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Abstract  

The alkaline synthesis of porous phenol-formaldehyde polymers containing iminodiacetic acid is described. Porosity is induced by the addition of a finely divided solid material (template) that is insoluble under the reaction conditions. This template is removed by dissolution after the polymerization is complete. Silica gel, carbonate salts and various other salts are used as templates. Resins containing different phenols are synthesized and their effectiveness for the removal of radioactive cesium and strontium from alkaline concentrated sodium salt brines is examined. This matrix typifies the composition of soluble defense nuclear waste.

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Abstract  

The effect of a number of synthetic variables on the affinities of resorcinol-formaldehyde-iminodiacetic acid resins for137Cs and90Sr was determined. Porosity was introduced into the resins by inclusion of CaCO3 as a solid template during the synthesis. Among the variables examined were reaction temperature, reactant ratio, choice of basic catalyst, and amount of added template. Only reaction temperature was found to have a clearly defined influence on affinity. Cesium-137 affinity increased with increasing reaction temperature. Affinity for90Sr was independent of reaction temperature below reflux temperature, but dropped drastically for resins synthesized at reflux. These results are explained mechanistically. The reproducibility of the resin synthesis is also examined.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: R. L. Brodzinski, R. A. Craig, S. D. Fink, W. K. Hensley, N. O. Holt, M. A. Knopf, E. A. Lepel, O. D. Mullen, S. R. Salaymeh, T. J. Samuel, J. E. Smart, M. R. Tinker, and D. D. Walker

Summary  

An online monitor has been designed, built, and tested that is capable of measuring the residual transuranic concentrations in processed high-level wastes with a detection limit of 370 Bq/ml (10 nCi/ml) in less than six hours. The monitor measures the (α,n) neutrons in the presence of gamma-ray fields up to 1 Sv/h (100 R/h). The optimum design was determined by Monte Carlo modeling and then tempered with practical engineering and cost considerations. A multiplicity counter is used in data acquisition to reject the large fraction of coincident and highly variable cosmic-ray-engendered background events and results in an S/N ratio ~1.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: L. Tandon, E. Hastings, J. Banar, J. Barnes, D. Beddingfield, D. Decker, J. Dyke, D. Farr, J. FitzPatrick, D. Gallimore, S. Garner, R. Gritzo, T. Hahn, G. Havrilla, B. Johnson, K. Kuhn, S. LaMont, D. Langner, C. Lewis, V. Majidi, P. Martinez, R. McCabe, S. Mecklenburg, D. Mercer, S. Meyers, V. Montoya, B. Patterson, R. Pereyra, D. Porterfield, J. Poths, D. Rademacher, C. Ruggiero, D. Schwartz, M. Scott, K. Spencer, R. Steiner, R. Villarreal, H. Volz, L. Walker, A. Wong, and C. Worley

Abstract  

The goal of nuclear forensics is to establish an unambiguous link between illicitly trafficked nuclear material and its origin. The Los Alamos National Laboratory (LANL) Nuclear Materials Signatures Program has implemented a graded “conduct of operations” type analysis flow path approach for determining the key nuclear, chemical, and physical signatures needed to identify the manufacturing process, intended use, and origin of interdicted nuclear material. This analysis flow path includes both destructive and non-destructive characterization techniques and has been exercized against different nuclear materials from LANL’s special nuclear materials archive. Results obtained from the case study will be presented to highlight analytical techniques that offer the critical attribution information.

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