ML20132E411
| ML20132E411 | |
| Person / Time | |
|---|---|
| Site: | Crystal River  |
| Issue date: | 07/18/1985 |
| From: | Thompson H Office of Nuclear Reactor Regulation |
| To: | FLORIDA POWER CORP. |
| Shared Package | |
| ML20132E392 | List: |
| References | |
| NUDOCS 8508010808 | |
| Download: ML20132E411 (15) | |
Text
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6 7590-01 UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION In the Matter of
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FLORIDA POWER CORPORATION, ET AL, Docket No. 50-302
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(Crystal River Unit No. 3
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Nuclear Generating Plant)
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EXEMPTION I.
The Florida Power Corporation (the licensee) and eleven other co-owners are the holders of Facility Operating License No. DPR-72 which authorizes operation of Crystal River Unit No. 3 Nuclear Generating Plant (the facility) at steady state reactor power levels not in excess of 2544 megawatts thermal.
The facility comprises one pressurized water reacMr at the licensee's "ite located in Citrus County, Florida. The license provides, among other things, that it is subject to all rules, regulations and Orders of the Nuclear Regulatory Commission (the Comission) now or hereafter in effect.
II.
On November 19, 1980, the Comission published a revised Section 10 CFR 50.48 and a new Appendix R to 10 CFR 50 regarding fire protection features of i
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 pl nt. One of these fifteen subsections III.G., which requires that one train of cables and equipment necessary to achieve and maintain safe shutdown be maintained free of fire damage, is the subject of
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this exemption.
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7590-01 '
The specific areas in which exemptions from the requirements of Section III.G. have been requested are as follows.
Fire exemption requests concern separation of redundant equipment within a fire area:
1.
Intermediate Building Redundant Emergency Feedwater System Pumps and Valves (Fire Area 18-95-200) 2.
Auxiliary Building Seawater Pump Room (Fire Area AB-95-3)
- 3.
Auxiliary Building Redundant Makeup Pumps (Fire Area AB-95-3) 4.
Auxiliary Building Redundant Makeup System Valves (Fire Area AB-95-3) 5.
Reactor Building Penetration Assemblies (Fire Area 18-119-201)
One exemption request concerns the fixed suppression system for a fire area:
1.
Control Complex HVAC Equipment Room (Fire Area CC-164-121)
Six additional exemption requests concern fire area boundaries, the acceptance criteria fer which are called out in Appendix A to Branch Technical Position (BTP) APCSB 9.5-1.
Deviations from these fire area boundary guidelines do not require exemption and are accordingly not addressed herein.
III.
By letters dated September 24, 1984 and October 5,1984, and superseded by letter dated December 11, 1984, the licensee requested an exemption from requirements specified in Section III.G of Appendix R of 10 CFR 50. The specific requests and the acceptability of the exemption are addressed below.
7590-01 A)
Exemptions from Section III.G.2.
Subsection III.G.2 of Appendix R requires that one train of cables and equipment necessary to achieve and maintain safe shutdown be maintained free of fire damage by one of the following means:
Separation of cables and equipment and associated non-safety a.
circuits of redundant trains by a fire barrier having a 3-hour rating.
Structural steel forming a part of or supporting such fire barriers
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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, I
fire detectors and an automatic fire suppression system shall be j
installed in the fire area; or Enclosure of cables and equipment and associated non-safety c.
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.
The licensee requests exemption from Section III.G.2 of Appendix R to the extent that it requires separation of redundant safe shutdown components by 3-hour fire rated barriers for fire areas as follows:
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7590-01 1)
Redundant Emergency Feedwater System Pumps and Valves (Fire Area 18-95-200)
This fire area is located on the 95 foot elevation of the Intermediate Building.
It is bounded by 3-hour fire rated walls on all sides. The ceiling and floor are reinforced concrete.
This area contains the A-train motor driven and the B-train turbine driven emergency feedwater system pumps. One of the pumps is required for
~~ safe shutdown.
The pumps are separated by a partial height concrete wall.
Pipes and conduits traverse the open areas above and beyond the end of the wall and an open trench passes under the wall.
Two A-train valves and cables for an A-train valve located in another fire area are exposed by the B-train punp. One of the exposed valves has a redundant valve located in another fire area.
The fuel load of oil, grease, and cable insulation corresponds to an equivalent fire severity of approximately 25 minutes.
Existing fire protection includes an area-wide ionization detection system, portable extinguishers, and one hose station.
