ML20072D349
| ML20072D349 | |
| Person / Time | |
|---|---|
| Site: | Zimmer |
| Issue date: | 06/16/1983 |
| 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, E-45, LOZ-83-0053, LOZ-83-53, NUDOCS 8306230196 | |
| Download: ML20072D349 (3) | |
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THE CINCINNATI GAS & ELECTRIC COMPANY CINCINNATI.OHBO 45201 June 16, 1983 LOZ-83-0053 J. WILUAME JR sENtOR VICE PRESIDENT NUCLEAR OPERA 7 EONS 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-45 FAILURE OF " STATIC-0-RING" MODEL SN PRESSURE SWITCH DURING ENVIRONMENTAL QUALIFICATION TESTING W.O.
57300, JOB E-5590, FILE 956C, E-45 This letter constitutes an interim report concerning the subject condition initially reported to the Commission on May 20, 1983 as a potentially reportable deficiency under the requirements of 10CFR50.55 (e).
The deficiency is that during Environmental Qualification
' Testing for High Energy Line Break (HELB)/LOCA conditions, a
. Static-O-Ring pressure switch, Model SN, failed by electrically shorting.
Review of the applications of these switches shows that a total n0mber of nineteen Static-O-Ring pressure switches are installed in safety-related applications.
These switches are Models SN, 6N, and 12N.
Due to the similar design of these models, the results of the Model SN testing are considered applicable to the 6N and 12N models.
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Mr. J.G.
Keppler Regional Administrator June 16, 1983~
LOZ-83-0053 Page 2 The nineteen applications consist of 4 unique system applications.
The systems affected are Residual Heat Removal (RH), Nuclear Boiler (NB), Reactor Core Isolation Cooling (RI) and Reactor Protection (RP).
The rasults of the failure mode effects analysis for each application is provided below.
(This analysis assumes common mode failure and shorting of all switches of this design at the same time / event).
RH - provides 1 permissive in a 2 out of 2 case for opening of ADS valves NB - inadvertant initiation of HPCS system RI - trip of RCIC system RP - failure to initiate scram due to high drywell pressure The failure modes of the NB and RP system create situations that are adverse to safe operation of the plant.
Therefore, this item has been determined to be reportable.
The corrective action identified below will be applied to all nineteen applications.
An Engineering Change Request (ECR) will be generated to replace these switches with qualified pressure switches.
The scheduling and completion of this corrective action is contingent upon NRC approval to proceed with this work or release of the i
November 12, 1982 " Order to Show cause and Order Immediately Suspending Construction".
Upon this approval or release, a projected schedule for completion of the corrective action will be submitted.
Mr..J.G. Keppl r Regional Administrator June 16, 1983.
LOZ-83-0053 Page 3 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 gAfgw
. WILLIAMS, J SENIOR VICE PRESIDENT
-DJS/HCB/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