ML20195D532
| ML20195D532 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 10/26/1988 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20195D522 | List: |
| References | |
| GL-86-10, NUDOCS 8811070045 | |
| Download: ML20195D532 (14) | |
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UNITED STATES NUCLEAR REGULATORY COMMISSION t.
wAsstNetoN.o.c.noess SAFETY EVALUATION BY_ THE OFFICE OF_ NUCLEAR REACTOR REGULATION EJ g AT10h 0F FIRE PROTECTION EXEMPTIONS FACILITY OPERATLNG LICENSE NO. NPFJ ARVJASAS POKER AhD LIGHT COMPAy ARVAhSAS NUCLEAR ONE,0 NIT NO. 2 2
DOCKET NO. 50-368 1.0 LHRODUCTION By letter dated August 15. 19F4 the licensee requested approval of a nurbar of exenptions from the technical requirenents of Sections Ill.G., !!!.J., and !!!.0..
of Appendix R to 10 CFR Part 50 By letters dated August 30, 1085 and October 29, 1907, the licensee requested approval of a number of additional exenptions from Appendix R.
Surplemental infernation van provided by the licer.see in letters to the staff dated October P0. 19FC. April ?? and June P4, 1987, and September 13, 1988. The staff's evaluation of this inforvation is contained in this report as follows:
Sectiens F.0 through 6.0 consist of the evaluation of specific exenption requests, and fection 7.0 consists of an evaluation of the licenste's fire ha7ards ar,alysis concerning non-fire-rated features in fire area boundaries.
Section !!!.G.? of Appendix P recuires that one train of cables and equipment necessary te achieve and nalotain safe shutdown be raintained free, of fire darage by ont of the following utans:
1.
Separation of cables and ec,uipment and associated non-safety circuits of redundant trains by a fire barrier having a 3-hour rating.
Structural steel forving a part of or supporting such fire barriers shall be protected to provide fire resistance equivalent to that required of the barrier; 7.
Separation of cables and equipment and associated non-safety circuits of redundant trains by horirental distance of r. ore than 20 feet containing no intervening corbustibles or fire hazards.
In addition, fire detectors and
,an automatic fire suppression systen shall be installed in the fire area; or 3.
Enclosure of cables and. equipment and associated non-safety circuits of one redundant train in a fire barrier having a 1-hour rating, in addition, fire detectors and an autoratic fire suppression systern shall be installed ir. the fire area.
8811070045 891026 PDR ADOCK 05000368 F
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If these conditions are not met,Section III.G.3 requires an alternative shut-down capability independent of the fire area of concern.
It also requires that a fixed fire suppression system be installed in the fire area of concern if it contains a large concentration of cables or other combustibles. These alter-native requirements are not deemed to be equivalenti however, they provide equivalent protection for those configurations in whien they are accepted.
Because it is not possible to predict the specific conditions under which fires may occur and propagate, the design basis protective features are specified in the rule rather than a design basis fire.
Plant specific features say require protection different from the measures specifiad in Section Ill.G.
In v>ch a case, the licensee must demonstrate, by fire hazards analysis, that existing protection in conjunction with proposed modifications will provide a level of safety ecuivalent to the technical requirements of Section !!!.G of Appendir R.
In sum ary, Section !!!.G is related to fire protection features for ensuring that systers and associated circuits used to achieve and naintain safe shutdown are free of fire danage. Fire protection configurations nust either neet the specific requirements of Section III.G or another fire protection configuration nust be justified by a fire hazard analysis.
The staff's general criteria for accepting a different fire protection configura-tion are the folleking:
The alternative assures that one train of equipment necessary to achieve not shutcown frcm either the control room or emergency control statiens is free of fire danage.
The alternative assures that fire danage to at least one train of equiprent necessary to achieve cold shutdown will te limited sucn that it can be repaired within a reasonable time (ninor repairs with conponents stored onsite).
Fedifications required to meet Section !!!.G would not enhance fire protection safety above that provided by either existing or proposed alternatives.
Podifications required to meet Section !!!.G would be detrirental to eserall facility safety.
