Text

License Amendment Request to Technical Specification (TS) 3.6.13, Ice Condenser Doors.
	ML16089A228
Person / Time
Site:	McGuire, Mcguire
Issue date:	03/24/2016
From:	Capps S; Duke Energy Carolinas
To:	; Document Control Desk, Office of Nuclear Reactor Regulation
References
	MNS-15-068
	Download: ML16089A228 (36)
	v • d • e

(~DUKE Steven D. Capps

~

Vice President ENERGY McGuire Nuclear Station Duke Energy MGOlVP I 12700 Hagers Ferry ~oad Huntersville, NC 28078 O: 980.875.4805 f: 980.875.4809 March 24, 2016 Steven.Capps@duke-energy.com Serial No.: MNS-15-068 10 CFR 50.90 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Duke Energy Carolinas, LLC (Duke Energy)

McGuire Nuclear Station (MNS), Units 1 and 2 Docket Numbers. 50-369 and 50-370 Renewed License Numbers NPF-9 and NPF-17

Subject:

License Amendment Request to Technical Specification (TS) 3.6.13, "Ice Condenser Doors" Pursuant to 10 CFR 50.90, Duke Energy Carolinas, LLC (Duke Energy) hereby requests a License Amendment to revise the Unit 1 and Unit 2 McGuire Nuclear Station (MNS) Technical Specification (TS) 3.6.13 to revise Condition B for an ice condenser lower inlet door invalid open alarm. This License Amendment Request (LAR) is needed to preclude an unnecessary plant shutdown caused by an invalid "OPEN" alarm from the "Inlet Door Position Monitoring System."

Approval of the proposed amendment is requested within one year of submittal. Once approved, the amendment shall be implemented within 120 days.

The Enclosure provides. Duke Energy's evaluation of the proposed TS change and the technical basis for the request. Proposed TS and Bases page markups are included as Attachments 1 and 2 to the Enclosure, respectively. Conforming TS Bases changes will be made Jn accordance with the MNS TS Bases Control Program. Marked-up TS Bases pages are provided in the Attachments for information only. Drawings and Photographs of the Ice Condenser Containment and the Ice Bays are provided in Attachment.3.

This LAR was discussed with the NRC staff in a public meeting on August 12, 2015.

Information provided at that time was preliminary, and changes were made to the TS markup based on comments during the management review process.

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

www.duke-energy.com

' I. r ' ,_4; U. S. Nuclear Regulatory Commission Serial MNS-15-068 Page2 In accordance with 10 CFR 50.91, a copy of this LAR is being sent to the designated official of the State of North Carolina.

This letter contains no new regulatory commitments. The MNS Updated Final Safety Analysis Report is not affected by this change.

If there are any questions or if additional information is needed, please contact Brian Richards, McGuire Regulatory Affairs at (980) 875-5171.

I declare under penalty of perjury that the foregoing is true and correct. Executed on March 24, 2016.

Sincerely, Steven D. Capps

Enclosure:

Evaluation of the Proposed Change

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U. S. Nuclear Regulatory Commission Serial MNS-15-068 Page 3 xc with Attachments C. Haney Regional Administrator, Region 11 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 G. E. Miller, Project Manager (MNS & CNS)

U.S. Nuclear Regulatory Commission 11555 Rockville Pike Mail Stop 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 N.C. 27699-1645

'. *1 ENCLOSURE Evaluation of the Proposed Change

Subject:

License Amendment Request to Technical Specification (TS) 3.6.13, "Ice Condenser Doors"

1.

SUMMARY

DESCRIPTION

2. DETAILED DESCRIPTION 2.1 Summary of Issue 2.2 Description of Proposed License Amendment

3. TECHNICAL EVALUATION 3.1 Background 3.2 Deterministic Justification

4. REGULATORY EVALUATION 4.1 Applicable Regulatory Requirements/Criteria 4.2 No Significant Hazards Consideration Determination 4.3 Conclusions

5. ENVIRONMENTAL CONSIDERATION

6. REFERENCES ATTACHMENTS:

1. Technical Specification Page Markups

2. Bases Page Markups

3. Drawings and Photographs of the Ice Condenser Containment and the Ice Bays

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1.0

SUMMARY

DESCRIPTION Pursuant to 10 CFR 50.90, Duke Energy Carolinas, LLC (Duke Energy) requests a License Amendment to revise the Unit 1 and Unit 2 McGuire Nuclear Station (MNS) Technical Specification (TS) 3.6.13 for revising Condition B for an invalid ice condenser lower inlet door open alarm.

The McGuire TS 3.6.13, "Ice Condenser Doors" Limiting Condition for Operation (LCO) requires the ice condenser lower inlet doors, intermediate deck doors, and top deck doors OPERABLE and closed during Modes 1, 2, 3, and 4. TS Surveillance Requirement (SR) 3.6.13.1 requires verification that all lower inlet doors indicate closed by the Inlet Door Position Monitoring System. This TS SR is controlled in accordance with the Surveillance Frequency Control Program and is-currently performed on a frequency of every 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months .

Currently, when one or more lower inlet doors (LIDs) cannot be verified closed by the Inlet Door Position Monitoring System, TS 3.6.13 existing Condition B requires_ verification of maximum ice bed temperature of 27°F every four hours and restoration of the LID to Operable status (closed position) within 14 days. If Condition B cannot be met, Condition C requires restoration of the LID to Operable status (closed position) within 48 hours5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months . If Condition C cannot be met, the Unit shall be in Mode 3 in 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and Mode 5 in 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months .

The proposed change will revise TS 3.6.13 Condition B to add a new Required Action when one or more ice condenser lower inlet doors are inoperable due to having an invalid open alarm.

Required Actions while in this Condition will be to verify ice bed temperature less than or equal to 27°F every four hours and to verify each LID is closed every 14 days. This License Amendment is needed to preclude an unnecessary plant shutdown caused by an invalid "ICE COND LOWER INLET DOORS OPEN" alarm.

This license amendment request was discussed with the NRC staff in a public meeting on August 12, 2015. Information provided at that time was preliminary, and changes were made to the TS markup based on comments during the management review process.

