1、Designation: C1865 18Standard Test Method forThe Determination of Carbon and Sulfur Content inPlutonium Oxide Powder by the Direct Combustion-InfraredSpectrophotometer1This standard is issued under the fixed designation C1865; the number immediately following the designation indicates the year ofori
2、ginal 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 is for the determination of the carbonand sul
3、fur contents in plutonium oxide (PuO2) powder. Themethod utilizes an induction furnace purged with oxygen forcombustion of the sample. Carbon dioxide and sulfur dioxideproduced by the combustion are swept into absorption cells andquantified by infrared absorption spectrophotometers. This testmethod
4、is an alternative to the methods for carbon and sulfurgiven in Test Method C697.1.2 Determination of the carbon and sulfur contents innuclear-grade sintered mixed oxide (MOX) fuel pellets re-quires the use of larger samples and is addressed in TestMethod C1853.1.3 The values stated in SI units are t
5、o be regarded asstandard. Units of measurement in parentheses are included forinformation only.1.4 This standard may involve hazardous materials,operations, and equipment. This standard does not purport toaddress all of the safety concerns, if any, associated with itsuse. It is the responsibility of
6、 the user of this standard toestablish appropriate safety, health, and environmental prac-tices and determine the applicability of regulatory limitationsprior to use.1.5 This international standard was developed in accor-dance with internationally recognized principles on standard-ization establishe
7、d in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2C697 Test Methods for Chemical, Mass Spectrometric, andSpectrochemic
8、al Analysis of Nuclear-Grade PlutoniumDioxide Powders and PelletsC753 Specification for Nuclear-Grade, Sinterable UraniumDioxide PowderC757 Specification for Nuclear-Grade Plutonium DioxidePowder for Light Water ReactorsC833 Specification for Sintered (Uranium-Plutonium) Diox-ide Pellets for Light W
9、ater ReactorsC859 Terminology Relating to Nuclear MaterialsC1068 Guide for Qualification of Measurement Methods bya Laboratory Within the Nuclear IndustryC1128 Guide for Preparation of Working Reference Materi-als for Use in Analysis of Nuclear Fuel Cycle MaterialsC1853 Test Method for The Determina
10、tion of Carbon (Total)Content in Mixed Oxide (U, Pu)O2) Sintered Pellets byDirect Combustion-Infrared Detection Method3. Terminology3.1 For definitions of terms used in this test method but notdefined herein, refer to Terminology C859.3.2 Definitions of Terms Specific to This Standard:3.2.1 accelera
11、ntthe material, like granular tungsten pow-der and iron, used for accelerating the combustion of theplutonium oxide powder.3.2.2 MOXnuclear fuel composed of a mixture of uraniumand plutonium oxides (U, Pu)O2).1This test method is under the jurisdiction of ASTM Committee C26 on NuclearFuel Cycle and
12、is the direct responsibility of Subcommittee C26.05 on Methods ofTest.Current edition approved Oct. 1, 2018. Published October 2018. DOI: 10.1520/C1865-18.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTM
13、Standards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized princ
14、iples on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.13.2.3 sinteringthe process of increasing the bonding in amass of powder or
15、a compact by heating below the meltingpoint of the main constituent.3.3 Acronyms:3.3.1 LANLLos Alamos National Laboratory3.3.2 LIMSLaboratory Information Management System3.3.3 NISTNational Institute of Standards and Technology3.3.4 SRNLSavannah River National Laboratory3.3.5 WRMWorking Reference Ma
16、terial4. Summary of Test Method4.1 The instrumentation used for carbon and sulfur contentdeterminations typically includes a computer controlled induc-tion furnace purged with oxygen. An analytical balance is usedto weigh a known amount of the PuO2powder for analysis. Themethod consists of combustin
17、g a weighed sample of approxi-mately 0.1 to1gofPuO2powder. The sample is covered withan accelerator material, usually granular tungsten and iron.Carbon dioxide and sulfur dioxide produced by the combustionare swept into absorption cells where each gas is quantified byinfrared (IR) spectrophotometers
18、. Blanks and quality controlstandards are analyzed following the same procedure as thatused for the analysis of the samples. Drift corrections areperformed, when necessary.5. Significance and Use5.1 Plutonium oxide powder is a component of MOX fuel.This test method can be used to determine whether t
19、he carbonand sulfur contents of the PuO2powder meets the requirementsof Specifications C757 and C753 or other requirements asdefined by agreement between the nuclear and fuel supplierand the customer.5.2 MOX is used as a nuclear-reactor fuel. To be used as afuel, MOX materials must meet specificatio
20、ns on the impurityelement contents in them. Examples of these requirements aregiven in Specification C833.5.3 This method is suitable for pure plutonium oxide pow-der.6. Interferences6.1 Ideally, calibration should be performed with a standardhaving a matrix identical to that of the sample. Matrix m
21、atchedcalibration standards are not available for PuO2powder mate-rials. Biased results can result if the calibration standardscombust at different conditions than the samples or if thecombustion behavior of the chosen standard is significantlydifferent from that of the PuO2powder material analyzed.
