ML19350B313
| ML19350B313 | |
| Person / Time | |
|---|---|
| Site: | Humboldt Bay, Diablo Canyon |
| Issue date: | 03/11/1981 |
| From: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | Crane P PACIFIC GAS & ELECTRIC CO. |
| References | |
| NUDOCS 8103200252 | |
| Download: ML19350B313 (1) | |
Text
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UNITED STATES
~94 8
NUCLEAR REGULATORY COMMISSION o
E REGION V 1990 N. CALIFORNIA BOULEVARD
/
SUITE 202, WALNUT CREEK PLAZA 4u,a WALNUT CR EEK, CALIFORNIA 94596 March 11, 1981 Docket Nos. 50-133, 50-275, 50-323 m
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Pacific Gas and Electric Company r
P. O. Box 7442 (e
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San Francisco, California 94106
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Attention: Mr. Philip A. Crane, Jr.
Assistant General Counsel y
~Gb fQ Gentlemen:
The enclosed IE Information Notice No. 81-06 contains information that may be applicable to your facility regarding the failure of an ITE Medel K-600 circuit breaker. No specific action or response is requested at this time; however, pending the results of NRC staff evaluations of this matter, further licensee actions may be requested.
Should you have any questions regarding this information notice, please contact this office.
Sincerely, (C
b R. H. Engelken Director
Enclosure:
IE Information Notice No. 81-06 cc w/ enclosure:
J. D. Shiffer, PG&E W. Raymond, PG&E R. C. Thornberry, PG&E (Diablo Canyon)
E. Weeks, PG&E,(Humboldt Bay)
E. B. Langley, Jr., PG&E elosso 0 6 9
'a SSINS No.: 6835 Accession No.:
8011040269 IN 81-06 UNITED STATES D
NUCLEAR REGULATORY COMMISSION oa 2
J lnl
_L, 0FFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 March 11, 1981 IE Information Notice NO. 81-06:
FAILURE OF ITE MODEL K-600 CIRCUIT BREAKER
Purpose:
The purpose of this information notice is to provide early notification of a matter that could adversely affect the safety of nuclear power plants.
Toward this end, this information notice alerts holders of operating licenses and construction permits of a possibly-generic deficiency involving Model K-600' circuit breakers manufactured by ITE.
Description of Circumstance:
By letter dated February 20, 1981, the Sacramento Municipal Utility District ~
informed us that, while performing preventive maintenance on electrical circuit
- breakers at its Rancho Seco facility, an ITE Model K-600 breaker was observed not to trip. An investigation revealed that a tripping coil wire had slipped out of its terminal. Further examinations revealed that the coil wire size twas AWG 20, whereas the mating lug was-sized for AWG 16-14 wire. A check of other ITE electrical breakers indicated that the problem may be generic.
Subsequent to the letter, the Sacramento Municipal Utility District informed us orally that ITE Model K-1600 breakers have the same deficiency and that
-Model K-3000 breakers may be similarly affected.
The information provided by the Sacramento Municipal Utility District is pre-l liminary and will be followed by a complete report. Consequently, we have not l
yet evaluated the safety significance of this event. Nevertheless, the information herein is being provided as an early notification of a possibly l
.significant event. Although no specific action uor response is requested at L
this time, recipients should review the information for possible-applicability -
to their facilities.
If NRC evaluations so indicate, further licensee actions l
may be requested.
If you have any question regarding _the information contained herein, please contact the Director of the appropriate NRC Regional Office.
Attachment:
Recently issued IE Information Notices 4
0 o
Subject Issue Issued to 81-05 Degraded DC System at 2/10/81 All power reactor Palisades facilities with an OL or CP 81-04 Cracking in Main Steam 2/27/81 All power reactor Lines facilities with an OL 81-03 Checkiist for Licensees 2/12/81 All power reactor Making Notifications of facilities with an Significant Events in OL Accordance with 10 CFR 50.72 7
81-02 Transportation of 1/23/81 All Radiography Radiography Devices licensees 81-01 Possible Failures of-1/16/81 All power reactor General Electric Type facilities with an HFA Relays OL or CP.
80-45
. Potential Failure of 12/17/80 All PWR facilities BWR Backup Manual Scram with an OL or CP Capability 80-44 Actuation of ECCS in the
'12/16/80 All PWR. facilities Recirculation Mode While with an OL or CP in Hot Shutdown 80-43 Failures of the Continuous 12/5/80 All nowar raac+or
. u ter Level Monitor for facilities with an a
4 the Scram Discharge Volume OL or OP at Dresden Unit No. 2 80 42 Effect of Radiation on.
11/24/80 All power reactor Hydraulic Snubber Fluid.
80-41 Failure of Swing Check' 11/10/80 All power reactor Valve.in the Decay Heat facilities with am
~ Removal System at Davis-OL or CP Besse Unit No. l' OL = Operating Licenses CP = Construction Permits