1、Designation: C 1453 00 (Reapproved 2006)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 C 1453; the number immediately following the de
2、signation 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 (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the
3、 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 t
4、he obligation to be aware of and conform to all interna-tional, national, or federal, state and local regulations pertain-ing to possessing, shipping, processing, or using source orspecial nuclear material.1.3 This standard does not purport to address all of thesafety concerns, if any, associated wi
5、th 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:2C 696
6、 Test Methods for Chemical, Mass Spectrometric, andSpectrochemical Analysis of Nuclear-Grade Uranium Di-oxide Powders and PelletsC 753 Specification for Nuclear-Grade, Sinterable UraniumDioxide PowderC 776 Specification for Sintered Uranium Dioxide PelletsC 1267 Test Method for Uranium by Iron (II)
7、Reduction inPhosphoric Acid Followed by Chromium (VI) Titration inthe Presence of VanadiumC 1287 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 U3O8byrepe
8、ated 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 C 696 and C 1287.3,44. Significance and Use4.1 The test method is designed to show whether or not amateria
9、l meets the specifications as given in SpecificationsC 753 or C 776.4.2 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
10、 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 co
11、nversion 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.6.3 Analytical B
12、alance, 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.1This test method is under the jurisdiction of ASTM committee C26 on NuclearFuel Cycle and is the direct responsibility of Subcommittee
13、 C26.05 on Methods ofTest.Current edition approved July 1, 2006. Published September 2006. Originallyapproved in 2000. Last previous edition approved in 2000 as C 145300.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annu
14、al 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., “Prepara
15、tion of Stoichiometric U3O8,”Analytical Chemistry, ANCHA Vol 25, 1961, p. 579.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.8. Procedure8.1 Transfer 2 to 12 g of UO2powder or pellets to a taredplatinum crucible and weigh to within
16、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 for3hat9006 25C.8.2 Remove the crucible from the furnace, allow to cool inthe air
17、 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 6 0.3 mg is obtained.8.4 Other ignition and cooling schemes may be used as longas the analyst verifies the pr
18、ecision and the bias of themeasurement.9. Calculation9.1 Uranium ContentCalculate as follows:U, wt% 5 0.8480 W 2 WI!/S! X 100 2 C (1)where:0.8480 = U3O8to uranium conversion factor for naturaluranium.This factor will require adjustment whenthe uranium isotopic abundance deviates fromnatural uranium.
19、 See Appendix X1.2.W = Grams of U3O8after ignition.I = Total of all detected nonvolatile impurities ex-pressed as grams of oxide per gram of ignitedU3O8. See Table 1 to obtain oxide conversionfactors for many common impurity elements en-countered. The impurities are determined as de-scribed in eithe
20、r Test Method C 696 or C 1287.S = Initial sample weight, in g.C = Total of all nonvolatile impurities analyzed as lessthan the lower detection limit of the analyticalmethod. The detection limit values shall be takenas the concentration of that element. The total isexpressed as percent. These impurit
21、ies are deter-mined as described in Test Method C 696 orC 1287. Alternatively, the these impurities can beconsidered to contribute a total correction of0.01 % to the uranium percent.9.2 Oxygen-to-Uranium RatioCalculate as follows fromthe original sample U, wt%:O/U 5 100 2 Uwt% 2 Z 2 m!A!# /15.999!Uw
22、t%!# (2)where:O = atom % of oxygenU = atom % of uraniumU wt% = U, weight %, as calculated in 9.1Z = total non-volatile impurities correction, %, asdetermined in Test Method C 696 or C 1287.m = moisture and volatile impurity content, %, deter-mined in Test Method C 696 or C 1287.A = atomic weight of
