ML20084L430
| ML20084L430 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 04/18/1984 |
| From: | Eisenhut D Office of Nuclear Reactor Regulation |
| To: | GEORGIA POWER CO. |
| Shared Package | |
| ML20084L432 | List: |
| References | |
| TAC-43754, TAC-43755, TAC-47143, TAC-48071, TAC-48072, TAC-48748, TAC-48749, TAC-54802, TAC-54803, TAC-61626, TAC-61627, NUDOCS 8405140459 | |
| Download: ML20084L430 (25) | |
Text
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7590-01 UNITED STATES OF AMERICA NUCLEAR REGULATURY COMMIS5 ION In the Matter of GEORGIA POWER COMPANY, ET AL Dockets Nos. 50-321 and 50-366 (Edwin I. Hatch Nuclear Plant,
)
Units Nos. I and 2)
)
EXEMPTION I.
The Georgia Power Company (GPC or the licensee) and three other co-owners are the holders of Facility Operating Licenses Nos. OPR-57 and NPF-5 which authorize operation of the Edwin I. Hatch Nuclear Plant, Units 1 and 2 (Hatch or the facilities) at steady state reactor power levels not in excess of 2436 megawatts thermal for each unit. The* facilities are boiling water reactors located at the licensee's site in Appling County, Georgia.
The licenses are sub,iect to all rules and regulations of the Nuclear Regulatory Comission (the Comission).
II.
On November 19, 1980, the Commission published a revised Section 10 CFP 50.48 and a new Appendix R to 10 CFR 50 regarding fire protection features of nuclear power plants (45 FR 76602). The revised Section 50.48 and Appendix R became effective on February 17, 1981.
Section III of Appendix R contains fifteen subsections, lettered A through 0, each of which specifies requirements for a particular aspect of the fire protection features at a nuclear power plant. One of these fifteen subsections, !!I.G. is the subject of this 3
Exemption.
Specifically, Subsection !!I.G.2 recuires that one train of cables and equipment necessary to achieve and raintain safe shutdown be maintained free of fire damage by one of the following means:
5140459 840418 DRADOCKOSOOOg F
2-7590-01 Separation of. cables and equipment and associated non-safety circuits a.
of redundant trains by a fire barrier having a 3-hour rating.
Struc-tural steel forming a part of or supporting such fire barriers shall be protected to provide fire resistance equivalent to that required of the barrier, b.
Separation of cables and equipment and associated non-safety circuits or redundant trains by a horizontal distance of more than 20 feet with no intervening combustibles or fire hazards.
In addition, fire detectors and an automatic fire suppression system shall be installed in the fire area; or Enclosure of cable and equipment and associated non-safety circuits c.
of one redundant train in a 'f,1re barrier having a 1-hour rating.
In addition, fire detectors and an automatic fire suppression system shall be installed in the fire area.
l III.
By letters dated July 1,1982, as supplemented by letters dated April 28, May 27, November 16 and 30 and December 20, 1983, the licensee requested an exemption from the requirements of Subsection III.G.2 of Appendix R in 26 areas of the Hatch Nuclear Plant, Units 1 and 2.
The acceptability of the exemption request for each of these 26 areas is addressed below. More details are contained in the Commission's related Safety Evaluation dated April AB,1984 IV..
AREAS: 4160V Transformer Rocm - Unit 1 West 600V Switchcear Room ~' Unit 1
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. 7590-01 1
TFe licensee reouested exerptions from Section III.G.2 in these two areas to the extent that it reouires the installation of automatic fire suppression systems and requires that redundant shutdown divisions be separated by complete 3-hour fire rated barriers.
Both roons are bounded by walls, floor and ceiling of reinforced concrete and masonry block. The walls have a minimum fire resistance rating of 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />. All openings in the walls are protected by 3-hour fire rated doors, dampers or penetration seals.
Ccmbustible materials located in the 4160V Transformer Roon include cable insulation in conduit and fire retardant-type transformer oil, which represent a negligible fire load. Combustible material located in the West 600V Switchgear Room includes cable insulation, which represents a fire load of 25,000 BTU /sq. ft., and if totally consumed, would equal a fire severity of approximately 20 minutes on the ASTM E-119 time-temperature curve. Existing fire protection in both rooms cons *sts of smoke detection systems, portable fire extinguishers and ranual hose stations.
