Fast Reactor Physics Konstantin Mikityuk , FAST reactors group @ PSI fast.web.psi.ch
Activities on reactor design for fast ignition
description
Transcript of Activities on reactor design for fast ignition
ILE OsakaActivities on reactor design for fast ignition
T. Norimatsu, H. Azechi, Y. Kozaki, Y. Fujimoto, T. Jitsuno, T. Kanabe, R. Kodama, K. Kondo, N. Miyanaga, H. Nagatomo, M. Nakatsuka, H. Shiraga, K. A.
Tanaka, K. Tsubakimoto, M. Yamanaka, R. Yasuhara, and Y. Izawa,
Institute of Laser Engineering, Osaka University, 2-6, Yamada-oka, Suita, Osaka 565-0871, Japan, E-mail; [email protected]
Presented at
Japan-US workshop on Laser IFE
March 21-23, 2005, GA. San Diego, USA
ILE Osaka
Outline• Introduction
– IFE plant Design Committee– Roadmap
• Chamber concept– KOYO-F with a wet wall
• Protection scheme for the final optics
• Scenario for fuel loading and injection
• Summary
ILE Osaka
IFE plant design committee was organized under collaboration of ILE, Osaka and IFE Forum.
• Chairman: K. Tomabechi Blue; from companyVice chairman: Y. Kozaki, T. Norimatsu Black; form university
• Supervisor groupK. Ueda, M. Nishikwam K. Okano, T. Yamanaka, A. Nosaka, Y. Ogawa, H. Kan, A. Koyama, T. Konishi, N. Tanaka, A. Sagara, Y. Hirooka, H. Nakazato, Y. Soman, H. Azechil K. Mima, S. Mori, Y. Nakao, N. Miyanaga, M. Nishikawa, K. Tanaka
• Plasma working groupH. Azechi, H. Shiraga, K. Mima, R. Kodama, Y. Nakao, H. Nagatomo, S. Ishiguro, T. Jozaki
• Laser working groupN. Miyanaga, Y. Suzuki, Y. Owadano, T. Jitsuno, M. Nakatsuka, H. Fujita, K. Yoshida, H. Nakano, T. Kanabe, H. Kubomura, Y. Fujimoto, T. Tsubakimoto, T. Kawashima, H. Furukawa, J. Nishimae
• Target working groupT. Norimatsu, A. Iwamoto, M. Nishikawa, M. Nakai, H. Yoshida, T. Endo
• System working groupY. Kozaki, K. Okano, A. Sagara, Kunugi, T. Konishi, H. Furukawa, M. Nishikawa, Y. Sakawa, Y. Ueda, K. Hayashi, Y. Soman, M. Nakai
ILE Osaka
Fast ignition can reduce the required laser energy because of the smaller PV work.
rh
h < c/4
rcrc
rh < rc/4h ~ c
Fast heating needs petawatt laser.Critical issue is energy coupling.
Central ignition Fuel capsule is compressed with 4MJ laser to nucleate a hot core for self ignition.
Compression Ignition Burn
Heating laser 1-10 ps pulse length 50 - 100 kJ
Compression laser 10 ns pulse length 50-500 kJ
Fast ignition Fuel capsule is compressed with 0.5 MJ laser to a high density and ignited by a PW laser.
