ML20113H478

Responds to NRC Bulletin 92-001, Failure of Thermo-Lag 330 Fire Barrier Sys to Maintain Cabling in Wide Cable Trays & Small Conduits Free from Fire Damage. Hourly Fire Watch Patrols Established in Affected Fire Zones

ML20113H478
Person / Time
Site:	Oyster Creek
Issue date:	07/24/1992
From:	J. J. Barton GENERAL PUBLIC UTILITIES CORP.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
C321-92-2209, IEB-92-001, IEB-92-1, NUDOCS 9208040012
Download: ML20113H478 (13)

Text

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GPU Nuclear Corporation Nuclear a m ', = = 388 fof Aed n,ver. New Jersey 097310388 009 971-4000 Wnters Direct D ai Numt>er.

July 24, 1992 C321 92 2209 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555 Gentlemen:

Subjact: Oyster Creek Nuclear Generating Station Docket No. 50-219 Response to NRC Bulletin 92-01 Ref: NRC Bulletin 92 01, " failure of Thermo-Lag 330 fire Barrier System to Maintain Cabling in Wide Cable Trays and Small Conduits free from fire Damage", dated June 24, 1992.

In accordence with the requested actions of NRC Bulletin 92-01, this letter identifies (1) the areas of the Oyster Creek plant which have Thermo-Lag 330 fire barrier material installed, (2) compensatory measures implemented in response to the bulletin, and (3) measures being taken to ensure or res%re fire barrier operability.

Thermo-Lag 330 fire barriers have been installed at Oyster Creek to protect conduit, duct work, drywell penetrations and stairwell enclosures; no cable trays were protected. There are 15 locations within the reactor building, turbine building and office building where Thermo-Lag 330 fire barriers are installed. Three of these locations are not conduit pratective installdtions.

The remaining 12 locations are within 7 fire zones identified as TB f2 llc, TB-fZ-llD, RB-fZ-lf2, RB fz-10, RB-fZ-lE, OB fz-6A, and OB-fz 6B. Specific items protected in each fire zone are identified in Attachment 1.

Immediately upon receiving the bulletin, hourly fire watch patrols were established in the above fire zones until an evaluation of the functionality of the specific installations could be made. This is the compensatory measure required by plant technical specification 3.12.E for a non-functional fire barrier.

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ADOCK 05000219 PDR

[ r/'p' i GPU Nuclear Corporat'on is a subs 4 ary of General Putsc Ut+ttes Corporaton g

C321-92 2209 Page 2 of 3 There are two locked high radiation areas in the plant containing lhermo-Lag 330 fire barriers. After evaluating the installed fire barriers and the actual fire hazards in these two areas, it was concluded that the barriers would parform their intended function in the event of a fire, and maintaining a fire watch patrol for the purpose of fire detection would result in unnecessary plant personnel exposure. Accordingly, on June 26, 1992 a fixed camera was installed in the travelling in-core probe (TIP) drive room located in fire zone RB-FZ-lE for remote observation of the TIP drive room by an hourly fire watch patrol, and on July 1,1992, the fire watch patrol for fire zone RB-FZ-lF2 (reactor building southwest corner room) was secured.

On July 16, 1992, after evaluating the specific installations, it was concluded that the fire barriers in fire zones TB-fZ-llc, 18-fZ-llD, RB-FZ-If 2, RB fZ-10 and RB-fZ-lE are functional and the fire watch patrols in these zones were secured. The functionality of the fire barriers in OB-FZ-6A and OB-fZ-6B (480 volt switchgear room) was considered indeterminate and the fire watch patrol is being maintained for this area. Our evaluation of the functionality of the lhermo-Lag 330 fire barriers installed at Oyster Creek is provided in Attachment 2. Our evaluation includes consideration of actual combustible loads, barrier tests and analyses for specific configurations, installation quality controls, on-going fire barrier inspection, and control of combustibles.

