FIELD: nuclear power engineering. SUBSTANCE: acoustic pulse signals are measured at three points located on periphery of reactor core above heads of fuel assemblies symmetrical in respect to center. Measured pulses are amplitude-discriminated from background acoustic noise. Sodium boiling is recognized by presence of pulses across check points within time space Δt = l/V ,, where 1 is maximum distance between sensors; V is acoustic signal speed in sodium. Measured time spaces between pulses are compared with tabulated data for each fuel assembly and point of sodium boiling is located. EFFECT: improved reliability of check. 3 dwg
