Some thoughts and remarks onStructural Materials and Data Bases
Fusion road map, R&D,Issues in qualification and validation of materials
Facilities needed ….
Eberhard Diegele (F4E) With contributions from Michael Rieth (KIT)( )
International Workshop, MFE Road Mapping in the ITER Era 7th S t b 2011 P i t7th September 2011, Princeton
This contribution and any comments during the workshopdo not necessarily represent the opinion or the policy of the EC or F4E
ContentContentAddress: Structural Materials
– Preliminaries– BB and divertor structural materials issues – Data bases – Status of R&D (Spotlights)
• Advantages &• Issues & Limitations
• Sources of Uncertainties• Fabrication: Technology and Joininggy g
– Facility needs– Concluding thoughts
Preliminaries
Slide 3
Materials Development[Mission for DEMO][Mission for DEMO]
Mission:Development, testing and qualification of structural (and functional)Development, testing and qualification of structural (and functional)
materials suitable to design and to construct BB and divertors for DEMO (and FPP).
The aim is to ha e materials & ke fabrication technologies & (materialsThe aim is to have materials & key fabrication technologies & (materials systems) needed for DEMO fully developed and validated within the next two decades.
Scope: Fusion Power Plant – driven by “economy”: Structural materials to allow operation of BB of 5 6 (fp)years beforeStructural materials to allow operation of BB of 5-6 (fp)years before replacement for a as large as possible T-window (thermal efficiency)2-3 fpy for Divertor
Note: Need to compromise on what seems to be achievable at time of (i) DEMO start and (ii) operation of a second/final phase and (iii) FPP.
Slide 4
Don”t expect a BB structural material to achieve the whole wish list such as 100-150 dpa & 1500-2000 appm He in 2030/2035 as to be fix and firm
Materials-design “synergy”an iterative and integrated approachan iterative and integrated approach
Materials development and DEMO/FPP design require an iterative processTh b t il bl t i l d th i ti d t d l• The best available materials and their properties are used to develop designs (this includes change in material selection when severe issues are anticipate – or new approaches and concepts or reduction in scope)in scope)
• Design studies such as the former EU PPCS [ARIES US] identify objectives for improvement and can guide materials R&D
• [Upcoming] design studies exploit advances assumed to be• [Upcoming] design studies exploit advances assumed to be achievable in a 10-20 year time frame and define milestones and scope for the R&D program.
. >> Progressive development of materials & materials data base – materials models – design methodologies – design analyses and design improvements
• Irradiation effects remain a major source of uncertainty in design and analysis• What can we do in the absence of high-fluence data simulating the
Slide 5
What can we do in the absence of high fluence data simulating the correct n-spectrum ?
Candidate materials for I l tIn vessel componentsRequirementsPlant Requirements:
Environmental compatibility
Impact on Material Selection:Low activation Environmental compatibility
SafetyCost-effectivenessReliability
Low level waste(Sufficient) Temperature windowPerformance and lifetimeReliability
Sustainability
Attractive physical & mechanical properties
Elements to design alloysFe, Cr, Ta, Ti, W, V, Si, C [only few others]
Attractive physical & mechanical propertiesHigh radiation resistanceReliable manufacturing processes
Options for structural materials narrow down for breeding blankets or divertorRAFM (Reduced Activation Ferritic Martensitc) steels ODS (Oxide Dispersion Strengthened) RAFM & RAF steels
Tungsten alloys
ODS (Oxide Dispersion Strengthened) RAFM & RAF steels SiC/SiC composites
Slide 6
Tungsten alloys Vanadium alloys (?)
[Copper alloys NO in view of FPP! Execpt to realize components in test facilities
Materials Development The Challenge towards DEMOThe Challenge towards DEMO
Microstructure evolution under n-irradiation
Damage to lattice (cascades -> point defects -> clustering of defects) [dpa]
Transmutations (He and H -> formation of bubbles and/or voids) [appm]
1st Challenge: Degradation of properties.To understand life time limiting phenomena.
