Background information for NDT qualification of Finnish disposal canisters of spent fuel

This report presents a review to basic concepts, which are applied in the qualification of nondestructive testing (NDT) techniques. The qualification systems developed and used in some countries are briefly described in the beginning of the report. Anyway the report mainly discusses the qualification practices applied in the Finnish nuclear industry. The Finnish Radiation and Nuclear Safety Authority (STUK) in the YVL Guide 3.8 define the Finnish qualification approach applied for the in-service inspections. The principles presented in this document follow the views of the international organisations: Nuclear Regulator Working Group (NRWG) and European Network for Inspection and Qualification (ENIQ). For the practical qualification work a national guideline is established using so called SP -documents that include specific rules and instructions for execution of qualifications in accordance with YVL Guide 3.8 principles. Altogether the Finnish qualification system can be seen very well to follow the European (ENIQ) methodology. The report discusses several qualification terms and documents. Thus the normally necessary tasks and parts of a qualification are described. The qualification can be seen as a project that includes several tasks, which will be performed by different parties. Enough resources and time should be reserved for the planning and control of a qualification project to ensure its fluent progress. Some tasks are discussed in the report taking into account the situation in the qualification cases that are seen to be linked to the inspections of disposal canisters of spent fuel.