title: Gamma-radiolytic stability of new methylated TODGA derivatives for minor actinide recycling.
abstract: The stability against gamma radiation of MeTODGA (methyl tetraoctyldiglycolamide) and Me2TODGA (dimethyl tetraoctyldiglycolamide), derivatives from the well-known extractant TODGA (N,N,N',N'-tetraoctyldiglycolamide), were studied and compared. Solutions of MeTODGA and Me2TODGA in alkane diluents were subjected to (60)Co γ-irradiation in the presence and absence of nitric acid and analyzed using LC-MS to determine their rates of radiolytic concentration decrease, as well as to identify radiolysis products. The results of product identification from three different laboratories are compared and found to be in good agreement. The diglycolamide (DGA) concentrations decreased exponentially with increasing absorbed dose. The MeTODGA degradation rate constants (dose constants) were uninfluenced by the presence of nitric acid, but the acid increased the rate of degradation for Me2TODGA. The degradation products formed by irradiation are also initially produced in greater amounts in acid-contacted solution, but products may also be degraded by continued radiolysis. The identified radiolysis products suggest that the weakest bonds are those in the diglycolamide center of these molecules.
authors.affiliation: Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT), Madrid 28040, Spain. hitos.galan@ciemat.es.
authors.forename: Hitos
authors.initials: H
authors.lastname: Galán
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Zarzana
authors.forename: Andreas
authors.initials: A
authors.lastname: Wilden
authors.forename: Ana
authors.initials: A
authors.lastname: Núñez
authors.forename: Holger
authors.initials: H
authors.lastname: Schmidt
authors.forename: Richard J M
authors.initials: RJ
authors.lastname: Egberink
authors.forename: Andrea
authors.initials: A
authors.lastname: Leoncini
authors.forename: Joaquín
authors.initials: J
authors.lastname: Cobos
authors.forename: Willem
authors.initials: W
authors.lastname: Verboom
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Modolo
authors.forename: Gary S
authors.initials: GS
authors.lastname: Groenewold
authors.forename: Bruce J
authors.initials: BJ
authors.lastname: Mincher