Nuclear analyses for the ITER Diagnostic Equatorial Port 8

The ITER diagnostic Equatorial Modular Port Plugs (EPPs) are located in the equatorial vacuum vessel ports. Port plugs consist of structural components, shielding elements, services and tenant systems and they are designed to operate in a harsh nuclear environment. Main functions of the port plugs are to provide nuclear shielding and to host tenants systems. Shielding performance optimization and calculation of heat release across the port plugs and on their systems are both crucial for technically sound integration layout of a port plug. Also, assessment of radiological waste is necessary for the decommissioning procedure. Neutronic analyses presented in this paper are focused on the standard shielding and integration solutions on a representative Equatorial Modular Port Plug of port number 8. This Port Plug hosts the Disruption Mitigation System (DMS) and other five diagnostic systems distributed in the three Diagnostic Shielding Modules (DSM): Lost Alpha Monitor, Tangential Neutron Spectrometer, Visible Spectroscopy system, Density Interferometer Polarimeter and the Flow Monitor. Highly detailed MCNP model of the EPP#8 has been developed and integrated in the ITER 40 degrees MCNP C -Model. The model has been used to calculate the relevant nuclear quantities: neutron and gamma fluxes distribution, nuclear heating in the EPP#8 components, tritium and helium production at the ITER end of life and the displacement damage will be presented in the paper for the In-Vessel region.