JRP CALL information
Supported By

European Commission

Short description of the workNeptunium is a minor actinide that is produced in a nuclear power reactor. The neptunium recovery, through the PUREX process, is currently difficult. Indeed, the PUREX raffinate is characterized by a very complex mixture of several elements in a high concentration of nitric acid and a high ionic strength. In this environment, neptunium can be found in several oxidation states, making it more difficult to separate with other actinides. In the 60s, Sullivan et al showed that the neptunium, in its form neptunyl Np(V), could form complexes with many other elements such as actinides or metals present in the PUREX media. This interaction was shown by UV-Vis spectrophotometry, monitoring the absorption band of the f-f transition of Np(V) at 980nm. During the complexation, this band decreases strongly in favor of a new bands corresponding to the cation-cation interaction. This band appears separate from the main one by a more or less significant shift depending on the complexing element.
This study aimed to revive the work of Sullivan on spectrophotometry and Guillaume’s work on Raman. As originally planned in the project, the elements Fe, Cr and Rh were studied. Two other elements were also added to this list: dysprosium and ruthenium. Dysprosium was investigated to demonstrate an interaction between Np(V) and a characteristic element of the lanthanide group. Ruthenium was studied for its interest in the PUREX process, an interaction between Np(V) and this element was observed by Ch. Maurice during her PhD. The manipulations were used to conduct a thorough study on the effect that Np(V) has on Fe(III) and Dy(III) and continuing qualitatively the study of elements Cr(III), Rh(III) and Ru(III). Complexation constant was calculated in two different environments for Fe and Dy.

Main visitor contact data
Name: Arnaud Deroche
Organisation: CEA

JRP Identification
JRP nr: TALI-C06-14
JRP title: Neptunium – Fission products Interactions
JRP scope: Scope 1: Actinide separation chemistry

Visited Associated Pooled Facility
Visited APF during the stay: NNL - Central Lab
Name of the APF Contact Person: Chris Mason

Other APF and organisation involved in the JRP
Other organisations involved:
Other APF involved in the project:

Description of the work done at the associated pooled facility
Start date of the stay: 10/23/2015
End date of the stay: 12/18/2015
Quantity of access: 41
Access Unit: Days