NG-13-0084, NextEra Energy Duane Arnold, Llc'S, Overall Integrated Plan in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order Number EA-1

NextEra Energy Duane Arnold, Llc'S, Overall Integrated Plan in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order Number EA-12-

ML13063A148
Person / Time
Site:	Duane Arnold
Issue date:	02/28/2013
From:	Richard Anderson NextEra Energy Duane Arnold
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
EA-12-049, NG-13-0084
Download: ML13063A148 (55)

Text

NExTera" ENER RC February 28, 2013 NG-1 3-0084 10 CFR 2.202 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-001 Duane Arnold Energy Center Docket No. 50-331 Renewed Op. License No. DPR-49 NextEra Energy Duane Arnold, LLC's Overall Integrated Plan in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order Number EA-12-049)

References:

1. NRC Order Number EA-12-049, Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events dated March 12, 2012, Accession No. ML12056A045

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

Implementation Guide," Revision 0, dated August, 2012, Accession No. ML12242A378

4. Letter, R. Anderson (NextEra Energy Duane Arnold, LLC) to U.S.

NRC, "NextEra Energy Duane Arnold, LLC's Initial Status Report in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order Number EA-12-049)," NG 0426, dated October 29, 2012, Accession No. ML12305A378 On March 12, 2012, the Nuclear Regulatory Commission ("NRC" or "Commission")

issued an order (Reference 1) to NextEra Energy Duane Arnold, LLC (hereafter, NextEra Energy Duane Arnold). Reference 1 was immediately effective and directs NextEra Energy Duane Arnold to develop, implement, and maintain guidance and strategies to maintain or restore core cooling, containment, and spent fuel pool cooling NextEra Energy Duane Arnold, LLC, 3277 DAEC Road, Palo, IA 52324

Document Control Desk NG-13-0084 Page 2 of 3 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 by February 28, 2013.

The NRC Interim Staff Guidance (ISG) (Reference 2) was issued August 29, 2012 which endorses industry guidance document NEI 12-06, Revision 0 (Reference 3) with clarifications and exceptions identified in Reference 2. Reference 3 provides direction regarding the content of this Overall Integrated Plan.

Reference 4 acknowledged NextEra Energy Duane Arnold's receipt of Reference 2 and provided the initial status report regarding mitigation strategies, as required by Reference 1.

The purpose of this letter is to provide the Overall Integrated Plan pursuant to Section IV, Condition C.1, of Reference 1. This letter confirms NextEra Energy Duane Arnold has an Overall Integrated Plan developed in accordance with the guidance for defining and deploying strategies that will enhance the ability to cope with conditions resulting from beyond-design-basis external events that satisfies the requirements of Reference 1.

The information in the enclosure provides the NextEra Energy Duane Arnold Overall Integrated Plan for mitigation strategies pursuant to Reference 3. The enclosed Overall Integrated Plan is based on conceptual design information that is current as of this letter. As design details and associated procedural guidance are finalized, additional information, as well as revisions to the information contained in the enclosure to this letter, will be communicated to the NRC in the 6-month Integrated Plan updates as required by Reference 1.

This letter contains no new regulatory commitments.

If you have any questions or require additional information, please contact Ken Putnam at 319-851-7238.

I declare under penalty of perjury that the foregoing is true and correct.

Executed on February 28, 2013 Richard L. Andersoný Vice President, Duane Arnold Energy Center NextEra Energy Duane Arnold, LLC

Enclosure:

Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events

Document Control Desk NG-1 3-0084 Page 3 of 3 cc: NRC Regional Administrator (Region Ill)

NRC Resident Inspector (DAEC)

NRC Licensing Project Manager (DAEC)

Enclosure to NG-13-0084 Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events 51 Pages to Follow

Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events INDEX Description Page Determine Applicable Extreme External Hazards 2 Key Site Assumptions to Implement NEI 12-06 Strategies 3 Extent to which the Guidance, JLD-ISG-2012-01 and NEI 12-06 are being followed 6 Provide Sequence of Events and identify any Time Constraint required for success including 6 the technical basis for the time constraint Identify how Strategies will be deployed in all modes 9 Provide a Milestone Schedule 10 Identify how Programmatic Controls will be met 10 Describe Training Plan 11 Describe Regional Response Center Plan 11 Maintain Core Cooling-BWR Installed Equipment Phase 1 13 Maintain Core Cooling-BWR Portable Equipment Phase 2 15 Maintain Core Cooling-BWR Portable Equipment Phase 3 19 Maintain Containment-BWR Installed Equipment Phase 1 21 Maintain Containment-BWR Portable Equipment Phase 2 23 Maintain Containment-BWR Portable Equipment Phase 3 25 Maintain Spent Fuel Pool Cooling-BWR Installed Equipment Phase 1 26 Maintain Spent Fuel Pool Cooling-BWR Portable Equipment Phase 2 28 Maintain Spent Fuel Pool Cooling-BWR Portable Equipment Phase 3 30 References 31 Attachment IA: Sequence of Events Timeline 33 B: NSSS Significant Reference Analysis Deviation Table 36 : BWR Portable Equipment Phase 2 37 : BWR Portable Equipment Phase 3 38 : Milestone Schedule 39 : Systems Credited for Core Cooling Baseline Coping 40 : Required Instruments 43 : Injection Point to RPV 45 : Instrument Power Connections 46 : Proposed Location of Storage Facilities 47 0: Offsite 4160V AC Connection to an Essential Bus 48 1: Spent Fuel pool Vent 49 2: Implementation Action Items 50 Page 1 of 51

Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events

1. General Integrated Plan Elements - BWR Determine Applicable Extreme Input the hazards applicable to the site; seismic, externalflood, External Hazards high winds, snow, ice, cold, high tenips.

Describe how NEI 12-06 sections 5 - 9 were appliedand the Ref: NEI 12-06, Section 4 - 9 basisfor why the plant screened outfor certain hazards.

JLD-ISG-2012-01, Section 1.0 Duane Arnold Energy Center (DAEC) reactor center line is at latitude 420 6' 02" N, longitude 910 46' 36" W per UFSAR 2.1 (Reference 18). DAEC used NEI 12-06, Sections 4-9 and Appendix B to evaluate applicable external hazards. Each of the five classes of hazards identified applies to the DAEC site.

Seismic:

• Seismic design of DAEC safety related structures are discussed in UFSAR Section 3.7 (Reference 1).

• The DAEC UFSAR was reviewed to perform a limited evaluation of the potential for soil liquefaction as result of a design bases earthquake. UFSAR Section 2.5.4.5.3 (Reference 2) discusses excavation practices used to ensure liquefaction will not occur in the building areas.

Based on this no additional evaluations of liquefaction is planned for FLEX strategies unless storage and transport paths are over previously un-excavated ground (Action 29).

• Seismic re-evaluations pursuant to the 10 CFR 50.54(f) letter of March 12, 2012 are not completed and therefore not assumed in this submittal. As the re-evaluations are completed, appropriate issues will be entered into the corrective action process and addressed (Action 1).

External Flooding:

• Design Bases of site includes flooding from the Cedar River as a result of maximum precipitation. Warning time of several days exist for flooding of this nature, UFSAR 3.4 (Reference 3)

" Design Bases flood (el. 764.1' msl) is above plant grade so FLEX strategies must address deployment with a flood present.

• Flood re-evaluations pursuant to the 10 CFR 50.54(f) letter of March 12, 2012 are not completed and therefore not assumed in this submittal. As the re-evaluations are Page 2 of 51

Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events completed, appropriate issues will be entered into the corrective action process and addressed (Action 2).

Storms with High Winds:

• DAEC plant site is located adjacent to the Cedar River approximately 2.5 miles northeast of Palo, Iowa (Reference 43) and is not a coastal site exposed to hurricanes.

• Regional history with tornadoes exists for the DAEC.

DAEC location falls in Region 1 of Figure 7.2 of NEI 12-

06. This would correspond to a location with a one in a million probability of tornado winds speeds approaching 200 mph. The DAEC design bases (300 mph) for safety related structures bounds this value, UFSAR 3.3 (Reference 4).

Snow, Ice and Low Temperatures:

0 Regional experience with snow, ice and low temperatures exist. From Figure 8.2 of NEI 12-06 DAEC is located in Region 5 corresponding to the highest region for ice severity.

High Temperatures:

• Regional experience with high temperatures exists for DAEC. Environmental design for DAEC electrical equipment is discussed in UFSAR section 3.11 (Reference 5). The normal environmental service conditions for areas containing safety related equipment at DAEC are described in a controlled document, QUAL-SC101 (Reference 6).

Key Site assumptions to Provide key assumptions associatedwith implementation of implement NEI 12-06 FLEX Strategies:

strategies.

All assumptions in NEI 12-06, Section 3.2.1 apply including the Ref: NEI 12-06, Section 3.2.1 following:

• Prior to the event the reactor has been operating at 100 percent rated thermal power for at least 100 days or has just been shut down from such a power history as required by plant procedures in advance of the impending event.

• At the time of the postulated event, the reactor and supporting systems are within normal operating ranges Page 3 of 51

Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events for pressure, temperature, and water level for the appropriate plant condition. All plant equipment is either normally operating or available from the standby state as described in the plant design and licensing basis.

• Off site personnel resources 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 will be fully staffed by 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after the event.

• 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 event by providing adequate capability to maintain or restore core cooling, containment, and 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 protect the public health and safety will be incorporated into the unit emergency operating procedures in accordance with established 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) (Reference 12).