The l'.ensee proposes (1) to rotate the exposed A-train valve so that its motor operator will be located behind the partial height wall with respecttotheturbinedrivenpump;(2)toenclosethevalvewithina1-hour
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7590-01
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i i l fire rated enclosure; (3) to install automatic sprinklers throughout the fire I
area, except in the tendon access gallery; (3) to protect one train of redundant cables with 1-hour fire rated barriers; (4) to modify all cables traversing the space between the pumps to eliminate them as intervening combustibles;and(5)toinstallasteelplateacrossthedraintredhto x
prevent flame propagation through the trench.
The technical requirements.,of Section III.G.2 are not met because redundant shutdown components are not separated by 3-hour fire rated barriers.
The concern was that a fire,would damage both emergency feedwater i
systems. However, the area-wide detection system provides reasonable r
assurance that a fire anywhere in the fire area would be detected in its early stages and extinguished by the plant fire brigade before damage to redundant safe shutdown equipment occurs.
If rapid fire growth occurs prior to brigade arrival, the automatic sprinklers would operate and control or extinguish the fire.
7 The partial height wall separating the pumps, the valve enclosure, and the cable protection would provide passive protection and would prevent t
damage to these systems by flame impingement and radiant heat energy until the fire brigade arrivas or the sprinkler system operates. Therefore, we have reasonable assurance that one emergency feedwater system train will be available for safe shutdown afte) a fire in this area.
The tendon access gallery contains negligible combustibles. Therefore.
sprinkler protection is not required in this area.
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7590-01
. Based on our evaluation, we conclude that the existing fire protection 1
with the proposed modifications provides reasonable assurance that one train of the emergency feedwater system will be available for safe shutdown after a fire. Therefore, the exemption in Fire Area IB-95-200 is granted.
- 2) Auxiliary Building Seawater Pump Room (Fire Area AB-95-3)
This fire area is located on the 95 foot elevation of the Auxiliary Building. The Seawater Pump Room is located within this fire area. The room is bounded by reinforced concrete walls, floor, and ceiling.
The room has open doorways to 6he reactnr coolant pump seal injection filter room and the nuclear service booster pump room.
Redundant shutdown equipment in the room includes the emergency nuclear services and decay heat closed cycle cooling water system pumps, the emergency nuclear services and decay heat service seawater pumps, and their N
associated circuits. The minimum separation distance between redundant pumps is approximately 10 feet.
Combustible materials consists of oil, grease, cable insulation, and a s negligible amount of ordinary combustibles. The estimated fire severity is less than 12 minutes.
Existing fire protection consists of an ionization detection system, portable extinguishers, and one hose station.
The licensee proposes to install sprinkler protection throughout the room, except in the heat exchanger area, and to enclose one train of
, redundant cables in 1-hour fire rated barriers.
7590-01 The technical requirements of Section III.G.2 are not met because redundant safe shutdown equipment is not separated by 3-hour fire rated barriers.
The concern was that a fire would damage redundant safe shutdown components resulting in loss of safe shutdown capability.
The detection system provides reasonable assurance that a fire in the fire area would be detected before significant flame propagation or temperature rise occurs. The fire brigade would then extinguish the fire using available equipment before redundant equipment in the Seawater Pump Room is damaged.
If fire brigade response is delayed or rapid fire growth occurs, the automatic sprinkler system would operate, resulting in fire control, reduced room temperatures, and protection of redundant equipment.
The 1-hour fire rated cable protection will provide passive protection and provide reasonable assurance that one train of redundant circuits will be maintained free of damage until the fire is extinguished.
The combustible loading in the heat exchanger area is negligible.
Therefore, the absence of automatic sprinklers in this area is acceptable.
Based on our evaluation, we conclude that the existing fire protection with the proposed modifications provides reasonable assurance that one train of safe shutdown components located in the Seawater Pump Room will be available following a fire. Therefore, the licensee's request for exemption in the Seawater Pump Room is granted.
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7590-01
. 3)
Auxiliary Building Redundant Makeup Pumps (Fire Area AB-95-3)
This fire area is located on the 95 foot elevation of the Auxiliary Building.
The makeup pump area is located in this area and is enclosed by' reinforced concrete valls with offset open doorways at the northeast to southeast The pump area is divided into three cubicles by two reinforced corners.
concrete walls. The cubicles are connected by an open 3-foot wide corridor.
There are ventilation exhaust ducts in the dividing walls. One cable tray
_. traverses all three cubicles.
The ceiling in each end cubicle is 3-hour fire rated. The ceiling in the center cubicle is reinforced concrete with penetrations to the floor above.
