Gamma radiolytic stability of the novel modified diglycolamide 2,2′-oxybis(N,N-didecylpropanamide) (mTDDGA) for grouped actinide extraction

Abstract

The radiolysis behavior of a new diglycolamide for solvent extraction of actinides and lanthanides was studied. The observed degradation rate was lower than for the reference molecule and 22 degradation compounds were identified.

Interinstitutional Study of the New EURO-GANEX Process Resistance by Gamma Irradiation Test Loops

“…This hypothesis should be confirmed by further experiments. All cis -mTDDGA DCs observed are in agreement with the studies performed by Verlinden et al , …”

“…From the results obtained in Figure , k ′ is 0.0023 kGy –1 for CIEMAT, 0.0018 kGy –1 for CEA, and 0.0011 kGy –1 for INL. The CIEMAT and CEA values are in agreement with the one obtained by Verlinden et al (0.0028 kGy –1 when 0.05 mol/L cis -mTDDGA is irradiated in contact with 2.5 mol/L HNO 3 ) . This is lower than the TODGA dose constant (0.0038 kGy –1 in ref , 0.0034 kGy –1 in ref , irradiating the organic phase with nitric acid aqueous phase in both studies), indicating the higher stability of cis -mTDDGA against radiolysis.…”

“…Figure shows the concentration of cis -mTDDGA remaining in the irradiated solvent samples from the CIEMAT Náyade, CEA Marcel, and INL loop tests. As Verlinden et al reported, the degradation of cis -mTDDGA follows a kinetic law of pseudo first order with respect to the monoamide concentration. By plotting the concentrations C as a function of absorbed dose (in kGy), it is possible to determine a constant k ′ according to the following equation: C = C 0 e – k ′ dos .…”

“…Therefore, based on this finding, cis -mTDDGA should be more stable than TODGA. However, only few studies about the cis -mTDDGA radiolytic resistance have been performed, ,, irradiating solutions of 0.05 mol/L cis -mTDDGA alone and in contact with 2.5 mol/L HNO 3 in static conditions. Based on these initial studies, cis -mTDDGA exhibits increased radiolytic stability toward γ radiation compared to TODGA.…”

Synthesis and evaluation of new modified diglycolamides with different stereochemistry for extraction of tri- and tetravalent metal ions

“…16,[21][22][23] Another approach with interesting results concerns diastereomers of the doubly methylated TODGA derivative with methyl substitutions in the backbone. 24,25 Usually, DGAs present higher affinity for Cm over Am. For the methylsubstituted derivatives an inverse selectivity of Am over Cm by the Me 2 -TODGA anti-diastereomer was observed, which was explained by the orientation influencing the interaction between the nitrate ions and the extracted metal complex.…”