ML20213G467
| ML20213G467 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 11/06/1986 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20213G452 | List: |
| References | |
| NUDOCS 8611180134 | |
| Download: ML20213G467 (35) | |
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o UNITED STATES g
[
g NUCLEAR REGULATORY COMMISSION ENCLOSURE 2 0
-2 WASHINGTON, D. C. 20656
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATIVE TO APPENDIX R' EXEMPTIONS REQUESTED FOR VIRGINIA ELECTRIC AND POWER COMPANY NORTHANNAPdWERSTATION UNITS 1 AND 2 DOCKET NOS. 50-338 AND 50-339
1.0 INTRODUCTION
By letter dated May )1,1984, the Virginia Electric and Power Comp 10 CFR 50, Appendix R.
This submittal requested exemptions from Sections III.G and III.J of Appendix R to 10 CFR 50.
By letters dated October 31, t
1984; August 21, 1985; and March 21, 1986, the Licensee trar.smitted revisions to their Appendix R evaluation. The exemption requests identified in these submittals are the subject of this evaluation.
This evaluation is based in part on the attached Technical Evaluation Report (TER) written by the NRR contractor Franklin Research Center (FRC). This TER has been reviewed by the staff and it is in agreement with the conclusions reached in the FRC TER.
Section III.G.I of Appendix P requires fire protection features to be provided for structures, systems, and components important to safe shutdown and capable of limiting fire damage so that:
a.
One train of systems necessary to achieve and maintain hot shutdown conditions from either the control room or emergency control station (s) is free of fire damage; and b.
Systems necessary to achieve and maintain cold shutdown from either the control room or emergency control station (s) can be repaired within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.
i Section III.G 2 of Appendix R, except as provided for in Paragraph III.G.3, requires that one train of cables and equipment, including associated nonsafety circuits that could prevent operation or sause meloperation due to hot shorts, open circuits, or shorts to ground, necessary to achieve and maintain safe shutdown be maintained free of i
fire damage by one of the following means:
l Separation of cables and equipment and associated nonsafety circuits a.
of redundant trains by a fire barrier having a 3-hour rating.
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Structural steel feming a part of or supporting such fire barriers shall be protected to provide fire resistance equivalent to that required of the barrier.
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b.
Separation of cables and equipment and associated nonsafety circuits of redundant trains by a horizontal distance of more than 20 feet with no intervening combustible or fire hazards.
In addition, fire detectors and an automatic fire suppression system shall be installed in the fire area.
c.
Enclosure of cables and equip' ment and associated nonsafety circuits of one redundant train in a fire barrier having a 1-hour rating.
In addition, fire detectors and an automatic fire suppression system shall be installed in the fire area.
If the above conditions are not met, or where redundant trains of systems required for hot shutdown may be subject to damage from fire suppression activities or from the rupture or inadvertent operation of fire suppression systems,Section III.G.3 requires that there be alternative or dedicated shutdown capability independent of cables, systems, or components in the fire area of concern.
It also requires that fire detection and a fixed suppression system be installed in the fire area, zone, or room of concern.-
Because it is not posjible to predict the specific conditions under which fires may occur and propagate, design basis protective features rather than the design basis fire are specified in the rule. Plant-specific features may require protection different from the measures specified in Section III.G.
In such a case, the Licensee must demonstrate, by means of a detailed fire hazards analysis, that existing protection or existing protection in conjunction with proposed modifications will provide a level of safety equivalent to the technical requirements of Section III.G of Appendix R.
In summary,Section III.G is related to fire protection features for ensuring that one train of systems and associated circuits necessary to achieve and maintain safe shutdown are free of fire damage. Either fire protection configurations must meet the specific requirements of Section III.G or an alternative fire protection configuration must be justified by a fire hazards analysis. Generally, the staff will accept an alternative fire protection configuration if:
o The alternative ensures that one train of equipment necessary to achieve hot shutdown from either the control room or emergency control station (s) is free of fire damage.
o The alternative ensures that fire damage to at least one train of equipment necessary to achieve cold shutdown is limited so that it can be repaired within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> (minor repairs using components storedonthesite).
o Fire-retardant coatings are not used as fire barriers.
Modifications required to meet Section III.G would not enhance fire o
protection safety levels above that provided by either existing or proposed alternatives.
1 o
Modifications required to meet Section III.G would be detrimental to overall facility safety.
A number of the exemptions from Section III.G of Appendix R requested in the Licensee's submittal concerned fire area boundaries. The acceptance criteria for fire area boundaries,are delineated in Appendix A to BTP i
APCSB 9.5-1, not in Appendix R to 10 CFR 50.
Deviations from Appendix A fire area boundary guidelines do not require exemptions. Accordingly, the fire area boundary exerptions have been reviewed as deviations from Appendix A guidelines rather than exemptions from Appendix R to 10 CFR 50, as delineated in GS 86-10.
Section III.J of Appendix R requires that emergency lighting units with at least an 8-hour battery-powered supply be provided in all areas needed for operation of safe shutdown equipment and in access and egress routes thereto.
2.0 AUXILIARY, FUEL,ANDDECONTAMINATIONBUILDINGS(FIREAREA11) j 2.1 Exemption Request'ed 4
An exemption was requested from the requirements of Section III.G.3 to i
the extent that it requires fire detection and fixed suppression systems l
to be provided throughout the fire area, room, or zone under consideration.
2.2 Discussion The Licensee has stated in exemption request 1 that Fire Area 11 does not meet the requirements of Section III.G.3 because fire detection and fixed suppression systems are not provided throughout the area.
North Anna Power Station is a two-unit plar.t with selected capabilities to allow components from one unit to be used as a means of alternate shutdown for the other unit. The licensee has stated that this condition 1
exists for this area. Therefore, the requirements of Section III.G.3 apply.
l Fire Area 11 consists of the auxiliary, fuel, and decontamination buildings. The buildings are located side by side in a north-south i
orientation, with the auxiliary building to the north, the decontamination building to the south, and the fuel building in the i
center. This fire area contains the six charging pumps, four component cooling water (CCW) pumps, and associated cabling and valves for all of the pumps. All barriers separating adjacent fire areas are 3-hour rated with electrical and mechanical penetrations sealed.
il The auxiliary building is a four-story structure consisting of the i
244-foot, 6-inch; 259-foot, 6-inch; 274-foot, 0-inch; and 291-foot, 10-inch elevations. The CCW and charging pumps are located on the 244-foot, 6-inch elevation, with the CCW pumps in the main open floor e
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4 area of this elevation. Each charging pump is located in a separate cubicle accessed from the 259-foot, 6-inch elevation.
The fuel and decontamination buildings sections of Fire Area 11 are each a two-story structure. The fuel building contains the auxiliary monitoring panel (AMP), which is used given a fire in the control room, emergency switchgear rooms, or cable vault / tunnel. No safe shutdown equipment is located in the decontamination building.
An automatic fire detection system, which annunciates in the control room, is provided in Fire Area 11. Smoke detectors are provided on each elevation of the auxiliary building, but they do not naet the criteria of full area coverage. Detectors are installed in all areas with significant amounts of combustibles and near safe shutdown components.
Each charging pump cubicle has one ceiling mounted and one duct mounted smoke detector. Detection is provided near the CCW pumps and their power feeds, charging pump power feeds, and associated valves on the 244-foot, 6-inch and 259-foot, 6-inch. elevations.
The fuel building is provided with ceiling mounted smoke detectors and one duct mounted smokt! detector, whereas the decontamination building is provided with ceiling mounted smoke detectors.
A sprinkler system is installed over the CCW and charging pumps and their power feeds on the 259-foot, 6-inch and 244-foot, 6-inch elevations. Automatic suppression is not provided in either the fuel or decontamination buildings. Portable extinguishers and manual hose stations are provided throughout Fire Area 11 for fire fighting purposes.
Automatic suppression is not provided within the charging pump cubicles.
2.2.1 Charging Pump System Configuration and Separation There are six charging pumps arranged side by side in individual cubicles on the 244 feet, 6 inches elevation of the auxiliary building. The charging pump system primarily provides make-up water for the reactor coolantsystem(RCS). The three pumps to the east are for Unit I and the remaining three are for Unit 2.
A cross-connection is provided between the discharge headers of the two unit's charging pumps. This cross-connection is nomally closed, but can be used by opening two manual valves in charging pump cubicles 1C and 2A.
The cubicles are constructed of heavy concrete walls on three sides, and the fourth side is a removable wall made of concrete beams. These walls have an inherent 3-hour fire rating. See Section 7.0 for additional details on the capabilities of the removable concrete wall.
The cubicle walls extend from the floor to the ceiling and penetrations through the walls are sealed to a rating of 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />. There is a single J
hatch in each cubicle at the floor of the 259 feet, 6 inches elevation to permit personnel entry into the cubicles.
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- The power feeds for the charging pumps extend up through their respective cubicles and exit the top of the 259 feet, 6 inches elevation. There is a minimum of a 20-foot horizontal separation between the power. feeds for Units 1 and 2 charging pumps as they exit their respective cubicles and head in a northerly direction to the auxiliary building into the cable vault and tunnel of the respectiva units.
