ASTM C1865-18

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: C1865 − 18
Standard Test Method for
The Determination of Carbon and Sulfur Content in
Plutonium Oxide Powder by the Direct Combustion-Infrared
Spectrophotometer
This standard is issued under the fixed designation C1865; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 2. Referenced Documents
1.1 This test method is for the determination of the carbon 2.1 ASTM Standards:
and sulfur contents in plutonium oxide (PuO ) powder. The C697 Test Methods for Chemical, Mass Spectrometric, and
method utilizes an induction furnace purged with oxygen for Spectrochemical Analysis of Nuclear-Grade Plutonium
combustion of the sample. Carbon dioxide and sulfur dioxide Dioxide Powders and Pellets
producedbythecombustionaresweptintoabsorptioncellsand C753 Specification for Nuclear-Grade, Sinterable Uranium
quantified by infrared absorption spectrophotometers. This test Dioxide Powder
method is an alternative to the methods for carbon and sulfur C757 Specification for Nuclear-Grade Plutonium Dioxide
given in Test Method C697. Powder for Light Water Reactors
C833 Specification for Sintered (Uranium-Plutonium) Diox-
1.2 Determination of the carbon and sulfur contents in
ide Pellets for Light Water Reactors
nuclear-grade sintered mixed oxide (MOX) fuel pellets re-
C859 Terminology Relating to Nuclear Materials
quires the use of larger samples and is addressed in Test
C1068 Guide for Qualification of Measurement Methods by
Method C1853.
a Laboratory Within the Nuclear Industry
1.3 The values stated in SI units are to be regarded as
C1128 Guide for Preparation of Working Reference Materi-
standard. Units of measurement in parentheses are included for
als for Use in Analysis of Nuclear Fuel Cycle Materials
information only.
C1853 TestMethodforTheDeterminationofCarbon(Total)
1.4 This standard may involve hazardous materials,
Content in Mixed Oxide ((U, Pu)O ) Sintered Pellets by
operations, and equipment. This standard does not purport to Direct Combustion-Infrared Detection Method
address all of the safety concerns, if any, associated with its
use. It is the responsibility of the user of this standard to 3. Terminology
establish appropriate safety, health, and environmental prac-
3.1 For definitions of terms used in this test method but not
tices and determine the applicability of regulatory limitations
defined herein, refer to Terminology C859.
prior to use.
3.2 Definitions of Terms Specific to This Standard:
1.5 This international standard was developed in accor-
3.2.1 accelerant—the material, like granular tungsten pow-
dance with internationally recognized principles on standard-
der and iron, used for accelerating the combustion of the
ization established in the Decision on Principles for the
plutonium oxide powder.
Development of International Standards, Guides and Recom-
3.2.2 MOX—nuclearfuelcomposedofamixtureofuranium
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee. and plutonium oxides ((U, Pu)O ).
This test method is under the jurisdiction ofASTM Committee C26 on Nuclear
Fuel Cycle and is the direct responsibility of Subcommittee C26.05 on Methods of For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Test. contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Current edition approved Oct. 1, 2018. Published October 2018. DOI: 10.1520/ Standards volume information, refer to the standard’s Document Summary page on
C1865-18. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C1865 − 18
3.2.3 sintering—the process of increasing the bonding in a availability of sufficient quantities of O , and the presence of
mass of powder or a compact by heating below the melting impurity elements that can consume O .
point of the main constituent.
6.3 Sample and standard masses (and particle sizes of the
3.3 Acronyms: oxide materials) should be similar so that combustion condi-
3.3.1 LANL—Los Alamos National Laboratory
tions and behaviors are as similar as possible to prevent a
systematic bias between the sample and standard data.
3.3.2 LIMS—Laboratory Information Management System
6.4 Daily, or before each use, the analyzer is checked with
3.3.3 NIST—NationalInstituteofStandardsandTechnology
a blank and one or more quality control standards of known
3.3.4 SRNL—Savannah River National Laboratory
carbon or sulfur concentration. The instrument is calibrated
3.3.5 WRM—Working Reference Material
dailywithstandardstraceabletoanationalstandardsbodysuch
as the National Institute of Standards and Technology (NIST).
