Present status of the FRACTESUS project: Numerical and experimental round robins on irradiated and unirradiated materials

The FRACTESUS project aims to determine the effect of specimen size on the fracture toughness properties. The project has entered its last year and many preliminary data are available. In this contribution, we report on the status of the three main inter-laboratory round robins (RR) that have been completed: i) numerical round robin; ii) experimental round robin on unirradiated materials; and iii) experimental round robin on irradiated material. The numerical round robin is completed by nine different laboratories and shows that the different numerical tools and set-ups used by the different laboratories provide comparable and consistent results. The experimental round robin on six unirradiated materials is completed by 13 different laboratories (>480 fracture toughness tests). Except for the 73W weld material, the reference temperatures T0 obtained from MC(T) specimens by the different laboratories compares well to the ones obtained from large (mostly 1T-C(T)) specimens. The experimental round robin on the irradiated 73W weld material is performed by seven different laboratories (>112 fracture toughness tests). Similar to the unirradiated case, T0 obtained from the MC(T) data set largely underestimates T0 from large specimens by about the same amount.