Although the r:!ority of installed fire barriers are considered functional i (largely due to low combustible loads) and technical specification requirements are being applied accordingly, compilance with 10 CFR 50, Appendix R, Section Ill.G, which requires a 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> or 5 hour5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> rated barrier, is considered indeterminate at this time. The resolution of this Appendix R compliance issue is being handled in accordance with GPUN Procedure 1000-ADM-7215.01, " Material Nonconformance Reports and Receipt Deficiency Notices". -

This procedure allows continued use of non-conforming material if engir.eering justification is provided. Attachment 2 provides this juctification.

Appropriate actions to restore (or confinn) fire barrier operability are Seing developed through an industry program being coordinated by NUMARC. This program will include establishment of a fire barrier test database, development of guida,ce for applicability of tests, development of generic installation guidance, and consideration and coordination of additional testing as appropriate. We will apply the results of these ef forts, as appropriate, to the Thermo-Lag fire barriers in the 480 volt switchgear room and to the resolution of the Appendix R compliance issue.

We are confident that the high level of protection provided by the fire

- protection program at Oyster Creek is being maintained. We are sensitive to the significance of the Thermo-Lag fire endurance test failures identified in Bulletin 92-01 and will continae to monitor developments in this area.

' C321-92-2209 Page 3 of 3 If there are any questions regarding this matter, please call rir .chael Heller, Licensing Engineer, at (609) 971-4680.

Since aly  !

s John J. B rion Vice P sident and Director Oystet treek SwornandSubscribedtobeforemethisd day of 1992.

hM.taryPublicofNewJerseyeacb%(kws JUDf1N M.CROWE Notary Pubuc of New Jersey My Commission Expires /MC/9f Attachments cc: Administrator, NRC Region 1

' NRC Resident inspector Oyster Creek NRC Project Manager

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' Attachment'l [

Oyster Creek Thermo-Lao 330 Fire Barrier Installations ,

l FIRE ZONE /LOCATIONL CDNDUIT OR' SIZE: T-LAG CIRCUIT # DESCRIPTION PErlETRATION #~ PATING

,. TB-FZ-11C . 85-71 4" 3 Hr' 86-71 Power Feed Circuit to Switchgear ID 4160V Switchgear Rm Turbine Bldg l i Elev 23'-6" 1  !

l TB-FZ-110 86 4" 1 Hr 86-71 Power Feed Circuit to Switchgear ID B t CGCTB071 I" 1 Hr 86-66 EDG 2 Differential Prot Ckt Elev 3'-6" CGCTB017 1" 1 Hr 86-GC0016 EDG 2 Differential Prot Ckt t ,

! CGCTB030 1%" 1 Hr 62-93 125V DC Dist Ctr "B" to 460V USSIB3 l j CGCTB029 1*- 1 Hr 62-100 125V DC Dist Ctr "B" to 460V Swar ID

f. t CGCTB020 1%" 1 Hr 62-93 125V DC Dist Ctr "B" to 460V USS1b 62-100 125V DC Dist Ctr "B" to 460V Swgr 103 t t

I?-25 3%" 1 Hr 14-25 Pcwer Feed Circuit to USS192  !

14-28 2%" 1 Hr 14-28 Power Feed Circuit to USSIB3 RB-FZ-IF2 CGPA2002 1%" 1 Hr 62GP0228 125V DC Dist Ctr "B" to 460V USSIB Reactor Bldg- 62GP0229 125V DC Dist Ctr "B" to 460V Smyr ID3 j' SW Corner Room l

Elev (-)19' RB-FZ-10 CGXA3028 1" 1 Hr 82GXO849 Indicator Ckt (LT/IGO68)

Reactor Bldg

. Elev 51,. CGCA1027 2" 1 Hr 22GCl259 Position Indicator (V-14-32) 22GCl258 Control Ckt (V-14-37) 21GC2671 Valve Power /Centrol Ckt (V-II-34)62-153 2" 1 Hr 62-153 125V DC Dist Ctr "C" to MCC-DC2 s

