In-situ, long-term monitoring system for radioactive contaminants

This report presents the results of the first phase of the project entitled ''In-situ, Long-term Monitoring System for Radioactive Contaminants.'' Phase one of this effort included four objectives, each with specific success criteria. The first objective was to produce dosimetry grade fibers and rods of aluminum oxide. The success criterion for this milestone was the production of aluminum oxide rods and fibers that have a minimum measurable dose (MMD) of 100 mrem or less. This milestone was completed and the MMD for the rods was measured to be 1.53 mrem. Based on the MMD, the ability of the sensor to measure sup 1 sup 3 sup 7 Cs, sup 9 sup 0 Sr/ sup 9 sup 0 Y, and sup 9 sup 9 Tc was evaluated. It was determined that the sensor can measure the release limit of these radionuclides (50 pCi/cm sup 3) in 150 h, 200 h, and 54,000 h, respectively. The monitor is adequate for measuring sup 1 sup 3 sup 7 Cs and sup 9 sup 0 Sr/ sup 9 sup 0 Y but is unsuitable for measuring sup 9 sup 9 Tc in soil. The second objective was to construct a prototype sensor (dosimeter and fiber optic channel). There were three success criteria for this milestone: (1) Perform measurements with the sensor for both gamma and beta radiation with a standard deviation of 10% or less; (2) Demonstrate the ability of the sensor to discriminate between gamma and beta radiation; and (3) Obtain similar or relatable results for differing lengths of fiber optic cable. These milestones were met. The sensor was able to measure gamma radiation repeatedly with a standard deviation of 3.15% and beta radiation with a standard deviation of 2.85%. Data is presented that demonstrates that an end cap can be used to discriminate between beta plus gamma radiation using beta radiation from a sup 9 sup 0 Sr/ sup 9 sup 0 Y source, and gamma radiation alone...