Sensitivity analysis of the effect of spent fuel out-of-pile residence time and actinides recovery ratio on the performance of nuclear energy system with closed fuel cycle

Highlights: • Pu and TRU composition when recycled in FRs was obtained by 3D burnup simulating. • Sensitivity of fuel out-of-pile time and actinides recovery ratio were studied. • The installed capacity and HLW generation were sensitive to the key parameters. • The recommended target for the key parameters in future R&D was proposed. - Abstract: The sustainable development of nuclear energy depends on maximization of uranium utilization and minimization of waste produced. Sensitivity analysis was made on the influence of out-of-pile residence time and the actinides recovery ratio on nuclear energy system performance; a series of recommended values were given; the effect of closed fuel cycle on the reduction of high-level waste(HLW) was analyzed. The following conclusions were drawn: 1) when Pu or transuranics(TRU) multi-cycled in fast reactors(FRs), the composition would reach equilibrium; for the referenced CFR1000, the fissile Pu took an equilibrium fraction of 70%, and the minor actinides(MA) took an equilibrium fraction of 3%(in TRU recycle); 2) the installed FRs capacity was sensitive to out-of-pile residence time and recovery ratio; the HLW generation was only sensitive to recovery ratio; the recommended value was, out-of-pile time be no more than 5a and actinides recovery ratio be no less than 99.9%; 3) the synergistic development of pressurized water reactors(PWRs) and FRs could, not only improve uranium utilization, but also effectively reduce HLW generation; compared with PWRs with once-through cycle, FR with closed-fuel-cycle could reduce the long-term radioactive toxicity of HLW to 1/5–1/6 for Pu recycle and 1/7–1/8 for TRU recycle (both with 99.9% recovery).