ML19326B934
| ML19326B934 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 08/22/1978 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML19326B928 | List: |
| References | |
| NUDOCS 8004180649 | |
| Download: ML19326B934 (50) | |
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.s FIRE PROTECTION SAFETY EVALUATION REPORT BY THE OFFICE OF NUCLEAR REACTOR REGULATION U.S. NUCLEAR REGULATORY CCMMISSION IN THE MATTER OF ARKANSAS' POWER & LIGHT COMPANY ARKANSAS NUCLEAR ONE - UNIT 1 DOCKET NO. 50-313 O
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n TABLE OF CONTENTS PAGE
- 1. 0 INTRODUCTION......................................................
1-1 2.0 FIRE PROTECTION GUIDELINES........................................
2-1 2.1 Overall Objectives...........................................
2-1 2.2 General Cesign Criterion 3
" Fire Protection"...............
2-1 3.0
SUMMARY
OF MODIFICATIONS..........................................
3-1 3.1 Portable Radio Communication Equipment.......................
3-1 3.2 Separation of Power Cables in Manho1es.......................
3-1 3.3 Protection of Redundant Cables in the Hallway -
Elevation 372 Feet..................................-......
3-1 3.4 Protection of Redundant Cables in the Switchgear Rooms.......
3-1 3.5 Protection of Redundant : ables in the Condensate Demineralizer Area.........................................
3-1 3.6 Protection of Redundant Circuitry in the Control Room False Floor Space..........................................
3-2 3.7 Protection of Redundant Cables in the Cable '
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Spreading Room.............................................
3-2 3.8 Protection of Redundant Cables in'the Upper North Electrical Penetration Room................................
3-2 3.9 Portabl e Extinguisher for the Control Room...................
3-2 3.10 Smoke Detectors..............................................
3-2 3.11 Manual Hose Stationr........................................
3-2 3.12 Cable Penetration Firestops..................................
3-3 3.13 Portabl e Smo ke Exhaust Equipment.............................
3-3 3.14 Emergency Lighting...........................................
3-3 3.15 Reactor Coolant Pump 011 Collection System...................
3-3 3.16 Associated Circuits..........................................
3-3 3.17 Automatic Operation of Sprinkler Systems......................
3-3 3.18 Control of Fire 0cors........................................
3-3 3.19 Administrative Control Changes...............................
3-3 4.0 EVA LUAT ION OF P LANT F EATUR ES......................................
4-1 4.1 Safe Shutdown Systems........................................
4-1 4.2 Fire Detection and Signaling System....................
4-1 4.3 Fire Control Systems..........................................
4-2 4.3.1 Water Systems.........................................
4-2 4.3.1.1 Water Supply.....................
4-2 4.3.1.2 Fire Pumps...................................
4-2 4.3.1.3 Fire Water Piping System.....................
4-3
- 4. 3.1. 4 Interior Fire Hose Stations.................
4-4 i
TABLE OF CONTENTS (Cont'd)
PAGE 4.3.1.5 Water Suppression Systems....................
4-4 4.3.1.6 Foam.........................................
4-4 4.3.1.7 Effects of Suppression Systems on Safety Systems.......................J............
4-5 4.3.2 Gas Fire Suppression Systems..........................
4-5 4.3.3 Portable Fire Extinguishers 1-5 4.4 Ventilation Systems and Breathing Equipment..................
4-5 4.4.1 Smoke Removal.........................................
4-5 4.4.2 Filters...............................................
4-6 4.4.3 Breathing Equipment.............................'......
4-6 4.5 Floor 0 rains.................................................
4-6 4.6 Lighting Systems.............................................
4-7 4.7 Communication Systems........................................
4-7 4.8 Electrical Cable.....................
4-7
- 4. 9 Fire Barrier Penetrations....................................
4-7 4.9.1 Fire 0cors...........................................
4-7 4.9.2 Ventilation Duct Penetrations.........................
4-8 4.9.3 Electrical Cable Duct Penetrations....................
4-8 4.10 Separation Criteria..........................................
4-8 4.11 Fire Barriers..............................
4-10 4.12 Access and Egress............................................
4-10 4.13 Toxic and Corrosive Products.................................
4-10 4.14 Nonsafety-Related Areas......................................
4-11 5.0 EVALUATION OF SPECIFIC P LANT AREAS................................
5-1 5.1 Auxiliary Building - Elevation 317 Feet......................
5-1 5.2 Auxiliary Building Hallway - Elevation 372 Feet..............
5-2
- 5. 3 Auxiliary Building...........................................
5-3 5.4 Piping Penetration Areas - Auxiliary Building................
5-4 5.5 Containment Electrical Penetration Areas.....................
5-5 5.6 Emergency Feedwater Pump Room................................
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- 5. 7 Switchgear Rooms.............................................
5-7 5.8 Cable Spreading Room........................................
5-8
- 5. 9 B a t t e ry R o o m s................................................
5-9 5.10 Diesel Generator Rooms.......................................
5-10 5.11 Control Rocm................................................
5-11 5.12 Reactor Building..........u.................................
5-12 5.13 Intake Structure - Service Water Pumps 5-14 5.14 Yard Area....................................................
5-14 5.15 Fuel Oil Storage Vault...............................g.......
5-15 11
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TA8LE OF CONTENTS (Cont'd)
PAGE 5.16 Electrical Equipment Room - Elevation 368 Feet...............
5-16 5.17 Turbine Building.............................................
5-17 6.0 ADMINISTRATIVE CONTR0LS...........................................
6-1 7.0 TECHNICA L S P ECIFICATIONS....................................... '...
7-1
8.0 CONCLUSION
S.......................................................
8-1 9.0 CONSULTANTS' REP 0RT...............................................
9-1 WD W
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- 1. 0 INTRODUCTION Following a fire at the Browns Ferry Nuclear Station in March 1975, the Nuclear Regulatory Commission initiated an evaluation of the need for improving the fire protection programs at all licensed nuclear power plants.
As part of this continuing evaluation the NRC, in February 1975, puolished a report by a special review group entitled, " Recommendations Related to Browns Ferry Fire," NUREG-0050.
This report recommended that improvements in the areas of fire prevention and fire control be made in most existing facilities and that consideration be given to design features that would increase the ability of nuclear facilities to withstand fires without the loss of important functions.
To implement the report's recem-
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mendations, the NRC initiated a program for reevaluation of the fire protection programs at all licensed nuclear power stations and for a comprehensive review of all new license applications.-
The NRC issued new guidelines for fire protection programs in nuclear power plants which reflect the reccmaendations in NUREG-0050.
These guidelines are contained in the following documents:
a)
" Standard Review Plan for the Review of' Safety Analysis Reports for Nuclear Power Plants," NUREG-75/087, Section 9.5.1, " Fire Protection,"
May 1976, which includes " Guidelines for Fire Protection for Nuclear Power Plants" (BTP APCSB 9.5-1), May 1, 1976.
b)
" Guidelines for Fire Protection for Nuclear Power Plants" (Appendix A to BTP APCSB 9.5-1), August 23, 1976.
c)
" Supplementary Guidance on Information Needed for Fire Protection i
Program Evaluation," October 21, 1976.
d)
" Sample Technical Specifications," May 12, 1977.
e)
" Nuclear Plant Fire Protection Functional Responsibilities, Adminis-trative Controls and Quality Assurance," June 14, 1977.
f)
" Manpower Requirements for Operating Reactors," memo from E.G. Case to R. Boyd, V. Stello, and R. Mattson dated May 11, 1978.
All licensees were requested to:
(1) compare their fire protection programs with the new g'aidelines; and (2) analyze the consequences of a postulated fire in each plant area.
We have reviewed the licensee's analyses and have visited the plant to examine the relationship of safety-related components, systems and struc-tures with both combustibles and the associated fire detection and suppression systems.
Our review has been limited to the aspects of fire protection within the NRC's jurisdiction, i.e., those aspects related to the protection of public health and safety.
We have not considered aspects of fire protection associated with life safety of onsite personnel and with property protection unless they impact the health and safety of the public due to potential release of radioactive materigl.
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This report summarizes the status of our evaluation of the fire protection
' program at Arkansas Power and Light Company's Arkansas Nuclear One -
Unit 1 Plant.
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2.0 FIRE PROTECTI0tl GilIDELINES i
2.1 General Desian Cri erion 3
" Fire Protection" t
The Commission' ic criterion for fire protection is set forth in General Desigr.
iterion 3 Appendix A to 10 CFR Part 50, which states:
" Structures, systems, and c:nconents important to safety shall be designed and located to minimize, consistent with other safety reouirements, the probability and effect of fires and explosions.
" Noncombustible and heat resistant materials shall be used wherever practical throughcut tne unit, particularly in loca-ticr.s such as the containment and the control room.
" Fire detection and protection systems of appropriate capacity and capability shall be provided and designed to rinimize the adverse effects of fires on structures, systems, and components in:ortant to safety.
" Fire fighting systems shall bi designed to assure that their ru:ture or inadvertent operation does not significantly impair tne safety cacability of these structures, systeme, and corconen ts. "
2.2 Sucolementary Guidance Guidance en the implementation of GDC-3 for existing nuc' lear pcwer plants has been provided by the NRC staff in " Appendix A" of Brancn Technical P:sition 9.5-1, " Guidelines for Fire Frotection for Nuclear Power Plants.
Appencix A provides for a comprehensive program assuring a substan-tial level of fire protection, beyond minimums that mignt be deemed, to satisfy GCC-3.
The overall objectives of the fire protection program ecccdf ed in STP 9.5-1 and Acpendix A, are to:
(1) recuce the likelinced of occur-ence of fires;
. (2) prom:tly detect anc extinguish fires if they occur; (3) maintain the capability to safely shut dcwn the piant if fires occur; and (a) prevent the release of a significant amount of radioactive material if fires occur.
Le have used the guidance of Apoendix A as appr0priate in our review.
We have evaluated alternatives proposed by the licensee to various specific aspects of Appendix A using the overall objectivesoutlined 2-1
above to assure that there ob'jectives are met for the actual relation-ship of combustibles, safety related equipment and fire protection features of the facility.
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4 3.0
SUMMARY
OF MODIFICATIONS The licensee plans to make certain plant modifications to improve the fire protection program as a result of both his and the staff's evaluations.
The proposed modific '. ions are summarized below.
The implementation
. schedule for these modifications is in Table 3.1.
The licensee has agreed to this schedule.
The sections of this report which discuss the modifica-tions are noted in parentheses.
Certcin items listed below are marked with an asterisk to indicate that.
the NRC staff will require additional information in the form of design details, test results, or acceptance criteria to assure that the design is acceptable prior to actual implementation of these modifications.
The balance of other modifications has been described in an acceptable level of detail.
