Abstract
Moderator Temperature Coefficient is defined as the reactivity change per unit moderator temperature change. The measured moderator temperature and reactivity signals have noise. In order to estimate moderator temperature coefficient correctly, elimination of signal noise is important. From this point of view, wavelet transform analysis is known as an effective method. A basic idea of reactivity coefficient estimation is that the analyzed reactivity component is divided by the analyzed component of the relevant parameter. We carried out numerical simulations of moderator temperature coefficient measurement by using wavelet transform and good results were obtained. Using this method we estimated moderator temperature coefficients for measurement data in actual reactors. The results have proved that the method is applicable for estimation of moderator temperature coefficients in the actual reactors. It is expected to reduce the required data length during the measurement. We expect to estimate the other reactivity coefficients with the data of short transient.
