ML20136G994
| ML20136G994 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 05/02/1980 |
| From: | Macdougall E BROOKHAVEN NATIONAL LABORATORY |
| To: | Ferguson R NRC |
| Shared Package | |
| ML20136D968 | List: |
| References | |
| FOIA-85-425 800502, NUDOCS 8508200120 | |
| Download: ML20136G994 (1) | |
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F r em E Dn LLL BRO KHAVEN NATIONAL LABORATORY ASSOCIATED UNIVERSITIES, INC.
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s Upton. New York 11973 Department of Nuclear Er.ergy (516) 345- 2362 May 2, 1980 Mr. Robert L. Ferguson Chemical Engineering U.S. Nuclear Regulatory Commission Washington, D.C. 20555 RE: San Onofre, Fire Protection Review
Dear Bob:
Further to our talk yesterday, we have the following San Onofre items where the licensee has submitted information, but we considered that it was not adequate to comment on:
Item 3.1.1 1-4 and 6-11 - Fire Detection Systems Item 3.1.2(c) - Fire Water Supply, improve intertie -
connection Item 3.1.5 -
Water Suppression System (a) 480 volt SWGR room wall directed water spray (c) turbine lube oil area wall and structural steel directed water spray (e) Hydrogen seal oil unit foam system Item 3.1.15(e) .M - Oli Collection System for reactor coolant pumps On this last item 3.1.15(e) at Leo Derderian's request, Mario Antonetti will review the prints. We will forward his comments to you on this and two other items from the licensee's letter of January 23, 1980 in the next few days.
Sincerely yours, Edward A. MacDougall EAM:sd Reactor Engineering Analysis cc.: R. Hall 8508200120 PDR FOIA 850722 BELL 85-425 PDR
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h G. gage babcock & associates,inc.
CHICAGO SAN F R ANCISCO LOS ANGELES NEW YORK NEW YORK OFFICE A J. LONGHITANO. P. E. 105 KISCc AVENUE, MT. KISCO. NEW YORK 10549 MANAGER (914) 666-2981 NYC (212) 562 7638 July 5, 1978 File No. 7722 Thermal Reactor Safety Division Department of Applied Science Brookhaven National Laboratories Upton, New York 11973 Attention: Mr. Robert Hall Building No. 130 RE: Review of Fire Hazard Analysis - San Onofre Nuclear Generating Station Unit 1 Gentlemen:
After reviewing the Fire Hazard Analysis submitted by Southern California Edison Company, dated March, 1977, on their San Onofre Nuclear Generating Station Unit 1, the attached list of initial Questions and Recommendations were developed.
The copy of the Questions and Recommendations has been for-warded to Mr. Robert Ferguson of NRC. These will be used during July 14th.
the site visit to the Utility dated July 9th through Very truly yours, GAGE-BABCOCK & ASSOCIATES, INC.
Mario A. Antonetti, P.E.
MAA/ims Enclosure cc: Mr. Robert Ferguson linclear Regulatory Cosenission*
ENGINEERS / CONSULTANTS RISK ANALYSIS & LOSS CONTROL / SYSTEMS DESIGN / MUNICIPAL FIRE DEFENSE SERVICES 1
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QUESTIONS
- 1. Describe the consequences of a hydrogen fire in the pipe tunnel when the break simulates the largest demand on the hydrogen system.
- 2. Describe the emergency power supply for the alarm system if offsite power is lost.
- 3. Provide the candidate inspection report made by Nuclear Mutual Limited.
- 4. Describe emergency power supplied to the fire pumps upon the loss of offsite power.
- 5. Provide a list of water suppression systems which do not have a waterflow alarm annunciating in the control room.
- 6. How are the hose stations inside containment supplied with water?
- 7. Provide a list of the redundant equipment affected by a fire in the pipe tunnel.
- 8. Will the proposed curb around each of the service trans-formersbe of sufficient height to contain the entire oil capacity of the transformer and the required amount of extinguishing media?
- 9. Will the proposed curb around the lube oil storage tank con-tain the oil capacity of either tank and the required amount of extinguishing media?
- 10. Does the gasoline line to the screen wash pump have a fusible link shut-off device?
- 11. When will the emergency generators and day tank located in Zone No. 9E be removed?
l gage babcock & associates I
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,.- i RECOMMENDATIONS I
- 1. The gasoline fire pump should be tested weekly.
- 2. An oil collection system should be provided for the reactor coolant pumps inside containment.
- 3. A fire wall should be provided between the service trans-former.
- 4. A curb should be provided at the entrance to the lube oil storage shed.
- 5. In situ tests should be conducted with a suitable smoke generation device to verify that the products of combustion from a fire would be promptly detected by installed smoke detectors and that ventilation air flow pattern in the area does not significantly reduce or prevent detection response.
Bench tests should be conducted to verify that smoke detec-tors will provide prompt response and have adequate sensi-tivity to the products of combustion for the combustibles in the area where smoke detectors are installed. If any fire detection systems are found to be inadequate, appropriate modifications should be made to provide adequate detection system performance.
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gage babcock & associates i
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, , o UNITED STATES
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- f , NUCLEAR REGULATORY COMMISSION 1 *
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j MEMORANDUM FOR: D. Eisenhut, Assistant Director for Systems and Projects, Division of Operating Reactors 1
FROM: G. Lainas, Chief, Plant Systems Branch, Division of Operating Reactors
SUBJECT:
SAN ONOFRE UNIT I FIRE PROTECTION PROGRAM i
On July 10 to 13,1978, a site visit was made by the fire protection review team to evaluate the San Onofre Unit I fire protection program.
