ML20063L854
| ML20063L854 | |
| Person / Time | |
|---|---|
| Site: | Byron, Braidwood, 05000000 |
| Issue date: | 09/03/1982 |
| From: | Tramm T COMMONWEALTH EDISON CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, 4954N, 82-03, 82-04, 82-3, 82-4, NUDOCS 8209090248 | |
| Download: ML20063L854 (2) | |
Text
/
\\ Commonwrith Edison
- l/
f
) one First N tional Plaza. Chicigo Ilknois
~
~7 Address Reply to: Post Office Box 767 e'
Chicago, Illinois 60690 September 3, 1982 Mr. James G.
Keppler, Regional Adminis trator Directorate of Inspection and Enforcement - Region III U.S.
Nuclear Regulatory Commission 799 Roosevelt Road.
Glen Ellyn, IL 60137
Subject:
Byron Station Units 1 and 2 Braidwood Station Units 1 and 2 Emergency Diesel Generat ir Field Relay Failure NRC Do cket No s. 50-454, 50-455, 50-456, and 50-457 Reference (a):
Augus t 2, 1982, letter from T.
R.
Tramm to J.
G.
Keppler.
Dear Mr. Keppler:
This is to provide a final report on a diesel generator relay deficiency which was identified at Byron.
For your tracking purposes it was numbered 82-04 f or Byron Station and 82-03 for Braidwood Station.
As indicated in the interim report provided in reference (a), degradation of electrical contacts on the speed sensing auxi-liary relays (14FX and 14FRX) was discovered during testing o f the Byron 18 emergency diesel generator.
Our subsequent investigation revealed that the 120 VAC voltage sensing relays were chattering due to voltage buildup.
This chattering was causing burning and pitting of the speed sensing auxiliary relay contacts.
Replacing the voltage sensing relays with a DC version will provide a "clea n e r "
switch from the de-energized state to the energized state and will eliminate the contact chatter.
The following corrective actions are being taken:
1.
Speed sensing auxiliary relays (14FX and 14FRX) are I
being replaced with heavy duty relays.
2.
The 120 VAC voltage sensing relays (VR) are being l
replaced with 125 VDC relays and a diode rectifier circuit.
1 8209090248 820903 SEP
- 7. E02>
PDRADOCKOSOOO4g s
as M
J.
G. Keppler September 3, 1982 Please address further questions regarding this matter to this office.
Very truly yours, Y v ~. _
j f T. R.
Tramm Nuc ear Licensing Administrator 1m 4954N
.