Acoustic monitoring of power-plant valves. Final report
Advanced surveillance diagnostics were applied to key nuclear power plant valves to improve the availability of the power plant. Two types of valves were monitored: BWR three-stage, pilot-operated safety/relief valves and PWR feedwater control valves. Excessive leakage across the pilot-disc seat in BWR safety/relief valves can cause the second-stage pressure to reach the critical value that activates the valve, even though the set pressure was not exceeded. Acoustic emissions created by the leak noise were monitored and calibrated to indicate incipient activation of the safety/relief valve. Hydrodynamic, vibration, control and process signals from PWR feedwater control valves were monitored by a mini-computer based surveillance system. On-line analysis of these signals coupled with earlier analytic modelling identified: (1) cavitation, (2) changes in stem packaging tightness, (3) valve stem torquing, (4) transducer oscillations, and (5) peak vibration levels during power transients. These conditions were detected by a pattern recognition algorithm that continuously measured the signals for abnormal signatures.
- Research Organization:
- Technology for Energy Corp., Knoxville, TN (USA)
- OSTI ID:
- 5277910
- Report Number(s):
- EPRI-NP-2444; ON: DE82905282; TRN: 82-015777
- Resource Relation:
- Other Information: Portions of document are illegible
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
BWR TYPE REACTORS
RELIEF VALVES
NUCLEAR POWER PLANTS
VALVES
PWR TYPE REACTORS
ACOUSTIC MONITORING
ALGORITHMS
AVAILABILITY
FEEDWATER
LEAKS
PATTERN RECOGNITION
SIGNALS
SURVEILLANCE
CONTROL EQUIPMENT
EQUIPMENT
FLOW REGULATORS
HYDROGEN COMPOUNDS
MATHEMATICAL LOGIC
MONITORING
NUCLEAR FACILITIES
OXYGEN COMPOUNDS
POWER PLANTS
REACTORS
THERMAL POWER PLANTS
WATER
WATER COOLED REACTORS
WATER MODERATED REACTORS
210200* - Power Reactors
Nonbreeding
Light-Water Moderated
Nonboiling Water Cooled
210100 - Power Reactors
Nonbreeding
Light-Water Moderated
Boiling Water Cooled