2.0 DIESELGENERATORROOk,EXHAUS1FANOUTLETSjFIREAREAB FIRE 20NE211a-1) n
?.1 E erption Requested l
The licensee requested approval of an exemption from the technical requirenents of Section !!!.G of Appenoix R to 10 CFR Part 50 to the extent that it requires that redundant, shutdewn-related systers be separated by a horizontal distance of at least 70 feet free of intervening corbustibles and be protected by automatic fire suppression and detection systers.
o 2.?.
Discussion in Fire Zone 2114-! of Unit 2. redundant diesel generator ' exhaust fan outlets are separated from each other by less than 20 feet of horizontal distance, and a fixed automatic fire suppression system is not installed.
Fire Zone 2114-I is on elevation 386 feet of Unit 2, which is located as follows:
North of the Unit 1/ Unit 2 fire wall boundary West of Fire Zone 2115-! (boric acid rakeup tank room) and Fire Area G.
from which it is separated by a rated fire wall South of Fire Area G Above the Unit 2 north and south ertrgency diesel gererator roor:s (Fire Zones 2094-0 and 2003-P in Fire Areas JJ and KK. respecti':ely).
Redundant diesel generator exhaust fan outlets are adjacent to each other and are separated by a horizcntal distance of less than 20 feet.
Fire Zone 2114-!
is not rcofed.
The corbustible loading in inis zone is approxirnately 275 Btu per square fcot, which prcduces an equivalent Hverity of less than 1 Finute on the ASTP E-110 tint-terperature curve.
The licensee cow,itted to install a 3-bcur rated door in the opening of the reinforced concrete wall sepratirg the redundant fan outlets.
2.3 Fvaluatier.
The technical requirerents of Section !!!.G of Appendix R are not ret in this area because redundant diesel generator exhaust fan outlets are not separated by at 1cest 20 feet free of intervening corbustibles. The lack of area-wide fire detection and suppression systers in Fire Area B does not require an exemption per the guidance issued in Generic Letter (GL) 86-10. The staff was concerned tnat because of the absence of at least 20 feet of separation between the exhaust fan outlets, a pathway existed which could allow fire to spread and darage the redundant systers. Also, the lack of fixed suppression systems and fire detectors throughout this fire area could pennit a fire to spread and result in the loss of safe shutdown capability. However, be<:ause of the light corbus-tible 1cading in these fire :ones, it is not expected that a fire of significant duration or magnitude will occur. There are no intervening conbustibles between the redund6rt safe shutdown systers.
If a fire were to cccur in or near one of the exhaust fans, it would be expected to develop slowly with initial low heat release and slow terperature rise. The 16cn of a roof over Fire Zone 2114-1 wculd precludt any accurulation of hot g6ses
over this equiprent. Further, in order for the fire to certously affect the redundant equiprent, it would have to spread over and down into the roor. below, which is not considered credible. The licensee has fulfilled their comitment to install 3-hcur rated fire doors between redundant trains of equipmenti thus the possibility of a single fire in one of these fire zones damaging redundant l
equipment is extremely unlikely, despite the horizontal separation distance l
of less than 20 feet between redundant trains.
2.4 Conclusion Based on the above evaluation, the staff concludes that the licensee's alternative l
fire protection configuration provides an equivalent level of safety to that achieved by compliance with Section !!!.G Appendix R.
Therefore, the' licensee's ree,uest for exemptiun from the requirenents for 20 feet of separation, free of l
intervering conbustibles between the diesel generator exhaust fan outlets should be approved. The licensee's fire hazards evaluation concerning the absence of i
arta-wide fire detectors and a fire suppression system in Fire Area B conferr.s j
with the guidance in GL E6-10.
No exenption for this condition is, therefore t
rtquired.
l 3.0 UNIT 2CONTROLROOPANDPRINTERROCM{FIREAREAG FIRE 20NE P199-G1 t
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.EetptiLn,Eequested l
Tre licensee requested approval of ar exerption from the technical requirerents
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of Section 111.G.3. of Apperdix R to 10 CFR Part 50 to the extent that it requires the installation of a fixed fire suppression system in an area, roer. or zone for which an alternate shutdown capability has been provided.