The licensee has committed to ccmpletely protect the redundant shutdcwn divisien in each room by a 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> fire rated barrier.
The smoke detection systems provide reasonable assurance of early fire awareness and response by operating personnel and the plant fire brigade.
The combustible material in these rooms is limited and widely dispersed.
Consequently, we do not expect a fire to propagate rapidly and with a hign heat release rate. The 2-hour rated perimeter walls and reinforced concrete ceiling will confine the fire to the room of origin unti.1 the arrival of the fire brigade. The fire brigade has sufficent manual fire fighting equipment available to extinguish the fire. Therefore, an automatic fire suppression system is not necessary to limit damage. The 1-hour fire barrier will protect one shutdown related pathway within these rooms until the fire brigade arrives.
. 7590-01 Based on our evaluation, we conclude that the existing protection, with the modifications the licensee has committed to make, will provide a level of fire protection equivalent to that provided by Section III.G.2. Therefore, the licensee's request for exemption for these two areas is granted.
AREAS: Control Building Working Floor, EIl.112 Feet - Unit 1 West DC Switchgear Room - Unit 1 East DC Switchgear Room - Unit 1 East 600V Switchgear Room - Unit 1 4160V Transformer Room - Unit 2 West DC Switchgear Room - Unit 2 East DC Switchgear Room - Uait 2 West 600V Switchoear Room - Unit 2 East 600V Switchgear Room - Unit 2 The licensee requested exemptions from Section III.G.2 in these nine areas to the extent that it reouires that redundant shutdown divisions be separated by complete 3-hour fire rated barriers.
These rooms are all bounded by walls, floors and ceilings of reinforced concrete and masonry block. Some of the walls are not 3-hour fire rated; l
however, all walls have a minimum fire resistance rating of 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />.
Openings in the walls are protected by 3-hour rated doors, dampers or penetration seals.
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1 7590-01 Cables and components of only one safe shutdown pathway are vulnerable to fire damage in these rooms.
Systems associated with the other required pathway are either located outside the room, in a separate fire area, or will be completely protected in a 3-hour fire rated enclosure (Control Building Working Floor - El.112 feet). The fire Ioads in these areas range from 21,000 to 48,000 BTU /sq. ft.
Existing fire protection in each of these rooms consists of fire detection systems, portable fire extinguishers and manual hose stations. The Control Building Working Floor area also has partial coverage by an automatic fire suppression system.
The fire loading in these locations is low. Combustible materials are generally dispersed throughout the area. Therefore, a fire, if one should occur, will not be of significant magliitude or duration. Because each room is equipped with fire detectors, we expect the fire to be discovered in its initial stages before serious damage occurs. The fire brigade will then be summoned and will extinguish the fire with portable fire fighting equipment.
Because the minimum fire rating of the perimeter walls and floor / ceiling is at least 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />, we have reasonalle assurance that the damacing effects of a fire will be confined within the room of origin until suppression is achieved. The systems associated with the required redundant shutdown pathway are located outside the fire area and will not be affected by the fire.
O a 7590-01 Based on our evaluation, we conclude that the existing protection will provide a level of fire protection equivalent to that provided by Section III.G.2, and therefore, the licensee's request for exemption for these areas is granted.
AREAS:
Reactor Building North of Column Line R7 - Unit 1 Reactor Building South of Column Line R7 - Unit 1 Reactor Building North of Column Line R19 - Unit 2 Reactor Building South of Column Line R19 - Unit 2 The licensee requested exemptiodt from Section III.G.2 in these areas.to the extent that redundant shutdown systems are required to be protected by either 1) a 3-hour fire rated barrier, or 2) a 1-hour fire rated barrier and area-wide automatic fire detection and suppression systems.
Both the Unit 1 and Unit 2 reactor buildings are divided into two fire areas. The dividing line for Unit 1 is approximately along column line R7 and for Unit 2 is approximately along column line R19. The two areas for each Unit are separated from each other by a combination of existing concrete walls, the drywell and an automatic sprinkler system and draft curtain which the licensee has committed to install along the common boundary between these two areas where no physical barrier exists.
