLEX) Integrated Plan Maintain RCS Inventory Control PWR Portable Equipment (Phase 2)

Snow, Ice, and Structures to provide protection of the FLEX equipment will be constructed to Extreme Cold meet the requirements identified in NEI 12-06, Section 11. The structures will List Protection or be built prior to the FLEX implementation date (Open Item 21 ).

schedule to protect The ONS procedures and programs are being developed to address storage structure requirements, deployment path requirements, and FLEX equipment requirements relative to the hazards applicable to ONS (Open Item 4).

High Temperatures Structures to provide protection of the FLEX equipment will be constructed to List Protection or meet the requirements identified in NEI 12-06, Section 11. The structures will schedule to protect be built prior to the FLEX implementation date (Open Item 21 ).

The ONS procedures and programs are being developed to address storage structure requirements, deployment path requirements, and FLEX equipment requirements relative to the hazards applicable to ONS (Open Item 4).

Deployment Conceptual Modification (Attachment 3 contains Conceptual Sketches)

• Strate!!V Modifications Protection of connections Identify Strategy including how the equipment Identify modifications Identify how the connection will be deployed to the point of use. is protected Phase 2 inventory makeup strategy Primary

• HPI Injection Header Connections are inside the and Alternate: Connections Aux Bldg on QA-1 or

• Equipment deployed outside is stored in a (Open Item 25). seismically robust piping.

FLEX equipment storage building.

• FLEX Equipment

• Some equipment to complete Alternate Storage Building strategy inside connections may be (Open Item 21 ).

prestaged in the Aux Bldg.

• Towing vehicles and debris clearing machinery are deployed from the FLEX equipment storage building.

• Pumps, hoses, and fittings are trailer mounted for ease of deployment.

Deploy portable power distribution equipment Repower SSF RCMUP Connections will be on or

• Generators, transformers, power panel or portable high pressure within QA-1 or robust SSCs boards, and associated cabling. pump, CFT isolation or (MCCs, power panelboards, vent valves, RCS Head electrical terminal blocks, and Loop vent valves etc.)

(Ooen Item 22).

Notes: None.

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ONS Mitigating Strategies (FLEX) Integrated Plan Maintain RCS Inventory Cont.1;01 PWR Portable Equipment (Phase 3)

Provide a general description of the coping strategies using Phase 3 equipment including modifications that are proposed to maintain core cooling. Identify methods (Low Leak RCP Seals and/or borated high pressure RCS makeup) and strategies utilized to achieve this coping time.

At the end of Phase 2, based on preliminary analysis the RCS will be between 240 to 250'F (Open Item 10).

The Phase 3 capability is to sustain RCS Phase 2 makeup by:

(a) supplying spare makeup pumps, generators, and redundant capability (b) supplying boration RCS makeup will be controlled using one of the following strategies from Phase 2:

Primary Strategy: SSF RCMUP repowered in Phase 2. Suction will be from the SFP to the RCP seal injection lines (Open Item 22).

Alternate Strategy: Portable high pressure low flow injection pump taking suction from the missile protected portion of the BWST and discharging into existing vent lines on the HPI injection header (Open Item 25).

Details:

Provide a brief Site-specific procedures and/or FSGs will be developed using industry description of guidance to address the criteria in NEI 12-06, Section 11.4 (Open Procedures I Strategies I Item 4).

Guidelines Confirm that procedure/guidance exists or will be developed to support implementation Identify modifications None.

List modifications Key Reactor Parameters Same as Phase 2.

List instrumentation credited or recovered for this coping evaluation Deployment Conceptual Modification (Attachment 3 contains Conceptual Sketches Strategy Modifications Protection of connections Identify Strategy including how the equipment Identify modifications Identify how the connection is will be deploy_ed to the point of use. protected Same as Phase 2. Same as Phase 2. Same as Phase 2.

Notes: None.

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ONS Mitigating Strategies {FLEX) Integrated Plan Maintain Containment PWR Installed Equipment (Phase 1)

Determine Baseline coping capability with installed coping3 modifications not including FLEX modifications, utilizing methods described in Table 3-2 ofNEI 12-06:

• Containment Spray

• Hvdroe:en ie:niters (ice condenser containments onlv)

Provide a general description of the coping strategies using installed equipment including modifications that are proposed to maintain containment. Identify methods (containment spray/Hydrogen igniter) and strategy(ies) utilized to achieve this coping time.

Based on planned mitigating strategies and preliminary reviews of existing analysis (Reference 19 and 24 ), containment integrity is not expected to be challenged for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. Additional analysis will be required beyond 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. Therefore, there are no Phase I actions required at this time. (Open Item 26).

ONS does not have ice condenser containments.

Details:

Provide a brief NIA description of Procedures I Strategies I Guidelines Identify modifications NIA Key Containment SEISMIC EVENT Parameters An indication of containment pressure during Phase I coping is not List instrumentation credited required based on preliminary reviews of existing containment response for this coping evaluation. analysis (Reference 19 and 24) for a loss of AC power event. Re-power will be addressed in Phase 2.

FLOOD EVENT An indication of containment pressure during Phase 1 coping is not required based on preliminary reviews of existing containment response analysis (Reference 19 and 24) for a loss of AC power event. Re-power will be addressed in Phase 2.

Notes: None.

3 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.

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ONS Mitigating Strategies {FLEX) Integrated Plan Maintain Containment PWR Portable Equipment (Phase 2)

Provide a general description of the coping strategies using on-site portable equipment including modifications that are proposed to maintain core cooling. Identify methods (containment spray/hydrogen igniters) and strategies utili=ed to achieve this coping time.

Based on planned mitigating strategies and preliminary reviews of existing analysis (Reference 19 and 24), contai1,1ment integrity is not expected to be challenged for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. Additional analysis will be required beyond 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> (012en Item 26).

Details:

Provide a brief Site-specific procedures and/or FSGs will be developed using industry description of Procedures guidance to address the criteria in NEI 12-06, Section 11.4 (012en I Strategies I Guidelines Item 4).

Confirm that procedure/guidance exists or will be developed to support implementation Identify modifications None.

List modifications Key Containment SEISMIC EVENT Parameters Wide Range RB Pressure List instrumentation credited (Note: Not a priority item based 011 preliminmy review of or recovered for this coping existing containment response analysis) evaluation.

FLOOD EVENT Indication of Wide Range RB Pressure will be available using portable instrumentation in the East Electrical Penetration Room.

Storage I Protection of Equipment:

Describe stora2e I protection plan or schedule to determine storage requirements Seismic Structures to provide protection of the FLEX equipment will be constructed to List hott* equipment is meet the requirements identified in NEI 12-06, Section 11. The structures will protected or schedule be built prior to the FLEX implementation date (012en Item 21 ).

to protect The ONS procedures and programs are being developed to address storage structure requirements, deployment path requirements, and FLEX equipment requirements relative to the hazards applicable to ONS (012en Item 4).

Flooding Oconee intends to locate the FLEX storage facility above the current flood List how equipment is levels as identified in Reference 63 unless better informed by ongoing flood protected or schedule hazard re-analysis and flooding mitigation modification plans (012en Item 21 ).

to protect Severe Storms with Structures to provide protection of the FLEX equipment will be constructed to High Winds meet the requirements identified in NEI 12-06, Section 11. The structures will List how equipment is be built prior to the FLEX implementation date (012en Item 21 ).

protected or schedule The ONS procedures and programs are being developed to address storage to protect structure requirements, deployment path requirements, and FLEX equipment requirements relative to the hazards applicable to ONS (012en Item 4).

