Two-phase flow degradation on Fukushima-Daiichi Unit 2 RCIC turbine performance

Figures & data

Table 1. Fukushima Daiichi Unit 2 RCIC design specifications.

	RCIC design specifications
	Upper	Lower
	pressure limit	pressure limit
Pressure (MPa)(abs)	7.83	1.14
Power (kW)	373	60
Speed (RPM)	4500	200
Pump Head (m)	850	160
Water mass flow rate injected to RPV (kg/s)	26	26
Steam mass flow rate injected to RPV (kg/s)	2.51	2.51

Figure 1. Methodology flow chart.

Figure 2. Mass flux using non-homogeneous equilibrium model.

Figure 3. NHEM degradation coefficient.

Figure 4. TEPCO Decay heat.

Figure 5. TEPCO RPV/drywell pressure.

Figure 6. Mass flow rates.

Figure 7. RCIC RELAP/Scdap nodalization.

Figure 8. Mass injected-extracted from S/C using the old model.

Figure 9. Mass injected-extracted from S/C using the new model.

Figure 10. Suppression chamber water level.

Figure 11. CST water mass flow rate.

Figure 12. Turbine power.