• Recovery of damaged plant equipment is conservatively excluded from FLEX.

• No specific initiating event is used. The initial condition is assumed to be a loss of off-site power (LOOP) at a plant site resulting from an external event that affects the off-site power system either throughout the grid or at the plant with no prospect for recovery of off-site power for an extended period. The LOOP is assumed to affect all units at a plant site.

• All installed sources of emergency on-site ac power and SBO Alternate ac power sources are assumed to be not Page 4 of 51

Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events available and not imminently recoverable.

" Cooling and makeup water inventories contained in systems or structures with designs that are robust with respect to seismic events, floods, and high winds, and associated missiles are available.

" Normal access to the ultimate heat sink is lost, but the water inventory in the UHS remains available and robust piping connecting the U-IS to plant systems remains intact. The motive force for River Water Supply pumps is assumed to be lost with no prospect for recovery.

• Fuel for FLEX equipment stored in structures with designs which are robust with respect to seismic events, floods and high winds and associated missiles, remains available.

• Permanent plant equipment that is contained in structures with designs that are robust with respect to seismic events, floods, and high winds, and associated missiles, are available.

• Other equipment, such as portable ac power sources, portable back up dc power supplies, spare batteries, and equipment for 50.54(hh)(2), may be used provided it is reasonably protected from the applicable external hazards.

" Installed electrical distribution system, including inverters and battery chargers, remain available provided they are protected consistent with current station design.

" No additional events or failures are assumed to occur immediately prior to or during the event, including security events.

" Equipment designed to withstand external events is assumed to be available.

" Spent fuel in dry cask storage is outside the scope of FLEX.

• All boundaries of the SFP are intact, including the liner, gates, transfer canals, etc.

• Although sloshing may occur during a seismic event, the initial loss of SFP inventory does not preclude access to Page 5 of 51

Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events the refueling deck around the pool.

• SFP cooling system is intact, including attached piping.

• SFP heat load assumes the maximum design basis heat load for the site.

Extent to which the guidance, Include a descriptionof any alternatives to the guidance, and JLD-ISG-2012-01 and NEI 12- provide a milestone schedule ofplannedaction.

06, are being followed.

Identify any deviations to JLD- Full compliance with JLD-ISG-2012-01 (Reference 44) and NEI ISG-2012-01 and NEI 12-06. 12-06 (Reference 45) is expected. Where there are interpretations of NEI-12-06 or the Interim Staff Guidance requirements, DAEC Ref: JLD-ISG-2012-01 will follow those interpretations jointly developed by the NRC NEI 12-06, Section 13.1 and NEI.

r -

Provide a sequence of events Strategies that have a time constraintto be successful should be and identify any time identified with a technical basis and ajustificationprovided that constraint required for success the time can reasonably be met (for example, a walk through of including the technical basis deployment).

for the time constraint.

Describe in detail in this section the technical basis for the time Ref: NEI 12-06, Section 3.2.1.7 constraintidentified on the sequence of events timeline JLD-ISG-2012-01, Section 2.1 Attachment ]A.

DAEC Response:

Immediate operator actions for implementation of Phase I FLEX strategies are consistent with existing immediate actions specified for DAEC Station Blackout requirements under 10 CFR 50.63.

Initial operator actions are as described in Abnormal Operating Procedure (AOP) 301.1 (Reference 21) consistent with the existing Station Blackout analysis described in UFSAR Section 15.3.2 (Reference 8) with the exception that emergency reactor vessel depressurization will not be performed when the suppression pool water temperature reaches the Heat Capacity Temperature Limit as listed in existing Emergency Operating Procedures (References 22 and 23). Revisions to these procedures will be made as noted in the Milestone Schedule (Attachment 4) (Action 3). The timeline for deployment of initial portable equipment under Phase 2 of the FLEX strategies are anticipated to be completed within approximately the first 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. Experience with deploying similar equipment/strategies has shown that this is achievable with the on shift staff (Reference 24), but this will need to be verified via formal procedural validation when the final equipment, hookups and procedures are developed (Action 4).

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Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events See attached sequence of events timeline (Attachment IA).

Time Constraint Sequence of Events:

0 0 hour0 days <br />0 hours <br />0 weeks <br />0 months <br />s: LOOP and EDG Failure

• 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />s: Operators perform additional load shedding

• 4-8 hours: Prior to depletion of station safety-related batteries, use a portable diesel generator to power station battery chargers

• 4-8 hours: Prior to RCIC failure, align a portable diesel driven pump to inject water to the RPV, Manually depressurize the reactor using SRVs to allow low pressure injection.

• 4-72 hours: Open vent path on the refuel floor to reduce moisture accumulation. Actual timing of this will vary with fuel loading in the pool and time since discharge (References 36 and 37)

• 14-19 hours: Initiate re-fueling of portable equipment

• 8-16 hours: Prior to containment failure, vent the containment through a reliable hardened vent.

• 10-16 hours: Establish charging capability for batteries in portable communication equipment.

• 45-72 hours: Prior to SFP water level decreasing to the top of spent fuel, initiate make-up to the SFP using a portable diesel driven pump. Actual timing of this will vary with fuel loading in the pool and time since discharge (References 36 and 37)

• 24-72 hours: Supplement on site equipment with 4160 V AC diesel driven generator and portable pumps from Regional Response Center (RRS) to restore power to a 4160 V Essential bus and restoring water from the Cedar River.

Technical Basis Support Information

1. On behalf of the Boiling Water Reactor Owners Group (BWROG), GE-Hitachi (GEH) developed a document (NEDC-33771P, Revision 1 (Reference 7)) to supplement the guidance in NEI 12-06 by providing additional BWR-specific Page 7 of 51

Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events information regarding the individual plant response to the Extended Loss of AC Power (ELAP) and loss of Ultimate Heat Sink (UHS) events. The document includes identification of the generic event scenario and expected plant response, the associated analytical bases and recommended actions for performance of a site-specific gap analysis. In the document, GEH utilized their NRC approved containment analysis code (SHEX) to develop the generic ELAP event response. As part of this document, generic Mark I containment and NSSS evaluations were performed. The analysis is applicable to the DAEC (a BWR Mark I plant) coping strategy because it supplements the guidance in NEI 12-06 by providing BWR-specific information regarding plant response for core cooling, containment integrity, and spent fuel pool cooling. The guidance provided in the NEDC-33771P will be utilized as appropriate to develop coping strategies and for prediction of the plant's response.

Plant specific analysis of Reactor Pressure Vessel (RPV) and containment response and impacts will be performed consistent with the final DAEC strategies as noted on the milestone schedule and as recommended in NEDC-33771P.

In response to INPO IER 11-4 (Reference 25) DAEC performed a plant specific study of the stations capability to cope with an extended station blackout using the MAAP code (Reference 26). This study yielded similar results to NEDC 33771P and was used to inform the selection of planned improvements.

2. The existing analysis for 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> SBO coping is detailed in UFSAR 15.3.2. Final plant specific analysis for an ELAP will be performed with equivalent acceptance criteria with the exception of Condensate Storage Tank (CST) inventory and suppression pool level which will be altered in recognition of the external hazards and revised duration of the mitigating strategies (Action 5).

Technical Basis Support information, see attached NSSS Significant Reference Analysis Deviation Table (Attachment IB).

Loss of access to the ultimate heat sink scenarios are bounded by ELAP scenarios as all installed River Water Supply pumps, which provide the plant makeup from the UHS, are AC powered.

Phase 3 evaluations will ensure adequate inventory of water can be provided directly from the Cedar River or other sources independent of the normal River Water Supply pumps (Action 6).

Page 8 of 51

Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events Identify how strategies will be Describe how the strategies will be deployed in all modes.

deployed in all modes.

At DAEC, the FLEX strategies will be implemented by the use of Ref: NEI 12-06, Section 13.1.6 approved procedures, qualified individuals and storage of portable support equipment in approved locations (Action 7).

Emergency Management Guidelines provide an integrated overview of plant procedures used for any emergency event to facilitate integrated response by key decision makers regardless of plant mode (Reference 35).

In addition, FLEX strategies will have administrative controls to ensure that during on-line maintenance and refueling outages, temporary equipment storage and utilization, will not adversely affect FLEX deployment (Action 8). Plant Modes are defined in Technical Specification Table 1.1-1. (Reference 27). FLEX strategies achieve acceptable results in all plant modes.

• Mode 1 (Power Operations) - this is expected to be the limiting condition for FLEX strategies and forms the basic assumption for sizing and selection of equipment.

" Mode 2 (Startup) - this mode exists for relatively short periods of time with lower levels of decay heat than if the event is initiated in Mode 1. No additional or modified strategies have been identified for this mode

• Mode 3 (Hot Shutdown) - this mode exists for relatively short periods of time with lower levels of decay heat than if the event is initiated in Mode 1. No additional or modified strategies have been identified for this mode.

" Mode 4 (Cold Shutdown) - this mode exists for relatively short periods of time and is expected to be less limiting than if the event is initiated in Mode 1. Core cooling strategies of Phase I using steam driven equipment will either not be used, or will only be used once plant heat up has occurred and steam is available. Portable equipment for Phase 2 is equally capable of performing required functions, and it is not anticipated that shorter response times will be needed than from Mode 1.