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ONS Mitigating Strategies (FLEX) Integrated Plan Maintain Containment PWR Portable Equipment (Phase 2)

Snow, Ice, and Structures to provide protection of the FLEX equipment will be constructed to Extreme Cold meet the requirements identified in NEI 12-06, Section 11. The stmctures will List how equipment is be built prior to the FLEX implementation date (Open Item 21 ).

protected or schedule The ONS procedures and programs are being developed to address storage to protect structure requirements, deployment path requirements, and FLEX equipment requirements relative to the hazards applicable to ONS (Open Item 4).

High Temperatures Structures to provide protection of the FLEX equipment will be constructed to List how equipment is meet the requirements identified in NEI 12-06, Section 11. The structures will protected or schedule be built prior to the FLEX implementation date (Open Item 21 ).

to protect The ONS procedures and programs are being developed to address storage structure requirements, deployment path requirements, and FLEX equipment requirements relative to the hazards applicable to ONS (Open Item 4 ).

Deployment Conceptual Modification (Attachment 3 contains Conceptual Sketches Strate~ Modifications Protection of connections Identify Strategy including how the equipment Identify modifications Identify how the connection is will be deployed to the point of use. protected None. None. None.

Notes: None.

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ONS Mitigating Strategies (FLEX) Integrated Plan Maintain Containment PWR Portable Equipment (Phase 3)

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

See Phase 2 Response.

Details:

Provide a brief Site-specific procedures and/or FSGs will be developed using industry description of Procedures guidance to address the criteria in NEI 12-06, Section 11.4 (Open I Strategies I Guidelines Item 4).

Confirm that procedure/guidance exists or will be developed to support implementation Identify modifications None.

List modifications Key Containment Same as Phase 2.

Parameters List instrumentation credited or recovered for this coping evaluation.

Deployment Conceptual Modification (Attachment 3 contains Conceptual Sketches Strate!!\' Modifications Protection of connections Identify Strategy including how the equipment Identify modifications Identify how the connection is will be deployed to the point of use. protected Same as Phase 2. Same as Phase 2. Same as Phase 2.

Notes: None.

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ONS Mitigating Strategies (FLEX) Integrated Plan Maintain Spent Fuel Pool Cooling PWR Installed Equipment (Phase 1)

Determine Baseline coping capability with installed coping4 modifications not including FLEX modifications, utilizing methods described in Table 3-2 of NEI 12-06:

• Makeup with Portable Injection Source Provide a general description of the coping strategies using installed equipment including modifications that are proposed to maintain spent fuel pool cooling. Identtfy methods (makeup via portable injection source) and strategies utilized to achieve this coping time.

Upon a loss of power/loss of SF cooling:

• Abnormal procedures contain curves that predict SFP temperatures versus times and heat loads .

(Reference 27 and 28)

• The Engineering Manual, Emergency Response Plan has guidance to establish vent paths (Reference 46).

Per design drawings Reference 12 and .Ll., time to boil is estimated at 6.1 hours1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> (U3 pool) and 7 hours8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br /> (Ul/U2 pool). These values are based on the licensed abnormal heat load (full core offload) of 30.8 million BTU/hr for U3 pool and 34 million BTU/hr for the U l/U2 pool (Reference 40). Design analysis also supports that sufficient coping time exists to establish inventory makeup in Phase 2 prior to fuel damage (Reference 45).

SFP level indication will be available via NRC Order EA 12-051.

Details:

Provide a brief Approved abnormal operating procedures contain guidance for description of Procedures monitoring level and determining when to establish makeup to the SFP.

I Strategies I Guidelines (Reference 27 and 28)

Confirm that procedure/guidance exists or will be developed to support implementation Identify modifications Modifications to SFP level instruments per NRC Order EA 12-051.

List modifications Key SFP Parameters Spent Fuel Pool Primary Level List instrumentation credited Spent Fuel Pool Alternate Level or recovered for this coping In accordance with NRC Order EA 12-051 and NEI 12-02.

evaluation.

Notes: None.

4 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.

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ONS Mitigating Strategies (FLEX) Integrated Plan Maintaio Spent Fuel Pool Cooling PWR Portable Equipment (Phase 2)

Provide a general description of the coping strategies using on-site portable equipment including modifications that are proposed to maintain spent fuel pool cooling. Identify methods (makeup via portable injection source) and strategies utilized to achieve this coping time.

Actions to be taken prior to the onset of boiling include:

• Verify Operation of SFP level instrumentation.

• Installation of the 8.5.b SFP spray nozzle and routing the flexible hose from the spray nozzle to the accessible staging location outside.

The capability to provide 200 gpm per unit as required per Table D-3 in NEI 12-06 will be provided (Open Item 27). This capability bounds the maximum boil off rates (Reference 12 and .LlJ Based on preliminary analysis, one pump can supply both Spent Fuel Pools (Open Item 27).

For the U 1/U2 pool, the boil down time to reach a level approximately 1O' above the fuel racks is 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. To reach a level 1' above the fuel racks is 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. The maximum rate of inventory loss considering 29 gpm RCMU feed to both units and 56.9 gpm boil off is 114.9 gpm (Reference 12).

For U3, the maximum rate of inventory loss considering 29 gpm RCMU feed to U3 and 33.3 gpm boil off is 62.3 gpm. Boil down times are bounded by the Ul/U2 pool (Reference 13).

Seismic:

Analysis will be performed to verify SF cooling can be achieved with a portable diesel driven pump (Open Item 27). The pump suction will come from the plant intake canal at a location separate from the intake pump structure (Figure 1). The discharge will be into one of two connection options.

Primary Strategy: Permanently installed Spent Fuel Pool fill line located in the Unit 1 and Unit 3 Cask Decontamination Rooms (Figure 5 and§.). Analysis will be performed to verify seismic robustness (Open Item 28).

Alternate Strategy: Flexible hose pulled from the spray nozzle at the pool deck to the staging location outside (Figure 7 and ~).

Flood:

Analysis will be performed to verify SF cooling can be achieved with a portable diesel driven pump (Open Item 27). The pump suction will come from CTP-1 (Figure 2). The discharge will be into one of two connection options.

Primary Strategy: Permanently installed Spent Fuel Pool fill line located in the Unit 1 and Unit 3 Cask Decontamination Rooms (Figure 5 and§.). Analysis will be performed to verify seismic robustness (Open Item 28).

Alternate Strategy: Flexible hose pulled from the spray nozzle at the pool deck to the staging location outside (Figure 7 and ~).

See Phase 2 response for Core Cooling for sustaining CTP-1 inventory.

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ONS Mitigating Strategies {FLEX) Integrated Plan Maintain Spent Fuel Pool Cooling PWR Portable Equipment (Phase 2)

Details:

Provide a brief Site-specific procedures and/or FSGs will be developed using industry description of Procedures guidance to address the criteria in NEI I 2-06,Section I I .4 (Open I Strategies I Guidelines Item 4).

Con.firm that procedi!re/guidance exists or will be developed to support implementation Identify modifications None required.

List modifications Key SFP Parameter Spent Fuel Pool Primary Level List instrumentation credited Spent Fuel Pool Alternate Level or recovered for this coping In accordance with NRC Order EA I 2-05 I and NEI I 2-02.

evaluation.

Storage I Protection of Equipment:

Describe storage I protection plan or schedule to determine storage requirements Seismic Structures to provide protection of the FLEX equipment will be constructed to List how equipment is meet the requirements identified in NEI 12-06,Section I I. The structures will protected or schedule be built prior to the FLEX implementation date (Open Item 2 I).

to protect The ONS procedures and programs are being developed to address storage structure requirements, deployment path requirements, and FLEX equipment requirements relative to the hazards applicable to ONS (Open Item 4).

Flooding Oconee intends to locate the FLEX storage facility above the current flood List how equipment is levels as identified in Reference 63 unless better informed by ongoing flood protected or schedule hazard re-analysis and flooding mitigation modification plans (Open Item 21 ).

to protect Severe Storms with Structures to provide protection of the FLEX equipment will be constructed to High Winds meet the requirements identified in NEI I 2-06,Section I I. The structures will List how equipment is be built prior to the FLEX implementation date (Open Item 2 I).

protected or schedule The ONS procedures and programs are being developed to address storage to protect structure requirements, deployment path requirements, and FLEX equipment requirements relative to the hazards applicable to ONS (Open Item 4).

