Applications of EXAFS in Nuclear Fuel Research and Development

EXAFS was used to investigate the local atomic environment of materials designed for the transmutation of minor actinides. Am L3–edge EXAFS indicate, that 241Am infiltrated in porous spinel pellets forms a perovskite-like AmAlO3 phase during sintering. After 10 years of storage, selfirradation through the 241Am decay amorphizes the AmAlO3 phase and only the first oxygen coordination shell around Am is detected. In a second study, the local structure of the inert matrix fuel analog (Zr1-xUx)N was probed both at the Zr K and U L3-edge. The bond distance between U and its six surrounding N atoms follows the Vegard law. In contrast, the Zr-N bond distance at low x (high Zr) increases with x. At x > 0.6 (Zr1-xUx)N the Zr-N distance ceases to increase and remains relatively constant at 2.32-2.35 A, indicating a limited ability of Zr to accept the (Zr1-xUx)N lattice expansion induced by uranium.

WALTER Marcus;  SOMERS Joseph;  FERNANDEZ CARRETERO Asuncion; 

2007-07-18

Organisation for Economic Co-Operation and Development (OECD)

JRC37943

https://publications.jrc.ec.europa.eu/repository/handle/JRC37943,