The costs for inspecting nuclear power plant piping are growing as plants age, due to increasing requirements. The way in which inspections are done at present requires the removal of the insulation, the layout of a grid on the region of interest, and then the manual placement of a transducer on each grid point for a thickness measurement. This takes a considerable amount of time during which the operator is exposed to radiation. Estimated costs are $2,000 to $10,000 per location. As well, thinning occurring between grid points may be missed. A technique, based on Lamb wave tomography, has potential to reduce costs by obviating the need to remove insulation, and speeding up the data taking process by electronic switching. As well, the method provides images that contain data that might have fallen between grid points in the manual method.