ASTM C696-99

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Designation:C696–99
Standard Test Methods for
Chemical, Mass Spectrometric, and Spectrochemical
Analysis of Nuclear-Grade Uranium Dioxide Powders and
Pellets
This standard is issued under the fixed designation C696; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope
Sections
1.1 These test methods cover procedures for the chemical,
C 1413 Test Method for Isotopic Analysis of Hydroly-
mass spectrometric, and spectrochemical analysis of nuclear-
sed Uranium Hexafluoride and Uranyl Nitrate So-
lutions By Thermal Ionization Mass Spectrometry
grade uranium dioxide powders and pellets to determine
compliance with specifications.
2. Referenced Documents
1.2 Theanalyticalproceduresappearinthefollowingorder:
2.1 ASTM Standards:
Sections
C753 Specification for Nuclear-Grade, Sinterable Uranium
Uranium by Ferrous Sulfate Reduction in Phosphoric Dioxide Powder
Acid and Dichromate Titration Method
C761 Test Method for Chemical, Mass Spectrometric,
C 1267 Test Method for Uranium By Iron (II) Reduc-
Spectrochemical, Nuclear, and RadiochemicalAnalysis of
tion In Phosphoric Acid Followed By Chromium
(VI) Titration In The Presence of Vanadium
Uranium Hexafluoride
Uranium and Oxygen Uranium Atomic Ratio by the 7-13 3
C776 Specification for Sintered Uranium Dioxide Pellets
Ignition (Gravimetric) Impurity Correction Method
2 C1267 Test Method for Uranium By Iron (II) Reduction In
Carbon (Total) by Direct Combustion-Thermal Con-
ductivity Method
PhosphoricAcid Followed By Chromium (VI)Titration In
C 1408 Test Method for Carbon (Total) in Uranium 3
The Presence of Vanadium
Oxide Powders and Pellets By Direct Combustion-
C1287 Test Method for Determination of Impurities In
Infrared Detection Method
Total Chlorine and Fluorine by Pyrohydrolysis Ion- 14-20
Uranium Dioxide By Inductively Coupled Plasma Mass
Selective Electrode Method 3
Spectrometry
Moisture by the Coulometric, Electrolytic Moisture 21-28
C1347 PracticeforPreparationandDissolutionofUranium
Analyzer Method
Nitrogen by the Kjeldahl Method 29-36
Materials for Analysis
Isotopic Uranium Composition by Multiple-Filament
C1408 Test Method for Carbon (Total) in Uranium Oxide
Surface Ionization Mass Spectrometric Method
Powders and Pellets By Direct Combustion-Infrared De-
Spectrochemical Determination of Trace Elements in 37-44
High-Purity Uranium Dioxide
tection Method
Silver, Spectrochemical Determination of, by Gallium 45 to 46
C1413 Test Method for Isotopic Analysis of Hydrolysed
OxideCarrier D-C Arc Technique
Uranium Hexafluoride and Uranyl Nitrate Solutions By
Rare Earths by Copper Spark-Spectrochemical
Method
Thermal Ionization Mass Spectrometry
Impurity Elements by a Spark-Source Mass Spectro-
D1193 Specification for Reagent Water
graphic Method
C 761 Test Method for Chemical, Mass Spectromet- E 115 Practice for Photographic Processing in Optical
ric, Spectrochemical, Nuclear, and Radiochemical
Emission Spectrographic Analysis
Analysis of Uranium Hexafluoride
3 E116 Practice for Photographic Photometry by Spectro-
C 1287 Test Method for Determination of Impurities
In Uranium Dioxide By Inductively Coupled chemical Analysis
Plasma Mass Spectrometry
E130 Practice for Designation of Shapes and Sizes of
Surface Area by Nitrogen Absorption Method 47-53
2 Graphite Electrodes
Total Gas in Reactor-Grade Uranium Dioxide Pellets
Thorium and Rare Earth Elements by Spectroscopy E217 Test Method for Uranium by Controlled-Potential
Hydrogen by Inert Gas Fusion 54-63
Coulometry
Uranium Isotopic Analysis by Mass Spectrometry
Discontinued January 1999. See C696–80.
