1、Designation: C781 08 (Reapproved 2014)C781 18 An American National StandardStandard Practice forTesting Graphite and Boronated Graphite Materials for High-Temperature Gas-Cooled Nuclear Reactor Components1This standard is issued under the fixed designation C781; the number immediately following the
2、designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope Scope*1.1 This practice cover
3、s the application and limitations of test methods for measuring the properties of graphite and boronatedgraphite materials. These properties may be used for the design and evaluation of high-temperature gas-cooled reactor components.1.2 The test methods referenced herein are applicable to materials
4、used for replaceable and permanent components as definedin Section 7 and Section 9, and includes fuel elements; removable reflector elements and blocks; permanent side reflector elementsand blocks; core support pedestals and elements; control rod, reserve shutdown, and burnable poison compacts; and
5、neutron shieldmaterial. Specific aspects with respect to testing of irradiated materials are addressed.1.3 This practice includes test methods that have been selected from existingASTM standards,ASTM standards that have beenmodified, and new ASTM standards standards and guides that are specific to t
6、he testing of materials listed in 1.2. Comments onindividual test methods for graphite and boronated graphite components are given in SectionsSection 8 and . 10, respectively. Thetest methods are summarized in Tables 1 and 2Table 1.1.4 The values stated in SI units are to be regarded as standard. Th
7、e values given in parentheses are for information only.afterSI units are provided for information only and are not considered standard.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to es
8、tablish appropriate safety safety, health, and healthenvironmental practices and determine theapplicability of regulatory limitations prior to use.1.6 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on P
9、rinciples for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2C559 Test Method for Bulk Density by Physical Measurements of Manufactured Carbon and Grap
10、hite ArticlesC561 Test Method for Ash in a Graphite SampleC577 Test Method for Permeability of RefractoriesC611 Test Method for Electrical Resistivity of Manufactured Carbon and Graphite Articles at Room TemperatureC625 Practice for Reporting Irradiation Results on GraphiteC651 Test Method for Flexu
11、ral Strength of Manufactured Carbon and Graphite Articles Using Four-Point Loading at RoomTemperatureC695 Test Method for Compressive Strength of Carbon and GraphiteC709 Terminology Relating to Manufactured Carbon and Graphite (Withdrawn 2017)3C747 Test Method for Moduli of Elasticity and Fundamenta
12、l Frequencies of Carbon and Graphite Materials by Sonic ResonanceC749 Test Method for Tensile Stress-Strain of Carbon and GraphiteC769 Test Method for Sonic Velocity in Manufactured Carbon and Graphite Materials for Use in Obtaining an ApproximateValue of Youngs Modulus1 This practice is under the j
13、urisdiction of ASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of SubcommitteeD02.F0 on Manufactured Carbon and Graphite Products.Current edition approved May 1, 2014Oct. 1, 2018. Published July 2014November 2018. Originally approved in 1977. L
14、ast previous edition approved in 20082014 asC781 08.C781 08 (2014). DOI: 10.1520/C0781-08R14.10.1520/C0781-18.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the sta
15、ndards Document Summary page on the ASTM website.3 The last approved version of this historical standard is referenced on www.astm.org.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous versi
16、on. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes secti
17、on appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1TABLE 1 Summary of Test Methods for Graphite ComponentsNOTE 1Designations under preparation will be added when approved.Graphite Components include:
18、 Fuel, Removable Reflector and Core SupportElements; Pebble Bed Reflector, Key and Sleeves and Dowel Pins, Permanent Side Reflector Elements and Dowel Pins, Core Support Pedestals andDowels.Fuel, Removable Reflector,Test Methodand Core Support Elements;Pebble Bed Reflector,Key and Sleeves;and Dowel
19、PinsFabricationAs Manufactured Bulk Density C838As Manufactured Bulk Density C838Mechanical PropertiesCompressive Strength C695Compressive Strength C695Tensile Properties C749ATensile Properties C749Poissons Ratio E132BPoissons Ratio E132, C747Flexural Strength C651AFlexural Strength C651, D7972Frac
