Semantic search
Jump to navigation
Jump to search
| Entered date | Event description | |
|---|---|---|
| ENS 56196 | 1 November 2022 15:33:00 | The following is a synopsis of information provided by Nutherm International via fax: Nutherm was notified by the customer that a Sola / Hevi-Duty uninterruptible power supply provided under an Exelon purchase order did not power up properly. The unit was returned to Nutherm for failure analysis. Inspection of the internals showed damage to transistors. When energized, the output was out of specification. This UPS had been supplied for use at Clinton Power Station. No other units are impacted by this defect or failure to comply. This issue has been identified as a single failure on this component only. This issue will not impact any future procurements. |
| ENS 54914 | 25 September 2020 19:59:00 | The following is a summary of the report provided by the notifier: Pursuant to 10 CFR 21.21(d)(3)(ii), Nutherm International, Inc. is providing written notification of the identification of a potential defect found in Eaton D26 relays. On July 23, 2019, Eaton Corporation released a letter, 'Update on Reports of Size 1 & 2 AC Contactors that Failed to Open When Deenergized'. This letter described a condition observed on AC contactors after being energized for a long period of time without being 'cycled'. Eaton also stated that this would occur in only a few isolated cases in continuously energized applications. The cause of the problem is the coating on each of the steel laminations in the cores of these devices. This steel is coated with an organic insulating varnish classified as C3. This coating, when heated for a long time period, can migrate from the lamination surfaces to the edges at the area between the separate core pieces (referred to as armatures and magnets). This substance is sticky and can potentially hold the core pieces together with enough strength to overcome the forces of the device's return springs. Potentially impacted components may include: Freedom contactors NEMA Size 00 through 5 A200 contactors NEMA Size 00 through 4 D15 Relays D26Relays AR Relays (AC Only) BF Relays (AC Only and including NBF relays) Vacuum contactors NEMA Size 4 Nutherm identified that they had supplied the Eaton relays to the following facilities: Dresden Nuclear Station Quad Cities Nuclear Station Palisades Nuclear Power Plant HB Robinson Steam Electric Plant Point Beach Nuclear Plant If you have any questions please contact Adrienne Smith at 618-244-6000, extension 3034, email adrienne.smith@nutherm.com or Kyle Mitchell at 618-244-6000, extension 3097 email kyle.mitchell@nutherm.com. |
| ENS 52938 | 30 August 2017 11:33:00 | The following excerpted report was received via fax: On the basis of our evaluation, it is determined that Nutherm lnternational, Inc. does not have sufficient information to determine if the subject condition would, or has, created a Substantial Safety Hazard or would have created a Technical Specification Safety Limit violation as it relates to the subject plant applications. On 8/28/2017 Cooper notified the NRC of a reportable condition under 10CFR Part 21. An Allen Bradley relay base model 700DC exhibited early failure after 133 hours of service. This relay, model 700DC, has been dedicated/qualified for multiple applications for various plants. The Allen Bradley 700DC series relay coil failed after 133 hours of service. This failure was determined by Cooper Nuclear Station to have been a component infant mortality likely caused by a manufacturing flaw that likely occurred due to a tensioning issue at the start of the coil wire winding process. Failure of the coil will result in failure of the relay, which could result in a safety hazard. Nutherm International, Inc. has concluded its review of all procurements of the 700DC series relays that use the coil in question and have found forty-nine (49) units shipped to customers which could potentially have this defect: Nebraska Public Power Cooper Nuclear Station and Indiana Michigan Power Company Donald C. Cook Nuclear Plant. Initial actions of determining the units affected were completed 8/30/2017. The impacted customers were notified of this condition 8/30/2017. Nutherm International, Inc. does not have sufficient information to determine this condition would, or has, created a Substantial Safety Hazard or would have created a Technical Specification Safety Limit violation as it relates to the subject plant applications. Nutherm has no current orders for these units and has no units in stock. No further actions will be taken at this time. This issue has been identified as a 'component infant mortality' failure caused by a manufacturing flaw. The manufacturing flaw appears to be a random failure and was identified by Cooper Nuclear Station as likely to have occurred due to a tensioning issue at the start of the coil wire winding process. Failure of the coil would be expected to occur within a few days of operation. The units that have been installed and in operation for more than two months could be considered to not contain this random manufacturing flaw. Point of Contact: Thomas Sterbis - 618-244-6000 See also NRC event: 52934 |
| ENS 51938 | 17 May 2016 15:51:00 | The following report was received from the manufacturer via fax: Nutherm International, Inc. reported on a defect found in "Moore Industries SCT Signal Converter (Part Number SCT/4-20MA/10-50MA/117VAC/UB) based upon the failure analysis of a failed component. The conclusion was that the wire insulation in T2 transformer was damaged by the transformer manufacturing facility during assembly. This damage reduced the insulation resistance and dielectric breakdown between the windings of the transformer. These damaged transformers were subsequently installed by Moore Industries into the signal converters. The failure of the transformer resulted in early, catastrophic failure of the signal converter. Moore Industries tested the transformers remaining in stock and found one (1) of the remaining two-hundred nineteen (219) transformers exhibited this condition. In all documented cases involving failure of this transformer, the impacted units had passed pre-installation functional testing but failed within four months after installation. Affected nuclear power stations include: Peach Bottom Atomic Power Station and the Sequoyah Nuclear Station. |