ML15343A012
| ML15343A012 | |
| Person / Time | |
|---|---|
| Site: | McGuire, Mcguire  |
| Issue date: | 12/07/2015 |
| From: | Capps S Duke Energy Carolinas |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| MNS-1 5-091, TAC MF2983, TAC MF2984 | |
| Download: ML15343A012 (15) | |
Text
DUKE Steven D. Capps Vice President ENERGMcGuire Nuclear Station Duke Energy MGO1VP 112700 Hagers Ferry Road Huntersville, NC 28078 o: 980.875.4805 f: 980.875.4809 Steven.Capps@duke-energy.com 10 CFR 50.90 December 07, 2015 Serial: MNS-1 5-09 1 U.S. Nuclear Regulatory Commission Washington, DC 20555-001 ATTENTION: Document Control Desk Duke Energy Carolinas, LLC (Duke Energy)
McGuire Nuclear Station, Units 1 and 2 Docket Nos. 50-369 and 50-370 Renewed License Nos. NPF-9 and NPF-17
Subject:
Response to NRC letter dated October, 26, 2015, "McGuire Nuclear Station, Units 1 AND 2: Request for Additional Information Regarding License Amendment Request Nuclear Service Water System Allowed Outage Time Extension (TAC NOS. MF2983 AND MF2984)" (Agencywide Documents Access and Management System (ADAMS) Accession No. ML15289A555)
References:
- 1. Duke Energy Letter dated June 30, 2015, "License Amendment Request for Temporary Changes to Technical Specifications for Correction of an 'A' Train Nuclear Service Water System (NSWS) Degraded Condition" (ADAMS Accession No. ML15191A025)
- 2. Nuclear Regulatory Commission (NRC) Letter dated July 27, 2015, "McGuire Nuclear Station, Units 1 and 2 - Acceptance Review of License Amendment Request RE:
Temporary Changes to Technical Specifications for Correction of Nuclear Service Water System Degraded Condition (TAC NOS. MF6409 AND MF641 0)" (ADAMS Accession No. ML15202A661)
- 3. Duke Energy Letter dated August 11, 2015, "Response to Request for Additional
--- Information Regarding-License Amendment Request for Temporary-Changes to -
Technical Specifications for Correction of an 'A' Train Nuclear Service Water System (NSWS) Degraded Condition (TAC Nos. MF6409 and ME 6410)" (ADAMS Accession No. ML15247A066)
- 4. NRC Letter dated August 27, 2015, "McGuire Nuclear Station, Units 1 AND 2: Request for Additional Information Regarding License Amendment Request Nuclear Service Water System Allowed Outage Time Extension (TAC NOS. MF2983 AND MF2984)"
(ADAMS Accession No. ML15237A416)
US Nuclear Regulatory Commission December 07, 2015 Page 2
- 5. Duke Energy Letter dated September 24, 2015, "Response to Request for Additional Information Regarding License Amendment Request for Temporary Changes to Technical Specifications for Correction of an 'A' Train Nuclear Service Water System (NSWS) Degraded Condition (MF2983 AND MF2984)" (ADAMS Accession No. ML15275A155)
- 6. NRC Letter dated September 14, 2015, "McGuire Nuclear Station, Units 1 AND 2:
Request for Additional Information Regarding License Amendment Request Nuclear Service Water System Allowed Outage Time Extension (TAC NOS. MF2983 AND MF2984)" (ADAMS Accession No. ML15252A276)
- 7.
Duke Energy Letter dated October 08, 2015, "Response to Request for Additional Information Regarding License Amendment Request for Temporary Changes to Technical Specifications for Correction of an 'A' Train Nuclear Service Water System (NSWS) Degraded Condition (MF2983 AND MF2984)" (ADAMS Accession No. ML15313A174)
- 8.
