Calculation of intake retention functions for intake of activated dusts in the fusion reactors

Activated dusts will be one of the main source terms to cause occupational radiation exposure during maintenance inside the plasma chamber or in accident at fusion reactors such as ITER and fusion DEMO reactors. In order to estimate the intake of activated dusts and committed dose from these, intake retention functions and daily excretion functions are necessarily needed. Since the activated dusts have not been considered in fission reactors, however, the intake retention functions and excretion functions have not been calculated. In this study, thus, we calculated the whole-body retention functions and excretion functions for activated dusts. Radioactive tantalum, tungsten, and rhenium which are produced from tungsten-based divertors were selected as concerned nuclides. Since contaminated wound can occur from explosion accidents, intake from contaminated wound was also included in intake routes as well as inhalation and ingestion. Birchallʹs algorithm was used to calculate the retention and excretion functions and the functions were fitted as sum of exponential terms using ORIGIN software. The calculated functions in this study will be usefully used to estimate the intake of the activated dusts when the ITER and fusion DEMO reactors start to operate.