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Morning Report for August 10, 2000
Headquarters Daily Report AUGUST 10, 2000 *************************************************************************** REPORT NEGATIVE NO INPUT ATTACHED INPUT RECEIVED RECEIVED HEADQUARTERS X REGION I X REGION II X REGION III X REGION IV X PRIORITY ATTENTION REQUIRED MORNING REPORT - HEADQUARTERS AUGUST 10, 2000 Licensee/Facility: Notification: Part 21 Database MR Number: H-00-0048 Abb Automation Date: 08/10/00 Allentown,Pennsylvania Subject: Part 21 - Defective Siemens Output Interface Relays for ABB Type 27N, 87B, 81, 47H, and 50D Protective Relays Discussion: VENDOR: ABB Automation PT21 FILE NO: mm-18-0 DATE OF DOCUMENT: 08/02/00 ACCESSION NUMBER: SOURCE DOCUMENT: LETTER REVIEWER: REXB, D. Skeen ABB Automation Incorporated (ABB), located in Allentown, Pennsylvania, notified the NRC that a piece part (small double pole, double throw output relay) on some of ABB's protective relay assemblies was defective. The ABB protective relays employ a solid state electronic sensing unit in combination with an electro-mechanical output relay to provide the interface with external control circuitry. The output interface relay (part number RTE24048) is made by Siemens. The defect is the epoxy seal on the underside of the relay housing. The Siemens relay is intended to be a sealed unit, such that when ABB performs the wave soldering and washing process during assembly of the protective relay unit, no water is introduced into the internals of the Siemens relay. However, ABB discovered that 19 of 67 relays failed during testing. ABB contacted Siemens and found that there was a problem with the epoxy seals on relays with a date code prior to the 10th week of 2000. The Siemens relays were manufactured in Austria using a one-step epoxy sealant. Two possible failure mechanisms were identified: (1) an insufficient amount of epoxy may have been applied, and (2) the ultraviolet light method of curing the epoxy may not be effective in assuring a complete seal during the wave solder and washing process. Water intrusion into the Siemens relay can result in (1) corrosion of the armature, causing it to stick and hold the normally open contacts in the closed position, or (2) the contacts may become corroded and experience either intermittent contact or no contact operation. ABB has identified all customers who procured the protective relay units as 1E nuclear safety-related equipment. The plants affected are Oyster Creek Nuclear Station, Peach Bottom Atomic Power Station, Limerick Generating Station, and Perry Nuclear Power Plant. ABB has informed these customers of the defective Siemens relays and recommended that the ABB protective relay units be returned to the Allentown, Pennsylvania facility for replacement of the Siemens relays with those of another approved manufacturer. In addition, ABB has issued a Product Advisory Recall letter to customers who may have received the affected product for non-safety applications. Contacts: Steve Alexander, NRR Dave Skeen, NRR 301-415-2995 301-415-1174 HEADQUARTERS MORNING REPORT PAGE 2 AUGUST 10, 2000 MR Number: H-00-0048 (cont.) Email: sda@nrc.gov Email: dls@nrc.gov _
Page Last Reviewed/Updated Thursday, March 29, 2012
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