20、ture Toughness BFracture Toughness D7779Modulus of Elasticity C747Modulus of Elasticity C747, C769Physical PropertiesBulk DensityMachined Specimens C559Bulk DensityMachined Specimens C559Surface Area (BET) C1274Surface Area (BET) C1274Permeability C577A,BPermeability C577A,BApparent Porosity C1039Ap
21、parent Porosity C1039Spectroscopic Analysis BSpectroscopic Analysis BElectrical Resistivity C611Electrical Resistivity C611Thermal PropertiesLinear Thermal Expansion E228AThermal Conductivity E1461AThermal Conductivity E1461AChemical PropertiesOxidative Mass Loss C1179BOxidative Mass Loss C1179, D75
22、42Sulfur Concentration C816Sulfur Concentration C816Ash Content C561AAsh Content C561AEquivalent Boron Content C1233AEquivalent Boron ContentC C1233AA Modification of this test method is required. See Section 8 for details.B New test methods are required. See Section 8 for details.C There is no iden
23、tified need for determining this property.property for core support pedestals and dowels.TABLE 2 Summary of Test Methods for Boronated Graphite ComponentsNOTE 1Designations under preparation will be added when approved.Compacts NeutronShieldMaterialControlRodBurnablePoisonReserveShutdownBulk Density
24、 C838 C838 C838 D4292Linear Thermal Expansion A E228A E228A BParticle Size C C C D2862Mechanical Strength:Compressive Strength C695A C695A C695A BImpact Performance B B B CChemical Properties:Sulfur Concentration C C C CHafnium Concentration C C C CRelative Oxidation Rate C C C CBoron Analysis:Total
25、 Boron C C C CBoron as Oxide C C C CB4C Particle Size D2862D D2862D D2862D D2862DC781 182C816 Test Method for Sulfur Content in Graphite by Combustion-Iodometric Titration MethodC838 Test Method for Bulk Density of As-Manufactured Carbon and Graphite ShapesC1039 Test Methods for Apparent Porosity, A
26、pparent Specific Gravity, and Bulk Density of Graphite ElectrodesC1179 Test Method for Oxidation Mass Loss of Manufactured Carbon and Graphite Materials in AirC1233 Practice for Determining Equivalent Boron Contents of Nuclear MaterialsC1274 Test Method for Advanced Ceramic Specific Surface Area by
27、Physical AdsorptionD346 Practice for Collection and Preparation of Coke Samples for Laboratory AnalysisD1193 Specification for Reagent WaterD2854 Test Method for Apparent Density of Activated CarbonD2862 Test Method for Particle Size Distribution of Granular Activated CarbonD3104 Test Method for Sof
28、tening Point of Pitches (Mettler Softening Point Method)D4175 Terminology Relating to Petroleum Products, Liquid Fuels, and LubricantsD4292 Test Method for Determination of Vibrated Bulk Density of Calcined Petroleum CokeD5600 Test Method for Trace Metals in Petroleum Coke by Inductively Coupled Pla
29、sma Atomic Emission Spectrometry(ICP-AES)D7219 Specification for Isotropic and Near-isotropic Nuclear GraphitesD7542 Test Method for Air Oxidation of Carbon and Graphite in the Kinetic RegimeD7775 Guide for Measurements on Small Graphite SpecimensD7779 Test Method for Determination of Fracture Tough
30、ness of Graphite at Ambient TemperatureD7846 Practice for Reporting Uniaxial Strength Data and Estimating Weibull Distribution Parameters for Advanced GraphitesD7972 Test Method for Flexural Strength of Manufactured Carbon and Graphite Articles Using Three-Point Loading at RoomTemperatureE11 Specifi
31、cation for Woven Wire Test Sieve Cloth and Test SievesE132 Test Method for Poissons Ratio at Room TemperatureE228 Test Method for Linear Thermal Expansion of Solid Materials With a Push-Rod DilatometerE261 Practice for Determining Neutron Fluence, Fluence Rate, and Spectra by Radioactivation Techniq
32、uesE639 Test Method for Measuring Total-Radiance Temperature of Heated Surfaces Using a Radiation Pyrometer (Withdrawn2011)3E1461 Test Method for Thermal Diffusivity by the Flash MethodE1269 Test Method for Determining Specific Heat Capacity by Differential Scanning CalorimetryE2716 Test Method for
33、Determining Specific Heat Capacity by Sinusoidal Modulated Temperature Differential ScanningCalorimetry3. Terminology3.1 DefinitionsTerminology C709D4175 shall be considered as applying to the terms used in this practice.4. Significance and Use4.1 Property data obtained with the recommended test met
34、hods identified herein may be used for research and development,design, manufacturing control, specifications, performance evaluation, and regulatory statutes pertaining to high temperaturegas-cooled reactors.nuclear reactors that utilize graphite.4.2 The referenced test methods are applicable prima
35、rily to specimens in the non-irradiated and non-oxidized state. Many arealso applicable to specimens in the irradiated or oxidized state, or both, provided the specimens meet allTesting irradiatedspecimens often requires specimen geometries that do not meet the requirements of the test method. The u
