ML12053A019

Additional Planned Fire Risk Reduction Modifications

ML12053A019
Person / Time
Site:	Browns Ferry
Issue date:	02/17/2012
From:	James Shea Tennessee Valley Authority
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML12053A019 (14)

Text

Tennessee Valley Authority, 1101 Market Street, Chattanooga, Tennessee 37402 February 17, 2012 10 CFR 50.4 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Browns Ferry Nuclear Plant, Units 1, 2, and 3 Facility Operating License Nos. DPR-33, DPR-52, and DPR-68 NRC Docket Nos. 50-259, 50-260, and 50-296

Subject:

Additional Planned Fire Risk Reduction Modifications for Browns Ferry Nuclear Plant Units 1, 2, and 3

Reference:

Letter from WVA to NRC, "Revised Submittal Schedule for License Amendment Request to Adopt National Fire Protection Association (NFPA) 805, Performance-Based Standard for Fire Protection For Light Water Reactor Generating Plants, 2001 Edition for Browns Ferry Nuclear Plant Units 1, 2, and 3," dated January 13, 2012.

At a public meeting between the representatives of the Tennessee Valley Authority (TVA) and the NRC staff on December 8, 2011, TVA described its strategy for reducing fire risk at the Browns Ferry Nuclear Plant (BFN). That strategy includes performing modifications to BFN and its associated procedures in parallel with development of a license amendment request to adopt National Fire Protection Association (NFPA)

Standard 805. The objective of the parallel approach has been to achieve meaningful reduction in fire risk at BFN while pursuing the improved regulatory basis provided by the NFPA Standard 805. As discussed at the December 8, 2011, meeting, TVA has completed several key modifications to the facility that have improved risk and substantially reduced the number of time critical operator manual actions required to implement the current safe shutdown fire strategy.

By letter dated January 13, 2012 (Reference), TVA provided a revised schedule for submitting an application to adopt the NFPA Standard 805 for BFN. In that letter, TVA also committed to provide a detailed list of additional planned modifications and associated implementation schedules for reducing fire risk at BFN. TVA committed to provide that information by February 17, 2012. Enclosure 1 to this letter contains a detailed list of planned fire risk reduction modifications and the planned implementation schedules.

U.S. Nuclear Regulatory Commission Page 2 February 17, 2012 The modifications and associated implementation schedules in the Enclosure 1, Table 2 are new commitments.

If you have any question on these matters, please contact Tom Hess at (423)751-3487.

Respeaully,

/J 4Shea aenger, Corporate Nuclear Licensing

Enclosures:

1. National Fire Protection Association (NFPA) 805 Parallel Modification Strategy

2. Regulatory Commitments cc (Enclosures):

NRC Regional Administrator - Region II NRC Senior Resident Inspector - Browns Ferry Nuclear Plant

ENCLOSURE I Tennessee Valley Authority Browns Ferry Nuclear Plant, Units 1, 2, and 3 National Fire Protection Association (NFPA) 805 Parallel Modification Strategy

ENCLOSUREI NATIONAL FIRE PROTECTION ASSOCIATION (NFPA) 805 PARALLEL MODIFICATION STRATEGY Introduction As discussed in the public meeting between the NRC staff and the Tennessee Valley Authority (TVA) representatives on December 8, 2011 and by letter dated January 13, 2012 (Reference 1), TVA is pursuing the strategy of performing modifications to Browns Ferry Nuclear Plant (BFN) and its associated procedures in parallel with development of a license amendment request to adopt NFPA Standard 805, "Performance-Based Standard for Fire Protection for Light-Water Reactor Electric Generation Plants," 2001 Edition. The objective of the parallel approach is to achieve meaningful reduction in fire risk at BFN while pursuing the improved regulatory basis provided by NFPA Standard 805. TVA has completed several key modifications to the facility that have improved risk and substantially reduced the number of time critical operator manual actions required to implement the current safe shutdown fire strategy.

While finalizing the submittal of the NFPA 805 application, TVA is continuing its approach of developing and implementing additional fire risk reduction modifications to BFN design and procedures.

Completed Modifications Beginning in 2009, internal reviews and risk insights from the NRC significance determination process (SDP) conducted as a result of EA-09-307 (Reference 2) were utilized to identify risk improvements which would be consistent with the NFPA 805 transition. Table 1 provides a summary of the modifications that have already been completed for BFN.

