Source term estimation for the MARIA research reactor and model of atmospheric dispersion of radionuclides with dry deposition

Source term is the amount of radionuclide activity, measured in becquerels, released to the atmosphere from a nuclear reactor, together with the plume composition, over a specific period. It is the basis of radioprotection-related calculation. Usually, such computations are done using commercial codes; however, they are challenging to be used in the case of the MARIA reactor due to its unique construction. Consequently, there is a need to develop a method that will be able to deliver useful results despite the complicated geometry of the reactor site. Such an approach, based upon the Bateman balance equation, is presented in the article, together with the results of source term calculation for the MARIA reactor. Additionally, atmospheric dispersion of the radionuclides, analysed with the Gauss plume model with dry deposition, is presented.