ML13331A884
| ML13331A884 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 05/30/1986 |
| From: | Medford M Southern California Edison Co |
| To: | Lear G Office of Nuclear Reactor Regulation |
| References | |
| TAC-54880 NUDOCS 8606030154 | |
| Download: ML13331A884 (29) | |
Text
REQULAT*
INFORMATION DISTRIBUTIONOSTEM (RIDS)
ACCESSION NBR:8606030154 DOC.DATE: 86/05/30 NOTARIZED: NO DOCKET #
FACIL:50-206 San Onofre Nuclear Station, Unit 1, Southern Californ 05000206 AUTH.NAME AUTHOR AFFILIATION MEDFORDM.O.
Southern California Edison Co.
RECIP.NAME RECIPIENT AFFILIATION LEARG.E.
PWR Project Directorate I
SUBJECT:
Forwards requests for exemptions from IOCFR5OApp R, III.G.2.b for Fire Zones 1-YD-14-4C,1-YD-14-4FI-TB-20-9D &
1-TB-14-9E & from 10CFR50,App R,III.G.3 for Fire Zone 1-AB-20-2N for approval.
DISTRIBUTION CODE: AOO6D COPIES RECEIVED: LTR / ENCL J SIZE:__t"r TITLE: OR Submittal: Fire Protection NOTES:License Exp date in accordance with IOCFR2,2.109.
05000206 RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PWR-A PD1 PD 01 3
3 DUDLEY,R 1
1 INTERNAL: ADM/LFMB 1
0 ELD/HDS2 1
0 IE WHITNEY,L 1
1 NRR PWR-A DIR 1
1 NRR PWR-B DIR 1
1 NRR STANG,J 07 2
2 JO6 1
0 NRR/DHFT DIR 1
1 04 1
1 RON5 1
1 EXTERNAL: 24X 1
1 LPDR 03 1
1 NRC PDR 02 1
1 NSIC 05 1
1 TOTAL NUMBER OF COPIES REGUIRED: LTTR 20 ENCL 17
0*
/,----7 Southern California Edison Company P. 0.
BOX 800 2244 WALNUT GROVE AVENUE ROSEMEAD, CALIFORNIA 91770 M. 0.
MEDFORD TELEPHONE MANAGER. NUCLEAR LICENSING (818) 302-1749 May 30, 1986 Director, Office of Nuclear Reactor Regulation Attention: G. E. Lear, Director PWR Project Directorate No. 1 U. S. Nuclear Regulatory Commission Washington, D. C. 20555 Gentlemen:
Subject:
Docket No. 50-206 Fire Protection Exemption Requests San Onofre Nuclear Generating Station Unit 1 During the San Onofre Unit 1 Fire Protection Audit, May 19 through 23, 1986, the inspection team provided new guidance regarding the acceptable means of compliance with Section III.G of 10 CFR 50 Appendix R. The application of this new guidance results in the need to reevaluate the III.G.1 compliance evaluations previously submitted and resubmit evaluations or requests for exemption as appropriate. Accordingly, SCE is submitting as an enclosure to this letter Requests for Exemption from 10 CFR 50 Appendix R III.G.2.b for fire zones 1-YD-14-4C, 1-YD-14-4F, 1-TB-20-9D and 1-TB-14-9E; and from 10 CFR 50, Appendix R, III.G.3 for fire zone 1-AB-20-2N.
In addition, as requested by the NRC Inspection Team, the previously submitted requests for exemption for fire zones l-TB-8-9A and 1-TB-35-9B are being resubmitted to incorporate a design change which removed an alternate shutdown component from these zones.
In accordance with 10 CFR 50.12 (a)(ii), the technical bases, provided in the enclosed fire zone requests for exemption, demonstrate that special circumstances are present such that application of the regulations in San Onofre Unit l's particular circumstances is not necessary to achieve the underlying purpose of the requirements of 10 CFR 50 Appendix R III.G.
As stated in 10 CFR 50 Appendix R, the underlying purpose of III.G is to assure that one train of safe shutdown equipment and its associated circuits are free of fire damage so that they remain available to safely shutdown the plant. The III.G.2.b requirements for 20 foot separation with no intervening fire hazards along with fire detection and automatic suppression in the fire area are intended to prevent propagation of a fire between redundant trains. SCE is providing the technical bases to demonstrate that a fire in a zone will not affect the redundant safe shutdown equipment located outside that zone and that installation of additional fire detection and automatic suppression is not necessary. The III.G.3 requirements for fire detection and fixed suppression in the fire area/zone under consideration, where alternate or dedicated shutdown is provided, are intended to limit the extent of fire damage on the ability to safely 8606030154 860530 PDR ADOCK 05000206 F
0 0
Mr. G.
May 30, 1986 shutdown the plant. SCE is providing the technical bases to demonstrate that a fire will not affect the alternate or dedicated shutdown capability and that the existing fire protection features are adequate. Therefore, the installation of additional fire detection and automatic suppression in the fire area/zone would not enhance, to a significant degree, the ability to maintain one train of safe shutdown equipment free of fire damage due to the special circumstances of each individual fire zone/area discussed in the requests for exemption.
In addition, implementing additional modifications to provide fire detection and automatic suppression in these fire zones would result in an unnecessary burden upon SCE since the costs associated with compliance in these fire zones are not commensurate with the resulting improvement in the ability to safely shutdown the plant after a fire and are in excess of those required to meet the underlying purpose of the rule. These costs include:
- 1) The capital cost associated with engineering and installation of additional fire protection modifications.
- 2) The operational costs associated with the increased surveillance and maintenance on the additional fire protection equipment.
- 3) The additional engineering analysis and possible resulting modifications involved in the potential impact of spurious operation or rupture of fire suppression systems on safety related equipment and normal operations.
Therefore, the requests for exemption enclosed meet the requirements of 10 CFR 50.12 paragraph (a)(2)(ii) in that special circumstances are present.
