Profile of a successful life-extension program

The presentation will discuss the preparation, development, confirmation, performance and aftermath of a successful inservice inspection for life-extension. The equipment had been designed and constructed during the mid-fifties with a design life of between 20--25 years. The inspection for life-extension of a steam generator, a pressurizer and a reactor vessel was performed during 1982--1983. The development of test specimen blocks containing fatigue cracks of various sizes and locations was critical to evaluating competing ultrasonic techniques and procedures. The development and confirmation phases resulted in the use of several advanced ultrasonic techniques being used during the inspection. High gain/high resolution and multiprobe transducer configurations, procedures and techniques were used during the examination phases, while all ultrasonic indications were investigated using tip diffraction characterization procedures during the evaluation. As a result of this experience, several additional advances and programs were initiated, resulting in further improvements to the ultrasonic inspection programs used both inservice and in manufacturing of pressure vessels. The following is an accounting of what the author believes to be the first, and perhaps only, inservice inspection of a reactor and related equipment for the purpose of life extension. This report tells many of the details, problems, tribulations and success associated with the inspection and the resulting improvements