BURNUP SENSITIVITY CALCULATIONS WITH CBZ FOR LIGHT WATER REACTOR ASSEMBLY PROBLEMS

Go Chiba

doi:10.1051/epjconf/202124715013

Abstract

Sensitivities of k∞ and nuclides number densities during nuclear fuel burnup with respect to nuclear data are calculated with a reactor physics code system CBZ. Sensitivity calculations are carried out with the depletion perturbation theory applicable to nuclear fuel assemblies including burnable absorbers. Numerical results are presented both for BWR and PWR assemblies, and those demonstrate usefulness and effectiveness of burnup sensitivity calculation capabilities for LWR fuel assemblies.

Highlights

Uncertainty quantification of reactor physics parameters/related quantities and data assimilation using measurable parameters/quantities have become important subjects to ensure reliability of numerical predictions and to reduce uncertainty of these predictions in the field of reactor physics
One of important capabilities of the CBZ code system is sensitivity calculations of nuclear fuel burnup-related parameters/quantities with respect to nuclear data[3]. This capability is based on the generalized perturbation theory for nuclear fuel burnup problems, the depletion perturbation theory, which has been established in the past by researchers such as Gandini[4] and Williams[5]
Our research group has implemented sensitivity calculation capability based on this theory into the CBZ code system, and light water reactor (LWR) fuel assemblies including burnable absorbers can be handled with at present

Summary

Introduction

Uncertainty quantification of reactor physics parameters/related quantities and data assimilation using measurable parameters/quantities have become important subjects to ensure reliability of numerical predictions and to reduce uncertainty of these predictions in the field of reactor physics. One of important capabilities of the CBZ code system is sensitivity calculations of nuclear fuel burnup-related parameters/quantities with respect to nuclear data[3]. This capability is based on the generalized perturbation theory for nuclear fuel burnup problems, the depletion perturbation theory, which has been established in the past by researchers such as Gandini[4] and Williams[5]. Our research group has implemented sensitivity calculation capability based on this theory into the CBZ code system, and light water reactor (LWR) fuel assemblies including burnable absorbers can be handled with at present. To mitigate time-discretization errors in fuel assembly burnup problems, some advanced numerical schemes such as the predictor-corrector (PC) method are mandatory, and the depletion perturbation theory applicable to the PC method has been established during our previous work[6]

Methods

Results

Conclusion