Further, SCE has concluded that the granting of these exemptions would not present an undue risk to the public health and safety, and are consistent with common defense and security.
Your expeditious review and approval of the enclosed requests for exemption would be appreciated. SCE is available to support your efforts and will meet with your staff at their convenience, if necessary.
If you have any questions, or if we can provide additional information, please let me know.
Sincerely, Enclosure cc:
F. R. Huey, USNRC Senior Resident Inspector, Units 1, 2, and 3
- 3. B. Martin, Regional Administrator, Region V
Enclosure REQUESTS FOR EXEMPTIONS FROM 10 CFR 50 APPENDIX R SAN ONOFRE NUCLEAR GENERATING STATION UNIT 1
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FIRE ZONE 1-YD-20-4C TITLE:
Doghouse FIGURE:
3-1, 3-3 DESCRIPTION OF DEVIATION Statement of Problem The separation of circuits in fire area 1-YD-14-4 for letdown isolation valve, CV-526, (1-YD-20-4C), and seal water return isolation valve, CV-528, (1-YD-20-4C), from their redundant counterparts, CV-525 (1-YD-20-4A) and.
CV-527 (1-YD-20-4A) do not meet the requirements of 10CFR50 Appendix R, Section III.G.2.b in that area wide automatic fire suppression and detection is not provided in combination with a minimum of 20 foot horizontal separation with no intervening combustibles.
AREA DESCRIPTION Physical Characteristics Fire area 1-YD-20-4 is the yard area and consists of the following fire zones:
1-YD-20-4A, 1-YD-20-4B, 1-YD-20-4C, 1-YD-14-4D, l-YD-(-7)-4E, and 1-YD-14-4F, and 1-YD-20-4G.
Fire zone 1-YD-20-4C is located at the west end of the reactor building enclosure structure at elevation 20' 0".
The walls are all reinforced concrete construction, approximately 2'-3" thick. The ceiling is also of reinforced concrete constructon approximately 2'-0" thick.
This zone has the following unsealed openings:
- 1.
There are approximately 43 penetrations in the west wall of this zone communicating to zone 1-YD-14-4D. These penetrations vary in size from 1" to 10" in diameter carrying instrument lines, conduits or pipes varying in size from 3/8" to 8" in diameter.
- 2.
There is a gate opening into zone 1-YD-20-48.
Combustibles The in-situ combustible loading for the Doghouse is minimal, and consists of plastic coated flexible conduit for remote operated valves.
Other in-situ combustibles for the Doghouse consists of Class A materials (protective clothing) and plastic materials required to control radioactive contamination. The total value is conservatively assumed to be 50 pounds.
The total in-situ represent a fire duration of less than 5 minutes.
3692h :6831 F Revision 0
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FIRE ZONE 1-YD-20-4C FIRE PROTECTION CAPABILITY Detection Early warning ultraviolet flame detectors are provided in this fire zone.
Suppression Portable fire extinguishers and fire hose stations are available in adjacent fire zones for manual fire fighting capability.
BASES FOR EXEMPTION An exemption is requested from 10CFR5O Appendix R,Section III.G.2.b, which requires that redundant trains be separated by a horizontal distance of more than 20 feet with no intervening combustibles in combination with area wide automatic fire suppression and detection. The technical bases which justify the exemption request are detailed below.
- 1.
Letdown isolation valve CV-526, and seal water return isolation valve, CV-528, and their associated circuits are routed in the subject fire zone.
The redundant valves for letdown isolation, CV-525, and seal water return isolation, CV-527, and their associated circuits are routed in fire zone 1-YD-20-4A. The circuits for the redundant valves, CV-525 and CV-527, are located over 130 feet from fire zone 1-YD-20-4C with a minimum of 40 feet with no intervening combustibles at the interface of fire zones 1-YD-20-4B and 1-YD-20-4A (fire zone 1-YD-20-48 intervenes between fire zones 1-YD-20-4C and 1-YD-20-4A).
The redundant valves, therefore, will remain available for seal water return and letdown isolation.
- 2. Due to low combustible loading in fire zone 1-YD-20-4C a fire is not likely to propagate through the unsealed penetrations to adjacent zone 1-YD-14-40.
- 3. The San Onofre Fire Department consists of professionally trained, full-time personnel whose primary responsibility is fighting fires at San Onofre. The Fire Department is certified by the State of California Fire Marshall's office to provide fire suppresion activities. A minimum of five certified fire fighters are on duty per shift. The first arriving fire fighters under normal circumstances can be expected to be on scene within five minutes of the receipt of an alarm.
CONCLUSION Based on the above described configuration, the addition of a fixed fire suppression system to provide coverage throughout the fire area would not enhance to a significant degree, the safe shutdown capability of San Onofre Unit 1 beyond that provided by the existing configuration.
-2 3692h:6831F Revision 0
FIRE ZONE 1-YD-14-4F TITLE:
Condensate Storage Tank Area FIGURE:
3-1 DESCRIPTION OF DEVIATION Statement of Problem The separation of redundant trains of charging pumps RWST suction isolation valves, MOV-11000 (1-YD-14-4D and 1-YD-14-4F), MOV-1100B (1-YD-14-4D), MOV-883 (1-YD-14-4D and 1-YD-14-4F),
RWST suction bypass valve FCV-5051 (1-YD-20-4G),
volume control tank (VCT) isolation valve MOV-1lOOC (1-YD-14-4D and 1-YD-14-4F) and charging pump G-8A trip circuitry from LT-1100 (1-YD-14-4D) within the fire area do not meet the requirements of 10CFR5O Appendix R,Section III.G.2.b in that area wide automatic suppression and detection is not provided in combination with a minimum of 20 feet of horizontal separation with no intervening combustibles.
The specific relationship between the redundant and associated circuits is described in items 5, 6 and 7 of the Bases for Exemption.