2.0 DETAILED DESCRIPTION 2.1 Summary of Issue On May 13, 2013, the Control Room received an annunciator alarm: "ICE COND LOWER INLET DOORS OPEN" on Unit 1. Upon validation at the local door position display panel located in upper containment, this alarm corre~ponded to the LIDs located in Ice Condenser bays 21 through 24. TS 3.6.13 Condition B Required Actions were entered. Completion time for restoring the ice condenser door to OPERABLE status and closed position is 14 days. In a parallel path, McGuire proactively began working on an Emergency license amendment, which was later not submitted once the issue was resolved.

Initial troubleshooting on May 14, 2013, determined that at least one of the limit switches for the LIDs in bays 21 through 24 had an open contact. The local door position display panel located in upper containment allows the monitoring of LID position (OPEN/CLOSED) in groups of four bays (i.e., eight LID panels) each. Once the Control Room LID alarm indicator was illuminated, inspection of the local display panel allowed the determination of which set of bay doors was Page 2of11

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implicated. Subsequent use of specialized tooling from the upper ice condenser plenum isolated the open limit switch contact to the right side door of bay 21 (door 21 R).

During the Unit 1 End of Cycle 22 refueling outage (spring 2013), an LID seal (the seal around the periphery of the door portal frame) was replaced in bay 21. This seal, corresponding to LID 21 R, placed the limit switch of the Inlet Door Position Monitoring System in a slightly different position due to the new seal thickness. The limit switch was not adjusted following the seal replacement, which likely increased its sensitivity to movement. While the required channel check on the Inlet Door Position Monitoring System prior to Mode change was successful, operation at full thermal power in lower containment likely created conditions different enough to heighten this sensitivity.

On May 13, 2013, the Lower Containment Ventilation System fans had been shifted from low speed to high speed to cool lower containment for entry to work on valve 1NV-61. This also caused a slight temporary variation in lower containment pressure, which can decrease the differential pressure across the LIDs between lower containment and the ice condenser lower plenum. It was following this evolution that the LID 21 R limit switch indicated open on the local door position display panel and in the Control Room.

On May 14, 2013, with the use of a light and video camera lowered down into the ice bays, Engineering and Maintenance verified that the LIDs in bays 21 through 24 were in fact closed.

No air movement (between lower containment and the ice bays) was detected and no melting of ice or frosting on the LIDs was noted. These would be indications that an LID was slightly cracked open.

It was concluded that at least one LID limit switch was slightly out of adjustment, and the troubleshooting effort isolated the open limit switch contact to the one on LID 21 R. The limit switches cannot be adjusted during power operation due to personnel dose concerns. The LID limit switches are located near the reactor coolant piping and components in lower containment; therefore, adjusting these limit switches would be dose prohibitive.

Several attempts were made to re-seat the suspect LID to the indication limit switch. These included cooling the ice conc:lenser area to increase the cold head and lightly pushing on each door remotely with specialized tooling. On May 16, 2013, with the use of specialized tooling, enough pressure was applied to LID 21 R to make the limit switch contact and clear the alarm.

After waiting 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months (length of the SR frequency), TS 3.6.13 Condition B Required Actions were .exited. The LID 21 R limit switch was readjusted to accommodate the new door seal thickness during the subsequent Unit 1 refueling outage (fall 2014).

In light of the issue summary, Duke Energy is requesting this TS change in the event that an LID alarm is received and the alarm cannot be cleared by use of special tooling (light pressure on the affected UD). Due to the existence of 48 LID panels per unit, the potential exists for future similar alarms. New door seals may not be as compressed as old seals. Lower containment ventilation realignments and temperature changes could activate a similar alarm situation. This TS change is necessary to preclude an unnecessary plant shutdown.

Maintenance procedures governing the inspections and corrective actions for LIDs addressing seal replacement(s) have been modified to include a limit switch adjustment post seal replacement.

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2.2 Description of Proposed License Amendment TS LCO 3.6.13 requires the ice condenser lower inlet doors, intermediate deck doors, and top deck doors OPERABLE and closed during Modes 1, 2, 3, and 4. TS SR 3.6.13.1 requires verification that all lower inlet doors indicate closed by the Inlet Door Position Monitoring System. This TS SR is controlled in accordance with the Surveillance Frequency Control Program, and is currently performed on a frequency of every 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months . When one or more LIDs cannot be verified closed by the Inlet Door Position Monitoring System, TS 3.6.13 Condition B requires verification of maximum ice bed temperature of 27°F every 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months and restoration of the LID to Operable status (closed position) within 14 days. If Condition B cannot be met, Condition C requires restoration of the LID to Operable status (closed position) within 48 hours5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months .

If Condition C cannot be met, the Unit shall be in Mode 3 in 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and Mode 5 in 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months .

The limit switches for the Inlet Door Position Monitoring System cannot always be adjusted during power operation due to personnel dose concerns. The LID limit switches are located near the reactor coolant piping and components in lower containment; therefore, adjusting these limit switches may be dose prohibitive.

If necessary, the proposed change to TS 3.6.13 would allow door position monitoring by an alternative method other than the Inlet Door Position Monitoring System for the affected LID(s) only for verification of Operability. If necessary, TS 3.6.13 Action Note 1 allows separate condition entry for each ice condenser door.

Duke Energy proposes a revised Condition B to TS 3.6.13 as follows:

CONDITION REQUIRED ACTION COMPLETION TIME B. One or more ice B.1 Verify maximum ice bed Once per 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months condenser doors temperature is :5 27°F.

inoperable for reasons other than Condition A,

NOTE----------~

or not closed.

Required Action B 2.1

applies only when one or more ice condenser lower inlet doors are inoperable due to having an invalid open alarm.

B.2.1 Verify affected lower inlet Once per 14 days door is closed.

OR B.2.2 Restore ice condenser door 14 days to OPERABLE status and closed positions.

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3.0 TECHNICAL EVALUATION

3.1 Background

Ice Condenser Door Design and Operation:

Refer to Attachment 3 "Drawings and Photographs of the Ice Condenser Containment and the Ice Bays."

The Ice Condenser doors consist of the lower inlet doors, the intermediate deck doors, and the top deck doors. The functions of the doors are to:

Seal the ice condenser from air leakage and provide thermal/humidity barriers during the lifetime of the unit; and

Open in the event of a Design Basis Accident (OBA) to direct the hot steam-air mixture from the DBA into the ice bed, where the ice would adsorb energy and limit containment peak pressure and temperature during the accident transient.

Limiting the pressure and temperature following a OBA reduces the release of fission product radioactivity from containment to the environment.

