Objectif
Cracking in the heat-affected zone of core shroud welds due to stress corrosion is one of the life limiting phenomena in boiling water reactors. The susceptibility of weld material to stress corrosion cracking is increased by the presence of residual stresses and neutron irradiation. The objective of this project is to assess the correlation of the weld residual stresses and microstructure / microchemistry after irradiation and the specific stress corrosion resistance of the core shroud weld and deduce indications on the mechanism of the cracking process. Representative test welds will be produced that will be irradiated in materials test reactors to relevant neutron dose levels. Moreover, an in-service weld material will be used from a decommissioned reactor. The various irradiated materials will be examined for weld residual stresses, corrosion and mechanical behaviour and microstructure/microchemistry by the different partners.