Protecting People and the EnvironmentUNITED STATES NUCLEAR REGULATORY COMMISSION
UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF NUCLEAR REACTOR REGULATION
WASHINGTON, D.C. 20555
May 31, 1989
Information Notice No. 88-88, SUPPLEMENT 1: DEGRADATION OF WESTINGHOUSE
ARD RELAYS
Addressees:
All holders of operating licenses or construction permits for nuclear power
reactors.
Purpose:
This information notice is being provided to update information regarding
problems identified in Westinghouse ARD relays. It is expected that recipi-
ents will review the information for applicability to their facilities and
consider actions, as appropriate, to avoid similar problems. However, sugges-
tions contained in this information notice do not constitute NRC requirements;
therefore, no specific action or written response is required.
Description of Circumstances:
Information Notice No. 88-88 discussed a deficiency identified by Pacific
Gas and Electric Co. (PG&E) regarding the sand-based coil potting compound
used in Westinghouse ARD relays. According to PG&E, this compound had
apparently deteriorated and granules had migrated to the coil spool area where
they lodged between the relay's coil spool and armature. The increased
armature drag resulted in increased relay contact resistance that affected the
signal trans-mitted by these relays in voltage sensitive circuits.
Discussion:
Westinghouse previously believed that the sand-based compound had been used
only in certain ARD relays manufactured before 1972. However, further
investi gation by Westinghouse determined that the sand-based coil potting
compound was used in the manufacture of safety-related and commercial grade
ARD relays until 1981. Westinghouse has indicated that even though PG&E
recently identified several relays with degraded sand-based compound, as
discussed in Information Notice 88-88, no other similar failures have been
reported in recent years.
8905240023
.. IN 88-88, Supplement 1
May 31, 1989
Page 2 of 2
No specific action or written response is required by this information notice.
If you have any questions regarding this matter, please contact the technical
contact listed below or the Regional Administrator of the appropriate regional
office.
Charles E. Rossi, Director
Division of Operational Events Assessment
Office of Nuclear Reactor Regulation
Technical Contact: Jaime Guillen, NRR
(301) 492-1170
Attachment: List of Recently Issued NRC Information Notices
.. Attachment IN 88-88,
Supplement 1 May 31,
1989 Page 1 of 1
LIST OF RECENTLY ISSUED
NRC INFORMATION NOTICES
_____________________________________________________________________________
Information Date of
Notice No._____Subject_______________________Issuance_______Issued to________
89-50 Inadequate Emergency 5/30/89 All holders of OLs
Diesel Generator Fuel or CPs for nuclear
Supply power reactors.
89-49 Failure to Close Service 5/22/89 All holders of OLs
Water Cross-Connect or CPs for nuclear
Isolation Valves power reactors.
89-48 Design Deficiency in the 5/22/89 All holders of OLs
Turbine-Driven Auxiliary or CPs for nuclear
Feedwater Pump Cooling power reactors.
Water System
89-47 Potential Problems With 5/18/89 All holders of OLs
Worn or Distorted Hose or CPs for nuclear
Clamps on Self-Contained power reactors and
Breathing Apparatus fuel facilities.
89-46 Confidentiality of 5/11/89 All holders of
Exercise Scenarios licenses for fuel
cycle facilities
and byproduct
material licensees
having an approved
emergency response
plan.
89-45 Metalclad, Low-Voltage 5/8/89 All holders of OLs
Power Circuit Breakers or CPs for nuclear
Refurbished with Sub- power reactors.
standard Parts
89-44 Hydrogen Storage on the 4/27/89 All holders of OLs
Roof of the Control Room or CPs for nuclear
power reactors.
88-82, Torus Shells with Corrosion 5/2/89 All holders of OLs
Supp. 1 and Degraded Coatings in or CPs for BWRs.
BWR Containments
89-43 Permanent Deformation of 5/1/89 All holders of OLs
Torque Switch Helical or CPs for nuclear
Springs in Limitorque power reactors.
SMA-Type Motor Operators
_____________________________________________________________________________
OL = Operating License
CP = Construction Permit
