ML19256E368
| ML19256E368 | |
| Person / Time | |
|---|---|
| Site: | Fort Calhoun  |
| Issue date: | 10/17/1979 |
| From: | Reid R Office of Nuclear Reactor Regulation |
| To: | William Jones OMAHA PUBLIC POWER DISTRICT |
| References | |
| NUDOCS 7911020231 | |
| Download: ML19256E368 (3) | |
Text
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UNITED STATES
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NUCLE AR REGULATORY COMMISSION o.
WASHINGTON, D. C. 20555
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October 17, 1979 Docket No. 50-285 Mr. W. C. Jones
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Division Panager, Production Operations Omaha Public Power District 1623 Harney Street Omaha, thbraska 68102
Dear fir. Jones:
We are currently reviewing the adequacy of th-offsite power systems of nuclear power plants and in particular, the loss of offsite power events at your facility.
One aspect of this review concerns the history of experienced total and partial nower outages and attendent degraded voltage or frequency conditions of the grid, la our review of this matter we have drawn upon the inforration provided to us via Licensee Event Reports and followup letters which you have sent to us. Our review of these reports indicated that loss of offsite power events have occurred at Fort Calhoun Station, Unit No.1 on September 26, 1973, March 13,1975, fiarch 29, 1976, February 10 and August 22, 1977.
In order
-to complete our review of loss of offsite power events we require additional i nformation.
This information should be provided to us in the form of answers to the questions listed in the enclosure.
Please provide your response to the enclosed questions for the Fort Calhoun Station, Unit No.1 tc f;RC within 90 days of the receipt of this letter.
Sincerely, W
h-7 Robert W. Reid, Chia #
Operating Reactors Branch fa Division of Operating Reactors
Enclosure:
Request for M::itional Infornation cc w/ enclosure:
See next page 1259 325 791102o 3 3 I
[
s 53".a Public Pc>eer District cc:
Margaret D. A. Paradis
' eEceuf, Lard, LeiDy 5 fiacRae
,,333 New Har.oshire Avenue. t:W.
I
..a shi ngten, D. C.
20036 Blair Public Library 1665 Lincoln Street Bl air, < ebraska 68003 P00R ORIGNA 1259 326
ENCLOSURE PROPOSED CUESTI0 tis FOR LOSS OF OFF SITE SUP.VEY A.
For losses of offsite power where less than all offsite power was lost:
1.
How many circuits to the offsite network are normally available and how mr.ny were 1 cst curing the event?
2.
What was the cause of the event?
3.
Why did the other lines not fail when some dic fail?
4 Was any voltage increase or decrease experie aed just prior to or during the outage?."If so, please give details, vel: ace reached, affects, etc.
5.
Was any frequency decay experienced just prior to or during the outagt?
If so, please give details, icwest frequency reached, dechy rate, affects on equipment operation, etc.
S.
How long was power unavailable from the circuit?
7.
Date of Event.
E.
For losses of all offsite power:
1.
How icng was the power off? How long for partial recovery?
Please give details.
2.
If turbi.ne trip occurred, how soon after did loss of offsite power occur?
3.
If power was recovered promptly (1) minutes er less), was it due to automu,:
or manual actions?
4.
Was any voltage increase or decrease experienced just prior to or during
- the outage? If so, please give details, voltages reached, affects, etc.
5.
Was any frequency decay experienced just prior to or during the outage?
If so, please give details, lowest frequency reached, decay rate, affects on equipment operation, etc.
6.
Cate of Event.
O.
risre :nsre any cther less cf effsite pcwer events Other than we have listed?
- so, :Isase ;ive cetails of eac, event.
Q $$Y P
1259 327