Experience gained during 10 years transmutation experiments in Dubna

Abstract

Transmutation, the procedure of transforming long-lived radioactive isotopes into stable or short-lived, was proposed for reducing the amount of radioactive waste resulting from technological applications of nuclear fission. The Accelerator Driven Systems (ADS) provide the possibility to generate intense neutron spectrum yielding in an effective transmutation of unwanted isotopes. Such experiments are being carried out for the last 10 years in Synchrophasotron / Nuclotron accelerators at the Veksler-Baldin Laboratory of High Energies of the Joint Institute for Nuclear Research in Dubna, Russia. Thick Pb and Pb-U targets, surrounded by moderators, have been irradiated by protons in the energy range of 0.5-7.4 GeV. Neutron fluence measurements have been performed by different techniques of passive detectors (neutron activation detectors, solid state nuclear track detectors). Transmutation of 129 I, 237 Np, 239 Pu was studied. The results of these experiments are presented and discussed.