JRP CALL information
Supported By

European Commission

Short description of the work
The presence of structural defects in nuclear fuel induced either by the fission during in-pile operation or by self irradiation during storage (interim or long term), induces changes in the fuel properties. Among these properties the thermal conductivity degradation may have a strong impact on reactor applications and would lead to safety limitations.
In this context, MA bearing (U,Pu)O2 transmutation target samples with various MA contents were studied by XAS (X-ray absorption spectroscopy) at the ROBL beamline of the ESRF synchrotron. During the 15 shifts supplied in the framework of a Talisman JRP, XANES (X-ray absorption near edge structure) and EXAFS (extended X-ray absorption fine structure) spectra were recorded at both LIII and LII edges of each actinides on fresh, i.e. undamaged, and damaged samples. The goal is to characterise the electronic and structural environment of axctinide elements in these fuels and link it to the thermal conductivity modification.
Preliminary analysis of the EXAFS spectra indicates the presence of structural defects associated to an increase of both interatomic distances and Debye-Waller factors in the damaged samples. Further analysis of the EXAFS spectra, coupled with XRD (X-ray diffraction), will provide an accurate description of the nature of these structural defects. In addition, in-situ HT-XRD will allow studying their thermal recovery with the temperature.
A publication of the full analysis of these results in a peer-reviewed journal is planned.

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

JRP Identification
JRP nr: TALI-C01-18
JRP title: Local structure of damaged and annealed minor actinides bearing transmutation fuels
JRP scope: Scope 3: Actinide materials

Visited Associated Pooled Facility
Visited APF during the stay: HZDR - ROBL
Name of the APF Contact Person: Andreas Scheinost

Other APF and organisation involved in the JRP
Other organisations involved: CEA Cadarache (Philippe Martin)
Other APF involved in the project:

Description of the work done at the associated pooled facility
Start date of the stay: 6/12/2014
End date of the stay: 6/17/2014
Quantity of access: 15
Access Unit: Shifts
Misc.: Work during week-ends

Other APF visitors of the JRP during the stay
Visitor 2: Philippe Martin (CEA Cadarache)
Visitor 3: Alice Seibert (JRC-ITU)
Visitor 4: Jean-Francois Vigier (JRC-ITU)
Visitor 5: Andrea Cambriani (JRC-ITU)