Snow, Ice, and Structures to*provide protection of the FLEX equipment will be constructed to Extreme Cold meet the requirements identified in NEI 12-06,Section I I. The structures will List how equipment is be built prior to the FLEX implementation date (Open Item 21 ).

protected or schedule The ONS procedures and programs are being developed to address storage to protect structure requirements, deployment path requirements, and FLEX equipment requirements relative to the hazards applicable to ONS (Open Item 4).

High Temperatures Structures to provide protection of the FLEX equipment will be constructed to List how equipment is meet the requirements identified in NEI I2-06,Section I I. The structures will protected or schedule be built prior to the FLEX implementation date (Open Item 2 I).

to protect The ONS procedures and programs are being developed to address storage structure requirements, deployment path requirements, and FLEX equipment requirements relative to the hazards applicable to ONS (Open Item 4).

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ONS Mitigating Strategies (FLEX) Integrated Plan Maintain Spent Fuel Pool Cooling PWR Portable Equipment (Phase 2)

Deployment Conceptual Design (Attachment 3 contains Conceptual Sketches Stratel!V Modifications Protection of connections Identify Strategy including how the equipment Identify modifications Identify how the connection is will be deployed to the point of use. protected Phase 2 inventory makeup strategy Option 1 None. The *fill line connections are and Option 2: in the Aux Bldg (Open Item

• Equipment deployed outside is stored in a 28). FLEX hose is deployed FLEX equipment storage building. all the way to the pool deck.

• Some equipment to complete Option 2 inside connections may be pre-staged in the Aux Bldg.

• Towing vehicles and debris clearing machinery are deployed from the bunker.

• Pumps, hoses, and fittings are trailer mounted for ease of deployment.

Notes: None.

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ONS Mitigating Strategies {FLEX) Integrated Plan Maintain Spent Fuel Pool Cooling PWR Portable Equipment (Phase 3)

Provide a general description of the coping strategies using Phase 3 equipment including modifications that are proposed to maintain spent fuel pool cooling. Identify methods (makeup via portable injection source) and strategies utilized to achieve this coping time.

Phase 2 will leave the SFPs with inventory makeup capability.

The Phase 3 capability is to sustain Phase 2 Spent Fuel Pool makeup by:

(a) supplying spare makeup pumps and redundant capability (b) integrate filtration and demineralization (c) the capability to add boron as needed See Phase 3 response for Core Cooling for sustaining CTP-1 inventory.

Details:

Provide a brief Site-specific procedures and/or FSGs will be developed using industry description of Procedures guidance to address the criteria in NEI 12-06, Section 11.4 (Open I Strategies I Guidelines Item 4).

Confirm that procedure/guidance exists or will be developed to support implementation Identify modifications None List modifications Key SFP Parameter Spent Fuel Pool Primary Level List instrumentation credited Spent Fuel Pool Alternate Level or recovered for this coping In accordance with NRC Order EA 12-051 and NEI 12-02.

evaluation.

Deployment Conceptual Design (Attachment 3 contains Conceptual Sketches)

Strate!!V Modifications Protection of connections Identify Strategy including how the equipment Identify modifications Identify how the connection will be deploved to the point of use. is protected Same as Phase 2. Same as Phase 2. Same as Phase 2.

Notes: None.

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ONS Mitigating Strategies (FLEX) Integrated Plan Safety Functions Support PWR Installed Equipment Phase 1 Determine Baseline coping capability with installed coping~ modifications not including FLEX modifications.

Provide a general description of the coping strategies using installed equipment including station modifications that are proposed to maintain and/or support safety functions. Identify methods and strategies utilized to achieve coping times.

For the bounding T=O event (Seismic), Phase 1 coping will initially rely on the SSF and the associated SSF control room instrumentation.

SSF Instrumentation

1. RCS Pressure I 3. Pressurizer Level I 5. ASWFlow I

2. RCS Thot & RCS Tcold I 4. Steam Generator Level I 6. Five (5) Core Exit T/Cs I (Reference 41, 42, 55, and UFSAR Section 7.5.2.2.1 and Table 9-16)

Note that Reactor coolant system heat removal can be directly monitored by RCS parameters and controlled by SG level without SG pressure indication (Reference 42 and UFSAR Section 9.6.4.6.2).

Main control instrumentation fed from the vital l&C buses will remain available as described below.

Essential Instrumentation and Vital I&C A vital battery load reduction analysis will be completed to determine expected battery life with manual stripping of all loads except those components and instrumentation that are essential to supporting the FLEX strategy (Open Item 12). Extension of battery life is to provide margin for deployment of FLEX equipment for Phase 2. This instrumentation is consistent with the instrumentation outlined in PWROG generic FLEX Support Guidelines and Interfaces and NEI 12-06.

The load reduction scheme will require removal of non-essential loads beginning at T+2hrs, the estimated time to identify an event as an ELAP condition, with completion of load shedding within 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />.

The instrumentation and components that are powered from the vital buses and are required to support the strategy are as follows:

1. RCS Wide Range Pressure 4. Steam Generator Level 7.RVLIS

2. RCS Thot 5. Steam Generator Pressure 8. Excore Nl-1,2

3. Pressurizer Level 6. Core Exit T/Cs 9. RB Nonna) and Emergency Sump Level (Reference 7, 43, and 56)

For the bounding event with advanced warning (Flood), normal plant equipment and instrumentation will be available to support Phase 1 coping.

HVAC Upon loss of AC power, all Auxiliary Building power is lost, and thus no HV AC systems are available.

Abnormal procedures for degraded control room area cooling include steps to open electrical cabinet doors and control room doors (Reference 66 and 67). Based on a preliminary review of existing analyses (Reference 53), no additional actions are expected to be required during Phase 1. Additional analysis will be required (Open Item 32).

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.

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ONS Mitigating Strategies (FLEX) Integrated Plan Safety Functions Support PWR Installed Equipment Phase 1 Lighting NFPA 805 lighting is available in many areas where manual actions (eg. connecting hoses, power cables, or operating pumps or compressors) are necessary. The NFPA 805 lights have self contained batteries with an 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> life (Reference 57). An evaluation will be performed to determine if there are areas where manual actions are performed that do not have existing NFPA 805 lighting (Open Item 29).

Communication Strategies to mitigate a loss of communication systems will be developed in accordance with the response to 10 CFR 50.54(t) Recommendation 9.3 and NEI 12-01. (Open Item 30).

Staffing An ERO Staffing Analysis will be performed in accordance with 10 CFR 50.54(t) Recommendation 9.3 and NEI 12-01 which will include ensuring adequate on-shift and augmented staff are available to support, install, and operate FLEX mitigation strategy equipment (Open Item 31 ).

Details:

Provide a brief Site-specific procedures and/or FSGs will be developed using industry description of Procedures guidance to address the criteria in NEI 12-06, Section 11.4 (Open I Strategies I Guidelines Item 4).

Confirm that procedure/guidance exists or will be developed to support implementation.

Identify modifications None.

List modifications and describe how they support copinf! time.

Key Parameters As noted above.

List instrumentation credited for this coping evaluation phase.

Notes: None.

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ONS Mitigating Strategies (FLEX) Integrated Plan Safety Functions Support PWR Portable Equipment Phase 2 Provide a general description of the coping strategies using on-site portable equipment including station modifications that are proposed to maintain and/or support safety functions. Identify methods and strategies utilized to achieve coping times.

