recent progress of the r&d and design for high temperature...
TRANSCRIPT
S. Konishi, K.Ibano, F. Okino, K. Noborio,
T. Shibata, Y. Yamamoto and R. Kasada
Kyoto University
Recent progress of the R&D and design for
high temperature blanket and
biomass hybrid concept
Japan-US Workshop on
Fusion Power Plants and Related Advanced Technologies
UC San Diego, La Jolla,
Mar. 8, 2012
Background Kyoto University pursues the Biomass Hybrid concept from
various aspects.
Particular interest is on Socio-Economics and possible
scenario for early introduction of Fusion, with minimal
extrapolation of the current technology.
Safety, environment and the adoptation to the future
energy system are our current concern.
Contents - LiPb blanket and tritium recovery / SiC study
- zero-carbon electricity system with Micro DC grid.
- Tritium in the environment
Introduction Institute of Advanced Energy, Kyoto University
High Plasma Q not required
18 10
10 22
10 21
10 20
10 19
1 10 100
T(kev)
Break-even
Q=1,η=1
Electricity
generation
Q=20,
ηe=0.33
biofuel
Q=5,
ηf=2.7
-0.6
Negative power
ITER
DEMO
Driven and pulsed
operation is acceptable
High temperature blanket
To be developed.
High output temperature is
required for gasification
efficiency is required
Biomass Hybrid Concept
Net
6Pf
Net
8Pf
Institute of Advanced Energy, Kyoto University
GNOME
4
Droplet and Diffusion
2 2 2
2 21
6 11 exp /t
n
MDn t
M n
a
droplet diameter is a
key factor for
optimum design of
the extraction system
Institute of Sustainable Science Institute of Advanced Energy, Kyoto University
5
A: Tritium balance study
To explicate the recovery
rate of Biomass Gasification
fusion reactor GNOME
B: Tentative observation of droplet
formation
from 1mm dia. nozzle by an
experimental setup (one point data )
Institute of Sustainable Science Institute of Advanced Energy, Kyoto University
Development of Vacuum Sieve Tray
Rp=5.2m Gasificationreactor
Pn ~1MW/m2
Hydrogen
Fuel
≧900oCHigh temp.
extraction
High η
IHX
Tritium Balance in plant
biomass
HEX
Tritium
4.5E - 04
LiPb Pb
Recovery System 1
Tritium Recovery System 2
Reactor Plasma
2.3 E - 8 2.5 E - 10
-
0.724 m 3 /s 0.652 m 3 /s
Permeation
Recovery
Consumption Blanket
4. 7 E - 04
Generation Permeation
IHX
Tritium
4.5E - 04
Pb
Recovery System 1
Tritium Recovery System 2
Reactor Plasma
T Recovered tritium
2.3 E - 8
2.3E- 08
2.5 E - 10
4.7E- 04
0.724 m 3 /s 0.652 m 3 /s
Permeation Consumption
Stock
2.3 E - 0 5 Stock
Stock
2.3 E - 0 5 Stock
[mol/s] Recovery
Blanket
4. 7 E - 04
Generation Permeation
IHX permeability , tritium confinement of
Entire power plant needs maturity and
Demonstration for social understanding.
Net TBR 1.05
n
T3-OS14
Yamamoto
Environ-mental release
Institute of Sustainable Science Institute of Advanced Energy, Kyoto University
Φ=4mm
+
+
0 2
2 2
2 2 4
) 1 2 ( exp[
) 1 2 (
8 1
j
t
l
D j
j M
M
] t
depth=√D
T2
LiPb
Blanket
IHX
Φ=4.6 m
H = 1.2m
at 500oC
Vacuum Sieve Tray
Vac.
