Хвильове ядерне горіння у сферичній геометрії

Abstract

Every year, human energy consumption is constantly growing, so the role of nuclear energy will only increase over time. However, the reserves of 235U, which is the main ssile nuclide in nuclear energy, are limited and should be depleted in the coming decades. But this problem can be avoided if we use the huge reserves of 238U. This article aims to investigate the feasibility of implementing one of the regimes of a fundamentally new and not yet practically implemented process in nuclear energy the nuclear traveling wave in a uranium-plutonium medium, where plutonium-239 is formed from 238U. A nuclear traveling wave may form in a uranium-plutonium medium as a moving wave of plutonium239 ssion. This paper considers the possibility of the formation of such a wave in a spherical uraniumplutonium medium, and the study is conducted in spherical geometry. A majority of works studying the traveling wave mode of nuclear ssion consider 1D or cylindrical 3D geometry. There are only a few works devoted to the study of this problem in spherical geometry. It should also be noted that the nuclear reactions considered in the present paper involve the participation of epithermal neutrons, which also signi cantly distinguishes our work from previous works on this topic, because most of them consider thermal neutrons. Since this problem is spherically symmetric, it allowed us to replace 3D modeling of the whole sphere with 1D modeling along the radius of this sphere. We have developed kinetic equations describing a nuclear traveling wave and modeled it by numerically solving these kinetic equations. An improved explicit-implicit numerical calculation scheme was used, which allowed us to increase the temporal step of the simulation.