• Mode (5 Refuel) - This mode exists for relatively short periods of time. Primary containment functions are not applicable in Mode 5. Core cooling functions would not rely on active installed equipment. Due to the lower decay heat level in the reactor, response times with portable equipment for core cooling are expected to be bounded by Mode 1 requirements. Fuel pool cooling assumptions for decay heat are sufficient to ensure Page 9 of 51

Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events adequate fuel pool makeup with portable equipment in Mode 5 (Reference 19).

Provide a milestone schedule. The dates specifically requiredby the order are obligated or This schedule should include: committed dates. Other dates are planneddates subject to

• Modifications timeline change. Updates will be provided in the periodic (six month) o Phase 1 Modifications status reports.

o Phase 2 Modifications See attached milestone schedule Attachment 4 o Phase 3 Modifications

• Procedure guidance DAEC Response:

development complete o Strategies See attached Milestone Schedule, Attachment 4 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 Identify how the programmatic Provide a description of the programmaticcontrols equipment controls will be met. protection, storage and deployment and equipment quality. See section 11 in NEI 12-06. Storage of equipment, 11.3, will be Ref: NEI 12-06, Section 11 documented in later sections of this template and need not be JLD-ISG-2012-01, Section 6.0 included in this section.

See section 6. 0 ofJLD-ISG-2012-01.

DAEC will implement a FLEX program, containing the necessary administrative procedures to control the FLEX equipment's physical protection, storage, deployment and quality. The procedure will identify ownership and responsibility, including but not limited to, configuration control, maintenance and testing (Action 8).

FLEX equipment will be procured as commercial grade equipment, but with augmented quality requirements (Action 9).

Design requirements for FLEX equipment will be documented Page 10 of 51

Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events and controlled via the existing plant modification process.

Existing plant maintenance programs will be used to identify and document maintenance and testing requirements. Preventative Maintenance work orders (PMs) will be established and testing procedures will be developed in accordance with the PM program. Testing and PM frequencies will be established based on type of equipment and considerations made within EPRI PM Template guidelines (Action 10). The control and scheduling of the PMs will be administered under the existing site work control processes. DAEC will assess the addition of FLEX program description into UFSAR and Technical Requirements Manual (Action 11).

Describe training plan List trainingplansfor affected organizationsor describe the plan for trainingdevelopment Ref: NEI 12-06, Section 11 A Systematic Approach to Training (SAT) will be used to evaluate training requirements for station personnel based upon changes to plant equipment, implementation of FLEX portable equipment, and new or revised procedures that result from implementation of the FLEX strategies..

Training modules for personnel that will be responsible for implementing the FLEX strategies, and ERO personnel will be developed to ensure personnel proficiency in the mitigation of beyond-design-basis external events (BDBEEs). The training will be implemented and maintained per existing DAEC training programs. The details, objectives, frequency, and success measures will follow the plant's SAT process. FLEX training will ensure that personnel assigned to direct the execution of mitigation strategies for BDBEEs will achieve the requisite familiarity with the associated tasks, considering available job aids, instructions, and mitigating strategy time constraints.

Training will be completed prior to final implementation of the requirements of this order per Milestone Schedule (Attachment 4)

(Action 12).

Describe Regional Response The industry will establish two (2) Regional Response Centers Center plan (RRC) to support utilities during beyond design basis events.

Each RRC will hold five (5) sets of equipment, four (4) of which will be able to be fully deployed when requested, the fifth set will have equipment in a maintenance cycle. Equipment will be moved from an RRC to a local Assemble Area, established by the Strategic Alliance for FLEX Emergency Response (SAFER) team and the utility. Communications will be established between the affected nuclear site and the SAFER team and required Page 11 of 51

Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events equipment moved to the site as needed. First arriving equipment, as established during development of the nuclear site's playbook are planned to be 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 (Action 13). A contract has been issued to the administrator of SAFER for DAEC participation.

Notes:

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Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events Maintain Core Cooling Determine Baseline coping capability with installed coping] modifications not including FLEX modifications, utilizing methods described in Table 3-1 of NEI 12-06:

• RCIC/HPCI/IC

• Depressurize RPV for injection with portable injection source

• Sustained water source BWR Installed Equipment Phase 1:

Provide a general descriptionof the coping strategies using installedequipment including modifications that areproposed to maintain core cooling. Identify methods (RCIC/HPCJ/JC)and strategy (ies) utilized to achieve this coping time.

Staff Position from JLD-ISG-2012-01: NEI 12-06 provides an acceptable method of developing strategies to maintain or restore core cooling capabilities.

DAEC Plan: DAEC will utilize NEI 12-06 as the method to develop core cooling strategies.

During Phase 1, core cooling will be assured using installed equipment consistent with the existing station blackout analysis described in UJFSAR Section 15.3.2 (Reference 8) using RCIC and/or HPCI to maintain reactor water level above the top of the fuel. The existing SBO analysis described in UFSAR 15.3.2 demonstrates Phase 1 core cooling is assured for a minimum of four hours. For initial strategy planning and development this four hours will continue to be assumed even though it is anticipated that further evaluations will likely demonstrate a longer coping period for Phase 1. The systems credited for Phase I core cooling, their functions and anticipated limitations are shown in Attachment 5. If the condensate storage tanks are unavailable, the suppression pool provides an inventory of water (Technical Specification 3.6.2.2, Reference 9) for make up during Phase I that is greater than the volume assumed in UFSAR 15.3.2. Evaluation of temperature affects from this alternate water source will be performed as noted in and the associated analysis Schedule Milestone shown in Attachment 2 (Action 14).

Details:

Provide a brief description Confirm thatprocedure/guidanceexists or will be developed to support of Procedures / Strategies / implementation Guidelines Procedure revisions to enhance Phase 1 core cooling strategies are in progress. Emergency Operating Procedures will be revised consistent with revised Boiling Water Reactor Owners Group (BWROG) recommendations to extend the availability of steam driven core cooling systems (Action 3). Enhanced battery load shedding guidance will be incorporated into station procedures for loss of AC power to extend the availability of DC power (Action 15).

' 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.

Page 13 of 51

Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events Identify modifications List modifications No modifications to installed equipment are planned for Phase I Core Cooling.

Key Reactor Parameters List instrumentationcreditedfor this coping evaluation.

Reactor Pressure Vessel Level and Pressure are key parameters for indication to allow operators to successfully implement Phase 1 Core Cooling strategies (Reference 28) (See Attachment 6 for a summary of required instruments).

Notes:

Page 14 of 51

Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events Maintain Core Cooling BWR Portable Equipment Phase 2:

Provide a general descriptionof the coping strategies using on-site portable equipment including modifications that areproposedto maintain core cooling. Identify methods (RCJC/HPCI/JC)and strategy (ies) utilized to achieve this coping time.

During Phase 2, core cooling will be ensured by using portable diesel driven pumps aligned to inject to the reactor pressure vessel. Plant modifications will be required to provide a second injection path beyond that in the existing procedures. To ensure the capability of the diesel driven pumps to inject requires that the reactor be depressurized. This is accomplished by using installed safety relief valves. Multiple safety relief valves are available with four dedicated safety related pneumatic accumulators (UFSAR Section 5.2.2.4.2, Reference 10). The accumulators are nominally 200 gallons in size and would allow for extended cycles under the conditions assumed for FLEX (Reference 29). DC power is required for operation of these valves (UFSAR 6.3.3.1.3) (Reference 30). DC power will be ensured by utilizing a portable diesel generator connected to the battery chargers via existing plug-in connections for the charger power supplies. If for any reason the station batteries and DC power distribution cannot be preserved, existing procedures provide an alternative method of supplying power directly to the safety relief valves utilizing a battery cart (Reference 31). To ensure that the portable equipment can be connected under flooding conditions defined in NEI 12-06, a plant modification is required to establish a flood staging area for portable equipment that preserves the capability to connect this equipment with the design bases flood present (Action 16) . Portable Phase 2 equipment is listed in Attachment 2.

Deployment route from the staging area will be evaluated based on an assessment of the damage in the affected area and the equipment will be deployed in accordance with this assessment (Action 17).

Details:

Provide a brief description Confirm thatprocedure/guidanceexists or will be developed to support of Procedures / Strategies / implementation Guidelines Existing severe accident management or abnormal operating procedures will be revised or new procedures developed to reflect the following (Action 7):

" Addition of one portable 480 Volt generator and two 120 VAC generators for alternate instrument power connections

" Diverse injection point for connection of portable pump to RPV

• New portable equipment storage locations

• Deployment locations for portable equipment during floods

• Strategies for replenishing fuel supplies for portable equipment Identify modifications List modifications The following modifications are planned:

• Install connections for a portable 480 V diesel generator to re-power 125 VDC battery chargers (1D12 and 1D120), 250 VDC Page 15 of 51

Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events battery charger ID43 and 480 VAC load center I B03 (Attachment

8) for required instruments shown in Attachment 6 or connect 120 VAC generator to I Y 11 and I Y21 for required instruments shown in Attachment 6 or connect 120 VAC generator to the instruments locally. This will require a 120 VAC generator near the Control Room and a second 120 VAC generator near the 1A4 Essential Switchgear Room. The plant will be modified to allow quick connections. Connections would only have to be made to the instruments in one division as required by NEI 12-06 (Action 18).

• Install connections for a portable diesel driven pump to allow makeup to the RPV. A 4" branch will be installed on the 12" GBC-005, Residual Heat Removal Service Water (RHRSW) piping upstream of MO 1942 in South East (SE) Corner Room. A buried 8" suction pipe will be routed from Pump House to the south wall of the rollup door in Turbine Building (Attachment 7) (Action 19).

