Experimental study on sodium droplet combustion and spatial temperature distribution characteristics

In the operation of the sodium-cooled fast reactor, the accident caused by the leakage and combustion of liquid sodium is common and frequent. In this paper, the combustion and spatial temperature distribution characteristics at the different distances from the center of droplet and the different angles (0-30°) were studied by carrying out the experiments of the oxidation and combustion under initial temperatures (200-350°C) of sodium droplet, oxygen concentrations (12-21%) and ambient atmosphere temperatures (80°C and 180°C). The experiment results show that the ambient atmosphere temperature cannot change the three stages (surface oxidation, preignition, and combustion) of sodium droplet combustion but it will change the characteristics of every stage. When the temperature of sodium droplet excesses the characteristic temperature (600°C), the temperatures of all spatial measuring points begin to rise noticeably. The peak temperature of the sodium droplet that completely burned could roughly reach 580-1000°C. The distributions of the spatial maximum temperature in three angle directions are in conformity with exponential function as the distance increases. The study provides the technical support on the evaluation and analysis of various forms of sodium fire accidents.