ML13304B445

Revised License Amendment Request for One-Time Change to Technical Specification 3.8.4, DC Sources-Operating for Battery Replacement

ML13304B445
Person / Time
Site:	Mcguire, McGuire
Issue date:	10/28/2013
From:	Capps S Duke Energy Carolinas
To:	Document Control Desk, Office of Nuclear Reactor Regulation
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ML13304B444	List: ML13304B445
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Download: ML13304B445 (38)

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DUKE Stm D_ Capp Viace Preskdent ENERGYI McGuire Nudlear Staion MG01VP 1 12700 Hagers Ferry Road Hunknuille, NC 28078 o: 980.875.4805 f: 980.875.4809 S.emn.CappsQauke-eergy.com October 28, 2013 10 CFR 50.90 U.S. Nuclear Regulatory Commission Washington, DC 20555-001 ATTENTION: Document Control Desk

Subject:

Duke Energy Carolinas, LLC McGuire Nuclear Station, Units 1 and 2 Docket Nos. 50-369 and 50-370 Revised License Amendment Request for One-Time Change to Technical Specification 3.8.4, "DC Sources-Operating" for Battery Replacement In accordance with the provisions of 10 CFR 50.90, Duke Energy Carolinas, LLC (Duke Energy) proposes a license amendment request (LAR) for the Renewed Facility Operating Licenses (FOL) and Technical Specifications (TS) for the McGuire Nuclear Station, Units 1 and 2.

On August 9, 2012, Duke Energy submitted a risk based LAR to revise the McGuire TS 3.8.4 Condition A to allow replacement of the existing shared 125 VDC vital batteries while at power.

This revised LAR supersedes the risk based LAR withdrawn from NRC consideration on January 17, 2013. Duke Energy has replaced the risk based evaluation with a deterministic engineering justification to evaluate operating both units with one vital battery inoperable for an extended period of time.

This approach was discussed with the NRC in a public meeting on August 7, 2013 and the LAR is based on the precedents provided in Attachment 1.

This revised LAR would be applicable one-time for each of the four shared battery channels.

The vital batteries were last replaced in 1997 under a risk based one-time TS change. Battery replacement is currently scheduled for 2015 and 2016.

Since battery replacement. cannot be accomplished within the Completion Times burrently' allowed by TS 3.8.4 due to the number of activities, inspections, and tests, the proposed LAR would extend the Completion Time to 14 days for each battery channel replacement. During each vital battery replacement, the associated DC channel will remain energized by being cross-tied (bus tie with breakers) to another operable DC channel as allowed by TS 3.8.4 Condition A. In addition, a temporary battery will be available as a defense in depth, backup DC power supply.

www.duke-energy.com"

US Nuclear Regulatory Commission October 28, 2013 Page 2 provides Duke Energy's evaluation of the LAR which contains a description of the proposed changes, the technical evaluation, the regulatory analysis, the determination that this LAR contains No Significant Hazards Considerations, the basis for the categorical exclusion from performing an Environmental Assessment/Impact Statement, and precedents for the LAR. , pages 24 and 25, provides two drawings to support the LAR. Due to the security sensitive nature of the drawings, Duke Energy requests that these drawings be withheld from public disclosure pursuant to 10 CFR 2.390(d)(1). Duke Energy classifies these drawings as Sensitive Unclassified Non-Safeguard Information (SUNSI). When these pages are separated from the remainder of the LAR, this LAR is de-controlled. provides the existing Technical Specification page for McGuire Units 1 and 2, marked-up to show the proposed changes. The reprinted Technical Specification page will be provided to the NRC upon issuance of the approved amendments. provides a portion of the existing TS Bases pages marked-up to show the corresponding proposed Bases changes. The TS Bases change will be processed after LAR approval under the McGuire Bases Control Program (TS 5.5.14). identifies Regulatory Commitments made in support of this LAR.

Duke requests NRC review and approval of this LAR by October 31, 2014 to facilitate the current battery replacement schedule. Duke has determined that a 30 day implementation grace period will be sufficient to implement this LAR.

In accordance with Duke internal procedures and the Quality Assurance Topical Report, the proposed amendment has been reviewed and approved by the McGuire Plant Operations Review Committee.

Pursuant to 10CFR50.91, a copy of this LAR has been forwarded to the appropriate North Carolina state officials.

Please direct any questions you may have in this matter to Lee A. Hentz at (980) 875-4187.

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

Sincerely, Steven D. Capps

US Nuclear Regulatory Commission October 28, 2013 Page 3 Attachments:

1. Evaluation of Proposed Amendment

2. Marked-Up McGuire Technical Specification Pages

3. Marked-Up McGuire Technical Specification Bases Pages

4. Regulatory Commitments cc w/ Attachments:

V. M. McCree Administrator, Region II U.S. Nuclear Regulatory Commission Marquis One Tower 245 Peachtree Center Ave., NE, Suite 1200 Atlanta, GA 30303-1257 J. Zeiler NRC Senior Resident Inspector McGuire Nuclear Station J. C. Paige, Project Manager U.S. Nuclear Regulatory Commission 11555 Rockville Pike Mail Stop 0-8 G9A Rockville, MD 20852-2738 W. L. Cox, Ill, Section Chief North Carolina Department of Environment and Natural Resources Division of Environmental Health Radiation Protection Section 1645 Mail Service Center Raleigh, NC 27699-1645

ATTACHMENT 1 EVALUATION OF PROPOSED AMENDMENT 1.0

SUMMARY

DESCRIPTION 2.0 DETAILED DESCRIPTION

3.0 TECHNICAL EVALUATION

3.1 System Description 3.2 Vital Battery Sizing Analysis 3.3 Battery Replacement Discussion 3.4 Temporary Battery Discussion 3.5 Compliance with Current Regulations 3.6 Defense in Depth Considerations 3.7 Evaluation of Safety Margins 3.8 Configuration Risk Management 3.9 Conformance with NUREG-0800 BTP 8-8 Recommendations 3.10 Conclusion

4.0 REGULATORY EVALUATION

4.1 Applicable Regulatory Requirements/Criteria 4.2 Precedents 4.3 Significant Hazards Consideration

5.0 ENVIRONMENTAL CONSIDERATION

S

1.0

SUMMARY

DESCRIPTION Pursuant to 10 CFR 50.90, Duke Energy Carolinas, LLC (Duke Energy) proposes a license amendment request (LAR) for the Renewed Facility Operating License (FOL) and Technical Specifications (TS) for McGuire Nuclear Station, Units 1 and 2.

The proposed LAR would revise the McGuire TS 3.8.4 Condition A to allow replacement of the existing shared 125 VDC vital batteries while at power. This proposed LAR would be applicable one-time for each of the four shared battery channels. The batteries were last replaced in 1997 under a risk based one-time TS change. All four battery channels are currently operable but are nearing their 20 year nominal service life. Battery replacement is currently scheduled for 2015 and 2016.

Since battery replacement cannot be accomplished within the Completion Times currently allowed by TS 3.8.4 due to the number of activities, inspections, and tests, the proposed LAR would extend the Completion Time to 14 days for each battery channel replacement. Battery replacement cannot be performed during a single unit refueling outage either since the batteries are shared between two units. During each vital battery replacement, the associated DC channel will remain energized by being cross-tied (bus tie with breakers) to another operable DC channel as allowed by TS 3.8.4 Condition A.

In addition, a temporary battery will be available as a defense in depth, backup DC power supply.

Duke Energy originally submitted this as a risk based LAR on August 9, 2012. This revised LAR supersedes the risk based LAR withdrawn from NRC consideration on January 17, 2013. For this revised LAR, Duke Energy has replaced the risk based evaluation with a deterministic engineering justification.

Duke Energy has also reviewed NUREG-0800, Branch Technical Position (BTP) 8-8, "Onsite and Offsite Power Sources Allowed Outage Time Extensions," and has incorporated into this LAR the recommendations and guidance of BTP 8-8 where applicable.

This approach was discussed with the NRC in a public meeting on August 7, 2013 and the LAR is based on the precedents provided in Attachment 1.

