ASTM C751-20

Standard Specification for Nuclear-Grade Boron Carbide Pellets

SCOPE
1.1 This specification applies to boron carbide pellets for use as a control material in nuclear reactors.  
1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units 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: 31-Dec-2019
• ICS: 27.120.30 - Fissile materials and nuclear fuel technology
• ICS: 71.060.50 - Salts
• Technical Committee: C26 - Nuclear Fuel Cycle
• Drafting Committee: C26.03 - Neutron Absorber Materials Specifications

Relations

• Replaces: ASTM C751-16 - Standard Specification for Nuclear-Grade Boron Carbide Pellets
• Effective Date: 01-Jan-2020
• 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 C791-19 - Standard Test Methods for Chemical, Mass Spectrometric, and Spectrochemical Analysis of Nuclear-Grade Boron Carbide
• Effective Date: 01-Feb-2019
• Refers: ASTM C750-18 - Standard Specification for Nuclear-Grade Boron Carbide Powder
• Effective Date: 01-Jun-2018
• 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 C750-09(2014) - Standard Specification for Nuclear-Grade Boron Carbide Powder
• Effective Date: 01-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 C791-12 - Standard Test Methods for Chemical, Mass Spectrometric, and Spectrochemical Analysis of Nuclear-Grade Boron Carbide
• Effective Date: 01-Jun-2012
• Refers: ASTM C791-11 - Standard Test Methods for Chemical, Mass Spectrometric, and Spectrochemical Analysis of Nuclear-Grade Boron Carbide
• Effective Date: 01-Jul-2011
• 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

Overview

ASTM C751-20: Standard Specification for Nuclear-Grade Boron Carbide Pellets defines the requirements for boron carbide pellets intended for use as a neutron-absorbing control material in nuclear reactors. Developed by ASTM International, this specification ensures standardized practices for pellet composition, physical properties, dimensions, visual quality, sampling, certification, packaging, and quality assurance. By adhering to ASTM C751-20, manufacturers, suppliers, and buyers can be confident in the reliable performance and safety of boron carbide pellets used in the demanding nuclear industry.

Key Topics

• Material Scope: This standard covers boron carbide pellets used specifically as control materials in nuclear reactors.
• Chemical Composition: Strict limits are set for total boron, carbon, calcium, iron, fluoride, chloride, and water content. The boron carbide powder used must comply with ASTM C750.
• Physical Properties: Requirements include dimensional compliance, density specifications, and visual appearance standards regarding chips, cracks, fissures, and other defects.
• Sampling and Testing: The standard mandates thorough sampling, inspection, and analytical testing, guided by referenced ASTM methods, to assure conformity.
• Packaging and Shipping: Pellets must be packaged securely in sealed containers, with clear identification and traceability for lot, weight, supplier, and other details.
• Quality Assurance and Certification: Sellers must provide certificates of compliance, and buyers may specify additional quality assurance measures per recognized frameworks like ANSI/ASME NQA-1 and relevant federal codes.

Applications

ASTM C751-20 nuclear-grade boron carbide pellets are primarily applied in:

• Nuclear Reactors: Used as neutron absorber material within reactor control rods, boron carbide pellets help regulate nuclear reactions by absorbing excess neutrons, thus playing a critical role in reactor safety and operational control.
• Nuclear Material Management: Due to their consistent chemical and physical properties, pellets conforming to ASTM C751-20 are suitable for use in high-integrity nuclear waste storage, shielding, and emergency shutdown systems.
• Supply Chain Assurance: The specification provides a reliable basis for procurement and manufacturing processes in the nuclear industry, ensuring mutual understanding, consistency, and quality between suppliers and buyers.

Related Standards

For full compliance and broader context, the following standards and regulatory documents are referenced or related to ASTM C751-20:

• ASTM C750: Specification for Nuclear-Grade Boron Carbide Powder.
• ASTM C559: Test Method for Bulk Density by Physical Measurements of Manufactured Carbon and Graphite Articles.
• ASTM C791: Test Methods for Chemical, Mass Spectrometric, and Spectrochemical Analysis of Nuclear-Grade Boron Carbide.
• ASTM C859: Terminology Relating to Nuclear Materials.
• ASTM E105: Practice for Probability Sampling of Materials.
• ANSI/ASME NQA-1: Quality Assurance Program Requirements for Nuclear Facilities.
• 10 CFR 50 (U.S. Code of Federal Regulations): Domestic Licensing of Production and Utilization Facilities for energy and nuclear applications.

