ML20102A280
| ML20102A280 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 07/20/1992 |
| From: | Skolds J SOUTH CAROLINA ELECTRIC & GAS CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| IEB-92-001, IEB-92-1, NUDOCS 9207240178 | |
| Download: ML20102A280 (5) | |
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9 Document Control Desk U. S. Nuclear Regulatory Commission Washington, D.C. 20555 Gentlemen:
Subject:
VIRGIL C. SUMMER NUCLEAR STATION DOCKET NO. 50/395 OPERATING LICENSE N0. NPF-12 RESPONSE TO NRC BULLETIN 92-01 South Carolina Electric & Gas Company submits the attached Fire Barrier Report pursuant to NRC Bulletin 92-01, Failure of Thermo-Laa 330 Fire Barrier System to Maintain Cablina in Wide Cable Trays and small Conduit Free from Fire Damaae, Requested Action #3. This report satisfies the requirements of Technical Specifications 6.9.2 identifying fire barriers which are inoperable for greater than seven days.
I declare that the statements and matters set forth herein are true and correct to the best of my knowledge, information, and belief.
Should you have any questions, please call at your convenience.
Very truly yours,
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John L. Skolds MBR:lcd Attachment c:
- 0. W. Dixon R. R. Mahan R. J. White S. D. Ebneter G. F. Wunder General Managers NRC Resident Inspector J. B. Knotts Jr.
File (815.02)
HUCLEAR EXCELLENCE - A SUMMER TRADITION!
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i Attachment to Document Control Desk letter 1EB 920001-Page'l of 4 SOUTH CAROLINA ELECTRIC & GAS COMPANY FIRE BARRIER REPORT PER NRC BULLETIN 92-01 AND TECHNICAL SPECIFICATIONS 6.9.2 Thermo-Lag 330' fire barrier material is used in five locations at Virgil C.
Summer Nuclear Station. Each installation is designed to provide 1-hour fire barriers to meet the separation requirements of 10 CFR 50, Appendix R.
A revie( of these installations found two barriers which meet the conditions identified in the bulletin requiring compensatory actions:
Thermo-Lag Par.els are used to protect Cable Tray 3088. This cable tray is eighteen inches wide and supplies various A-Train loads.
Table B (attached) identifies the affected loads.
Thermo-Lag preshaped conduit sections are used-to protect a three
-inch conduit which-supplies DC power to the Main Control Board.
In addition, compensatory actions were initiated for two other barriers:
-Thermo-Lag Panels and a steel frame is used to enclose two conduits which contained Nuclear Instrument signal cables. This installation is identified by Thermal Science. Inc. as a Self Supported Structure. Due to its size and similarities in construction this barrier may be-susceptible to the same type of failures as the large cable trays.
l Thermo-Lag Panels and Flexi-Blanket is used to protect Unistrut and threaded rods which suspend an M-Board fire barrier over the "A" Service Water Booster Pump. This is an upgrade to a preexisting fire barrier previously reviewed by the NRC.
Thermo-Lag preshaped conduit sections are used to protect two conduits which provide "A" TVain power to the "C" Chiller._ This barrier is installed to maintain swing component capability.
Initially, compensatory actions were established for this fire barrier. "owever, based on the definition of "small diameter conduits" received from the NRC and.NUMARC meeting of July 7, l
1992, compensatory actions have been suspended for this area, l
~ The location, type and purpose of all Thermo-Lag '.nsta11ations is identified on Table A (attached).
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Attachment to Document Control Desh Letter lEB 920001 Page 2 of 4-Upon receipt of this bulletin a Non Conformance Notice (NCN) and Removal and
' -Restoration Sheet (R&R) were initiated to identify the condition of the Thermo-Lag fire barriers. A roving-fire watch was established on June 25, 1992 to tour each room containing a Thermo-Lag fire barrier. Station procedures require an inspection of each room on an hourly basis, provided the fire detection capability exists._ In the event of a loss of fire detection capability, a continuous fire watch will be established in each
- area.
South Carolina Electric & Gas Company has established compensatory ections as required by NRC Bulletin 92-01. We will continue to work with Thermal Science,-Inc., and the industry to develop a course of action to ensure the fire barriers are capable of performing their design function.
This course of action may include one or more of the following:
1.
Review available test documentation to reaffirm acceptability of existing fire barriers. This may require performance of site specific fire-endurance tests.
2.
Receive and review adequate test documentation to upgrade the present installations.
3.
Replacement of Thermo-Lag-fire barriers with a tested, approved fire barrier system.
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? Attachment to Document Control Desk Lettern IEB-920001-Page~3 of;4 TABLE A THERMO-LAG FIRE BARRIERS FIRE BARRIER NRCB 10 #
TYPE SIZE LOCATION 92-01 FUNCTION APPLICABILITY 24A-TW 'SSS
- 8 X 13" CB 36-03 No Separation of NI-31 and NI-32 signal cables y
from N!-33 power cable.
l 58-TN Cable 18" IB 12-02S Yes Protection of Cable l
Tray IB 36-02 Tray 3088, (see table B t-for components l
supplied) 59-TW Conduit 4"
18 26-01 No Protection of "C-Chiller, A-Train power supply.
74-TW Conduit 3"
CB 12-04 Yes Protection of DC power L
to Main Control Board.
.76-TW Panels N/A IB 12-02S No Protection of supp 'ts for M-Board fire Flexi-.
barrier over "A" Blanket Service Water Booster l
Pump.
SSS*: Self Supported Structure made from prefabricated panels, CB: Control Building i
i IB: Intermediate Building r
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-Attachment.to_Oocument Control Desk Letter
-IEB 920001 Page 4 of 4
,1 TABLE B Components supplied through Cable Tray 3088:
Equipment Safety Number Name-Class XFN0038A Battery & Charging Room Air Handling Unit (NNS)
"A" Supply Fan XFN0039A Battery Room Exhaust Fan "A" (NNS)
XES2001A Speed Switch, Component Cooling Pump "A" (SR)
XES2001C Speed Switch, Component Cooling Pump "C" (SR)
XPN7200A Cont"ol Room Evacuation Panel (SR)
XSW0001
-Reartor Trip Switchgear (SR)
XCA0001A S.S. Power Cabinet 1A (NNS)
XCX5201 Diesel Generator "A" Control Cubicle (SR)
XPN5504 Diesel Generator "B" Relay & Terminal Panel (SR)
YES0006 Diesel-Generator "A" Starter DC Fuel Oil Pump (SR)
XEX4201 -Olesel Generator-"A" Exciter Regulator Cubicle (SR)
XPN5248 Relay-&_lsolation Fuse Panel (SR)
XBC1A DC Distribution Bus 1A Battery Charger (SR)
XBCIA-1B DC Distribution Bus 1A-18 Backup Battery Charger (SR)
XPN5259 Isolation Fuse Panel (SR)
XSWlDA-7.2 KV Switchgear, Bus IDA (SR)
XSW10A1..
ESF-480 Volt Unit Substation, Bus 10A1 (SR)
- XSWiDA2 ESF 480 Volt Unit Substation. Bus 10A2 (SR)
XPN6011 Reactor Protection Under Frequency & Under (SR)
Voltage Panel 1 XPN7106 Main Control Board Termination Cabinet (SR)
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