. 7590-01 Cerbustible material within both areas of each unit consists of cable insulatien, lube oil, health physics supplies and charcoal filters.
Existing fire protection in both areas of each unit includes:
an automatic sprinkler systen and fire detectors for the Heating, Ventilation and Air Conditioning (HVAC) room on elevation 164 feet, a smoke detection system at the ceiling of working floor elevation 130 feet, portable fire extinguishers and ranual hose stations.
For Unit 1 only, it also includes a sprinkler system below 130 feet elevation in the High Pressure Coolant Iniection (HPCI) room for the north half and in the southwest corner room for the south half.
For Unit 2 only, it also includes automatic sprinkler systems located in the northwest corner room below elevation 130 feet for the north half and a sprinkler system in the HPCI room below elevati"on 130 feet for the south half.
The north half of the Unit I reactor building primarily contains components and cables for safe shutdown pathway 2, and the south half primarily contains components and cables for safe shutdown pathway 1.
The licensee has committed that those pathway I systems that are located in the north half and those pathway 2 systems that are located in the south half of the reactor building will be protected by a 1-hour fire rated barrier or will be relocated outside these respective fire areas.
The north half of the Unit 2 reactor building primarily contains components and cables of safe shutdown pathway 1, and the scuth half primarily contains components and cables for safe shutdown of pathway 2.
The licensee has cormitted that those pathway 2 systems that are located in the north half and those pathway I systens that are located in the south half of the reactor building will either be protected by a complete 1-hour fire rated barrier or will be relocated outside these respective fire areas.
. 7590-01 These 1-hour fire rated barriers will extend throughout the respective i
area and extend to a point 20 feet inside the opposite half of the reactor building. Those required pathway 1 circuits that are not protected by a fire barrier will be relocated outside of this fire area. Also, within the area that will be protected by the automatic sprinkler system, all required safe shutdown related circuits will be enclosed in a 1-hour barrier.
For both Unit I and Unit 2, the area that will be covered by the automatic 4
sp.rinkler system will extend frcm the east-west centerline of the reactor building into each fire area to a distance of 20 feet beyond the last redundant opposite train component. Where only one train of ecuipment exists, the area of sprinkler coverage will be 20 feet wide. On elevation 185 feet, the area south of columns R7 on Unit 1 and R19'on Unit 2 will be sprinklered except for the decontamination room. Draft curtains at the ceilwsg at R7 en Unit I and R19 on Unit 2 will be installed to facilitate sprinkler cperation and restrict smcke spread from one area to another.
The licensee has also committed to install a fire detection system in the sprinklered areas on elevation 158 feet and in the torus rooms of both Hatch Units 1 and Unit 2.- Additional rodifications committed to by the licensee for Hatch Unit 2 only include installation of an autoratic halon fire suppression system above renote shutdown panels 2CE2 - P001B and 1A, upgrade and extension of the existing missile shield around.and behind these panels, and installation of a noncombustible partition between these panels from the back of the panel to the missile shield. The licensee also committed to install a fire detection system at these shutdown panels.
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. 7590-01 The existing fire detection systens and the comnitted additional fire detectors provide reasonable assurance that a fire will be detected in its initial stages before significant damage occurs. The fire will then be suppressed manually by the plant fire brigade before it represents a serious threat to shutdown systems. The fire suppression systems, fire barriers, the '
large open areas of the reactor building, and the existing spatial separation between redundant divisions provide assurance that one division will remain free of fire damage until the fire brigade arrives.
Based on our evaluation, we conclude that the existing fire protection, with the proposed modifications, will achieve a level of safety equivalent to that provided by Section III.G.2. Therefore, the licensee's request for exemption in the reactor building (Udits 1 and 2) is granted.
AREA: Control Buildine Health Physics Area - Unit 2 The licensee requested an exemption from Saction III.G.2 in this area to the extent that it requires a complete area-wide automatic fire suppression system.
The area is bounded by walls, floor and ceiling of reinforced concrete and masonry construction. All penetrations of these fire barriers are protected by 3-hour fire rated doors, dampers or penetration seals. Redundant systems are separated by approximately 40 feet in this area. The fire load consists of 5160 BTU /sq. ft. which corresponds to an ASTM E-119 fire severity of less than 5 minutes. Existing fire protection includes a smoke detection system, which provides area-wide coverage, manual hose stations and carbon dioxide hose reels.
