United States Nuclear Regulatory Commission - Protecting People and the Environment

Information Notice No. 83-63, Supplement 1: Potential Failures of Westinghouse Electric Corporation Type SA-1 Differential Relays

                                                           SSINS No.:  6835 
                                                           IN 83-63        
                                                           Supplement 1    

                               UNITED STATES 
                       NUCLEAR REGULATORY COMMISSION 
                   OFFICE OF INSPECTION AND ENFORCEMENT  
                          WASHINGTON, D.C.  20555  
                                     
                              February 15, 1984

Information Notice No. 83-63, SUPPLEMENT 1:    POTENTIAL FAILURES OF 
                                                                              WESTINGHOUSE  ELECTRIC 
                                                                              CORPORATION TYPE SA-1 
                                                                              DIFFERENTIAL RELAYS 

Addressees: 

All nuclear power reactor facilities holding an operating license (OL) or 
construction permit (CP). 

Purpose: 

This information notice supplements the Information Notice No. 83-63, 
"Potential Failures of Westinghouse Electric Corporation (W) Type SA-1 
Differential Relays," dated September 26, 1983. That information notice 
addressed the random trip output caused by relays containing S.T. SEMICON 
silicon-controlled rectifiers in type SA-1 relays. 

This information notice supplement is provided as notification of two 
potentially significant problems pertaining to insufficient 
surge-withstand-capability (SWC) and internal capacitor failures in W type 
SA-1 relays. These problems were identified by W and Brown Boveri Electric 
(BBE) since the issuance of Information Notice No. 83-63. 

Description of Circumstances: 

W type SA-1 relays are differential relays used on some safety-related 
systems and designed to sense a fault within the differential circuit to 
protect either a transformer, generator, switchgear, or distribution system 
bus. A differential relay trip output will open the circuit breakers to 
isolate the differential circuit when a fault occurs. Internal capacitor 
failures or insufficient SWC could result in a malfunction of the SA-1 
relay, thereby preventing the isolation of the differential circuit when a 
fault occurs and possibly damaging safety-related electrical equipment or 
systems important to safety. 

On October 24, 1983, BBE informed the NRC of capacitor failures in W type 
SA-1 relays. On November 1 and November 3, 1983, W and BBE reported 
supplemental information pertaining to the capacitor failures and also 
provided information that the relays did not fully meet the SWC requirements
of ANSI C37.90-1978. 

In regard to the capacitor problem, W type SA-1 relays contain tantalum 
capacitors. These capacitors have leaked electrolyte, apparently as a result
of corrosion. Rather than replacing only the tantalum capacitors, W proposed
to replace the entire printed circuit module with a new module part No. 
408C673GOl to bring the relay in line with the latest design. 

8401190045 
.

                                                      IN 83-63 Supplement 1 
                                                      February 15, 1984    
                                                      Page 2 of 2          

The second problem pertains to insufficient SWC requirements of the W type 
SA-1 relay. A non-nuclear utility informed W about an SA-1 relay that 
provided incorrect trip signals in a protection application. The utility 
believed the incorrect trips were caused by electrical noise. W engineers 
investigated the situation by testing in accordance with Section 9, SWC 
tests, of ANSI C37.90-1978, and found incorrect trips for crest values of 
the oscillatory SWC test value above 1.8 kV. This does not meet the full 
range requirement specified in the ANSI standard. 

As a result of this finding, W developed a surge protection module that 
brings the SWC capability to a level in excess of the ANSI requirements. 
SA-1 relays having style number 154C21G01 incorporates the new surge 
protection module. W recommends that any SA-1 relay not equipped with a 
surge suppression module should have this module added.  

The attached list of SA-1 relay customers was submitted to the NRC by W and 
BBE. It should be noted that this list may be incomplete and does not 
include all end-users. 

Although no written response to this information notice supplement is 
required, it is suggested that licensees review the information conveyed by 
this notice for applicability to their facilities. 

BBE has informed the NRC that detailed information pertaining to required 
SA-1 relay field modification, part replacement instructions, relay 
calibration instructions, and documentation changes was distributed via BBE 
regional offices to its known SA-1 relay customers. However, it is not clear
that other users of SA-1 relays have been so notified.  Accordingly, users 
of SA-1 relays, who have not received these instructions, may request them 
from Westinghouse Electric Corporation, Power Systems, Relay-Instrument 
Division, 4300 Coral Ridge Drive, Coral Springs, Florida 33065. 

