Hydrolysis of Uranium Nitrides

Abstract

Studies were made on the hydrolysis of uranium nitrides (UN and cubic U2N3) by superheated steam. The resulting gaseous products were mainly hydrogen, though with U2N3 the hydrogen generation was replaced by that of nitrogen at higher temperatures. The condensed water contained ammonia, but not hydrazine. Both UN and U2N3 powders were ultimately converted to UO2, after hydrolysis at temperatures up to 600°C; intermediate products (formed below 400°C) were presumably UO2(N) or UN1,7, in the case of UN and UN18 with U2N3. The reaction mechanisms corresponding to the formation of such chemical species were estimated mainly from the behavior of nitrogen and hydrogen evolution and from the yield of ammonia. The effect brought by N2 atmosphere on the ammonia formation and on the dissolution of nitrogen into solids were studied also by the hydrolysis under flowing N2 gas. It was revealed that the yield of ammonia increased and the dissolution was inhibited by N2 atmosphere. © Taylor & Francis Group, LLC.