22、6.2 Incomplete combustion can be caused by sample massesthat are too large. When this occurs, results can be improved byreducing the sample mass to promote complete combustion.Combustion produces a mixture of CO, CO2, and SO2. Theproportion of CO/CO2and SO2produced during the combus-tion depends on,
23、 among other factors: temperature, the accel-erant properties, the coupling between the accelerant and thesample material, particle size of the oxide material, theavailability of sufficient quantities of O2, and the presence ofimpurity elements that can consume O2.6.3 Sample and standard masses (and
24、 particle sizes of theoxide materials) should be similar so that combustion condi-tions and behaviors are as similar as possible to prevent asystematic bias between the sample and standard data.6.4 Daily, or before each use, the analyzer is checked witha blank and one or more quality control standar
25、ds of knowncarbon or sulfur concentration. The instrument is calibrateddaily with standards traceable to a national standards body suchas the National Institute of Standards and Technology (NIST).6.5 Weighing accuracy of the samples is critical to themethod. If the balance meets the specification in
26、 7.1,iscalibrated in accordance with manufacturers guidance, and isoperated following facility guidelines for handling of theanalytical balances, the potential for weighing uncertainties tobe a major source of error is insignificant.6.6 During normal operating conditions it is ensured that thefurnac
27、e is operated at 99.9 % purity).8.9 Platinized silica-gel (CO to CO2and SO2to SO3oxidizing catalyst).8.10 Silicone grease (used for O-rings).9. Reference Materials9.1 The calibration of the analyzer is made by means of areference material standard from a national standards bodysuch as the U.S. Natio
28、nal Institute for Standards and Technol-ogy (NIST) or equivalent.9.2 Standard materials in steel matrices (steel pins, steelrings, steel granules, and steel powder) are available and havebeen found to be satisfactory. Matrix matched standards forPuO2are rarely available.9.3 As a best practice, analy
29、tical facilities are encouraged todevelop well characterized, matrix matched working referencematerials (WRMs) of similar carbon and sulfur contents as thesamples analyzed routinely. During routine carbon and sulfuranalysis following this method, these WRMs can then be usedas quality control standar
30、ds. See Guide C1128 for guidance onpreparation of WRMs.10. Precautions10.1 Because of the toxicity of plutonium, all operationsshould be performed within approved glove boxes fitted withappropriate filters to protect personnel from uptake of smallparticles of plutonium. A detailed discussion of the
31、necessaryprecautions is beyond the scope of this test method. Personnelinvolved in these analyses should be familiar with safehandling practices for radioactive materials and trained appro-priately.10.2 Containment devices shall be operational, with currentinspections and glove change dates.10.3 Spe
32、cific hazards associated with the analyzer are thehigh-temperature components, high-voltage components, andcorrosive/reactive/toxic reagents. High-pressure oxygen andnitrogen are regulated as recommended by the manufacturer, toprovide an oxidant/carrier gas stream and to actuate the furnacepedestal.
