Satoshi Konishi Institute of Advanced Energy, Kyoto University · Institute of Advanced Energy, Kyoto University Satoshi Konishi Institute of Advanced Energy, Kyoto University Contents

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


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 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


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


◯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


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


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


・ 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.


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.


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


・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

Documents

Satoshi Konishi Institute of Advanced Energy, Kyoto University · Institute of Advanced Energy, Kyoto University Satoshi Konishi Institute of Advanced Energy, Kyoto University Contents