3.1 Portable Radio Communication Ecuicment Portable radio communication equipment will be provided, and available for fire brigade use (4.7).
- 3. 2 Separation of Power Cables in Manholes Redundant power cables for service water pumps and fuel transfer pumps will be separated by a barrier where redundant cables are in a common manhole in the yard area (5.14).
83.3 ProtectionofRedundantCablesintheHallway-Eievation372 Feet To protect redundant safe shutdown cables in the auxiliary building hallway -
elevation 372 feet, either a deluge system actuated by heat and smoke detectors and coating of cables where redundant cables are in proximity will be provided, or all cables will be coated and smoke detectors and a wet pipe sprinkler system installed (5.2).
83.4 Protection of Redundar.t Cables in the Switchoear Rooms Cables which are from the opposite division to the cables in each switch-gear room will be separated by a fire retardant board or blanket where redundant cables are in proximity to eaca other (5.7).
3.5 Protection of Redundant Cables in the Condensate Demineralizer Area An existing wet pipe sprinkler system will be extended to protect redundant safe shutdown cables (5.3).
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3.6 Protection of Redundant Circuitry in the Control Room False Floor Scace The Halon system in the control room false ceiling and floor will be
' modified to be actuated by smoke detectors (5.11).
All exposed cables in the false floor space will be coated with a flame retardant coating (5.11).
23.7 Protection of Redundant-Cables in the Cable Screadina Room To protect redundant cables, either a deluge system actuated by heat and smoke detectors will be provided, or all exposed cables in cable trays will be coatad with a flame retardant coating (5.8).
83.8 Protection of Redundant Cables in the Uccer North 51ectrical Penetration Room Where redundant diesel generator cables are in proximity, a barrier will be provided between the cables, and the manual sprinkler system will be converted to automatic operation (5.5).
3.9 Portable Extincuisher for the Control Room A portable water or halon extinguisher wi11 be provided in or adjacent to the control ream (5.11).
3.10 Smoke Detactors Smoke detectors will be provided in each control reem cabinet whi.ch contains safe shutdown equipment (5.11).
Additionalsmokedetectorswillbecrevidedsuchthatdetectorsarg)provided in all safety-related areas containing significant combustibles Smoke detectors will be provided in various safety-related areas which contain no comcustibles but whien contain reduncant safe shutdcwn caciing in conduit (4.2).
Power sucolies for fire detect:rs will be modified so that all fire detec-tors will be powered frem an emergency power source (a.2).
46 3.11 Manual Hose Stations Manual hose stations accessible to all safety-related acui: ment on eleva-icn 317 feet of tne auxiliary building will be provicec (5.1).
Manual hose stations will be proviced in the reactor cuilcing (5.12).
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c3.15 Cable Penetration Firestoos The cable penetration firestop design will be tested, and existing firestops upgraded where required by the testing (4.9.3).
3.13 Portable Smoke Exhaust Eouioment Portable smoke exhaust units with flexible ductwork will be provided so that three units are avafiable for each ANO-1 and ANO-2 (4.4.1).
3.14 Emergency Lighting Fixed emergency lights will be provided in the control room independent of existing normal and emergency lighting (4.6).
Portable hand held sealed beam lanterns will be provided for fire brigade use (4.6).
83.15 Reactor Coolant Pumo Oil Collection System The reactor coolant pump oil collection system will be upgraded to provide collection capability at all potential teakage points (5.12).
83.16 Associated Circuits The effects of fires involving associated circuits (circuits which are connected to safety systems iat perform non-safety functions) are being evaluated by the licensee.
Results of the evaluation will be provided by January 15, 1979. Where a fire involving associated circuits may affect operation of safe shutdown equipment, modifications such as rerouting of cables or installation of relay contacts will be made to preclude disabling of safe shutdown equipment.(4.10) 3.17 Automatic Actuation of Sor.1kler Systems The manually actuated sprinkler systems in the diesel generator rooms will be modified to automatic actuation (5.10).
- 3.18 Control of Fire Doors Fire doors which separate redundant safe shutdown equipment or which separate safe shutdown equipment from large oil hazards will either be locked.or provided with electrical supervision to alarm if opened (4.9.1).
3.19 Administrative Control Chances Procedures are being developed or changed to incorporate controls over combustible materials and ignition sources, fire brigade staffing and training, fire fighting procedures, quality assurance provisions, and definition of fire prctection duties and responsibilities (6.0).
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.s Table 3.1 Implementation Dates for Procosed Modifications Implementation Dates 3.1 Portable Radio Communication Equipment March 31,1979 3.2 Separation of Power Cables in Manholes End of 1980 Refueling 3.3 Protection of Redundant Cables in the Hallway.- Elevation 372 Feet (98J) 3.4 Protection of Redundant Cables in the Switchgear Rooms (99-M, 100-N) 3.5 Protection of Redundant Cables in the July 1979 Condensate Ofmineralizer Area (73-W) 3.6 Protection of Redundant Circuitry in the Control Room False Floor Space (129-F) 3.7 Protection of Redundant Cables in the Cable Spreading Room (97-R)
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3.8 Protection of Redundant Cables in the Upper
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NorthElectricalPenetrationRoom(149-E) 3.9 Portable Extinguisher for the Control Room (129-F)
November 15, 1978 3.10 Smoke Detectors
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3.11 Panual Hose Stations (Reactor Building and Elevation 317 feet of the Auxiliary Building) 3.12 Cable Penetration Firestops End of 1980 Refueling 3.13 Portable Smoke Exhaust Equipment December 1, 1978 3.14 Emergency Lignting December 1, 1978 3.15 Reactor Coolant Pump Oil Collection System End of 1980 Refueling 3.16 Associated Circuits End of 1980 Refueling 3.17 Automatic Operation of Sprinkler Systems (149-E, 86-G, 87-H) 3.18 Control of Fire Doors March 31, 1979 3.19 Administrative Control Changes 90 days after SER issuance (Numbers in parentheses refer to fire zone designations in the AP&L fire hazards analysis.)
n - By the end of the next refueling outage.
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4.0 EVALUATION OF PLANT FEATURES 4.1 Safe Shutdown Systems There are several arrangements of safe shutdown systems which are,apable of achieving safe shut down subsequent to a fire.
The exact arrangement available in a fire situation will depend upon the effects. of the fire on such systems, their power supplies and control stations.
To preclude a single event from affecting redundant systems, these systems are separated into two safety divisions, either of which would be capable of achieving safe shutdown.
During or subsequent to a fire, safe shutdown could be achieved using safety related equipment such as:
the reactor trip sys. tem; the barated water tank, makeup pumps, and parts of the letdown and makeup and chemical acditive systems for volume and reactivity control; emergency feedwater system; conCinsate storage tank; residual heat removal system; and steam relief.
These safety-relt.ted systems could be used to bring the reactor down to hot shutdown conditions, and then be used for cooldown to cold shut-down conditions.
Supporting. systems a.9d equipment such as the emergency diesel generators, engineered safety features batteries, and service water system would also be required.
We have evaluated the separation between redundant safe shutdown systems and components to determine that they are either separated from each otrer or protected by suppression systems such that a fire will not affect redundant equipment, and therefore a sufficient number of systems and components will be available to perform their shutdown function following a fire. The adequacy of separation between redundant shutdown equipment is discussed in other sections of this report.
4.2 Fire Detection and Signalino System The plant has a protective signaling system which transmits fire alarm and superviscry signals to the control room for audible and visual operator notification.
The system includes actuation and trouble signals from fire detectors, water spray systems, and fire pumps.
In general, the system complies with those portions of the NFPA Standards which are considered essential for a facility of this type.
Some compo-nents of the signaling system are not provided with an emergency power su'pply if offsite AC power is lost; however, the licensee has propased to provide a' suitable emergency power source for these components.
The main annun-ciator panel in the control room is not listed by a recognized testing laboratory; however, an increased frequency of testing to assure opera-bility will be performed as required by the technical specifications. Some fire detectors are not listed by a recognized testing laboratory; the 4-1
s licensee has proposed to replace these units where located in areas containing safety-related systems.
Smoke detectors have been provided in many areas of the plant and in the control room ventilation system to provide fire notification. Heat detectors are used to actuate Halon v;ppression systens,in the control 4
room ceiling and raised floor arr.as.
Infra-red detectors are provided in the diesel generator rooms. Pneamatic rate-of-rise type detectors which actuate water spray systems arr, provided at potential turbine building oil fire hazards and outside transformers.
There are sevsrai areas in the plant that contain safety-related equipment and cabling _which are' not provided with fire detectors. The licensee has proposed to instaf f detectors in such areas which contain combustibles ~
and in certain areas containing redundant safe shutdown systens with no combustible loading. The licensee has also proposed to improve fire protection in the control room by the addition of smoke detectors in cabinets containing safe shutdown systens, and by the use of smoke detectors in lieu of heat detectors to actuate halon suppression systems in the area.
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We find that, subject to implementation of these modifications, the fire detection and signaling. system satisfies the. objectives outlined in Sec-tion 2.2 of this report and is, therefore, acceptable.
4.3 Fire Control Svstems 4.3.1 Water systems 4.3.1.1 Water Sucoiy Fire water is supplied by two fire pumps located in the intake structure.
These pumps are shared by Unit 1 and Unit 2.
The two fire pumps take suction from separate service water bays which are normally supplied from Dardanelle Reservoir through intake screens.
The service bays can also be supplied from the emergency cooling water pond which is the ultimate heat l
sink.
The ultimate heat sink would not be degraded by fire water supply requirements.
We find that the fire water supply system conforms to the provisions of Appindfx A to BTP 9.5-1 and is, therefore, acceptable.
4.3.1.2 Fire pumos Two vertical shaft centrifugal fire pumps are provided, each with a design capacity of 2,500 gallons per minute at a discharge pressure -af 125 pounds per square inch gauge. One fire pump is electric motor driven; the other is driven by a diesel ~ engine having an 8-hour fuel supply tank located in the same room as the pumo.
Additional diesel fuel is available from onsite storage tanks.
Either of the two fire pumps has sufficient capacity to supply the maximum sprinkler demand with adequate reserve available for fire hoses.
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An automatic electric jockey pump maintains pressure on the fire water
. piping system.
The fire pum; ; are arranged to start automatically when a large amount of flow drops the pressure on the system; the. pumps can also be started manually from the control room.
Bo?.h fire prmps will continue to operate until they are shut off manually; the electr!c pump can be stopped from the control room, but the diesel pump can only be stopped at the intake structure.
The two fire pumps are housed in the fire resistant intake structure in individual rooms, separated by-a fire barrier.
The.:entroller for eacn fire pump is located in the associated pump room.
Sota controllers are approved for fire pump service.