36、ser is cautioned toconsider standard. Specific instructions or recommendations with respect to testing non-conforming geometries can be found inSTP 15784 and/or Guide D7775the instructions given in the test methods When testing irradiated specimens at elevatedtemperatures, the effects of annealing s
37、hould be considered (see Note 1).NOTE 1Exposure to fast neutron radiation will result in atomic and microstructural changes to graphite. This radiation damage occurs when energeticparticles, such as fast neutrons, impinge on the crystal lattice and displace carbon atoms from their equilibrium positi
38、ons, creating a lattice vacancy andan interstitial carbon atom. The lattice strain that results from displacement damage causes significant structural and property changes in the graphite andis a function of the irradiation temperature and dose. When the temperature of the graphite is brought above
39、the temperature at which it was irradiated,4 Tzelepi, N. and Carroll, M., Eds., Graphite Testing for Nuclear Applications: The Significance of Test Specimen Volume and Geometry and the Statistical Significanceof Test Specimen Population, STP1578-EB, ASTM International, West Conshohocken, PA, 2014, h
40、ttps:/doi.org/10.1520/STP1578-EBA Modification of this test method is required. See Section 10 for details.B There is no identified need for determining this property.C New test methods are required. See Section 10 for details.D Additional test methods are required. See Section 10 for details.C781 1
41、83enough energy is provided that the structure of the graphite will anneal back to its original condition. Therefore, measurement techniques that bring thespecimen temperature above the irradiation temperature can result in property values that change during the measurement process. For this reason,
42、measurements made on irradiated test specimens below the irradiation temperature will produce results that are representative of the irradiation damage.However, measurements made at temperatures above the irradiation temperature could include the effects of annealing.4.3 Additional test methods are
43、in preparation and will be incorporated. The user is cautioned to employ the latest revision.5. Sample Selection5.1 All test specimens should be selected from materials that are representative of those to be used in the intended application.6. Test Reports6.1 Test results should be reported in accor
44、dance with the reporting requirements included in the applicable test method. Whererelevant, information on grade designation, lot number, billet number, orientation, and location (position of sample in the originalbillet) shall be provided.6.2 Information on specimen irradiation conditions shall be
45、 reported in accordance with Practices C625 and E261 or referencedto source information of equivalent content.GRAPHITE COMPONENTS7. Description and Function7.1 The following are identified as typical components of a graphite moderated gas-cooled reactor based on historical designs.This list is not i
46、ntended to be inclusive of all possible components, which will depend upon the particular reactor design.7.2 Fuel and Removable Reflector Elements:7.2.1 A In manufactured carbons and graphites, a fuel element is a removable graphite element that contains channels for thepassage of coolant gas, the f
47、uel material (typically in the form of a compact containing coated particle fuel), the alignment dowelpins, and for the insertion of a handling machine pickup head. A fuel element may also contain channels for reactivity controlmaterial (control rods), reserve shutdown compacts, and burnable poison
48、compacts, and nuclear instrumentation.7.2.2 The fuel elements serve multiple functions, including (1) vertical and lateral mechanical support for the fuel elements andremovable reflector elements above and adjacent to them, and for the fuel, reactivity control materials, and nuclear instrumentationw
49、ithin them, (2) moderation of fast neutrons within the core region, (3) a thermal reservoir and conductor for nuclear heatgenerated in the fuel, (4) a physical constraint for the flow of coolant gases, and (5) a guide for and containment of fuel material,reactivity control materials, and nuclear instrumentation.7.2.3 A removable reflector element is a removable graphite element that contains channels for the alignment dowel pins andthe insertion of a handling machine pickup head. A removable reflector element may also contain channels for the passage ofcoolant gas,