4. Summary of Test Method
6.5 Weighing accuracy of the samples is critical to the
4.1 The instrumentation used for carbon and sulfur content
method. If the balance meets the specification in 7.1,is
determinations typically includes a computer controlled induc-
calibrated in accordance with manufacturer’s guidance, and is
tion furnace purged with oxygen.An analytical balance is used
operated following facility guidelines for handling of the
toweighaknownamountofthePuO powderforanalysis.The
analytical balances, the potential for weighing uncertainties to
method consists of combusting a weighed sample of approxi-
be a major source of error is insignificant.
mately 0.1 to1gofPuO powder. The sample is covered with
6.6 Duringnormaloperatingconditionsitisensuredthatthe
an accelerator material, usually granular tungsten and iron.
furnace is operated at <1700 °C. Except when exothermic
Carbondioxideandsulfurdioxideproducedbythecombustion
reactions are triggered inside the induction furnace, furnace
are swept into absorption cells where each gas is quantified by
temperatures do not exceed the normal operating temperatures.
infrared (IR) spectrophotometers. Blanks and quality control
standards are analyzed following the same procedure as that 6.7 COandSO areoxidizedtoCO andSO whenexposed
2 2 3
used for the analysis of the samples. Drift corrections are to the heated platinized silica reagent. CO detection by IR is
performed, when necessary. much more sensitive than the detection of CO.After detection,
the odorous/toxic SO in the exhaust system is converted to
5. Significance and Use SO .
5.1 Plutonium oxide powder is a component of MOX fuel. 6.8 Carbon is seen as a common environmental contami-
nant. A few of the more common sources of carbon interfer-
This test method can be used to determine whether the carbon
andsulfurcontentsofthePuO powdermeetstherequirements ences is CO and CO from the air or carrier gas, crucibles,
2 2
reagents, tools, and work area. To minimize blanks, the work
of Specifications C757 and C753 or other requirements as
defined by agreement between the nuclear and fuel supplier areas are to be maintained clean.
and the customer.
6.9 Carrier gases may contain H O, CO, or CO gases as a
2 2
5.2 MOX is used as a nuclear-reactor fuel. To be used as a contaminant. This will cause a high background for carbon
fuel, MOX materials must meet specifications on the impurity results. These contaminates may be scrubbed from the carrier
element contents in them. Examples of these requirements are gas prior to introduction of the gas to the sample chamber, or
given in Specification C833. alternatively, minimized through the use of ultra-pure gas.
5.3 This method is suitable for pure plutonium oxide pow-
6.10 An additional known contaminant is methane (CH )or
der. other organic gases, or both, which are part of the total
hydrocarbonspecification(THC)foroxygensupplies.Aheated
6. Interferences incoming gas scrubber is required to remove this contamina-
tion or higher purity grade of oxygen is required.
6.1 Ideally, calibration should be performed with a standard
6.11 As received, crucibles typically have inherent carbon
having a matrix identical to that of the sample. Matrix matched
calibration standards are not available for PuO powder mate- contaminationlevelsat20ppmto40ppmrelativetoa1gsteel
sample, but it can be as much as several hundred ppm. This
rials. Biased results can result if the calibration standards
combust at different conditions than the samples or if the contamination from the handling, packaging, and storage
conditions of the crucibles varies by lot and by manufacturer.
combustion behavior of the chosen standard is significantly
different from that of the PuO powder material analyzed. For ultra-trace analysis (<100 ppm) and trace analysis (<1000
ppm), the crucibles must be cleaned prior to use by a high
6.2 Incompletecombustioncanbecausedbysamplemasses
temperature bake out. Measured blanks takes into account the
thataretoolarge.Whenthisoccurs,resultscanbeimprovedby
contributions from crucible blanks.
reducing the sample mass to promote complete combustion.
