Shielding Optimisation of the ITER ICH&CD Antenna for Shutdown Dose Rate

Shielding Optimisation of the ITER ICH&CD Antenna for Shutdown Dose Rate

Shielding Optimisation of the ITER ICH&CD Antenna for Shutdown Dose Rate 150 150 UKAEA Opendata
CCFE-PR(17)37

Shielding Optimisation of the ITER ICH&CD Antenna for Shutdown Dose Rate

The Ion Cyclotron Heating and Current Drive (ICH&CD) system will reside in ITER equatorial port plugs 13 and 15. Shutdown dose rates (SDDR) within the port interspace are required to be less than 100 Sv/h at 106 s cooling. A significant contribution to the SDDR results from neutrons streaming down gaps around the port frame, and the mitigation of this streaming is the main subject of these analyses. An updated MCNP model of the antenna was created and integrated into an ITER reference model. Shielding plates were defined in the port gaps, and scoping studies conducted to assess their effectiveness in several configurations, based on which a front dog-leg arrangement was selected for high resolution 3-D activation analysis using MCR2S. It was concluded that the selected configuration reduced the SDDR from ?500 Sv/h to 220 Sv/h but were still in excess of dose rate requirements. Approximately 30% of this was due to cross-talk from neighbouring ports. In addition, increased dose rates were observed in the port interspace along the lines of sight of the removable vacuum transmission lines. Design optimisation is continuing, however an integrated approach is needed with regard to ITER port plug design and the shielding of surrounding systems.

Collection:
Journals
Journal:
Fusion Engineering and Design
Publisher:
Elsevier
Published date:
10/01/2015