" Construct two new storage facilities for storing portable equipment (Attachment 9) (Action 20).

Key Reactor Parameters List instrumentationcredited or recoveredfor this coping evaluation.

Reactor Pressure Vessel Level and Pressure are key parameters for indication to allow operators to successfully implement Phase 1 Core Cooling strategies (Reference 28) (See Attachment 6 for a summary of required instruments). At least one set of instruments will be available for critical parameters.

Page 16 of 51

Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events Maintain Core Cooling BWR Portable Equipment Phase 2 Storage / Protection of Equipment :

Describe storage / protection plan or schedule to determine storage requirements Seismic List how equipment is protectedor schedule to protect Storage building design will be consistent with NEI 12-06, Section 5.3.1 and will be constructed per Attachment 4, Milestone Schedule.

Flooding List how equipment is protected or schedule to protect Note: If stored below current flood level, then ensure Storage building design will be consistent with NEI 12-06, Section 6.2.3.1 procedures exist to move and will be constructed per Attachment 4, Milestone Schedule. If located equipment prior to exceeding below the flood level, procedures will be established to move equipment flood level, prior to flood levels impacting the equipment.

Severe Storms with High List how equipment is protectedor schedule to protect Winds Storage building design will be consistent with NEI 12-06, Section 7.3.1 and will be constructed per Attachment 4, Milestone Schedule. The buildings will be separated to minimize potential for single tornado path interacting with both buildings. The buildings will accommodate extreme straight winds for the area but tornado winds may damage structure.

Portable equipment will be secured against wind.

Snow, Ice, and Extreme List how equipment is protectedor schedule to protect Cold Storage building design will be consistent with NEI 12-06, Section 8.3.1 and will be constructed per Attachment 4, Milestone Schedule.

High Temperatures List how equipment is protectedor schedule to protect Storage building design will be consistent with NEI 12-06, Section 5.3.1 and will be constructed per Attachment 4, Milestone Schedule.

Deployment Conceptual Modification (Conceptual Sketches are included in attachments)

Strategy Modifications Protection of connections Identify Strategy including how Identify modifications. Identify how the connection is the equipment will be deployed to protected.

the point of use. Two new commercial grade structures (Action 20). Portable equipment will be New storage buildings will be Modifications to connection points deployed to a connection point Page 17 of 51

Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events constructed with physical to ensure protection are discussed that is protected from external separation. Paths for deployment above (Actions 18 and 19). events.

will be reviewed to ensure they are not susceptible to significant soil liquefaction during a seismic event (Action 29).

Notes: DAEC has selected four FLEX building locations as shown on Attachment 9. They are Interim Spent Fuel Storage Installation (ISFSI) area, Well Water Road area, Switchyard Area and North of Construction Support Center (CSC) area. Out of these four DAEC will select two locations based on constructability and cost (Action 20).

Page 18 of 51

Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events Maintain Core Cooling BWR Portable Equipment Phase 3:

Provide a general description of the coping strategies usingphase 3 equipment including modifications that areproposedto maintain core cooling. Identify methods (RCJC/HPCI/JC)and strategy (ies) utilized to achieve this coping time.

During Phase 3, off site resources are expected to be available to replace or augment those core cooling capabilities describe in Phase I and 2. Use of Phase 2 strategies can maintain core cooling indefinitely provided an adequate inventory of water is available. Water can be pumped from the Cedar River to replenish inventories if needed (Action 6). Restoration of essential 4160 volt AC power via a portable diesel generator will be provided in Phase 3 (Action 21). With 4160 volt AC power restored, permanently-installed, safety related equipment required for make-up and cool down of Reactor Pressure Vessel (RPV) will again be available.

Details:

Provide a brief description Confirm thatprocedure/guidanceexists or will be developed to support of Procedures / Strategies / implementation Guidelines Severe accident management procedures will be revised or new procedures established to support mobilization of regional response center equipment and connection to station equipment (Actions 7 and 13).

Identify modifications List modifications Connection points will be established for connection of an off site 4160 volt AC generator to an essential on site AC distribution, 4160 V Switchgear 1A4, (Attachment 10) (Acton 21).

Key Reactor Parameters List instrumentationcredited or recoveredfor this coping evaluation.

Reactor Pressure Vessel Level and Pressure are key parameters for indication to allow operators to successfully implement Phase 3 Core Cooling strategies (See Attachment 6 for a summary of Required Instruments). Instrumentation required for Phase 3 is same as that required for Phase 1 and Phase 2.

Deployment Conceptual Modification (Conceptual Sketches are included in attachments)

Strategy Modifications Protection of connections Identify Strategy including how Identify modifications Identify how the connection is the equipment will be deployed to protected the point of use. Transfer panel (disconnect switch) will be installed in the turbine Transfer panel (disconnect switch)

Page 19 of 51

Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events The portable 4160 volt AC building (Action 21). will be installed in the turbine generator will be moved into the building which is designed for the turbine building truck bay (south) external conditions specified.

or turbine building (north). These are robust locations protected from flooding. Mobilization of the generator from the Regional Response Center in anticipation of flooding will be initiated by the flooding response procedure.

Cables will be pre-located allowing ready connection (Attachment 10). Under conditions other than flooding the 4160 volt generator can be located outside and connection locations used will be determined based on equipment damage observed (Action 21).

If needed, water will be pumped from the Cedar River to the plant to replenish water inventories (Action 7).

Notes:

Page 20 of 51

Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events Maintain Containment Determine Baseline coping capability with installed coping 2 modifications not including FLEX modifications, utilizing methods described in Table 3-1 of NEI 12-06:

• Containment Venting or Alternate Heat Removal

" Hydrogen Igniters (Mark III containments only)

BWR Installed Equipment Phase 1:

Provide a general description of the coping strategies using installed equipment including modifications that areproposed to maintain core cooling. Identify methods (containmentvent or alternative/ Hydrogen Igniters) and strategy (ies) utilized to achieve this coping time.

During Phase I heat can be removed from containment via existing installed vents from the Torus. The vent capacity is sized to accommodate the decay heat required at the time of venting. DAEC is a Mark 1 containment and therefore, the vent capability will be upgraded in accordance with NRC Order EA-12-050 (Reference 32) to improve the reliability during a beyond-design-bases event. Containment performance using the venting strategy will be evaluated consistent with generic work performed by the BWROG in NEDC 33771P (Action 14).

Details:

Provide a brief description Confirm that procedure/guidanceexists or will be developed to support of Procedures / Strategies / implementation Guidelines Initial containment isolation capability remains unchanged from that described in UFSAR 15.3.2 (Reference 8). Current procedures support the use of containment venting to control containment pressure (References 23, 33, and 34). Following modifications required by NRC Order EA-12-050 DAEC procedures will be revised to be consistent with the updated configuration.

Identify modifications List modifications Modifications will be those defined by NRC Order EA-12-050.

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.

Page 21 of 51

Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events Key Containment List instrumentationcreditedfor this coping evaluation.

Parameters Containment Pressure, Suppression Pool Temperature and Suppression Pool level are key parameters for indication to allow operators to successfully implement Phase I Containment strategies (See Attachment 6 for a summary of required instruments). Additional instruments noted in NRC Order EA-12-050 will be installed consistent with NRC Order EA- 12-050.

Notes:

Page 22 of 51

Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events Maintain Containment BWR Portable Equipment Phase 2:

Provide a general descriptionof the coping strategies using on-site portable equipment including modifications that areproposed to maintain core cooling. Identify methods (containment vent or alternative/

Hydrogen Igniters) and strategy (ies) utilized to achieve this coping time.

During Phase 2 no additional strategies are needed beyond those defined in Phase 1. To add additional assurance of venting capability, provisions will exist to use portable pneumatic supplies to open containment vent valves assuming the loss of the normally installed electrical control power or pneumatic sources (Action 22). Electrical control power can be extended using portable 480 volt generators supplying battery chargers as discussed for Phase 2 Core Cooling strategies (Action 18).

Details:

Provide a brief description Confirm thatprocedure/guidanceexists or will be developed to support of Procedures / Strategies / implementation.

Guidelines Procedures will be revised to ensure the modified containment vent system can be opened using portable pneumatic supplies (Action 22).

Identify modifications List modifications.

No additional modifications.

Key Containment List instrumentationcredited or recoveredfor this coping evaluation.

Parameters Containment Pressure, Suppression Pool Temperature and Suppression Pool level are key parameters for indication to allow operators to successfully implement Phase I Containment strategies (See Attachment 6 for a summary of required instruments) (Reference 28).

Storage / Protection of Equipment:

Describe storage / protection plan or schedule to determine storage requirements Seismic List how equipment is protectedor schedule to protect Storage building design will be consistent with NEI 12-06, Section 5.3.1 and will be constructed per Attachment 3, Milestone Schedule.

Flooding List how equipment is protected or schedule to protect Note: If stored below current flood level, then ensure Storage building design will be consistent with NEI 12-06, Section 6.2.3.1 procedures exist to move and will be constructed per Attachment 3, Milestone Schedule. If located equipment prior to exceeding below the flood level, procedures will be established to move equipment flood level, prior to flood levels impacting the equipment.

