Part 21 Report - 1997-640
ACCESSION #: 9708070153
14685 W. 105th Street o Lenexa,
Kansas 66215-5964 USA
Tel. 913.888.2630 - Fax 913.888.0767
Mr. Anil S. Gautam, NRC
Subject: 10CFR21 dated October 14, 1994
Dear Mr. Gautam:
In July of 1993 SOR began to manufacture pressure, vacuum, and
temperature switches that were qualified by SOR test report 9058-102. In
September of 1994 SOR was notified of a manufacturing defect by Nebraska
Public Power (Ref. RGA 2125, seven defective units) and Connecticut
Yankee (Ref. RGA 2117, one defective unit). In addition SOR assembly
personnel had identified the same defect (Ref. MRR 1479, one defective
unit). The defect was identified as a crack in the lead wire insulation.
This prompted SOR to issue a 10CFR21 and investigate the cause of the
defect. The cause of the cracked insulation was a heavy coating of epoxy
on the wires outside of the potted area and was due to poor workmanship.
This condition went undetected because SOR quality inspectors did not
notice the coating of epoxy on the wires.
As noted in the Part 21 Notification, the following corrective action was
taken in October 1994:
1. The Work Order formats for the conduit seals were revised to include
specific instructions not to allow epoxy on the wires. In addition,
there is an inspection step at the end of the Work Order that
instructs the inspector to examine the wire and reject any that have
epoxy on the wire. Each of these steps must be signed off on the
Work Order by Manufacturing and QA personnel for each order of
2. Shrink tubing was added to the lead wires where they exit the
conduit seal. The purpose of this tubing is to protect the wire
insulation during shipping and handling. This step is signed off on
the assembly procedure by Manufacturing and it is reviewed by QA
personnel for every switch.
3. The wire manufacturers recommended minimum bend radius was added to
the SOR General Instructions that are provided to the customer with
The conduit seals are manufactured as a sub-assembly in a separate
environmentally controlled room. Therefore, there is no danger of epoxy
contamination on any other parts of the switches.
Reference Corrective Action Report 0357.
Colbert Turnev, V. P. Quality Joseph G. Modig, Engineer
*** END OF DOCUMENT ***
Page Last Reviewed/Updated Friday, January 31, 2020