A neutron monitor for in-situ real-time determination of transuranics in aprocessed waste effluent stream

A pilot plant operation at the Savannah River Site will remove Sr-90, Cs-13 7, and transuranics from a high-level liquid waste stream prior to encapsul ation in a Saltstone Facility. Monitors are required to determine the conce ntrations of all radionuclides, including transuranics, in real-time on thi s processed waste stream. A neutron counter used to measure the concentrati on of each actinide isotope present in the stream is described. The neutron counter assembly consists of nested annular layers of shielding, reflector s, detectors, and moderators. On-line, live-time system control and calibra tion is provided by a time-tagged neutron source embedded in the moderator assembly.