Conceptual Design of Advanced Blanket Using Liquid Li-Pb

Transcription

1 Japan- US workshop on Fusion Power Plants and related advanced technologies with participation of EU February 5-7, 2007 at Kyoto, Japan Conceptual Design of Advanced Blanket Using Liquid Li-Pb Y. Yamamoto, Y. Ueno, and S. Konishi Inst. of Advanced Energy, Kyoto University

2 Li-Pb blanket studies at Kyoto Univ. Topics include in this talk Li-Pb loop and its operation SiC-LiPb blanket concept development Deuterium permeability evaluation of SiC materials at high temperature Solid electrolyte cell studies for LiPb purity control

3 LiPb Loop in Kyoto University Expansion Tank Test section operated above 600 Magnet Trap temperature [ ] 350~450 Ar Li-Pb Filter 2 Flow Meter EM Pump Filter 1 Drain Tank inventory [liter] Flow rate[l/min] fluid material 6 0~5 Li-Pb SUS316

4 LiPb Loop in Kyoto University

5 High Temperature Operation 運転記録 700 Operation velocity : 0.7~1.0 cm/s 700 Temperature [deg.c] HT CS1 CS2 CS Hour [h] 16 hours operation above 650, maximum temperature is 710 Temperature fluctuated due to flowing rate fluctuations

6 MHD pressure drop measurement φ150 iron coil Magnetic Field Lorentz Force Liquid Li- Pb Flow φ50 Li-Pb P =σb 2 vl loss σ : resisntance v : velocityl : diameter insulator 3/4 tube B : Magnetic field Magnetic Field Strength [T] Eddy Current Eddy Current Current [A]

7 MHD pressure drop measurement Pressure [kpa] Measure Calc T = 350 [deg.] B = 0.11 [T] Temperature 350 Magnetic Field 0.11T Flow rate 1.75~4.5 [l/min] velocity 18.27~47.25 [cm/s] Flow Speed [cm/s]

8 Compatibility tests SiC/SiC composite tube was installed in the LiPb loop Tube section was heated above 600 degree C with LiPb flow Possible corrosion is observed with mucroscopes. SiC/SiC tube Inner surface of SiC after exposure Test section : heated and cooled

9 Compatibility test 2 Same compatibility test being performed with stainless steel, Ferritic steel and other candidate materials. Stainless steel tube Microscope image Electron-microscope image

10 R&D for LiPb-SiC blanket 1) LiPb-RAFM blanket with SiC insert compatibility issue thermal insulation MHD pressure drop tritium solubility LiPb Dual coolant:lipb+he SiCinsert 2) SiC Heat Exchanger program Dual coolant for high temperature heat heat extraction with He from LiPb using SiC components. high temperature He as secondary heat transfer medium. He SiC IHX High temperature He

11 SiC-LiPb Blanket Concept Outer blanket calculation model 1.RAFS module box (~500ºC) 2.SiC/SiC active cooling panel Li-Pb Flow 3.High temp. outlet (~900ºC) Module box temperature made of the RAFS must keep under 500 ºC. Li-Pb outlet temperature target 900 ºC. We propose the new model of active cooling in Li-Pb blanket. This concept is equipped He coolant channels in SiC/SiC composite and provides more efficient isolation between the RAFS and high temperature Li-Pb. We evaluate the feasibility of high temperature blanket in this model.

12 Model of Calculation (ANISN) 1MW/m 2 Neutron Flux Plasma Region 100 [cm] One Dimensional Neutron Transport Code (ANISN) TBR Neutron Shield Nuclear Heating Li 17 -Pb 83 SiC/SiC:1.5 [cm] 0.5x0.5cm He Channel FW(F82H):1.5 [cm] 0.5x0.5 He Channel (8MPa) Li-Pb [cm] (Net thickness [cm]) 6 Li [%] 40.5~55 (45~59.5) 7.4 ~ 90

13 Neutron Shielding Neutron Neutron Flux flux [n/s/cm [n/s/m 2 ] 2 ] Distribution of Neutron Flux 14MeV 0.1MeV Total Distance Wall thickness from the center [cm] [cm] All Neutron Flux 6 Li = 90%, TBR = 1.2, Li-Pb = 40.5 cm With thickness of 43 cm can be obtained ; 10 2 decrease 0.1 MeV 10 2 decrease 14 MeV 10 3 decrease Neutron Flux on blanket back Neutron [n/s/cm Flux [n/s/cm 2 ] 2 ] Relation with Thickness (Li-Pb) and Neutron Flux on end of blanket MeV 0.1 MeV Total 6 Li = 90%, TBR = Thickness Li-Pb thickness (Li-Pb) [cm] 50cm Li-Pb (6Li 90%) provides these parameters.