Essential Instrumentation and Vital l&C The key reactor parameters that must be monitored in Phase 2 are the same that must be monitored in Phase I with the addition of the following (these parameters are not fed from the vital buses):

I I. RCS Tcold I 3. RB Wide Range Pressure I

12. RCS High Point Vent Valve position indication I 4. RCS Head Vent Valve position indication I (Reference 58 and 59).

Power will be maintained to those parameters that are fed from the vital I&C panelboards by repowering the vital battery chargers with portable power distribution equipment which will recharge the vital batteries and ultimately repower the vital 120 VAC panelboards via the vital inverters. The above identified parameters that are not fed from the vital panelboards will be repowered directly from the portable power distribution system. This will be the primary repower strategy (Open Item 22).

The alternate repower strategy will use portable instrumentation installed in the Electrical Penetration Rooms to repower the key instrumentation parameters. Instrumentation parameters will be repowered on a priority bases starting with those variables currently required by References 18 and 25. The alternate repower strategy supports Phase 2 coping for the maximum flood event and minimizes reliance on installed infrastructure with respect to all other BDBEEs (Open Item 20).

HVAC Further analysis will be performed (Open Item 32).

Potential mitigating strategies may include:

• Opening electrical cabinet doors

• Opening control room doors

• Opening battery room doors

• Opening penetration room doors

• Opening electrical equipment room doors

• Installing fans

• Installing spot coolers Once the vital battery chargers are repowered by the portable power distribution equipment, hydrogen buildup within the battery rooms will begin to occur due to a lack of ventilation. Based on a preliminary review of existing analysis (Reference 22), there will be adequate time to implement Phase 2 portable ventilation strategies prior to hydrogen concentrations becoming a concern. Additional analysis will be required (Open Item 24).

Lighting Hard hat LED lights will be procured to ensure operators can safely move through the plant during an ELAP.

Additional portable lighting will be procured to provide lighting in the yard, to replace some of the emergency lighting once it is depleted and to enhance lighting in other areas of the plant as deemed necessary (Open Item 29).

Communication Strategies to mitigate loss of communication systems will be developed in accordance with 10 CFR 50.54(f), Recommendation 9.3 and NEI 12-01. (Open Item 30).

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ONS Mitigating Strategies (FLEX) Integrated Plan Safety Functions Support PWR Portable Equipment Phase 2 Portable Power Distribution A portable power distribution scheme will be developed to repower required equipment using portable diesel generators, transformers, power panels and cables. Equipment required to be re-powered include:

• Vital battery chargers

• Core Flood Tank (CFT) isolation valves (Primary) or Core Flood Tank Vent Valves (Alternate)

• Reactor High Point Vent Valves and the Reactor Head Vent Valves

• RCS Tcold

• RB wide range pressure indications

• SSF RCMUP (Primary) or portable high pressure reactor makeup pump (Alternate)

• Portable lighting

• Portable HV AC equipment for the control rooms, penetration rooms, electrical equipment rooms, and vital battery rooms Permanent connections will be installed or identified (such as MCC back feed receptacles or terminal blocks) to provide power to existing components from the portable power distribution equipment (Open Item 22).

Connection points in electrical penetrations or electrical terminal blocks in the Penetration Rooms will be identified to support connection of portable instrumentation and repower capability for the reactor high point and head vent valves as an alternate approach (Open Item 20).

Fuel Oil for Portable Equipment Fuel oil will initially be provided from the buried SSF Diesel Engine Fuel Oil Storage Tank (maintains a minimum of 25,000 gallons) (Reference 54 and 60) using portable fuel oil transfer pumps. The fuel oil will transferred to a refueling trailer for FLEX equipment refueling. A fuel oil analysis will need to be performed to determine daily consumption rates and verify storage requirements. (Open Item 14).

Staffing An ERO Staffing Analysis will be performed in accordance with 10 CFR 50.54(f), Section 9.3 and NEI 12-0 I which will include ensuring adequate on-shift and augmented staff are available to support, install, and operate FLEX mitigation strategy equipment (Open Item 3 I).

Details:

Provide a brief Site-specific procedures and/or FSGs will be developed using industry description of Procedures guidance to address the criteria in NEI 12-06, Section 11.4 (Open I Strategies I Guidelines Item 4).

Confirm that procedure/guidance exists or will be developed to support implementation with a description of the procedure I stratef!V I f{uideline.

Identify modifications

• Repower required loads (Open Item 22).

List modifications necessary

• Repower required loads at electrical penetrations or electrical for Phase 2 terminal blocks in the penetration rooms (Onen Item 20).

Key Parameters As previously identified.

List instrumentation credited or recovered for this coping evaluation.

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ONS Mitigating Strategies (FLEX) Integrated Plan Safety Functions Support PWR Portable Equipment Phase 2 Storage I Protection of Equipment :

Describe storage I protection plan or schedule to determine storage requirements Seismic Structures to provide protection of the FLEX equipment will be constructed to List how equipment is meet the requirements identified in NEI 12-06, Section 11. The structures will protected or schedule to be built prior to the FLEX implementation date (Open Item 21 ).

protect The ONS procedures and programs are being developed to address storage structure requirements, deployment path requirements, and FLEX equipment requirements relative to the hazards applicable to ONS (Open Item 4).

Flooding Oconee intends to locate the FLEX equipment storage building above the List how equipment is current CAL Flood levels as identified in Reference 63 unless better informed protected or schedule to by ongoing flood hazard re-analysis and flooding mitigation modification plans protect (Open Item 21 ).

Note: If stored below current flood level, then ensure procedures exist to move equipment prior to exceeding flood level.

Severe Storms with Structures to provide protection of the FLEX equipment will be constructed to High Winds meet the requirements identified in NEI 12-06, Section 11. The structures will List how equipment is be built prior to the FLEX implementation date (Open Item 21 ).

protected or schedule to The ONS procedures and programs are being developed to address storage protect structure requirements, deployment path requirements, and FLEX equipment requirements relative to the hazards applicable to ONS (Open Item 4).

Snow, Ice, and Structures to provide protection of the FLEX equipment will be constructed to Extreme Cold meet the requirements identified in NEI 12-06, Section 11. The structures will List how equipment is be built prior to the FLEX implementation date (Open Item 21 ).

protected or schedule to The ONS procedures and programs are being developed to address storage protect structure requirements, deployment path requirements, and FLEX equipment requirements relative to the hazards applicable to ONS (Open Item 4).

High Temperatures Structures to provide protection of the FLEX equipment will be constructed to List how equipment is meet the requirements identified in NEI 12-06, Section 11. The structures will protected or schedule to be built prior to the FLEX implementation date (Open Item 21 ).

protect The ONS procedures and programs are being developed to address storage structure requirements, deployment path requirements, and FLEX equipment requirements relative to the hazards applicable to ONS (Open Item 4).

Deployment Conceptual Design (Attachment 3 contains Conceptual Sketches)

Strate!!\' Modifications Protection of connections Identify Strategy including how the equipment Identify modifications Identify how the connection is will be deployed to the point of use. protected See Individual Strategies. See Individual Strategies. See Individual Strategies.

Notes: None.

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ONS Mitigating Strategies (FLEX) Integrated Plan Safety Functions Support PWR Portable Equipment Phase 3 Provide a general description of the coping strategies using Phase 3 equipment including modifications that are proposed to maintain and/or support safety functions. Identify methods and strategies utilized to achieve coping times.

Sustain Phase 2 capabilities with redundant and replacement equipment from the Regional Support Centers.

Refueling Establish offsite Fuel Oil delivery logistics (Ogen Item 9).

Details:

Provide a brief Site-specific procedures and/or FSGs will be developed using industry description of Procedures guidance to address the criteria in NEI 12-06, Section 11.4 (Ogen I Strategies I Guidelines Item 4).

Confirm that procedure/guidance exists or will be developed to support implementation *with a description of the procedure I stratezy I ~uideline.