By following the guidelines of ASTM C751-20, stakeholders ensure the manufacture, testing, and delivery of boron carbide pellets meet stringent international safety, reliability, and quality standards essential for 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:C751 −20
Standard Specification for
Nuclear-Grade Boron Carbide Pellets
This standard is issued under the fixed designation C751; 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 2.3 U.S. Government Document:
10 CFR 50 Title 10, Code of Federal Regulations, Energy
1.1 This specification applies to boron carbide pellets for
Part 50—Domestic Licensing of Production and Utiliza-
use as a control material in nuclear reactors.
tion Facilities
1.2 The values stated in SI units are to be regarded as
3. Terminology
standard. The values given in parentheses after SI units are
3.1 Definitions:
provided for information only and are not considered standard.
3.1.1 Terms shall be defined in accordance with Terminol-
1.3 This international standard was developed in accor-
ogy C859, except for the following:
dance with internationally recognized principles on standard-
3.1.2 buyer—the organization issuing the purchase order.
ization established in the Decision on Principles for the
3.1.3 pellet lot—quantity of pellets produced from one
Development of International Standards, Guides and Recom-
boron carbide powder lot using one set of process parameters;
mendations issued by the World Trade Organization Technical
the pellet lot size shall be agreed upon between seller and
Barriers to Trade (TBT) Committee.
buyer.
3.1.4 powder lot—a fixed quantity of boron carbide powder
2. Referenced Documents
blended together such that samples taken in accordance with
2.1 ASTM Standards:
Section 7 on Sampling can be considered as representative of
C559 Test Method for Bulk Density by Physical Measure-
the entire fixed quantity.
ments of Manufactured Carbon and Graphite Articles
3.1.5 seller—boron carbide pellet supplier.
C750 Specification for Nuclear-Grade Boron Carbide Pow-
4. Chemical Composition
der
C791 Test Methods for Chemical, Mass Spectrometric, and
4.1 Thestartingboroncarbidepowderusedtoproducethese
Spectrochemical Analysis of Nuclear-Grade Boron Car- pellets shall be in accordance with Specification C750.
bide
4.2 Analytical chemistry methods used to test pellets for
C859 Terminology Relating to Nuclear Materials
conformance with this specification shall be those of Test
E105 Practice for Probability Sampling of Materials
Methods C791 or demonstrated equivalent methods agreed
upon between buyer and seller.
2.2 ANSI Standard:
10 10
ANSI/ASME NQA-1 Quality Assurance Program Require-
4.3 The B concentration (grams B per unit volume or
ments for Nuclear Facilities
grams B per unit length) may be specified by the buyer. The
buyer should consider the following in specifying the allow-
able range in B concentration:
4.3.1 Variations in chemical composition,
This specification is under the jurisdiction of ASTM Committee C26 on
Nuclear Fuel Cycle and is the direct responsibility of Subcommittee C26.03 on 4.3.2 Bulk pellet density,
Neutron Absorber Materials Specifications.
4.3.3 Boron isotopic composition, and
Current edition approved Jan. 1, 2020. Published February 2020. Originally
4.3.4 Pellet dimensions.
approved in 1975. Last previous edition approved in 2016 as C751 – 16. DOI:
10.1520/C0751-20.
4.4 The finished boron carbide pellets shall conform to the
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
chemical analysis in Table 1.
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. Available from U.S. Government Printing Office, Superintendent of
Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St., Documents, 732 N. Capitol St., NW, Washington, DC 20401-0001, http://
4th Floor, New York, NY 10036, http://www.ansi.org. www.access.gpo.gov.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C751−20
TABLE 1 Chemical Analysis of Finished Boron Carbide Pellets
materials such as plastics and paper used in packaging.
Constituent Limits Cleaning solutions, if used, shall be free of halides or nonvola-
Total boron (B) 81.0 % weight, max tile additives and shall be removed from the pellets prior to
73.0 % weight, min
sampling and packaging.
Nitric acid-soluble boron (B) 0.5 % weight, max
Water-soluble boron (B) 0.2 % weight, max
Calcium (Ca) 0.3 % weight, max 7. Sampling
Iron (Fe) 1.0 % weight, max
Total boron + total carbon (B+C) 98.0 % weight, min 7.1 Sampling plans to meet acceptance criteria and inspec-
Fluoride (F) 25 µg/g, max
tion and measurement procedures that describe the method of
Chloride (Cl) 75 µg/g, max
A compliance with this specification shall be approved by the
Water 750 µg/g, max
buyer prior to manufacture of the required pellets. The degree
A
Ultimate usage of the pellets in a control rod may require drying to a lower
of sampling varies with the application and for this reason
moisture level.
should be specified in the purchase order. Practice E105 is
referenced as a guide.
5. Physical Requirements
7.2 Powder and pellet samples taken shal
...

