Dose rates in ITER maintenance areas: How to achieve acceptable values

The radiation dose rate in ITER maintenance areas is one of the important safety-related quantities. Until recently it was assumed that acceptable values (i.e. <100 μSv/h at a time 106 s after shut-down) could be reached. However, with the detailed design progressing it becomes evident that the presence of gaps in the design will lead to unacceptable high dose rates in important locations. In this paper an evaluation of the dose rate in the equatorial port interspace is presented. The current dose rate seems to exceed the ITER requirement by a factor of 10. Suggestions are presented to improve the situation.