Rapid fusion method for the determination of refractory thorium and uranium isotopes in soil samples

Journal Article · Fri Feb 13 23:00:00 EST 2015 · Journal of Radioanalytical and Nuclear Chemistry

DOI: https://doi.org/10.1007/s10967-015-3972-1 · OSTI ID:1171511

Maxwell, Sherrod L. ^[1]; Hutchison, Jay B. ^[1]; McAlister, Daniel R. ^[2]

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1. Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)
2. PG Research Foundation, Lisle, IL (United States)

Recently, approximately 80% of participating laboratories failed to accurately determine uranium isotopes in soil samples in the U.S Department of Energy Mixed Analyte Performance Evaluation Program (MAPEP) Session 30, due to incomplete dissolution of refractory particles in the samples. Failing laboratories employed acid dissolution methods, including hydrofluoric acid, to recover uranium from the soil matrix. The failures illustrate the importance of rugged soil dissolution methods for the accurate measurement of analytes in the sample matrix. A new rapid fusion method has been developed by the Savannah River National Laboratory (SRNL) to prepare 1-2 g soil sample aliquots very quickly, with total dissolution of refractory particles. Soil samples are fused with sodium hydroxide at 600 ºC in zirconium crucibles to enable complete dissolution of the sample. Uranium and thorium are separated on stacked TEVA and TRU extraction chromatographic resin cartridges, prior to isotopic measurements by alpha spectrometry on cerium fluoride microprecipitation sources. Plutonium can also be separated and measured using this method. Batches of 12 samples can be prepared for measurement in <5 hours.

• Research Organization: Savannah River Site (SRS), Aiken, SC (United States)
• Sponsoring Organization: USDOE
• Grant/Contract Number: AC09-08SR22470
• OSTI ID: 1171511
• Report Number(s): SRNL-STI--2014-00628
• Journal Information: Journal of Radioanalytical and Nuclear Chemistry, Journal Name: Journal of Radioanalytical and Nuclear Chemistry Journal Issue: 2 Vol. 305; ISSN 0236-5731
• Publisher: SpringerCopyright Statement
• Country of Publication: United States
• Language: English