Time delay estimation: Application to flow rate measurement of cooling fluid in nuclear power plants

Precise measurement of the coolant flow rate is of utmost importance for the control and safety of PWR nuclear power plants. In this paper several methods based on generalized cross-correlation of γ-radioactivity signals are tested. We examine the influence of hydrodynamical parameters such as velocity profile and turbulence on the measurement. We show that recently proposed sophisticated estimates (PHAT-SCOT) are not efficient for our purpose and that the Hannan-Thomson (HT) estimate is just slightly better than classical cross correlation (CC).