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3.P hseussien Fire Area G includes portions of elevations 272. 386, ano 40a feet.
It is corprised of the ANO-1 control roor and cable spreading room and the ANO-?
control rocn. cable spreading rocn. health physics area, upper south electrical peretration room, core protection calculator panel rece, and the printer rocm adjacent to the ANO-2 control roer.
The control roors are separated from each other by a wall containing larinated glass doors and com on ventilation louvers.
j Alternate shutdown is provided for this fire area, i
l Corbustibles include paper, clothing, and cable insulation. The control rooms i
are continually occupied. The conbustible loading in the ANO-2 control roor/
printer roce (Fire Zone 2199-G) is approximately 34,180 Btu per square foot, which produces an equivalent fire severity of 26 minutes on the ASTM E-Il9 tire-terperature curve.
Fire prctection in Fire Zone 2199-G consists of smoke detectors in each safety-
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related cabinet and portable fire extinguishers.
In addition, physical separa-tien is provided tetween adjacent control pantls.
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5 3.3 -Evaluation The fire protection in this fire area does not coinply with the technical require-ments of Section 111.G.3 because a fixed fire suppression system is not installed throughout the control room and printer room.
The corkustible loading in these rooms is v ierate, consisting of paper. clothing, and electrical cable insulation.
If a fire were to occur, it is expected that it would develop at a slow to nederate rate.
Ionization snoke detectors are provided in the n iety-related control cabinets and the roors are contirually occupied. The separation between adjacent contro!
l parels limits the spread of fire. The alarns for the detectors annunciate in the control retn.
If a fire occurs, it is espected to be prorptly detected. The control rocn crerators will alert the plant fire brigade to extinguish the fire i
narually if the crerators have not.
Separation of adjacent control parels, smoke detectors, continual occupancy of the control rcons. portable extinguishers, and alternate shutdown capability for this fire area all provide reasonable assurance that a fire ir. Fire Zone 219E-0 >:ill not prevent a safe plant shutdown.
3.4 Cenclusion Based on the abeve evaluatien it is cercluded that the existing fire protection 3
features previde a level of fire protecticn equivalent to the technical require-I t.ents of Section I!!.G.? cf Appendix R.
Therefore, the exenption request for L
1 providir.g fi>td fire suppression in Fire Zere P199-0 should be approved, j
4.0 UFFERAh0t.Ok'ERSOUTHplplhGpEhElRAT10hFOCFSjFIREAREAEE, FIRE 70hE E 004-0D AW PbW-33J ""' " ~ """"'~"""
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i 4.1 Ereert_ionfegested 1
The licenset requested approval of ar. exenption fron, the technical requirenents of Sectien III.G.F.b. of Appendix R to the extent it requires the installatier.
of an autoratic fire suppression system in an area where redundant shutdewn
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systers are separated by nore than 20 feet, free of intervening contustibles, and protected by an autoratic fire detection system.
i 4.2 Discussion Fire Zone 2CE4-00:
The upper south piping penetration roon is a high-radiation area on elevation i
354 feet.
It is scuth of the reactor contatorent, torth cf Fire Area FH. east of the plant exterior, and includes reors 20EF and 7083.
It is above the lower south piping perttration rcen (Fire Zone 2055-JJ) and below the electrical penetration roos (Fire Zone F137-1 of Fire Area G). The relevant safe shutdown ccrponents located in Fire Zone 20F4-00 are two of the four high i
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-c-pressure safety irdection (HPSI) outlet valves for HPSI header nurber 1 and the charging punp discharge header isolation valve for norral reactor coolert syster (RCS) rakeup.
Other safety and ncn safety related valves, including the other two HPS! header nur.ber 1 outlet valves, are also located in this Zone, but are not relevant to this exerption request. HPS! header number 1 is designed 4
to function as an alternate RCS makeup path from the charging punps. However, only two of the four HFSI Outlet valves are at least 20 feet horizental distance away from the charging header outlet valve. Therefore, the other two HPSI cutlet valves are not relevant to this exerption request. The relevant HPS! valves artFCV5015-1(34 feetaway)and2CV5055-1(20 feetaway).
