Nanometer uranium dioxide and preparation method of composite material powder thereof

Abstract

The invention discloses nanometer UO2 used for the preparation of a novel nuclear fuel pellet and a preparation method of compound powder thereof. According to the nanometer UO2 and compound powder thereof (including but not limited to nanometer UO2 powder, nanometer UO2 / SiC, nanometer UO2 / carbon nanotubes, nanometer UO2 / graphene, nanometer UO2 / nanometer diamond composite material powder) preparedand obtained by adopting a hydrothermal method or a precipitation method, the prepared and obtained powder can serve as a raw material for preparing the novel nuclear fuel pellet in a nuclear power station, and has the characteristics of high melting point, high heat conduction, good anti-radiation performance, high fission gas accommodating capacity and excellent mechanical property.

Description

technical field [0001] The invention relates to a preparation method of nano uranium dioxide and its composite material powder. Background technique [0002] Uranium dioxide (UO 2 ) is currently the most widely used nuclear fuel in commercial nuclear reactors. It has excellent thermal, chemical, and radiation stability, as well as high melting point, retention of solid fission products, and strong ability to block the diffusion of gaseous fission products. However, relying on the characteristics of phonon heat transfer causes its thermal conductivity to drop sharply under high temperature and irradiation conditions, and its heat export ability declines rapidly. Therefore, the current UO 2 The operating temperature of the -Zr nuclear fuel system is only 700-1200°C. In an accident state, the cooling system of the reactor fails, the heat in the reactor cannot be dissipated, the temperature of the core rises rapidly, and the exothermic oxidation reaction and hydrogen release ...

AI Technical Summary

Problems solved by technology

In an accident state, the cooling system of the reactor fails, the heat in the reactor cannot be dissipated, the temperature of the core rises rapidly, and the exothermic oxidation reaction and hydrogen release reaction between the metal Zr cladding and water vapor are intensified at high temperature, releasing A large amount of heat and hydrogen, the hydrogen explodes at high temperature, the cladding tube ruptures due to various adverse reactions and the deformation and extrusion of the fuel pellets, the pellets melt due to excessive temperature, and the reactor pressure vessel due to excessive internal pressure Large and damaged nuclear accidents that eventually lead to the release of radioactive materials (R.O.Meyer, Nucl.Technol., 155, 2006, 293.)