Comparative study on neutronic characteristics of cylindrical and three-petal fuel rod

To make up for deficiencies in neutronics calculation of three-petal-shaped fuel rods (TPF), further determine neutron transport characteristics of TPF in conventional assemblies. This paper uses DGA-OpenMC to build neutronic calculation models for cylindrical and petal-shaped fuel assemblies (CFA and TPFA) under different . It compares influences of fuel rod types and on neutronic characteristics. Results show the following. First, when is within [3.18, 7.38], k ∞ of CFA is 1342±40pcm to 2125±40pcm higher than that of TPFA, and flux distribution of CFA is more uniform. Analysis of nuclear reaction rates finds that fission nuclear reaction rate of CFA is higher, while resonance absorption nuclear reaction rate of TPFA is higher. Second, when increases, neutron energy spectrum of assemblies softens, and uniformity of flux distribution decreases. Data shows that when water uranium ratio increases from 3.18 to 7.38, f R of CFA and TPFA increase by 1.22%.