NRC Letter dated October 26, 2015, "McGuire Nuclear Station, Units 1 AND 2: Request for Additional Information Regarding License Amendment Request Nuclear Service Water System Allowed Outage Time Extension (TAC NOS. MF2983 AND MF2984)"
(ADAMS Accession No. ML15289A555)
By letter dated June 30, 2015 (Reference 1 ), Duke Energy requested a license amendment for the Renewed Facility Operating Licenses (FOL) and Technical Specifications (TS) for the McGuire Nuclear Station, Units 1 and 2, to allow temporary changes to T'S 3.5.2, Emergency Core Cooling System (ECCS) - Operating; TS 3.6.6, Containment Spray System (CSS); TS 3.7.5, Auxiliary Feedwater (AFW) System; TS 3.7.6, Component Cooling Water (CCW) System; TS 3.7.7, Nuclear Service Water System (NSWS); TS 3.7.9, Control Room Area Ventilation System (CRAVS); TS 3.7.11, Auxiliary Building Filtered Ventilation Exhaust System (ABFVES);
and TS 3.8.1, AC Sources-Operating.
By letter dated August 11, 2015 (Reference 3), Duke Energy responded to NRC letter dated July 27, 2015 (Reference 2), request for additional information (RAI) needed for completion of NRC staff review of the proposed license amendment request (LAR).
By letter dated September 24, 2015 (Reference 5), Duke Energy responded to NRC letter dated August 27, 2015 (Reference 4), RAI needed for completion of NRC staff review of the proposed LAR.
By letter dated October 08, 201 5(Reference 7_), Duke Energy responded to NRC letter dated_ -
September 14, 2015 (Reference 6), RAI needed for completion of NRC staff review of the proposed LAR.
By letter dated October 26, 2015 (Reference 8), the NRC provided Duke Energy a fourth RAl needed for completion of the NRC staff review of the LAR. The enclosure provides Duke Energy's response to the RAl question.
US Nuclear Regulatory Commission December 07, 2015 Page 3 There is one new regulatory commitment with this submittal. There is a minor change to Commitment 1 that clarifies the original intent of the commitment. Attachment 1, Regulatory Commitments in the enclosure incorporates new Commitment 32 and revisions to the commitments made through the RAI process for this LAR.
The June 30, 2015, LAR concluded that the proposed change presents No Significant Hazards Considerations, and does not require an environmental assessment. This conclusion has not changed as a result of the RAI responses in the enclosure.
Pursuant to 10 CFR 50.91, a copy of this LAR has been forwarded to the appropriate North Carolina state officials.
Please direct any comments or questions regarding this submittal to George Murphy at (980) 875-5715.
I declare under penalty of perjury that the foregoing is true and correct. Executed on December 07, 2015.
Sincerely, Steven D. Capps
Enclosure:
Response to Request for Additional Information
US Nuclear Regulatory Commission December 07, 2015 Page 4 cc w/
Enclosure:
C. Haney 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 McGu ire Nuclear Station G. E. Miller, Project Manager U.S. Nuclear Regulatory Commission 11555 Rockville Pike Mail Stop 0-8 G9A Rockville, MD 20852-2738 W. L. Cox, III, Section Chief North Carolina Department of Environment and Natural Resources Division of Environmental Health Radiation Protection Section 1645 Mail Service Center Raleigh, NC 27699-1 645
ENCLOSURE Response to Request for Additional Information
Response to Request for Additional Information REQUEST FOR ADDITIONAL INFORMATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO A LICENSE AMENDMENT REQUEST SUPPORTING CORRECTION OF A NUCLEAR SERVICE WATER SYSTEM DEGRADED CONDITION DUKE ENERGY CAROLINAS. LLC MCGUIRE NUCLEAR STATION, UNITS 1 AND 2 DOCKET NOS. 50-369 AND 50-370 By letter dated June 30, 2015 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML15191A025),
Duke Energy Carolinas, LLC (Duke Energy) submitted a license amendment request (LAR) to temporarily change McGuire Nuclear Station (MNS), Units 1 and 2, Technical Specifications (TSs) for correction of a degraded condition affecting the 'A' Train of the nuclear service water system (NSWS). The requested amendment would temporarily change the following TSs to allow the inoperability of the 'A' Train of the NSWS for a total of up to 14 days:
TS 3.5.2, Emergency Core Cooling System (ECCS) -
Operating; TS 3.6.6, Containment Spray System (CSS); TS 3.7.5, Auxiliary Feedwater (AFW)
System; TS 3.7.6, Component Cooling Water (CCW) System; TS 3.7.7, Nuclear Service Water System (NSWS); TS 3.7.9, Control Room Area Ventilation System (CRAVS); TS 3.7.11, Auxiliary Building Filtered Ventilation Exhaust System (ABFVES), and TS 3.8.1, AC Sources-Operating.