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- i FIRE ZONE /LOCATIGil? CONDUIT OR SIZE T-LAG CIRCUIT # DESCRIPTION ~

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PENETRATION # RATING

.- r RB-FZ-10'(Cont)- CRCAIO26 i Hr 63RC0712 Control and Ind Ckt (V-14-35) l Reactor ~ Bldg 63RC0713 Control and Ind Ckt (V-14-35) [

Elev 51' 63RC0710 Control and Ind Ckt (V-14-33) l 63RC0711 Control and Ind Ckt (V-14-33) j CGPA3026 2' I Hr 12GP0816 Power Ckt (V-14-37) 12GP0817 Power Ckt (V-14-32) s CGCR3021 1" 1 Hr 22GCl258 Control Ckt (V-14-37)

CGCR2086 1" 1 Hr 22GCl298 Valve Ckt (V-16-1)

RB-FZ-IE- CRCAIO26 2" 1 Hr 63RC0710 Control & Ind Ckt (V-14-33)

Reacter Bldg 63RC0711 Control & Ind Ckt (V-14-33)

Elev 23' 63RC0712 Control & Ind Ckt (V-14-35) 63RC0713 Control & Ind Ckt (V-14-35)  ;62-153 2" k 1 Hr 62-153 125V DC Dist Ctr "C" to MCC-DC2 i CGCA2010 1%" 1 Hr 63GP0749 Control Ckt (V-16-12) 63GC0751 Control Ckt (V-16-14)  ;

63GP0744 Control Ckt for PS-215-1044 t

CGPA2008 3" 1 Hr 62GP0225 Power Feed Ckt (V-16-2) 62GP0226 Power Feed Ckt (V-16-14) ,

i Penetration 8. NA 1 Hr MA Electrical penetration boxes enclosed i 9 18 & 19 by Thermo-Lag. Mounted on drywell wall .

CGCR302i_ . 1"' I Hr 22GC1258 Control Ckt (V-14-37)

CC 93019 1" 1 Hr 12-GP0816 Valve Power Feed Ckt (V-14-37) -

CRXR2050 1" I Hr 82-598' TE-58 Channel "B" Cirs.uit i

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FIRE ZONE / LOCATION' CONDUIT OR; SIZE T-LAG CIRCUIT # DESCRIP & N PENETRATION # EATING RB-FZ-1E (Cont)' NA  ! NA 1 Hr NA Thermo-Lag on steel enclosure over Reactor Bldg stairwell. to Northeast Corner Room.  !

Elev 23' Penetration 44' NA- 1 Hr NA Electrical penetration boxes enclosed ,

& 54 by Thermo-tag. ?iounted on drywell wall.

OB-FZ-6A CNXA 1125 2" 1 Hr 822XO830 Process Inst Ckt (DPT-622-1008) 480V Switchgear Rm 822X0831- Process Inst Ckt'(DPT-622-1009)

Offic'e Bldg 822X0829 Process inst Ckt (PT-6.??-1018)

Elev 23'-6" 832X0403 Process Inst Ckt (TE-622-1020) 832X0404 Process Inst Ckt (TE-622-1021) .!

822X0835 . Process Inst Ckt (DPT-622-1010) j 822x0836 Process Inst Ckt (DPT-622-10ll) .!

822X08.34 Process Inst Ckt (Pi-622-1019) .j OB-FZ-6B CNPA1042 '1" 1 Hr 12NP0826 Power Feed (FN-56 ^04) 480V Switchgear Rm 12NP0825 Power Feed (FN-56-v07)

Office Bldg riev 23'-S" CNCA1043 3" 1 Hr 22NCl241 Control Ckt (FN-56-004/007) 1 CNCA1041 3" 1 Hr 22NCl241 l Control Ckt (FN-56-004/007)

CNCA1040 2" 1 Hr 212C2674 Control Ckt for DM56-015 212C2681 Control Ckt for Damper DM56-017 -l 222Cl243 Control Ckt for Alt Fan FN56-008 "f 21NC2678 Control Feed from CSP-IA2 .