Page 23 of 51

Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events Severe Storms with High List how equipment is protectedor schedule to protect Winds Storage building design will be consistent with NEI 12-06, Section 7.3.1 and will be constructed per Attachment 4, Milestone Schedule. The buildings will be separated to minimize potential for single tornado path interacting with both buildings. The buildings will accommodate extreme straight winds for the area but tornado winds may damage structure.

Portable equipment will be secured against wind.

Snow, Ice, and Extreme List how equipment is protectedor schedule to protect Cold Storage building design will be consistent with NEI 12-06, Section 8.3.1 and will be constructed per Attachment 4, Milestone Schedule.

High Temperatures List how equipment is protected or schedule to protect Storage building design will be consistent with NEI 12-06, Section 5.3.1 and will be constructed per Attachment 4, Milestone Schedule.

Deployment Conceptual Design (Conceptual Sketches are included in attachments)

Strategy Modifications Protection of connections Identify Strategy including how Identify modifications Identify how the connection is the equipment will be deployed to protected the point of use. Two new commercial grade structures. Portable equipment will be New storage buildings will be deployed to a connection point constructed with physical that is protected from external separation (Action 20). Paths for events.

deployment will be reviewed to ensure they are not susceptible to significant soil liquefaction during a seismic event (Action 29).

Notes: DAEC has selected four FLEX building locations as shown on Attachment 9. They are ISFSI area, Well Water Road area, Switchyard Area and North of CSC area. Out of these four DAEC will select two locations based on constructability and cost (Action 20).

Page 24 of 51

Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events Maintain Containment BWR Portable Equipment Phase 3:

Provide a general descriptionof the coping strategies usingphase 3 equipment including modifications that areproposed to maintain core cooling. Identify methods (containmentvent or alternative/ Hydrogen Igniters) andstrategy (ies) utilized to achieve this coping time.

During Phase 3 off site resources are expected to be available to replace or augment those containment cooling capabilities describe in Phase I and 2. Use of Phase 2 strategies can maintain containment indefinitely provided an adequate inventory of water is available. Water can be pumped from the Cedar River to replenish inventories if needed (Action 6). Restoration of essential 4160 Volt AC power via a portable diesel generator will be provided in Phase 3 (Action 21). With 4160 Volt AC power restored, permanent-installed, safety related equipment required for make-up and cool down of Suppression Pool will again be available.

Details:

Provide a brief description Confirm thatprocedure/guidanceexists or will be developed to support of Procedures / Strategies / implementation Guidelines Same as core cooling.

Identify modifications List modifications Same as core cooling.

Key Containment List instrumentationcredited or recoveredfor this coping evaluation.

Parameters Containment Pressure, Suppression Pool Temperature and Suppression Pool level are key parameters for indication to allow operators to successfully implement Phase 3 Containment strategies (See Attachment 6 for a summary of required instruments). Instrumentation required for Phase 3 is same as that required for Phase 1 and Phase 2.

Deployment Conceptual Design (Conceptual Sketches are included in attachments)

Strategy Modifications Protection of connections Identify Strategy includinghow Identify modifications Identify how the connection is the equipment will be deployed to protected the point of use. Same as core cooling.

Same as core cooling.

Same as core cooling.

Notes:

Page 25 of 51

Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events Maintain Spent Fuel Pool Cooling Determine Baseline coping capability with installed coping3 modifications not including FLEX modifications, utilizing methods described in Table 3-1 of NEI 12-06:

Makeup with Portable Injection Source BWR Installed Equipment Phase 1:

Provide a general descriptionof the coping strategies using installedequipment including modifications that areproposed to maintain spentfuel pool cooling. Identify methods (makeup with portable injection source)and strategy (ies) utilized to achieve this coping time.

DAEC will utilize NEI 12-06 as the method to develop strategies and guidance for Spent Fuel Pool (SFP)

Cooling. UFSAR section 9.1.2.3.2 (Reference 19) discusses makeup requirements of 53.05 gpm at approximately 45 hours5.208333e-4 days <br />0.0125 hours <br />7.440476e-5 weeks <br />1.71225e-5 months <br /> (Reference 20) after a complete loss of cooling assuming a maximum core off-load into a fuel pool. Cycle specific evaluations of actual spent fuel pool loading (References 36 and 37) indicate that substantially lower make up needs and substantially longer response periods would normally be available to respond to a loss of SFP cooling.

During Phase 1 the existing inventory of water in the spent fuel pool is relied on to maintain the spent fuel cool and prevent fuel damage. The installed configuration of the pool ensures an appropriate volume of water. The normal volume of water in the SFP is approximately 233,000 gallons (Reference 36). Technical Specification 3.7.8 (Reference 11) requires that the water level is maintained and periodically checked. NRC Order EA-12-051 (Reference 38) requires the installation of additional reliable fuel pool monitoring instruments to ensure operators have reliable indication of the status of spent fuel pool cooling. Once the SFP begins to boil, large quantities of high temperature moisture will enter the atmosphere in the reactor building.

To reduce the potential that this moisture could adversely impact equipment performance or accessibility to the reactor building by personnel, a modification will be made to the refuel floor to create an alternate manual ventilation point that allows moisture to exit the building (Action 23). This conceptual modification is displayed in Attachment 11. Use of the manual ventilation path will impair the secondary containment but will allow the restoration of secondary containment when the alternate ventilation is no longer needed to vent moisture, During normal operation inadvertent opening of secondary containment via the alternate ventilation point will be positively precluded via administrative and physical controls.

Details:

Provide a brief description Existing abnormal operating procedures (Reference 37) discuss operator of Procedures / Strategies response to a loss of spent fuel pool cooling. Procedures will be updated to Guidelines reflect modifications to SFP indication and ventilation (Action 7).

Identify any equipment SFP Level indication will be modified per NRC Order EA-12-051. A modifications manual ventilation capability (to provide a vent path for steam release from SPF to outside secondary containment) will be added to the refuel floor to 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.

Page 26 of 51

Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events minimize the consequences of boiling of the SFP (Attachment 11) (Action 23).

Key SFP Parameter Per NRC Order EA-I 2-051 spent fuel pool level indication will be modified to provide enhanced indication for spent fuel pool cooling strategies.

Notes:

Page 27 of 51

Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events Maintain Spent Fuel Pool Cooling BWR Portable Equipment Phase 2:

Provide a general descriptionof the coping strategies using on-site portable equipment including modifications that areproposedto maintainspentfuel pool cooling. Identify methods (makeup with portable injection source) and strategy (ies) utilized to achieve this coping time.

It is expected that no operator actions are needed during the initial response to a loss of AC power to maintain the spent fuel covered with water. Once water inventory in the SFP begins to be depleted, make up using portable pumps can be established via any of several paths (Reference 37). Portable Phase 2 equipment is listed in Attachment 2. The capacity of the portable pump will be greater than the boil off rate for SFP.

Deployment route from the staging area will be evaluated based on an assessment of the damage in the affected area and the equipment will be deployed in accordance with this assessment.

Schedule:

Provide a brief description Confirm thatprocedure/guidanceexists or will be developed to support of Procedures / Strategies / implementation Guidelines Existing abnormal operating procedures (Reference 37) and severe accident management procedures (References 39 and 40) support make-up of water to the SFP. Procedure will be revised as necessary to reflect new portable equipment storage locations and redundancy (Action 7).

Identify modifications List modifications SFP Level indication will be modified per NRC Order EA- 12-051. A manual ventilation capability (to provide a vent path for steam release from SPF to outside secondary containment) will be added to the refuel floor to minimize the consequences of boiling of the SFP (Attachment 11) (Action 23).

Key SFP Parameter Per EA 12-051 Per NRC Order EA-12-051 spent fuel pool level indication will be modified to provide enhanced indication for spent fuel pool cooling strategies.

Storage / Protection of Equipment :

Describe storage / protection plan or schedule to determine storage requirements Seismic List how equipment is protectedor schedule to protect Storage building design will be consistent with NEI 12-06, Section 5.3.1 and will be constructed per Attachment 4, Milestone Schedule.

Flooding List how equipment is protectedor schedule to protect Page 28 of 51

Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events Note: If stored below current flood level, then ensure Storage building design will be consistent with NEI 12-06, Section 6.2.3.1 procedures exist to move and will be constructed per Attachment 4, Milestone Schedule. If located equipment prior to exceeding below the flood level, procedures will be established to move equipment flood level. prior to flood levels impacting the equipment.

Severe Storms with High List how equipment is protectedor schedule to protect Winds Storage building design will be consistent with NEI 12-06, Section 7.3.1 and will be constructed per Attachment 4, Milestone Schedule. The buildings will be separated to minimize potential for single tornado path interacting with both buildings. The buildings will accommodate extreme straight winds for the area but tornado winds may damage the structure.

Portable equipment will be secured against wind.

Snow, Ice, and Extreme List how equipment is protectedor schedule to protect Cold Storage building design will be consistent with NEI 12-06, Section 8.3.1 and will be constructed per Attachment 4, Milestone Schedule.

High Temperatures List how equipment is protectedor schedule to protect Storage building design will be consistent with NEI 12-06, Section 5.3.1 and will be constructed per Attachment 4, Milestone Schedule.

Deployment Conceptual Design (Conceptual Sketches are included in attachments)

Strategy Modifications Protection of connections Identify Strategy including how Identify modifications Identify how the connection is the equipment will be deployed to protected the point of use. Two new commercial grade structures. Portable equipment will be New storage buildings will be deployed to a connection point in constructed with physical a protected area.

separation (Action 20). Paths for deployment will be reviewed to ensure they are not susceptible to significant soil liquefaction during a seismic event (Action 29).

