Environment source terms for ex-vessel FW/SB LOCA accident sequences in ITER EDA

The paper presents the environmental source term EST evaluation results for some ITER accident sequences, with reference to the activated materials contribution. The assessment is based on the end-of-1994 ITER baseline design and it refers to ex-vessel LOCAs in the first wall FW and shielding blanket SB heat transport system HTS. The main ITER characteristics are: fusion power 1.5 GW, average neutron power load on the outboard first wall 1 MW/m2, fluence 3 MW-y/m2, average pulse length 1,000 s, dwell time 1,200 s. The structural material for FW and SB is AISI 316L. (Mn 1.8 wt.%, Co 0.17 wt.%) stainless steel. Four independent loops for FW and SB heat transport system are considered. The European multi-code approach is briefly described jointly with the computer tools used for the assessment. A sensitivity analysis has been performed to verify the impact of the water chemistry on the environmental release composition and mass