The 'A' Train of the shared NSWS would be inoperable while the safety-related supply from the MNS Nuclear Service Water Pond was drained and isolated to correct a degraded condition affecting that line.
Based on the NRC staff's review of the September 24, 2015 response, the NRC staff has determined the following additional information is necessary to support completion of its technical review:
SBPB-RAI-003 The LAR includes the potential activity to install a piping penetration in the drained section of the NSWS within the auxiliary building if required for personnel access to remove suspected blockage. In SBPB-RAI-001, the U.S. Nuclear Regulatory Commission (NRC) staff requested additional information on how using the single valve 0RN-7A for isolation was consistent with defense-in-depth. Duke's response to SBPB-RAI-00 1 discussed administrative controls that would be used to maintain the valve in the closed position and the leakage rate into the area around valve 0RN-7A that has been evaluated as acceptable. Although the tag out process and other administrative controls would provide some level of assurance that the valve would remain closed, the NRC staff requests Duke provide additional discussion of measures that would limit the potential for significant leakage past valve 0RN-7A and measures that could be taken to remediate significant leakage.
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Response to Request for Additional Information This discussion should include the following:
Potential for development of significant leakage (e.g., qualification of valves for isolation function, operating experience with water-hammer following flow interruption, and Potential for inadvertent valve operation to cause leakage in excess of evaluated limits for internal flooding)
Likelihood of successful remediation (e.g., conditions allowing re-closure of valve 0RN-7A and independence of other measures to isolate flow through 0RN-7A, such as closure of valve 0RN-12AC)
Duke Energy Response SBPB-RAI-003
- Potential for development of significant leakage (e.g., qualification of valves for isolation function, operating experience with water-hammer following flow interruption High confidence exists that the potential for development of significant leakage past 0RN-7A is extremely low. 0RN-7A is a safety related component and is designed as such. It is designed to be operated over the range of flow and pressure conditions that could occur during normal and emergency operation, including the isolation of the Lake Norman flowpath.
Proper operation and function of 0RN-7A is demonstrated by the historical examples of operation up through the most recent performance of A Train NSWS surveillance testing, including System Flush testing and Flow balance testing. Some of this testing requires the isolation of the Lake Norman flowpath. Also, this MOV is managed under the safety related MOV program (Generic Letters 89-10 and 96-05).
Prior to entering the extended Completion Time (CT) authorized by the TS amendment, 0RN-7A will have been evaluated to ensure that that leakage is within acceptable limits.
Additionally, if it is necessary to open the NSWS piping manway in the auxiliary building, 0RN-7A isolation will be rechecked prior to opening the manway that leakage is acceptable.
Engineering has reviewed the potential events that could occur while the NSWS piping manway in the auxiliary building is open for transients that could affect the isolation function of 0RN-7A. The following transients were reviewed: loss of offsite power (LOOP), safety injection (SI), and realignment activities that would occur after a seismic event.
For a LOOP, a SI, or a combination LOOP/SI, the expected NSWS transient is minimized by the alignment of the NSWS committed to in the LAR. The placement of the NSWS trains in their post LOOP/SI response configurations, with A NSWS aligned to Lake Norman and B NSWS aligned to the Standby Nuclear Service Water Pond (SNSWP), eliminates any NSWS transients that would occur resulting from an automatic Page 3 of 5
Response to Request for Additional Information change in configuration driven by ESFAS.
A LOOP would result in the stopping of the running NSWS pumps during bus stripping and restarting of the pumps following EDG restoration of power to the essential 4160 volt busses. The short duration of the transient and expected system pressure response would not be expected to result in a water hammer event or challenge to the 0RN-7A isolation function.
