Abstract: Uranium trioxide is reduced to uranium dioxide using microwave radiation or radiofrequency radiation directed in such a way that the radiation encounters an interface between uranium trioxide and the uranium-containing reduction product without first having passed through that product. By this method, and also using a reducing gas, it is possible to obtain UO2 with an O:U ratio less than 2.04:1.

Abstract: Uranium trioxide Is reduced to uranium dioxide using microwave radiation or radiofrequency radiation directed in such a way that the radiation encounters an Interface between uranium trioxide and the uranium-containing reduction product without first having passed through that product. By this method, and also using a reducing gas, it is possible to obtain UO2 with an O:U ratio less than 2.04:1.

Abstract: Uranium fluoride compounds, in which the uranium is preferably present in the tetravalent or higher valency state, are reacted with a strong mineral acid, to yield a gaseous phase of hydrogen fluoride and a precipitate that is a uranium salt of the mineral acid. The precipitate can be subjected to thermal decomposition to recover the mineral acid and to obtain an oxide of uranium. The process provides an economical way of obtaining hydrogen fluoride from byproduct depleted UF.sub.6.

Abstract: Selection criteria are disclosed for choosing a coreactant RX that will improve the isotope separation in laser-activated chemical reactions which may proceed by the steps: ##STR1## The step of coreactant activation can be important in some exchange reactions but unnecessary in others. That is for some laser-activated chemical reactions, the second step may be absent.The selection criteria are based on the relative magnitudes of the bond-energies and therefore vibrational frequencies in the molecules .sup.i MY and RX, and the requirements for forming a Vanderwaals-like attachment complex. Also, the upper and lower limit of tolerable thermal (non-laser) reaction speeds are defined. It is shown further that it is necessary to restrict suitable RX candidates to those species which yield .sup.i MX product that does not participate in subsequent chemical reactions which cause isotope scrambling. The employment of a second auxiliary coreactant is recommended in certain cases if its interaction with the complex (.

Abstract: A compound MF.sub.n, where M is a metal and n is the valency of the metal and has a value between 1 and 6, is subjected to a thermal plasma at a temperature in excess of 3000 K to dissociate it into the metal and fluorine. Also present in the reactor is an added reactant that will react with the metal or the fluorine to prevent their recombination so that there is formed fluorine gas or a fluoride other than the fluoride of the metal M.

Abstract: An isotope separation arrangement for separating a preselected isotope from a mixture of chemically identical but isotopically different molecules by either photon-induced pure rovibrational or vibronic selective excitation of the molecules containing the atoms of the isotope to be separated from a lower to a higher energy level, and a chemical reaction of the higher energy level molecules with a chemically reactive agent to form a chemical compound containing primarily the atoms of isotope to be separated in a physicochemical state different from the physicochemical state of the mixture of chemically identical but isotopically different molecules. The chemical compound containing the atoms of the isotope to be separated may be subsequently processed to obtain the isotope.