Graphite Materials for the U.S

ANRIC your success is our goal

SUBSECTION HH, Subpart A

Timothy Burchell

CNSC Contract No: 87055-17-0380 R688.1 Technical Seminar on Application of ASME Section III to New Materials for High Temperature Reactors Delivered March 27-28, 2018, Ottawa, Canada ANRIC your success is our goal Society and a Fellow of ASME. other related working groups and subgroups. Dr. Composite Materials, and a member of Subgroup on Materials, Fabrication and Examination the Subgroup and on High Temperature Reactors, Chair of the Working Group on memberGraphite of and the Committee on Construction of Nuclear Facility Components (BPV Award in 2015. Dr. Academy of Science’s Institute of Metals Research in 2006 and the ASTM D02 CommitteeHe is a Eagle Battelle Distinguished Inventor; received the reactors. Laboratories in the U.K. he monitored the condition of graphite moderators in gas the thermal physical properties of carbon materials. As a Research Officer at Berkeley isotropic Nuclear and near isotropic graphite and carbon on the structure and properties of fission and fusion reactor relevant carbon materials, including include: fracture behavior and modeling of nuclear Generation Nuclear Plant graphite development tasks at ORNL. His current research interests acquire reactor graphite property design data. Currently, Dr. Temperature Gas Carbon Materials Technology (CMT) Group Leader and was manager of the Modular characterization High of carbon and graphite materials for the U.S. Department of Energy. Division He of was the Oak the Ridge National Laboratory (ORNL). He is engaged in the development Nuclear and Material Science and Technology Group within the Materials Science and Dr.Technology Tim

Burchell BIOGRAPHICAL INFORMATION

is Distinguished R&D staff member and Team Lead for Nuclear Graphite in the - Cooled Reactor Graphite Program responsible for the research project to Burchell TIM TIM BURCHELL

remains very active in both the ASTM and ASME. He is currently a

- carbon composites; radiation creep of Burchell - grade graphite; the effects of neutron damage Hsun

is a Fellow of the American Carbon

Lee Lecture Award from the Chinese Burchell

is the leader of the Next - - III),member of

cooled power graphites , ANRIC your success is our goal GRAPHITE GRAPHITE I GRAPHITE MATERIALS SUBPARTA Temperature High Reactors Division Section III, 5 –

Manufacture & Application

–

Subsection Subsection HH

ANRIC your success is our goal IV. III. II. I. Presentation Overview of

ASME ASME GraphiteCode for EffectsReactor Environmental Properties and Structure and ManufactureApplications • • • • Mechanical Properties Physical Properties Porosity and texture graphite crystalSingle and polycrystalline synthetic – – – – Strength and Strength fracture constants Elastic Electrical Thermal

ANRIC your success is our goal MANUFACTURE GRAPHITE SYNTHETIC • graphitization • controlled pyrolysis binder • distillates heavyoil calcination of • properties affecttexture method and greenand forming artifact • coal •

Long cycle cycle Long times ~9 months Acheson or longitudinal Firstbakestage, acritical is Petroleum from coke morphology Coke filler particle of Pitch from coke calcination - tarpitch

ANRIC your success is our goal Graphitizing Manufacture Furnace Temperature, °C 1000 1500 2000 2500 3000 500 0 0

Slow heating and cooling heating and Slow during cooling baking escape allows of of pyrolysisgasses minimizes and thermalgradients 5 Load furnace Power On Power

10 Cool 15

– Repair Unpack 20 Time, Time, days

Bakingand Reload

25 Graphitization 30 35 Cool

Unpack Baking 40

Repair

Reload

45 ANRIC your success is our goal Manufacture Manufacture Green bodies packed in coke and placed in steel saggers Modern car bottom carbon/graphite baking furnace -

Baking

ANRIC your success is our goal Baked artifacts surrounded by a coke pack and covered with sand to Graphitization Manufacture exclude air. Electric current flow through the coke –

Acheson - pack pack & artifacts

ANRIC your success is our goal Carbon atoms migrate to thermodynamically more stable graphitic lattice structure Furnace covered with sand to exclude air, current flows though the bakedartifact Graphitization Manufacture and 3D ordering achieved (degree of ordering depends on feedstock type) –

Longitudinal

ANRIC your success is our goal Manufacture Manufacture graphitization furnace orsolid fluoride additives to formulation Can Can be performed with solid fluoride additives to Acheson Post graphitization halogen gas process -

Purification

ANRIC your success is our goal • • • • Manufacture Chlorine purifiedgraphite Chlorine Thermallypurified graphite Unpurifiedgraphite FluorinePurification • • • • • • • • Graphitized over3000 materials “clean” raw Effective for Boron for Effective Boron effectivefor not impurities total< 5 ppm chlorides asvolatile removeimpurities treatment to chlorine High temperature >100 ppm >100 impurities total >500 impurities total ppm

° - C

Purification

ANRIC your success is our goal Microstructure Synthetic Graphite Grade AGOT graphite microstructure (viewed under under Grade microstructure AGOT graphite (viewed polarized polarized light)

ANRIC your success is our goal Microstructure Synthetic Graphite Grade PGA graphite (with (viewed underpolarized light)

- grain) microstructure

ANRIC your success is our goal Microstructure Synthetic Graphite Grade Grade IM1 - 24 graphite graphite microstructure 24(viewed under polarized polarized light)

ANRIC your success is our goal Microstructure Synthetic Graphite Grade Grade NBG (viewed under (viewed under polarized light) - 18 graphite 18graphite (with

- grain) microstructure microstructure grain)

ANRIC your success is our goal Grade Grade IG Microstructure Synthetic Graphite - 110 graphite graphite 110 (viewed microstructure under polarized polarized light)

ANRIC your success is our goal • • • • • • • graphite Texture in synthetic of: arises because Texture Synthetic Graphite coke and binder binder coke and porosity) Forming method (preferential of filler orientation Porosity Recycle morphology fraction and Filler coke type Size and distribution shape of filler particle Filler and cokescracks binder and Crystal domain anisotropy, binder coke size

Texture imparts anisotropy!

ANRIC your success is our goal • • • • • • Applications Aerospace Mechanical electronic and Electrical manufacture Semiconductor Metalprocessing Nuclear • • • • • • • • • Electric motor brushes, resistance heating elements, heating electrodes Electric brushes, resistance motor EDMelements, boats crucibles, crystal processing, Si Casting dies Hall furnace electrodes Arc(steel re Stay tuned!! Stay systems thermal and protection seals Bearings, lithium cells (bipolar Fuel plates), rocket motor throats and nozzles, missile jet throats plates cones, thrust nozzles, missile and nose motor rocket -

Heroult

cell cell electrolysis) cathodes (aluminum

melting) - ion ion rechargeable batteries

ANRIC your success is our goal APPLICATIONS THE LARGEST THE LARGEST MARKET FOR ARTIFICIAL GRAPHITE IS

– ARC FURNCE ARC FURNCE ELECTRODES INDUSTRY) (STEEL

ABOUT 1,000,000 ABOUT TONS PER YEAR PRODUCED

ANRIC your success is our goal ASTM has ASTM has number of Specifications, a and Vol. Published in annually 5.05 under jurisdiction the of committeeDO2.F Standards, guidelinesprocedures and ASTM International ASTM

