ML20138J484

Forwards Addl Info Re Concentration of Combustibles Inside Containment & Addl Justification for Deviation on Automatic Fixed Sprinkler Sys Requested in

ML20138J484
Person / Time
Site:	Vogtle
Issue date:	12/09/1985
From:	Bailey J GEORGIA POWER CO., SOUTHERN COMPANY SERVICES, INC.
To:	Adensam E Office of Nuclear Reactor Regulation
References
GN-759, NUDOCS 8512170533
Download: ML20138J484 (6)

Text

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Georgin Power Company Routa 2. Box 299A -

. W ynisboro, Georgia 30830

- Telephone 404 554-9961 404 724-8114

' Southern Company Services, Inc.

Post Office Box 2625 -

' Birmingham, Alabama 35202

• . Telephone 205 8704011 1

December 9, 1985 1.

Director of Nuclear Reactor Regulation File:- X6BB06 Attention: Ms. Elinor G. Adensam, Chief. Log: GN-759 Licensing Branch #4 Division of Licensing U.S. Nuclear Regulatory Commission Washington,.D.C. 20555 NRC' DOCKET NUMBERS 50-424 AND 50-425 CONSTRUCTION' PERMIT NUMBERS CPPR-108 AND CPPR-109 V0GTIE' ELECTRIC GENERATING' PLANT-UNITS 1 AND 2 FIRE PROTECTION PROGRAM Dear Mr. Denton o

During their review of the GPC request.to not insta11'an automatic sprinkle'r system inside containment, ::he NRC staff required additional information related to the concentration of combustibles inside containment. The. requested information and additional justification for the deviation requested in our letter to the NRC dated September 30, 1985, is provided in the enclosure to this letter.

If. your staff requires any add'itional information, please do not hesitate to contact.ne.

Sincerely, J. A. Bailey Project Licensing Manager JAB /RLK/caa Enclosure

• xc: . D. O. Foster . G. Bockhold, Jr.

~

R. A. Thomas T. Johnson (w/o Enclosure)

J. E. Joiner, Esquire D. C. Teper (w/o Enclosure)

B. W. - Churchill, Esquire L. Fowler M. A. . Miller (2) W. C. Ramsey B. Jones (w/o Enclosure) Vogtle Project File L. T. Gucwa 8512170533 851209 1 l I

PDR ADOCK 05000424 p PDR

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o ATTACHMENT DEVIATIONS FROM CMEB 9.5-1 DESCRIPTION OF DEVIATION VEGP is committed to conformance with Branch Technical Position (BTP) CMEB 9.5-1. Paragraph C.7.a of CMEB 9.5-1 as presented in FSAR Appendix 9B, recommends the installation of automatic fixed sprinkler systems for fire protection in containment. Contrary to this commitment, VEGP does not intend to install automatic fixed sprinkler systems for-fire protection-in containment.

JUSTIFICATION VEGP has provided fire suppression and/or manual fire fighting capability for all significant fire hazards in containment. Any credible fire which could occur would not impair the ability to achieve and maintain safe (cold) shutdown. This provision of fire protection and this ability to accomplish safe shutdown is not dependent on the existence of automatic fixed sprinkler systems.

The installation of automatic fixed sprinkler systems in the VEGP containment would not significantly increase the level of protection beyond that provided by the following protection measures and other design features which will exist:

1. The reactor coolant pumps are provided with an oil collection system that directs. leaking lubricant away from hot surfaces into a remote collection tank. This system is designed, engineered, and installed so as to withstand a safe shutdown earthquake. These collection tanks are provided with flame arrestors in the tank vents. In addition, infrared flame detectors are strategically located in the vicinity of the reactor coolant pumps. This fire detection provides early warning of a fire should one occur. ~This fire detection system alarms locally and in the control room.

2. Local standpipe hose stations are strategically located in

• containment to allow manual fire fighting should a fire occur. Each hose station is also provided with a portable fire extinguisher.

3. Charcoal filter units in containment are provided with an integral water suppression system.

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4. Electrical cable trays in containment containing safety-related cables and the trays containing the pressurizer heater cables, are provided with line-type heat detectors which provide early warning of an incipient fire condition by alarming locally and in the control room.

5. All electrical cables used in containment are IEEE 383 qualified (demonstrate. minimal flame spread) thereby limiting the capability of a fire to spread along the cables should a fire occur.

6. The~ effects of a fire are contained locally because the height and volume of the containment structure allow excellent heat dissipation and because of the low combustible loading.

7. The number of equivalent

• standard 24-inch-wide cable trays (both safety-related and non-safety-related) stacked one above the other is less than six. There is only one set of cable trays stacked five high. Typically, a " stack" of cable trays consists of only one electrical separation division (i.e., A, B, C, D, or N). Cable trays of the redundant safety-related trains never cross.

8. Separation of safe shutdown trains (equipment and cables) is as presented in the following table. In general, the west and north portions of the containment annulus area outside the secondary shield wall and the north steam generator / reactor coolant pump area inside the secondary shield contains safe shutdown Train B equipment and cables.