One other scenario was reviewed. Following a seismic event that results in the loss of the Lake Norman water source, the plant would rely on the B Train NSWS pumps drawing suction from the SNSWP. Existing plant procedures follow this strategy.
Because the B NSWS Train will already be aligned to the SNSWP there is no impact on 0RN-7A.
The LAR includes a defense in depth contingency for a subsequent failure of one B Train NSWS pump after the seismic event and loss of Lake Norman. This contingency would align the affected unit's A NSWS pump suction path to the B SNSWP and provide NSW to the unit that lost its B NSWS pump.
This contingency would require closure of the auxiliary building access manway before execution of the strategy. Any hydraulic transient created by the realignment of the A NSWS pump to the B SNSWP would be of no consequence to NSWS leakage because the NSWS piping manway would be closed.
- Potential for inadvertent valve operation to cause leakage in excess of evaluated limits for internal flooding)
In order to prevent inadvertent operation of 0RN-7A, MNS will perform the following actions to ensure that the position of this valve is physically restrained with several barriers in place to prevent operation or movement of the valve while the NSWS piping access manway in the auxiliary building is open:
o The operating hand wheel for 0RN-7A will be in the closed position and restrained with a lock and tag.
o A mechanical stem locking device will be installed on 0RN-7A to prevent ANY movement of the valve disk.
o Electrical isolation of the 0RN-7A motor operator will be established by disconnecting the output wiring in the 0RN-7A breaker cubical from the load side of the motor starter, which opens the electrical path from the breaker to the motor operator of 0RN-7A before opening the NSWS access manway in the auxiliary building. These motor leads will be tagged to prevent reconnection until the NSWS access manway in the auxiliary building is closed.
o A dedicated person with no other duties will be stationed in the room where 0RN-7A and the access manway are located to monitor for 0RN-7A leakage and to prevent anyone from operating 0RN-7A while the NSWS piping manway is open.
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Response to Request for Additional Information
- Likelihood of successful remediation (e.g., conditions allowing re-closure of valve 0RN-7A and independence of other measures to isolate flow through 0RN-7A, such as closure of valve 0RN-12AC)
With the barriers that will be established, there is no apparent credible scenario that would result in inadvertent operation of 0RN-7A while the NSWS piping is open. Based on the information provided above with respect to the characteristics of ORN-7A, the probability of failure of RN-7A or an event that would cause significant leakage are both extremely low.
The following response would be initiated before ORN-7A leakage exceeded the pre-defined acceptable limit or before any significant impact to the plant or equipment in the vicinity of 0RN-7A could occur:
- A change in leakage would be immediately observable by dedicated monitoring personnel These personnel would immediately notify the control room If the manway could not be immediately closed, then the following actions could isolate the flowpath from Lake Norman within 15 minutes:
o The A NSWS pumps would be stopped from the control room o
0RN-12AC and 0RN-13A would be closed from the control room (this would isolate the flowpath from Lake Norman) o The B Train NSWS pumps would be started from the control room (this action would have no impact on A NSWS Train or 0RN-7A) 0RN-12AC and ORN-13A are also safety related components and are designed as such.
They are designed to be operated over the range of flow and pressure conditions that could occur during normal and emergency operation, including the isolation of the Lake Norman flowpath.
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ATTACHMENT 1 Regulatory Commitments
REGULATORY COMMITMENTS - Final The following table identifies those actions committed to by Duke Energy in this document. Any other statements made in this licensing submittal are provided for informational purposes only and are not considered to be regulatory commitments. Please direct any questions you may have in this matter to George Murphy at 980-875-5715.
The 'A' Train NSWS pumps will remain aligned to Lake Norman during the extended CT until the system is ready for post maintenance testing.
2 Any maintenance that is performed on the remaining portions of 'A' Train NSWS during the period in which the 'A' NSWS piping from the SNSWP is not available will be evaluated for impact on the ability of the system to operate while taking suction from the Lake Norman Low Level Intake (LLI) and will be limited to a 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> completion time.
3 The 'B' Train NSWS will be placed in its ESFAS alignment to the SNSWP water source with the 'B' Train pumps in standby prior to starting the LAR activity and remain in this alignment until the 'A' Train NSWS SNSWP water source is restored and ready for post maintenance testing.
