The point-burnup program is widely used in the design of nuclear power plants. However, the burnup library owned by point-bunrup program is mainly used in thermal neutron reactors such as light water reactors and heavy water reactors, not for fast neutron reactors.

This study aims to conduct research on the processing methodology of burnup libraries tailored to the characteristics of micro-fast neutron reactors.

Firstly, the multi-group transport library suitable for micro fast neutron reactor was obtained by resonance self-shielding effect correction calculation. Secondly, the multi-group neutron energy spectra in the core were obtained by transport calculation based on the geometric model of micro fast neutron reactor, and then merging groups into single group effective cross sections. Subsequently, the nuclide composition at the end of the current burnup step was obtained by burnup calculation based on single group effective cross section. The above process was repeated until all burnup steps were calculated, and finally a ORIGEN-S burnup library (BULFUR-70) suitable for micro fast neutron reactor at different burnup depths was generated. Finally, calculation results for Megapower micro nuclear reactor using above-generated ORIGEN-S burnup library were verified by comparing with that of Monte Carlo program OpenMC.

The comparison results show that good agreement is exhibited for burnup calculations of the core nuclear fuel with relative errors of within ±5% (except for ²³⁹Pu, which shows a relative error of 6.24%) whilst the relative errors are within ±10% in activation calculations for structural materials such as stainless steel.

Verification results demonstrate that the method of burnup library generation proposed in this study is correct, and the generated burnup library can be used for source term analysis and shielding analysis of micro fast neutron reactor, supporting computational analyses of core radioactive accumulation, core decay heat, spent fuel assembly source strength, and reactor inner component activation after shutdown.