The licensee has committed to provide automatic sprinkler protection over the shutdown related systems in the area.
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. 7590-01 Because the fire load is small, any postulated fire will tend to cause damage over a limited area. Because redundant shutdown divisions are separated by about 40 feet, we expect that damage will be sustained by only one pathway. The area is equipped with a complete smoke detection system.
Therefore, a fire will be discovered early and would be put out by the fire brigade before serious damage resulted.
If a fire should propagate rapidly and produce elevated temperatures, which would represent a threat to shutdown related systems in the area, the sprinkler system will activate to protect the vunerable systems until the arrival of the fire brigade.
Based on our evaluation, we conclude that the existing protection with the proposed modification will provide a level of fire protection equivalent to that provided by Section III.G.2. *Therefore, the licensee's request for exemption in the Control Building Health Physics Area - Unit 2 is granted.
ApEA: Control Building Switchgear Hallway - Unit 2 The licensee reouested an exemption from Section III.G.2 in this area to the extent that it requires that redundant shutdown divisions be separated by complete 3-hour rated fire barriers.
The area is bounded by walls, floor and ceiling of reinforced concrete and masonry block. With the exception of an opening into the control building south corridor, all penetrations of the fire ar'a boundaries are protected against the propagation of fire.
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- 11 7590-01 Cembustible material located in this area consists principally of cable insulation in four cable trays, which represent a fire load of approximately 45,000 BTV/sq. ft. This corresponds to an ASTM E-119 fire severity of approximately 1/2 hour. Existing fire protection includes an area-wide smoke detection system, manual hose stations and carbon dioxide hose reels.
Both the control building switchcear hallway and the control building south corridor are equipped with smoke detectors. We, therefore, expect that a fire would be discovered in its initial stages before significant heat build-up occurred. The existing spatial separation between shutdown systers provides assurance that only one shutdown pathway would be damaged before the fire brigade responds and suppresses the fire.
If the fire were to propagate throuch the unprotected perimeter wall opening before the arrival of the fire brigade, the automatic sprinkler system in the south corridor will activate and oischarge water in a pattern which would limit the propagation of hot gases.
Therefore, the absence of a complete fire barrier will not prevent the achievement and maintenance of safe shutdown conditions.
Based on our evaluation, we conclude that the existing protection, with the ccmmitted modifications, provides a level of fire protection eouivalent to that provided by Section III.G.2. Therefore, the licensee's recuest for exemption in the Centrol Building Switchgear Hallway-Unit 2 is granted.
AREA: Control Buildina Station Battery Rooms - Units 1 & 2 The licensee requested an exemption from Section III.G.2 to the extent that it requires the installation of a 3-hour rated fire barrier between redundant trains of safe shutdown related cable and eouipment.
. 7590-01 Each battery room is enclosed by walls, floor and ceiling of reinforced concrete or masonry block construction having a fire resistance rating of 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />.
HVAC duct penetrations of the walls are protected by fire danpers.
Access to these rooms is via a single watertight door that is not fire rated.
Safe shutdown equipment located in each room consists of one safety division of station batteries and redundant circuits for the drywell air systen. The licensee has ccmmitted to reroute these circuits as needed to conform to the separation criteria of Section III.G. The licensee states that replacing this door with one that is fire rated will degrade plant safety because the station batteries must be protected from a circulatory water flood, and a non-watertight fire rated door would not provide sufficient protection.
Combustible material located in these roons include cable insulation, battery casing and hydrogen gas which represent a fire lead of approximately 30,000 BTU /so ft.
Existing fire protection consists of a smoke detection systen, manual hose stations and portable fire extinguishers.
The fuel load in these areas is icw.
If totally consuned, the combustibles would produce a fire which corresponds to a fire severity on the ASTM E-119 time-temperature curve of less than 25 minutes.
It is our judgment that a fire in these areas, if one shculd occur, would not be of significant ragnitude or duration.
It would be discovered early by the smoke detection system and extinguished by the fire br4gade using manual fire fighting equipment. Because the door is watertight, it would prevent smoke from passing through it. Since it is constructed of 5/8-inch thick steel, the door would act as an effective radiant heat shielo.