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 version. Because
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: C751 − 16 C751 − 20
Standard Specification for
Nuclear-Grade Boron Carbide Pellets
This standard is issued under the fixed designation C751; 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
1.1 This specification applies to boron carbide pellets for use as a control material in nuclear reactors.
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.after
SI units 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.
2. Referenced Documents
2.1 ASTM Standards:
C559 Test Method for Bulk Density by Physical Measurements of Manufactured Carbon and Graphite Articles
C750 Specification for Nuclear-Grade Boron Carbide Powder
C791 Test Methods for Chemical, Mass Spectrometric, and Spectrochemical Analysis of Nuclear-Grade Boron Carbide
C859 Terminology Relating to Nuclear Materials
E105 Practice for Probability Sampling of Materials
2.2 ANSI Standard:
ANSI/ASME NQA-1 Quality Assurance Program Requirements for Nuclear Facilities
2.3 U.S. Government Document:
Title 10,10 CFR 50 CFR, Energy Part 50 (10 CFR 50) Licensing of Domestic Title 10, Code of Federal Regulations, Energy
Part 50—Domestic Licensing of Production and Utilization Facilities
3. Terminology
3.1 Terms shall be defined in accordance with Terminology C859 or ASTM Dictionary of Engineering Science and Technology,
except for the following:
3.1 Definitions:
3.1.1 Terms shall be defined in accordance with Terminology C859, except for the following:
3.1.2 buyer—the organization issuing the purchase order.
3.1.3 pellet lot—quantity of pellets produced from one boron carbide powder lot using one set of process parameters; the pellet
lot size shall be agreed upon between seller and buyer.
3.1.4 powder lot—a fixed quantity of boron carbide powder blended together such that samples taken in accordance with Section
7 on Sampling can be considered as representative of the entire fixed quantity.
3.1.5 seller—boron carbide pellet supplier.
3.2 buyer—the organization issuing the purchase order.
This specification is under the jurisdiction of ASTM Committee C26 on Nuclear Fuel Cycle and is the direct responsibility of Subcommittee C26.03 on Neutron Absorber
Materials Specifications.
Current edition approved April 1, 2016Jan. 1, 2020. Published April 2016February 2020. Originally approved in 1975. Last previous edition approved in 20122016 as
C751 – 07 (2012).C751 – 16. DOI: 10.1520/C0751-16.10.1520/C0751-20.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Available from American National Standards Institute, 11 W. 42nd St., 13thInstitute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036.10036, http://www.ansi.org.
Available from U.S. Government Printing Office, Washington, DC 20402. Superintendent of Documents, 732 N. Capitol St., NW, Washington, DC 20401-0001,
http://www.access.gpo.gov.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C751 − 20
3.3 pellet lot—quantity of pellets produced from one boron carbide powder lot using one set of process parameters. The pellet
lot size shall be agreed upon between seller and buyer.
3.4 powder lot—a fixed quantity of boron carbide powder blended together such that samples taken in accordance with Section
7 on Sampling can be considered as representative of the entire fixed quantity.
3.5 seller—boron carbide pellet supplier.
4. Chemical Composition
4.1 The starting boron carbide powder used to produce these pellets shall be in accordance with Specification C750.
4.2 Analytical chemistry methods used to test pellets for conformance with this specification shall be those of Method Test
Methods C791 or demonstrated equivalent methods agreed upon between buyer and seller.
10 10 10
4.3 The B concentration (gram(grams B per unit volume or grams B per unit length) may be specified by the buyer. The
buyer should consider the following in specifying the allowable range in B concentration:
4.3.1 Variations in chemical composition,
4.3.2 Bulk pellet density,
4.3.3 Boron isotopic composition, and
4.3.4 Pellet dimensions.
4.4 The finished boron carbide pellets shall conform to the chemical analysis in Table 1.
TABLE 1 Chemical Analysis of Finished Boron Carbide Pellets
Constituent Limits
Total boron (B) 81.0 % weight, max
73.0 % weight, min
Nitric acid-soluble boron (B) 0.5 % weight, max
Water-soluble boron (B) 0.2 % weight, max
Calcium (Ca) 0.3 % weight, max
Iron (Fe) 1.0 % weight, max
Total boron + total carbon (B+C) 98.0 % weight, min
Fluoride (F) 25 μg/g, max
Chloride (Cl) 75 μg/g, max
A
Water 750 μg/g, max
A
Ultimate usage of the pellets in a control rod may require drying to a lower
moisture level.
C751 − 20
5. Physical Requirements
5.1 Physical Dimensions:
5.1.1 Dimensional requirements shall be in accordance with applicable drawings and purchase order documents.
5.1.2 Pellet dimensions shall be measu
...