ANRIC your success is our goal . . ASTM ASTM Standards Irradiation Irradiation Dose Components Subjected to Low Neutron Nuclear Graphite Suitable for D7301 graphite Isotropic and Near D7219 (An ASME (An ASME Requirement) - - 08 Standard Specification for 08 Standard Specification for

- isotropic Nuclear -

Specifications

ANRIC your success is our goal What is Specified What is Specified The byASTM? ...... flexural), flexural), E CTE, strength Properties: density, (tensile, compressive, ratio Isotropypurity and chemical Method of determining temperature graphitization Graphitization temperature (2700 recycle Green mix Maximum filler sizeparticle of Method determining coke CTE isotropy Coke and (CTE) type Quality assurance (NQA assurance Quality traceability Marking and

ANRIC your success is our goal . . . . Practices StandardASTM C783 Core Sampling ofC783 GraphiteCore Sampling Electrodes Gas for GraphiteHigh Materials and C781 Boronated Testing Graphite Graphite Results C625 Irradiation Reporting on Manufactured Carbon and Carbon Manufactured Graphite to C709 TerminologyStandard Relating - Cooled Nuclear Reactor Components NuclearCooled

- Temperature

ANRIC your success is our goal ...... Methods ASTM StandardTest and and Temperature at Graphite Articles Room Resistivity of Electrical Carbon C611Manufactured Materials Mechanical testing C565Tension and of Carbon Graphite C562Moisture in a Graphite Sample Graphite C561Ash in a Sample C560Chemical of Graphite Analysis Carbon Graphite Manufactures and Articles Measurement Density of Physical Bulk by C559

ANRIC your success is our goal . . . . . Methods (continued) ASTM StandardTest C748 Rockwell Hardness of Rockwell Graphite C748 Resonance Frequencies and of Carbon Sonic Graphite by of C747Moduli and Elasticity Fundamental Method Thermal Pulse Carbon Thermal C714Diffusivity and of Graphite by Compressive and C695of Strength Carbon Graphite Temperature Room and Four Using Graphite Articles Strength C651Flexural of Manufactured Carbon

- Point Point Loading at

Materials

ANRIC your success is our goal . . . . . Methods (continued) ASTM StandardTest Graphite Graphite Materials Hardness C886Scleroscope Testing and of Carbon Graphite Shapes Density C838Bulk of As Titration Method in Graphite Sulfur C816 Combustionby Modulus Graphite for Use Young’sin Obtaining Carbon in Manufactured Velocity Sonic C769and C749Tensile Strain and of Stress Carbon Graphite

- Manufactured and Manufactured Carbon

- Iodometric Iodometric

ANRIC your success is our goal . . . . Methods (continued) ASTM StandardTest in in Air Materials and Carbon Manufactured Graphite Loss C1179 OxidationMass of Electrodes Density andof Graphite Bulk Gravity, Porosity, C1039ApparentApparent Specific Electrode Graphite C1025 Bending Modulus ofin Rupture of in Kinetic the Regime and Graphite D7542Air Oxidation ofCarbon

ANRIC your success is our goal GuidelinesandPractices New Methods, ASTM Test . Guidelines Guidelines and Practices test has methods,(relatively) new several D02.F on ASTM and Carbons Manufactured Graphite

• • • Parameters for Graphites for Advanced Parameters Weibull and Distribution StrengthEstimatingData D7846 Temperature Ambient Graphite of atToughness of FractureDetermination D7779 specimens Small graphite D7775 - - - 11 11 16 , Standard Practice for Reporting , Uniaxialfor Standard Reporting Practice (2015), for (2015), TestMethod Standard (2015), Guide Standardfor Measurementson

ANRIC your success is our goal and and (continued) Practices Test New ASTM Methods, Guidelines • • • • Evaluation of Nuclear Grade Grade Evaluation Graphite of Nuclear D8093 Graphite with Molten Salt D8091 in Observed Micrographs of Optical Graphite Microstructural Microtextural Features and D8075 Temperature Three Point Articles using at Room Loading of Carbon Strength Manufactured and Graphite D7972 - - - - 16 14 16 16 , Standard Guide , for Nondestructive Standard Guide , for Standard Impregnation of Guide , for Standard Categorization of Test , Method for Flexural Standard

ANRIC your success is our goal . Currently Development Currently in New Methods ASTM Test development: has several Test Methods Guides in and D02.FASTM on manufactured carbons and graphite • • • • • Chemical Chemical purityby Elastic Sonic Constants Graphites Evaluationof AreaPorosity and Nuclear Surface in StandardGuide for of UseAdsorption Gas Methodfor the Tensile StrengthaBrazilian Disc using Specimen Geometry Chromatography Fluorine, sulfur and graphite chlorine in byCombustion Ion – – GDMS ICP - OES

ANRIC your success is our goal . Published STP an also ASTM Committee D02.F has Applications: STP 1578, Graphite Testing for Nuclear Specimen Population Specimen Geometry and The of Test Specimen Significance the the Statistical

Significance Significance Volume and Volume and

of of Test ANRIC your success is our goal or by phone at Feel free to contact

(416) (416) 727 ThankYou! Richard Richard Barnes - 3653 (cell) email at

or (416) (416) 255 [email protected]

- 9459 9459 (office)

ANRIC your success is our goal ANRIC your success is our goal ANRIC your success is our goal GRAPHITE GRAPHITE II GRAPHITE MATERIALS SUBPARTA Temperature High Reactors Division Section III, 5 –

Structure Structure & Properties

–

Subsection Subsection HH

ANRIC your success is our goal IV. III. II. I. Presentation Overview of

ANRIC your success is our goal Structure SingleGraphite Crystal BOND ANISOTROPY

• • • • • • • size l Coherence l lengths, = 0.670nm = 0.246nm Crystal size:cell unit ABC…) get ABA repeat (can stacking between graphene planes Weak bonds of attraction in Strong, bond covalent stiff c

- are crystal measures are of plane

and and

ANRIC your success is our goal Domain Optical& Crystallites Sciences Sciences of Carbon Materials, Marsh & Reinoso

ANRIC your success is our goal Domain Optical& Crystallites

Sciences Sciences of Carbon Materials, Marsh & Reinoso

ANRIC your success is our goal . . • . in Porosity Graphite 2. 1. . 3. 60% porosity> openof is Most containsporositygraphite ~>20% Syntheticbulkdensity1.6graphite= singleGraphite density2.26 = crystal g/cc Three classes of porosity classes Threeof be porosity may identified identified in synthetic graphite: crystals in the filler coke coke binder. and the filler crystals in the anisotropic shrinkageof formed Thermal bythecracks manufacture; gases stageduring the baking of phase entrapmentformed Gas from pores binder pyrolysis during mixing forming; and body bythe in of thevoids Those greenformed filling byincomplete impregnant

pitch, the voids originally occur occur originally thevoids pitch,

1.9 1.9 g/cc

ANRIC your success is our goal • • • • • • Nuclear Graphite Graphite Structural Features: Pore Size Pore Size Grain DomainOptical Micro “Coherent Crystallite Domain” 6.7(a=Å) A, Lattice 2.45 c=