1 3
These test methods are under the jurisdiction of ASTM Committee C-26 on Annual Book of ASTM Standards, Vol 12.01.
Nuclear Fuel Cycle. Discontinued as of May 30, 1980.
Current edition approved Jan. 10, 1999. Published March 1999. Originally Annual Book of ASTM Standards, Vol 11.01.
{1 6
published as C696 – 72. Last previous edition C696 – 93 . Annual Book of ASTM Standards, Vol 03.05.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
C696
E305 Practice for Establishing and Controlling Spectro- URANIUM BY FERROUS SULFATE REDUCTION IN
chemical Analytical Curves PHOSPHORIC ACID AND DICHROMATE
E402 TestMethodforSpectrographicAnalysisofUranium TITRATION METHOD
Oxide (U O ) by Gallium Oxide-Carrier Technique This Test method was discontinued in January 1999 and
3 8
replaced by Test method C1267.
3. Significance and Use
URANIUM AND OXYGEN TO URANIUM ATOMIC
3.1 Uranium dioxide is used as a nuclear-reactor fuel. In
RATIO BY THE IGNITION (GRAVIMETRIC)
order to be suitable for this purpose, the material must meet
IMPURITY CORRECTION METHOD
certain criteria for uranium content, stoichiometry, isotopic
composition, and impurity content. These test methods are
7. Scope
designed to show whether or not a given material meets the
specifications for these items as described in Specifications 7.1 This test method covers the determination of uranium
and the oxygen to uranium atomic ratio in nuclear-grade
C753 and C776.
3.1.1 An assay is performed to determine whether the uranium dioxide powder and pellets.
material has the minimum uranium content specified on a dry
8. Summary of Test Method
weight basis.
3.1.2 The stoichiometry of the oxide is useful for predicting
8.1 A weighed portion of UO is dried under reduced
its sintering behavior in the pellet production process.
pressure in a nitrogen atmosphere, desiccated, and weighed.
3.1.3 Determination of the isotopic content of the uranium
ThedriedoxideisthenconvertedtoU O byignitionat900°C
3 8
intheuraniumdioxidepowderismadetoestablishwhetherthe
(8, 9).
effective fissile content is in compliance with the purchaser’s
specifications. 9. Interferences
3.1.4 Impurity content is determined to ensure that the
9.1 The weight of U O is corrected for the nonvolatile
3 8
maximum concentration limit of certain impurity elements is
impurities present as determined by spectrographic analysis.
not exceeded. Determination of impurities is also required for
An extended ignition time may be required if significant
calculation of the equivalent boron content (EBC).
amounts of anions that are difficult to decompose are present.
4. Reagents
10. Apparatus
4.1 Purity of Reagents—Reagent grade chemicals shall be
10.1 Vacuum Oven, capable of maintaining and controlling
used in all tests. Unless otherwise indicated, it is intended that
temperatures to 180°C and equipped with double stopcocks
all reagents shall conform to the specifications of the Commit-
and a vacuum gage (range from 0 to 102 kPa (0 to 30 in. Hg)).
tee onAnalytical Reagents of theAmerican Chemical Society,
10.2 Drying Tower— Prepare a U-tube filled with a carbon
where such specifications are available. Other grades may be 9
dioxide absorbent and a suitable moisture absorbent, that is,
used, provided it is first ascertained that the reagent is of
anhydrous magnesium perchlorate Mg(ClO ) .
4 2
sufficiently high purity to permit its use without lessening the
10.3 MuffleFurnace,capableofmaintainingandcontrolling
accuracy of the determination.
temperatures to 1000°C.
4.2 Purity of Water— Unless otherwise indicated, refer-
ences to water shall be understood to mean reagent water
11. Procedure
conforming to Specification D1193.
11.1 Transfer approximately 5 to 10 g of UO powder or up
to 50 g of pellets to a tared platinum crucible and weigh to
5. Safety Precautions
within 0.1 mg.
