ML17339A560
| ML17339A560 | |
| Person / Time | |
|---|---|
| Site: | Turkey Point  |
| Issue date: | 01/26/1980 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML17339A559 | List: |
| References | |
| NUDOCS 8002150221 | |
| Download: ML17339A560 (20) | |
Text
SUPPLEMENT TO THE FIRE PROTECTION SAFETY EVALUATION REPORT BY THE OFFICE OF NUCLEAR REACTOR REGULATION U.S.
NUCLEAR REGULATORY COMMISSION IN THE MATTER OF FLORIDA POWER AND LIGHT COMPANY TURKEY POINT UNITS 3 and 4
DOCKET NOS. 50-250 and 50-25l
CONTENTS
- 1. 0 INTRODUCTION
- 2. 0 MODIF I CAT IONS/REQUIREMENTS
, 3. 0 EVALUATION 3.1 Smoke Detection Systems 3.2 Reactor Coolant Pumps 3.3 Water Supply
'.4 Auxiliary Building Corridor 3.5 Cable Spreading Area
1.0'NTRODUCTION Our initial safety evaluation report (SER) pertaining to the reevaluation of fire protection at the Turkey Point facility was issued by letter from A. Schwencer to Florida Power and Light Company dated March 21, 1979.
In Section 3 of the SER, certain items were identified as incomplete and requiring further information from the licensee and evaluation by the staff.
The Florida Power and Light Company in letter(s) dated April 5, 1979 and May 21, 1979, submitted additional information to resolve these incomplete items.
Me have reviewed this information and have found that additional modifications are required to meet the fire protection guidelines identi-fied in Section 2.0 of our SER.
Section 2 '
of this report summarizes the additional modifications proposed by the licensee and the requirements which will resolve our concerns.
Sec-tion 3.0 of this report provides the results of our evaluation.
Brookhaven National Laboratory under contract to the NRC has provided the services of fire protection consultants who participated in the evaluation of the fire protection program and in the review of information provided on incomplete items.
They have also participated in the preparation and review of this Supplement to the Safety Evaluation Report.
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2.0 MODIFICATIONS AND 'RE UIREMENTS
.2.1 Modifications The licensee has proposed the modifications summarized below.
The implementation schedule for these proposed modifications is shown in Table 2.1.
A complete description'f each proposed modification is given in the licensee's documentation.
2.1.1 Smoke Detection S stems None 2.1.2 Reactor Coolant Pum s
None 2.1.3 Water Su 1
A curb to prevent an oil fire from flowing into the condensate pump pit to reduce the maximum water demand.
2.1.4 Auxiliar Buildin Corridor None 2.1.5 Cable S readin Area None 2.1.6 Technical S ecifications for Existin E ui ment None 2.2 Re uirements 2.2.1 As a result of our evaluation, we find that the licensee must make additional modifications to improve the fire protection program.
These modifications are summarized below.
The sections of this report which more fully describe the modifications and provide our basis for these modifications are noted in parenthesis.
Smoke Detection S stems (3.2.1)
We will require that an evaluation by an independent registered fire protection engineer (as defined in our guidance dated February 3, 1978, attachment 1} knowledgeable in fire detection be performed to certify the adequacy of smoke detection systems in lieu of in-situ testing.
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Reactor Coolant Pum s (3.2.2)
We will require that the licensee install an oi,l collection system for the reactor coolant pumps.
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I 23.2.
We will require a vertical standpipe for other water services be provided in the existing 500,000 gallon raw water storage tank.
We will require a new water storage tank to provide an adequate supply of water dedicated totally to fire, protection needs.
The tank will be installed in accordance with NFPA 22.
We will also require diesel driven fire pump(s) with automatic start features be installed to take suction from the new tank.
The installation will be ',n accordance with NFPA 20.
We will require that the connection to the yard main from the new pump(s) and tank will be separated from the existing connection by a substantial distance.
Proper valving adjacent to this connection shall also be installed.
Auxiliar Buildin Corridor (3.2.4)
We will require the installation of an automatic sprinkler system in the auxiliary building corridor to protect -the-cable trays from exposure fire.
