29th Symposium on Fusion Technology (SOFT 2016)

P2.049 Neutronics analysis of the in-vessel components of the ITER plasma-position reflectometry system

6 Sep 2016, 14:20

1h 40m

Foyer 2A (2nd floor), 3A (3rd floor) (Prague Congress Centre)

Board: 49

Poster D. Diagnostics, Data Acquisition and Remote Participation P2 Poster session

Speaker

Raul Luis (Instituto de Plasmas e Fusão Nuclear)

Description

The ITER Plasma Position Reflectometry (PPR) system will be used to estimate the distance between the position of the magnetic separatrix and the first-wall at four pre-defined locations, also known as gaps 3, 4, 5, and 6, complementing the magnetic diagnostics system. For gaps 4 and 6, the antennas are to be installed in-vessel between two blanket shield modules. The microwave signal is routed to/from the antennas using rectangular oversized waveguides that enter/exit the vacuum vessel through feed-outs located in upper ports 01 and 14, respectively. The antennas and adjacent waveguides are directly exposed to the plasma through cut-outs in the blanket shield modules and are therefore subject to high radiation doses from neutrons and photons, which may cause irradiation-induced changes in the material properties and compromise the integrity of these components. Here, we report on the preliminary neutronics analysis of these components of the PPR system using the Monte Carlo simulation code MCNP6, with the objective of estimating the thermal loads and amount of radiation damage. The first step consisted of translating the CAD models of the antennas and waveguides to MCNP6, using ANSYS SpaceClaim and the CAD-based modelling program MCAM. The resulting models were integrated in the ITER C-lite neutronics model provided by F4E and used to estimate the heat loads, DPAs and particle flux spectra in the components. The results, complemented with a finite element analysis carried out with ANSYS Mechanical, are presented in this paper. The operational temperature and the structural effects due to long-term irradiation are analyzed and discussed, and an evaluation is made on the necessity of prototyping some components to perform irradiation tests. The thermal loads obtained through the neutronics analysis presented here will be used as input in the global integrity analysis of the in-vessel components of the ITER PPR system.