Studies on the biological half-lives of three important radionuclides released in nuclear power reactor operations

The four important parameters involved in the calculation of internal radiation dose to the human body, per unit intake of a radionuclide are 1) weight and size of the body organs; 2) the biological (retention) half-life of the radionuclide; 3) radiation weighting factors for the type of radiations emanating from the radionuclide; and 4) the organ weighting factors for the organs being irradiated (target organs). Whereas, for a particular radionuclide, the radiation weighting factor and the organ weighting factors may remain constant for all humans, the other two parameters, namely, the organ weights and biological half-life, are population specific and may differ from one population group to another. For a realistic dose estimation, the population specific data on organ weights and biological half-lives for various radionuclides therefore, are needed.