The charging pump suction valves are located to the east and to the west of the charging pump cubicles for Units 1 and 2 on the 244 feet, 6 inches elevation. The valves are not within cubicles, but there is a wall between the valves and the cubicles. There is a separation distance of at least 100 feet between the twa. sets of suction valves.
2.2.2 CCW System Configuration and Separation The four CCW pumps are located in a row parallel to the charging pump cubicles, approximately 30 feet to the north on elevation 244 feet, 6 inches. The CCW system is required to remove heat from the RCS via the residual heat removal (RHR) system loop during cold shutdown.
The CCW system includes four pumps and heat exchangers via a common discharge header, which can be aligned to service either or both units.
Only one pump is needed per unit for cold shutdown.
The pumps are mounted on pads that are approximately 15 feet apart on center. The distance between the closest Unit 1 CCW pumps is less than 20 feet. However, the outer two pumps are more than 40 feet apart.
The power feeds for the CCW pumps extend up to the 259 feet, 6 inches elevation. The power feeds for the center Unit 2 CCW pump is provided with a 1-hour rated fire wrap until a horizontal separation of 20 feet is achieved from the Unit 1 CCW pump power feeds.
Cable trays on the 259 feet, 6 inches elevation pass over the CCW pumps and between associated charging and CCW pumps power feeds. These trays are provided with fire stops consisting of marinite boards on the top and bottom of the tray. The center is filled with 10 inches of silicone foam.
2.3 Evaluation Fire Area 11 does not comply with the technical requirements of Section III.G.3 of Appendix R because fire detection and fixed suppression are not installed throughout the area.
The staff was concerned that because of the absence of area-wide automatic suppression and detection systems, a fire of significant magnitude could develop and damage all four CCW pumps, al' charging pumps, and/or associated cabling and valves.
However, the combustible loading in Fire Area 11 is low (anequivalent fire severity of less than 20 minutes).
For elevation 244 feet, 6
inches, the fire severity is less than 5 minutes and approximately 10 minutes on elevation 259 feet, 6 inches. The combustibles consist primarily of cable insulation and lube oil contained in the charging pump cubicles.
Additionally, smoke detectors are provided over the CCW pumps and within the charging pump cubicles. The Licensee has comitted to expand the fire detection to areas with large amounts of cable and areas containing safe shutdown components. Because of the presence of these detectors, a fire in the CCW pump area or a charging pump cubicle should be detected in its incipient stage. The alarms from these detectors are annunciated in the main control room. The fire brigade would be dispatched to extinguish the fire manually using hose lines or portable extinguishers.
A sprinkler system is installed over the CCW and charging pumps and their power feeds on the 259 feet, 6 inches and 244 feet, 6 inches elevations.
This system should provide fire control for a fire at the pumps until the fire brigade arrives. Manual control at the CCW pumps is not necessary l
to control the individual CCW pumps during a fire in this area.
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The two most remote CtW pumps are separated by more than 40 feet. The center Unit 2 CCW pumps power feeds are provided with a 1-hour fire rated wrap until a horizontal separation of 20 feet is achieved from the Ur.it I CCW pump power feeds. The spatial separation between the CCW pumps and the protection of the pumps' power feeds provide adequate passive protec-tion until a fire can be controlled by the suppression system or the fire brigade.
The six charging pumps are separated by heavy concrete walls that have an j
inherent fire rating that exceeds 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />. The power feeds for the charging pumps are separated by a minimum of 20 feet of horizontal separation.
The fire stops installed in cable trays effectively reduce the potential of fire spread along the trays.
The staff finds that the installation of area-wide automatic fire suppression and detection systems would not significantly increase the level of fire protection for Fire Area 11.
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2.4 Conclusion Based on the above evaluation, the staff concludes that the existing fire protection features in conjunction with the additional ionization detectors and sprinkler system coverage provide a level of fire protection equivalent to the technica requirements of Section III.G 3 of Appendix R.
Therefore, the exemption request for providing area-wide automatic suppression and detection systems throughout Fire Area 11 1
thould be granted.
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3.0 CONTAINMENT INCORE INSTRUMENT TUNNEL (FIRE AREAS 1-1 AND 1-2) l 3.1 Exemption Requested i
An exemption was requested from the requirements of Section III.G.2.d to the extent that it requires redundant cables and equipment to be
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separated by 20 feet with no intervening combustibles.
I 3.2 Discussion The Licensee has stated in exemption request 2 that Fire Areas 1-1 and i
1-2, both in the incore instrument canals and outside of the canals at j
the 216-foot, 11-inch elevation, do not meet the requirements of Section j
III.G.2.d because less than 20 feet of separation exists between redundant excore neutron flux detector cables.
I Fire Areas 1-1 and 1-2 are the primary containments for the plant, Units 1 and 2, respectively. Each area is a multi-level structure with floor 4
elevations from 216 feet, 11 inches to 291 feet, 10 inches. The incore instrumentation canal is located below elevation 231 feet, 6 inches. The i
east, west, and soutM walls of each canal are 3-foot-thick reinforced i
concrete. The circular wall to the north of each canal is constructed of 4-foot, 6-inch reinforced concrete. The ceiling and floor of each canal 1
are 2-foot-thick reinforced concrete.
Access to each canal is through a steel hatch located at elevation 238 feet, 6 inches. There is a 24-foot-vertical steel ladder within each hatchway that provides access to the canal floor.
l The canals contain no exposed combustibles. All cables in the canal are enclosed in rigid steel conduits.
4 The incore instrument canal and tunnel for each unit contains cables for i
four channels of source range neutron flux indication. Two of the channels were provided as part of the nuclear instrumentation system and i
two channels were added in 1984-85. One of the new channels for each unit is used to provide neutron flux indication at the AMP in the fuel building. The other three channels provide neutron flux indication in j
the control room.
The redundant channels for the new excore neutron flux detectors are routed in rigid steel conduit and separated by a 10-foot horizontal
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distance with no intervening combustibles in the canal. Upon exiting the canals, the redundant trains run in opposite directions until a minimum i
of 20 feet of separation free of intervening combustibles exists between the trains.
1 There is no fixed combustible loading near or within the can Is. The potential for transient combustibles is limited since the access hatch is i
normally locked and access is controlled.
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3.3 Evaluation Fire Areas 1-1 and 1-2 at the incore instrument tunnels do not comply with the technical requirements of Section III.G.2.d of Appendix R because redundant cables and equipment, specifically, excore neutron flux detector cables, are not separated by 20 feet with no intervening combustibles.
The combustible loading near the canals is nonexistent. The canals contain no fixed combustibles. The potential for transient combustibles to be introduced and stored in the canals is low.
A major factor that reduces the potential for damage to redundant source range neutron flux cables is that they are contained in rigid steel conduits. The conduits provide a level of passive protection from radiant energy of a fire.
The 10-foot separation between redundant cables, the nonexistent I
combustible loading, and the use of rigid conduit provide sufficient passive protection to ensure that one division of source range neutron flux cables would remain free of fire damage.
With the fire protection features as described above, there is reasonable assurance that a fire in the containment incore instrument tunnels will not prevent the plcnt from safely shutting down.
3.4 Conclusion 1
i Based on the above evaluation, the staff concludes that the existing fire protection features provide a level of fire protection equivalent to the technical requirements of Section III.G.2.d of Appendix R.
Therefore, i
the exemption request from the requirement of a 20-foot separation l
between redundant excore neutron flux detector cables should be granted.
4.0 QUENCH SPRA) PUMPHOUSE(FIREAREAS15-1AND15-2)
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4.1 Exemption Requested l
An exemption was requested from the specific requirements of Section III.G.3 to the extent that it requires an automatic fire suppression system throughout the fire areas.
i 4.2 Discussion j
The Licensee has stated in exemption request 3 that Fire Areas 15-1 and 15-2 do not meet the requirements of Section III.G.3 because automatic fire suppression systems are not installed throughout each area.
I Fire Areas 15-1 and 15-2 include the quench spray pump house (QSPH) and safeguards building for Units 1 and 2.
The Unit 1 QSPH is adjacent to the safeguards area and separated by a reinforced concrete wall with two ventilation duct penetrations.
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The Unit 2 QSFH and safeguards area are separated by approximately 30 fest on grade (elevation 272 feet, 0 inch), although they do abut at elevation 256 feet 0 inch below grade. Like the the Unit I arrangement, the Unit 2 QSPH and safeguards area are separated by a reinforced concrete wall on the lower elevation and by two concrete walls and a 30-foot-open space on grade. There are two ventilation duct penetrations between the two areas spanning the 30 feet distance on the exterior between the areas.
Each QSPH contains a quench spray pump, instrumentation racks for the steam generator pressure transmitters, and the recirculation spray a
cooling system and related components. Alternative shutdown capability is provided in the main steam valve house (Fire Area 17).
l The safeguards area contains components of the safety injection system including the low head safety injection pumps and valves and components of the recirculation spray system for both pumps and valves. The safeguards area does not contain any equipment required for an. Appendix R safe shutdown.
