Ultra-sensitive examination of environmental samples with SRL Underground Counting Facility

The ability to detect contaminants at very low-levels in environmental samples promises early identification and correction of harmful industrial practices. To achieve this capability, the Savannah River Laboratory Underground Counting Facility (SRLUCF) was developed. This paper appraises resulting improvements in detection sensitivity, and discusses recent applications. SRLUCF utilizes hardware and software customized for low-level counting. An uninterruptible power supply limits data losses. An MCA-coupled-IBM/PC-XT system collects HPGe, dual-coincidence NaI(Tl), and NaI(Tl) background spectra, which are analyzed by computer codes GRABGAM, GRABDUAL, and GRABNAI. These codes incorporate numerous efficiencies, integral peak-fitting, and comprehensive I/O-features. Spectral files may be transferred to any IBM-PC for further analysis. The facility improves detection sensitivity via extended counting times, background reduction, and improved detector efficiency. A constant background extends counting time from one to ten days