FLAT WALL HELICAL FIRST WALL AND INTEGRATED ONCE-THRU FW/BLANKET CONCEPTS 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 QTYUIOP APEX4-04-02
FW/BLANKET DESIGN NECESSARY AND DESIRABLE ATTRIBUTES Adequate tritium breeding ● Assessed items 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 ● QTYUIOP APEX4-04-02
The Flat-Helical FLIBE/Liquid Lead /Dry Wall APEX Design Slower moving Liquid Flibe in (FLIBE-4&5) Center • A cross sectional view at mid- plane of the suggested Dry Wall - Fast moving Liquid Flibe APEX Design that uses slow in the FW flowing Lead as a multiplier and Twisted FLIBE as a breeder /multiplier Guiding Blades coolant media. All connections are • A fast FLIBE flows in the first at the bottom wall in a helical fashion around the module. 30 cm • The supporting structure in zone FLIBE- 2 4 cm Steel FLIBE-5 #5 is in a form of a helix with one Twisted Guiding FLIBE- 3 turn in the poloidal direction Blades FLIBE-4 (1 cm) Liquid Lead (4 cm) FLIBE- 1 Plasma (FW) Liquid Lead/FLIBE FW University of 4/10/02 Wisconsin-Madison For APEX-Dry wall
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 30 cm length (one upward and one downward) FLIBE- 2 4 cm Steel the frictional pressure drop is minimal. FLIBE-5 • The coolant speed is fast where needed Twisted Guiding FLIBE- 3 and slow where not needed. Blades FLIBE-4 (1 cm) • Simplicity in manufacturing a double Liquid Lead wall with helical guiding blades. (4 cm) FLIBE- 1 Plasma (FW) • Design guide lines for temperatures are satisfied. 5mm 3mm • However interface temperature at FW lead/steel could reach 810°C, and it is a 810 °C concern?. 690 °C 730 °C 640 °C Lead 680 °C 600°C University of 4 cm Wisconsin-Madison
INTEGRATED ONCE-THRU FW/BLANKET CONCEPT “Looking for a simple and credible design” Concept Evaluation Approach • 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 of a poloidal module • Provided results for neutronics/structural and safety assessment QTYUIOP APEX4-04-02
s s s COSMOS PROGRAM IS SETUP INTO Pb COOLANT TO ANALYZE THE DESIGN CHANNELS INPUTS: POWER DENSITIES � HEA T TRANSFER COEFF � PRESSURE DR OPS FLiBe IN FROM Pb COOLANT CHANNELS TO OUTPUTS: SIDEWALL CHANNELS = 24 MPA < 100 MPA PRIMARY < = APPROX 300 MPA 300 MPA + = 2nd P OUT FROM THE CENTRAL FLIBE ZONE ONCE-THRU FLOW CONFIGURATION
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/m 2 , the design can handle heat flux of 1 MW/m 2 (13% of NWL) • NCF/Pb interface T~720° C, T Pb-max ~1320° C • Pressure drops are inputs to structural analysis Mid-plane Pb-zone Tmax and Tinterfaces Mid-plane FW Tmax & Tinterface First wall and total pressure drop (Max NWL=7.5 MW/m2, 500/700 C) (max NML=7.5 MW/m2, 500/700 C) (NWL=7.5 MW/m2, 500/700 C) 1.4 1400 Pb Tmax 1000 1300 950 1.2 Total frictional 900 1200 Tmax 1 Pressure drop, MPa 850 1100 Temperature, C Temperature, C 800 0.8 1000 750 900 0.6 Pb/NCF Tinterface FW 700 800 650 0.4 Flibe/NCF Tinterface 700 600 0.2 600 550 Flibe/NCF Tinterface 500 0 500 0.5 1 1.5 2 0.5 1 1.5 2 0.5 1 1.5 2 Heat flux, MW/m2 Heat flux, MW/m2 Heat flux, MW/m2 QTYUIOP APEX4-04-02
SELECTED THERMAL HYDRAULIC RESULTS AT MID-PLANE (Inputs: Average neutron wall loading @ 5 MW/m 2 and max neutron wall loading @ 7.45 MW/m 2 .) Case 1 2 3 4 First Wall at mid-plane FW Heat flux, MW/m 2 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/m 2 K 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 QTYUIOP APEX4-04-02
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 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 QTYUIOP APEX4-04-02
Guidelines for blanket concept assessment peak nuclear heating in blanket for 1 MW/m 2 Flibe 8 W/cm 3 NCF 8 W/cm 3 Pb 7.7 W/cm 3 Be 8.5 W/cm 3 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% QTYUIOP APEX4-04-02
• 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% 1.30 1.25 1.20 Local TBR 1.15 1.10 OB IB 1.05 1.00 0.95 0.90 0 20 40 60 80 100 % Li-6 QTYUIOP APEX4-04-02
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. 120 150 100 S m for 12YWT S t for 12YWT 100 80 b /K eff (MPa) p=1 MPa b /K (MPa) S m for MA957 60 T avg =750°C 50 40 P S t for MA957 P p=1 MPa 20 T avg =750°C 0 0 0 10 20 30 40 50 60 0 10 20 30 40 50 60 Channel Width (mm) 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. QTYUIOP APEX4-04-02
Hydrogen production blanket, Tin=500° C, Tout=950° C (First wall channel: 0.5 cm deep and 1 cm wide) • With an average neutron wall loading of 2 MW/m 2 , the design can handle heat flux of ~0.54MW/m 2 (18%) , limited by NCF/Flibe interface T in the Pb zone • NCF/Pb interface T~730° C, T Pb-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 Mid-plane FW Tmax $ Tinterface Mid-plane Pb-zone Tmax and Tinterfaces First wall and total pressure drop (Max NWL=3 MW/m2, 500-950) (max NML=3 MW/m2, 500/950 C) (NWL=3 MW/m2, 500/950 C) 1100 0.45 Pb Tmax Total frictional 850 0.4 1000 800 0.35 Tmax Pressure drop MPa 750 0.3 900 Temperature, C Temperature, C 0.25 700 Pb/NCF Tinterface 800 0.2 Flibe/NCF Tinterface FW 650 700 0.15 600 Flibe/NCF Tinterface 0.1 600 550 0.05 0 500 500 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.5 1 1.5 2 0.5 1 1.5 2 Heat flux, MW/m2 Heat flux, MW/m2 Heat flux, MW/m2 QTYUIOP APEX4-04-02
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