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  • Author or Editor: H. Ramebäck x
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Abstract  

A procedure for the analysis of90Sr,154Eu,237Np,239Pu,241Am and242−244Cm was developed. Separation was done with the separating agent, di-2(ethyl hexyl)-phosphoric acid (HDEHP), and results in fractions containing the different elements to be analysed.90Sr analysis was done by analysing its daughter nuclide90Y, detected through the Cherenkov radiation emitted by this high energy β-emitter.154Eu was detected using γ-spectrometry with a lower Compton background as a result of the removal of other fission products.241Am could also be detected with γ-spectrometry or together with242−244Cm with α-spectrometry. The long-lived radionuclides237Np and239Pu were detected using inductively coupled plasma mass spectrometry (ICP-MS).

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Abstract  

The possibility of using di-(2-ethylhexyl)-phosphoric acid (HDEHP) in solvent extraction for the separation of neptunium, plutonium, americium and curium from large amounts of uranium was studied. Neptunium, plutonium, americium and curium (as well as uranium) were extracted from HNO3, whereafter americium and curium were back-extracted with 5M HNO3. Thereafter was neptunium back-extracted in 1M HNO3 containing hydroxylamine hydronitrate. Finally, plutonium was back-extracted in 3M HCl containing Ti(III). The method separates238Pu from241Am for α-spectroscopy. For ICP-MS analysis, the interferences from238U are eliminated: tailing from238U, for analysis of237Np, and the interference of238UH+ for analysis of239Pu. The method has been used for the analysis of actinides in samples from a spent nuclear fuel leaching and radionuclide transport experiment.

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Abstract  

In radiological emergency, rapid determination of radiostrontium will be necessary. The required quantification levels will be relatively high which offers smaller sample sizes and shorter ingrowth and counting times. In this paper a rapid method for the determination of 90Sr in fresh milk in emergency preparedness is presented. The method is based on microwave digestion, chemical separation of Sr, ingrowth of 90Y and Cherenkov measurements. In order to minimize the total analysis time, a mathematical model was developed. For a given number of samples the model minimizes the analysis time by optimizing the ingrowth and counting time in order to reach a detection limit fit-for-purpose.

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Abstract  

The age of plutonium is defined as the time since the last separation of the plutonium isotopes from their daughter nuclides. In this paper, a method for age determination based on analysis of 241Pu/241Am and 240Pu/236Pu using ICP-SFMS is described. Separation of Pu and Am was performed using a solid phase extraction procedure including UTEVA, TEVA, TRU and Ln-resins. The procedure provided separation factors adequate for this purpose. Age determinations were performed on two plutonium reference solutions from the Institute for Reference Materials and Measurements, IRMM081 (239Pu) and IRMM083 (240Pu), on sediment from the Marshall Islands (reference material IAEA367) and on soil from the Trinity test site (Trinitite). The measured ages based on the 241Am/241Pu ratio corresponded well with the time since the last parent-daughter separations of all the materials. The ages derived from the 236U/240Pu ratio were in agreement for the IRMM materials, but for IAEA367 the determination of 236U was interfered by tailing from 238U, and for Trinitite the determined age was biased due to formation of 236U in the detonation of the “Gadget”.

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