One substantial challenges in actinide separation science is associated with programmatic needs to isolate microscopic amounts (1010 atoms) of high purity (99.9999%) Np from macroscopic quantities (gram to kilogram) of U and Pu. There are additionally scenarios where microscopic amounts of Pu needs to be isolated from bulk uranium matrixes. These separations are complicated by quantity differences between the analyte (Np or Pu) versus the contaminate (U + Pu or U, respectively). Currently, programmatic methods rely on bulk extraction of Np using the thenoyltrifluoroacetone (TTAH) chelate (Figure 1). Unfortunately, the extraction is unreliable and generates large quantities of organic radioactive waste. When this extraction works, it is quite effective at selectively removing the desired actinide analyte from the bulk matrix. Hence the TTA extraction has become known in the community as the “best of the worst” solution to the AnIV/AnIV purification problems. This presentation will represents the first in a series of studies focused on advancing understanding of the TTAH extraction processes for +4 metal ions. Herein, we have rigorously characterized a series of MIV(TTA)4 (M = ZrIV, HfIV, CeIV, ThIV, UIV, NpIV, and PuIV) and MIII(TTA)41- (M = CeIII, NdIII, SmIII, and YbIII) coordination complexes. Although, Prasad and co-workers first prepared many of these compounds in 1966, numerous chemical properties were not characterized, such as their solid-state structure and solution-phase behavior. Our contribution will detail convenient methods to prepare the M(TTA)4x- (x = 0, 1) compounds. Additionally, we will discuss the using these M(TTA)4x- (x = 0, 1) compounds as standards to facilitate characterization the organic phase of an actual TTAH extraction of PuIV and NpIV into o-xylene from hydrochloric acid.

Improving extraction of +4 actinides

254th National Meeting (2017)

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