Combustion produces a mixture of CO, CO , and SO . The 6.12 Accelerants can be a significant source of carbon
2 2
proportion of CO/CO and SO produced during the combus- contamination. Several manufacturers or lots may need to be
2 2
tion depends on, among other factors: temperature, the accel- screened prior to selecting an appropriate accelerant that has
erant properties, the coupling between the accelerant and the minimal C contamination. Measured blanks takes into account
sample material, particle size of the oxide material, the the contributions from accelerant blanks.
C1865 − 18
6.13 Opened reagents (sodium hydroxide and magnesium 8.8 Oxygen (>99.9 % purity).
perchlorate) absorb water, CO, and CO from the atmosphere
8.9 Platinized silica-gel (CO to CO and SO to SO
2 2 3
after opening. This contamination will decrease the efficiency
oxidizing catalyst).
or capacity of reagents.
8.10 Silicone grease (used for O-rings).
6.14 Environmental dust and skin residues often contain
large amounts of carbon that will bias results. Good house-
9. Reference Materials
keeping of the workspace and use of clean tools and gloves are
9.1 The calibration of the analyzer is made by means of a
sufficient to keep this contamination source low.
reference material standard from a national standards body
6.15 Even with the use of air filters for the building air
such as the U.S. National Institute for Standards and Technol-
circulation system, wild fires in neighboring areas can tempo-
ogy (NIST) or equivalent.
rarily increase the carbon blanks significantly.
9.2 Standard materials in steel matrices (steel pins, steel
rings, steel granules, and steel powder) are available and have
7. Apparatus
been found to be satisfactory. Matrix matched standards for
7.1 Analytical Balance, with a combined standard uncer-
PuO are rarely available.
tainty of 60.1 mg.
9.3 As a best practice, analytical facilities are encouraged to
7.2 Carbon/Sulfur Analyzer, consisting of an induction fur-
develop well characterized, matrix matched working reference
nace that is purged with oxygen. Carbon dioxide and sulfur
materials (WRMs) of similar carbon and sulfur contents as the
dioxide produced during combustion are swept into absorption
samples analyzed routinely. During routine carbon and sulfur
cells where each gas is quantified by an infrared detection
analysis following this method, these WRMs can then be used
system. The apparatus is usually computer controlled.
as quality control standards. See Guide C1128 for guidance on
7.2.1 The analyzer typically uses the following chemicals:
preparation of WRMs.
tungsten and iron (accelerants for combustion), magnesium
perchlorate (oxidizer), sodium hydroxide (CO trap), and
10. Precautions
cellulose (SO trap). Alternate chemicals with equivalent
properties may be used. 10.1 Because of the toxicity of plutonium, all operations
should be performed within approved glove boxes fitted with
7.3 Induction Furnace, for heating samples.
appropriate filters to protect personnel from uptake of small
7.4 Crucible Tongs, for handling crucibles.
particles of plutonium. A detailed discussion of the necessary
precautions is beyond the scope of this test method. Personnel
7.5 Low-Carbon Sample Crucibles, for analyzing samples.
involved in these analyses should be familiar with safe
7.6 Stainless Steel Scoop, for transferring sample amounts
handling practices for radioactive materials and trained appro-
to sample crucible.
priately.
8. Reagents and Materials
10.2 Containment devices shall be operational, with current
inspections and glove change dates.
8.1 Purity of Reagents—Unless otherwise stated, reagent
grade chemicals shall be used, where available. All reagents
10.3 Specific hazards associated with the analyzer are the
shall conform to the specifications of the Committee on
high-temperature components, high-voltage components, and
Analytical Reagents of theAmerican Chemical Society, where
corrosive/reactive/toxic reagents. High-pressure oxygen and
such specifications are available. Other grades may be used,
nitrogenareregulatedasrecommendedbythemanufacturer,to
provided it is first ascertained that the reagent is of sufficiently
provideanoxidant/carriergasstreamandtoactuatethefurnace
high purity to permit its use without compromising the quality
pedestal. A pressure relief valve, set to relieve at appropriate
of the measurements.
pressure levels, is sometimes installed in the line. Exercise
appropriate caution when working with compressed gases.