Identify modifications Same as Phase 2.

List modifications necesswy for Phase 3 Key Parameters Same as Phase 2.

List instrumentation credited or recovered for this coping evaluation.

Deployment Conceptual Design (Attachment 3 contains Conceptual Sketches)

Strategy Modifications Protection of connections Identify Strategy including how the equipment Identify modifications Identify how the connection will be deployed to the point of use. is protected Same as Phase 2. Same as Phase 2. Same as Phase 2.

Notes: None.

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ONS Mitigating Strategies (FLEX) Integrated Plan PWR Portable Equipment Phase 2 Use and (potential I flexibility) diverse uses Pe1formance Criteria Maintenance Core RCS SFP Instrumentation Accessibility Maintenance I PM requirements List portable equipment Cooling Inventory Minimum of 130 gpm per unit or Maintenance will be perfom1ed Two (2) High Flow/Low Head Diesel Driven Pumps x x 390 gpm total, @ approximately 15 in accordance with NEI 12-06, psig Section 11.5 (Ogen Item 5)

One (1) Medium Minimum of250 gpm per pool or Maintenance will be perfom1ed Flow/Low Head Diesel x 500 gpm total @ approximately 15 in accordance with NEI 12-06, Driven Pump psig Section 11.5 (Ogen Item 5)

Maintenance will be performed Fire Hose with Storz 5 inch hose (length TBD) &3 inch Connectors x x x hose (length TBD) in accordance with NEI 12-06, Section 11.5 (Ogen Item 5)

Maintenance will be perfonned Four (4) 600 VAC Generator x x x 500 KVA in accordance with NEI 12-06, Section 11.5 (Ogen Item 5)

Maintenance will be perfonned 2 diesel driven hydraulic Size for pump specified next line power unit trailers x x x  ::::18 gpm/2800 psi in accordance with NEI 12-06, Section 11.5 (Ogen Item 5)

Maintenance will be performed 2 Hydraulic drive sump pumps x x x 500 gpm@ 60 ft head in accordance with NEI 12-06, Section 11.5 (Ogen Item 5)

Maintenance will be perfom1ed (2)Pneumatic Sump 1500 gpm Pumps x in accordance with NEI 12-06, Section 11.5 (Ogen Item 5)

Maintenance will be performed Diesel Air Compressor to drive sump pumps x in accordance with NEI 12-06, Section 11.5 (Ooen Item 5)

Maintenance will be perfonned (I) Diesel Fuel Transfer pump/ gasoline driven x x x x x in accordance with NEI 12-06, Section 11.5 (Ooen Item 5)

Maintenance will be perfonned Fuel Oil Refueling Truck/Trailer x x x x x in accordance with NEI 12-06, Section 11.5 (Ogen Item 5)

The equipment and performance criteria provided in this list are best estimates based on information available at the time the list was developed and may change as designs are finalized and implementation proceeds. Therefore, the list is not considered to be final nor regulatory commitments.

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ONS Mitigating Strategies (FLEX) Integrated Plan PWR Portable Equipment Phase 2 Use and (potential I flexibility) diverse uses Pe1forma11ce Criteria Maintenance Core RCS SFP Instrumentation Accessibility Maintenance I PM requirements List portable equipment Cooling Inventory Maintenance will be perfonned Heavy Trailer Tow Truck x x x x x in accordance with NEI 12-06, Section 11.5 (Ogen Item 5)

Maintenance will be perfonned Front end loader x x x x x in accordance with NEI 12-06, Section 11.5 (Ogen Item 5)

Maintenance will be perfonned Fire Hose Trailers x x x in accordance with NEI 12-06, Section 11.5 (Ooen Item 5)

Maintenance will be perfonned Electric Conductor Trailers x x in accordance with NEI 12-06, Section 11.5 (Ogen Item 5)

Maintenance will be perfonned Indoor LED Lighting Strings x in accordance with NEI 12-06, Section 11.5 (Ogen Item 5)

Maintenance will be perfonned Portable Fans x in accordance with NEI 12-06, Section 11.5 (Ogen Item 5)

Maintenance will be perfonned Portable Spot Coolers x in accordance with NEI 12-06, Section 11.5 (Ogen Item 5)

Maintenance will be perfonned Minimum of 4 Portable Generators x Approx. 120 V AC, 6 KW in accordance with NEI 12-06, Section 11.5 (Ooen Item 5)

Maintenance will be perfonned Hydraulic Hoses w/ Quick Connects x in accordance with NEI 12-06, Section 11.5 (Ooen Item 5)

Maintenance will be perfonned Flexible Electric Total feet & size TBD in accordance with NEI 12-06, Conductor Section 11.5 (Ogen Item 5)

The equipment and performance criteria provided in this list are best estimates based on information available at the time the list was developed and may change as designs are finalized and implementation proceeds. Therefore, the list is not considered to be final nor regulatory commitments.

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ONS Mitigating Strategies (FLEX) Integrated Plan PWR Portable Equipment Phase 2 Use and (potential I flexibility) diverse uses Pe1fonnance Criteria Maintenance Core RCS SFP Instrumentation Accessibility Maintenance I PM requirements List portable equipment Cooling Inventory Minimum of2 trailer Maintenance will be perfom1ed mounted Boom and x x x 2000 lb. actual capacity in accordance with NEI 12-06, Battery\Manual Wench Section 11.5 (Ooen Item 5)

Minimum of 4 portable Approx. 600 Amps, other specs TBD Maintenance will be perfomled power distribution panel x x Transfom1ers: 600/208 V AC & in accordance with NEI 12-06, board/transformer trailers 600/120 VAC Section 11.5 (Ogen Item 5)

Four (4) Diesel or Electric Maintenance will be perfomled RCS Makeup Approx. 40 gpm @

Low Capacity/High x 2000 psig in accordance with NEI 12-06, Pressure Pumps Section 11.5 (Ooen Item 5)

The equipment and performance criteria provided in this list are best estimates based on information available at the time the list was developed and may change as designs are finalized and implementation proceeds. Therefore, the list is not considered to be final nor regulatory commitments.

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ONS Mitigating Strategies (FLEX) Integrated Plan PWR Portable Equipment Phase 3 Use and (potential I flexibility) diverse uses Performance Criteria Notes List portable equipment Core Containment SFP Instrumentation Accessibility One (I) 5.8 MW 5.8MW Will supply power to one safety 6.9 kV Generator x x x x 6.9kV train and be used for plant recovery.

Demin Water Skid x 500 gpm capacity Boric Acid addition skid x Raw water Logistics x x Approx. 700,000 gpd Fuel Oil Logistics x x Raw Water Filtration Units x x 500 gpm Four (4) High Flow/Low Head Diesel Driven Pumps x x Per the RRC pump spec.

Fire Hose with Storz 5 inch hose (length TBD) &

Connectors x x 3 inch hose (length TBD)

Three (3) 600 VAC Generator x x x 500 KVA One (I) Diesel Fuel Transfer pump - gasoline driven x x x One (I) Fuel Oil Refueling Truck/Trailer x x x Portable Fans x Portable Spot Coolers x Minimum of 4 Portable Generators x Approx. 120 VAC, 6 KW Three (3) Diesel or Electric, RCS Makeup Approx. 40 Low Capacity, High Pressure x gpm @ 2000 psig Pumps The equipment and performance criteria provided in this list are best estimates based on information available at the time the list was developed and may change as designs are finalized and implementation proceeds. Therefore, the list is not considered to be final nor regulatory commitments.

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ONS Mitigating Strategies (FLEX) Integrated Plan Phase 3 Response Equipment/Commodities Item Notes Radiation Protection Equipment Analysis will be performed to detennine radiation protection equipment requirements (Open Item 9).

• Survey instruments

• Dosimetry

• Off-site monitoring/sampling Commodities Analysis will be performed to detem1ine commodities requirements (Open Item 9).