4 Procedures will be established to provide an additional defense in depth contingency that could be used in the event of an extremely low probability of a loss of the Lake Norman water source due to a seismic event. The procedures will ensure that system operation is maintained within design limits (less than or equal to 2 NSWS pumps running on a header), control of maximum system flow, and that system configuration prevents interaction of the degraded equipment with the functional equipment.
5 Fukushima Response FLEX modifications will be installed and the FLEX strategies will be available for implementation as additional defense-in-depth on both units.
6 During the period in which the 'A' NSWS suction path from the SNSWP is non-functional, no discretionary maintenance or discretionary testing will be planned on the following:
1A EDG 2A EDG The 'A' Train of NSWS excluding the activities described in the LAR for the 'A' Train NSWS piping to the SNSWP.
The 'B' Train of NSWS, ECCS, CSS, AFW, CCW, CRAVS, ABFVES or the EDGs The switchyard and other offsite power sources The SSF Page 2 of 6
7 A condition in which repairs couid impact the ability of an SSC to perform its Safety Function would result in termination of activities. The inspection may identify a condition that cannot be resolved within the 14 day completion time. Should such a condition be identified then the system will be restored to its current OBDN condition.
If the ROV survey presents any opportunities for a less intrusive or less time consuming solution for addressing the OBDN condition, then these opportunities will be pursued, as appropriate.
8 In an activity planned to be performed separate from the 14 day completion time repair activity, 0RN-7A will be tested for leakage and adjusted if necessary to minimize leakage.
9 In an activity planned to be performed separate from the 14 day completion time repair activity the SNSWP isolation flange will be test fitted to the 'A' SNSWP pipe.
10 Procedure guidance will establish controls to limit evacuation air pressure to less than a predetermined value in order to prevent air intrusion into the operating NSWS.
11 Dedicated personnel with procedure guidance will be provided to close the NSWS access manway in the auxiliary building in the event of any of the following:
An Engineered Safety Feature (ESE) actuation Entry into RPIOIAI57001006 Natural Disasters Entry into RPIO/AI57001007 Earthquake 12 This activity will be controlled under the Infrequently Performed Test or Evolution (IPTE) process defined in Fleet Directive AD-OP-ALL-i106, "Conduct of Infrequently Performed Tests or Evolutions", and Duke Energy's Work Management and Execution procedures.
13 During periods when the auxiliary building NSWS piping manway is open, dedicated personnel having communication to the main control room with procedures to continuously monitor and respond to 0RN-7A leakage will be in place. If leakage increases and reaches the pre-determined leak rate limit, the repair activity will be stopped, and the manway will be closed. If conditions prevent the prompt closure of the manway, then operations will place the 'B' NSWS train in operation, secure 'A' NSWS operations and isolate the 'A' NSWS train to stop the leakage as follows:
If the manway cannot be immediately closed then perform the following actions to isolate the flowpath from Lake Norman within 15 minutes:
Stop the A NSWS pumps from the control room Close 0RN-12AC and 0RN-13A from the control room to isolate the flowpath from Lake Norman Start B Train NSWS pumps 14 If the NSWS piping manway in the auxiliary building is opened then prior to the breach of the NSWS piping an evaluation of 0RN-7A leakage will be performed to validate proper isolation and that leakage is within acceptable limits.
15 McGuire will communicate with the Transmission Control Center (TCC) to ensure that the McGuire Control Room is notified in the event of potential grid disturbances in order that an appropriate plant response can be formulated.
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16 The Work Control Center or 0CC will monitor weather forecasts and radar during the activities that require the NSWS piping personnel access points to be open to assess the potential for severe weather conditions (tornado, thunderstorms).
17 Training will be provided in accordance with the Systematic Approach to Training (SAT) process to Operations personnel on this TS change and the associated evolution to inspect and correct the degraded condition in the 'A' NSWS supply piping from the SNSWP.
18 Operations will review applicable abnormal operating procedures related to the response to an earthquake, the loss of the Lake Norman and the loss of NSWS prior to making 'A' NSWS suction path from the SNSWP inoperable and each shift until 'A' Train NSWS operability is restored.