Planned Modifications The NFPA 805 transition analysis has progressed to the point where a number of modifications to support the NFPA 805 transition have been identified. TVA has further identified a subset of these modifications that can be implemented while still maintaining compliance within the BFN current Appendix R licensing basis to reduce fire risk and eliminate Operator Manual Actions (OMAs) before NFPA 805 transition. In order to accomplish the TVA strategy of risk reduction in parallel with NFPA 805 transition, these modifications are currently being scheduled for design and implementation in accordance with the plant work control process.

Table 2 provides a summary and planned completion milestone for the currently identified NFPA 805 modifications which have been selected for implementation. Each modification is identified by the Design Change Notice (DCN) number and the stage of the DCN, if applicable, that addresses a specific piece of plant equipment. Each stage of a DCN is designed to be implemented separately. Table 2 also includes a brief description of how the modification will address fire risk. The schedule date provided reflects the current planned refueling outage or online window for removing the affected equipment from service and the Commitment Milestone represents a later date by which TVA is confident that the modification will be implemented considering changing plant conditions and schedules.

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References

1.

Letter from TVA to NRC, "Revised Submittal Schedule for License Amendment Request to Adopt National Fire Protection Association (NFPA) 805, Performance-Based Standard for Fire Protection for Light Water Reactor Generating Plants, 2001 Edition for Browns Ferry Nuclear Plant Units 1, 2, and 3," dated January 13, 2012.

2.

Letter from NRC to TVA, EA-09-307, "Final Significance Determination of Yellow and White Findings and Notice of Violation (NRC Inspection Report Nos.

05000259/2010007, 05000260/2010007 and 05000296/2010007), Browns Ferry Nuclear Plant," dated April 19, 2010.

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Table 1: List of Completed Modifications of Plant Equipment or Procedures DCN #1 Description Basis for Modification Completion Stage #

Date 69786/Si Removed power from the Condensate Storage In the event of a fire in Fire Area (FA) 26 (Turbine 9/23/10 Tank (CST) supply and return valves to the Building), this modification eliminated the High Pressure Coolant Injection System requirement to switch HPCI or RCIC suction to the (HPCI) and the Reactor Core Isolation Cooling Suppression pool and increases the availability of System (RCIC) to prevent spurious closure, the CSTs as makeup source.

1-FCV-002-0170 & 0171 2-FCV-002-0162 & 0163 3-FCV-002-0166 & 0167 69786/S2 Deleted requirements to manually start Unit 3 In the event of a fire in numerous FAs, this 9/23/10 Diesel Auxiliary Board room fans by crediting analysis eliminated OMAs to start the fans locally.

automatic start capability 3-FAN-030-0243 and 3-FAN-030-0244 69786/S4 Changed Breaker 710 on Battery Board 3 to In the event of a fire in numerous FAs, this 9/23/10 be normally OPEN.

modification eliminated OMAs that were required to open breaker 710 to limit battery loading.

70011 Installed incipient fire detection in 250V In the event of a fire in the 250V RMOV Board 1A 3/31/11 Reactor Motor Operated Valve (RMOV) Board Sections 1-6 (FA 5), cable trays located directly 1A Sections 1-6 above this ignition source impact safe shutdown.

The incipient detection system reduces the probability of a serious fire from this source.

70019 Installed cable tray bottom covers in selected The cable tray covers delay cable tray ignition for 4/4/11 areas where redundant divisions are in close at least 20 minutes and increase the probability proximity above Unit 1, 2, and 3 Electrical that a cable tray fire will be suppressed prior to its Board Rooms on Reactor Building Elevation spreading to other trays.

593'.

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DCN#/

Decito ai o

oiiainCompletion Stage #

Decito ai o oiiainDate 69957 Installed a 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> fire barrier between the Installation of the barrier provided additional 10/28/11 Turbine Building and Intake structure tunnel divisional separation which allowed for a general separating the Intake and the Turbine Building revision to the Safe SSIs for the Intake and into separate fire areas Turbine Building fire areas (FAs 25 and 26). This revision eliminated operator actions which were no longer required and abandoned the Self Induced Station Blackout (SISBO) strategy used previously, in these FAs.

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Table 2: List of Planned Modifications of Plant Equipment or Procedures DCN#/

Description

.Basis for Modification.........Completion Stage #

Milestone 70434/Si Install fuses in ammeter In the event of fire damage to cables between Battery Board 1 and COMPLETE circuit for Battery Board 1.

the Control Room, multiple hot shorts could cause the ammeter (12/23/11) cables to auto ignite and spread the fire to other areas.

