Authors & Affiliations
National Research Nuclear University "MEPhI", Moscow, Russia
This paper is devoted to a mathematical model for the transport of radioactive impurities in the near-boundary layers of the atmosphere and create its practical implementation.
The model is based on the fact that the propagation of an impurity in the atmosphere is described by a semiempirical advection-diffusion equation. Also, it considers availability of impurities of various types, which can be transformed into each other. Unlike the stationary model of Pascuilla-Gifford used in the IAEA, this approach allows solving a dynamic system of equations, considering changing weather conditions, and help to provide a solution on a three-dimensional space. This was achieved by the finite element method, which solve a system of differential equations on an adaptive differential grid. This allows more accurate solution in areas where increased detail is required, without significantly increasing the complexity of the calculations.
Using different software tools, a computational grid was created, numerical solution of physical processes, which are described by partial differential equations, and a graphical display of the results, were implemented.
In the future, the created software package can be used to teach the behavior of NPP personnel in emergency situations and in the planning of evacuation.
impurity transport, atmosphere, turbulence, diffusion, finite element method
1. Techniques and decision making in the assessment of off-site consequences of an accident in a nuclear facility, Safety series, no. 86. Vienne, IAEA, 1987. 185 p.
2. Metodika rascheta kontsentratsiy v atmosfernom vozdukhe vrednykh veshchestv, soderzhashchikhsya v vybrosakh predpriyatiy [The procedure for calculating the concentrations in the air of harmful substances contained in the emissions of enterprises]. St. Petersburg, Gidrometeoizdat Publ., 1997.
3. Skvortsov A.V. Triangulyatsiya Delone i ee primenenie [Delaunay triangulation and its application]. Tomsk, Tomsk University Publ., 2002.
4. Kozlov V.F. Spravochnik po radiatsionnoy bezopasnosti [Handbook of radiation safety]. Moscow, Energoatomizdat Publ., 1991. 352 p.
5. Berlyand M.E. Sovremennye problemy atmosfernoy diffuzii i zagryazneniya atmosfery [Modern problems of atmospheric diffusion and air pollution]. St. Petersburg, Gidrometeoizdat Publ., 1975. 448 p.
6. Belov I.V., Bespalov M.S., Klochkova L.V. et al. Sravnenie modeley rasprostraneniya zagryazneniy v atmosfere [Comparison of models of the distribution of contaminants in the atmosphere]. Matematicheskoe modelirovanie - Math modeling, 1999, vol. 11, no. 8, pp. 52-64.
7. Nyidstadt F.T.M., Van Dopa H. Atmosfernaya turbulentnost' i modelirovanie rasprostraneniya primesey [Atmospheric turbulence and modeling of impurity distribution]. St. Petersburg, Gidrometeoizdat Publ., 1985. 351 p.
8. Belov I.V., Bespalov M.S., Klochkova L.V. Transportnaya model' rasprostraneniya gazoobraznykh primesey v atmosfere gorod [Transport model of the distribution of gaseous impurities in the atmosphere city]. Matematicheskoe modelirovanie - Math modeling, 2000, vol. 12, no. 11, pp. 38-46.