71NC0802 Alarm Ckt for RSP i 7

71NC6809 Alarm Ckt for LSP-IA2 I 62-173 2" 1 Hr 62-173 Conduit is within Thermo-Lag enclosure  ;

of adjacent conduit. Protection not j required for this circuit. 1 l

12-604 2" 1 Hr 12-604 "C" Battery Room Ventilation {

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FIRE ZONE / LOCATION : CONDUIT.OR' SIZEi T- LAG :- CIRCUIT #l . DESCRIPTION PENETRATION #1 RATING' OB-FZ-6B (Cont)62-161 2"- i Hr '62-161 125V DC Dist Ctr "C" to Panel DC-F 480VLSwitchgear'Rm Office Bldg 62-158' 2" 1 Hr 62-158 125V DC Dist Ctr "C":to USSIA2 Elev 23'-6" 12-603- 2" l' Hr - 12-603' Mtr Fdr. Ckt "C" . Battery Room Vent Fan II 12-602 2" 1 Hr- :12-602- Mtr Fdr Ckt "C" Battery Room Vent 12-601 2" 1 Hr 12-601 460V Power Feed to "C2" Battery Room. i 12-600 2" 1 Hr 12-600 460V Power Feed to "Cl" Battery Charger .

22-1126 3" 1 Hr 22-1120 Fan 2 Control"C" Battery' Room 22-1119 Fan 1 Control "C" Battery Room ,11-861 Fan Control Power "C" Battery Room -l CGPA-1044- 1" 1 Hr ll2P1406 Halon Power Feed from Inst Panel 4C '-

HA NA 1 Hr NA' HVAC Duct with Thermo-Lag t

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Attachment Z-Evalualign of the functionali_tv of Thermo-Laa 330  ;

Fire Barriers Installed at Oyster Cregt

1. Introduction i NRC. Bulletin 92401 notifies licensees of failures in fire endurance

. testing associated with Thermo-Lag 330 fire barrier systems manufactured by Thermal- Science, Inc. (TSI). These fire barriers are installed to protect safe shutdown capability as required by 10 CFR 50, Appendix R.

The fire barriers of concern include I hour and 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> pre-formed assemblies installed .on small conduit (less than 4" diameter) and wide H cable. trays (wider than 14"). q Thermo-Lag 330 fire barriers have been installed at-0yster Creek to protect = conduit, duct work, drywell penetrations and stairwell enclosures;- no cable trays were protected. There are 15 locations within; the reactor building- turbine building and office building where Thermo-Lag 330 fire barriers are installed. Three of these locations are not conduit protective installations. The remaining 12 locations are within 7 fire zones identified as TB-FZ-Ilc, TB-FZ-llD, RB-FZ-lF2, RB-FZ-lD, RB-FZ-lE,_0B-FZ-6A, and OB-FZ-68.

II. Relevant Reouirements 10 CFR 50.48, " Fire protection", requires the licensee to meet the requirements of 10 CFR 50,- Appendix R, Section Ill.G, " Fire protection of safe shutdown capability". The objective of Section.III.G is to

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ensure that at least one means of achieving and maintaining safe shutdown conditions will remain available during and after any postulated fire in the plant. _ Licensees can' satisfy Section III.G by separating one safe shutdown train from its redundant train with fire rated barriers. The fire resistance rating required of the. barrier, either 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> or 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />, depends on the other fire protection fettures provided in the fire areal Thermo-Lag 330 fire barrier systems were installed at Oyster Creek to satisfy these- separation requirements.

In addition, .0yster Creek Technical Specification 3.12.E.1 requires an-hourly fire watch patrol be established when a fire barrier is E determined to be non-functional.