70434/S2 Install fuses in ammeter In the event of fire damage to cables between Battery Board 2 and 9/27/13 circuit for Battery Board 2.

the Control Room, multiple hot shorts could cause the ammeter cables to auto ignite and spread the fire to other areas.

70434/S3 Install fuses in ammeter In the event of fire damage to cables between Battery Board 3 and 9/16/12 circuit for Battery Board 3.

the Control Room, multiple hot shorts could cause the ammeter cables to auto ignite and spread the fire to other areas.

70434/S4 Install fuses in ammeter In the event of fire damage to cables between Battery Board 4 and 6/22/12 circuit for Battery Board 4.

the Control Room, multiple hot shorts could cause the ammeter cables to auto ignite and spread the fire to other areas.

70434/S5 Install fuses in ammeter In the event of fire damage to cables between Battery Board 5 and COMPLETE circuit for Battery Board 5.

the Control Room, multiple hot shorts could cause the ammeter (12/23/11) cables to auto ignite and spread the fire to other areas.

70434/S6 Install fuses in ammeter In the event of fire damage to cables between Battery Board 6 and 4/6/12 circuit for Battery Board 6.

the Control Room, multiple hot shorts could cause the ammeter cables to auto ignite and spread the fire to other areas.

70054 Install controls in the Main In the event of a fire in FA 22 (4kV Shutdown Board Room 3EA Prior to restart Control, Room to isolate and 3EB), OMAs are currently required at 4kV Shutdown Board from Unit 3 4kV Shutdown Board 3EC 3EC to isolate control circuit faults and operate switchgear locally.

Refueling outage from fire damage in 4kV Local actions are in the vicinity of the fire and may be hampered 15 (Spring 2012)

Shutdown Board 3EA.

by smoke and firefighting activities. The modification will eliminate the need for the OMAs.

70490/51 Isolate and abandon local In the event of a fire in FAs 25-1 and 25-2 (Intake Structure), 2 1/11/13 control station for Residual OMAs are currently required at 4kV Shutdown Board 3EA to Heat Removal Service isolate control circuit faults and operate the switchgear locally. The Water (RHRSW) Pump modification will eliminate the need for the OMAs.

A3.

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DCN #

Description Basis for Modification Completion Stage.. #

Milestone

• 70490/S2 Isolate and abandon local In the event of a fire in FA 25-1 (Intake Structure), an OMA is 10/12/12 control station for RHRSW currently required at 4kV Shutdown Board 3EC to isolate control Pump BI.

circuit faults and operate the switchgear locally. The modification will eliminate the need for this OMA.

70490/S3 Isolate and abandon local In the event of a fire in FA 25-1 (Intake Structure), an OMA is 12/14/12 control station for RHRSW currently required at 4kV Shutdown Board C to isolate control Pump B2.

circuit faults and operate the switchgear locally. The modification will eliminate the need for this OMA.

70490/S4 Isolate and abandon local In the event of a fire in FA 25-1 (Intake Structure), an OMA is 12/14/12 control station for RHRSW currently required at 4kV Shutdown Board C to isolate control Pump B3.

circuit faults and operate the switchgear locally. The modification will eliminate the need for this OMA.

70490/S5 Isolate and abandon local In the event of a fire in FAs 25-1, 25-3 (Intake Structure) and 26 1/4/13 control station for RHRSW (Turbine Building), 3 OMAs are currently required at 4kV Pump C1.

Shutdown Board B to isolate control circuit faults and operate the switchgear locally. The modification will eliminate the need for the OMAs.

70490/S6 Isolate and abandon local In the event of a fire in FAs 25-1, 25-3 (Intake Structure), and 26 3/1/13 control station for RHRSW (Turbine Building), 3 OMAs are currently required at 4kV Pump C2.

Shutdown Board B to isolate control circuit faults and operate the switchgear locally. The modification will eliminate the need for the OMAs.

70490/S7 Isolate and abandon local In the event of a fire in FAs 25-1 and 25-3 (Intake Structure), 2 3/1/13 control station for RHRSW OMAs are currently required at 4kV Shutdown Board 3EB to Pump C3.

isolate control circuit faults and operate the switchgear locally.

The modification will eliminate the need for the OMAs.

70490/S8 Isolate and abandon local In the event of a fire in FA 25-1 (Intake Structure), an OMA is 2/22/13 control station for RHRSW currently required at 4kV Shutdown Board 3ED to isolate control Pump D1.

circuit faults and operate the switchgear locally. The modification will eliminate the need for this OMA.