8.2 Anhydrous magnesium perchlorate (MgClO ), also
called Anhydrone.
10.4 Ensure that the gas cylinder is fitted with facility
approved regulator that has been inspected. Also ensure that
8.3 Sodium hydroxide (NaOH) on an inert base (CO trap).
the gas cylinder is securely fastened in place.
8.4 Cellulose (SO trap).
10.5 For handling of crucibles, use tongs or tweezers, not
8.5 Iron chips (accelerator).
fingers.
8.6 Tungsten powder (accelerator).
10.6 Use appropriate precautions for handling corrosives,
8.7 Glass wool (to trap particulates).
oxidizers, and gases.
10.7 Caution shall be used around the furnace surfaces,
which may be hot during operation and for 10 minutes after
Reagent Chemicals, American Chemical Society Specifications, American
use. Post appropriate warning signs (following facility
Chemical Society, Washington, DC. For suggestions on the testing of reagents not
listed by the American Chemical Society, see Analar Standards for Laboratory procedures), when applicable.
Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
10.8 The furnace pedestal is a pinch point hazard when
and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
MD. operating the nitrogen supply valve and when raising or
C1865 − 18
lowering the furnace pedestal. Foreign objects (hands, glove- are changed, or when control chart data indicate that the
box gloves, cleaning tools, etc.) shall be kept out of the path of instrument is failing to meet established performance criteria.
the furnace pedestal. For blank determinations, three or more measurements are
recommended.
11. Preparation and Verification of Apparatus Prior to
12.2 Calibration standards analyzed as quality control (QC)
Sample Analysis
standards may require preparation prior to analysis. Follow the
11.1 Perform initial instrument set up in accordance with instructions provided by the manufacturer of the standard in
theircertificateofanalysistopreparethestandards.ForWRMs
manufacturer instructions. Ensure that all gas pressures are in
the desired ranges based on manufacturer recommendations. or other matrix matched standards prepared in-house the
preparation steps can be drying in an oven at 105 to 110 °C for
11.2 Perform the required daily checks on the balance to
at least 1 h.
ensure that it performs at acceptable levels.
12.3 Transfer the dried standards immediately to a desicca-
11.3 Prior to calibration or analysis, perform any required
tor. Discard any dried standards not used within 24 h of drying.
maintenance tasks based on manufacturer recommendations.
NOTE 1—Steel pin certified reference materials may be used for
11.4 Prior to calibration or analysis, ensure that instrument
instrument calibration or verification. When these are used, there is no
parameters are within the range specified by the manufacturer.
requirement to clean, dry, or pre-weigh the pins prior to use.
11.5 Perform an instrument leak test. If a leak is detected,
12.4 Prepare blank standards by adding one scoop of each
follow manufacturer instructions for trouble shooting.
accelerator into prepared crucibles. The amount of accelerator
material added must be sufficient to cover the sample and
11.6 Pre-fire crucibles in a muffle or tube furnace at tem-
couple with the RF field. For the Los Alamos National
peratures of at least 1000 °C for2horat more than 1250 °C
Laboratory (LANL) data presented in Annex A1, 1.5 g
for at least 15 min. Pre-fired crucibles are removed from the
accelerator material was added. Follow manufacturer guidance
heat, allowed to cool on a tray, and placed in a desiccator. The
on the mass of the accelerator material that needs to be added.
crucibles are then handled with clean tongs and removed
Some manufacturers recommend that empty crucibles are
individually from the desiccator for use. They must not be
analyzed until a stable area measurement is obtained. This is
allowed to remain in an open-air environment too long as they
followed by blanks (crucibles plus accelerator).
