The rim-effect in high burnup UO(2) nuclear fuel
An interesting physical phenomenon occurs in the cold outer zone (the rim) of UO(2) nuclear fuel when the reactor operation is extended to fuel burnups exceeding about 45 MWd/kg metal. It consists of the subdivision of the grains of the original sintered structure into typically 1.0 E4 to 1.0 E5 very small subgrains (polygonisation). This new structure was characterised with high resolution electron microscopy and its oxygen potential was measured. Parallel experiments using ion implantation with high energy fission products yielded results on some parameters important for the formation of the new structure (temperature, necessary amounts of radiation damage and effects of type and concentration of fission products). These results and the mechanism of polygonisation of UO(2) are reported and the implications of the phenomenon for the technological use of UO(2) as nuclear fuel are discussed.
Bibliographic Reference: Paper presented: 8. World Ceramic Conference (CIMTEC-8), Florence (IT), June 29 - July 4, 1994
Availability: Available from (1) as Paper EN 38135 ORA
Record Number: 199410766 / Last updated on: 1994-11-28
Original language: en
Available languages: en