ASTM D7219-19

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it 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 version
of the standard as published by ASTM is to be considered the official document.
Designation: D7219 − 08 (Reapproved 2014) D7219 − 19 An American National Standard
Standard Specification for
Isotropic and Near-isotropic Nuclear Graphites
This standard is issued under the fixed designation D7219; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope Scope*
1.1 This specification covers the classification, processing, and typical properties of as-manufactured nuclear grade graphite
billets with dimensions sufficient to meet the designer’s requirements for fuel elements, moderator or reflector blocks, in a high
temperature gas cooled reactor. The graphite classes specified here wouldmay be suitable for reactor core applications where
neutron irradiation induced dimensional changes are a significant design consideration.dimensional change due to fast neutron
irradiation has a significant impact on design, provided they meet the requirements of the ASME code.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
(See IEEE/ASTM SI 10.)
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
C559 Test Method for Bulk Density by Physical Measurements of Manufactured Carbon and Graphite Articles
C709 Terminology Relating to Manufactured Carbon and Graphite (Withdrawn 2017)
C781 Practice for Testing Graphite Materials for Gas-Cooled Nuclear Reactor Components
C838 Test Method for Bulk Density of As-Manufactured Carbon and Graphite Shapes
C1233 Practice for Determining Equivalent Boron Contents of Nuclear Materials
D346 Practice for Collection and Preparation of Coke Samples for Laboratory Analysis
D2638 Test Method for Real Density of Calcined Petroleum Coke by Helium Pycnometer
D4175 Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants
IEEE/ASTM SI 10 American National Standard for Use of the International System of Units (SI): The Modern Metric System
2.2 ASME Standard:
NQA-1 Quality Assurance Program Requirements for Nuclear FacilitiesFacilities, Sec III Div 5 Sub Sect HH sub-part A:
Graphite Materials (HHA)
3. Terminology
3.1 Definitions—Definitions relating to this specification are given in Terminology C709D4175.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 baking/re-baking charge—charge, n—in carbon and graphite technology, number of billets in a baking/re-baking furnace
run.
This specification is under the jurisdiction of ASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of Subcommittee
D02.F0 on Manufactured Carbon and Graphite Products.
Current edition approved May 1, 2014Nov. 1, 2019. Published July 2014November 2019. Originally approved in 2005. Last previous edition approved in 20082014 as
D7219 – 08.D7219 – 08 (2014). DOI: 10.1520/D7219-08R14. 10.1520/D7219-19.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Available from American Society of Mechanical Engineers (ASME), ASME International Headquarters, ThreeTwo Park Ave., New York, NY 10016-5990.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7219 − 19
3.2.2 bulk density—density, n—in carbon and graphite technology, mass of a unit volume of material including both permeable
and impermeable voids.
3.2.3 extrusion forming lot—lot, n—in carbon and graphite technology, number of billets of the same size extruded in an
uninterrupted sequence.
3.2.4 grain, n—in manufactured carbon and graphite, particle of filler material (usually coke or graphite) in the starting mix
formulation; also referred to as granular material, filler particle, or aggregate material; the term is also used to describe the general
texture of a carbon or graphite body, as in the descriptions listed below:
3.2.4.1 coarse grained, adj—containing grains in the starting mix that are substantially greater than 4 mm in size.
3.2.4.2 medium coarse grained, adj—containing grains in the starting mix that are generally less than 4 mm in size.
3.2.4.3 medium grained, adj—containing grains in the starting mix that are generally less than 2 mm in size.
3.2.4.4 medium fine grained, adj—containing grains in the starting mix that are generally less than 1 mm in size.
3.2.4.5 fine grained, adj—containing grains in the starting mix that are less than 100 μm in size.
3.2.4.6 superfine grained, adj—containing grains in the starting mix that are less than 50 μm in size.
3.2.4.7 ultrafine grained, adj—containing grains in the starting mix that are less than 10 μm in size.
3.2.4.8 microfine grained, adj—containing grains in the starting mix that are less than 2 μm in size.
3.2.5 green batch—batch, n—in carbon and graphite technology, mass of coke, recycle green mix, recycle graphite, and pitch
that is required to produce a forming lot.
3.2.6 green mix—mix, n—in carbon and graphite technology, percentage of mix formulation, pitch and additives required for
the forming lot, which is processed and ready to be formed.
3.2.7 graphite billet—billet, n—in carbon and graphite technology, extruded, molded, or iso-molded graphite artifact with
dimensions sufficient to meet the designer’s requirements for reactor components.
3.2.8 graphite grade—grade, n—in carbon and graphite technology, designation given to a material by a manufacturer such that
it is always reproduced to the same specification and from the same raw materials and mix formulation.
3.2.9 graphitization charge—charge, n—in carbon and graphite technology, number of billets of the same grade in a
graphitizing furnace run.
3.2.10 graphitizing furnace run—run, n—in carbon and graphite technology, total number of billets graphitized together in one
graphitization furnace.
3.2.11 high purity nuclear graphite—graphite, n—in carbon and graphite technology, nuclear graphite with an Equivalent
Boron Content less than 2 ppm.
3.2.12 impregnation charge—charge, n—in carbon and graphite technology, number of billets in an autoclave cycle.
3.2.13 isotropic nuclear graphite—graphite, n—graphite in which the isotropy ratio based on the coefficient of thermal
expansion is 1.00 to 1.10.
3.2.14 low purity nuclear graphite—graphite, n—in carbon and graphite technology, nuclear graphite with an Equivalent Boron
Content greater than 2 ppm but less than 10 ppm.
3.2.15 mix formulation—formulation, n—percentages of each specifically sized filler used to manufacture a graphite grade.