Gain for commercial reactor
US NIF
KOYO
0.01 0.1 1 10
Laser Energy (MJ)
1
10
100
Fu
sio
n G
ain
Fast ignirionCentral ignition
KOYO-F (solid wall)
KOYO-F (liquid wall)
ILE Osaka
Actual energy and power of heating laser required for fast ignition after S. Atzeni, (Phy.Plasmas’99)
Assuming high energy electron range ;d = 0.6 g/cm2
• Eh = 140{/(100g/cc)}-1.85 kJ • Pb = 2.6{/(100g/cc)}-1.0 PW • Ib = 2.4X1019 {/(100g/cc)}0.95 W/cm2 • rb = 60{/(100g/cc)}-0.975 m
d
R
rb
EL= 60 - 100 kJ
40 60 80 1000
50
100
150
Targ
et
Gain
Driver Energy for Core Heating, Edh [kJ]
Pure DT10mg/cc Foam
30mg/cc Foam
ILE Osaka
Roadmap toward laser fusion power plant by fast ignition
Road map of Fueling
FIREX (Fast Ignition Realization Experiment)
2005 2010 2015 2020 2025 2030
Conceptual design Design LFER Laser Fusion Experiment ReactorHigh Repetition
Test Facility
DEMO Power PlantDesign
Cryogenic Technology
Foam method
Controlled beta layering
Mass production
Elemental technology Shell, Cone, Assembling
Fuel loading
Injection
Pneumatic method
Coil gun method
Full injection system Continuou mode
DesignOff site
Target Factory
DesignOn site
Fueling system
Tracking
Optical phase conjugationmethod
Optical Correlator method
System integration
Multi injection system Burst mode
ILE Osaka
Outline• Introduction
– Reactor Design Committee– Roadmap
• Chamber concept– KOYO-F with a wet wall
• Protection scheme for the final optics
• Scenario for fuel loading and injection
• Summary
ILE Osaka
Basic specification of KOYO-F with liquid wall
• Plant with 5 modular reactors– Electric output power 1200 MW
(250MW for laser)
• Laser 1100kJ+100kJRep-rate 4 Hz x 4Operation power 250 MW
• Target gain 160Blanket gain 1.15Thermal output power 770 MW/reactor
• Conversion efficiency 40 %
ILE Osaka
Wet wall reactor for fast ignition scheme
• KOYO-F has 1.1 MJ, 32 beams for compression, 100kJ heating laser and two target injectors.
• Thermal out put 200 MJ/shotRep-rate 4 Hz
• KOYO-F has vertically off-centered irradiation geometry to simplify the protection of ceiling.
ILE Osaka
Layout of heating laser makes new issue.
30 compression beams + heating laser 32 compression beams + heating laser
(0,0,0)
(1,0,0)
In the case of (0,0,0) layout, 80 % energy of neighboring 3 beams irradiates the cone.Power control is necessary.
ILE Osaka
In the previous cascade reactor, chamber clearance would be the critical issue.
Ten kg of LiPb will evaporate by a microexplosin. Top-open geometry will form an upwardflow, which would make the clearance time longer.
ILE Osaka
The first wall is pours metal plates that are saturated with liquid LiPb and are tilted to make a down flow after collisions at the center.
Average gas pressure assuming pure laminar flowY. Kozaki et al., IAEA, FEC
Mixing of surface flow is necessary to reduce the vapor pressure before the next laser irradiation.
ILE Osaka
To keep the surface wet, pours metal will be used.
• Pours metal allows penetration of Liquid LiPb, resulting the surface is always kept wet.
This scheme can save the electric power to circulate the heavy liquid LiPb.1MW for the surface flow0.3 MW for blanket.
Ferrite
1m
0.1m
400oC0.8m3/s
400oC2.1m3/s
500oC550oC
Vav=0.4m/s
Vav=0.1m/s
t=1.3 oC/shott=0.5 oC/shot
1 m
Graphite
1 m
LiPb Blanket
0.2 m
Gass buffer to prevent "water hammer" Porous metal
Average flow rate0.1 m/s
0.2 m/s
ILE Osaka
For laser and utilities
250MWe
Concept of cooling system
For 1st wall
Electric power1450MWeT -> E 41%
Electric output
1200MWe
Turbine
By SohmanJNC
Generator
Steam generator
Blanket
400℃
400℃
550℃
500℃
Blanket
Liquid wall
Reactor
4 reactors
(LiPb)
(LiPb)
(LiPb)
(LiPb)
3.1×10 7 kg/h (0.83m 3 /s)
8.38×10 7 kg/h (2.22m 3 /s)Fusion yield (with blanket)
770MWt (870MWt)
,750MWt
,150MWt
ILE Osaka
Outline• Introduction
– Reactor Design Committee
• Chamber concept– KOYO-F with a wet wall
• Protection scheme for the final optics
• Scenario for fuel loading and injection
• Summary
ILE Osaka
P 1
Motion of ablated plume
1016
1017
1018
1019
1020
1021
1022
1023
103
104
105
Number Density
Temperature
(b)
Tem
peratu
re (Kelv
in)
Nu
mb
er
Den
sity
(cm-3
) Time = 2982.1 ns
0 0.2 0.4 0.8 1.00.6x (mm)
Reference H. Furukawa, Y. Kozaki, K. Yamamoto, T. Johzaki, and Kunioki Mima, ‘ Simulation on Interactions of X-Ray and Charged Particles with First Wall for IFE Reactor ‘ Submitted to Fusion Engineering and Design (2004).
