Simultaneous quantitative analysis of 3H and 14C radionuclides in aqueous samples via artificial neural network with a liquid scintillation counter.

Liquid scintillation counters are common instruments used in the measurement of pure beta-emitting radionuclides, and while they represent a conventional radiometric technique, they are still competitive for their potential to measure multiple radionuclides simultaneously. In this work, we propose an algorithm based on an artificial neural network (ANN) for the simultaneous analysis of the beta-ray spectra of 3H and 14C in dual beta-labeled samples using a liquid scintillation counter. We achieved percentage deviations below 5.0% using the proposed algorithm in 16 out of 18 cases, with RMSDs below 1.5% in 17 out of 18 cases. The trained ANN also produced activity ratios with high accuracy even while having to deal with highly fluctuating spectra. Results demonstrate that the rapid predictions with a short measurement time from our proposed ANN method are compatible with the calculated ones from previous studies that were obtained with long measurement times.

Material mixture solution analysis by a hybrid L-edge/L-XRF densitometer.

The hybrid L-edge/L-XRF densitometer (HLED) was developed for determining the concentrations of nuclear materials in solutions by combination of two complementary assay techniques, L-edge densitometry (LED) and X-ray fluorescence (XRF). In this study, nonradioactive surrogate material mixture solutions (gold as a major analyte and lead as a minor analyte) were evaluated for feasibility for the multi-element nuclear material assay by hybrid analysis of LED and L-XRF, and the major analyte was characterized using L-edge densitometry. The exponential calibration method of material mixture solution for L-XRF is proposed considering the total density with matrix effects. The method was verified through analysis of uncertainties, biases and comparison with International Target Value (ITV).

Development of a prototype hybrid L-edge/L-XRF densitometer for nuclear fuel assay.

The hybrid L-edge/L-XRF densitometer (HLED) was developed for on-site nuclear fuel assays intended for safeguards purpose. The HLED can simultaneously measure both X-ray photon transmissions and characteristic X-ray emissions, which characterizes the elemental composition of samples of interest to determine the concentration of actinide-bearing materials, such as plutonium and uranium, in a nuclear fuel. A prototype of the HLED equipment was fabricated and tested to study the feasibility of nuclear material assays using a surrogate material (lead) to avoid radiation effects from nuclear materials. The uncertainty of the L-edge and L-XRF characteristics of the sample material are discussed in the article.