On August 29, 1978, a follow up meeting was held with the licensee to discuss and resolve staff concerns resulting for our site visit and evaluation of the fire protection program. Based upon our evaluation of the information provided by the licensee in his fire hazards analysis, and the above noted discussions with the licensee, it became apparent that the capability to safely shutdown could be lost due to the potential consequence of a major fire in two areas of the plant existing where the configuration of com-bustibles, shutdown cables, and fire suppression capability does not provide reasonable assurance that such a fire in these areas could be controlled. The areas of concern are the 4160 volt switchgear room and the adjacent turbine lube oil reservoir and conditioner area. The chronology of the events which led to this conclusion are given in Attachment A. A summary of the fire hazards associated with each of these areas is given in Attachment B.
As a result of discussion with the licensee of the concerns for existing fire protection measures, Southern California Edison Co.npany agreed on September 1,1978, to implement additional fire i
j protection measures on an as early as possible schedule as noted ,
in Attachment C for the two areas of concern. These measures will l remain in effect until the unit is shutdown for refueling, presently scheduled for September 15, 1976. These interim measures are adequate to satisfy the staff's concern for fire protection under existing conditions for this interim period.
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A telecon was held on September 5,1978, for further discussion with SCEC on the status of implementation of interim fire protection neasures mentioned above and additional steps to be taken prior to resumption of plant operations following the refueling outage
, of San Onofre, Unit I. As discussed in the Chronology, Attachment A, the staff concurred that the interim measures were adequate and scheduled further discussions with SCEC for the week of September 11 on the additional steps to be taken prior to startup of the plant.
I G. Lainas, Chief Plant Systems Branch Division of Operating Reactors Attachments:
A - Chronology B - Areas of Concern for Present
- Fire Protection C - Interim Fire Protection Measures cc
- V. Stello D. Eisenhut 1 B. Grimes 3
S. Hanauer
- D0R - Branch Chief 1 R. Ferguson V. Benaroya T. Wambech A. Burger PSB - Section C l
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1 . ATTACHMENT A CHRON0 LOGY i
i The following is a chronology of events leading to the imple-l mentation of interim fire protection measures at San Onofre i Unit I.
- 1. July 10 to 13, 1978: The fire protection review team
- conducted a tour of the facility to evaluate the ade-quacy of the fire protection progran, including modifications proposed b,y the licensee in his Fire.
Hazards Analysis, dated March 1977. Primary emphasis was placed upon those additional fire protection modifi-cations which the staff felt were necessary to insure an adequate fire protection program for the facility.
The impact of potential fires under existing conditions was not specifically addressed at this time but was lef t to subsequent review.
- 2. July 17, 1978 through August 25, 1978: Further review of San Onofre fire protection was not conducted during this time other than noted before due to the review teams effort to complete other outstanding' fire protection evaluations consisting of:
a) A meeting July 27, 1978 with fire protection consultants to discuss generic fire protection issues. ,
b) Issuance of Hillstone Unit Draft SER on August 1,- 1978.
c) Issuance on July 31, 1978 of minutes of the San Onofre site visit were issued.
d) Development of comments for project management in response to San Onofre arguments for a 3-man fire brigade.
4 e) A meeting on August 9,1978 with Northeast
, Utilities to discuss administrative controls, fire brigade training and size.
f) Issuance on August 15, 1978 of the Turkey Point Units 3 and 4 Draft SER was issued. ,
1 g) A site visit at Quad Cities Units 1 and 2 during the period I of August 21 to 25,1978. l l
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. 3. On August 28, 1978, the fire protection review team met to discuss the forthcoming meeting to be held on August 29 with Southern California Edison Company (SCEC) on San Onofre 4
fire protection concerns. At this time, R. Ferguson was notified of staff concern for consequences of fires under existing conditions. It was decided to discuss this further with the 2
licensee during the next days meeting.
- 4. On August 29, 1978, a meeting was held with the licensee to discuss resolution of staff concerns for San Onofre fire protection program. At the time the licensee confirmed that the staff's conclusion on the consequences of fire damage under existing conditions was valid and could threaten shutdown capability. This conclusion was subsequently discussed with R. Ferguson and G. Lainas.
A meeting was scheduled by D. Ziemann for the 30th between G. Lainas and Mr. Ken Baskin of SCEC, since Mr. Baskin was to be in Bethesda for NRC discussions on another matter.
- 5. On August 30, 1978, G. Lainas discussed the staff's concern with D. Eisenhut. The ' proposed meeting with Baskin did not occur due to schedule mix up, but G. Lainas did talk to him via telephone before he departed Dulles Airport. A telecon was scheduled for the following day.
- 6. On August 31, 1978, Lainas, Ferguson, and Dunning talked by phone to K. Baskin, et.a1 of SCEL. At this time the licensee proposed to establish an hourly fire watch patrol of the 4160 volt switchgear room and early implementation of fire protection modifications for this area, and agreed to expedite the implementation of the permanent modifications for this area. Baskin promised an implementation scheduled in two weeks.
- 7. On September 1,1978, Ziemann, Berger, Wombach, Ferguson and Dunning telephoned SCEC and indicated to Messers Baskin and ORiega those actions ( Attachment C) which the staff felt were necessary to be implemented at the earliest opportunity to provide adequate fire protection for the 4160 volt switchgear room and turbine lube oil areas. We also requested that casuality procedures be developed to insure
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-3 the capability fo safe shutdown in the event of a severe fire i arf plant area. SCEC agreed to rsue g this subject an to report their finding via telephone on September 6,1978.
- 8. At 3:30 pm on September 5, 1978, a conference call was held with Southern California Edison personnel, K. Baskin,
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O. Ortega and R. Krieger. D0R personnel participating in the call were G. Lainas, D. Ziemann, A. Burger, R. Fersuson, T. Dunning and V. Panciera. (Baskin A stated that Southern California Edison had taken the following interim measure to improve fire protection in the g vicinity of the 4160V Swi(tchgear room and the adjacent area containing the lube oil reservoir and lube oil conditioner.
- a. A continuous fire watch was installed in the areas.
