Boundary conditions were set as follows: room temperature of 293 К (20°C) in each part of the facility and atmospheric pressure of 1 bar. The level in the pools is at the elevation of 10 m, which is the equivalent of 2.85 m measured from the bottom of the pool. The initial velocity of the fluid is 0 m/s everywhere in the facility. The input heating power was 99 kW in equal radial distribution in the 3 heated channels of the core. Upper plenum was filled with water totally. Table II shows the performed scenarios and status of the isolation valves. The initial condition of the experiments did not fully correspond the condition of the reference reactor in a LOCA situation after the depressurization period. The initial temperature is close to room temperature when density differences, which create the natural circulation, doesn’t exist yet.

TABLE I. THE GEOMETRICAL CHARACTERISTICS OF THE MODIFIED PACTEL FACILITY