2.0 DETAILED DESCRIPTION 2.1 Summary of the Requested Technical Specification Change The proposed LAR would revise the Completion Time for Required Action A.2.2 of TS 3.8.4, "Restore channel of DC source to OPERABLE status," from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 14 days on a one-time temporary basis. A footnote would be added to the TS page stating:

"The Completion Time that one channel of DC source can be inoperable as specified by Required Action A.2.2 may be extended beyond the "72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />" for up to a total of 14 days as part of the battery replacement project. This allowance may be used one-time for each of the four DC channels. Upon completion of the battery replacement project, this footnote is no longer applicable and will expire on December 31, 2016."

Page 1 of 26

The marked-up TS 3.8.4 page illustrating the proposed change is provided in . provides a portion of the existing TS Bases pages marked-up to show the corresponding proposed Bases changes. The TS Bases change will be processed after LAR approval under the McGuire Bases Control Program (TS 5.5.14).

2.2 Discussion of Need to Replace Vital Batteries Each vital battery bank consists of 60 GNB NCN-27 Flooded Lead Calcium (1945 Amp-Hr) battery cells, which were procured through third party qualifier Nuclear Logistics, Inc. (NLI).

The GNB safety related battery cells have a vendor advertised service life of 20 years, however, industry operating experience indicates that 15 to 18 years is a much closer approximation. McGuire's vital batteries were last replaced in 1997. Recent testing on all four batteries demonstrated that three have a capacity in excess of 100% while the fourth battery has a capacity of 99%. In May of 2006, positive post seal nut and jar lid cracking on the battery cells was discovered. This was evaluated by NLI for McGuire and the phenomenon was determined to be nodular corrosion. Approximately 50% of the cells are currently affected by this phenomenon. All four vital battery channels are currently operable but are nearing their 20 year nominal service life.

Cracks on the positive post seal nuts can and will result in increased terminal and connection resistances over time. The following was provided by NLI:

The design function of the post seal components is to prevent the release of acid to the atmosphere. The seal nut is a part of the post seal components; its specific function is to compress the o-ring to form a seal.

The post seal components have no structural role in the battery cell. The failure of any of the seal components will not impact the seismic qualification of the battery. The failure of the seal components can result in a path for acid (electrolyte) to travel from the cell to the cell post. This will result in terminal post blackening. This is not an operability issue but may result in additional maintenance work. The long-term effect of the seal leakage is the corrosion product build-up at the intercell connections, with a corresponding build-up of resistance. As leaks continue to occur, the cell post blackens and a layer of corrosion forms between the post and the intercell connectors. Over time this causes a higher joint resistance.

3.0 TECHNICAL EVALUATION

3.1 System Description

The 125 VDC Vital Instrumentation and Control (l&C) Power System is provided to supply power to nuclear safety related instrumentation and control loads requiring an uninterrupted power source to maintain safe reactor status.

Page 2 of 26

The design of the McGuire 125 VDC I&C power system is such that four batteries, chargers and distribution centers serve both units. Each of the four vital batteries and chargers are connected through their own respective distribution center which is shared by both units. The loads served from these distribution centers are unitized, providing a 125 VDC power panelboard and inverter for each unit. The distribution centers are designed to provide cross-tie capability with its "associated" distribution center of the same train (load group).

Sharing of the 125 VDC I&C power system between units was reviewed and approved by the NRC and documented in the McGuire Safety Evaluation Report (SER)

Supplement 1 dated June 6, 1978. A modified version of Updated Final Safety Analysis Report (UFSAR) Figure 8-35 of the Vital I&C power system is provided on page 24 (Figure 1) that includes the temporary battery connection.

The 125 VDC I&C power system consists of four independent and physically separate load channels. Each channel is comprised of a battery, a charger connection box, a battery charger, a 125 VDC distribution center provided with undervoltage and ground detection equipment, and two 125 VDC power panelboards. Channels A and C are associated with Train A, while Channels B and D are associated with Train B as shown in the below Table. The Train A and B loads are concentrated on Channels A and D respectively, while Channels C and B supply mainly channel related loads.

Train Designation Channel Main Equipment Designation

'A' Train A Channel EVCA battery EVCA charger EVDA bus/distribution center C Channel EVCC battery EVCC charger EVDC bus/distribution center

'B' Train B Channel EVCB battery EVCB charger EVDB bus/distribution center D Channel EVCD battery EVCD charger EVDD bus/distribution center Each battery is separately housed in a ventilated room apart from its charger and distribution centers, which separates it from the other batteries and equipment trains by 3-hour rated fire barriers. In addition, these smaller battery rooms are contained inside a larger battery room area which separates the equipment from other areas of the plant by 3-hour rated concrete walls provided with 3-hour rated doors and frames. Each battery room is supplied with redundant ventilation to prevent the buildup of hydrogen to dangerous levels. A layout drawing of the battery area is provided on page 25 and 26 (Figure 2).

Each battery room, and the associated charging equipment area, is provided with fire detection (smoke detectors) instrumentation which alarm and annunciate in the Control Page 3 of 26

Room. Manual hose stations and portable fire extinguishers are in the area provided for fire suppression.

Since the 125 VDC I&C power system is a Class 1 E system (safety related), all related equipment is located in the Auxiliary Building. The Auxiliary Building is classified as a Category 1 structure, as such, is designed to withstand, without loss of function, the most severe natural phenomena (e.g., tornadoes, hurricanes, earthquakes, floods, and external missiles).

During normal operation, the batteries are floated on the buses and assume load without interruption upon loss of a battery charger or AC power source. Battery chargers EVCA, EVCB, EVCC, and EVCD provide DC power to their respective distribution centers and maintain their respective batteries at float conditions. The 125 VDC distribution centers supply power to their respective 125 VDC power panelboards and the 120 VAC power inverters (see attached Figure 1). The distribution center and power panelboard circuit breakers are closed except for the bus tie breakers and the spare battery charger distribution center breakers in EVDS.

When one battery and/or its charger is removed from its bus, REQUIRED ACTION statement A.2.1 of Technical Specification 3.8.4 is invoked by closing tie breakers between DC channels, ensuring normal loads are still energized by a full capacity charger and battery of the same affected train. For this alignment (cross-tied), one battery is serving two channels on one train. On the other train, two batteries are serving two channels, while assuring train independence at all times. All four vital batteries, including the one serving two channels during the Allowable Outage Time (AOT), are sized to serve normal and emergency loads of both buses. They independently have the capacity to automatically supply minimum engineered safety feature DC loads for a design basis event (DBE) assuming a loss of offsite power (LOOP) in the 125 VDC system on one unit and safe shut down of the other unit.

In an 18 month period this cross-tie alignment is performed at least eight times, twice for each battery for regular testing and preventative maintenance. The Modified Performance Test requires this alignment for 48-54 hours and the annual inspection requires approximately 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.

During a LOOP on one or both trains, the essential motor control centers feeding the Vital I&C battery chargers associated with the affected train will be load shed by the Emergency Diesel Generator (EDG) load sequencer. No more than eleven seconds after the diesel generator start signal, the affected essential motor control centers and battery chargers will be reloaded onto the essential bus by the sequencer. During the time period that the affected essential motor control centers and battery chargers are de-energized, the batteries, alone, feed the vital instrumentation and control loads. If for some reason both of one unit's EDGs fail, two chargers can be manually aligned to the opposite unit's EDGs.

For DBEs, any single vital battery by itself can supply an entire train of DC loads. The interaction between each unit's 125 VDC system is limited such that allowable combinations of maintenance and test operations as governed by the plant Technical Specifications will not preclude the system's capability to automatically supply power to minimum Engineered Safety Feature (ESF) DC loads in either unit, assuming a LOOP on one unit.

Page 4 of 26

3.2 Vital Battery Sizing Analysis All four vital batteries have been sized to carry the load duty cycle during DBE and LOOP conditions for their respective bus/train while maintaining battery terminal voltage above 105 VDC for 60 cells in a cross-tied alignment. Each battery carries DC relays, trip coils, lights and momentary charging spring motor loads, as well as two inverters.