AREA DESCRIPTION Physical Characteristics Fire area 1-YD-20-4 is the yard area and consists of the following fire zones:
1-YD-20-4A, 1-YD-20-4B, 1-YD-20-4C, 1-YD-14-4D, 1-YD-(-7)-4E, and 1-YD-14-4F, and 1-YD-20-4G.
Fire zone 1-YD-14-4F is located outdoors at the southwest end of the turbine building and is separated from the turbine building by 8" concrete block walls on the north and east sides.
The south and west boundaries of the zone are delineated by the vital area fence. This zone is adjacent to the Turbine Building (1-TB-8-9A) and Yard Area 1-YD-14-4D.
This zone has the following unsealed penetrations that communicate with fire zone 1-TB-8-9A.
- 1. A four-inch gap, flashed with sheet metal, runs along the entire length of the north and east walls. This gap is located between the top of the concrete block wall and beneath the concrete pad of the turbine and heater decks.
- 2. A 30'-2" by 41-10" louvered opening is located in the east wall 20'-0" from grade level and 36'-10" from the south wall of the turbine building. Two 8" pipes are routed through 10" diameter unsealed openings in the east wall.
Both openings are at elevation 28'-0" with one located 10'-0" and one ll'-6" from the north wall.
Four 3" conduits are routed throught 5" diameter unsealed openings in the east wall, located within one foot of the top of a 1-1/2 hour-rated fire door.
The door is located 30'-7" from the south turbine wall of the turbine building. Four 3" openings for pipes and conduits are located approximately 3'-0" below the turbine deck and 35'-0" from the south turbine wall.
Two 2" openings, one for conduit and one spare are locate approximately 8' below the turbine deck and 16'-6" from the south turbine wall.
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FIRE ZONE 1-YD-14-4F One nonrated door located in the east portion of the north wall at elevation 20-'O".
- 3. There are a total of 16 unsealed openings in the west portion of the north wall at elevation 14'-O".
These unsealed openings range in size from 1" to 14" in diameter.
Combustibles The in-situ combustible loading in fire zone 1-YD-14-4F consists of oil located in the transformers at the south end of the zone, oil in the oil/water separator on the west side of the zone, hydrogen in tanks at the northwest corner of the zone, cable trays routed from the west proximity to the southwest corner of the turbine building. The total fire loading is 371,954 Btus/sq.ft., with an equivalent fire severity of 4.65 hours7.523148e-4 days <br />0.0181 hours <br />1.074735e-4 weeks <br />2.47325e-5 months <br />.
No significant transient combustibles are expected.
FIRE PROTECTION CAPABILITY Detection No detection is provided for this fire zone.
Suppression Portable fire extinguishers are provided within the fire zone for manual fire fighting capability. Hose stations and other fire extinguishers are located in adjacent fire zones.
BASES FOR EXEMPTION An exemption is requested to 10CFR50 Appendix R, Section III.G.2.b, which requires that redundant trains of safe shutdown equipment be separated by a horizontal distance of more than 20 feet with no intervening combustibles in combination with area wide automatic fire suppression and detection.
The technical bases which justify the exemption request are detailed below:
- 1.
Fire zone 1-YD-14-4F is open to the environment allowing heat and products of combustion to be rapidly dissipated to the atmosphere.
- 2. The calculated fire duration of 4.65 hours7.523148e-4 days <br />0.0181 hours <br />1.074735e-4 weeks <br />2.47325e-5 months <br /> does not take into account the configuration of the area and separation of the fire hazards.
The hydrogen cylinders are 12 feet away from the oil separator, but are located below the wall of the oil separator. Since this is an outside area, a fire at (for example) the oil separator is not expected to ignite the hydrogen cylinders since there are no significant intervening combustibles, the hydrogen in cylinders is not easily ignited since they are located in an open air environment, and heat from the fire will dissipate to the atmosphere.
-2 3693h:6825F Revision 0
FIRE ZONE 1-YD-14-4F
- 3. The hydrogen cylinders, the oil separator and the station auxiliary transformer C are located approximately 18 feet, 30 feet and 28 feet respectively from the openings to 1-TB-8-9A. This ensures heat and products of combustion will be dissipated to the atmosphere. The radiant and convective heat that reaches the openings is not expected to be sufficient to propagate the fire into fire zone 1-TB-8-9A.
- 4. The auxiliary transformer is provided with 1'6" high curbs to contain an oil leak and prevent the spread of such a fire.
- 5. Circuits for MOV-1100D are routed through this fire zone (1-YD-14-4F).
The redundant valve, MOV-1100B, cables are routed through adjacent fire zones 1-YD-14-4D and 1-TB-8-9A approximately 120 feet north of this fire zone.
For a fire in zone 1-YD-14-4F to affect the redundant cables it would have to propagate through the penetrations in the 8" concrete wall and traverse approximately 120 feet via cable trays in fire zone 1-TB-8-9A in order to reach the redundant cables of MOV-1100B.
- 6. The cables for RWST isolation valve MOV-883 are routed in this fire zone. A fire in this zone could cause MOV-883 to spuriously close.
Should this occur in combination with a loss of letdown, charging pump G-8A will trip on low VCT level initiated by LT-1100, thereby preventing damage to the charging pump. Manual operator actions are taken to electrically isolate and open MOV-883. The circuits for LT-1100 are located in fire zone 1-YD-14-4D approximately 250 feet from the subject fire zone with no direct propagation path and are provided with a one-hour rated barrier.
- 7. Damage to cables for the volume control tank (VCT) isolation valve, MOV-1100C, could cause the valve to spuriously close. The installation of RWST suction bypass valve, FCV-5051, around MOV-1100B and MOV-11000 precludes a loss of charging pump suction should MOV-1100C spuriously close. If MOV-1100C spuriously remains open, charging pump G-8A will trip on low VCT level if letdown is lost coincidentally. The cables associated with FCV-5051 are routed in fire zone 1-YD-20-4G approximately 190 feet away with no direct propagation path for a fire in 1-YD-14-4F.
