Predicted performance of systems for Bulk Soil Assay, Barrel Inspection, and Decommissioning

In this project performances are predicted for new neutron interrogation systems designed to detect pollutant elements, uranium and transuranics (TRU), and gamma-ray emitters for Bulk Soil Assay, Barrel Inspection, and Decommissioning problems in the DOE Environment Restoration program. These new systems, which are based on the associated-particle time-of-flight (APTOF) technology are expected to save up to four times their $1.00 per hour operating costs relative to their alternatives for these problems. The key component required for practical use of the APTOF technology is a small sealed-tube neutron-generator (STNG) that incorporates a position sensitive alpha detector used to sense the alpha particle associated with emission of a 14-MeV neutron in the (D,T) reaction. The STNG makes possible a unique Inelastic-Gamma Imaging and Spectroscopy (IGRIS) system which provides a coarse three-dimensional image of the densities of elements in a target. Additional measurement capabilities as Capture-Gamma Ray Spectroscopy (CGRS) carried out simultaneously with IGRIS, Passive (STNG off) Gamma Ray Spectroscopy (PGRS), and Gamma-Ray Coincidence Spectroscopy (GRCS) carried out simultaneously with IGRIS, CGRS, and PGRS. These measurements are complementary and synergistic with each other. For example, the imaging capability of IGRIS can be used to estimate neutron and gamma-ray attenuations to correct any of these measurements. Predicted minimum detectable levels (MDLS) for several elements and radionuclides were measured and are presented