Possible use of accelerator driven subcritical reactors for minor actinides incineration

The possible interest of accelerator driven subcritical reactors for minor actinides incineration is examined. The physics of neutron multiplying syst ems is recalled. The differences between critical and subcritical reactors' control are described, with emphasis on the importance of the delayed neut rons fraction. The: minor actinides fuel evolution is studied with the conc lusion that fast neutron spectra are clearly more efficient then thermal ne utron spectra. It is, also, shown that characteristic times for incineratio n should be in the order of 10 years. The number of minor actinides inciner ators necessary for 60 PWRs is estimated to be about 6 with total thermal p ower of 9 GW. These reactors: will, also, be able to trans mute essentially all Te-99 and I-129 produced by the 60 PWR. The excess electricity cost fo r MA incineration is estimated to be about 5%. (C) 2000 Academie des scienc es/Editions scientifiques et medicales Elsevier SAS.