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EFDA EUROPEAN FUSION DEVELOPMENT AGREEMENTC L O S E S U P P O R T U N I T G A R C H I N G
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Overview of Reactor Studies in Europe
David MaisonnierEFDA CSU Garching
EFDA EUROPEAN FUSION DEVELOPMENT AGREEMENTC L O S E S U P P O R T U N I T G A R C H I N G
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Outline
● European Framework: the DEMO Conceptual Study● He-cooled divertor● Blanket segmentation and maintenance● Conversion cycles● Non-electricity production applications of fusion● Future work
● FZK segmentation and maintenance scheme proposal : T Ihli● DEMO Parameters / System Studies : D. Ward● DEMO Physics Issues : L. Horton
EFDA EUROPEAN FUSION DEVELOPMENT AGREEMENTC L O S E S U P P O R T U N I T G A R C H I N G
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System Studies,the European Framework
EFDA EUROPEAN FUSION DEVELOPMENT AGREEMENTC L O S E S U P P O R T U N I T G A R C H I N G
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Background● PPCS (Power Plant Conceptual Studies) completed in 2004,
final report issued April 2005.
● 5 different models considered: A (WCLL), B (HCPB) and AB (HCLL) based on limited physics extrapolations, C (Dual Coolant) based on more advanced physics and D (Self Cooled) based on very aggressive hypothesis.
● It is now necessary to develop a concept of DEMO: the device that will bridge the gap between ITER and the first-of-a-kind reactor.
EFDA EUROPEAN FUSION DEVELOPMENT AGREEMENTC L O S E S U P P O R T U N I T G A R C H I N G
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PPCS● Not all PPCS conclusions were anticipated. Some are positive
(maintenance concept of “large module”), some are less positive (overall plant efficiency with helium outlet temperature of 500 ºC).
● A detailed review of the physics basis and of the engineering aspects of the PPCS have led to the following conclusions:
consider a physics basis for DEMO more aggressive than that of PPCS models A, B and AB;assess feasibility of a He-cooled DEMO;optimise energy conversion cycle with He at 500 ºC;assess steady-state vs. pulsed devices.
EFDA EUROPEAN FUSION DEVELOPMENT AGREEMENTC L O S E S U P P O R T U N I T G A R C H I N G
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DEMO
● DEMO Study proposal formally approved mid 2004, work started Jan. 2005.
● Work in 2005 has focused on the DEMO physics basis.● A large interest in this field of activity has emerged within the
physics community (extremely positive).● A number of “generic” engineering and technological aspects
are being investigated.● The design work proper should start in 2006
EFDA EUROPEAN FUSION DEVELOPMENT AGREEMENTC L O S E S U P P O R T U N I T G A R C H I N G
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He-cooled Divertor
EFDA EUROPEAN FUSION DEVELOPMENT AGREEMENTC L O S E S U P P O R T U N I T G A R C H I N G
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Design Features of He-cooled Divertor
● To achieve peak heat load of at least 10 MW/m²● Reduce the thermal stresses (small modules)● Short heat conduction paths from plasma-facing to cooling
surface● High heat transfer coefficients with as small flow rate and small
pumping power as possible● 100 – 1000 thermal cycles between operating and room
temperatures (test requirement)
EFDA EUROPEAN FUSION DEVELOPMENT AGREEMENTC L O S E S U P P O R T U N I T G A R C H I N G
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HEMJ and HEMS concepts (FZK)
● Tests of HEMJ and HEMS mock-ups; definition and execution of the test program; assessment of test results :
HHF experiments using small scale (1-finger) W mock-ups for the current optimised HEMJ and HEMS design variants;investigation of fabrication processes for 9-Finger module W mock-ups;study on the real mock-ups (reference design) to be tested in large-scale in a big helium loop.