We will require the licensee to provide those items for the auxiliary building corridor for which he has indicated a reevaluation as follows:
We will require fire detection systems in the chemistry laboratories (hot and cold labs) and in the new laundry facility.
We will require 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> rated fire doors in the auxiliary bu.lding for the chemistry laboratories (hot and cold labs) and new laundry facility.
We will require 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> rated fire dampers for ventilation ducts in the chemistry laboratories (hot and cold labs) and the new laundry facility to isolate these areas from the auxiliary corridor.
We will requir plastic barrels in the auxiliary building corridor used to collect radiation protective clothing be replaced with barrels made of a fire retardant material.
We will require alternate shutdown capabi',ity independent of the auxiliary building corridor.
Cable S readin Area We will reouire the installation of an automatic gas suppression system in the cable spreading room.
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We will require a booster hose station for the cable spreading room.
We will require that access doors from the cable spreading area to the turbine building have a l-l/2 hour rating.
We will require alternate shutdown capability independent of the cable spreading area.
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3.0 EVALUATION 3.1 The following provides our evaluation of the incomplete items.
Numbers in.
parenthesis following each heading refer to the sections of our previously issued SER which address these incomplete items.
Smoke Oetection S stems (3.2.1)
Our SER noted that bench tests would be conducted on a minimum of 50Ã of the installed smoke detectors in each zone to verify that the detectors will provide prompt response and have adequate sensitivity to the products of combustion for the combustibles in the areas where they are installed.
If detection systems were found to be inadequate, appropriate modifications would be made to provide adequate detection system per ormance.
With regard to the adequacy of the smoke detection
- systems, we requested that in situ testing be conducted with a suitable smoke generation device to verify that the location and placement of smoke detectors is adequate to
' 'ive prompt response and that the ventilation air flow patterns in the area do not significantly reduce or prevent detection system response.
The licensee has not found a suitable means to conduct such tests in a manner which does not introduce further safety considerations.
A practical solu-
,. tion to this type of testing is not yet available to determine prompt response.
We indicated in o'ur previous SER that an evaluation by an inde-pendent registered fire protection engineer (as defined in our guidance dated February 3, 1978, attachment
- 1) knowledgeable in fire detection be performed to cer tify the adequacy of smoke detection systems in lieu of in-situ testing.
The NRC is currently developing alternate acceptance criteria for the detector installation.
We will address this issue when such criteria become available.
3.2 Reactor Coolant Pum s (3.2.2)
Our SER noted that we had requested that an oil collection system be provided for each of the reactor coolant pumps.
The licensee had deferred action on this recommendation pending the final resolution of an EPRI study, "Evaluation and Test of Improved Fire Resistant Fluid Lubricants for Water Reactor Coolant Pump Motors."
We indicated that if a suitable lubricant was not found, the licensee would provide a system, to suppress potential fires or provide for the removal of potential oil leakage to a safe location by December 1980.
We have not received any new information from the licensee;
- however, we have discussed the results of the study with Mr. Roy Swanson of EPRI, who is the project manager in charge.
Mr. Swanson has indicated that the study may reach a favorable conclusion and that a non-combustible lubricating oil for installed reactor coolant pumps will be available in the immediate 3-1
future.
However, this will require careful monitoring to assure the integrity of the oil.
The monitoring will require the installation of remote capability to perform the monitoring.
Because such an installation will require much greater risks and controls associated in assuring the integrity of the oil,,the staff does not deem this a vtable approach at this time or for the near term future.
'I We will, therefore, require that the Reactor Coolant Pump lubrication system be protected by either an oil collection system, or an automatic fire suppression system.
Oil collection systems shall be capable of collecting lube oil from all potential pressurized and unpressurized leakage sites in the reactor coolant pumps'ube oil systems and drain the oil to a vented closed container.
Requirements for a flame arrestor in the vent shall be determined on the basis of flash point characteristics of the oil involved.
Leakage points to be protected shall include lift pump and piping, overflow lines, lube oil cooler, oil fill and drain lines and plugs, flanged connections on oil lines and lube oil reservoirs where such features exist on the reactor coolant pumps.
Leakage shall be collected and drained to a closed container that can hold the entire lube oil system inventory.
The drain line shall be large enough to accommodate the largest potential oil leak.