Both the QSPH and safeguards area are equipped with smoke detectors that annunciate in the control room. The Licensee has comitted to install additional smoke detectors in the QSPH to provide full area coverage.
Portable extinguishers are provided on each level of both the QSPH and safeguards area. Exterior hose houses and hydrants are located nearby for fire fighting purposes.
The combustible loading in the QSPH and safeguards area is low, consisting primarily of cable insulation with minor amounts of grease and lube oil.
4.3 Evaluation 1
The fire protection in the QSPH and safeguards area does not comply with 1
the technical requirements of Section Ill.G.3 of Appendix R because an t
automatic fire suppression system is not installed throughout each area.
The staff was concerned that because an area-wide automatic suppression system is not installed, a fire of significant magnitude could develop and damage redundant steam generator pressure transmitters.
However, the combustible loading in these areas are low, consisting primarily of cable insulation with minor amounts of grease and lube oil.
If a fire were to occur, it is expected that it would develop slowly with initial low heat release and slow rise in room temperature.
Each QSPH and safeguards area is protected by a fire detection system consisting of ionization smoke detectors. The Licensee has committed to provide additional detectors in the QSPH to provide full area, coverage.
Because of the presence of these detectors, a fire in these areas should be detected in its incipient stage. The alams for these detectors are annunciated in the main control room. The fire brigade would be dispatched to extinguish the fire manually, using the hose lines or portable extinguishers.
Instrumentation racks for the steam generator pressure transmitters are located in these fire areas, specifically each QSPH. The Licensee has comitted to provide alternative shutdown capability for the transmitters in Fire Area 17. This fire area is separated from the QSPH and. safeguards area by qualified 3-hour rated fire barriers.
Based on the fire protection features described above, the staff finds that the installation of ar area-wide automatic fire suppression system would not significantly increase the level of fire protection for these areas.
With the fire protection features as described above, there is reasonable assurance that a fire in the QSPH and safeguards area will not prevent the plant from safely shutting down.
4.4 Conclusion Based on the above evaluation, the staff concludes that the existing fire protection in conjunction with additional ionization detectors provide a level of fire protection equivalent to the technical requirements of Section III.G.3 of Appendix R.
Therefore, the exemption request from providing area-wide automatic suppression for Fire Areas 15-1 and 15-2 should be granted.
5.0 MAIN STEAM VALVE HOUSE (FIRE AREAS 17-1 AND 17-2) 5.1 Exemption Requested An exemption was requested from the specific requirements of Section III.G.3 to the extent that it requires automatic fire suppression systems throughout each of the fire areas.
5.2 Discussion The Licensee has stated in exemption request 4 that Fire Areas 17-1 and 17-2 do not meet the requirements of Section III.G.3 because automatic fire suppression systems are not installed throughout each area.
Fire Areas 17-1 and 17-2 are the main steam valve houses for Units 1 and 2, respectively. Each fire area is located in a separate structure north of and adjacent to the containment building (Fire Areas 1-1 and 1-2), the QSPH(FireAreas15-1and15-2),andthecablevaultsandtunnels(Fire Areas 3-1 and 3-2).
Fire Areas 17-1 and 17-2 are multi-level structures consisting of the 272, 282, 297, and 307-foot, 6-inch elevations.
The fixed combustible loading in these areas is low, consisting primarily of cable insulation and grease.
Ionization smoke detectors are provided in each of the fire areas at the upper elevation. These detectors alann in the control room.
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. addition, portable fire extinguishers and exterior hose stations are available for manual fire fighting.
Fire Areas 17-1 and 17-2 contain the main steam code safety valves, the power operated relief valves (PORVs), and the steam supply valves to the turbine-driven auxiliary feedwatei- (AFW) pump. The steam supply valves for the turbine-driven pump fail open and the PORVs fail closed.
A fire in either of these areas has the potential to damage the control of the PORVs from the control room. This will result in the opening of the code safety valves. The steam supply valves to the turbine-driven AFW pump fail open and no manual operation of steam supply is required from these fire areas.
Alternate shutdown capability is available by manually opening the PORVs by handwheels.
5.3 Evaluation The fire protection in the main steam valve houses does not comply with the technical require ^ments of Section III.G.3 of Appendix R because an automatic fire suppression system is not installed throughout each area.
Fire Areas 17-1 and 17-2 contain the main steam code safety valves, PORVs, and the steam supply valves for the turbine-driven AFW pump.
The combustible loading in these areas is low, consisting primarily of cable insulation and grease.
If a fire were to occur, it is expected that it would develop slowly.
Ionization smoke detectors are provided in each of the areas at the upper elevation. The alarms for these detectors are annunciated in the main control room.
The fire brigade will be dispatched and will extinguish the fire manually using the hose lines or portable extinguishers.
Until the fire is extinguished by the fire brigade, the low combustible loading, the use of code safety valves, the fire detection, and the ability to manually operate the PORVs all will provide sufficient protection to ensure that a fire in the above fire areas will not prevent a safe plant shutdown.
4 5.4 Conclusion Based on the above evaluation, it is concluded that the existing fire protection features provide a level of fire protection equivalent to the technical requirements of Section III.G.3 of Appendix R.
Therefore, the exempflon request for providing automatic fire suppression thr,oughout Fire Areas 17-1 and 17-2 should be granted.
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. 6.0 AUXILIARY FEEDWATER PUMP HOUSE (FIRE AREAS 14B-1 AND 14B-2) 6.1 Exemption Requested Exemptions were requested from the requirements of Section III.G.3 to the extent that it requires automatic' fire suppression system throughout each '
of the identified fire areas and from Section III.L.2.d to the' extent it requires direct readings of process monitoring variables necessary to perform and control required functions.
6.2 Discussion The Licensee has stated in exemption requests 5 and 23 that the AFW pump house for each unit does not meet the requirements of Section III.G.3 because area-wide automatic fire suppression is not installed.
In addition, level monitoring of the emergency condensate storage tank (CST' does not meet the requirements of Section III.L.2.d because of potential fire damage to redundant level transmitters and cables.
North Anna Power Station is a two-unit plant with selected capabilities to allow components from one unit to be used as a means of alternate shutdown for the other unit. The licensee has stated that this condition exists for this area. Therefore, the requirements of Section Ill.G.3 apply.
Additionally, the licensee has provided alternative shutdown capability for emergency Condensate Storage Tank level indication.
Fire Areas 14B-1 and 14B-2 contain the motor-driven auxiliary feedwater AFW pumps for Units 1 and 2, respectively.
In addition, the AFW pump discharge valves and level transmitters for each unit's emergency CST are also located in these areas.
Each fire area is located in a separate structure which is distinct from all other plant structures and dedicated solely to the AFW pump system.
The walls and roofs of Fire Areas 148-1 and 148-2 are constructed of 24-inch-thick reinforced concrete. All penetrations of the north wall into the turbine-driven AFW pump fire area are sealed to a 3-hour fire ra ting. A fire in Fire Area 14B-1 or 148-2 has the potential to damage both motor-driven AFW pumps. AFW pump discharge valves, and the level transmitters for each unit's emergency CST.
If the motor-driven pumps become inoperable, the turbine-driven pump can be used.
Loss of the level indicators for the emergency CST would require that the pump suction pressure indicator located in the turbine-driven pump fire area to be used as an indication of emergency CST level. The. Licensee has committed to provide procedures detailing the use of AFW pump suction pressure as a means to detemine adequate emergency CST level.
The fixed combustible loading in each area is low, consisting of grease and lubricating oil.
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Ionization smoke detectors, which alann in a the control room, are provided throughout Fire Areas 148-1 and 148-2. Portable extinguishers
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and exterior hose stations are available for manual fire fighting purposes.
j 6.3 Evaluation The fire protection in the AFW pump houses does not comply with the technical requirements of Sections III.G.3 and III.L.2.d of Appendix R because an automatic fire suppression system is not installed throughout each area and because a fire can damage redundant emergency CST level transmitters.
Both motor-driven AFW pumps, redundant level transmitters for each unit's emergency CST, and AFW pump discharge valves are located in these fire areas. Due to the lack of an automatic suppression system, there was concern that a fire of significant magnitude could develop and damage both pumps and redundant level transmitters.
I However, the combustible loading in Fire Areas 148-1 and 148-2 is low, consisting primarily of' grease and lubricating oil within equipment.
In addition, smoke detectors are provided throughou't these fire areas.
Because of the presence of these detectors, a fire in the motor-driven AFW pump fire areas should be detected in its incipient stage. The alarms from the detectors are annunciated in the main control room. The fire brigade would be dispatched to extinguish the-fire manually using j
hose lines or portable extinguishers.
l The Licensee has provided alternative shutdown capability for emergency l
CST level by reading the turbine-driven AFW pump suction pressure indicator located in a separate fire area. The Licensee has stated that i
procedures exist detailing the use of the turbine-driven AFW pump suction pressure indicator in the turbine-driven AFW pump fire area as an alternative means of A termining emergency CST level.