The ice condenser is an annular compartment enclosing approximately 300 degrees of the perimeter of the upper containment compartment, but penetrating the operating deck so that a portion extends into the lower atmosphere of the lower compartment from the ice bed inside the ice condenser. The top deck doors are above the ice bed and exposed to the atmosphere of the upper compartment. The intermediate deck doors, located below the top deck doors, form the floor of a plenum at the upper part of the ice condenser. The lower inlet doors (LID) form the insulated barrier between the ice condenser and the lower containment. There are 48 LIDs arranged in pairs of two (24 bays in all). This upper plenum area is used to facilitate surveillance and maintenance of the ice bed and contains the air handling units that remove heat from the ice bed. Equalization vents, located at the periphery of the intermediate and top decks, are provided to balance small pressure differentials occurring across the decks during normal operation.

The ice baskets held in the ice bed within the ice condenser are arranged to promote heat transfer from steam to ice. This arrangement enhances the ice condenser's primary function of condensing steam and absorbing heat energy released to the containment during a OBA.

In the event of a OBA, the ice condenser lower inlet doors (located below the operating deck) open due to the pressure rise in the lower compartment. This allows air and steam to flow from the lower compartment into the ice condenser. The resulting pressure increase within the ice condenser causes the intermediate deck doors and the top deck doors to open, which allows the air to flow out of the ice condenser into the upper compartment. Steam condensation within the ice condenser limits the pressure and temperature buildup in containment. A divider barrier separates the upper and lower compartments and ensures that the steam is directed into the ice condenser through the LIDs.

The ice serves as a containment heat removal system and is adequate to absorb the initial blowdown of steam and water from a OBA. The water from the melted ice drains into the lower compartment where it serves as a source of borated water (via the containment sump) for the Page 5of11

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Emergency Core Cooling System (ECCS) and the Containment Spray System heat removal functions in the recirculation mode. The ice and the recirculated ice melt (via the Containment Spray System) also serve to clean up the containment atmosphere.

The ice condenser doors ensure that the ice stored in the ice bed is preserved during normal operation (doors closed) and that the ice condenser functions as designed if called upon to act as a passive heat sink following a OBA.

The LIDs are provided with tension spring mechanisms that produce a small closing torque on the door panels as they open. The zero load position of the spring mechanisms is set such that, with zero differential pressure across the door panels, the gasket holds the door slightly open.

The developed ice condenser cold head assists with compression of the LID gasket seals, and also serves to re-close the LIDs should the panels briefly and inadvertently break away from the seal during normal operation.

For small incidents, initial inlet door opening (location and magnitude) is determined by local lower compartment pressure. As the developed ice condenser cold head is lost through open doors, the remainder of the doors will also tend to open, providing numerous pathways for steam to enter the ice condenser. For larger incidents, the doors open fully and flow distribution is controlled by the flow area and pressure drops of inlet ports. The doors are provided with shock absorber assemblies to dissipate the larger door kinetic energies generated during large break incidents.

LID Position Indication:

For door monitoring purposes, the ice condenser is divided into six zones. Each zone contains four inlet door assemblies, or a total of eight door panels. Each lower inlet door panel is provided with a single pole double throw limit switch for position indication and alarm. Each zone is provided a pair of monitor lights (one for "Door Open" and one for "Door Closed" indication) on the door position display panel. A "Door Open" indication is given if any door panel within a zone is opened.

A Control Room alarm "ICE COND LOWER INLET DOORS OPEN" is provided on an annunciator panel. This alarm is activated if any door panel in any zone is opened.

The door position display panel is accessible during normal plant operation in the event an ice condenser door open alarm is annunciated in the Control Room.

Ice Bed Temperature Monitoring:

Resistance temperature detectors (RTDs) and temperature switches are located in various parts of the ice condenser. They serve to verify attainment of a uniform equilibrium temperature in the ice bed and to detect general gradual temperature rise in the cooling system.

Ice Bed RTDs include two that are plenum mounted and forty-five that are probe assembly mounted, attaching to the lattice frame located throughout the ice bed. These forty-eight (forty-seven with one spare) Ice Bed RTDs tie into a temperature scanner unit. The scanner multiplexes the ice condenser RTDs signals to a recorder in the main control room. There are also six temperature switches located at various points in the ice bed to serve as backup indication should the scanner unit or recorder fail to operate. These inputs provide an alarm on Page 6of11

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the Control Room annunciator panel for a preset deviation from limits of ice bed equilibrium temperature.

3.2 Deterministic Justification LID position (OPEN/CLOSED) is generally based on the contact state of the limit switches located on the 48 LIDs. During the Modes of Applicability, LID position is important for ice condenser Operability determination, since an open LID (gross leakage) will allow thermal energy from lower containment to enter the ice bed, challenging the ice inventory available for OBA scenarios. There are several methods besides the Inlet Door Position Monitoring System to check the ice bed for unwanted thermal energy ingress, including monitoring the installed RTDs in the ice bed. This monitoring is currently part of TS 3.6.12 (Ice Bed) and TS 3.6.13; so a parallel method to the Inlet Position Monitoring System is already in place providing defense-in-depth for potential inadvertent gross LID leakage.

Additionally, the existence of gross ingress of air from lower containment through an open LID will remove the remaining cold head in the ice condenser lower plenum, causing the opening of the other LIDs. Once this occurs, the local door position display panel will show many bay groups. illuminated. This result is unavoidable if the cold head is lost, and was the basis for the ice condenser system design in order to protect against preferential melting of ice bed inventory in a localized area. Thus, if the local door position display panel is not showing other bay groups of LIDs off their seals, it is highly unlikely that an LID is open to the point of allowing gross leakage, and only small volume leakage past an LID seal or a limit switch issue is indicated.

The LID design also accommodates the potential for small volume leakage around the door seal, for which the limit switch contact may still show the LID position as closed. By design, some leakage around the LID seals into the lower ice condenser plenum is expected during normal operation since the sealing surface can be uneven, and minor pressure perturbations in lower containment can result in brief LID unseating. Any potential for frost development at the seal due to these processes has been addressed by the door design. With the seal located on the outside (i.e., the lower containment side) of the LID surface, frost buildup is not possible due to the temperature that exists at the door/seal interface.

