Tritium monitoring system for near ambient measurements

The authors describe the current status of research on an improved tritium measurement system at the Oak Ridge National Laboratory (ORNL) for the US Navy. Present tritium-in-air monitoring systems installed by the Navy can reliably measure to less than 10 μCi/m³, but medical and safety issues are pushing measurement needs to below 1 μCi/m³, which is equivalent to 1-10 μCi/ml in liquid samples, using calcium metal converter. A significant effort has been expended over the past 10 years by the Navy RADIAC development program at ORNL on various schemes to improve the detection of tritium in both air and liquid at near ambient levels. One such scheme includes a liquid flowthrough system based on an NE 102 sponge scintillator with dual photomultiplier tubes for tube noise rejection