Study of reaction kinetics of hydrated electron with tetravalent actinoid ions in acidic media using pulsed radiolysis method

By the method of pulsed radiolysis rate constants of hydrated electron reactions with Pu4+, Np4+, U4+, Th4+ and Ce4+ ions in solutions of HClO4 and H2SO4 by competing reaction of hydrated electron with H+ ions have been evaluated. It is shown that for Pu, Np, U rate constants are within the range (6.0±1.5)x1010 l/(mol·s) and do not depend on redox potential of the pairs, although the potentials vary from 0.98 V (Pu4+/Pu3+) to -0.6 V (U4+/U3+). Further shift of the potential to the negative side in case of thorium results in the drop of rate constant value