PROGRESS ON THE OVERALL POWER CORE

CONFIGURATION OF THE ARIES-ACT

X.R. Wang1, M. S. Tillack1, S. Malang2

1University of California, San Diego, CA2Fusion Nuclear Technology Consulting, Germany

ARIES-Pathways Project MeetingGaithersburg, MDOctober 13-14, 2011

REVIEW OF THE DESIGN FEATURES OF THE ARIES-AT POWER CORE

All the components including the inboard blanket and shield, outboard blanket and shield and divertor are cooled by LM LiPb.

The inboard blanket, outboard blanket, upper and lower divertor modules are integrated with the HT shield (structural ring) into one replaceable unit, and the unit is attached to the bottom structure of the VV.

All the connections/disconnections between coolant access pipes and individual component are located the outside of the outboard HT shield where the He-generation should be low enough to allow for re-welding.

All LM access pipes should be designed as concentric tubes with the cold inlet flow (~650 ᵒC) in the annulus, cooling in this way the inner tube (1100 ᵒC) to the allowable temperature (~1000 ᵒC) of the SiC/SiC.

One sector (22.5 degree)

ARIES-ACT (Aggressive Physics)R=5.5 mA=1.375 mElongation=2.2

ARIES-ACT (Aggressive Physics)R=5.5 mA=1.375 mElongation=2.2

Plasma

OB divertor plate

IB divertor plate

Dom plate

IB FW

OB FWResults of CAD analysis: Total plasma surface area=~475 m2

Total plasma volume=~417 m3

Total FW surface area=~452 m2

(AIB=140 m2,AOB=312 m2)Total Divertor surface area=~143 m2

Geometry Definitions of the FW and divertor plates (from Chuck):Thickness of SOL at mid-plane=10 cmCurved FWOB divertor location=R-a/2IB divertor location=R-a

Geometry Definitions of the ACT FW and Divertor Plate Are Based on the ACT-1B Strawman

Geometry Definitions of the ACT FW and Divertor Plate Are Based on the ACT-1B Strawman

TWO POSSIBLE DESIGN OPTIONS FOR THE ACT-1 POWER CORE

CONFIGURATIONDesign Option #1 Design Option #2

IB Blanket Pb83Li17 cooled SiC/SiC structure

Pb83Li17 cooled SiC/SiC structure

IB HT Shield Pb83Li17 cooled steel and SiC/SiC tube

Helium-cooled steel structure and ODS tube

1st OB Blanket Pb83Li17 cooled SiC/SiC structure

Pb83Li17 cooled SiC/SiC structure

2nd OB Blanket Pb83Li17 cooled SiC/SiC structure

Pb83Li17 cooled SiC/SiC structure

OB HT Shield Pb83Li17 cooled steel and SiC/SiC tube

Helium-cooled steel structure and ODS tube

Upper/Lower Divertors

Helium-cooled W-based divertor

Helium-cooled W-based divertor

POWER CORE CONFIGURATION FOR THE DESIGN OPTION #1 (LIPB-COOLED

HT SHIELD)

Thickness radius

Inboard:

Vacuum vessel: 0.4 m HT shield: 0.24 m IB blanket: 0.35 m Outboard:1st Blanket: 0.30 m 2nd Blanket: 0.45 m HT shield: 0.15 m Vacuum vessel: 0.25 m Vertical build:W divertor target: ~0.07 m (He, ODS steel and W)Replaceable HT shield: 0.30 m (He, FS and ODS steel)HT shield: 0.3 m (SiC, FS and LiPb, ODS, He)(0.15 m, 15% SiC, 10% LiPb, 75% FS for ARIES-AT)Vacuum vessel: 0.4 m

Composition: the same as the ARIES-AT

One of the He-cooled W-based divertor concepts would be integrated into the power core.

INTEGRATION OF THE HE-COOLED W-BASED DIVERTOR IN THE ACT POWER

CORE Fingers arranged over the entire plate Imping-jet cooling, Tin/Texit=700/800 ᵒC Allowable heat flux up to~14 MW/m2

Avoiding joints between W and ODS steel at the high heat flux region

~550,000 units for a power plant

Fingers arranged over the entire plate Imping-jet cooling, Tin/Texit=700/800 ᵒC Allowable heat flux up to~14 MW/m2

Avoiding joints between W and ODS steel at the high heat flux region

~550,000 units for a power plant

T-Tube divertor: ~1.5 cm dia. X 10 cm long Impinging-jet cooling, Tin/Texit=700/800 ᵒC Allowable heat flux up to~11 MW/m2

~110,000 units for a power plant

T-Tube divertor: ~1.5 cm dia. X 10 cm long Impinging-jet cooling, Tin/Texit=700/800 ᵒC Allowable heat flux up to~11 MW/m2

~110,000 units for a power plant

Plate divertor: 20 cm x 100 cm Impinging-jet cooling, Tin/Texit=700/800 ᵒC Allowable heat flux up to~9 MW/m2

~750 units for a power plant

Plate divertor: 20 cm x 100 cm Impinging-jet cooling, Tin/Texit=700/800 ᵒC Allowable heat flux up to~9 MW/m2

~750 units for a power plant

Two zone divertor (any combination of the plate and finger and T-tube)

Fingers for q>~8 MW/m2, plate for q<~8 MW/m2

Decreased number of finger units

Two zone divertor (any combination of the plate and finger and T-tube)

Fingers for q>~8 MW/m2, plate for q<~8 MW/m2

Decreased number of finger units

One of the divertor concepts to be integrated in the ACT power core.

