ML20113C433
| ML20113C433 | |
| Person / Time | |
|---|---|
| Site: | Wolf Creek  |
| Issue date: | 01/13/1985 |
| From: | Koester G KANSAS GAS & ELECTRIC CO. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| KMLNRC-85-028, KMLNRC-85-28, NUDOCS 8501220321 | |
| Download: ML20113C433 (6) | |
Text
o KANSAS GAS AND ELECTRIC COMPANY THE ELECTAC COMPANY GLENN L NOESTER weca Passiotht. hucLean January 13, 1985 Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Cormiission Washington, D.C.
20555 10iLNRC 85-028 Re:
Docket No. STN 50-482 Subj : Fire Protection, Control Room Halon System
Dear Mr. Denton:
%e Wolf Creek control rom Halon systs is a total flooding system provided for autmatic fire suppression for cables routed in a concealed trench traversing the control rom floor. We system design is based on NFPA No.
12A-1973 with a design objective of maintaining a Halon concentration of >5%
for >10 minutes. Preoperational testing of the system has demonstrated that this objective has been met except for a small section at the top of the vertical cable chase extending a few feet below the floor of the upper cable spreading rom.
Kansas Gas and Electric (KG&E) has implenented a design change to imorove the control rom Halon system performance. This change provides for automatic, timed initiation of the backup Halon bank after the discharge of the primary Halon bank. It is expected that this design charge will extend the Halon soak time in the upper few feet of the vertical chase to about 7 minutes with concentrations in excess of 5 percent.
We initial problem with Halon concentrations aM the design change discussed above are identical to those discovered and implemented at Union Electric Company's Callaway Plant. The NRC has determined that the Halon system design aM performance at Callaway are acceptable.
KG&E believes the revised control roon Halon systen design is satisfactory because of the following factors:
1.
We cables in the chases aM trenches are for Load Group 2 only.
2.
The cables have been qualified to IEEE-383 standards.
3.
We cables are non-power cables.
4.
The control room is continuously manned, thus allowirg for a rapid response to a fire.
5.
The wall chase is provided with access panels so it is not concealed.
6.
Ionization type tire detection is provided within the chase aM trench enclosure.
N 8501220321 850113 J J,/l i
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201 N. Market -Wichita, Kansas - Mail Address: RO. Box 208 I Wichita, Kansas 67201 - Telephone: Area Code (316) 261-6451
Mr. Harold R. Denton Page 2 Revised FSAR pages which reflect the Halon system design change and performance are enclosed. 'Ihese pages will be formally incorporated in the next FSAR revision. Should you have any questions on this matter, please contact me or Mr Otto Maynard of my staff.
Yours very truly, fY Glenn L. Koester Vice President - Nuclear GLK: dab Enclosure xc: PO'Connor HBundy WGuldemond m
Enclosure to KMLNRC 85-028 SNUPPS Where possible, the hand extinguishers are located conveniently and ready for immediate use.
Carbon dioxide, pressurized water and potassium bicarbonate-(dry chemical) type portable extinguishers are provided as appropriate for the class of combustible and the type of equipment located in the hazard Figure 9.5.1-2 shows the approximate location and type area.
of fire extinguishers installed in the power block buildings.
l Carbon dioxide extinguishers are 20-pound capacity with a I
minimum UL rating of 10 B:C.
Dry chemical extinguishers l
(Purple K) are at least 20-pound capacity with a minimum UL rating of 80 B:C.
The capacity of the pressurized water i
extinguishers is 2-1/2 gallons each, with a UL rating of 2-A.
In addition, a wheeled dry chemical extinguisher (s) i (Purple K) is provided for the turbine building.
Self-contained breathing apparatus and protective clothing will be available in the plant to permit access to hazard
')
areas during and after a fire.
l HALON 1301 SYSTEM - Halon 1301 fire suppression systems are designed based on NFPA No. 12A-1973 and are provided locally I
to protect the areas shown in Table 9.5.1-1.
The systems are total flooding type and are designed to maintain a minimum 5-percent concentration at the height of the highest combustible in the room for 10 minutes.
The Halon 1301 storage cylinders
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are mounted on racks located outside the hazard areas.
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100-percent reserve bank is provided for each bank of cylinders.QrustgT)
The one piece extruded storage cylinders are charged to 600 l
l psig and are designed to meet the requirements of the U.S.
Department of Transportation.
Each cylinder has a control head (normally closed) which is opened by applying pilot
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pressure from the pilot cylinder and a preasure indicator.
All manifold and distribution piping is galvanized.
A local control panel is provided with each system to perform the following functions:
a.
Sound a local alarm horn and initiate Halon dis-charge on second level of detection.
b.-
Transmit discharge alarm to the control room.
Close selected ventilation dampers and shut off asso-c.
ciated ventilation and/or air conditioning fan motors.
d d.
Supervise and transmit a trouble alarm to the control room on power failure.
I Check valves are provided to prevent the loss of Halon if i
any cylinder is disconnected.
Bleeder valves are provided to prevent accidental reserve bank discharge after the main (IN SE R.j % m.P"c'^4 mceMh b. mg be, 6-less h 10 Wade; b T k.e.
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SNUPPS
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Hose racks are operated manually by plant personnel.
