ASTM_C_1076_-_09_2015.pdf

Designation:C107609(Reapproved 2015)Standard Specification forNuclear Grade Hafnium Oxide Pellets1This standard is issued under the fixed designation C1076;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 pellets of stabilized cubichafnium oxide used 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 ArticlesC859 Terminology Relating to Nuclear MaterialsC1098 Specification for Nuclear-Grade Hafnium OxidePowderE105 Practice for Probability Sampling of Materials2.2 ANSI Standard:3ANSI/ASME NQA-1 Quality Assurance Requirements forNuclear Facility Applications2.3 U.S.Government Document:4Code of Federal Regulations,Title 10,Part 50Energy(10CFR 50)Domestic Licensing of Production and Utili-zation Facilities3.Terminology3.1 Definitions:3.1.1 Terms shall be defined in accordance with Terminol-ogy C859 except for the following:3.1.2 buyerorganization issuing the purchase order.3.1.3 pelletfabricated geometric shape of stabilized cubichafnium oxide having a chemical composition as described inSection 4.3.1.4 pellet lotthe pellets produced from one hafniumoxide powder lot using one set of process parameters.Pellet lotsize shall be agreed upon between the seller and the buyer.3.1.5 phase transformationrearrangement of the atomicordering of a crystalline lattice as a material is cycled througha critical transformation or inversion temperature.The changefrom one crystalline phase to another may be accompanied bya volume change that could lead to cracks or defects in articlesfabricated from such materials.5,63.1.6 powder lota specified quantity of hafnium oxidepowder with stabilizing additive,blended together such thatsamples taken in accordance with Section 7 can be consideredas representative of the entire quantity.3.1.7 sellerhafnium oxide pellet supplier.3.1.8 stabilizing additivea material which,when presentin sufficient concentration in the subject material exhibiting thephase transformation,produces a stabilized crystalline phasethat does not undergo a transformation or inversion at anytemperature within the expected fabrication or usage regime ofthe manufactured pellet.The potentially deleterious volumechange is therefore avoided.4.Chemical Composition4.1 The starting hafnium oxide powder shall be in accor-dance with Specification C1098.4.2 A stabilizing additive shall be utilized with the hafniumoxide.The recommended stabilizing additive is yttrium oxide(Y2O3).The typical concentration range is 7 to 10 weight%Y2O3in the finished product.References to other stabilizingadditives(such as calcium oxide(CaO)and magnesium oxide(MgO)may be found in the literature and these additives maybe used if agreed upon by the buyer and seller.It is cautioned,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 Jan.1,2015.Published January 2015.Originallyapproved in 1987.Last previous edition approved in 2009 as C1076 09.DOI:10.1520/C1076-09R15.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Sevice at serviceastm.org.For Annual Book of ASTMStandardsvolume information,refer to the standards Document Summary page onthe ASTM website.3Available from American National Standards Institute(ANSI),25 W.43rd St.,4th Floor,New York,NY 10036,http:/www.ansi.org.4Available from U.S.Government Printing Office Superintendent of Documents,732 N.Capitol St.,NW,Mail Stop:SDE,Washington,DC 20401,http:/www.access.gpo.gov.5Curtis,C.E.,Doney,L.M.,and Johnson,J.R.,“Some Properties ofHafnium-Oxide,Hafnium-Silicate,Calcium-Hafnate,and Hafnium-Carbide,”Jour-nal of American Ceramics Society,Vol 37,1954,pp.458465.6Brown,L.M.,and Madiyasni,K.S.,“Characterization of Alkoxy-DerivedYttria-Stabilized Hafnia,”Journal of American Ceramics Society,Vol 53,1970,pp.590594.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 however,that the buyer should be aware of potential destabi-lization during thermal cycling when MgO or CaO is used.4.3 Use analytical chemistry methods as agreed upon be-tween the buyer and the seller.4.4 The hafnium concentration,in grams of hafnium perunit volume or grams of hafnium per unit length,may bespecified by the buyer.In specifying the allowable range inhafnium concentration,the buyer should consider the follow-ing:4.4.1 Variations in chemical composition,4.4.2 Pellet bulk den