Quality control and nondestructive testing in reactor pressure vessel fabrication

Abstract

The objectives of this paper are to briefly outline a quality control program for the design and fabrication of a nuclear reactor pressure vessel which will meet all nuclear and safety requirements, and to show how nondestructive testing can help to achieve the broad objective.

Failure in materials, components, and assembly has demonstrated that our present techniques of fabrication are not sufficient alone to assure repeated reliability in critical components. Flaws and inhomogeneities occur even when using the best processes and properly controlled procedures. Thus an adequate and well integrated nondestructive testing program is necessary to assure the quality level required in a nuclear reactor pressure vessel. The principal nondestructive methods used in the fabrication of reactor pressure vessels are: visual, X-ray and gamma radiography, ultrasonics, magnetic particle, and liquid penetrant. The nondestructive testing program must include the inspection of plate material, forging, casting, cladding, and welds. Various methods and their application to the nondestructive testing of pressure vessels and components will be illustrated and discussed.