Either only one of these two HPSI cutlet valves or the charging outlet valve is required to be open for safe shutdown. The charging valve is pcwered from the energency elec-trical train op;osite to that which supplies the HPS! valves. So these valves i
are t,oth physically.and electrically redundant to the charging salve. The charging valve is a r.ctr. ally cren rotor-operated vahe, which would not be spuriously closed because of fire danage in this Fire Zone. All three valves can be narually operated 1ccally.
The cortustible centents in this fire 2cne consist of electrical cable insulation (cat.lesintravs). The conbustible it edirg is approxirately 3?,770 Stu per square foot, dich produces an equivalent fire severity of 25 trinutes en the ASTM E-119 tire-terprature curvt.
Intervening centustibles are not present between the redurdant valvts.
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The associated purps are nct reciuired for safe shutdown until at Itast li hcurs after a fire.
Firt protectier, in this firt rene consists of fire detectors and hose reels.
Fire Zone 20!5-N:
l The 1cter south piping pr.etraticn rect is e tigh-radiaticn area located en e'esation 355 fett.
It is south of the reactor ccr tainnent, north and west of i
Fire Area 00, it is et' eve Fire Area E and below Fire Zcne 2CF4-00.
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The licensee stated that the fire protection features and characteristics of Fire Ione TC55-N are siniler tc those previously described in Fire Zone 1
1 2084-00.
The conbustible 1cading in Fire Zone TC55-N is approxirately 50,000 Stu per square fcet, which produces an equivalent fire segerity of 3F tinutes on the ASTM E 119 tire-terperature curve.
4.3 Evaluation The fire protectior in fire Zor.es TCF4-0D and 2055-N tees not cort y with the l
tectnical requirenents of Sectien 111.G.T.b of Appocis R to 10 CFR Fart 50 j
berause autc>ratic fire suppression systers are not installed ir these zor.es which contair. catles, (quiprent, and associated nersafety circuits of redundert treins stparated t.) a tertrontal distance of rore than 70 fect free of intervening ccetustitles or fire hazards, and are protected by fire detectors.
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7 The staff was originally concerned that the lack of automatic suppression systers ray perrit i fire to spread and result in the loss of safe shutdown capability.
However, because of the moderate combustible Iceding in these fire zones and the arrangerent of the cables in trays, a fire of significant ragnitude is not expected to occur.
The cables in trays are not considered an intervening corbustible for the safe shutdctn-related valves because the trays are at least 4 feet above the valves.
in addition, the valves are distributed a ng a distance of s. ore than 34 feet.
limiting the lilelihood that all three valves could be damaged by a single fire.
Further, the valves can be manually operated locally.
If a fire were to occur i
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- res, it rould be detected by the fire detection syster, which would annunciate in the control roct. The control room operators wculd then i
dispatch the plant fire brigade to extinguish the fire.
Cespite the moderate centustible loading in these fire zor.es and the lacn of a 1
fixed suppressicn syster, tLere is reaserable assurance that a fire will not result in the loss of safe stutdown capability. Therefore, it is found that j
1 the irstellatich cf a fixed suppressicn system in Fire Zenes 2084-DD and 20!!-JJ t
j would net sigr,1ficartly increase the level of fire protection.
4.4 Qnclusion i
Based on the ateve evaluatien, the staff concludes that the licensee's alternate I
fire protectico confip r6 tion provides an equivalent lesel of fire protectich to ttat achieved by conferr-ance with Sectiub !!!.G.3 cf Appendix F,.
Therefore.
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the licensce's reeuests fer exception in the ateve-referenced location should t
j te approved.
