Halden reactors IFA-511.2 and IFA-54x: Experimental series under adverse core cooling conditions Original Research Article

The experimental series IFA-511 and IFA-54X, carried out at the Halden Boiling Heavy Water Reactor (HBWR), investigated fuel performance characteristics under adverse core cooling conditions. Specific objectives of the experiments were to compare thermal responses of nuclear fuel rods with those of electrically heated rods and to study cladding ballooning. The present paper deals with a systematic analysis of the experimental data, giving emphasis to some aspects of the reflood phenomenon in the nuclear and electrical rods such as precursory cooling and the relationship between peak cladding temperatures and quenching temperatures.