1、Designation: C1408 09C1408 16Standard Test Method forCarbon (Total) in Uranium Oxide Powders and Pellets ByDirect Combustion-Infrared Detection Method1This standard is issued under the fixed designation C1408; the number immediately following the designation indicates the year oforiginal adoption or
2、, 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 carbon in nuclear-grade uranium ox
3、ide powders and pellets to determinecompliance with specifications.1.2 Gadolinium oxide (Gd2O3) and gadolinium oxide-uranium oxide powders and pellets may also be analyzed using this testmethod.1.3 This test method covers the determination of 5 to 500 g of residual carbon.1.4 This test method descri
4、bes an induction furnace carrier gas combustion system equipped with an infrared detector. It mayalso be applied to a similar instrument equipped with a thermal conductivity detector.1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this
5、standard.1.5.1 The preferred system of units is micrograms carbon per gram of sample (g/g sample) or micrograms carbon per gramof uranium (g/g U).1.6 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 sta
6、ndard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C753 Specification for Nuclear-Grade, Sinterable Uranium Dioxide PowderC776 Specification for Sintered Uranium Dioxide PelletsC8
7、59 Terminology Relating to Nuclear MaterialsC888 Specification for Nuclear-Grade Gadolinium Oxide (Gd2O3) PowderC922 Specification for Sintered Gadolinium Oxide-Uranium Dioxide Pellets2.2 NIST Standard:3NIST SRM 101G Standard Reference MaterialsStainless Steel3. Terminology3.1 DefinitionsExcept as o
8、therwise defined herein, definitions of terms are given in Terminology C859.3.2 Definitions of Terms Specific to This Standard:3.2.1 acceleratoran igniter and a flux which promotes both combustion and a fluid melt by effectively lowering the meltingpoint of the sample.4. Summary of Test Method4.1 Th
9、e powered or crushed test specimen and an appropriate accelerator (metal flux) are added to a crucible, placed within aninduction-heated furnace and burned at a nominal temperature of 1600 to 1700C in a stream of oxygen. A catalyst converts thecarbon monoxide (CO) to The carbon in the sample is oxid
10、ized to primarily carbon dioxide (CO2) with some carbon monoxide1 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 June 1, 2009March 1, 2016. Published July 2009M
11、arch 2016. Originally approved in 1998. Last previous edition approved in 20042009 asC1408 98 (2004).C1408 09. DOI: 10.1520/C1408-09.10.1520/C1408-16.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Stand
12、ardsvolume information, refer to the standards Document Summary page on the ASTM website.3 Available from National Institute of Standards and Technology (NIST), 100 Bureau Dr., Stop 1070, Gaithersburg, MD 20899-1070, http:/www.nist.gov.This document is not an ASTM standard and is intended only to pr
13、ovide the user of an ASTM standard an indication of what 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 th
14、e standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1(CO) formed.Acatalyst converts the CO to CO2 and the products of combustion are scavenged free of sulfur compoun
15、ds, halogens,and water vapor. The CO2 is swept into an infrared cell detector. The amount of carbon is automatically determined from storedcalibration data, and is displayed or printed out, or both, by the carbon analyzer.4.2 The actual configuration of the system may vary with vendor and model. Typ
16、ical systems include columns of materials suchas copper oxide, platinized silica gel, magnesium perchlorate, sodium hydroxide, and cellulose to purify the CO2 stream.5. Significance and Use5.1 Uranium dioxide is used as a nuclear-reactor fuel. Gadolinium oxide is used as an additive to uranium dioxi
17、de. In order tobe suitable for this purpose, these materials must meet certain criteria for impurity content. This test method is designed todetermine whether the carbon content meets Specifications C753, C776, C888, and C922.6. Interferences6.1 Contamination of carrier gas, crucibles, or samples wi
18、th extraneous sources of carbon may cause a positive bias. The blankcorrection will help to minimize the bias from carrier gas and crucibles. Interference from absorbed carbon on samples may beeliminated by keeping the sample in an inert atmosphere or vacuum.6.2 Powdered Gd2O3 samples may adsorb CO/
19、CO2 from the atmosphere. Sample preheating to 120 for 2 h is recommendedin this case.6.3 The purification system typically associated with the recommended combustion and detection equipment is designed tominimize other expected sources of interferences, such as sulfur, halogens, and water. The exter
20、nal/auxiliary purification systemsare designed to minimize/remove hydrocarbons, water, and CO2. Special scrubbers are used for halogens created during samplecombustion.7. Apparatus7.1 Low-Carbon Analyzer, consisting of an induction-heated furnace suitable for operation at 1600 to 1700C, an infraredd
21、etector for measuring carbon dioxide, and auxiliary purification systems.7.2 Crucibles, expendable alumina or similar refractory material. Both the crucible and cover, if used, must be pre-ignited ata temperature of 1000C or higher for a time sufficient to produce constant blank values.7.3 Muffle Fu
22、rnace, capable of attaining temperature of 1000C, for pre-igniting crucibles.7.4 Tongs and Forceps, for handling crucibles and lids.7.5 Stainless Steel Scoops and Spatulas8. Reagents and Materials8.1 Purity of ReagentsReagent grade chemicals shall be used in all tests. Unless otherwise indicated, it
23、 is intended that allreagents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society, wheresuch specifications are available.4 Other grades may be used, provided it is first ascertained that the reagent is of sufficiently highpurity to permit its
24、 use without lessening the accuracy of the determination.8.2 AcceleratorsCopper metal, metal and iron chip mixture, tin-tungsten mixture5, copper oxide, granular tin, and tin and ironchip mixture, or high purity iron chip accelerators for increased combustion temperature. These materials are availab
25、le inappropriate purity and form from carbon analyzer vendors. The criterion for satisfactory results is the absence of significantadditional carbon release upon recombustion of the specimen.8.3 Cellulose Trap PackingSurgical grade cotton or equivalent.8.4 Carbon Dioxide and Moisture AbsorbentsSodiu
