QTYUIOP APEX4-04-02 FW/BLANKET DESIGN NECESSARY AND DESIRABLE - - PowerPoint PPT Presentation

APEX4-04-02

QTYUIOP

by C.P.C. Wong, S. Malang, M. Sawan, M. Friend,

• S. Majumdar, E. Mogahed, B. Merrill

*

• Variation to the ARIES-AT approach
• Flat wall helical first wall and integrated once-thru FW/blanket concepts
• The ARIES-AT/NCF concept approach has potential to be used for

hydrogen production

Presented by C. Wong APEX project meeting, April 17-19, 2002 San Diego, California

FLAT WALL HELICAL FIRST WALL AND INTEGRATED ONCE-THRU FW/BLANKET CONCEPTS

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FW/BLANKET DESIGN NECESSARY AND DESIRABLE ATTRIBUTES

• Adequate tritium breeding
• Sound structural design
• Acceptable thermal hydraulics
• Reliable materials performance over lifetime/maintainable
• High power density
• Safety and environmental impacts

— Low tritium inventory and favorable tritium control — Low afterheat, passive safety and minimum radioactivity release — Class-C waste disposal

• High power conversion efficiency
• Suitable first wall coating and coupling with the divertor design
• Compatibility with plasma operation
• Possibility of high Tout for hydrogen production

Assessed items

4/10/02

• A cross sectional view at mid-

plane of the suggested Dry Wall - APEX Design that uses slow flowing Lead as a multiplier and FLIBE as a breeder /multiplier coolant media.

• A fast FLIBE flows in the first

wall in a helical fashion around the module.

• The supporting structure in zone

#5 is in a form of a helix with one turn in the poloidal direction The Flat-Helical FLIBE/Liquid Lead /Dry Wall APEX Design

University of Wisconsin-Madison

4 cm

Fast moving Liquid Flibe in the FW Liquid Lead (4 cm) FLIBE-4 30 cm Steel

Liquid Lead/FLIBE FW For APEX-Dry wall

Slower moving Liquid Flibe in Center

Plasma

All connections are at the bottom

Twisted Guiding Blades

FLIBE- 2 FLIBE- 3 (1 cm) FLIBE- 1 (FW) (FLIBE-4&5) FLIBE-5

Twisted Guiding Blades

University of Wisconsin-Madison

The Flat-Helical FLIBE/Liquid Lead /Dry Wall APEX Design

• The total frictional pressure

drop shows a minimum at FW channel width of 3.5 mm.

• Unfortunately it gives about

70°C temperature difference in the FLIBE film at the Pb back coolant side.

• Working near the optimum

at about 4 mm FW channel width gives a total temperature rise 102°C, and about 5.75 ATM total frictional pressure drop.

University of Wisconsin-Madison

The Flat-Helical FLIBE/Liquid Lead /Dry Wall APEX Design

Conclusions

• With a coolant loop of the shortest

length (one upward and one downward) the frictional pressure drop is minimal.

• The coolant speed is fast where needed

and slow where not needed.

• Simplicity in manufacturing a double

wall with helical guiding blades.

• Design guide lines for temperatures are

satisfied.

• However interface temperature at

lead/steel could reach 810°C, and it is a concern?.

4 cm

Liquid Lead (4 cm) FLIBE-4 30 cm Steel

Plasma

FLIBE- 2 FLIBE- 3 (1 cm) FLIBE- 1 (FW) FLIBE-5

Twisted Guiding Blades 600°C 640 °C 690 °C 3mm 5mm 680 °C 730 °C 810 °C Lead FW

4 cm

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INTEGRATED ONCE-THRU FW/BLANKET CONCEPT

“Looking for a simple and credible design”

• Started with a configuration with the ARIES maintenance scheme
• Considered fabrication possibility
• Initiated calculation of energy balance
• Analyzed thermal hydraulics for key zones at top/middle/bottom
• f a poloidal module
• Provided results for neutronics/structural and safety assessment

