Explore the possible advantages of using thorium-based fuel in a pressurized water reactor (PWR) Part 1: Neutronic analysis

This study discusses the effect of using Th-232 instead of U-238 on the neutronic characteristics and the main operating parameters of the pressurized water reactor (PWR). MCNPX version 2.7 was used to compare the neutronic characteristics of UO2 with (Th, U-235)O-2 and (Th, U-233) O-2. Firstly, the infinity multiplication factor (K-inf), thermal neutron flux, and power distribution have been studied for the investigated fuel types. Secondly, the effect of Gd2O3 and Er2O3 on the K-inf and on the radial thermal neutron flux and thermal power has been investigated to distinguish which of them is more suitable than the other in reactivity management. Thirdly, to illustrate the effectiveness of Th-232 in decreasing the inventory of both the actinides and non-actinides, the concentration of plutonium (Pu) isotopes and minor actinides (MAs) has been simulated with the fuel burnup. Besides, due to their large thermal neutron absorption cross-section, the concentrations of Xe-135, Sm-149, and Sm-151 with the fuel burnup have been investigated. Finally, the main safety parameters such as the reactivity worth of the control rods (rho(CR)), the effective delayed neutron fraction beta(eff), and the Doppler reactivity coefficient (DRC) were calculated to determine to which extent these fuel types achieve the acceptable limits. (C) 2021 Korean Nuclear Society, Published by Elsevier Korea LLC.

Automated summary

This study investigates the impact of using Th-232 instead of U-238 on the neutronic characteristics and operating parameters of a pressurized water reactor (PWR). The study compares the neutronic characteristics of different fuel types and examines parameters such as the multiplication factor, neutron flux, and power distribution. The study also analyzes the effectiveness of different materials, Gd2O3 and Er2O3, in reactivity management, and simulates the concentration of isotopes and actinides during fuel burnup. Safety parameters, including reactivity worth, delayed neutron fraction, and Doppler reactivity coefficient, are calculated to determine if the fuel types meet acceptable limits.