STYLE: Project Overview

The purpose of this paper is to introduce a new EUROATOM project focusing on the structural integrity assessment of reactor coolant pressure boundary components (RCPB) relevant to ageing and life time management. The project started in January 2010 and will last 4 years. The project is coordinated by AREVA NP GmbH with 20 partner organizations from Europe, one collaborator from USA and one collaborator from Russia: AEKI, Hungary; AREVA NP GmbH, Germany (coordination, WP2 leader); AREVA NP SAS, France; Bay Zoltan, Hungary; British Energy Generation Ltd., UK (WP7 leader); CEA, France (WP1 leader); EDF, France; IdS, France; INR, Romania; IWM, Germany; JRC, Netherlands (WP4 leader); NRI, Czech Republik; NRG, Netherlands; SCK-CEN, Belgium; Serco Assurance Technical Services, UK (WP3 and WP5 leader); University of Bristol, UK; University of Manchester, UK; Technatom, Spain; Vattenfall, Sweden (WP6 leader); VTT, Finland. Within STYLE (Structural integrity for lifetime management – non-RPV components) realistic failure models for some of the key components will be identified. The range of assessment tools considered will include those for assessment of component failure by advanced fracture mechanics analyses validated on small and large scale experiments, quantification of weld residual stresses by numerical analysis and by measurements, stress corrosion crack initiation/ growth effects and assessment of RCPB components (excluding the reactor pressure vessel) under dynamic and seismic loading. Based on theoretical and experimental results, performance assessment and further development of simplified engineering assessment methods (EAM) will be carried out considering both deterministic and probabilistic approaches. Integrity assessment case studies and large scale demonstration experiments will be performed on Mock-ups of safety-relevant components. These will include a repair weld in an aged butt-welded austenitic pipe, a dissimilar narrow gap TIG weld (following the EPR design) and a cladded ferritic pipe. Moreover experiments on specimens and feature test pieces will be carried out to support the large scale Mock-up analyses. The end product of the project (“STYLE TOOLS”) will comprise best practice guidelines on the use of advanced tools, on improvement and qualification of EAM as a part of European Leak-before-break (LBB) procedures and on life time management of the integrity of RCPB components in European nuclear power plants. The project will interact with the European Network of Excellence NULIFE.