can be contaminated with airborne particulate (dust).Although
this procedure is typically reserved for low carbon (<0.1 %)
12.5 Weigh target quantities of the calibration and QC
and sulfur (<0.01 %) determination, the effects can be noticed
standards using countertop balance and transfer to clean, tared
on high carbon results when smaller sample weights are used.
crucibles. The actual weight of the calibration and QC stan-
Prepare sufficient number of crucibles as a batch to complete
dards shall fall within 615 % of the specified target values.
all analyses necessary for a set of samples. Use of crucibles
12.6 Weightargetquantitiesofthesamplesusingcountertop
prepared in separate batches requires additional verification
balanceandtransfertoclean,taredcrucibles.Theactualweight
analyses. For <100 ppm carbon content measurements, the
of the sample analyzed shall fall within 615 % of the specified
crucibles need to be pre-fired at 1350 °C (pre-firing at such
target values.
high temperature will cause a few percent of the crucibles to
12.7 Analyze sample blanks using new, empty ceramic
crack).
crucibles (or as defined by the manufacturer).Analysis of three
11.7 Transfer the pre-fired (cleaned) crucibles into a desic-
or more blanks is recommended.
cator for storage. Use the cleaned crucibles within 24 h of
12.8 Analyze aliquots of calibration material for each cali-
firing. Any crucibles not used within this time period shall be
bration point specified on the calibration sheet.
fired again or discarded.
12.9 Ensure that the calibration curve is linear (regression
12. Instrument Calibration
coefficient >0.997). Recalibration will be necessary, if the
calibration curve is non-linear.
12.1 The calibration range and the number of standards will
depend upon the instrument used and the expected range of
12.10 Compare QC standard results to pre-established ac-
carbon and sulfur in the samples being analyzed. The initial
ceptance criteria. If acceptance criteria are not met, evaluate
calibration curve for the instrument must be established using
the cause and take appropriate corrective action.
standards covering the entire range of samples that are ex-
NOTE 2—With regard to number of QC standards analyzed, analytical
pected to be analyzed at the facility. Once a firm calibration
laboratories adopt specific criteria based on the quality assurance program
curve is established and linear behavior is assured, a one point
requirements or on the data quality objectives of the specific project. The
following is an example of criteria that could be adopted. Traceable QC
calibration, preferably at or close to the origin of the curve and
standards shall be analyzed prior to analysis of samples, after analysis of
in the range of the concentrations routinely measured will be
every ten samples, and after analysis of a set of samples. WRMs,
sufficient.The drift of the calibration curve depends on, among
characterized to the desired levels of precision and accuracy (total
other factors, type of samples analyzed, laboratory environ-
uncertainty) by the analytical facility, may be used as QC standards.
mental conditions, maintenance, analyst and the instrument
13. Sample Analysis
capabilities. The user will have to establish a recalibration
frequency by taking into consideration the above factors. At a 13.1 Ablank measurement is performed prior to analysis of
minimum, recalibration is required when critical components the sample to ensure that carbon and sulfur backgrounds are
C1865 − 18
not above acceptable limits established by the user. The blank 14.3 The sulfur content is calculated as follows (typically,
measurement result is saved and subtracted from the sample this calculation is performed by the analyzer software):
measurement results to account for contributions from the
S 2 S
~ !
s b
@S# 5 (4)
crucible and carrier gas.
W
13.2 The amount of sample used for analysis can vary
where:
depending on the instrument used. Follow manufacturer guid-
[S] = micrograms of sulfur per gram sample (Pu Oxide),
ance on the mass of sample to be measured using the carbon
S = micrograms of sulfur in sample (Pu Oxide),
s
and sulfur analyzer.
S = micrograms of sulfur in a blank run, and
b
NOTE 3—The number of replicates required per sample or lot will W = grams of sample (Pu Oxide).
depend on the instrument used, the operating conditions, the client
If multiple replicates are measured, the average content of
specifications, and the data quality objectives set by the facility for the
sulfur [S] is calculated as:
specific project. Typically two
...