F i DEMO Fi i G IV
g p>> To improve materials.ITER 1 dpa ->> DEMO / FPP order of 100 dpa For comparison DEMO Fission Gen IVDisplacement per atom [dpa] 80 (50-100) up to 100
1000 (F )Transmutation (He) [appm]
~ 1000 (Fe)~ 5000 (SiC)
~ 20
2nd Challenge:
Slide 7
gTo manage the excessive amount of Helium.
Data bases
Slide 8
Road Map for breeder blanketsFl f d t & i f ti
Advanced stage, Commercial
Primary Option
> Flow of data & information
DEMOAdvanced Blanket Tests
Advanced Options
Limited Efforts Design Const. Operation
Licensing
Advanced Blanket Tests
D i Lif i
ITER Test Blanket Modules
Development of Blanket and Materials
Complimentary• MTR for irradiation campaignsDesign
Data
Lifetime
Evaluation &
Regulation
Development of Blanket and MaterialsPrimary option (1st generation): RAF/M, Water of He cooled BlanketAdvanced materials (V Alloys,Advanced materials (V Alloys, SiC/SiC) Advanced High
Development of Blanket and Materials
Primary option (1st generation): RAF/M, Water of He cooled Blanket
Materials
campaigns•Develop and validate models at man le els
Li, Flibe, High T Gas)
SiC/SiC) Advanced High Temperature Blankets (Liquid LiPb,
Li, Flibe, High T Gas)g p
Materials (ODS steels, V Alloys, SiC/SiC) for
high temperature blankets
many levels (multi-physics)
Slide 9
IFMIFEVEDA,
ConstructionIrradiation Tests, Blanket Functional Tests,
Licensing data
Material Data (Base) Interaction Design – Materials R&D
Which materials ?
Which data are needed ?
When / at which step in the design process are they needed ?When / at which step in the design process are they needed ?
How are data generated ?
Which facilities are needed ?
What is the status ?
What else is needed ?Modelling (various reasons and various models)
Extrapolations (?)JustificationsGuidance on useModelling (various reasons and various models)
[come back on this in IFMIF presentation]Assistance in designing: Development of design rules or guidelines on usage
Guidance on useInteraction with other areas
Slide 10
Property depend on fabrication, product form, environment (use)
Material Data Base Required for TBM or DEMO (BB)Required for TBM or DEMO (BB)
Requires extensive material data basesRequires extensive material data bases
Full set: Data are required on all properties
Influence: safety, reliabilityInfluence: safety, reliability Influence: performance or operational limitsDetermine: life time [to replacement]
• in the whole T-range of application (including off-normal conditions!) • under various environmental condition • In particular under n-irradiation
Slide 11
Material Data Base Required for TBM or DEMO (BB)Required for TBM or DEMO (BB)Requires extensive material data bases (continued)
For various product forms (eg different plate thickness used for TBM such asFor various product forms (eg different plate thickness used for TBM such as 5 mm, 14 mm, 25 mm, 40 mm have different characteristics)
Multiple heats (minimum 5, from different produces) are required to get a “code qualified material” approved
(Technical) Specification usually allow variations that need to be accounted for [example from RAFM: Low activation, material “too clean” implies issues to fulfil some minimum mechanical properties at low and high T)
Different data kind of data needed: “data base with real data and properties” are needed for verification analyses and “best estimates” in life time analysesare needed for verification analyses and best estimates in life time analyses
Vs Engineering data (“averaged” or “minimum” with fixed safety factors or on statistical approaches)
Slide 12
statistical approaches) ....
This is not to scare you
Slide 13
Slide 14
Material Data Base Required for TBM or DEMO (BB)Required for TBM or DEMO (BB)
Data required for design (and licensing) are different from data measured orData required for design (and licensing) are different from data measured or required during R&D phases
Each data point must be traceable in any details (from product heat number, orientation and location of specimens following standards verified )orientation and location of specimens, following standards..., verified,... )
During Materials R&D> Few data for (fast) screening (not avfull set of properties and conditions)
Typical example “fast fracture” Charpy impact test valuable [Code requiresTypical example fast fracture Charpy impact test valuable [Code requires fracture mechanics properties fracture toughness J and K]Therefore, often data gathered during R&D phases are not usable for design
In particular, properties/data often are hardly comparable between materials produced in small quantity at lab scale and from industrial fabrication.