EFDA EUROPEAN FUSION DEVELOPMENT AGREEMENTC L O S E S U P P O R T U N I T G A R C H I N G
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HEMJ ConceptFinger unit
18 mm
W alloy
W
Steel
9-Finger-Units Stripe-Units
EFDA EUROPEAN FUSION DEVELOPMENT AGREEMENTC L O S E S U P P O R T U N I T G A R C H I N G
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HEMJ CFD analysis
800
1000
1200
1400
1600
4 8 12 16Mass flow [g/s]
Max
. thi
mbl
e te
mpe
ratu
re [°
C] 8 MW/m² 10 MW/m²12 MW/m²
EFDA EUROPEAN FUSION DEVELOPMENT AGREEMENTC L O S E S U P P O R T U N I T G A R C H I N G
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HEMJ temperature windows
He
Tmax, allow. W thimble
600°C700 °C outl.
600 °C inl.
ODS Eurofer
1170 °C (calculated)*
3410 °C(TS)
2500°C (ELMs, disrupt.)
Tmax, allow. W tile
1711 °C (Tmax, tile, calculated)*
Tile
Thimble
700°C (700 °C)
300°C650°C
W WL10
*) HEMJ, reference, 10 MW/m2
600°C(DBTT, irr.)
700°C(DBTT, irr.)
300°C(DBTT)
2500°C (ELMs, Disr.)
1300°C(RCT, irr.)
Tile
Thimble
EFDA EUROPEAN FUSION DEVELOPMENT AGREEMENTC L O S E S U P P O R T U N I T G A R C H I N G
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HETS concept (ENEA)
● Manufacture of a mock-up (scale 1:1) of one HETS elementsThe mock-up will be manufactured in the reference materials (W and W alloys), and using the heat exchange part geometry defined from the previous works.
● Test campaignThe mock-up will be tested in order to find the pressure drop and heat transfer coefficients of the He at temperatures as near as possible to the foreseen service temperatures.
EFDA EUROPEAN FUSION DEVELOPMENT AGREEMENTC L O S E S U P P O R T U N I T G A R C H I N G
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HETS concept
EFDA EUROPEAN FUSION DEVELOPMENT AGREEMENTC L O S E S U P P O R T U N I T G A R C H I N G
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HETS manufacturing
● MaterialsW alloy (dome, armour)Densimet (mushroom, support, manifolds)
● Machining from rods● Finishing by electro erosion● High temperature brazing process (1150°C – filler in Ni alloy)
Armour, dome, mushroom, support, hot manifolds
● Lower temperature brazing (1050 °C)Cold manifolds, pipes
EFDA EUROPEAN FUSION DEVELOPMENT AGREEMENTC L O S E S U P P O R T U N I T G A R C H I N G
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Test Schedule (all concepts)
● Completion of “individual modules” mock-ups fabrication: end 2005● Completion of tests and assessment of results: end April 2006● Draft final report: end May 2006● Final report: May / June 2006
EFDA EUROPEAN FUSION DEVELOPMENT AGREEMENTC L O S E S U P P O R T U N I T G A R C H I N G
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Blanket Segmentationand Maintenance
EFDA EUROPEAN FUSION DEVELOPMENT AGREEMENTC L O S E S U P P O R T U N I T G A R C H I N G
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Blanket and Maintenance
● The scope is to revisit alternative segmentations of the blanket and alternative maintenance schemes, in particular the vertical segments (“bananas”) and the MMS (“multi-module-segment”).
● A detailed presentation of the FZK proposal will be made by T. Ihli.
● We are considering various combinations of blanket concepts (HCLL, HCPB and DC) and of segmentations (large modules, bananas and MMS)
● We plan to make a selection before summer to lauch the DEMO design phase proper.
EFDA EUROPEAN FUSION DEVELOPMENT AGREEMENTC L O S E S U P P O R T U N I T G A R C H I N G
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Multi-Module-Segment
Combine the advantages of both the modules and the bananas.
