Today’s Event Notification Report on the Nuclear Regulatory Commission’s website has three items about potentially defective electric and mechanical parts supplied to nuclear utilities:
1. Georgia’s United Controls International (UCI) provided an update on a previously-reported defect in electrical switches and relays that the company manufactures. According to the Event Report:
Since 2009, the manufacturing process of the contact assembly of the SBM switch contacts has changed to have the whole assembly (contact holder and contact tip) tin plated. This was discovered while investigating an SBM switch that failed at a customer site due to high contact resistance across closed contacts.
The report concludes: “At this time, UCI is unable to evaluate if this manufacturing change may have an adverse effect on the capability of the General Electric SB1 switches and GE HEA relays to perform in their intended safety related application.”
Among the nuclear utilities receiving the potentially-defective parts were FPL in Florida, with two of the switches delivered to the Turkey Point nuclear power plant and eleven to Saint Lucie; 22 to the Omaha Public Power District, which owns the Fort Calhoun nuclear power plant; eleven to Duke Energy for the Oconee nuclear power plant and one to NextEra for the Seabrook nuke.
In addition to the American utilities listed above, UCI sent six switches to CFE, which operates the Laguna Verde nuclear power plant in Mexico, and two switches were sent to An tung Utility in Taiwan.
An interesting line from this Event Report: “The purpose of this letter is to provide the NRC with a report in general conformity of the requirements of 10CFR Part 21.21.” I interpret this wording to mean: ‘We’re kinda fulfulling our statutory requirements,’ or ‘Close enough for nuclear power.’ After all, it’s not rocket science.
2. QualTech NP of Huntsville, Alabama, notified the NRC and the Nebraska Public Power District (NPPD) of a potentially-defective relay provided to NPPD for use in the Cooper nuclear power plant. The report concerns “a flaw or defect in the start wrap of the magnet wire. The flaw created an arc that involved windings directly beneath the start wrap which resulted in an open circuit on the coil windings.”
More interesting wording: “This failure is classified as infant mortality….” I don’t know if infant mortality is a legitimate term-of-art, gallows humor or crass insensitivity, but it’s pretty gross in any case.
3. And Baldor Electric Co. of Flowery Mound, Georgia, notified the NRC that there was a potential defect in AC motors sent to DTE Electric Company for use in the Unit 2 reactor at the Enrico Fermi nuclear power plant in Michigan. The Event Report indicates that the motor “contains a design where the shaft journal is not long enough to allow the proper fit between the motor shaft and the o-ring of the inpro seal rotating element.” Baldor’s investigation was spurred by the return of a defective motor in which the inpro seal failed.