• Food

• Potable water Fuel Requirements Add information on site specific fuel consumption rates and available supplies. (Open Item 9 and 14).

Heavy Equipment Transportation equipment will be provided to move to large skids/trailer mounted equipment provided from

• Transportation equipment offsite (Open Item 9) .

• Debris clearing equipment The equipment and performance criteria provided in this list are best estimates based on information available at the time the list was developed and may change as designs are finalized and implementation proceeds. Therefore, the list is not considered to be final nor regulatory commitments.

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ONS Mitigating Strategies (FLEX) Integrated Plan Attachment lA-1 Sequence of Events Timeline - Seismic Response Note: The SSF is designed to operate for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> (UFSAR 9.6.3 Standby Shutdown Facility System Descriptions). Deployment of Phase 2 FLEX equipment will begin as soon as ELAP condition is recognized.

ELAP New Time Action Elapsed Constraint 6

item Time Action YIN Remarks I Applicability 0 3 Unit Trip on LOOP Plant @l 00% power 1 60 sec Emergency Operating Procedure implemented N Existing; approved Procedure 2 60 sec - AP/2S SSF EOP implemented: N Time Critical Action upon the loss of RCP 20min Feed SG within 14 min seal injection and Component Cooling.

Supply RCP seals within 20 min Guidance for stabilization directed by Stabilize RCS pressure l 9SO to 22SO psig. AP/25.

3a 20 min-. Crew follows guidance in EOP Blackout Tab to N Load shed inverters, Align ADVs, Purge H2 1 hr stabilize plant from generators, Start Station Backup Diesel Instrument Air System compressors, etc.

3b 20 min-. Crew enters AP/l-2,3/l 700/03S (Loss of SFP N Sets up checks of SFP level and 1 hr Cooling and/or Level) temperature. Addresses increases in SFP (Spent Fuel Pool) temperature due to loss of cooling. Will spray pool and/or makeup with portable diesel driven pump as necessary.

4 4S min - Crew detennines event is ELAP and enters FSGs y Crew exhausts all efforts to regain power in 2 hrs the EOP Blackout tab. Input from Charlotte SOC (System Operating Center) confirms that return of grid is not possible. FSGs will be developed fOnen Item 4).

Sa 2-3 hrs Perfonn additional Vital Battery deep load y Extension in battery life to be determined shedding based upon load shed analysis. Provides MCR indication of key variables to gain margin with respect to Phase 2 FLEX deployment times (Onen Item 12).

Sb 2hr - 12 Crew begins cool down of RCS using SSF and y FSGs to direct a cooldown using the ADV hrs ADVs, limited only by the ability to maintain while feeding from the SSF will have to be pressurizer level. developed (Open Item 4). This cooldown using the SSF will utilize both SGs. Current licensing for the SSF does not permit cooldown below 525°F. ONS site specific analysis will be performed to support this action (Onen Item 10).

6 Instructions: If No or NA is selected, provide justification in the remark column.

If yes is selected, include a technical basis discussion as required by NEI 12-06, Section 3.2.1.7.

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ONS Mitigating Strategies (FLEX) Integrated Plan ELAP New Time Action Elapsed Constraint 6

item Time Action YIN Remarks I Applicability Sc 2hr-72 FLEX equipment deployed: y FSGs will be developed that will direct hrs Portable diesel-driven pump with suction from deploying FLEX Equipment and strategies intake canal feeding 1 SG per unit (Open Item 4 ). Strategies to deploy pump Establish RCSMU using one of the following: exist, time will have to be determined.

Repower of the SSF RCMUP will require

• Repowered SSF RCMU pump with new analysis to determine time. Installation suction from SFP of portable makeup pump supplying makeup

• Portable low capacity, high head makeup from the BWST will require new analysis.

pump taking suction from missile Venting the CFTs or isolating CFTs will protected portion of BWST require new analysis. Repower of all Repower CFT vent valves or CFT isolation electrical loads will require new analysis valves using power from portable generators to (Open Item 22). New analysis required for allow venting or isolation of CF tanks once time to install portable lighting (Open Item 29) and ventilation fans for the vital RCSMU established.

battery rooms, electrical equipment rooms, Repower required electrical loads.

and control rooms. Deployment must be Install portable lighting and ventilation fans for completed before end of Phase I coping.

the vital battery rooms, electrical equipment rooms, and control rooms.

6 12hrs- Feed SGs with high capacity low head diesel y FSGs will be developed directing the 72hrs driven portable pump taking suction from the cooldown using I S/G per unit (Open Item Lake Keowee intake. :D and making up from one of the two Make up to RCS using one of two options in options in 5c. ONS site specific analysis to support cooldown will be developed (Open action item Sc.

Item 10).

Cool down and maintain RCS temp 240 - 2SO °F.

7 72 hr End of generic WCAP analysis NA End of analytical simulation.

Page 42 of 58

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ONS Mitigating Strategies (FLEX) Integrated Plan Attachment lA-2 Sequence of Events Timeline - Flood Response Note: All three units will be shutdown, required boron added, and the maximum Tech Spec cool down rate established during the 3 .0 hours0 days <br />0 hours <br />0 weeks <br />0 months <br /> before the flood inundates the site.

ELAP New Time Action Elapsed Constraint 7

item Time Action YIN Remarks I Applicability 0 Condition A declaration for Jocassee dam Plant @I 00% power 1 60 sec AP/47 (External Flood Mitigation) implemented N Existing; approved Abnormal Procedure for external flooding.

2a 60 sec - CRS: trips unit, Borates RCS to CSD conditions, N Approved guidance, run by control room 3.0 hrs closes CFT isolations, increases levels in Pzr and team. Completed before flood hits site.

SGs, and begins plant cool down.

2b 60 sec - OSM activates OSC/TSC, classifies event, N Approved guidance, run by OSM.

3.0 hrs conducts site assembly, request increased staffing, Completed before flood hits site.

and directs SFP monitoring.

2c 60 sec - WCC SRO: Dispatches operators and N Approved guidance, run by WCC SRO, 3.0 hrs maintenance to align portable Hale Pump, notifies completed before flood hits site. Request to maintenance to pre-stage the portable stage portable instrumentation will be added to AP-47.

instrumentation in the Pen Rooms and notifies Security.

3a 2.86 hrs Flood crests Intake Canal Dike and begins N flooding ONS yard. (Power is assumed to be lost) 3b 2.86 hrs Crew enters AP/1-2,3/1700/035 N Addresses increases in SFP (Spent Fuel (Loss of SFP Cooling and/or Level) Pool) temperature due to loss of cooling.

Will spray pool and/or makeup with portable diesel driven pump as necessary after flood recedes.

4 3.00 hrs SSF lost N 5 3.00 hr - Open ADVs (Atmospheric Dump Valves) Feed N Action directed by AP-4 7 on loss on all 72 hrs SGs with Hale pump taking suction from CTP I. feed.

6 8.00 hr - When the flood recedes, establish FLEX RCS y FSGs will be developed that will direct 72 hrs makeup: deploying FLEX Equipment and strategies Makeup to RCS using one of the following: (Open Item 4). Repower of the SSF

• Repowered SSF RCMUP with suction from RCMUP will require new analysis to determine time (Open Item 22). Installation SFP. of portable makeup pump supplying

• Portable low capacity, high head pump makeup from the BWST will require new taking suction from missile protected portion analysis (Open Item 25). Time to deploy ofBWST. and connect the portable instrumentation panel will be determined as well as the Connect the portable instrumentation. portable lighting (Open Item 20) and Install portable lighting and ventilation fans for ventilation fans.

the Electrical Penetration Rooms.

