1、Designation: C1456 08C1456 13Standard Test Method forDetermination of Uranium or Gadolinium (or both) inGadolinium Oxide-Uranium Oxide Pellets or by X-RayFluorescence (XRF)1This standard is issued under the fixed designation C1456; the number immediately following the designation indicates the year
2、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 describes the steps necessary for the pr
3、eparation and analysis by X-ray fluorescence (XRF) of gadoliniumor uranium (or both) in gadolinium oxide-uranium oxide pellets or powders.1.2 This test method requires the use of appropriate internal standard(s). Care must be taken to ascertain that samples analyzedby this method do not contain the
4、internal standard element(s) or that this contamination has been corrected for mathematicallywhenever present. Such corrections are not addressed in this test method.1.3 This standard contains notes that are explanatory and are not part of the mandatory requirements of the standard.1.4 The values st
5、ated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety
6、 and health practices and determine the applicability of regulatorylimitations prior to use. Specific precautions are given in Section 8 and various notes throughout the method.2. Referenced Documents2.1 ASTM Standards:2C1118 Guide for Selecting Components for Wavelength-Dispersive X-Ray Fluorescenc
7、e (XRF) Systems (Withdrawn 2011)3D1193 Specification for Reagent WaterE135 Terminology Relating to Analytical Chemistry for Metals, Ores, and Related Materials2.2 Other DocumentANSI/HPS N43.2-2001 Radiation Safety for X-ray Diffraction and X-ray Fluorescence Analysis Equipment33. Terminology3.1 Defi
8、nitionsFor definitions of terms used in this guide, see Terminology E135.3.2 Symbol: LiTB = lithium tetraborate (see 7.4).4. Summary of Test Method4.1 Solution or pellet standards containing the equivalent of 110 % gadolinium oxide and 9099 % uranium oxide andappropriate internal standards are place
9、d in the sample holder of an X-ray spectrometer and exposed to an X-ray beam capable ofexciting the uranium and gadolinium L- emission lines and the appropriate emission line for the internal standard. The intensitiesgenerated are measured by an appropriate detector. The intensity ratio values obtai
10、ned from this data are used to calibrate the X-rayanalyzer.4.2 Samples are prepared in the same manner as the standards and analyzed using conditions and curves generated from thosestandards.NOTE 1Yttrium and strontium have been used successfully as internal standards for uranium and samarium for ga
11、dolinium. Scatter lines also have1 This test method is under the jurisdiction of ASTM Committee C26 on Nuclear Fuel Cycle and is the direct responsibility of Subcommittee C26.05 on Methods of Test.Current edition approved Dec. 1, 2008July 1, 2013. Published January 2009July 2013. Originally approved
12、 in 2000. Last previous edition approved in 20002008 asC1456 00.C1456 08. DOI: 10.1520/C1456-08.10.1520/C1456-13.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the
13、standards Document Summary page on the ASTM website.3 Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http:/www.ansi.org.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of wha
14、t changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the
15、 official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1been used as internal standard lines.4 An explanation of internal standard method is found in several sources.5,65. Significance and Use5.1 This test method is applica
16、ble to samples containing 21 to 10 % gadolinium oxide and 90 to 98 %99 % uranium oxide onthe “as received” basis. The method may be used to determine concentration of either uranium, gadolinium, or both.5.2 Either wavelength-dispersive or energy-dispersive X-ray fluorescence systems may be used prov
17、ided the softwareaccompanying the system is able to accommodate the use of internal standards.6. Apparatus6.1 X-Ray SpectrometerSee Guide C1118 or the manufacturersmanufacturers operating manuals for the selection of theX-ray spectrometer. The method is valid for either energy-dispersive or waveleng
18、th-dispersive systems.6.2 Sample Cups/HoldersPrepare liquid sample cups for the X-ray spectrometer as described by the manufacturer. Vented,disposable sample cups with snap-on caps are satisfactory for most such analyses; such cups decrease the likelihood ofcontamination between samples. Sample hold
19、ers for fused pellets should keep any pellet chips from getting into the moving partsof the instrument.6.3 Window FilmPolyester, polyethylene, and polypropylene films have been used successfully as the film window for cupsor holders, or both. Tests should be performed to determine the serviceability
