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| Entered date | Event description | |
|---|---|---|
| ENS 53856 | 1 February 2019 13:53:00 | The following was received via fax and email from SOR: Exelon Limerick generating station notified SOR on December 8, 2018 via email regarding corrective action needed for the R-series housing on two of their emergency diesel engines. Limerick reported that the field wire lugs were in close contact with the switch cover gasket and had degraded the EPR (Ethylene Propylene Rubber) housing cover material enough to short to the cover which, in turn, tripped the 1A control fuse. Limerick reported that the uninsulated terminals and wiring were already available at the switch location during installation and used without modification. Limerick's immediate corrective action was to land the field wiring on the bottom tier of the terminal block and insulate the lugs. EPR is known to be an effective electrical insulator, and is used as insulation for many electrical cables. For this reason, the EPR cover gasket was used on the SOR R-series nuclear housing to offer sufficient electrical insulation. Due to the failure at the Limerick generating station and subsequent evaluation at SOR, the EPR gasket alone does not provide sufficient electrical insulation between the terminal block connections and the metallic housing cover when uninsulated terminals are installed. This direct connection will cause heating of the gasket and eventual direct short through the EPR material. SOR does not have the capability to perform further evaluations to determine if a safety hazard exists as the specific customer installation practices is unknown. The end user must confirm for each application the wire installation applied with this specific model string. The plants who are potentially affected by this deviation are in the process of being notified by email and/or postal letter and are: - Callaway - Braidwood - Byron - Limerick - Quad Cities - Davis Besse - St. Lucie - H.B. Robinson SOR has completed or is implementing the following corrective actions: - Completed the identification of the customers potentially affected by this deviation within this notification - Initiated customer complaint 21 and corrective action (CAR) 1003 - Released ECO 5443 to add 3.5" wide Nomex insulation paper to the terminal block units - Created a modified cover gasket with a Kapton insulation piece for field units - Revision to SOR General Instruction to require customers to use insulated terminal connections targeting completion by February 28, 2019 - Investigate modification to SOR insulation resistance and dielectric tests targeting completion by February 28, 2019 Should you have any additional questions regarding this matter, please contact: For general inquiries: Linda Coutts Inside Sales Representative Email: lcoutts@sorinc.com Tel 913-956-3071 For technical inquiries: Mike Bequette Vice President of Engineering Email: mbeguette@sorinc.com Tel 913-956-3040 Sara Roos Senior Engineer Email: sroos@sorinc.com Tel 913-956-3049 |
| ENS 53121 | 15 December 2017 18:02:00 | The following is a excerpt from a report received via email: "On October 18, 2017 a deviation in the original qualification testing of SOR safety-related switches was discovered by a NRC vendor inspection conducted from October 16-20, 2017. SOR continues to evaluate those items cited by NON 99900824/2017-201-01 Items 1 through 3 and other effects on safety related components identified by SOR. The qualification test report was written in 1992. Due to the age of the report, SOR continues to retrieve records and consult contracted sources. The evaluation is expected to be completed as soon as possible or by February 27, 2018. If you have any questions regarding this matter, please contact: Mike Bequette, Vice President of Engineering Email: mbequette@sorinc.com Tel 913-956-3040
The following is an excerpt from a report received via email: SOR has identified the following reportable deviations: The Test Report did not account for all (Measuring and Test Equipment) uncertainties. The following are affected: -Qualified Life -LOCA (Loss of Coolant Accident) profile -HELB1 (High Energy Line Break) profile -HELB2 profile During qualification testing, observed repeatability in excess of 1 percent of span was not adequately addressed for some models. The following will be affected: -Vacuum switches (post LOCA only) -Temperature switches The Test Report presents data that is intended to provide a means to calculate reductions in qualified life depending on the conditions of the end use. However, there is a risk that this information could be overlooked by the end user. Following are the potential contributing factors to qualified life: -Temperature rise due to electrical load on switch element -Temperature rise on direct mount temperature switches due to elevated process temperature SOR has conducted or is conducting the following corrective actions: -Provided details in this report regarding the NQ models strings and non-standard models potentially affected -Identified the contact list of customers potentially affected by this deviation within this notification -Notifying the utilities as indicated with a copy of this notification attached targeting completion by February 8, 2018 -Revise and update test report 9058-102 to revision 3 targeting completion and availability by February 28, 2018 Notified R1DO (Powell), R2DO (Heisserer), R3DO (Duncan), R4DO (Deese), and Part 21 Group (via email). |
| ENS 51363 | 2 September 2015 15:31:00 | |
