Hercules and Wand: High-Sensitivity Waste Assay Systems for Verification of Low- Density Clean Waste at LANL
S. C. Myers
The High Efficiency Radiation Counter for Ultimate Low Emission Sensitivity (HERCULES) and the Waste Assay for Nonradioactive Disposal (WAND) Systems are currently being used at the Los Alamos National Laboratory (LANL) to verify the absence of DOE-added radioactivity in low density wastes, such as paper and plastics. The two systems are believed to possess the greatest sensitivity available to detect the low-energy x-rays and gamma-rays associated with isotopes of plutonium, americium, and uranium. Minimum detectable concentrations achievable by both systems are generally less than 0.19 Bq per gram of low-density waste. The WAND system is operated by feeding low-density material onto a slow moving conveyor belt, which passes the waste under a bank of six well-shielded Phoswich detectors. The system software analyzes the radiation signals from four regions of interest (ROIs) in real time during consecutive 10 second assays. The HERCULES system performs 500-1000 second counts on waste that remains in its plastic bag or cardboard box. HERCULES consists of a single vertical array of three Phoswich detectors that are fixed adjacent to a rotating bag or box of low-density waste. The advantages and disadvantages of operating each system are discussed in the body of this report.
This abstract was presented at the 33rd Annual Midyear Meeting, "Instrumentation, Measurements, and Electronic Dosimetry", QA/QC Session, 1/30/2000 - 2/2/2000, held in Virginia Beach, VA.