Fast Reactors and Accelerator Driven Systems Knowledge Base

Conference Article: Verification and improvement of the signal processing technique using experimental data

Sing, O.P.;Srinivasan, G.S.;Vyjayanthi, R.K.;Prabhakar, R. (Indira Gandhi Centre for Atomic Research, Kalpakkam (India))

Abstract

International Atomic Energy Agency (IAEA) has organized the Co-ordinated Research Programme (CRP) on Acoustic Signal Processing for the Detection of Boiling or Sodium/Water Reaction in LMFR over the period 1990-1995. This was an extension of an earlier CRP on Signal Processing Techniques for Sodium Boiling Noise Detection which ended in 1988. The objectives of the extended CRP were to evaluate the suitability of signal processing techniques for the detection of boiling noise under very poor signal to noise ratio conditions and then to develop the techniques further to cover leak detection in the Steam Generator Units of Liquid Metal Fast Reactors. The Indian analysis showed that Determinant and Trace features and Adaptive Learning Network techniques were able to detect with very good discrimination boiling signals down to a signal to noise ratio (S/N) of -12 dB. Determinant and Trace features were very sensitive to boiling noise and could detect signals even down to -21 dB S/N, but with a lower reliability of detection. Among the various analysis techniques evaluated by India on the acoustic leak noise data during the period 1991-1994, Determinant and Trace of covariance matrix constructed from auto power spectral density proved to be the most sensitive features for leak noise detection. These features have detected leak signals even down to -24 dB S/N, but with reduced reliability of detection below -16 dB. The data for the final year of the CRP (1995) were generated from the end-of-life acoustic leak experiments on the evaporator unit of the Prototype Fast Reactor at Dounreay, United Kingdom. The Indian analysis on this data pertained to the detection of onset and duration of leak signal, to the identification of injection medium, to the determination of leak noise transmission characteristics and to the detection of leak location.

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key words: Fast Neutron Spectrum Systems, Nuclear Technology
Reference:
Acoustic signal processing for the detection of sodium boiling or sodium-water reaction in LMFRs. Final report of a co-ordinated research programme 1990-1995
International Atomic Energy Agency, Vienna (Austria)
IAEA-TECDOC--946, pp:149-178