Radioecological model calculations for natural radionuclides released into the environment by disposal of phosphogypsum.

The Dutch phosphogypsum, 2 Tg.y-1, is disposed of into the Rhine. This leads to an increase of the U-238 chain radionuclides along the Dutch coast off Rotterdam, decreasing in northerly direction into the German Bight. The calculated increase of activity concentrations in sea food causes an increase of the individual radiation dose of maximal 150 muSv.y-1 and of the collective dose of the Dutch of 170 manSv.y-1. Increase of the radiation dose from stacking phosphogypsum is one order of magnitude lower.