skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Purification of alkaline solutions and wastes from actinides and technetium by coprecipitation with some carriers using the method of appearing reagents: Final Report

Technical Report ·
DOI:https://doi.org/10.2172/663471· OSTI ID:663471
; ; ; ; ; ; ; ;  [1]
  1. Russian Academy of Sciences, Moscow (Russian Federation). Inst. of Physical Chemistry

The coprecipitation of transuranium elements (TRU) and technetium from alkaline solutions and from simulants of Hanford Site tank wastes has been studied in reducing and oxidizing conditions on uranium(IV,VI) hydroxocompounds, tetraalkylammonium perrhenate and perchlorate, and on hydroxides of Fe(III), Co(III), Mn(II), and Cr(III) using the method of appearing reagents (MAR). Coprecipitations in alkaline solution have been shown to give high decontamination factors (DF) at low content of carrier and in the presence of high salt concentrations. Uranium(IV) hydroxide in concentrations higher than 3 {times} 10{sup {minus}3} M coprecipitates Pu and Cm in any oxidation state from 0.2 to 4 M NaOH with DFs of 110 to 1000 and Np and Tc with DFs of 51 to 176. Technetium (VII) coprecipitates with (5 to 8) {times} 10{sup {minus}4} M tetrabutylammonium (TBA) perrhenate in 0.01 to 0.02 M TBA hydroxide from 0.5 to 1.5 M NaOH to give DFs of 150 to 200. Coprecipitations of Np and Pu with Co(OH){sub 3}, Fe(OH){sub 3}, Cr(OH){sub 3}, and Mn(OH){sub 2} obtained by the MAR from precursors in the range from pH 10.5 to 0.4 M NaOH give DFs from 80 to 400.

Research Organization:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Organization:
USDOE Office of Environmental Restoration and Waste Management, Washington, DC (United States)
DOE Contract Number:
AC06-76RL01830
OSTI ID:
663471
Report Number(s):
PNNL-11988; R&D Project: 26743; ON: DE98059329; BR: EW4030; TRN: 99:000799
Resource Relation:
Other Information: PBD: Sep 1998
Country of Publication:
United States
Language:
English