1. Natural convection flow in a cask storage warehouse For Toyo Engineering PHOENICS Version : 3.5.1 DETAILS : BFC grid Three-Dimensional steady flow with heat transfer Buoyancy-influenced flow Surface to surface radiation included NX*NY*NZ=288*74*42=895,104 NOTES : The purpose of this model is to establish the temperature distribution and the air flow rate.

2. Geometry x-y plane nx×ny=288×74 x-y plane nx×nz=288×42

3. outlet Heat source : 22.6[kw] Air in Air out cask External temperature 23.2 External temperature 23.2 Q A2A2 A1A1 A1A1 A2A2 Q Radiation model in the cask

4. Result

5. Velocity FlowRate[m3/s] per one cask Experimental data Result of PHOENICS 0.28 0.3

6. Temperature

7. Natural convection flow in a nuclear reactor For Denchuken PHOENICS Version : 3.6 DETAILS : Cylindrical-polar grid Three-Dimensional steady or transient flow with heat transfer Buoyancy-influenced flow Surface to surface radiation included NX*NY*NZ=40*45*80=144,000 NOTES : When an accident happens in the nuclear system, eg the cooling system may fail. Hence, heat will be released solely by natural convection of air flow. The purpose of this model is to establish the distribution of temperature and the air flow rate under these circumstances.

8. PRACS IHX(Heat sink Q=-28.55[MW]) Liquid Na convection zone Pump(11m 3 /min) Steady::on Transient::off Radial shield Reflector Argon gas zone Air convection zone Air inlet (connected to stack) Air outlet (connected to stack) Air Flow Liquid Na Flow Core (Heat source Q=30[MW]) Structure of porous media zone

9. Boundary conditions Heat source and Heat sink: Steady:-28.55[MW] Transient:0[WM] Steady:30[MW] Transient: change profile

10. Pump power : Steady:11[m 3 /s] Transient: change profile.

11. Body force (Buoyancy): Liquid Na convection zone Air convection zone

12. Resistance force in the porous medium zone: where K: Pressure resistance coefficient. (This is different in each zone) ρ:density U velocity

13. Radiation : Q2Q2 Q1Q1 radiation Q A2A2 A1A1 A1A1 A2A2 Q

14. Energy source in the porous medium zone : where

15. Pressure value in the air convection zone boundary : P ITOP i A i [m 2 ]k i [-]n 11.00.32 21.00.252 3-0.6572 45.281.31 53.480.761 61.262.61 7-0.31742 81.01.52 91.07.02 i=1 to 5 i=6 to 10 The value of pressure in the air convection zone boundary is renewed while it is calculated from the next experience equation. P OTOP ΔP f1 ΔP f2 ΔP f3 ΔP f4 ΔP f5 ΔP f6 ΔP f7 ΔP f8 ΔP f9 Δh out Δh in P OUT P IN Δh

16. Result

17. Temperature distribution (steady) Maximum temperature [ ] Experimental data Result of PHOENICS 550 540.6699

18. Pressure distribution (steady) Pressure drop [MPa] in Na convection zone Experimental data Result of PHOENICS 2.5 2.51

19. Air flow rate in the air convection zone. Maximum temperature in the liquid Na convection zone.

20. Transient simulation in a vapor turbine PHOENICS Version : 3.5.0 DETAILS : Cartesian grid Three-Dimensional transient flow NX*NY*NZ=222×218×98=4,742,808

21. Inlet of vapor Outlet Air :Fixed temperature Nozzle Box : Fixed temperature

22. RESULT

24. 90° 0° 30° 60° 120° 150° 180° SLICE POINT1 POINT2