ASTM C785-08(2022)

Standard Specification for Nuclear-Grade Aluminum Oxide Pellets

SCOPE
1.1 This specification applies to pellets of aluminum oxide that may be ultimately used in a reactor core, for example, as filler or spacers within fuel, burnable poison, or control rods. In order to distinguish between the subject pellets and “burnable poison” pellets, it is established that the subject pellets are not intended to be used as neutron-absorbing material.  
1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.  
1.3 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.

General Information

• Status: Published
• Publication Date: 30-Jun-2022
• ICS: 27.120.30 - Fissile materials and nuclear fuel technology
• ICS: 71.060.20 - Oxides
• Technical Committee: C26 - Nuclear Fuel Cycle
• Drafting Committee: C26.03 - Neutron Absorber Materials Specifications

Relations

• Refers: ASTM C859-24 - Standard Terminology Relating to Nuclear Materials
• Effective Date: 01-Jan-2024
• Refers: ASTM C559-16(2020) - Standard Test Method for Bulk Density by Physical Measurements of Manufactured Carbon and Graphite Articles
• Effective Date: 01-May-2020
• Refers: ASTM C809-19 - Standard Test Methods for Chemical, Mass Spectrometric, and Spectrochemical Analysis of Nuclear-Grade Aluminum Oxide and Aluminum<brk/>Oxide-Boron Carbide Composite Pellets
• Effective Date: 01-Feb-2019
• Refers: ASTM C559-16 - Standard Test Method for Bulk Density by Physical Measurements of Manufactured Carbon and Graphite Articles
• Effective Date: 01-Jan-2016
• Refers: ASTM C859-14a - Standard Terminology Relating to Nuclear Materials
• Effective Date: 15-Jun-2014
• Refers: ASTM C859-14 - Standard Terminology Relating to Nuclear Materials
• Effective Date: 15-Jan-2014
• Refers: ASTM C859-13a - Standard Terminology Relating to Nuclear Materials
• Effective Date: 01-Jun-2013
• Refers: ASTM C859-13 - Standard Terminology Relating to Nuclear Materials
• Effective Date: 01-May-2013
• Refers: ASTM C809-13 - Standard Test Methods for Chemical, Mass Spectrometric, and Spectrochemical Analysis of Nuclear-Grade Aluminum Oxide and Aluminum<brk/>Oxide-Boron Carbide Composite Pellets
• Effective Date: 01-Jan-2013
• Refers: ASTM C859-10b - Standard Terminology Relating to Nuclear Materials
• Effective Date: 01-Nov-2010
• Refers: ASTM E105-10 - Standard Practice for Probability Sampling Of Materials
• Effective Date: 01-Oct-2010
• Refers: ASTM C859-10a - Standard Terminology Relating to Nuclear Materials
• Effective Date: 01-Aug-2010
• Refers: ASTM C559-90(2010) - Standard Test Method for Bulk Density by Physical Measurements of Manufactured Carbon and Graphite Articles
• Effective Date: 01-May-2010
• Refers: ASTM C859-10 - Standard Terminology Relating to Nuclear Materials
• Effective Date: 01-Feb-2010
• Refers: ASTM C1233-09 - Standard Practice for Determining Equivalent Boron Contents of Nuclear Materials
• Effective Date: 01-Jun-2009

Overview

ASTM C785-08(2022) - Standard Specification for Nuclear-Grade Aluminum Oxide Pellets provides requirements for the manufacture, quality, and delivery of aluminum oxide pellets used within nuclear reactor cores. This specification is essential for producers and purchasers of aluminum oxide pellets intended for non-neutron-absorbing applications such as fillers or spacers in nuclear fuel, burnable poison, or control rods. The standard distinguishes these aluminum oxide pellets from those designed as neutron absorbers ("burnable poison" pellets) and ensures reliable performance and safety in demanding nuclear environments.

