1、Designation: C751 16Standard 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 pare
2、ntheses 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 rega
3、rded 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
4、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. Gove
5、rnment 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
6、 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
7、 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 che
8、mistry 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 shoul
9、d 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 1.1Thi
10、s 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 app
11、roved 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.3Availa
12、ble 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 States15. Physical Requiremen
13、ts5.1 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.
14、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
15、 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.
16、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
17、 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 area. No single chip shall exceed a d
18、epth of 1.02 mm(0.040 in.).5.3.3 CracksIndividual cracks not exceeding 90 of cir-cumference in length are acceptable provided other require-ments of the specification are met. Acceptable number ofcracks shall be specified by the buyer.5.3.4 Fissures and other defects shall be evaluated withrespect t
19、o the criteria of 5.3.1, 5.3.2, and 5.3.3.5.4 Mechanical PropertiesRequired mechanical proper-ties and test methods shall be mutually agreed upon betweenbuyer and seller.6. Cleanliness6.1 Finished pellets shall be handled in a manner to avoidcontamination by grinding fluids and dust, agents and orga
20、nicmaterials such as plastics and paper used in packaging.Cleaning solutions, if used, shall be free of halides or nonvola-tile additives and shall be removed from the pellets prior tosampling and packaging.7. Sampling7.1 Sampling plans to meet acceptance criteria and inspec-tion and measurement pro
21、cedures that describe the method ofcompliance with this specification shall be approved by thebuyer prior to manufacture of the required pellets. The degreeof sampling varies with the application and for this reasonshould be specified in the purchase order. Practice E105 isreferenced as a guide.7.2
22、Powder and pellet samples taken shall be sufficient, asnecessary, for quality verification tests, acceptance tests, ref-eree tests, and the retention of archive samples.7.3 Archive samples shall be retained and disposed of inaccordance with the buyers instructions.8. Inspection and Certification8.1
23、The seller shall inspect the material covered by thisspecification and shall furnish the buyer with certificates oftests showing the results of testing and inspection performed oneach pellet lot prior to shipment. The seller shall certify thateach pellet lot is in compliance with the provisions of t
24、hisspecification.9. Rejection and Rehearing9.1 Unless buyer and seller agree otherwise, rejection andacceptance shall be on a pellet lot basis.9.2 Pellet lots that fail to conform to the requirements of thisspecification may be rejected by the buyer. The seller maypetition the buyer to waive selecte
25、d requirements for identifiedout-of-specification lots. Decision to grant such waiver belongsto the buyer. The buyer shall approve, prior to use, any remedyproposed to bring rejected lots into specification.9.3 In the event of disagreement over the results of analyses,samples shall be submitted to a
26、 mutually selected referee forresolution.10. Packaging and Shipping10.1 The pellets shall be packaged in sealed containers forshipment from the seller to the buyer. The seller shall beresponsible for using the shipping container to ensure thepellets arrive still in conformance with this specificatio
27、n.10.2 Each container shall be clearly marked with the fol-lowing: Boron carbide pellets, purchase order number, gross,net, and tare weights, lot number, and name of seller.11. Quality Assurance11.1 Quality assurance requirements shall be agreed uponbetween the buyer and seller when specified in the
28、 purchaseorder. Code of Federal Regulations Title 10 Part 50 AppendixB and ASTME NQA-1 are referenced as guides.TABLE 1 Chemical Analysis of Finished Boron Carbide PelletsConstituent LimitsTotal boron (B) 81.0 % weight, max73.0 % weight, minNitric acid-soluble boron (B) 0.5 % weight, maxWater-solubl
29、e boron (B) 0.2 % weight, maxCalcium (Ca) 0.3 % weight, maxIron (Fe) 1.0 % weight, maxTotal boron + total carbon (B+C) 98.0 % weight, minFluoride (F) 25 g/g, maxChloride (Cl) 75 g/g, maxWater 750 g/g, maxAAUltimate usage of the pellets in a control rod may require drying to a lowermoisture level.C75
30、1 16212. Keywords12.1 Boron carbide pellets; B4C neutron absorber; controlmaterialASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the v
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