Each cubicle contains one makeup pump and its supporting lube oil and gear oil pumps. One end pump is powered and controlled by A-train circuits, the other end pump by B-train circuits and the center pump by either A or B-train circuits.
The equivalent fire severity per cubicle is approximately 5 minutes.
Existing fire protection consists of hose stations and portable extinguishers located adjacent to the cubicles.
The licensee proposes (1) to install ionization detectors in the makeup pump area; (2) to install automatic sprinklers in the corridor that connects the pump cubicles; (3) to seal all ceiling penetrations; (4) to install 3-hour fire rated dampers in the exhaust ducts in the dividing walls; and (5) to seal the cable tray penetrations in the dividing walls, b
o 7590-01 The technical requirements of Section III.G.2 are not met because redundant safe shutdown ccmponents are not separated by 3-hour fire rated I
barriers.
I We were concerned that a fire originating either outside of or within the makeup pump area would result in loss of safe shutdown capability.
However, because the fuel load is low, we do not expect a fire of significant magnitude or duration to occur in the makeup pump area.
If a fire occurs
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anywhere in the fire area, it would be detected by the ionization detectors and extinguished by the plant fire brigade before spreading into the makeup pump area or from the cubicle of origin.
l If rapid fire growth occurs in the fire area, the cubicle walls, penetration seals, duct dampers, and corridor sprinklers provide reasonable assurance that fire damage would be Ifmited to no more than one cubicle.
In our opinion, under these conditions, any fire would, at most, cause damage to one shutdown system, but would not propagate horizontally and damage either of the two adjacent pumps before self-extinguishing or being extinguished by the plant fire brigade.
Based on our evaluation, we conclude that the existing fire protection with the proposed modifications provides an equivalent level of safety to that achieved by compliance with Section III.G. Therefore, the licensee's request for exemption in the makeup pump cubicles is granted.
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a 7590-01 4)
Auxiliary Building Redundant Makeup System Valves (Fire Area AB-95-3)
This fire area is located on the 95 foot elevation of the Auxiliary Building. Three redundant makeup system block valves are located in a hallway in this area. The hallway is bounded on the west by the Reactor Building and on the east by a reinforced concrete wall. There are open doorways to the north, northeast, and south. The floor and ceiling are reinforced concrete. Two small penetrations to the 119 foot elevation will
-- be sealed.
One A-train makeup system block valve is located between and within 20 feet of two B-train valves. The fuel load in the hallway corresponds to an equivalent fire severity of less than 2 minutes.
Existing fire protection consists of one hose station adjacent to the hallway and two portable extinguishers in the hallway.
The licensee proposes to install ionization detectors and automatic sprinklers in the hallway and to protect the A-train valve cables with 1-hour fire rated barriers.
The technical requirements of Section III.G.2 are not met because redundant shutdown equipment is not separated by 3-hour fire rated barriers.
Our concern was that a fire would damage the redundant makeup system block valves.
Because the fuel load is low, we do not expect a fire of significant magnitude or duration to occur.
If a fire does occur, it would be detected by the ionization detectors and extinguished by the plant fire brigade before damaging the redundant valves.
If rapid fire growth occurs.
the sprinkler system will operate and control or extinguish the fire.
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7590-01
. Moreover, the 1-hour fire rated cable protection will protect the A-train valve cables until the fire brigade arrived or the sprinkler system operates.
Therefore, we have reasonable assurance that loss of shutdown capability would not occur.
Based on our evaluation, we conclude that the existing fire protection 2
with the proposed modifications provides a level of protection equivalent to the requirements of Section III.G. Therefore, the exemption for the hallway containing the makeup system valves is granted 5)
Reactor Building Penetration Assemblies (Quadrants I and IV) (Fire Area I8-119-201)
This fire area is the 119 foot elevation of the Intermediate Building.
It is bounded on all sides by 3-hour fire rated walls.
The ceiling is formed by the building roof and has open vents to the outside. THe floor is partially basemat and is partially over Fire Area 18-95-200.
The fire area contains Reactor Building penetration assemblies in Quadrant I that are redundant to penetration assemblies in Quadrant IV. The penetration assemblies are separated by less than 20 feet with intervening combustible cable insulation between them.
The fuel load consists of approximately 70,000 pounds of cable insulation, 3,000 pounds of Class A combustibles, and 600 pounds of plastic.
This corresponds to an equivalent fire severity of approximately 60 minutes.
Existing fire protection includes area-wide ionization detectors, two hose stations, and portable extinguishers.