Slide 15
Fusion Materials Development Path
Materials Performance/Component specific Loading - Stage- IVDemonstrate solution to concept-specific issuesPerformance under complex loading history (T, stress, multi-axial strain fields & gradients) & environmental conditions
Qualified Material, Demonstration of Performance - Stage- IIIComplete database for final design & licensingValidate constitutive equations & models
Demonstration of Performance Limits - Stage- IIDatabase for conceptual design
Demonstrate life time goals (He issue)
Database for conceptual designDemonstrate proof-of-principle solutions, design methodologyEvaluation-modification cycle to optimize performance
Materials Screening & Materials “Design”` - Stage- IIdentify candidate alloy composition, compatibility, irradiation stability proof of principle for fabrication and joining
Slide 16Idea taken from a presentation of S. Zinkle, UCSB 2002
stability, proof of principle for fabrication and joining technologies -Validation of models and tools (microstructure)
EU Milestone: Generate engineering data base for candidate materialdata base for candidate material
• Review the current material data or knowledge base for austenitic Associations, R&D
stainless steels, RAFM steels (EUROFER), EUROFER ODS (9% Cr), ODS Ferritic steels (12-14 Cr), Tungsten alloys, Copper alloys, and SiC/SiC composite relevant for fusion devices beyond ITER & assess options that
di d d i MAR 2001 ( V ll ) f th i t ti lwere disregarded in MAR 2001 (eg Va alloys) for their potential• Clearly and uniquely define a material (chemical composition, fabrication
process, heat treatment, level of development, eg industrial availability l b l )vs. lab scale) . In particular,
• (i) Compile for each of the materials mentioned above, all physical and mechanical data needed for design (for a full list see eg Appendix A.Gen of the ITER structural design code) In particular clearly indicate if measurementsITER structural design code). In particular, clearly indicate if measurements techniques deviate from standards (eg ASTM)
• (ii) Indicate and describe fabrication processes and semi-finished products available and limitations in fabrication or machining.available and limitations in fabrication or machining.
• (iii) Review data from irradiations campaigns, for displacement damage and, as far as possible, He and H /dpa ratio production levels of relevance for DEMO design. In any case clearly indicate the origin of data and irradiation conditions
Slide 17
(irradition source, reactor, spallation etc)
Milestone: Generate engineering data base for candidate material (II)data base for candidate material (II)
Associations, EU
• For each material considered, generate a design space in terms of operating limits (temperature, stress levels, exposure times, life time..). Try to identify areas of safe operation versus areas definitely excluded. [Notes (i) there is no unique approach, it may depend on the material and its relative state of development (ii) in-between safe design space and areas not recommended to be used there is design space where it is up t th h i f th i d d i ]to the choice of the engineer and designer]
• Identify and clearly describe the key issues and limiting factors and/or y y y gproperties (eg as function of parameters like maximum stress, exposure times, neutron fluence, irradiation temperature ..)
• Identify R&D needs/requirements and define milestones with time period as of 5, 10, 15 years
Slide 18
Status vs, requirements will drive the R&D priorities
Presentation of some reference materials
•Advantages vs & drawbacks•Advantages vs & drawbacks
•Status
•Key issues to be resolved
•Open fabrication / manufacturing issues
G f “ /fGive some indication of “design/fabrication readiness”R&D needs & Milestones
Slide 19
EUROFER (-type) Steel(s)
AdvantagesFM steels well established (in fission) Good balance of propertiesFM steels well established (in fission). Good balance of properties.Well-know fabrication technology. Various options for joining (TBM FW/box: techniques demonstrated). Significant data base to start immediate CDA (conceptual design).
Issues & LimitationsLimited to ~300/350-550°CLimited to 300/350-550 C.Embrittlement at low T and high dose. Concern: Effects of transmutational helium >1000appm He (!)
To be confirmed. Further potential to be evaluated.
Slide 20
Qualification and Validation for TBMQ
Characterisation (up to low dpa)Ph i l ti
On schedule.D t b t bPhysical properties
Mechanical propertiesData base to be completed in time.
Design allowable limits On schedule.Color codeGreen: ready / no further issuesYellow: on schedule / only minor issues open
gTo be completed in time.
