ASTM C1430-07(2011)e1

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: C1430 − 07 (Reapproved 2011)
Standard Test Method for
Determination of Uranium, Oxygen to Uranium (O/U), and
Oxygen to Metal (O/M) in Sintered Uranium Dioxide and
Gadolinia-Uranium Dioxide Pellets by Atmospheric
Equilibration
This standard is issued under the fixed designation C1430; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
ε NOTE—A units statement was added editorially in June 2011.
1. Scope C1287Test Method for Determination of Impurities in
Nuclear Grade Uranium Compounds by Inductively
1.1 This test method applies to the determination of
Coupled Plasma Mass Spectrometry
uranium, the oxygen to uranium (O/U) ratio in sintered
uraniumdioxidepellets,andtheoxygentometal(O/M)ratioin
3. Summary of Test Method
sintered gadolinium oxide-uranium dioxide pellets with a
3.1 Theuranium,andeitherO/UorO/M,aredeterminedby
GdO concentration of up to 12 weight %. The O/M calcula-
measuring the weight change of a sintered pellet after it has
tions assume that the gadolinium and uranium oxides are
been exposed to an equilibrating atmosphere to bring it to the
present in a metal dioxide solid solution.
stoichiometric condition. Sintered pellets are weighed and
1.2 The values stated in SI units are to be regarded as
loaded into a sample boat.The boat is placed in a tube furnace
standard. No other units of measurement are included in this
capable of holding a temperature of 800 6 10°C. The furnace
standard.
is purged with a moist gas flow of 4% hydrogen and 96%
argon or nitrogen to remove all air. The temperature of the
1.3 This standard does not purport to address all of the
furnace is raised to 800°C and held at this temperature with
safety concerns, if any, associated with its use. It is the
constant gas flow for 4 h. The furnace then is turned off and
responsibility of the user of this standard to establish appro-
allowed to cool, with gas purge on, to room temperature. The
priate safety and health practices and determine the applica-
samples are removed from the furnace and reweighed.
bility of regulatory limitations prior to use.Forspecifichazards
statements, see Section 8.
3.2 The weight change, gadolinia content, and chemical
impurity content are used to calculate % uranium and the O/U
2. Referenced Documents
or O/M.
2.1 ASTM Standards:
4. Significance and Use
C696Test Methods for Chemical, Mass Spectrometric, and
SpectrochemicalAnalysis of Nuclear-Grade Uranium Di- 4.1 Uranium dioxide is used as a nuclear-reactor fuel. This
oxide Powders and Pellets test method is designed to determine whether the percent
C776Specification for Sintered Uranium Dioxide Pellets uranium and O/U or O/M content meet Specifications C776
and C922.
C922SpecificationforSinteredGadoliniumOxide-Uranium
Dioxide Pellets
5. Interferences
C968Test Methods for Analysis of Sintered Gadolinium
5.1 Parameters for temperature, gas composition, gas flow,
Oxide-Uranium Dioxide Pellets
and moist air purge must be monitored and maintained care-
fully within the limits set in the procedure.
ThistestmethodisunderthejurisdictionofASTMCommitteeC26onNuclear
Fuel Cycle and is the direct responsibility of Subcommittee C26.05 on Methods of 5.2 This test method assumes that chemical impurities meet
Test.
Specifications C776 and C922 limits. Potential method inter-
Current edition approved June 1, 2011. Published June 2011. Originally
ferences from higher impurity concentrations will require
approved in 2000. Last previous edition approved in 2007 as C1430–07. DOI:
evaluation.
10.1520/C1430-07R11E01.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
5.3 Furnace tubes or boats made from metals that oxidize
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
under the test conditions may prevent proper equilibration by
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. consuming available oxygen.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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C1430 − 07 (2011)
5.4 Preciseweighingofsamplesiscriticaltotheaccuracyof 7. Standard Materials
this test method. 3
7.1 NBL , NBL-traceable, or equivalent, uranium dioxide
5.5 Loss of weight due to pellet chipping would invalidate pellets. Analyze at least one standard pellet per batch.
the analysis. Handle pellets with care.
8. Hazards and Precautions
5.6 This test method assumes that pellets are sintered. It
8.1 Take proper safety precautions for handling uranium.
does not correct for moisture or volatile additives.
5.7 This test method assumes that UO -Gd O pellets have 8.2 Thefurnace,sampletubeandsampleboatsareheatedto
2 2 3
800°C. Care must be taken to avoid burns.
formed a solid solution; however, the error from incomplete
dissolution of Gd O would be very small (see the calculation
2 3
8.3 Exercise appropriate caution when working with com-
in 10.2).
pressed gasses.
