ML20072D910
| ML20072D910 | |
| Person / Time | |
|---|---|
| Site: | Zimmer |
| Issue date: | 06/15/1983 |
| From: | Williams J CINCINNATI GAS & ELECTRIC CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, LOZ-83-0051, LOZ-83-51, NUDOCS 8306230442 | |
| Download: ML20072D910 (2) | |
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j-S THE CINCINNATI GAS & ELECTRIC COMPANY
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CINCINNATI OHIO 45201 June 15, 1983 LOZ-83-0051 s.wim m sn SEN#04 vsct PREssoENT NUCLE &N OPERATSONS Docket No. 50-358 U.S. Nuclear Regulatory Commission Region III' 799 Roosevelt Road Glen Ellyn, Illinois 60137
' Attention:
Mr. J.G.
Keppler Regional Administrator Gentlemen:
RE:
WM. H. ZIMMER NUCLEAR POWER STATION - UNIT 1 10CFR50.55(e), ITEM E-28, DEFICIENCY IN DG CONTROL LOGIC W.O.
57300, JOB E-5590, FILE NO. 956C, E-28 This letter. constitutes an interim report concerning the subject condition initially reported to the Commission on September 13, 1982 as a potentially reportable deficiency under the requirements of 10CFR50.55(e).
As stated in our previous report, QA-2107, dated November 8, 1982, a sequence of events could lead to the paralleling of all three (3) emergency buses on the same diesel generator, subsequent overloading of that diesel generator, and a potential l
loss of an essential bus.
This sequence of events occurs because the emergency diesel generator energizes the incoming potential transformers that supply voltage signals to the Essential Relay Panel (ERP).
Consequently, the ERP cannot determine that offsite power has been lost.
The corrective action for this deficiency requires a logic change to the ERP's to trip the diesel generator circuit breaket with an ESF actuation signal when the generator is operated in parallel with an onsite or offsite power source.
The engineering for this change is underway.
Engineering Change Request (ECR)-843 has been approved to implement the design change to resolve the deficiency.
Modifications to the ERP's will be performed by Vitro Labs.
The scheduling and completion of this modification is contingent upon the NRC release of the November 12, 1982 " Order to Show Cause and Order
-Immediately Suspending Construction".
Upon this release, a 8306230442 830615 gDRADOCK05000g JUN 2 01883 7p1
Mr. J.G.
Keppler Regional Administrator June 15, 1983 LOZ-83-0051' Page:2 projected schedule for completion of the corrective action will be submitted.
We trust the above will be found acceptable as an interim report under 10CFR50.55 (e).
Very truly yours, THE CINCINNATI GAS & ELECTRIC COMPANY By S,
d.
SENIOR VICE PRESIDENT DJS/DJS/sfr cc:
NRC Office of Inspection' & Enforcement Washington, D.C.-
20555 NRC Senior Resident Inspector ATTN:
W.F. Christianson NRC Zimmer Project Inspector, Region III ATTN:-
E. R. Schweibinz
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