NDTnet 1998 Aug, Vol.3 No.8

Full-Text -Abstract

The precise NDT techniques used in the field usually arise from the involvement of suitably qualified staff in the production of procedures within the constraints of accepted codes and standards. The inspectors who carry out NDT must be qualified to ensure they have the necessary competence. However, qualification schemes tend to assess general competence rather than the competence needed for a specific inspection. If the latter poses problems beyond those examined by the qualification scheme, "job specific" additions to the basic qualification are sometimes required.

The traditional approach to the provision of confidence in NDT outlined above is perfectly adequate for the majority of inspections. However, there are two situations where these measures may be inadequate. The first arises whenever the NDT plays a significant role in the demonstration of plant safety and the consequences of failure are severe. The second is where the NDT method is new and there are no relevant personnel qualification schemes or standards yet in existence. In these situations, the need to assess and demonstrate the performance of the NDT techniques applied to specific components is increasingly being required as a necessary precursor to the use of those methods. Such demonstrations usually involve the application of the proposed inspection to test pieces replicating the components in question containing deliberately introduced defects. Exercises such as the PISC series and others in the nuclear area showed that there is often a large gap between the performance which is anticipated and that which is actually achieved in practice. This has led to formal requirements in many countries operating nuclear plant that the performance of the proposed methods should be shown to match the structural integrity requirements. Some involvement of independent third parties in the demonstration process is frequently required. The need for similar arrangements for the inspection of major components in conventional plant is currently being considered. A key input to such decisions will arise from performance evaluation exercises in which industrial NDT methods are applied to realistic test pieces.

Abstract Source:
Book of Abstracts, 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN: 87-986898-0-00

Full-Text Source:
Proceedings of the 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN:

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