We find that the fire pumps conform to the provisions of Appendix A to BTP 9.5-1 and are, therefore, acceptable.
4.3.1.3 Fire Water Pioing System Each of the two fire pumps has a separate discharge into the 12-inch underground fire loop which encircles both Unit 1 and Unit 2.
Valving is arranged so that a single break in the discharge piping will not remove both fire pumps from service.
All yard fire hydrants, fixed water suppres-sion systems, and interior fire hose stations are supplied by the fire loop.
Sectionalizing valves are provided on the loop to allow isolation of various sections for maintenance or repair.
For certain areas inside the plant, both fixed suppression systems and interior fire hose stations are supplied by a common piping system, so that both primary and backup protection cod be lost by a single break or closure of a control valve.
For such M ping system failures, hoses could be run from outside hydrants to provide protection during the short interval while repairs are being made.
Such alternative protection is required to be provided by the technical specifications.
Valve position is assured as follows:
Some fire water system control valves are electrically supervised; others, including those on_the underground fire loop and at the fire pumps. are not. The facility's technical specifications require a periodic check of the position for those valves which are not locked, sealed, electrically supervised, or otherwise secured in position to assure that valves are maintained in the open position.
Yard fire hydrants have been prov'ided at approximately 250- to 300-foot intervals around the exterior of the plant.
An auxiliary gate valve is
.provided on each hydrant lateral to permit maintenance without removing a portion of the fire loop from service.
A hose house at each fire hydrant is equipped with 2-1/2-inch fire hose and other manual fire fighting
)
tools.
The hydrant hose threads are compatible with those of the local i
fire' department.
We find that the fire water piping system satisfies the objectives of Section 2.2 of this report and is, therefore, acceptable.
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4.3.1.4 Interior Fire Hose Stations
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' Stations with 73 feet of 1-1/2-inch fire hose have been provided through-out the plant, except in containmeret.
There are a few areas in the auxil-fary building that contain safety-related systems which cannot be reached from the existing hose stations.
The licensee has proposed to install additional fire hose station; so that all such areas containing combustibles can be reached with not greater c.1an 100 feet of hose; fire hose station capability will also be provided inside containment.
Nozzles on the hose lines are cf the adjustable spray typei in areas of potential electrical fires, they are of a type rated for this service.
We find that, subject to implemt. cation of these modifications, the interior fire hose installation satisfies the objectives of Section 2.2 of this report and is, therefore, acceptable.
4.3.1.5 Water Sucaression Systems Automatic wet pipe sprinklers are provided in portions of the turbine building containing lube oil piping, and in some areas of the auxiliary building including the cable spreading room.
Automatic water spray systems are provided on outside oil-filled transformers and on lube oil storage and pump areas in the turbine builcing.
Manually operated deluge systems are provided in the diesel generator rooms and diesel fuel tank bunkers.
Manus 11y operated closed head sprinklers are provided in the electrical penetration areas, both inside and outside containment.
The licensee has proposed to change the manually operated systems in the diesel generator rooms, and in one electrical penetration area to automatic operation.
Insomeareascontainingmultipletiersofelectricall,cabTeontrays, ceilirg level sprinklers may be unable to effectively suppress fires in the lower trays. However, our review of these areas indicates that with the separation provided and the modifications proposed, the protective systems as installed will prevent loss of redundant systems required for safe shutdown.
For details of each specific area, see Section 5.0.
We find that, subject to implementation of these modifications, the water suppression systems satisfy the objectives of Section 2.2 of this report and are, therefore, acceptable.
4.3.1.6 Foam The plant has available a supply of foam and a nozzle for manual fire fighting. We find that the foam and the nozzle for manual fire fichtina conforms to 'the provisions of Appendix A to BTP 9.5-1, and are therefore acceptable.
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. 3.1.'7 Effects of Sucorest N Systems on Safety Systems The discharge of water from the operation of fire suppression systems has 1
been considered in the plant design.
Floor drainage has been provided in
.all plant areas having sprinklers and fire hose.
In areas where the floor drainage capacity is such that the expected maximum discharge of fire suppression systems could cause a water build-up in excess of 2 inches, all safety-related equipment necessary for safe shutdown has been located to preclude damage. Water spray from automatic suppression system actua-tien or piping breaks will not incapacitate safe snutdown cystems.
We find that the protection provided safety systems from the effects of suppression systems satisfies the objective's of Section 2.2 of this' r'eport and is, therefore, acceptable.
4.3.2 Gas Fire Sucoression Systems Separate automatic, total flooding Halon 1301 fire suppression systems are provided for the control room ceiling space, the auxiliary control room raised floor space and ceiling space, and the record storage room.
A low pressure carbon dioxide system is being installed to protect the main turbine bearings and exciter housing.
The gas suppression systems are designed to comply with NFPA standards 12 and 12A, as applicable.
The systems in the control room concealed ceiling space and auxiliary control room concealed ceiling and floor space are activated by heat detectors which cauld delay response.
The licensee has proposed to modify these systems to provide actuation by sacka detectors to increase their operating speed and effectiveness.
For de, tails of each specific area, see Section 5.0.
We find that, subject to implementation of these modifications, the gas fire suppression systems conform to the provisions of Appendix A to BTP 9 5-1 and are, therefore, acceptable.
4.3.3 Portable Fire Extincuishers Portable carbon dioxide and dry chemical fire extingt(ishers have been pro-vided throughout the plant in accordance with the requirements of NFPA 10,
" Portable Fire Extinguishers." The licensee has proposed to provide a water or Halon 1211 type extinguisher at the control room to combat deep-seated fires.in electrical insulation and fires in Class A combustibles.
Subject to implementation of the above described modification, we find the portable fire extinguisher installation conforms to the provisions of Appendix A to BTP 9.5-1 and is, therefore, acceptable.
4.4 Ventilation Systems and Breathino Eouicment 4.4.1 Smoke Removal The plant has special ventilation systems in the control room and the computer room that may be used for smoke removal. Smoke and heat relief vents are provided in the turbine building roof. The
.E5F pump rooms are provided with an airpurge damper that could be used to remove smoke via the building ventilation system. The diesel generator rooms' exhaust ventilation systems could be utilized to remove smoke and heat from these areas.
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Other portions of the plant did not have exhaust systems designed specifically for smoke removal.
However, the. ventilation systas.in most areas could be used for limited smoke removal.
The effectiveness of these systems is limited because:
fans and other equipment may not be able to withstand high temperatures and could be rendered inoperative by heat from a significanc fire; the capacity and configuration of the normal air-handling system may preclude effective smoke removal; heat actuated dampers may close; and some ventilation system power supply cables may be affected by a fire.
In view of the potential limitations of dependence upon normal air handling systems for smoke removal, the licensee has proposed to provide portable smoke removal fans and ducting of a type used in public fire fighting and which we find acceptable for nuclear power facilities. Subject to implementation of this modification; the smoke removal capability satisfies the objectives identified in Section 2.2 of this report and is, there-fore, acceptable.
4.4.2 Filters The pre-filters and HEPA filters utilize a low fire hazard filter media.
Charcoal filter units are enclosed in substantial metal housings and the units serving the control room and the penetration rooms are provided with detectors which will alarm in the control room if overheating occurs.
The filter units do not present a significant fire exposure to safe shutdown
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systems.
We find that fire protection for the filters satir.fies the objectives of Section 2.2 of this report and is, therefore, acceptable.
4.4.3 Breathing Eouicment A sufficient number of self-contained breathing units with spare bottles and refill capability is provided at the facility to supply the operating crew and fire brigade for a period of at least 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.
We find that the breathing equipment conforms to the provisions of Appendix A to STP 9.5-1 and is, therefore, acceptable.
4.5 Floor Drains The floor drainage system for the auxiliary building is separate from that of the turbine building, except for,the diesel generator rooms and one small equipment drain.
The drains fcr the diesel generator rooms have been equipped with backwater valves to prevent the spreading of flammable liquid fires via the floor drain system. sThe elevation of the equipment drain with respect to the main drainage aader precludes fire spread.
The diesel fuel storage vaults are equipped with individual sump pumps that are connected to a main sump by drains with normally closed valves; this will prevent a fire from involving more than one vault through the floor drain system.
We find that the protection to prevent the spread of fire through floor drain systems satisfies the objectives of Section 2.2 of this report and is, therefore, acceptable.
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4.6 Lighting Systems In addition to the normal plant lighting, emergency lighting systems powered by either the emergency generators or the 125-volt station battery syst.em are provided. Battery powered wall mounted emergency lighting units are provided in some areas. The licensee has proposed to install additional battery powered wall mounted emergency lighting units in the control room, since_ this room could lose both normal and emergency lighting as a result of fire damage to distribution panels and associated electrical cables in the turbine building. Fires in other areas would not cause loss of both normal and emergency lighting to areas providing access to the fire area.
The licensee has also proposed to provide battery powered sealed beam portable lights for use by fire brigade personnel.
We find that, subject to implementation of these modifications, the light-ing systems satisfy the objectives of Section 2.2 of this report and are, therefore, acceptable, i
4.7 Communicatio. Systems Communicati... systems include an in plant PAX and a 4-channel intercom system.
Portable radios and fixed repeaters'are being provided for security use which will also be available for emergency use by the fire brigade, should the PAX and intercom systems be damaged by a fire.
The communications systems meet the objectives outlined in Section 2.2 of this report and are, therefore, acceptable.
4.8 Electrical Cable The cables used in the plant were required to pass IPCEA Standard S-19-81 flame tests.
The flame tests showed that the ANO-1 cabling does not burn vigorously in
'the configurations used in the test.
We find that retest to the IEEE Standard 383 procedure and criteria would not provide information that would change any of our reccmmendations or conclusions.
Accordingly, we find the electrical cables used at the Arkansas Unit 1 plant acceptable.
4.9 Fire Barrier Penetrations 4.9.1 Fire Doors Doorway penetrations in barriers between fire areas are equipped with 3-hour labeled fire doors.
The licensee has proposed to either lock or alarm fire doors inmediately separating fire zon'es containing safe shutdown equipment from redundant equipment or trom large fire hazards.
We find that protection of doorway penetrations in fire barriers conforms to the provisions of Appendix A to STP 9.5-1 and is, therefore, acceptable.
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4.9.2 Ventilation Duct Penetrations
' Fire dampers equivalent to the barrier requirements have been provided where ventilation ducts pass tnrougn fire barriers. We find that this conforms to the provisions of Appendix A to STP 9.5-1 and is, therefore, acceptable.
4.9.3 Electrical Cable Penetrations Electrical cable penetrations in fire barriers.have been sealed with constructions using mineral board, ceramic fiber and sprayed mastic or cellular concrete. The licensee has proposed to provide the results of fire tests to demonstrate the fire resistance of cable penetration seals when exposed to an ASTM E-119 type test fire, and to upgrade seals ta acceptable standards.
