ML17252A887

Letter Regarding a 09/13/1973 Incident Relating to the Maintenance of the Inner Doors and Other Safety Interlocks at Indian Point Unit No. 2

ML17252A887
Person / Time
Site:	Indian Point
Issue date:	09/27/1973
From:	Cobean W Con Edison, Consolidated Edison Co of New York
To:	O'Leary J US Atomic Energy Commission (AEC)
References
3-2-12
Download: ML17252A887 (2)

Text

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DOCKETED USAEc 0CT1 1973~

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~~~- Cons_olidated _l;di~on Company of New York, Inc ..

~ti~ 1:.1 4 Irving Place .. New York, NY 10003 September 27, 1~;;~

Indian Point Unit No. 2 .;~

Docket No. 50-247 A.O. 3-2-12 Mr. John F. O'Lea~y, Director Directorate of Licensing ..... ')

Off ice of Regulation U. S. Atomic Energy Commission Washington, D. C. 20545

Dear Mr. O'Leary:

On September 13, 1973 during maintenance of the closure mech-anism of the 80' elevation outer door of the vapor container, and while the reactor was in a shutdown condition, the inner door was partially opened for a short period. An investiga-tion was undertaken to determine the cause of the occurrence.

This investigation included discussions with personnel in-volved as well as a review of station procedures relating to the maintenance of these doors and other safety interlocks at Indian Point Unit No. 2.

As a result of this investigation, we have revised and supple-mented our procedures so as to prev~nt not only a recurrence of this particular condition but also to.prevent similar con-ditionsiin the facility.

Our corrective action includes several tiers of precautions.

The first tier is designed-to minimize the need for mainten-ance of the doors of the vapor container. This will be ac-complished by having a member of the operating force open and close the doors when passage by non-operating personnel is required, and the facility is not in a cold shutdown con-dition as defined by the Technica1*specifications. At such times-, the* door operator will also maintain surveillance of the interlock mechanism to assure its continued operability.

The second tier includes specific precautions to prevent re-currence of this condition. Signs have been posted in the entrance chamber in those places where the interlock can be.

overriden requiring that the mechanical interlock not be de-7321

Mr. John

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0' Leary *

"feated withouf--prior approval ny the Watch Foreman. - The pro-cedures further require that prior to commencement of main-tenance on these doors, :o~ the interlock mechanism, signs must be posted notifying persons not to attempt to use these doors. In addition to such signs, the procedures require that prior to the commencement of maintenance, an individual must be stationed to prevent the improper use of these doors during the period required for maintenance.

The third tier is designed to prevent similar conditions in the facility. Approved procedures set forth instructions for the control1ed def eat of any electrical or mechanical interlocks in*the f~sility for maintenance purposes.

As previously indicated, at the time of the reported condi-tion, the reactor was in a shutdown condition (1900F with a shutdown margin> 4% ~k/k). There are, therefore, con-sidered to be no safety implications to the occurrence.

Our Station Nuclear Safety Committee and the Nuclear Facili-ties Safety Committee have reviewed this occurrence and ap-prove the corrective actions taken.

Very truly yours,

(_9jOJ,)~_.Jl.Q. b ,~

Warren R. Cobean, Jr.

Manager - Nuclear Power Generation Department cc/ Mr. James P. O'Reilly