Recovery of trivalent minor actinides (MA) and of all transuranium elements (TRU) from highly active raffinate could be achieved with i-SANEX (innovative Selective ActiNide EXtraction) and GANEX (Grouped ActiNide EXtraction) processes respectively. All chemicals involved in the partitioning of highly radioactive fuel solutions have to be resistant towards radiation, since radiolysis can have a huge impact on system safety and performances. In this work, two innovative hydrophilic complexing agents, 2,6-bis[1-(propan-1 -ol)-1,2,3-triazol -4- y1)]pyridine (PyTri-Diol) and 2,6-bis[1-(propan-1,2-diol)-1,2,3-triazol-4-yl))pyridine (PyTri-Tetraol) , have been investigated as they proved to have high selectivity for actinides. In particular, the radiolytic stability of the stripping solvents was studied after irradiation up to 200 kGy with 6°Co sources. For this purpose, HPLC and ESI-MS (coupled with HPLC) analyses were performed on irradiated PyTri-Diol solutions to quantify the ligand consumpt ion and identify the main ligand by-products. Exceptional ligand stability towards radiolysis was assessed and further confirmations were achieved by UV-vis and NMR. Moreover, in order to verify whether gamma irradiation affects ligand performance, batch liquid-liquid extraction tests were performed. Irradiated stripping solutions were contacted with fresh TODGA-based organic phases previously loaded from different feeds, conveniently spiked with trace amounts of MA, TRU and lanthanides representatives.
Effects of gamma irradiation on innovative stripping solvents for i-SANEX/GANEX processes
Walter Panzeri;
2016
Abstract
Recovery of trivalent minor actinides (MA) and of all transuranium elements (TRU) from highly active raffinate could be achieved with i-SANEX (innovative Selective ActiNide EXtraction) and GANEX (Grouped ActiNide EXtraction) processes respectively. All chemicals involved in the partitioning of highly radioactive fuel solutions have to be resistant towards radiation, since radiolysis can have a huge impact on system safety and performances. In this work, two innovative hydrophilic complexing agents, 2,6-bis[1-(propan-1 -ol)-1,2,3-triazol -4- y1)]pyridine (PyTri-Diol) and 2,6-bis[1-(propan-1,2-diol)-1,2,3-triazol-4-yl))pyridine (PyTri-Tetraol) , have been investigated as they proved to have high selectivity for actinides. In particular, the radiolytic stability of the stripping solvents was studied after irradiation up to 200 kGy with 6°Co sources. For this purpose, HPLC and ESI-MS (coupled with HPLC) analyses were performed on irradiated PyTri-Diol solutions to quantify the ligand consumpt ion and identify the main ligand by-products. Exceptional ligand stability towards radiolysis was assessed and further confirmations were achieved by UV-vis and NMR. Moreover, in order to verify whether gamma irradiation affects ligand performance, batch liquid-liquid extraction tests were performed. Irradiated stripping solutions were contacted with fresh TODGA-based organic phases previously loaded from different feeds, conveniently spiked with trace amounts of MA, TRU and lanthanides representatives.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
