Experimental evaluations of seawater effects on thermal-hydraulic behavior at severe accident, 2; Seawater thermal hydraulic experiments with annular tube test section

Liu, W.; Jiao, L.; Nagatake, Taku ; Takase, Kazuyuki; Yoshida, Hiroyuki  ; Nagase, Fumihisa 

In the Fukushima Daiichi Nuclear Power Plant accident, seawater was injected into the reactors to cool down nuclear fuels. Core cooling with seawater has never been assumed and the effect of seawater on heat transfer in core is not clear. Then, effects of seawater on thermal-hydraulic behavior must be investigated to understand the phenomena occurred in the accident and to evaluate current state of the reactor cores. This paper reports thermal-hydraulic experiments and data including heat transfer rate and pressure drop using aqueous sodium chloride solution and manmade seawater in an annular tube, which simulate a whole reactor core. The experiments are performed under atmospheric pressure condition, with salinity, mass flux, inlet temperature and heat flux used as parameters.