1、Designation: C 784 05Standard Specification forNuclear-Grade Aluminum Oxide-Boron Carbide CompositePellets1This standard is issued under the fixed designation C 784; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last
2、revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification applies to pellets composed of mix-tures of aluminum oxide and boron carbide that may beultimately used
3、 in a reactor core, for example, in neutronabsorber rods.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:2C 559 Test Method for Bulk Density by Physical Measure-ments of Manufacture
4、d Carbon and Graphite ArticlesC 750 Specification for Nuclear-Grade Boron Carbide Pow-derC 809 Methods for Chemical, Mass Spectrometric, andSpectrochemical Analysis of Nuclear-Grade AluminumOxide and Aluminum Oxide-Boron Carbide CompositePelletsC 859 Terminology Relating to Nuclear MaterialsC 1031 S
5、pecification for Nuclear Grade Aluminum OxidePowderE11 Specification for Wire-Cloth Sieves for Testing Pur-posesE 105 Practice for Probability Sampling of Materials2.2 ANSI Standard:ANSI/ASME NQA-1 Quality Assurance Program Require-ments for Nuclear Facilities32.3 Government Standard:Title 10, Code
6、of Federal Regulations, Energy Part 50(10CFR50), Domestic Licensing of Production and Utili-zation Facilities43. Terminology3.1 Definitions:3.1.1 Terms shall be defined in accordance with Terminol-ogy C 859 except for the following:3.2 Definitions of Terms Specific to This Standard:3.2.1 buyerorgani
7、zation issuing the purchase order.3.2.2 pelleta fabricated geometric shape of aluminumoxide-boron carbide having a chemical composition as de-scribed in Section 4.3.2.3 pellet lotthat quantity of pellets produced from onepowder mixture lot using one set of mixing and processparameters. Pellet lot si
8、ze shall be agreed upon between theseller and the buyer.3.2.4 powder mixture lota specified quantity of aluminumoxide and boron carbide made up of powders from one or moresources blended together such that samples taken in accordancewith Section 7 can be considered as representative of the entirespe
9、cified quantity.3.2.5 sellerpellet supplier.4. Technical Requirements4.1 Major ConstituentsAluminum oxide-boron carbidepellets shall be fabricated using major constituents that meetthe requirements of Specifications C 750 and C 1031.4.2 Chemical Composition:4.2.1 Use analytical chemistry methods in
10、accordance withMethods C 809 or demonstrated alternate methods agreed uponbetween the buyer and the seller.4.2.2 The finished pellets shall conform to the followingchemical analysis:Si 2.0 weight % maxFe + Cr + Ni 0.6 weight % maxMg 1.0 weight % maxNa 0.2 weight % maxCa 0.3 weight % maxHf 200 g/g pe
11、llet max1This 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 Jan. 1, 2005. Published February 2005. Originallyapproved in 1976. Last previo
12、us edition approved in 1996 as C 784 96e1.2For 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 Ame
13、rican National Standards Institute, 11 W. 42nd St., 13thFloor, New York, NY 10036.4Available from Superintendent of Documents, U.S. Government PrintingOffice, Washington, DC 20402.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.F 50
14、g/g pellet maxF + Cl + I + Br 100 g/g pellet maxGd 25 g/g pellet maxSm 50 g/g pellet maxEu 50 g/g pellet maxDy 50 g/g pellet maxAny elemental impurity not listed in 4.2.2 shall not exceed 1weight % as determined by emission spectroscopy. The sum ofall impurities shall not exceed 4.0 weight %. A wate
15、r-solubleboron limit may be required in certain designs in which case itshall be determined on a sample crushed to pass through a No.100 mesh (150-m) U.S. standard sieve (see SpecificationE11.)4.2.3 Should elements not listed in 4.2.2 be of concern, theirinclusion in the listing shall be mutually ag
16、reed upon betweenthe buyer and the seller.4.2.4 In specifying the allowable range in10B concentrationthe buyer shall consider the following:4.2.4.1 Variations in chemical composition,4.2.4.2 Bulk pellet density,4.2.4.3 Boron isotopic composition,4.2.4.4 Pellet dimensions, and4.2.4.5 Typical units ar
17、e grams of10B per unit volume orgrams of10B per centimeter length.4.2.5 The hydrogen impurity (including moisture content),the detailed procedure for measuring hydrogen, and packagingrequirements associated with hydrogen contamination, shall beagreed upon between the buyer and the seller.5. Physical
18、 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. Sampling plans to meetacceptance criteria shall be agreed upon
19、 between the seller andthe buyer to ensure that the pellets represented by the sampleare within the required tolerances.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 C 559 or an alternative method approved by the b
