Estimation of moderator temperature coefficient of actual PWRs using wavelet transform

摘要

Recently, an applicability of wavelet transform for estimation of moderator temperature coefficient was shown in numerical simulations. The basic concept of the wavelet transform is to eliminate noise in the measured signals. The concept is similar to that of Fourier transform method in which the analyzed reactivity component is divided by the analyzed component of relevant parameter. In order to apply the method to analyze measured data in actual PWRs, we carried out numerical simulations on the data that were more similar to actual data and proposed a method for estimation of moderator temperature coefficient using the wavelet transform. In the numerical simulations we obtained moderator temperature coefficients with the relative error of less than 4%. Based on this result we applied this method to analyze measured data in actual PWRs and the results have proved that the method is applicable for estimation of moderator temperature coefficients in the actual PWRs. It is expected that this method can reduce the required data length during the measurement We expect to expand the applicability of this method to estimate the other reactivity coefficients with the data of short transient.