The Halden Reactor test series IFA-650 was part of the joint international programme of the Halden Reactor Project. These tests addressed the LOCA performance of high burnup fuel irradiated in commercial nuclear power plants.
IFA-650.9 (PWR fuel): considerable ballooning, fuel fragmentation and relocation, when subjected to LOCA were indicated.
The fuel was provided by Framatome ANP and had been irradiated in the Swiss NPP Gösgen to 89.9 MWd/kgU. The rod power was set to 25 kW/m to achieve a target peak cladding temperature of 1100°C. Due to fuel relocation, the temperature measured with the lower cladding thermocouple approached 1200°C, and the test was terminated to avoid even higher temperatures. Cladding failure occurred at about 800°C, which was 130 s after the start of blow-down.
A special feature of this experiment is the strong fuel fragmentation, relocation and dispersal.