Analysis of the Structure and the Thermal Behavior of the UO sub 2 --PuO sub 2 Fuel in the Irradiation Experiment FR2 Capsule Test Series 5A

摘要

In the Karlsruhe FR2 research reactor nine fuel pins were tested in a total of three irradiation capsules within the framework of the 5a test series. The fuel pins contained UO sub 2 --PuO sub 2 fuel pellets. The irradiation times were different for the three capsules. They reached burnup values of approximately 6, 17, and 47 MWd/kgMe for rod power levels of 400 to 600 W/cm and cladding surface temperatures between 500 and 700 exp 0 C. A detailed analysis of the fuel structure was carried out in order to determine the fuel surface temperature. For this purpose two models were used which describe the formation of the columnar crystal zone or the zone where the directed growth of the grain depends upon the irradiation time and the temperature profile in the fuel. (ERA citation 04:046483)