ML20132E427
| ML20132E427 | |
| Person / Time | |
|---|---|
| Site: | Crystal River  |
| Issue date: | 07/18/1985 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20132E392 | List: |
| References | |
| NUDOCS 8508010812 | |
| Download: ML20132E427 (5) | |
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k UNITED STATES NUCLEAR REGULATORY COMMISSION a
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j WASHINGTON, D. C. 20555
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO FIRE PROTECTION EXEMPTIONS FLORIDA POWER CORPORATION ET AL.
CRYSTAL RIVER UNIT 3 NUCLEAR GENERATTNG PLANT DOCKET NO. 50-302
1.0 INTRODUCTION
By letters dated September 24, 1984, October 5,1984 and superseded by letter dated December 11, 1984, Florida Power Corporation (the licensee for the Crystal River Unit No. 3 Nuclear Generating Plant) requested, among other things, six exemptions from Section III.G.2 of Appendix R of 10 CFR 50.
The exemptions are concerned with the following six areas to the extent that they require separation of redundant safe shutdown components by 3-hour fire rated barriers.
1.
Auxiliary Building Open Stairway (Fire Areas AB-95-3 and AB-119-6) 2.
Auxiliary Building Reactor Coolant Bleed Tank Room (Fire Areas AB-95-3 and AB-119-6) 3.
Auxiliary Building Elevator Shaf t (Fire Areas AB-95-3 and AB-119-6) 4 Auxiliary Butiding Open Stairway and Pipe Chase (Fire Areas AB-95-3 and 1
AB-119-6) 5.
Auxiliary Building Decay Heat Pits (Fire Areas AB-75-4, AB-75-5, and AB-95-3) 6.
Intermediate Building Ceiling / Floor Penetrations (Fire Areas IB-95-200 and IB-119-201)
Sectio. III.G.2 of Appendix R contains requirements for fire protection within fire areas. Our review indicates that the six exemption requests are associated with fire area boundaries for which Section III.G.2 of Appendix R does not apply. Acceptable guidelines for the establishment of fire area boundaries are set forth in Appendix A to BTP APCSB 9.5-1 in Section D.1(j).
Therefore we have reviewed these six fire areas for conformance with the guidelines given in Appendix A of BTP APCSB 9.5-1.
Fire areas 1 through 4 above are evaluated as part A of the evaluation below and Fire areas 5 and 6 are covered in part B and C respectively.
Additional exemption requests contained in the above-noted letters from the licensee have been addressed in a separate Exemptiori from the requirements of 10CFR Part 50, Appendix R.
A.
Auxiliary Building Fire Area Penetrations (Fire Areas AB-95-3 and A8-119-6)
These fire areas are located on the 95 foot and the 119 foot elevations of i
the Auxiliary Building. They are connected by (1) an open stairway in the northeast corner of the building, (2) open doorways from the Reactor Coolant Bleed Tank Room, (3) an elevator shaft in the middle of the building, and (4) an open stairway and pipe chase in the southwest corner of the building.
There are safe shutdown components in both fire areas.
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. Existing fire protection includes area-wide ionization detection systems, portable extinguishers, and hose stations.
The open staimay in the northeast corner connects a hallway that runs the length of the north end of Fire Area AB-95-3 with.a hallway that runs the length of the north end of Fire Area AB-119-6.
The hallways are bounded by reinforced concrete and 3-hour fire rated walls with reinforced concrete floors and ceilings. There are openings from both hallways to adjacent fire zones. An HVAC duct penetrates the north wall of the Fire Area AB-95-3 hallway.
The fuel load of cable insulation, Class A materials, and plastics corresponds to an equivalent fire severity of 1.6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> for the Fire Area AB-95-3 hallway and 4.6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> for the fire Area AB-119-6 hallway.
The licenee proposes (1) to install automatic sprinklers throughout both hallways and in areas adjacent to the hallways; (2) to install a draft stop and close-spaced sprinklers around the perimeter of the stairway opening
_ between the 95 foot and 119 foot elevations; (3) to protect at least one train of redundant cables in each hallway and the stairway vicinity, i.e.,
the space defined by the staimay and extending 10 feet west to column line 302 and 20 feet south to column line J on both elevations, with 1-hour fire rated barriers; (4) to protect a sufficient number of cable trays in the stairway vicinity to reduce the anticipated fire severity to less than 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />; (5) to seal all ceiling / floor penetrations between the hallways with the exception of the open stairway; and (6) to install a 3-hour fire rated i
damper in the Fire Area AB-95-3 hallway HVAC duct.
The Reactor Coolant Bleed Tank Room extends from the floor of Fire Area AB-95-3 to the ceiling of Fire Area AB-119-6 and is open to both areas via an offset open passageway on each elevation.
l The Reactor Coolant Bleed Tank Room is bounded on all sides by reinforced concrete walls. Makeup ventilation flow enters the room through these i
openings and is exhausted through a closed duct.
i There are no redundant safe shutdown components located in the Reactor Coolant Bleed Tank Room. The nearest safe shutdown component to the room is located 16 feet from the 95 foot elevation room entrance.
3 The room contains approximately 3300 pounds of cable insulation which correspondes to a fire severity of approximately 10 minutes.
