IE Circular No. 78-09 - Arcing of General Electric Company Nema Size 2 Contactors
CR78009
UNITED STATES
NUCLEAR REGULATORY COMMISSION
WASHINGTON, D. C. 20555
MAY 31, 1978
MEMORANDUM FOR: B. H. Grier, Director, Region I
J. P. O'Reilly, Director, Region II
J. G. Keppler, Director, Region III
K. V. Seyfrit, Director, Region IV
R. H. Engelken, Director, Region V
FROM: Norman C. Moseley, Director, Division of Reactor
Operations Inspection, Office of Inspection and
Enforcement
SUBJECT: IE CIRCULAR 78-09 - ARCING OF GENERAL ELECTRIC
COMPANY NEMA SIZE 2 CONTACTORS
The subject circular is transmitted for issuance by close of business within
three days after date of this letter. The Circular should be issued to all
holders of Reactor Operating licenses or Construction Permits. Also enclosed
is a draft copy of the transmittal letter.
Norman C. Moseley, Director
Division of Reactor Operations
Inspection
Office of Inspection and Enforcement
Enclosures:
1. Draft Transmittal Letter
2. IE Circular 78-09
CONTACT: V. D. Thomas, IE
49-28180
.
(Transmittal letter for IE Circular 78-09 to each holder of an NRC Operating
License or Construction Permit.)
IE Circular No. 78-09
Addressee:
The enclosed IE Circular No. 78-09, is forwarded to you for information. No
written response is required. Should you have any questions related to your
understanding of this matter, please contact this office.
Sincerely,
Signature
(Regional Director)
Enclosures:
1. IE Circular No. 78-09
2. List of IE Circulars
Issued in 1978
.
UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF INSPECTION AND ENFORCEMENT
WASHINGTON, D. C. 20555
June 5, 1978
IE Circular No. 78-09
ARCING OF GENERAL ELECTRIC COMPANY SIZE 2 CONTACTORS
During routine preventive maintenance of a nonsafety related motor starter
at Millstone Unit No. 2, the movable contacts in a General Electric Company
(GE) NEMA Size 2 contactor (Part No. CR206D000EEH) were found to have been
burned. Binding in the movable part of the contactor prevented a good
electrical contact with the stationary contacts resulting in arc-burn
damage. GE indicated the cause to be oversized copper tip support binding in
the phenolic tip carrier. GE reportedly modified their tooling to correct
for the manufacturing problem and inspected the contactor spare part kits in
their warehouse for oversized tip supports.
The Northeast Nuclear Energy Company subsequently inspected the remaining GE
NEMA Size 2 contactors installed at this facility and replaced oversized tip
supports in three safety related and five other contactors.
All holders of an operating license or a construction permit should be aware
that the above described GE contactor may be installed in safety related
systems at their facilities and give consideration to assuring that these
contactors do not have oversized tip supports which could cause poor
electrical contact. You may want to also review your spare parts inventories
for the plant to assure that similar contactors are not being held for use
in safety related systems. Your review of this matter should consider
whether corrective or preventive actions need to be implemented at your
facility to alleviate the contact problems as discussed.
No written response to this Circular is required. If you require additional
information regarding this matter, contact the Director of the NRC Regional
Office.
1 of 1
Page Last Reviewed/Updated Tuesday, March 09, 2021