Subject to implementation of these modifications, the cable penetration seals in fire barriers meet the objectives outlined in Section 2.2 of this report and are, therefore, acceptable.
4.10 Secaration Criteria The licensee has stated that the separation of the reactor protection system and engineered safety features is ac:0mplished y spatial separation in accordance with the folicwing criteria:
"(1)
Seoaration distances for trays containing reduncant cables are as follows:
(a) Hori: ental Separation In rocms containing heavy rotating machinery cr hign pressure pipe lines, a minimum separation of 20 feet or a 5-inen thick reinforced c:ncreta wall is provided.
In fire hazard areas a separation of 3 feet or a barrier equivalent to one inch of transite, c:vered with a sneet of 15 guage stael is provided.
(b) Vertical Separaticn A vertical sacaration of 5 feet is generally crevided. Where pnysical conditions ce not permit 5 feet of separation, either the Icwer tray is equieted with a solid stael c0ver or the u::er tray is equicped witn a solid s ael bott:m, or a :arrier, similar to tne one descriced for hori:0ntal secaration, is proviced.
(2)
Redundant cables are routed only in conduits inside the cable spread-ing reem and under the raised ficer in the controi recm.
(3)_
Redundant wiring and c:mconents in c:ntrol beards, :aneis, acc racks are either secaratec ey a steel barrier or a: leas-5 inches Of scace.
Scme wiring anc ccmcenents are c:mmen :: tqe twc reduccant 4-3
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.s safeguard channels. Also in many cases interlocks are required between equipment of different channels to perform certain safety functions.
The cables containing these common or interlocking conduc-tors are color coded gre(n when they are routed through the raceway system between panels belonging.to different safeguard channels.
These cables Ef4 run in flexible steel conduits inside the control panels.
The flexible steel conduit is extended as close to the terminals as physically possible.
r (4)
Separate cable tray, conduit and penetration systems are installed for the following classes of cable; 8 KV, 5 KV, 600-volt power and control, and the instrumentation cable.
In general, power cables are run in the top trays, with control and instrumentation in the lower trays.
(5)
Shielded instrumentation cables and thermocouple cables are not run in the same trays as the control cables.
(6)
Non-engineered safeguard circuits and engineered safeguard circuits may share the same cable trays, but the routing is controlled such that the non-engineered safeguards circuits will not cross over into other redundant engineered cable trays.. Where a non-vital cable from a channel "2" redundant source (ac or de) is routed with the vital cables that are supplied from the other redundant source, channel "1", ;.:d vice versa, this non-vital cable is run in steel conduit between the channel "2" source and the channel "1" cable tray and vice versa.
(7)
Protection system, safety feature system, and Class lE electrical system components mounted on control boards, panels, and relay racks are designed for operator convenience and pnysical separation between redundant wiring and components.
Generally, redundant channel wiring enters the control panels in conduits.
The bulk of redundant wiring inside control panels are separated by a steel barrier.
However, wiring which is common to two different redundant channels exist.
These common wires are color coded green.
For example this necessitrtes that in certain cases green wires must pass through red compartments.
However these wires are routed in conduits inside the panels except where physically impossible.
In this case, with the approval of engineering and QA, these wires will be fireproofed using a suitable fireproofing tape.
The conduit is terminated or the wires are taped as close as possible to the device to which these wires are connected. "
In general, separation between redundant divisions far exceeds these minimum requirements and is such that most fires would not cause functional loss of redundant safe shutdown equipment.
The separation criteria does not preclude the crossing of such cables nor does it consider the possibility of. heat buildup in a room.
However, the licensee has performed a detailed fire hazards analysis for each area of the plant containing cafety-related 4-9
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equipment to determine the possible effects of fires on safe plant shutdown.
4 Each of the safety-related areas is discussed in more detail in Section 5.0 of this report.
In various. areas the licensee has proposed certain modifi-cations where the existing cable separation was found ir. adequate to assure that fire will not cause damage to radundant safe shutddn equipment. The specific areas where this additional protection is to be pwided are identified in Section 5.0 of this report.
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The licensee has proposed to evaluate the effects of fires on nonsafety-related circuits associated with safe shutdown systems to determine whether these systems.could be disabled by a fire involving associated circuits. Where such disabling may occur, the licensee has proposed to eliminate the possibility by modifications. This may include rerouting ~of cables or isolating the '
associated circuits with relay contacts.
We find that either of these modifications provides an acceptable. solution should any such situations be discovered in the evaluation.
4.11 Fire Barriers
, Substantial fire barriers have been provided throuchout the plant.
The 1,1censee's fire hazards analys,is concludes that the basic wall, floor and ceiling structures bounding each fire area have adequate resistance to prevent the spread of an unsuppressed fire through the barrier.
In some d ases, fire zone boundaries are not established by fire barriers.
- However, the licensee's fire hazards analysis indicates that sufficient separation 13 provided by, sp, ace,, low combustible loadin.g and other construction features 3
to preclude fire spread between zones.
The staff did not identify in its review any barriers that required modifications to a higher fire resistance rating, or areas where separation of fire zones was inadequate to prevent involvement of equipment in adjacent zones by a fire.
The fire barriers meet the objectives outlined in Section 2.2 of this report and are, therefore, acceptable.
4.12 Access and Earess All safety-related areas and areas containing. safe shutdown equipment are reasonably accessible in a fire situation with many areas having two or
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more entrances.
Fires in the few safe shutdown areas having only one entrance would not hinder access to the areas, and the light to moderate combustible loading in these areas would not prevent entrance into these areas to suppress fires which may occur.
On this basis, we find that existing access and' egress capability.is acceptable.
4.13 Toxic and Corrosive Combustion Products The products'of ccmbustion of many polymers are toxic to humans and corrosive to metals.
Prompt fire detection and extinguishment is relied upon to minimize the generation of such products.
Additionally, proposals have
-been made by the licensee for portable smoke rec. oval equipment and train-ing of the fire brigade in the use of this equipment and in the use of emergency breathing appliances. We find that, subject to implementation 4-10 i
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s of the proposed modifications described in this report, the measures taken to control and prevent development of toxic and corrosive ecmbustion
' products satisfy the objectives in Section 2.2 of this report and are, therefore, acceptable.
4,14 Nonsafety-Related Areas We have evaluated the separation by distance or by fire barriers of safe shutdown systems from nonsafety-related areas to determine that fires in such areas will not adversely affect the ability to safely shut down the plant.
Nonsafety-related areas wnich potentially pose a fire hazard to safe shutdown equipment are addressed in Section 5.0 of this report.
The licen'see has considered the effects of fires in radwaste areas in performing the fire hazards analysis and found that no fires would result
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in releases of plant effluents to the plant environment.
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s 5.0 EVALUATION OF SPECIFIC PLANT AREAS The licensee has performed a fi.e hazards analysis of the facility to i,
determine the fire loading of varicus plant areas, to identify the conse-quences of fires in safety-relatad and adjoining cor. safety-related aress, and to evaluate the adequacy of existing and preposed fire protection systems. We have evaluated the assumotions, methodolcgy, and conclusions of the fire ha:ards analysis in detail, as well as supplemental drawings showing cable routing and separation.
The results of the fire hazards analysis, other decketad information and site visit ooservations were used in the staff's evaluation of specific plant areas to assure that the cojectives stated in Section 2.1 were met.
The staff's evaluation of specific areas is discussed in tne following subsections.
5.1 Auxiliary Buildino levation 317 Feet 5.1.1 safety-Relatac Ecuicment The safety-relatad equipment in these areas include the decay heat removal heat exchangers and pumps, the reactor building spray pumps, and safety related cabling.
The equipment that may : required for safe shutdcwn in a fire emergency includes the decay heat removal heat exchangers anc pumps, and safety-related cabling.
The pumos for each division are locatad in separata recms. Mcwever, the walls are not three-hour fire-ratad.
5.1. 2 Cemoustibles The significant ccmbustible in this area is a moderate amount of lubricating oil associated with the pumps. Cabling for the pumps is contained in conduit.
5.1. 3 Consecuences if No Fire Sucoression 1
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An unmitigated lubricating oil fire in the pump rcoms would not likely spread out of the affected recm,' due to the limited amcunt of oil in each pumo.
An unmitigated lubricating oil fire in these areas would not affect redundant safe shutdown related cables due to the icw-ccmbustible loading, and the secaration frem each other and frem ccmbustibles in the area.
5.1. 4 Fire Protaction Sys:ams There is no fire cetection or aut matic suceressica for the ;umo recms or access areas.
The licensee relies on portacle extinguishers, anc hose stations at the next higner elevation, to fignt fires in these areas.
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o 5.1. 5 Adecuacy of Fire Protection With prompt fire detection, manual suppression would be adequate to extin-guish fires in these areas and limit involvement of safety equipment.
However, the fire protection for these areas is inadequate due to the lack of cmoke detectors and water hose stations.
5.1. 6 Modifications and Recommendations The 1fcensee has proposed to provide smoke detectors in these areas and hose stations that can reach the combustibles in these areas with an effective hose stream.
Subject to implementation of these modifications, we find that fire protec-tion for these areas satisfies the objectives detailed in Section 2.2 of this report and is, therefore, acceptable.
5.2 Auxiliary Buiiding Hallway at Elevation 372 Feet 5.2.1 Safety-Related Eouiement This area is adjacent to the cable spreading room and a battery room on one side, and the other battery room and a switchgear room on the other side,,
and has a doorway to the turbine building. The area is bounded by three-hour fire-rated walls.
A considerable quantity of safety-related and nonsafety-related cables are in open trays and in conduits.
Safe shutdown systems that potentially may be affected are service water, diesel generators, makeup pumps, and emergency feedwater.
5.2.2 Combustibles
.The significant combustible material in this area consists of a large quantity of electrical caole insulation in open cable trays.
5.2.3 Consecuences if No Fire Sucoression An unmitigated fire in this area could involve redundant safety divisions due to heat generation, radiant energy, or direct flame impingement.
The licensee's fire hazards analysis shows that separation of safe shutdown cables is generally good.
However, there are a few locations where cables affecting redundant safe shutdown systems cross and an unmitigated fire,in, this area could cause loss of control of these systems from the control room, requiring manual operation of valves and switchgear to operate safe shutdown equipment.
5.2.4 Fire Protection Systems There is no automatic suppression or fire detection capability in this area.
Manual hose stations and hand held extinguishers are available for i
fighting fires in this area.
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5.2.5 Adecuacy of Fire Protection The existing manual suppression capability would be adequate to control fires in this area if promptly detected; however, it may not be adequate to prevent involvement of redundant safe shutdown equipment.