The licensee proposes to install automatic sprinkler protection in the passageway to the Reactor Coolant Bleed Tank Room on the 95 foot elevation and in adjacent zones that contain safe shutdown components. The licensee also proposes to protect at least one train of redundant safe shutdown circuits in zones adjacent to the Reactor Coolant Bleed Tank Room with 1-hour fire rated barriers.
. The elevator shaft is bounded on three sides by reinforced concrete walls.
Elevator doors form the fourth boundary..These doors cannot be opened simultaneously in both fire areas.
The fuel load in the shaft is negligible.
The licensee proposes to install automatic sprinklers in all areas around the elevator shaft that contain safe shutdown components or circuits, and to enclose at least one train of safe shutdown circuits in these areas in 1-hour fire rated barriers.
The shaft for the open stairway and pipe chase in the southeast corner of the building is bounded by reinforced concrete walls, floor, and ceiling.
There are open doorways from the shaft on both elevations.
The primary fuel load in the lower elevation stairway is approximately 5000 pounds of cable insulation. This represents an equivalent fire severity of approximately 30 minutes. The fuel load of miscellaneous combustibles in the upper elevation of the shaft yields an equivalent fire severity of
~~ approximately 5 minutes.
The licensee proposes (1) to install automatic sprinklers throughout the lower elevation stairway and in areas that contain safe shutdown equipment outside of the stairway on both elevations, (2) to install a draft stop and water curtain around the perimeter of the stair opening, (3) to install a draft stop around the perimeter of the pipe chase opening, and (4) to protect at least one train of redundant safe shutdown circuits in each fire area with 1-hour fire rated barriers.
The existing fire protection with the proposed modifications meets the guidelines in Section D.I.(j) of Appendix A to BTP APCSB 9.5-1, and is therefore acceptable.
B.
Auxiliary Building Decay Heat Pits (Fire Areas AB-75-4, AB-75-5 and AB-95-3)
The two Decay Heat Pits are located on the 75 foot elevation of the Auxiliary Building. The pits are separated by a commmon 3-hour fire rated wall.
The pit boundaries are external reinforced concrete below grade walls. The ceilings are reinforced concrete. There is an open entrance hatchway to Fire Area AB-95-3, the 95 foot elevation of the Auxiliary Building, in the ceiling of each pit.
The pit hatchways are around a corner from each other and are approximately 50 feet apart. They are surrounded by 24-inch high curbs.
The combustible loading in each pit yields an equivalent fire severity of less than 10 minutes per. pit.
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1 Existing fire protection includes an area-wide ionization detection system in each pit and hose stations and portable extinguishers near each pit hatchway.
The licensee proposes to install automatic sprinklers over and beyond both hatchways in Fire Area AB-95-3 and to enclose at least one train of redundant cables serving the decay heat pumps in 1-hour fire rated barriers throughout Fire Area AB-95-3.
The existing fire protection with these proposed modifications meets the guildeines in Section D.1.(j) of Appendix A to BTP APCSB 9.5-1 and is therefore acceptable.
C.
Intermediate Building Ceiling / Floor Penetrations (Fire Areas 18-95-200 and 18-119-201)
Both fires areas are bounded by 3-hour fire rated wallt. The ceiling / floor assembly separating the fire areas is reinforced concrete and except for the following open penetrations offers fire resistance equivalent to 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />s:
(1)
I
~ fifteen pipe penetrations, (2) four tendon stressing fitting openings, and (3) two ceiling gratings.
Both fire areas contain redundant safe shutdown components and circuits.
The pipe penetrations are 8 to 16 inches in diameter. On average, each is occupied about 30 percent by the pipe. Each penetration is sleeved with a steel pipe which extends from 3 to 36 inches above the floor.
Each tendon stressing fitting opening is approximately 9 square feet in area. Each opening is surrounded by a steel enclosure that extends approximately 30 inches from the floor.
Each opening is covered by grating.
The ceiling gratings are located directly below the main steam lines. There are no combustible materials or safe shutdown components above or below these gratings.
The fuel load in Fire Area 18-119-201 consists of approximately 70,000 pounds of cable insulation, 3100 pounds of ordinary combustibles, and 600 pounds of plastics. This corresponds to an estimated equivalent fire severity of 60 minutes. The fuel load in Fire Area 18-95-200 consists of approximately 23 i
gallons of oil and grease and 11,300 pounds of cable insulation. The estimated fire severity is 25 minutes.
Exisitng fire protection includes area wide ionization detection systems, hose stations and portable extinguishers.
The licensee proposes to install a wet pipe sprinkler system throughout each fire area and to enclose one train of redundant cables in each area in 1-hour fire rated barriers.
The existing fire protection with these proposed modifications meets. the guidelines in Section D.I.(j) of Appendix A to BTP APCSB 9.5-1 and is therefore acceptable.
D.
Co-
'on Basec review, we find the existing fire protection with the proposed modific.
.ns in the Auxiliary Building fire area penetrations (Fire Areas AB-95-3 and AB-119-6), Auxiliary Building Decay Heat Pits (Fire Areas AB-75-4, AB-75-5, and AB-95-3), and Intermediate Building Ceiling / Floor Penetrations (Fire Areas 18-95-200 and IB-119-201) to be in accordance with the guidelines of Appendix A to BTP APCSB 9.5-1. Section D.1.(j), and therefore acceptable.
Principal Contributor:
K. S. West Dated: July 18,1985 m
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