5.0 LEVIL TRANSrlT1Eks FOR 1HE SAFE 1Y-GFACE CONDENSATE ST05 AGE 1Aht p Mn M Eb bl W T Ahb' 2)" "'" """""" " ~~ "* ""' " ~
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5.1 Freertion Regue,sted 4
The Itcensee requested approval of exerptions from the technical requirerents I
of Section !!!.G.I. of Appendia R to 10 CFR Part 50 to the extent that it requires
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a 3-kNr fire barrier between redundant safe shutdown systers, i
i 5.2 Discussion l
The Sa'fety-Grade Condensate Storage Tank (CCST) for each unit is located in the i
j yard approxtrately 142 feet west of the Auxiliary Building (to the centerline of l
the tank) and is surrounded ty an 16 inch thick concrete wall approxirately i
five feet high. There is a valve pit adjacent to the north side of the tank ard cuiside tre wall. The pit ressures 11'f" by 12'6' and is connected to i
tre luxiliar) Euilding t'y a pipe chese. The chase is separated fror the Auxiliary Evilding ty a 3 heur fire berrier. The walls of the chase and pit are reinforced cencrete ard telcw grade. The roof of the chase and a portion i
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of the roof of the pit is rade of rettoyable, concrete slabs. The remainder of the roof of the pit is reinforced concrete. Access to the pit is through an adjacent open hatchway.
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At least one train of RCST level indication is required for safe shutdown in order to provide infor*ation to the operators so that appropriate Facual actions l
ray be initiated to align EFW suction to an alternate water supply before the condensate inventory in the QCST is exhausted. Several hours are available before CCST level indication is required. One level transritter is located i
inside ttt pit and the other transmitter is located next to the tank, in 4r4
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the wall, and under a tornado rissile shield. Cabling for the transeitter located in the pit is enclosed in conduit and is routed through the pipe chase
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to the Auxiliary Euildiig. Cabling fcr the other transmitter is routed in l
concrcte-encased ccrduit ertedded in the ground adjacent to the pipe chase. At the tank, tre conduit er.erys inside tte wall and under the nissile shield, t
At the Foxiliary Luildir% (t energes fror the grourd and is routed up the side of tbt tuilding, where it renttrates the building dout 25 feet abo %e the ground.
This portion of the ccrduit is enclosed by steel einsile barrier.
l The valve pit, the pipe chase and the area inside the wall ccntain no in situ contustibits. All ca: ling is er;1osed in ecoduit.
Fire suppression capability l
consktt of a fire hydrant and bcse house located in the ircediate viciliity at t
the south side of the Mr3 Then are no tyternal fire tazards that could cenprornise tie crerability cf Leth f
level trarsritters. The warehouse are office are m b located creater than 50 ftet Mst of the tank, and each is ecHpped with ta autoratic fire suppressior.
i syster. The erergency diesti fuel tenis are located in a below-grade vWP l
approxiretely FCC feet to the north.
The above-ground bulk diesel fuel n oragt i
tent is located about 300 ftet to the north and 15 ericlosed t.y 'e earthen dike i
sized tu contain the entin solune of fuel in the tank.
l Ttt licenset justifies the e>enption cn the Lasis that there are no ur.rritigated fire hazards in the vicitity of the transmitters and that t,te pbpical cor.fi-t guration, as described at>vt is sufficient to assure that at least one tians-ritter and its associated cabling will rerain free of fire darage, j
!.3 Evaluation i
I T:- technical requirerents of Section !!!.G.? are not met in the above refererced t
b :ttons tecause redundant CCST lesci transmitters anc their associated cabling
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ir, not corpletely separated by a 3-hour fire-rated barrier.
L The staff was originally concerned that a fire could result in damage to the redundant conpenents or cables. Fut, as described by the licensee, there are ro significant urritigated in-situ firt tazards which would represent a risk
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to these systers.
Ir. additico, access to these locations is difficult which j
.g-would preclude the introduction of significant quantities of transient combustibles.
If a fire did occur under these circumstances it would be expected to be of limited magnitude. The smoke and hot gases produced by the fire would tend to te dissipated in the open air, away from the subject systems. The fire would be able to be extinguished by the plant fire brigade using the existing nonnal fire fighting equipment. Pending arrival of the brigade, the physical co. fig-uration of the areas, including the wall and tornado missile shield, wil';
provide sufficient protection to assure that at least one safe shutdown diver-sion will remain free of fire damage. Therefore, the provision of addi ional fire protection to conform witt 4he criteria of Section III.G.? will not signi-ficantly increase fire safety.