7 24 hr Provide alternate source of feed using embedded y CTP-1 contains at least I E6 gallons of CCW water to replenish CTP 1 for next 5.75 water which will supply inventory for 3 days. units for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. Water in CCW lines could add approximately 5.75 days (Open Item 16). FSGs to access this water and transfer to CTP-1 will be developed along with determination of time to align the eouioment <Onen Item 4 ).

8 72 hr End of generic WCAP analysis End of analytical simulation 7

Instructions: If No or NA is selected, provide justification in the remark column.

If yes is selected, include a technical basis discussion as required by NEI 12-06, Section 3 .2.1. 7.

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ONS Mitigating Strategies {FLEX) Integrated Plan Attachment lB NSSS Significant Reference Analysis Deviation Table Parameter of WCAP value Item interest (WCAP-17601-P Au2ust 2012 Revision 0) WCAP pa2e Plant applied value Gap and discussion 1 RCS Makeup Assumes no makeup throughout Makeup supplied less than 20 mins Makeup provided by SSF RCMU after ELAP. pump. Maintains RCP seal cooling until RCS temperature is below 500°F. The SSF is designed to operate for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

2 TDEFDWP Assumes adequate steam generator pressure 4.2.1.6 TDEFWP fails. No steam supply. Steam generator feed supplied Steam Supply maintained to support running the TDEFWP. from SSF ASW Pump< 14 mins after ELAP.

3 Cool down Assumes 75°F/hr cool down established at 2 4.2.1.19 Cool down matched to SSF RCMUP SSF RCMUP supplies 29 gpm hours. capacity. RCMU. Cool down, started at recognition of ELAP event (approx. 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />), is limited to maintain pressurizer level considering this MU capability.

Site specific analysis in progress.

4 Asymmetric Assumes both SGs are fed for 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> then 5.3.3.2 Feed both SGs maintaining temperature SSF RCMU and ASW feed are SG Feed feed SG on loop opposite the pressurizer. until ELAP identified. Begin cool designed to operate for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

down using both SGs fed from SSF When SSF is no longer in use, feed ASW. Continue feeding both SGs until SGs with portable diesel driven SSF no longer in use. Feed one SG pump following WCAP strategy.

preferably in loop opposite the Site specific analysis in progress.

pressunzer.

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ONS Mitigating Strategies (FLEX) Integrated Plan Attachment 2 - Milestone Schedule

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Activity M M M

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Ucensln Actions Submit Integrated Plan 6 Month Status Update Implementation Complete Modifications Develop Modifications Procurement Identify Significant Material/Equipment Material/Equipment Procurement/Delivery Im lamentation Wa1kdowns Conduct N-1 Outage Walkdowns Conduct Implementation Walkdowns Steffi Conduct Staffing Analysis Tratn Develop Training Program Implement Training ures Develop FLEX Supporting Guidelines (FSGs)

Develop Strategies/Playbook with RRC Install Offsite Delivery Pad Im lementatlon Implement Modifications "The dates and sequences provided in this milestone schedule are best estimates based on information available at the time the schedule was developed and may change as designs are finalized and construction proceeds. Therefore, these dates and sequences are not considered to be regulatory commitments."

Page 45 of 58

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ONS Mitigating Strategies (FLEX) Integrated Plan Attachment 3 - Conceptual Sketches E

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Contains Security Sensitive Information - Withhold from public disclosure under 10 CFR 2.390(d)(l)

ONS Mitigating Strategies {FLEX) Integrated Plan I .

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Contains Security Sensitive Information - Withhold from public disclosure under 10 CFR 2.390(d)(l)

ONS Mitigating Strategies (FLEX) Integrated Plan Figure 3 Page 48 of 58

Contains Security Sensitive Information - Withhold from public disclosure under 10 CFR 2.390(d)(l)

ONS Mitigating Strategies (FLEX) Integrated Plan Unit *f l\Jo,.i h k~,**_;.. ... ~

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Contains Security Sensitive Information - Withhold from public disclosure under 10 CFR 2.390(d)(l)

ONS Mitigating Strategies (FLEX) Integrated Plan

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Contains Security Sensitive Information - Withhold from public disclosure under 10 CFR 2.390(d)(l)

ONS Mitigating Strategies (FLEX) Integrated Plan n Hose Pull e:rnergemy Matceup Connection (Ground floor)

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Contains Security Sensitive Information - Withhold from public disclosure under 10 CFR 2.390(d)(l)

ONS Mitigating Strategies {FLEX) Integrated Plan Un 1&2 SFP F;,lt..,,.~ ~tu.

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Contains Security Sensitive Information - Withhold from public disclosure under 10 CFR 2.390(d)(l)

ONS Mitigating Strategies (FLEX) Integrated Plan F".J:.,, 4';..

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Contains Security Sensitive Information - Withhold from public disclosure under 10 CFR 2.390(d)(l)

ONS Mitigating Strategies (FLEX) Integrated Plan Attachment 4 - References The following references are provided for infonnation only. Their inclusion within this document does not incorporate them into the current licensing basis (CLB) by reference nor does it imply intent to do so. References which have not been docketed are available onsite for NRC examination and inspection.

Item #u Reference

Description:

1 NEI 12-06, "Diverse and Flexible Coping Strategies (FLEX) Implementation Guide", Revision 0, August 2012 2 Oconee Nuclear Station Updated Final Safety Analysis Report, Revision 21, 2011 Update NRG Order EA-12-049, "Issuance of Order to Modify Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-3 Basis External Events", March 12, 2012 Japan Lessons-Learned Project Directorate JLD-ISG-2012-01, "Compliance with Order EA-12-049, Order Modifying License with Regard 4 to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events", Interim Staff Guidance, Revision 0, August 29, 2012 5 WCAP-17601-P, Reactor Coolant Svstem Response to ELAP for Westinghouse, Combustion Engineering, and B&W, August 2012 PA-PSC-0965, PWROG generic FLEX Support Guidelines and Interfaces (Controlling Procedure Interface and Recommended 7

Instruments), Revision 0, December 2012 NEI 12-01, Guideline for Assessing Beyond Design Basis Accident Response Staffing and Communications Capabilities, Revision 0, May 8

2012 NEI 12-02, Industry Guidance for Compliance with NRG Order EA-12-051, To Modify Licenses with Regard to Reliable Spent Fuel Pool 9 Instrumentation, Revision 1, August 2012 12 ONS Units 1 and 2 Engineering Instructions: Loss of Spent Fuel Cooling Heat Up Times Due to Decay Heat 13 ONS Unit 3 Engineering Instructions: Loss of Spent Fuel Cooling Heat Up Times Due to Decav Heat Confirmatory Action Letter - Oconee Nuclear Station, Units 1, 2 and 3 Commitments to Address External Flooding Concerns (CAL 2 14 003), June 22, 2010 ONS Engineering Manual: Evaluation by Station Management in the TSC - Beyond Design Basis Mitigation Strategies for External Flood 18 Mitigation 19 ONS Calculation: Containment Response Following the Loss of All AC Power 22 ONS Calculation: Operability Evaluation for PIP 99-2499 Hydrogen Gas Generation in the Station's Battery Rooms Duke Energy Calculation: Thermal Hydraulic Analyses in Support of IER L 1 11-4 Extended Loss of AC Power Containment Integrity 24 Analysis and Other Plant Support 25 Abnormal Operating Procedure: External Flood Mitigation 27 Abnormal Operating Procedure: Unit 1& 2 Loss of SFP Cooling and/or Level 28 Abnormal Operating Procedure: Unit 3 Loss of SFP Cooling and/or Level 30 Abnormal Operating Procedure: Standby Shutdown Facility Emergency Operating Procedure 33 Design Basis Specification for the 120 VAC Vital l&C Power System 8

Reference numbers are not sequential. Some documents that were identified as potential references during the development of this document were not used in the final version; therefore, this table does not list them. The references that were used, maintained its original item number assigned to it during the development process.

