ML19319C234
| ML19319C234 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 04/07/1977 |
| From: | Roe L TOLEDO EDISON CO. |
| To: | Stolz J Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML19319C215 | List: |
| References | |
| 257, NUDOCS 8002060806 | |
| Download: ML19319C234 (4) | |
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April 7, 1977 g,
Director of Nuclear Reactor Regulation ggg Attention:
Mr. John F. Stolz, Chief Light Water Reactors Branch No.1 Division of Project Management United States Nuclear Regulatory Co= mission Washington, D. C.
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Dear Mr. Stolz:
OI&E Region III in their inspection report 77-06 reported a Deviation from the FSAR concerning fire detection installations in the Davis-Besse Nuclear Power Station Unit No.1 emergency diesel generator and diesel fire pu=p rooms.
In response to question 9.5.4 contained in Revision 4 of the FSAR,
[_sj we stated that infrared flame detectors would be used in these rooms while V
the actual installed detection system utilizes photoelectric smoke detectors.
In the final design of detection systems, it was evaluated that smoke from potential oil fires could mask detection by infrared devices and a more i
sensitive detection system for these areas would be obtained through the use of photoelectric smoke detection devices. The final design and installation proceeded on this basis, but the FSAR was inadvertently not changed accord-ingly.
To document the above, enclosed with this letter are revised FSAR pages 9.5.4-1, 9.5.4-2 and 8.3.1-6, which will be submitted in the next revision to the FSAR.
Yours very truly, LL'R.s COPY SENT REGION -f-Enclosure cc:
Mr. James G. Keppler y
Regional Director, Region III 8002000.POS THE TOLEDO EDISON COMPANY EDISON PLAZA 300 MAOISON AVENUE TOLEDO. CHIO 43652
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9.5.4 Describe, with the aid of drawings, the fire detection and protection system provided in the circulating water pump house, turbine room, auxiliary building, transformer areas, diesel generator rooms and all other areas where fire protection is required for the safe shutdown of the plant.
For the above areas provide the following infor=ation:
a.
Describe the principles of c7eration, calibration and set point of the sensing drvices that will detect the fire and automatically ac'.uate the fire da=pers in all ducts containing this equipment.
Indicate if the operator has the ability to override the automatic controls actuating the fire dampers.
b.
Indicate the location and distance between detectors and relate the accuracy and sensitivity of the detectors to the maximum possible size of an undetected fire assuming the flow of ventilation air in the area carries the ?cabustion products away from the detector.
_ RESPONSE Figures 3-38, 3-35, 3-39, 3-40, 3-48, 3-47, and 3-59 illustrate the areas where essential equipment is located. All areas not protected by coverage 9protectedbyportablefireextinguishers.
as illustrated in figure 9-14 (station fire protection system) will be i
a.
Fire (Impers are designed for horizontal or vertical installation as required, conform to the standards of the National Fire Codes, NFPA 90A, and rcquire a UL label.
They are arranged to close automatically and remain tightly closed upon the operation of a fusible link.
The link temperature rating is between 160F and 170F.
There is no autom :ic overide.
1 b.
Detectors have 'oeen located in areas not covered by sprinkler systems and where a danger of fire is assumed to exist.
All major e]tetrical equipment, such as large motors, switchgear assemblies, generators, motor control centers, electrical cabinets, and large concentracions of cable tray, have ionization detectors installed to detect the incipient or smoldering stages of fire.
Underwriters Laboratories (U.L.) rates ;hese ionization detectors for 3,600 square feet of area protection to provide detection times equiv: lent to a sprinkler head protecting a 100 square foot area.
Detectors have teen located to cover approxi=ately 400 square feet and with an air flow of 500 fpm nr less, which is well within the detector rating.
27 l
fs Revision 27 l
9.5.4-1
D-B
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In the office building area where paper or paper products are located, rate-of-rise and fixed temperature detectors, with a U.L. rating of-2,500 feet coverage, have been applied on an average of 500 feet to minimize the response time.
As a backup to the ceiling mounted detectors, smoke and temperature detectors have also been installed in the suctions to the HVAC return air ducts.
c.
In areas where oil may be used, such as the emergency diesel generator rooms 3 emergency diesel generator day tank rooms, and diesel fire pump room, detectors and sprinkler systems hav>a been installed.
In the emergency diesel generator rooms and diesel fire pump room, photoelectric smoke detectors and manually operated dry pipe, fusible head type sprinkler systems have been provided. Photoelectric smoke detectors provide an area 27 coverage of about 900 square feet. In the emergency diesel generator day tank rooms, wet pipe, fusible head type automatic sprinkler systems have been installed. Flow indicating switches installed in each sprinkler system have been provided for alarm.
In the diesel fire pump day tank room an infrared flame detecter has been installed and provides an area coverage of about 2,000 square feet with a minimum of a 3 second time delay.
1 l
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-.e, 9.5.4-2
m D-B the rate at 100 percent load.
Ecwever, a low-low level alarm is estab-lished with 4750 gallons still remaining in the tank.
This quantity of fuel oil can maintain full load diesel operation for 25 hours2.893519e-4 days <br />0.00694 hours <br />4.133598e-5 weeks <br />9.5125e-6 months <br /> or approximately 22.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> at 110 percent loads, assuming the same reasonable increase in the fuel oil consumption rate used earlier.
21 i
h.
Figure 3-38 indicates the physical arrangement of the diesel generators, 4
fuel oil day tanks, and starting air system. Physical separation is provided to each diesel generator and its associated auxiliary systems.
Missiles Internal missiles generated by one unit will not affect the redundant unit since the walls act as missile barriers. A high crankcase pressure switch is provided which will alarm.
These units are located in the auxiliary building which is protected from externe.1 missiles generated
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by a tornado. There are no other external missiles which can affect these units.
fires Each diesel generator room is protected by a dry type sprinkler system with fused heads. Water is admitted to the system through a manual valve located outside the diesel generator rooms. Alarm check valves
- are provided.
Photoelectric smoke detectors are provided for alarm.
27 In addition, portable fire extinguishers are provided for each room. The diesel oil day tank rooms are protected with a wet pipe, link-and-lever automatic sprinkler system. Alar 1 check valves are also provided. Fire walls and doors separate each diesel generator and its associated auxiliary systems.
Flooding See figure 9.3.4-4 in the Response to Question 9.3.4 for the floor drainage system.
Fcur-inch drains are provided in each room to accom-odate fuel oil spills, rupture of a hot water heating system pipe, or leak in a diesel engine heat exchanger component cooling water line.
See table 9-6 of the FSAR for a single failure analysis of the component cooling water line. Also, refer to the Response to Question 9.2.5.
For external flooding see the Response to Question 2.4.2.
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Revision 27 8.3.1-6
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