ML19345F916
| ML19345F916 | |
| Person / Time | |
|---|---|
| Site: | Fort Saint Vrain  |
| Issue date: | 01/23/1981 |
| From: | Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | Millen C PUBLIC SERVICE CO. OF COLORADO |
| References | |
| NUDOCS 8102190534 | |
| Download: ML19345F916 (1) | |
Text
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UNITED STATES PDR:HQ NUCLEAR REGULATORY COMMISSION LPDR f.s
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REGION IV MII NSIC 611 RYAN Pt AZA ORIVE. SUITE 1000 1
ARUNGTON. TEXAS 76011 STATE January 23, 1981 Occket No. 50-267 g
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Public Service Ccmpany of Colorado 9
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ATTN: Mr. C. K. Millen Senior Vice President 2
FE B 0 21981 *"' O-P. O. Box 840 4-
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ol Gentlemen:
Dfg The enclosed IE Circular No. 81-01 centains rect:mmen ations that may be applicable to ycur facility with regard to design preolems asscciated with the subject indicating pushcut cn switches.
Shculd you have any questions regarding this circular or the reccmmendatiens contained therein, please centact this office.
Sincerely,
. l.
'Karl V. Seyfrt.
4 Di rector
Enclosures:
I 1.
IE Circular No. 81-01 2.
List of Recently issued IE Circulars cc:
- 3. W. Warambourg, Nuclear Production Manager Fort St. Vrain Nuclear Station P. 0. Box 368 Plattaville, Colcraco 30651 L. Brey, Manager, Quality Assurance 810 219 0 'S'bt
SSINS No.:
6830 Accession No.:
8008220280 lEC 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 PJSHBUTTON 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 proble4 involving certain indicating pushbutton 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, shorting could occur between the metallic plunger and the energized indicator lamp connection inside the
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