Gamma and pulsed electron radiolysis studies of CyMe4BTBP and CyMe4BTPhen: Identification of radiolysis products and effects on the hydrometallurgical separation of trivalent actinides and lanthanides
Journal article, 2021

The radiolytic stability of the highly selective ligands CyMe4BTBP and CyMe4BTPhen against ionizing gamma radiation was studied in 1-octanol solution. CyMe4BTBP and CyMe4BTPhen are important extractants for a potential treatment of used nuclear fuel. They were studied under identical experimental conditions to directly compare the effects of gamma and pulsed electron radiolysis on the ligands and systematically study the influence of structural changes in the ligand backbone. Distribution ratios of Am3+, Cm3+ and Eu3+, the residual concentration of CyMe4BTBP and CyMe4BTPhen in solution, and the formation of radiolysis products were studied as a function of absorbed gamma dose and presence of an acidic aqueous phase during irradiation. Quantitative and semi-quantitative analyses were used to elucidate the radiolysis mechanism for both ligands. Addition products of alpha-hydroxyoctyl radicals formed through radiolysis of the 1-octanol diluent to the ligand molecules were identified as the predominant radiolysis products. These addition products also extract trivalent metal ions, as distribution ratios remained high although the parent molecule concentrations decreased. Therefore, the utilization time of a solvent using these extractants under the harsh conditions of used nuclear fuel treatment could be considerably longer than expected. Understanding the radiolysis mechanism is crucial for designing more radiation resistant extractants.

Used nuclear fuel

Radiolysis

Nuclear waste treatment

N-Donor extractants

Solvent extraction

Author

H. Schmidt

Forschungszentrum Jülich

A. Wilden

Forschungszentrum Jülich

G. Modolo

Forschungszentrum Jülich

Dirk Bosbach

Forschungszentrum Jülich

B. Santiago-Schubel

Forschungszentrum Jülich

M. Hupert

Forschungszentrum Jülich

B. J. Mincher

Idaho National Laboratory

S. P. Mezyk

The California State University

J. Švehla

Institute of Inorganic Chemistry of the Academy of Sciences of the Czech Republic, v.v.i.

B. Gruner

Institute of Inorganic Chemistry of the Academy of Sciences of the Czech Republic, v.v.i.

Christian Ekberg

Chalmers, Chemistry and Chemical Engineering, Energy and Material

Radiation Physics and Chemistry

0969-806X (ISSN)

Vol. 189 109696

Subject Categories

Chemical Process Engineering

Other Chemistry Topics

Organic Chemistry

DOI

10.1016/j.radphyschem.2021.109696

More information

Latest update

7/30/2021