Notes: DAEC has selected four FLEX building locations as shown on Attachment 9. They are 1SFSI area, Well Water Road area, Switchyard Area and North of CSC area. Out of these four DAEC will select two locations based on constructability and cost (Action 20).

Page 29 of 51

Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events Maintain Spent Fuel Pool Cooling BWR Portable Equipment Phase 3:

Provide a general descriptionof the coping strategies usingphase 3 equipment including modifications that areproposed to maintain spentfuel pool cooling. Identify methods (makeup with portable injection source) and strategy (ies) utilized to achieve this coping time.

During Phase 3 off site resources are expected to be available to replace or augment those SFP cooling capabilities describe in Phase 1 and 2. Use of Phase 2 strategies can maintain SFP cooling indefinitely provided an adequate inventory of water is available. Water can be pumped from the Cedar River to replenish inventories if needed (Action 6). Restoration of essential 4160 Volt AC power via a portable diesel generator will be provided in Phase 3 (Action 21). With 4160 Volt AC power restored, permanently-installed, equipment required for make-up and cool down of the SPF will again be available.

Schedule:

Provide a brief description Confirm thatprocedure/guidanceexists or will be developed to support of Procedures / Strategies / implementation Guidelines Spent fuel pool makeup with portable pump will continue until 4160V AC power is restored and forced cooling and heat transfer established.

Identify modifications List modifications No additional modifications.

Key SFP Parameter Per EA 12-051 No additional indication.

Deployment Conceptual Design (Conceptual Sketches are included in attachments)

Strategy Modifications Protection of connections Identify Strategy including how the Identify modifications Identify how the connection is equipment will be deployed to the protected point of use. No additional modifications Same as core cooling.

No additional strategies.

Notes:

Page 30 of 51

Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events

References:

1. UFSAR Section 3.7, Seismic Design, (Docketed)

2. UFSAR Section 2.5.4.5.3, Excavation, (Docketed)

3. UFSAR Section 3.4, Water Level (Flood) Design, (Docketed)

4. UFSAR Section 3.3, Wind and Tornado Loadings, (Docketed)

5. UFSAR Section 3.11, Environmental Design of Electrical Equipment, (Docketed)

6. QUAL-SC101, DAEC Environmental and Seismic Service Conditions

7. NEDC-33771P, Rev. 1, GEH Evaluation of FLEX Implementation Guidelines

8. UFSAR 15.3.2, Station Blackout, (Docketed)

9. Technical Specification 3.6.2.2, Suppression Pool Water Level, (Docketed)

10. UFSAR Section 5.2.2.4.2, Safety/Relief Valves, (Docketed)

11. Technical Specification 3.7.8, Spent Fuel Storage Pool Water Level, (Docketed)

12. Task Interface Agreement (TIA), Acceptability of Proceduralized Departures from Technical Specifications (TSs) Requirements at the Surry Power Station, (TAC Nos MC4331 and MC4332) dated September 12, 2006 (Accession No. ML060590273), (Docketed)

13. CAL-E08-007, 250 VDC System Battery Sizing

14. CAL-E08-008, 125 VDC System Battery Sizing

15. APED-A61-089, SBO Compliance

16. EC 275056, Study of DAEC 125 VDC System

17. CAL-M06-007, Room Heat-up Analysis for DAEC during SBO

18. UFSAR 2.1, Geography and Demography, (Docketed)

19. UFSAR 9.1.2.3.2, Cooling Considerations, (Docketed)

20. CAL-M97-019, Thermal Hydraulic Evaluation of the DAEC SPF

21. AOP 301.1, Abnormal Operating Procedure 301.1 Station Blackout

22. EOP 1, RPV Control

23. EOP 2, Primary Containment Control

24. Fire Brigade Drill to Provide Makeup to the RPV and Drywell dated March 20, 2011

25. INPO IER LI 4 dated September 29, 2011, Near-Term Actions to Address the Effects of an Extended Loss of All AC Power in Response to the Fukushima Daiichi Event

26. Erin Engineering Report dated 11/11/11, Evaluation Report of DAEC Capabilities to Respond to Station Blackout for INPO IER LI 4

27. Technical Specification Table 1.1-1 Modes, (Docketed)

28. Technical Support Guideline Section 3 Control Parameter Assessment Guideline

29. CAL-M83-002, Adequacy of the Accumulator for ADS

30. UFSAR Section 6.3.3.1.3 Automatic Depressurization System, (Docketed)

31. SAMP 707, Emergency SRV Operation using DC Power

32. NRC EA-12-050 dated March 12, 2012, Issuance of Order to Modify License with Regard to Reliable Containment Hardened Vents, (Docketed)

33. Technical Support Guideline Appendix C Containment Venting Guideline

34. SEP 301.3, Torus Vent via Hard Pipe Vent

35. EMG, Rev. 7, Emergency Management Guideline

36. CAL-M12-022, DAEC Outage 23 (Cycle 24) Spent Fuel Decay Heat and Associated Calculations

37. AOP 435, Loss of Fuel Pool Cooling/Inventory

38. NRC EA-12-051 dated March 12, 2012, Issuance of Order to Modify Licenses with Regard to Reliable Spent Fuel Pool Instrumentation

39. SAMP 712, Spent Fuel Pool Makeup and Spray

40. SAMP 718, Spent Fuel Pool Makeup via the RHR System with the Portable Diesel Fire Pump

41. Fire Brigade Drill to Provide Makeup Spent Fuel Pool dated March 21, 2011 Page 31 of 51

Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events

42. NG-12-0430 Response to 50.54(f) Request for Information Regarding Near Term Task Force Recommendation 9.3 Emergency Preparedness

43. UFSAR 1.2, General Plant Description, (Docketed)

44. JLD-ISG-2012-01 dated August 2012, Compliance with Order EA- 12-049, Order Modifying Licenses with regard to Requirements for Mitigation Strategies for Beyond Design Basis External Events, (Docketed)

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

46. GEH Report 000-0155-1545-RO dated February 2013, RCIC Pump and Turbine Durability Evaluation-Pinch point Study Page 32 of 51

Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events Attachment 1A Sequence of Events Timeline ELAP Remarks / Applicability New Time Action Elapsed Constraint item Time Action Y/N N Plant @100% power 0 Event Starts Consistent with UFSAR 15.3.2 (Reference 8)

Reactor scrams, primary containment isolation Groups 1-5 occur, Safety Relief Valves (S/RV's) and Low-low set control reactor pressure, RCIC and HPCI initiate to control reactor water level.

Following initial reactor vessel level recovery HPCI 0-2 min Automatic Plant Response N is secured and RCIC is the preferred make up system.

For Phase 1, the installed equipment is designed to start automatically and procedures do address manual start if they fail to start automatically (Reference 22).

Operators initiate a controlled reactor depressurization using S/RV's. Sufficient pressure is 2 30 min Controlled Reactor Depressurization N maintained for steam driven systems (RCIC/HPCI) to operate, (References 8 and 21).

Reference UFSAR 15.3.2. Existing analysis Operators use procedures to maintain addresses identified areas for ELAP with the adequate room cooling to ensure exception of possible impacts on instrument inverters 3 60 min necessary equipment is maintained N that could affect critical instruments. Additional functional by opening cabinets and analysis will be performed in accordance with the doors. milestone schedule (Attachment 4) (Action 24).

Scoping studies indicate it is possible to extend availability of station batteries to approximately 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> if load shedding is performed at approximately 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> (Reference 16). Final load shedding analysis, revision to procedures and validation of time constraint will be performed in accordance with the milestone schedule (Attachment 4) (Action 15).

Existing station battery design ensures a minimum of Prior to depletion of station safety 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> of capacity (References 13 and 14).

4-8 related batteries use a portable diesel hours generator to supply power to station battery chargers.

4-8 Existing analysis demonstrates adequacy of steam 6 hours Prior to the loss of all steam driven Y driven systems for a 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> coping period (Reference reactor vessel make up, align a portable 15). BWROG RCIC Durability Study Page 33 of 51

Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events ELAP Remarks / Applicability New Time Action Elapsed Constraint item Time Action Y/N diesel driven pump to inject water to the (Reference 46) performed by GEH will be screened reactor. Manually depressurize the to perform plant specific analysis beyond the current reactor using S/RV's to allow low 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> coping period (Action 25). Final procedure pressure injection, revisions and validation of time critical actions (Actions 4 and 7), incorporating updated expected RCIC mission time, will be performed in accordance with the milestone schedule (Attachment 4):

Actual timing of this will vary with fuel loading in the pool and time since discharge (References 36 and 37). Ventilation of the refuel floor to reduce Prior to significant accumulation of environmental impacts of a boiling pool is planned.

4-72 moisture on the refuel floor due to fuel y This will require modification of the plant.

hours pool temperature, open a vent to Procedure revisions and validation of procedures for minimize moisture accumulation. venting the refuel floor will be performed in accordance with the milestone schedule (Attachment

4) (Actions 4, 7 and 23).

Actual timing of refueling will vary with timing of use of portable equipment and how heavily loaded 8 14 Prior to portable equipment fuel Y but based on typical consumption rates of portable hours depletion initiate re-fueling, equipment (Reference 25) (Action 27).