Consequently, it is feasible to determine the LID position (OPEN/CLOSED) if the limit switch becomes non-functional for any reason by monitoring other parameters in the lower ice condenser plenum, such as local ice bed/lower plenum bay temperatures. The LIDs can be viewed via a camera lowered through the ice bed flow channels from the intermediate deck elevation. If any significant quantity of moist air from lower containment is leaking past a LID seal, it will do so near the top of the door, and in addition create a visible vapor/mist as the movement of warm air moisture condenses in the cold air conditions present in the lower ice condenser plenum area.

The current frequency for performing a LID closed verification is on a 12 hour1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months frequency, controlled in accordance with the Surveillance Frequency Control Program, and is performed with the Inlet Door Position Monitoring System. The frequency of 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months ensures that operators on each shift are aware of the status of the doors. In the event that a visual inspection, combined with no notable ice bed temperature change, indicates one or more ice condenser lower inlet doors has an invalid open alarm as indicated by the Inlet Door Position Page 7of11

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Monitoring System, the maximum ice bed temperature is verified :::;; 27°F once every 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months , and the affected lower inlet door must be verified closed every 14 days. The normal operating temperature range is 10°F to 25°F in the ice condenser lower support structure. In addition, the open/closed status of the remaining LIDs will be performed using the door position display panel located in upper containment on a 12 hour1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months frequency per TS SR 3.6.13.1, in accordance with the Surveillance Frequency Control Program.

For dose reasons that prohibit normal access to inspect the LIDs, a remote video camera system may be used. The camera is a waterproof inspection camera suited for extreme environmental conditions. The camera head is attached to a long cable and displays picture on a monitor with video recording capability. The camera employs high resolution and zoom capability. A camera control box gives the user the manual capability to adjust camera settings.

The camera also employs an adjustable spot and flood lights to allow the ability to light up a narrow target or a wide area.

For inspection using a remote camera system, a light and camera are lowered approximately 54 feet to each lower inlet door in the affected zone every 14 days from the Ice Condenser intermediate deck area. The camera will be used to look for frost and condensation on the door surface, vapor/mist coming from the top of the door, ice formation on the concrete floor, and air movement between lower containment and the ice bay. Air movement will be detected via a flag attached to the camera. The inspection every 14 days is justified based on the high confidence that the ice bed temperature is verified at or below 27°F every four hours, and the remaining LI Ds are verified closed per TS SR 3.6.13.1. If the local door position display panel is not showing other zones of lower inlet doors off their seals, it is highly unlikely that a lower inlet door is open to the point of allowing gross leakage, and only small volume leakage past the door seal or a limit switch issue is indicated. The current TS 3.6.13 allowance for the 14 day Required Action if an LID is open provides further confidence in the soundness of the ice bed inventory as long as ice bed temperatures are maintained at or below 27°F by the Ice Condenser cooling system. Personnel ice condenser entries are currently performed on a weekly basis (every 7 days in accordance with the Surveillance Frequency Control Program) to satisfy SR 3.6.13.2. This surveillance is a visual inspection to verify each intermediate deck door is closed and not impaired by ice, frost, or debris. The inspection by video camera will procedurally identify the correct zone and door panels. The video camera will not be permanently installed in containment and will be removed while not in use.

As discussed in the Bases for TS 3.6.13, ice bed temperature is required to be monitored once per four hours to ensure that the open or inoperable LID is not allowing enough air leakage to cause the maximum ice bed temperature to approach the melting point. The frequency of four hours is based on the fact that temperature changes cannot occur rapidly in the ice bed because of the large mass of ice involved. Current TS 3.6.13 Required Action B.2 Completion Time of 14 days is based on long term ice storage tests that indicate that if the temperature is maintained below 27°F, there would not be a significant loss of ice from sublimation.

Once the control room alarm "ICE COND LOWER INLET DOORS OPEN" is received, the annunciator light will remain in al~rm until the condition is cleared. The control room alarm "ICE COND LOWER INLET DOORS OPEN" is a symptom for entry into AP/1/A/5500/34 "Shutdown Loss of Coolant Accident (LOCA)" (Revision 22). This abnormal procedure (AP) provides actions for protecting the reactor core in the event of a LOCA that occurs during either Mode 3 with Cold Leg Accumulators isolated or Mode 4. Three other symptoms are available for entry into this AP: "Pzr level - GOING DOWN IN AN UNCONTROLLED MANNER", "Reactor Coolant System (NC) subcooling - GOING DOWN IN AN UNCONTROLLED MANNER, and Page 8of11

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"Containment floor and equipment sump level(s) - GOING UP". Thus, entry into the AP is not singularly reliant upon the "ICE COND LOWER INLET DOORS OPEN" alarm, and is only a diagnostic symptom during Modes 3 and 4.

4.0 REGULATORY EVALUATION

4.1 Applicable Regulatory Requirements/Criteria This License Amendment that modifies a Technical Specification Condition does not alter or revise the current bounding MNS Ice Condenser System safety analyses of record in .any way.

Consequently, MNS will remain in compliance with the applicable regulations and requirements.

These are:

10CFR50, Appendix A, General Design Criterion (GDC) 16, "Containment Design," which requires that the reactor Containment and associated systems provide an essentially leak-tight barrier against the uncontrolled release of radioactivity to the environment; GDC 38, "Containment Heat Removal," which requires that a system be provided to remove heat from the reactor Containment; GDC 40, "Testing of Containment Heat Removal System," which requires appropriate periodic testing to assure system operability, GDC 50, "Containment Design Basis," which requires that the reactor containment structure be designed with conservatism to accommodate applicable design parameters (pressure, temperature, leakage rate).

TS 3.6.13 for the Ice Condenser Doors also satisfies Criterion 3 of 10 CFR 50.36, which is the NRC regulation that addresses the content of nuclear plant Technical Specifications.

4.2 No Significant Hazards Consideration Determination Pursuant to 10 CFR 50.90, Duke Energy Carolinas, LLC (Duke Energy) requests a License Amendment to revise the McGuire Nuclear Station (MNS) Technical Specification (TS) 3.6.13 for adding a new Required Action for an invalid ice condenser lower inlet door open alarm. This License Amendment Request (LAR) is needed to preclude an unnecessary plant shutdown caused by an invalid "OPEN." alarm from the "Inlet Door Position Monitoring System."

