The research proposed under this effort is focused on addressing the need for improved real-time in-situ sensing approaches for monitoring radionuclide contamination in the soils surrounding waste disposal facilities. Specifically this proposal focuses on the development of an approach for detecting technetium-99, which is a major risk driver at the Hanford site. The sensing approach that is proposed will also detect other beta-emitting radionuclides and therefore will address characterization and monitoring needs for strontium-90 and other beta-emitting particles. The objective of the proposed research is to establish the feasibility of a method for detecting beta-emitting isotopes of technetium-99, strontium-90 and yttrium-90 in soil at concentrations on the order of 100 pCi/gm; the method should be suitable to be implemented for in-situ monitoring in sub-surface soils. Specifically, in Phase I we will experimentally fabricate and demonstrate a wireline CPT -sized integrated beta and gamma sensor for characterization of radiologically contaminated soils with both gamma and beta emitters. This will provide the basis for improved development and field testing of the sensor for 99Tc detection in Phase II. The technical approach proposed involves integrating a well-designed beta spectroscopy sensor with a gamma detecting crystal, which can be deployed using wireline Cone Penetrometer Technique (CPT) during retraction of the rods. The new sensor will extend beyond the end of the CPT rods during removal from the penetration, permitting the beta sensor to be in direct contact with the soil and make a complete, real time profile of the soil contamination as the rods are retracted. Commercial Application: The development of the proposed sensing approach will lead to significant cost savings for characterizing and monitoring subsurface soils for radioactive waste contamination. By utilizing the Cone Penetrometer Technique for deployment, the sensor will be able to provide real-time continuous profiles of the contaminated soil layers. In addition, less drilling waste and also less worker exposure will occur when fielding applications are conducted using this innovative approach as compared to traditional drilling and sampling techniques.
