Ammonium uranyl carbonate (AUC) based process of simultaneous partitioning and reconversion for uranium and plutonium in fast breeder reactors (FBRs) fuel reprocessing

Processing used nuclear fuel with nanoscale control of uranium and ultrafiltration

“…Manipulation of these materials on the nanoscale may allow for the replacement of complex chemical extraction with a simple, physical size-selective filtration method, resulting in the alleviation of many of the problems associated with currently utilized liquid-liquid extraction techniques. Our approach utilizes alkaline aqueous solutions with added peroxide, and builds upon earlier studies of broadly similar systems [14][15][16].…”

Development of a versatile sample preparation method and its application for rare-earth pattern and Nd isotope ratio analysis in nuclear forensics

“…Subsequently the precipitate was rinsed with high-purity water. Selective re-dissolution of uranium from the precipitate was done with 10 mL 1 % (NH 4 ) 2 CO 3 as uranium forms soluble di- and tri-carbonato complexes between pH 5–8 [ 15 ]. This step was repeated three to five times until clear solution was obtained assuring that U was removed from the sample to the highest extent possible.…”

Coprecipitation of actinide peroxide salts in the U–Th and U–Pu systems and their thermal decomposition

“…The secondary electron (SE) mode was used to examine sample morphology with magnifications in the range from 200× to 5000×. Energy dispersive X-ray spectroscopy (EDS) analyses through point spectra were 125( 25) 109( 11) 99 (10) Table 2 Experimental conditions of the U-Pu peroxide coprecipitation tests, along with the individual U and Pu precipitation yields (%) and slurry filtering rates (mg min −1 )…”

“…Coprecipitation methods are widely used for the preparation of mixed oxide constituting technological ceramics. Regarding the specific methods considered for MOx fuel, several routes were already investigated with great attention: the denitrification route 5,6 and hydroxide route, in fact the coprecipitation of ammonium diuranate and Pu(OH) 4 7,8 and its derivatives using hydroxylamine, 9 the carbonate route, 10 oxalate route, 11,12 peroxide route 13 and sol-gel methods. 14,15 Each of these coprecipitation methods, which has its own advantages (but also drawbacks), affords either mixed UO 2 -PuO 2 batches or fluorite based solid solutions for a wide range of concentrations, after an appropriate heat-treatment.…”