Fabrication and technologies joining Comprehensive, some Orange: just started / in delay / some open issuesRed: seriously in delay / serious issues
Fabrication and technologies joining p ,processes need to be implemented in codes !
Design rule development Not yet on scheduleDesign rule development Not yet on schedule.High temperature rulesto be developed.
Compatibility with breeder (LiPb)
Slide 21
Sufficient data to start a process to make EUROFER a code-qualified material, eg. as of RCC-MX
Joining Process DevelopmentAchievements and remaining Issuesg
Grid assembly(11 mm thick.) First wall
YAG Laser
4kW0.3 m/min
10 kW2 m/min
( )HIP / Diffusion Welding
TIG 130 A0.1 m/min
Box assembly
NGTIG 140-230 A~0.1 m/minassembly
Laser/MIG hybrid
YAG 4.5 kW+ MIG 21 Ay
1 m/min
Electron beam
~80 mA10 /
Challenge: Dimensions few mm,Less than required from testing standards
Slide 22
beam 10 mm/sY. Poitevin, F4E
Next challenge: Several joining techniques not yet code qualified (not included in any nuclear code), e.g. any diffusion weld, any hybrid
q g
Ferritic-martensitic steels embrittlement(ductile-brittle-transition)
Bcc steels become brittle if irradiated, For EUROFER most pronounced below ~ 325ºC E Gaganidze, KIT
200
250
300
Tirr =300-330°C
°C)
100
150
ΔD
BTT
( Additional increase above ~500/700 to 1000 appm He
0 10 20 30 40 50 60 70
0
50 KLST DBTT (FZK, NRG) ISO-V DBTT (SCK)
Δ
Results from fission neutrons
Embrittlement can be [to some extend] mitigated
0 10 20 30 40 50 60 70
Dose (dpa)
b tt e e t ca be [to so e e te d] t gatedeither using higher operating temperatures above 350ºC when irradiated (required only at or close to First Wall) or annealing for some hours at 500-550 ºC (needs further investigation!)
Slide 23
further investigation!)• .
He effect on DBTT
Spallation Kurtz, Odette, Yamamoto, DaiP t 2010Spallation
sources Porto 2010
MTR results
ModellingIFMIF[Spallation]
Slide 24
[Spallation]Fe54 / Boron doping …
Role of Helium - another exampleSwellingSwelling
From irradiation in fast breeder reactors:Negligible swelling for RAFMs-Negligible swelling for RAFMs steels up to high dose
-Triple beam indicates swelling p g(strongly dependent on micro-structure /product form)
Area for modelling efforts and Prediction -Area for modelling efforts and verification (eg implantation or other standard tricks)
from modelling
Kurtz Odette Yamamoto
Slide 25
Kurtz, Odette, YamamotoPorto 2010
Validation towards DEMOValidation towards DEMO
Characterisation (up to low dpa) Data up to 70 dpa.Physical propertiesMechanical properties
He- effect ?
Design allowable limitsDesign allowable limits---------
•Fabrication and technologies joining Developed.•Fabrication and technologies joining pData up to 10 dpa (3 options)
•Design rule development High temperature rulesTo be developed. Failure mechanisms?
•Compatibility with breeder (LiPb) Might need development of coatings.
Slide 26Okay up to 30-50 dpa. Effect of He unclear. Limitation ?
EUROFER–ODS Fabrication StepsFabrication Steps
• Mechanical alloying of powder • EUROFER composition (9Cr-1W Ta V) + 0.3% Y2O3 + additions
• HIP (Hot Isostatic Pressure) Th h i l t t t t hi d ti• Thermo-mechanical treatment to achieve good properties
Mechanical Alloying
SteelHot Isostatic
PressingAlloying
MA powder
PowderElementalPowders
Pressing
MA powder
Steel canAttrition Mill
Y2O3
Powder
Hot RollingHeat Treatment Hot Extrusion
plate bar
Slide 27
plate bar
EUROFER ODS Steel 9Cr-1W Ta V + 0 3% Y2O39Cr-1W Ta V + 0.3% Y2O3
AdvantagesGood high T strength (creep tensile creep fatigue)Good high T strength (creep, tensile, creep-fatigue). Indications for higher irradiation resistance and improved tolerance against Helium. Nano structure (nano grains and nano dispersoides Y2O3 Y2Ti2O7)Nano-structure (nano grains and nano-dispersoides Y2O3, Y2Ti2O7)
Strengthen the material without loss of ductility.Act as re-combination centers (sinks) for irradiation induced defects. S b ittl tSuppress embrittlement.
