Transcript
Page 1: Some thoughts and remarks on Structural Materials and Data ... · Some thoughts and remarks on Structural Materials and Data Bases Fusion road map, R&D, Issues in qualification and

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

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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

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Preliminaries

Slide 3

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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

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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 ?

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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

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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.

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Data bases

Slide 8

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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

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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)

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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

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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) ....

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This is not to scare you

Slide 13

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Slide 14

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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

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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)

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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)

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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

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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

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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

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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

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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

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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!)• .

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He effect on DBTT

Spallation Kurtz, Odette, Yamamoto, DaiP t 2010Spallation

sources Porto 2010

MTR results

ModellingIFMIF[Spallation]

Slide 24

[Spallation]Fe54 / Boron doping …

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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

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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 ?

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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

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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).

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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

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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

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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

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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

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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).

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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)

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Tungsten Divertorg

Slide 35

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Application

Example of the strong

relation

Semi-finished products Properties

Slide 36

Semi finished products

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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

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Selection of Structural Materials for HT (He, gas cooled) Divertor ConceptsHT (He, gas cooled) Divertor Concepts

Slide 38

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M t i l S l tiMaterial Selection

For Gas Cooled Divertor

Slide 39

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Slide 40

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Slide 41

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Slide 42

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Slide 44

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Slide 45

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Surprise !Pure W is the only yductile

Slide 46

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Slide 47

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By no way a structural material

Rods

Slide 48

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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

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o ods

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The result The result

The typical failure mode

[also in other case of “new i i t i l”] Michael likes

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promising material”] Michael likes this picture

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Facility needs

How to simulate 14 Mev neutrons-Transmutation products< Leave this mainly to the IFMIF-< Leave this mainly to the IFMIF presentation>

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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)

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Multi-ion-beam irradiation facilitiers

Complementary Modelling essential

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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

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unknown failure modes FNSF or FNTFComplimented by modelling

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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?

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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

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IFMIF irradiationmechanical property DEMO

Blanket DesignH. Tanigawa, Vienna Dec 2011, IAEA, modified

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Some thoughtsInstead of a summary y

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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

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materials in time before DEMO•Joints and welds need also qualification !

voluntary cooperations

e2

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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

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owner) >> Proceed after gain in experience and confidence in partnership

e3

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Thank you for you attentiony y

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