| ENS 50299 | 23 July 2014 15:15:00 | The following information was originally received in NRC Region IV on July 16, 2014 via email. Relevant portions of the submittal are provided below without graphs, tables or pictures. SOR is a supplier of basic components to the nuclear power industry. The components of concern for this notification are SOR nuclear qualified Pressure and Temperature switches with TA housings manufactured from 2004 through 2009. The defect being reported is a potential out of tolerance condition concerning the machined sealing surface for an environmental seal on the SOR nuclear TA housing. Other switches with a similar defect have the potential to not meet their intended safety function. Summary: SOR Inc. began a 10CFR21 evaluation on 6/4/14 upon receipt of three SOR pressure switches, model number 5TA-B45-U8-C1A-JJTTNQ (SN's 041100627, 041100628, and 041100629). These were returned from Entergy Nuclear Vermont Yankee (VY) due to inspections which questioned the suitability of the sealing surfaces on the face of the housings where the cover O-ring seals. The product evaluation was concluded on 6/24/14 and it was determined that this issue is a reportable defect as defined by 10CFR Part 21. If the switch housing has an inadequate machined sealing surface, the potential exists for steam permeation into the switch housing during accident conditions. This could result in an increase in set point as well as allow moisture into the housing potentially causing electrical consequences such as current leakage or a short. It is anticipated that the above noted condition represents a small percentage of the total number of housings from this batch of castings. Also, the potential risk is thought to be small due to a second redundant seal on the cover. This condition is being reported as a conservative measure. Evaluation: There are 2 (redundant) environmental seals on the cover of the nuclear TA housing. One O-ring seals on the undercut of the cover threads (151 O-ring). This seal is not in question and is not part of this evaluation. The other O-ring seals between the face of the enclosure and the O-ring groove on the cover (042 O-ring). This is the seal that is the subject of this evaluation. Redundant O-ring seals are used on the SOR 'TA' cover to minimize steam permeation into the housing during LOCA or HELB conditions. The consequences of permeation are that it can result in an increase in the set point and also allow moisture into the housing which could have electrical consequences. The returned switches have a suspect sealing surface on the face of the housing where one of the two O-rings (the 042 O-ring) is intended to seal. For the purposes of this Part 21 evaluation, consideration needs to be given to whether this suspect sealing surface could result in increased permeation into the switch enclosure. Switches #041100627 and 041100628 both have an area on the face of the housing where the casting did not have sufficient material for cleanup when the housing was machined. This area was characterized by use of the SOR CMM and measuring the area where the O-ring is expected to seal. Switch #041100629 was different from #041100627 and 041100628 in that it had one small indentation in the sealing surface which was immeasurable but does not meet surface finish requirements. The TA housings on the returned switches are clearly out of tolerance. It is SOR's position that the environmental seals on any switch with a similar defect has the potential to not meet its' intended safety function. . . Evaluation of Previous Shipments: SOR has validated shipments for a quantity of 56 pressure and temperature switches with the subject TA housing. Potentially affected customers/utilities include: TVA/Watts Bar, TVA/Browns Ferry, TVA/Sequoyah, Entergy Nuclear/Vermont Yankee, Entergy Operations/River Bend, Southern California Edison, Third Qinshan Nuclear/QSNPP-3-A (TQNPC), Fairbanks Morse Engine, STP Nuclear Operating Co., Hydro Quebec /Gentilly II, Progress Energy/Shearon Harris, Control Components Inc./Korea Hydro Nuclear Shin-Kori & Wolsong, Control Components Inc./KHPN Shin Kori 3 & 4, Korea Hydro & Nuclear/KHPN Yonggwang NPP #5, Konan Engineering/Yonggwang Nuclear, and First Energy/Davis-Besse Nuclear. (Total Potentially Affected = 56. Root Cause: The returned TA housing castings did not meet print and therefore did not allow enough material for cleanup of the machined sealing surface. Permanent Corrective Action: SOR internal documentation is being changed to require 100% inspection of the raw casting height. Also, the 1/8 (inch) minimum finish dimension is being added to the housing machining drawings. Action by Nuclear Power Plant: SOR recommends that the application for each switch noted in the above table be reviewed to determine if it is being used in a LOCA or HELB application. If so, SOR recommends an inspection to visually check for an adequate sealing surface of the housing . This inspection is also recommended for switches that have not yet been installed. The minimum required sealing surface is 1/8 (inch) (0.125 (inch)). After inspection, all units should have the 042 and 151 O-rings replaced if the units do not exhibit the deviation. SOR will send replacement O-rings at no charge upon request. If units are found that do not meet the acceptance criteria, they will be replaced free of charge by SOR. Contact SOR Director of Customer Service, Greg Barber for the replacements: Greg Barber 913-956-3059 gbarber@sorinc.com
The following information was excerpted from a facsimile: Korea Hydro Nuclear power plants were added to include Shin-Kori 1 & 2; Shin Wolsong 1 & 2. Notified the Part 21 Reactors Group via email. |