^ -111. _ Eyaluatian A.- Fire' Barrier Endurance Testino L ~

L  : Industrial Testing Laboratories (ITL) Report No. 86-8-207, dated August 14, 1986, documents a hour fire endurance test conducted on a 4" L diameter. conduit test assembly protected with the pre-shaped conduit section design of the Thermo-Lag 330 Fire Barrier System. All Thermo-Lag pre-shaped conduit sections installed on the test assembly were y previously manufactured'and shipped to Oyster Creek by TSI. These

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C321-92-2209 Attachment 2 Page 2 of 6 materials were returned to TSI from Oystcr Creek's in-house stock for use in this test program. The test assembly was exposed to the standard time / temperature environment of ASTM E-119 for 65 minutes, followed by a 3 minute minimum water hose stream test. Examination of the cable within the test assembly, following the fire endurance and water hose stream test, indicated that they were all intact, functional and free from heat or fire damage. The report further documents that the highest average cable surface temperature recorded was 108 F and the maximum individual thermocouple cable surface temperature was 122 F.

The adequacy of the fire rated barriers installed at Oyster Creek is -

also supported by ITL Report No. 82-11-80, November 1982 (5 " generic" tests, I hour cable t rays and conduits) and 82-11-81, November 1982 (5

" generic" tests, 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> cable trays and conduits). These tests included 4" conduit and were accepted by American Nu" lear Insurers (ANI) for conduit sized up to a maximum of 4" diameter and were considered to bound smaller diameter conduit. GPUN is aware that URC Information Notice 92-46 identifies a concern about the acceptability of considering these test results representative of prefabricated Thermo-Lag installations since the test specimens were made using direct application techniques and a cure accelerator. We believe the test results do provide some decree of assurance that the fire barriers installed at Cyster Creek are effective despite the different application methods.

B. Installation Ouality Control The installation of 151 Thermo-Lag 330 was in accordance with Oyster Creek Installation Specification 40?730-002, which invoked TSI Technical -

Note 20684, "Thermo-Lag 330 Fire Barrier System Installation Procedures -

Manual Power Genercting Plant Applications" Installation drawings incorporated TSI's recommendations. The installation specification required trained and certified installers, resulting in a high quality installation in accordance with TSI's qualified design details, The work was classified as " Nuclear Safety Related" and "Important to Safety" and applicable quality assurance requirements were in force, including installation inspections and post installation walkdowns.

In addition, a records review has confirmed the following:

1. All Thermo-Lag preformed sections were site receipt inspected against apprcpriate inspection criteria. Some sections were rejected and discarded, while others that were initially rejected were demonstrated by the manufacturer to be within the tolerances of sections that successfully passed the ASTM E-Il9 test.

2. All installers and QC inspectors witnessing installation were formally trained and certified by TSI. All materials used were verified to be of proper quality and type.

C321-92-2209 Attachment 2 Page 3 of 6

3. All installation and inspection work was actually performed by certified installers and QC inspectors and was properly documented.

4. All final L.stallation inspections were performed with satisfactory results. Non-compliances noted during the installation were adequately addressed and did not violate the original design.

5. All fire zones with Thermo-Lag 330 fire barriers are included in an on-going surveillance program that checks for cracks and other _

signs of degradation as well as proper band spacing (12" or less).

C. On-Goinq Jire Barrier Inspection Station procedure 645.6.028, "Thermo-Lag Envelope System Fire Barrier Surveillance", provides detailed instructions to verify, visually, the functionality of Thermo-Lag fire barriers installed to comply with 10 CFR 50, Appendix R requirements. This surveillance / inspection is conducted at least once every 18 months and prior to declaring a fire barrier functional following repairs or maintenance in acc dance with technical specification 4.12.E. The precedure requn es v /al verification that retaining bands / wires are in place (not toose) with a maximum spacing of 12 inches, and that no visible damage, cracks or missing pieces exist.

D. Control of Combustible 2 GPUN Procedure 5000-ADM-7370.01, " Fire Protection Evaluation", assures -

that combustibles added to fire areas are accounted for, considered and cumulatively totallad. In addition, Station Procedure 120.5, " Control of Combustibles", establishes guidelines governing the introduction of transient combustibles into fire areas. The quantities of transient combustibles permitted into any fire area / zone are specified. Approval by the Site Fire Protection Cocrdinator is required if q:antities exceed the specified limits. Overall totals are administratively controlled.