70490/S9 Isolate and abandon local In the event of a fire in FA 25-1 (Intake Structure), an OMA is 2/15/13 control station for RHRSW currently required at 4kV Shutdown Board D to isolate control Pump D2.

circuit faults and operate the switchgear locally. The modification I will eliminate the need for this OMA.

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Stage#

Description Basis for Modification Completion Milestone 70490/S10 Isolate and abandon local In the event of a fire in FA 25-1 (Intake Structure), an OMA is 12/14/12 control station for RHRSW currently required at 4kV Shutdown Board D to isolate control Pump D3.

circuit faults and operate the switchgear locally. The modification will eliminate the need for this OMA.

70491/$1 Install relays to isolate 4kV In the event of a fire in FA 8 (4kV Shutdown Board Room D), an Prior to restart Shutdown Board A Normal OMA is currently required at 4kV Shutdown Board A to isolate from Unit 1 Feeder Breaker 1614 control circuit faults and operate the breaker locally. The Refueling outage control circuit from fire modification will eliminate the need for this OMA.

10 (Fall 2014) damage in 4kV Shutdown Board D.

70491/S2 Install relays to isolate 4kV In the event of a fire in FAs 2-3 (Unit 2 Reactor Building) and 9 (4 Prior to restart Shutdown Board A kV Shutdown Board Room C), 2 0MAs are currently required at from Unit 1 Alternate Feeder Breaker 4kV Shutdown Board A to isolate control circuit faults and operate Refueling outage 1716 control circuit from the breaker locally. The modification will eliminate the need for the 10 (Fall 2014) fire damage in 4kV OMAs Shutdown Board C.

70491/S3 Install relays to isolate 4kV In the event of a fire in FAs 3-1, 3-2, 3-3 (Unit 3 Reactor Building),

Prior to restart Shutdown Board A and 22 (4kV Shutdown Board Rooms 3EA and 3EB), 4 OMAs are from Unit 1 Crosstie Breaker 1824 currently required at 4kV Shutdown Board A to isolate control Refueling outage control circuit from fire circuit faults and operate the breaker locally. The modification will 10 (Fall 2014) damage in 4kV Shutdown eliminate the need for the OMAs.

Board 3EA.

70491/S12 Install relays to isolate 4kV In the event of a fire in FA.9 (4kV Shutdown Board Room C),an Prior to restart Shutdown Board D OMA is currently required at 4kV Shutdown Board D to isolate from Unit 2 Normal Feeder Breaker control circuit faults and operate the breaker locally. The Refueling outage 1724 control circuit from modification will eliminate the need for this OMA.

17 (Spring 2013) fire damage in 4kV Shutdown Board C.

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DCNge#

Description Basis for Modification CMilestone 70491/S13 Install relays to isolate 4kV In the event of a fire in FAs 3-2, 3-3 (Unit 3 Reactor Building), 21 Prior to restart Shutdown Board D (Unit 3 Diesel Generator Building), and 23 (4kV Shutdown Board from Unit 2 Crosstie Breaker 1826 Rooms 3EC and 3ED), 4 OMAs are currently required at 4kV Refueling outage control circuit from fire Shutdown Board D to isolate control circuit faults and operate the 17 (Spring 2013) damage in 4kV Shutdown breaker locally. The modification will eliminate the need for the Board 3ED.

OMAs.

70492 Separate normal power In the event of a fire in FA 13 (Unit 3 Electrical Board Room, Prior to restart cables for 480 RMOV Division 1), an OMA is required at 480V RMOV Board 3B to from Unit 3 Board 3B from FA 13.

isolate the normal power feed and transfer to alternate power feed.

Refueling outage The modification will eliminate the need for the OMA.

16 (Spring 2014) 70493/$1 Install incipient fire In the event of a fire in the Auxiliary Instrument Room of any unit Prior to restart detection in the Unit 1 (FA 16), shutdown from outside the control room is required. The from Unit 1 Auxiliary Instrument incipient detection system reduces the probability of a serious fire Refueling outage Room.

requiring control room abandonment by identifying combustion 10 (Fall 2014) products before a significant fire develops.

70493/S2 Install incipient fire In the event of a fire in the Auxiliary Instrument Room of any unit Prior to restart detection in the Unit 2 (FA 16), shutdown from outside the control room is required. The from Unit 2 Auxiliary Instrument incipient detection system reduces the probability of a serious fire Refueling outage Room.

requiring control room abandonment by identifying combustion 17 (Spring 2013) products before a significant fire develops.

