A diagnostics technique of fuel elements within aperiodic pulse reactors with the metallic core

A diagnostics technique over the state of fuel elements (FE) within the core of aperiodic pulse reactors (APR) has been developed. Physically, the technique is based on the following assumptions: - The oscillation spectrum of the reactor's power in the fission pulse 'tail' is connected directly with the spectrum of mechanical vibrations of the core's fuel elements; - The mechanical oscillation spectrum changes when defects (cracks) appear in the fuel element. The technique consists in recording of the dependence of the reactor's power on time, determination of spectral characteristics of power oscillations in the pulse 'tail' and further comparison thereof with appropriate values recorded for the initial core state (when all FEs have no available defects). Match of operational spectral characteristics with spectral characteristics of the initial core's state serves as a criterion of FE integrity. (author)