These cables are also routed underground from 1-YD-20-4G through 1-YD-14-4D to 1-AB-(-3)-2A. The trip signal originates from LT-1100 whose circuits are located approximately 250 feet away in fire zone 1-YD-14-4D. This circuit is provided with a one-hour fire rated barrier which ensures adequate time for operator actions if necessary.
- 8. The San Onofre Fire Department consists of professionally trained, full-time personnel whose primary responsibility is fighting fires at San Onofre. The Fire Department is certified by the State of California Fire Marshall's office to provide fire suppresion activities. A minimum of five certified fire fighters are on duty per shift. The first arriving fire fighters under normal circumstances can be expected to be on scene within five minutes of the receipt of an alarm.
-3 3693h:6825F Revision 0
FIRE ZONE 1-YD-14-4F CONCLUSION Based on the above described configuration, the installation of additional fixed suppression and fire detection to provide coverage throughout the fire area would not enhance to a significant degree, the safe shutdown capability of San Onofre Unit 1 beyond that provided by the existing configuration.
-4 3693h:6825F Revision 0
FIRE ZONE 1-TB-20-9D TITLE:
Main Transformer Area FIGURE:
3-1 DESCRIPTION OF DEVIATION Statement of Problem Cables for the charging pump RWST suction isolation valve MOV-1100D are located in 1-TB-20-9D. Cables for the redundant (to MOV-1100D) valve MOV-1100B are located in adjacent fire zone 1-TB-8-9A. Cables for charging pump RWST suction valve MOV-883 are also located in 1-TB-20-9D.
Cables for redundant (to MOV-883) charging pump suction valve from VCT MOV-1100C are located in fire zone 1-TB-8-9A. Cables for charging pump trip circuitry LT-1100 required to prevent pump damage due to spurious operation of MOV-883 are located in fore zone 1-TB-35-96. The separation of the above described redundant and associated circuits does not meet the requirements of 10 CFR 50, Appendix R, Section III.G.2.b in that automatic suppression and detection is not provided throughout the area in combination with a minimum of 20 feet of horizontal separation with no intervening combustibles.
AREA DESCRIPTION Physical Characteristics Fire area 1-TB-8-9 consists of fire zones 1-TB-8-9A, 1-TB-35-9B, 1-TB-10-9C, 1-TB-20-9D and 1-TB-14-9E.
Fire zbne 1-TB-20-9D, Main Transformer Area, is located in the southeast corner of fire area 1-TB-8-9 and is open to the atmosphere and bounded with non-rated walls on the west and north sides.
The west wall is concrete block. The north wall is concrete block and chain link fence. This zone is adjacent only to the turbine building ground floor (1-TB-8-9A).
The zone is enclosed by a 8 inch curb to contain any transformer oil leakage.
The zone has the following unsealed penetrations:
- 1. A 6" gap, flashed with sheet metal, runs along the entire length of the west wall and along the north wall up to the chain link fence. This gap is located between the top of the concrete block wall and the bottom of the concrete pad of the turbine and heater decks.
- 2. Two louvered openings are located in the west wall, one 3'-3" by 15'-0" and one 31'-6" by 6'-0", located 2'-0" from the south wall of the turbine building and 7'-0" from ground elevation and 41'-0" from the ground elevation, respectively. a 4'-8" by 3'-0" screened vent is located in the west wall, 22'-0" from the south wall of the turbine building and 12'-6" from ground elevation. A 2-1/2" conduit is routed through a 3" diameter unsealed opening in the west wall, 37'-3" from the south wall of 3679h:6829F Revision 0
FIRE ZONE 1-TB-20-9D the turbine building, 8'-0" from ground elevation. A 2-1/2" pipe is routed through 4" diameter unsealed opening in the west wall, adjacent to the north wall and 12'-0" from ground elevation. A 4" by 3" unsealed hole is located in the west wall, adjacent to the north wall and 13'-4" from ground elevation.
- 3. The north wall extends 27'-4" east from the west wall before ending, leaving a 23'-7" by 15'-6" opening, covered by chain link fence, as the remainder of the north fire zone boundary.
Combustibles The in-situ combustible loading in fire zone 1-TB-20-9D consists of 15,358 gallons of transformer oil located in three transformers. Two of these transformers are located approximately 15'-0" from the west wall, the third is 21'-10" from the west wall and 17'-0" from the northwest. The fire loading for this zone is 746,899 BTU/sq.ft., with an equivalent fire severity of 9.34 hours3.935185e-4 days <br />0.00944 hours <br />5.621693e-5 weeks <br />1.2937e-5 months <br />.
Due to the type of equipment located in this zone, no significant quantities of transient combustibles are expected during normal operation.
FIRE PROTECTION CAPABILITY Detection No detection is provided for this fire zone.
Suppression Portable fire extinguishers and hose stations are provided in adjacent fire zones for manual fire fighting capability.
BASES FOR EXEMPTION An exemption is requested from 10CFR50 Appendix R, Section III.G.2.b which requires that redundant trains be separated by a horizontal distance of more than 20 feet with no intervening combustibles or fire hazards in combination with area wide automatic fire suppression and detection. The technical bases which justify the exemption request are detailed below:
- 1.
For fires in fire zone 1-TB-20-9D the heat and products of combustion will be released to the atmosphere reducing the possibility of propagation into adjacent fire zones. The 8" curb prevents the spread of a running liquid transformer oil fire by containing it within the zone boundaries.
-2 3679h:6829F Revision 0
FIRE ZONE 1-TB-20-9D
- 2. The redundant charging RWST isolation valve MOV-1100B will remain available because its circuits in the adjacent fire zone 1-TB-8-9A are routed over approximately 120 feet away from 1-TB-20-9D. A fire would have to take a torturous path through penetrations on the north or west walls of the fire zone, into 1-TB-8-9A, and propagate through the turbine building over 120 feet via cable trays.
