WASTE CHARACTERIZATION USING APSTNG TECHNOLOGY

摘要

The associated-particle sealed-tube neutron generator (APSTNG) interrogates the inspected object with 14-MeV neutrons generated from the deuterium-tritium reaction and detects the alpha-particle associated with each neutron inside a cone encompassing the region of interest. Gamma-ray spectra from resulting neutron reactions inside the inspected volume identify fissionable materials and many nuclides. Flight-times determined from detection times of the gamma-rays and alpha-particles separate the prompt and delayed gamma-ray spectra and can yield coarse tomographic images from a single orientation. The high-energy neutrons and gamma-rays penetrate large objects and dense materials. The gamma-ray detector and neutron generator can be located on the same side of the interrogated object, so walls and other confined areas can be inspected, as well as sealed containers. No collimators or radiation shielding are needed, the neutron generator is relatively simple and small, and commercial-grade electronics are employed. A complete system could be transported in an automotive van. Laboratory experiments and limited field tests indicate APSTNG technology could be useful in characterizing radioactive waste in drums, walls, soils, and processing systems, particularly for unknown or heterogeneous configurations that may significantly attenuate radiation. Also, toxic chemicals could be identified that would help classify the radwaste as to mixed waste content, and the ability to detect pockets of water may address criticality concerns.