Update of the cooling design of the ITER EC upper launcher

ITER will be equipped with four EC (Electron Cyclotron) upper launchers of 8 MW microwave power each with the aim to counteract plasma instabilities during operation. The structural system of these launcher antennas will be installed into four upper ports of the ITER vacuum vessel. During operation the port plug structure will be heated by nuclear heating from neutrons and photons and thermal radiation from the plasma. Also stray radiation and power losses from the Microwave (MW) system can create local heating of the port plug structure. This is why the port plugs must be equipped with a powerful heat removal system based on cooling water circuits. Beside reliable dissipation of up to 600 kW total heat applied to the port plug also good flow characteristics, adequate distribution of coolant in parallel branches and steady temperature gradients between interacting cooling water channels must be ensured by proper layout of the cooling system. This paper outlines an update of the cooling system according to design changes of the EC upper port plugs induced by the latest blanket geometry specifications. All relevant results of thermo-hydraulic analyses for different operation scenarios and fault conditions are presented as well as the thermo-mechanical behavior and manufacturing aspects.