The selection of the divertor depends on the peak heat flux and heat flux profile of the ACT-1.

Tubular or T-Tube He-cooled SiC/SiC divertor

Impinging-jet cooling, Tin/Texit=700/800 ᵒC Allowable heat flux up to~5 MW/m2

Tubular or T-Tube He-cooled SiC/SiC divertor

Impinging-jet cooling, Tin/Texit=700/800 ᵒC Allowable heat flux up to~5 MW/m2

W-baseddivertor

OB divertor plate

W-Ta-ODS joints

The Modified W-Ta-ODS Joints Indicated Simpler Fabrication and Smaller Strains

The Modified W-Ta-ODS Joints Indicated Simpler Fabrication and Smaller Strains

The original design The modified design

Avoided ratcheting Reduced plastic strains in the ODS and Ta rings Simpler design and simpler fabrication steps Avoided singularities Added braze layer in the joints for analysis Assumed the material properties of the Cu to

simulate the braze material, because we lacked alloy composition and properties for real brazes

~11,000, 000 non-linear structural nodes

ODS Ta W ODS Ta W

Explosive weldedDiffusion welded

TIG or Laser

Brazed

BrazedBrazed

*Dara Navaei, Master’s thesis (draft), “Elastic-plastic analysis of the transition joint for a high performance divertor target plate”

Pure Ta, εallow=~15% at RT and 5% at 700 ᵒCODS-EUROFER, εallow =~2.3% and 2.4% at RT and 700 ᵒCPure W, εallow=~0.8% at 270 and 1.0% at 700 ᵒCPure Cu, εallow=~15% (unirradiated)

Strain Limits:

REPLACEABLE UNIT FOR THE SECTOR MAINTENANCE

Like the ARIES-AT power core configuration, the inboard blanket, outboard blanket, upper and lower He-cooled divertor are integrated with the HT shield into a replaceable unit for the sector maintenance.

All LM access pipes are designed as concentric tubes (the cold inlet flow (~650 °C) in the annulus, the hot outlet flow in the inner tube (1100 °C) ).

He access pipes are also designed as concentric tubes (700/800 °C for outer/inner tubes), and the advanced ODS steel (12CrYWTi*)is assumed for the tube material.

LiPb: Tin=~650 ᵒC, Texit=1100 ᵒC

He: Tin=~700 ᵒC, Texit=800 ᵒC

TAURO: LiPb: Tin=~640 ᵒC, Texit=950 ᵒCPower conversion efficiency: ~55% with optimized compression ratio of 1.77.

*R.L. Klueh, J. of Nuclear Materials, 307-311(2002) 455-465.

COOLANT ROUTING FOR THE POWER CORE DESIGN OPTION #1 (LIPB-COOLED

HT SHIELD) Size of the access pipes (thermal power is based on the ARIES-AT):

Circuit 1: series flow through the inboard shield and inboard blanket region Total thermal power=~354+110=464 MW Total mass flow rate=~5574 kg/s, ~348 kg/s per sector (∆T=1100-650=450 ᵒC) Diameter of the access tube=~0.22 m (assuming vPb-Li ≤ ~2 m/s)

Circuit 2: flow though the first outboard blanket region Total thermal power=~901 MW Total mass flow rate=~10,823 kg/s, 677 kg/s per sector Diameter of the access tube=~0.32 m (assuming vPb-Li ≤ ~2 m/s)

Circuit 3: series flow through the outboard shield and the second outboard blanket region

Total thermal power=~142+70=212 MW Total mass flow rate=~2547 kg/s, ~159 kg/s per sector Diameter of the access tube=~0.08 m (assuming vPb-Li ≤ ~2 m/s)

Circuit 4: Helium-cooled the upper divertor Total thermal power=~148 MW Total mass flow rate=~285 kg/s, ~18 kg/s per sector(∆T=800-700=100 ᵒC, P=10 MPa) Diameter of the access tube=~0.3 m (assuming vhelium ≤100 m/s)

Circuit 5: Helium-cooled the lower divertor Total thermal power=~148 MW Total mass flow rate=~285 kg/s, ~18 kg/s per sector(∆T=800-700=100 ᵒC, P=10 MPa) Diameter of the access tube=~0.3 m (assuming vhelium ≤100 m/s)

LAYOUT OF THE COOLANT CIRCUITS AND THE ACCESS PIPES TO THE

COMPONENTS

Circuit 1: series flow through the inboard shield and inboard blanket region

Circuit 2: flow though the first outboard blanket region

Circuit 3: series flow through the outboard shield and the second outboard blanket region

Circuit 4 & 5:Helium-cooled the upper and lower divertor

Flow distribution

CUTTING/RE-WELDING OF THE ACCESS PIPES FOR SECTOR MAINTENANCE:

OPTION #1

Bottom view showing the space of all 5 access pipes penetrating through the vacuum vessel and coil structural cap.

