Reduction of americium (VI) in alkali medium by high concentrations of ozone

As reported, Am(VI) is oxidized to Am(VII) in 4 M NaOH solution at O{degrees}C either by passing ozone-oxygen mixture containing 50 mg O{sub 3}/1 or upon {gamma}-irradiation of solutions supersaturated with N{sub 2}O or aerated solutions containing K{sub 2}S{sub 2}O{sub 8}. In the course of oxidation, yellow solution becomes greenish. The steady-state concentration of Am(VII) is 40-60% to the starting Am(VI) concentration. The mechanism of Am(VI) oxidation has not been examined; as for Np(VI), its radiation-chemical oxidation is effected in solutions saturated with N{sub 2}O predominantly by O{sup {minus}}{sub 3} radical anion and in aerated solutions of K{sub 2}S{sub 2}O{sub 8} exclusively by O{sup {minus}}{sub 3}. In the case of {gamma}-irradiation of Am(VI) solution, an oxidant is also O{sup {minus}}{sub 3}: Am(VI) + O{sup {minus}}{sub 3}{r_arrow} Am(VII) + O{sub 2} + O{sup 2{minus}}.