A fire in these areas will not affect the availabil'ity of the j
turbine-driven AFW pumps. The turbine-driven AFW pump fire areas are
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separated from the motor-driven AFW pump fire areas by 3-hour rated fire barriers.
With the fire protection features as described above and alternative i
shutdown procedures, there is reasonable assurance that a fire in the motor-driven AFW pump areas will not prevent the plant from safely shutting down due to loss of redundant motor-driven AFW pumps and valves j
or emergency CST level transmitters.
i 6.4 Conclusion Based on the above evaluation, the staff concludes that the existing fire protection features provide a level of fire protection equivalent to the technical requirements of Sections III.G.3 and III.L.2.d of Appendix R.
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Therefore, the exemption requests from the requirements for prbviding automatic suppression in the motor-driven AFW pump houses (Fire Areas 14B-1 and 14B-2) and from direct reading of emergency CST level should be granted.
3 7.0 CHARGING PUMP CUBICLES (ELEVATION 244 FEET, 6 IN ES) k 1
7.1 Exemption Requested u.
T An exemption was requested from the specific requirements of Section III.G.2.a to the extent that it requires the separation of cables, equipment, and associated nonsafety circuits of redundant trains by a fire barrier having a 3-hour fire resistance rating.
Si 7.2 Discussion J
The Licensee has stated in exemption request 7i hat Units 1 and Unit 2 t
charging pump cubicles do riot meet the requiren(ents of Section III.G.2.a because of the removable concrete wall.
Thechargingpumpcubiclesarelocatedonthefk4 feet,6 inches elevation of the auxiliary building. The cubieles are approximately 9 feet, 6 inches wide by 24 feet, 6 inches long,: and 14 feet high.
Three of the four walls of each charging pump cubicle are constructed of 3-hour rated reinforced concrete. The fourth nall is constructed of close-fitting, interlocking reinforced concrete 11es. The ties are 1-foot-thick and have a protective steel plate on all interlocking surfaces.
The ends of the ties fit in between the flanges of beams to provide stability, f
n The combustible loading on elevation 244 feet, 6 inches of the auxiliary building is low, consisting primarily of cable insulation. The area imediately adjacent to the subject wall is aiorridor and is free of fixed combustibles.
a n
The combustible loading within the charging putnp cubicles consists of approximately 30 gallons of lube oil contained'in each pump.
There are no fixed combustibles in close proximity to th) subject wall. t-An ionization smoke detection system is provided in the auxilidry building and includes one ceiling mounted and one duct mounted detector in each charging pump cubicle. The smoke detection system provides separate alarms for each cubicle and for each elesation of thelauxiliary building in the control room.
e Portable extinguishers and fire hose stations are provided foryire fighting purposes, r
15 -
7.3 Evaluation The charging pump cubicles located on the 244-foot, 6-inch elevation of the auxiliary building do not comply with the technical requirements of Section III.G.2.a of Appendix R because the north wall of each cubicle is not a 3-hour rated fire barrier..The north wall is a removable concrete wall.
The combustible loadings in the general area of the auxiliary building and within each charging pump cubicle is low. The principal combustibles consist of cable insulation and lube oil contained within the charging pumps. There is no combustible material in contact with or penetrating the removable wall.
Ionization smoke detectors are provided in the auxiliary building and within each charging pump cubicle. The alarms from these detectors are annunciated in the main control room. Upon detection of a fire, the fire brigade would be dispatched and would extinguish the fire wi.th the hose lines or portable extinguishers.
A major factor that red'uces the risk of fire propagation through this removable wall is that its thickness exceeds a typical 3-hour rated wall and all joints and seams are tight-fitting.
Until the fire is extinguished, the separation and intennediate barriers between the charging pumps, the lack of intervening combustibles, and the low combustible loading of the auxiliary building corridor near the walls and the charging pump cubicles will provide sufficient passive protection to ensure that one shutdown division would remain free of fire damage, 7.4 Conclusion j
Based on the above evaluation, the staff concludes that the existing fire protection features provide a level of fire protection equivalent to the technical requirements of Section III.G.2.a of Appendix R.
Therefore, the exemption request for the removable wall in each charging pump cubicle should be granted.
8.0 o 4-to 20-MA SIGNALS IN TWISTED PAIR INSTRUMENT CABLE, PROTECTED FROM HOT SHORTS o
125-VDC CIRCUITS IN RIGID METAL CONDUIT, PROTECTED FROM HOT SHORTS 8.1 Exemption Requested Exemptions were requested from the specific requirements of Section III.G.2 to the extent that it requires the protection of low current instrument circuits and 125-Vdc circuits that could prevent operation or cause maloperation due to hot shorts.
1
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4
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8.2 Discussion The Licensee has requested, in exemption requests 19 and 20, exemption from Appendix R for 4 to 20 mA signals carried by instrument cables which are routed in raceway with other instrument cables and for 125-Vdc circuits serving high/ low pressure interfaces that are routed in dedicated rigid steel conduits. Areas in which one or more of these circuits are installed are the cable vault and tunnel, main control room, containment, emergency switchgear room, and main steam valve house.
The Licensee states that the condition of all four conductors of two adjacent low current level instrument circuits, which are routed in raceway with other instrument cables, fusing together in the correct polarity with low impedance is not credible. Additionally, a direct short (positive and negative conductors contact each other) or short to ground will cause a zero signal output.
The 125-Vdc circuits that are routed within a cable tray and provide motive power to high/ low pressure boundaries that are susceptible to hot shorts must be protected in accordance with Section III.G.2 of Appendix R.
The Licensee has committed to route these circuits in dedicated steel conduit. Additionally, there are procedures requiring the circuits to be deenergized in the event of a fire.
l The Licensee has committed to provide a new isolation switch in the emergency switchgear room to ensure the circuits can be deenergized from either the control room or from the emergency switchgear rooms.
8.3 Evaluation l
Sections III.G.2 and III.L.7 of Appendix R define circuit failure modes as hot shorts, open circuits, and shorts to ground.
For consideration of
)
spurious actuations, all possible functional failure states must be evaluated, i.e., the component could be energized or deenergized by one or more of the above failure uiodes.
Guidance concerning which circuit failure mode must be considered in identifying circuits associated by spurious actuation is provided in Generic Letter 86-10, which states that for ungrounded de circuits, if it l
can be shown that only two shorts of the proper polarity without grounding could cause spurious operation, no further evaluation is necessary, except for circuits involving high/ low pressure interfaces.
l The Licensee has routed circuits involving high/ low pressure interfaces in dedicated rigid steel conduits. Additionally, there are procedures that require the circuits to be deenergized in the event of a fire. The circuits can be deenergized from the main control room and thi emergency switchgear rooms.
The probability of getting a hot short of the proper polarity without groundingoftwoindependentdecircuits(onecircuitwithinadedicated conduit and one circuit from outside the conduit) is considered 1
.---,--,--,..----m-e--.------...-,mrm---,--w,-
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_ 17 sufficiently low as not to require evaluation. This guidance is contained in 5.3.1 of Generic Letter 86-10.
j Based on the above question and answer guidance contained in Generic Letter 86-10, an exemption request for the above circuits is not required.
i 8.4 Conclusion Based on the above evaluation, the staff concludes that the 4-to 20-mA instrument cables and the 125-Vdc circuits identified in the Licensee's submittal meet the guidance contained in Generic Letter 86-10.
Therefore, the exemption request from protecting the circuits from hot shorts is not necessary.
9.0 SEPARATION OF INSTRUMENTATION INSIDE CONTAINMENT, INTERVENING COMBUSTIBLES WITH FIRE STOPS 9.1
_ Exemption Requested An exemption was requested from the requirements of Section III.G.2.d to the extent that it regu' ires redundant cables and equipment separated by 20 feet or by radiant energy shields be free of intervening combustibles.
9.2 Discussion The Licensee has stated in exemption request 27 that primary and alternate trains of cabling for primary plant instrumentation inside the containment are separated by more than 20 feet or by radiant energy shields, but intervening combustibles exist in certain areas. The instrumentation of concern are RCS hot and cold leg temperatures, steam generator level, excore neutron flux monitoring, RCS pressure and pressurizer level.
Fire Areas 1-1 and 1-2 are the primary containments for Units 1 and 2, respectively.
Primary and alternate trains of instrumentation are routed through two different penetration areas within each containment. There is an electrical penetration area into each unit's cable vault / tunnel area and a second electrical penetration area for each containment is provided into the fuel building. These two penetration areas are each separated by more than 20 feet horizontally and 30 feet vertically for each unit.
Radiant energy shields have been placed between primary and alternate instrumentation or compor.ents located less than 20 feet apart.
Fire rated conduit wraps have been provided where there is less than 20 feet of horizontal separation, regardless of the open vcrtical exposure. The wrap is provided until a distance of 20 feet of horizontal separation is achieved or until a barrier which is constructed of heavy concrete is encountered.