Recovery ratio 45%
reruirement
Tritium in hydrogen
product
Inventory control
[mol] :gas release M(t )
[mol] :dissolved tas M∞
D t
[m]
[m2 s-1]
[s] :time
:radius of the droplet r0
:diffusion coefficient
[m] :depth l
Tritium Recovery Process
2mm
30mm
1
exp[ 6
1 n
t
2 r
D
M
M 2 2 n ]
t 2 2 n
Institute of Sustainable Science Institute of Advanced Energy, Kyoto University
Tritium Recovery Process T
ritiu
m c
on
ce
ntr
atio
n in
pro
du
ct h
yd
rog
en
(B
q/m
3)
Regulation for HTO
Tritium permeability through
IHX [mol Pa-1/2 s-1 m-1]
0 0.2 0.4 0.6 0.8 1 10 1
10 2
10 3
10 4
10 5
10 6
Tritium recovery ratio[-]
10 -14
10 -15
10 -13
SiC fiber
35%
Target recovery ratio >35% in the LiPb stream
Natural background
-Recovery ratio determined from the contamination of product.
-Requirement is a function of permeability through IHX
assumed
Institute of Sustainable Science Institute of Advanced Energy, Kyoto University
9
Water (H2O) vs. Liquid Pb-17Li
Density Visco-
sity
Surface
tension
Temp
eratu
re
Velo
city
Length Reynolds
number
Froude
number
Weber
number
ρ[Kg/m3] μ[Pa·sec]
σ[N/m] T(C) V[m/sec]
L[m] ρUL/μ U2/gL ρU2 L/σ
H2O 1.0E+3 1.0E-3 0.07 20 3 1.0E-3 3.0E+3 9.2E+2 1.3E+2
Pb-
17Li
9.7E+3 1.5E-3 0.45 400 3 1.0E-3 1.9E+4 9.2E+2 2.0E+2
Pb-
17Li
9.6E+3 1.2E-3 0.44 500 3 1.0E-3 2.5E+4 9.2E+2 2.0E+2
Boundary equilibrium equation s
m
n S Fluid-1
Fluid-2 C
H2O & Pb-17Li
Both Surface tension regime material
1 2 1
' ' 'd
p zFr Re We
+ + n E' n n
Institute of Sustainable Science Institute of Advanced Energy, Kyoto University
10
Deducing formula
0L d L
q dt q
cosr a kz +
2
2 20 1
2U s s a k
a
12
2021
21
V
dVT
I kaa
kaI ka
Energy minimum by
Euler-Lagrange-Equation
Institute of Sustainable Science Institute of Advanced Energy, Kyoto University
11
01.89dropletd D
0
qta e
Deducing formula
Fastest grow rate at
ka=0.6970 overwhelm
Institute of Sustainable Science Institute of Advanced Energy, Kyoto University
12
Experimental Result
droplet dia. vs. nozzle
Institute of Sustainable Science Institute of Advanced Energy, Kyoto University
13
Liquid metal Pb-17Li droplet
A: Theoretically deduced droplet size formula is
B: Effective range is less than ϕ2.2mm
Both good accordance with the experimental
results and well applicable for extraction system
design engineering
What is achieved in this study
01.89dropletd D
Institute of Sustainable Science Institute of Advanced Energy, Kyoto University
SiC/SiC cooling panel
SiC cooling panel
・Actively cooled SiC
panel to control
heat transfer
・isolate outer RAFM
vessel structure
・obtain high
temperature LiPb
for heat
Institute of Advanced Energy, Kyoto University
Blanket parameters
Heat flux to the FW 0.2 MW/m2
Neutron flux from the plasma 0.5 MW/m2
Boundary temperature at the
LiPb/SiC interface
1000 oC
He temperature at F82H
channel
350 oC
He temperature at SiC
channel
850 oC
Heat transfer coefficient of He
coolant at F82H channel
10000 W m-2 K-1
Heat transfer coefficient of He
coolant at SiC channel
7000 W m-2 K-1
Thermal conductivity of F82H 33.3 W m-1 K-1
Thermal conductivity of SiC 20 W m-1 K-1
複雑形状の接合 Fabrication R&D for SiC cooling panels Institute of Advanced Energy, Kyoto University
LiPb circulated >900゜C
SiC module
Installed in 900 ゜ C vessel
IHX heat transfer from LiPb to He
Loop operated >900 ゜ C
Only in the test vessel
ヒーティングコイル
アルミナ管
Institute of Advanced Energy, Kyoto University
LiPb/He dual coolant loop
EMP
T
T
Dump
tank
T
T
T
Gas
Chromato-
graph
hygro
meter
cooler
heater
GC
T
Primary loop
Secondary loop
Expansion
tank
P
F
F
P
MS
B Zr
GC
T
T
economizer
heater
9 00℃
900℃ 700℃
700℃
~200℃
SiC
tube
IHX
module
Test vessel
T
Test
section1
Test
section2
Test
section3
Institute of Advanced Energy, Kyoto University
In CVD SiC,
diffusion in grain
boundary weems
major path.