If you have any questions regarding this matter, please contact the Regional
Administrator of the appropriate NRC Regional Office, or the listed 
technical contact. 


                                   Edward L. Jordan, Director 
                                   Division of Emergency Preparedness 
                                     and Engineering Response 
                                   Office of Inspection and Enforcement 

Technical Contact:  W. Laudan, IE 
                    (301) 492-9759 

Attachments: 
1.   SA-1 Relay Customers 
2.   Recently Issued IE Information Notices
.

                                                    Attachment 1           
                                                    IN 83-63 Supplement 1  
                                                    February 15, 1984      
                                                    Page 1 of 2            

                           SA-1 RELAY CUSTOMERS 

                                             WESTINGHOUSE G.O.   CUSTOMER 
SA-1 RELAY CUSTOMER           SERIAL NO.     NO. & ITEM          ORDER NO. 

Beloit Power Systems          5256A          RK43470-N1-9        01507 
Beloit, WI                    5257A          RK43470-N1-9        01507 
                              5258A          RK43470-N1-9        01507 
                              5259A          RK43470-NI-9        10507 
                              5486           RK43330-N1-25       01401 
                              5487           RK43330-N1-25       01401 
                              7437           RK44202-N1-3        32476 
                              7438           RK44202-N1-3        32476 
                              7439           RK44202-N1-3        32476 
                              7440           RK44202-N1-3        32476 
                              7441           RK44202-N1-3        34276 
                              7442           RK44202-N1-3        32476 
                              7443           RK44202-N1-3        32476 
                              7444           RK44202-N1-3        32476 
                              7455           RK44202-N1-3        33858 

Brown Boveri Electric, Inc.   4772           PH68-333-N1-H1      J96608-53566
Chalfont, PA                  5768A          PH69899-N1-D        J52531-53170
                              6912           PH61036-N1-C        J57018-51128
                              7808           PH61316-N1-1        J66315-51128
                              8416           PH61459-N1-C        T70418-41059
                              8417           PH61459-N1-C        T70418-41059
                              8418           PH61459-N1-C        T70418-41059

Brown Boveri Electric Inc.    4310           T170147-N1-36       5-30852 
Tulsa, OK                     5074           T169994-N1-36       5-41094 
                              5254           T171248-N1-37       5-10342 
                              5255           T171248-N1-37       5-10342 
                              6864           T172584-N1-36       5-41633 
                              7434           T170147-N1-36B      5-30852 
                              7435           T171248-N1-36X      5-20342A 
                              7436           T171248-N1-36X      5-10342A 
                              7607           T171249-N1-36       5-10343 

Cooper Energy Services        7802           CB64416-N1-1        370941511 
Mt. Vernon, OH                7803           CB64416-N1-1        370941511 
                              7804           CB64416-N1-1        370941511 
                              7805           CB64416-N1-1        370941511 
                              7806           CB64416-N1-1        370941511 
                              7897           CB64416-N1-1        370941511 
                              5767           CB63404-N1-1        3609J8150 
                              8060           CB64596-N1-1        360944935 
                              8061           CB64596-N1-1        360941935 
.

                                                      Attachment 1         
                                                      IN 83-63 Supplement 1 
                                                      February 15, 1984    
                                                      Page 2 of 2          

                       SA-1 RELAY CUSTOMERS (Con't) 

                                             WESTINGHOUSE G.O.   CUSTOMER 
SA-1 RELAY CUSTOMER           SERIAL NO.     NO. & ITEM          ORDER NO. 

Duke Power Company            5778A          CH11784-N1-1        F3527-82 
McGuire Nuclear Station       8338           CH13915-N1-1        H31257-85 
Cornelius, NC                 8339           CH13915-N1-1        H31257-85 

Siemens Allis, Inc.           4713           MK20280-N1-P        WAH378586V 
Raleigh, NC                   4714           MK20280-N1-D        WAH378586V 
                              5007           MK20280-N1-J1       WAH378586V 

Systems Control Corp.         5766A          AP42372-N1-1        74178-8 
Iron Mountain, MI             5769A          AP42372-N1-1        74178-8 

Washington Public Power       6996           NA-40038-Y1         01YNO85 
Supply System                 6997           NA-40038-Y1         01YNO85 
Portland, OR                  6903           NA-40038-Y1         01YNO86 
                              6904           NA-40038-Y1         01YNO86 
.
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