NSSS Approach to Equipment Qualification

For the past few years, the nuclear industry has been attempting to resolve a multitude of equipment qualification problems. New standards have introduced new problems. New calculations of containment post-accident environments have required new test programs. This discussion is aimed toward developing a logical program of qualification for class IE electronic equipment addressing both the initial demonstration of this qualification and maintaining qualified status throughout the design life of the hardware. One of the areas of major concern is the aging question that must be answered in order to determine the qualified life of Class IE equipment. This paper presents an aging evaluation proposal using Arrhenius techniques that provides a method of verifying the original qualified life projection. To establish and maintain coontinuity of the design and qualification of a vendor\´s product, control of the procurement manufacturing and testing of these products is extremely important. For instance, a method of developing a spare parts inventory must be considered in order to maintain the "identity" of installed units. Over the years, product design changes will occur, and the availability of components becomes a concern. The means to do this are available and in use today and it should be implemented throughout the industry. What makes up an adequate qualification program? Does performing one test on a prototype unit alone establish the qualification of a vendor\´s model or line of equipment? An adequate sample from a production line is three units.