Design Requirements:

1. Should a station blackout (SBO) occur, each battery shall be capable of supplying its respective channel for a period of one hour while maintaining a terminal voltage at or above 105 VDC. Within one hour, power can be restored to a battery charger from the opposite unit emergency diesel generator.

2. The duty cycle used in the calculation is consistent with a LOOP and a DBE without AC power being available to the chargers. The charging spring motors, for 4KV and 600V breakers, is the most limiting random load and are included in the duty cycle.

This duty cycle bounds the situation where no AC power is available from either the standby or offsite source.

3. Each charger is sized to carry its own individual load plus the DC loads of another charger in a back-up capacity and recharge its associated battery within eight hours while supplying its normal loads.

Assumptions:

1. The inverter terminal voltage is assumed to be the minimum rated input voltage (100 VDC). A lower input voltage results in higher load currents in the battery duty cycle for constant power loads such as the inverters. The inverter input voltage is expected to be above 100 VDC during the duty cycle. Therefore the use of 100 VDC as the inverter terminal voltage is conservative.

2. In addition to the worst case loading on distribution centers EVDA, EVDB, EVDC, and EVDD each train's distribution center is assumed to have three breaker charging spring motors starting, due to a signal from the Diesel Generator Load Sequencer in the 0-1 minute period (74.88 Amps per motor starting) and one random charging spring motor running in the 59-60 minute period. This is consistent with the guidance in IEEE 485-1983 sections 4.2.3 and 4.3.2 and IEEE 450-1995, and is modeled in the vital battery sizing calculation.

Design Inputs:

1. McGuire's low voltage load list

2. IEEE 485-1983 for lead acid battery sizing

3. The minimum temperature of the battery room is 60 0 F, for a temperature correction factor of 1.11

4. The aging factor is for 80% end of life capacity, for a factor of 1.25

5. Load growth factor is 1.15 Page 5 of 26

The following table provides the worst case Vital DC bus loading values for cross- tied alignments.

Train A EVDA Loads 0-1 minute 1-59 minutes 59-60 minutes Battery Panelboard EVDA 2.68A 1.52A 1.52A Battery Panelboard 1EVDA 299.38A 50.75A 135.63A Battery Panelboard 2EVDA 306.36A 46.86A 131.74A Inverter Panelboard 1EKVA 104.7A 104.70A 104.7A Inverter Panelboard 2EKVA 110.35A 110.35A 110.35A EVDC Loads Battery Panelboard EVDC 2.68A 1.52A 1.52A Battery Panelboard 1EVDC 5.05A 0.90A 0.90A Battery Panelboard 2EVDC 5.05A 0.90A 0.90A, Inverter Panelboard 1EKVC 64.13A 64.13A 64.13A Inverter Panelboard 2EKVC 65.49A 65.49A 65.49A Total Train A cross-tied load 965.87 A 447.11 A 616.87 A Train B EVDB Loads 0-1 minute 1-59 minutes 59-60 minutes Battery Panelboard EVDB 2.68A 1.52A 1.52A Battery Panelboard 1EVDB 5.05A 0.90A 0.90A Battery Panelboard 2EVDB 5.05A 0.90A 0.90A Inverter Panelboard 1 EKVB 79.30A 79.30A 79.30A Inverter Panelboard 2EKVB 80.50A 80.50A 80.50A EVDD Loads Battery Panelboard EVDD 2.68A 1.52A 1.52A Battery Panelboard 1 EVDD 291.53A 37.60A 122.48A Battery Panelboard 2EVDD 297.46A 40.61A 125.49A Inverter Panelboard 1EKVD 100.21A 100.12A 100.21A Inverter Panelboard 2EKVD 97.34A 97.34A 97.34A Total Train B cross-tied load 961.78 A 440.38 A 610.16 A Conclusion The vital batteries are sized according to Train A cross-tied alignment loading since it is the most limiting. From the Table above, Train A loading is equivalent to removing 459 Amp Hours (AH) from the battery in 60 minutes. Adjusting the load for battery aging, temperature, and load growth, 732AH would be the assumed worst case amp hours removed on a battery rated for 975 AH at the one hour rate.

This analysis demonstrates that, under the cross-tied alignment, the vital batteries are adequately sized to ensure the Vital I&C Power System will perform its design function under worst case conditions.

Page 6 of 26

Battery Testing History Every 18 months a Modified Performance Test (MPT) is performed in accordance with IEEE Standard 450-1995 to satisfy both the service test and performance test requirements. The MPT uses the Train A cross-tied duty cycle again, since it is the most limiting. The MPT discharges the battery at 997A for the first minute followed by a load of 868A until the battery reaches 105V. Results of the last three tests per battery are shown below. The acceptance criteria is > 80% capacity (60 minutes), based on the 75 minute discharge rate, adjusted for temperature to 77 0 F. 100% capacity indicates the battery discharged to 105VDC in 75 minutes.

EVCA Battery Test Results Date Capacity 3/30/2009 109.8%

02/01/2011 107.2%

07/23/2012 103.7%

EVCB Battery Test Results Date Capacity 01/25/2010 110.0%

11/29/2011 106.7%

05/14/2013 105.8%

EVCC Battery Test Results Date Capacity 08/18/2009 102.6%

02/08/2011 105.5%

01/17/2012 102.7%

EVCD Battery Test Results Date Capacity 06/16/2009 104.0%

04/18/2011 98.6%

08/28/2012 99.0%

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3.3 Battery Replacement Discussion The new GNB NCN-27 vital batteries are essentially the same as the existing NCN-27.

Jar size and material have not changed, however the cells are now rated at 1944AH instead of 1945 AH at the 8-hour discharge. The replacement batteries will be sized in accordance with IEEE Std. 485-1983 and will meet the current licensing basis and perform the same safety function as the existing batteries.

From discussions regarding the nodular corrosion phenomenon with battery vendors, other nuclear stations, and industry experts there is currently no permanent solution to the issue as the batteries age. Different vendors have mitigating strategies, however none are able to guarantee their cells will not experience cracking as the cell ages. As indicated by the performance tests, the McGuire NCN-27 Batteries have shown minimal capacity loss for their age.

Replacing batteries will require the existing cells to be disconnected and removed from their mounting rack one cell at a time. Each cell weighs approximately 385 pounds and the rack's side rails must be disassembled to remove the cells. Next the cells are lowered onto a rolling rack to push them out of the battery room.

The new cells will be transported to the respective vital battery room, and installed into the racks one cell at a time. New intercell connectors, intertier jumpers and cables will be connected and tested for connection resistance. After installation, the new battery will receive a freshening charge followed by the TS Surveillance Requirement (SR) voltage and resistance measurements to validate battery operability.

Each new vital battery bank will receive a commissioning charge followed by a Modified Performance Test (MPT). The MPT is a test of battery capacity using a constant current, modified by increasing the current to "bound" the currents required in the battery service test. The MPT will satisfy the TS Surveillance Requirements 3.8.4.7 (Battery Service Test) and 3.8.4.8 (Performance Discharge Test) requirements.

IEEE Standard 450-1995 requires that the battery must be on float charge for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> before performing the MPT. After the MPT the new battery will need to charge 40 hours4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br /> before it can be put in service. The additional 60 hour6.944444e-4 days <br />0.0167 hours <br />9.920635e-5 weeks <br />2.283e-5 months <br /> contingency allowance in the time line is to allow for complications during removal or installation of the battery.

It has been determined that the replacement of each battery bank will take a maximum of approximately 14 days. The time that a battery bank is removed from service for replacement will be kept to a minimum.

The replacement time line (per channel) is as follows:

Page 8 of 26

ACTIVITY TIME REQUIRED Cross-tie the associated channel and take the old 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> battery out of service.

Remove old battery (isolate power, disconnect 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> cables and connectors, remove cells).

Transport new cells to battery room. 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> Install new battery (install new cells, attach 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> connectors and all associated hardware)

Re-torque battery rack connections. Torque 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> connectors and connect power cables.

