A portion of ATM-109 fuel was removed from its cladding, dissolved in concentrated nitric acid, filtered, and partially evaporated. The equal ali­quots of the dissolved fuel solution were diluted to the same volume by the variable nitric acid solutions to adjust uranium concentration to approxi­mately 0.7 M and the acid strength to 0.3, 1.3, 2.5, 3.8, and 5.1 M to mimic the feed stream for a PUREX or UREX process in uranium concentration and provide a range of acid variations that might occur in the feed stream. The uranium and other fuel component concentrations remained the same in each sample, regardless of the acid strength.

Using a batch technique for the first stage of the PUREX process, the acid-adjusted aqueous solutions were contacted with equal volume of a 30 vol% TBP/n-dodecane solvent. The mixtures were allowed to reach an

4.10 Raman spectra of (A) ATM-109 BWR commercial fuel 0.3 M HNO3 feed, raffinate, and simple feed simulant solution (1.33 M uranyl nitrate in 0.8 M HNO3); and (B) TBP-dodecane extraction solutions of ATM-109 feed and simple feed simulant solutions.

equilibrium distribution; then, the phases were separated. The feed, raffinate, and extract samples were subjected to spectroscopic analysis as described in the next section.