5.2.6 Modifications and Recommendations The licensee has proposed to provide a directional spray system actuated by heat and smoke detection and provide flame retardant cable coating where redundancies are in proximity, or coat all trays with flame retardant and provide smoke detection and a wet pipe sprinkler system. We find that, subject to implementation of either of the above described modifications, fire protection for the hallway-elevation 372 feet of the auxiliary building satisfies the objectives detailed in Section 2.2 of this report and is, therefore, acceptable.
53 Auxiliarv Building 5.3.1 Safety-Relateo Equipeg The safety related control room, cable spreading room, switchgear rooms, electrical penetration areas, piping penetration areas, diesel generator rooms, battery rooms, auxiliary feedwater pump rooms and hallway at elevation 372 feet are in the auxiliary building, but are addressed in other sections of this report.
The remainder of the auxiliary building contains areas with safety-related cables; a few of these areas contain redundant safe shutdown cables. The makeup pumps are also within this area, each located in a separate room. The makeup pumps would be required for safe shutdown to provide primary system inakeup and boration.
5.3.2 Combustibles The significant combustibles in these areas of. the auxiliary building are a small amount of cable insulation and a moderate amount of lubricating oil associated with the makeup pumps.
5.3.3 Consecuences if No Fire Sucpression The licensee has evaluated the consequences of fires in these rooms and shown that, in most areas, the separation of redundant cables from combus-tibles or the separation between redundant cables is such that it is highly unlikely that an unmitigated fire would involve such cables.
In the condensate demineralizer area, however, an unmitigated fire may cause loss of redundant safe shutdown systems.
5.3.4 Fire Protection Svstem There are no detection devices in these areas of the auxilia y building. Two 1
areas are provided with sprinkler protection, the laboratory /demineralizer area and the controlled access area. Hose stations are accessible to all areas and portable extinguishers are provided.
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4 5.3.5 Adecuacy of Fire Protection With promot fire detec, tion, manual suopression would be adequate to control fires in these areas and limit the effects of the fire. Lack of detection' may allow the fire to continue unnecessarily. Despite suppression, in the condensate demineralizer area a fire may affect redundant safe shutdown systems due to the proximity of the cables to each other.
5.3.6 Modifications and Recommendations The licensee has proposed to install smoke detection devices in these areas to detect cable fires or other fires that may jeopardize safety related equipment. Additionally, an automatic wet pipe sprinkler system
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will be extended to protect redundant safe shutdewn cabling in the condensate demineralizer area. Subject to implementation of these modifications, we find fire protection for these areas ratisfies the objectives detailed in
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Section 2.2 of this report and is, therefore, acceptable.
5.4 Pioing Penetration Areas - k2xiliary Building 5.4.1 Safety-Relatec ioutoment Each of the piping penetration areas general,1y has cables and valves associated with one of the redundant divisions.
There are, however, a few cables ano valves from the redundant division located in these areas. _Some of.this equipment would be recuired for safe shutdown.
5.4.2 Combustibles These areas contain no exposed combustibles. Cabling is contained in conduit.
5.4.3 Consecuences if No Fire Sucaression Postulated fires in these areas could only result from transient combus-tibles. ' Cue to the secaration of redundant cabies, ' ires in most locations would not affect redundant scuipment. In a few it:ations, redundant safe shutdown cabling is in proximity to each other and may be damaged in a fire involving transients, although unlikely.
- 5. 4. a Fire.otection Systems Fire detection or automatic suoeressian ecuipment has not bee'n provided in
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?cr able extingu sners are located within and adjacent to these areas.
i these areas. Manual hose stations are not accessible to all of these areas with the existing hose available at the hose station.
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y 5.4.5 Adecuacy of Fire Protection Due to the low combustible loading, manual fire protection using portable extinguishers would be adequate to extinguish fires in these areas and to prevent the loss of redundant safe shutdown equipment.
However, without adequate detection in these areas, fires could proceed undetected and allow the damage of safety-related equipment some of which may be used for safe shutdown.
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5.4.6 Modifications and Recommendations The licensee has proposed to install smoke detectors in the piping penetration areas to detect fires in transient combustibles.
Subject to implementation of th'is modification, we find that fire protection for th6 piping penetration areas satisfies the objectives of Section 2.2 of this report and is, therefore, acceptable.
5.5 Containment Electrical Penetration Areas 5.5.1 Safety-Related Ecuioment There are four containment electrical penetration areas in the auxiliary building. These areas are mainly devoted to the passing of cables of one division into containment. There are, however, a few cables from the redundant division routed through these areas in two of the four areas.
5.5.2 Combustibles The significant combustible materials in these areas consist of a moderate amount of organic type electrical cable insulation in open trays and in a motor control center cabinet.
5.5.3 Consequences if No Fire Sucoression
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A few cables from the redundant division were routed through two of these areas. The licensee has evaluated the loss of cables in these areas and has found that for three areas the complete loss of the cables would not affect redundant safe shutdown equipment. In one of the areas, diesel generator exhaust fans could be affected.
5.5.4 Fire Protection Systems The primary means of fire suppression in each of these areas is a closed head sprinkler system with a manually initiated inline control valve.
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The ionization type detectors are provided for early warning to allow manual fire suopression before the postulatea fire is able to significantly
. propagate. Manual hose stations and hand held portable extinguishers are provided as backup.
5.5.5 Adecuacy of Fire Protection for three of the penetration areas the existing sprinkler system protectior.
is adequate to prevent involvement of redundant safe shutdown equipment.
For the one penetration area wnere recundant cables required for safe shutdown are located, the separation is not suf'icient.to assure a fire could'be extinguished prior to involvement of redundant cables.
A local fire could cause damage to occur to redundant safe shutdown cables due to tne proximity of the cables and the lack of auto-matic initiation of the suppression system.
5.5.6 Modifications and Recommendations The licensee has proposed, in the upper north electrica'1 penetration area,
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to modify the existing sprinkler <ystem to provide automatic actuation and to install barriers between redurcant safe shutdcwn related cables to protect against both being affected by.a fire.
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Subject to imolementation of the above descrfbed modifications we find that the fire protection for these areas satisfies the objectises of Section 2.2 of this report and 1s, therefore, acceptable.
5.6 Emercency Feecwater Pumo Roci 5.6.1 safety-Reiatec ioutoment The two safety-related emergency feecwater pumps are located in this rocm.
At least one emergency feecwater pump snould be available for safe shutdown.
5.6.2 Combustibies The significant combustible in these rooms is a few quarts of lube oil associated wil_h the pumos.
5.6.3 Consecuences if No Fica Sucaression Due to the low comoustible contents of the area,' there is sufficient separation between the emergency fuel water pumps that only one pump would be effected cy an unmitigated fire.
5.6.4 Fire Protection Systems There is no detection or automatic fire suppression for this recm.
A manuai-hose station accessible to this room is availacle.
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5.6.5 Adequacy of Fire Protection
'With prompt fire detection, manual fire suppression capability pro-vided would be adequate to suppress fires in the emergency feed-water pump rooms and may allow suppression of a fire before either errergency feedwater pump is lost. The lack of detection would allow the fire to continue unnecessarily.
- 5. 6. 6 Modifications and Recommendations The licensee has proposed to add smoke detection devices in this area to provide prompt notification to the control room for fires in these areas.
Subject to implementation of this modification, we find that fire protec-i tion for these areas conforms to the provisions' of Appendix "A" te BTP 9.5-1 and is, therefore, acceptable.
5.7 Switchaear Rooms
- 5. 7.1 Safety-Related Eouioment The two switchgear rooms are located on elevation 372 feet of the auxiliary building.
Each of the rooms contains primarily four kilovolt switchgear and associated cablina of one safety.di. vision.
There are a few cables from the redundant division routed through each of the switchgear rooms.
5.7.2 Combustibles The switchgear rooms contain combustible electrical cable insulation in trays and inside electrical cabinets.
The trays are lightly loaded and j
4 represent only a moderate, fire load.
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5.7.3 Consequences if No Fire Sucoression In either switchgear room, an unsuppressed fire could result in severe damage to the electrical cables and cabine.ts of the associated safety train.
In addition, an unsuppressed fire in either of the switchgear rooms could potentially result in the loss of redundant safety-related equipment some of which is required for safe shutdown.
- 5. 7. 4 Fire Protection Systems There e no automatic fire suppression systems provided for tne st'itchgear rooms.
Each room is enclosed by walls with a three-hour fire rati.
Ionization smoke detectors are installed to provide prompt warning in the control room. The fire suppression capability consists of manual hose 4
stations and portable extinguishers.
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- 5. 7. 5 Ada.,~v of Fire Protection The man"*1 fire protection provided for these areas would be adequate to control and extinguish a fire in either of these areas. However, Nre is a remote possibility that a fire in either switchgear room suld affect redundant safe shutdown cables prior to suppression of the fire due to the proximity of certain cables.
- 5. 7. 6 Modifications and Recommendations The licensee has proposed to provide fire retardant board or blanket barriers to prevent fire from involving redundant cables required for safe shutdown in each of the switchgear rooms.
We find that, subject to implementation of this modification, fire protec-tion for the switchgear rooms satisfies the objoctives of Section 2.2 of this report and is, therefore, acceptable.
5.8 Cable Screading Room 5.8.1 Safety-Related EcTifoment The cable spreading room is located at elevation 374 feet directly below the control room. Redundant divisions of safety-related cables are routed through the room.
5.8.2 Combustibles
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The significant combustibles in this area consist of a large amount of organic type electrical cable insulation.
All safety-related cables are in conduit located above the nonsafety cables in open trays.
5.8.3 Consecuences if No Fire Sucoression An unmitigated fire in this room could become large enough to affect cables from both redundant divisions due to direct involvement or due to heat boildup in the room.
A loss of the cable spreading room would cause che loss of control of redundant safe shutdown equipment. from the control room.,
5.8.4 Fire Protection Systems Automatic smoke detectors mounted at ceiling level are provided.
Detectors provide alarms in the control room. An automatic closed head sprinkler system is provided to suppress fires. Hose stations accessible to the area are also available.
5.8.5 Adequacy of Fire Protection The ionization type smoke detactor will pmvide rapid response to in-cipient fires in cable trays. The autonatic suppression system provided l
may not be adequate to suppress localized fires rapidly enough to pre-l vent the involvement of redundant safe shutdown equiement due to the location of the sprinkler heads and the need for heat buildup to actuate i
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the system. Some redundant cables may becore involved in a ' fire in a localized area. Hose stations are easily accessible to the room and adequate access is provided to fight fires ranually.
- 5. 8. 6 Modifications and Recommendations The licensee has proposed to either: modify the existing sprinkler system to a spray system actuated by heat and smoke detectors; or to provide flame retardant coatings for each open cable tray in con-junction with the existing sprinkler system.
