ML20078R508

Interim Deficiency Rept,Item S-17 Re Main Steam Line Break Analysis.Initially Reported on 831020.Auxiliary Bldg Pressure Differential Resulting from High Energy Line Breaks Not Unacceptable for Masonry Walls.Final Rept by 840116

ML20078R508
Person / Time
Site:	Zimmer
Issue date:	11/08/1983
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-83-0214, LOZ-83-214, S-17, NUDOCS 8311150175
Download: ML20078R508 (2)

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THE CINCINNATI GAS & ELECTRIC COMPANY sE ' "

CINCINN ATI, OHIO 4520t November 8, 1983 LOZ-83-0214 J. WILLI AMS, J R 4 scheon vics entsectNT mucLEAR omanafsons 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 S-17, MAIN STEAM LINE BREAK ANALYSIS W.O. 57300, JOB E-5590, FILE NO. 956C, S-17 This letter constitutes an interim report concerning the subject condition initially reported to the Commission on October 20, 1983 as a potentially reportable deficiency under the requirements of 10CFR50.55(e).

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It was assumed in the Final Safety Analysis Report, Appendix D, Analysis of Effects of High-Energy Line Breaks (HELB) Outside the Primary Containment, "that the ventilation duct which exists j from the pipe tunnel (steam tunnel) and passes through the Auxiliary Building (AB) ruptures at time zero, thus opening a flowpath to the Auxiliary Building." In October, 1983 Sargent &

Lundy (S&L) informed CG&E that preliminary results of additional HELB analysis indicated that during a HELB, pressures released to the steam tunnel and ultimately-to the AB would create a pressure differential above that which is acceptable for masonry walls in the AB. Failure of these masonry walls (i.e. by falling) could jeopardize safety related equipment mounted on or near them.

This preliminary advice from S&L was the basis for identifying this patentially reportable deficiency.

CG&E has since been notified by S&L that refinement of the analysis now shows that the pressure differential in the AB resulting from a HELB will not be unacceptable for the masonry walls and will not jeopardize any safety related equipment.

CG&E will review the S&L calculations to determine their acceptability and will submit a final report by January 16, 1989.

8311150175 831108 PDR ADOCK 05000350 S PDR NOV ,

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Mr. J.G. Keppler ,

Regional Administrator  ;

November 8, 1983 .'

LOZ-83-0214 3 Page 2 i, 4

We trust the above will be found acceptable as an interim report under-10CFR50.55(e).

t Very truly yours, THE CINCINNATI GAS & ELECTRIC COMPANY

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. WILLIAMS, .'

SENIOR VICE PR SIDENT DJS/sfr cc: NRC Office of Inspection & Enforcement Washington, D.C. 20555 NRC Resident Site Supervisor -

ATTN: W.M. Hill NRC Zimmer Project Inspector, Region III ATTN: E. R. Schweibinz '

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