Role of (n, xn) reactions in ADS, IAEA-benchmark and the Dubna Cascade Code

Abstract

Dubna Cascade Code (version-2004) has been used for the Monte Carlo simulation of the 1500 MWt accelerator driven sub-critical system (ADS) with 233U + 232Th fuel using the IAEA benchmark. Neutron spectrum, cross-section of (n, xn) reactions, isotopic yield, heat spectra etc. are simulated. Many of these results that help in understanding the IAEA benchmark are presented. It is revealed that the code predicts the proton beam current required for the 1500 MWt ADS for K eff = 0.98 to be 11.6 mA. Radial distribution of heat is fairly in agreement with other codes like the EA-MC and it needs nearly 1% less enrichment than given by other codes. This may be because the code takes care of the role of larger order of the (n, xn) reactions. It is emphasized that there is a strong need to study (n, xn) reactions both theoretically and experimentally for better design.