|Source:||Idaho National Engineering Laboratory|
|Date:||10/1/95 Record No.: 10256|
|Contact:||James Seydel, 208-526-6000|
INEL has extensive experience beginning with the operation of their own reactor facilities under conditions different from design, and extending to the Advanced Test Reactor, commercial plants, and oil refineries. The approach begins with a detailed review of all components and systems, followed by a prioritization based on importance (cost of repair, impact on safety and availability, etc.) The next phase examines all that is known about these components (operating history, records, NDE, etc.) and an analysis of possible failure mechanisms. When specific data is lacking, (e.g., for old materials), proxy data are sought. All degradation processes are considered (embrittlement, fatigue, corrosion, erosion, etc.), along with whatever processes were not considered in the original design.
The research approach to plant life extension involves:
- Quantify of fracture toughness as result of time-at-temperature
- Correlate changes in fracture toughness with NDE results or sample measurements
- Develop procedures for predicting end-of-life
- Establish weld repair practices for aged materials
- Develop NDE sensing techniques for use on-line (high temperature) and during scheduled maintenance to monitor aging materials, as noted earlier. They pioneered automated transducer systems in the 1970s, and commercialized the AMDATA system with EPRI in the 80s.
INEL has long experience with Lifetime Extension Sensors development; e.g., for on-line crack propagation, fracture toughness measurement, and large components and structures