5.1 Proper precautions should be taken to prevent inhala-
11.2 Place the crucible in a vacuum oven set at room
tion, or ingestion of uranium dioxide powders or dust during
temperature, seal the oven, and reduce the pressure to approxi-
grinding or handling operations.
mately 95 to 102 kPa (28 to 30 in. Hg).
11.3 Closethevacuumvalveandslowlyflushtheovenwith
6. Sampling
dry nitrogen.
6.1 Criteria for sampling this material are given in Specifi-
11.4 Close the nitrogen inlet and reduce the pressure to 95
cation C753 and Specification C776.
to 102 kPa (28 to 30 in. Hg). Repeat the nitrogen flush as in
6.2 Samples can be dissolved using the appropriate disso-
step 11.3 to give a total of three flushes.
lution techniques described in Practice C1347, but final
11.5 Closethenitrogeninletvalve,reducethepressureto95
determination of applicability must be made by the user.
to 102 kPa (28 to 30 in. Hg), set the temperature at 45°C for
powder samples or 160°C for pellets, and maintain these
conditions for 4 h. After 4 h of heating turn off the heat and
Annual Book of ASTM Standards, Vol 03.06.
allow the oven to cool to room temperature while under
Reagent Chemicals, American Chemical Society Specifications, American
reduced pressure.
Chemical Society, Washington, DC. For suggestions on the testing of reagents not
listed by the American Chemical Society, see Analar Standards for Laboratory
Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
and National Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville,
MD. Ascarite has been found satisfactory for this purpose.
C696
TABLE 1 Conversion Factors for Impurity Correction
11.6 Turn off the vacuum valve and slowly introduce dry
nitrogen until the oven door can be opened. Impurity Assumed Oxide Form Gravimetric Factor
11.7 Transfer the crucible to a desiccator and cool. Remove
Al Al O 1.89
2 3
Ba BaO 1.12
the crucible and weigh immediately (8).
Be BeO 2.78
11.8 Place the crucible containing the dried oxide in a
Bi Bi O 1.11
2 3
muffle furnace set at 900°C. Ignite powder samples for 3 h.
Ca CaO 1.40
Cd CdO 1.14
Pellets should be preheated at 500°C for 3 h, then ignited 3 h
Co Co O 1.41
2 3
at 900°C.
Cr Cr O 1.46
2 3
11.9 Remove the crucible from the furnace, allow to cool in
Cu CuO 1.25
Fe Fe O 1.43
2 3
the air 2 to 3 min then place the crucible in a desiccator and
Li Li O 2.15
cool to room temperature. Weigh the crucible and repeat steps
Mg MgO 1.66
11.8 and 11.9 until a constant weight is obtained.
Mn MnO 1.58
Mo MoO 1.50
11.10 Submit the ignited sample for spectrographic analy- 3
Na Na O 1.35
sis.
Ni NiO 1.27
PP O 2.29
2 5
12. Calculation
Pb PbO 1.15
Sb Sb O 1.26
2 4
12.1 Loss on Vacuum Drying—Calculate as follows based
Si SiO 2.14
on original sample:
Sn SnO 1.27
Ti TiO 1.67
Loss,wt% 5 @~S 2 W !/S# 3100 (1)
VV O 1.79
2 5
Zn ZnO 1.24
where:
Zr ZrO 1.35
Ta Ta O 1.22
S = initial sample mass, and 2 5
WWO 1.26
W = sample mass after vacuum drying, g.
12.2 Uranium Content— Calculate as follows:
U,wt% 5 @~0.8480 ~W 2 W I!/S! 3100# 20.01% ~Note1! (2)
2 2
CARBON (TOTAL) BY DIRECT COMBUSTION-
where:
THERMAL CONDUCTIVITY METHOD
0.8480 = U O to uranium conversion factor for natural
3 8
This Test Method was discontinued in January 1999 and
uranium.Correctionsmustbemadeinthisfactor
replaced by Test Method C1408
as the uranium isotopic abundance deviates from
natural uranium,
TOTAL CHLORINE AND FLUORINE BY
W = grams of U O after ignition,
2 3 8
PYROHYDROLYSIS ION-SELECTIVE ELECTRODE
S = initial sample mass, and
METHOD
I = total grams of all impurity-element oxides per
gram of ignited U O (Note 2).