20、 of any film chosen before insertion into theinstrument.6.4 Solution Dispenser (optional)The dispenser for the internal standard solution, if used, should be capable of reproduciblydispensing the internal standard solution to a level of 0.1 % relative standard deviation of the volume dispensed.6.5 M
21、uffle Furnace, 1100C capacity.7. Reagents and Materials7.1 Purity of MaterialsReagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that allreagents conform to the specifications of the Committee of Analytical Reagents of the American Chemical Society where s
22、uchspecifications are available.7 Other grades may be used provided it is first ascertained that the reagent is of sufficiently high purityto permit its use without lessening the accuracy of the determination.7.2 Purity of WaterUnless otherwise indicated, references to water shall mean reagent water
23、 conforming to SpecificationD1193.7.3 Gadolinium Oxide, Gd2 O3It is recommended that the standards be prepared using same batch as in pellets/powder.7.4 Lithium Tetraborate, Li2B4O7, fusion grade.7.5 Nitric Acid, HNO3, concentrated (70 %).7.6 Samarium Oxide, Sm2O3, or other suitable internal standar
24、d for gadolinium (see Note 1).7.7 Uranium Oxide, U3O8, NBL CRM-129 (or equivalent).8NOTE 2High purity UO2 may be used if certification of uranium analysis is not required.7.8 Yttrium Oxide, Y2O3, or other suitable internal standard for uranium (see Note 1).8. Technical Precautions8.1 XRF equipment a
25、nalyzes by the interaction of ionizing radiation with the sample.Applicable safety regulations and standardoperating procedures must be reviewed prior to the use of such equipment.All modern XRF spectrometers are equipped with safetyinterlocks to prevent accidental penetration of the X-ray beam by t
26、he user. Do NOT override these interlocks without propertraining (See ANSI/HPS N43.2-2001).8.2 Instrument performance may be influenced by environmental factors such as heat, vibration, humidity, dust, stray electronicnoise and line voltage stability. These factors and performance characteristics sh
27、ould be reviewed prior to use of this test method.4 Andermann, G, and Kemp, J.W., “Scattered X-Rays as Internal Standards in X-Ray Spectroscopy,” Analytical Chemistry, Vol 20 (8), 1958.5 Bertin, E.P., Introduction to X-Ray Spectrometric Analysis, Plenum Press, New York and London, 1978.6 Tertian, R.
28、 and Claisse, F., Principles of Quantitative X-Ray Fluorescence Analysis, Heyden and Son, London, Philadelphia and Rheine, 1982.7 Reagent Chemicals, American Chemical Society Specifications, American Chemical Society, Washington, DC. For suggestions on the testing of reagents not listed bythe Americ
29、an Chemical Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and NationalFormulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.8 The sole source of supply of the apparatus known to the committee at this time is U
30、.S. Department of Energy, New Brunswick Laboratory, D350, 9800 South CassAvenue,Argonne, IL 60439,ATTN: Reference Material Sales. If you are aware of alternative suppliers, please provide this information toASTM International Headquarters.Your comments will receive careful consideration at a meeting
31、 of the responsible technical committee,1 which you may attend.C1456 1329. Preparation of Apparatus9.1 Chamber EnvironmentThe liquid standards and samples used in this method are corrosive. Some fumes will be emittedfrom the sample cups. These fumes may be detrimental to the spectrometer chamber. It
32、 is desirable to flush this chamber with aninert gas (usually helium) before and during analysis. Some X-ray spectrometers control the change of sample chamber atmosphere(air, vacuum, helium) automatically through the software; in others, it must be done manually. Follow the instrumentmanufacturers
33、recommendations to achieve the inert gas environment. Allow sufficient stabilization time before analysis. Fusedpellet standards and samples may be analyzed using either a vacuum or helium environment. Line intensities will be slightly higherusing a vacuum environment. WarningCare must be taken to a
34、ssure that a vacuum environment is not chosen with liquidsamples. Analyze standards and samples under the same environment.9.2 X-Ray Power SupplyIf the power to the X-ray tube is not controlled by the instrument software, set the proper combinationof voltage and current for the instrument in use. Th
35、ese settings must be determined by the user for his instrument and choice ofX-ray tube. Allow sufficient stabilization time prior to analysis.10. Calibration and Standardization10.1 Internal Standard Solution:10.1.1 Weigh 45 g of the internal standard compound chosen for uranium and 5 g of the inter
36、nal standard compound chosenfor gadolinium into a beaker. Cover with a minimum amount of water. Add concentrated nitric acid slowly.NOTE 3For yttrium oxide and samarium oxide, the reaction will be slow and may require heating. If strontium carbonate is used for uranium, thereaction will be vigorous.
