22.08.2015   Natural circulation data and methods for advanced water cooled nuclear power plant designs

Emergency Condenser 2. Bundle

It could be calculated that the tube wall is responsible for more than 50 percent of the total heat transfer resistance. Therefore, a second bundle was used with the geometrical data.

total length: about 10 m

inner diameter: 44.3 mm

wall thickness: 2.0 mm.

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FIG. 4. The design of the Emergency Condenser (EC).

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3 MPa

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FIG. 5. Power transfer to the water pool with the EC with four tubes.

In addition, the bundle was oriented in a vertical position, under an angle of 40.9° and in a horizontal position.

The experimental results and a comparison with ATHLET calculations are shown in Fig. 6. From sensitivity studies it has been evaluated that the thermalhydraulic codes like ATHLET or CATHARE are calculating well the integral power transferred, but deviate substantially in the in-tube heat transfer by condensation processes. Therefore, special tests with a single tube only and an improved instrumentation were performed. In addition, special tests and measurements for 3D-temperature fields in the water pool have been performed, see the isothermes in Fig. 7 for one of the tests.