Intervening combustibles in the form of cables trays exist between primary and alternate trains of instrumentation separated by more '-
than 20 feet or by radiant energy shields.
In order to mitigate the
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y potential of fire spread along these trays, the Licensee has committed to install vertical and horizontal fire stops where the cable trays constitute a potential intervening combustible.
The horizontal fire stops are 36-inch-long inarinite boards on the top and bottom of the tray with 10 inches of silicone foam in between. The fire stops are located in various areas selected to prevent fire propagation between redundant safe shutdown components or circuits along the interven-ing cable trays.
Cable tray covers have been installed on trays near the cable vault / tunnel penetration areas.
In addition, a cable tray bottom has been installed on the lowest horizontal cable tray.
Heat and smoke detectors which alann in the control room are located in the primary containment. Also, there are portable fire extinguishers located inside of the containment. Dry standpipes are available for use by the fire brigade.
9.3 Evaluation The fire protection for Fire Areas 1-1 and 1-2 does not comply with the technical requirements of Section III.G.2.d of Appendix R because intervening combustibles, specifically, cable in trays exist between primary and alternate trains of cabling for primary plant instrumentation which is separated by more than 20 feet or by radiant energy shields.
The Licensee has comitted to provide fire stops between redundant instrumentation components or cabling to mitigate the consequences of intervening combustibles.
The location and design of the fire stops will inhibit fire propagation along the cable trays between redundant safe shutdown circuits or components. With the fire protection features described above, there is reasonable assurance that a fire within the containment will not prevent the plant from safely shutting down due to loss of primary and alternate trains of identified instrumentation cabling resulting from fire propagation along intervening combustibles.
9.4 Conclusion Based on the above evaluation, the staff concludes that the existing fire protection features combined with the proposed cable tray fire stops provide a level of fire protection equivalent to the technical requirements of Section III.G.2.d of Appendix R.
Therefore, the exemption request from the specific requirements of Appendix R requiring no intervening combustibles should be granted.
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10.0 AUXILIARY BUILDING VENTILATION EQUIPMENT AREA, FIRE AREA 10.1 Exemption Requested An exemption was requested from the requirements of Section III.G.2.b to the extent that it requires full area detection and suppression throughout Fire Area 11.
10.2 Discussion The Licensee has stated in exemption request 28 that Fire Area 11 for each unit does not meet the requirements of Section III.G.2.b because full area detection and suppression are not provided.
Fire Area 11 consists of the auxiliary, fuel, and decontamination buildings for Units I and 2.
The buildings are located side by side in a north south orientation, with the auxiliary building to the north, the decontamination building to the south, and the fuel building in the center. Additional details concerning Fire Area 11 are provided in Section 2.0.
~
The Lic,nsee has installed new auxiliary building ventilation fans and has ensured that fan locations and redundant trains of cabling are separated by more than 20 feet. The two new ventilation fans are installed on the roof of the auxiliary building, elevation 319 feet, 4 inches.
The fans are installed to ensure that ventilation for the charging pumps and the CCW pumps will be available following a fire in the auxiliary building or in other areas. The fans are installed on a concrete slab located above the CCW heat exchanger cubicle.
Elevation 291 feet, 6 inches of the auxiliary building contains the normal auxiliary building exhaust fans, containment purge supply fans, miscellaneous supply and exhaust fans, and ventilation system charcoal fil ters. The new ventilation fans are located on the roof so that approximately 40 feet of separation is maintained.
10.3 Evaluation The fire protection for Fire Area 11 does not comply with the technical requirements of Section III.G.2.b of Appendix R because an automatic fire suppression and detection systems are not installed throughout Fire Area 11.
The staff was concerned that because of.the absence of area-wide automatic suppression and detection systems, a fire of significant magnitude could develop end damage the normal auxiliary building exhaust fans and the new ventilation fans. However, the combustible loading in Fire Area 11 is low (an equivalent fire severity of less than 20 minutes).
Additionally, an automatic fire detection system is placed in all areas with significant amounts of combustibles and areas containing safe
. shutdown components. Because of the presence of these detectors, a fire should be detected in its incipient stage. The alarms from these detectors are annunciated in the main control room. The fire brigade i
would be dispatched to extinguish the fire manually using hose lines or portable extinguishers.
The new ventilation fans are located on the roof so that approximately 40 feet of separation is maintained from the old fans. Once the duct is inside the auxiliary building, hard and flexible ducts are routed down to the CCW pump area, to charging pump cubicles and penetration areas. The flexible duct is contained in a fireproof enclosure and stored in an area that will not be affected by a fire in Fire Area 11.
At the roof elevation, the two trains are separated by more than 20 feet horizontally, with no intervening combustibles. The cables are routed in separate fire areas except at the fan location.
A fire in the nonnal switchgear room may disable the new ventilation fans in the auxiliary building, but the existing ventilation would net be affected.
The staff finds that the installation of aree-wide automatic fire suppression and detection systems would not significantly increase the level of fire protection for Fire Area 11.
10.4 Conclusion Based on the above evaluation, the staff concludes that the existing fire protection features combined with the new ventilation system in the auxiliary building provide a level of fire protection equivalent to the technical recuirements of Section III.G.2.b of Appendix R.
Therefore, the exemption request from the requirement of full area suppress b. ar.d detection in Fire Area 11 should be granted.
11.0 o EMERGENCY LIGHTING IN THE SEAL WATER FILTER AREA, USE OF PORTABLE LIGHTS o
EMERGENCY LIGHTING IN THE CONTRnl ROOM, USE OF DIESEL GENERATOR POWER SUPPLY o
EMERGENCY LIGHTING FOR EXTERIOR ACCESS ROUTES, USE OF SECURITY LIGHTING AND PORTABLE LIGHTS 11.1 Exemption Requested Exemptions were requested from the requirements of Section III.J to the extent that it requires all areas needed for operation of safe shutdown equipment and in access and egress routes thereto be provided with emergency lighting units with at least an 8-hour battery supply.
. 11.2 Discussion The Licensee has detemined in exemption requests 31, 32, and.33 that the above areas do not meet the requirements of Section III.J of Appendix R because 8-hour battery-powered emergency lighting is not installed.
The seal water filter area (SWFA) is located south of the charging pump cubicles on the 244-foot, 6-inch elevation of the auxiliary building.
The SWFA consists of a series of c,oncrete cubicles approximately 6 feet deep and 10 feet wide. They contain seal water filters, heat exchangers, and injection filters.
The auxiliary building is part of Fire Area 11, which is described in more detail in Section 2.0.
The Licensee's procedures for Appendix R safe shutdown for certain fire areas requires an operator to enter each SWFA to verify the position of
~
valves and, if needed, to open or close any that are not aligned. There are currently no battery-powered emergency lights in the SWFA. Portable constant recharge lanterns are installed directly outside of the SWFA for use by the operator during emergency shutdown procedures.
The SWFA cubicles are locked, high radiation areas. The general area dose rate is normally 2 rem /hr. The operator only needs to be in the cubicles long enough to verify valve alignment and to manually operate any valve not aligned. This procedure only needs to be verified once.
No other entries or constant attendance in the SWFA will be needed. No gauges or instruments need to be observed in the SWFA. Access and egress routes to the SWFA cubicles have fixed 8-hour battery-powered emergency lights. Normal 8-hour emergency lighting is provided in the area outside of the SWFA so the portable lanterns will be illuminated.
The portable lights are contained in locked metal cases with a break-away lock. The lights are visually checked periodically and incorporated into the emergency lighting periodic test program.
The control room emergency lighting units are diesel-powered as opposed to an 8-hour battery-powered supply. The Licensee's basis for the use of diesel-backed emergency lighting in the control room includes the following:
1.
The plant emergency diesel generators have a fuel capacity in excess of 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.
2.
Power feeds are routed such that no single fire outside the control room could affect both power supplies for the control room lights.
i 3.
The lights are arranged in a configuration that the lights from each unit's diesel cover both sides of the control room.
4.
An illumination test has been perfomed to verify the adequacy of the lighting level to perform required operations when powered from either diesel.
During the short transition from loss of offsite power to diesel generator power, lights having a battery power supply will be illuminated within the control room complex.
Operator access routes to various safe shutdown components may require travel outside of the buildings. Lighting for these exterior routes is provided by station security lighting and by portable lights. The security lighting is powered by the station security diesel in the event of the loss of offsite power.
Safe shutdown components are located within several buildings that require exterior access. These buildings are the main steam valve house, AFW pump house, QSPH, fuel oil pump house, SW pump house, and auxiliary SW pump house and yard vault pit.
Shutdown procedures for the exterior buildings require the operator to assemble at the Appendix R locker area and acquire portable lights. The inventory of the Appendix R locker is checked periodically to ensure that adequate lights are availab'le and that the batteries are functional.
11.3 Evaluation
~
The fire protection in the above areas does not comply with the technical requirements of Section III.J of Appendix R because 8-hour battery-powered emergency lighting is not installed in all areas needed for operation of safe shutdown equipment and in access and egress routes thereto.
