The target application, taking into consideration the number of different WWER type reactors as well as the transferability of the results to other components and other plants, is ultrasonic testing of a shell weld of one WWER-1000 reactor pressure vessel in Kozloduy NPP, Bulgaria. The main actors of the Pilot Study are, in line with its concept, the Bulgarian Nuclear Regulatory Authority, the Kozloduy NPP, the INETEC Institute for Nuclear Technology, Croatia, as ISI vendor, the GIDROPRESS, Russian Federation, which is the design institute of the WWER nuclear steam supply systems, the newly established independent Bulgarian Qualification Body, and the Electric Power Research Institute (EPRI), USA, as consultant. With co-ordination of the IAEA, representatives of the aforementioned institutions create the core working team of the Pilot Study.

The working methodology of the Pilot Study is that, following step by step the IAEA qualification process, EPRI compiles draft documents using inputs from the team members and these documents are being discussed with the representatives of the Member States (managers/engineers from utilities/NPPs, regulatory authorities, technical support organisations, research institutes and ISI vendors responsible for structural integrity assessment or ISI) in workshops. Also experts representing industrialised countries and having ISI qualification infrastructure, including European Network for Inspection Qualification (ENIQ), are invited to these workshops.

In the framework of the Pilot Study, technical specification (consisting of component data, target flaw size calculation, required inspection effectiveness, etc. ), ISI procedure, qualification procedure, technical justification are being prepared or foreseen to be prepared. The Technical Co-operation project will continue at Member State's request in 2001-02, and that if so, practical trials as important issue of ISI qualification are to be focused on.

The presentation is intended to describe the main achievements of the Pilot Study's activity.