ASTM_C_751_-_16.pdf

Designation:C75116Standard Specification forNuclear-Grade Boron Carbide Pellets1This standard is issued under the fixed designation C751;the number immediately following the 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.Scope1.1 This specification applies to boron carbide pellets foruse as a control material in nuclear reactors.1.2 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.2.Referenced Documents2.1 ASTM Standards:2C559 Test Method for Bulk Density by Physical Measure-ments of Manufactured Carbon and Graphite ArticlesC750 Specification for Nuclear-Grade Boron Carbide Pow-derC791 Test Methods for Chemical,Mass Spectrometric,andSpectrochemical Analysis of Nuclear-Grade Boron Car-bideC859 Terminology Relating to Nuclear MaterialsE105 Practice for Probability Sampling of Materials2.2 ANSI Standard:ANSI/ASME NQA-1 Quality Assurance Program Require-ments for Nuclear Facilities32.3 U.S.Government Document:Title 10,CFR,Energy Part 50(10 CFR 50)Licensing ofDomestic Production and Utilization Facilities43.Terminology3.1 Terms shall be defined in accordance with TerminologyC859 or ASTM Dictionary of Engineering Science andTechnology,except for the following:3.2 buyerthe organization issuing the purchase order.3.3 pellet lotquantity of pellets produced from one boroncarbide powder lot using one set of process parameters.Thepellet lot size shall be agreed upon between seller and buyer.3.4 powder lota fixed quantity of boron carbide powderblended together such that samples taken in accordance withSection 7 on Sampling can be considered as representative ofthe entire fixed quantity.3.5 sellerboron carbide pellet supplier.4.Chemical Composition4.1 The starting boron carbide powder used to produce thesepellets shall be in accordance with Specification C750.4.2 Analytical chemistry methods used to test pellets forconformance with this specification shall be those of MethodC791 or demonstrated equivalent methods agreed upon be-tween buyer and seller.4.3 The10B concentration(gram10B per unit volume orgrams10B per unit length)may be specified by the buyer.Thebuyer should consider the following in specifying the allow-able range in10B concentration:4.3.1 Variations in chemical composition,4.3.2 Bulk pellet density,4.3.3 Boron isotopic composition,and4.3.4 Pellet dimensions.4.4 The finished boron carbide pellets shall conform to thechemical analysis in Table 1.1This specification is under the jurisdiction of ASTM Committee C26 onNuclear Fuel Cycle and is the direct responsibility of Subcommittee C26.03 onNeutron Absorber Materials Specifications.Current edition approved April 1,2016.Published April 2016.Originallyapproved in 1975.Last previous edition approved in 2012 as C751 07(2012).DOI:10.1520/C0751-16.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3Available from American National Standards Institute,11 W.42nd St.,13thFloor,New York,NY 10036.4Available from U.S.Government Printing Office,Washington,DC 20402.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 5.Physical Requirements5.1 Physical Dimensions:5.1.1 Dimensional requirements shall be in accordance withapplicable drawings and purchase order documents.5.1.2 Pellet dimensions shall be measured to ensure com-pliance with the buyers requirements.5.2 Density:5.2.1 Pellet density limits shall be specified by the buyer.5.2.2 The method of density measurement shall be TestMethod C559 or an alternative method approved by the buyer.Sampling plans to meet the acceptance criteria shall be agreedupon between the buyer and the seller.The method of densitymeasurement and the method of compliance with 5.2.1 shall beapproved by the buyer.5.3 Visual AppearanceVisual examination shall be con-ducted on finished pellets in accordance with Section 7 onSampling.As soon as practical after finished pellets areavailable,the seller and buyer shall jointly select two sets ofvisual standards for defining the requirements of 5.3.1,5.3.2,and 5.3.3.One set of standards shall be used each by the sellerand buyer as an acceptance standard in the visual examinationof the pellets.The method of measurement of defects in case ofa dispute shall be approved by the buyer.Maximum permis-sible defects are defined as follows:5.3.1 End ChipsPellet end surfaces shall not be chippedbeyond 10%of the end-face surface area,and no chip shallexceed 1.02 mm(0.040 in.)in depth.5.3.2 Circumferential ChipsPellet circumferential sur-faces shall not be chipped beyond 5%of the circumferentialsurface ar