Concept Evaluation Approach

INTO Pb COOLANT CHANNELS FLiBe IN FROM Pb COOLANT CHANNELS TO SIDEWALL CHANNELS OUT FROM THE CENTRAL FLIBE ZONE

ONCE-THRU FLOW CONFIGURATION

COSMOS PROGRAM IS SETUP TO ANALYZE THE DESIGN INPUTS: POWER DENSITIES HEA T TRANSFER COEFF PRESSURE DR OPS OUTPUTS:

s

PRIMARY

= 24 MPA < 100 MPA

s s

P 2nd + = APPROX 300 MPA 300 MPA = <

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Mid-plane FW Tmax & Tinterface (NWL=7.5 MW/m2, 500/700 C)

500 550 600 650 700 750 800 850 900 950 1000 0.5 1 1.5 2 Heat flux, MW/m2 Temperature, C

Mid-plane Pb-zone Tmax and Tinterfaces (Max NWL=7.5 MW/m2, 500/700 C)

500 600 700 800 900 1000 1100 1200 1300 1400 0.5 1 1.5 2 Heat flux, MW/m2 Temperature, C

First wall and total pressure drop (max NML=7.5 MW/m2, 500/700 C)

0.2 0.4 0.6 0.8 1 1.2 1.4 0.5 1 1.5 2 Heat flux, MW/m2 Pressure drop, MPa

Performance of the Integrated Once Thru Concept

(First wall channel: 1 cm deep and 1.5 cm wide)

• With an average neutron wall loading of 5 MW/m2,

the design can handle heat flux of 1 MW/m2 (13% of NWL)

• NCF/Pb interface T~720° C, TPb-max~1320° C
• Pressure drops are inputs to structural analysis

Tmax Pb Tmax Flibe/NCF Tinterface Pb/NCF Tinterface Flibe/NCF Tinterface FW Total frictional

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Case 1 2 3 4 First Wall at mid-plane FW Heat flux, MW/m2 0.75 0.9 1.05 1.5 Tout, ˚C 539.7 542.5 545.2 552.9 Tcoolant at mid-plane, ˚C 519.8 521.2 522.6 526.4 Flibe Velocity, m/s 4.69 4.77 4.86 5.11 Re 5758 5923 6088 6583 h, W/m2K 7566 7736 7905 8412 FW/Flibe Tinterface, ˚C 643 661 678 726 FW Tmax, ˚C 735 767 798 887 Pb-Zone, 5.6 cm thick at mid-plane NCF and Flibe interface, ˚C 659.44 659.46 659.52 659.8 NCF and Pb interface, FW ˚C 721.78 721.8 721.86 722.2 Pb Tmax, ˚C 1316 1316 1316 1316 Pressure drop First wall pressure drop, MPa 0.58 0.6 0.62 0.67 Total module frictional pressure drop, MPa 0.94 0.97 0.998 1.08

SELECTED THERMAL HYDRAULIC RESULTS AT MID-PLANE (Inputs: Average neutron wall loading @ 5 MW/m2 and max neutron wall loading @ 7.45 MW/m2.)

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zone Thickness Flibe NCF Pb 1 First wall 3 mm 1 2 FW Flibe channel, poloidal 10 mm 0.83 0.17 3 NCF wall 3 mm 1 4 Pb mulitplier 56 mm 0.27 0.17 0.56 5 NCF wall 2 3 mm 1 6 Flibe channel+side wall 197 mm 0.983 0.017 7 Flibe channel back wall 10 mm 1 8 Back wall Flibe channel 15 mm 0.83 0.17 9 Back wall 3 mm 1 Total 300 mm

50 cm secondary blanket (94% Flibe, 6% NCF) used in OB region

Preliminary Neutronics Analysis for the Integrated Once thru FW/blanket Concept

Neutronics performed to determine TBR and provide input for thermal hydraulics analysis Radial build for the front FW/blanket

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Guidelines for blanket concept assessment peak nuclear heating in blanket for 1 MW/m2

Flibe 8 W/cm3 NCF 8 W/cm3 Pb 7.7 W/cm3 Be 8.5 W/cm3 Power density falls radially with 15 cm e-folding

Local TBR not very sensitive to Pb zone thickness due to high threshold energy of (n,2n) in Pb. Only ~3% enhancement in TBR achieved by increasing Pb zone from 4 to 8 cm Local TBR values using the radial build of the once thru design and natural Li OB 1.197, IB 0.949 Ø Enriching Li to 30-50% Li-6 enhances TBR by ~7%

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0.90 0.95 1.00 1.05 1.10 1.15 1.20 1.25 1.30 20 40 60 80 100

OB IB

Local TBR % Li-6

• Local TBR not very sensitive to Pb zone thickness due to high threshold energy of (n,2n) in Pb.