The Licensee has provided an acceptable level of emergency lighting to ensure access and egress to emergency control stations. These include the following:
o Dedicated, controlled, and maintained portable lights are located at pre-designated locations.
o Security perimeter lighting is powered by the security diesel generator.
o Redundant diesel-backed emergency lighting is provided for the control room.
The location and control of the emergency lighting should ensure access and egress to areas required to achieve and maintain safe shutdown. With the features described above, there is reasonable assurance that adequate lighting for all required areas is provided and that the lack of 8-hour battery-powered emergency lighting units in the areas above will not prevent the plant from safely shutting down.
11.4 Conclusion Based on the above evaluation, the staff concludes that the existing security lighting and control room lighting combined with the location
and controls of dedicated portable lights provide a level of fire protection equivalent to the technical requirements of Section III.J of Appendix R.
Therefore, the exemption requests from the requirement for 8-hour battery powered emergency lighting in the above areas should be granted.
12.0 REFUELING WATER STORAGE TANK, LACK OF LEVEL INDICATION 12.1 Exemption Requested An exemption was requested from the requirements of Section III.L.2.d to the extent that it requires process monitoring to be capable of providing direct readings of process variables necessary to perform and control required functions.
12.2 Discussion The Licensee has stated in exemption request 34 that the level monitoring of the refueling water storage tank (RWST) does not meet the requirements of Section III.L.2.d because a fire occurring in any one of several fire areas such as the control room or the emergency switchgear room may result in the loss of'RWST level indication.
An RWST is provided for each unit. The RWST provides make-up water to the RCS via the charging pumps for reactor coolant inventory and reactivity control. Level indication for the RWST is provided in the control room for normal operations. A fire in the control room and either unit's emergency switchgear room or cable vault / tunnel could cause
} the loss of this indication.
No redundant or alternate method is
~ provided for obtaining either a direct or indirect level indication.
Plant technical specifications require that 475,058 gallons of water be available in the RWST of each unit that is operating. The Licensee has performed an analysis and determined that less than 10 percent of the volume of the RWST is required to attain cold shutdown.
The discharges of the charging pump for the two units are cross-connected and provide alternate shutdown capability to each other. Each unit's charging pumps take suction from the re:pective unit's RWST.
There are administrative controls to ensure that if one unit is not l
operating, there will be sufficient volume in that unit's RWST to safely shut down the operating unit should the operating unit's charging pumps
[
become disabled. This shutdown would be achieved using the charging pump g
discharge cross-connection.
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12.3 Evaluation The fire protection for the RWST does not comply with the technical e
requirements of Sectior-III.L.2.d of Appendix R because a fire can damage a
RWST level indication pd no alternate means of process monitoring is provided. Therefore, girect readings of the process variables necessary
o
_ 24 to perform and control required functions at the control room and the remote shutdown panel is not provided.
The amount of water taken from the RWST for RCS make-up during an Appendix R safe shutdown is less than 10 percent of the minimum RWST volume allowed by the Licensee's technical specifications.
Administrative controls are provided to ensure that there is sufficient quantity of water available in the RWST of a unit that is not operating to supply the charging pumps for the operating unit if necessary.
The staff finds that there is a sufficient margin of RWST volume to achieve Appendix R safe shutdown.
12.4 Conclusion i
Based on the above evaluation, the staff concludes that the existing RWST inventory combined with the administrative controls and the quantity of water available in the RWST of a unit that is not operating provide a level of fire protection equivalent to the requirements of Section III.L.2.d of Appendix'R. Therefore, the exemption request from direct reading of RWST level should be granted.
13.0 CHILLER ROOMS 13.1 Exemption Requested AnexemptionwasNguestedfromtherequirementsofSectionIII.G.2.ato the extent that it requires the separation of cables, equipment, and associated nonsafety circuits of redundant trains by a fire barrier having a 3-hour fire resistance rating.
13.2 Discussion The Licensee has stated in exemption request 25 that unrated ventilation openings exist between Units 1 and 2 chiller rooms into the turbine building basement (Fire Area 8).
Both unit's chiller rooms are located on the 254-foot, 0-inch elevation of the service building. The chiller rooms are both bounded to the south 4
by the respective unit's emergency switchgear and air conditioner rooms.
The wall between these areas is 3-hour rated.
The north wall of each chiller room is adjacent to the turbine building basement, elevation 254 feet 0 inch. This wall is a minimum of 12-inch-thick concrete. The doors between these areas are 3-hour rated installed in channel steel frames similar to those described in Section 14.2.3. There are also two ventilation openings in this wall for each chiller room.
1
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_ 24 to perform and control required functions at the control room and the remote shutdown panel is not provided.
The amount of water taken from the RWST for RCS make-up during an Appendix R safe shutdown is less than 10 percent of the minimum RWST volume allowed by the Licensee's technical specifications.
Administrative controls are provided to ensure that there is sufficient quantity of water available in the RWST of a unit that is not operating to supply the charging pumps for the operating unit if necessary.
The staff finds that there is a sufficient margin of RWST volume to achieve Appendix R safe shutdown.
12.4 Conclusion Based on the above evaluation, the staff concludes that the existing RWST inventory combined with the administrative controls and the quantity of water available in the RWST of a unit that is not operating provide a level of fire protection equivalent to the requirements of Section III.L.2.d of Appendix ^R.
Therefore, the exemption request from direct reading of RWST level should be granted.
13.0 CHILLER ROOMS 13.1 Exemption Requested AnexemptionwasNguestedfromtherequirementsofSectionIII.G.2.ato the extent that it requires the separation of cables, equipment, and associated nonsafety circuits of redundant trains by a fire barrier having a 3-hour fire resistance rating.
13.2 Discussion The Licensee has stated in exemption request 25 that unrated ventilation openings exist between Units 1 and 2 chiller rooms into the turbine building basement (Fire Area 8).
Both unit's chiller rooms are located on the 254-foot, 0-inch elevation of the service building. The chiller rooms are both bounded to the south by the respective unit's emergency switchgear and air conditioner rooms.
The wall between these areas is 3-hour rated.
The north wall of cach chiller room is adjacent to the turbine building basement, elevation 254 feet 0 inch. This wall is a minimum of 12-inch-thick concrete. The doors between these areas are 3-hour rated installed in channel steel frames similar to those described in Section 14.2.3.
There are also two ventilation openings in this wall for each chiller room.
,n--.,,,. _ _.. _.
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....,,.--r--,--
. Each opening is approximately 4 feet by 4 feet. These openings are the only unsealed penetrations between the two chiller rooms and the turbine building. Each opening is protected with a missile barrier consisting of three rows of 1/4-inch-thick steel beams.
Elevation 254 feet, 0 inch of the' turbine building has an area-wide sprinkler system. Automatic deluge systems protect the major lube oil components located on this elevation.
Both chiller rooms are provided with smoke detectors which annunciate in the control room.
There is a masonry wall between Units 1 and 2 side of the turbine building, dividing the basement and mezzanine levels. This wall separates the ventilation openings to each unit's chiller room. One chiller room is capable of maintaining sufficient cooling to keep the control room tenable for over 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.
Fire extinguishers are located throughout both areas and hose stations are located in the turbine building adjacent to the chiller rooms.
13.3 Evaluation Units 1 and 2 chiller rooms, located on elevation 254 feet, O inch of the service building, do not comply with the technical requirements of Section III.G.2.a of Appendix R because unrated ventilation openings exist into the turbine building basement.
Smoke detectors are provided in each unit's chiller room adjacent to each of the ventilation openings.
Because of the detectors, a fire within the chiller room will be detected in its incipient stage. The alarms from these detectors are annunciated in the main control room. The fire brigade will be dispatched and would extinguish the fire manually using the hose lines or portable extinguishers provided.
Areas in the turbine building adjacent to these openings are provided with full area sprinkler systems. Automatic deluge spray systems are installed on major lube oil components located on this elevation. There are no combustibles which pass through the ventilation openings.
A full height masonry wall on elevation 254 feet, 0 inch of the turbine building separates the ventilation openings of Units 1 and 2 chiller A single chiller room will provide sufficient cooling to keep the rooms.
control room tenable for over 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.
Until the fire is extinguished by the fire brigade or automatic suppression systems, the spatial separation and intervening masonry wall in the turbine building, the general area fire suppression system in the turbine building, the fire detection system in the chiller rooms, and the lack of intervening combustibles will provide sufficient protection to provide reasonable assurance that a chiller room would remain free of
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. fire damage. We also have reasonable assurance that a fire in the above area will not prevent the plant from safely shutting down.
13.4 Conclusion Based on the above evaluation, the staff concludes that the existing fire protection features provide a level of protection equivalent to the i
technical requirements of Section III.G.2.a of Appendix R.
Therefore, the exemption request for the unrated ventilation openings from each unit's chiller room into the turbine building basement should be granted.
14.0 o Emergency Switchgear Room / Chiller, No Fire Damper o
Emergency Switchgear Room, Fire Door Frames o
Fire Doors, Frames Not Fire Rated o
Fire Doors, Conduit in Door Frames Control Room Stairwell Emergency Switchgear Room Wall Fire o
Barrier Rating Cable Vault / Tunnel and Auxiliary Building Wall, Fire Barrier o
Rating Auxiliary Building / Turbine Building Pipe Tunnel, Lack of Fire Barrier o
Control Room / Turbine Building, Bulletproof Doors o
o' Conduit Passing Through Fire Barriers, Lack of Internal Seals 14.1 Exemptions Requested Exemptions for the following configurations were requested from Section III.G.2 of Appendix R to the extent that it requires separation of redundant safe shutdown components by 3-hour rated fire barriers.
Section III.G.2 of Appendix R contains requirements for fire protection within fire areas.
It does not apply to fire area boundaries.
Acceptable guidelines for establishing fire area boundaries are set forth in Appendix A to BTP APCSB 9.5-1 in Section D.1.(j). Therefore, these areas have been reviewed for conformance with Appendix A guidelines.
14.2 Discussion 14.2.1 Emergency Switchgear Room / Chiller, No Fire Damper The Licensee has stated in exemption request 14 that a penetration between the air conditioning room (Fire Area 6-1) and the chiller room (Fire Area 8) is not provided with a fire damper. The penetration is a 12-inch-diameter schedule 40 pipe.
. The penetration arrangement was identified in the 1979 Fire Protection Safety Evaluation Report issued by the NRC staff. Subsequently, the arrangement was found acceptable by the NRC staff as stated in a letter dated July 9, 1979. As indicated in Generic Letter 86-10. "if a fire 1
area boundary has been specificall hazards analysis performed in the,y identified and justified in the fire Appendix A process and evaluated and accepted by the staff, the fire area boundary need not be reviewed as part of the reanalysis for compliance with Section III.G of Appendix R."
Therefore, the subject penetration remains acceptable for continued use in the fire area boundary as described.
14.2.2 Emergency Switchgear Room, Fire Door Frames The Licensee has stated in exemption request 15 that two door assemblies in the emergency switchgear fire area boundary are not fire rated. These two door assemblies are oversized door openings used for equipment access during construction.
The opening has been reduced to a standard double door frame by a steel structure.
The first door (Fire Do'or S54-8) is located between Fire Areas 6-1 and 6-2.
The second door (Fire Door S54-11) is located between Fire Areas 6-2 and the turbine building fire area.
The emergency switchgear rooms are protected by smoke detectors which annunciate in the main control room.
In addition, a total flooding halon fire suppression system has been installed.
The turbine building basement has an automatic sprinkler system installed throughout the area.
There are numerous fire extinguishers located throughout both areas.
Hose stations are located in or near both areas.
irm Licensee has performed an analysis evaluating the capability of these doors to perform in these fire area boundaries based on the installed fire protection systems, combustible quantity, and confi found them comparable to Underwriter's Laboratories (UL)guration and i
labeled doors.
14.2.3 Fire Doors, Frames Not Fire Rated The Licensee has stated in exemption request 16 that several door assemblies in fire area boundary walls have frames which do not have a label from a recognized testing laboratory.
The subject doors include:
o Door S54-5 Unit 1 emergency switchgear room (ESGR) to Unit I cable tunnel o
Door 554-9 Unit 2 ESGR to Unit 2 cable tunnel o
Doors S71-16, 17, All four emergency diesel generator 18, and 19 rooms to the turbine building 1
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. o Door 71-19A Door from technical support center HVAC room to turbine building o
Doors S76-25 and 26 Units 1 and 2 control rooms to the turbine building o
Doors S94-7, 8, 9, Battery rooms 1-I,1-III, 2-I, and 1
and 10 2-III to the cable spreading room o
Doors A80-1 and 2 Rod drive room to the auxiliary building, both units.
These frames consist of steel channels which are an integral part of a poured concrete wall. The Licensee has performed an analysis which shows that the frames are equivalent to labeled frames due to their construction. The analysis considered the combustible quantity.
configurations, and fire protection systems on each side of such doors.
All of the above areas are equipped with rate compensated and/or smoke detectors. The cable s'preading room, cable tunnel, rod drive area, and diesel generator rooms are equipped with a total flooding C0 fire 7
suppression system. The emergency switchgear rooms are equipped with a manually actuated halon system.
In addition, the cable tunnel has a backup deluge system and a closed-head sprinkler system, which are manually activated.
Fire extinguishers are located throughout all the areas and hose stations are located nearby.
14.2.4 Fire Doors, Conduit in Door Frames The Licensee has stated in exemption request 17 that several door assemblies in fire boundary walls have conduits penetrating into the door frames. These conduits carry cable for security devices such as card readers or door monitoring. This type of conduit penetration has not been tested for a 3-hour fire rating.
The fire doors involved include:
4 o
Door S54-5 Unit 1 emergency switchgear room (ESGR) to Unit I cable vault / tunnel o
Door 554-6 Unit 1 ESGR to the control room stairwell o
Door S54-7 Unit 2 ESGR to the control room-stairwell o
Door S54-8 Door between Units 1 and 2 ESGRs
e
. o Door S54-9 Unit 2 ESGR to Unit 2 cable vault / tunnel
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o Door S54-11 Unit 2 ESGR to the turbine building o
Door S76-25 Unit 2 control room to the turbine j
~ building o
Door S76-26 Unit I control room to the turbine building i
o Doors S71-16, 17, Doors between each emergency diesel 18, and 19 generator room and the turbine building o
Doors S94-7, 8, 9, Battery rooms 1-I,1-III, 2-I, and and 10 2-III in the cable spreading rooms Detection is provided in all areas adjacent to the above doors. The conduits penetrate only one side of the frame (where the conduits and frame meet) and all egnnections are tight.
The Licensee has evaluated the affected fire door assemblies and determined that they provide an adequate margin of fire resistance considering the fire loading on both sides of each of the door assemblies.
14.2.5 Control Room Stairwell / Emergency Switchgear Room Wall, Fire Barrier Rating The Licensee has stated in exemption request 21 that the stairwell wall between the control rcom complex (Fire Area 21) and the Unit 2 emergency switchgear room (Fire Area 6-2) is not fire rated for 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />.
The stairwell between the control room complex and the Unit 2 emergency switchgear room is considered part of the control room complex fire area (Fire Area 2). The wall between the stairwell and the Unit 2 ESGR is constructed of 8-inch-thick masonry blocks. The Licensee has performed an analysis evaluating the capability of this wall to perform in this fire area boundary based on the installed fire protection systems and adjoining spaces, the combustible loading configuration within these areas, and comparison with masonry walls of known fire resistance rating.
The evaluation concluded that the 8-inch-thick masonry wall provides an adequate margin of fire resistance based on the NRC's staff guidance.
14.2.6 Cable Vault / Tunnel and Auxiliary Building Wall, Fire Barrier Rating The Licensee has stated in exemption request 22 that there is an l
8-inch-thick masonry block wall between sections of the 259 feet, 0 inch elevation of the cable vault / tunnel (Fire Areas 3-1 and 3-2) and the l
auxiliary building (Fire Area 11) that is not rated for 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />.
, The Licensee has stated that the subject wall is rated for a minimum of 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />. Additionally, both the cable vaults and tunnels, and the auxiliary building are equipped with smoke detectors which annunciate in the control room.
The cable vault and tunnel is equipped with an automatic total flooding C0 fire suppression system and a closed-head manual sprinkler system. A p
partial sprinkler system is installed on the 259-foot, 0-inch and the 244-foot, 0-inch elevations of the auxiliary building, reducing the probability of fire exposure to the subject wall.
The 8-inch-thick masonry wall combined with the fire protection features described above provide an adequate margin of fire resistance based on the NRC staff's guidance.
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14.2.7 Auxiliary Building / Turbine Building Pipe Tunnel, Lack of Fire Barrier The Licensee has stated.in exemption request 24 that a pipe tunnel is located below the ground floor of the service building and provides a routing from the turbire building to the auxiliary building for various pipes. A rated barrier or seal does not exist at either end of the j
tunnel.
The tunnel has negligible combus.tible loading in the form of pipe insulation on chilled water lines. The tunnel opens vertically into the turbine building at the floor level. This elevation of the turbine building is equipped with an area-wide automatic sprinkler system and deluge systems protect major lube oil components.
The combustible loading in the cuxiliary building is low to moderate.
The 244-foot elevation where the tunnel exits into the Auxiliary Building contains small cable runs and only small amounts of lube oil in pumps.
The area near the tunnel in the auxiliary building is also protected by automatic sprinklers. Smoke detectors exist on the auxiliary building side of the pipe tunnel.
There is a 3-foot-wide dike around the turbine building tunnel opening which prevents flammable liquids from entering the tunnel.
l 14.2.8 Control Room / Turbine Building, Bulletproof Doors The Licensee has stated in exemption request 26 that two door assemblies l
in the fire area boundary wall between the control room and the turbine building have been modified by installing 1/4-inch-thick steel plates on the exterior of the door for bulletproof resistance.
l The doors of concern are S76-25 and S76-26. Door S76-25 is a double-leaf door between the Unit 2 side of the control room and the turbine building. Door S76-26 is a single leaf door between the Unit I side of I
the control room and the turbine building.
l l
l
. Smoke detectors are installed on the ceiling of the control room and in the subfloor area. An automatic halon fire suppression system is also installed in the subfloor area.
The turbine building has an automatic sprinkler system throughout the building except over the operating floor. There are fire extinguishers located throughout both areas and the hose stations are located outside of the control room.
The subject doors are UL labeled and 3-hour fire rated.
In order to l
satisfy security requirements, 1/4-inch-thick steel plates were added to each leaf of the doors. These doors were then certified for a bullet resistance rating in accordance with UL-752..At the time of the i
modification, acceptable 3-hour rated bullet resistant doors were not available.
l The Licensee has performed an analysis which demonstrates the
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acceptability of these doors for service in a fire area boundary. The technical basis for the evaluation considered installed fire protection systems, configuration of the turbine building and control room doors, transient combustibles, and administrative procedures.
l 14.2.9 Conduit Passing Through Rated Fire Barriers, Lack of Internal Seals The Licensee has stated in exemption request 35 that several conduit penetrations through 3-hour rated fire barriers between fire areas containing redundant safe shutdown components are not sealed internally with a fire stop material providing a penetration seal equivalent to the rating of the fire barrier.
Generic Letter 86-10 provides guidance on conduit and cable tray penetrations through fire barriers. This guidance states that openings through fire barriers which separate fire areas should be sealed or i
closed to provide a fire resistance rating at least equal to the barrier.
Openings inside conduits larger than 4 inches should be sealed at the barrier penetration. Openings inside conduits 4 inches or less in diameter should be sealed at the fire barrier unless the conduit extends at least 5 feet on each side of the barrier and is sealed at both ends or at the barrier with noncombustible material to prevent the passage of i
smoke and hot gases.
l As an alternative to the above guidance, the Licensee has proposed the following configurations for the internal sealing of conduit penetrations. These criteria are an acceptable deviation from the
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guidelines.
1.
Conduits are sealed internally at the fire barrier to the rating of the fire barrier.
.n-. -. -, - - - -..,,
. 2.
The conduits are sealed on at least one side of the fire barrier and both areas have fire detection near the penetration.
3.
When the conduits penetrate a fire barrier and are unsealed, fire detection is installed near the conduit penetration on both sides of the barrier. Additionally, fixed suppression is installed on at least one side of the barrier near the conduit penetration or the fire loading on both sides of the barrier is 20 minutes or less.
14.3 Evaluation The guidelines of Section D.1.(jl of Appendix A to BTP APCSB 9.5-1 are not met for the above fire area boundaries as described.
The staff was concerned that a fire in any of these areas would penetrate the subject fire barriers resulting in loss of safe shutdown capability.
Because of the fire protection features provided, it is not expected that a fire of significant magnitude or duration will occur in any of the fire areas.
If a fire does occur, it would be detected by the ionization detectors and extinguished by the plant fire brigade or automatic suppression systems before spreading to another fire area through the barriers. The Licensee's analysis demonstrates that the integrity of fire area boundaries is not jeopardized.
14.4 Conclusion Based on the above evaluation, it is concluded that the existing fire protection features provide an adequate level of fire protection and, therefore, they are acceptable deviations from the guidelines of Section D.1(j) of Appendix A to RTP APCSB 9.5-1 15.0 WITHDRAWN EXEMPTION REQUESTS In various revisions of the Licensee's report describing compliance with 10 CFR 50, Appendix R, exemptions were requested for the areas listed below. The exemptions were to the extent that Appendix R requires 20 feet of separation, 3-hour rated boundaries, and 3-hour rated fire dampers in boundaries or 8-hour emergency lighting.
Subsequently, the Licensee elected to protect the necessary safe shutdown equipment with alternate modifications or determined that the equipment was not necessary. The Licensee has committed that the alternatives are in full compliance with Appendix R.
Therefore, the following exemption requests are no longer necessary.
o Unit RHR Pumps, Less Than 20 Feet of Separation o Control Room / Emergency Switchgear Rooms, Fire Damper Rating o Control Room / Battery Rooms, Fire Damper Rating
- = _ _. - _ _ _ _ - -.
' Control Room / Turbine Building, No Fire Damper o
Control Room / Cable Spreading Rooms, Fire Damper Rating o
Quench Spray Pump House and Safeguard Area, Non-Rated Damper o
Emergency Switchgear Room / Chiller Room, No Fire Damper o
Fire Doors. Security Modifications to Latch Keepers o
Emergency Lighting in Containment, Use of Portable Lights o
o Establishing Letdown, Using Nonshift Personnel 16.0
SUMMARY
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Based on the evaluation, the staff finds that the level of fire safety in the areas listed below is equivalent to that achieved by compliance with technical requirements of Section III.G of Appendix R and, therefore, the Licensee's request for exemption in the following areas should be granted:
Auxiliary, Fuel, and Decontanination Buildings, Fire o
i Area 11.
Lack of fixed automatic fire suppression and detection 3
systems throughout the fire area. See Section 2.0 for additional information.
4 o Containment Incore Instrument Tunnel, Fire Areas 1-1 and 1-2.
I Lack of 20 feet of separation between redundant excore i
neutron flux detector cables. See Section 3.0 for additonal information.
o Quench Spray Pump House, Fire Areas 15-1 and 15-2.
Lack of fixed automatic suppression systems throughout each fire area. See Stction 4.0 for additional information.
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o Main Steam Valve House, Fire Areas 17-1 and 17-2.
Lack of fixed automatic suppression systems throughout each main steam valve house. See Section 5.0 for additional information.
o Auxiliary Feedwater Pump House, Fire Areas 14B-1 and 14B-2.
Lack of direct readings of process monitoring variables necessary to perform and control required functions.
See Section 6.0 for additional information.
. o Charging Pump Cubicles. Elevation 244 Feet, 6 Inches.
Lack of 3-hour rated fire barriers separating redundant saf'e shutdown equipment. See Section 7.0 for additional information.
o Separation of Instrumentation, Containment.
Redundant cables and equipment separated by 20 feet or by radiant energy shields with intervening combustibles. See Section 9.0 for additional information.
Auxiliary Building Ventilation Equipment Area, Fire Area 11.
o Lack of autcmatic fire suppression and detection systems throughout the fire area. See Section 10.0 for additional information.
o Chiller Rooms, Elevation 254 Feet, O Inch.
I Lack of 3-hour rated fire barriers between redundant safe shutdown equipment. See Section *3.0 for additional information.
)
Based on the evaluation, the staff finds that the level of fire safety in the areas listed below is equivalent to that achieved by compliance with the technical requirements of Section III.J of Appendix R and, therefore, the Licensee's request for exemption in these areas should be granted, Emergency Lighting in the Seal Water Filter Area, Use of o
Portable Lights o Emergency Lighting in the Control Room, Use of Fuel Generator Power Supply Emergency Lighting for Exterior Access Routes, Use of Security o
Lighting and Portable Lights. Lack of emergency lighting units with at least an 8-hour battery supply in all areas needed for operation of safe shutdown equipment and access and egress routes thereto.
Based on the evaluation, the staff finds that the level of fire safety in the areas listed below meets the guidance provided for compliance with Section III.G of Appendix R and, therefore, the Licensee's request for exemption from Section III.G.2 is not required.
o 4-to 20-mA Signals in Twisted Pair Instrument Cable o 125-Vdc Circuits in Rigid Metal Conduit
1
, Protection of low current instrument circuits and 125-V dc circuits that could prevent operation or cause maloperation due to hot shorts. See Section 8.0 for additional information.
Based on the evaluation, the staff finds that the level of fire safety for the following fire area boundaries is equivalent to that achieved by conformance with the guidelines of Section D.I.(j) of Appendix A to BTP APCSB 9.5-1 and are therefore acceptable, o Emergency Switchgear Room / Chiller Rocrr, Fire Area 6-1 o Emergency Switchgear Room, Fire Area 6-2 o Fire Coors (Frames not Fire Rated), Various Fire Areas o Fire Doors (Conduit and Door Frames), Various Fire Areas o Control Roon: Stairwell / Emergency Switchgecr Room Wall, Fire Area 2 o Cable Vault /Tunnei/ Auxiliary Building Fire Wall, Fire Area 3-1 o Auxiliary / Turbine Building Pipe Tunnel, Fire Area 8 o Control Room / Turbine Building (Eulletproof Ccors), Fire Area 2 o Conduit Passing Through Rated Fire Barriers (Lack of Internal Seals), Varicus Fire Areas 17.0 PRINCIPAL CONTRIBUTORS: John Stang and Tom Rotella This safety evaluation was prepared based on a technical evaluation repcrt prepared by Franklin Research Center (FRC) under a contract with the U.S.
Nuclear Fegulatory Comission (NRC).
Date: November 6,1986