An existing containment hardened vent was installed under Generic Letter 89-16. Upgrades to that vent will be required under NRC Order EA-1 2-050 8-16 Prior to exceeding containment limits, (Reference 32). Final analysis with respect to the hours vent the containment through a reliable Y upgraded hardened vent will be performed under that hardened vent. Order. Procedure revisions and validation of time critical actions will occur as part of that modification.

During the DAEC assessment of communications under NRC recommendation 9.3 (Reference 42), it Establish charging capability for was identified that portable communication 10 10-16 batteries in portable communications y equipment could be enhanced by establishing a hours equipment and ensure portable method to recharge batteries (Action 26) and ensure equipment is adequately fueled. portable equipment is able to be re-fueled (Action 27).

Existing analysis of loss of spent fuel pool cooling under conservative assumptions indicates that a minimum of 45 hours5.208333e-4 days <br />0.0125 hours <br />7.440476e-5 weeks <br />1.71225e-5 months <br /> is available prior to water level Prior to spent fuel pool water level decreasing to the top of stored fuel (Reference 20).

11 45-72 decreasing to the top of spent fuel Y Cycle specific evaluations of heat loads are hours initiate make-up to the pool using a. performed and incorporated in operating procedures portable diesel driven pump. that indicate heat loads can be much less than this bounding analysis (References 36 and 37). Past experience indicates that deployment of a portable Page 34 of 51

Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events ELAP Remarks / Applicability New Time Action Elapsed Constraint item Time Action Y/N pump can be completed in less than two hours (Reference 41). No additional time validation is warranted given the large margin in response time.

An extended loss of AC power can be mitigated using a combination of installed equipment and portable equipment that will be stored on site. The Regional Response Center equipment provides a Supplement on site equipment with reliable back up to this on site equipment for 12 24-72 equipment from the Regional Response Y extended operation. This will provide added Center. assurance that consumables are replenished, and begin the transition to recovery by restoring power to a 4160 Volt Essential bus and restoring water from the Cedar River (Actions 6, 13 and 21).

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Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events Attachment 1B NSSS Significant Reference Analysis Deviation Table (NEDC 33771P, GEH Evaluation of FLEX Implementation Guidelines)

Item Parameter of interest NEDC value NEDC Plant applied value (NEDC 33771P Revision 1, page January 2013)

None Page 36 of 51

Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events Attachment 2 BWR Portable Equipment Phase 2 Use and (potential/flexibility)diverse uses PerformanceCriteria Maintenance List portable Core Containment SFP Instrumentation Accessibility Maintenance / PM equipment requirements Two (2) Diesel X X X Sized consistent with Will follow EPRI PM Driven Pumps existing requirements template requirements under 10CFR 50.54.hh Two (2) 480 X X X X Sized for charging Will follow EPRI PM VAC essential 125 and 250 VDC template requirements Generator Batteries Two DC Power X X Sized for SRV solenoid Will follow EPRI PM Carts (Secondary) (Secondary) operation template requirements Two (2) X X Sized for operation of Will follow EPRI PM Nitrogen (Secondary) (Secondary) containment vent valves template requirements Bottles Four (4) X X Sized for powering critical Will follow EPRI PM 220/120 VAC (Secondary) (Secondary) instruments and area template requirements Generators lighting Two (2) X X X X X Sized to refuel portable Will follow EPRI PM (Support) (Support) (Support) (Support) (Support) equipment template requirements Fuel Oil Transfer Pump X X X X Sized to transport on site Will follow EPRI PM Two (2) Tow (Support) (Support) (Support) (Support) (Support) portable equipment template requirements Vehicles Two (2) X X X X X Sized to move typical Will follow EPRI PM Debris (Support) (Support) (Support) (Support) (Support) concrete barriers on site template requirements Removal Equipment Page 37 of 51

Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events Attachment 3 BWR Portable Equipment Phase 3 Use and (potential/flexibility)diverse uses Performance Criteria Maintenance List portable Core Containment SFP Instrumentation Accessibility Maintenance / PM equipment requirements Three Portable X X X Sized to pump water from high capacity the Cedar River to the pumps DAEC Pump House at flow rates adequate to support plant cool down Two (2) 4160 X X X X X Sized to power essential 4160 Volt Generators VAC loads needed to support will be mobilized to site Generator plant cool down during flood preparations or when requested by the DAEC emergency coordinator Page 38 of 51

Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events Attachment 4 Milestone Schedule Original Target Date FLEX Implementation Activity Status February 2013 Submit Overall Integrated Implementation Plan Complete August 2013 Submit 6 Month Status Report Open Complete Revision to Emergency Operating Procedures to Extend December 2013 Operation of Steam Driven Pumps Open February 2014 Submit 6 Month Status Report Open August 2014 Complete Regional Response Center Arrangements Open August 2014 Submit 6 Month Status Report Open RFO 24 (Fall 2014) First Refueling Outage of Implementation Period Open January 2015 Complete Site Specific Analysis of NEDC-33771P Rev. I Open February 2015 Submit 6 Month Status Report Open March 2015 FLEX Storage Buildings Completed Open May 2015 Identified Portable Equipment Stored on Site Open August 2015 Submit 6 Month Status Report Open December 2015 Issue Modification Packages Open February 2016 Submit 6 Month Status Report Open May 2016 Complete Staffing Study for Flex Implementation Open August 2016 Complete Implementing Procedure Development and Validation Open August 2016 Submit 6 Month Status Report Open September 2016 Complete Required Training Open RFO 25 (Fall 2016) Final Implementation Outage for Modifications Open December 2016 Submit Completion Report Open Page 39 of 51

Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events Attachment 5 Systems Credited for Core Cooling Baseline Coping (Reference 15)

System Function and Limitation on Core Cooling Coping Duration Reactor Core Isolation Provides the primary means for reactor vessel inventory control Cooling (RCIC) throughout the baseline coping period. In the event RCIC is unavailable, HPCI can be used as an alternate. RCIC may limit the coping duration for core cooling. RCIC may become unavailable due to environmental conditions, NPSH impacts on suction sources, depletion of control power, or system isolations or failure. A more detailed review of RCIC limitations on coping duration will be performed as a part of FLEX implementation (Action 25).

High Pressure Coolant Assists RCIC in initial recovery of reactor vessel inventory following Injection (HPCI) the initial loss of AC power. Acts as a backup to RCIC in the event RCIC is unavailable. HPCI may become unavailable due to environmental conditions, NPSH impacts on suction sources, depletion of control power, or system isolations or failure. Sizing of HPCI is such that operation may be difficult when steam supply is limited later in the coping period. If the industry evaluations to extend the mission time for RCIC do not yield the required results, further evaluation will be performed on the HPCI system to determine if it can support RCIC operation to achieve the desired mission time.

125 VDC Provides control power to RCIC, Safety Relief Valves (SRV's) and key instrumentation used for decision making. 125 V DC battery capacity will likely limit the baseline coping duration. A detailed review of battery capacity and potential enhancements to load shedding strategies will be performed as part of FLEX implementation (Action 15).

250 VDC Provides control power to HPCI. 250 VDC battery capacity is not expected to alter baseline coping duration. A detailed review of 250 VDC battery mission time will not be performed unless the results of 125 VDC and RCIC reviews indicate there is a significant potential to alter the coping duration.

Safety Relief Valves Controls reactor pressure within specified limits during initial (SRV) response to a loss of AC power. SRV functionality is required to allow the transition to Phase 2 of core cooling, the reactor must be sufficiently depressurized to allow portable low-head pumps to inject water to the RPV. SRV's may limit the coping duration due to environmental conditions, loss of control power, or depletion of pneumatic supply. A more detailed review of these limitations on SRV operation will be performed as a part of FLEX implementation (Action 28).

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Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events Low-Low Set Logic Controls safety relief valves in initial response to reactor pressure (LLS) vessel isolation to limit stresses on SRV tail pipes. Shortly after initial operation the LLS logic will no longer be needed. Thus, the LLS logic does not limit coping duration.

Control Rod Drives Ensures reactor is shutdown as an immediate response to loss of AC (CRD) power. Once shutdown, the reactor will remain shutdown regardless of the status of AC power. The CRD system does not limit the coping duration.

Reactor Protection Ensures reactor is shutdown as an immediate response to loss of AC System (RPS) power. Once shutdown, the reactor will remain shutdown regardless of the status of AC power. RPS power also supplies instrumentation in portions of the containment isolation logic. However, these instruments trip (i.e. fail safe) on loss of RPS power. The RPS system does not limit the coping duration for core cooling.

Condensate Storage Provides the preferred initial water inventory for RCIC and HPCI Tanks (CST) make-up to the RPV. CST's are not fully protected from external hazards such as tornado missiles. If the CST's are unavailable, the suppression pool will be the credited source of water inventory.

Consequently, no detailed evaluation of the effect of CST's on coping duration will be performed as part of FLEX implementation.

Torus (Suppression Provides protected source of water inventory for RCIC and HPCI in Pool) and Containment the event the CST's are not available. Provides a suppression pool for Structure SRV discharge. The suppression pool temperature may limit the coping duration for each Phase. RCIC and HPCI operation can be adversely affected by suction source water temperature. SRV operation can affect suppression pool temperature in any of the Phases. A more detailed review of suppression pool temperature response will be needed as part of FLEX implementation. This will be performed consistent with generic work being performed on this topic by the BWROG in NEDC 33771P (Action 14).

Nuclear Boiler and Main Provide a source of steam to the HPCI and RCIC turbines and Steam maintains the floodable volume for core cooling. The nuclear boiler and main steam system do not limit the coping duration for core cooling under the FLEX strategies.