Key Topics

Key areas covered in ASTM C785-08(2022) include:

• Scope and Purpose: Defines that the pellets are not intended as neutron-absorbing material, emphasizing their role as structural or filler components within reactor assemblies.
• Units of Measurement: Inch-pound units are standard, with SI conversions provided for reference.
• Material Requirements: Specifies permissible chemical composition, including maximum impurity levels for elements such as boron, silicon, iron, magnesium, sodium, calcium, hafnium, fluorine, chlorine, iodine, and bromine.
• Physical and Mechanical Properties:
  • Dimensional tolerances must comply with purchase order and agreed drawings.
  • Pellet density and mechanical properties are specified through buyer-seller agreement, with referenced test methods.
  • Visual inspection criteria for defects including chips and cracks.
• Sampling and Inspection: Outlines procedures for sampling, acceptance, and quality verification to ensure conformance to specification.
• Packaging and Shipping: Sets requirements for packaging integrity and labeling to maintain pellet quality during transport.
• Cleanliness: Finished pellets must be free from contaminants, and cleaning methods must avoid introducing halides or nonvolatile residues.

Applications

Nuclear-grade aluminum oxide pellets are essential in:

• Nuclear Reactor Cores: Used as non-absorbing fillers or spacers within fuel, control rods, or burnable poison rod assemblies. This structural application helps maintain proper geometry, separation, and movement of core components.
• Quality and Safety: The specification ensures that the pellets have consistent physical and chemical characteristics, which is crucial for safety, performance, and compliance in nuclear power plants.
• Regulated Procurement: The standard is frequently referenced in procurement, supply chain management, and quality assurance programs for nuclear facility components.

By following ASTM C785-08(2022), manufacturers and buyers can be assured of the pellets’ suitability for demanding nuclear applications, helping to meet regulatory requirements and prevent operational failures resulting from substandard materials.

Related Standards

ASTM C785-08(2022) references several other standards and regulatory documents to ensure comprehensive control and quality. These include:

• ASTM C559: Test Method for Bulk Density by Physical Measurements of Manufactured Carbon and Graphite Articles.
• ASTM C809: Test Methods for Chemical, Mass Spectrometric, and Spectrochemical Analysis of Nuclear-Grade Aluminum Oxide and Aluminum Oxide-Boron Carbide Composite Pellets.
• ASTM C859: Terminology Relating to Nuclear Materials.
• ASTM C1233: Practice for Determining Equivalent Boron Contents of Nuclear Materials.
• ASTM E105: Guide for Probability Sampling of Materials.
• ANSI/ASME NQA-1: Quality Assurance Requirements for Nuclear Facility Applications.
• Code of Federal Regulations, Title 10, Part 50 (10CFR50): Domestic Licensing of Production and Utilization Facilities.

Keywords: nuclear-grade aluminum oxide, ASTM C785, reactor core fillers, spacer pellets, nuclear material specification, quality assurance, chemical composition, pellet inspection, nuclear facility materials, pellet packaging.

By leveraging ASTM C785-08(2022), organizations enhance their compliance with international best practices and regulatory requirements, ensuring safe and effective operation within the nuclear industry.

Standards Content (Sample)