19 The repair work on the NSWS 'A' Train suction from the SNSWP will be scheduled during a period in which hurricanes and tornadoes have a lower likelihood of occurrence.
20 The Outage Command Center (0CC) will be manned while performing the activities authorized by this amendment.
21 The following list of equipment will be protected:
'B'Train NSWS 1B EOG 2B EDG 1B ECCS 2B ECCS 1B CSS 2B CSS 1 BAFW 2B AFW 1B CCW 2B CCW B CRAVS B ABFVES Auxiliary Building WZ Sump and equipment supporting function of sump SSF including Standby Makeup pumps for Unit 1 and Unit 2 Unit 1 TDCAP Unit2TDCAP Unit 1 Containment Ventilation Cooling Water System (RV)
Unit 2 Containment Ventilation Cooling Water System (RV) 22 If required to be installed the new personnel access opening to be located on the 'A' Train NSWS piping in the auxiliary building will be designed and installed in accordance with the Engineering Change Process.
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23 Foreign Material Exclusion (FME) will be controlled during the proposed activities in accordance with AD-MN-ALL-0002, Foreign Material Exclusion (FME). Any debris resulting from the obstruction removal activity will be mechanically cleaned out before the system is closed for return to service per FME plan developed in accordance with the above procedure. The system will be video inspected and reversed flushed from the LLI to the SNSWP with isolation to downstream components to force any sediment back to the SNSWP.
24 Following 'A' Train NSWS restoration, testing will be performed to verify that the as left NSWS performance meets or exceeds pre-activity performance including 'A' Train NSW pump NPSH conditions.
25 Prior to entering the 14 day CT perform an evaluation to ensure that there will be no anticipated impact to 'A' NSWS water supply from the LLI from Alewife fish the during 14 day CT.
26 The new personnel access piping opening (in the auxiliary building) will be controlled by using procedures developed or revised for this purpose to maintain positive control of the opening and to prevent an unmonitored release.
27 The ERAT program includes the option to use a SSA (Safety Significant Activity) code which will cause the risk condition color to be "YELLOW". MNS will use this code during the activities described in this LAR.
28 Designated operators will be available to execute the manual actions associated with aligning the affected unit's 'A' Train NSWS pump to the 'B' NSWS SNSWP via the Main Supply Crossover piping.
29 If the contingency personnel access opening is installed, then Security personnel will establish the proper controls and compensatory measures prescribed by security procedures and the security plan.
30 In support of the contingency the following conditions will be established before the start of activities in the LAR:
- The 'A' valve (0RN-14A) will be opened prior to the evolution and power will be removed from the valve operator.
- The 'B' valve (0RN-15SB) will be maintained closed with the ESFAS signal from each unit blocked prior to the evolution. Maintaining 0RN-15B closed with power removed satisfies operability requirements for the 'B' Train NSWS.
The 'B' valve (0RN-15SB) can be opened from the control room after power is restored if conditions warrant the use of this contingency.
31 Operations will utilize the concurrent dual verification process when operating 0RN-.7A.
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32 In order to prevent inadvertent operation of 0RN-7A, MNS will perform the following actions to ensure that the position of this valve is physically restrained with several barriers in place to prevent operation or movement of the valve while the NSWS piping access manway in the auxiliary building is open:
The operating hand wheel for 0RN-7A will be in the closed position and restrained with a lock and tag.
A mechanical stem locking device will be installed on 0RN-7A to prevent ANY movement of the valve disk.
Electrical isolation of the 0RN-7A motor operator will be established by disconnecting the output wiring in the 0RN-7A breaker cubical from the load side of the motor starter which opens the electrical path from the breaker to the motor operator of 0RN-7A before opening the NSWS access manway in the auxiliary building. These motor leads will be tagged to prevent reconnection until the NSWS access manway in the auxiliary building is closed.
A dedicated person with no other duties will be stationed in the room where 0RN-7A and the access manway are located to monitor for 0RN-7A leakage and to prevent anyone from operating 0RN-7A while the NSWS piping manway is open.
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