Equalize charge on new battery to restore 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> capacity lost during storage/movement.

Pre-MPT new battery float charge 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> Perform quarterly maintenance and TS SR voltage 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> and resistance measurements.

Perform MPT 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> Post-MPT charge 40 hours4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br /> Re-align new battery to the bus. 5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> Removal/installation contingency allowance 60 hours6.944444e-4 days <br />0.0167 hours <br />9.920635e-5 weeks <br />2.283e-5 months <br /> Total time 329 hours0.00381 days <br />0.0914 hours <br />5.439815e-4 weeks <br />1.251845e-4 months <br /> (=14 days)

In addition, each battery replacement will be controlled by a Critical Activity Plan in accordance with the Duke Energy Nuclear Station Directive (NSD) 213, "Risk Management Process." The key components of a Critical Activity Plan are a written plan for accomplishing the activity, a designated activity manager, contingency plans if problems develop, clear criteria for aborting the activity, training needs evaluated, pre-job briefings, and plan review and approval by the Plant Operations Review Committee (PORC).

3.4 Temporary Battery Discussion For the unlikely scenario where the vital battery supporting the cross-tied channels is lost or disabled; a temporary battery would be utilized to support recovery of one of the lost DC channels and associated loads as a defense in depth measure. The temporary battery bank would be manually tied to the DC side of the standby battery charger (EVCS) via safety related EVDS Distribution Center breaker 1B. It will not be credited for operability of the associated DC channels. In this scenario, with more than one DC channel inoperable, McGuire would enter TS 3.8.4 Condition B. This would require both Units to be in Mode 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and Mode 5 within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. The manual connections to the temporary battery are designed to be accomplished by Operations Page 9 of 26

within 60 minutes once it has been determined it can be done safely and this strategy is desired to support event recovery.

The temporary battery is a full capacity, identical battery bank procured for 1E usage and sized in accordance with IEEE Standard 485-1983, using the load profile for a LOOP coincident with a DBE on one unit and safe shutdown of the other unit. Voltage drops from the temporary battery to each distribution center have been accounted for in the battery sizing, such that existing voltage drop analysis from the Vital DC distribution centers (EVDA, EVDB, EVDC and EVDD) to their respective loads remains bounding.

The temporary battery bank will be located in Room 700 of the McGuire Service Building (shared load center room) due to space limitations in the battery room in the Auxiliary Building. The Service Building, which is located between the Unit 1 and 2 Turbine Buildings, is not a Seismic Category structure and the temporary battery will not be seismically mounted. The temporary battery bank will remain disconnected via a disconnect box but available if needed. The disconnect box is seismically mounted and located in the Auxiliary Building / Battery Room. The cables from temporary battery to the disconnect box are non-safety related. The cables from the disconnect box to the EVDS distribution center and spare charger will be Class 1 E safety related. See attached Figure 2 for the layout drawing of the battery area.

Efforts were made to locate the temporary battery in a seismic, category 1 structure to further reduce the risks associated with external events. No suitable location could be found that did not introduce other complications such as train related cable separation challenges, cable length challenges, ventilation availability, and fire protection challenges, i.e., potential impact on other protected safety related SSCs due to a lack of fire barriers. The placement of the temporary battery in Service Building was done previously and the area was modified in the 1997 time frame with the necessary cables and disconnect boxes. This area is protected from turbine missiles by the turbine pedestal.

A temporary charger will also be installed to maintain the temporary battery at 132VDC.

The temporary charger will have a disconnect to electrically isolate it from the temporary battery and the DC bus.

The temporary battery will receive a full complement of TS Surveillances tests including a MPT prior to the first vital battery replacement. In addition, all applicable TS Surveillance tests will be performed on the temporary battery configuration during periods of battery bank replacement. Should the temporary battery/cell not pass a TS Surveillance, the replacement would not begin until appropriate corrective actions have been taken so the temporary battery/cell can pass the Surveillance.

The ambient temperature and hydrogen concentration of the area containing the temporary battery will be monitored once per 12-hour shift to ensure they remain within battery specifications. The ventilation in this area will be supplemented with fans to ensure good air flow and mixing across the temporary battery. The area is provided with fire detection instrumentation.

At some point after the first battery bank is replaced but prior to the last (fourth) replacement, one of the older, removed batteries will be set-up as the temporary battery so the initial temporary battery can be installed as one of the new vital batteries. As Page 10 of 26

previously stated, the older batteries are fully operable and equivalent to the replacement batteries.

3.5 Compliance with Current Regulations This LAR itself does not propose to deviate from existing regulatory requirements, and compliance with existing regulations is maintained by the proposed one time change to the plant's Technical Specification requirements. Additional details may be found in the Regulatory Evaluation section of this LAR.

3.6 Defense in Depth Considerations This proposed LAR meets the defense-in-depth principle consisting of a number of elements. These elements and the impact of the proposed change on these elements are as follows:

• A reasonable balance among prevention of core damage, prevention of containment failure and consequence mitigation is preserved.

The proposed LAR would revise the McGuire TS 3.8.4 Condition A to allow replacement of the existing 125 VDC vital batteries while at power. This proposed LAR would be applicable one-time for each of the four battery channels. During each vital battery replacement, the associated DC channel will remain energized by being cross-tied (bus tie with breakers) to another operable DC channel as currently allowed by TS 3.8.4 Condition A. All four vital batteries have been sized to carry the load duty cycle for their respective bus/train while maintaining battery terminal voltage in a cross-tied alignment during a LOOP with a DBE on one unit and safe shut down of the other unit. Due to this robust design, the safety functions of the 125 VDC I&C system are preserved. Cross-tying two channels to one battery is a normal alignment that Operations performs approximately eight times in an 18 month operating cycle to accommodate battery discharge testing and annual inspection for each of the four batteries. In addition, a temporary battery will be available as a defense in depth, backup DC power supply.

The proposed LAR does not introduce a new accident or transient since no new equipment is installed, existing equipment is not operated in a new manner, and thus no new accident initiator is introduced. The temporary battery remains disconnected via a disconnect box but available if needed. The 125 VDC I&C power system is not an initiator of any analyzed design basis events, therefore, the proposed LAR does not increase the likelihood of an accident or transient.

The temporary battery remains electrically isolated from the Vital DC distribution centers during normal operations. Existing hatch doors and fire stops would prevent a fire in the area of the temporary battery (room 700 of the service building) from spreading into the battery room. Security is stationed at the hatch door as long as it is open and is able to close the door as needed. Analysis of hydrogen production of the temporary battery has validated that the existing ventilation of Room 700 and the floors above it prevents hydrogen concentrations greater than 2%. Fans will be placed near the temporary battery to prevent pockets of hydrogen from collecting on the ceiling.

Page 11 of 26

• Over-reliance on programmatic activities to compensate for weaknesses in plant design is avoided.

The proposed LAR does not change the plant design. The 125 VDC I&C power system is designed to be operated with a vital battery carrying an entire train's loads as needed.

Except for weekly Technical Specification Surveillances of the vital batteries, in service battery rooms will remain locked. During each vital battery replacement, certain important equipment will be protected and compensatory measures will be in place.

These measures are consistent with normal plant practices. Applicable approved procedures will also be utilized during this activity. This is not considered to be an over-reliance on programmatic activities. No new specific programs are being initiated during the battery replacement evolutions.

• System redundancy, independence and diversity are maintained commensurate with the expected frequency and consequences of challenges to the system.

During each vital battery replacement, the associated DC channel will remain energized by being cross-tied (bus tie with breakers) to another operable DC channel as currently allowed by TS 3.8.4 Condition A. All four vital batteries have been sized to carry the load duty cycle for their respective bus/train while maintaining battery terminal voltage in a cross-tied alignment during a LOOP with a DBE on one unit and safe shut down of the other unit. Cross-tying two channels to one battery is a normal alignment that Operations performs approximately eight times in an 18 month operating cycle. During each vital battery replacement, certain important equipment will be protected and compensatory measures will be in place to offset the impact on system redundancy. In addition, a temporary battery will be available as a defense in depth, backup DC power supply. As such, system redundancy, independence and diversity are maintained.