We find that, subject to imo.lementation of either of these modifications, fire protaction for the cable spreading room satisfies the cojectives of Section 2.2 of this report and is, therefore, acceptable.
5.9 Battery Rooms
- 5. 9.1 Safaty-Related Ecuicment There are two engineered safety features battery rooms located at elevation 372 feet, each is enclosed by three-hour fire rated wails, floor, and ceiling.
Each room contains the cattaries and cables from only one of the two redundant divisions of safety equipment.
5.9.2 Combustibles The significant combustibles in the battery rooms are the plastic battery cases. Hydrogen buildup is precluded by continuously operating venti-lation exhaust fans. An alarm in the control room is provided to signal loss of ventilation flow.
5.9.3 Consecuences if No Fire Sucoression An unsuppressed fire in a battary room could cause the loss of one of the redundant batteries, but would not affect the reduncant battery.
- 5. 9. 4 Fire Protection Systems Automatic smoke detection which alarms to the control rocm is provided.
Portable extinguishers are available and tire hose stations are access-
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ible to the rooms.
5.9.5 Adecuacy of Fire Protaction In view of tne limited quantity of combustibles, the redundant battery would not be affected since the fire woulo be contained by the three-hour rateo fire enclosure. The detection and suppression provided is adequate to detect and extinguish fires which may occur in these rooms.
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5.9.6 Modifications and Recc=mendations Ne find the fire protection for the battery recms conforms to the provisions of Appendix A to STP 9.5-1 and is, therefore, acceptable.
5.10 Diesel Generator Roems 5.10.1 safety-Relatec Ecutement Each of the two redundant diesel generator recms contains a diesel generator unit along with associatad safety-related control panels, cabling, and fuel oil day tank. Only one division of this equipment is necessary for safe shutdown upon loss of offsite pcwer.
5.10.2 combustible Significant cembustibles in each recm include diesel generator lubricating
-oil, diesel fuel oil in fuel lires and the day tank, and electrical caole insulation.
The day tanks are located integral with the base of the diesel generator in a heavy welded steel enclosure.
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5.10.3 Consecuences if No Fire Sucoression An unmitigatad fire in one diesel generator reem could cause loss of i
availaoility of one redundant division of safety-related equipment i' normal AC power is also not availacle.
The reduncant diesel generator would not be affected due to the separation of the diesels by three-hour fire-rated walls and doors.
5.10.4 Fire Protection Systems The primary suceression in each recm is a manually actuated deluge system which can be Operated frem the control recm.
5ackup suppression is orc-vided by a hose station located outside of the recms and pertable extin-guishers.
Early warning fire detection is proviced by flame and smoke detectors.
5.10.5 Adecuacy of Fire Protection The sprinkler system would be adequate to centrol large fires and sucerers small fires, once manual action was taken to activate tne s rinkler sys'.ac.
Mcwever, tne lack of automatic actuaticn could alicw fires to bec:me unnecessa"ily large prior to manual actuation.
Smoke detection is adequate to provide early warning of fires.
5.10.6 Modifications and Recommendatiens The licenses has proposed to mcdify tne sucoression system for the diesel generator recms to be an aut:matically actuatec system :: insure prompt suppression of 'fres in these areas.
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Subject to implementation of this modificatidn, we find th'at fire protection for the diesel generator rocms conforms to the provisions of Appendix A to
'STP 9.5-1 and is, therefore, acceptable.
5.11 Control Room 5.11.1 safety-seiated cuicment The control roem contains safety-related cables within c:ntrol caminets and consoles.
Certain of these cables and control cabinets would be required for safe shutdown. Redundant safety-related cables, some of which are required for safe shutdown, are located in the below/ floor space.
5.11.2 Combustibles The significant combustibles in this area consist of electrical cable insulation, electrical ccmconents in panels and consoles, and a small amount of class A ccmcustibles such as log books, drawings, cperating procedures and computer printcuts.
The below/ficar space contains a moderate amount of cable insulation.
5.11.3 Consecuences if No Fire Suceression A postulated unmitigated fire in the control room below/ floor space has the potential for damaging redundant safety-related cabling some of which may be required for safe shutdown. The safety related cabling is in conduit, but may be exposed by fires in nonsafety re-lated cables in open trays.
A postulated fire in certain control room cabinets or consoles would affect safe shutdown systems. The redundant systems are, however, located in separate cabinets. Due to the separation provided and the Iow :omoustible load, it is unlikely that an unmitigated fire would affect redundant systems.
5.11.4 Fire Protection Systems Smoke detect rs are lccated abcVe the ceiling and in the exhaust ducts wnich ventilate the control cabinets. Smoke detectors are not provided inside of panels or consoles. Autcmatic Halon systems actuated by heat detectors are provided for, the above ceiling and belcw ficor spaces.
F0rtaole fire extinguishers are located in the c ntrol rocm, and a Tanual nose station is located outside the control recm. However, no Class A rated extinguisher is provided.
5.11.5 Adecuacy of Fire Cretection The location of the detectors in the ventilation exhaust duct is such that tne c0mcustion precucts from a smali fire in a canel would be diluted :y air frem other sources causinc a reduction in tne system's cacactifty to detect such a fire. Fires may, therefore, cause significant damage to safecy-related systems.
In view of :ne light combustible loading and the separation provided, with prompt detection, manual succression would be adequate to control and suppress fires which may occur.
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j The automatic Halon system for the below floor space uses heat sensors to actuate the system which act more slowly than smoke detectors and hence, may allow damage to redundant safe shutdown systems prior to actuation.
5.11.5 Modifications and Recommendations The licensee has proposed to install smoke detectors in each safety-related cabinet and console containing safe shutdown equiement and to provide a portable water or Halon 1211 class A extinguisher.
The licensee has also proposed to modify the Halon systems for tha belcw floor and above ceiling spaces to provide a faster response by using smoke detectors for actuation.
In addition, to prevent damage to re-dundant systems prior to actuation of the Halon system, the licensee has proposed to coat the exposed nonsafety-related cable in open trays in the below/ floor space with a flame retardant coating.
Subject to implementation of these mocifications, we find fire protaction for the control room conforms to the provisions of Appendix A to 37.8 9.5-1 and is, therefore, ac:eptable.
.5.12 Reactor Buildinc 5.12.1 Safety-Reiatac scutement Safety-relatad equip =ent in containment incluces:
reactor vessei primary coolant piping, core flood tanks, pressurizer, instrumentation, containment air coolers, valves, and associated cabling.
5.12.2 Combustibles Significant combustibles in conta.inment, include a large quantity of elec-trical cacie insulation and the lubricating oil associated with each of the four reactor coolant puma motors. The cable insulation is most hignly concan-trated at the penetration areas in containment; however, the caoles are divisionally separated into different vicely secaratac penetration areas.
5.12.3 Consecuences if No Fire Suceression An unmitigated fire involving oil from a reactor coolant cump would. ost likely result in damage to only one pump due to the oil containst syste #ce oil leaks which limits the armunt of oil available to burn to a small amount and because the pumps are widely separated in separate cubicles, thus, there is sufficient physical separation. The separation of cables is such that a fire in the vicinity of one pump would not cause loss of safe shutdown capability. However, the adequacy of the oil collection system has not been demonstrated by tne licensee.
An unsucpressed ' ire in electrical cables at the penetration areas inside on-tainment would cause sicnificant danage to safety-relatec caoles, but wouic only involve cables froh one safety division and would not affect safe snu:-
cown of the olant.
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5.12.4 Fire Protection Systems i
Manually controlled closed-head f. ire suppression systems are provided at the electrical penetration areas in containment.
These systems have fasible element heads, and control valves actuated by control switches in the control roca or from a pull box near the control valve.
In addition, fonization detectors are provided to give early warning of fire conditions.
Portabla extinguishers are provided at various elevations in containment; however, no manual hose stations are provided.
Lubrir.ating oil catch basins for the reactor coolant pumps are provided which would' drain oil leakage to a container, and thus mitigate the effects of a reactor coolant pump actor fire; however, the adecuacy of these basins to collect oil from all potential leakage points has not been demonstrated by the licensee.
Adecuacy of Fire Protection 5.12.5 The sprinkler systems at the cable penetration areas would be adecuate to control fires in these areas and reduce the loss of safety-related ecuip-ment.
The reactor oil catch basins which drain to diked tanks at the bottom floor of the reactor building may not serve for all possible leaks.
portable extinguishers would not be adecuate to suppress cable insulation fires or in resi. dual oil on the reactor coolant ouro.
5.12.6 Modifications ana Recommendations The licensee has proposed to (1) evaluate the reactor coolant pump oil containment system and to upgrace the containment system where necessary to assure that oil leaks are contained in accordance with guidelines given by tne staff and comitted to by the licensee, and (2) provide hose ststions within containment to fight fires.
We find that, subject to imolementation of these modi #fcations, One fire protection for the reactor building conforms to the :rovisions of Appendix A to 5TP 9.5-1 and is, therefore, acceptable.
5.13 Intake Structure - Service 'datar Pumos 5.13.1 5afety-seia:ao dout: ment The intake structure contains three service water ;cmos and One electrical cabling asscciatad witn taese :umas.
At least one of :nese pcmos would ce required for safe snutdown. The two fire pumps are also located in this area, in separate three-hour fire-rated enclosures.
5.13.2 Comoustibles The signi#icant concustibles in :nis area incluce a s all accan: of luericating oil associated with the service water cumas, a small amount of electrical caole insulation, and ne luce oil anc cay tank fuel succly for tne diesel fire pumo.
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5.13.3 Consecuences if No Fire Sucaression An unsuppressed service water pump lubricating oil fire would not affect more than one service water pump due to the small quantity of oil, the physical separation and barriers between pumps, and the open vents to atmosphere to relieve any heat buildup. An unsuppresud fire in either fire pumo soon would only affect that pump due to the fire rated enclosure.
5.13.4 Fire Protection Systems There is no fire detection or autcmatic fire sucpression in this area.
Yard hydrants and hose houses are located within reach of this area.
5.13.5 Adecuacy of Fire Protection Fire protection for this area is inadecuate in.that no means to detect fire in this area which contains safety-related equipment has been provided.
l With prempt detectice, manual hoses and extinguisners would be adequate to extinguish fires in the area.
I 5.13.6
.M:difications and Recemmendations l
The licensee has proposed to install smoke detectors in the intake struc-ture to alarm in the control room in event of a fire.
Subject to imolementation of' this modification, we find fire protection
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for the intake structure satisfies the cbjectives detailed in Section 2.2 of this report and is, therefore, acceptacle.
j 5.11 Yard Area 5.14.1 5afety-Related ecufement The safety-related equi: ment in the yard area incluces undergrcund pcwer cables to the ser,vice water pumas at tne intake structure, the two under-ground diesel fuel storage tanks, and tne refueling water tank.
