Kinetics of thermal decomposition of nitrosonium trinitratouranylate and anhydrous uranyl nitrate

A study was made on kinetics of NO[UO2(NO3)3] and UO2( NO3)2 decomposition in vacuum and under isothermal conditions. It was shown that nitrosonium trinitratouranylate (NTN) is transformed in 130-180 deg C range to anhydrous uranyl nitrate. The process proceeds in the stage and possesses the apparent activation energy (Ea) equal to 26.1+-2.4 Cal/mol. It was shown that decomposition of anhydrous uranyl nitrate down to amorphous uranium trioxide is accomplished in diffusion-kinetic region and proceeds without formation of intermediate compounds. The calculated Esub(a) of the process was equal to 32.1+-1.3 Cal/mol, which correlates satisfactorily with activation energy calculated according to the data of derivatographic measurements