Duke Energy has evaluated whether a significant hazards consideration is involved with the proposed amendment by focusing on the three standards set forth in 10 CFR 50.92, "Issuance of amendment," as discussed below:

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

Response: No The proposed change will not increase the probability of accident previously evaluated. The Ice Condenser performs an entirely mitigative function. The proposed change does not result in Page 9of11

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any physical change to the plant which would affect any accident initiators. No structures, systems, or components (SSCs) involved in the initiation of postulated accidents will be operated in any different manner. The probability of occurrence of a previously evaluated accident will not be significantly increased. The proposed change involves use of an alternate method of verifying that the lower inlet doors to the ice condenser are closed. This proposed change has no effect on the ability of the ice condenser to perform its function.

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

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

Response: No The proposed change does not alter the design function or operation of any SSC that may be involved in the initiation of an accident. The Ice Condenser. will not become the source of a new type of accident. No new accident causal mechanisms will be created. The proposed change does not create new failure mechanisms, malfunctions, or accident initiators.

Therefore, the proposed change does riot create the possibility of a new or different kind of accident from any previously evaluated.

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

Response: No Margin of safety is related to the confidence in the ability of the fission product barriers to perform their intended functions. These barriers include the fuel cladding, the reactor coolant system pressure boundary, and the containment barriers. The proposed change involves use of a method to verify the lower inlet doors to the ice condenser are closed when an invalid alarm is providing indication of an open door. This proposed change has no effect on the ability of the ice condenser to perform its function. Hence, the proposed change will not affect containment barriers. Nor does the proposed change have any effect on fuel cladding or the reactor coolant pressure boundary.

Therefore, existing safety margins will be preserved, and the proposed change does not involve a significant r~duction in the margin of safety.

4.3 Conclusions In conclusion, 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 the Commission's 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.

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5.0 ENVIRONMENTAL CONSIDERATION

S A review determined that the proposed amendment would change a requirement with respect to installation or use of a facility component located within the restricted area, as defined in 10 CFR 20, or would change an inspection or surveillance requirement. 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 offsite, or (iii) a significant increase in individual or cumulative occupational radiation exposure.

Accordingly, the proposed amendment meets the eligibility criteria 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.

6. 0 REFERENCES

1. UFSAR Chapter 6.2.2, "Ice Condenser System."

2. UFSAR Chapter 7.6.5, "Ice Condenser System."

3. MNS TS and Bases 3.6.13, "Ice Condenser Doors."

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ENCLOSURE ATTACHMENT 1 Technical Specification Page Markups

I.

'Revised TS Condition B' on Page 3.6.13-1 CONDITION REQUIRED ACTION COMPLETION TIME B. One or more ice B.1 Verify maximum ice bed Once per 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months condenser doors temperature is :5 27°F.

inoperable for reasons AND other than Condition A,

NOTE------------

or not closed.

Required Action B.2.1 applies only when one or more ice condenser lower inlet doors are inoperable due to having an invalid open alarm.

B.2.1 Verify affected lower inlet Once per 14 days door is closed.

OR B.2.2 Restore ice condenser door 14 days to OPERABLE status and closed positions.

' I!,* * {v.

Ice Condenser Doors 3.6.13 3.6 CONTAINMENT SYSTEMS 3.6.13 Ice Condenser Doors LCO 3.6.13 The ice condenser lower inlet doors, intermediate deck doors, and top deck doors shall be OPERABLE and closed.

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

ACTIONS

~------------------------------------------------NOTE-------------------------------------------------------------

1. Separate Condition entry is allowed for each ice condenser door.

2. Entry into Condition B is not required due to personnel standing on or opening an intermediate deck or top deck door for short durations to perform required surveillances, minor maintenance such as ice removal or routine tasks such as system walkdowns.

CONDITION REQUIRED ACTION COMPLETION TIME A. One or more ice A.1 Restore lower inlet door to 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months Replace with condenser lower inlet OPERABLE status.

'Revised TS doors inoperable due to Condition B' being physically restrained from opening.

\

\-* - ---- ----

('"'\,.,-

~-- B.1 VeFify ma*iFRl:lm ise 13eEl Onse peF 4 hol:lFS sonElenseF ElooFs ternperatl:lm is < 27°F.

inoperal31e foF Feasons otheF than ConElition A OF AfID not sloseEl.

B.2 Restore ise sonElenseF ElooF 14 Elays to OPeRABbe statl:ls ans sloseEl positions.

(continued)

McGuire Units 1 and 2 3.6.13-1 Amendment No. 256/236

I.

.

r-Ice Condenser Doors 3.6.13 CONDITION REQUIRED ACTION COMPLETION TIME C. Required Action and c. 1 Restore ice condenser door 48 hours5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months associated Completion to OPERABLE status and Time of Condition B not closed position.

met.

D. Required Action and D.1 Be in MODE 3. 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months associated Completion Time of Condition A or C AND not met.

D.2 Be in MODE 5. 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.6.13.1 Verify all lower inlet doors indicate closed by the Inlet In accordance with Door Position Monitoring System. the Surveillance Frequency Control Program SR 3.6.13.2 Verify, by visual inspection, each intermediate deck door In accordance with is closed and not impaired by ice, frost, or debris. the Surveillance Frequency Control Program SR 3.6.13.3 Verify, by visual inspection, each top deck door: In accordance with the Surveillance

a. Is in place; and Frequency Control Program

b. Has no condensation, frost, or ice formed on the door that would restrict its opening.

(continued)

McGuire Units 1 and 2 3.6.13-2 Amendment No. 261/241

I 1 *~ f ......

ENCLOSURE ATTACHMENT 2 Bases Page Markups (For Information Only)

Add TSB Insert 1 to Page B 3.6.13-5 For door monitoring purposes, the ice condenser is divided into six zones. Each zone contains four lower inlet door assemblies, or a total of eight door panels. Each lower inlet door panel is provided with a limit switch for position indication and alarm. Each zone is provided a pair of monitor lights (one for "Door Open" and one for "Door Closed" indication) on the door position display panel located in upper containment. A "Door Open" indication is given if any door panel within a zone is opened. A Control Room alarm ("ICE COND LOWER INLET DOORS OPEN")

is provided on an annunciator panel. This alarm is activated if any door panel in any zone is opened. The door position display panel is accessible during normal plant operation in the event an ice condenser door open alarm is annunciated in the Control Room.