• • • • • • • • • Scale 5 Scale is phenomena chemistry+Coking Carbonization transport Lc order of Extent3D Scale of largest pores (10 largestpores Scale (10 of for Different binder phases within filler or be Pores could (10 filler particles to Usuallylargestrefers SyntheticGraphite Controls of Isotropy

- = Stack Height, La = Stack Width =StackWidth (250 =Stack Height, La crack

100 100 microns (between planes, about about crystallite) (between theof planes, size isomolded

(extended orientation of (extendedof crystallites) orientation

graphite -

350 350 microns)

- - 1000 1000 microns) 600

Å )

ANRIC your success is our goal Flexural Flexural Strength,MPa MPa Compressive Strength, Strength,Tensile MPa Young'sModulus, GPa µΩ.m Resistivity, Electrical given temperaturerange) Expansion,10 Coefficient of Thermal ambienttemperature) W/ ThermalConductivity, Density, Bulkg/cm µm Particle Size, Maximum MethodForming WG Synthetic Synthetic graphite @ properties RT

m.K

Properties - with with grain, AG

Typical (Measured at - 6 /K (over

against grain

(20 Isomolded AXF POCO - 145 7.4 1.8 500 90 65 11 14 85 5 -

Graphite Graphite Grade and Manufacturer

(350 Toyo 10(mean) Isomolded IG 10.8 1.82 140 9.2 - 4.8 54 90 37 450 - - Tanso 43

° C)

(20 Isomolded Mercen 2020 15.5 - 1.77 9.3 4.3 500 45 80 30 85 15

30.8 (WG) (WG) 30.8 (WG) 66.4 (WG) 10.1 25(mean) 27.2 (WG) Isomolded 23.1 (AG) (AG) 23.1 (@500 27.9 (AG) 67.4 (AG) 11.7 (AG) 9.7 (WG) 9.7 (WG) 3.0 (WG) 112(AG) 125(WG) 9.7 9.7 (AG) 3.6 (AG) 1.76 GTI ATJ °

(20 21.5 (WG) (WG) 21.5 (WG) 11.2 72.5 (AG) 72.5 (AG) 20.5 (AG) 11.0 156 (WG) 8.9 (WG) 8.9 (WG) 4.5 (WG) 150(AG) 28 (WG) 28(WG) 72(WG) 9.0 9.0 (AG) 4.7 (AG) NBG 26(AG) molded Carbon vibro 1600 - 1.88 SGL 200 - 18 - °

19.3 (AG) 19.3 19.8(WG) (AG) 12.1 (@500 152 (WG) 8.9 (WG) 8.9 (WG) 4.9 (WG) 6.9 (WG) 8.5 (WG) 2.1 (WG) 107(AG) Extruded 6.9 6.9 (AG) 4.3 (AG) 4.1 (AG) 3.2 (AG) 3000 AGR GTI 1.6

ANRIC your success is our goal Specific Heat Specific Temperature Dependence of

Specific Heat, J/Kg.K 1200 1600 2000 2400 400 800 300 Calculated from ASTM C781 ASTMfrom Calculated 800 Temperature, K 1300

1800

Experimental data Experimental value Calculated 2300

2800

ANRIC your success is our goal ExpansionBehavior Crystal Single Thermal

ANRIC your success is our goal Thermal Expansion Thermal Temperature Dependence of

Thermal Expansion (%) 0.4 0.5 0.6 0.7 0.8 0.9 0.1 0.2 0.3 0 0 Thermal closure of aligned porosityof aligned closure Thermal 100 (a)

200 Poco 300 IG-110 400 Temperature Temperature (C) PCEA PCEA WG 500

600 PCEA PCEA AG

700 800

900 1000 ANRIC your success is our goal Coefficient of Coefficient Thermal Expansion Dependence Temperature of

Average CTE (x10-6/C) 0 1 2 3 4 5 6 7 8 9 0 (b) Thermal closure of aligned porosity of aligned closure Thermal 100

200 Poco 300 IG-110 400 Temperature Temperature (C) 500 PCEA PCEA WG

600 700 PCEA PCEA AG 800

900

1000 ANRIC your success is our goal HOPG Thermal HOPG ConductivityThermal Temperature Dependence of hnnsatrn,efc fitisc defectsintrinsicof effect scattering, Phonon

ANRIC your success is our goal the Thermal Conductivitythe Thermal Temperature Dependence of

Thermal Conductivity (W/m.K) 110 130 150 170 30 50 70 90 0 Anisotropy in extruded thermalconductivity 200 400 600 800 Temperature (K) Temperature 1000

1200 1400 Against Grain With Grain 1600

1800

2000 ANRIC your success is our goal the the Resistivity Electrical Temperature Dependence of Electrical Resistivity, ρ, (μΩ.m) 10.0 12.0 14.0 16.0 6.0 8.0 0.0 2.0 4.0 0 500 Electron transportmechanism 1000 Temperature,K 1500 2000

2500

3000

3500 ANRIC your success is our goal Crystal Graphite Crystal Graphite (Kelly, 1981) Elastic Of Constants Single C C C C C Elastic Elastic moduli, 44 33 13 12 11

1060 180 GPa 36.5 36.5 4.0 4.0 15 - ± ±

± 4.5

5 20

20 1

S S S S S 44 33 13 12 11 Elastic compliances,Elastic

10 2222 - - - 13 9.8 9.8 275 3.3 3.3 1.6

Pa ± ± ± - ± -

1 2500

0.3 0.8 0.6

ANRIC your success is our goal axisMeasurementand Axis with Angle Miss Of TheVariationReciprocal OfModulus Young’s

Reciprocal Young's Modulus, E-1 (Pa-1) 0.00E+00 1.00E-11 2.00E-11 3.00E-11 4.00E-11 5.00E-11 6.00E-11 7.00E-11 Angle between directionofmeasurement and crystalc 0 0.2 0.4 - orientation Between Between orientationThec 0.6 0.8

1 - axis, φ ( φ 1.2 Radians) 1/E (S441/E only) E 1/ 1.4

1.6 - ANRIC your success is our goal the the c angle with of miss of modulusthe reciprocal ShearVariation

Reciprocal Shear Modulus G-1 (Pa-1) 1.5E-10 2.5E-10 - 1E-10 2E-10 5E-11 axis and measurement axis andaxis 0 0 Angle between directionofmeasurement and crystalc 0.2 0.4 0.6 - orientation between orientation 0.8 1 1.2 - axis, φ ( φ 1/G 1.4 Radians)

1.6

ANRIC your success is our goal petroleum coke synthetic petroleum coke synthetic graphite temperature with forpitch Modulus Typical increase Young’s

Increase in Young's Modulus, [(Et/Et(298)) - 1] 0.00 0.10 0.20 0.30 0.40 0.50 0.60 0 Petroleum-coke Pitch-coke 500 Measurement Temperature, K 1000 1500

- coke coke and 2000 2500

ANRIC your success is our goal • • stress that majorcontrol the two factors There are synthetic graphite Stress of stresses within the body and thus thus within ofthe stresses bodyandthe the which distribution, controls distribution andmorphology The defect/crack stress, applied an the dictates to respond how crystals constant of the C The magnitude stress that stress each crystallite experiences. - strain strain of synthetic behaviorgraphite: - strain strain of behavior