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.
Designation: C785 −08 (Reapproved 2022)
Standard Specification for
Nuclear-Grade Aluminum Oxide Pellets
This standard is issued under the fixed designation C785; 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 2.2 ANSI Standard:
ANSI/ASME NQA-1 Quality Assurance Requirements for
1.1 This specification applies to pellets of aluminum oxide
Nuclear Facility Applications
that may be ultimately used in a reactor core, for example, as
2.3 U.S. Government Document:
fillerorspacerswithinfuel,burnablepoison,orcontrolrods.In
Code of Federal Regulations, Title 10, Part 50, Energy
order to distinguish between the subject pellets and “burnable
(10CFR50) Domestic Licensing of Production and Utili-
poison” pellets, it is established that the subject pellets are not
zation Facilities
intended to be used as neutron-absorbing material.
1.2 The values stated in inch-pound units are to be regarded
3. Terminology
as standard. The values given in parentheses are mathematical
3.1 Definitions—Terms shall be defined in accordance with
conversions to SI units that are provided for information only
Terminology C859 except for the following:
and are not considered standard.
3.2 Definitions of Terms Specific to This Standard:
1.3 This international standard was developed in accor-
3.2.1 buyer—organization issuing the purchase order.
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
3.2.2 pellet—fabricated geometric shape of aluminum oxide
Development of International Standards, Guides and Recom- having a chemical composition as described in Section 4.
mendations issued by the World Trade Organization Technical
3.2.3 pellet lot—that quantity of pellets produced from one
Barriers to Trade (TBT) Committee.
aluminum oxide powder lot using one set of process param-
eters whose limits have been agreed upon between the seller
2. Referenced Documents
and the buyer.
2.1 ASTM Standards:
3.2.4 powder lot—a specified quantity of aluminum oxide
C559 Test Method for Bulk Density by Physical Measure-
powder made up of powders from one or more sources,
ments of Manufactured Carbon and Graphite Articles
blended together such that samples taken in accordance with
C809 Test Methods for Chemical, Mass Spectrometric, and
7.1 can be considered as representative of the entire specified
Spectrochemical Analysis of Nuclear-Grade Aluminum
quantity.
Oxide and AluminumOxide-Boron Carbide Composite
3.2.5 seller—aluminum oxide pellet supplier.
Pellets
C859 Terminology Relating to Nuclear Materials
4. Chemical Composition
C1233 Practice for Determining Equivalent Boron Contents
of Nuclear Materials 4.1 Use analytical chemistry methods in accordance with
E105 Guide for Probability Sampling of Materials Methods C809 or alternate methods agreed upon between the
buyer and the seller.
This specification is under the jurisdiction of ASTM Committee C26 on 4.2 The finished aluminum oxide pellets shall conform to
Nuclear Fuel Cycle and is the direct responsibility of Subcommittee C26.03 on
the following chemical analysis:
Neutron Absorber Materials Specifications.
Current edition approved July 1, 2022. Published July 2022. Originally approved
in 1976. Last previous edition approved in 2015 as C785 – 08 (2015). DOI:
10.1520/C0785-08R22. Available from American National Standards Institute (ANSI), 25 W. 43rd St.,
For referenced ASTM standards, visit the ASTM website, www.astm.org, or 4th Floor, New York, NY 10036, http://www.ansi.org.
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM AvailablefromU.S.GovernmentPrintingOfficeSuperintendentofDocuments,
Standards volume information, refer to the standard’s Document Summary page on 732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401, http://
the ASTM website. www.access.gpo.gov.
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C785 − 08 (2022)
5.4.1 End Chips—Pellet end surface shall not be chipped
B O + boric acid 0.01 weight % max
2 3
Si 2.0 weight % max
beyond 10 % of the end-face surface area and no chip shall
Fe + Cr + Ni 0.6 weight % max
exceed 1.0 mm (0.040 in.) in depth.
Mg 1.0 weight % max
5.4.2 Circumferential Chips—Pellet circumferential sur-
Na 0.2 weight % max
Ca 0.3 weight % max
faces shall not be chipped beyond 5 % of the circumferential
Hf 200 µg/g pellet max
surface area. No single chip shall exceed a depth of 1.0 mm
F 50 µg/g pellet max
(0.040 in.).
F + Cl + I + Br 100 µg/g pellet max
5.4.3 Cracks—No single crack shall exceed 90° of circum-
Any element impurity not listed in 4.2 shall not exceed 1
ference in length.
weight % as determined by emission spectroscopy. The sum of
5.4.4 Fissures and other defects shall be evaluated with
all impurities shall not exceed 4.0 weight %.
respect to the criteria of 5.4.1, 5.4.2, and 5.4.3.
4.2.1 The total equivalent boron content (EBC) of the
finished aluminum oxide pellets shall not exceed 400 mg/g on
6. Cleanliness
apelletweightbasis.ThetotalEBCisthesumoftheindividual
6.1 The finished pellets shall be handled in a manner to
EBC values. Practice C1233 contains a list of elements to be
avoid contamination by grinding fluids and dust, cleaning
considered in calculating the total EBC. The EBC of each
agents, and organic materials such as plastics and paper used in
impurity element shall be calculated individually using the
packaging. Cleaning solutions, if used, shall be free of halides
following equat
...