Michael J. Avioli

An Expert System for Power Plant NDE

Expert systems are computer software that embody the knowledge of expert(s) in such a form that the system can offer intelligent advice to solve the problem. Knowledge and expertise are principal assets, which, along with capital assets comprised of plant and equipment, make up a modern electric utility. Thus, the capability of expert systems technology to capture the intellectual resources may be beneficial for the industry [1].

Natural Focusing for the Detection of Defects Beyond Elbows

Long range ultrasonic guided wave inspection is advancing rapidly and is commonplace today. Benefits of using longitudinal or torsional modes are being established in special circumstances of improved sensitivity, resolution, or penetration power. The possibility of inspection under insulation, coatings, or with water filled pipes or around elbows is possible. Detection of defects beyond a pipe elbow is difficult for axisymmetric wave impingement onto the elbow. For non-axisymmetric input to the elbow region, however, via partial loading around the circumference, allows natural focusing to occur because of angular profile variation around the circumference of the pipe. An experiment is reported here to demonstrate this process.Copyright

Nuclear Power Plant Costs as a Function of NDE Reliability

The economic efficiency and safety of any power plant depends on the proper functioning of its component systems. The functioning of such systems (e.g., piping) is evaluated through performance of periodic nondestructive examinations (NDE). The results of these examinations determine actions the power plant owner must take regarding inspected components. If a component is found malfunctioning or containing a defect, the owner may decide to repair or replace the component. If the results of NDE indicates that the component is functioning as it should or is defect-free, he would most certainly take no action but to record such a finding for future reference. Any action the owner takes, though, depends on NDE results and involves risks associated with either not identifying defective components or mislabeling components defective when they are not. Nuclear power plants, because of their unique circumstances, must pay costs for these types of errors that far exceed those in other industries. This paper depicts the framework for relating inspection capability to the economics of power plant operation.