• Defenses against potential common cause failures are preserved and the potential for the introduction of new common cause failure mechanisms is assessed.

As previously discussed, important equipment will be protected and compensatory measures will be in place to offset the impact on system redundancy and potential common cause failures. These measures will include avoiding (to the extent possible) severe weather conditions and periods of system grid instability during the proposed TS Completion Time extension. As such, appropriate measures will be taken to preserve defenses against potential common cause failures and no new common cause failure mechanisms will be introduced.

0 Independence of barriers is not degraded.

The proposed vital battery replacement activity does not directly impact the three principle barriers or otherwise cause their degradation. Independence of barriers is not degraded because the proposed TS Completion Time extension has no impact on the physical barriers.

Page 12 of 26

0 Defenses against human errors are preserved.

Appropriate training will be provided to Operations and Maintenance personnel for the battery replacement evolution and, as discussed above, equipment protection and compensatory measures will be in place. Applicable approved procedures will also be developed and utilized during this activity including the connection to the temporary battery.

In addition, each battery replacement will be controlled by a Critical Activity Plan in accordance with the Duke Energy Nuclear Station Directive (NSD) 213, "Risk Management Process." The key components of a Critical Activity Plan are a written plan for accomplishing the activity, a designated activity manager, contingency plans if problems develop, clear criteria for aborting the activity, training needs evaluated, pre-job briefings, and plan review and approval by the Plant Operations Review Committee (PORC). As such, defenses against human errors are preserved.

• The intent of the plant's Design Criteria is maintained.

This activity is a TS Completion Time extension to allow replacement of the station vital batteries with a like-for-like design. As such, this activity does not modify the plant design or the design criteria applied to systems, structures, or components (SSCs) during the licensing process. The 125 VDC I&C power system is designed to be operated in the proposed (cross-tied) manner. Additional details regarding compliance with the GDCs are provided in Section 4.1.

Standby Shutdown System As additional defense in depth, McGuire was designed with a Standby Shutdown System (SSS) to meet 10 CFR 50 Appendix R (Fire Protection Program) and 10 CFR 50.63 station blackout (SBO) requirements.

The SSS is designed to mitigate the consequences of certain postulated fire, sabotage incidents and SBO events by providing capability to achieve and maintain hot standby conditions by controlling and monitoring vital systems from locations external to the control room. This capability is consistent with the requirements in 10 CFR 50 Appendix R which permits control of safe shutdown outside the control room and at a limited number of local equipment stations.

The primary components that support the SSS function are an independent diesel generator, reactor coolant system (RCS) makeup pump, the turbine driven auxiliary feedwater (AFW) pump, and RCS instrumentation.

Since the SSS provides an alternate means to achieve and maintain a hot standby condition following the above mentioned postulated events, the system (except for interfaces with existing safety related systems) was designed in accordance with accepted Fire Protection, SBO, and security requirements and is not designed to withstand seismic loadings. This SSS is not nuclear safety related.

Page 13 of 26

Compensatory Measures and Commitments

1. The following SSCs will be protected and elective maintenance deferred during each respective vital battery replacement:

Battery EVCA replacement

• Vital channels B, C, D

" McGuire Switchyard

• Unit 1 and 2 main step-up transformer yard

• Unit 1 and 2 6.9kV switchgear room

• Standby Shutdown facility and associated equipment (SSS)

" Emergency Diesel Generators (EDG) 1B, 2B

• Component Cooling water trains (KC) 1B, 2B

" Nuclear Service Water trains (RN) 1B, 2B

" Motor driven Auxiliary Feedwater (CA) pumps 1B, 2B

• Unit 1 and 2 Turbine driven CA pumps

" Diesel powered Instrument Air (VI) compressors G, H Battery EVCB replacement

• Vital channels A, C, D

" McGuire Switchyard

• Unit 1 and 2 main step-up transformer yard

" Unit 1 and 2 6.9kV switchgear room

• SSS

" EDG 1A, 2A

" KC trains KC 1A, 2A

• RN trains RN 1A, 2A

• Motor driven CA pumps 1A, 2A

" Unit 1 and 2 Turbine driven CA pumps

• Diesel powered VI compressors G, H Battery EVCC replacement

" Vital channels A, B, D

" McGuire Switchyard

• Unit 1 and 2 main step-up transformer yard

• Unit 1 and 2 6.9kV switchgear room

• SSS

• EDG 1B, 2B

" KC trains KC 1B, 2B

• RN trains RN 1B, 2B

" Motor driven CA pumps 1B, 2B

" Unit 1 and 2 Turbine driven CA pumps

" Diesel powered VI compressors G, H Page 14 of 26

Battery EVCD replacement

• Vital channels A, B, C

" McGuire Switchyard

" Unit I and 2 main step-up transformer yard

" Unit 1 and 2 6.9kV switchgear room

• SSS

• EDG 1A, 2A e KC trains KC 1A, 2A e RN trains RN 1A, 2A o Motor driven CA pumps 1A, 2A

• Unit 1 and 2 Turbine driven CA pumps

• Diesel powered VI compressors G, H

2. A temporary battery located in the Service Building is available as a defense in depth measure. The temporary battery will be charged and has the necessary connections to tie-in to any of the four DC distribution centers, if necessary.

3. The ambient temperature and hydrogen concentration of the area containing the temporary battery will be monitored once per a 12-hour shift to ensure they remain within battery specifications.

4. The ventilation in the area containing the temporary battery will be supplemented with fans to ensure good air flow and mixing across the temporary battery.

5. Appropriate training will be provided to Operations Shift personnel, maintenance and vendor technicians regarding the vital battery replacement evolution, emergency procedures, and temporary battery alignment.

6. Alignment procedures for the temporary battery will be in place for Operations.

7. The manual connections to the temporary battery are designed to be accomplished by Operations within 60 minutes once it has been determined it can be done safely and this strategy is desired to support event recovery.

8. Pre-job briefings will be provided to Maintenance and Vendor personnel each shift during the vital battery replacement evolutions.

9. The temporary battery will receive a full complement of TS surveillances tests including a MPT prior to the first vital battery replacement.

10. All applicable TS surveillance tests will be performed on the temporary battery configuration during periods of battery bank replacement.

11. Prior to the start of each TS Completion Time extension and daily thereafter, McGuire will monitor the National Weather Service for potential severe weather conditions. To the extent practical, severe weather conditions will be avoided.

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12. Prior to the start of each TS Completion Time extension and daily thereafter, McGuire will contact the Transmission Control Center (TCC) regarding system grid stability. To the extent practical, system grid instability will be avoided.

3.7 Evaluation of Safety Margins

• Codes and standards or alternatives approved for use by the NRC are met (e.g.,

proposed LAR not in conflict with approved codes and standards).

The design and operation of the vital batteries are not altered by the proposed TS CT extension. Each battery is adequately sized for cross-tie operation and this evolution is performed periodically throughout a fuel cycle for testing and maintenance. This alignment is allowed by the McGuire Technical Specifications for a limited period of time.

Since the 125 VDC I&C power system is a Class 1E system (safety related), all related equipment (including the vital batteries and cross-tie features) is located in the Auxiliary Building. The Auxiliary Building is classified as a Category 1 structure, as such, is designed to withstand, without loss of function, the most severe natural phenomena (e.g., tornadoes, hurricanes, earthquakes, floods, and external missiles).

• Safety analysis acceptance criteria in the plant licensing basis are met or proposed revisions provide sufficient margin to account for analysis and data uncertainties.

The safety analysis acceptance criteria stated in the UFSAR are not impacted by this change. The proposed change will not allow plant operation in a configuration outside the design basis. The requirements regarding the vital batteries credited in the accident analysis will remain the same. As also discussed in this LAR, a comparable temporary battery bank and the Standby Shutdown System will also be available for loss of DC power recovery and accident mitigation.

As such, it can be concluded that safety margins are not impacted by the proposed change.

