Methodology for NDA Performance Assessment

In the framework of the R&D programme of the Joint Research Centre of the Commission of the European Communities, a considerable effort is being dedicated to performance assessment of NDA techniques taking account of field conditions. By taking account of field conditions is meant measurement samples of the size encountered in practice and training which allows inspectors to design cost efficient verification plans for the real situations encountered in the field. Special laboratory facilities referred to as PERLA are being constructed for this purpose. These facilities will be used for measurement experiments and for training. In the paper, performance assessment is discussed under the headings of measurement capability and in-field effectiveness. Considerable emphasis is given to the role of method specific measurement error models. The authors outline the advantages of giving statistical error models a sounder basis in the physical phenomenology of the measurement method. They consider that this will produce a greater economy in the requirements of measurement data and standards to quantify performance characteristics. They also emphasize that this is one of the elements for planning cost-efficient safeguards verifications.