Study of nitrate complex formation with trivalent Pm, Eu, Am and Cm using a solvent extraction technique

Abstract

Summary The separation of actinides and lanthanides is an important question in the treatment of spent nuclear fuel in the transmutation concept. To find an efficient and well functioning separation process it is necessary to study the chemistry of the elements in the two groups in different aqueous media. The stability constants of the nitrate complex formation with Pm, Eu, Am and Cm were determined using solvent extraction. The extraction was studied using the synergistic system of 2,6-bis-(benzoxazolyl)-4-dodecyloxylpyridine and 2-bromodecanoic acid in tert -butyl benzene. As the nitrate ion concentration in the aqueous phase was increased, a decrease in separation between actinides and lanthanides was seen owing to complex formation between the different elements and the nitrate ions.