26、m hydroxide (NaOH) on a fibrousan inert support and magnesiumperchlorate (Mg(ClO4)2.9. Carbon Standard Materials9.1 NIST SRM steel standards or equivalent:9.1.1 The 101, 131, 133, 339, and 343 series, ranging from approximately 20 g/g sample to 1500 g/g sample have been foundsatisfactory.4 Reagent C
27、hemicals, American Chemical Society Specifications, American Chemical Society, Washington, DC. For suggestions on the testing of reagents not listed bythe American Chemical Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and N
28、ationalFormulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.5 The sole source of supply of the apparatus, Lecocel accelerator, known to the committee at this time is LECO Corporation. If you are aware of alternative suppliers,please provide this information toASTM Headquarters. Your
29、comments will receive careful consideration at a meeting of the responsible technical committee,1 that you mayattend.C1408 1629.2 LECO6 or SYLAB steel standards79.2.1 The 1 g steel pin standards or steel rings, ranging from approximately 5 gg sample to 500 gg sample have been foundsatisfactory.10. H
30、azards and Precautions10.1 Take proper safety precautions to prevent inhalation, or ingestion of uranium dioxide powders or dust during grinding orhandling operations.10.2 Operation of equipment presents electrical and thermal hazards. Follow manufacturer recommendations for safe operation.10.3 This
31、 procedure uses hazardous chemicals. Use appropriate precautions for handling corrosives, oxidizers, and gases.11. Preparation of Apparatus11.1 Change instrument column packing and reagents as recommended by manufacturer.11.2 Set the operating controls of the instrument system according to the opera
32、ting instructions for the specific equipment used.11.3 Condition the apparatus by combustion of several blanks prepared with sample crucible and accelerator in the amount tobe used with the samples. Successive blanks should approach a constant value, allowing for normal statistical fluctuations.12.
33、Calibration12.1 The calibration range and number of standards will depend upon the instrument used. Two to four standards containing50 to 600 g g carbon are recommended.12.2 Add a volumetrically measured or weighed portion of accelerator and weighed portion of standard to a pre-ignited samplecrucibl
34、e. (The amount of accelerator will depend upon the instrument used and operating conditions.)12.3 Load and combust the standards according to the manufacturers recommended operating conditions.12.4 Calibrate the instrument according to operating instructions. Calibration coefficients are normally st
35、ored in themicroprocessor memory.12.5 Recalibration frequency will depend upon the type of instrument used. As a minimum, recalibration is required whencritical instrument components are changed, or when control standards data indicate that the instrument is failing to meetperformance criteria.13. P
36、rocedure13.1 Crush pellet samples to obtain approximately 1-mm (18 mesh) particles. (The particle size required may vary accordingto the instrument used and operating conditions.)13.2 Measure or weigh accelerator into a pre-ignited sample crucible. (The amount of accelerator will depend upon theinst
37、rument used and operating conditions.)conditions. This needs to remain constant to ensure proper accuracy and precision.Varying the load is a source of bias.)13.3 Weigh a portion of sample, (0.3 g to 2 g is suggested) suggested, depending upon the instrument model) to the nearest 0.01g, into the cru
38、cible. The sample size should be chosen to provide adequate sensitivity and accuracy at low carbon concentrations,but should contain less than 200 g of carbon.13.4 Load the crucible into the induction furnace and combust the sample according to the manufacturers recommendedoperating conditions. (Com
39、bustion time will vary with the instrument used, but it is typically in the 30 to 120-s range.) Recordthe result.13.5 Remove the sample crucible and examine it for incomplete combustion. The crucible contents should be a uniformly fusedmass. Results from incompletely fused samples shall not be accep
40、ted.14. Calculation14.1 Calculate the carbon content as follows:gCper gof sample5Cs 2Cb!/W (1)where:Cs = micrograms of carbon in test specimen,Cb = micrograms of carbon in a blank run, andW = grams of test specimen.6 LECO, 3003000 Lakeview Ave. St. Joesph, MichaganMichigan 49085 USA.7 SYLAB, 11 Imp.
41、 Courtes patures, F57073 Metz Cedex, 03, France.C1408 16314.2 For samples requiring carbon results expressed as g carbon per g U, convert results to uranium basis as follows:C,g/gU basis5 C g/g3100%U content of sample (2)15. Precision and Bias15.1 The precision and bias for this test method will dep
42、end data for NIST 101G, primary steel standard was collected bymultiple operators over a one year period using one instrument. As the data are dependent upon the instrument used and theoperating conditions.operating conditions, each laboratory will need to determine its own statistics.15.2 The relat
43、ive standard deviation for a NIST 101G steel standard (136 g/g) analyzed on the same instrument was 3.4 %.The bias, as measured by percent recovery of the standards value, was +1.4 %. These data represent 45 standards precision datafor Uranium Oxide Powder Working Standard was collected by multiple
44、operators over a one year period using one instrument,instrument.over a one-year period.14.3 The relative standard deviation for a 36 g/g working uranium oxide powder standard analyzed at one laboratory was8.0 %. The bias, as measured by percent recovery of the standards value, was +7.0 %. These dat
45、a represent 214 standardsmeasured by multiple operators using one instrument, over a one-year period.16. Keywords16.1 carbon content; gadolinium oxide; gadolinium oxide-uranium oxide; impurity content; uranium oxideASTM International takes no position respecting the validity of any patent rights ass
46、erted 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 to revision at any time b
47、y 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 Headquarters. Your comments will recei
48、ve 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 is copyrighted by ASTM Inter
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