70493/S3 Install incipient fire In the event of a fire in the Auxiliary Instrument Room of any unit Prior to restart detection in the Unit 3 (FA16), shutdown from outside the control room is required. The from Unit 3 Auxiliary Instrument incipient detection system reduces the probability of a serious fire Refueling outage Room.

requiring control room abandonment by identifying combustion 16 (Spring 2014) products before a significant fire develops.

70494 Separate normal cables In the event of a fire in the Battery Board Room 1 (FA 17), High Prior to restart required for Unit 1 RCIC Pressure Injection is not available. 7 OMAs are required within 20 from Unit 1 from FA 17.

minutes to support Unit 1 shutdown. This modification will make Refueling outage Unit 1 RCIC available and extend the time available for OMAs to 2 10 (Fall 2014) hours and reduce the risk of human error.

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ENCLOSURE 2 Tennessee Valley Authority Browns Ferry Nuclear Plant, Units 1, 2, and 3 Regulatory Commitments

ENCLOSURE 2 REGULATORY COMMITMENTS TVA commits to completing the following modifications by the dates listed.

Modification 29/7Commitment1 Date 1

Install fuses in ammeter circuit for Battery Board 2.

9/27/13 2

Install fuses in ammeter circuit for Battery Board 3.

9/16/12 3

-Install fuses in ammeter circuit for Battery Board 4.

6/22/12 4

Install fuses in ammeter circuit for Battery Board 6.

4/6/12 Prior to restart from Unit 3 Install controls in the Main Control Room to isolate 4kV Shutdown fUein o

Board 3EC from fire damage in 4kV Shutdown Board 3EA.

15 (Spring 2012)

Isolate and abandon local control station for Residual Heat 1/11/13 Removal Service Water (RHRSW) Pump A3.

7 Isolate and abandon local control station for RHRSW Pump BI.

10/12/12 8

Isolate and abandon local control station for RHRSW Pump B2.

12/14/12 9

Isolate and abandon local control station for RHRSW Pump B3.

12/14/12 10 Isolate and abandon local control station for RHRSW Pump C1.

1/4/13 11 Isolate and abandon local control station for RHRSW Pump C2.

3/1/13 12 Isolate and abandon local control station for RHRSW Pump C3.

3/1/13 13 Isolate and abandon local control station for RHRSW Pump D1.

2/22/13 14 Isolate and abandon local control station for RHRSW Pump D2.

2/15/13 15 Isolate and abandon local control station for RHRSW Pump D3.

12/14/12 Prior to restart Install relays to isolate 4kV Shutdown Board A Normal Feeder from Unit 1 16 Breaker 1614 control circuit from fire damage in 4kV Shutdown Refueling outage Board D.

10 (Fall 2014)

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• Modification Commitment.

Date Install relays to isolate 4kV Shutdown Board A Alternate Feeder Prior to restart 17 Breaker 1716 control circuit from fire damage in 4kV Shutdown Refueling outage Board C.

Rfeigotg 10 (Fall 2014)

Prior to restart Install relays to isolate 4kV Shutdown Board A Crosstie Breaker from Unit 1 1824 control circuit from fire damage in 4kV Shutdown Board 3EA.

Refueling outage 10 (Fall 2014)

Prior to restart Install relays to isolate 4kV Shutdown Board D Normal Feeder 19 Breaker 1724 control circuit from fire damage in 4kV Shutdown Refueling outage Board C.

Rfeigotg 17 (Spring 2013)

Prior to restart Install relays to isolate 4kV Shutdown Board D Crosstie Breaker from Unit 2 1826 control circuit from fire damage in 4kV Shutdown Board 3ED.

Refueling outage 17 (Spring 2013)

Prior to restart Separate normal power cables for 480 RMOV Board 3B from FA from Unit 3 21

13.

Refueling outage 16 (Spring 2014)

Prior to restart 22 Install incipient fire detection in the Unit 1 Auxiliary Instrument from Unit 1 Room.

Refueling outage 10 (Fall 2014)

Prior to restart Install incipient fire detection in the Unit 2 Auxiliary Instrument from Unit 2 Room.

Refueling outage 17 (Spring 2013)

Prior to restart Install incipient fire detection in the Unit 3 Auxiliary Instrument from Unit 3 Room.

Refueling outage 16 (Spring 2014)

Prior to restart from Unit 1 25 Separate normal cables required for Unit 1 RCIC from FA 17.

fUein o Refueling outage 10 (Fall 2014)

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