ML19345F912

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Forwards IE Circular 81-01, Design Problems Involving Indicating Pushbutton Switches Mfg by Honeywell Inc. No Written Response Required
ML19345F912
Person / Time
Site: Cooper 
Issue date: 01/23/1981
From: Seyfrit K
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
To: Pilant J
NEBRASKA PUBLIC POWER DISTRICT
References
NUDOCS 8102190528
Download: ML19345F912 (1)


Text

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REGION IV ARLINGTON, TEXAS 76011 611 RYAN Pt.AZA oRIVE. SUITE 1000 b,

January 23, 1981

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ATTN:

J. M. Pilant, Director Licensing & Quality Assurance v,s. *y* b,,, 7 Post Office Box 499 2

Columbus, Nebraska 68601

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Gentlemen:

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The enclosed IE Circular No. 81-01 contains reccmendations that may be aaplicable to your facility with regard to design problems associated with the subject indicating pushbutton switches.

Should you have any questions regarding this circular or the reccmendations contained therein, please contact this office.

Sincerely, O

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r1 Y. Seyfrit,.

Director i

Enclosures:

1.

IE Circular No. 5$-01 2.

List of Recently issued IE Circulars L. C. Lessor, Sucerintendent Cooper Nuclear Station Post Office Box 98 Br wnville, Nebraska 58321 i

8102190 &

SSINS No.:

6830 Accession No.:

8008220280 IEC No. 81-01 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D. C. 20555 January 23, 1981 IE CIRCULAR NO. 8!-01:

DESIGN PROBLEMS INVOLVING INDICATING PUSHBUTTON SWITCHES MANUFACTURED BY HONEYWELL INCORPORATED

Background:

By letter dated September 18, 1980 (J. M. Curran to R. H. Engelken), Southern California Edison Company (SCE) notified NRC of design problems involving certain indicating pushbuttoa switches.

The subject switches are of the type designated as Series 2 indicating pushbutton switches that are manufactured by the Micro Switch Division of Honeywell Incorporated.

The switches identified by SCE as having design deficiencies are used on the containment isolation panels at San Onofre Unit 1 (Docket No. 50-206).

SCE identified two problems with the subject switches, both of which manifest themselves during relamping:

(1) a short circuit may be induced; and (2) the circuit controlled by the switch may inadvertently be actuated.

Although the specificity of this circular is restricted to the previously mentioned Series 2 switches the deficiencies cited may be common to other indicating pushbutton switches.

Accordingly, holders of operating licenses and construction permits should scrutinize the design of other indicating pushbutton switches in their facilities for susceptiblity to the above problems.

By letter dated October 10, 1980 (J. G. Haynes to R. H. Engelken), SCE submitted a detailed followup report addressing the defective switches.

Sections of the SCE report containing relevant information have been excerpted and included in the paragraphs that follow.

Sections so excerpted are identified by quotation marks.

Discussion:

The SCE report provided the following details of the problems previously mentioned:

" 1.

The design of indicating pushbutton switches is such that during insertion of the lamp assembly into the switch housing, shrrting could occur between the metallic plunger and the energized indicator lamp connection inside the

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