The door in conjunction with the ventilation system would prevent convective heat from
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7590-01 increasing to a s!gnificant level so as to damage safety systems. Therefore.
a 3-hour fire rated door is not necessary to provide reasonable assurance that one safety divi,1on would remain free of fire damage, l
Based on our evalsation, we conclude that the existino fire protection will provide a level of safety equivalent to that provided by Section III.G.2.
Therefore* the licensee's request for exemption for the Control Building Station Battery Rooms - Units 1 & 2 is granted.
AREA: Turbine Building Condenser Bay - Unit 2 The licensee requested an exemption from Section III.G.2 to the extent that it requires the installation of a 3-hour rated fire barrier between redundant trains of safe shutdown related cable and equipment.
The area is bounded by walls, fThor and ceiling constructed of reinforced concrete. However, unsealed electrical penetrations in the west perimeter wall and unsealed mechanical penetrations in the ceiling ccmmunicate with adjoining plant locations, which the licensee has designated as separate fire areas. There are no pathway 2 systems located within this fire area. The combustible material in this location consists of turbine lube oil ard cable insulation which represent a fire load of about 360,000 BTU /sq. ft. or a fire severity of approximately 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> on the ASTM E-119 time-temperature curve.
Existing fire protection includes an automatic sprinkler system which protects the drain cooler area, a fire detection system, manual hose stations and portable fire extinguishers.
The principal fire hazard in the condenser bay, which is associated with a turbine oil spill, is mitigated by the presence of the automatic fire suppression system.
If a turbine oil or other fire should occur within this area, we expect the existing fire detection system to activate and summon the fire brigade During the time delay until the arrival i
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. 7590-01 of the fire brigade, the reinforced concrete perimeter walls and ceiling would, to a significant extent, confine the damaging effects of a fire to this area.
A small quantity of smoke and hot gases would be expected to propagate beyond the perireter of these fire areas because of the unprotected penetrations.
However, these penetrations are located away from the redundant shutdown systems. Therefore, hot gases passing through the penetrations would not affect components or cabling of the redundant division. The remaining products of combustion would be so diluted by ambient air conditions and the temperature of the air mass would be so diminished that they would not present a threat to the redundant division. Consequently, we have reasonable assurance that if a fire were to occur within this area, safe shutdown conditions could'be achieved and maintained.
Based on our evaluation, we conclude that the existing fire protection will achieve a level of safety equivalent to that provided by Section III.G.2.
Therefore, the licensee's request for exemption for the Unit 2 Turbine Building Condenser Bay is granted.
AREAS: Turbine Building East Cableway - Unit 2 East Cableway - Common Turbine Building West Cableway, El.112 feet The licensee requested an exemption from Section III.G.2 to the extent that it reouires the installation of a 3-hour rated fire barrier between redundant trains of safe shutdown related cable and equipment.
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. 7590-01 The East Cableway - Unit 2 area is bounded on two sides by 3-hour rated fire valls. The other two sides are open to an adjoining plant location. The floors and ceiling are of reinforced concrete construction.
The licensee has committed to protect the required pathway I systems that are located within this cableway by a 1-hour fire rated barrier. Combustible material within this area consists primarily of cable insulation and oil, which represent a fuel load of approximately 340,000 BTU /sa. ft. or a fire severity of about 4-1/2 hours.
Existing fire protection includes an area-wide automatic sprinkler system, an open-head deluge-type fire suppression system for the oil conditioner unit, an area-wide smoke detection system, portable fire extinguishers and manual hose stations.
The East Cableway - Common area 'is bounded on three sides by reinforced cencrete anc masonry block walls having a 3-hour fire rating. The fourth side is open to an adjoining plant location. The floor and ceiling are of reinforced concrete construction. The licensee has committed to protect the required systems associated with the redundant pathway with a 1-hour fire barrier.
In lieu of protecting the cables for the compressed nitrogen system valve (2T48-F026), the licensee has committed to lock the valve open to assure proper alignment for safe shutdown. Combustible material withir this area consists primarily of cable insulation which represents a fire load of approximately 220,000 BTU /sq. ft. or a fire severity of about 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> based on the ASTM E-119 time-temperature curve.