44 , which which ,

ANRIC your success is our goal graphite graphite (WG) forcurvemedium Typical compressive stress

Compressive Stress, MPa 10 15 20 25 30 35 40 45 50 0 5 0.00 0.20 0.40 0.60

0.80 - Strain, % grain extruded 1.00

1.20 1.40 - strain strain 1.60 1.80 2.00 ANRIC your success is our goal (WG) formedium Typical stress tensile Tensile Stress, MPa 10 12 14 16 0 2 4 6 8 0

0.05 - grain extruded extruded grain graphite 0.1 Strain, %

0.15 - strain strain curves 0.2 0.25 ANRIC your success is our goal variationtextures of of range thegraphiterepresentingsynthetic for wide a strengthfractionaland porosity Themean correlation between 3

Mean 3-pt. Flexure Strength, MPa 25 30 35 40 45 50 10 15 20 0 5 0.12 0.16 FractionalPorosity 0.2

0.24 - pt flexure pt y = y179.18e R² 0.8042 = 0.28 - 9.623x

0.32 ANRIC your success is our goal the variation of of thevariationtextures syntheticwide of range graphiterepresenting fillersize coke particle strengthmean anda for The correlation mean between 3 Mean 3-pt. Flexure Strength, MPa 10 15 20 25 30 35 40 45 50 0 5 0 0.2 0.4 0.6 Mean Mean Filler ParticleSize, mm 0.8

1 1.2 - pt flexure pt

1.4 y = y44.385e 1.6 R² 0.8655 = - 0.765x 1.8

2 ANRIC your success is our goal Synthetic Synthetic Graphite CrackPropagationin F

500 F 

the presencethe ofpores [P], and crack [C] which which [C]haveand crack H pores presumably under pores presumablyunder propagated through the through propagated photomicrograph of the photomicrograph ofthe microstructure microstructure of grade coke fillercoke particles [F] - the influence influence the of their 451 revealinggraphite stress fieldsstress An An optical

ANRIC your success is our goal behavior behavior predictions & model Graphite multiaxial strength Axial Stress (MPa) -65 -60 -55 -50 -45 -40 -35 -30 -25 -20 -15 -10 10 15 20 25 -5 0 5 0 Hoop Stress Hoop(MPa) Stress 5 10 15 20 Q1 Predicted Failure Mean Stress Data Experimental stress (PR=0.18) Effective (net) • • • • initiated at ORNL stresstesting quadrant NBG criterion mode fracture mixed incorporating Shetty model Burchell NBG 2 & Extended NBG to of H testing stressquadrant 1 Previous nd - - - 451 & IG & 451

183 18modeled with stress quadrants stress

rd st

and and 4 and 2 and - 110

- th 181 nd

ANRIC your success is our goal resistance thermal Graphite shock ratio expansion coefficient, E the Young's modulus, and is the K thermal conductivity, σ yield the strength, α thermal the .

Thermal Thermal Shock FOM, Carbon Graphite does notmelt butrather sublimesat T>3300K Wrought Wrought beryllium Graphite, Graphite, Graphite, IG Material Pure tungsten Pure - carbon carbon composite

AXF -

110 - 5Q

~0.5x10 124,904 FOM ~1x10 ~1x10 84,844 6 4



is Poisson's is Poisson's

ANRIC your success is our goal or by phone at Feel free to contact

(416) (416) 727 ThankYou! Richard Richard Barnes - 3653 (cell) email at

or (416) (416) 255 [email protected]

- 9459 9459 (office)

ANRIC your success is our goal ANRIC your success is our goal ANRIC your success is our goal GRAPHITE GRAPHITE III GRAPHITE MATERIALS SUBPARTA Temperature High Reactors Division Section III, 5 –

Environmental Effects

–

Subsection Subsection HH

ANRIC your success is our goal IV. III. II. I. Presentation Overview of

ANRIC your success is our goal • Effects EnvironmentalReactor effects areconsidered: followingThe reactorenvironmental – – – Radiationdamage Salt coolant Gas • • • oxidation Acute (Air) Of concern concern Of all to graphitemoderated HTRs of Primarily - coolant

: - radiolytic /graphiteinteractions ( graphiteinteractions oxidation concern

oxidation : in in GCR Chronic

( moisture

oxidation )

)

ANRIC your success is our goal . . . . Moisture) and OxidationThermal(Air Steam in Helium Coolant Steam accident Air ingress degradation will property cause moderated reactors and oxidation Air/steamgraphite in occur all can Oxidation = Oxidation LossCarbon of solid (Graphite) • • • • C +2H C +H C CO C+O 2 +C 2 → 2 O 2 → CO

→ →

2CO 2

CH CO CO +H 4

ANRIC your success is our goal • • • Moisture) and OxidationThermal(Air Graphitepurityan effect has also sincesome Toburnpredict weight(burn loss Propertiesdegrade ofas oxidative function a impurities act act impuritiesas oxidationcatalysts – – Diffusivity) species core/graphite within (Effectiveblock Local partial pressure (orconcentration) oxidizing of concentration) oxidizing of species range of temperature partial and pressure (or Kinetics oxidation of reactions over the appropriate

- off we need towe know: off need - off)

ANRIC your success is our goal . . . . Wear/Abrasion Graphite Wear rates need to to established needbe rates Wear temperature) pressure and Friction effectcoefficients Helium, (in of wear ofcomponents needed establish Tribologicalto aredata fission product transport transport product fission mechanism aWear products possible(dust) represents • • • Pebble Pebble Graphite on Pebble Pebble on Graphite on graphite

ANRIC your success is our goal . . . . . In Problem Cooled HTRGs He Radiolytic Oxidation is a not moderated moderated will reactors cause property and oxidation Air/steamgraphite in occur all can oxidation Helium cooled reactors immune from are radiolytic measures Special gaseousinclude inhibitors phase properties lossdegrade can Radiolytic weight physical carbon oxidize temperatures at reactor CO degradation 2

+ g =CO

2 *, an activated *,that activated an species can

ANRIC your success is our goal Reactors For Graphite Salt Molten • • • • • • • • What What are “issues” the for cooledsalt graphite Finer grains grains Finer pores ≡finer ≡lower permeability graphiteshould What Reactor aSaltCooled use? spots Hot salt fueled is in if pores retained Tritium build TRISO fuel fission products retains challenged Not by damagedose high temperatureor Fission Fission Gas buildup Salt permeation (into pores) • • fine Grained Grained fine Generally<50 Xe 135 ,Tritium - up up in salt permeatesgraphiteif graphite

moderatedreactors?

