Information Notice No. 82-55: Seismic Qualification of Westinghouse AR Relay with Latch Attachments Used in System
SINNS, No.: 6835
NUCLEAR REGULATORY COMMISSION
OFFICE OF INSPECTION AND ENFORCEMENT
WASHINGTON, D. C. 20555
December 28, 1982
Information Notice No. 82-55: SEISMIC QUALIFICATION OF WESTINGHOUSE AR
RELAY WITH LATCH ATTACHMENTS USED IN
WESTINGHOUSE SOLID STATE PROTECTION
All holders of a nuclear power reactor operating license (OL) or
construction permit (CP).
This Information Notice is provided as an early notification of a
potentially significant problem pertaining to Westinghouse (W) AR relays
fitted with type ARMLA latch devices which are not seismically qualified and
may be used in safety-related systems at nuclear facilities. Specifically,
the generic implications of the problem, as it applies to spare units, may
affect both PWR and BWR operating plants and plants under construction.
The Nuclear Regulatory Commission (NRC) staff is reviewing the problem and
its effects. If the evaluation so indicates, NRC may request further
licensee action. In the interim, we expect the recipients of this
Information Notice to review the information herein for applicability to
their facilities and to take appropriate actions. No specific action or
response is required at this time.
Description of Circumstances:
Virginia Electric and Power Company (VEPCO) reported that one of the two
types of latch mechanisms used with the Westinghouse type AR relay is not
qualified for seismic Category 1 use. The licensee reports that both types
of latch mechanisms are used in the Westinghouse solid state protection
systems (SSPS) at both units of the North Anna Nuclear Power Station.
One type of latch attachment, W ARLA performs the latch function by
mechanical means; and the other type, W ARMLA performs the latch function by
magnetic means. The ARMLA relay is a product replacement for the
discontinued ARLA relay. The type ARMLA relay, used as a replacement for the
type ARLA relay unit, was found by W to be seismically unqualified for use
in the safety-grade SSPS.
On December 14, 1982, Westinghouse Nuclear Service Division (NSD) issued
Revision 1 of Technical Bulletin No. NSD-TB-82-03 to Westinghouse-supplied
nuclear plants using the SSPS, apprising them of the problem. An extract
from W NSD-TB-82-03 is attached for your information and appropriate use
December 28, 1982
Page 2 of 2
The technical bulletin specifies an acceptable replacement unit, qualified
by Westinghouse, which has been provided with an adaptor base for mounting
in place of an AR relay unit.
It is well to note, that since the AR relay is not unique to Westinghouse
PWR power plants, the problem may also exist at other nuclear power plants.
Therefore, it is advisable for all nuclear power plants to review their
replacement and spare parts records to ascertain that no W ARMLA units have
been installed, or are being held as spare parts, safety-related
If you have any questions regarding these matters please contact the
Regional Administrator of the appropriate NRC Regional Office or this
Edward L. Jordan, Director
Division of Engineering and
Office of Inspection and Enforcement
Technical Contact: V. D. Thomas
1. Extract from Westinghouse Technical Bulletin NSD-TB-82-03, Rev. 1.
2. List of Recently Issued IE Information Notices
December 28, 1982
EXTRACT FROM WESTINGHOUSE TECHNICAL BULLETIN NSD-TB-82-03, "AR RELAY LATCH
ATTACHMENTS," DATED JUNE 24, 1982
In most of the Solid State Protection Systems (SSPS) in the field,
Westinghouse Type AR relays were utilized as the slave relays, and those
requiring latch features were fitted with type ARLA latch attachments which
perform the latch function by mechanical means. The manufacturer has
discontinued the ARLA latch attachments, replacing it with a line of ARMLA
latch devices which perform the latch function via magnetic means. The ARMLA
device, however, is an unqualified replacement fOr the safety grade SSPS.
... An acceptable seismically replacement is a ... latching relay,
especially qualified by Westinghouse and provided with an adapter base for
mounting in place of an AR relay. This assembly (... with conversion
mounting bracket) is identified as Westinghouse EMD (Hunt Valley) Part
There have been reports that some plants, after ordering replacement ARLA
attachments, have received (and may have installed) unqualified ARMLA
All affected plants should review their replacement and spare records to
make certain that no ARMLA devices have been installed, or are in spares,
for safety grade applications. Our initial evaluation concluded that
malfunctioning ARMLA devices could have no adverse impact on safety.
However, review of new information has revealed the potential for spurious
latching, or malfunctions which could prevent latching or unlatching when
required. Although the NRC is aware of this information, neither they nor
Westinghouse have sufficient information to clearly identify affected
plants. Therefore, Westinghouse recommends that utilities which have
installed ARMLA devices in the protection system consider reportability to
the NRC. ARMLA magnetic latch attachments have a gold colored (brass)
plunger protruding from the latch assembly, whereas the ARLA plunger is
greyish or off-white non-metallic material.
Spare or replacement requirements should be filled by the Westinghouse-
qualified ... latching relay here no ARLA device is available.
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