ML20072P729
| ML20072P729 | |
| Person / Time | |
|---|---|
| Site: | Byron, Braidwood, 05000000 |
| Issue date: | 03/28/1983 |
| From: | Swartz E COMMONWEALTH EDISON CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, 6284N, 82-04, 82-05, 82-4, 82-5, NUDOCS 8304040359 | |
| Download: ML20072P729 (2) | |
Text
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'N Commonwealth Edison
[C
) ons First Nationti Pina, Chic 1go. Illinois J Addrus R; ply to: Post Offica Box 767
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/ Chicago, Illinois 60690 March 28, 1983 Mr. James G. Keppler, Regional Administrator Directorate of Inspection and Enforcement - Region III U.S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, IL 60137
Subject:
Byron Generating Station Units 1 and 2 Braidwood Generating Station Units 1 and 2 Undetectable Failure in Solid State Protection System NRC Docket Nos. 50-454, 50-455, 50-456, and 50-457 Reference (a):
T. R.
Tramm letter to J. G. Keppler dated September 14, 1982.
Dear Mr. Keppler:
Reference (a) provided the thirty (30) day report pursuant to 10 CFR 50.55(e) concerning an undetectable failure in the Solid State Protection System (SSPS) at our Byron and Braidwood Stations.
The purpose of this letter is to provide the final report concerning this matter.
For your tracking purposes, this deficiency is numbered 82-05 for Byron Station and 82-04 for Braidwood Station.
The attached Revised Figure 1 shows the addition of a permanent jumper to the pushbutton test switch as recommended by Westinghouse to resolve this problem.
With new jumper added, Master relay M will always be energized with the Relay Mode Selector Switch is in the Test Position.
the If proving Lamp L remains lit after the pushbutton has been released, operator will know that the contacts shunting the proving lamp have not reclosed.
Please address any further questions that you or your staff may have concerning this matter to this office.
Very truly yours, E. Douglas Swa Nuclear Licensing Administrator l
cc:
Region III Inspector - B/B l
Attachment 4AR291983 6284N 8304040359 830328 r
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Logic 5
M N crl ef. Re.b Mode Gelec4ee Life.L h
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h flormal Operation: " Logic" contacts.close to pick.up Master relay M.
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Master relay contacts close to apply 120VAC to Slave relay S.
Slave relay contacts close to power the Safeguards device.
During Testing.: Relay mode selector switch (not shown) to " Test" position suitches 120VAC to 15VOC.
Pushbutton test switch picks up Master relay M and applies 15VDC to Slave relay coil thru proving lamp L.
Slave relay is not energized because of reduced voltage of 15VDC.
Problem:
If contacts shunting the proving lamp do not reclose when pushbutton is released and system is return to flormal, then 120VAC would be applied 1
thru the proving lamp if Safeguards actuation were called for.
Resolution: A permanent jumper wire has been added to the pushbutton test switch to provide continuous power to the master relay coil while the relay mode selector switch is in the test position.
If the proving lamp remains lit after the pushbutton has' been released, the operator.will know that the contacts shunting the proving lamp have not reclosed.
S!PPLIFIED SKETCll O'F SAFEGUARDS ACTUAT10fl RELAY TEST!'.G Iff THE SSPS REVISED f/6BM 1-
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