Satoshi Konishi Institute of Advanced Energy, Kyoto University · Institute of Advanced Energy,...
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High Temperature Blanket and ItsSocio-Economic Issues
Institute of Advanced Energy, Kyoto University
Satoshi KonishiInstitute of Advanced Energy, Kyoto University
Contents- Fast track and Development Strategy in Japan- Power plant design- Hydrogen production- Safety and environmental impact
Fast Track : the next stepInstitute of Advanced Energy, Kyoto University
Fusion study is in the phase to show a concrete plan for Energy.-Power plant design and strategy following ITER are required.
Common understanding・Resource constraint (Energy)・Global warming problem (Environment)
・Growth in developing countries (Economy)
Energy Demonstration in 2030? Technical feasibility
Combined Demo-Proto steps Social feasibility
Strategy varies in each Parties due to different social requirements.
2000 2010 2020 2030
PowerDemo
ITER
TBM
Tokamak
IFMIF
Concept Design Const. Test
Const. BPP
Test
Generation
EPP
module1 module2
High beta, long pulse
KEP EVEDA Const. New line10dpa/y 20dpa/y
RAF In pile irradiation Full irrad.1/2 irrad.
Fast Track Discussion in JapanInstitute of Advanced Energy, Kyoto University
Evolution required In a same facility
Drawn from Fast track working group in Japan, 2002,Dec.
Institute of Advanced Energy, Kyoto UniversitySocio-Economic Aspect of Fusion
・Future energy must respond to the demand of the society.・Social and Economical feasibility of fusion depends onhigh temperature blanket and its feature.
Fusion
Other Energy
Outcome/benefit
Energy Supply
Present ProgramsSocial viewpoint
Damage/cost/”Externality”
Future Social
Demand
GovernmentPublic
funding
Socially Required
Government
Outcomefunding
FusionDevelopment
Previous ProgramsResearchers’ viewpoint
Technically feasible
Generation
Institute of Advanced Energy, Kyoto University
Near Future Plants
-Reduced Activation Ferritic steels (RAFs) are expected as blanket material candidates.
-Considering temperature range for RAFs, 500 C range is maximum, and desirable for efficiency.
Power Plant Design
-From the aspect of thermal plant design, ONLY supercritical water turbine is the available option From fire-powered plant technology.
-No steam plants available above 650 degree C.
Flow diagram of indirect cycle
BlanketReheater Turbines
Tritiated waterprocessing
Steam Generator
Booster pump
Feed water heater(divertor heat)
CVCS Feed water pump
Institute of Advanced Energy, Kyoto University
Institute of Advanced Energy, Kyoto UniversityThermal plant efficiency
Direct cycle turbine train generates 1160MW of electricity.Thermal efficiency is estimated to be 41%.
Institute of Advanced Energy, Kyoto UniversityComparison of Generation Cycles
Other thermal Plants:BWRs – 33% PWRs – 34% Supercritical Fire – 47%Combined gas turbine - >60%
direct indirect He gas
Main steam pressure 25MPa 16.3MPa 10MPaTurbine temp. 500℃ 480℃ 500 ℃Coolant flow rate 1250kg/s 1260kg/s 1865kg/sVapor flow rate 1250kg/s 1037kg/s 908kg/sTotal generation 1200MW 1090MW 1028MWThermal efficiency 41.4% 38.5% 35.3%Technical issues tritium in steam expansion
coolant generator volume
FindingsInstitute of Advanced Energy, Kyoto University
-Supercritical water cycles is desirable and possible(technically difficult).
- No gas turbine system is effective in temperature ~500 C.- With steam generator, gas cooled is less effective than water.- Plant design limited above 650 C.
Possible Advanced Plant Options-High temperature cycle can be planned with He gas turbine at ~900 C. -Only dual coolant LiPb blanket has possibility for high temperature in ITER/TBM.-At high temperature, use of heat for hydrogen productionmay be an attractive choice.
High temperature material does not guarantee economy.Improvements may be required in the DEMO generation.
