Acceptance Criteria for the Mark I Containment Long Term Program (Generic Letter 79-57)


                               UNITED STATES 
                          WASHINGTON, D. C. 20555 

Docket No. 50-220 

     Mr. Donald P. Dise 
     Vice President - Engineering 
     Niagara Mohawk Power Corporation 
     300 Erie Boulevard West 
     Syracuse, New York 13202 

     Dear Mr. Dise: 


     The staff has completed its review of the generic aspects of the Mark 
     I Containment Long Term Program (LTP). The results of this review are 
     reflected in the enclosed acceptance criteria, which are intended to be
     used to perform individual plant-unique analyses for each Mark I 
     facility. These criteria have been developed from the staff's 
     evaluation of the Mark I LTP Load Definition Report, Plant Unique 
     Analysis Applications Guide, and related suppression pool hydrodynamic 
     experimental and analytical programs, which have been submitted by the 
     Mark I Owners Group. 
     In developing these criteria, we have considered verbal comments 
     provided by representatives of the Mark I Owners Group on a draft of 
     the criteria issued August 2, 1979. These comments were presented to 
     the staff during a meeting held on August 15, 1979, and supplemented by 
     additional information provided in a letter from General Electric dated
     September 7, 1979. This information and internal comments by the staff 
     and our consultants have resulted in some modifications to the draft 
     criteria. However, others of the Owners Group recommendations were not 
     adopted for the NRC criteria, based on the staff's judgment relative to
     the interpretation of specific data or analyses. 

     In certain cases, the staff's generic criteria identify specific 
     hydrodynamic load assessment techniques that will have to be evaluated 
     on a plant-specific basis. However, deviations from any other generic 
     criteria should be avoided. 

     The criteria also identify additional experimental verification that 
     must be obtained for "condensation oscillation" load uncertainty. This 
     requirement was communicated to you earlier in our letter dated October
     2, 1979. 

Mr. Donald P. Dise                - 2 -

Within 30 days of your receipt of this letter, we request that you provide 
the schedule for submittal of the LTP plant-unique analysis for your 
facility. In developing this schedule, you should consider that we are 
continuing to target the completion of this program and the termination of 
the exemption issued for your facility for December 1980. The staff 
presently expects to issue the generic Safety Evaluation Report supporting 
these criteria In December 1979. Should you have any questions regarding 
this action contact C. Grimes (301-492-8204). 

                                        Darrell G. Eisenhut, Acting Director
                                        Division of Operating Reactors 

As stated

cc w/enclosure
See next page 

Mr. Donald P. Dise
Niagara Mohawk Power Corporation   - 3 -


Eugene B. Thomas, Jr., Esquire
LeBoeuf, Lamb, Leiby & MacRae 
1757 N Street, N. W. 
Washington, D. C. 20036 

Anthony Z. Roisman
Natural Resources Defense Council
917 15th Street, N. W.
Washington, D. C. 20005 

Oswego County Office Building
46 E. Bridge Street
Oswego, New York 13126 


Page Last Reviewed/Updated Thursday, March 25, 2021