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Complexes cesium-actinide

In the second project, gathering nine teams from six EC countries, more than 150 new extractants were prepared and studied, and the target was reached for the decategorization of waste. Dialkoxy calix[4]arene-crown-6 for cesium, octaamide calix[8] arenes, and CMPO-like calixarenes for actinides display much higher complexing and extracting abilities than other classical extractants, crown ethers, or dicarbollides proposed and sometimes used for this purpose. [Pg.202]

Distribution ratios and transport were carried out on real HAW arising from dissolution of a mixed oxide of uranium and plutonium (MOX) fuel (burnup 34,650 MW d/tU), where uranium and plutonium have been previously extracted by TBP.86 The experiments were performed in the CARMEN hot cell of CEA Fontenay aux Roses with two dialkoxy-calix[4]arene-crown-6 derivatives (diisopropoxy and dini-trophenyl-octyloxy). High cesium distribution ratios were obtained (higher than 50) by contacting the HAW solution with diisopropoxy calix[4]arene-crown-6 (0.1 M in NPHE). Moreover, the high selectivity observed with the simulated waste was confirmed for most of the elements and radionuclides (actinides or fission products Eu, Sb, Ce, Mo, Zr, and Nd). The residual concentration or activity of elements, other than cesium, was less than 1% in the stripping solution, except for iron (2%) and ruthenium (8%) the extraction of these two cations, probably under a complexed... [Pg.229]

In the early 1990s, there existed several classes of extractants for actinides (CMPO), for cesium and more generally alkali cations, and for strontium and alkaline earth cations (crown ethers and cosan). The combination of these extractants and the grafting of these functions on calixarene platforms have led to new classes of extremely efficient and selective extractants, in particular calixarene-crown, which are presently applied in the United States to treat the huge amounts of waste at the SRS. Calixarenes/ CMPO, crown ethers/cosan, CMPO/cosan, and more recently calixarenes/CMPO/ cosan are promising compounds. It is desirable that these studies, conducted at the international level, continue in particular to obtain a better understanding of the complex mechanisms of extraction of these compounds.127187... [Pg.285]


See other pages where Complexes cesium-actinide is mentioned: [Pg.217]    [Pg.98]    [Pg.217]    [Pg.202]    [Pg.217]    [Pg.3025]    [Pg.681]    [Pg.390]    [Pg.264]    [Pg.571]    [Pg.370]   
See also in sourсe #XX -- [ Pg.337 ]




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