ML20244C650

Submits Findings Based on Review of NFPA Code Deviations Associated W/Preaction Water Sys in Plant Cable Spreading Room & Intake Structure

ML20244C650
Person / Time
Site:	Browns Ferry
Issue date:	06/06/1989
From:	Black S Office of Nuclear Reactor Regulation
To:	Kingsley O TENNESSEE VALLEY AUTHORITY
References
TAC-00459, TAC-459, NUDOCS 8906150070
Download: ML20244C650 (4)

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UNITED STATES o NUCLEAR REGULATORY COMMISSION

.g WASHINGTON, D. C. 20555

1. June 6, 1989 Docket cos. 50-259 and 50-260 Mr. Oliver D. Kingsley, Jr.

Senior Vice President, Nuclear Power Tennessee Valley Authority 6N 38A Lookout Place 1101 Market Street Chattanooga, Tennessee 37402-2801 Dear Mr. Kingsley

SUBJECT:

NFPA CODE DEVIATIONS - CABLE SPREADING ROOM AND INTAKE STRUCTURE, BROWNS FERRY NUCLEAR PLANT, UNITS 1 AND 2 (TAC 00459)

On March 21, 19.89 Messrs. Rex Wescott and David Notley of the Nuclear Regulatory Commission (NRC) reviewed the National Fire Protection Association code deviations associated with preaction water systems in the Browns Ferry Units 1 ar.d 2 Cable Spreading Room (CSR) and the Intake Structure. Discussions were also held with TVA staff during the review.

The NRC staff's findings based on this limited visit are as follows:

1. The exposed piping in the intake structure aids visual detection of damage to piping or individual sprinklers. Hence, air supervision, for the purpose of automatically detecting such damage, may be delayed until after restart.

2. The CSR preaction sprinkler system has sprinkler heads more than 12 inches below the ceiling. This is not in conformance with NFPA require-ments and is likely to result in delayed actuation in the event of a fi re. Other sprinkler heads in the CSR are located and/or oriented in a manner which makes timely actuation even less likely.

For the ceiling sprinklers in the CSR, the depth of the support beams is greater than the distance c' the sprinklers from the ceiling. Therefore, in the event of fire, therp would eventually be a trapping of hot gases to actuate the sprinklers. This would limit the extent of damage in d.e CSR, although not as effectively as a properly designed suppression system. These ceiling sprinklers provide area coverage of the cable spreading room, therefore all arrays of cable trays are covered, even i

those in close proximity to the heads least likely to actuate.

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PDR ADOCK 05000259 P PDC

- i-Mr. Oliver D. Kfngsley, Jr.

2-Based on the above, the NRC staff considers the existing water suppression system in the CSR to be sufficient to stop fire spread from one tier of cable trays to an adjacent tier. The staff also believes that there is very little likelihood of combustible material being stored in the CSR such that an exposure fire could affect adjacent tiers of cable trays. Also, TVA has committed (Part III of TVA's Fire Protection Report Supplement) to upgrade the alarm and detection system in the CSR by July 1990. Therefore, a detection system with greater reliability will be in effect shortly after restart.

The staff considers that an upgraded suppression system would provide additional margin for the control of fires which are still confined to a single cable tray.

Therefore, the staff would like you to consider the following modifications prior to restart.

1. Providing manual and/or automatic control of the heating, ventilating and air conditioning system to include separate control of the intake and exhaust for smoke control.

2. Replacement of existing sprinkler heads with quick response heads.

Supporting analyses should include a calculation showing the relative response times of quick response heads and the existing heads.

3. Extending the riser nipples on the upright heads to achieve the code required distance from the ceiling and providing additional anchoring so as to not invalidate the existing seismic analysis of the sprinkler system.

A written response concerning your evaluation of these items is requested within 60 days of receipt of this letter.

The reporting and/or recordkeeping requirements contained in this request affect fewer than ten respondents; therefore, OMB clearance is not required under P. L.96-511.

Sincerely, Original signed by Suzanne C. Black, Assistant Director for Projects TVA Projects Division Office of Nuclear Reactor Regulation cc: see next page DISTRIBUTION Docket Filez ADSP Reading BWilson NMarkisohn NRC PDR~ DCrutchfield WSlittle MSimms Local PDR BDliaw GGears OGC Projects Reading SBlack DMoran BGrimes TVA TP Reading RPierson TDaniels EJordan ACRS(10) GPA/CA BFN Rdg. File GHubbard RWescott

• SEE PREVIOUS CONCURRENCET Quay 0FC : NRR:TVA:PSB: NRR:lVA:BC* : TVA:AD/TP* : NRR:TVA/PM*: TVA: A /P NAME : RWescott  : GHubbard  : RCPierson : GGears  : SBl  :  :

_____:........____:..__.......__:...___ .____:......_____  : 6/05/89

6/(0/89 ....: . ______  : .:_________..

