ML20137F823
| ML20137F823 | |
| Person / Time | |
|---|---|
| Site: | Fort Calhoun  |
| Issue date: | 08/21/1985 |
| From: | Andrews R OMAHA PUBLIC POWER DISTRICT |
| To: | Butcher E Office of Nuclear Reactor Regulation |
| References | |
| LIC-85-357, NUDOCS 8508270095 | |
| Download: ML20137F823 (2) | |
Text
g Omaha Pubilt Power District 1623 Harney Omaha. Nebraska 68102 402/536 4000 August 21, 1985 L IC-85-357 Mr. Edward J. Butcher, Acting Chief Operating Reactors Branch #3 Division of Licensing Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington. DC 20555
References:
(1)
Docket No. 50-285 (2)
Letter OPPD (R. L. Andrews) to NRC (J. R. Miller) dated May 23,1985 (LIC-85-215)
Dear Mr. Butcher:
Addi tional Infonnation Concerning Reactor Coolant Pump Trip In a recent letter (Reference 2), the Omaha Public Power District responded to a question regarding the components necessary to trip the reactor coolant pumps. The District's response included a statenent concerning the station's 130VDC control power system.
In order to clarify this statement, the District offers the following explanation of the difference between "125VDC" and "130VDC". The term "125VDC" is a nominal value. The rating of the battery chargers is 130VDC. Thus, althnugh the systen is referred to as 125VDC, since the load is supplied from the battery chargers,130VDC is more indicative of actual voltage supplied. To correct this situation, please find attached the revised page to our Reference (2) submittal incorporating this information.
If you have further questions concerning this matter, please contact us.
hM R. L. Andrews Division Manager Nuclear Production RLA/DJM/rh Attachment cc:
LeBoeuf, Lamb, Leiby & MacRae 1333 New Hampshire Avenue, N.W.
Washington, DC 20036 Mr. E. G. Tourigny, NRC Project Manager Mr. L. A. Yandell, NRC Senior Resident Inspector gjB2 095 850821 hO P
OCK 05000283
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I PDR cmploymengn augopporturury asse4
District Response The four RCP's are supplied fra each of the four 4.16KY buses, RC-3A bus 1A1, RC-3B bus 1A2, RC-3C bus 1A3, and RC-3D bus 1A4. Tripping of the RCP breakers in a DBA (Design Basis Accident) situation is acceplished, nonnally, by trip-ping the breaker from the control switch in the control room.
This tripping requires the station's 125 VDC control power systen, the control l
switch, the breakers, and their operating mechanisms.
In the event the control rom switch fails to trip the breaker, the trip may be accomplished locally either by electric control switch, or manually in the breaker cubicle.
It should be noted that for electrically tripped breakers the l
buses may be switched to an alternate control power supply which is operated fra the switchgear rom.
Reliability of the Fort Calhoun 4.16KY systen is maintained through periodic breaker maintenance, relay maintenance, and trip check testing. The operating history of the 4.16KV systen has been excellent. The District has a systen in place to track information from INP0 and the NRC so that failures at other plants of various electrical equipment are evaluated for their potential of occurring at the Fort Calhoun Station. Maintenance and service on the Fort Calhoun electrical systen is affected by these notices. Thus, actions to modify equipment to prevent malfunctions observed at other plants, but not observed at Fort Calhoun, have been and will continue to be taken.
Question #4B If necessary, as a result of the location of any critical caponent, include the effects of adverse containment conditions on RCP trip reliability. D e-scribe the basis for the adverse contairinent parameters selected.
District Response In accordance with the District's 10 CFR 50.49 program, (electrical equipment qualification) none of the equipment needed to trip the RCP's is considered to be in a " harsh" envirorinent under postulated accident conditions. Access for local tripping will not be inhibited under any accident analyzed in the Updated Safety Analysis Report.
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