E. Fire Zone Sp_ecific Analysis Our evaluation of the functionality of the f're barriers in each fire zone is provid d below.

1. TB-FZ-llc. 4160 Volt Swilthaear Room t Turbine Blda. Elev. 73'-6" This fire zone contains a 4" conduit above the 4160 volt switchgear room protected with a 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> rated barrier. The zone does not have an area wide automatic suppression system. The combustible load is high (exceeds 240,000 BTV/sq-ft) primarily due to hydrogen seal oil piping which passes through the zone. The combustible loading-assumes a major oil line break and fire.

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C321-92-2209 Attachment-2 Page 4 of 6 i However, such-a scenario is considerably less probable than a fire involving the ordinary in-situ combustibles and cable-insulation present. Nonetheless, in consideration of the catastrophic type of fire, a 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> barrier was provided on the conduit containing circuitry required to achieve safe shutdown in the-event of a fire. The acceptability of the fire barrier for the 4" diameter conduit has been adequately documented by 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> duration tests (Ref. ITL Report No. 82-11-80). We are confident that the three hour fire barrier provided meets the requirements of 10 CFR 50 Appendix R, Section Ill.G.2.a. In addition, ionization type fire detection and several automatic sprinklers are provideo in the area of the oil piping and protected conduit. Based on t?e cbove,

-the installed conduit fire barrier is considered functional.

2. TB-FZ-llD._Tyrbine_Buildina-Basement. Elev. 3'-6" This-entire fire zone is provided with automatic sprinkler fire protection, therefore, conduit fire barriers with a 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> rating were utilized in accordance with 10 CFR 50, Appendix R. Conduit sizes-protected range from 1" to 4" diameter. The acceptability of the fire barrier for the 4" conduit is supported by I hour duration tests (Ref. ITL Report -th). -86 8-207 and 82-11-80). Since this fire zone has a current combustible load below 40,000 BTV/sq-ft, and_ since 80,000_ BTU /sq-f t- is the ~ general I hour fire load, there is considerable, margin between the actual fire conditions and the severe test exposure fire. Since the area has sprinkler '

protection'and does not contain the quantity or concentration of combustible' loads to approximate the ASTM E-Il9 standard time vs.

temperature curve for exposure fire, the installed conduit fire barriers are, considered functional,

3. RB-FZ-lF2. Reactor Euildina Southwest Corner Room. Elev.1-)19' This fire zone contains -l%" conduit protected by a 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> rated fire barrier. The. zone:is provided with ionization detection for early warning of a fire condition and is' virtually devoid of combustible loads _(36 BTU /sq-ft) which could-generate a fire of magnitude' approaching that prescribed by ASTM E-Il9. The t

acceptabil.ity of the fire barrier for the -l %" conduit is supported by 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> duration tests (Ref. ITL Renort No. 86-8-207 and 82-11-80). Based on the above, the installed conduit fire

> barrier is considered functional. -In addition, this zone is a locked high radiation area and entry for the purpose of fire detection would result in uariecessary exposure to plant personnel.

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C321-92-2209 Attachment 2 Page 5 of 6 4: RB-FZ-lD. Reactor Buj.Lding. Elev. 51' -

This fire zone contains I hour rated fire barrier in 3 locations protecting 1" and 2" conduit. The zone has' a combustible load of )

around 20,000 BTV/sq ft and is limited by the zone boundary analysis of _the fire Hazards Analysis Report (Volume 2, Section 1.3) to a maximum of 40,000 BTU /sq f t. This limit is well below the 80,000 BTV/sq-ft load which would be necessary to approximate an exposure fire.similar to the standard ASTM E-Il9 time vs.

temperature curve. The acceptability of the fire barrier for this diameter conduit is supported by I hour duration tests (Ref. ITL Report No. 86-8-207 and 82-11-80). In addition, ionization detection is nrovided for all but a small portion of this zone and -

deluge sprinkler systems are provided for the major cable tray routings. These systems are supplemented by hose stations and portable extinguishers, Therefore, since the combustibles to create the severe fire exposure of the tested configuration are not present, the installed fire barriers are considered functional.