In Hexoloy(a),
diffusion in bulk
Is regarded as
major path.
D2
D2
D2 D2
D2
D2
0.75 0.80 0.85 0.90 0.95 1.00 1.05 1.10 1.1510-18
10-17
10-16
10-15
10-14
10-13
10-12
10-11
10-10
10-9
10-8
perm
eation
(mol/
sec)
1000/T (1/K)
Permeation
experiment
Diffusion experiment
d
pA
p
SDn
h
s
▼CVD SiC
(permeation experiment)
○CVD SiC [This work]
(permeation experiment)
◀Hexoloy
(permeation experiment)
◆α SiC powder
(solution diffusion experiment) ▲β SiC fiber
(solution diffusion experiment)
□CVD SiC [This work]
(solution diffusion experiment)
Institute of Sustainable Science Institute of Advanced Energy, Kyoto University
Hydrogen permeation through SiC
Name ITER GNOME Slim-CS CREST ARIES-
RS ARIES-
AT PPCS-A PPCS-B PPCS-C PPCS-D
Country Japan Japan Japan U.S. U.S. Euro Euro Euro Euro Group Kyoto JAERI CRIEPI ARIES ARIES
proposed
year 2010 2007 2000 1998 2000 2005 2005 2005 2005
Major radius Rp m 6.2 5.2 5.5 5.4 5.52 5.2 9.55 8.6 7.5 6.1 Minor radius a m 2 1.7 2.1 1.6 1.38 1.3 3.2 2.9 2.5 2.0 Plasma current Ip MA 15 10.4 16 12 11.32 12.8 30.5 28 20.1 14.1 Toroidal field Bt T 5.3 4.4 6 5.6 7.98 5.86 7 6.9 6 5.6 Maximum field Bmax T 11 16 12.5 16 11.1 13.1 13.2 13.6 13.4 Safety factor qy 3.6 5.3 4.3 Average temperature <Te> keV 8.9 13 17 15.4 18 22 20 16 12 Average density <ne> 1020 m-3 0.61 1.1 2.1 2.15 1.1 1.2 1.2 1.4 Improvement factor HHy2 1.4 1.3 1.37 1.2 1.2 1.3 1.2 Imporvement factor H89P 2.59 3.2 2.65 Normalized beta bN 3.1 4.3 5.5 4.8 5.4 3.5 3.4 4 4.5 Bootstrap current
fraction fBS % 45 66 83 88 45 43 63 76
Normalized density fGW 0.54 0.97 1.3 0.915 1.2 1.2 1.5 1.5
Fusion power Pfus MW
500
(700) 324 2877 2970 2170 1755 5000 3600 3410 2530
Conversion efficiency η 2 0.41 0.38 0.59 0.31 0.37 0.43 0.60
Current drive power PCD
73
(100) 60.7 83 97 81 34.6 246 270 112 71
Neutron wall load Pn
0.57
(0.8) 0.48 3.1 4.5 4 3.3 2.2 2 2.2 2.4
Energy multiplication Q 10 5.3 35 20 13.5 30 35 Structure material V & steel ferrite ferrite ferrite ferrite SiCf/SiC Support material SiCf/SiC SiCf/SiC
breeder material
solid Li2ZrO3 Lq. Li LiPb LiPb Li ortho-
silicate
w/ Be LiPb LiPb
Coolant
LiPb water water Lithium LiPb water (15
Mpa)
He (8
Mpa) LiPb LiPb
Coolant temp. oC > 900 610 1100 300 300-500 700-1100
DEMO power/tritium system
plasma blanket IHX
turbine
Heat
rejection
Tritium
recovery
Reactor hall
divertor
Fuel
cycle
detritiation
plant
detritiation
detritiation
Tritium in power system is the major issue from TBM to DEMO.