3.8 Configuration Risk Management 10 CFR 50.65 (a)(4), "Requirements for Monitoring the Effectiveness of Maintenance at Nuclear Power Plants," requires that prior to performing maintenance activities, risk assessments shall be performed to assess and manage the increase in risk that may result from proposed maintenance activities. These requirements are applicable for all plant modes.

The proposed LAR is not expected to result in any significant changes to the current configuration risk management program. The existing program uses a blended approach of quantitative and qualitative evaluation of each configuration assessed. The McGuire on-line computerized risk software, Electronic Risk Assessment Tool (ERAT),

considers both internal and external initiating events with the exception of seismic events. Thus, the overall change in plant risk during maintenance activities is expected to be addressed adequately considering the proposed amendment.

Page 16 of 26

McGuire has several Nuclear System Directives (NSD) and Work Process Manual (WPM) procedures that are in place to ensure that risk significant plant configurations are avoided. These documents are used to address the Maintenance Rule requirements, including the on-line (and off-line) Maintenance Policy requirement to control the safety impact of combinations of equipment removed from service. The key documents are as follows:

" NSD 213, "Risk Management Process"

" NSD 403, "Shutdown Risk Assessment (Modes 4, 5, 6, and No-Mode) per 10 CFR 50.65 (a)(4)"

" NSD 415, "Operational Risk Management (Modes 1-3) per 10 CFR 50.65 (a)(4)"

• WPM-609, "Innage Risk Assessment Utilizing Electronic Risk Assessment Tool (ERAT)"

" WPM-608, "Outage Risk Assessment Utilizing Electronic Risk Assessment Tool (ERAT)"

More specifically, the NSDs referenced above address the process; define the program, and state individual group responsibilities to ensure compliance with the Maintenance Rule. The Work Process Manual procedures provide a consistent process for utilizing the computerized software assessment tool, ERAT, which manages the risk associated with equipment inoperability.

The Electronic Risk Assessment Tool (ERAT) is a computer program used to facilitate risk informed decision making associated with station work activities. Its guidelines are independent of the requirements of the Technical Specifications and Selected Licensee Commitments and are based on probabilistic risk assessment studies and deterministic approaches.

Additionally, prior to the release of work for execution, Operations personnel must consider the effects of severe weather and grid instabilities on plant operations. This qualitative evaluation is inherent of the duties of the Work Control Center Senior Reactor Operator (WCC SRO). Responses to actual plant risk due to severe weather or grid instabilities are programmatically incorporated into applicable plant emergency or response procedures.

The key safety significant systems impacted by this proposed LAR are currently included in the Maintenance Rule program, and as such, availability and reliability performance criteria have been established to assure that they perform adequately.

3.9 Conformance with NUREG-0800 BTP 8-8 Recommendations Duke Energy has also reviewed NUREG-0800, Branch Technical Position (BTP) 8-8, "Onsite and Offsite Power Sources Allowed Outage Time Extensions." The purpose of this BTP is to provide guidance from a deterministic perspective for developing and reviewing license amendment requests for one-time or permanent TS Completion Time Page 17 of 26

extensions for EDGs and offsite power sources from the current TS Completion Time up to 14 days to perform online maintenance.

Duke Energy has incorporated into this LAR the below recommendations and guidance of BTP 8-8 where applicable to this vital battery replacement project:

• A supplemental power source (a full sized battery) will be available for defense-in-depth.

• The supplemental power source can be manually connected within one hour using approved procedures.

• The availability of the supplemental power source is a compensatory measure and commitment.

• The TS Completion Time extension is limited to 14 days and will be used one time per battery.

• Battery replacements will not be scheduled if severe weather conditions are anticipated.

• The Transmission Control Center will be contacted daily regarding system grid stability.

• Important safety systems will be protected and elective maintenance deferred during each battery replacement. The complete list of protected equipment is contained in section 3.6.

• The Unit 1 and 2 Turbine Driven Auxiliary Feedwater pumps will be considered protected equipment.

3.10 Conclusion All four McGuire vital battery channels are currently operable but are nearing their 20 year nominal service life. During the time period of each vital battery bank replacement, the associated DC channel will remain energized by being cross-tied to another operable DC channel as allowed by TS 3.8.4 Condition A. This is a normal plant alignment performed numerous times during a fuel cycle for vital battery maintenance and surveillance testing. In addition, a temporary battery will be available as a defense in depth, backup DC power supply.

The results of the deterministic engineering justification described above provide assurance that the systems and equipment required to safely shutdown the plant and mitigate the effects of a design basis accident will remain capable of performing their safety functions.

The proposed TS Completion Time extension is consistent with NRC guidance and meets the following principles:

Page 18 of 26

1. Meets the current regulations

2. Consistent with the defense-in-depth philosophy

3. Maintains sufficient safety margins Based on the considerations discussed above, (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with NRC regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public

4.0 REGULATORY EVALUATION

4.1 Applicable Regulatory Requirements/Criteria 10 CFR 50, Appendix A, General Design Criterion (GDC) 5, "Sharing of structures, systems, and components." Structures, systems, and components important to safety shall not be shared among nuclear power units unless it can be shown that such sharing will not significantly impair their ability to perform their safety functions, including, in the event of an accident in one unit, an orderly shutdown and cooldown of the remaining units.

10 CFR 50, Appendix A, General Design Criterion (GDC) 17, "Electric Power Systems," requires, in part, that "An onsite electric power system and'an offsite electric power system shall be provided to permit functioning of structures, systems, and components important to safety ... The onsite electric power supplies, including the batteries, and the onsite electric distribution system, shall have sufficient independence, redundancy, and testability to perform their safety functions assuming a single failure. Provisions shall be included to minimize the probability of losing electric power from any of the remaining supplies as a result of, or coincident with, the loss of power generated by the nuclear power unit, the loss of power from the transmission network, or the loss of power from the onsite electric power supplies."

10 CFR 50, Appendix A, GDC 18, "Inspection and Testing of Electric Power Systems," requires, in part, that "Electric power systems important to safety shall be designed to permit appropriate periodic inspection and testing ... "

10 CFR 50.63, "Loss of All Alternating Current Power," requires, in part, that "Each light-water-cooled nuclear power plant licensed to operate must be able to withstand for a specified duration and recover from a station blackout ..."

Sharing of the 125 VDC I&C power system between Units, and conformance to GDC 5, was reviewed and approved by the NRC and documented in the McGuire Safety Evaluation Report (SER) Supplement 1 dated June 6, 1978.

During the time period of each vital battery bank replacement, the associated DC channel will remain energized by being cross-tied to another operable DC channel as allowed by TS 3.8.4 Condition A. This is a normal plant alignment performed numerous Page 19 of 26

times during a fuel cycle for vital battery maintenance and surveillance testing. In addition, a temporary battery will be available as a defense in depth, backup DC power supply.

All four vital batteries have been sized to carry the load duty cycle for their respective bus/train while maintaining battery terminal voltage in a cross-tied alignment during a LOOP with a DBE on one unit while safely shutting down the other unit. Each battery carries DC relays, trip coils, lights and momentary charging spring motor loads, as well as two inverters.

McGuire is designed with a Standby Shutdown System (SSS) to meet 10 CFR 50 Appendix R (Fire Protection Program) and 10 CFR 50.63 station blackout (SBO) requirements. In addition, a temporary battery will be available as an additional, backup DC power supply.

Thus during the replacement periods, compliance with the above regulatory requirements will not be affected. In addition, the new 125 VDC batteries are essentially the same in design and function to the existing batteries thus will continue to meet the above regulatory requirements.

4.2 Precedents The following LARs to replace the station batteries have been submitted and approved by the NRC. McGuire has reviewed these LARs, the RAIs, and the NRC Safety Evaluations and has modeled this submittal after these:

1. Duane Arnold received NRC approval on October 1, 2002 (NRC ADAMS ML No.

022280041).

2. Indian Point received NRC approval on September 19, 2001 (NRC ADAMS ML No. 011990082).

3. Braidwood received NRC approval on March 26, 1999 (NRC ADAMS ML No.

021820479).

