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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° 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. [ABSTRACT FROM AUTHOR]

The standard modular Equatorial Port Plug (EPP) in ITER is at its final stage of design. It serves as common platforms for different diagnostics systems which are integrated together in three cassettes called Diagnostic Shielding Module (DSM). The equatorial port #12 will host an EPP with six diagnostics: the Visible-Infrared Camera and the H-α Monitor integrated in DSM #1, the Glow Discharge Wall Conditioning, the Radial X-rays Camera and the Hard X-rays Monitor, installed in DSM #2 and the Core Thomson Scattering in DSM #3. The EPP should not only serve as a diagnostic port, but also it has to provide the necessary shielding to allow for maintenance in port interspace and in port cell. This work is devoted to nuclear analyses performed to assess the nuclear loads and the shielding performance of the system. A very detailed neutronic model of EPP #12 has been developed and integrated in a 40° ITER sector MCNP model (C-model). The implemented model has been used to evaluate the neutron and gamma flux distributions, nuclear heating, radiation induced damage, tritium and helium concentration at the ITER end of life in the port plug area. [ABSTRACT FROM AUTHOR]