1 2
3
Institute of Sustainable Science Institute of Advanced Energy, Kyoto University
Blanket and tritium flow
breeder coolant Tritium
recovery
IHX Genera-
tion
Detri-
tiation
solid Water
/ He
Isotopic
/chemical
Steam
generator
Rankine Isotope
WDS
Solid gas chemical Steam
generator
Rankine
Isotope
WDS
Liquid
metal
metal physical Steam
generator
Rankine
Isotope
WDS
Liquid
metal
gas chemical g-g IHX
Brayton
metal physical hybrid
Primary coolant issue : accidental release
Institute of Sustainable Science Institute of Advanced Energy, Kyoto University
Source: The 2011 Pacific Coast of Tohoku Pacific Earthquake and the Seismic Damage of the NPPs, p9, Report to IAEA from NISA and JENES, 4th April, 2011
Reactor Building
(R/B)
Pressure
Containment
Vessel (PCV)
Dry Well
Spent Fuel Pool
Reactor Pressure
Vessel (RPV)
Suppression Chamber Source: http://nei.cachefly.net/static/images/BWR_illastration.jpg
In the case of BWR..
Blanket and tritium flow
breeder coolant Tritium
recovery
IHX Genera-
tion
Detri-
tiation
solid Water
/ He
Isotopic
/chemical
Steam
generator
Rankine Isotopic
WDS
Solid gas chemical Steam
generator
Rankine
Isotopic
WDS
Liquid
metal
metal physical Steam
generator
Rankine
Isotopic
WDS
Liquid
metal
gas chemical g-g IHX
Brayton
metal physical Metal-gas
IHX
hybrid
Secondary coolant issue : permeation in normal operation
Institute of Sustainable Science Institute of Advanced Energy, Kyoto University
SiC-He heat Exchanger
Heat exchange
element
Heat exchanger
unit
vessel
insulation
2ndary
Tubes/
connect
bellows
2ndary
He in 1mary He in
2ndary
He out
1mary
He out
1mary He in 1mary
He out
1mary
Tubes/
inlet
insulation
Heat exchange
element
2ndary
He out
2ndary
He in
2ndary He out
2ndary
Tubes
Institute of Sustainable Science Institute of Advanced Energy, Kyoto University
DETRITIATION
SYSTEM
BUILDING
DETRITIATION
SYSTEM
FUEL LOOP PIPING
VACUUM
VESSEL DETRITIATION
SYSTEM
TURBINE
GENERATOR HX
Tritium confinement
volume
plume
soil
plant
deposition
Ground water
Emission controlled by confinement
and active detritiation both in
Normal and accidental
Condition.
Crops vegetables
Grazing animals
dose
Contami- nation
Institute of Sustainable Science Institute of Advanced Energy, Kyoto University
Yearly change of tritium concentration
0.1
1
10
0 20 40 60 80 100
Operatinf time (year)
Atm
osph
ere
HTO
conc
entr
atio
n
(Bq/
m3)
0.001
0.01
0.1
1
10
100
-100 -80 -60 -40 -20 0 20 40 60 80 100
Distance from fusion plant (km, -West, +East)
Atm
osp
here
HTO
Cocentr
atio
n (B
q/m
3)
1st year 2ndyear4th year 10th year20th year 40th year60th year 80th year100th year
Change on the tritium concentration in the atmosphere
during prolonged operation is analyzed.