Location of cutting/re-welding

The locations of the PF coils have been modified based on the ARIES-AT’s PF coils in order to allow the gravity support of the power core and access pipes penetrating through the coil cap to connect the coolant ring header at the bottom.

CUTTING/RE-WELDING OF THE ACCESS PIPES FOR SECTOR MAINTENANCE:

OPTION #2 All the 5 access pipes will

penetrate the vacuum port, one from upper port and 4 from the lower port.

The disconnections/connections of the access pipes are located behind the second vacuum door (the first door is the outside door).

All 5 access pipes need to be cut and removed from the port.

DESIGN OPTIONS FOR REMOVABLE VERTICAL POSITION AND FEEDBACK

COILS

The ARIES-AT like design option: The vertical position coils and feedback coils would be attached to the vacuum door, and need to break the joints and removed horizontally.

Alternative design option: The vertical position coils and feedback coils would be vertically removed up and down to the grooves of the VV.

Vertical Position Coils(normal conducting coils)

Both options work well with the configuration of the access pipes penetrating through the VV door and port.

POWER CORE CONFIGURATION FOR THE DESIGN OPTION #2 (HE-COOLED HT

SHIELD)

1st design option: LiPb flow through upper/lower divertor regions or just flow through the lower divertor region for maintaining constant velocity and avoid toroidal manifold at the inboard blanketOne LiPb circuit with 2 access pipe bundles (1/2 blanket sector per bundle) for all blanketsNeed thickness inputs for both inboard and outboard HT shieldMay also need a new radial build

Alternative design option: ARIES-AT like configuration3 LiPb circuits2 Helium circuits

He-cooled He-cooled

COOLANT ROUTING FOR THE POWER CORE DESIGN OPTION #2 (HELIUM-

COOLED SHIELD)

Circuit 1: LiPb flow through both the inboard blanket and 2 outboard blanket regions

Total thermal power=~354+901+142=1397 MW Mass flow rate/sector= ~1048 kg/s (∆T=1100-650=450 ᵒC) 2 access pipe bundles including all the 24 blanket channels (0.6 x 0.6 for each bundle)

Circuit 2: Helium series flow through outboard HT shield and the upper divertor

Total thermal power=~148+110=258 MW Mass flow rate/sector=~31 kg/s (∆T=800-700=100 ᵒC, P=10 MPa) Diameter of the access tube=~0.4 m (assuming vhelium ≤~100 m/s)

Circuit 3: Helium series flow through inboard shield and the lower divertor Total thermal power=~148+70=218 MW Mass flow rate/sector=~26.2 kg/s (∆T=800-700=100 ᵒC, P=10 MPa) Diameter of the access tube=~0.36 m (assuming vhelium ≤~100 m/s)

ACCESS PIPE BUNDLE APPLIED IN OVERALL LAYOUT FOR MINIMIZING 3D

MHD ∆P

(Access pipe bundle, proposed by Mark)Constant flow cross section Two access pipe bundles are arranged to connect all the 36 inboard

and outboard blanket channels (12 for the inboard and 24 for the outboard blanket).

He-cooled HT shield may be a better design option to simplify the LiPb coolant circuits and reduce the 3D MHD uncertainty.

Multiple small ducts

LAYOUT OF THE LIPB COOLANT CIRCUIT AND THE ACCESS PIPES FOR

THE DESIGN OPTION #2

Connecting to the LiPb Ring Header

ARIES-AT like design1st LiPb circuit

Constant flow cross-section

IB blanket

1st OB blanket

2nd OB blanket

Connecting to 36 blanket channels channel by channel

Cross-section of the outboard blanket channels for one half sector

Discussion Discussion Need to make selections:Integration of the He-cooled divertor concepts (a few design options)

Finger T-Tube Plate SiC/SiC with W coating tubular or T-tube concept Two zone divertor (any combinations)

Inboard and outboard shield (2 options) LiPb-cooled

Helium-cooled

The location of the disconnections/connections of all the access pipes (2 options) Behind the outboard shield, penetrating through the bottom coil cap

Behind the second vacuum door (inner), penetrating through the vacuum port

The way to remove the vertical position and feedback coils (2 options) Horizontal movement (ARIES-AT like design option): need to break the joints of the coils

and remove the coils with the second vacuum door together

Vertical movement: need to pull two coils up and two coils down to the grooves of the top and bottom VV parts.