The functionalities of the Darwin radioactivity calculation form and the radiation protection studies

The characterisation of the radioactive sources relative to the evolution of nuclear fuels or to the activation under particles flux (generally neutrons) of structures of a nuclear equipment or a simple isotope decay is a step in the radiation protection studies. This characterisation needs to know a fundamental knowledge: the radionuclides concentration. This one changes with time, and follows the coupled differential equations of first order in time, the generalised Bateman equations. The objective of this paper is to present the functionalities of the Darwin form, developed by the Cea and dedicated to the study of radioactivity. (N.C.)