4. McGuire received NRC approval on February 7, 1997 (NRC ADAMS ML No.

013230346).

5. Oconee Nuclear Station received NRC approval on August 30, 2010 (NRC ADAMS ML No. 102210354).

6. Salem Unit 2 received NRC approval on September 1, 2010 (NRC ADAMS ML No. 102150499)

The following TS Completion Time extension LARs were originally developed as risk based LARs then submitted with a deterministic justification only. McGuire has reviewed these LARs and modeled this submittal after these also.

1. Browns Ferry Nuclear received NRC approval on October 5, 2011 (NRC ADAMS ML No. 11227A258).

2. Oconee Nuclear Station LAR submitted to the NRC on June 27, 2012 NRC ADAMS ML No. 12181A312).

Page 20 of 26

4.3 Significant Hazards Consideration Pursuant to 10 CFR 50.90, Duke Energy Carolinas, LLC (Duke Energy) proposes a license amendment request (LAR) for the Renewed Facility Operating License (FOL) and Technical Specifications (TS) for McGuire Nuclear Station, Units 1 and 2.

The proposed LAR would revise the McGuire TS 3.8.4 Condition A to allow replacement of the existing shared 125 VDC vital batteries while at power. This proposed LAR would be applicable one-time for each of the four shared battery channels. The vital batteries were last replaced in 1997. All four battery channels are currently operable but are nearing their 20 year nominal service life. Battery replacement is currently scheduled for 2015 and 2016.

Since vital battery replacement cannot be accomplished within the Completion Times currently allowed by TS 3.8.4 due to the number of activities, inspections, and tests, the proposed LAR would extend the Completion Time to 14 days for each battery channel replacement. During the time period of each battery bank replacement, the associated DC channel will remain energized by being cross-tied to another operable DC channel as allowed by TS 3.8.4 Condition A. This is a normal plant alignment performed numerous times during a fuel cycle for vital battery maintenance and surveillance testing. In addition, a temporary battery will be available as a defense in depth, backup DC power supply.

Duke Energy has concluded that operation of the McGuire Nuclear Station Units 1 & 2 in accordance with the proposed changes to the Technical Specifications does not involve a significant hazards consideration. Duke Energy's conclusion is based on its evaluation, in accordance with 10CFR50.91(a)(1), of the three standards set forth in 10CFR50.59(c) as discussed below:

1. Does the proposed amendment involve a significant increase in the probability or consequences of an accident previously evaluated?

Response: No.

Removing one vital battery from service for a limited period of time does not involve a significant increase in the probability or consequences of an accident.

All four vital batteries have been sized to carry the load duty cycle for their respective bus/train while maintaining battery terminal voltage in a cross-tied alignment during a LOOP with a DBE on one unit and safe shut down of the other unit. The vital battery cross-tie alignment is part of the McGuire licensing basis, is in the Technical Specifications, and is routinely performed.

In addition, for defense-in-depth and risk mitigation measures, a fully sized temporary battery will be available as a defense in depth, back-up DC power supply for plant recovery and accident mitigation.

Therefore, the proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.

Page 21 of 26

2. Does the proposed amendment create the possibility of a new or different kind of accident from any accident previously evaluated?

Response: No.

Operation in accordance with the proposed LAR does not create a new plant configuration, nor adversely affect how the plant is currently operated. During the time period of each vital battery bank replacement, the associated DC channel will remain energized by being cross-tied to another operable DC channel as designed and as allowed by TS 3.8.4. This is a normal plant alignment, it maintains train independence, and is performed numerous times during a fuel cycle for vital battery maintenance and surveillance testing.

No new accident causal mechanisms are created as a result of this proposed LAR. No changes are being made to any structure, system, or component which will introduce any new accident causal mechanisms. The temporary battery remains physically and electrically isolated from the rest of the 125VDC system via an open disconnect switch. The cable between the spare charger and the disconnect will remain de-energized by isolation from the charger's DC output breaker and both crosstie breakers. This proposed LAR does not impact any plant systems that are accident initiators and does not impact any safety analysis.

Therefore, the proposed changes do not create the possibility of a new or different kind of accident from any accident previously evaluated.

3. Does the proposed amendment involve a significant reduction in the margin of safety?

Response: No.

The proposed LAR does not physically alter the present plant design nor affect how the plant is currently operated. This activity only extends the amount of time that vital DC channels are allowed to be cross-tied. So a significant reduction in the margin of safety does not occur.

Margin of safety is related to the confidence in the ability of the fission product barriers to perform their design functions during and following an accident situation. These barriers include the fuel cladding, the reactor coolant system, and the containment system. The performance of the fuel cladding, reactor coolant and containment systems will not be impacted by the proposed LAR.

Therefore, it is concluded that the proposed changes do not involve a significant reduction in the margin of safety.

Based upon the above evaluation, Duke Energy concludes that the proposed amendment presents no significant hazards consideration under the standards set forth in 10 CFR 50.92(c) and, accordingly, a finding of "no significant hazards consideration" is justified.

Page 22 of 26

5.0 ENVIRONMENTAL CONSIDERATION

S A review by Duke Energy has determined that the proposed amendment would temporarily change a requirement with respect to use of a facility component located within the restricted area, as defined in 10 CFR 20. However, the proposed amendment does not involve (i) a significant hazards consideration, (ii) a significant change in the types or significant increase in the amounts of any effluent that may be released onsite, or (iii) a significant increase in individual or cumulative occupational radiation exposure.

Accordingly, the proposed amendment meets the eligibility criterion for categorical exclusion set forth in 10 CFR 51.22(c)(9).

Therefore, pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the proposed amendment.

Page 23 of 26

FIGURE 2, BATTERY AREA DRAWING LEGEND

• Halon Extinguisher O C02 Extinguisher

-3 Hr fire barrier

\ fire door

" Electrical Equipment*

- - 3/C 500MCM x2 cable This drawing is representative of the battery room layout, only relevant equipment is shown and the drawing is not to scale.

• All Vital I&C channel related equipment are to the left or right of their respective channel related batteries.

Page 26 of 26

ATTACHMENT 2 Marked-Up McGuire Technical Specification Page

DC Sources - Operating 3.8.4 3.8 ELECTRICAL POWER SYSTEMS 3.8.4 DC Sources -Operating LCO 3.8.4 The four channels of DC sources shall be OPERABLE.

APPLICABILITY: MODES 1, 2, 3, and 4.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. One channel of DC A. 1 Restore channel of DC 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> source inoperable, source to OPERABLE status.

OR A.2.1 Verify associated bus tie 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> breakers are closed between DC channels.

AND A.2.2 Restore channel of DC 72hours source to OPERABLE status.

B. Required Action and B.1 Be in MODE 3. 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> Associated Completion Time not met. AND B.2 Be in MODE 5. 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />

• The Completion Time that one channel of DDC source can be inoperable as specifie d by chanhan he hanlofB "72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />" 14 days as part of the for upfortoeach batry replacement project. This allowance may beyond the be used one-time of the four DC Requitr ed Atio n Ai2.2t maye extended I y7=IIU M cG uire Units 1 and 2 h8,lo3.8.4-1 a, Am endm ent No. -

ATTACHMENT 3 Marked-Up McGuire TS Bases Pages

DC Sources-Operating B 3.8.4 BASES APPLICABLE SAFETY ANALYSES (continued)

a. An assumed loss of all offsite AC power or all onsite AC power; and

b. A worst case single failure.

The DC sources satisfy Criterion 3 of 10 CFR 50.36 (Ref. 8).

LCO Each DC channel consisting of one battery, battery charger for each battery and the corresponding control equipment and interconnecting cabling supplying power to the associated bus within the train is required to be OPERABLE to ensure the availability of the required power to shut down the reactor and maintain it in a safe condition after an anticipated operational occurrence (AOO) or a postulated DBA. Loss of any channel of DC does not prevent the minimum safety function from being performed (Ref. 4).

An OPERABLE channel of DC requires the battery and respective charger to be operating and connected to the associated DC bus.