3 8
14. Scope
NOTE 1—All nonvolatile impurity values reported as less than the
14.1 This test method covers the determination of chlorine
threshold of detection are considered to contribute a total correction of
andfluorineinnuclear-gradeuraniumdioxide.Witha1to10-g
0.01 % to the uranium percent.
sample, concentrations of 5 to 200 µg/g of chlorine and 1 to
NOTE 2—See Table 1 to obtain conversion factors for many common
200 µg/g of fluorine are determined without interference.
impurity elements encountered.
12.3 Oxygen-to-Uranium Ratio—Calculate as follows from
15. Summary of Test Method
the original sample, U wt %:
15.1 The halogens are separated from powdered uranium
O/U 5 @~100 2 U wt % 2 Z 2n!~A!#/@15.999~U! wt%# (3)
dioxidebypyrohydrolysisinaquartztubewithastreamofwet
oxygen at a temperature of 900 to 1000°C (10, 11, 12, 13).
where:
Chloride and fluoride are volatilized as acids, absorbed in a
A = atomic mass of uranium based on isotopic abundance,
buffersolution,andmeasuredwithion-selectiveelectrodes(13,
O = atom % of oxygen,
14, 15).
U = atom % of uranium,
n = moisture content, %, and
16. Apparatus
Z = total impurities correction, %.
16.1 Pyrohydrolysis Equipment—A suitable assembly of
13. Precision and Accuracy
apparatus is shown in Fig. 1.
13.1 ForatomicratiosofO/Uintherangefrom2.00to2.10 16.1.1 Gas Flow Regulator and Flowmeter.
the standard deviation was found to be 0.007 absolute at 95 % 16.1.2 Hot Plate, used to warm the water saturating the
confidence level. sparge gas to 50 to 80°C.
C696
FIG. 1 Pyrohydrolysis Apparatus
NOTE 3—Dehydrate 165 g of Na WO in a large platinum dish.
16.1.3 CombustionTubeFurnace,havingaboreofabout32
2 4
1 Transfer the dried material to a mortar, add 116 g of WO , and grind the
mm (1 ⁄4in.), a length of about 305 mm (12 in.), and the 3
mixture to ensure good mixing. Transfer the mixture into a platinum dish
capability of maintaining a temperature of 1000°C.
and heat with a burner for 2 h. Cool the melt, transfer the flux to a mortar
16.1.4 Quartz Reaction Tube (Fig. 2)—The exit end
andgrindtoacoarsepowder.Storethefluxinanairtightbottle.Mixabout
should not extend over 51 mm (2 in.) beyond the furnace with
8 g of flux with each portion of sample to be pyrohydrolyzed.
a ground joint connecting to the delivery tube. The delivery
17.2 Buffer Solution— Dissolve 0.1 g potassium acetate
tube extends into a polyethylene absorption vessel with a tip
(KC H O ) in water, add 0.050 mL of acetic acid (CH CO H,
2 3 2 3 2
capable of giving a stream of fine bubbles.
sp gr 1.05), and dilute to 1 litre.
16.1.5 Combustion Boat—Aplatinum or quartz boat with a
17.3 Chloride, Standard Solution (1 mL = 100 µg Cl)—
10-ml capacity (89 to 102 mm (3 ⁄2to 4 in.) long, 12.7 mm
Dissolve 165 mg of dry sodium chloride (NaCl) in water and
1 3
( ⁄2in.) wide, and 9.53 mm ( ⁄8 in.) high).
dilute to 1 litre.
16.1.6 Absorption Vessel—A 50-mL polyethylene graduate
17.4 Distilled Water— The water must be free of all
or tube is satisfactory.
chlorides and fluorides.
16.2 Ion-Specific Electrodes—A fluoride-specific activity
17.5 Fluoride, Standard Solution (1mL=50µgF)—
10 11
electrode ; chloride-specific electrode.
Dissolve 111 mg of sodium fluoride (NaF) in water and dilute
16.3 pH Meter and Double-Junction Reference Electrode,
to 1 lit
...