Nondestructive Quantitative Analysis of Difficult-to-Measure Radionuclides ¹⁰⁷Pd and ⁹⁹Tc

Abstract

Considering the expanding demand for nuclear waste management of the spent nuclear fuel materials in near future, a nondestructive analytical scheme applicable to one of the most difficult-to-measure nuclides 107Pd, which emits no decay γ-rays and whose half-life is too long to be decayed out during a human lifetime, was designed. The scheme consists of a sophisticated instrument capable of the detection of γ-rays by Ge detectors coupled with time-of-flight measurement of neutrons and a high-intensity pulsed neutron beam and can simultaneously perform time-of-flight-coupled prompt γ-ray analysis (TOF-PGA) as well as PGA and neutron resonance capture analysis (NRCA). The analytical capability for simulated samples of the Tc–platinum group metals (Tc-PGMs) obtained by the group-partitioning process of spent nuclear fuels, which contain not only 107Pd but also 99Tc and other difficult-to-measure fission products, was evaluated. It was confirmed that although PGA and NRCA can accurately analyze both nuclides in individual, single substances, only TOF-PGA can analyze 107Pd as well as 99Tc in the Tc-PGM-simulated sample. The TOF-PGA measurement technique can be widely used for the nondestructive analysis of 107Pd and 99Tc in nuclear wastes.

Interrogating a Mixed Actinide Basket Using High-Resolution γ-Ray Spectrometry: A Nuclear Forensic Perspective on Possible Smuggling Scenarios

“…Among them, a quick and reasonable estimate of the amount of nuclear (fissile) material present in a package under custody would aid in making an “on-site” conclusion on the severity and the radiological threat associated with the diversion, which has significant credence on the immediate legal actions and further proceedings. Nuclear nondestructive techniques such as gamma-ray spectrometry, neutron counting, and calorimetry, which fall under the category of the radiometric assay, are very useful for elemental and isotopic quantification. − The chemical aspects need to be considered while doing the radiometric assay. For example, quantification of radioisotopes using γ-rays would require careful consideration of the atomic number of the elements present within the sample to account for attenuation of the γ-rays in the sample.…”