Issues & LimitationsReduced fracture toughness & higher DBTT.Scalability of fabrication process (from “kg” to “tons”).Few options for joining (“non-melting”: diffusion bond, stir friction).(Currently lack of industrial partners in the EU).
Application: EUROFER ODS is not foreseen to replace RAFM steels 1-by-1,
rather than to complement EUROFER.
Slide 28
pFabrication of a full BB box questionable (would need different design
approach & fabrication).
Dual Coolant Breeder ConceptExample for Material System(s)Example for Material System(s)
Basic idea from mid 1990-ties by FZK (S. Malang) and US Aries (ST) design teams (eg. M Tillack F Najmadi et al )
The DCLL uses a material system of EUROFER-ODS, EUROFER structure M Tillack, F. Najmadi, et al.)EUROFER ODS, EUROFER structure & SiC/SiC
Function (Design)/Material-R&D /Fabrication/Fabrication – are integrated:EUROFER-ODS • fabricated as thin plates• diffusion bonded to EUROFER
structure (not dissimilar!).( )Further examples of material systems:(i) Corrosion needs to be studied in a EUROFER SiC LiPb systemEUROFER-SiC-LiPb system.(ii) EUROFER needs tritium barriers and
coatings against corrosion.Charm of the concept;- To use the HT capability of ODS
Slide 29
(iii) FW is multi-layer: EUROFER/ODS/W-armour.
- To avoid LT low fracture toughness- To avoid welding
Ferritic (nano composite) steels (12-13-14)Cr-(1-2)W (0.3-0.5)Ti V + 0.3% Y2O3(12 13 14)Cr (1 2)W (0.3 0.5)Ti V + 0.3% Y2O3
AdvantagesSimilar (and better than) 9%Cr FM ODS:Similar (and better than) 9%Cr FM ODS:
Higher T; potential for higher radiation resistance…. Issues & Limitations (Similar as 9%Cr ODS and worse)
Low fracture toughness [Key issue to resolve].Fabrication of components
S
Similar conclusions as EUROFER ODSStatus
Worldwide activities (US, JP). EU started in 2005.Rapid growths of new approaches methods and ideas
EUROFER ODS
Rapid growths of new approaches, methods and ideas.Promising (individual) results.
Application: Back-bone for high-T gas-cooled divertor.Potential for BB unclear (only with new design approach).
Slide 30
New NFA / ODS materialsNew NFA / ODS materials - provide huge opportunities in terms of properties- are challenging to design a complex component
M h i l H t I t ti
are challenging to design a complex component
MaterialMechanical
AlloyingSteelPowderElemental
Powders
Hot Isostatic Pressing
MA powder
Steel canAttrition Mill
Y2O3Powder ?
Hot Rolling
Attrition Mill
Heat Treatment Hot Extrusion
?Technology Application
Slide 31
Technology Application
Material
Why not combine materialsWhy not combine materials Such as NCF and RAFM and use their respective strengths Plasma near 10
cm from ODS with
Applicationsimple geometry that can be fabricated The rest, complicated
in structure isin structure, is fabricated from RAFM
Slide 32
SiC/SiC Ceramic Composites
AdvantagesHigh T application (600-1100°C).High T application (600 1100 C).Good (uniaxial tensile and bending) strength (Shear an issue?!).Flexible to “engineer” properties (fibres; matrix to fibre volume, weaving, interface)interface).(Only) non-metallic, non-magnetic option.
Issues & LimitationsLarge amount of transmutated(He) -> differential swelling (fibre/matrix).Limited thermal conductivity after irradiation (fundamental issue !?).Inherently “limited deformability”- (Critical under accidental conditions)Inherently limited deformability (Critical under accidental conditions) Needs new design approaches and methodologies.Reliable joining technology at large scale for various geometries (?).
