Comparison between HELIOS critical-depletion calculations and a PWR thorium cell burnup benchmark

A comparison between the HELIOS computer code and a pin cell burnup benchmark is presented in this paper. The benchmark is based on a thorium fuel pin cell moderated with light water. The burn-up dependent eigenvalue and isotopes concentrations obtained with HELIOS were compared with those obtained with state-of-the-art transport codes (MOCUP, INEEL-MOCUP and CASMO4). The pin cell model considers eight azimuthal regions in the moderator zone and two radial regions in the fuel. The analysis with HELIOS was carried out with cross section libraries of 35 and 190 energy groups. The HELIOS results showed that the average absolute difference as a function of burnup were less than 1% δk/k in the eigenvalue and an average absolute difference of around 5% in the isotopes concentration, with respect to CASMO4 code.