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ONS Mitigating Strategies {FLEX) Integrated Plan Item#" Reference

Description:

37 EPRI 1012023, Experience Based Seismic Verification Guidelines for Piping Systems 38 EPRI 1019199, Experience Based Seismic Verification Guidelines for Piping and Tubing Systems NRC Letter to Licensees, dated March 12, 2012, Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) 39 Regarding Recommendations 2.1, 2.3, and 9.3 of the Near Term Task Force Review of Insights from the Fukushima Dai-ichi Accident 40 Design Basis Specification for the Spent Fuel Cooling System 41 Design Basis Specification for the SSF RCMU System 42 Design Basis Specification for the SSF ASW System 43 ONS Drawing: One Line Diagram 120 VAC and 125 VDC Instrumentation Vital Buses NRC Order Number EA- 12-051, Order Modifying Licenses with Regard to Requirements for Reliable Spent Fuel Pool Instrumentation, 44 dated March 12, 2012 45 ONS Calculation: Analysis for Use of Spent Fuel Pool Inventory for SSF 46 ONS Engineering Manual: Engineering Emergency Response Plan 47 AWWAD100, American Water Works Association Standard for Welded Carbon Steel Tanks for Water Storage.

48 ONS Calculation:"Resulting Flood Heights Due to Intake Dike Diversion Wall" "ONS Unit 1, 2, and 3 Slides for Public Meeting on Mitigation Strategies For NRC Order EA-12-049", Nov. 2012, ADAMS Accession 50 Number ML13004A365 51 ONS Emergency Operating Procedure, (U1, U2, & U3) 52 ONS Chemistry Procedure: Operation and Sampling of CTP-1 and CTP-2 53 ONS Calculation: Auxiliary Building GOTHIC Heat Up Analysis-PSW Event Cases 54 Technical Specification 3.10.1 _SSF, SR 3.10.1.4 55 Technical Specification Bases 3.10.1, Table 3.10.1-1 56 Design Basis Specification for the Inadequate Core Cooling Monitor (ICCM) 57 ONS Instrumentation Procedure: Maintenance and Testing of Self-Contained Battery Packs on Emergency Lights 58 ONS Drawing: One Line Diagram Auxiliary Circuits 208/120 VAC 59 ONS Drawing: One Line Diagram 240/120 VAC Auxiliary Circuits Comp., ICS, and Reg. Supply 60 ONS Flow Diagram: Fuel Oil System (SSF Diesel Engines) 61 Design Basis: Specification for the Seismic Design 62 ONS Calculation: External Flood Mitigation Flow Model Safety Evaluation by The Office of Nuclear Reactor Regulation Related to Duke Energy Carolinas, LLC Confirmatory Action Letter -

63 Comments to Address Extended Flooding Concerns Closure of Inundation Site Results ONS Units 1, 2, and 3 Docket Nos 50-269, 50-270, and 50-287 dated January 28, 2011 64 ONS Calculation: Steam Generator Tube Rupture (SGTR)/Small Break Loss of Coolant Accident (SBLOCA) Boration Requirements 65 ONS Performance Test: Time Critical Actions Verification 66 Abnormal Procedure: Unit 1 & 2 Degraded Control Room Area Cooling 67 Abnormal Procedure: Unit 3 Degraded Control Room Area Cooling Page 56 of 58

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ONS Mitigating Strategies (FLEX) Integrated Plan Attachment 5 - Open Items Item Open Item Name Item Description 1 Revised PMP HMR51 Analysis Revised PMP analysis needed with owner accepted OSC number 2 Max flood level on site 'after modifications' ONS Calculation: Resulting Flood Heights Due to Intake Dike Diversion Wall, is approved analysis for current interim modifications 3 Deployment Path Program Admin program assessment needed to keep deployment path cleared 4 Procedures and FSGs Implement programmatic controls per NEI 12-06 5 FLEX Equipment Programmatic Control Purchase, design, testing/PMs, storage, and unavailability of FLEX equipment 6 Personnel Training Personnel training with respect to FLEX equipment deployment and operation 7 FLEX Basis Document FLEX basis document needs to be developed 8 Configuration Control Modification needed for portable equipment deployment pathways, connection points, basis document, etc 9 RRC Regional Response Center "Playbook" 10 Cool down Analysis Cool down analysis by SA group is pending 11 ADV Survivability and Accessibility Need verification that ADVs will survive BDBEE and will remain accessible 12 Load Shed Analysis Vital battery deep load shed analysis to provide margin for deployment of FLEX equipment for Phase 2 13 Hydraulic Analysis for Pump Flow (Intake Need analysis for one 3000 gpm Hale pump located near the B.5.b pump staging area, Canal to SGs) providing sufficient flow to three units for steam generator heat removal 14 Fuel Oil Consumption Analysis needed for fuel oil with respect to consumption rates, storage capability, coping times, and delivery specification 15 Hydraulic Analysis for Pump Flow Need analysis for one 3000 gpm Hale pump located at CTP-1 EFM staging area providing (CTP-1 to SGs) sufficient flow to three units for steam generator heat removal 16 Water in embedded CCW lines & Hydraulic Analysis needed on the volume of available water in the embedded CCW lines post event and Analysis for Pumping Configuration corresponding hydraulic analysis for pumping configuration to transfer CCW water to CTP-1 17 PSW Modification (EC 91877) PSW modification that replaces ASW feed line (2PSW-29 replaces 2CCW-516) 18 Alternate FLEX Connections Modification Modification needed for three taps to the SSF ASW feed lines (SG Makeup) 19 Breaking Siphons in Embedded CCW Modification needed to add first and second siphon break taps and valves to preserve CCW Piping inventory following a BDBEE 20 Instrumentation Repower (Alternate Modifications for penetration room portable instrument panel and connections Repower Strategy) 21 FLEX Equipment Storage Modification needed for FLEX equipment storage facility 22 Portable Power Distribution (Primary Modification needed to enable repower of required loads for phase 2 coping Repower Strategy)

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ONS Mitigating Strategies (FLEX) Integrated Plan Item Open Item Name Item Description 23 Long term SG and SFP Makeup Assessment needed on strategy for sustaining steam generator and SFP makeup inventory after CCW inventory is depleted ("River bed option")

24 Hydrogen Buildup Analysis* Evaluate existing analysis in OSC-7435 to ensure analysis bounds expected conditions for repower strategy 25 BWST Tap Analysis and Modification (RCS Hydraulic analysis for modification needed for portable pump to inject 40 gpm BWST water into Makeup) RCS at (1) HPI header and (2) HPI seals. Size BWST tap for shutdown reduced inventory makeup requirements (approx. 150 gpm) using a low pressure/high capacity pump injection into 1, 2, 3, BS-26 26 Containment Analysis Validate ONS Calculation: Containment Response Following the Loss of All AC Power is a bounding analysis for FLEX event out to 30 days 27 Hydraulic Analysis for Pump Flow (CTP-1 Hydraulic Analysis needed for one 1500 gpm or larger Hale pump located near the B.5.b pump to SFPs & Intake Canal to SFPs) staging area, or CTP-1 providing sufficient flow to two SFPs for heat removal. Consider FLEX hose through Boaas Box and SFP fill pipe 28 Robustness of SFP Refill Lines Need SQUG assessment of SFP refill lines with respect to seismic capabilities.

29 Lighting Evaluation Assessment needed with respect to Appendix R lighting versus areas with FLEX actions.

Develop specification of portable lighting needs 30 Communication Assessment 50.54{f), Section 9.3 communications assessment 31 NEI 12-01 Staffing Study Phase II staffing study will be needed to suooort FLEX deployment 32 HVAC Analysis Analysis needed for HVAC requirements i.e. opening doors to cabinets, opening doors (control rooms, battery rooms, and penetration rooms), installing fans, installing spot coolers, and repowering installed eQuipment Page 58 of 58