For external exposure to a point source , the distance in meters to the source must be entered. Note that the simplistic assumption of a point source introduces errors for real sources, in particular for small distances. The time can be entered in hours per year, or as percentage of total time, or continuous exposure can be selected. The new dose factors show significant differences from the old ones for the nuclides of interest. The calculator simplistically uses only the committed effective dose coefficients, rather than the organ specific dose coefficients.
All coefficients used are for adults.
The solubility class is selected according to the material type selected. For decay products, the calculator assumes the same solubility class as for the parent nuclide. It is assumed that the person is standing on a plane of soil contaminated to infinite depth. It is assumed that the person is standing on an infinite plane contaminated at the given specific surface activity. For external exposure to a point source , only gamma radiation is considered.