To provide adequate protection for an SSE, one of the following shall be provided:
(a)
The lube oil system components whose failure could result in leakage
.shall be designed to withstand an SSE without leakage; and, the drop-ping of oil collection system components during an SSE shall not cause loss of operability of safety-related equipment; or (b)
The oil collection system shall be designed to withstand an SSE and continue to be able to collect and dra.n leakage that may occur during an SSE.
In this case the oil collection system shall be adequate to collect oil from any external lube oil piping not designed to withstand an SSE, in addition to leakage from points identified above.
If an 'automatic fire suppression system is selected, either the automatic and manual fire suppression system or the lube oil system components whose failure could result in leakage shall be designed to withstand the SSE.
The above requirements are now included in Appendix R to 10 CFR Part 50 which became effective, on We, therefore, expect that the licen-see will co..form to this requirement.
Subject to conformance to this requirement, this item is satisfactorily resolved.
3.3 Our SER noted our requests that (a) an adequate supply of water for f'.re protection be physically dedicated (e.g.,
by a vertical standpipe},
(b) confirmation of. the licensees calculations on the adequacy of the screen wash
- pumps, as an alternate source of water for fi're fighting, to meet the maximum area of demand for fixed systems, and (c} should the 3-2
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screen wash pumps'rove to be an adequate alternate water source, that the proposed unconnected spool piece (Note:
The licensee now proposes a rolled up section of hose in lieu of a spool piece.} be permanently connected between the screen wash and fire water systems.
By letter dated May 21, 1979, the licensee indicated he would preclude an unmitigated fire from flowing flammable liquids into the condensate pump pit and thereby reducing the area of demand from 3945 square feet to 2685 square feet.
The licensee concludes that ince the area is reduced by curbing, the demand is reduced and he concludes that, therefore, the screen wash pumps and fire pumps do provide adequate capacity to satisfy the largest area of demand with the modifications of curbs.
We agree that the curb would prevent oil from flowing into the condensate pump pit and would likely prevent the opening of sprinkler heads located in the lower pit area; however, the curb will not prevent the heat from reaching the adjacent transformer and hydrogen seal oil areas where the sensing line from the transformer deluge system is located.
Thus, the deluge systems from the auxiliary, main transformers, and the hydrogen seal oil and the turbine building system could be set off by a single large fire, resulting in an overtaxed water supply.
- Further, the information provided is not sufficient to permit our independent determination"of the adequacy of the screen wash pumps.
Because the present water supp'ly..is not physically dedicated and because of the overlapping demand of fire areas described above, i.e.,
one fire pump (with one pump out of service) or alternatively the screen wash pumps cannot meet the maximum water demand...
The licensees Fire Hazards Analysis indicates that the two electrical;ly"....
powered fire pumps are supplied power as follows:
(a)
One pump (A) derives its power from fossil unit 2 load center 2C, and (b)
One pump (B) derives its power from nuclear unit 2 load c nter 3C.
The licensee further states that power can be supplied to fire pump 8 from the nuclear facilities diesel generators.
It is apparent that a loss of offsite power would cause the loss of function of both fire pumps.
It appears that a fire in the transformer area could cause this same event.
However, the staff has not been able to confirm this because of the absence of specific information of the fire pump cable routing.
Although the diesels can be connected to."upply power to fire pump 8, this operation would have to be manually accomplished.
The time required to restore power to fire pump B is not certain.
There is presently no procedure which would require the operator'to restore power to one of the pumps nor is it apparent that he would immediately recognize the need to perform this function.
The staff criteria Appendix R (not yet issued} requires that "each supply of the fire water distribution system shall be capable of providing for a period of two h'ours, the maximum expected water demands as determined by the fire'hazards analysis for safety related areas or other areas which present a fire exposure hazard to safety related areas.
To comply with these 3-3
3.4 requirements, the staff will require the following modifications to the licensee's present water supply system:
(a)
We will require a vertical standpipe for other water services be provided in the existing 500,000 gallon raw water storage tank.
(b)
We will require an additional water supply for the fire water loop.
This supply shall consist of:
(1)
A new water storage tank with sufficient storage capacity to adequately serve the overlapping demand described above for a period of two hours.
This tank shall comply with the requirements of NFPA 22.