7590-01 The licensee proposes (1) to install automatic sprinklers throughout the fire area: (2) to enclose one train of redundant cables in the fire area in 1-hour fire rated barriers where redundant assemblies exist within the same quadrant.
The technical requirements of Section III.G.2 are not met because redundant safe shutdown equipment is not separated by 3-hour fire rated barriers.
We were concerned that an undetected, unsuppressed fire in this fire
--area would result in damage to redundant safe shutdown components. However, we expect the ionization detectors to detect any potential fire before significant flame propagation or temperature rise occurs, and the 1-hour fire rated barriers to provide passive protection until the fire brigade extinguishes the fire.
If rapid fire growth occurs prior to fire brigade arrival, we expect the automatic sprinklers to operate, control fire spread, and prevent damage to redundant systems.
We also expect smoke and hot gases to vent through the large open roof vents, further reducing the potential for damage to more than one shutdown division.
Based on our evaluation, we conclude that the existing fire protection with the proposed modifications provides reasonable assurance that loss of shutdown capability will not occur. Therefore, the licensee's request for exemption for the Reactor Building Penetration Assemblies. Quadrants I and IV is granted.
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7590-01 B)
Exemptions from Section III.G.3 If the requirements of Section III.G.2 are not met Section III.G.3 requires that there be an alternative shutdown capability independent of the fire area of concern.
It also requires that a fixed suppression system be installed in the fire area of concern if it contains a large concentration of cables or other combustibles.
1)
The licensee requests exemption from Section III.G.3 of Appendix R to the extent that it requires the installation of a fixhd fire suppression system in the Control Complex HVAC Equipment Room (Fire Area CC-164-121).
This fire area is located in the 164 foot (upper) elevation of the Control Complex. The HVAC Equipment Room is located in this fire area and is bounded by 3-hour fire rated or exterior walls. The floor is 3-hour fire rated. There is no safe shutdown equipment on the roof.
The fire area contains the HVAC equipment required to maintain the air temperature in the control room, cable spreading room, essential switchgear rooms, battery rooms, e.nd inverter rooms within acceptable limits for safe plant shutdown.
Combustible materials consist primarily of charcoal in the charcoal filters. There are minor quantities of cable insulation, oil, and miscellaneous combustibles.
The total fuel load of approximately 80,000 BTU /ft yields an equivalent fire severity of I hour.
Existing fire protection includes an area-wide ionization detection system, portable extinguishers, and automatic water spray systems for the charcoal filter banks.
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7590-01 To ensure that the areas within the Control Complex containing safe shutdown equipment will be cooled adequately if this existing HVAC system is disabled by fire, a separate dedicated system is being provided. This system will be located in another fire area.
The technical requirements of Section III.G.3 are not met in this fire area because of the lack of a complete fixed fire suppression system.
We were concerned that a fire would disable the HVAC system, resulting
- in loss of cooling to safe shutdown equipment in the Control Complex such that safe shutdown couli not be achieved and maintained.
The principal fire hizards are the charcoal filters.
Each filter bank is protected by an automatic water spray system consistent with the requirements of Regulatory Guide 1.52. Therefore, we expect any fire in the filters to be controlled by these systems.
The water flow alarm will initiate fire brigade response resulting in extinguishment before the fire spreads from the filter involved.
We also expect any fire originating outside of the filters to be detected during its early stages by the area-wide detection system and extinguished by the fire brigade before damage to redundant equipment occurs.
If any fire disables the Control Complex HVAC system, the alternate ventilation cooling system will be used to cool the safe shutdown equipment located in the Control Complex that is required to achieve and maintain safe shutdown.
7590-01 Based on our evaluation, we conclude that the existing fire protection with the proposed modifications provides an equivalent level of safety to that achieved by compliance with Section III.G. Therefore, the licensee's request for exemption in the Control Complex HVAC Room is granted.
IV.
Accordingly, the Commission has detennined that, pursuant to 10 CFR 50.12, an exemption is authorized by law and will not endanger life or property or comon defense and security and is otherwise in the public interest and hereby grants an exemption from the requirements of Sections III.G.2 and III.G.3 of Appendix R to 10 CFR 50 to the extent discussed in Section III above.
Pursuant to 10 CFR 51.32, the Comission has determined that the issuance of the exemption will have no significant impact on the environment (50FR29005).
FOR THE NUCLEAR REGULATORY COMMISSION Div[TsionofLicensing Hu h... Thompson ir ctor U
Office of Nuclear Reactor Regulation Dated at Bethesda, Maryland this 18th day of July 1985 L