- 3. Circuits for the volume control tank isolation valve, MOV-1100C, are located in adjacent fire zone 1-TB-8-9A and are expected to remain free of fire damage due to the intervening walls and the large spatial separation. A fire would have to breach the west wall of fire zone 1-TB-20-9D and propagate via cable trays over 40 feet to affect the circuitry for MOV-1100C.
- 4. The cables for RWST isolation valve MOV-883 are routed in this fire zone. A fire in this zone could cause MOV-883 to spuriously close.
Should this occur in combination with a loss of letdown, charging pump G-8A will trip on low VCT level initiated by LT-1100, thereby preventing damage to the charging pump. Circuits for LT-1100 are located in fire area 1-TB-8-9 in fire zone 1-TB-35-9B over 160 feet from 1-TB-20-9D and are provided with a 1-hour rated barrier. Manual operator action is credited to electrically isolate and open MOV-883 to reestablish the RWST as the suction source for the charging pumps.
- 5.
Ionization and infrared detectors located at the south and of 1-TB-8-9A installed to actuate the water spray system installed over the hydrogen seal oil unit and alert the control room for prompt response by the fire department.
- 6. The San Onofre Fire Department consists of professionally trained, full time personnel whose primary responsibility is fighting fires at San Onofre. The Fire Department is certified by the State of California Fire Marshall's office to provide fire suppression activities. A minimum of five certified fire fighters are on duty per shift. The first arriving fire fighters under normal circumstances can be expected to be on scene within five minutes of the receipt of the alarm.
CONCLUSION Based on the above described configuration, the installation of additional fixed suppression and fire detection to provide coverage throughout the fire area would not enhance to a significant degree, the safe shutdown capability of San Onofre Unit 1 beyond that provided by the existing configuration.
-3 3679h:6829F Revision 0
FIRE ZONE 1-TB-14-9E TITLE:
Ramp FIGURE 3-1 DESCRIPTION OF DEVIATION Statement of Problem The separation of redundant trains of components associated with the thermal barrier pump, G-964, (1-TB-14-9E) and component cooling water pump, G-15A, (1-TB-8-9A) and the reactor protection system trip circuits (1-TB-14-9E) within the fire area does not meet the requirements of 10CFR50 Appendix R, Section III.G.2.b in that area wide automatic fire suppression and detection is not provided in combination with a minimum of 20 feet horizontal separation with no intervening combustibles.
AREA DESCRIPTION Physical Description Fire area 1-TB-8-9 is the turbine area and consists of the following zones:
1-TB-8-9A, 1-TB-35-9B, 1-TB-10-9C, 1-TB-20-90 and 1-TB-14-9E.
Fire zone 1-TB-14-9E is the ramp located on the east side of the Turbine Building. The zone is open to the atmosphere. Most of the west wall is chain link fence. There is no south wall.
The north wall is 3-hour rated.
The east wall and the small portion of west wall adjoining fire area l-PB-14-26, (East Cable Shaft) is reinforced concrete construction.
This zone has the following unsealed openings:
- 1. The west boundary of this zone directly communicates to zone 1-TB-8-9A.
- 2. There are nonrated bulletproof doors communicating with area 1-PB-14-8 (north wall of 1-TB-14-9E).
Combustibles The in-situ combustible loading in this fire zone consists of a cable tray running along the east wall, representing a combustible loading of 802 Btu/sq.ft. for an equivalent severity of less than 1 minute.
Transient combustibles in this zone is estimated to be one 55 gallon drum of lube oil for a combustible loading of 2,490 BTU/sq.ft., with an equivalent fire severity of less than 2 minutes.
FIRE PROTECTION CAPABILITY Detection No detection is provided for this fire zone.
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FIRE ZONE 1-TB-14-9E Suppression There are portable fire extinguishers and hose reels located in adjacent fire zone (1-TB-8-9A) at the southeast and northwest ends of this zone.
BASES FOR EXEMPTION An exemption is requested from 10CFR50 Appendix R, Section III.G.2.b which requires that redundant trains be separated by a horizontal distance of more than 20 feet with no intervening combustibles in combination with area wide automatic fire suppression and detection. The technical bases which justify the exemption are detailed below:
- 1. The in-situ combustibles in the fire zone consist of cables in a partially covered tray (61L1) running along the east wall of fire zone 1-TB-14-9E (Ramp) to the wall of 1-PB-14-8, (4kV switchgear room.)
The penetration into fire area 1-PB-14-8 is provided with a fire rated seal.
The in-situ combustible in fire zone 1-TB-14-9E (tray 61L1) is separated from the closest combustibles in adjacent fire zone 1-TB-8-9A, (Turbine Building Ground Floor) by a horizontal distance of 24 feet, which is free of intervening combustibles and open to the atmosphere.
- 2. The cables for Thermal Barrier Pump (G-964) are routed in the subject fire zone. The redundant cables for component cooling water pump (G-15A) are routed in fire area/zones 1-TB-8-9A, 1-FH-14-7, 1-PB-14-8, 1-YD-14-4D, 1-YD-20-4B and 1-PB-42-16. The circuits for redundant pump (G-15A) in 1-TB-8-9A are located over 70 feet from fire zone 1-TB-14-9E.
The north end of 1-TB-8-9A contains automatic suppression and detection providing protection of circuits for redundant pump G-15A.
- 3.
Damage to the RPS circuits, caused by a postulated fire, would result in a reactor scram and the fire would not affect the ability to safely shut the plant down.
- 4. The San Onofre Fire Department consists of professionally trained full time personnel whose primary responsibility is fighting fires at San Onofre. The Fire Department is certified by the State of California Fire Marshal's office to provide fire suppression activities. A minimum of five certified fire fighters are on duty per shift. The first arriving fire fighters under normal circumstances can be expected to be on scene within five minutes of the receipt of the alarm.