14 Tritium Breeding TBR Tritium Breeding Rate Total 6 Li 7 Li 6 Li = 7.4%, Li-Pb thickness [cm] [cm] Contribution to 7 Li for TBR is less than 5% of all. 6 Li concentration is needed. TBR Relation with Thickness (Li-Pb) and TBR % 30% 50% 70% 90% Li-Pb 層厚 [cm] Thickness (Li-Pb) [cm] TBR >= Li = 7.4 ~ 90% 6 Li 70% 55cm 6 Li 90% 50cm

15 Evaluation of Nuclear Heating Heat generation 発熱量 per unit [W/cm volume 2 ] [W/cm 3 ] Distribution of nuclear heating Photon Neutron Total 中心からの距離 Wall thickness [cm] 6 Li = 90%, TBR = 1.2, Li-Pb = 50cm Distribution of nuclear heating was calculated. Intense nuclear heating by neutron was observed at the front of Li-Pb Heat removal corresponds to this distribution must be designed. F82H He SiC/SiC Li-Pb

16 Heat Transfer Analysis Temperature of RAFS side must keep under 500ºC. Temperature of Li-Pb is determined by active cooling of SiC/SiC composite panel with He channels. v RAFS side ~500 [ºC] He Channel Li-Pb side L d 1 1. High Temperature Li-Pb 2. Large Nuclear Heating Max 500 [ºC] SiC/SiC Layer For example : T He =350 [ºC], V He = 8 [m/s] 600 [ºC]

17 Results of Heat Transfer Analysis He Flow Speed [m/s] He temp Max Li-Pb temperature is obtained as a function of He coolant flow speed. He Coolant Temp. = 350 ºC Max LiPb temp. He flow speed ºC 11.6 m/s Li-Pb side temperature [deg.c] 700ºC 800ºC 16.5 m/s 21.0 m/s Relation with Li-Pb side temperature and He velocity (P He = 8 [MPa]) SiC/SiC 1.5 cm, He channel 0.5x0.5cm 900ºC 25.5 m/s 900 ºC Li-Pb is possible with moderate He velocity.

18 Outlet Temp. and Velocity of Li-Pb Total accepted heat value on 体積発熱量 outlet [J/cm [W/cm 3 ] 3 ] 体積発熱量 Heat value [W/cm [J/cm 3 ] 3 ] 出口温度 Outlet [deg.] [ ] Li-Pb 流速 velocity [cm/s] [cm/s] Relation with outlet temperature and Li-Pb flow velocity Net thickness 54.5 cm, Li-Pb thickness 50 cm 6 Li = 90%, TBR = 1.2 Li-Pb inlet : 300ºC Mean Flow Path 100 cm, Flow path height 10cm Outlet [deg.] 出口温度 [ ] Required Li-Pb velocity is calculated. Outlet temp. 600ºC 700ºC 800ºC 900ºC LiPb flow speed 1.01 cm/s 0.78 cm/s 0.68 cm/s 0.51 cm/s The MHD pressure drop is considered to be negligible in this condition ( ~1 cm/s).

19 Conclusion LiPb-SiC blanket concept is now actively studied in Japan at Kyoto University. Experimental study is performed to confirm the and design. Some of the experiments are unique and valuable for international efforts for liquid blanket development, particularly DCLL or similar.

20 Long term plan Ultimate goal of this program in Kyoto is to develop a concept of high temperature blanket. Small scale blanket module will be demonstrated in 4 years. System and component design will be made. Small neutron source will be used for tritium transfer experiment. DCLL and further SiC-LiPb configuration will be possible to be tested under TBM. Feasibility of high temperature blanket is of extreme importance for efficient generation and hydrogen production process. (We also study socio-economics of fusion in future market.)