5.14.2 Cemeustibles
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The significant c:moustibies which were considered because of Oneir poten-tial for exposure to safety-rela:ed systems inclucec Oil-fillec transf:r :ers, underground diesel storage tanks, and an oil-firec auxiliary boiler ar.c fuel tank.
In accition, :te catential exis s fer :ne introdue:fon of significant ccmcustibles to the yard area, such as fuel oil trucks.
No significant c=custibles are located in the area of the refueling water storage tank.
5.14.3 Consecuences if No Fire Sucaression An unsuppressed fire in the transformers auxiliary boiler, or storage tanks in tne yard area would not present a significant fire ex:osure to safety-related systems because of intervening distance or barriers. Mcwever, the manholes contain redundant electrical caoles wnicn extend to :ne service water pumos at the intake structure. These cables are located in ::en trays wi:hin the mannoles 5-14
e separated vertically by about twelve inches with no barriers. An electrical fault in one cable may cause loss of the redundant cable.
5.14.4 Fire Protection Systems Yard hydrants and hose lines stored ir. hose houses are available for manual suppression as discussed in Section 4.3 of this report. Automatic water sprays are provided on the main and auxiliary station transformers.
5.14.5 Adequacy of Fire Protection We find that the fire protection provided in the yard area is adequate to suppress fires that may occur ;.id protect safety-related equipment.
The exception to this is the manholes where manual suppression would not be -
adequate to prevent involvement of redundant service water pump power cables in an electrical fault.
5.14.6 Modifications and Recommendations The licensee has proposed to install an adequate barrier between cable trays to assure that faults in service water pump cables in the manholes are prevented from affecting the redundant service water pump cables.
We find that, subject to implementation of this modification, fire protection for the yard area satisfies the objectives detailed in Section 2.2 of this report and is, therefore, acceptable.
5.15 Fuel Oil Storage Vault 5.15.1 Safety-Relatea Ecuicment The fuel oil storage vault is located outside, remote from other buildings.
The vault contains the four main storage tanks for the emergency diesel generators.
Each of the fuel tanks is located within a separate concrete enclosure in the vault building.
These tanks supply the diesels for both Units 1 and'2.
5.15.2 Combustibles Each of the fuel oil storage tanks contains 22,500 gallons of fuel oil.
5.15.3 Consequences if No Fire Sucoression An unmitigated fire in the hallway would not involve any of the fuel tanks due to the three-hour rated fire barriers between the hall and the tank rooms.
In addition, a fire in any of the tank rooms would not involve other tanks in as much as three-hour rated fire barriers exist between each tank.
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'5.15.4 Fire Protection Systems
'The fire suppression system provided for each of the diesel fuel tank rooms is manually actuated dry pipe sprinkler systems.
Smoke detectors which alarm in the control room are the means of detection for each fuel tank room.
Each of the fuel tanks is located in a pit to prevent oil spills from leaking into other areas and are separated from each other by three-hour fire rated walTs. Outside fire hydrants are within easy acciss of the building.
5.15.5 Adequacy of Fire Protection Systems The fire protection systems in the fuel oil storage vault are adequate to limit involvement to one fuel tank and to extinguish fires in the tank rooms.
5.15.6 Modifications and Recommendations No modifications are proposed or recommended for this area.
We ff.;d that the fire protection for the fuel oil storage facility conforms to the provisions of BTP 9.5-1, Appendix A, and is acceptable.
5.16 Electrical Ecuioment Room - Elevation 368 Feet 5.16.1 Safety-Relateo Ecuicment Tnis area contains primarily electrical cables and equipment (480 volt switchgear) related to one division of safety equipment.
A few of the redundant division cables are located within the area.
5.16.2 Combustibles The significant combustible in this area is a moderate amount of electrical cable insulation.
5.16.3 Consecuences if No Fire Sucoression An unmitigated fire in this area could affect cables from a large number of safety related systems of one division and a few cables of the redundant division.
However, safe shutdown of the plant would not be affected due to the availability of redundant systems which are not affected by a fire in this area.
5.16.4 Fire Protection Systems The primary protection for this area is afforded by portable extinguishers and by hose stations.
No detection is provided.
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O 5.16.5 Ad,equacy of Fire protection The supprsssion capability for this area is adequate to extinguish fires. However, the lack of fire detection capability would allow a fire to continue in this safety-related area and to involve safety systems unnecessarily.
5.16.6 Modifications and Recommendations The licensee has proposed to install fonization type smoke detectors to detect fires in their incipient stages to allow for promot fire brigade response and thereby reduce potential damage.
We find that, subject to implementation of this modification, fire protec-tion for this electrical equipment room satisfies the objectives of Section 2.2 of this report and is, therefore, acceptable.
5.17 Turbine Buf1dino 5.17.1 Safety-Relateo Ecuioment The licensee's fire hazards analysis shows that no safety-related equipment is located in the turbine building.
5.17.2 Combustibles The significant combustibles in the turbine building include cable
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insulation, oil associated with turbine lubrication, hydrogen seal ull, feedwater pumps, and other equipment, and hydrogen. The turbine lubricating oil piping is guarded pipe. The lubricating oil reservoir, conditioner, and clean and dirty lubricating oil storage tanks are
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located in three-hour fire-rated enclosures.
5.17.3 Consequences if No Fire Sucoression The fire barriers separating safety-related areas from the turbine building assure that unmitigated t_urbine building fires _have no acverse consequences on safety-related equipment located in adjacent areas.
The licensee's fire hazaros analysis shows that safe shutdown equipment is not located in the turbine building and therefore fires in this area would not cause loss of capability to perform safe shutdown.
5.17.4 Fire Protection Systems Automatic sprinkler systems designed in accordance with NFPA No. 13 requirements are provided for a cortion of the turbine buildir.g below the operating floor and for the lubricatino oil storace tanks.
Automatic deluge systems actuated by heat detectors, are provided for the feedwater pump lubricating oil reservoir, turbine lubricating oil reservoir and the hydrogen seal oil unit.
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The turbine bearing and the exciter housing are protected by automatic CO2
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' systems.
In addition, manual hose stations and portable extinguishers are provided throughout the turbire building.
5.17.5 Adecuacy of Fire Protection Since the major sources of combustibles are protected with automatic suppression systems and because fires in the turbine building would not prevent safe shutdown of the plant, we conclude that the fire protection for the turbine building is adequate.
5.17.6 Modifications and Recommendations e
We find that the fire protection for the turbine building conforms to the provisions of Appendix A to BTP 9.5-1 and is, therefore, acceptable.
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,,o 6.0 ADMINISTRATIVE CONTROLS The administrative centrols
"'r fire protection consist of the fire protection organization, the qualifications and training for fire protec-tion personnel, the controls to be exercised over combustibles and ignition sources, plans and procedures for fighting fires in the various plant areas, and the quality assurance provisions for fire protection.
The licensee has provided a detailed description of proposed administra-tive controis.
Plans and procedures stipulating the management and staff organization and its qualifications; the fire brigade training program; controls over combustibles and ignition sources; and the pre-fire plans for fighting fires are being developed and implemented.
The.
program and its implementing procedures as provided by letter from the licensee dated April 26, 1978, as supplemented by letters dated June 13, June 15, June 29 and July 7,1978 are found acceptable by the staff using items referenced in Sections 1.0(e) and 1.0(f).
We have evaluated the areas at ANO-1 to determine the minimum required fire brigade size to cope with fires that may occur, and have cetermined' that a five man brigade is required. The licensee has proposed a five man fire brigade to be available on site during all shifts, and in-dependent of demands placed on operating personnel and the security force in a fire situation. This requirement is being incorporated into the Technical Specifications with implementation 90 days after issuance of this report.
All five of the brigade members receive the same instruction and practice, including familiarization with the contents of the prefire plans with the exception that two members will not receive fire fighting strategy training because they are under the direction of a trained brigade leader. These two members do receive an acceptable level of training to perform their assigned tasks. Strategy training is only re-quired for brigade leaders and includes decision factors, direction of brigade, problem sessions and coordination of various pieces of equipment.
We find that, subject 1.0 implementation of the above described programmatic changes, the fire protection program satisfies the objectives identified in Section 2. 2 of this report and is, therefore, acceptable.
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7,0 TECHNICALSPECIFICATI0AS The Technical Specifications have previcusly been modified to incorporate interim Technical Specifications which include limiting conditions for operation and surveillance requirements for existing fire protection systems and administrative controls. A proposed Technical Specification change is to require that at least five individuals with fire protection training be on site at all times. This would be an increase in the size Fire Brigade. We find the change acceptable.
Following the implementation of the modifications of fire protection systems resulting from this review, the Technical Specifications will be similarly modified to incorporate the limiting conditions for operation and sur-veillance requirements for these modifications.
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8.0 CONCLUSION
S The licensee has performed a fire hazards analysis and has proposed certain mcdifications to improve tne fire protection pregram.
Additional modifications have been preposed by the licensee during the course of our review of the fire hazards analysis and our ensite evaluation of tne fire protection program.
These preposed modifications are summari:ed in Section 3.
In summary, significant steps are being taken to assure that safe shutdown can be accomplished and the plant maintained in a safe condition during and following potential fire situations. Upon imolementation of the licensee's precosed modifications summari:ed in Section 3, we find that the provisions of Section 2.0 are satisfied and that:
(1) Ccmoustibles in safety-related areas are limited to the extent practicable; (2) Fire detection and suppression systems will minimize, consistent with other safety requirements,the effects of fire on safety-related systems and will not in themselves significantly impair the capability of safety-related systems.
(3) Redundant safe shutdown systems are separated from each other and, where practicable, fr0m significant combustibles by barriers or distances, or are adecuataly protected by fire sucpression systems, such that a fire in any fire area will not prevent safe shutdown of the plant; (4) A fire in any fire :ene will not damage safety-related structures such that tney cannot perform their safety function;
(.5) The fire protection organi:ation has the professional qualifications to implement the fire protection prcgram, and acministrative ::n r:1s are adequate to maintain centrei of c:moustibles, ignition scurces, and the fire protaction organi:ation; and j
(6) A fire in any fire :ene will not cause the release of amounts of radioactive material in axcess of these considered in previous
, safety evaluations.
We find that the licensee's proposed mcdifications described herein are acceptable both sith rescect to the im rovements in the fire protection program tnat tney previce and wi.h res ec to : ntinued safe coeration of the facility.
-In the recort of :ne Special Review Grou: On the Browns Ferry Fire (NUREG-0050) dated Feoruary IN5, consiceration of the safety of Ocera-tien of all cperating nuclear :cwer :lants :encing -he ::: !sti:n :f Our detailec fire pro acti:n eval;.ation 4as presented.