CONCLUSION Based on the above described configuration, the installation of additional fixed fire suppression and fire detection to provide coverage throughout the fire area would not enhance to a significant degree, the safe shutdown capability of San Onofre Unit 1 beyond that provided by the existing configuration.
-2 3685h:6830F Revision 0
FIRE ZONE 1-AB-20-2N TITLE:
Reactor Coolant Filter Enclosure FIGURE:
3-3 DESCRIPTION OF DEVIATION Statement of Problem Redundant components associated with the charging pumps RWST suction isolation valves MOV-1100B (1-AB-(-3)-2A and 1-AB-20-2N), MOV-1100D (1-AB-(-3)-2A and 1-AB-20-2N), FCV-5051 (1-AB-(-3)-2A) volume control tank isolation valve, MOV-1100C (1-AB-(-3)-2A and 1-AB-20-2N) and charging pump G-8A trip signal from LT-1100 (1-AB-20-2N) are located within fire area 1-AB-(-3)-2.
Alternative shutdown capability is provided through the use of the safety injection system for fire zone 1-AB-20-2N due to the lack of separation of the redundant components noted.
Fire zone 1-AB-20-2N does not meet the requirements of Section III.G.3 of Appendix R in that fire detection and fixed fire suppression systems are not provided in the fire zone.
AREA DESCRIPTION Physical Characteristics Fire area 1-AB-(-3)-2 consists of the following fire zones:
1-AB-(-3)-2A Reactor Auxiliary Building, Lower Level 1-AB-20-2C Solid Waste Baling Room 1-AB-20-2D Waste Gas Cryogenic Treatment Room 1-AB-20-2F High Level Sold Waste Storage 1-AB-20-2G Resin Slurry Tank Room 1-AB-20-2H Protective Clothing Storage 1-AB-20-2I Boron Concentration Measuring Room 1-AB-20-2L Decontamination Room 1-AB-20-2N Reactor Coolant Filter Enclosures 1-AB-20-2P Boric Acid Mixing Room" The adjacent fire areas are 1-YD-14-4, Yard Area, of which fire zone 1-YD-14-40 surrounds 1-AB-(-3)-2, and 1-AB-20-3, Volume Control Tank Room.
The walls and floors of fire zone 1-AB-20-2N are constructed of reinforced concrete with a minimum thickness of 21 inches.
The floor of 1-AB-20-2N separating it from 1-AB-(-3)-2A is reinforced concrete with a thickness of approximately 26 inches. There are several unsealed penetrations in the floor that communicates with 1-AB-(-3)-2A. The north and east walls of this zone (1-AB-20-2N) are reinforced concrete a minimum of 21 inches thick. The adjacent areas/zones to these walls are 1-AB-20-3 to the north and 1-YD-14-4D to the east.
3678h:6826F Revision 0
FIRE ZONE 1-AB-20-2N The south and west walls are reinforced concrete of approximately 12 inches.
The south wall provides separation from 1-AB-20-2I. The penetrations in the south wall consist of one 3" pipe and one 3" conduit penetration. The west wall has a 2' x 9' fixed opening with a locked gate which serves as an entrance and opens to fire zone 1-YD-14-4D. The roof of 1-AB-20-2N is constructed of reinforced concrete.
Combustibles The in-situ combustible loading in this fire zone consists of Class A combustibles, plastics, and a cylinder of hydrogen gas.
The fire loading is 8314 BTU/sq. ft. with an equivalent fire severity of 6 minutes.
Due to the zone's confined nature and intended uses and designation as a radiologically controlled area, no significant quantities of transient combustibles for 1-AB-20-2N are expected to be found therein.
FIRE PROTECTION CAPABILITY Detection No detection is provided for this fire zone.
Suppression Portable fire extinguishers and fire hose stations are available approximately 30 feet away in the adjacent fire zone, 1-YD-14-4D.
BASES FOR EXEMPTION An exemption is requested from 10CFR50 Appendix R, Section III.G.3 which requires that fire detection and fixed fire suppression be installed in the zone for which alternate shutdown capability is provided. The technical bases which justify the exemption request are detailed below:
- 1. The in-situ combustible loading represents a fire with a duration of only 6 minutes of which 4 minutes is attributed to the hydrogen cylinder located in the zone.
- 2.
Due to the low in-situ combustible loading of 1-AB-20-2N a fire hazard threat does not exist for the hydrogen cylinder.
- 3. Due to the low in-situ combustible loading in fire zone 1-AB-20-2N, a fire is not likely to propogate through the fixed opening to adjacent zone 1-YD-14-4D.
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FIRE ZONE 1-AB-20-2N
- 4. The following fire zones adjacent to 1-AB-20-2N do not have redundant or alternate safe shutdown equipment or cables:
1-AB-20-2C Solid waste baling room 1-AB-20-2I Boron concentration measuring room 1-AB-20-2L Decontamination area 1-AB-20-2G Resin Tank Slurry Room 1-AB-20-3 Volume control tank room
- 5.
Portable fire fighting equipment is available in the yard area 1-YD-14-4D to provide prompt control of the fire.
- 6. Alternate shutdown equipment and circuits for the safety injection system are located in the following fire areas/zones: 1-CO-(-10)-l, 1-FH-14-7, 1-PB-42-16, 1-PB-14-8, 1-YD-20-4A, 1-YD-20-4B, 1-YD-14-4D, 1-YD-14-4F, 1-TB-8-9A, 1-TB-20-9D, 1-DG-20-17A and 1-DG-20-17B.
These circuits are independent of fire zone 1-AB-20-2N due to the large spatial separation of over 80 feet with no direct propagation path for a fire.
- 7.
Level transmitter LT-1100 is located in fire zone 1-AB-20-2N. If it were disabled in conjunction with the spurious operation of MOV-1100C resulting in a charging pump mechanical failure, alternate shutdown can be implemented using the safety injection sytem (SIS) whose components and cables are routed independent of fire area 1-AB-(-3)-2. The loss due to fire of the circuits for MOV-1100 B and D and FCV-5051 associated with charging pump suction will not affect the capability for the use of the safety injection system.
