Analysis of blowdown and refill phenomena observed in RD-14 loca experiments

Several series of loss-of-coolant experiments were conducted in the RD-14 test facility, and are analysed in this paper. The objective of the analysis is to obtain clear physical understanding of thermal-hydraulic phenomena that occur during the experiments; examples of these phenomena include periods of flow stagnation and flow reversal in the heated sections, the rise in the temperature of the fuel sheath, and phase separation or stratification. We also investigated the influence of various loop parameters, such as break location, break size, and primary pump operation, on the behaviour of the loop.