5. BE-EZ-lE. Rea_c_tsr_Buildinam Elev. 23' This fire zone.contains I hour-rated fire barrier in 4 locations

-protecting conduit with diameters ranging from 1" to 3". The zone has a combustible load of around 20,000 BTV/sq-f t and is limited by the zone boundary analysis of the Fire Hazards Analysis Report (Volume 2, Section 1,3) to a maximum of 40.000 BTU /sq-ft. This limit is well below the 80,000 BTU /sq-f t load which would be necessary to approximate an exposure fire similar to the standard ASTM E-119 time vs._ temperature curve. The acceptability of the-fire barrier for this diameter conduit is supported by 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> duration tests (Ref. ITL Report No. 86-8-207 and 82-11-80), in addition,nionization detection _ is provided for all but a small portion of this zone and deluge sprinkler systems are provided for the major cable tray routings. These systems are supplemented by hose stations and portable extinguisbers. Therefore, since the combustibles to create the severe-fire exposure 'of the tested configuration are not present, the installed fire barriers are L considered functlo'nal, Within this fire zone is the travelling in-core probe (TIP) drive-

-room which is a locked high radiation area. This room contains.2"

' conduit fire barrier. Entering this room for the purpose of fire-detection-would result in unnecessary exposure' to plant personnel.

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C321-92-2209 Attachment 2 Page 6 of 6 l

6, OB-FA-6 2 480 Volt Switchaear Room. Office Buildina. Elev. 23'~6" This area is divided into 2 fire zones (08-FZ-6A and OB-FZ-68) with 1" to 3" diameter conduit protected with I bour rated fire barriers. Both switchgear zones are protected with automatic halon total flooding suppression systems actuated by ionization and photoelectric smoke detection. Fire loads in both zones exceed 80,000 BTV/sq-ft, which includes oil filled transformers of r approximately 225 gallon capacity. Due to the potential transformer rupture / fire scenario with the attendant quantities of combustibles available, the adequacy of the 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> rated fire barriers on conduit in these zones is considered indeterminate.

F. Conclusio_n in an actual fire situation, the fire resistance required of a barrier depends on the expected severity of the fire to which it may be exposed.

The combustible loading in the fire areas at Oyster Creek containing Thermo-Lag fire barrier is known and is controlled. As discussed above, these loads are typically much lower than that needed to produce a fire approaching tbc severity of a test fire. In addition, an actual plant fire would ha.e a much slower temperature rise than the test fire, in large open volumes, such as most fire areas at Oyster Creek, a fu~. 7 developed fire nay occur in one part of the area, but it is not p . oable ,

that the entire volume (fire area) would flashover. Unless a fire

• reaches this stage, it i.s not likely to present a credible challenge to any fire. barrier. Further, the fire areas at Oyster Creek are equipped with appropriate passive and active fire protection features consistent with the defense-in-depth principle.

Based on this evaluation, the following conclusions are made:

1. The installed Thermo-Lag fire barriers in fire zones TB-FZ-llc, TB-FZ-IID, RB-FZ-lF2, RB42-10 and RB-FZ-1f are functional. The functionality of the ' ire barriers in OB-FZ-6A ana v8-FZ-6B (480 volt switchgear room) is indeterminate at this time. The fire watch patrols established in accordance with technical specification 3.12.E can be secured in the zones where the fire barriers are considered functional,

2. Excluding the installed Thermo-Lag fire barrier in fire zone TB-FZ-IIC (4160 volt switchgear room), compliance with 10 CFR 50, Appendix R, Section III.G, which requires a 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> or 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> rated barrier, is considered indeterminate at this time.

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