- 8.
The San Onofre Fire Department consists of professionally trained, full-time personnel whose primary responsibility is fighting fires at San Onofre. The Fire Department is certified by the State of California Fire Marshall's office to provide fire suppression activities. A minimum of five certified fire fighters are on duty per shift. The first arriving fire fighters under normal circumstances can be expected on scene within five minutes of the receipt of an alarm.
CONCLUSION Based on the above described low in-situ combustible loading, and separation of alternate components and cables such that they are independent of fire area 1-AB-(-3)-2, the addition of fire detection and automatic fire suppression in the zone would not enhance to a significant degree the protection of safe shutdown functions which is provided by the existing configuration.
-3 3678h:6826F Revision 0
0 FIRE ZONE l-TB-8-9A TITLE:
Turbine Building Ground Floor FIGURE:
3-1 DESCRIPTION OF DEVIATION Statement of Problem The fire area does not meet the requirements of Section III.G.3 of Appenidx R, in that partial area fire detection and fixed fire suppression systems are provided in the fire zone.
Dedicated shutdown capability has been provided for use in the event of a fire in this zone.
AREA DESCRIPTION Physical Characteristics The turbine building ground floor contains the condenser and main feedwater pump areas, the turbine lube oil reservoir area, and the auxiliary feedwater pumps. The north wall of the zone, which separates the zone from 4160V switchgear room (1-PB-14-8) is 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> rated. The walls of the lube oil storage shed (1-TB-14-10) are also 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> rated. The wall adjoining the east and west penetration areas (1-YD-20-4A, 1-YD-20-4B), and the east and south wall of the 480V switchgear room (1-FH-14-7) are 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> rated. The remainder of the zone walls are constructed of concrete block or reinforced concrete.
Three hour rated doors allow access to the 4160V switchgear room, the 480V switchgear room and the lube oil storage shed. A 1-1/2 hour rated door and a nonrated door open to the adjacent condensate storage tank area (1-YD-14-4F). Nonrated doors communicate with the yard area (1-YD-14-4D).
Combustibles The in-situ combustible loading in the turbine building ground floor is approximately 110,000 Btu/sq.ft., with an equivalent fire severity of 82 minutes. The in-situ loading consists primarily of localized combustibles resulting from the lube oil within the lube oil reservoir at the north end of the zone, cable insulation located along the inside perimeter of the zone above the lube oil and chemical feed area and in the center of the zone, around the condensers and the hydrogen seal oil unit and several banks of batteries located in the south end of the zone.
Transient combustibles in the fire zone are insignificant relative to the overall fire loading for the fire zone.
Redundant Equipment The turbine building ground floor contains the auxiliary feedwater pumps, motor control center 3, and cabling for the following systems used to achieve hot standby and cold shutdown.
3690h:6827F Revision 1
FIRE ZONE 1-TB-8-9A Reactor Coolant System Chemical and Volume Control System Main Steam System Auxiliary Feedwater System Component Cooling Water System Saltwater Cooling System Residual Heat Removal System Reactor Cavity Cooling Fans Essential Electric Systems ACTIVE FIRE PROTECTION CAPABILITY Dectection Four types of detectors are used to provide coverage of the hazards within the fire zone:
Cross-zoned infrared flame detectors are installed over the lube oil reservoir pump and conditioner areas.
Infrared detectors are also installed at the hydrogen seal oil unit and over the emergency air compressor.
Line type detectors are installed under the lowest cable trays above the lube oil reservoir area.
Ionization smoke detectors are installed at the lube oil reservoir area and at the south end of the turbine building in the area of the exciter.
Suppression Five automatic suppression systems are provided for the protection of the hazard areas within the fire zone:
An automatic wet pipe sprinkler system is provided for the protection of the chemical feed area.
An automatic wet pipe sprinkler system is provided for the protection of the chemical treatment area, the east wall and a portion of the south wall of the 480V switchgear room, the north wall of the chemical treatment area, and the structural steel at the north end of the fire zone.
An aqueous film forming foam system is provided for the lube oil reservoir and conditioner areas.
This system is actuated by the cross-zoned infrared detectors installed in this area.
Automatic water spray systems protect the cable trays routed in the north portion of the fire zone near the lube oil and chemical feed areas.
This system is actuated by line type heat detectors.
An automatic water spray system, actuated by infrared detectors, is provided for the protection of the hydrogen seal oil unit at the south end of the turbine building.
Portable fire extinguishers and fire hose stations are available within the fire zone, and in adjacent fire area/zones for manual fire fighting capability.
-2 3690h:6827F Revision 1
FIRE ZONE 1-TB-8-9A BASES FOR EXEMPTION An exemption is requested to 10CFR5O Appendix R,Section III.G.3, which requires that fire detection and fixed suppression be installed in this zone since dedicated shutdown capability is provided.
The technical bases which justify the exemption are detailed below.
- 1. The use of the dedicated shutdown (DSD) system is credited for a fire in this fire zone.
- 2. Cables and equipment for the auxiliary shutdown panel, C-38, have been relocated outside the fire zone, and used as the dedicated shutdown system panel.
All dedicated shutdown system components will be located outside the fire zone to provide indepedence.
- 3. The dedicated auxiliary feedwater pump, the dedicated shutdown diesel and electrical systems, and the dedicated shutdown panel will be located at the northwest corner of the yard area (1-YD-20-4G), and are independent from this fire zone, due to the large spatial separation of approximately 100 feet with isolated localized intervening combustibles.
- 4. The plant circuit breakers will be tripped in the control room to deenergize offsite power and prevent and mitigate spurious equipment operation. The operation of the plant circuit breakers can be accomplished at one panel, located near the control room exit, as the operators evacuate the control room. Circuits for the manual trip of the plant circuit breakers are routed outside this fire zone.