6. Apparatus
9. Procedure
6.1 Analytical Balance, capable of weighing to 6 0.0001 g.
9.1 Analyze samples as whole pellets. No preparation is
6.2 Tube Furnace, capable of controlling temperatures at required. The nominal sample size is 5–10-g pellet. Smaller
pellets may need to be composited (two pellets/test) to main-
800 6 10°C, that has been fitted with a fused quartz furnace
tain minimum weight.Avoid using chipped or cracked pellets.
tube.
9.2 Place a small weighing tray or watch glass on the
6.3 Fused Quartz Sample Boats.
balance pan. Tare the balance and check to ensure that the
6.4 Assorted Connectors, Tubing, Flasks, Stoppers, and
balance is stable. If the balance will not stabilize, do not
Delivery Tubes—The purge gas is passed through a humidifier,
proceed.
intothetubefurnace.Abubblerflaskisattachedtothefurnace
outlet to monitor gas flow (see Fig. 1). NOTE 1—The extremely small weight changes that are being measured
in this test method make it critical that the balance is working properly.
6.5 Gas Pressure Gage and Regulator.
9.3 Weigh a check weight at least daily to confirm that the
6.6 Purge Gas(4%hydrogen,96%argonor4%hydrogen
analytical balance is operating correctly.
and 96% nitrogen. Gas purity of 99.995% has been found to
perform satisfactorily.
6.7 Purge Gas Humidifier, with heater and controller ca- 3
Available from the New Brunswick Laboratory, 9800 S. Cass Ave., Argonne,
pable of maintaining water temperature at 35 6 10°C. IL.
FIG. 1 Assorted Connectors, Tubing, Flasks, Stoppers, and Delivery Tubes
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C1430 − 07 (2011)
9.4 Create a boat map to maintain sample identity.
~AW !
0.0593 =
o
.
AW 12 AW
~ !
u o
9.5 Use a pair of tweezers and carefully weigh the pellet.
Rezero the balance and repeat the pellet weighing until a
consistent weight is obtained. Carefully place the pellet in the
10.2 O/M (UO -Gd O Pellets):
2 2 3
quartz sample boat. Repeat for each pellet.
PelletO/M 52.000 2∆ O/M (2)
9.6 Include one or two equilibrated standard control pellets
~W 2 W !
2 1
with each sample batch.
52.000 2
~W ! @0.05931~%Gd O 30.00026!#
2 2 3
9.7 Carefully place the loaded boat into the sample tube.
where:
Position the boat as close to center of the furnace tube as
possible. W = Weight of sample before
equilibration, g,
9.8 Fit the purge gas connection to end of tube and clamp.
W = Weight of sample after
Make certain that the water in the humidifying flask is at 35 6
equilibration, g,
10°C(65°Cisoptimal)andcheckthegascylinderpressureto
%Gd O = Measured Gd, expressed as stoi-
2 3
verify there is sufficient gas to complete the cycle.
chiometric weight % Gd O , and
2 3
9.9 Turnonthegasflowandallowthechambertopurgefor
(% Gd O )(0.00026) = Correction factor for weight gain
2 3
approximately five minutes. due to formation of oxygen-rich
UO-Gd O solid solution during
2 3
NOTE 2—The flow rate of the purge gas and the length of the purge
sintering. For processes that do not
cycle will vary with the size of the furnace tube.Apurge of greater than
producea100%solidsolution,this
or equal to three furnace volumes/minute is the recommended minimum.
The flow rate must be adequate to maintain a positive pressure inside the
factor should be evaluated to deter-
sample chamber.
mine if modification is necessary
9.10 AttachaPyrex®deliverytubewithgroundglassfitting (see Appendix X1).
to the exit end of the furnace, and place the end in a container
10.3 Percent Uranium:
of water to verify and monitor the gas flow.
10.3.1 Percent Uranium, Based on Sample Weight:
9.11 Turn on the furnace and bring the temperature to
800°C.
9.12 After temperature is reached, allow the pellets to
TABLE 1 Stoichiometric Factors to Convert Metals to Oxides
equilibrate for a minimum of 4 h. Monitor the system occa-
A
Oxide Conversion Factors for Impurity Calculation
sionally during the run to ensure constant temperature and gas
Element Oxide Factor
flow.
Al Al O 1.89
2 3
BB O 3.23
2 3
9.13 At the end of the 4-h cycle, turn the furnace down to
Ba Ba O 1.12
50°C and allow the samples to cool. The purge gas flow must
Be Be O 2.78
Ca Ca O 1.40
be maintained until the samples reach 50°C. Then, turn off the
Cd Cd O 1.14
carrier gas and allow the pellets to cool to room temperature.
Co Co O 1.41
2 3
Cr Cr O 1.46
2 3
NOTE 3—If the samples are allowed to cool to room temperature while
Cu Cu O 1.25
thepurgegasisflowing,thewaterinthepurgegaswillbegintocondense
Dy D
...