ML20002B365
| ML20002B365 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 09/30/1979 |
| From: | Rosa F Office of Nuclear Reactor Regulation |
| To: | Crutchfield D Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML13330A156 | List: |
| References | |
| NUDOCS 8012110439 | |
| Download: ML20002B365 (2) | |
Text
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NUCLEAR REGULATORY COMMISSION y
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MEMORANDUtt FOR:
D. Crutchfield, Br,.ich Chief, SEPB, DDR, NRR FROM:
F. Rosa, Chief, PSB, DSS
SUBJECT:
D. C. SYSTEM 110NITORING NiD AfifiUflCIATION In response to your memorandum of September 25, 1979, we offer the following commnts on D.C. power system monitoring and annunciation:
The specific requirements for D. C. power system monitoring derive from5.
the general requirements embodied in Section of IEEE Std 308-1974, and in Regulatory Guide 1.47.
In surmiary, these general requirements simply state that the D.C. system (batteries, dis-tributien systems and chargers) shall be monituad to the extent that it is shown to be ready to perform its intended function. Accordingly, the guidelines used by PSB in the licensing review of the D.C. power system designs are as follows:
As a minimum, the following indications and alams of the Class 1E D.Cl power system status shall be provided in the control room:
Battery current (am.eter-charge /discharoe)
Battery charger output current (ammeter}
D.C. b.
voltage (soltmeter).
Battery charger output voltage (voltmeter) r Battery high discharge rate alam l
D.C. bus undervoltage and overvoltage alam l
D.C. bus ground alarm (for ungrounded system)
Battery breaker (s) or fuse (s) open alam Battery charger output breaker (s) or fuse (s) open alarm Battery charger trouble alam (one alam for a number of abnomal' conditions which are usually indicated locally)
It should be noted that some additional status indications and alams are provided in the control room or locally by most current designs.
l We have concluded that the above cited monitoring, augmented by the periodic test and surveillance requirements included in the Technical Specifichtfor.s.
provide the required assurance tut t.e Class 1E D.C. power system is ready 5
to perform its intended safety /ur.iic.9 l
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-2 L'e note that our above guidelines differ from and are more conservative than the E.G.&G. reco=2ndations cited in your memorandum.
r A s%f Faust Rosa, Chief Power Systems Branch Division of Systems Safety i
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