Gamma radiation effects on potassium pertechnetate in carbonate media

Gamma radiation effects on the stability of the oxidation state of radioele ments and diffusion within the framework of nuclear waste repositories are often neglected, although it may influence physicochemical processes and th us transfer to biosphere and geosphere. This knowledge is essential to mode l transport phenomena. This study reports on effects of gamma irradiation o n technetium in carbonate media, which is representative of natural systems . Depending on media compositions, the gamma irradiation on pertechnetate l eads to formation of Tc(IV) only in the absence of carbonate. CO3- radicals are able to re-oxidise technetium intermediate oxidation states to the +7 state. (C) 2000 Elsevier Science Ltd, All rights reserved.