Fusion Contribution with hydrogenInstitute of Advanced Energy, Kyoto University
coaloil Unconventional oil
gas
Unconventional gas
nuclearhydro
0
10
20
30
1900 1950 2000 2050 2100year
Renewable hydrogen
renewables
actual estimated
Gton
oil eq
uivale
nt/ye
ar
Fusion hydrogenFusion electricity
Hydrogen Production by Fusion
Fusion can provide both high temperature heat and electricity- Applicable for most of hydrogen production processes
As Electricity-water electrolysis, SPE electrolysis : renewables, LWR-Vapor electrolysis : HTGR
As heat-Steam reforming:HTGR(800C),
-membrane reactor:FBR(600C)-IS process :HTGR(950C)
-biomass decomposition: HTGR
Institute of Advanced Energy, Kyoto University
From 3GW heat efficiency electricity Energyconsumption
Hydrogenproduction
300C-electrolysis 1GW 28 6kJ/ mol 25 t / h900C-electrolysis 1 .5GW 23 1kJ/ mol 44t /h900C-vapor electrolysis 1 .5GW 18 1kJ/ mol 56t /h
33 %50 %50 %
900C-biomass ー ー 60 kJ/ mol 34 0t / h
Energy Eficiency
◯amount of produced hydrogen from unit heat・low temperature(300℃)generation→ conventional electrolysis
・high temperature(900℃)generation→ vapor electrolysis
・ high temperature(900℃) → thermochemicalproduction
Institute of Advanced Energy, Kyoto University
◯Processing capacity: 3GWt・2500t/h waste 340t of H2
2500 t/h
H2 340 t/h
600℃
FusionReactor3GWth
biomassCO 2.4E+06 kg/hH2 1.7E+05 kg/h
CO2 3.7E+06 kg/h
ChemicalReactor
Heat exchange,Shift reaction
cooler
Turbine
Steam(770 t/h)He
1.38E+07 kg/h
H2O
Institute of Advanced Energy, Kyoto UniversityUse of Heat for Hydrogen Production
1.3x106 fuel cell vehicles (6kg/day)or 6.4 GWe (70% fc)
The
expe
rimen
tal r
esul
ts o
f th
e ch
ange
in c
arbo
n at
oms
com
bine
d in
ca
rbon
ized
gas
es[m
ol.%
]
0
5
10
15
20
25
30
CO2CH4CO
0.0005
0.0010
0.0015
0.0020
0.0025
0.003035 65 85 35 65 85
H2 by measurementH2 by calculation
[cm3/min]
Am
ount
of h
ydro
gen
prod
uctio
n [m
ol]
4 5flow rate
steam concentration [%]
The
expe
rimen
tal r
esul
ts o
f th
e ch
ange
in c
arbo
n at
oms
com
bine
d in
ca
rbon
ized
gas
es[m
ol.%
]
0
5
10
15
20
25
30
CO2CH4CO
0.0005
0.0010
0.0015
0.0020
0.0025
0.003035 65 85 35 65 85
H2 by measurementH2 by calculationH2 by measurementH2 by calculation
[cm3/min]
Am
ount
of h
ydro
gen
prod
uctio
n [m
ol]
4 5flow rate
steam concentration [%]
Hydrogen from biomass and heatInstitute of Advanced Energy, Kyoto University
Institute of Advanced Energy, Kyoto University
EXHAUSTSEFFLUENTS
SOLID WASTEBLANKETREPLACEMENT
PRIMARY LOOPS
DISPOSAL RELEASE
RELEASE
EXHAUSTDETRITIATIONDECONTAMINATION
OF SOLID WASTES
TURBINEGENERATOR
ISOTOPESEPARATION
FUELINGSTORAGE
TRITIUMEXTRACTION
PLASMA
BLANKET
EVACUATION PURIFICATION
High temperature, pressureLarge processOut of primary enclosureE i t l l
SECONDARY LOOPS:100g tritium
BLANKETREPROCESSING
LOADINGIN/OUT
HX
WATERDETRITIATION
Fusion safety and environmental impact
①Solid WasteImpact pathway ②Tritium Release from Coolant
③Fuel Processing exhaust
OFF-SITE
FUEL STORAGE
550 g*
FUELING50 g
ISOTOPE SEPARATION
190 g
PURIFICATION100 g
EFFLUENTPROCESSING
~1 g
WATERDETRITIATION
~1 g
COOLANT~1 g
HOT CELL500 g
WASTE TEMPORARY
STORAGE
VACUUMVESSEL1100 g
COOLINGSYSTEMS
PRIMARY FUEL SYSTEM
STACKLOAD IN
EFFLUENTS
ITER SITE INVENTORY:2800 g
TORUS EXHAUST
130 g
POWER REACTOR:probably less<100g
<100g
<100g 〜10g
〜10g
LOAD OUT
Inventory distribution compared with ITER
Institute of Advanced Energy, Kyoto University
POWER BLANKET (example)Institute of Advanced Energy, Kyoto University
High TemperatureHigh PressureFine tubingsTritium Production
1st wall
Cooling tubes
780K supercritical waterLi ceramic pebblesHe/H2 sweep for tritiumrecovery
Tritium Permeation could be ~100g day
Institute of Advanced Energy, Kyoto University
・ Normal tritium will be dominated by release from coolant・ Largest detritiation system will be for coolant ・ Fusion safety depends on ACTIVE system.
