Study of the possibility of using Europium and Pyrex alloy as burnable absorber in PWR

Abstract

The pursuit for an optimum burnable absorbers (BAs) takes a great interest due to their importance for regulating and control the reactivity of the reactor. MCNPX code is used to simulate the effect of Europium and Pyrex on the neutronic characteristics of PWR and compare it with the conventional burnable absorber. The thermal neutron flux and the power distribution through PWR assembly are analyzed to investigate the effect of gadolinium and europium on it. The PWR assembly is filled in a different fuel burnup process with 2% Gd2O3 and 2% Eu2O3 as integral burnable absorbers (IBAs). Despite the fact that the absorption cross section of gadolinium is larger than europium, the effective multiplication factor in the case of (UO2+Gd2O3) IBAs rods increases more than that in the case of (UO2+Gd2O3) IBAs rods. The Pyrex alloy is investigated in the Burnable poison rods (BPRs) to compare its effect on the neutronic characteristics of PWR with the conventional material such as B4C and (Ag-In-Cd). The effect of these materials on the Keff values has been analyzed. Due to the high absorption cross section of 135Xe and 149Sm resulting from the fission process, it was important to study the effect of different BAs materials on their concentration. The 239Pu and 241Pu concentrations resulting from the burning process have been calculated for the suggested BAs materials.