United States Nuclear Regulatory Commission - Protecting People and the Environment

Results of the Public Workshops (Generic Letter 89-10, Supplement 1)


June 13, 1990


TO:         ALL LICENSEES OF OPERATING NUCLEAR POWER PLANTS AND HOLDERS OF
            CONSTRUCTION PERMITS FOR NUCLEAR POWER PLANTS, AND INDIVIDUALS 
            ON THE ATTACHED DISTRIBUTION LIST

SUBJECT:    SUPPLEMENT 1 TO GENERIC LETTER 89-10:  RESULTS OF THE PUBLIC 
            WORKSHOPS 


In September 1989, the NRC staff held three public workshops to discuss 
Generic Letter 89-10, "Safety-Related Motor-Operated Valve Testing and 
Surveillance."  This generic letter, issued on June 28, 1989, requests 
holders of nuclear power plant operating licenses and construction permits 
to establish a program to provide for the testing, inspection, and 
maintenance of safety-related motor-operated valves (MOVs) and certain other 
MOVs in safety-related systems.  Attached for the use of licensees and 
construction permit holders are the results of the public workshops.  

This supplement to Generic Letter 89-10 includes the opening remarks by NRC 
representatives and the responses provided by the NRC staff to all 
significant questions.  These responses reflect the best information 
currently available to the staff from research and operating experience 
regarding the operability of MOVs under design-basis conditions.  For 
example, the staff believes that, at the present time, the most reliable 
means of demonstrating operability of an MOV under design-basis conditions 
is to perform a test of the MOV in situ under those conditions.  Such 
testing in situ, however, will not be practicable for some MOVs within the 
scope of Generic Letter 89-10.  For those instances, the staff indicated in 
the generic letter that alternatives to testing the MOV in situ may be 
developed by the licensee or permit holder.  The staff discussed several 
possible alternatives at the workshops, including potential problems and 
limitations associated with those alternatives, and various factors that 
should be considered when a licensee or permit holder intends to use one of 
those alternatives.

This generic letter supplement has been prepared to assist licensees and 
permit holders in developing programs that will provide assurance of MOV 
operability under design-basis conditions.  Because the workshops were held 
to answer specific questions on the generic letter, the supplement does not 
contain all of the information necessary to develop and implement such 
programs.  Therefore, licensees and permit holders, together with the 
Nuclear Management and Resources Council (NUMARC), should coordinate their 
efforts in developing and implementing MOV programs.  In this regard, NUMARC 
is preparing guidelines for use by licensees and permit holders in 
implementing the generic letter.  NUMARC is also working with the Electric 
Power Research Institute to establish a research program aimed, in part, at 
determining the relationship between MOV performance characteristics.  The 
NRC staff will also provide the industry with additional information on MOV 
operability as it becomes available.



9006070427 
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Generic Letter 89-10                 - 2 -
Supplement No. 1 


Licensees and permit holders should review the entire package because the 
staff guidance in the generic letter supplement should be considered in the 
context of all questions and responses.  This supplement has been approved 
in accordance with NRC procedures for generic guidance and reflects the 
current staff positions concerning the implementation of the generic letter.  
Staff positions expanded, clarified, or modified following the workshops are 
identified in the supplement.  For example, the staff position on the scope 
of the generic letter, provided in the response to Question 3, has been 
modified with respect to dampers and other MOVs not located in piping 
systems.  In addition, as discussed in the response to Question 9, the 
prevention of inadvertent MOV operation within the context of the generic 
letter has been limited to the potential for MOV mispositioning from the 
control room.

As a result of operating experience and research results, the NRC staff 
determined that MOV tests beyond those acceptable in the past are necessary 
to satisfy the NRC regulations.  This determination constitutes backfitting.  
Consequently, the staff guidance in Generic Letter 89-10 contains provisions 
that were approved as backfits.  Those provisions include MOV testing beyond 
Section XI of the ASME Boiler and Pressure Vessel Code; consideration of the 
operability of position-changeable MOVs located in safety-related systems; 
testing of MOVs under design-basis conditions, where practicable, because of 
uncertainties regarding industry sizing equations, and the extrapolation and 
application of MOV test data; preparation or revision of procedures to 
ensure correct MOV switch settings; and maintenance of records of test 
methods, MOV failures, and corrective action (including trending).  In 
hindsight, the discussion in the generic letter should have referenced 
10 CFR 50.109 and also should have stated that licensees and construction 
permit holders were required to advise the NRC "if" the provisions of the 
generic letter would be met.  Nevertheless, the staff considers Generic 
Letter 89-10 to be a backfit and prepared the generic letter in accordance 
with NRC procedures for the issuance of staff guidance containing backfit 
provisions.

Please direct questions or comments regarding this generic letter supplement 
to the appropriate NRC project manager.


                            James G. Partlow
                            Associate Director for Projects
                            Office of Nuclear Reactor Regulation

Enclosure:  As stated 

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