APPLICABILITY The DC electrical power sources are required to be OPERABLE in MODES 1, 2, 3, and 4 to ensure safe unit operation and to ensure that:

a. Acceptable fuel design limits and reactor coolant pressure boundary limits are not exceeded as a result of AQOs or abnormal transients; and

b. Adequate core cooling is provided, and containment integrity and other vital functions are maintained in the event of a postulated DBA.

The DC electrical power requirements for MODES 5 and 6 are addressed in the Bases for LCO 3.8.5, "DC Sources- Shutdown."

ACTIONS A.1 and A.2 Condition A represents one channel of DC with a loss of ability to fully respond to a DBA with the worst case single failure. Two hours is provided to restore the channel of DC to OPERABLE status and is consistent with the allowed time for an inoperable channel of DC distribution system requirement.

McGuire Units 1 and 2 B 3.8.4-3 Revision No. 9ý

DC Sources-Operating B 3.8.4 BASES ACTIONS (continued)

If one of the required channels of DC is inoperable (e.g., inoperable battery, inoperable battery charger(s), or inoperable battery charger and associated inoperable battery), the remaining DC channels have the capacity to support a safe shutdown and to mitigate an accident condition. If the channel of DC cannot be restored to OPERABLE status, Action A.2 must be entered and the DC channel must be energized from an OPERABLE channel, from the same train, within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />. The capacity of the redundant channel is sufficient to supply its normally supplied channel and cross tied channel for the required time, in case of a DBA event. The inoperable channel of DC must be returned to OPERABLE status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> and the cross ties to the other channel open. The 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> Completion Time reflects a reasonable time to assess unit status as a function of the inoperable channel of DC and, if the DC channel is not restored to OPERABLE status, to prepare to effect an orderly and safe unit shutdown.

B.1 and B.2 If the inoperable channel of DC cannot be restored to OPERABLE status within the required Completion Time, the unit must be brought to a MODE in which the LCO does not apply. To achieve this status, the unit must be brought to at least MODE 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and to MODE 5 within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. The allowed Completion Times are reasonable, based on operating experience, to reach the required unit conditions from full power conditions in an orderly manner and without challenging plant systems.

The Completion Time to bring the unit to MODE 5 is consistent with the time required in Regulatory Guide 1.93 (Ref. 9).

SURVEILLANCE SR 3.8.4.1 REQUIREMENTS Verifying battery terminal voltage while on float charge for the batteries helps to ensure the effectiveness of the charging system and the ability of the batteries to perform their intended function. Float charge is the condition in which the charger is supplying the continuous charge required to overcome the internal losses of a battery (or battery cell) and maintain the battery (or a battery cell) in a fully charged state. The voltage requirements are based on the nominal design voltage of the battery and are consistent with the initial voltages assumed in the battery sizing calculations. The Surveillance Frequency is based on operating experience, equipment reliability, and plant risk and is controlled under the Surveillance Frequency Control Program.

McGuire Units 1 and 2 B 3.8.4-4 Revision No.(

Technical Specification Bases 3.8.4, Actions A.1 and A.2 Insert:

As part of the battery replacement project, the Completion Time that one channel of DC source can be inoperable as specified by Required Action A.2.2 may be extended beyond the "72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />" for up to 14 days. This allowance may be used one-time for each of the four DC channels. Upon completion of the battery replacement project, the Completion Time footnote is no longer applicable and will expire on December 31, 2016.

ATTACHMENT 4 Regulatory Commitments

REGULATORY COMMITMENTS The following Table identifies those actions committed to by Duke Energy McGuire in this document. Any other statements made in this submittal are provided for informational purposes and are not considered to be regulatory commitments.

COMMITMENT TYPE DUE DATE During replacement of battery EVCA, the following systems One time During EVCA and components will be protected and elective maintenance battery deferred: replacement.

• Vital channels B, C, D

• McGuire Switchyard

• Unit 1 and 2 main step-up transformer yard

• Unit 1 and 2 6.9kV switchgear room

• Safe Shutdown facility and associated equipment (SSS)

• Emergency Diesel Generators (EDG) 1 B, 2B

• Component Cooling water trains (KC) 1B, 2B

• Nuclear Service Water trains (RN) 1 B, 2B

• Motor driven Auxiliary Feedwater (CA) pumps 1 B, 2B

• Unit 1 and 2 Turbine driven CA pumps

• Diesel powered Instrument Air (VI) compressors G, H During replacement of battery EVCB, the following systems One time During EVCB and components will be protected and elective maintenance battery deferred: replacement.

• Vital channels A, C, D

• McGuire Switchyard

• Unit 1 and 2 main step-up transformer yard

• Unit 1 and 2 6.9kV switchgear room

" SSS

• EDG 1A, 2A

• KCtrains KC 1A, 2A

• RN trains RN 1A, 2A

" Motor driven CA pumps 1A, 2A

• Unit 1 and 2 Turbine driven CA pumps

• Diesel powered VI compressors G, H 1 of 3

COMMITMENT TYPE DUE DATE During replacement of battery EVCC, the following systems One time During EVCC and components will be protected and elective maintenance battery deferred: replacement.

• Vital channels A, B, D

" McGuire Switchyard

• Unit 1 and 2 main step-up transformer yard

• Unit 1 and 2 6.9kV switchgear room

• SSS

• EDG 1B, 2B

• KC trains KC 1B, 2B

• RN trains RN 1B, 2B

• Motor driven CA pumps 1 B, 2B

• Unit 1 and 2 Turbine driven CA pumps

• Diesel powered VI compressors G, H During replacement of battery EVCD, the following systems One time During EVCD and components will be protected and elective maintenance battery deferred: replacement.

• Vital channels A, B, C

• McGuire Switchyard

• Unit 1 and 2 main step-up transformer yard

• Unit 1 and 2 6.9kV switchgear room

• SSS

• EDG 1A, 2A

• KCtrains KC 1A, 2A

• RN trains RN 1A, 2A

• Motor driven CA pumps 1A, 2A

• Unit 1 and 2 Turbine driven CA pumps

• Diesel powered VI compressors G, H A temporary battery located in the Service Building is One time During each available as a defense in depth measure. The temporary TS Completion battery will be charged and has the necessary connections Time extension to tie-in to any of the four DC distribution centers, if necessary.

The ambient temperature and hydrogen concentration of the Ongoing until Prior to area containing the temporary battery will be monitored once temporary installation of per a 12-hour shift to ensure they remain within battery battery is temporary specifications. removed. battery.

2 of 3

COMMITMENT TYPE DUE DATE The ventilation in the area containing the temporary battery Ongoing until Prior to will be supplemented with fans to ensure good air flow and temporary installation of mixing across the temporary battery. battery is temporary removed, battery.

Prior to the start of each TS Completion Time extension and Ongoing Prior to the daily thereafter, McGuire will monitor the National Weather start of each Service for potential severe weather conditions. To the TS Completion extent practical, severe weather conditions will be avoided. Time extension Prior to the start of each TS Completion Time extension and Ongoing Prior to the daily thereafter, McGuire will contact the Transmission start of each Control Center (TCC) regarding system grid stability. To the TS Completion extent practical, system grid instability will be avoided. Time extension Appropriate training will be provided to Operations Shift One time Prior to battery personnel, maintenance, and vendor technicians regarding replacements.

the vital battery replacement evolution, emergency procedures, and temporary battery alignment.

Pre-job briefings will be provided to Maintenance and Ongoing Prior to battery Vendor personnel each shift during the vital battery replacements.

replacement evolutions.

Alignment procedures for the temporary battery will be in One time Prior to battery place for Operations. replacements The manual connections to the temporary battery are Ongoing During each designed to be accomplished by Operations within 60 TS Completion minutes once it has been determined it can be done safely Time extension and this strategy is desired to support event recovery.

The temporary battery will receive a full complement of TS One time Prior to battery surveillances tests including an MPT prior to the first vital replacements.

battery replacement.

All applicable TS surveillance tests will be performed on the Ongoing During each temporary battery configuration during periods of battery TS Completion bank replacement. Time extension 3 of 3