Transmutation of Pu-239 With spallation neutrons

Incineration studies of plutonium were carried out at the Synchrophasotron of the Joint Institute for Nuclear Research (JINR), Dubna, using proton bea ms with energies of 0.53 GeV and 1.0 GeV. Solid lead targets (8 cm in diame ter and 20 cm long) were surrounded with 6 cm thick paraffin as neutron mod erator and then irradiated. The transmutation of Pu-239 and the associated production of fission products Sr-91, Sr-92, Sr-97, Mo-99, Ru-103, Ru-105, Sb-129, Te-132, I-133, I-135 and Ce-143 were studied in the present work. T he plutonium samples teach 449 mg) were placed on the outer surface of mode rator. For 1.0 GeV proton beam, the fission rate of Pu-239 is 0.0032 atoms per proton in one gram plutonium samples, for 0.53 GeV proton, this value i s 0.0022. The experimental uncertainty is about 15%. The experiments are co mpared to two theoretical model calculations with moderate success, using t he Dubna Cascade Model (CEM) and the LAHET code. The practical incineration rate of Pu-239 is very high. For example: if one uses 10 mA, 1 GeV proton beams under the same (fictive) experimental conditions, the incineration ra te of Pu-239 via fission is 3 mg out of the 449 mg sample per day. For 0.53 GeV protons the corresponding rate is 2 mg per day.