Theoretical Characterization of a Dual-Purpose gamma Thermometer

摘要

The local heat generation rate (LHGR) in a pressurized water reactor is typically inferred from measurements of the thermal neutron flux. However, since the thermal neutron flux exhibits a large amount of structure positionally within a PWR fuel assembly, an alternate instrument, the gamma thermometer (GT), has been proposed as a means of improving the LHGR inference. Since the gamma flux is related to the fission rate, and since the gamma flux exhibits very little structure within a fuel assembly, the use of a gamma-based LHGR detector could significantly improve the measurement accuracy. More recently, a further application of the gamma thermometry principle has been advanced: that of a fluid level indicator for in-core measurements. The results of a two-part study directed at establishing the feasibility of such a device, are the subject of this paper. (ERA citation 06:023510)