On the automated assessment of nuclear reactor systems code accuracy

Use of Fast Fourier Transform for Sensitivity Analysis

“…where | Δ F ( f 0 ) | is the mean value of the difference signal and it is equivalent to the mean error (ME) in the time domain as defined in ref. [8]. The measure fraction A0 shows when the frequency amplitudes are dominating or when the mean values (like constant differences) are dominating the sum of the amplitudes.…”

Application of Fast Fourier Transform for Accuracy Evaluation of Thermal-Hydraulic Code Calculations

“…This means that the transient related to the pressure drop has more or less ended. Tables 3 and 4 shows the comparison of FFTBM and Automated Code Assessment Program (ACAP) (Kunz et al, 2002) accuracy measures for the calculated pressurizer pressure and rod surface temperature shown in Figs. 4 and 5, respectively.…”

“…But on the other hand, the original FFTBM method has been effectively applied in obtaining information on code accuracy by several researchers in the literature. More recently, an automated code assessment program (ACAP) has been developed to provide a quantitative comparison between nuclear reactor system code results and www.intechopen.com Fourier Transforms -Approach to Scientific Principles 448 experimental measurements (Kunz et al, 2002). For the time record data the original FFTBM accuracy measure was modified and a new continuous wavelet transformation accuracy measure was included among several other accuracy measures developed for timing of events tables, scatter plots and steady state data.…”

Quantitative assessment of thermal–hydraulic codes used for heavy water reactor calculations

“…Besides FFTBM also other methods have been available for comparison of the experimental and calculated data (e.g. automated code assessment program (ACAP) (Kunz et al, 2002), stochastic approximation ratio based method (SARBM) (Prošek, 2002b;Prošek and Mavko, 2003b)). Nevertheless, only the FFTBM provides a procedure to quantify the whole calculation and therefore it is very widely used.…”