Existing fire protection includes an automatic sprinkler systen located throughout the area, an area-wide smoke i
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. 7590-01 detection system, a noncombustible radiant energy shield between redundant shutdown divisions, manual hose stations and portable fire extinguishers.
The West Cableway, El.112 ft. area is bounded by walls, floor and ceiling of reinforced concrete construction. There are no systems from the redundant shutdown capability located within the west cableway or adjoining areas.
Combustible material located in this area consists primarily of cable insulation.
Existing fire protection includes an area-wide automatic sprinkler system and heat detection system, manual hose stations and portable fire extinguishers.
If a fire were to occur within any of the above three areas, the existing fire detection system would activate during the early stages of a fire and surnon tne fire brigade.
If the room temperature rose significantly, the automatic sprinkler system would activate and suppress the fire while protecting the exposed shutdown systems. Until the fire burned itself out, or was extinguished manually by the fire brigade or automatically by the fire suppression system, the ccmmitted 1-hour fire barriers would provide reasonable assurance that one shutaown division would remain free of damage.
A small quantitiy of snoke and hot gases would be expected to propagate beycnd the perimeter of these fire areas because of the unprotected penetrations. However, these penetrations are located away from the redundant shutdown systems. Therefore, het gases passing through the penetrations would not affect components or cabling of the redundant division.
The remaining products of combustion would be so diluted by anbient a'r cerditions and the temperature of the air mass would be so diminished that they would not present a threat to the redundant division.
. 7590-01 If a fire were to occur outside of these areas, smoke and heat which would result from a fire would be dissipated throughout the area of fire origin. The existing smok'e and heat detection systems would activate or plant operators would discover the fire and summon the plant fire brigade.
The fire brigade would then extinguish the fire before shutdown systems within the areas became vulnerable.
If a sufficient temperature rise were to occur within these areas, the automatic sprinkler system would activate to protect the exposed systems. Therefore, complete 3-hour fire rated walls around the cableways would not significantly enhance the level of fire protection. We, therefore, have reasonable assurance that safe shutdown conditions could be achieved and maintained.
Based on our evaluation, we conclude that the existing fire protection, with the proposed modifications, wilt' achieve a level of safety equivalent to that provided by Section III.G.2. Therefore, the licensee's request for exemption for these three areas is granted.
AREA: Diesel Building Switchgear Room 2G - Unit 2 The licensee reouested an exemption from Section III.G.2 to the extent that it requires the installation of an area-wide automatic fire suppression system.
The room is enclosed by walls, floor and ceiling of reinforced concrete.
Combustible material located in this room includes cable insulation which represents a fire load of 53,460 BTV/sq. ft. or a fire severity of approximately 45 minutes. Existing fire protection consists of heat and smoke detection systems, portable fire extinguishers, a carbon dioxide hose reel and hose lines from outside hydrants. The licensee has committed to protect the reouired pathway 1 system in a 1-hour fire rated barrier.
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- 7590-01 Active protection in this area consists of the heat and smoke detectio'1 systems. We expect that they would activate in the early stages of a fire and summon the plant fire brigade which would extinguish the fire before serious damage occurs.
Passive protection is achieved by the I-hour fire rated barrier for the shutdown pathway 1 systems and the fire rated perimeter construction.
The combustible material in this room is limited and widely dispersed.
Consequently, we do not expect a fire would propagate widely or with a high heat release rate. The reinforced concrete walls, floor and ceiling will confine the fire to this rocm until the arrival of the fire brigade.
The brigade has sufficient manual fire fighting equipment available to extinguish the fire. Therefore, an automatic ffte suppression system is not necessary to limit damage. The 1-hour fire barrier, which completely protects the systems for one shutdown pathway until the fire brigade arrives, will provide reasonable assurance that safe shutdown can be achieved and maintained.
Based on our evaluation, we conclude that the existing fire protection, with the committed modifications, will provide a level of safety eouivalent to that provided by Section III.G.2. Therefore, the licensee's request for exemption for the Diesel Building Switchgear Room 2G - Unit 2 is granted.
AREA: Control Building Corridor - Common The licensee requested exemptions from Section III.G.2 in this arca to the extent that it requires:
- 1) a complete 3-hour fire rated barrier between redundant shutdown divisions; or 2) a 1-hour barrier between redundant divisions and area-wide automatic fire suppression and detection systems.
