Preliminary neutronic analyses on VHTR core design

In the present work, we have focused to design an annular and solid cylindrical prismatic, very high temperature reactor core (VHTR). The fundamental neutronic analyses using the continuous energy Monte Carlo code MVP2.0 and MVPBURN with the nuclear data library of JENDL-4.0 are carried out for the core with power of 100 MW_th. In the study, it was used the advanced TRISO fuel with a solid layer of ZrC deposited over the kernel in which ²³⁵U was enriched by 20% of. The preliminary neutronic results are compared between the cores operating at temperature of 850degC with and without ZrC additional layer and it shows that the effective neutron multiplication factor in BOC and discharged burnup are increased, while a core lifetime is reduced due to existence of the ZrC layer.Therefore, neutronic feature of an annular prismatic VHTR core with ZrC-containing TRISO fuel is improved for long term operation as higher fuel burnup in effect of inner reflector. (author)