TRITIUMTHROUGHPUT(kg/day)
TOTALTHROUGHPUT(kg/day)
TRITIUMINVENTORY(kg)
PRIMARYLOOP COOLANTPROCESS
1
30
60
0.5
0.5
500000
tritium flow
tritium leak/permeation
TRITIUMRECOVERY
PRIMARYLOOP
GENERATIONSYSTEM
SECONDARY LOOPS
BLANKET
reactor boundary
PLASMA
secondary confinementbuilding confinement
COOLANTPROCESS-ING
AIR DETRITIATION
PRIMARYCOOLANT
Generalized fusion plant
Normal release from Fusion Facility
・Detritiation for power train will depends on blanket types.・Normal detritiation for coolant will handle emergency spill.・Safety control with active system is not site specific.
Institute of Advanced Energy, Kyoto UniversityGeneralized detritiation system
Heat
BlanketHX
Tritium recovery
Turbine tritium
Heat
Tritium recoveryLow concentration
tritium
HeatHeat
Large throughputOnce through
Large enrichment-broad concentration rangeClosed cycle cascade
Tritium recoveryHigh concentrationQuick return
Processes large throughput, lower concentrationControls environmental releaseOperational continuously (including maintenance)
Detritiation systems of PlantInstitute of Advanced Energy, Kyoto University
Air Detritiation :- 1000 m3 / hour, possibly ci/m3 level- leak from generator, secondary loops, hot cell
Water Detritiation : (isotope separation)- 100 m3 / day, possibly 1000 ci/m3 level, 100g/day?- driving turbine
Solid Waste Detritiation :- 1 ton / day, possibly g / piece?- materials (lithium, berylium, Steel) recycle- needed both for resource and waste aspects.
TRITIUM IS CONFINED WITHINENCLOSURES ANDDETRITIATION SYSTEMS
Power train will be driven with tritium containing medium.
For gas driven system, large Expanson volume may be needed.
Institute of Advanced Energy, Kyoto UniversityTritium confinement
BUILDING
FUEL LOOP
VACUUMVESSEL DETRITIATION
SYSTEM
TURBINEHX
DETRITIATIONSYSTEM
Cryostat
Expansion pool Expansion pool
High temperature blanket will require improved permeation control.
Pressurized gas may require additional expansion volume.
TRITIUM FACILITY
DIFFUSIONW IND
SHALLOW SO IL
DE EP S OIL
DOS E E FFECT
INHALATIO N
SKIN ABS ORPTION
INJES TION
F IS H
NO RMAL/ ACCIDENTAL
TRITIUM REL EASE
PLU ME
ATMOSP HE RE HT OATMOSP HERE HT
SURFACE S OILPLANT
OBTP LANT HTO GRAZING ANIMAL
HTOG RAZING ANIMAL
OBT
HUMA N BO DY HTO
E FFE CTIV E DOSE E QUIVALE NT
DRINKING WATER
DRY DE POS ITION
W ET DE POSITIO N W ASHOUT
HUMAN BO DY O BT
SURFACE W ATER
TRITIUM BEH AV IOR T O C AUSE HUM AN DO S E
Emission from Fusion and Dose
Impact pathway of tritium suggests ingestion will be dominant.
Institute of Advanced Energy, Kyoto University
FindingsInstitute of Advanced Energy, Kyoto University
-Fusion plant detritiation will be dominated by powerplant configuration.- Normal tritium release will be controlled actively.- Off-normal spill can be recovered with normal detritiation.- High temperature plant will require improved tritium system.
-Measurable tritium will be released in airborne form.-Tritium accumulates in environment (far smaller natural BG).-Ingestion dose will be dominant.-For long run, C-14 may be a concern.
Conclusion
Fusion development is in the phase to study market・Fusion must find customers and meet their requests. ・Fusion must satisfy environmental and social issues.
Institute of Advanced Energy, Kyoto University
Development of advanced blanket is a key issue for fusion・Economy - not just temperature, but to maximize market ・Environment - not just low activation, but best total cost
and social value / least risk(Externality)
Development strategy (road map) for blanket is needed. ・ITER and DEMO require 2 or more generations of blankets.・staged improvement of blanket is planned with water-PB,and LiPb dual coolant concepts.
Conclusion 2
Possible blanket improvement・Independent from large increment of plasma
Institute of Advanced Energy, Kyoto University
・Continuous improvementcan be reflected in blanketchange.
(Improvement in DEMO phase)
・Multiple paths to meet various needs are possible.
・Flexibility in development ofentire fusion program isprovided by blanketdevelopment.
SHIELD
NEUTRON USE
METAL
WATER
Q=10 500sec
β N=2.5
Q=30
STEADY β N~3.5
GASINDUSTRIAL
HEAT
GENERATION
MARKET SELECTION
EXPERIMENTAL REACTOR (ITER)
DEMO REACTOR
COMMERCIAL REACTOR
SiC/SiCVanadium
Ferritic Steel
PLASMA DEVICE
BLANKETS
MATERIALS
SUPER CRITICAL
EFFICIENT COOLANTS
EFFICIENT GENERATION
Fast Track