5.7 km west
100 km west
•Tritium concentration increase for about 60 years on land.
•Tritium concentration on the sea surface is low and dose
not show accumulation
Emission rate: 1.35x1014 Bq/year
0.01
0.1
1
0 20 40 60 80 100
Operatinf time (year)A
tmos
pher
e H
TO
conc
entr
atio
n
(Bq/
m3)
Atmosphere HTO concentration after 100 years operation.
Tutorial course
・Environmental models converts emission to dose.
・Major dose from normal operation comes from ingestion
・mSv per person, per year per 1 gram emission.
particular concern is a damage for sales of food
products.
Total tritium dose during 1 year
operation calculated by NORMTRI.
Structure of NORMTRI model
Accumulation in the environment
Acknowledge W. Raskov and D. Galeriu
Institute of Sustainable Science Institute of Advanced Energy, Kyoto University
1.0E-03
1.0E-02
1.0E-01
1.0E+00
0 20 40 60 80 100
Operating time (year)
Atm
osp
here
HT
O
conc. (B
q/m
3)
1.0E-04
1.0E-03
1.0E-02
1.0E-01
0 20 40 60 80 100
Operating time (year)
Atm
osp
here
HT
O
conc. (B
q/m
3)
5.7 km west
100 km west
Operating time: 1 year Operating time: 2 years Operating time: 4 years Operating time: 10years Operating time: 20 years Operating time: 40 years Operating time: 60 years Operating time:80years Operating time: 100 years
•Considerably increases for 20 years
•Still negligible from dose, but easy to detect.
- If 100 plants operated 100 years?
Emission rate: 1.35x1014 Bq/year
Accumulation in the environment
Annual emission accumulates in the environment
Institute of Sustainable Science Institute of Advanced Energy, Kyoto University
With accumulation, dose is still below 10 mSv/year
•However, 15 times larger than the first year.
Tritium dose: 1 year operation
Tritium dose: 100 years operation
Effects on dose Institute of Sustainable Science Institute of Advanced Energy, Kyoto University
Coastal model Inland model
Coastal siting absorbs tritium by isotopic dilution
•Inland tritium also decreases by the tritium migration
•Existence of sink prevents environmental
accumulation.
Tritium concentration distribution
Effect of open water surface Institute of Sustainable Science Institute of Advanced Energy, Kyoto University
0.1
1
10
0 20 40 60 80 100
Operatinf time (year)
Atm
osph
ere
HTO
conc
entr
atio
n
(Bq/
m3)
0.001
0.01
0.1
1
10
100
-100 -80 -60 -40 -20 0 20 40 60 80 100
Distance from fusion plant (km, -West, +East)
Atm
osp
here
HTO
Cocentr
atio
n (B
q/m
3)
1st year 2ndyear4th year 10th year20th year 40th year60th year 80th year100th year
5.7 km west
100 km west
•Inland tritium continue to accumulate until balance
with decay.
•Little accumulation observed on the coast.
Emission rate: 1.35x1014 Bq/year
0.01
0.1
1
0 20 40 60 80 100
Operatinf time (year)A
tmos
pher
e H
TO
conc
entr
atio
n
(Bq/
m3)
Atmosphere HTO concentration after 100 years operation.
Stopped accumulation Institute of Sustainable Science Institute of Advanced Energy, Kyoto University
0.01
0.1
1
10
100
1000
-100 -80 -60 -40 -20 0 20 40 60 80 100
Distance from plant (km, W-E)
Ato
mosphere
HTO
concentr
ation (
Bq/m
3)
Off shore siting is even more effective.
Emission at 5 km from the coast decreases
Atmospheric tritium to 1/10.