- 5. The charging pump used for dedicated shutdown is located in the reactor auxiliary building lower level (1-AB-(-3)-2A) and will remain free of fire damage from a fire in this fire zone due to the large spatial separation of approximately 100 feet with isolated localized intervening combustibles.
- 6. The steam dump transfer control valve (SV-175) and associated circuitry have been relocated from the mezzanine of the turbine building to the penetration area (1-YD-20-4B) and provided with a 3-hour rated barrier, and will remain free of fire damage.
- 7. Operator action will be taken to manually control certain valves located outside the fire area, in order to initiate dedicated shutdown system operation.
- 8. Operator action will be taken to manually trip the turbine at the turbine stand on the turbine deck (1-TB-35-9B).
- 9. Operator action will be taken to manually close the reheater isolation valves, which are located within the fire area, after extinguishment of the fire.
-3 3690h:6827F Revision 1
FIRE ZONE 1-TB-8-9A
- 10. The existing fire suppression and detection systems within the fire zone provide protection commensurate with the hazards within the fire zone.
- 11.
The San Onofre Fire Department consists of professionally trained, full time personnel whose primary responsibility is fighting fires at San Onofre. The Fire Department is certified by the State of California Fire Marshall's office to provide fire suppression activities. A minimum of five certified fire fighters are on duty per shift. The first arriving fire fighters under normal circumstances can be expected to be onscene within five minutes of the receipt of an alarm.
CONCLUSION Based on the above described separation and existing protection, the installation of additional fixed fire suppression and fire detection to provide coverage throughout the fire zone would not enhance, to a significant degree, the safe shutdown capability of San Onofre Unit 1 beyond that provided by the existing configuration.
-4 3690h:6827F Revision 1
FIRE ZONE 1-TB-35-9B TITLE:
Turbine Deck FIGURE:
3-2 DESCRIPTION OF DEVIATION Statement of Problem The fire zone does not meet the requirements of Section III.G.3 of Appendix R, in that fire detection and fixed fire suppression systems are not provided throughout the fire zone. The circuits for the following control room instruments are routed in this fire zone: TE-2401A, 2412A, 2422A, TE-3402A, 3411A, 3421A and PT-425. Alternative hot leg temperature indication (TE-402A, 412A, 422A) and pressurizer pressure indication (PT-434A) is available through the use of the instruments at the dedicated shutdown panel (C-38) located in fire zone 1-YD-20-4G.
AREA DESCRIPTION Physical Characteristics The turbine deck is an exterior fire zone, which consists of the feedwater heater deck, located at elevation 35', and the turbine deck, located at elevation 42'.
The walls separating the zone from the control room complex (1-PB-42-16) are 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> rated.
The north end of the zone adjoins the steel containment sphere. The remainder of the walls separating the zone from other fire area/zones are reinforced concrete or concrete block, with a minimum thickness of 8 inches. The floor of the zone is reinforced concrete. A personnel access hatch and an equipment hatch allow access to containment from the zone. A nonrated sliding metal door and a nonrated rolling metal door communicate with the spent fuel storage room (1-FH-2-5). A nonrated rolling metal door also opens to the new fuel storage room (1-FH-42-6). A 3/4-hour rated door provides access to the south stairwell/locker room (1-PB-20-318).
Louvered ventilation openings communicate with the turbine building ground floor (1-TB-8-9A) and the new fuel storage room.
Combustibles The in situ combustible loading on the turbine deck is approximately 114 Btu/sq.ft., with an equivalent fire severity of under one minute. The in situ loading consists of oil and grease from the turbine lube oil system and the overhead crane.
3708h:6828F Revision 1
FIRE ZONE 1-TB-35-9B Redundant Equipment The turbine deck contains the turbine stop valves and cabling for the following redundant equipment used to achieve hot standby and cold shutdown:
Pressurizer pressure transmitter Primary system hot leg temperature transmitters Turbine stop valves Motor driven auxiliary feedwater pump Steam driven auxiliary feedwater pump Auxiliary feedwater flow control valves ACTIVE FIRE PROTECTION CAPABILITY Detection No fire detection is provided for this fire zone.
Suppression Portable fire extinguishers and six fire hose stations are available within the fire zone for manual fire fighting capability.
BASES FOR EXEMPTION An exemption is requested to 10CFR5O, Appendix R,Section III.G.3, which requires that fire detection and fixed suppression be installed in this zone since alternative shutdown capability is provided.
The technical bases which jusitfy the exemption request are detailed below.
- 1. Alternative hot leg temperature indication TE-402A, 412A, 422A and pressurizer pressure indication PT-434A are provided independent of this fire zone at the dedicated shutdown panel (C-38) in fire zone 1-YD-20-4G.
- 2. The combustible loading in the fire area results in an equivalent fire severity of under one minute.
- 3. Combustible gases and heat generated by a fire in the zone would be dissipated to the atmosphere.
- 4. Portable fire extinguishers and fire hose stations are immediately available for manual fire fighting purposes.
- 5. Operator action may be taken to locally control certain equipment located outside the fire zone.
- 6. Operator action may be taken to manually trip the turbine at the turbine stand.
-2 3708h:6828F Revision 1
FIRE ZONE 1-TB-35-9B
- 7. The San Onofre Fire Department consists of professionally trained, full time personnel whose primary responsibility is fighting fires at San Onofre. The Fire Department is certified by the State of California Fire Marshall's office to provide fire suppression activities. A minimum of five certified fire fighters are on duty per shift. The first arriving fire fighters under normal circumstances can be expected to be on scene within five minutes of the receipt of the alarm.
CONCLUSION Based on the above described configuration and minimal combustible loading, the addition of fire detection or fixed automatic suppression throughout this zone would not enhance, to a significant degree, the protection of safe shutdown capability of San Onofre Unit 1 beyond that provided by the existing configuration.
-3 3708h:6828F Revision 1
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