ML20113H481
| ML20113H481 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 07/29/1992 |
| From: | Shelton D CENTERIOR ENERGY |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| 2076, IEB-92-001, IEB-92-1, NUDOCS 9208040016 | |
| Download: ML20113H481 (4) | |
Text
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4 Donoid C. Shehon 300 Madson Avenue Vce Pressderd Nuclear Toledo, OH 43f620001 Devs Beste (419)249 2300 l
Docket Number 50-346 License Number NPF-3 Serial Number 2076 l
July 29, 1992 United States Nuch:ar Regulatory Commission Document Control Desk Vashington, D.C.
20S55 Subjec t :
Fire Protectior.: Response to NRC Bulletin No. 92-01, Failure L
'of Thermo-Lag 330 Fire Barrier System to Maintain Cabling in Vide Cable Trays-and Small Conduits Free From Fire Damage Gentlemen:
Toledo Edison _(TE) received Nuclear Regulatory Commission (NRC)
Bulletin No. 92-01, " Failure of Thermo-Lag 330 Fire Barrier System to
-Haintain Cabling-in Vide cable Trays and Small conduits Free From Fire Damage", on June 29, 1992 (TE Log. Number 1-2693).
Bulletin No. 92-01 provided notification of failure in_ fire endurance testing associated with the Thermo-Lag 330. fire barrier systems that are installed to protett safe shutdown capability, requested-that all operating reactor licensees take NRC-recommended actions and required that a yritten response be provided to the NRC describing the actions.taken associated with Bulletin No. 92-01. This letter provides TE's response to Bulletin No. 92-01 as applicable to the Davis-Besse Nuclear Fover Station (DBNPS).
L NRC Be_ quested Actio'1 1.
For those plants that use either 1--or 3-hour pre-formed Thermo-Lag
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330_ panels and conduit shapes, identify the areas of the plant which have Thermo-Lag 330 fire barrier material installed and L
determine the plant areas which use this material for protecting F
either small--diameter conduit _or vide trays'(vidths greater than 14 inches) that provide safe shutdown capability.
Action Taken 1.
Based on an' advance copy of Bulletin No. 92-01 received June 25, 1992, TE determined that ten rooms at the DBNPS have conduit four inches or less in diameter containing safe shutdown cables protectediby the pre-formed Thermo-Lag 330 fire barrier system as a n
one or three hour rated fire barrier (See attachment for a listing OhGgc5-9
.of the ten roome).- one of these rooms (Room 328, Component Cooling
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Docket Number 50-346 License Number NPF-3 Serial Number 2076 Page 2 Vater Pump Room) has conduit one inch and less in diameter containing safe shu,;)vn cables protected by the Thermo-Lag 330 fire barrier system.
The DBNPS does not have any larger than four Inches in diameter conduit containing safe shutdievn cables protected by the Thermo-Lag 330 fire barrier system and there are no cable trays containing safe shutdown cables which use the
. Thermo-Lag 330 fire barrier system.
NRC Requested Action 2.
In those plant areas in which Thermo-Lag fire barriers are used to protect vide cable trayo, small conduits, or both, the licensee should implement, in accordance with plant procedures, the appropriate compensatory measures, such as fire watches, consistent with those which vould be implemented by either the plant technical specifications or the operating license for an inoperable fire barrier.
Action Taken i
r 2.
Based on information ev..u t f an rulletin No. 92-01 regarding I
Texas Utilities Electric Coepany's test results on one inch
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conduit, the Thctmo-Lag 330 fire barrier system used in Room 520 on one inch or less diameter c'nduit was conservatively declared inoperable on June 26,-1992, pending further evaluation.
The compensatory measures taken vere the verification of the opernbility of the fire detectors on at least one side of the affected fire barrier and the establishment of an hourly fire watch patrol in.accordance with DBNPS Technical Specification (TS) 3.7.10, Fire Barriers -
In the remaining rooms which contain conduit between one and four inches in diameter protected by the Thermo-Lag 330 fire barrier system, the Thermo-Lag 330 fire barriers vere not declared inoperable, however, an hourly fire watch patrol vas also conservatively established by TE.
