Information Notice No. 83-63, Supplement 1: Potential Failures of WestinghouseElectric 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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Page Last Reviewed/Updated Tuesday, March 09, 2021
Page Last Reviewed/Updated Tuesday, March 09, 2021