- b. Foam equipment consisting of foam cans and pick up tubes is present in the areas,
- c. Access ladders have been placed in the 4160V switch room for fire fighting purposeg, %.
- d. A five man fire brigade is maintained on all shifts.
. e. . Pressurized water exti'nguishers and additional fire hose have been placed in the area.
- f. Fire fighter training in the use of foan equipment for the fire watch and fire brigade members is ongoing.
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- g. Sandbag dikes around 3 1ube oil reservoir and A conditioner is ongoing and should be completed by September 6.
K.Baskin also stated that casuality procedure measures y had also been investigated to provide an alternate source of power to 480V hot shutdown equipment. This needed equipment consists of the D. C. Thermal shield booster pump, component cooling water system, test charging pump, pressurizer level indication, primary loop temperature indication, pressurizer heaters and air supply to the steam dump valve.
Three possible sources of 480V AC power are:
- a. Power from offsite 12KV line which is stepped down
-through the.use of a temporary transformer.
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- b. 480V Power from Unit 2 construction site or from the Administration Building.
- c. 480V Power from a diesel generator which can be rented from a dealer.
h Baskin stated that SCEC had determined that it was not K feasible to provide an alternate source of 480V AC power prior to shutdown for refueling.
Zeimann stated that the interim measures taken by SCEC are considered adequate by the staff, subject to NRC management review for the short term operation up to shutdown for refueling (ie. the next 10 days) but that SCEC should continue to investigate measures such as casuality procedures, alternate sources of 480V AC power and additional fire protection o requirements that could be taken prior the startup of the plant after the refueling outage. Baskin agreed to pursue the investigation on an expedited basis and stated that SCEC will be prepared to discuss its recommendations during the week of September 11, 1978.
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- 9. Subsequent to.the telephone conversation, Lainas discussed i the interim measures taken by SCE and the staff position with 4 Eisenhut andVStello, and obtained their concurrence that the d measures taken were adequate.
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ATTACHMENT B AREAS OF CONCERN FGR PRESEJT FIRE PROTECTION The adequacy of present fire protection measures are of concern -
due to th potential consequences of a major fire under present conditio These areas are the 4160 volt switchgear room which )(
includes he cable spreading area for cables entering the control room above and the turbine lube oil reservoir and conditioner area which is adjacent to the 4160 volt and 480 volt switchgear rooms and through which redundant safety-related cables are routed. A brief summary of the fire hazards associated with each of these areas and the existing fire protection is as follows:
- 1. 4160 Volt Switchgear Room.
The electrical equipment in this area consists of both divisions of 4160 volt switchgear and one division of 480 volt swtichgear including motor control centers.
The height of the room is approximately 20 feet and the upper area serves as the cable spreading area for the control room. The major combustible in the area consist of 31,500 lb of electrical cable insulation which gives an average fire loading of 172,000 BTU /ft2 and equates to a fire severity in excess of 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />.
The existing fire protection for this area consists of smoke detectors installed in the overhead. Two fire hose stations are loacted outside the room at distances of 20 and 65 feet from the two access doors respectively. Portable CO2 extin-guishers consisting of one 50 lb unit and two 15 lb units are located inside the room. A fire ladder is located on the same elevation of the switchgear room within a reasonabJg distance.
Passive fire protection features consist of one hoW fire-proofing on exposed structural steel and concrete walls which have a fire rating of 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />. Fire stops have been installed in vertical cable Risers. Doors and ventilation pentrations do not have fire rated protection. Electrical equipment is not protected from potential water damage which is necessargfy due to the use of fire hoses in this area.
The fire hazards external to the area consist of the turbine lube oil reservoir which is located about 15 feet from the south west entrance to the roon. The Southeast entrance is at the base of a ramped driveway. Vehicles and equipment are moved down this ramp for access to the lower elevation of the turbine building. Oil in large quantities, 55 gallon drums, is transported via the driveway to storage areas in the turbine building.
The consequences of a severe fire in the 4160 volt switchgear room would result in a total loss of electrical power to equipment required for safe shutdown. The factors which contribute to the pro-bability of a severe fire with this consequence are the following:
- a. External fire hazards which could lead to a severe fire in the area.
- b. The limited capability of portable fire extinguishers to suppress a cable tray fire.
- c. The of fficulty that would be encountered by the fire brigade to obtain fire fighting access to a cable tray fire to use a portable extinguisher due to smoke obscuration and the problem of physical access to cable trays at the upper elevation within the room,
- d. The effective use of fire hoses in the area for cable tray fires is limited by problems of access and further the potential exists for water damage to =
electrical switchgear.
Modifications have been proposed by the licensee to provide additional fire protection measures for this area and to resolve the staff's concerns for the adequacy of the overall fire protection program including specific hazards associated with the 4160 volt switchgear roon. Those modifications will, however, take some time to impl ement. Therefore, interim fire protection measures have been implemented.
- 2. Turbine Lube Oil Reservoir and Conditioner Area.
The turbine lube oil reservoir and conditioner are located on the lower level of the turbine area between the 4160 and 480 volt switchgear rooms. Redundant safety-related cables are routed through the upper elevation of this area. The combustibles in this area consist of 19,000 lbs of electrical cable insulation and 15,000 gallons of lubricating oil which gives a fire loading of 754,000 BTU /ft2 and equates to a fire severity in excess of 9 hours1.041667e-4 days <br />0.0025 hours <br />1.488095e-5 weeks <br />3.4245e-6 months <br />.
The existing fire protection for this area consists of smoke detectors installed over the lube oil reservoir and conditioner and over the cable trays. Manually actuated water deluge sprinkler systems are provided over the luDe oil reservoir and the lube oil conditioner. Manual hose stations are provided in the area as well
. as two 20 lb che'mical extinguishers.
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4 The consequences of a severe fire in this area would expose i both switchgear rooms and result in the loss of all cables in the area. Fire from an oil spill fire would spread to adjacent
, areas due to the lack of a means to contain an oil spill. This would result in the loss of the capability to safely shutdown.