20、uyerprior to use. Sampling plans to meet acceptance criteria shallbe agreed upon between the seller and the buyer.5.3 Boron Carbide Homogeneity:5.3.1 The boron carbide shall be uniformly dispersed in thealuminum oxide matrix as determined by ceramographic ex-amination.5.3.2 The methods of ceramograp
21、hic preparation and ex-amination shall be approved by the buyer prior to use.5.3.3 Pellets selected by mutual agreement between thebuyer and the seller shall be used as standards of acceptabilityto satisfy the requirements of 5.3.1. The seller shall submit ashomogeneity standards, pellets representa
22、tive of each specifiedboron concentration (4.2.1).5.3.4 Particle size limits of boron carbide particles shall bespecified by the buyer in accordance with his particularapplication.5.4 Mechanical PropertiesRequired mechanical proper-ties and test methods shall be mutually agreed upon betweenthe buyer
23、 and the seller.5.5 Visual AppearanceVisual examination shall be con-ducted on finished pellets in accordance with Section 7. Theseller and the buyer shall agree on visual standards as repre-senting the requirements of 5.5.1, 5.5.2, and 5.5.3. Thesestandards shall be used as acceptance standards for
24、 the visualexamination of the pellets. The method of defect measurementshall be approved by the buyer prior to use. Maximumpermissible defects are defined as follows:5.5.1 End ChipsPellet end surface shall not be chippedbeyond 10 % of the end-face surface area and no chip shallexceed 1.0 mm (0.040 i
25、n.) in depth.5.5.2 Circumferential ChipsPellet circumferential sur-faces shall not be chipped beyond 5 % of the circumferentialsurface area. No single chip shall exceed a depth of 1.0 mm(0.040 in.).5.5.3 CracksNo single crack shall exceed 90 of circum-ference in length.5.5.4 Fissures and other defec
26、ts shall be evaluated withrespect to the criteria of 5.5.1, 5.5.2, and 5.5.3.6. Cleanliness6.1 The finished pellets shall be handled in a manner toavoid contamination by grinding fluids and dust, cleaningagents, and organic materials such as plastics and paper used inpackaging. Cleaning solutions, i
27、f used, shall be free of halidesand nonvolatile additives and shall be removed from the pelletsprior to sampling and packaging.7. Sampling7.1 Sampling plans to meet acceptance criteria and inspec-tion and measurement procedures that describe the method ofcompliance with this specification shall be e
28、stablished by theseller and submitted to the buyer for approval prior tomanufacture of the required product. The degree of samplingshall be specified on the purchase order. Practice E 105 isreferenced as a guide.7.2 Each sample taken shall be sufficient for quality verifi-cation tests, referee tests
29、 and archive samples as needed.7.3 Archive samples shall be retained and disposed by theseller in accordance with the buyers instructions.8. Inspection and Certification8.1 The seller shall inspect the material covered by thisspecification and shall furnish the buyer with certificates oftests showin
30、g 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 thisspecification.9. Rejection9.1 Unless the buyer and the seller agree otherwise, rejec-tion and acceptance shall be on a pelle
31、t 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 selected requirements for identifiedout-of-specification lots. Decision to grant such waiver belongsC784052to the buyer. The seller may al
32、so apply any remedy to bringrejected lots into specification providing he can demonstrate tothe buyer that such remedy does not impair the function orpreclude the certification of the rejected material.9.3 In the event of disagreement over the results of analysis,samples shall be submitted to a mutu
33、ally 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 assure thepellets arrive still in conformance with the specification, and
34、 toassure reasonable ease of unpacking.10.2 Each container shall be clearly marked with the fol-lowing:10.2.1 Aluminum oxide-boron carbide composite pellets,10.2.2 Purchase order number,10.2.3 Gross, net, and tare weights,10.2.4 Lot number, and10.2.5 Name of manufacturer.11. Quality Assurance11.1 Qu
35、ality assurance requirements shall be specified in thepurchase order. Code of Federal Regulations, Title 10, Part 50,Appendix B, and ANSI/ASME NQA-1 are referenced asguides.12. Keywords12.1 absorber pellets; aluminum oxide; boron carbide; poi-son pelletsASTM International takes no position respectin
36、g 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 validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standa
37、rd is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM Internationa
38、l Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.Th
39、is standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).C784053