(2)
Automatic starting diesel fire pump(s) with adequate capacity and pressure dedicated solely for fire protection.
The fire pump(s) shall be. designed and installed in accordance with NFPA 20.
(3)
The connection to the yard main from the new pump(s) and tank shall be separated from the existing connection by a substantial distance.
Proper valving adjacent to this connection shall also be installed to permit isolation in the*event'of a line break.
The above requirements are now included in:Appendix R to 10 CFR Part 50 which became effective on We, therefore, expect that the licensee will conform to these requirements.
.Subject-to conformance to these requirements, these items are satisfa".'torily'.resolved.
Auxiliar Buildin Corridor Our SER noted that we requested the installation of sprinklers to provide protection for redundant safety related cables from exposure fires in the auxiliary building corridor.
We also requested "additional information in our letter dated March 2, 1979 regarding the shutdown of both units following a fire in this area.
The licensee's submittal dated April 5, 1979, addt'essed this topic by referring to his Fire Hazards Analysis, L-77-51, dated February 25, 1977.
The licensee implies that the fire hazards analysis demonstrates the capa-bility of Turkey Point Units 3 and 4 to achieve safe shutdown conditions notwithstanding the effects of design basis fires.
By letter dated April 5, 1979, the licensee has withdrawn certain commitments detailed in Enclosure 2
of oi>r letter of March 2, 1979 pending his reevaluation of protection for the auxiliary building corridor.
We have reviewed the Fire Harzards Analysis, and we do not find it adequate to demonstrate the plants capability to safely shutdown both units indepen-dent of fire damage in the auxiliary building corridor.
The Fire Hazards Analysis does not specifically address the question of task/manpower in relation to a fire in the auxiliary building corridor to show that the plant has adequate procedures and manpower to shutdown both units indepen-dent of cabling therein.
It assumes that a fire which endangers redundant cables in this area cannot occur.
Our SER noted that the separation between 3-4
redundant divisions of cables required for safe shutdown was still under review by the NRC.
The adequacy of separation in certain fire areas was left open by the SER for further. staff review.
During the week of Octo-ber 16,
- 1979, NRC personnel visited the plant site to review the Auxiliary Building corridor and the Cable Spreading Room.
The minimum distance separating redundant divisions of safety-related -cable trays at Turkey Point is 12 inches vertically, 5-1/2 inches horizontally.
In safety-related areas of the plant, all or most of the cables are coated with a fire retardant material.
Tests run 'by the licensee showed very little, if any,'lame propagation along coated cables of the type used at the facility.
The results of these tests are used by the licensee to jus-tify the lack of suppression systems and solid barriers between redundant divisions of cables.
The fire retardant coating used at Turkey Point has also been tested at Sandia Laboratories.
The Sandia tests subjected coated cables to a larger exposure fire than that used in the licensee tests.
The cable tray directly exposed to the fire in the Sandia tests suffered considerable damage and burned for approximately 42 minutes.
Coated cables in a tray 10-1/2 inches above the exposed tray were also damaged.
Although the cables in the upper tray did not burn, propagation of"flames to the upper tray would have occurred if a larger expos'ure 'fire had been used, if the cables had been energized at rated current or if the coating had been applied and the cables arranged to simulate more closely a field installation.
It is therefore concluded.th'at the combination of fire retardant coating and the minimum separation;permitted between redundant divisions of cables at Turkey Point is not acceptable fire protection to assure safe shutdown capability.
It has been shown repeatedly that coated cables directly exposed to a flame (for several minutes) will be damaged and will ignite.
Although flame propagation is retarded by the coating, coated cables will burn and add their heat of combustion to the heat input to a compartment in a fire.
The lack-of adequate separation between redundant divisions of safe shutdown cables at Turkey Point could result in damage to both divisions from from direct flame impingement. from an exposure fire.
Transient combustibles are moved through the area.
A fifty-fivegallon drum of lube oil was observed in the area as well as a welding cylinder cart.
Radiation protective clothing is collected at a checkpoint in open plastic barrels.
The combustibles in this area pose an exposure fire hazard to the Flamemastic-coated cables which could exceed the protection offered by the flame retardant coatings.