Coastal model Off shore model
Tritium concentration distribution
Off-shore location Institute of Sustainable Science Institute of Advanced Energy, Kyoto University
• Tritium can be well controlled but normally discharged at below
legal limits.(annual, single plant.)
• Water detritiation requires further development and significant
cost is anticipated.
• Tritium in the environment and foods can easily be detected.
• Annually controlled emission can be accumulated and spreads.
• Releases from multiple sources can be summed.
• Canadians report tritium control experience in normal operation of Heavy Water Reactors (expensive coolant with minimal
loss with reasonable efforts) to be 1000Ci/y order /unit.
→Fusion should be as clean as fission with minimal cost.
Tritium in the Environment Institute of Sustainable Science Institute of Advanced Energy, Kyoto University
Electric grid capacities
Physics Today, vol.55, No.4 (2002)
Stability of the grid is region specific.
Eastern Grid
~500GW
Texas Grid
~53GW
Western Grid
~140GW
East Japan
~80GW
West Japan
~100GW
UTPTE ~270GW
Thailand ~20GW
Vietnam ~8GW
Extremely large Grids in a country Internationally connected Grids Delicately controlled grids - these are all exceptional in the future energy market.
Electric grid is a national security issue and
cannot be easily integrated.
Physics Today, vol.55, No.4
(2002)
Fusion startup could be a problem
-0.35
-0.3
-0.25
-0.2
-0.15
-0.1
-0.05
0
0 5 10 15 20 25 30
time(sec)
frequency(H
z)23MW/sec
77MW/sec
230MW/sec
All the generators on the grids are synchronized
→ Exactly same amount generated as demanded.
Sudden increase of demand or unstable generator
• Demands exceed generation capacity
• Frequency drops (~0.1%)
• Load to the generators
• Generator disconnected
Chain reaction kills the grid.
→unstable renewables can
initiate the blackout.
Zero-carbon energy Kyoto
Frequency drop by load
Small grid, large load,
Fast change should be
Avoided.
Fire
Hydro
Nuclear
Fire(Coal)
0 6 12 18 24(h)
variable
.
• For near term, leveling of
the load is important.
• Local generators, co-
generation and batteries
preferred.
• Increased renewable
jeopardizes grid
• For future, substitute of
fire power needed.
→load leveling power
is preferred. Can fusion be a base load?
Hydro
Solar
Wind
Load
Leveling
needed
Daily Peaks
Hydro
Base
load
・unpredictable change of generating power of renewable is large
・time constant of seconds
・controlled power to compensate this change needed
・connecting to grid decreases amplitude but not time constant
・fire power can provide only slow change (~5%/min)
4:00 8:00 12:00 16:00 20:00-0.2
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.85/14 (Cloudy)― Insolation Intensity
― DC Power
DC
Pow
er
[kW
]
Inso
lation Int
ensi
ty [
kW/m
2]
Inso
lation Int
ensi
ty [
kW/m
2]
Time
-0.02
0.00
0.02
0.04
0.06
0.08
0.10
0.12
0.14
0.16
0.18
4/15 4/30 5/15 5/30 6/14 6/290
20406080
100120140160180200220240
Spring (4/1-6/30)
Date
Ele
ctrica
l Ene
rgy
[kW
h/da
y]
Change of solar in a day
Required Stabilizing
power
Fluctuation of renewable
Daily change of solar
Future low carbon Systems
Battery
Large scale grid
generators
Local systems
Solar cell
Fuel
Electricity must be powered by
Carbon-free sources
Nuclear
(??)
Both large grid and local
systems are needed.
Fire
(fade out)
Fusion
(to come)
PHV,EV
Battery, generators and
fuel cells Stabilizes
fluctuation by renewables.
Large scale supply of fuels for
Fuel cells needed.
