Objective The performed activity can be seen as an example of how it is possible to integrate the approaches of Non-destructive testing and of fracture mechanics. The logic which is at the basis of Non-destructive testing acceptance criteria is of the 'yes/no' type. The discrimination between the two situations is substantially justified by the national experience which underpin each standard, and the intrinsic conservativeness of choices. The differences among the acceptance criteria of the national standards different are thus justified. A direct comparison among the defect acceptance criteria from standard to standard and within the standards, by the Non-destructive technique utilized, does not give meaningful results and may involve many arbitrary assumptions. An objective comparison and a quantitative analysis can be made when considering that the real aim of Non-destructive testing is to reject those which are considered to the potentially dangerous in a structure and, similarly, to consider as acceptable those defects which do not prejudice its reliability, i.e. its capacity of bearing operational loads in any operational condition for a set time. The acceptance criteria for the different techniques of Non-destructive testing do not represent anything else than the translation, in terms of an instrumental answer, of such prerequisites. The acceptability of a defect means, thus, to consider as acceptable the level of damage induced by the presence of the defect; to compare the standards is to compare this maximum level of damage which, in a more or less explicit way, the standard accepts. In this way it is possible and relevant to make comparisons, identify hierarchies and to find the real weight and significance of choices. The approach that has been developed is of general character, introducing in the NDE field the 'fitness for purpose' and the evaluation of this according to fracture mechanics. The procedure employed represents an example of how to operate, and it is therefore a possible starting point and an operational instrument for a wider critical analysis of the acceptance criteria of different standards (for instance In-service Inspection standards or NDE standards for material) which may also refer to other NDE methods (e.g. Eddy Current Testing). Thus, this approach may also be considered as a useful instrument to respond to the need felt within CEN for harmonization of the standards of the EEC countries. For the development of suitable protocols to meet specific needs, there is a need for synergic research and collaboration within the directly interest committees (CEN TC 121 and CEN 138). Programme(s) PRE-NUSAFECS C - Council Resolution of 22 July 1975 on the technological problems of nuclear safety, 1975- Topic(s) Data not available Call for proposal Data not available Funding Scheme CSC - Cost-sharing contracts Coordinator Ansaldo - Un'Azienda Finmeccanica SpA EU contribution No data Address Piazza Carignagno 2 16128 Genova Italy See on map Total cost No data