As noted above, modifications have also been proposed by the licensee to provide additional fire protection measures in this area and to resolve staff concerns. Interim fire protection measures have also been implemented for this area.
The interim measures proposed by the licensee improve his ability
, to detect a fire at an early stage of its development, limit the j extent of a fire and to extinguish it quickly. These measures therefore, reduce the short-term probability of a severe fire occurring and provide reasonable assurance the sufficient equipment will be available to safely shutdown.
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ATTACHMENT C INTERIM FIRE PROTECTION MEASURES l
The following interim fire protection measures were intiated i by Southern California Edison Company for San Onofre Unit I '
on September 1,1978.
- l. Fire Watch A continuous fire watch will be provided to cover the 4160 volt switchgear room and turbine lube oil reservoir and conditioner area.
- 2. Additional Fire Fighting Equipment The following will be provided:
A. 4160 voit Switchgear Room
- 1. Two fire ladders
- 2. Two Halon 1211 portable extinguishers
- 3. Two pressurized water extinguishers B. Turbine Lube Oil Reservoir and Conditioner Area
- 1. Foam concentrate
- 2. Two foam applicator nozzles with pick up tubes for use with 1 1/2 inch hose lines.
- 3. Two fog applicator nozzles to provide water shield protection for personnel using foam to suppress oil fire.
- 4. Additional hose lines to permit effective use of foam and fog equipment.
- 5. Sand bag dyke around lube oil reservoir and con-ditioner
- 3. Additional Fire Fighting Personnel A fire brigade of five individuals will be maintained on all operating shifts.
- 4. Additional Fire Brigade Training Drills will be conducted for each fire brigade shift for the 4160 volt switchgear room and turbine lube oil area. Hands on training on the use of foam equipment will be conducted.
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SUMMARY
OF STAFF REQUIREMENTS TO RESOLVE OPEN ITEMS SAN ON0FRE 1
~50-206 k
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/ 3.1.1 Fire Detection Systems h In the Fire Protection Safety EYaluation Report, it is our concern that automatic fire detectors be installed in the following areas containing safety related equipment and/or cables, circuits for prompt alarm.
(1) In the vital bus cabinet in the control roon..
(2) Above the motor control center in the lower area of the auxiliary building.
(3) In the solid waste baling room in the auxiliary building.
(4) In the pipe tunnel to the auxiliary building.
(5) In the oil storage shed in the east feedpump area of the turbine building.
(6) In the west feedpump area of the turbine building above the instrument air compressors.
(7) In the battery room located in the diesel generator building.
(9) In the area of the residual heat removal pumps in the containment.
(10) Electrical penetrations.
(11) Additional fire detection systems in areas as indicated in the licensee's fire hazards analysis.
The licensee has not responded to our concern and has not provided information to complete our review. In order to meet our requirement of Section III.1 of proposed Appendix R to 10 CFR Part 50, we will require automatic fire detection be installed in all the preceeding '
gi.5g areas. The detection system should meet the guidelines of NFPA 720.
. W .l.2(b) Fire Water Supply In the Fire Protection Safety Evaluation Report, it was our concern CM,1 that isolation valves were not provided in the above ground cross connection of the yard loop which is routed through the turbine building, to prevent the loss of both manual and automatic water suppression systems due to a single impairment.
By letter dated January 23, 1980, the licensee committed to install an additional valve in the cross connection through the turbine building. We informed the licensee that the installation of a single valve to the turbine building cross connection does not adequately isolate the automatic suppression systems and standpipe hose stations in the turbine building.
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AV pic To meet Section IIIB of proposed Appendix R to 10 CFR 50, the licensee should provide additional valves in the yard loop cross connection through the turbine building so that a single break will not simul-taneously impair any standpipe hose stations and an automatic (q F) suppression system.
/ 3.1.5(1); Water Suppression Systems In the Fire Protection Evaluation Report, it was our concern that the east wall of the 480 volt switchgear room may not resist a fire.
The licensee has not responded to our concern and has not provided the information to complete our review. In order to meet the require-
+ments of Section III.C of proposed Appendix R to 10 CFR 50, the licensee yl j should install a directional water spray system for additional connec-1.4 l tion at the east wall of the 480 volt switchgear room.
3.1.5(3) Water Suppression Systems In the Fire Protection Safety Evaluation Report, we were concerned about the ability of.the north wall and structural steel members in the turbine lube oil area to resist a fire.
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} The licensee has not responded to our concern and has not submitted j information for us to complete our review.
In order to meet the requirements of Section III.C of proposed Appendix R to 10 CFR 50, the licensee should install a directed
, water spray system for the north wall and structural steel in d4 9 ,
the turbine lube oil area.
/ 3.1.5(4) Water Suppression System j In the Fire Protection Safety Evaluation Report, we were concerned i about the concentration of combustibles in the north turbine area.
i l The licensee has not responded to our concern and has not submitted
- information for us to complete our review.
In order to meet the requirements of Section III.G of proposed Appendix R to 10 CFR 50 the licensee should provide a wet pipe automatic sprinkler system for the north end of the turbine building area 9A. The sprinkler system should meet the guidelines g q 1*l of NFPA 13.
/3.1.6 Foam Suppression Systems In the Fire Protection Safety Evaluation Report, we were concerned plqabout the fire protection provided for the lube oil reservoir.
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By letter dated January 23, 1980, the licensee comitted to modify
, the foam system. We informed the licensee that the proposed modifications are not acceptable for the following reasons:
(1) no indication of the discharge duration is provided; (2) adequate information on the type of fcam concentrate used or proportioning system has not been provided; (3) the valving is not adequate; and (4) no backup foam supply has been provided.