Although administrative control of com-bustibles will generally limit the size of exposure fires, it is not acceptable to rely on administrative controls to assure safe shutdown of the plant.
Because the licensee has not demonstrated that the plant can be safely shutdown after sustaining fire damage in the auxiliary building corridor, we will require the installation of an automatic sprinkler system designed to prevent exposure damage to cable tray systems in this area.
In addition, 3-5
we will require implementation of the recommendation in enclosure 2 of our letter of March 2, 1979.
The specific items are as follows:
'a)
We will require fire detection systems in the chemistry laboratories (hot and cold labs) and in the new laundry facility.
(b)
We will require 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> rated fire doors in the auxiliary building for the chemistry laboratories (hot and cold labs} and new laundry facility.
(c)
We will require 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> rated fire dampers for ventilation ducts in the chemistry laboratories (hot and cold labs) and the new laundry facility to isolate these areas from the auxiliary corridor.
(d)
We will require plastic barrels in the auxiliary building corridor used to collect radiation protective clothing be replaced with barrels made of a fire retardant material.
3.5 We will require that alternate shutdown capability be provided which is independent of the auxiliary building corridor to comply with Appendix R.
The above requirements are included in Appendix R to 10 CFR Part 50 which became effective on We, therefore, expect that the licensee
-will conform to these requirements.
Subject to conformance to these requirements, these items are satisfactorily resolved.
Gable S readin Area (3.2.5)
We noted in our SER that a capability independent of the cable spreading room should be provided to safely shutdown both units.
We requested infor-mation in our letter dated. March 2, 1979 to demonstrate that both units can be shutdown independent of a fire in the cable spreading room.
The licensee by letter dated April 5, 1979 addressed this topic by referring to his Fire Hazards Analysis, L-77-57 dated February 25, 1977.
The licen-see impl es that the fire hazards analysis demonstrates the capability of Turkey-Point Units 3 and 4 to achieve safe shutdown conditions notwith-standing the effects of a design basis fire; By letter dated April 5, 1979, the licensee withdrew certain commitments detailed in Enclosure 2 of our letter of March 2, 1979 pending his reevaluation of protection for the cable spreading area.
We will require the implementation of these withdrawn commitments.
We have reviewed the fire hazards analysis and we do not deem it adequate to demonstrate the capability to shutdown both units independent of fire damage in the cable spr eading room.
The Fire Hazards Analysis does not specifically address the task/manpower required to cope with a fire in the cable spreading room.
It does not show that the plant has adequate proce-dures and manpower to shutdown both units independent of cabling in the cable spreading room.
The cable spreading room is shared by both units.
It is located below the control room.
The area houses the reactor protection system instrument 3-6
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- racks, and cables are routed in the area which terminate at the control room control boards and panels, and at electrical equipment closures within the cable spreading room.
The combustibles in the area consist of electric wire and cable insulation materials and a small quantity of paper associated with the plant computer.
All cables routed through the area have been coated with a fire retardant coating.
An unmitigated fire in the cable spreading room could affect more than one division of safety-related equipment.
The licensees Fire Hazards Analysis indicates 12 inches vertically and 5-1/2 inches horizontally is represen-tative of the A to 8 tray spacing.
A common tray is used for cables from one division of both units.
Generally, cables from one unit are at one end of the tray, the other units cables are the other end;
- however, some cables cross from one end to the other and some cables leave the tray near the center and rise vertically adjacent to similar cables from the other division of both units.
Fire detection is provided throughout the area by ionization smoke detectors.
A portable dry chemical extinguisher is pro-vided in the area and additional portable fire extinguishers are located in nearby areas.
Two hose stations located on the turbine mezzanine deck serve the area.
For the same reasons we have noted in Section 3.4 herein, the licensee has not demonstrated that the plant can be safely shutdown, We will, therefore, require the installation of an automatic gaseous suppression system for the cable spreading room and an alternate shutdown capability independent of the cable spreading room.
We will require a booster hose station for the cable spreading room.
We will'equire that access doors from the cable'spreading area to the turbine building have a l-l/2 hour rating.
The above requirements are now included in Appendix R to 10 CFR Part 50 which became effective on We, therefore, expect that the licensee will conform to these requirements.
Subject to conformance to these reouirements, these items are satisfactorily resolved.
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