Supervision and Safety of Complex Systems

PART 3Characterizing Background Noise, IdentifyingCharacteristic Signatures in Test Cases andDetecting Noise in Reactors

 

A number of studies worldwide have been undertaken into fourth-generation reactors (Forum GEN IV). In this context, and given their results, work has focused on sodium-cooled fast reactors (SFR) with sodium as the caloporter fluid. Given the highly violent reaction between sodium and water, it is important to be able to detect even the slightest amount of water leaking into the sodium in a steam generator (SG) as early as possible. Research has therefore been carried out to apply continuous supervision techniques with a view to detecting any leak almost instantaneously. One of the means examined is that of passive acoustic detection of abnormal vibrations caused by a leak in the SG’s external wall.

This section reexamines the acoustic signals recorded in 1994 in the SGs in the Scottish prototype fast reactor (PFR) with deliberate injections of gas into the liquid sodium. All of the GIS 3SGS partner laboratories have applied several techniques, particularly signal treatment and classification in order to:

– identify signatures (patterns) using acoustic signals collected during the reactor’s operation and recognize them so that they can be used to detect the risk of boiling, leaks, shocks etc., as early as possible;

– determine the largest possible set of potential parameters characterizing signals;

– identify the most restricted subset possible that could distinguish ...