The influence of source locations of different multi-beam concept on the power density distribution and nuclear waste transmutation performance for ADS–NWT

Abstract

The multi-beam concept for the accelerator driven subcritical reactor (ADS) has the advantages in reducing the requirements for the accelerator and can flatten the power distribution of the core. However, the layout of the multi-beam should meet the goal of balancing the relationship between the total power density, the neutron leakage, and the nuclear waste transmutation performance. For the further study of the multi-beam concept for the ADS, this paper focuses on the influence of the source locations of different multi-beam concept on the power density distribution, the neutron leakage, and the nuclear waste transmutation performance for the ADS for a nuclear waste transmutation reactor (ADS–NWT). The different variations on the radial power density distribution and the nuclear waste transmutation performance for the three-, four-, six-, and seven-beam concept for ADS–NWT were analyzed. The results show that the related neutronics performance for the multi-beam concept for ADS-NWT is not only affected by the external source locations and the core geometry, but also affected by the keff and the interference effect between the spallation targets. Moreover, the fission reaction ratio and the fission reaction / (n, gamma) absorbtion ratio for minor actinides (MA) and plutonium (Pu) for the few beams concept are both higher than that for the many beams concept. Based on the analysis of the influence of source locations on the neutron spectrum, the total neutron flux, and the nuclear waste transmutation performance for MA and Pu, the related conclusions about how to arrange the best beam position from the perspective of nuclear waste transmutation and production capacity are provided.