To meet the requirements of Section III.G of the proposed Appendix R to 10 CFR Part 50, the licensee should provide a foam system with a discharge duration that meets the recommendations of NFPA 16, a backup foam supply with adequate valving between the foam supply gj and the tank connections.
/.1.7(a Gas Suppression System In the Fire Protection Safety Evaluation Report, we were concerned
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' ,p } about the design of the automatic total flooding Halon 1301 gas suppression system provided for the 4160 volt switchgear room. In addition, to provide adequate fire protection for the 480 volt switch-gear room, an automatic total flooding Halon 1301 gas suppression system should be provided.
By letter dated January 23, 1980, the licensee indicated that the Halon 1301 system for the 4180V switchgear room as well as the 480V switchgear room will be designed to provided a 6 percent concentration for a soak time of 10 minutes and that the discharge time will be 10 seconds. The licensee stated the use of a 6 percent concentration is based on the fact that the fire hazard is cable insulation, and there is little possibility of a deep seated fire occurring. We informed the licensee that the design criteria was not acceptable since both the design concentration and soak times are not adequate to extinguish a deep seated cable tray fire in either of the switch-gear rooms.
To meet the recommendation of NFPA 12A, the licensee should revise i the design criteria of the proposed system to provide for a 7 percent concentration for a 20 minutes soak time. The discharge time of ten seconds and capability for a second application remain unchanged, except that additional quantities of Halon 1301 will be required for both the primary and reserve systems to provide for the increased density and soak time. This applies to both the 4160V and 480V switchgear rooms.
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g,fe w STAFF POSITION SAN ON0FRE, UNIT 1 PF-27A Cable Spreading Area Staff Concern:
The cable spreading area is located in the upper half of the 4160 volt 3 switchgear room which has a ceiling height of approximately 20 feet.
Cables for redundant divisions of safety related systems are routed in
! open ladder cable trays in close proximity. The combustible loadina in the area consists of 31,500 lb. of electrical _ cable insulationconsisting
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of PCV, bu.tyl rubber, neoprene, and other materials that do not l . meet current flame test requirements. T51s insulatio1 gives an average fire loading of 172,000 BTU /ft2 and equates to a fire severity in excess of two hours. Electrical cables consist of instru-
! ment, control, and power cables. This area contains both divisions of 4160 volt switchgear and associated power and control cables. The availability of both the normal offsite power and emergency onsite power
- to all safety-related and shutdown systems is dependent upon systems in this area.
The licensee is completing modifications to provide the capability to shutdown with offsite power, independent of fire damage in this area, by the use of suitable casuality procedures. However, these modifi-cations will not prevent unacceptable consequences on shutdown i
capability if offsite power was lost as a result of a fire in the cable spreading area and switchgear room.
Fire detection is provided by ceiling mounted smoke detectors. Manual fire fighting is provided by hose stations located outside the area. The effectiveness of manual fire fighting is limited by the following considerations : Access to the upper elevations of the room would be required in order to direct water from hose stations on a cable fire due to the congestion of cable trays which would prevent such operations from the floor below. Visability in this situation would be greatly reduced due to the accumulation of smoke from a fire at the upper elevation of the room. This environment would require the fire brigade to use self contained breathing apparatus which would restrict their mobility in using fire ladders to gain access with a hose line. Water from hose streams if used in large quantities increases the potential of water damage to redundant divisions of essential switchgear.
An automatic total flooding Halon 1301 suppression system is a planned modification for the conbined switchgear room and cable spreading area, nowever, additional passive measures are apprcpriate to prevent a mdor electrical cable fire in the cable spreading ares for the following reasons:
- 1. The high fire loading due to cable insulation materials.
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- 2. The difficulties which would be encountered in combating a major cable fire in this area by manual means.
- 3. The vital nature of the area to effect safe shutdown.
Staff Position:
Passive measures should be taken to prevent a major electrical cable fire in the cable spreading areas. These measures should consist of the application of a: flame retardant coating to electrical cables or the combination of fire stops in cable trays and the use of suitable fire barriers to prevent fire propagation between adjacent cable trays.
PF-50A Shutdown Capability Staff Concern:
The 4160 volt switchgear room includes the cable spreading area and contains both divisions of 4160 volt switchgear and one of two divisions of 480 volt switchgear and motor control centers s The licensee is completing modifications to provide the capability to shutdown with offsite power, independent of fire damage in this area, by the use of suitable casuality procedures . These modifications include the provision of a new 12Kv line, stepdown transformer, and the means to connect this power to equipment in the 480 volt switchgear room, Make up to the primary system would be by the use of the small test pump since the changing pumps which operate from 4160 volt power would not be available by this shutdown method, The lisensee proposes to remove this alternate source of power en comple- ,
tion of the fire protection modifications for the facility, The proposed fire protection modifications for the 4160 volt switchgear room including the recomnendation for cable coating or a combination of fire stops and fire barriers, as noted in staff position 27A, do not, in themselves, provide adequate assurance that fire damage due to a major fire in this area, would not negate the capability to safely shutdown. As noted in licensee's submittal entitled " Separation and LOCA Environment Assessment of San Onofre Unit 1 Emergency Core Cooling Systems", dated December 1977, many systems which are used for safe '
shutdown including power distribution systems are not physically and/or electri.cally separated in accordance with the Commission's guidelines in Regulatory Guide 1.75. Further, it is a conclusion of the licensees fire hazards analysis that an alternate source of power is required for safe shutdown due to the physical arrangement of having both 4160 volt switch-gear buses located directly beneath the cable spreading area and in a Common room.
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Staff Position:
An alternate means should be provided to insure safe shutdown with either onsite or offsite power independent of systers which could be damaged by a fire in the 4160 volt switchgear room. It is recommended that consideration be given to a dedicated shutdown system which could resolve this concern and any concerns resulting from the Systematic Evaluation Program. The alternate shutdown means should meet the following critericn:
- 1. Following any fire, the plant thould be capable of achievina hot shutdown _ conditions using equipment and systems that are fret of
' fire,d.amage.