Each rack is controlled by a normally closed hose valve which may be opened without release of water until the last fold of hose is removed from the rack.
Hose nozzles are fully adjustable from complete shutoff to a straight stream, except in. areas where high voltage electrical equipment presents a shock hazard.
In such areas, hose nozzles without the straight stream capability are provided.
Halon 1301 system operation is initiated by a cross-zoned ionization smoke detection system.
The detectors are mounted in the ceiling of the area protected, sense particles of combustion, and provide early warning of fire to activate the suppression system, thus preventing the development of a deep seated cable tray fire.
The first zone of detection initiates an alarm locally and in the control room.
Detection by both zones sounds a local horn to warn against impending discharge and starts a discharge time delay device to permit personnel to leave the area.
Halon is discharged after a preset time delay by actuation of a solenoid valve on the pilot Halon cylinder, applying pilot pressure to the control heads on other cylinders in the bank, as required.
A minimum 5-percent Halon 1301 concentration is l
achieved in the enclosure to be protected.
In addition, the system is designed to provide a 5-percent concentration for l(
10 minutes at the elevation of highest combustible material r
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in each area protected.f Halon that is expelled is manifolded CId'ERTE) l and piped to the hazard area and discharged through nozzles.
Halon 1301 system piping does not contain Halon until the system is activated.
A pressure switch is provided to alarm in the control room, indicating Halon discharge.
Prior to Halon discharge, selected ventilation dampers close and selected ventilating and/or air conditioning fan motors associated with the hazard area shut down.
A transfer valve or switch is provided to manually transfer the actuation to the reserve bank after a mainbankdischarge.[Whereonebankofcylindersservesmore
@eT B than one area, solenold-operated selector valves are installed to direct the discharge to the affected area.
Local manual actuation is possible by pulling a lever in the pilot cylinder.
A pull pin and seal prevents accidental operation of the manual lever.
Pushbuttons are provided for areas served by l
Halon 1301 system for remote manual actuation.
Manual actuation is similar to detection by both zones of detection.
The time delay device is adjustable.
Each Halon system is provided with a momentary contact abort switch to delay the discharge for evacuation purposes.
A keylock switch is also provided to disable the system during maintenance operations.
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Rev. 14 9.5.1-23 l-3/84
SNUPPS TABLE 9.5.1-1 (Sheet 3)
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Switchgear rooms 5 percent minimum for l
10 minutes Control cabinet, 5 percent minimum for l
load center, and MG 10 minutes sets room Electrical pene-5 percent minimum for l
tration rooms 10 minutes Computer room proper 5 percent minimum for l
and below floor 10 minutes Control room cable 5 percent minimum for l
trenches and asso-10 minutes ('R.C.
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ciated wall chases s.or:
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Rev. 14
SNUPPS
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APCS 3 9.5-1 Appendix A swuPPs le) The proper type of hose nozzles to be supplied (e) Combination spray / straight-stream nozzles are pro-to each atea should be based on the fare hazard vided for all interior hose stations, except in areas analysis. The usual combination spray /straigh-with sensitive electrical equipment. In these areas, stream nozzle may cause unacceptable mechantcal nozzles will be Class 'C' type.
damage (for example, the delicate electronic equipment in the control room) and be unsuit-able. Electrically safe nozzles should be pro-vaded at locations where electrical equipment or cabling as located.
1 (f) Certain fires such as those insolving flammable (f) No foam extinguishing systems are provided in the liquids respond well to form suppression.
SNUPPS power bloan Suildings.
Consideratton should be given to use of any of the available foams for such specialized pro-tection application. These include the more common chemical and mechanical low-expansion foams, high-expansion foam, and the relatively i
new aqueous film-forming foam (ATFF).
E.4.
Halon Suppression Systems The use of Halon f are extinguishing agents should, Halon extinguishing systems are based on NFPA 12A-1973.
I as a minimum, comply with the requirements of NFPA Only approved agents are used.
12A and 125, 'Halogenated Fire Extinguishing Agent i
Systems - Halon 1301 and Halon 1211."
Only UL or Each Halon system is capable of attaining a 5-percent FM approved agents should be used.
minimum concentration. Each system is designed to main-tain a 5-percent minimum concentration at the highest In addition to the guidelines of NFPA 12A and 128,
@g(ustible material in the hazard area for 10 minutes.
comb preventattve maintenance and testing of the systems, w -V. Ge c4bs 4. (.3. 2
- 2. 3 a4A 9. S. l. 3.
3 )
ancluding check weightng of the Halon cylinders j
should be done at least quarterly.
The system actuation is by a cross-zoned, ionization-type detection system. Detection by the first zone alarms i
locally and in the control room. Detection by both zones will sound a local horn, close required dampers, shut off associated ventilation and/or air conditioning fan motors, and will discharge after a time delay for per.
4 sonnel evacuation. A momentary contact abort switch is provided in each local panel tc delay the discharge for evacuation purposes. Each local control panel has a separate key lock switch to disable system controls during maintenance operations. At such times, the system will indicate " trouble" on the annunciator panel in the control room. A 100-percent reserve bank is provided for each Halen system.
The Halon systems will be maintained and tested based on NFPA 12A-1973.
Rev. 15 g
9.5A-16 6/84
.