Nuclear Steam Supply Isolates the primary reactor coolant system as an immediate response Shutoff (NSSS) to the loss of AC power. Once isolations are complete no further action is required by the NSSS system and the NSSS system will not affect the core cooling coping time.

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Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events Main Steam Isolation Isolates the main steam lines as an immediate response to the loss of Valves (MSIV) AC power. Once isolations are complete no further action is required by the MSIV's and the system will not affect the core cooling coping time.

Room Heatup during an Heat up of key plant locations was performed for existing station SBO black out coping and up to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. This evaluation will need to be reviewed for the extended duration postulated for the FLEX strategies (Reference 17) (Action 24).

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Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events Attachment 6 Required Instruments Breakers to Re-Parameter Instrument Components Power Location of Range power in Loop Supply Components Instrument Loop PT4365A 201CH 1C22 Drywell PR4385A -10 to 1Y2127 Pressure 201ICH (E/S) 1Y2127 1C142 90 psig 1Y2128 PR4385A 1Y2128 1C29 PT4365B 213CH 1C56 Drywell (E/S) -10 to 1Y1113 Pressure PR4385B 213CH (E/S) 1YI113 1C06 90 psig IY1131 URS4384 1Y1131 1C29 TE4386G 1Y1128 Drywell TT4386G 1Y1128 1C142 TE4386J 1YI128 Drywell Drywell T 0 to 1Y1128 Temperature TR4383A TT4386J 1YI128 1C142 5OO 1Y1131 TE4386L 1Y1128 Drywell TT4386L 1YI128 1C142 TR4383A 1Y1131 1C29 TT4386E 1Y2127 Dryw-ell TE4386E 1Y2127 1C142 TE4386K 1Y2127 Dry-well Drywell T 0 to 1Y2127 Temperature TR4383B TT4386K 1Y2127 1C142 500 OF 1Y2128 TE4386H 1Y2127 Drywell TT4386H 1Y2127 1C142 TR4383B 1Y2128 1C29 LT4397A I/E4397A Torus Torus Water L14397A I/E4397A 1Yl136 1C09 1.5 to IY1136 Level 16 ft L14397A I/E4397A 1C03 LT4396B I/E4396B Torus Torus Water L14397B I/E4396B 1Y2136 1C09 1.5 to 1Y2136 Level 16 ft L14396B I/E4396B 1C03 Torus Water TIA4325 TE4325 I/E4325 Torus 20 to IY1128 Page 43 of 51

Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events Temperature TT4325 1Yl 128 IC 142 220 OF 1YI115 1YI131 T14325 n/E4325 1C208 1Y1 115 TY4325A I/E4325 1C392 I/E4325 E/S4565A 1C03 TY4325 E/S4565A 1C03 E/E4325 E/S4565A 1C03 TIA4325 TY4325 1C03 E/S4565A IYII15 1C03 TR4386A 1YI 131 1C29 UR4325 1Yl 115 IC03 RPV Pressure P14599A PT4599A I/E4599A 1C56 I/E4599A E/S4599A 1C09 0 to E/S4599A 1Y1136 1C09 1500 P14599A I/E4599A 1C03 RPV Pressure P14599B PT4599B 1Y2115 1C56 I/E4599B E/S4599B 1C09 0 to 1Y2136 E/S4599B 1Y2136 1C09 1500 P14599B I/E4599B I C03 Page 44 of 51

Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events ATTACHMENT 7:

INJECTION POINT TO RPV RX BLDG TURB BLDG INSTALL 4" BRANCH CONECTION ON RHRSW PIPING UPZSTREAM OF MO-Iq42 IN SE CORNER RM EXH B" BURIED PIPE REF:

ISO-GBC-005-01 P&ID BECH-MI13 P&IO BECH-M120 BECH-C127 BE'I-CI29 BECH-N233 BECH-"256 L.......................................................................................J...

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Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events TTTAcHMENT BI INSTRUMENT POWER CONNECTIONS (BEEH-M222]

IPORT RUNCABLES THROUGH 1A3 SWITCHUEAR 1A3 ODOR 12WITCHGEAR ROOM 1012 *{(EL. 757'-B51 1L11B Page 46 of 51

Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events ATTACHMENT 9 -PROPOSED LOCATIONS OF STORAGE FACILITIES CC051-002)

DAEC

.ISFSI

-s a-0 L

ELL U - D Approx.

m a_

a_ 1,00 F -t. .

i Approx* "

4-)---- --- - --- - - -

o_ .7 Page 47 of 51

Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events

.r.... .......

ATTACHMENT 10:

DFFSITE 41GS VAC CONNECTION TO AN ESSENTIAL BUS TURB BLOG NORTH IA4 SWITCHOEAR CABLE TRANSFER BETWEEN ROLLUF DOOR BUS DUCT PANEL AND 1A1 SWITCHGEAR (EL. 757'-G")

ALTERNATE CABLE IA4 SWITCHGEAR BUS DUCT TURB BLDG NORTH TURB BLDG PORTABLE 41G0V AC BETWEEN RDLLUP DOOR PO~RT~LE 41OVAC] RAILROAD l

ATR L*CKI SDTH GENERATOR AND IAI SWITCHGEAR (EL. 7.57'- . .

REF:

BECH-EB0ll BECH-MO22 E02 B-0 01 Page 48 of 51

Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events

.......................... .......F***.......................... ............ ......-----

ATTACHMENT 11: SPENT FUEL POOL VENT VALVE OAMPER ON MEZZANINE ABOVE ELEVATOR MACHINE RN / STAIRCASE. SOUTH (EL. B77'-.")

TUBING VALVE STATION RX BLDG SOUTH AIRLOCK BY STAIRWELL (EL.757'-6")

REFi BECH-C432 BECH-AB29 BECH-M279 L ..................................... ....................................

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Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events Attachment 12 Implementation Action Items Number Action Status 1 Seismic re-evaluations pursuant to the 10 CFR 50.54(f) letter of March 12, Open 2012 are not completed and therefore not assumed in this submittal. As the re-evaluations are completed, appropriate issues will be entered into the corrective action process and addressed.

2 Flood re-evaluations pursuant to the 10 CFR 50.54(f) letter of March 12, 2012 Open are not completed and therefore not assumed in this submittal. As the re-evaluations are completed, appropriate issues will be entered into the corrective action process and addressed.

3 Implement revisions to emergency operating procedures (EOP's) identified by Open the BWROG to extend operation of steam driven pumps for core cooling during ELAP.

4 Validate imnplementing procedures can be performed in a timely manner. Open 5 Final plant specific analysis for an ELAP will be performed with equivalent Open acceptance criteria with the exception of Condensate Storage Tank (CST) inventory and suppression pool level which will be altered in recognition of the external hazards and revised duration of the mitigating strategies.

6 Phase 3 activities will ensure adequate inventory of water can be provided Open directly from the Cedar River or other sources independent of the normal River Water Supply pumps.

7 Implement new and revised plant procedure for FLEX Strategies. Open 8 Implement administrative controls for the FLEX Program. Open 9 Procure FLEX portable equipment. Open 10 Establish preventive maintenance and testing of FLEX portable equipment. Open 11 Revise UFSAR and TRM as needed to reflect FLEX program. Open 12 Complete training of applicable personnel. Open 13 Establish "Playbook" for Regional Response Center interface with the DAEC. Open 14 Review generic BWROG analysis of FLEX implementation and perform a Open detailed review of suppression pool temperature to support FLEX strategies.

15 Perform analysis of final load shedding strategy for essential station batteries Open and implement in plant procedures.

16 Modify the plant to establish a flood staging area for portable equipment. Open 17 Evaluate deployment routes for portable equipment. Open 18 Modify the plant to facilitate connection of portable power supplies. This will Open include connection points for a 480 volt generator to essential battery chargers and 480 volt distribution panel IB03. Quick connection points will be established for 120 volt AC power to instrument power supplies.

19 Modify the plant to add suction and injection connection points for portable Open pump. The portable pump suction will allow access to the circulating water pit (Pump House) from a protected area (Turbine Building) during a design bases flood. The injection point will provide a redundant connection point for RPV makeup located in a protected area (Reactor Building).

20 Construct two FLEX portable equipment storage buildings. The buildings will Open be separated to minimize the potential for a single tornado path to interact with both buildings.

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Duane Arnold Energy Center Overall Integrated Plan with Regard to Mitigation Strategies for Beyond-Design-Basis External Events 21 Phase 3 activities will ensure essential bus can be re-powered using a portable Open 4160 V Generator. This will include a modification that establishes a transfer panel (disconnect switch) installed in the turbine building that provides a location for connection during a design bases flood and procedures for mobilization.

22 Procedures will provide for opening containment vent valves using portable -Open pneumatic supply.

23 Modify the plant to establish a manual vent capability for the reactor building Open near the spent fuel pool.

24 Update analysis of room heat-up during an ELAP. Open 25 Screen BWROG RCIC Durability Study for extending RCIC operation during Open an ELAP and make applicable improvements.

26 Establish methods to recharge communications equipment. Open 27 Establish methods to re-fuel portable equipment. Open 28 Review generic BWROG analysis of FLEX implementation and perform a Open detailed review of limitations on SRV operation to support FLEX strategies.

29 If FLEX transport paths are over previously un-excavated ground, review path Open for potential soil liquefaction during a seismic event.

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