- 2. The plant should be capable of maintaining hot shutdown conditions for .an extended time period significantly longer than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.
This capability should include the use of a charging pump.
- 3. Fire damage to systems necessary to achieve and maintain cold shutdown conditions should be limited so that repairs can be made and cold shutdown conditions achieved within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.
- 4. Repair procedures for cold shutdown systems should be prepared and material needed for such repairs should be on the site.
- 5. The hot shutdown condition must be achieveable with power from the offsite power system, and upon its loss, with power from the onsite power system. A dedicated power supply may be substituted
- for the onsite power system.
- 6. The power needed to achieve the cold shutdown condition may be obtained from any one of the offsite power, onsite power, or dedicated power systems.
- 7. The adequacy of_ these . minimum systems sh6uld be verified by a thorough evaluation of:
- a. Systems required for hot shutdown;
- b. Systems required for cold shutdown;
- c. Fire damage to pmver distribution systems; and
- d. Interactions caused by fire damage to power and water supply systems and to supporting systems.
.' PF Turbine Building - 4160V Switchgear Room Fire Zone 19A Fire Protection and Safe Shutdown Requirements Staff Concern The electrical equipment in this room consists of both divisions of 4160 volt switchgear and one division of 480 volt switchgear including motor control centers. The height of the room is approximately 20 feet and the upper area serves as the cable spreading area for the control room. The major combustible in the area consist of 31,500 lb of electrical cable insulation which gives an average fire loading of 172,000 BTU /ft and equates to a fire severity in excess of 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />.
The existing fire protection for this area consists of smoke detectors installed in the overhead. Two fire hose stations are loc'ated outside the room at distances of 20 and 65 feet from the two access doors respectively. Portable C02 extinguishers (one 50 lb unit and two 15 lb units) are located inside the room.
A fire ladder is located on the same elevation of the switchgecr room within a reasonable distance. Passive fire protection features consist of one hour, fire-proofing on exposed structural steel and concrete walls which have a fire rating of 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />. Fire stops have been installed in vertical cable risers. Door openings and ventilation penetrations do not have fire rated protection. Electrical equipment is not protected from the water spray which may occur during the use of fire hoses in this area.
The fire hazards external to the area consist of the turbine lube oil reservoir which is located about 15 feet from the southwest entrance to the room. The southeast entrance is at the base of a ramped driveway. Vehicles and equipment are moved down this ramp for access to ti,e lower elevation of the turbine building. Oil in 55 gallon drums, is transported via the driveway to storage areas in the turbine building.
The consequences of a severe fire in the 4160 volt switchgcar rocn would result in a total loss of electrical power (bath ensite and offsite AC power) to equipment required for safe shutdo :n.
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Staff Position 1.0 Fire Protection Requirement .
4 1.1 Permanent Modification and Measure Permanent modifications and measures should be made to improve i f fire protection in Fire Zone 8-4160 volt switchgear room. The
- fire protection modifications and measures should consist of the following
- 1. Installation of a double shot automatic halon system.
1
- 2. Placement of additional f' ire detectors in the room to ~
improve detection coverage. ,
- 3. Installation of three hour rated fire smoke dampers in the
- control room ventilation ducts at the ventilation equipment
- i room /switchgear room penetration and at the control room floor /switchgear room penetration. ,
4 4. Modification of the floor drainage system to improve capability of drainage system to accommodate fire fighting water accu-i mulation.
- 5. Installation of three. hour rated automatic fire dampers on the
, el lowered ventilation system in the south wall.
l 6. Installation of a hose reel at the southeast door.
- 7. Provision for a curb at the southeast door to prevent a
! combustible fluid spill on the ramp from entering the room.
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- 8. Sealing of all penetrations of the room withshaving a three i
hour fire rating.
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- 9. Installation of spray / splash shieldson all switchecar to j inhibit the entry of fire fighting water. ;
- 10. Installation of a three hour rated door in the southwest corners ,
) of the room. >
4 j 11. Provision for a curb at the door in the southwest corner of the reem with sufficient height to prevent the entry of fire suppression water from fire zone 9A, or verification that a curb is not .
needed.
12.- Provisions for reducing the potential for a cable tray fire I resulting in ' damage to redundant systeus b:/ the use of ficme retardant coatings on cables or the co?Mnitico of appropriate fire ba:riers between trays and the use of fire stops within k -
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- 13. Installation of an area sprinkler system in fire zone 9A to provide sufficient. cooling to the walls of the switchgear rooms i and the structural steel in the north end of the turbine
, building to assure their structural adequacy in the event of 4 a severe lube oil fire in fire zone 9A. .
[ l'.27 Interim Measures The following interim fire protection measures should be
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I implemented until the permanent modifications and measures have
] been completed: * <
i 1. Maintain continuous fire watch to provided fire fighting
- coverage for the 4160 volt switchgear room and the turbine lube oil ~ reservoir and conditioner area.
I
- 2. Provide equipment to facilitate fire fighting as follows:
. two fire ladders >
i two Halon 1211 portable extinguishers i two pressurized water extinguishers i
- 3. Maintain a fire brigade of five individuals on all
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l operating shifts.
- 4. Conduct drills for each fire brigade shift on a quarterly 1 basis to practice fire fighting techniques for extinguishment
! of fires in the 4160 volt switchgear room and turbine j lube oil reservoir and conditioner area. The drills should j include hands-on training in the use of foam equipment.
) 5. Implement additional specific fire protection measures for
) the turbine lube oil reservoir and conditional areas as. dis-i cussed in the staff position covering fire zone 9A.