37、 The strength of the internal standard solution may be changed to achieve optimum excitation with the equipment being used.The exact concentration of the internal standard solution is not critical; however, it is critical that the internal standard solution added to standards andsamples be the same.
38、10.1.2 Heat on a hot plate if necessary to complete the dissolution.10.1.3 Cool the solution to room temperature, and transfer to a 1000-mLvolumetric flask. Filter the solution if necessary. Diluteto volume with water and mix thoroughly.10.2 Calibration Standards:10.2.1 Liquid Standards:10.2.1.1 Pre
39、pare a calibration standard for each concentration level by weighing into a beaker the amounts of uranium oxideand gadolinium oxide (which have been ignited according to directions on analysis certificate), given in Table 1.10.2.1.2 Dissolve the oxide in 25 mL of water and 25 mL concentrated nitric
40、acid. Heat on a hot plate, if necessary to completethe dissolution. Reduce volume to 15 mL.10.2.1.3 When cool, transfer each solution to a properly labeled 25-mL volumetric flask containing the amount of internalstandard solution indicated in Table 1.TABLE 1 Uranium Oxide-Gadolinium Oxide Standards%
41、 U3O8A Wt. U3O8(g) % Gd2O3 Wt. Gd2O3(g) Internal Std(mL)90 0.9000 10 0.1000 591 0.9100 9 0.0900 592 0.9200 8 0.0800 593 0.9300 7 0.0700 594 0.9400 6 0.0600 595 0.9500 5 0.0500 596 0.9600 4 0.0400 597 0.9700 3 0.0300 598 0.9800 2 0.0200 599 0.9900 1 0.0100 5TABLE 1 Uranium Oxide-Gadolinium Oxide Stan
42、dards% U3O8A Wt. U3O8(g) % Gd2O3 Wt. Gd2O3(g) Internal Std(mL)90 0.9000 10 0.1000 591 0.9100 9 0.0900 592 0.9200 8 0.0800 593 0.9300 7 0.0700 594 0.9400 6 0.0600 595 0.9500 5 0.0500 596 0.9600 4 0.0400 597 0.9700 3 0.0300 598 0.9800 2 0.0200 599 0.9900 1 0.0100 5A Use of NBL CRM-129, or the equivale
43、nt, is recommended if uranium determi-nation is used for accountability purposes.C1456 133NOTE 4The internal standard solution may be added using a dispensing pipette if desired; however, care must be taken to assure that no adjustmentto the dispenser is made between use for standards and use for sa
44、mples.10.2.1.4 Dilute to volume with water and mix thoroughly.10.2.2 Pellet Standards:10.2.2.1 For each standard, weigh 15 g lithium tetraborate into a labeled crucible suitable for the fusion technique.NOTE 5Explanation of the fusion technique is beyond the scope of this guide. Description of the t
45、echnique may be found in several soucres.5,6Platinum, platinum-gold or graphite crucibles have been found acceptable.10.2.2.2 Add the amounts of uranium oxide and gadolinium oxide indicated in Table 1.10.2.2.3 Add the amount of internal standard solution (see 10.1) indicated in Table 1.NOTE 6The dry
46、-weight equivalent amount of internal standard compounds may be weighed directly into each crucible in place of internal standardsolution. If the solution is used with graphite crucibles, pipette into the center of the crucible. Do not allow the solution to touch the sides of crucible.10.2.2.4 Fuse
47、in a muffle furnace set at 10001100C until all materials are in solution. (The pellet will be clear and withoutstreaks. Mixing while melting is recommended).NOTE 7Automatic fusers are available and may be substituted, if desired. Follow the manufacturers operating instruction. Fusion in platinumcruc
48、ibles may also be done over an air-gas burner. If the pellet cracks or recrystallizes while cooling, remelting in the same crucible will not invalidateanalysis.10.3 Instrument Calibration:10.3.1 Follow the manufacturers instructions for the instrument in use to obtain intensity data for the uranium
49、L-, gadoliniumL- and the internal standard lines for each standard.10.3.2 Care must be exercised that the analytical conditions determined appropriate for the instrument in use are documented,or recorded, in sufficient detail that these may be reproduced in subsequent runs and when analyzing the samples.10.3.3 Calculate the analyte/internal standard ratios from the data obtained in 10.3.1. Calculate a calibration curve using theseratios. The calibration curve will normally be a straight line of form:Y5mX1b (1)where:Y = concentration of analyte
