ML19254D066
| ML19254D066 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 09/25/1979 |
| From: | Ziemann D Office of Nuclear Reactor Regulation |
| To: | Reed C COMMONWEALTH EDISON CO. |
| References | |
| NUDOCS 7910220312 | |
| Download: ML19254D066 (3) | |
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September 25, 1979
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Docket No. 50-10 Mr. Cordell Reed Assistant Vice President Commonwealth Edison Company Post Office Box 767 Chicago, Illinois 60690
Dear Mr. Reed:
RE: DRESDEN NUCLEAR POWER STATION, UNIT NO. 1 We are currently reviewing the adequacy of the 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 power outages and attendent voltage or frequency conditions of the grid.
In our review of this matter we have drawn upon the information provided to us via Licensee Event Reports and followup letters which you have sent to us. Our review of these reports indicated the loss of offsite power events have occurred at Dresden Nuclear Power Station, Unit 1 on January 22, 1978 and March 4, 1978.
To complete our review of loss of offsite power events we require the additional information concerning the station offsite grid indicated in the enclosure to this letter.
Please provide your response to the attached questions for the Dresden Nuclear Power Station, Unit I within 90 days of receipt of this letter.
Sincerely, t/ M W
Dennis L. Ziemann, Chief 6perating Reactors Branch #2 Division of Operating Reactors
Enclosure:
Request for Additional Infomation cc w/ enclosure:
See next page Ti94 06G 79102203i2__
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Mr. Cordell Reed September 25, 1979 CC Isham, Lincoln & Beale Counselors at Law One First National Plaza, 42nd Floor Chicago, Illinois 60603 Mr. B. B. Stephenson
. Plant Superintendent Dresden Nuclear Power Station Rural Route #1 Morris, Illinois 60450 U. S. Nuclear Regulatory Commission ATTN: Jimmy L. Barker P. O. Box 706 Morris, Illinois 60450 Susan N. Sekuler Assistant Attorney General Environmental Control Division 188 W. Randolph Street Suite 2315 Chicago, Illinois 60601 Morris Public Library 604 Liberty Street Morris, Illinois 60451 1i94 061
s ENCLOSURE REQUEST FOR ADDITIONAL INFORMATION LOSS OF 0FFSITE POWER A.
For losses of offsite power where less than all offsite power was lost:
1.
How many circuit's to the offsite network are normally available and how many were lost during the event?
2.
What was the cause of the event?
3.
Why did the other lines not fail when some did fail?
4.
Was any voltage inc. ease 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.
How long was power unavailable from the circuit?
7.
Date of Event.
B.
For losses of all offsite power:
1.
How long was the power off? How long for partial recovery?
Please give details.
2.
If turbine trip occurred, how soon after did loss of offsite power occur?
3.
Ibpower was recovered promptly (10 minutes or less), was it due to automatic 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 prict to or during the outage?
If so, please give details, lowest frecuency reached, decay rate, affects on equipment operation, etc.
6.
Cate of Event.
C.
Were there any other less of offsite power events other than we have listed.?
If so, please give details of each event.
3194 062