STATUS OF COLLABORATIVE RESEARCH PROGRAM BETWEEN PNNL AND RISO NATIONAL LABORATORY

PNNL and Riso have been collaborating since 1994 on a series of irradiation experiments on pure copper and various alloys of interest to the fusion materials community. The collaboration has been of great benefit to both institutes by sharing resources and experience. Past research has concentrated on examining the microstructural evolution during neutron irradiation and the influence this microstructural change exerts on the deformation response. Post-irradiation annealing experiments of both irradiated pure copper and CuCrZr yielded unique insights into the relationship between the microstructure and the deformation response. The results of that experiment also raised further questions regarding the stability and structure of the small defects produced during irradiation, particularly regarding the stability of these defects during annealing and how they interact with mobile dislocations. The focus of ongoing work has now shifted to examining the issues of defect stability in irradiated materials, dislocation generation from stress concentrations at interfaces in irradiated materials, and a new experiment on in-situ straining during irradiation and how this affects microstructural evolution and the relationship to mechanical properties.