Transmutation of MAs and LLFPs with a lead-cooled fast reactor

The management of nuclear wastes has long been a problem that hinders the sustainable and clean utilization of nuclear energy since the advent of nuclear power. These nuclear wastes include minor actinides (MAs: 237 Np, 241 Am, 243 Am, 244 Cm and 245 Cm) and long-lived fission products (LLFPs: 79 Se, 93 Zr, 99 Tc, 107 Pd, 129 I and 135 Cs), and yet are hard to be handled. In this work, we propose a scheme that can transmute almost all the MAs and LLFPs with a lead-cooled fast reactor (LFR). In this scheme, the MAs and the LLFPs are loaded to the fuel assembly and the blanket assembly for transmutation, respectively. In order to study the effect of MAs loading on the operation of the core, the neutron flux distribution, spectra, and the k eff are further compared with and without MAs loading. Then the LLFPs composition is optimized and the support ratio is obtained to be 1.22 for 237 Np, 1.63 for 241 Am, 1.27 for 243 Am, 1.32 for 79 Se, 1.53 for 99 Tc, 1.02 for 107 Pd, and 1.12 for 129 I, respectively, indicating that a self-sustained transmutation can be achieved. Accordingly, the transmutation rate of these nuclides was 13.07%/y for 237 Np, 15.18%/y for 241 Am, 13.34%/y for 243 Am, 0.58%/y for 79 Se, 0.92%/y for 99 Tc, 1.17%/y for 107 Pd, 0.56%/y for 129 I. Our results show that a lead-cooled fast reactor can be potentially used to manage nuclear wastes with high levels of long-lived radioactivity.