μ m

ANRIC your success is our goal . . . . Graphite IrradiationDamageResponse Of Factors Controlling Neutron The introduced by extrusion and molding. byand extrusion introduced molding Isostatic molding. technique Forming graphite and preferred. CTE coke asan of used CTE Higher isotropy. CTE is indication ratio behavior irradiation much Isotropic preferred. is isotropy). product and (both coke isotropy final isotropy Structural pore generation. of retardation strength sizespromotes and higher Small crystallite temperature. and (pitch/coke) precursor graphitization of function a is displacement retainless damage. Crystallinity graphitization): crystals graphitic (degree More of Crystallinity produces angraphite. produces isotropic

–

structural and and is structural anisotropy property

ANRIC your success is our goal ...... History Graphite section grade) (nuclear hasGraphite low a cross capture neutron reflector Neutron moderator Neutron criticality to experimental piles determine of team & to for Fermi assemblyavailable Enrico Graphite experimentalreactor (C, Needed nuclear moderator good H a Inthe beginning: York University, Columbia Pupin Laboratory, New First“piles” at • they they can efficiently fission Thermalize fast neutrons to sufficiently low energies that

- – –

Manhattan Project Project Manhattan

returns neutrons to the activeto core neutrons returns

Physics and Physics 92 U 235

1940s 2 O, O, D

2 O, Be) for for O, Be)

ANRIC your success is our goal ...... Moderator as Nuclear Graphite a in sufficient quantity, in sufficient readily machined material, Engineering adequate available strength, 1.70(>Sufficient density g/cc) ppm) < with (ultimately Boron 0.5Available content low purity (high required) neutron low crossSufficiently section absorption costlowRelatively Graphite for first reactors needed be: to

ANRIC your success is our goal . . . . graphites: flowed to improveddown What learned was the over years born Thusgeneration secondwere graphites properties in final artifactyieldisotropic the for cokes Needisotropic size crystallite role ofgraphite damagemechanismUnderstanding of and feedstocksources) (allowedHalogenalternate purification • • UK,IM1 H USA,

- 451 - - 24

– –

molded, coke molded, Gilsonite extruded,petcoke isotropic

high CTE which which high CTE

ANRIC your success is our goal H Near designed HTGR designed(FSV) HTGR GTand elementsFueland reflectorsin replaceablethe GA - 451 - isotropic graphites

• • • • - MHR reasonable strength &CTE High properties physical Near sizeparticle 500 petroleum coke isotropic Extruded, μ -

isotropic isotropic m mean filler m filler mean

ANRIC your success is our goal Graphite Graphite Crystal Structure ...... Cross In properties unique combination of crystal impart perfection anisotropy and Bond stacking ABAB sequence planes between bonding the (weak)der Van Waals in bonding basal plane (strong)Covalent structure hexagonal Carbon atoms in a - plane plane conductor - plane insulator plane

ANRIC your success is our goal Mechanism GraphiteMechanism In The Radiation Damage Displacement energy for carbon is for atom Displacement carbon approx. energy30 eV

ANRIC your success is our goal Is Temperature Is Temperature Dependent Radiation Damage Graphite In ...... vacancy lines. Above 900 loops. Above 650 strain and crystal perfection). crystallite boundaries (function of lattice planes and can be annihilated at vacancies which diffuse in the basal 300 Immobile below 300 VACANCIES up to 1400 which continue to grow at Above 300 interstitials. Above 100 Mobile at room temperature. INTERSTITIALS - 400

o C C formation ofclusters of2 o o o o o C C loops induce collapsing C formation of vacancy C form new basal planes C form into clusters of2 to 4

o C. C.

temperatures

- 4

ANRIC your success is our goal Graphitic Structures Graphitic Planes Layered Basal in Banhart , F. Rep. Rep. Prog . Phys.

1999 , 62, 1181 are indicated indicated are with arrows. of inserted ends the plane planes, basal two the interstitial between loop nano planes basal graphitic of a micrograph showing the A high

– 1221. - particle particle an with - resolution resolution electron

ANRIC your success is our goal (Effect Of Temperature) Volume Changes In H swelling irradiation axis induced thermal expansion and c porosityaccommodate Interplaner cracks and - 451

- ANRIC your success is our goal Energy Energy Release Temperature Low Stored [Adapted from [Adapted Graphite Nightingale,(1962)] Nuclear BurchellT,CarbonMaterials for AdvancedTechnologies,

Chpt . 13 (1999) p. p. 429 (1999) 13 . • recombination Frenkel pair associated with • • • • • New evidence? Traditionally Data Reactor test Hanford K T irr

~ 30 ~

o C

ANRIC your success is our goal Layered GraphiticLayered Structures Displacement Damage in Letters Shinohara, H.; Iijima, S. Urita , K.;

2005 Suenaga , 94, 155502. , K.; Sugai Physical Physical Review

, T.; 2 nm

defects. possible interlayer The arrows indicate nanotubes. double 300K, (c) 573K, in seconds). (a) 93K, (b) scale (0 to 220 irradiation flux & time with the same electron different temperatures interlayer defects at formation rates of images illustrating the electron microscope resolution transmission Sequential high - wall carbon

ANRIC your success is our goal Graphitic Graphitic Structures Displacement Damagein Layered Physical Letters Physical Review Urita , K.; Suenaga , K.; K.; , Sugai

2005 , Shinohara, H.; T.; , 94, 94, , 155502. . . .

of of of Sussex,Simulations UK: Heggie Telling, & University (~473 K) Wigner known for temperature temperatures recorded images different at in estimatedbilayer HRTEM unit of defectsper area theof clusters offormation rate Normalized The The line dotted shows the spiro - - energy release interstitial

I Iijima - V

pair pair , S. ANRIC your success is our goal Dimensional ChangeDimensional Neutron InducedIrradiation . . . . manufacture. microcracks form that aligned on during cooling Swelling in c dimensional crystallite and change texture. graphite are Graphite dimensional changes a of result eventually reaching reaching eventually zero. and falls volume porositythe shrinkage rate the strains crystallite causes of generation new irradiation, With further in incompatibilities shrinkage. and graphite volume net the bulk exhibits Therefore, the a

- direction initially direction accommodated is by

- axis shrinkage dominates axis shrinkage initially

ANRIC your success is our goal . . . Dimensional (continued) Change Neutron IrradiationInduced growth. to shrinkage from initial “turnaround” behavior thus Theexhibits volume graphite and pore new axis generation. growth c due to damagedoserate with increasing increasing atbegins swell an The to graphite generation. excessivedueoccurs pore/crack to Eventually loss Eventually loss ofintegrity mechanical

- ANRIC your success is our goal Texture) Changes in H Radiation Dimensional Induced

- 451 (Effect of 451 ANRIC your success is our goal Changes in Young’s Young’s ChangesModulus in Neutron InducedIrradiation • • • • volume expansion generationand pore/crack to reduction dueand turnoverEventual (densification) shrinkage to volume due increaseSubsequent dislocation pinning Initial rise to due s as ( E ) 1/2

ANRIC your success is our goal Umklapp and Defect and UmklappDefect Scattering Thermal Conductivity

Thermal Conductivity, W.m/K 100 120 140 160 20 40 60 80 0 0 IG-110 samples from (Tirr=600 HTK-7 200 400 Temperature, Temperature, 600 o C 800