5.4 Conclusicn Based on the above evaluation the staff concludes that the licensee's alternate fire protection configuration provides an equivalent level of safety to that achieved by compliance with Appendix R.
Therefore, the licensee's request for exemption fror,the requirements of Section III.G.2 for the QCST level trans-mitters and their related cabling should be granted.
6.0 REACTOR C00LAR PijMP Olt COL QC_ TION SYSTEM 6.1 Exemptions Requcsted The licensee requested approval of exemptions from the technical requirement, of Section 111.0 of Appendir R to 10 CFR Part 50 to the extent that it requi',es the reactor coolant pump (RCP) oil collection system to be sized to hold the contents of the entire lube oil system for all pumps and to be designed to withstand a safe shutdown earthquake (SSE).
6.2 Discussion The RCP Oil Collection Systems at each unit contains two tanks. These tanks are ea;n designed to hold the contents of one reactor coolant pump's lube oil inventory with margin. Oil leakage from the remaining pump in each RCS loop will be drained into the appropriate tank, until the tank capacity is reached, and then to an open curbing where it can be safely contained. The system is located above the floor of the Containment Building.
Safe shutdown circuitry is routed approximately forty feet above the elevation outride the primarv hield walls containing the reactor, RCPs, and other primary system components.
shield wall separates the heavy concentrations of safe shutdown circuitr>
the electrical penetration areas from the RCPs and the Oil Collection Sys' itself. Additionally, that circuitry is protected by localized automatic
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suppression and detectior, capability. The Reactor Coolant Pump motor lute oil systems are integral with the pun:p motors. The licensee stated in the August 15, 1984 submittal, that the lube oil systems are qualified to remain tunctional during and after an SSE.
- 6.3 Evaluation The technical requirements of Section 111.0 of Appendix R have not been tret because the oil collection system for the RCPs has not been sized to hold the oil from all of the pumps and is not seismically designed.
Generic Letter 86-10 states:
"Where the RCP lube oil syster is capable of withstanding the safe shutdown earthquake (SSE), the analysis should assurre that only random oil leaks from the joints could occur during the lifetine of the plant. The oil collection system, therefore, should be designed to safely channel the quantity of oil from one purrp to a vented closed container. Under this set of circunistances, the oil collecticn systen would not have to be seismically designed."
On the basis that the lube oil systerr at ANO-2 is capable of withstending the SSE withcut rupture and that the existing oil collection system will channel raram leans to a vented and closed container, the existing design conicms with the atose staff guidance.
6.4 Corclusio,n Based on the above evaluatiun, the licensee's alternate design of the oil collec-tien systert provides an equivalent level of safety to that achieved by compli-ance with Section III.0 of Appendix R.
Therefore, the licensee's request for e>eaption shculd be approved.
7.0 NON-FIRE-RATED FEATURES IN CER1AIN FIRE AREA B00hDARIES:
/NC-2 tank rooms, punp roorrs, and corridors; lack of fire barrier and structural steel protection; elevation 335 feet (fire area 00, fire rore 2040-00)
ANO-2 lower scuth electrical penetrat'co room, structural steel protection (fire area EE, fire zore 2111-T) t ANO-2upperandlowernorthpipingpenetrationarea,doorlatch(fireareaGG, fire zone 2001 "H)
ANO-2 upper north piping penetration area, unprotected structurel steel (fire area GG, tire zone 2081-HH)
ANO-2 corridor and rrotor control center, unprotected structural steel, elevations 372 and 374 feet, 6 inches (fire area JJ. fire zone 2109-U) 7.1 Exerrptions Requeged The licensee requested approval of exertptions frorn the technical requirerrents of Sectier 111.G of Appendix R to 10 CFR Part 50 to the extent it requires that redundant shutdckn-related systerns be separated by a ?-hour fire-rated barrier.
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7.2 Discussion Tank Rooms, P g p_ Rooms and Corridors The opening in the fire barrier betweet Fire Zone 2040-JJ of Fiie Area DD and in Fire Zone 2073-00 of Fire Area HH is not protected by fire-resistive con-struction. The structural steel supporting the fire barrier between Fire Zone 2040-JJ in Fire Area OD on elevation 335 feet and Fire Zones 2082 and 2083 in Fire Area EE on elevation 354 feet is not protected to provide a 3-hour fire resistance rating.