M t i l b t il d Diff t li tiMaterial can be tailored, Different applications: (1) Structural Material (long-term, today not mature).(2) As flow channel inserts for DCLL.
Slide 33
• Thermal insulation & Electrical insulation (mitigate MHD effects).
Degraded Properties at High Neutron Dose
Thermal conductivity degraded
d i di tiunder irradiation
~order of 10 W/mK or belosw
(required ~20 W/mK)(required ~20 W/mK)
SiC
W
Increased thermal conductivityby W-Fibres: (W,SiC)f/SiC R ti b t W d SiC
Slide 34Snead, Katoh et al., ICFRM-13
Reaction between W and SiC to be explored. (IJS, S. Novak)
Tungsten Divertorg
Slide 35
Application
Example of the strong
relation
Semi-finished products Properties
Slide 36
Semi finished products
Divertor options-Divertor options-ITER –like water-cooled (“low temperature”) > t t i htf d t l t DEMO-> not straightforward to apply to DEMO
-> order of magnitude higher n-irradiation ->> long term exposure to (thermo-mechanical loads) ->>> “high temperature end of T-window” limited by creep
-Gas-cooled->> need for high temperature structural materials
-Liquid options….C i t Hi h th l d ti it
Slide 37
37-Common requirement: High thermal conductivity
Selection of Structural Materials for HT (He, gas cooled) Divertor ConceptsHT (He, gas cooled) Divertor Concepts
Slide 38
M t i l S l tiMaterial Selection
For Gas Cooled Divertor
Slide 39
Slide 40
Slide 41
Slide 42
Slide 43
Slide 44
Slide 45
Surprise !Pure W is the only yductile
Slide 46
Slide 47
By no way a structural material
Rods
Slide 48
Slide 49
Cooled Divertor Concepts use Cooled Divertor Concepts use thin pipes/thimbles/platesthin pipes/thimbles/platesthin pipes/thimbles/platesthin pipes/thimbles/plates
Foam
HeatedSurface
!! Idea !!!! Idea !! Produce pipes
from rods
Slide 50
o ods
The result The result
The typical failure mode
[also in other case of “new i i t i l”] Michael likes
Slide 51
promising material”] Michael likes this picture
Facility needs
How to simulate 14 Mev neutrons-Transmutation products< Leave this mainly to the IFMIF-< Leave this mainly to the IFMIF presentation>
Slide 52
Fusion Materials Development PathFacilities needed
Performance under component specific loading Stage IVFNT(S)F“? CTF???
Qualified materials full demonstration of performance Stage III
„FNT(S)F“? CTF???Not any facility existing
Qualified materials, full demonstration of performance Stage III14 MeV neutrons or fusion specific n-spectra >>> IFMIF
To some limited extend ITER-TBM
Demonstration of performance limits Stage II
Fi i t (MTR f t ti lik J l H it )Fission reactors (MTR of next generation like Jules-Horowitz)
(IFMIF)
Materials “Design” R&D Stage I
Fission reactors (MTR)
Slide 53
Multi-ion-beam irradiation facilitiers
Complementary Modelling essential
The gapsand challenges
TransmutationHe/dpa He/H/damage
In service conditions and challenges
Where are main gaps in present knowledge1) Effect of Helium
He/H/damage
In service
2) Complexity of operational conditions
He/dpa effectaddressed in
conditions
Thermal fieldsGradients, Inhomogeneous
IFMIF
Pillar:Irradiation in (Fission) MTR
Time-temperature history, Multi-axial, Tritium, magnetic field,
B lliWhich experiments can be performed in MTR
MultiMulti--effectseffects + BerylliumCeramic / liquid Breeder
•To validate models•To reduce risk of operation in FPP•To identify the most critical condition / unknown failure modes
Slide 54
unknown failure modes FNSF or FNTFComplimented by modelling
Strategy of the neutron irradiation effect prediction technique development
FusionFusion neutronneutron irradiationirradiation datadata cannotcannot bebe acquiredacquired untiluntil IFMIFIFMIF willwill bebe inin operationoperationThe initial DEMO design target should be within the range where fusion neutron irradiation data is
H. Tanigawa, Vienna Dec 2011, IAEA, modified
The initial DEMO design target should be within the range where fusion neutron irradiation data isno too far off from the data trend obtained from fission irradiation experiments.