Changes o Unirradiated 25.8dpa 24.8dpa 12.1dpa C) 1000 1200

ANRIC your success is our goal compressive stress = 550 ATR Irradiation Irradiation in InducedGraphite Creep Graphite Radiation DamageNuclear in turnaround turnaroundstress compressive and delays applicationbystress. the ofTensile hastens stress dimensionalGraphitechange modifiedbehavior is Rel. Lin. Dimensional Changes (%) -4.0 -3.5 -3.0 -2.5 -2.0 -1.5 -1.0 -0.5 0.0 - 0 2E Graphite (WG),Graphite 2E ° C, 5 C, 5 5 MPa Fast Fluence /Neutron dpa 10

15 –

inelastic deformation inelastic 20 T irr 25

Rel. Lin. Dimensional Changes (%) -3.5 -3.0 -2.5 -2.0 -1.5 -1.0 -0.5 tensile stress T ATR 0.0 0.5 1.0 1.5 irr 0

= 500 = - 2E Graphite (WG),Graphite 2E 5 ° C, 5 Fast Fluence /Neutron dpa 10

MPa 15

25 30

ANRIC your success is our goal ATR Tensile Creep forBehavior Strain A of Comparison and Compressive Irradiation Temperature =500 G. Haag. Report No. Jul Creep Strain,% 1.8 0.2 0.4 0.6 0.8 1.2 1.4 1.6 1 2 0 0 - 2E Graphite 2E Neutron Dose Dose Neutron 10 1 - 4183, 4183, FZ - 550 2 22

o -

C J J Germany n/cm

[E>50 keV] 3

4 CreepStrain, %) (Compressive Poly. MPa) CreepStrain, % Poly. (Tensile CreepStrain, % Compressive Strain,% MPa TensileCreep ANRIC your success is our goal stress stress of 6 irradiation creep 900at the experimental strain fordata creep predicted Comparison of apparent and

Creep Strain, % -2.0 -1.0 2.0 3.0 4.0 5.0 0.0 1.0 0 T.D. Burchell, J. Neutron Dose, 10 Neutron MPa 0.5 Nucl .

. Mater. 381 (2008) 46 22 1 n/cm ° 2 [E>50 KeV] C under a tensile undera tensile C 1.5 - 54

2 Creep Apparent Predicted Correction Change Dimensional True Creep l) Creep (Experimenta Apparent ANRIC your success is our goal  Recognized to New Revision Kelly . . . . . Model Model c   sign of the the sign stress creepappliedof ofthe The sign Fx CTEnot affect that Pores do in Kelly the for accounted CTE that (alreadyPores affect higher doses at generation to for Needporeaccount    

E and s 0  – Fx k

sg Pore Generation Generation Pore ’ needs to be evaluatedneeds be to ’ -     Burchell model)Burchell

  g 0     Δ a a Fx c  x ’ term changes with ’ with term changes the   a a a x         - dX Burchell d

g T    

g   g 0

  F x  d g ANRIC your success is our goal term evaluated term Model Revised with

Strain, % -2.0 -1.0 2.0 3.0 4.0 5.0 0.0 1.0 0 NeutronDose, 10 0.5 22 1 n/cm

2 [E>50 KeV] KeV] [E>50 1.5 Δ Fx 2 ’ internalstress) Term(net Gen Pore Creep Apparent Predicted Correction Change Dimensional TrueCreep Creep (Experimental) Apparent ANRIC your success is our goal ...... Future Nuclear Graphite Fundamental Fundamental studies of creep damage mechanism & dose High experiments irradiation (irradiation creep) reformed and (super BAN) reused graphite Irradiated annealed crushed then and minimize storage disposal and graphite recycled Possible toincreased use of (BAN cokesSecondary technology Green ( coke temperature) of structure precursor graphitization pitch, (choice Fine with well filler particles ordered crystal

It is is for It Materials Science timesome

– iso

GrafTech - molding)

The The

Inc.)

ANRIC your success is our goal scale sub describe materialsfrom complex behavior the multiscaleand models linking Knowledge to STRUCTURE ATOMIC - simulations structure, Electronic nanoscale to the millimetric (component) millimetric (component) the to nanoscale nm

MD MD

STRUCTURE CRYSTAL models diffusionmodels, Meso - scale

 m

models mechanical Micro MICROSTRUCTURE MICROSTRUCTURE -

mm scalesimulations models and large Finite Element

STRUCTURES COMPONENTS &

ANRIC your success is our goal Rappeneau with Unirradiated Graphite Graphite Unirradiated with Irradiatedat 30 Graphite Energy Curve Stored Release for Energy Release Temperature High Stored

et al, CARBON 9 (1966) 115 o C Compared Compared C Cp

Curve

- 124 . . . .

higher higher temperatures at irradiated graphite reported NOT in rates Release > temperature athigh coalesce can Immobile vacancies clusters interstitial small annealing of Associated with LOW temperatures at in irradiated graphite observed ~1400 is at releasesecond peakA

o C ANRIC your success is our goal or by phone at Feel free to contact

(416) (416) 727 ThankYou! Richard Richard Barnes - 3653 (cell) email at

or (416) (416) 255 [email protected]

- 9459 9459 (office)

ANRIC your success is our goal ANRIC your success is our goal GRAPHITE GRAPHITE IV GRAPHITE MATERIALS SUBPARTA Temperature High Reactors Division Section III, 5 –

ASME ASME Code for Graphite

–

Subsection Subsection HH

ANRIC your success is our goal IV. III. II. I. Presentation Overview of

ANRIC your success is our goal . . Contents & Introduction GraphiteASME Codefor Contents High componentTemperature ofaReactor construction core designof and graphite on the rules Presents for the information

• • • Criteria for design of Graphite Graphite Criteria Components for design of Core of Structure Code the their HTRs and Graphite Core Components (GCC) – – – – Verification of design Verification method of design Comparison margins limits categories tressof ands Modes stressfailure, & CaseGCC SafetyReactor

ANRIC your success is our goal . . . . Reactor Nuclear of Role a in Graphite capture cross capturesection cross agrade) neutron low has Graphite (nuclear core active Neutron reflector & (carbongraphite)Neutron moderator materialHigh temperature • energies that the can efficiently energies efficiently the can that fission Thermalize tofast neutrons low sufficiently

–

returns the returns neutrons to

92 U 235

ANRIC your success is our goal ...... Reactor Nuclear of Role a in Graphite The graphite The reflector structure graphite contains vertical pebbles fuel In bed a structure pebble the graphite the retains the nuclear fuel the In coresprismatic fuel graphite elements retain not and form do a boundary pressure cores HTGR graphite constructed are blocks from the Graphite is material core structural reactor in graphite Reactivity alsocontrol is fuel elements penetrations for reactivity control

ANRIC your success is our goal Reactor Reactor (GT Turbine Gas Exchanger Heat Intermediate Generator or Turbine Helium Gas (H heat applications Helium for process outlet temperature Cycle) or 1000 efficiency (Brayton > 50% conversion - - MHR) Modular Modular Helium 2 core Graphite Reactor production)

C ANRIC your success is our goal Particle Particle Fuel GT The Code Graphite for ASME - MHR Utilizes CeramicCoated Utilizes MHR

ANRIC your success is our goal . Graphite ASME Codefor HTR (PBMR) Graphite Core Components