1020
1021
1022
1023
103
104
105
0 0.2 0.4 0.6 0.8 1
Num
ber D
ensi
ty (cm-3
) Tem
peratu
re (Kelv
in)
x (mm)
Temperature
Number Density
Simulation resultInitial condition for analytical model
140m/s
ILE Osaka
P 4
Saturation and Quenching of Pb plume in spherical isothermal expansion
A saturation wave , and a quenching wave propagate from outside to the center.When the saturation wave passed by, condensation starts. (The temperature
decreases.)
When the quenching wave passed by, condensation ends. ( The density is too low)
10-1
100
101
102
10-1 100 101 102
u0 = 105 cm / s
r (t
) / R
0
Time (s)
Quenching Wave
Saturation Wave
Plume Boundary
10-1
100
101
102
10-1 100 101 102
Time (s)
u0 = 3x104 cm / s
Plume Boundary
Quenching Wave
Saturation Wave
r (t
) / R
0
rc t / R t 1 Tc /T0 t rq t / R t 1 tk t d t / dt 1/2
ILE Osaka
Protection scheme of final optics by synchronized rotary shutters
0.05Torr Xe or D2
The rotational speed of the 1st disk is ~1000 rpm.
ILE Osaka
Simulation of liquid wall reactor started.
LiPb in 2004
ILE Osaka
No deposition of LiPb was observed on witness plate in 0.1 Torr H2.
0
20
40
60
80
100
0 200 400 600 800 1000 1200
No increase in absorption was obserbed.
Glass substrateTopBottom
Tra
ns
mit
tan
ce
(%
)
Wavelength (nm)
Pb deposition area
It seems that Pb vapor condenses on cold surface before forming aerosol.
3 cm
50 cm
1400K
800K
300K
500K
Pb vapor rich
H2
ILE Osaka
Pb vapor whose initial speed of 100 m/s can not reach final optics in 0.1 Torr buffer gas.
0.5m
100m/s
Pb get into the duct at the rage of 5 mg/shot.-> 473 kg/year !! Cleaning is necessary.
ILE Osaka
Compression beams
Fire position
Chamber center
Aerozol
Top view
Target injector
If evaporated vapors collide at the center and lose the momentum, the rep-rate would be limited.
Offset irradiation would be the solution.
In the case of LFE reactor, the fire position is not necessary at the chamber center.
ILE Osaka
Outline• Introduction
– Reactor Design Committee
• Chamber concept– KOYO-F with a wet wall
• Protection scheme for the final optics
• Scenario for fuel loading and injection
• Summary
ILE Osaka
Two or three injector will be used because it seems difficult to load fragile foam targets
into the sabots at 4 Hz
• Pneumatic acceleration with 80K He and fine adjustment by coils• V=300+/-1m/s 2 Hz operation
0 m10 m20 m30 m
1st 2nd
Pneumatic gun Coil gun
Differential pump zone
Sabot decelerator
Detection Differential pump Sabot collect
Fuel, Sabot loading zone Rotary shutter
10 m
2 Hz x 2 = 4Hz あるいは 3基に増やし、1台は故障時用のオプションも
ILE Osaka
Model target
• Foam insulated Solid DT with LiPb cone whose inner surface is parabolic
• Shell Outer insulator 250mg/cc 200m Gas barrier 2m Solid DT 200m
• Cone LiPb 0.5 g
Issue; Fabrication of cone with LiPb How to fill the fuel in short time?
3.46 mm
5 mm
8.5 mm
5 m
m3.5 mm
15o
1.06 mm
24.5oFor Reactor
ILE Osaka
Thermal cavitation technique is the solution for fuel loading in batch process.
