United States Nuclear Regulatory Commission - Protecting People and the Environment

Information Notice No. 85-17: Possible Sticking of ASCO Solenoid Valves

                                                           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 
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