Study into heat transfer in modeling the emergency cooling of a reactor core

Some results are given of experimental work in the field of heat transfer, obtained by processing data measured during the modeling of emergency cooling of WWER reactor cores. The experiments were made on the circular and semicircular channels of an equipment simulating core re-flooding after an accident associated with major loss of coolant. The heated lengths of the measurement segments were 2500 and 3500 mm. A small number of parameters were examined, viz. pressure, mass flow rate, steam content and wall temperature, whereas the effect of time-independent variables was not studied. Nevertheless, the results enable not only a qualitative but also a quantitative description of the process. (Z.M.)