The combustible contents in Fire Area DD include lobe oil in the charging pumps located in cubicles in Fire Zone 2040-JJ and electrical cable insulation in cable trays and FCCs. The licensee stated that the combustible leading in this fire rene is approxicately H,600 Btu per square foot, which produces an equivalent fire severity of 11 minutes on the ASTM E-119 tire-temperature curve. The cor-i bustible loading for the entire fire area is approximately 14,000 Btu per square foot, which produces an equivalent fire severity of 10 minutes on the ASTM E-119 time-tenperature curve. Fire detection is provided in Fire Zone 2040-JJ.
The cpening in the ceiling along the west well of Fire Zone 2040-JJ provides a path between the "red" ch6rging pump FCC on elevation 335 feet, which is 58 feet awey fron the openino and the "green" charging punp FCC on elevation 354 feet, whichisapproximatefy,80feetfromtheceiling. The licensee also installed a sprinkler system on elevation 354 feet at the west end of Fire Zone 2073-DD of Fire Area SH to protect the abcVe-described floor opening and the service wate. supply control valves to the diesel-facket cooling water heat exchangers for both emergency diesel generators.
The licensee performed an analysis te further evaluate the need for structural steel fire proofing. The analysis concluded that the only pctential problem in this zone was due to localized heating of the structural steel. To mitigate this problem, the licensee concitted, in the June 24, IcS7 letter, to implerent one or a combination of the following nodifications:
1.
Metal tray covers will be installed to provide continuous coverage of the portion of cabling which represents a localized heating problem to the steel.
2.
At least a one hour fire-rated cable wrap will be used to encompass the portion of cabling which represents a localized beating problem to the steel.
3.
A fire-rated structural steel coating of at least a one hour fire-rating will be applied over the applicable portions of the steel members suscep-tible to localired heating.
4 A partial sprinkler systen will be installed over the specific area which represents a localized teating problem to the steel. The system would be installed per the guidelines of NFPA 13.
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12-Lower South Electrical Penetration Nom Structural steel supporting the ceiling of Fire Zone 2111-T is not protected to provide a 3-hour fire resistance rating. The ceiling of Fire Zone 2111-T is a fire area boundary located between Fire Area EE (elevation 374 feet 6 inches) and rire Area G on elevation 386 feet. The combustible loading in Fire Zone 2111-T is approximately 24,900 Btu per square foot, which p.oduces an equivalent fire severity of 19 rainutes on the ASTM E-119 time-terrperature curve. The con.bustible loading in Fire Area EE is approximately 35,300 Btu per square fo't, which produces an equivalent fire severity of 26 minutes on the ASTM E-119 tine-terrperature curve.
Fire Zone 2111-T 1:, provided with a fixed automatic fire suppression system.
The licensee stated'that re-evaluation of the structural steel for the effects of localized beating indicated that either two beams or one colonn would have to feil doe to beating before the supported slab would fail. The failure of either two beams or one colunn is unlikely in a fully sprinklered room.
.UPPFf..an,d.,Lepy,F,or,th fjpjpdenetration Area The deer latch was on:itted fron the 3-bcur rated fire dooi that separates Fire Zone 2001-HH cf Fire Area GG from Fire Zone 2040-JJ in Fire Area DD on elevetion 235 feet.
Fire Zone 2081-HH is part of a high-energy line break-vent path. Therefore, door ??? rrust open when the pressure in the room reaches 0.25 psis. Since the typical fire door latch would not permit the door to open, the latch was ren.oved.
Fire Area GG includes Fire Zones 2081-HH and 2076-HH (the electrical equipnent room). The cenbustible loac'ing is approyirrately 03 Otu per square foot in Fire Zone 2081-HH and 5,033 Ptu per square foot in Fire Area GG, which produces an equivalent fire severity of 1 css than 1 minute and 4 minutes, respectively, on the ASTM E-119 tire-ttsperature curve.
