The effect of different fuels and clads on neutronic calculations in a boiling water reactor using the Monte Carlo method

Mehtap Düz,Selcan İnal

doi:10.1038/s41598-020-79236-8

Abstract

In this study, a Boiling Water Reactor (BWR) modeling was done for the reactor core divided into square lattice 8 × 8 type using the Monte Carlo Method. Each of the square lattices in the reactor core was divided into small square lattices 7 × 7 type in groups of four. In the BWR designed in this study, modeling was made on fuel assemblies at pin-by-pin level by using neptunium mixed fuels as fuel rod, Zr-2 and SiC as fuel cladding, H2O as coolant. In fuel rods were used NpO2 and NpF4 fuels at the rate of 0.2%-1% as neptunium mixed fuels. In this study, the effect on the neutronic calculations as keff, neutron flux, fission energy, heating of NpO2 and NpF4 fuels in 0.2%-1% rates, and Zr-2 and SiC clads were investigated in the designed BWR system. The three-dimensional (3-D) modelling of the reactor core and fuel assembly into the designed BWR system was performed by using MCNPX-2.7.0 Monte Carlo method and the ENDF/B-VII.0 nuclear data library.

Highlights

In this study, a Boiling Water Reactor (BWR) modeling was done for the reactor core divided into square lattice 8 × 8 type using the Monte Carlo Method
The 3-D modelling of the reactor core and fuel assembly into the designed BWR system was performed by using MCNPX-2.7.0 Monte Carlo method and the Evaluated Nuclear Data Files (ENDFs)/B-VII.[0] nuclear data library
Each square lattice was divided into small square lattices of 7 × 7 type, which consist of Zr-2 and SiC clads, 0.2–1% N pO2, NpF4 fuel rods, water and cruciform

Summary

Introduction

A Boiling Water Reactor (BWR) modeling was done for the reactor core divided into square lattice 8 × 8 type using the Monte Carlo Method. All of the nuclear reactors available today are fission reactors, and the spent fuel from these reactors includes uranium (about 95 wt%), plutonium (0.9 wt%), minor actinides; Np, Am and Cm (0.1 wt%) and fission products such as Cs, Sr, Tc and I (4 wt%)[3,4] These wastes, which may have a high radiotoxicity and a good source of energy remaining from the existing reactors, are stored for future use. Neptunium-added radioactive materials were used in this study to reduce the amount of minor actinides It was designed a BWR system using NpO2 and NpF4 fuels at the rate of 0.2–1% as neptunium mixed fuels, and Zr-2 and SiC as clad in the current study. Reactor power (MW) Radius of the cylinder (cm) Core height (cm) Ferritic steel width (cm) Fuel assemblies number Small square region size (cm) Fuel rod radius (cm) Clad radius (cm) Gap width (cm) Total fuel rod number Total cruciform number Absorber pins radius (cm)

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Conclusion