ASTM_C_1453_-_00_2011.pdf

Designation:C145300(Reapproved 2011)Standard Test Method forthe Determination of Uranium by Ignition and the Oxygen toUranium(O/U)Atomic Ratio of Nuclear Grade UraniumDioxide Powders and Pellets1This standard is issued under the fixed designation C1453;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 test method covers the determination of uraniumand the oxygen to uranium atomic ratio in nuclear gradeuranium dioxide powder and pellets.1.2 This test method does not include provisions for pre-venting criticality accidents or requirements for health andsafety.Observance of this test method does not relieve the userof the obligation to be aware of and conform to allinternational,national,or federal,state and local regulationspertaining to possessing,shipping,processing,or using sourceor special nuclear material.1.3 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.1.4 This test method also is applicable to UO3and U3O8powder.2.Referenced Documents2.1 ASTM Standards:2C696 Test Methods for Chemical,Mass Spectrometric,andSpectrochemical Analysis of Nuclear-Grade Uranium Di-oxide Powders and PelletsC753 Specification for Nuclear-Grade,Sinterable UraniumDioxide PowderC776 Specification for Sintered Uranium Dioxide PelletsC1267 Test Method for Uranium by Iron(II)Reduction inPhosphoric Acid Followed by Chromium(VI)Titration inthe Presence of VanadiumC1287 Test Method for Determination of Impurities inNuclear Grade Uranium Compounds by InductivelyCoupled Plasma Mass Spectrometry3.Summary of Test Method3.1 A weighed portion of UO2is converted to U3O8byrepeated ignition at 900C in air,to a constant weight.Corrections are made for nonvolatile and volatile impuritiesincluding moisture,based on independent determinations de-scribed in Test Methods C696 and C1287.3,44.Significance and Use4.1 The test method is designed to show whether or not amaterial meets the specifications as given in SpecificationsC753 or C776.4.2 The powders stoichiometry is useful for predicting theoxides sintering behavior in the pellet production process.5.Interferences5.1 The moisture content must be determined and a correc-tion must be made for the moisture content otherwise a highbias will occur for the O/U ratio.5.2 A nonvolatile impurity correction must be made other-wise a high bias will occur for the uranium value.An extendedignition time may be required if significant amounts of anionsthat are difficult to decompose are present.5.3 The U3O8to uranium conversion factor and the uraniumatomic weight will require adjustment for nonnatural isotopicconcentrations otherwise a bias will be present.6.Apparatus6.1 Desiccator,containing a moisture absorbent.6.2 Muffle Furnace,capable of maintaining and controllingtemperatures to 900 6 25C.1This test method is under the jurisdiction of ASTM committee C26 on NuclearFuel Cycle and is the direct responsibility of Subcommittee C26.05 on Methods ofTest.Current edition approved July 1,2011.Published July 2011.Originally approvedin 2000.Last previous edition approved in 2006 as C1453 00R06.DOI:10.1520/C1453-00R11.2For 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.3Jones,R.J.,Ed.,“Selected Measurement Methods for Plutonium and Uraniumin the Nuclear Fuel Cycle,”USAEC Document TID-7029,1963,AERDB,pp.9193.4Petit,G.D.and Keinberger,C.A.,“Preparation of Stoichiometric U3O8,”Analytical Chemistry,ANCHA,Vol 25,1961,p.579.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 6.3 Analytical Balance,capable of weighing to 6 0.1 mg.6.4 Platinumware.7.Reagents and Materials7.1 Anhydrous magnesium perchlorate Mg(ClO4)2,mois-ture absorbent,or equivalent.8.Procedure8.1 Transfer 2 to 12 g of UO2powder or pellets to a taredplatinum crucible and weigh to within 0.1 mg.8.1.1 UO2PowderPlace the platinum crucible containingthe UO2powder sample in a muffle furnace and ignite for 3 hat 900 6 25C.8.1.2 UO2PelletsPreheat the pellets at 500C for 3 h,inthe muffle furnace,then ignite for 3 h at 900 6 25C.8.2 Remove the crucible from the furnace,allow to cool inthe air 2 to 3 minutes,then place the crucible in a desiccatorand cool to room temperature.Weigh the crucible.8.3 Repeat the ignition for 3 h at 900C and repeat step 8.2until a constant weight of 60.3 mg is obtained.8.4 Other ignition and cooling schemes may be used as lon