Similarly, the east and south portions of the containment annulus area outside the secondary shield wall and the south steam generator / reactor coolant pump area inside the secondary shield contains safe shutdown Train A equipment and cables. While the secondary shield walls are not rated fire barriers, their ".hickness and penetration design for radiation shielding co,siderations provide a significant impediment to fire propagation past the barrier. In addition, the limited fire hazards inside containment as previously discussed, ara not situated so as to signi-ficantly challenge the ribility of the secondary shield walls to preclude fire propagation. As noted in the attached tables, some changes to the existing design.are required to accomplish the design objective.

• The definition of an equivalent standard 24-inch-wide cable tray is per BTP CMEB 9.5-1 section C.S.e.

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VEGP UNIT 1 CONTAINMENT FIRE EVEN'r SAFE SilUTDOWN EVALUATION (Notes at end of table)

MINIMUM HORIZONTAL DEVICE TAG NUMBER SEPARATION COMPONENT DESCRIPTION TRAIN 'A' TRAIN 'B' DISTANCE COMMENTS.

RCS hot leg / core exit temperature TE-0413A

• 40 ft'.

TE-0443A

• RCS cold leg temperature TE-0423B N/A See Note 3 TE-0433B l Pressurizer level LT-0459- LT-0460- 65 ft. See Note 4 RCS Pressure (wide range) PT-0405 PT-0403 24 ft. See Note 4 Neutron flux RE-13135A RE-13135B 88 ft.

Steam generator level (wide range) LT-0501 LT-0502 22 ft. See Note 5 LT-0504 LT-0503 CVCS normal charging path HV-8146 N/A See Note 6 CVCS letdown isolation HV-8160 N/A See Note 6 Steam generator blowdown isolation HV-15216A N/A See Note 6 HV-15216B HV-15216C HV-15216D

• Core exit thermocouples TE-10002, 10003, 10006, 10008 thru 10012, 10014, 10016 thru 10019, 10021 thru 10026, 10028, 10034, 10036, 10037, 10046 and 10050.

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VEGP UNIT 1 T MPAINMENP FIRE EVENT SAFE SHUTDOWN EVALUATION *

(Notes at end of table)

(Sheet 2 of 3)

MINIMiri

. HORIZONTAL DEVICE TAG NUMBER SEPARATION COMEONENT DESCRIPTION TRAIN 'A' TRAIN 'B' DISTANCE COMMENTS Steam generator blowdown sample HV-9553A' N/A See Note 6 isolation IW-9553B

, HV-9554A

( EW-9554B

! HV-9555A IW-9555B I HV-9556A IW-9556B Safety injection accumulator HV-8875A HV-8875E N/A See Note 7 vent valves IIV-8875B IW-8875F

, IW-8875C HV-8875G l HV-8875D HV-8875H HV-0943A IW-0943B RHR suction from the RCS IW-8701A IW-8702A 60 ft.

IW-8701B IN-8702B 1

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l NOTES:

1 Only components having circuits inside containment and which must remain operational to achieve safe l.

(cold) shutdown in the event of a containment fire are listed. Spurious actuation concerns (such as.the-pressurizer PORV's) are not alleviated by separation. Plant operators can determine that an undesired spurious actuation has occurred and take action to mitigate the consequences of the problem.

2. Safe shutdown can be achieved using only two steam generators. Because of their association with the motor driven auxiliary feedwater pumps, steam generators 1 and 4 (RCS loops 1 and 4) are considered Train A and steam generators 2 and 3 (RCS loops 2 and 3) are considered Train B. Safe shutdown devices associated with these steam generators and RCS loops have equivalent train associations.

3. All RCS cold leg temperature instrumentation is associated with separation Train B. Indirect indication of RCS cold leg temperature for loops 1 and 4 (see note 2) is available to the plant operators via steamline (steam generator) pressure indication. These steam line pressure transmitters are located outside the containment building.

4. Three hour rated raceway fire proofing and radiant energy shield required to obtain the horizontal separation distance.

5. The safety channel designation for steam generator level transmitters LT-0503 and LT-0504 is being changed to make them consistent with the train associations defined in note 2. Cable routings will maintain a minimum horizontal separation distance of at least 20 feet, either by location or by use of three hour rated protective coatings.

6. Redundant means to accomplish the function is not dependent on a device or electrical cables located inside containment.

7. Due to the proximity of the safety injection accumulator tank vent valves, it may not be possible to depressurize all accumulators following a fire inside the containment building. However, undesired accumulator injection into the RCS can also be precluded by closing the accumulator injection valve which is capable of being closed from the control room or by local manual operator actions. The combustible loadings in the vicinity of a safety injection accumulator tank are low and it is not expected that a single fire could cause damage to the cables at the redundant vent valves and the tank injection valves and also cause mechanical damage so as to preclude local manual operation of the injection valve.

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