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| Start date | Reporting criterion | Title | Event description | System | LER | |
|---|---|---|---|---|---|---|
| ENS 51280 | 19 May 2015 04:00:00 | 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect | Part 21 Report Involving Limit Switches Ea180 and Ea170 Manufactured in a Specific Date Range | The following information is an excerpt from a Namco Controls fax: Subject: Notification of Product Anomaly Namco Controls Division of Dynapar Corp EA180 & EA170 Limit Switches Manufactured March 25th 2014 through December 30th 2014. Dear Sir(s) / Madam(s), The purpose of this letter is to notify you of our resolution for the subject anomaly that was brought to our attention by the Nebraska Public Power District, Cooper Nuclear Station in Brownville, NE via our rep network (Mr. Curt Duphill) on May 19th 2015. On May 30th our senior engineer, Mr. Troy Kloss, visited the plant site during a plant shutdown to investigate the issue and determined that a Part 21 investigation was warranted. Dynapar's Namco Controls business sent out an early indication notice to customers as part of the investigation on 6/3/15 which included switches of date codes 1214 and 1314 (week-year). As a result of this initial notice, a second reported potential anomaly was identified by Salem Nuclear Power in Hancocks Bridge, NJ. However these switches at Salem were replaced previously and no root cause analysis was performed prior to the switches being discarded. Because of this anomaly the nuclear limit switch may not reliably state the condition of the device (in this case a main steam isolation valve) that the switch is measuring and could be a potential safety hazard depending on the nuclear power plant control logic. As a result of our internal investigation, we isolated the switch performance degradation to a compression spring in the limit switch assembly. We have validated lot control traceability of the compression spring in question, which contained 1100 suspect springs, to shipments within the subject date range and have determined 417 Namco limit switches were shipped to US customers with this potential anomaly. We are notifying the affected customers- see included list. In addition, Namco Controls has changed our inspection criteria as of 07/31/2015 for this item in order to prevent future occurrences. At this time, we have generated a Technical Bulletin (TB1501) summarizing the conclusions and recommendations. We will notify all customers, both domestic and foreign, by August 7th 2015. If you have any questions or concerns, please direct them to Quincy Hill, Quality Manager at qhill@dancon.com. Thank you. Kevin Sutherby Vice President & General Manager Namco Controls Division of Dynapar Corporation ksutherby@dancon.com 910.862.5411 (office) 2100 West Broad Street, Elizabethtown, NC 28337 The part numbers impacted are: EA170-11302,-12302,-21302,-31302,-32302,-41302,-42302-,51302, and EA180-11302,-11307,-11309,-11402,-12302,-12307,-12309,-12402,-21302,-21309,-21402,-22302,-22309,-31302,-31309,-31402,-32302,-32309,-32402 at the following facilities: Farley Nuclear Plant, Callaway Energy Center, Palo Verde Nuclear Generation Station, Fermi 2 Nuclear Power Plant, Millstone Nuclear Power Station, North Anna Power Station, Catawba Nuclear Station, McGuire Nuclear Station, Robinson Nuclear Plant, Harris Nuclear Plant, Columbia Generation Station , Arkansas Nuclear One, River Bend Nuclear Station, Waterford 3 Nuclear, Clinton Nuclear Station, LaSalle County Generating Station, Braidwood Generating Station, Limerick Generating Station, Byron Generating Station, Quad Cities Generating Station, Perry Nuclear Plant, Plant Hatch, Cook Nuclear Plant, Cooper Nuclear Station, Seabrook Station, Duane Arnold Energy Center, Salem/Hope Creek Nuclear Generation Station, South Texas Nuclear Project Electric Generating Station, Watts Bar Nuclear Plant, Wolf Creek Nuclear Operating Corporation, Prairie Island Nuclear. | Main Steam Isolation Valve |