Progress on source term evaluation of accidental events in the experimental fusion installation ITER

•Progress of the IRSN R&D activities related to the safety assessment of the ITER installation.•Simulation of an accidental scenario with the ASTEC code: loss of coolant in port cell and in vacuum vessel.•Location and chemical speciation of beryllium dusts and tritium. The French “Institut de Radioprotection et de Sûreté Nucléaire” (IRSN) in support to the French nuclear safety authority performs the safety analyses of the ITER experimental installation. We present the progress in the R&D activities related to a better evaluation of the source term in the event of an accident in this installation. These improvements are illustrated by an evaluation of the source term of a LOCA transient with the dedicated ASTEC code.