Chemistry Reference
In-Depth Information
Solvent
DMDOHEMA
HDEHP in HTP
3
Solvent
1
xtraction
8
1
Mo, Pd strip. 8
Feed
26 mL/h
Citric acid
pH
Aam < 0.04%-Cm 0.24%
Ru 96%
TMAOH
Mo>99% - Pd > 99%
Ru 4%
Am, Cm < 0.03%
Solvent
9
1 Lm, Y strip. 8
1
Zr, Fe strip. 8
1
An stripping
16
HEDTA
Citric acid
pH
Zr-Fe
> 99%
HNO
3
HNO
3
Oxalic acid
Ln-Y
> 99.9%
Am > 99.9% - Cm > 99.7%
Eu 0.04% - Nd 0.15%-
other Ln < 0.1%
Pd 0.5%-Ru < 0.01%
FIGURe 3.26
DIAMEX-SANEX/HDEHP process flowsheet tested at the CEA Marcoule
on a genuine PUREX raffinate. (Courtesy of Madic, C., Lecomte, M., Baron, P., Boullis, B.,
Compte-Rendu de Physique
, 3, 797-811, 2002.)
•
The Ln(III) are back-extracted in 1 M nitric acid
•
Zr and Fe are finally stripped by an acidic oxalic solution
The concept feasibility of this process was first validated by the successful imple-
mentation of an inactive countercurrent test using 48 stages of laboratory-scale mix-
er-settlers (6 mL mixing chamber and 17 mL settling chamber) in the G1 facility
at the CEA Marcoule. This inactive test was followed by a countercurrent hot test
in 2000, performed on a genuine highly active PUREX raffinate in the hot cells
of the ATALANTE facility (
3, 147, 246
). The flowsheet was implemented in two
sequences of approximately 6 hours each, as only 32 miniature centrifugal contac-
tors were available in the hot cells:
1. Extraction (eight stages), Mo and Pd stripping (eight stages), and An(III)
stripping (16 stages)
2. Ln(III) and Y(III) stripping (eight stages), and Zr and Fe stripping (eight
stages)
The main results of this hot test can be summarized as follows:
•
Satisfactory hydrodynamic behavior
•
High recovery yields for An(III):
>99.9% for Am(III) and >99.7% for
Cm(III) (0.2% of Cm(III) remained in the raffinates, but this should be
improved by two additional stages in the extraction section)
Satisfactory An(III)/Ln(III) DFs: DF
•
An/Ln
> 800 (less than 2 wt% of Ln(III)
in the An(III) product solution)