23、uranium based on isotopicabundance. See X1.1.15.999 = atomic weight of oxygen10. Precision and Bias10.1 UO2PowderThe precision for the O/U ratio for UO2powder is shown in Table 2. The bias was not determined asthere are no standards due to the relative reactivity of thepowder. The data in Table 2 we
24、re determined by one analystover a three-day period.10.2 UO2Pellets:10.2.1 The precision for the O/U ratio for UO2pellets isshown in Table 3.5The data were determined by two differentlaboratories. The data for Laboratory A were determined overseveral days by one analyst. The data for laboratory B we
25、redetermined over seven days by four analysts using threefurnaces.10.2.2 The precision for the uranium content for UO2pelletsis shown in Table 4.5The data were determined as describedfor Table 3.10.2.3 The reference value for G-2 working pellet standardwas obtained from the weighted average of eight
26、 ferroussulphate type titration measurements and nine ignition typemeasurements. The measurements were standardized against5Supporting data for Tables 2-X1.1 are available from ASTM Headquarters.TABLE 1 Oxide Conversion Factors for Impurity CorrectionImpurity Assumed Oxide Form Oxide Conversion Fact
27、orAAl Al2O31.89BB2O33.23Ba BaO 1.12Be BeO 2.78Bi Bi2O31.11Ca CaO 1.40Cd CdO 1.14Co Co2O31.41Cr Cr2O31.46Cu CuO 1.25Fe Fe2O31.43InBIn2O31.21Li Li2O 2.15Mg MgO 1.66Mn MnO21.58Mo MoO31.50Na Na2O 1.35Ni NiO 1.27PP2O52.29Pb PbO21.15Sb Sb2O41.26Si SiO22.14Sn SnO21.27Ti TiO21.67VV2O51.79Zn ZnO 1.24Zr ZrO21
28、.35Ta Ta2O51.22WW31.26AOxide conversion factor is defined as grams oxide per gram of element.BThis element is not required by the UO2Specifications C 753 and C 776 but isincluded for information only.TABLE 2 UO2Powder ResultsSample TypeUranium wt% AbsoluteStandardDeviationO/U RatioStandardDeviationN
29、o. ofDeterminationsSample A 87.796 0.005 2.065 0.001 12Sample B 86.996 0.004 2.225 0.001 12C 1453 00 (2006)2NBL 125 standard. One analyst performed the measurementsover two weeks. The determined uranium value was 88.103 %with a standard deviation of 0.053 %. The value is notstatistically different f
30、rom the values determined by this testmethod. The data does not indicate any statistically significantbias at the 88.103 % level.11. Keywords11.1 gravimetric; ignition; O/U ratio; oxygen; oxygen touranium ratio; uraniumAPPENDIX(Nonmandatory Information)X1. ADDITIONAL CALCULATIONS AND INFORMATIONX1.1
31、The atomic weight of uranium based on the mass fraction ofthe individual isotopes is calculated as follows:A 5 ( Fi Ai (X1.1)where:A = Atomic weight of uranium;Fi = Mass fraction of uranium isotope i; andAi = Atomic weight of uranium isotope i.X1.2 The conversion factor for U3O8to uranium is calcu-l
32、ated as follows:Conversion Factor 53A3A 1 8O(X1.2)where:A = Atomic weight of uranium;O = Atomic weight of oxygen (15.9994).For natural isotopic abundance uranium the conversionfactor is 0.8480.X1.3 Uranium TrioxideThe uranium content of UO3canbe determined using this test method.3(See Note X1.1). Th
33、eresults for the UO3were determined by a single set ofcomparative data. (See Table X1.1.)NOTE X1.1Sulphur, which is commonly present in UO3as UO2SO4is not completely volatilized in the conversion to U3O8if the ignition timeis less than 3 h.3ASTM International takes no position respecting the validit
34、y 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 standard is subject
35、 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 International Headquarter
36、s. 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.This standard i
37、s 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 servicea
38、stm.org (e-mail); or through the ASTM website(www.astm.org).TABLE 3 Comparison of Interlab O/U ResultsLaboratory Sample Type O/U RatioStandardDeviationNo. ofDeterminationsA Sintered depleted UO2pellet G-22.001 0.001 4B Sintered depleted UO2pellet G-22.000 0.002 18TABLE 4 Comparison of Interlab Urani
39、um ResultsMethod Laboratory Sample TypeUraniumwt%AbsoluteStandardDeviationNo. ofDeterminationsGravimetric A Sintered depletedUO2pellet G-288.106 0.003 4Gravimetric B Sintered depletedUO2pellet G-288.114 0.010 18Referencevalue, see10.2.3B Sintered depletedUO2pellet G-288.103 0.053 See 10.2.3TABLE X1.1 Uranium Content of UO3SampleGravimetricUranium %TitrimetricAUranium %UO382.78 Technician A Technician B82.74 82.81AThe titrimetric method refers to the Davies-Gray method in C 1267.C 1453 00 (2006)3