EFDA EUROPEAN FUSION DEVELOPMENT AGREEMENTC L O S E S U P P O R T U N I T G A R C H I N G
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MMS Maintenance (CEA)
EFDA EUROPEAN FUSION DEVELOPMENT AGREEMENTC L O S E S U P P O R T U N I T G A R C H I N G
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Possible flexible attachment concept (CIEMAT)
Fix central point4 hinged links (thermal expansion, poloidal torque)4 shear ribs (radial torque)
EFDA EUROPEAN FUSION DEVELOPMENT AGREEMENTC L O S E S U P P O R T U N I T G A R C H I N G
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Conversion cycles
EFDA EUROPEAN FUSION DEVELOPMENT AGREEMENTC L O S E S U P P O R T U N I T G A R C H I N G
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Scope● Assess an energy conversion system using a supercritical CO2
Brayton cycle and an energy conversion system using a supercritical Rankine cycle, considering the PPCS model AB as reference (HCLL blanket)
● This activity was launched considering the limited overall plantefficiency of the PPCS models B and AB due to the low helium outlet temperature (500 ºC) from the blanket
Model ABModel BModel A
34 %36 %31 (33) %Plant efficiency (net elec. power/fus. power)145813321546NET electric power (MWe)235321572066Gross electric power (MWe)418375110Pumping power (MW)429036005000Fusion power (MW)
EFDA EUROPEAN FUSION DEVELOPMENT AGREEMENTC L O S E S U P P O R T U N I T G A R C H I N G
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CO2 Brayton cycle● Interesting physical properties of the working fluid (critical
temperature near room temperature, moderate value of critical pressure, stability under 1400 °C).
● Small turbines needed.
● The low inlet temperature of helium imposes a relatively low turbine inlet temperature, which limits the efficiency.
● Possible improvement : “split” the cycle, i.e. separate heat coming from the blanket - 500 °C - from that coming from the divertor - 700 °C.
EFDA EUROPEAN FUSION DEVELOPMENT AGREEMENTC L O S E S U P P O R T U N I T G A R C H I N G
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Supercritical Rankine cycle● This cycle was considered as reference in PPCS model AB.
● Improvement of the heat exchange▪ blanket helium heat exchange divided into 2 stages▪ parallel exchangers
and more efficient HX curves▪ higher steam temperatures, increasing gross efficiencies▪ less steam mass flow, increasing net efficiencies
allow to increase the overall efficiency by 3-4 percentage points.
EFDA EUROPEAN FUSION DEVELOPMENT AGREEMENTC L O S E S U P P O R T U N I T G A R C H I N G
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Generic Tasks
EFDA EUROPEAN FUSION DEVELOPMENT AGREEMENTC L O S E S U P P O R T U N I T G A R C H I N G
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Topics Considered● Energy Storage System for a Pulsed DEMO
Assumptions for pulsed mode:Power output 1GWe
Pulse duration 4-8 hours with 5-20 minutes dwell time
Plasma shutdown 2 minutes
Plasma start-up 2 x 2 minutes (current ramp, start burn)
ESS stores energy while DEMO is operating and delivers energy during shutdown and re-start
● Non Electricity Production Applications for Fusion PowerHydrogen production
Actinide incineration
Others (desalination…)
EFDA EUROPEAN FUSION DEVELOPMENT AGREEMENTC L O S E S U P P O R T U N I T G A R C H I N G
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Energy Storage System
● For an assessment of a pulsed reactor we will consider one of the following:
Thermal Energy Storage
Compressed Air Energy Storage
Pumped Hydro Storage
Fuel cells
● In addition, limited amounts of power might be provided by other technologies
EFDA EUROPEAN FUSION DEVELOPMENT AGREEMENTC L O S E S U P P O R T U N I T G A R C H I N G
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Hydrogen Production● The socio-economic benefits of
producing hydrogen from a fusion plant will also be assessed.
Establish a more refined model of the hydrogen-producing fusion plant
Make comparisons with possible competitors
Detailed assessment of supplying all needs of Bavaria (58GW installed capacity) by fusion alone
EFDA EUROPEAN FUSION DEVELOPMENT AGREEMENTC L O S E S U P P O R T U N I T G A R C H I N G
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Future Work
EFDA EUROPEAN FUSION DEVELOPMENT AGREEMENTC L O S E S U P P O R T U N I T G A R C H I N G
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To be launched in 2006
● Start the conceptual design proper of a possible DEMO concept (He-cooled)
● Continue assessment of different technologies, of some alternative design options and of alternative applications, e.g.:
steady-state vs. pulsed machineshybrid vs. advanced physics scenariosalternative maintenance schemeslow vs. high temperature superconductors