• Thermal cavitation method can fill liquid fuel into foam layer without feed-back control.
• Required condition is;
Diameter of foam shell >>Vent port > Feeder port >> Cell size of foam
Vent holeFeeder hole
ILE Osaka
Demonstration of thermal cavitation with hemi foam shell
• Liquid D2 was evacuated by a heater outside the pot.
ヒーター
CCDカメラ
液体重水素
ILE Osaka
Step 1 Saturation of foam with liquid DT
ILE Osaka
Step 2 Evacuation by laser heating
ILE Osaka
Step 3 Finish
ILE Osaka
Extra fuel (5.4%) will be loaded due to the meniscus formed between cone and shell.
• Liquid fuel in outer meniscus will move to inside after stopping the laser irradiation.
• There is another extra liquid in the meniscus formed between the cone and inner surface of the foam layer.
• These extra fuel will compensate the shrinkage of hydrogen during freexing(15%)..
ILE Osaka
Fuel loading system by thermal cavitation method.
n=20 x 80 (for 13 min at 2 Hz)
12 cm
Air lock
Air lockAir lockCooling zone Freezing zoneLoading zone
Liquid N2
Liquid He
20 K He 100 torr
19 K DT 128 torr
19 K DT 128 torr
10 K DT 1 torr
DT Pump
DT Pump
2nd Tritium barrier
Vacuum vessel
3 hr
Vacuum Pump
TRS IS & Strage
To injector
Laser Not to scale
Tritium inventory100g
ILE Osaka
When gun length is 10 m, residual gas pressure at the next injection is estimated to be 0.03 atm, which may disturb
cryogenic layer.
For simplification, the gas is initially stationary and pumping starts at both ends at t=0.
Pevac pressure in tube at the next injection
tevac time needs for evacuation Our estimation indicated that the pressure of residual gas at the next injection is 0.03 atm.
Thermal load for cryogenic target?
Needs differential pumping system
This work is supported by Dr. T. Endo of Hiroshima Univ..
ILE Osaka
To vacuum
Radiation shield
To vacuum
Differential pumping
To vacuum
Room Temp. Atmospheric pressure
Cryogenic Temp. Vacuum
To vacuum
To vacuumTo vacuum
To coil gun
Concept of sabot / target loader
室温
10K
液体窒素温度
高速開閉バルブ全長の決定
乱流熱伝達率× 時間× 1/2(圧力低下分) 配管圧着時の両側からの熱流入量 でリボルバー部への熱流入量の決定。→ He冷却流量、電力評価 ↓ 元の10Kへの冷却に要する時間 ↓ 3Hzから回転部の大きさを決定
乗松 於 第3回 燃料系WG作業会 平成16年6月21日
ILE Osaka
ILE Osaka
The size of revolver needs about 60 cm in the diameter
• The thermal load due to propellant gas is ~1.2 kW.
• Heat exchange rate with liquid He is ~ 0.1 W/cm2.
• The diameter of revolver is estimated to be 60 cm, which makes hard to obtain high rep-rate.
4 Hz -> 2 Hz x 2
1.2 kW
60 cm
Estimation of thermal load 1
ILE Osaka
1 MW of electric power will be consumed to
operate a pneumatic injector.
室温
10K
液体窒素温度
Radiation shield
3 hr
280W
470W
to cool the revolver(280+470x2)×100=120 kW
66 kW
to cool thermal radiation66 ×10=660 kW
160 kW
to cool targets and egg plates200kW
In total 980kW / injector
Estimation of thermal load 2
ILE Osaka
ILE Osaka
Summary
• Conceptual design of KOYO-F is continued basing on a wet wall.
Critical issue of wet wall seems chamber clearance to achieve 4 Hz rep-rate.
• In a future laser fusion reactor, final optics at the end of 30m-long beam duct can be protected from metal vapor using a rotary shutter and 0.1 Torr hydrogen gas.
The vapor (v=100m/s) will stop within 6m from the entrance of beam port.
• Fuel loading in mass production process will be carried out by thermal cavitation technique. Accuracy of fuel loading (goal, < 1%) is future issue.