PowerPoint bemutat

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• Diagnostics in NPP Paks

• by Gábor Kiss

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Topics

• Reactor upper block leakage detection
• Reactor primary loops lose-part detection
• Rotating machinery vibration diagnostics
• Reactor noise diagnostics
• Summary

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Reactor upper block leakage detection
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Reactor upper block leakage detection

• Acoustic system
• Former system developed by the CPRI of Budapest
  at the beginning of the 80s.
• Installed on the Unit 3 4.
• Reconstructed in 2002-2003.
• Detectors
• Upper block at the Reactors simple nickel
  sealing of pipe branches
• Acoustic emission detectors 4/reactor
• Detectors connected to the surfaces by wave
  guides.
• Local RMS forming.

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Reactor upper block leakage detection
Detector

• Detector topology
• Four AE detectors connected with wave guiders to
  the control rod pipe.
• Good topology for accessing even more pipe
  branches.

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Reactor upper block leakage detection
Mounting detector and wave guider
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Reactor upper block leakage detection
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Reactor upper block leakage detection

• Development tasks
• Developing verification and validation methods in
  order to avoid false alarms.
• Calibration
• sprayed gases.
• Artificial real leakage.
• Building-up an alarm system to the control room.
• Intranet-based display of trends, alarms, etc...

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Reactor primary loops loose-part detection
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Reactor primary loops loose-part detection

• ALPS system. Developed in the 2000-2003 years.
• Requirements
• Detecting and identifying loose-parts and foreign
  objects.
• Localization.
• Weight estimation.
• Avoid false alarms.
• Ability of event storing and acoustic play
  backing.
• Simplified report generating.
• Event based noise handling.
• Teachable event classification and identification.

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Reactor primary loops loose-part detection

• Main circulating Pump accelerometers
  6 channel
• Main Isolation Valve accelerometers
  6 channel
• Steam generator accelerometers
  6 channel
• Reactor safety and control rod accelerometers
  6 channel
• Primary circle pressure fluctuation signals
  4 channel
• 28 channel
• These signals are available in the diagnostic
  laboratories.

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Reactor primary loops loose-part detection
System architecture
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Reactor primary loops loose-part detection

• Monitoring machines
• Located in the diagnostic laboratories.
• Windows NT
• 32 channel NI DSP card, real-time signal
  procession.
• Ring buffers in the operative memory of the
  computer.
• AR based signal whitening for eliminating the
  floor-noise.
• Preclassification of incoming burst signals.
• When the monitoring computer finds some burst
  signals, which are exceeding the pre-defined
  threshold, sends an event file to the main
  computer via network.

• Main expert computer
• Waits for the event files from the monitoring
  computers.
• Classification of the events.
• Acoustic playback. (listening)
• Display the diagrams.
• Expert reports.
• Store the event file.
• Intranet surface for the result publication.

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Reactor primary loops loose-part detection

• Calibration
• During the outages the maintenance people beats
  the primary loops pipes with known beating
  power.
• 125g weight, approx. 0,1J energy beatings.
• Known energy, weight and beating place gives a
  good reference.

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Reactor primary loops loose-part detection
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Reactor primary loops loose-part detection

• Identified and classified events
• Main isolation valve bascule noise
• Check valve vibration (stroke)
• Safety and control rod moving
• MCP starting
• Steam generator hotside air bleeding pipe noise.
• Main stem isolation quick-action valve operation
  stroke.
• Serious loose parts have not detected since 2001.

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Reactor primary loops loose-part detection

• Development tasks
• Automatic calibration.
• Remote impact hammers on primary loops
• Building-up an alarm system to the control room.

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Rotating machinery vibration diagnostics
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Rotating machinery vibration diagnostics

• Testing more than 500 rotating equipment.
• DLI ExpertAlert system with DC-7b and DCX-HH
  field analyzers.
• The system works since 1996.
• We have a quite large database and lot of
  experience.
• Faults can be detected in early phase.

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Rotating machinery vibration diagnostics

• Data collector collects triaxial data, makes
  spectras up to 6400 lines, with rotating
  synchronous averaging.
• Software engine uses empirical, rule based
  system.
• Vrms-,Spectrum-, cepstrum, demodulated data
  analysis.
• Expert system with detailed result

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Rotating machinery vibration diagnostics

• On-line system for MCP vibration monitoring

• DLI DCX Online system.
• In 2003 we started to realize on unit 1.
• Now the system works on 2 MCPs.
• The system connected to the ExpertAlert database.
• 3 triaxial accelerometer on every MCP.
• All the capabilities of off-line systems full
  time control

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Reactor noise diagnostics
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Reactor noise diagnostics

• On focus
• The reactors inner part vibration diagnostics.
• Safety and control rod
• Fuel assembly
• Core barrel motion monitoring.
• In-core coolant velocity measurement. Based on
  measuring the transport time between two axial
  neutron detectors.In1977 the measurements are
  succesfully verified the fact of thermal
  assymmetry of the reactor of the unit 2.

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Reactor noise diagnostics
The system realization

• The old system developed by the CPRI Atomic
  Energy Research Institute of Budapest at the
  beginning of the 80s. Its necessary to rebuild
  the old system.
• Input signals of the new system
• In-core SPND noise signals. (288 pcs).
• In-core thermocouple signals (228 pcs)
• Ex-core ionic chamber signals. (present time
  these are not available for diagnostic purposes)
• Safety control rod accelerometers. (6
  available)
• Getting the reactor parameters on-line from the
  plants process control computer VERONA by a
  planted web server.
• From present year the prototype will be tested on
  Unit 4 with a limited number of input channels.
  (64 channels)

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Reactor noise diagnostics
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Summary

• Diagnostic methods have demonstrated the
  usability in lot of cases.
• The acoustic based alarm and signaling systems
  complement the classical measuring methods.
• The application of diagnostic techniques help us
  to realize predictive maintenance in case of some
  rotating machinery.
• The importance of diagnostic methods are
  growing in the topics of power up rating and
  lifetime enhancement in our NPP.

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• Thank You for your attention!