JRP CALL information
Supported By

European Commission

Short description of the work
In the framework of the partitioning and transmutation, the Am recycling is one of the milestones requiring notably a full understanding of the Am electronical properties. Different XANES studies at LIII edges have shown different charge distribution in uranium-americium mixed oxides. U(IV) and Am(III/IV) were found in sol-gel synthesized materials while U(IV/V) and Am(III) were observed in powder metallurgy prepared compounds. In order to understand this discrepancy, the U and Am oxidations states in uranium-americium oxides have been studied using high resolution XANES (HRXANES) at M4 edge. Compared to L3 XANES, M4 HR XANES allows a significant improvement of the spectrum resolution by overcoming the core-hole lifetime broadening ffects leading then to sharper spectral features. In this context, the M4 XANES spectra of U reference compounds (UO2, U3O8, UO3), Am reference compounds (AmO2) and uranium-americium mixed oxides have been collected. Comparing these latter spectra with the U and Am reference samples, it has been established that Am is purely trivalent in uranium-americium mixed oxides while U is tetra- and pentavalent.

 

Main visitor contact data
Name: Dr. Damien Prieur
Organisation: JRC-ITU

JRP Identification
JRP nr: TALI-C02-08
JRP title: HRXANES study of the electonical structures of (U,Am)O2 and of associated binary systems UO2+x and AmO2-x
JRP scope: Scope 3: Actinide materials

Visited Associated Pooled Facility
Visited APF during the stay: KIT-INE - Beamline
Name of the APF Contact Person: Thorsten schafer

Other APF and organisation involved in the JRP
Other organisations involved: CEA Cadrache (Philippe Martin, Rene Bes); CEA Marcoule (Florent Lebretron, Thibaud Delahaye);
Other APF involved in the project:

Description of the work done at the associated pooled facility
Start date of the stay: 9/16/2015
End date of the stay: 9/20/2015
Quantity of access: 15
Access Unit: Shifts
Misc.: Work during week-ends

Other APF visitors of the JRP during the stay
Visitor 2: Dr. Philippe Martin (CEA Cadarache)
Visitor 3: Dr. Rene Bes (CEA Cadarache / SOLEIL)
Visitor 4: Thibaud Delahaye (CEA Marcoule)
Visitor 5: Florent Lebreton (CEA Marcoule)