ML19275A396

Discusses Consequences of Previously Reported Potentially Reportable Incident Re Interaction of nonsafety-grade Sys W/Steam Supply Equipment.Final Rept Will Be Provided Pending Further Investigation

ML19275A396
Person / Time
Site:	Marble Hill
Issue date:	09/27/1979
From:	Shields S PSI ENERGY, INC. A/K/A PUBLIC SERVICE CO. OF INDIANA
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
NUDOCS 7910040345
Download: ML19275A396 (2)

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0928790035 PUBLIC SERVICE INDIANA September 27, 1979 S. W. Shields vice p es. cent.

E ngineennq Mr. James G. Keppler, Director U.S. Nuclear Regulatory Commission Docket Nos.: STN 50-546 Region Ill STN 50-547 799 Roosevelt R ad Construction Glen Ellyn, Illinois 60137 Permit Nos.: CPPR-170 CPPR-171 _

Marble Hill Nuclear Generating Station Units 1 & 2

Dear Mr. Keppler:

On August 31, 1979, Mr. P. A. Blasioli of Public Service Company of Indiana, Inc.

(PSI) telephoned your office to notify you of a potentially reportable incident as required by 10CFR50.55 (e). PSI's nuclear steam supplier, Westinghouse Electric Corporation, during an investigation of the interaction of nonsafety grace systems with steam supply equipment, identified several systems which, if subjected to an adverse environment, could potentially lead to control system operation. This control system operation could impact protective functions. The consequences of this impact could yield results that are more limiting than those presented in the Marble Hill Safety Analysis Report. The nonsafety related control systems are:

1. Steam generator power operated relief valve control system.

2. Pressurizer power operated relief valve control system.

3. Main feedwater control system.

4 Automatic rod control system.

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Mr. James G. Keppler, Director September 27,1979 PS: was unable to determine that rs s incident was not significant and therefore elected to report it as potentially significant under 10CFR50.55 (e). To date, PSI is continuing evaluation of this matter. The results of the evaluation are not yet complete. This letter is intended to fulfill che requirements of an interim report as defined in 10CFR50.55 (e) (3). A final report will be filed upon completion of further investigation into the potential impact on the nonsafety related control system.

Sincer ly,

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S. W. Shields SB:ack cc: Director of Inspection & Enforcement U.S. Nuclear Regulatory Commission Washington, D.C. 20555 E. R. Schweibinz, P.E.

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