In Fig. 1 the configuration in the NOKO facility is shown; for more details about the facility and the effectiveness of the emergency condensers see [1], [2] and [3]; three tubes from the emergency condenser were used. At distances of about 1000 mm thermocouples were installed along the height of the vessel using existing flanges, see Fig. 2.

At two positions, 800 mm and 2000 mm above the return line, see Fig. 1, special grids equipped with up to 12 thermocouples were installed. The position of the thermocouples is
shown in Fig. 3; in Fig. 4 a photo of this grid is shown. The objective was the evaluation if cold or hot water plumes would develop inside the vessel.

The flooding of the reactor vessel to a level above the upper line of the emergency condensers is mandatory.

Before the start of the test the fluid in the pressure vessel was heated up to a — uniform — temperature of about 100°C while the condenser tank was at a temperature of about 30°C.

T 2.01 (2) T 2.02 (1) T 2.03(1)

T 2.04 (1) T 2.05(1)

T 2.06 (2)

T 2.07 (1) T 2.08(1)

T 2.09(1) T 2.10(1) T 2.11 (1)

T 2.12 (2)

FIG. I. The configuration in the NOKO-test FIG. 2. Pressure vessel with instrumentation, facility.