Non-Heating Experimental Study on External Reactor Vessel Cooling

As a key severe accident management strategy,External Reactor Vessel Cooling （ERVC） could terminate the physical process in the reactor pressure vessel and achieve the in-vessel molten debris retention. However,the strategy still needs to be investigated before its application in nuclear power plants. A slice geometry,full scale simulation experiment facility is designed to observe and investigate the two phase natural circulation of ERVC in CPR1000. The study is focused on the effects of the flow path geometry and size on the natural circulation. The experiment results reveal that the inlet/outlet area,penetration tubes and insulation influence the flow process at different levels and the inlet/outlet areas shows a dominating effect on the mass flow rate. The effect of penetration tubes on the boiling heat transfer need to be further evaluated. The maximum measured errors of air injection flowrate and circulation flowrate are 12.9% and 3.4% respectively.