DATE : 5/31/89  : ./31/89 5  : 6/01/89 OFFICIAL RECORD COPY _ _ . _ _ _ _ _ _ - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

Mr. Oliver D. Kingsley. Jr. Based on the above, the NRC staff considers the existing water suppression system in the CSR to be sufficient to stop fire spread from one tier of cable trays to an adjacent tier. The staff also believes that there is very little likelihood of combustible material being stored in the CSR such that an exposure fire could affect adjacent tiers of cable trays. Also, TVA has committed (Part III of TVA's Fire Protection Report Supplement) to upgrade the alarm and detection system in the CSR by July 1990. Therefore, a detection system with greater reliability will be in effect shortly after restart.

The staff considers that an upgraded suppression system would provide additional margin for the control of fires which are still confined to a single cable tray.

Therefore, the staff would like you to consider the following modifications prior to restart.

1. Providing manual and/or automatic control of the HVAC system to include separate control of the intake and exhaust for smoke control.

2. Replacement of existing sprinkler heads with quick response heads.

Supporting analyses should include a calculation showing the relative response times of quick response heads and the existing heads.

3. Extending the riser nipples on the upright heads to achieve the code required distance from the ceiling and providing additional anchoring so as to not invalidate the existing seismic analysis of the sprinkler system.

A written response concerning your evaluation of these items is requested within 60 days of receipt of this letter.

The reporting and/or recordkeeping requirements contained in this request affect fewer than ten respondents; therefore, OMB clearance is not required under P. L. 96 511.

Sincerely, Suzanne C. Black, Assistant Director for Projects TVA Projects Division Office of Nuclear Reactor Reculation cc: see next page DISTRIBUTION PDR BGrimes EJordan ACRM10)

Local PDR WLittle GPA/CA Projects Rdg.

ADSP R/F BDLiaw GHubbard DNotley TVA TP R/F BW11 son RWescott DKubicki Docket File JRutberg SBlack OGC

.DCrutchfield RPierson GGears BFN Rdg.

OFC : TVA:P5B  : TVA:PS  : TVA TP : TVA:P:PM  : TVA:AD/P  :  :

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NAME : RWescott  : GHubbard  : RCP on : GGea '#: SBlack  :  :

'DATE : 5/J//89 ..... ..:.: b..........:.../

5/7//89 /89  : 6/o /89 .  : 6/ /89  :  :

1 0FFICIAL RECORD COPY

I" l j . s" Mi.' Oliver D. Kingsley, Jr. cc:

General Counsel Chairman, Limestone County Comission Tennessee Valley Authority P. O. Box 188 400 West Sumit Hill Drive Athens, Alabama 35611 E11 833 Knoxville, Tennessee 37902 Claude Earl Fox, M.D.

State Health Officer Mr. F. L. Moreadith State Department of Public Health Vice President, Nuclear Engineering State Office Building Tennessee Valley Authority Montgomery, Alabama 36130 400 West Sumit Hill Drive W12 A12 Regional Administrator, Region II Knoxville, Tennessee 37902 U.S. Nuclear Regulatory Comission 101 Marietta Street, N.W.

Dr. Mark 0. Medford Atlanta, Georgia 30323 Vice President and Nuclear Technical Director Mr. Danny Carpenter Tennessee Valley Authority Senior Resident Inspector SN 1578 Lookout Place Browns Ferry Nuclear Plant Chattanooga, Tennessee 37402-2801 U.S. Nuclear Regulatory Comission Route 12, Box 637 Mr. M. J. Ray, Acting Director Athens, Alabama 35611 Nuclear Safety and Licensing Tennessee Valley Authority Dr. Henry Myers, Science Advisor SN 1578 Lookout Place Comittee on Interior Chattanooga,. Tennessee 37402-2801 and Insular Affairs U.S. House of Representatives Mr. O. J..Zeringue Washington, D.C. 20515 Site Director Browns Ferry Nuclear Plant Tennessee Valley Authority Tennessee Valley Authority Rockville Office P. O. Box 2000 11921 Rockville Pike Decatur, Alabama 35602 Suite 402 Rockville, Maryland 20852 Mr. P. Carter i Site Licensing Manager Browns Ferry Nuclear Plant Tennessee Valley Authority P. O. Box 2000 l Decatur, Alabama 35602 Mr. G. Campbell Plant Manager Browns Ferry Nuclear Plant Tennessee Valley Authority P. O. Box 2000 Decatur, Alabama 35602 1

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