Accumulation of “rich” fission irradiation database within above range is essential.It is critical to characterize and estimate materials performance under high does fusionp g
neutron irradiation using simulation experiments and computational modeling to predictthe range
Elongation
Fission dataNon-irradiation data++
Irradiation data by fission reactor tests
++ +
+
++
+
+Fusion neutron
irradiation data(IFMIF)Data needs to be obtained in early stage of IFMIF
Prediction from simulation experiments and computational
It is important to predict It is important to predict where the He/H effects where the He/H effects become criticalbecome critical
of IFMIF+
Slide 550
Dose (dpa), He (appmHe), log
computational modeling
become critical become critical 30~50dpa/ ~700appmHe?
Strategy on the address fusion neutron irradiation effects
Experimental understandingExperimental understanding Mechanical understandingMechanical understanding
Dislocation damage, He effects, H effects, etc.
Neutron irradiation (fission) Ion beam irradiation)
Theory of Irradiation effect
Mechanical Microstructure
Mechanical property data
SSTT
Microstructure data
Mechanical property
model
Microstructureevolution
model
Structure deformationNano
hardness(Hm)
Hardness(Hv)
TensileTensileToughne
ss
TEMTEM
SEM Theoretical predictionTheoretical predictionC t ti lC t ti l
St uctu e de o at omodel
ResidueCreep
Fatigue
(Misc)
Computational Computational SimulationSimulation
Irradiation fields correlation (dpa/s, PKA)Point defect migration, agglomeration
Microstructure evolution
correlation
Interpretation of mechanical
Others
(Misc)Evaluation of
fusion neutron irradiation effects on mechanical property DEMO
Microstructure evolutionEtc.
of mechanical properties
Slide 56
IFMIF irradiationmechanical property DEMO
Blanket DesignH. Tanigawa, Vienna Dec 2011, IAEA, modified
Some thoughtsInstead of a summary y
Slide 57
IssuesStrategy and potential for solutionStrategy and potential for solution
“Material” Issue Strategy / gyMitigation
RAFM steel •Limited by He transmutation•~700 / 1000 appm
Limited margin for improvement 700 / 1000 appm pUse NCF/ODS
SiC/SiC •Limited thermal conductivity after n-irradiation
unclearirradiation
ODS steels •Procurement of material DEMO/FPP needs1000 tons (today typically 10-100 kg at best)•Manufacturing of complex components
unknown
Manufacturing of complex components(blanket box)
Irradiation facilities
•The future availability of fission reactors withhigh fluence (~20 dpa/y) is not ensured
Only at political levelfacilities high fluence ( 20 dpa/y) is not ensured level
IFMIF volume •Limited volume. Limited capacity to qualify inshort time more one (max two) structuralmaterials in time before DEMO
Pre-selectionPreferable voluntary
Slide 58
materials in time before DEMO•Joints and welds need also qualification !
voluntary cooperations
e2
Strong Need forCoordination and CollaborationCoordination and CollaborationResources for MD were limited are limited and will be limited• ITER running out of budget, financial crises (EU US JP)ITER running out of budget, financial crises (EU US JP)• “Tradition “: in a world of decision makers and committees populated with
plasma physicists & (over)confidence in parts of the material science communityNew effort in coordinated activities of partners willing to share effort,New effort in coordinated activities of partners willing to share effort, resources and results (exchange), respecting rules of IPR.Bi- / tri-lateral agreements or revival of IEA agreement Objectives:Objectives:
Reduce no. of variants (chem. compositions) Focus on the key issue (either a property or technology)Seek for solutions in reasonable time (eg NCF ready in 10-15 years, W-divertor in 15 y. [Minimize the risk to fail
Easy to start with: standardization of SSTT, development of design y , p gmethodology, development of software (link mechanical data from data bases to microstructure), common data base development or handbooks (mainly in future, today some data is classified of difficult to identify
Slide 59
owner) >> Proceed after gain in experience and confidence in partnership
e3
Thank you for you attentiony y
Slide 60