The cenbustible leading in Fire Zone 2040-JJ is approximately 15,200 Btu per square foot, which produces an equivalent fire severity of Il minutes on the ASTM E-119 time-terrperature curve.
Fire Area GG is protected throughout by a fire detection system which annunciates in the control room.
Fire 2cne 2040-JJ is sirrilarly protected.
Upper North Piping,Penetratier Area The structural steel supporting the ceiling of Fire Zone 2081-HH is not 3rotected to provide a 3-hour fire resistance rating. The ceiling is a fire area youndary between Fire Areas CG and B on elevation 3f8 feet.
The conbustible loading and fire protection in Fire Area GG and Fire Zone 2081-HH is described above.
' Corridor and Motor Control Center The structural steel supporting the ceiling of Fire Zone 2109-V is not protected to provide a 3-hour fire resistance rating. The ceiling is part of the boundary between Fire Area JJ on elevation 372 feet and Fire Area G on elevation 386 feet.
The corrbustible loading in Fire Area JJ is approxirr.ately 53,300 Btu per square foot, which produces an equivalent fire severity of 40 ininutes on the ASTM E-119 tirne-terrperature curve. The corrbustible contents of Fire Zone 2109-U are cable insulation in trulti-level cable trays, conduit, and safety-related electrical equiprrent.
Fire protection in the fire zone consists of fire detectors throughout the tor.e.
a deluge sprinkler system actuated by sr.oke, and lir1.-type heat detectors.
7.3 Evelvation The above-referenced features exist in the boundary construction nf individual fire areas ard, as such, corre within the guidance issued in GL 86-10. No exerp-tier.s for these conditions are therefore necessary. The staff considers the licensee's subtrittals as constituting the ree,uired fire hazards analysis. The steff's principal concern was that a fire of significant n'agnitude would propa-gate fror. the arca of fire origin into the adjoining fire area and dar. age redun-dant syststrs required for safe shutdown.
If a fire were to occur in the sub-ject locatiens, it would be detected in its fortrative stages by the existing fire detection systert.s. The fire brigade would be dispatched and would sur-press the fire before significant darrage occurred.
Pending arrival of the brigade, the existing construction is adequate to confine the effects of the fire to the area of origin. Therefore, the lack of a corrplete fire-rated tarrier at these locations is not significant from a fire-safety standpoint.
7.4,Cpnclusion The licensee's analysis of the non-fire-rated features in the perirr.eter of the subject fire areas conferins with the guidance in GL 86-10 and is, therefore, acceptable.
8.0 ENVIROWENTAL CONSIDERAT10h5 The NR,C staff has previously concluded, pursuant to 10 CFR 51.32, that the issuance of these exeraptions will not have a significant impact on the quality of the hunan environtrent (53 FR 29398, August 4,1988).
9.0
SUMMARY
Based on its evaluation, the staff concluies that the licensee's alternate fire protection configuration in the identified areas provides an equh alent
level of safety to that achieved by compliance with Appendix R.
Therefore, the licensee's request for exemption for the following conditions should be approved:
1.
Lack of 20 feet of separation free of intervening combustible materials between redundant shutdown-related systems in the diesel generator room exhaust fan outlets area (Fire Area B Zone 2114-I).
2.
Lack of a fixed fire suppression system in the control room and printer room (Fire f.rea G, Zone 2199 G).
3.
Lack of an automatic fire suppression system in the upper and lower south piping penetration rooms (Fire Area EE, Zones 2084-DD and 2055-JJ).
4 Lack of a complete 3-hour fire-rated barrier between redundant level trans-mitters for the safety grade condensate storage tank (Yard Area).
5.
Lack of a reactor coolant pump oil collection system that is designed to withstand a safe shutdown earthquake and sized to hold the oil from all four reactor coolant pumps.
In addition, based on its evaluation of ine licensee's submittals, the staff concludes that the licensee's analysis of the non-fire-rated features in certain fire area boundaries, as described rbove, conform with the guidance issued in GL 86-10 and are, therefore, acceptable.
Oated: October 26, 1988 Principal Contri'. Jtor:
D. Kubicki e
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