SEPARATION OF ISOTOPES

1522736 Isotope separation KRAFTWERK UNION AG 26 May 1976 [30 May 1975] 21946/76 Heading C1A A method of separating first molecules containing a first isotope of a first element from second molecules containing a second isotope of the first element; each of the first and second molecules further containing a second element which is present among the first molecules and among the second molecules in a plurality of isotopic forms, the ratio of the number of atoms of the first element to the number of atoms of the second element being the same in the first and second molecules, comprises: (a) irradiating (e.g. by means of a laser) the first and second molecules with radiation of a frequency such that first molecules having a particular isotopic content of the second element are selectively excited; (b) removing the excited molecules from the molecules which have not been excited, by a physical and/or chemical process; (c) reacting the molecules which have not been excited with a co-reactant comprising the second element in its natural isotopic composition, so as to produce, by isotope exchange, further first molecules having the particular isotopic content of the second element; and (d) repeating at least steps (a) and (b) with the product of this reaction. The method may be used for separating 235U and 238U when the first and second molecules are UCl 6 or U(BH 4 ) 4 .