Reactivity noise on the United Kingdom prototype fast reactor

Abstract

This paper reports measurements of power noise on the Dounreay Prototype Fast Reactor (PFR). The noise spectrum and its dependence on plant operating conditions, such as coolant flow rate and the depth of insertion of control rods is described. The measurements are compared with predictions based on out-of-pile tests on components. It is shown that the PFR has a low level of power noise and the probable sources of the noise are identified. The use of power noise as a method of detecting vibration of a new design of absorber rod is discussed with a practical example.