33、 A pressure relief valve, set to relieve at appropriatepressure levels, is sometimes installed in the line. Exerciseappropriate caution when working with compressed gases.10.4 Ensure that the gas cylinder is fitted with facilityapproved regulator that has been inspected. Also ensure thatthe gas cyli
34、nder is securely fastened in place.10.5 For handling of crucibles, use tongs or tweezers, notfingers.10.6 Use appropriate precautions for handling corrosives,oxidizers, and gases.10.7 Caution shall be used around the furnace surfaces,which may be hot during operation and for 10 minutes afteruse. Pos
35、t appropriate warning signs (following facilityprocedures), when applicable.10.8 The furnace pedestal is a pinch point hazard whenoperating the nitrogen supply valve and when raising or3Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggest
36、ions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.C1865 183lowering the furnace pe
37、destal. Foreign objects (hands, glove-box gloves, cleaning tools, etc.) shall be kept out of the path ofthe furnace pedestal.11. Preparation and Verification of Apparatus Prior toSample Analysis11.1 Perform initial instrument set up in accordance withmanufacturer instructions. Ensure that all gas pr
38、essures are inthe desired ranges based on manufacturer recommendations.11.2 Perform the required daily checks on the balance toensure that it performs at acceptable levels.11.3 Prior to calibration or analysis, perform any requiredmaintenance tasks based on manufacturer recommendations.11.4 Prior to
39、 calibration or analysis, ensure that instrumentparameters are within the range specified by the manufacturer.11.5 Perform an instrument leak test. If a leak is detected,follow manufacturer instructions for trouble shooting.11.6 Pre-fire crucibles in a muffle or tube furnace at tem-peratures of at l
40、east 1000 C for2horatmore than 1250 Cfor at least 15 min. Pre-fired crucibles are removed from theheat, allowed to cool on a tray, and placed in a desiccator. Thecrucibles are then handled with clean tongs and removedindividually from the desiccator for use. They must not beallowed to remain in an o
41、pen-air environment too long as theycan be contaminated with airborne particulate (dust). Althoughthis procedure is typically reserved for low carbon (0.997). Recalibration will be necessary, if thecalibration curve is non-linear.12.10 Compare QC standard results to pre-established ac-ceptance crite
42、ria. If acceptance criteria are not met, evaluatethe cause and take appropriate corrective action.NOTE 2With regard to number of QC standards analyzed, analyticallaboratories adopt specific criteria based on the quality assurance programrequirements or on the data quality objectives of the specific
43、project. Thefollowing is an example of criteria that could be adopted. Traceable QCstandards shall be analyzed prior to analysis of samples, after analysis ofevery ten samples, and after analysis of a set of samples. WRMs,characterized to the desired levels of precision and accuracy (totaluncertaint
44、y) by the analytical facility, may be used as QC standards.13. Sample Analysis13.1 A blank measurement is performed prior to analysis ofthe sample to ensure that carbon and sulfur backgrounds areC1865 184not above acceptable limits established by the user. The blankmeasurement result is saved and su
45、btracted from the samplemeasurement results to account for contributions from thecrucible and carrier gas.13.2 The amount of sample used for analysis can varydepending on the instrument used. Follow manufacturer guid-ance on the mass of sample to be measured using the carbonand sulfur analyzer.NOTE
46、3The number of replicates required per sample or lot willdepend on the instrument used, the operating conditions, the clientspecifications, and the data quality objectives set by the facility for thespecific project. Typically two or three replicates are measured so that anaverage of two/three analy
47、ses are reported for a sample or sample lot.NOTE 4The number of samples or lots that can be analyzed prior toa recalibration depends on the instrument used and the operating condi-tions. Typically ten samples can be analyzed before checking the analyzercalibration via the analysis of a blank and a r
48、eference material standard.13.3 Samples are analyzed following guidance provided bythe instrument manufacturer.13.4 A blank measurement is performed after sample analy-sis to ensure that blank concentrations are not above acceptablelimits established for the instrument.NOTE 5If the blank is above th
49、e acceptable limits established for theinstrument, the furnace should be cleaned and another blank should beanalyzed. If the blank is still not low enough, the results obtained for thesample cannot be reported.14. Calculation14.1 The carbon content is calculated as follows (typically,this calculation is performed by the analyzer software):C# 5Cs2 Cb!W(1)where:C = micrograms of carbon per gram sample (PuO2),Cs= micrograms of carbon in sample (PuO2),Cb= micrograms of carbon in a blank run, andW = grams of sample (PuO2).If multiple replicates are measured, the aver
