1. GE’s ESBWR by
T. G. Theofanous

2. ESBWR SA Containment Highlights
UDW
EVE
LDW
BiMAC
Not to scale
+PCCS no LT failure

3. ESBWR SA Complexion

4. SA Threats and Failure Modes
Direct Containment Heating (DCH)
Energetic Failure of UDW, Liner (thermal) Failure
Ex-Vessel Explosions (EVE)
Pedestal/Liner Failure, BiMAC-Pipes Crushing
Basemat Melt Penetration (BMP)
BiMAC Thermal Failure (Burnout, Dryout, Melt Impingement)

5. Direct Containment Heating (DCH)

6. DCH: Key features of the geometry
Highly non-uniform
gas flow
Representative but
not to scale

7. DCH in suppression pool containments: model verification basis
IET CLCH Model
1:1 Scale
PSTF Vent Clearing Model
and 1:40 scale

8. Validation Basis: IET DCH Tests… GE PSTF Vent Clearing
CLCH model. Complete transient

9. Actual blowdowns used as inputs for comparison
PSTF
IET

10. Comparison to PSTF data

11. Comparison to IET-1RR and -8 data

12. Comparison to IET-1 data

13. Quantification of Loads
Regime I
HYPOTHETICAL
Regime II
Creep Rupture, Bounding

14. Case F
Regime III
More Dynamics
Case G

18. More sensitivities run on condensation and gas-cooling efficiency,
oxidation efficiency, composition of DW atmosphere, etc…

19. Minimum (bounding) Margins to Energetic DCH Failure
Upper Bound Load
Fragility

20. Ex-Vessel Explosions (EVE) Pedestal/Liner Failure, BiMAC-Pipes Crushing

21. Sample SE calculations
~ 1 ton/s melt release
1, 2, 5 m deep pools
Saturated and subcooled water
~100 kPa s on the floor
kPa s on the side walls

22. Pedestal model in DYNA3D
Verified extensively in
High Explosive work

23. Pedestal damage in DYNA 3D
600 kPa s loading

24. Pedestal Failure Margins to EVE 1 to 2 m Subcooled Pools
Upper Bound Load
Lower Bound Fragility
Significant upwards revision of previously used failure criteria on pedestal walls

25. BiMAC Structural Configuration
Ie Schedule 80 pipes

26. DYNA3D model of BiMAC

27. BiMAC damage in DYNA3D
200 kPa s loading

28. BiMAC Failure Margins Due to EVE 1-2 m subcooled pools
Upper Bound Load
Subcooled 1-2 m
Upper Bound Load
Saturated Low Level

29. Lower Drywell

30. BiMAC Detail

31. BiMAC Flow Path

32. Natural convection patterns

33. The Peaking at the Edge of Near-Edge Channels is the most Limiting

34. Summary of Power Split and Peaking Factor Results
from the Direct Numerical Simulations (all fluxes in kW/m2 )
Case No.
qup
qdn qs
qup / qdn
qmax / qdn or s A 63 30
N/A
2.1
1.25 B
120 54
2.2 C
178 80
C-3D
238 68
3.5
1.2
M-3D
286 85
280
3.4
3.0 / 1.4 M
255
125
330
2.0 N
126
340
1.9
3.0 / 1.2 O
168 83
245
The 3D results were confirmed with further calculations that included
refined meshes, and a 10-fold increase in viscosity due to addition of
the sacrificial concrete.

35. Sample calculations of turbulent natural convection

36. Local peaking mechanism

37. Bounding estimates of thermal loads
Central Channels:
Near-Edge Channels:

38. The ULPU facility

39. Coolability Limits for BiMAC Applicability based on similarity of geometries and flow/heating regimes

40. Thermal Loads against Coolability Limits in BiMAC Channels

41. Thermal Margins for BiMAC Local Burnout

42. Natural convection boiling in inclined channels: the SULTAN facility
Vertical and 10 degrees inclination
Characteristic length: 3 and 15 cm
Channel length: 4 m
Pressure: 0.5 MPa
Power levels 100 to 500 kw/m2
Detailed pressure drop data
Top-heated plate, 15 cm wide

43. Boiling in inclined channels: Sample comparisons for inclination

44. Natural convection in BiMAC: stable, self-adjusting flow

45. Thermal Margins for BiMAC no-Dryout due to water depletion or flow starvation

46. Conclusion (3): Summary of containment threats and mitigative mechanisms or systems in place for responding to them
Threat
Failure Mode
Mitigation
DCH
Energetic DW Failure
Pressure Suppression Vents
Reinforced Concrete Support
UDW Liner Thermal Failure
Liner Anchoring System
LDW Liner Thermal Failure
Reinforced Concrete Barrier
Gap Separation from UDW
EVE
Pedestal/Liner Failure
Dimensions and Reinforcement
BiMAC Failure
Pipe Size and Thickness
Pipes Embedded into Concrete
BMP
&
CCI
BiMAC Activation Failure
Sensing & Actuation Instrumentation
Diverse/Passive Valve Action
Local Burnout
Natural Circulation
Water Depletion
Local Melt-Through
Refractory Protective Layer