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. 7590-01 The area is bcunded by 2-and 3-hour fire rated walls with openings protected by fire doors fire dampers and penetration seals. However, the east portion of the south wall is open to the switchgear hallway, and the west wall is open to the fan room in the service building. The floor and ceiling are of reinforced concrete construction.
It was assumed that all systems for safe shutdown pathway 1 were lost in a fire in this area. The licensee has committed that those required pathway 2 systems that cannot be repaired with 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, as stipulated in Section III.G.1, will be completely protected by a 1-hour fire rated barrier.
The barrier for essential panel (R 25-S002) will extend from the floor to the top of the panel. The barrier will be open at the top to allou adequate ventilation of the panel.
The combustible material in this* area consists primarily of cable insulation which represents a fuel load of approximately 334,000 BTU /sq. ft.
In addition, a 1-inch hydrogen gas line which has a 2-inch protective pipe casing, passes along the west wall of the corridor. A compressed gas cylinder centaining a mixture of 107-methane and 90% argon is located in the area within a concrete block enclosure.
Existing fire protection includes an automatic sprinkler system installed at the level of the ceiling. Additional sprinklers are installed beneath the lowest cable trays in the north corridor to protect against exposure fires. The sprinkler system does not extend to the rest rooms, the decontamination rooms in the health physics area and the HVAC room, all of which are part of the same fire area, but contain no safe-shutdcwn equipment. Additional protection includes a complete area-wide smoke detection system, portable fire extinguishers and manual host stations.
. 7590-01 If a fire were to occur within the corridor, the existing smoke detection system would activate during the early stages of a fire and summon the fire brigade.
If room temperatures rose significantly, the sprinkler system would activate and suppress the fire while protecting the exposed shutdown systems and limiting further fire spread.
Until the fire was cornpletely extinguished, adequate passive protection is available to ensure that one shutdown pathway will be free of fire damage. This passive protection includes varying degrees of spatial separation between redundant divisions and 1-hour fire rated barriers. Although the barrier at panel R25-S002 does not extend from floor to ceiling, it is high enough to protect the panel from radiant heat and direct flame impingement; coupled with the existence of the automatic sprinkler systen, the barrier provides reasonable assurance that the panel will remain free of damage.
If a fire were to occur outside of the control building corridor, the 2-and 3-hour fire rated walls and reinforced concrete floors and ceiling would tend to limit fire propagation into this area.
Because of the unorotected openings, a cuartity of smoke and heat is expected to enter this fire area.
However, the sprinkler systen and 1-hcur fire barriers are expected to limit damage to the systems associated with shutdown pathway 1.
The redundant pathway would then be available to achieve and maintain safe shutdown conditions.
With regard to the unsprinklered rooms within this area, no shutdown related systems are located within them.
Consecuently, localized fire damage would not affect safe shutdown. The sprinkler system in the corridor and the fire brigades provide reasonable assurance that if the fire were to spread beyond these rooms, one shutdown divisior would remain free of damage.
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. 7590-01 Based on our evaluation, we conclude that the licensee's alternate fire protection configuration, with committed modifications, will provide a level of safety equivalent to that provided by Section III.G.2.
Therefore, the licensee's request for exemption in the Control Building Corridor - Common is granted.
AREA: River Intake Structure The licensee requested an exemption from the requirements of Section III.G.2 to the extent that it requires the installation of a complete, area-wide automatic fire suppression system.
The building is enclosed within walls, floor and ceiling of reinforced concrete.
Safe shutdown equipment located within this fire area includes both safety divisions of Residual Heat Redbval (RHR) service water pumps and associated cabling and motor control centers (MCC) for both units.
In addition, this area contains both safety divisions of plant service water pumps and associated cabling and MCCs for both units.
Redundant safety circuits are located in conduit and cable trays and are either separated by more than 20 feet without intervening combustibles, or one train will be protected by a 1-hour fire rated barrier as described in the May 27, 1983, revision to the licensee's Appendix R report. One-half inch steel plate barriers have been installed to separate RHR service water pumps and MCCs for each unit, and to separate the service water pumps from the remainder of the equipment in the building.
Combustible materials located in the area include cable insulation and lube oil representing a fire load of 55,000 BTU /sq. ft.
