Acoustic resonances as a means of blockage detection in sodium-cooled fast reactors

The author outlines the basis of a system giving early warning of the presence and build up of a local blockage in sodium-cooled fast reactor sub-assemblies. The method uses acoustic resonances and reports on the analysis of signals recorded during special experiments on the Dounreay Fast Reactor. These tests proved the detectability of the standing waves and showed theoretical predictions of their frequency and shift in the presence of a blockage to be in good agreement with measurements. (Aurh.)