–

Pebble Pebble Type

ANRIC your success is our goal Ceramic Coated Particle Particle Coated Ceramic Fuel The Pebble Pebble Type HTR 6 diameter6 incm (pebble)fuel(carbon)ball a combinedintographite are fuelThe particlesTRISO Utilizes Utilizes

ANRIC your success is our goal . Graphite ASME Codefor (HTTR)HTRType ComponentsCore Graphite

–

Prismatic

ANRIC your success is our goal

Structures (GradeStructures IG HTR HTR Core bottom ofbottomtheCore collectionarea - fuelpebble - 10 10 showingthe 10 Graphite Reactor Internal

- 110) Top of the graphite graphite Top ofthe core ofHTR core

- 10

ANRIC your success is our goal ASME Code Graphite Code for ASME HTR HTR (MSRE, Oak Ridge) Graphite Core Components

• • • • • slot slot X 64 ins 2 inch square section with ½ in Company)(UCC)(GrafTech) CGB Graphite (National Carbon X 64 in tall Core dimensions 54 graphite core of vessel and up through Salt mixture flows down outside coolant salt Uranium fuel dissolved in the pp.118 APPLICATIONS TECHNOLOGY, & VOL. 8, REF:P.N andHaubenreichJ.R.Engel. NUCLEAR

- 136, Feb. Feb. 136, 1970. THE MSRE THE -

Molten Molten Salt

- tall. tall. 3.7 tons in core

in in diameter

ANRIC your success is our goal MSRE Graphite Stringer Graphite ArrangementMSRE Graphite ASME Codefor REF: R.C. Robertson. ORNL TM 728, “Development REF:Robertson. R.C. 728, and “Development ORNLTM Operation Report 1: pt Description ofDescription Reactor 80, Pub.Design, p. Ridge National Oak Laboratory, Jan 1965.

ANRIC your success is our goal . CODE (2017 OVERVIEW HHB OF Graphite ASME Codefor GRAPHITE GRAPHITE MATERIALS REQUIREMENTS, SUBPART B: SUBSECTION HA GENERAL

• • • • • • • • • Mandatory Appendix HAB HAB HAB HAB HAB HAB HAB Graphite Core Components HAB HAB Certificates of Authorization Application Forms for Forms, Instructions, and Certificate Holder's Data Report ------9000 Glossary 8000 Certificates and Data 7000 Reference Standards 5000 Authorized Inspection 4000 Quality Assurance 3000 Responsibilities and 2000 Classification of 1000 Introduction Duties Reports

- I

• GRAPHITE MATERIALS CORE SUPPORT STRUCTURES, SUBPART A: SUBSECTION HH CLASS A NONMETALLIC – – – – – – – – – – – – preparation) Defects and in Flaws Graphite (in course of HHA Nonmandatory Appendix Effects Environmental In Graphite HHA Nonmandatory Appendix Structural aMaterial HHA Nonmandatory Appendix Grades for Generation Design of Datafor Graphite HHAMandatoryAppendix for Preparation aof Material DataSheet HHAMandatoryAppendix Specifications HHAMandatoryAppendix HHA HHA HHA HHA HHA HHA and Reports and Testing ------8000 Nameplates, Stamping, Nameplates, 8000 and Installation 5000 Machining, Examination, 4000 Design 3000 Materials 2000 Introduction 1000

- - -

III Requirements III Requirements II Requirements I Graphite Material - - - D Guidance on B A Graphite as ) Examination

ANRIC your success is our goal ...... IOU’s HHB Graphite ASME Codefor Code alignment Process Zone (PZ) Size relationship) HHB 3217 FEM analysis volumes (change from Grain Size (GS) to HHB 3144 Make the HHA code inclusive of graphite all moderated HTRs Appendix Appendix HHA Appendix HHA • • • • • • • • ARTICLE HHA 6000 Testing ARTICLEHHA 6000 Article HHA Article HHA Tobecome HHA Article HHA Article pending case change Code code and (derived a PZvaries to mm, microns few fromGS a tens from (These Appendices inare the course of preparation) Fatigue - - - - 5000 Installation 5000 Examination and Installation 4000 Machining, Examination, Testing and

D D GUIDANCE ON DEFECTS AND FLAWS IN GRAPHITE IX CLAEANLINESS - -

5000 Examination 5000 and InstallationFabrication 4000

(in (in course of preparation)

– s t

and and K Ic )

ANRIC your success is our goal . . . Differences Design Graphite Code lifetime: Design for effects of environment reactor over core assessment:damage tolerant Core catering assembly component vs.design, for Design methodology code • • • • • • Chemical attackChemical Oxidation Irradiation reliability for structural of partsselection and Designer classification qualification App defines Man. IIImaterials materialsuncertainty relatedto Design margin

–

PROBABILISTIC:

ANRIC your success is our goal HHA Graphite Code for ASME . . The following material issues The followinghadissues be material to retaining structural not material,pressure is but core moderatorGraphite nuclear is and considered drafting code: when • • • Graphite Graphite Material Issues graphite graphite Graphite (seeIII) Effect of environment reactor on the nuclear Manufacture of Graphite (seegraphite I) Differences between nuclear and graphite steel - 2000 MATERIALS

ANRIC your success is our goal MATERIALS Code forASMEGraphite: Fast Fast neutronflux influences the material thermalMaterial are neutronflux properties on initiation theprimary dependsCrack peaknon Local are stresses due of plasticity stresses Relief topeak with Strength decreases increasing strength Small of datascatter the Highstrain, strength,tensile fracture and stress becanYield defined elastic behavior of Regionlinear properties (increases the(increases NDT) properties dependent stress temperature toughnessfracture Properties & behavior of graphite are

fundamentally fromdifferent steel

Steel

- critical

Fast Fast neutronflux changesmaterial all Material thermalproperties are neutronflux initiationCrack ondependsthetotal stress peakLocal stresses causecan damage Relief of stresses bypeak micro Strengthincreases withincreasing temperature scatter Large of thestrength data Low tensile strength, strain fracture and stress Yield is definable not nonAlways change and irradiation andchangeirradiation creep properties, inducesand dimensional independent toughnessfracture Nuclear Nuclear (Ceramic)Graphite - linear behavior linear

HHA

- - 2000 cracking

ANRIC your success is our goal Nuclear Nuclear Graphite Manufacture . . . . specific. are Grades supplier data Sheet) design reactor (materials for characterization requires complete Current production grades these adopts ASME code QAfor properties and minimum requirements provides Specifications Nuclear ASTM Graphite

ANRIC your success is our goal Contents HHA HHA ASSESSMENT HHA HHA - - - 3300 REQUIREMENTS FOR DESIGN OF DESIGNREQUIREMENTS OF THE GRAPHITE FOR COREASSEMBLY3300 DESIGNBY ANALYSIS 3200 GENERALDESIGN3100 -

HHA 3140HHACONSIDERATIONS SPECIAL Loadings)(DesignandCRITERIA Service3120HHA LOADING (CLASSIFICATION) COMPONENT CORE 3110HHA GRAPHITE HHA HHA HHA 3000 3000 DESIGN: Table of - - - - 3210 DESIGN CRITERIA GCC DESIGNCRITERIA 3210 3240 EXPERIMENTAL LIMITS EXPERIMENTAL3240LIMITS OF PROBABILITY COMPONENTS CORE FAILURE3230LIMITS FOR GRAPHITE COMPONENT STRESSLIMITS FOR COREGRAPHITE 3220

HHA HHA HHA HHA HHA HHA HHA HHA HHA HHA HHA Components HHA

------3217 CalculationProbability 3217 of Failure of Derivation3216Equivalent Stress of Stress 3215Analysis Terms 3214 to AnalysisRelatingStress stress Basisfordetermining 3213 General ForGraphite Core Requirements 3212Design foracceptabilityRequirements 3211 Compressiveload 3145 Fatigue3144 AbrasionErosion3143and Irradiation3142 Damage Oxidation3141 - GCC

—

DESIGN BY DESIGNBY TEST

—

SIMPLIFIED ASSESSMENT SIMPLIFIED

—

FULL

ANRIC your success is our goal DESIGN FOR DESIGN CRITERIAGCC .