Solar cell
Fuel cells
SOFC
Power
[kW]
Max.pow
er[kW]
capacity[
kWh] units area[m2] Vol.[m3]
Solar 633 566.2 - - 4740 -
battery 364.7 420 2625 7 - 16.7 Fuel cell - 988 - - - 5.6
計 998 1974 2625 7 4740 22.2
0 4 8 12 16 20 24-400
-200
0
200
400
600
800
1000
1200
Time [h]
SOFC+NaS+Solar①, Summer, Fine
Large scale grid
SOFC
NaS-2
NaS-1
Solar
Ele
ctrica
l Ene
rgy
[kW
h/h]
0 4 8 12 16 20 24-400
-200
0
200
400
600
800
1000
1200
Time [h]
SOFC+NaS+Solar①, Summer, Rain
Large scale grid
SOFC
NaS-2
NaS-1
Solar
Ele
ctrica
l Ene
rgy
[kW
h/h]
Carbon-free elcecticty systems
Future Energy Systems
FIRE
NUCLEAR
0 6 12 18 24(h)
Load
following
power
Battery
Large scale grid
FC
Fuel Cells
DC Microgrid
Solar cell
Fuel (H2 / CO)
Electricity will be powered by
Carbon-free sources
Fusion
Day peak will be supplied by
Battery and fuel cells.
Institute of Sustainable Science Institute of Advanced Energy, Kyoto University
AC
DC
Office
Only for start- up ~ 400 MW
Fusion reactor (2 GW)
Large-scale
power generation
Day
Only night, for NaS
Office
Transport etc. 6.5 GL/day
DC Microgrid
DC Microgrid
DC Microgrid
Large scale grid
0
100
200
300
400
500
600
700
Fusion start-upCharge of NaS
Fission,Hydro
SOFC
16 20 24 4 8 12
Time [h]
Ele
ctr
ical Energ
y [
MW
h]
H2 16 GL/day
2.9 GL/day
Indirectly supplied by fusion
6.7 GL/day・104Microgrid
Fusion and grid Institute of Advanced Energy, Kyoto University
Fusion will be started by
night sources
0 5 10 15 200
5
10
15
20
25
IV-② SOFC+NaS+Solar
従量電灯B
シナリオI-IV (2025 target)
積算
コス
ト [
億円
/μ
G]
導入年数 [年]
2025cost(NEDO)
• Micro Grid can be cheaper
than large Grid for long runs.
• combination of generation
technology is needed to
stabilize the supply.
• Carbon-free system can be
made before 2050.
0 4 8 12 16 20 24-800
-400
0
400
800
1200
1600Large scale grid
NaS-2NaS-1
SOFC Solar
Time [h]
SOFC+NaS+Solar②, Summer, Fine
Ele
ctrica
l Ene
rgy
[kW
h/h]
generator [105¥/kW]
SOFC 20
Solar 12
NaS 29
Commercial electricity
Year from the introduction Cu
mula
tive c
ost [1
08¥/s
yste
m]
Cost of micro grid electricity Institute of Advanced Energy, Kyoto University
biomass hybrid from tritium aspect
○Fusion –biomass hybrid may demonstrate fusion energy
earlier than pure fusion electricity.
・small power generation has better market chance.
・cost requirements for the product (hydrogen, oil) may be
easier (eventually. Depends on oil price and carbon tax)
・fusion-fuel cell combination may be a preferred option.
○High temperature blanket/divertor are realistic challenge
・SiC-LiPb blanket being developed.
・low pressure system is preferred from safety aspects
○ Tritium self sufficiency and environmental effect is concerned.
・tritium recovery from breeder needs demonstration (TBM)
・demonstrated safety will be important to launch DEMO
・environmental tritium contamination needs social understanding.
Institute of Advanced Energy, Kyoto University
• Fuel production from biomass continued to be
studied.
• Fukushima accident required additional consideration
for fusion safety.
• High temperature, low pressure LiPb blanket has
preferred safety features.
• Public is aware of Existing radioactive contamination.
• Energy security with renewables will be a major
concern in the future.
• Fusion needs an adequate position in the future
energy system.
Conclusion Institute of Advanced Energy, Kyoto University