The fclicwing
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quotations from the report summarize the basis for our conclusion that the continued operation of the facility, pending implementation of all facility' modifications, does not present an undue risk to the health and safpty of the public.
"A probabklity assessment of public safety nr risk in quantitative terms is given in the Reactor Safety Study (WASH-1400). As the result of the calculation based on the Browns Ferry fire, the study concludes that the potential for a significant release of radioactivity.from such a fire is about 20% of that calculated frca all other causes analyzed.
This indicates that predicted potential accident risks from all causes were not greatly affected by consideration of the Browns Ferry fire.
This is one of the reasons that urgent action in regard to reducing risks due to potential fires is not required.
The study (WASH-1400) also points out that 'rather straight-forward measures, such as may already exist at other nuclear plants, can significantly reduce the likelihood of a potential core melt accident that might result from a large fire.'
" Fires occur rather frequently; however, fires involving equipment unavailability comparable to the Browns Ferry fire are quite infrequent (see Section 3.3 of [NUREG-0050]).
The Review Group believes that steps already taken since March 1975 (see Section 3.3.2) have reduced this frequency significantly.
" Based on its review of the events transpiring before, during and after the Browns Ferry fire, the Review Group concludes that the probability of disruptive fires of the magnitude of the Browns Ferry event is small, and that there is no need to restrict operation of nuclear power plants for public safety.
However, it is clear that much can and should be done to reduce even further the likeli-hood of disabling fires and to improve a~ssurance of rapid
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extinguishment of fires that occur.
Consideration should be given also to features that would increase further the ability of nuclear facilities to withstand large fires without loss of important functions should such fires occur."
We have determined that the license amendment does not authorize a change in effluent types or total amounts nor an increase in power level and will not result in any significant environmental impact.
Having made this determination, we have further concluded that the amencment involves an action which is insignificant from the stancpoint of environ-mental impact and pursuant to 10 CFR 51.5(d)(4) that an environmental impact statement, or negative declaration and environmental impact appraisal need not be prepared in connection with the issuance of this amendment.
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-s We have concluded, based on the considerations discussed above, that:
(1) because the amendment does not involve a significant increase in the
' probability or consequences of accidents previously considered and does
- not involve a significant decrease in a safety margin, the amendment does not involve a significant hazards consideration, (2) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and (3) such activities will be conducted in compliance with the Commission's regulations and the issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public.
Dated: August 22, 1978 e
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e 9.0 CONSULTANTS' REFORT Under contract to Nuclear Regulatory Commission, Brookhaven National Laboratory has provided the services of fire protection consultants who participated in the evaluation of the licensee's fire protection program and in the preparation of the Safety Evaluation Report (SER).
Their report, " Fire Protection in Operating Nuclear Power Stations - Arkansas-Unit 1," dated July.1978, discus-ses several matters which have been addressed in the SER.
The consultants' report contains recommendations which have, for the most part, been imple-mented during our evaluation.
The consultants' recommendations which we have not adopted, along with our basis therefor, are identified herein.
1.
Consultants' Comment: Minimize Fire Effects "SER Item 8.0(2) concludes that fire detection and suppression will mir.imize the effects of fire on safety-related systems.
The consultant does not concur in this conclusion.
There are usually several protective approaches that can be utilized for a given fire hazard, with each approach offering certain advantages and disadvantages in terms of limiting tne fire extent, damage due to the f.fre suppression agents employed, reliability, and cost effectiveness.
In most cases, it is technically possible to reduce the damage potential to a very low level, but cost penalties often become severe.
The fire protection systems that are being provided and reccmmended are to assure safe shutdown capability and will not necessarily minimize fire damage to all safety-related systems."
Staff Resoonse We agree with the consultants' comments that additional steps could always be taken to further reduce physical damage to structures, systems and components important to safety. However, we are using in our conclusion the term " minimize" in the context of its use in Appendix A to BTP 9.5-1 and GDC-3 where it means a general level of detection and suppression capability to provide reasonably prompt detection and suppression. This level of protection is afforded to all safety s'ystems, not only where required to prevent loss of safe shutdown capability.
2.
Consultants' Commen't': Valve Supervision "SER Item 4.3.1.3 indicates that the position of fire protection system valves will be controlled by locks or seals with periodic inspections.
Locking or sealing programs depend upon ongoing acministrative controls that are subject to human failure.
Locks can also prevent prcmpt water shutoff if piping ruptures.
It is recommended that electrical suoer-vision be required on all control valves for fire protection systems protecting areas containing or exposing safety related equipment."
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. Staff Resconse The guidelines of Appendix A to BTP 9.5-1 allow electrical supervision, locking, or sealing with tamper prcof scals with periodic inspection as means of assuring that valves in fire protaction water system are in the correct position. Valves on other systems in the plant are presently under similar administrative control. The plant Technical Specifications require a monthly check of all valves in the flow path to fire suppres-sion systems. A review by the staff of Licensee Event Reports for all plants using such periodic checks indicates that valves being in the in-correct position have not been a significant contributor to valvc related failures. Additionally, s'anding water as a result of failure of sup-
- pression system piping will not damage safety-related equipment due to curbs, drains, mounting of equipment above floor levci, grating and doorways. To date, the staff has not found any data that indicates that electrical valve supervision will significantly improve the avail-ability of fire suppression systems in nuclear power plants.
3.
Consultants' Ccmment:
Seismic Oamace "The SER does not consider the effect of seismic damage on primary and back-up fire protection systems, although Sranch Technical Position 9.5-1 addresses this item for new plants.
It is reccmmended that the potential that a seismic event could cause both a fire and damage to the protactive features provided to coce with the fire te further evaluatec.
This should incluce fires startad in ncn-seismically qualified systems or areas that spread to safety-related systems because protective systems are damaged."
Staff Resconse Altnough BTP 9.5-1 calls for certain fire protection piping to be seismically qualified for new plants, the guidelines of Appendix A to STp 9.5-1 do not require seismic qualification for fire protection systems at operating plants. The basis for the Appendix A position is the acceptably low likelihood of an earthquake caused fire of safety significance. This low likelinood is a result of the lack of self-ignitable combustibles in the safety-related areas of the plant, the barriers between fire zones, the cefense-in ' depth approach to fire protection (control of combustibles, fire suppression, detectors, trained en-site fire brigades) and the seismic qualificaticn cf safety-related structures.
4.
Censultants' Ccement:
imoke Removal "SER Item A.2.1 indicatas that portable fans and cuc s will te accected as the means for removing smoke f cm many planc areas.
Pires in elec3rical insulation can generata cecicus amounts of dense smo<e wnica hamcer fire control efforts by rencering d a a mosenere toxic and reducing visicility in the area.
Procerly used, self-containec brea ning accara as can minimi:e the pecblem of toxic atmoschere, but li-la can be ccne to improve visibility excec to remcve -he smoke frca the building.
Massive changes will ce recuirec in nos areas of tnis plant if ef fective permanent smoke removal systems are recuired, ne cesign of.nich,40uid also have to incluce censicera.icn of radioac.ivity releases. Wh11e por: Acte fans and cucts may ce effec.ive for smo<e ccstrol in many 9-2
instances, there is concern that they will not be sufficient for a major
' fire in some areas of tne plant.
It is recommended that this itam be held open until better guidelines are ceveloced for the evaluation of smoke generation potential and smoke removal systam design."
Staff Resoonse:
Additional information and imoroved equipment would provide some benefit in the design and construction of fixed ventilation systems to be used for smoke removal in future plants.
However, a massive plant redesign of current plant ventilation systems is not warranted because portable smoke removal ecuipment can be used in those plant areas with inadequate fixed smoke removaT systems. Portable smoke removal units have been used in fire service for a sufficient length of tire so that the limits on their use is well understood.
In plants where smoke removal Is dependent on such equipment, smoke removal is not generally initiated until the room atmosphere is coated sufficiently, cy fixed sprinkler operation or manual hose fogging tu permit entry by fire fighting personnel.
Ventilation prior to this time serves no purpose but to add oxygen to active fire sites.
The current fire service portaole smoke removal unita have a sufficiently high temperature casability to remove smoke when the hot gases are cooled enough for fire brigade entry.
The manual fire fignting consultants have_m_ade their evaluations of the fire fighting capabilities of a number of plants and have r'ecomended use of the portable smoke exaaust systems. We require the licensees to develop prefire plans which include the proper use of ventilation equipment in each plant area of concern.
This is addressed in our Adminis.trative Controls review.
Consequently, there is adequate information available at this time to continue to evaluate plant smoke removal casaoility.
The use of fire suppression equipment, fire barriers and other fire protaction measures are evaluated based on tne need for immediata ac:ess into an area and the limitations imocsad by the currently available portacle smoke removal units.
These concerns are evaluated on an area basis at esca plant sita due consideration of the advice of the manual fire fignting consultants.
5.
Consultants' Coment: L'nsuooressed Turbine Buildino Fires "SER Item 5.17 concluces that fire orotaction in the turbine building is acceptable.
However, the licensee's fire hazard analysis coes not adequately accress the consequences of an unsuooressed luce oil fire in the turbine builoing (see Octooer 24, 1977 let ar from L. ?. Herman to R. E. Hall on this suoject)."
Staff Ressonse In the above mentioned lettar, Mr. Herman states his belie? -hat manual fire fighting.oulo not provice an effective cac<uo to automatic scopres-sion systems in the turo4ne ouilding, anc trat automatic suopression systems are not hignly reliaole. He suggests tnat ali plants snoulc be 9-3
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designed to sustain an unsuppressed turbine building fire that could result in collapse of 'he turbine building.
The staff does not deem such a design basis event assumption ta be consistent with criteria used in evaluating other plant areas.
In other areas such as in the cable spreading room, our conclusions are based on the effects of fire with automatic and manual suppression systems. We, therefore, have allowed the licensee to evaluate the effects of fires in the turbine building assuming the automatic suppres-sion systems protecting major oil hazards functions as designed.
We have determined that the oil hazards in the turbine building are pro-tected as follows: automatic sprinklers are provided for a portion of the turbine building below the operating floor and for the lubricating oil storage tan ks. Automatic deluge water systems are provided for the feedwater pumps, lubricating oit ?cservoir, turbine lubricating oil reservoir, and the hydrogen sea l
'd nait.
!a addition, manual hose stations and portable extinguishers s provided throughout the turbine building to supplenent these automatic suppression systems.
We have found that these systems provide adequate protection to assure the integrity of the turbine building. The staff believes that the reliability of such systems is at least equivalent to suppression systems in other areas of the plant and does not warrant design of tne turbine building to sustain an unsuopressed fire.
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