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- Aneheim, Emma, 1982, et al.
(författare)
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A TBP/BTBP-based GANEX Separation ProcessPart 2: Ageing, Hydrolytic, and Radiolytic Stability
- 2011
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Ingår i: Solvent Extraction and Ion Exchange. - : Informa UK Limited. - 0736-6299 .- 1532-2262. ; 29:2, s. 157-175
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Tidskriftsartikel (refereegranskat)abstract
- The waste from nuclear power plants worldwide has to be isolated from man and his environment for about 100,000 years to equal the levels of natural uranium. If, however, the long-lived actinides could be separated from the spent fuel and transmuted, then the isolation time could be shortened to about 1,000 years. This does, however, require the selective separation of the actinides from the rest of the waste. Several processes exist for such a separation, of which one is the Group ActiNide Extraction (GANEX) process. A novel GANEX process has been developed at the Chalmers University of Technology utilizing the properties of already well known extractants by combining BTBP and TBP into one solvent. The stability provided by this GANEX solvent towards ageing, hydrolysis, and radiolysis has been investigated. The results show that the actinide distribution ratios are maintained after a long duration of contact with strong nitric acid. The solvent has also been found to be stable towards radiolysis up to 200 kGy in contact with 4 M nitric acid.
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| 3. |
- Aneheim, Emma, 1982, et al.
(författare)
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Fission product interactions with nitrogen donor ligands used for spent nuclear fuel treatment
- 2013
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Ingår i: Polyhedron. - : Elsevier BV. - 0277-5387. ; 50:1, s. 154-163
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Tidskriftsartikel (refereegranskat)abstract
- The so called BTBP (bis-triazine bi-pyridine)-type molecules have been developed for liquid-liquid extraction in the advanced reprocessing of used nuclear fuel. One solvent composition that has proven to be promising for such an application is the combination of CyMe4-BTBP and tri-butyl phosphate (TBP) in cyclohexanone. This solvent can extract the actinides successfully but unfortunately some fission products are also co-extracted. One of the most problematic fission products is palladium, but silver and cadmium are also extracted by the proposed solvent, which has been investigated here. In this study it was found that CyMe4-BTBP in cyclohexanone, when extracting palladium from nitric acid, forms complexes that are soluble both in the organic and aqueous phase. The predominant complex observed in both phases established with mass spectrometry and confirmed by NMR is a 1:1 complex, contrary to silver that forms 2:2 complexes and cadmium that forms 1:2 complexes. The nitrate dependency of the palladium extraction from nitric acid into a BTBP containing organic phase was found to be two. However, with higher ionic strengths, such as under process conditions, the palladium was found to be salted out into the organic phase.
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| 4. |
- Fermvik, Anna, 1978, et al.
(författare)
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Radiolysis of C5-BTBP in cyclohexanone irradiated in the absence and precence of an aqueous phase
- 2012
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Ingår i: Radiochimica Acta. - : Walter de Gruyter GmbH. - 0033-8230 .- 2193-3405. ; 100:4, s. 273-282
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Tidskriftsartikel (refereegranskat)abstract
- Spent nuclear fuel contains many highly ra-dioactive species; hence solvents used in reprocessing willbe subjected to radiolysis. In this study, solvents containingone of the BTBP molecules intended for the separation oftrivalent actinides and lanthanides, the so called C5-BTBP,have been subjected to radiolysis and hydrolysis. We presenthere that this compound shows a dramatic decrease in bothdistribution ratios and separation factor when irradiated withhigher doses up to 50 kGy; particularly in the presence ofan aqueous phase. Furthermore, fast hydrolytic degradation isobserved, which significantly contributes to the overall degreeof decomposition. This is supported by speciation studies per-formed by HPLC and LC-MS methods. Proposed structuresof the highest-yield degradation products are presented andthey seem to confirm previously drawn structures for theseproducts. From these studies it can be concluded that thepresence of nitric acid or nitrate during irradiation leads tohigher content of species containing keto groups.
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