OPTICAL-PROPERTIES OF URANIUM HEXAFLUORIDE AND THE PRODUCTS OF ITS THERMAL-DECOMPOSITION

The optical properties of uranium hexafluoride are treated. This compo und is of practical interest from the viewpoint of nuclear power engin eering [1] because of its unique physical features: UF6 combines fissi onable properties with a very low vaporization temperature equal to 56 .5 degrees C [2]. On the basis of analysis of the available experiment al data, it is demonstrated that, at low temperatures (< 1000 K), the diffusion approximation is unacceptable for the calculation of radiati on transfer because of the absence of absorption from the spectral reg ions that are responsible for radiation transfer at these temperatures . Based on thermodynamic examination of the composition of UF6 at temp eratures higher than 10 000 K, detailed analysis is carried out of the elementary processes of absorption, which define the spectral coeffic ient of absorption in a wide range, and integral quantities are obtain ed that are characteristic of radiation transfer, namely, Rosseland an d Planck mean values of the absorption coefficients and coefficients o f radiant heat conductivity.