Technology International Incorporated 0f Virginia
US Department of Energy

Parameter Identification Technique, A New Approach to Wear Measurement in LMFBR

CUSTOMER:  U.S. Department of Energy (DOE), German Town, MD and Oak Ridge,

 TN

SUBCONTRACTOR: Argonne National Laboratory, West, Idaho Falls, ID

Subcontractor Team: Ronald W. King and Reed Manson

CONTRACT #: DOE-05-84ER80121.000

STARTING DATE: 9-13-84

DURATION:30 months

AMOUNT: $549,932

PRINCIPAL INVESTIGATOR: Dr. Shahla Keyvan

OTHER KEY PERSONNEL: Richard E. Jarka - Dr. Abdo A. Husseiny - Pamela Hoeppel - Dr. Neerchal K. Nagaraj - Dr. Enju Liang

TECHNICAL MONITOR:      Andrew Van Echo, DOE

PUBLICATIONS/REPORTS:

Hagenson, Randy L., Husseiny, Abdo A., and Keyvan Shahla (1984). Coal fired plant extension and modernization. Trans. Am. Nucl. Soc., 46:5.

Husseiny, Abdo A. and Keyvan, Shahla (1986, October). Classification of equipment for detection of wear in LMR's based on EBR-II operation experience. Proceedings, Operability of Nuclear Systems in Normal and Adverse Environment, Albuquerque, American Nuclear Society/European Nuclear Society, pp. 134-141.

Keyvan, Shahla, Jarka, Richard E., Hoeppel, Pamela, Husseiny, Abdo A., Nagaraj, Neerchal K., King, Ronald W., and Manson, Reed (1987, October).  Parameter Identification Technique, A New Approach to Wear Measurement in LMFBR.  U.S Department of Energy (DOE) Contract # DE-ACO5-84ER8Ol2l, Report # DOE/ER/8Ol2l-lO, Phase II.

Van Echo, Andrew, Keyvan, Shahla, and King, Ronald W. (1986, October).  On-line wear monitoring in liquid metal reactors. Proceedings, Operability of Nuclear Systems in Normal and Adverse Environment, Albuquerque, American Nuclear Society/European Nuclear Society, pp. 278-282.

Keyvan, Shahla, Jarka, Richard E., Husseiny, Abdo A., King, Ronald W., and Manson, Reed (1985, March).  Parameter Identification Technique, A New Approach to Wear Measurement in LMFBR.  U.S. Department of Energy (DOE) Contract # DE-ACO5-84ER8Ol2l, Report # DOE/ER/8Ol2l-l, Phase I.

Keyvan, Shahla, Husseiny, Abdo A. and Hagenson Randy L. (1984). Extension and Refurbishment of Nuclear Power Stations. Trans. Am. Nucl. Soc., 46, 559.

Keyvan, Shahla, and Grossmann, L. M. (1984).  A unified model for on-line monitoring of reactor abnormalities and dynamic modes. Trans. Am. Nucl. Soc., 46, 741.

Keyvan, Shahla, and Grossmann, L. M. (1984).  Resolution of the negative real root phenomenon in stochastic time series analysis. Trans. Am. Nucl. Soc., 46, 419.

PATENTS:

Husseiny; Abdo A. (May 11, 1993). System for prognosis and diagnostics of failure and wearout monitoring and for prediction of life expectancy of helicopter gearboxes and other rotating equipment. United States Patent # 5,210,704; Technology International Incorporated (LaPlace, LA)

Summary

The results of Phase I included an effort to develop and implement a novel technique for on-line early detection of degradation and wear in LMFBR equipment. The approach evolves around design of a wearout monitor (WONITOR) as a diagnostic tool capable of providing the operator with indication of early symptoms of aging of specific equipments during operation.  Phase I is concerned about evaluation of the feasibility of and identification of the requirements for the development of the WONITOR.

The WONITOR has to be designed for specific equipments.  Hence, candidate equipments for demonstration of the capability of WONITOR are selected.  LMFBR equipments for which early detection of wear is critical have been identified, using EBR II as a specific case.  The selected equipments are then rank ordered; using value-impact analysis, according to the impact of their performance on LMFBR safety and productivity.  The intermediate heat exchanger and the primary centrifugal pumps top ranked other primary equipments.

The WONITOR is based on adaptation of parameter identification techniques using regression models to analyze fluctuation data from measurements of parameters related to the equipments of interest.  Such parameters are identified as flow rate measurements, temperatures, and pressure.  Considering the case of EBR II, fluctuation data from such measurements are evaluated and found adequate for providing information on the state of the selected equipment.  No additional instrumentation or sensors seemed to be necessary for the information required for implementation of the WONITOR.  Ultrasonic techniques and in-service visual inspection are explored as means of localization of wear following its detection.  A combination of both methods is conceptualized.

Specifications of the WONITOR are detailed including software logic, hardware, ancillary equipments, and layout of the system in the plant proper.  Implementation cost estimates are found in the neighborhood of $360,000 in 1985 dollars.  The present development of the WONITOR indicates that the system can be easily applied to other equipment in LMFBRs. The system can be directly adopted for light water reactors.  Also, the wear monitor is suitable for wear detection of equipment operating in hostile environments or in operation environments inaccessible to human.

The objective of the Phase II work was to design a wearout monitor for on-line diagnostic surveillance. The approach is to utilize operation data to identify measures associated with aging of specific equipment, then, to monitor these wear measures through the use of updated operation signal data.  Results include: theoretical equipment modeling for intermediate heat exchanger and pump, sensitivity analysis, operation and simulation data analysis, signal characteristic determination and correlation analysis.  Identification of wear related parameters and development of wear measure parameters for monitoring purposes for selected IHX and pump wear scenarios.  The software modules are integrated into a user-friendly menu-driven wear monitor system called WONITOR.  The project results provided a system for early detection of wear in nuclear power plant equipment which would assist in plant maintenance and operation.  Minor modifications can be employed to adapt the monitoring system to other processes.

Patent Summary

A wearout monitor for failure prognostics is a prognosis tool to predict incipient failure in rotating mechanical equipment. The wearout monitor provides maintenance management of a plant or process with information essential to planning preventive maintenance strategies. The monitor also assists in constructing a data base for development and implementation of policies for plant life extension, refurbishment, and modernization. The apparatus identifies systems of operation degradation of the whole system, as well as diagnosis of signs of commencing aging cycles of specific equipment, components or parts of equipment during operation. Data from the system is stored and also supplied to a central processing unit which includes an expert system, rule-based failure data bank, a predictor, a performance evaluator and a system identifier. The results of the predictions are supplied to management terminals or other indicators for subsequent use. Combination of prognostics and diagnostics of the symptoms of existing fault in mechanical equipment allows continuous on-line monitoring of systems to predict failures at early stages before leading to catastrophic breakdown and to assure safe and economic operation. By providing correlations between defect sizes and life expectancy of a rotating mechanical component, the monitor can provide the operator of the equipment with a warning time that indicates the time before loss of operation, thereby being critical to operation of transport systems wherein gearboxes can lead to loss of transmission power and subsequent loss of life particularly in helicopters.