Monitoring thermal fatigue damage in nuclear power plant materials using acoustic emissionProceedings of SPIE (2012)
Proactive aging management of nuclear power plant passive components requires technologies to enable monitoring and accurate quantification of material condition at early stages of degradation (i.e., pre-macrocrack). Acoustic emission (AE) is well-suited to continuous monitoring of component degradation and is proposed as a method to monitor degradation during accelerated thermal fatigue tests. A key consideration is the ability to separate degradation responses from external sources such as water spray induced during thermal fatigue testing. Water spray provides a significant background of acoustic signals, which can overwhelm AE signals caused by degradation. Analysis of AE signal frequency and energy is proposed in this work as a means for separating degradation signals from background sources. Encouraging results were obtained by applying both frequency and energy filters to preliminary data. The analysis of signals filtered using frequency and energy provides signatures exhibiting several characteristics that are consistent with degradation accumulation in materials. Future work is planned to enable verification of the efficacy of AE for thermal fatigue crack initiation detection. While the emphasis has been placed on the use of AE for crack initiation detection during accelerated aging tests, this work also has implications with respect to the use of AE as a primary tool for early degradation monitoring in nuclear power plant materials. The development of NDE tools for characterization of aging in materials can also benefit from the use of a technology such as AE which can continuously monitor and detect crack initiation during accelerated aging tests.
Citation InformationR. M. Meyer ; P. Ramuhalli ; B. E. Watson ; S. G. Pitman ; T. J. Roosendaal and L. J. Bond "Monitoring thermal fatigue damage in nuclear power plant materials using acoustic emission", Proc. SPIE 8347, Nondestructive Characterization for Composite Materials, Aerospace Engineering, Civil Infrastructure, and Homeland Security 2012, 83470D (April 26, 2012); doi:10.1117/12.915458;.