2.0 Safe Shutdown Requirements 2.1 Pennanent Modifications
, R .1. Permanent modifications should be made to assure that safe plant shutdown can be achieved following a severe fire using equipment and systems that are independent of the 4160 volt i switchgear room. These modifications should accomplish the
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following functions required for safe shutdown:
i 1. Place the reactor in a subcritical condition and tiaintaining the reactor in a subcritica! condition, 1-e
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- 2. Bring the reactor to safe hot conditions (primary system temperature of 535*F1 and primary system pressure of 2100 psig) and maintain it at a safe hot safe condition for I' an extended period of time (i.e. longer than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />).
This condition should be achievable without reliance on offsite power. ,
- 3. Maintain the reactor coolant system inventory.
- 4. Bring the reactor to cold shutdown conditions within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. This condition may rely upon the use of offsite powc'. ,
T. Repair procedure if required to achieve cold shutdown should j exist and availabic material needed for such repairs should
.be on site.
2.2 Interim Modification The following interim shutdown modifications and measures should be provided until permanent modifications have been accomplished:
- 1. Installation of an alternate onsite power source independent of the 4160V switchgear hoog sufficient to provide shutdown power to the 480V switchgear room.
- 2. Installation of an alternate onsite power source independent of the 4160V switchgear room sufficient to provide power to one chcrging pump.
- 3. Modification to valves required for hot shutdown to assure proper valve position is achieved following a fire in the 4160V switchgear room.
- 4. Verification that valves required for hot shutdown are not subject to adverse operation as a result o'f a fire in the 4160V switchgear room.
- 5. Installation of local Volume Control Tank level indicaticn chargir.g pump location.
- 6. Development of a casualty procedure to fa::iji, tat 4shu,tdlrin,, ., 7., , , . _
dsing equipment powered from the 480V switctIgEl W 6Mn'.ilid ' ~ ~ ~ ;
casualty procedure should include sieplified ficw diagrams ]
of the syste.ns required for safe shutden ar,d a e,cription )
H of the operation of these systems.
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- 7. Installation of a three-hour rated door at the south end of the 480V switchgear room.
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PF Turbine Building - Chemical Feed and Lubricating 011 ,
- Reservoir Area - Fire zone 9A Fire Protection and safe Shutdown Requirement f Staff Position
.. The turbine lube oil reservoir and conditioner,are located 4
on the lower level of the turbine area between the 4160 and i 480 volt switchgear rooms. Redundant safety-related cables ,
- are routed through the upper elevation of this area. The
- combustibles in this area consist of 19,000 lbs of electrical j
cable insulation and 15,000 gallons of lubricating oil which gives
! a fire loading of 754,000 BTU /ft2 and equates to a fire
- I severity in excess of 9 hours1.041667e-4 days <br />0.0025 hours <br />1.488095e-5 weeks <br />3.4245e-6 months <br />.
] .
j -
The existing fire protection for this area consists of smoke I detectors installed over the lube oil reservoir and conditioner -
l and over the cable trays. Manually actuated water deluge sprinkler f systems are provided over the lube oil reservoir and the lube oil conditioner. Manual hose stations are provided in the area as well. as two 20 lb dry chemical extinguishers.
j The consequences of a s'evere fire in this area would expose both switchgear rooms and res' ult in the loss of all cables in the area. Fire from an oil spill fire would spread to adjacent areas due to the lack of a means to contain an oil spill. This would result in the loss of the capability to
! safely shutdown.
.l j 1.0 Staff Position
] Fire Protection Requirements ..
1 j Permanent modification should be made and certain measures taken l to improve fire protection in Fire Zone 9A - Chemical Feed and Lubricating Oil Reservoir Area. These fire protection
]I i modifications and measures should consist of the following:
- 1. Installation of a Foam system over the lube oil reservoir f .and conditioners.
] 2. Relocation and addition of detectors to provido full area coverage ,
i 3. Installation of a system providing a directed water spray to protect cable trays and installation of inline ttsperature i
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," detectors for cable trays in the area to actuate directed l
water spray, i 4. Installation of a backup area sprinkler system to protest the building structure in the north end of the turbine building and the walls of the 4160V and 480V Switchgear room which are common to Fire Zone 9A. This system is to be actuated by area detectors independent of the signa.1 source used to actuate the foam system.
- 5. Upgrading of the penetration seals inc.othen north wall of the n aucu n,a rc turbine building to provide a fire rating 4wittr;the fire hazard and sprinkler protection provided. ,
- 6. Modification of fire water crossover piping in fire zone i
9A to permit isolation of the firewater systen. in the event of a line break.
- 7. Provision for a curb at the east door to the 480V switchgear room of sufficient height to prevent entry of fire suppression water from fire zone 9A, or verification that a curb is not needed.
1.2 Interim Measures '
The following specific interim measures should be implemented until the permanent fire protection modifications and measures have been completed:
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- 1. Provide a systengof foam concentrate in the area.
- 2. Provide two foam applicators with pick up tubes for use with a l 1/2 inch hose line.
- 3. Provide two fog applicator nozzles to provide water shield protectors for personnel using foam to suppress an oil fire.
- 4. Provide additional hose lines to permit effective use of foam and fog equipment.
- 5. Install a permanent dike around the lube oil reservoir and conditioner to contain any oil spill.
2.0 Safe Shutdown Requirements Verify that cables passing throubh fire zone 9A are not required to achieve and maintain safe hot shutdoan and cold shutdoun of the plant, or provide safe shutdown cai'.M :lity .nhpcndent of Fire Zone 9A. This verif ication shouN Lc pec'cu mi prior to plant startup following the present refooling outa r.
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Item 3.2.3 Turbine Building Structure Item 3.2.3 of the San Onofre Unit 1 SER requires the licensee to evaluate the effect of a fire involving the hydrogen seal oil system on the structural integrity of the turbine building
~
if there was no fire suppression system. Item 3.2.3 states:
"The licensee is evaluating the effect of a fire involv-ing the hydrogen seal oil system on the structural steel of the turbine building without the benefit of a fire suppression system."