In the event that a visual inspection, combined with no notable ice bed temperature change, indicates one or more ice condenser lower inlet doors has an invalid open alarm as indicated by the Inlet Door Position Monitoring System, Condition B.2.1 is entered. The maximum ice bed temperature is verified :::; 27°F once per 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months and the affected lower inlet door must be verified closed every 14 days. In the event that dose prohibits a local inspection of the door( s ),

from the Ice Condenser intermediate deck area, a light and camera are lowered approximately 54 feet to each lower inlet door in the affected zone. The camera will be used to look for frost and condensation on the door surface, vapor/mist coming from the top of the door, ice formation on the concrete floor, and air movement between lower containment and the ice bay. Air movement will be detected via a flag attached to the camera. The 14 day inspection is justified based on the high confidence that the maximum ice bed temperature is verified at or below 27°F every 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months , and the remaining lower. inlet doors are verified closed per TS SR 3.6.13.1. If the local door position display panel is not showing other zones of lower inlet doors off their seals, it is highly unlikely that a lower inlet door is open to the point of allowing gross leakage, and only small volume leakage past the door seal or a limit switch issue is indicated.

Add TSB Insert 2 to Page B 3.6.13-6 The open/closed status verification of lower inlet door(s) having an invalid open alarm by the Inlet Door Position Monitoring System is performed per Condition B. The remaining lower inlet doors are verified closed at the local door position display panel located in upper containment.

Ice Condenser Doors B 3.6.13 B 3.6 CONTAINMENT SYSTEMS B 3.6.13 Ice Condenser Doors BASES BACKGROUND The ice condenser doors consist of the lower inlet doors, the intermediate deck doors, and the top deck doors. The functions of the doors are to:

a. Seal the ice condenser from air leakage and provide thermal/humidity barriers during the lifetime of the unit; and

b. Open in the event of a Design Basis Accident (OBA) to direct the hot steam-air mixture from the OBA into the ice bed, where the ice would absorb energy and limit containment peak pressure and temperature during the accident transient.

Limiting the pressure and temperature following a OBA reduces the release of fission product radioactivity from containment to the environment.

The ice condenser is an annular compartment enclosing approximately 300° of the perimeter of the upper containment compartment, but penetrating the operating deck so that a portion extends into the lower containment compartment. The lower inlet doors separate the atmosphere of the lower compartment from the ice bed inside the ice condenser. The top deck doors are above the ice bed and exposed to the atmosphere of the upper compartment. The intermediate deck doors, located below the top deck doors, form the floor of a plenum at the upper part of the ice condenser. This upper plenum area is used to facilitate surveillance and maintenance of the ice bed and contains the air handling units that remove heat from the ice bed. Equalization vents located at the periphery of the intermediate and top decks are provided to balance small pressure differentials occurring across the decks during normal operation.

The ice baskets held in the ice bed within the ice condenser are arranged to promote heat transfer from steam to ice. This arrangement enhances the ice condenser's pr:imary function of condensing steam and absorbing heat energy released to the containment during a OBA.

In the event of a OBA, the ice condenser lower inlet doors (located below the operating deck) open due to the pressure rise in the lower compartment. This allows air and steam to flow from the lower McGuire Units 1 and 2 B 3.6.13-1 Revision No. 115

BACKGROUND (continued) compartment into the ice condenser. The resulting pressure increase within the ice condenser causes the intermediate deck doors and the top deck doors to open, which allows the air to flow out of the ice condenser into the upper compartment. Steam condensation within the ice condenser limits the pressure and temperature buildup in containment. A divider barrier separates the upper and lower compartments and ensures that the steam is directed into the ice condenser.

The ice, together with the containment spray, serves as a containment heat removal system and is adequate to absorb the initial blowdown of steam and water from a OBA as well as the additional heat loads that would enter containment during the several hours following the initial blowdown. The additional heat loads would come from the residual heat in the reactor core, the hot piping and components, and the secondary system, including the steam generators. During the post blowdown period, the Air Return System (ARS) returns upper compartment air through the divider barrier to the lower compartment. This serves to equalize pressures in containment and to continue circulating heated air and steam from the lower compartment through the ice condenser, where the heat is removed by the remaining ice.

The water from the melted ice drains into the lower compartment where it serves as a source of borated water (via the containment sump) for the Emergency Core Cooling System (ECCS) and the Containment Spray System heat removal functions in the recirculation mode. The ice and the recirculated ice melt (via the Containment Spray System) also serve to clean up the containment atmosphere.

The ice condenser doors ensure that the ice stored in the ice bed is preserved during normal operation (doors closed) and that the ice condenser functions as designed if called upon to act as a passive heat sink following a OBA.

APPLICABLE The limiting DBAs considered relative to containment pressure and SAFETY ANALYSES temperature are the loss of coolant accident (LOCA) and the steam line break (SLB). The LOCA and SLB are analyzed using computer codes designed to predict the resultant containment pressure and temperature transients. DBAs are assumed not to occur simultaneously or consecutively.

Although the ice condenser is a passive system that requires no electrical power to perform its function, the Containment Spray System and ARS also function to assist the ice bed in limiting pressures and temperatures.

Therefore, the postulated DBAs are analyzed with respect to Engineered Safety Feature (ESF) systems, assuming the loss of one ESF bus, which McGuire Units 1 and 2 B 3.6.13-2 Revision No. 115

APPLICABLE SAFETY ANALYSES (continued) is the worst case single active failure and results in one train each of the Containment Spray System and the ARS being rendered inoperable.

The limiting OBA analyses (Ref. 1) show that the maximum peak containment pressure results from the LOCA analysis and is calculated to be less than the containment design pressure. For certain aspects of transient accident analyses, maximizing the calculated containment pressure is not conservative. In particular, the cooling effectiveness of the ECCS during the core reflood phase of a LOCA analysis increases with increasing containment backpressure. For these calculations, the containment backpressure is calculated in a manner designed to conservatively minimize, rather than maximize, the calculated transient containment pressures, in accordance with 10 CFR 50, Appendix K (Ref. 2).

The maximum peak containment atmosphere temperature results from the SLB analysis and is discussed in the Bases for LCO 3.6.5, "Containment Air Temperature."

For very small break events occurring in the lower compartment that do not by themselves produce sufficient breakaway pressure to open the lower inlet doors, slowly released steam will migrate through the Divider Barrier into the upper compartment. In this situation, the Containment ARS will actuate at its defined pressure setpoint (including a defined time delay) and open the lower inlet doors, returning the steam/air mixture to the lower compartment and displacing it into the ice condenser where the steam portion of the flow will be condensed (Ref. 1). The Containment ARS can also be actuated manually.