Existino fire protection consists of a smoke detection system, a wet-pipe automatic sprinkler system protecting the RHR and plant service water pump motors, manual hose stations and portable fire extinguishers.
. 7590-01 The technical requirements of Section III.G.2 are not met in this area l
because of the absence of an area-wide automatic fire suppression system.
In addition, the fire barriers between the pumps and MCCs are not 1-hour fire rated.
In this area the smoke detection system will provide reasonable assurance of early fire awareness and response by operating personnel and the plant fire brigade. The fire loading in this location, which includes anticipated transient combustibles, is low.
If the combustibles were totally consumed, they would produce a fire which corresponds to a fire severity on the ASTM time-temperature curve of less than 50 minutes; but this fire would be unlikely to occur because of the existing level of fire protection.
It is our judgment that a fire in this area would not be significant and would not breach the protection provided by phytical fire barriers until the fire self-extinguished or was suppressed by the plant fire brigade. We, therefore, have reasonable assurance that one safe shutdown pathway will be free of fire damage.
Based on our evaluation, we conclude that the existing fire protection, with the committed modification, will provide a level of safety eouivalent to that provided by Section III.G.2. Therefore, the licensee's request for exemption for the River Intake Structure is granted.
AREA:
East Corridor, Control and Turbine Building and Condensate Pump Area, E1 112 Feet The licensee requested an exemption from the technical requirements of Section III.G.2 to the extent that it requires that redundant shutdown divisions be separated by complete 3-hour fire rated barriers.
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, 7590-01 The area is bounded by 3-hour fire rated walls, floor and ceiling.
However, the common walls between this location and the condenser and west e
cableway areas are of non-fire rated reinforced concrete.
In addition, an open stairway connects this area with the east cableway. There are no pathway 2 systems within this area. The fire load has been estimated to be approximately 34,000 BTU /sq. ft. or a fire severity of about 25 minutes.
Existing fire protection includes an area-wide fire detection system, manual hose stations and portable fire extinguishers.
Combustible materials within this area are limited. We, therefore, do not expect a fire to propagate rapidly or produce significantly elevated temperatures. Because of the fire detection system, we expect a fire to be detected early and suppressed by the)lant fire brigade before significant damage resulted. Because of the open stairway into the east cableway, smoke and heat from a fire is expected to propagate into this area; but, if this occurs, the automatic sprinkler system in the east cableway will activate te protect exposed shutdown related cables and limit further fire spread.
Systems from only one shutdown pathway are located within the area, and a redundant shutdown capability is outside of this location.
It is therefore our judgment that, because of the masonry and reinforced concrete perineter construction, coupled with the sprinkler system in the east cableway, fire damage would be limited and systems from just one shutdown pathway would be lost. The redundant pathway would remain free of damage so as to achieve and maintain safe shutdown conditions.
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. 7590-01 Based on our evaluation, we conclude that the licensee's alternate fire protection conficuration will provide a level of safety equivalent to that provided by Section III.G.2. Therefore, the licensee's request for exemption for the East Corridor, Contrcl and Turbine Building and Condensate Pump Area, El. 112 feet is granted.
l V.
Accordingly, the Commission has determined that, pursuant to 10 CFR 50.12, the exemptions requested by the licensee's letters as referenced and discussed in III. and IV. above are authorized by law, will not endanger life or property or the common defense and security, are otherwise in the public interest, and are hereby granted.
The Commission has determined that the granting of these Exemptions will not result in any significant environmental impact and that pursuant to 10 CFR 51.5(d)(4) an environmental impact statement or negative declaration and environmental inpact appraisal need not be prepared in connection with this action.
A copy of the Safety Evaluation dated April 18, 1984 related to this action is available for public inspection at the Commission's Public Document Roem,1717 H Street, N.W., Washington, D.C.
20555 and at the Applino County Public Library, 301 City Hall Drive, Baxley, Georgia.
. 7590-01 This Exemption is effective upon issuance.
FOR THE NUCLEAR REGULATORY COMMISSION
.llL'tb1 f'1 jJa2'.
Lli arrell G. -Ett enhut, Di or Division of IV censing Office of Nuclear Reactor Regulation Dated at Bethesda, Maryland this 18th day of April,1984
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