• • • • • • • • GCC (supporting (supporting HHA Article GCC overview design for Brief of criteria the Determination Determination Limits of of Failure Modes addressed Role of GCC in a Safety HTR Case Verification Comparison of Margins Method Probabilistic Method Probabilistic Material Curve Reliability

– –

Full AssessmentFull Simplified Assessment

- 3000)

ANRIC your success is our goal . . . . . the in HTR GCCcasesafety components where no single failure is critical to the functional thewhere components single to functional failure critical no is of GCC, assuredtolerance bythusassemblies damage manyis of single of athe bylimiting ensuredconsequences failure GCA opposed aAs tolerance pressureavessel, is damage in to IntegrityFunctional failure Core ensurethatdesign Graphite AssemblyA (GCA) shall the components graphite is ensure possible to againstnecessarilyItcracking of not Strength shows high Graphite variability is brittle Graphite quasi integrity of of theassembly integrity

(cracking) (cracking) of a

GCC of of the

does not result in the loss of in of not theloss does result Graphite Core Assembly Graphite

ANRIC your success is our goal . MODES OF FAILURE The identified The of identified for graphite failure modes are: • • • • Environmental Environmental effects (Elastic Buckling Instability) Fatigue Brittle fracture – – – Neutron Irradiation Neutron Oxidation loss of function. Materials dependent. Based on small number of parts cracking. Related to . . Helium impurities (H Air ingress (acute oxidation)

2 O, CO, H)

ANRIC your success is our goal . OF DETERMINATION LIMITS Key Code Assumptions:Key

• • • the design the design margin. this and statistically determine variability from is It the materials characterize possible to graphite accounted for. be mustgrade uniform variability ensure reliability, in the fixed For graphite, adequate on stressescalculated is design It possible comparing by toparts specimen test resultstest specimen DesignMargin

Design Margins Design

to strengthlimits .

incorporating incorporating

do do not

based based

ANRIC your success is our goal . . OF DETERMINATION LIMITS categories based on part classification. of reliability targets, allocated for stress Design Margins to be provided by means Probabilistic approach selected.

ANRIC your success is our goal CURVE MATERIALS RELIABILITY • curve. reliability material by thecharacterised is strengthmaterial in The variability – – limits. 95% confidence using introduced Conservatism Nemeth Bratton) & strength (Ho, Schmidt, material characterise the to Distribution Use Weibull a

ANRIC your success is our goal SIMPLIED ASSESSMENT SIMPLIED • • Note: Note: The Allowable stress is now a function of material quality. Using Using Weibull: assessment:Simplified – cl POF 1 ln Sc S service level. POF target for the forpart this the reliability curveand Material from stress calculated the value, in calculated the design a partto the stress Compare highest allow      

(

 m 1 S m B a M s e a d t e

o r i n a

l D

P D e O e s F p i g

e R n n

e d M q e a u n r i t r g , e i n d S

t C I

b a C s e o d n

s o e n r

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ANRIC your success is our goal • • (Contd.) ASSESSMENT SIMPLIFIED required POF and material variability (m) The Designmargin can becalculated a as functionof Note: Fora typicalgrade, 5 m< 15 < are typical.

ANRIC your success is our goal (Contd.) ASSESSMENT SIMPLIFIED . Schematic Schematic of simplified assessment.

ANRIC your success is our goal FULL ASSESSMENT FULL HHA • • Full Full assessment takes accountof the actual ofbending). least in a simple stress distribution in the case that the entire part is at the same stress (or at Note that the simplified assessment assumes distribution ofstress in the part. – failure of the failurethe ofpart. will result level probabilityina oflower Smallermaterialof at the volumes stress same - 3000 DESIGN: 3000

ANRIC your success is our goal ASSESSMENT HHA - 3000 DESIGN DESIGN :FULL 3000

ANRIC your success is our goal . . HHA Or, modified a Weibull approach as Weibull’s weakest link. Typically be means of some integral such - P 3000 DESIGN 3000:FULL ASSESSMENTDESIGN fV

 L

H 1

 

exp ow is ow is this achieved? exp    

       j n   1 V     s S     s c j (     x m s ,  o V y V , z j )         m

d V

   

ANRIC your success is our goal . . . . . HHA Sources internationally use today. design to values that margin are in design The margin can compared be anticipated. the fromwhich load failure at is guards failure against by offbacking design Incorporation of margin (Sm) (St) strength the to Design Stress (distance mean the tensile from same units Converted the to moduli 5 15). to from levels different of(Weibull variability SupportsCore with materials for Assessed Both for and Blocks Core • • • • RDMCI RDMCI Methodology (South Africa) JAEA Design Methodology ASME CE Draft UK UK Methodology

- Comparison to Comparisonother to margins 3000 :FULL DESIGN ASSESSMENT

ANRIC your success is our goal HHA - Comparison to Comparisonother to margins 3000 :FULL DESIGN ASSESSMENT

ANRIC your success is our goal . . other Comparison to margins HHA problems. problems. Test of the methods over range a of Verification of Methods • • Demonstrate accuracyDemonstrate conservatism. or document. criteria into a verification caseintegrate the to completedWork volunteers by - 3000 DESIGN 3000:FULL ASSESSMENT DESIGN

ANRIC your success is our goal . . . . Criteria Verification No additional additional Noincluded uncertainties in the billets) following: strength tensile mean of (Billet values 24 typical (NBG Analysis of experimental Material bias: and variability a for suitable acceptance? What is basis acceptance criteria. • • • • • • Experimental accuracy (confidence mean in Experimental(confidence accuracy prediction) / Analysisaccuracy convergence within +/ billets 95% fall of within +/ billets 50% fall of billets from parttestsfew Typical grade of material thefor same all Materialdata

Acceptance - 18) billet provides billet 18)data the - - 18% mean18% material of the 6% themeanmaterial of

ANRIC your success is our goal RESULTS VERIFICATION

–

TYPICAL TYPICAL ANRIC your success is our goal HHA - 3000 DESIGN 3000:ASSESSMENT DESIGN Design Process Steps Design

ANRIC your success is our goal or by phone at Feel free to contact

(416) (416) 727 ThankYou! Richard Richard Barnes - 3653 (cell) email at

or (416) (416) 255 [email protected]

- 9459 9459 (office)