In addition to calculating the overall peak containment pressures, the OBA analyses include the calculation of the transient differential pressures that would occur across subcompartment walls during the initial blowdown phase of the accident transient. The internal containment walls and structures are designed to withstand the local transient pressure differentials for the limiting OBAs.

The ice condenser doors satisfy Criterion 3 of 10 CFR 50.36( c)(2)(ii) (Ref.

3).

LCO This LCO establishes the minimum equipment requirements to assure that the ice condenser doors perform their safety function. The ice condenser lower inlet doors, intermediate deck doors, and top deck doors must be closed to minimize air leakage into and out of the ice condenser, with its attendant leakage of heat into the ice condenser and loss of ice McGuire Units 1 and 2 B 3.6.13-3 Revision No. 115

I LCO (continued) through melting and sublimation. All lower inlet doors, intermediate deck doors, and top deck doors must be OPERABLE to ensure the proper functioning of the ice condenser in the event of a OBA. Ice condenser door OPERABILITY includes the absence of any obstructions that would physically restrain the doors from opening (i.e., prevent initial breakaway under any circumstances), and for the lower inlet doors, being adjusted such that the initial opening torques are within prescribed limits. The ice condenser doors function with the ice condenser to limit the pressure and temperature that could be expected following a OBA.

APPLICABILITY In MODES 1, 2, 3, and 4, a OBA could cause an increase in containment pressure and temperature requiring the operation of the ice condenser doors. Therefore, the LCO is applicable in MODES 1, 2, 3, and 4.

The probability and consequences of these events in MODES 5 and 6 are reduced due to the pressure and temperature limitations of these MODES. Therefore, the ice condenser doors are not required to be OPERABLE in these MODES.

ACTIONS Note 1 provides clarification that, for this LCO, separate Condition entry is allowed for each ice condenser door.

Note 2 provides clarification that entry into the Conditions and Required Actions is not required for short duration(< 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months ) routine activities during Modes of Applicability for the Intermediate Deck and Top Deck Doors.

A.1 If one or more ice condenser lower inlet doors are inoperable due to being physically restrained from opening, the lower inlet door(s) must be restored to OPERABLE status within 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months . The Required Action is necessary to return operation to within the bounds of the containment analysis. The 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months Completion Time is consistent with the ACTIONS of LCO 3.6.1, "Containment," which requires containment to be restored to OPERABLE status within 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months .

B.1 and B.2 If one or more ice condenser doors are determined to be partially open or otherwise inoperable for reasons other than Condition A, or if a door is found that is not closed, it is acceptable to continue unit operation for up to 14 days, provided the ice bed temperature instrumentation is monitored once per 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months to ensure that the open or inoperable door is not McGuire Units 1 and 2 B 3.6.13-4 Revision No. 115

ACTIONS (continued) allowing enough air leakage to cause the maximum ice bed temperature to approach the melting point. The Frequency of 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months is based on the fact that temperature changes cannot occur rapidly in the ice bed because of the large mass of ice involved. The 14 day Completion Time is based on long term ice storage tests that indicate that if the temperature is maintained below 27°F, there would not be a significant loss of ice from sublimation. If the maximum ice bed temperature is > 27°F at any time or if the doors are not closed and restored to OPERABLE status within 14 days, the situation reverts to Condition C and a Completion Time of 48 hours5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months is allowed to restore the inoperable door to OPERABLE status or enter into Required Actions D.1 and D.2.

Ice bed temperature must be verified within the specified Frequency as augmented by the provisions of SR 3.0.2. Entry into Condition B is not required due to personnel standing on or opening an intermediate deck or top deck door for short durations(< 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months ) to perform required surveillances, minor maintenance such as ice removal, or routine tasks such a system walkdowns ITSB Insert 1 1--)!9>-

C. 1 If Required Actions B.1 er B.2 are not met, the doors must be restored to OPERABLE status and closed positions within 48 hours5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months . The 48 hour5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months Completion Time is based on the fact that, with the very large mass of ice involved, it would not be possible for the temperature to increase to the melting point and a significant amount of ice to melt in a 48 hour5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months period.

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

SURVEILLANCE SR 3.6.13.1 REQUIREMENTS Verifying, by means of the Inlet Door Position Monitoring System, that the lower inlet doors are in their closed positions makes the operator aware of an inadvertent opening of one or more lower inlet doors. The Surveillance Frequency is based on operating experience, equipment McGuire Units 1 and 2 B 3.6.13-5 Revision No. 115

I, SURVEILLANCE REQUIREMENTS (continued) reliability, and plant risk and is controlled under the Surveillance

Frequency Control Program.

TSB Insert 2 r..---~:111...

SR 3.6.13.2 Verifying, by visual inspection, that each intermediate deck door is closed and not impaired by ice, frost, or debris provides assurance that the intermediate deck doors (which form the floor of the upper plenum where frequent maintenance on the ice bed is performed) have not been left open or obstructed. In determining if a door is impaired by ice, the frost accumulation on the doors, joints, and hinges are to be considered in conjunction with the lifting force limits of SR 3.6.13.7. The Surveillance Frequency is based on operating experience, equipment reliability, and plant risk and is controlled under the Surveillance Frequency Control Program.

SR 3.6.13.3 Verifying, by visual inspection, that the top deck doors are in place and not obstructed provides assurance that the doors are performing their function of keeping warm air out of the ice condenser during normal operation, and would not be obstructed if called upon to open in response to a OBA. The Surveillance Frequency is based on operating experience, equipment reliability, and plant risk and is controlled under the Surveillance Frequency Control Program.

SR 3.6.13.4 Verifying, by visual inspection, that the ice condenser lower inlet doors are not impaired by ice, frost, or debris provides assurance that the doors are free to open in the event of a OBA. 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 3.6.13-6 Revision No. 115

SURVEILLANCE REQUIREMENTS (continued)

SR 3.6.13.5 Verifying the initial opening torque of the lower inlet doors provides assurance that no doors have become stuck in the closed position and maintains consistency with the safety analysis initial conditions. Verifying the doors are free to move provides assurance that the hinges and spring closure mechanisms are functioning properly and not degrading.

The verifications consists of:

a) Ascertaining the opening torque (torque required to just begin to move the door off of its seal) of each door when pulled (or pushed) open and ensuring this torque is .::: 675 in-lb, as resolved to the vertical hinge pin centerline, and b) Opening each door manually to the full extent of its available swing arc (i.e., up to slight contact with the shock absorber) and releasing the door, verifying that the spring closure mechanisms are capable of returning the door toward the closed position.

