Radiation Balance of Spent Nuclear Fuel from Thermal Reactors and the Equivalent Uranium Mass for Natural Organisms

Generalized Approach to Comparative Assessment of the Effect of Radiation from Nuclear Fuel Cycles on Biota

“…The objective is to attain equality of the potential biological danger of the wastes and natural raw material (comparison of the initial and fi nal stages of the fuel cycle) [4]. In developing this concept taking account of the dose loads on the general population and the biota one can talk about striving toward radioecological equivalence in the raw-material-wastes system [5].In a more general formulation of the problem, on the level of management of radioactive materials in a complete cycle it is expedient to use the principle of integral comparative assessment of different scenarios of the development of nuclear power [6]. This principle consists in the evaluation of the radioecological safety of open and closed NFC taking account of the following: 1) the set of objects comprising the NFC (from mining the raw materials to disposal of the wastes); 2) different regimes of functioning of NFC objects, including analysis of the consequences of accidental emissions; and 3) effect on not only humans but also living objects of the environment.…”

“…The objective is to attain equality of the potential biological danger of the wastes and natural raw material (comparison of the initial and fi nal stages of the fuel cycle) [4]. In developing this concept taking account of the dose loads on the general population and the biota one can talk about striving toward radioecological equivalence in the raw-material-wastes system [5].…”

“…where D n i is the irradiation dose rate to the nth representative organism from the ith radionuclide, mGy/day; C n i is the reduced dose conversion factor, (mGy/day)/(Bq/kg) [5,14]; q i (t) is the average concentration of a radionuclides in the surface layer of the soil, Bq/kg; S i is the area of the territory contaminated by the ith radionuclide, m 2 ; ρ is the density of the soil, kg/m 3 ; and h is the thickness of the surface layer of the soil, m. The generalized radiation action index I i can be used to assess the radiation action of the ith radionuclide on the set of representative organisms within the framework of the problem posed:…”

“…Six representative organisms belonging to different taxonomic groups and having different dimensions were considered to make assessments: grasses, trees (pines), mice, elk, earthworms, collembolans [5].…”