A comprehensive assessment of the nuclear heat deposition in the ITER Vacuum Vessel

Abstract This study presents the first comprehensive computation of nuclear heat deposition in the ITER Vacuum Vessel (VV) using the E-lite model, a complete 360° reference neutronics model of the ITER tokamak. Accurate characterization of nuclear heat in the ITER VV is critical for maintaining safe operation. Significant updates to E-lite were made, focusing on two key areas: improved blanket representation and inclusion of previously missing components. Our findings indicate a total nuclear heat deposition of 18.87 MW in the VV, marking a 4.4% increase from previous estimates. Conservative maximum power deposition during a DT 500 MW inductive pulse is estimated at 20.8 ± 2.3 MW (1 σ ). Detailed 3D maps of nuclear heat deposition were generated, revealing energy distribution across different VV regions and identifying areas with volumetric power deposition above 0.61 W cm −3 , a threshold to prevent mechanical stress. Detailed 3D maps of nuclear heat deposition provide critical input for the thermo-hydraulic analyses necessary for ITER design verification.