The opening torque test a) should be performed first to minimize the loss of cold head in the ice condenser and prevent any preconditioning of the seal area. During the freedom of movement test b) the cold head is not required, and once the effect of cold head is reduced through outflow, the door may not completely return to its seal from the open position.

The opening torque test limiting value of 675 in-lb is based on the design cold head pressure on the closed lower inlet doors of approximately 1 pound per square foot. The Surveillance Frequency is based on operating experience, equipment reliability, and plant risk and is controlled under the Surveillance Frequency Control Program.

SR 3.6.13.6 (deleted)

SR 3.6.13.7 Verifying the OPERABILITY of the intermediate deck doors provides assurance that the intermediate deck doors are free to open in the event of a OBA. The verification consists of visually inspecting the intermediate doors for structural deterioration, verifying free movement of the vent assemblies, and ascertaining free movement of each door when lifted with the applicable force shown below:

McGuire Units 1 and 2 B 3.6.13-7 Revision No. 115

SURVEILLANCE REQUIREMENTS (continued)

Lifting Force

a. Adjacent to crane wall < 37.4 lb

b. Paired with door adjacent to crane wall s 33.8 lb

c. Adjacent to containment wall s 31.8 lb

d. Paired with door adjacent to containment s 31.0 lb wall The Surveillance Frequency is based on operating experience, equipment reliability, and plant risk and is controlled under the Surveillance Frequency Control Program.

REFERENCES 1. UFSAR, Chapter 6.

2. 10 CFR 50, Appendix K.

3. 10 CFR 50.36, Technical Specifications, (c)(2)(ii).

4. MCS-1558.NF-00-0001 "Design Basis Specification for the NF System".

McGuire Units 1 and 2 B 3.6.13-8 Revision No. 115

. I' ENCLOSURE ATTACHMENT 3 Drawings and Photographs of the Ice Condenser Containment and the Ice Bays

c Q}

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(.) CIJ 2 a..

Simplified Ice Condenser Containment

~

Top View Side View

c 0 Q) C")

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Ice Condenser Lower and Upper Plenum Details jg a..

~

I Toµ Deck Beam and Grading Air Dlstnbunon Ducts -=r __

TopdWdP~" -, - -

Lower Inlet

.... crane Wall Air DiSt. Duct

'- ,_ Intermediate Deck Doors Turning Vanes Containment L.mer Check -vapor Barner

/Valve IC!! Baskets

. 1 .-~ ** .*

Ice Condenser Floor .,,.. CraneWall Crane Wall Wall Panel ~1-*

~--

Side View - Ice Condenser Lower Plenum il*I~

Side View - Ice Condenser Upper Plenum

Attachment 3 Page 4 of 8 Ice Condenser Unit Component Identification INTERMEDIATE DECK----

AIR DISTRIBUTION DUCTS ICE BASKET --~

SHELL STEAM GENERATOR DIVIDER DECK LOWER INL ET DOORS LOWER SUPPORT STRUCTURE

c ......

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(.) cu Containment Wall

~ a..

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Top View of Lattice Steel and Basket Configuration

Attachment 3 Page 6 of 8 View of Lower Support Structure

Attachment 3 Page 7 of 8

Attachment 3 Page 8 of 8 Ice Condenser Flow Channels

(~DUKE Steven D. Capps

~

Vice President ENERGY McGuire Nuclear Station Duke Energy MGOlVP I 12700 Hagers Ferry ~oad Huntersville, NC 28078 O: 980.875.4805 f: 980.875.4809 March 24, 2016 Steven.Capps@duke-energy.com Serial No.: MNS-15-068 10 CFR 50.90 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Duke Energy Carolinas, LLC (Duke Energy)

McGuire Nuclear Station (MNS), Units 1 and 2 Docket Numbers. 50-369 and 50-370 Renewed License Numbers NPF-9 and NPF-17

Subject:

License Amendment Request to Technical Specification (TS) 3.6.13, "Ice Condenser Doors" Pursuant to 10 CFR 50.90, Duke Energy Carolinas, LLC (Duke Energy) hereby requests a License Amendment to revise the Unit 1 and Unit 2 McGuire Nuclear Station (MNS) Technical Specification (TS) 3.6.13 to revise Condition B for an ice condenser lower inlet door invalid open alarm. This License Amendment Request (LAR) is needed to preclude an unnecessary plant shutdown caused by an invalid "OPEN" alarm from the "Inlet Door Position Monitoring System."

Approval of the proposed amendment is requested within one year of submittal. Once approved, the amendment shall be implemented within 120 days.

The Enclosure provides. Duke Energy's evaluation of the proposed TS change and the technical basis for the request. Proposed TS and Bases page markups are included as Attachments 1 and 2 to the Enclosure, respectively. Conforming TS Bases changes will be made Jn accordance with the MNS TS Bases Control Program. Marked-up TS Bases pages are provided in the Attachments for information only. Drawings and Photographs of the Ice Condenser Containment and the Ice Bays are provided in Attachment.3.

This LAR was discussed with the NRC staff in a public meeting on August 12, 2015.

Information provided at that time was preliminary, and changes were made to the TS markup based on comments during the management review process.

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

www.duke-energy.com

' I. r ' ,_4; U. S. Nuclear Regulatory Commission Serial MNS-15-068 Page2 In accordance with 10 CFR 50.91, a copy of this LAR is being sent to the designated official of the State of North Carolina.

This letter contains no new regulatory commitments. The MNS Updated Final Safety Analysis Report is not affected by this change.

If there are any questions or if additional information is needed, please contact Brian Richards, McGuire Regulatory Affairs at (980) 875-5171.

I declare under penalty of perjury that the foregoing is true and correct. Executed on March 24, 2016.

Sincerely, Steven D. Capps

Enclosure:

Evaluation of the Proposed Change

I ..

U. S. Nuclear Regulatory Commission Serial MNS-15-068 Page 3 xc with Attachments C. Haney Regional Administrator, Region 11 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 G. E. Miller, Project Manager (MNS & CNS)

U.S. Nuclear Regulatory Commission 11555 Rockville Pike Mail Stop 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 N.C. 27699-1645

'. *1 ENCLOSURE Evaluation of the Proposed Change