Nondestructive Assay of Fissile Material Samples in Support of Nuclear Safeguards

Samples of fissile material can be assayed by bombarding with 300-to 600-keV neutrons and counting delayed neutrons from fission. Interrogating neutron energy selection is based upon considerations of sample penetrability and insensitivity of response to nonfissile isotopes. Significant cost savings in nuclear safeguards and quality control are possible.