Structural Health Monitoring of the Dry Cask Storage of Nuclear Fuels Using P.W.A.S. Research
Managing spent nuclear fuel is not an easy task. Since exhausted nuclear fuel cannot be immediately disposed of, one primary alternative is Dry Cask Storage. The fuel is instead contained for long periods of time, until its harmful aspects have dissipated. The major concerns are the substantial decay heat and radiation given off by the spent fuel, and the effects they have with the containers; which are typically steel. Maintaining the structural integrity of the storage casks is of utmost importance due to the radiological hazards present if it were to be compromised. A serious cause for concern arises, where the health of the casks, and any potential damage or failures, need to be continuously monitored. An isolated pressure boundary, added to the decay heat and radiation flux from the fuel, create a complex environment for many methods of observation. The proposed solution, is Piezoelectric Wafer Active Sensors, or P.W.A.S.
P.W.A.S., quite simply, are transducers. An energy input from one source is converted to a different type
of energy then exits. For the P.W.A.S. in this application, the conversion is either an electrical to elastic-mechanical impulse, or vice versa. The sensors are first attached to the walls of the Dry Cask Storage containers. The P.W.A.S. can then detect any cracks or other types of failures in the steel, plus, provide diagnostics via electrical output. A change in the output signal indicates a distortion in structural composition. The sensors have been found to withstand the necessary temperatures from the decay heat flux. However, finding an appropriate radiation source for this research has been problematic. A suitable source has been found and I can provide more updates in the near future.