JRP CALL information
Supported By

European Commission

Short description of the work
We carried out a series of laser melting experiments at the ITU to confirm these findings on our homogeneous MOX samples fabricated in the LEFCA laboratory in CEA Cadarache (Pu/U+Pu at% = 14, 24, 35, 46, 54 and 62). To achieve this aim we used pressurized argon to fill the sample chamber during the experiments. The oxygen potential of this gas mixture does not induce a strong departure from stoichiometry of MOX during melting. Another series of experiments were performed to study how the departure from the thoroughly investigate pseuo-binary (UO2-PuO2) might affect the melting behaviour. For this purpose we have melted the samples in pressurized air, which is highly oxidizing for MOX in a certain temperature domain, which lies within the whole considered range of temperature, that the sample experiences during laser melting (300-3000K).

After the melting experiments the treated samples were studied at the ANKA synchrotron. Post-mortem examinations (XRD, Raman, XAS etc.) after laser melting experiments are needed to study the changes induced in the sample’s properties. In this case the post-mortem XAS examinations were divided in two parts. First experimental campaign was dedicated to high energy (17-19 keV) measurements. We collected data at the L edges, mainly to study local structure and electronic properties around the cations. Four pairs of samples were chosen (MOX14, MOX46, MOX54, MOX62), each with the same composition, with one sample melted in air and the other in Ar. We recorded spectra at room temperature at the U L3, U L2 and Pu L3 edges.
The second experimental campaign was dedicated to high resolution XANES measurements at low energy (3.5-4 keV) in addition to the aforementioned experiments. These were done to precisely determine the influence of the U/Pu ratio in stoichiometric MOX on the spectra. Data was collected at U M4 and Pu M5 edges on samples MOX24, MOX46 and MOX62.

Main visitor contact data
Name: Dr. Michal Strach
Organisation: CEA Cadarache

JRP Identification
JRP nr: TALI-C03-13
JRP title: Minimum melting temperatures and HR-XANES studies of (Ux,Pu1-x)O2 with varying plutonium content.
JRP scope: Scope 3: Actinide materials

Visited Associated Pooled Facility
Visited APF during the stay: KIT-INE - Laboratories
Name of the APF Contact Person: T. Schäfer

Other APF and organisation involved in the JRP
Other organisations involved: CEA Cadarache
Other APF involved in the project: JRC-ITU - Labs & Hot-cells

Description of the work done at the associated pooled facility
Start date of the stay: 2/5/2015
End date of the stay: 6/2/2015
Quantity of access: 18
Access Unit: Days
Misc.: Work during week-ends

Other APF visitors of the JRP during the stay
Visitor 2: Philippe Martin (CEA Cadarache)
Visitor 3: Damien Prieur (JRC-ITU)
Visitor 4: Enrica Epifano (CEA Cadarache)