Activation analysis for the ITER divertor cassette

A detailed three-dimensional model (3-D) has been developed for the diverto r cassette in the ITER design. The layered configurations of the dome PFC a nd vertical targets were modeled accurately with the front tungsten layer m odeled separately. 3-D neutronics calculations have been performed to deter mine the detailed spatial distribution of the neutron flux in the divertor cassette. A detailed activation analysis has been performed for zones repre senting the different critical components of the divertor cassette. The cal culations have been performed for two operational scenarios. Special attent ion has been given to the top 1 cm tungsten layer of the divertor dome. The radioactivity generated in the tungsten layers of the divertor is mostly d ominated by W-187 during the first day after shutdown. The GlidCop copper a nd 316 SS-LN parts of the divertor also generated considerable levels of ac tivity and decay heat. Nevertheless, the analysis showed that the tungsten Plasma Facing Component (PFC) is clearly the most critical part of the dive rtor from the decay heat generation point of view.