Remote Detection of Leaks in High Level Waste Storage Tanks

The purpose of this research was to characterize three devices potentially capable of remotely detecting signatures of a leak from high-level waste (HLW) storage tanks, specifically ones found at the Savannah River Site and the Hanford Site. The hazard HLW found within these tanks include 137Cs, a gamma-ray emitter, and 90Sr, an electron emitter leading to heat generation. These pose health risks to the personnel and maintenance problems and environmental safety issues if released to the environment. Additionally, pinpointing the location of a leak is a task that could lead to the mitigation of excess waste leaking from the tank. There were three objectives of this work, each associated with its respective leak detection device. The first objective was to validate a Kromek CZT gamma spectrometer by measuring sealed 137Cs sources with various activity levels. The second objective was to use a FLIR Duo-R thermal camera to image heated metal objects of varying shapes to highlight how a hotspot stands out against a cooler background in thermal imaging. The third and final objective was using a Roga Instruments iSV1611 USB ultrasonic microphone to measure high frequency noises that would be associated with pressurized gas or a liquid leaking from a crack in a tank. Testing each device set a benchmark for accuracy that can be scaled to larger scale experiments and field work. The experiments completed with these devices provided accurate data used to characterize them to be used in the field. The gamma spectrometer data was compared to known data of 137Cs emissions, and the microphone measured known frequency emissions with extreme accuracy. The thermal camera provided the data numerically, but visually provided great indication of the desired hotspots. The data acquired allowed for a conclusion to be made on the accuracy of these devices to be used to detect a leak in a HLW tank. Future work considered would be large scale experiments and field applications.