ML20092H038

Special Rept 95-04:on 970707,noncompliance w/10CFR50,App R,Section II.G.2 Requirements Documented on Problem Evaluation Rept.Affected Rooms Being Covered by Hourly,Roving Fire Watch Patrol

ML20092H038
Person / Time
Site:	Sequoyah
Issue date:	09/14/1995
From:	Shell R TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
95-04, 95-4, NUDOCS 9509200225
Download: ML20092H038 (5)

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Tennessee Valley Authority, Post Office Box 2000, Soddy-Dasy, Tennessee 37379-2000 september 14, 1995 U.S. Nuclear Regulatory Commission ATTN Document Control Desk Washington, D.C. 20555 Gentlemen:

In the Matter of- ) Docket No. 50-327 Tennessee Valley Authority )

SEQUOYAH NUCLEAR PLANT (SQN) - UNIT 1 - FACILITY OPERATING LICENSE DPR 10 CFR 50, APPENDIX R - SPECIAL REPORT 95-04, REVISION 1 The enclosed special report revision provides information concerning an additional noncompliance with the requirements of 10 CFR 50, Appendix R.

This report was originally submitted on July 26, 1995.

If you have any questions concerning this submittal, please telephone ,

J. W. Proffitt at (615) 843-6651.

sincerely, R,A 2ldl R. H. Shell SQN Site Licensing Manager Enclosure cc: See page 2 t

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%gv 9509200225 950914

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.U.S. Nuclear Regulatory commission-Page.2 . .

september 14, 1995 cc'(Enclosure):

Mr; D. E.:Lasarge, Project Manager

. U.S. Nuclear. Regulatory commission One White Flint,. North 11555'Rockville Pike Rockville, Maryland 20852-2739 NRC Resident Inspector sequoyah Nuclear Plant

'2600 Igou Ferry Road i soddy-Daisy,' Tennessee 37379-3624 ,

Regional Administrator U.S. Nuclear Regulatory Commission' ,

Region II 101 Marietta street, NW, suite 2900 Atlanta, Georgia 30323-2711 i

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ENCLOSURE SEQUOYAH NUCLEAR PLANT (SQN)

SPECIAL REPORT 95-04, REVISION 1 14-DAY POLLOW-UP REPORT

' Description of Condition A noncompliance with 10.CFR 50, Appendix R,Section II.G.2 requirements, was documented on Problem Evaluation Report (PER) SQ950685PER on July 7, 1995. The PER was revised on September 6, 1995, to document the identification of an additional noncompliance.

Section II.G.2 requires redundant safe shutdown components to be separated from each other by one of the following methods:

1. separation of cables and equipment and associated nonsafety circuits of redundant trains by a fire barrier having a 3-hour rating.

2. separation of cables and equipment and associated nonsafety circuits of redundant trains.by a horizontal distance of more than 20 feet with no intervening combustible or fire hazards. In addition, fire detectors and an automatic fire suppression system shall be installed in the fire area.

3. Enclosure of cables and equipment and associated nonsafety circuits-of one redundant train in a fire barrier having a 1-hour rating. In addition, fire detectors and an automatic fire suppression system shall be installed in the fire area.

ggggition 1 l

l. During the performance of an enhancement to the Appendix R program, a I concern was identified involving the following Unit 1 cables that are not t

separated as described above.

cable No. Cable Used For i

i IV5598B' control for 1-PCV-68-334 reactor coolant system (RCS) pressuriser power-operated relief valve (PORV) 1PL4975A Power supply for Emergency Diesel Generator (D/G) Aux Board 1Al-A

, 1PL4978A Power supply for Emergency D/G Aux Board 1A2-A 1

The interaction area is in 480-volt shutdown Transformer Room 1A on Elevation 749 of the auxiliary building.

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Condition 2 i: .

. During the continued performance of the Appendix.R program review, the i following condition was identified. The interaction is located in 125-volt Vital Battery Board Room:II. .

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Cable No. Cable Used For IV5607A Normal control power supply for RCS PORV 1-PCV-68-340A i IV5608A Auxiliary control power supply for RCS PORV 1-PCV-68-340A '

B76 Control power supply for the emergency D/G 15-5

control circuit ,

I cause of condition 1 1 Cable IV55985 is routed in cable trays in 480-volt shutdown Board-Transformer Room 1A on Elevation 749 in the auxiliary' building. Cables 1PL4975A and IPL4978A are routed in conduit in the same room with less i ~than 20 feet of separation from Cable IV55985 with no installed 1-hour rated fire barriers. A single fire in the area could cause spurious opening of the solenoid-operated 1-PCV-68-334 valve and inoperability of

D/G 1A-A. For spurious opening of 1-PCV-68-334, RCS pressure control is L maintained by closing motor-operated PORV Block Valve 1-FCV-68-333.

! During a loss of offsite power, the block valve is powered from D/G 1A-A. Therefore, a loss of offsite power coincident with a fire in

this area could result in the loss of RCS pressure control.

, Cable IV55985 does not contain wire combinations that could cause r

j. spurious operation. However, for high/ low pressure devices, spurious l

operation from hot shorts with other cables in the cable tray must be

considered.

This issue was identified as a result of an enhancement to the Appendix R

program. Specifically, this upgrade will establish a database that -

5 relates fira zones to the Appendix R cables in those fire zones. The

i. problem was identified while data was being collected for this database.

i i cause of Condition 2 I It was recognized in March 1985 that the power cables for 1-PCV-68-334 were routed through 125-volt Vital Battery Board Room II. It was -

(- incorrectly. determined that an interaction did not exist in this room  ;

i since 1-FCV-68-322 (block valve for 1-PCV-68-334) would be available.

Cables for Block Valve 1-PCV-68-332 are not in the area but are powered  ;

j~ from train a which is not available because of the possible loss of the {

train B D/G (due to cable B76 being in the same area). Control Cable B76

) is routed from 125-volt Vital Battery Board II, Panel 4, to the shutdown

, Board'15-B. relay logic panel.and provides control power for the D/G 18-B remote control circuit. To ensure compliance with 10 CFR 50, Appendix R,

? power from D/G 13-3 is required for the closure of the block valve should the same postulated fire cause the spurious opening of 7'

valve 1-PCV-68-340A.

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, ~3-a corrective Actions The affected rooms are being covered by an hourly, roving fire watch l patrol. In addition, the involved room is protected by fira detectors and an automatic fire suppression system.

These cable interactions will be resolved as a part of the ongoing Thermolag issue resolution.

A review of the Unit 2 equivalent cables was performed, and it was determined that this condition does not exist on Unit 2.

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