The licensee was also required to provide a report to NRC on the methods used to perform the analysis.
The hydrogen seal oil unit is located under the turbine deck in the south end of the turbine building. Exposed steel structur-al members in the area would be directly exposed by a fire in-volving the hydrogen seal oil from a leak either at the seal oil unit or at a point along the piping. An unmitigated fire could cause structural damange and possible collapse, with resultant j i
damage to safety-related circuits and equipment in or adjacent GAGE-BABCOCK & ASSOCIATES
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I to the turbine building.
In their letter dated December 26, 1979, the licensee pre-sented a summary of their evaluation of the effects of fires involving the hydrogen seal oil system on the structural steel of the turbine building. Included in their letter was a list of assumptions used for the analysis, a brief descrip-tion of the methods used in the analysis, and their conclusions.
The calculations and details of the head transfer model the li-censee used were not included with the letter. The licensee concluded that a fire involving 12,300 gallons of seal oil burning for a duration in excess of eight hours would create peak temperatures in the structural steel of 640 F, and thus would not effect the structural integrity of the steel.
By letter dated April 16, 1980, Brookhaven National Labora-tories analyzed the evaluation by the licensee and made the following comments:
"In general, it appears as though the analysis performed by the licensee considers a point source of heat and its effect on a single point along a steel beam. The only GAGE-BABCOCK & ASSOCIATES
.- . . . . -- . . :- X X - -
. 2 heat input to the beam is from radiation from the point source of heat, and credit for heat loss is considered to the air and other surrounding surfaces. The basic facts that the fire will be three dimensional, and that all other surfaces (the slab) and mediums (air) will be heated simultaneously have been disregarded.
This heating of all elements in the area will affect all surfaces at varying rates, and to consider a simple heat transfer solution similar to that presented as a definitive answer to the concerns expressed by the staff is not acceptable."
By letter dated September 26, 1980, the licensee responded to BNL's concern about the various assumptions it had made in its report entitled, " Area 9E Fire Study, DC-584." The licensee stated that based on the fact that conservative calculations were performed which resulted in temperatures which would not effect the structural integrity of the steel columns, area automatic sprinklers were not warranted in this area. -
l The licensee had previously committed to install an automatic !
foam system and curbing for the hydrogen seal oil unit with 0
GAGE-BABCOCK & ASSOCIATES
.,~
manual fire suppression as backup.
In order to meet the requirements of Section III G of Appen-dix R to 10CFR Part 50, the licensee should sleeve all hy-drogen seal oil system piping (and vented to a safe location) that passes through fire areas containing safety-related j equipment and/or cable conduit. With the proposed automatic
- foam system and curbing for this area, an acceptable. level of fire protection will be provided.
f GAGE-BABCOCK & ASSOCIATES l l
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kHY6M M 0011 Janwary 74, 1995 RECEWED M C l'RG A P G44rmgr '"
4 5$45. 2. 1. STILLY - Station Engineering Manager
- J. 3. WABOLD - Statten Maintermace Manager SusJEtis Potential Tailure of Electric Control
.. Devites for Brown levert 4160 Volt Switbgear Circuit treakers San smarre teclear Senerating station, getts tu Encleturts: 1. Letter 3. J. pestar (864) to 9. 9. to66 (EPc). dated l Septse6er 25,198431ebject: teatrol perice for Type E l Circuit areakers 1.5 kV threWgh 15 kW 600 through 150 RVA ,
and S* M4 through 3000 ;
- 3. Letter S. 3. Duvall (5SC) to N#t, dated Karzh 19, 1984; I l .,
Sw63MIt*CentrolDevice(10CitPartiltapert)
- 3. lahibit 'l' Addendes to Brote lever 1 Instraction Seok II 5.t.1-1 (8.1.1-2) Type SM 350 3000 Only )
l
- 4. EuMbit 'C' 7.54,15E and SE343000A Circuit trukers l
- Ranufactered Af ter 1978
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- 5. EuMbit 'B' - Letter 3. 3. Savail (36C) to V. Stelle. Jr.
- (WRC), dated March 22, 1963; subjects Sre e Scrort Electric
", Centrol Bevice fet Medium Voltage strtelt Breakers
- 6. List of Affacted treakers -
- 1. Latter 5. F. McCluster to 9. F. traig, dated Reesaber 9,1984. Lag M-9908 See te reported circuit breater failures resulting free adjustment errors at the Zimmer Reclear Plant, Brows Snori (171) 4.16 kT switchgear sirteit breaters at San Onefre Units tu shoeld be taspected. The matore of the potential einfanction is less of ability to electrics 11y 'close* the circett treakers. Maneal slestag weeld, however, coatleet to be operable as weeld l both anneal and elettric 'opos' of the breeters.
Enclesirro so. 6 is a list of 50sts 243 cirenit breaters that any be so affected. Ice receamend taspection of these breakers for the setject defect. ,
Please note 3404. RAM, SAM, 3406 are Elf etwipment. L/
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If twerrectly 6djusted er damaged limit switches are dissevered for the above hajned equissuret, the necessary repatra sheeld be accagitsbed by mous of I hm-Coeformance Report (sca stwo me s1rtett breeter mistustices han l occurred with 50885 fu ett poent me Fernal incident reports to the att are I reqvtred. The general notare of his totential pre 61ee has been efl1stally I consunicated to the mac by Brown Beverl as of Rank 19.19M. l
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, We do not seasider this sitaatten to be a significest safety problem for )
l 50ess 143 as it appears that the falteres having ocevered elsew9mre were l caused by adjastaest errors, which have met been espertenced with Soets tu ete1paest. l 11 is tapertant, however, that the mechselsal adjustment of all potentially l misfuncitseing circutt breakers be checked, and if necessary, corrected er '
repatred in acterdaecs with the seclesed Brown severt regetrasents. ;
Flosse call me if you have any seestices.
- 8. P. 38115
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