Only ~3% enhancement in TBR achieved by increasing Pb zone from 4 to 8 cm

• Local TBR values using the radial build of the once thru design and natural Li OB 1.197 IB
• Enriching Li to 30-50% Li-6 enhances TBR by ~7%

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Integrated once thru poloidal flow blanket The bending stresses are compared with allowable stresses in Fig. a-b as functions of channel width for a coolant pressure of 1 MPa. It is evident that 12YWT would be acceptable for all channel widths

• considered. Even MA957 will be acceptable for channel widths < 23 mm.

20 40 60 80 100 120 10 20 30 40 50 60 P

b/K (MPa)

Channel Width (mm) S

m for 12YWT

S

m for MA957

p=1 MPa T

avg=750°C

50 100 150 10 20 30 40 50 60 P

b/K eff (MPa)

S

t for 12YWT

S

t for MA957

p=1 MPa T

avg=750°C

Channel Width (mm)

Variation of (a) modified primary bending (Pb/K) stresses and (b) modified primary bending stresses (Pb/Keff) with channel width for integrated poloidal once thru blanket design.

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QTYUIOP Hydrogen production blanket, Tin=500° C, Tout=950° C

Mid-plane FW Tmax $ Tinterface (NWL=3 MW/m2, 500/950 C)

500 550 600 650 700 750 800 850 0.2 0.3 0.4 0.5 0.6 0.7 0.8 Heat flux, MW/m2 Temperature, C

Mid-plane Pb-zone Tmax and Tinterfaces (Max NWL=3 MW/m2, 500-950)

500 600 700 800 900 1000 1100 0.5 1 1.5 2 Heat flux, MW/m2 Temperature, C

First wall and total pressure drop (max NML=3 MW/m2, 500/950 C)

0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5 1 1.5 2 Heat flux, MW/m2 Pressure drop MPa

(First wall channel: 0.5 cm deep and 1 cm wide)

• With an average neutron wall loading of 2 MW/m2,

the design can handle heat flux of ~0.54MW/m2 (18%) , limited by NCF/Flibe interface T in the Pb zone

• NCF/Pb interface T~730° C, TPb-max~990° C
• Pressure drop is lower than the reference case
• Design is not optimized, but indicates the possibility of Tout @ 950° C
• Thermal insulation, e.g. Porous SiC/Flibe, will be needed in the Flibe channel

Tmax Flibe/NCF Tinterface Pb Tmax Pb/NCF Tinterface Flibe/NCF Tinterface Total frictional FW

APEX4-04-02

QTYUIOP OBSERVATIONS

• S. Malang’s ARIES-AT FW/blanket general approach seems to be

applicable to the NCF/Flibe combination of materials

• Recirculated FW-Coolant with pump, Helical FW with flow control and

integrated once-thru concepts are all based on similar approach,this shows convergence of ideas and group verification of quantified results. Further narrowing of concept will be done.

• All concepts are not optimized, but they exhibit the possibility of getting

high outlet coolant temperature for hydrogen production.

• Key uncertainties are allowable temperatures: Pb/NCF (To Be or not to

Be?), Flibe/SiC (thermal insulator) and Pb.

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Issues for the integral once thru poloidal flow concept

• Top and bottom flow distribution
• Fabrication
• Compatibility: NCF/Flibe, NCF/Pb
• Maximum allowed temp. for Pb
• Thermal physical properties of Flibe
• Limited heat flux capability
• NCF material issues
• NCF impacts on plasma operation and confinement
• Stabilizing coil design

Common issues with other Pb multiplier concepts: