Abstract: [Solving Means] A resonance calculation program is configured to calculate an effective cross section including Step S4 of setting a calculation point in the gray range in the resonance region; Step S5 of calculating a neutron flux set at the calculation point and corresponding to a macroscopic cross section based on Method of Characteristics; Step S6 of fitting a fitting equation to the calculated macroscopic cross section and the calculated neutron flux, and calculating first and second rational coefficients; Step S7 of calculating a background cross section based on the first rational coefficient; Step S8 of interpolating the effective cross section, with the background cross section used as an argument; Step S9 of calculating the neutron flux based on the background cross section; and Step S10 of calculating the effective cross section based on the effective cross section, the neutron flux, and the second rational coefficient obtained at the coefficient calculation step.

Abstract: [Problem to be Solved] To provide a resonance calculation program capable of evaluating a physical quantity such as an effective cross section in a radial direction of a circular region of a fuel rod by making a resonance calculation based on the equivalence principle.

Abstract: A nuclear-characteristic calculating program for calculating a nuclear characteristic of a fuel rod that contains nuclear fuel and burnable poison includes a first scattering model that can represent a simple scattering of the neutron and a second scattering model that can represent a complicated scattering of the neutron. The nuclear-characteristic calculating program includes step of calculating, when a burnup of the fuel rod is before a set burnup at which the burnable poison is considered to lose neutron absorption capability, the nuclear characteristic of the fuel rod by using the second scattering model, step of switching, when the burnup of the fuel rod is the set burnup, the scattering model from the second scattering model to the first scattering model, and step of calculating, after performing step of switching, the nuclear characteristic of the fuel rod by using the first scattering model.

Abstract: [Problem to be Solved] To provide a resonance calculation program capable of evaluating a physical quantity such as an effective cross section in a radial direction of a circular region of a fuel rod by making a resonance calculation based on the equivalence principle.

Abstract: [Problem to be Solved] To provide a nuclear-characteristic calculating program that can suppress an increase of calculation time without degrading calculation accuracy when calculating a nuclear characteristic of a fuel rod that contains burnable poison. [Solution] A nuclear-characteristic calculating program for calculating a nuclear characteristic of a fuel rod that contains nuclear fuel and burnable poison includes a first scattering model that can represent a simple scattering of the neutron and a second scattering model that can represent a complicated scattering of the neutron.

Abstract: [Solving Means] A resonance calculation program is configured to calculate an effective cross section including Step S4 of setting a calculation point in the gray range in the resonance region; Step S5 of calculating a neutron flux set at the calculation point and corresponding to a macroscopic cross section based on Method of Characteristics; Step S6 of fitting a fitting equation to the calculated macroscopic cross section and the calculated neutron flux, and calculating first and second rational coefficients; Step S7 of calculating a background cross section based on the first rational coefficient; Step S8 of interpolating the effective cross section, with the background cross section used as an argument; Step S9 of calculating the neutron flux based on the background cross section; and Step S10 of calculating the effective cross section based on the effective cross section, the neutron flux, and the second rational coefficient obtained at the coefficient calculation step.