Development of a Fiber Optically Coupled Raman Video Probe for the Non-Destructive Inspection of Concrete in Light Water Reactors

Concrete is widely used in light water reactor (LWR) constructions as building foundation and support, shielding material and for radiation containment. The importance of concrete in providing protection to LWR structures are found in the containment building, spent fuel pool and cooling towers. The integrity of construction materials like concrete is an important consideration and concern for LWR facilities since degradation of these structural materials can lead to costly maintenance and downtime and also increases the risk of safety. The cause of concrete deterioration can be attributed mainly to chemical attack from chemicals present in the concrete or environment that can lead to chemical changes in the concrete over time. Technologies that can assess the integrity of LWR structures and provide means to mitigate the degradation of reactor structures will help prolong reactor life and diminish the risks of structural failure. A portable, nondestructive assessment (NDA) Raman spectroscopy instrumentation and fiber optically coupled sampling probes with microscopic imaging will be developed. The Raman probe is used to obtain Raman spectra and petrographic image of not only the surface of the concrete structures, but also depth profiles using smallholes drilled into the structure. These data will be used to assess the onset or presence of chemical corrosion in the concrete structure. Commercial Applications and OtherBenefits: The principal market for the NDA Raman tool is in inspection of civil engineering structures. As the current program is focused on concrete aging in light water reactors, likely customers include the NRC as instrumentation provided to their regional inspectors. In addition, operators of the nearly 450 nuclear reactors worldwide are potential customers for instruments to conduct their own periodic in-house inspections.