ENVIRONMENTAL SOURCE TERMS DURING A FEW REFERENCE ACCIDENT SEQUENCES (RAS) OF NET ITER PLANT

This paper outlines the multi-code methodological approach foreseen to estimate the environmental releases of the activated corrosion/erosio n products involved in accidents scenarios of a fusion machine. The ra dioactive releases associated with some Reference Accident Sequences R AS for the Next European Torus NET have been calculated, based on the following items: Radioactive Inventory RI, Process Source Term PST, an d Environmental Source Term EST evaluation. The assessment concerns th e NET Basic Performance Phase. Various materials (such as AISI 316L, g raphite, beryllium, and boron carbide for the PFC, and water as coolan t) and operating conditions (normal running and conditioning) are cons idered. Different codes have been used and compared. The final environ mental releases have been obtained by using RELAP5/Mod.3, FUMO, NAUA-M od.5 M, and ANITA codes.