- NRC Requested Action 3.
Each licensee, within 30 days of receiving this. bulletin, is required-to provide a written notification stating whether it has or does not have Thermo-Lag 330 fire barrier systems installed in its facilities.
Each licensee who has installed Thermo-Lag 330 fire barriers is required to inform the NRC, in vriting, whether it has taken the above actions and is required to describe the measures being taken to ensure or restore fire barrier operability.
Action Taken
- 3.
As discussed above, the DBNPS has Thermo-Lag fire barrier systems installed on up to 13ur anch diameter conduit. The actions taken include establishment of compensatory measures as discussed in item 2 above..
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Docket Number 50-340 License Number NPF-3 Serial Number 2076 Page 3 Following timely establishment of the above mentioned compensatory measures, TE performed an engineering evaluation of conduit protected b/ the Thermo-Lag 330 fire barrier system to determine whether TE's ability to safely shutdown the plant was adversely-affected.
This engineering evaluation (available onsite for NRC review) detetmined that, based on the combustible loading of the ten listed fire areas, the Thermo-Lag 330 fire barrier system vill I
ptovide adequate protection from a fire and that TE's ability to safely shutdown the plant was not adversely affected.
In addition, Room 328, which contains the conduit one inch and less in diameter, is equipped with area fire detection and automatic fire suppression i
vhich will provide early varning and suppression of fires.
Toledo Edison representatives attended the NRC meeting on July 7, 1992 in Rockville, Maryland during which Bulletin No. 92-01 vas discussed.
Utilizing the information presented at that meeting and NRC' Generic Letter 91-18. "Information to Licensees Regarding Two NRC Inspection Manual Sections on Resolution of Degraded and i
Nonconforming Conditions and on Operability", dated November 7, 1991 TE evaluated the operability of the Thermo-Lag 330 fire barrier system _ installed _on the-small conduit at the DBNPS.
This evaluation (available onsite for NRC review) determined that the Thermo-Lag 330 fire barrier system on the small conduit can be considered operable, but nonconforming. This nonconforming condition does not pose a threat to the public health and safety.
Accordingly, the hourly fire watch patrols established by TE as compensatory measures in response to Bulletin No. 92-01 vere considered to be no longer necessary and vere terminated on
,1uly 21, 1992..
!!ovever, because the Thermo-Lag 330 fire barrier system is in a nonconforming design condition, it is necessary to take corrective action.- As tl.e qualification of the Thermo-Lag 330' fire barrier system.is_an unresolved generic industry concern, TE considers that continuing to follow, evalvate, and participate in-industry activities to resolve this issue constitutes appropriate corrective action at this time,
- Should you have any questions regarding this response, please contact Mr. R. W. Schrauder, Manager - Neclear Licensing, at (419) 249-2366.
I Ver tr Oy,'yours, s
s s, l'BR/dic attachment
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.A.- B.-Davis, Regional Administrator, NRC Region III J. B. Ilopkins, NRC/NRR DB-1 Sen101 Project Manager V. Levis, NRC Region III, DB-1 denfor Resident Inspector Utility Radiological Safety Board I
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i Docket Number 50-346
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License Number NPT-3 Scrial' Number 2076 Attachment Page 1 List of Rooms at the Davis-Besse Nuclear Power Station with Small Conduit Protected by the Thermo-Lag 330 Fire Barrier System Containing Safe Shutdown Cables CONDUIi ROOH NO.
DESCRIPTION SIZE IN ROOH (INCllES) 53 Service Vater Valve Room 3, 4 105 Emergency Core Cooling System Pump Room 1-1 3
- 113A Hatch Area 3
1 114 Hiscellaneous Vaste Monitor Tank and Pump Room 3, 4 313 llatch Area 1%
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314 No. 4 Hechanical Penetration Room 2, 3 323 Ifigh Voltage Switchgear Room B 4
324 Auxiliary Shutdown Panel and Transfer Switch 2
Room f
328 Component Cooling Vater llent Excbeger and 3/4,1,1%,2 Pump Room 427:
No. 2 Electrical Penetration Room 3
- Continuation of same conduit vrapped in Room 105 I
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