Groundwater contamination from 90Sr is an environmental challenge posed topresent and former seat back nuclear weapons related sites.Traditional methods of extractinggroundwater samples and performing laboratory analyses are expensive, time-consumingand induce significant disposal challenges.The authors present here a prototype countercapable of measuring 90Sr groundwater concentrations in-situ at or below the drinking waterlimit of 8 pCi/liter.The 90Y daughter of 90Sr produces high-energy electrons, which cancreate Cerenkov light.
Photomultiplier tubes convert the Cerenkov light into an electronicpulse, which then undergoes signal processing with standard electronics.Strontium-90concentrations near the drinking water limit can be measured in a matter of hours if it is insecular equilibrium with Grinders the 90Y daughter.The prototype counter is compact, can bedeployed in an American Standard 6-inch, well while operated by a single person, andtransmits the results to a central monitoring location.