Estimation of the moderator temperature coefficient of reactivity via noise analysis using closed-loop transfer functions

The accuracy of the estimation, via noise analysis, of the moderator temperature coefficient (MTC) of reactivity is investigated, assuming that closed-loop data are used in the estimators. The noise field is generated through numerical simulations. The focus is on the approach using the proportionality between estimated and actual MTC values during the fuel cycle. The results show that the bias induced on the proportionality constant (calibration factor) depends, as expected, on the strength of the feedback. However, it remains within tolerable limits, considering that the introduced uncertainty is less-than-or-equals, slant30%, which is comparable with the measurement uncertainty of the standard boron dilution method.