United States Nuclear Regulatory Commission - Protecting People and the Environment

Information Notice No. 92-24: Distributor Modification to Certain Commercial-Grade Agastat Electrical Relays

                                UNITED STATES
                        NUCLEAR REGULATORY COMMISSION
                    OFFICE OF NUCLEAR REACTOR REGULATION
                           WASHINGTON, D.C.  20555

                               March 30, 1992


NRC INFORMATION NOTICE 92-24:  DISTRIBUTOR MODIFICATION TO CERTAIN 
                               COMMERCIAL-GRADE AGASTAT ELECTRICAL RELAYS


Addressees

All holders of operating licenses or construction permits for nuclear power 
reactors.

Purpose

The U.S. Nuclear Regulatory Commission (NRC) is issuing this information 
notice to alert addressees to part modifications and serial number changes 
that authorized distributors (ADs) have made to commercial-grade Agastat 
Series 7000 electrical relays.  These alterations may affect the subsequent 
dedication of the relays for safety-related use.  It is expected that 
recipients will review the information for applicability to their facilities 
and consider actions, as appropriate.  However, suggestions contained in 
this information notice are not NRC requirements; therefore, no specific 
action or written response is required.

Description of Circumstances

On April 22, 1991, after being informed by Spectrum Technologies USA, 
Incorporated, (Spectrum) that nameplate labels for Agastat Series 7000 
relays could have been altered, the NRC staff performed a review of the 
manufacture and distribution of those relays.  Agastat relays are 
manufactured by the Amerace Corporation (Amerace), Livingston, New Jersey, 
and its commercial-grade relays are distributed by its authorized 
distributors.  In early 1991, Spectrum ordered six Agastat Model 7032 PBB 
commercial-grade relays from the Westinghouse Electric Supply Company 
(WESCO).  Spectrum specified in the purchase order that the relays be 
traceable to the manufacturer Amerace and that the relays be from the same 
lot and date code.  Spectrum included these requirements because Spectrum 
intended to dedicate the relays for safety-related use.  WESCO ordered the 
relays from an authorized Amerace distributor, Control Components Supply 
(CCS), Short Hills, New Jersey.  However, the relays did not have the 
required traceability to Amerace because of modifications that CCS made to 
the relays, and because of changes CCS made to the serial number nameplates 
the relays may not have been from the same production lot. 

Amerace representatives have told the NRC that its authorized distributors 
are allowed to modify its commercial-grade relays to comply with a 
customer's specific requirements.  Those modifications may include changing 
the electrical 


9203230145 
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coil module for different voltage level applications, adding or changing the 
electrical contact assembly module, or changing the time duration disc and 
wafer.  

Amerace personnel have also told the NRC that

(1)  The first four digits of the serial number indicate the year and week 
     of manufacture.  The next four digits in the serial number designate 
     the sequential order of relay assembly for a particular week.  For 
     example, Agastat Model 7012 PC, serial number (S/N) 91161875, was the 
     1,875th relay to be assembled the 16th week of 1991 at the Amerace 
     Corporation, Livingston, New Jersey facility.  Amerace used similar 
     marking systems for its subassembly coil and contact modules.  
     
(2)  When an AD modifies a commercial-grade 7000 series relay, the AD should 
     install a new nameplate label with the original S/N containing an "F" 
     prefix.  For example, an AD could change the contact and coil modules 
     appropriately in the above Model 7012 PC relay and yield a Model 7014 
     QE relay.  However, the S/N on the nameplate should be changed to 
     F91161875.  The F designator would indicate that the relay had been 
     "field" modified.  The NRC staff determined that Amerace did not 
     contractually state this policy to its ADs (see NRC Inspection Report 
     No. 99900296/91-01).  After the NRC performed its review, Amerace 
     issued a notification letter to its ADs stating this policy.  
     Attachment 1 is a copy of the Amerace notification letter. 

(3)  Before performing the final calibration, test, and acceptance of the 
     7000 series relays, Amerace heat stabilizes each relay by maintaining 
     it at a specific temperature for 4 hours.  This heat stabilization 
     mates the timing disc with the ceramic timing wafer to prevent timing 
     drift and to ensure repeat accuracy.  The process also stress-relieves 
     the nonmetallic parts.  Amerace requires that its 7000 series relays be 
     stabilized again after they are modified such as by changing the timing 
     disc.  To comply with the Agastat model number that was ordered, CCS 
     changed the timing discs of the six relays that were supplied to 
     Spectrum.  However, the staff found no evidence that the relays had 
     been restabilized.

Discussion

From October 1991 through January 1992, the NRC staff conducted several 
meetings with representatives of Amerace and CCS.  The NRC staff found that, 
when CCS modifies an Agastat 7000 Series relay, CCS typically removes the 
Amerace installed label, assigns the relay a new number, types the new 
serial number and other relevant information on a blank label, and affixes 
the new label to the modified relay.  However, the blank labels that the NRC 
staff observed at the CCS facility do not contain the F prefix to indicate 
that the 7000 Series Agastat relays were modified.  The NRC staff found that 
CCS had disassembled, modified, and reassembled the six relays discussed 
herein.  However, the labels affixed by CCS did not contain the required F 
prefix, and the labels did not contain the original Amerace serial number.  
CCS had assigned new serial numbers which indicated that the relays were 
manufactured in 1991 to reflect 
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that the relays had been modified by CCS in 1991.  However, Amerace 
personnel informed the NRC that the six relays had been manufactured in 
1989.

The NRC also found that CCS does not heat stabilize the 7000 Series Agastat 
relays that it modifies, although Amerace has stated that the heat 
stabilization treatment is necessary on modified 7000 series relays to 
ensure repeat accuracy and to relieve the stress to nonmetallic parts.  The 
NRC staff reviewed CCS's customer list and found that the list contained the 
names of 25 NRC nuclear power plant licensees and several other Amerace ADs.  

This information suggests that consecutive serial numbers on 
commercial-grade Agastat relays, obtained through an authorized distributor, 
may not ensure traceability to a particular production lot.  Amerace has 
stated that its ADs do not heat stabilize the 7000 series relays after they 
are modified.  As discussed in NRC Inspection Report No. 99900296/91-01, 
Amerace told the NRC that there are differences between its Class 1E 
qualified relays and its commercial-grade 7000 series relays, such as design 
control, internal components, and the level of inspection that is applied.  
Similar differences may exist between commercial-grade components and the 
safety-related product line of other manufacturers.  The availability of a 
safety-related product line is often an indicator of substantive differences 
from the commercial-grade product.  In any case, it is important that 
information relied on when upgrading commercial-grade components for use in 
safety-related applications be supported by objective evidence of quality to 
support the suitability of use of the component.

This information notice requires no specific action or written response.  If 
you have any questions about the information in this notice, please contact 
the technical contact listed below or the appropriate Office of Nuclear 
Reactor Regulation (NRR) project manager.




                                   Charles E. Rossi, Director
                                   Division of Operational Events Assessment
                                   Office of Nuclear Reactor Regulation

Technical contact:  Joseph J. Petrosino, NRR
                    (301) 504-2979

Attachments:
1.  Amerace Letter on Field Modifications of Agastat Relays
2.  List of Recently Issued NRC Information Notices
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