Protecting People and the EnvironmentUNITED STATES NUCLEAR REGULATORY COMMISSION
SSINS No.: 6835
IN 85-17
UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF INSPECTION AND ENFORCEMENT
WASHINGTON, DC 20555
March 1, 1985
Information Notice No. 85-17: POSSIBLE STICKING OF ASCO SOLENOID VALVES
Addressees:
All nuclear power reactor facilities holding an operating license (OL) or
construction permit (CP).
Purpose:
This notice is provided to inform recipients of a potential problem with
ASCO solenoid valves that may prevent the main steam isolation valves
(MSIVs) from closing on BWRs and may prevent other safety functions on BWRs
or other types of plants. It is expected that recipients will review the
information for applicability to their facilities and consider actions, if
appropriate, to preclude a similar problem occurring at their facilities.
However, suggestions contained in this information notice do not constitute
NRC requirements; therefore, no specific action or written response is
required.
Description of Circumstances:
On February 10, 1985, at Grand Gulf Unit 1, one inboard and two outboard
MSIVs failed to remain shut following manual closure. The problem is now
attributed to failure of the ASCO solenoid valves used to provide fast
closure of the MSIVs in the event of an accident.
At the time of the event, the plant was using a slow-closure procedure to
close the MSIVs prior to a drywell entry following a reactor scram. The pro-
cedure calls for one set of solenoid valves to slowly close the MSIVs and
another set of solenoid valves, which are the fast closure solenoid valves
used in an accident, to hold the MSIVs closed. Evaluations and tests
perform-ed subsequent to the event have attributed the problem to the second
set of solenoid valves (type HTX 8323-20V). Each of these solenoid valves
contains two solenoids, one solenoid rated at 16 watts and the other
solenoid rated at 6 watts.
Preliminary test results, to date, have reproduced spurious sticking of the
solenoid actuator of the solenoid valve when the solenoids are subjected to
temperatures of about 180F. However, these tests have not been defini-
tive.
8503010448
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IN 85-17
March 1, 1985
Page 2 of 2
Discussion:
Although the NRC is not aware of all applications of this type of dual sol-
enoid valve in all types of plants, a list provided by General Electric of
BWRs that are believed to use this valve for closing the MSIVs includes:
Brunswick 1 & 2
Clinton
Cooper
Duane Arnold
Fitzpatrick
Grand Gulf 1 & 2
Hatch 2
LaSalle 1 & 2
Shoreham
No specific action or written response is required by this information
notice. If you need additional information about this matter, please contact
the Regional Administrator of the appropriate NRC regional office or the
technical contact listed below.
Edward L. Jordan, Director
Division of Emergency Preparedness
and Engineering Response
Office of Inspection and Enforcement
Technical Contact: Eric W. Weiss, IE
(301) 492-9005
Attachment: List of Recently Issued IE Information Notices