Moisture measurement for radioactive wastes using neutron activation of copper

Laboratory tests have demonstrated the use of neutron activation of copper to measure the moisture in radioactive wastes. Neutrons from a source scatter and return to activate the copper in the probe, the amount of activation varying with moisture content. A low-background spectrometer counts the gamma rays from activated 64Cu. The calibration of count rate vs moisture was measured with waste simulants of three moisture contents (15%, 20% and 25% by weight). The technique can also measure the neutron flux from spontaneous fission of actinide nuclides and neutrons from (α, n) reactions on light elements.