Information Notice No. 86-03: Potential Deficiencies in Environmental Qualification of Limitorque Motor Valve Operator Wiring

                                                            SSINS No: 6835 
                                                            IN 86-03       

                                UNITED STATES
                            WASHINGTON, DC 20555

                              January 14, 1986

                                   QUALIFICATION OF LIMITORQUE MOTOR VALVE 
                                   OPERATOR WIRING 


All nuclear power reactor facilities holding an operating license (OL) or a 
construction permit (CP) 


This notice is provided to alert recipients of potential generic problems 
regarding the environmental qualification of electrical wiring used in 
Limitorque motor valve operators It is expected that recipients will review
this 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 notice do not constitute NRC 
requirements; therefore, no specific action or written response is required

Description of Circumstances: 

On September 30, 1985, Commonwealth Edison (Zion Generating Station) 
reported to the NRC that it had discovered four Limitorque motor-valve 
operators with jumper wires different from those tested by Limitorque in its 
environmental qualification program Subsequently, the Tennessee Valley 
Authority (TVA) notified the NRC that the manufacturer of the internal 
control wiring of its Limitorque operators at Sequoyah Nuclear Plant either 
could not be identified or qualification could not be established where the 
manufacturer was known Similar circumstances have recently been identified 
at other nuclear plants 


The results of NRC inspections at Limitorque and TVA have determined that 
even though Limitorque has conducted environmental qualification testing of 
motor valve operators, the qualification test reports do not specifically 
address wiring or wiring qualification Limitorque has installed wires from 
several different manufacturers in safety-related operators 


                                                            IN 86-03       
                                                            January 14, 1986
                                                            Page 2 of 2    

Limitorque stated that it can provide or reference documentation to support 
qualification of wires it has installed; however, valve manufacturers, 
licensees, and/or others may have added additional wires that are not 
qualified by this data The NRC physical inspection of Limitorque operators 
at the Sequoyah plant determined that some valve operators contained wires 
not qualified by the Limitorque tests 

The NRC staff considers the resolution of this issue to be part of the 
licensee's environmental qualification program to establish and maintain the
qualified status of electrical equipment within the scope of 10 CFR 5049 

Because qualification of Limitorque installed wiring may be based on 
separate qualification tests of wire, it is important that adequate analyses 
have been performed and that documentation exists to demonstrate that the 
separate wire qualification tests encompass the parameters for the valve 
operator qualification If additional wiring has been added or replaced 
after operator shipment from Limitorque, then additional documentation may 
be appropriate for establishing qualification of the additional wires and 
subsequently the valve operators for the valve operator specific 

No specific action or written response is required by this information 
notice If you have any questions about this matter, please contact the 
Regional Administrator of the appropriate NRC regional office, or this 

                                   Edward L Jordan Director 
                                   Division of Emergency Preparedness 
                                     and Engineering Response 
                                   Office of Inspection and Enforcement 

Technical Contact:  G Hubbard, IE
                    (301) 492-9759

Attachment: List of Recently Issued IE Information Notices 


Page Last Reviewed/Updated Thursday, August 20, 2020