3.2.16 molding forming lot—lot, n—in carbon and graphite technology, number of billets molded from a molding powder lot.
3.2.17 molding powder lot—lot, n—sufficient quantity of re-milled and blended green batch produced from an uninterrupted
flow of raw materials, or produced in a sequence of identical materials batches, to produce a molding forming lot.
3.2.18 near isotropic nuclear graphite—graphite, n—graphite in carbon and graphite technology, graphite in which the
isotropy ratio based on the coefficient of thermal expansion is 1.10 to 1.15.
3.2.19 nuclear graphite class—class, n—in carbon and graphite technology, designation of a nuclear graphite based upon its
forming method, isotropy, purity and density (see Table 1).
3.2.20 production lot—lot, n—in carbon and graphite technology, specified number of billets made in accordance with this
specification and additional requirements determined by the purchaser.
3.2.21 purification charge—charge, n—in carbon and graphite technology, number of billets in a purification run.
3.2.22 recycle green mix—mix, n—in carbon and graphite technology, ground non-baked billets or non used green mix
manufactured in compliance with the mix formulation specified here.
4. Significance and Use
4.1 Purpose—The purpose of this specification is to document the minimum acceptable properties typical properties of
as-manufactured nuclear graphite and levels of quality assurance and traceability for isotropic and near-isotropic nuclear grade
D7219 − 19
TABLE 1 ASTM Standard Classes of Nuclear Graphite
Purity
B C
A CTE Isotropy Ratio Bulk Density,
Class B Class Designation
Ash Content, Boron Equivalent,
(α /α ) g/cm (min)
AG WG
ppm (max) ppm (max)
Isomolded, isotropic—High Purity 1.0-1.1 300 2 1.7 IIHP
Isomolded, isotropic—High Purity 1.0-1.1 2 1.7 IIHP
Isomolded, isotropic—Low Purity 1.0-1.1 1000 10 1.7 IILP
Isomolded, isotropic—Low Purity 1.0-1.1 10 1.7 IILP
Isomolded, near-isotropic—High Purity 1.1-1.15 300 2 1.7 INHP
Isomolded, near-isotropic—High Purity 1.1-1.15 2 1.7 INHP
Isomolded, near-isotropic—Low Purity 1.1-1.15 1000 10 1.7 INLP
Isomolded, near-isotropic—Low Purity 1.1-1.15 10 1.7 INLP
Extruded, isotropic—High Purity 1.0-1.1 300 2 1.7 EIHP
Extruded, isotropic—High Purity 1.0-1.1 2 1.7 EIHP
Extruded, isotropic—Low Purity 1.0-1.1 1000 10 1.7 EILP
Extruded, isotropic—Low Purity 1.0-1.1 10 1.7 EILP
Extruded, near-isotropic—High Purity 1.1-1.15 300 2 1.7 ENHP
Extruded, near-isotropic—High Purity 1.1-1.15 2 1.7 ENHP
Extruded, near-isotropic—Low Purity 1.1-1.15 1000 10 1.7 ENLP
Extruded, near-isotropic—Low Purity 1.1-1.15 10 1.7 ENLP
Molded, isotropic—High Purity 1.0-1.1 300 2 1.7 MIHP
Molded, isotropic—High Purity 1.0-1.1 2 1.7 MIHP
Molded, isotropic—Low Purity 1.0-1.1 1000 10 1.7 MILP
Molded, isotropic—Low Purity 1.0-1.1 10 1.7 MILP
Molded, near-isotropic—High Purity 1.1-1.15 300 2 1.7 MNHP
Molded, near-isotropic—High Purity 1.1-1.15 2 1.7 MNHP
Molded, near-isotropic—Low Purity 1.1-1.15 1000 10 1.7 MNLP
Molded, near-isotropic—Low Purity 1.1-1.15 10 1.7 MNLP
A
These classes may be further modified by the grain size as defined in Terminology size.C709 (see Table 2).
B
Determined in accordance with Practice C781.
C
Determined in accordance with Test Method C559.
D
Determined in accordance with Practice C1233.
graphites. The properties which are considered suitable for the application will depend on the design requirements and on the range
of materials that can be available from the manufacturer.
5. Materials and Manufacture
5.1 Nuclear Graphite Classes—See Table 1.
5.2 Raw Materials:
5.2.1 Fillers:
5.2.1.1 The filler shall consist of a near-isotropic or isotropic coke derived from a petroleum oil or coal tar.
5.2.1.2 The coke shall have a coefficient of linear thermal expansion (CTE), determined in accordance with Practice C781 and
-6 -1 -6 -1
measured over the temperature range 2525 °C to 500°C,500 °C, of between 3.5 × 10 °C and 5.5 × 10 °C .
5.2.1.3 The coke shall be sampled and distributed as described in Table 32.
5.2.1.4 Graphite manufactured in compliance with this specification but failing to meet the property requirements of Sections
6 and 7 may be used as recycle material in the mix formulation.
5.2.1.5 Recycle green mix manufactured from raw materials in compliance with this specification may be used in the mix
formulation.
5.2.1.6 The maximum filler particle size used in the mix formulation shall be 1.68 mm.
5.3 Binder—The binder(s) shall consist of coal tar pitch of the same grade from the same manufacturer. The specific binder(s)
used shall be identified to the purchaser and be traceable through the forming lot.
5.4 Impregnant—The impregnant(s) shall consist of a petroleum or coal tar pitch of the same grade from the same manufacturer.
The specific impregnant used shall be identified to the purchaser and be traceable through the impregnation steps.
5.5 Manufacturing or Processing Additives—Additives (for example, extrusion aids) may
...