ASTM C1204-14(2023)
(Test Method)Standard Test Method for Uranium in Presence of Plutonium by Iron(II) Reduction in Phosphoric Acid Followed by Chromium(VI) Titration
Standard Test Method for Uranium in Presence of Plutonium by Iron(II) Reduction in Phosphoric Acid Followed by Chromium(VI) Titration
SIGNIFICANCE AND USE
4.1 Factors governing selection of a method for the determination of uranium include available quantity of sample, sample purity, desired level of reliability, and equipment availability.
4.2 This test method is suitable for samples between 20 mg to 300 mg of uranium, is applicable to fast breeder reactor (FBR)-mixed oxides having a uranium to plutonium ratio of 2.5 and greater, is tolerant towards most metallic impurity elements usually specified for FBR-mixed oxide fuel, and uses no special equipment.
4.3 The ruggedness of the titration method has been studied for both the volumetric (6) and the weight (7) titration of uranium with dichromate.
SCOPE
1.1 This test method covers unirradiated uranium-plutonium mixed oxide having a uranium to plutonium ratio of 2.5 and greater. The presence of larger amounts of plutonium (Pu) that give lower uranium to plutonium ratios may give low analysis results for uranium (U) (1)2, if the amount of plutonium together with the uranium is sufficient to slow the reduction step and prevent complete reduction of the uranium in the allotted time. Use of this test method for lower uranium to plutonium ratios may be possible, especially when 20 mg to 50 mg quantities of uranium are being titrated rather than the 100 mg to 300 mg in the study cited in Ref (1). Confirmation of that information should be obtained before this test method is used for ratios of uranium to plutonium less than 2.5.
1.2 The amount of uranium determined in the data presented in Section 12 was 20 mg to 50 mg. However, this test method, as stated, contains iron in excess of that needed to reduce the combined quantities of uranium and plutonium in a solution containing 300 mg of uranium with uranium to plutonium ratios greater than or equal to 2.5. Solutions containing up to 300 mg uranium with uranium to plutonium ratios greater than or equal to 2.5 have been analyzed (1) using the reagent volumes and conditions as described in Section 10.
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. For specific hazard statements, see Section 8.
1.5 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.
General Information
Relations
Standards Content (Sample)
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: C1204 − 14 (Reapproved 2023)
Standard Test Method for
Uranium in Presence of Plutonium by Iron(II) Reduction in
Phosphoric Acid Followed by Chromium(VI) Titration
This standard is issued under the fixed designation C1204; 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.
1. Scope ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
1.1 Thistestmethodcoversunirradiateduranium-plutonium
mendations issued by the World Trade Organization Technical
mixed oxide having a uranium to plutonium ratio of 2.5 and
Barriers to Trade (TBT) Committee.
greater. The presence of larger amounts of plutonium (Pu) that
give lower uranium to plutonium ratios may give low analysis
2. Referenced Documents
results for uranium (U) (1) , if the amount of plutonium
2.1 ASTM Standards:
together with the uranium is sufficient to slow the reduction
C852Guide for Design Criteria for Plutonium Gloveboxes
step and prevent complete reduction of the uranium in the
C1128Guide for Preparation of Working Reference Materi-
allotted time. Use of this test method for lower uranium to
als for Use in Analysis of Nuclear Fuel Cycle Materials
plutoniumratiosmaybepossible,especiallywhen20mgto50
C1168PracticeforPreparationandDissolutionofPlutonium
mg quantities of uranium are being titrated rather than the
Materials for Analysis
100mg to 300 mg in the study cited in Ref (1). Confirmation
of that information should be obtained before this test method
3. Summary of Test Method
is used for ratios of uranium to plutonium less than 2.5.
3.1 Samples are prepared by dissolution techniques detailed
1.2 Theamountofuraniumdeterminedinthedatapresented
in Practice C1168 and Ref (2). Aliquants containing 20mg to
in Section 12 was 20mg to 50 mg. However, this test method,
300 mg of uranium, as selected by the facility procedure, are
as stated, contains iron in excess of that needed to reduce the
prepared by weight. The sample is fumed to incipient dryness
combined quantities of uranium and plutonium in a solution
after the addition of sulfuric acid. The sample is dissolved in
containing 300 mg of uranium with uranium to plutonium
dilute sulfuric acid prior to titration.
ratios greater than or equal to 2.5. Solutions containing up to
3.2 Uranium is reduced to uranium(IV) by excess ferrous
300 mg uranium with uranium to plutonium ratios greater than
(iron(II)) in concentrated phosphoric acid (H PO ) containing
or equal to 2.5 have been analyzed (1) using the reagent 3 4
sulfamic acid. The excess iron(II) is selectively oxidized by
volumes and conditions as described in Section 10.
nitric acid (HNO ) in the presence of molybdenum(VI) cata-
1.3 The values stated in SI units are to be regarded as
lyst. After the addition of vanadium(IV), the uranium(IV) is
standard. No other units of measurement are included in this
titratedwithchromium(VI)toapotentiometricendpoint (3, 4).
standard.
3.3 A single chromium(VI) titrant delivered manually on a
1.4 This standard does not purport to address all of the
weight or volume basis is used. The concentration of the
safety concerns, if any, associated with its use. It is the
chromium(VI) solution is dependent upon the amount of
responsibility of the user of this standard to establish appro-
uranium being titrated (see 7.8).Automated titrators that have
priate safety, health, and environmental practices and deter-
comparable precisions can be used.
mine the applicability of regulatory limitations prior to use.
NOTE 1—An alternative ceric (V) sulfate or nitrate titrant may also be
For specific hazard statements, see Section 8.
used, providing that the user demonstrates equivalent performance to the
1.5 This international standard was developed in accor-
dichromate titrant.
dance with internationally recognized principles on standard-
3.4 For the titration of uranium alone, the precision of the
modified Davies and Gray titration method has been signifi-
ThistestmethodisunderthejurisdictionofASTMCommitteeC26onNuclear
cantly improved by increasing the amount of uranium titrated
Fuel Cycle and is the direct responsibility of Subcommittee C26.05 on Methods of
Test.
Current edition approved Jan. 1, 2023. Published January 2023. Originally
approved in 1991. Last previous edition approved in 2014 as C1204–14. DOI: For referenced ASTM standards, visit the ASTM website, www.astm.org, or
10.1520/C1204-14R23. contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Theboldfacenumbersinparenthesesrefertothelistofreferencesattheendof Standards volume information, refer to the standard’s Document Summary page on
this test method. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C1204 − 14 (2023)
to 1 g and delivering about 90% of the titrant on a solid mass 6.2 pH Meter,withindicator(platinumhasbeenfoundtobe
basis followed by titration to the end point with a dilute titrant satisfactory) and reference (saturated calomel has been found
(5). This modification has not been studied for the titration of to be satisfactory) electrodes.
uranium in the presence of plutonium, and confirmation of its
NOTE 2—The indicator electrode should be changed or cleaned if there
applicability should be obtained by the facility prior to its use.
is a titration problem such as less distinct than normal end point break or
end point drift, or, if desired, prior to use when more than a week has
3.5 The modification of the Davies and Gray titration
passed since its last use. Suggested cleaning procedures for platinum
method,asdescribedoriginallyinRef (4),maybeusedinstead
electrodes are detailed in Appendix X2.
of the method described herein, where laboratories have
NOTE3—Thereferenceelectrodeshouldbecoveredwitharubbertipor
demonstrated no plutonium interference at the uranium to
submerged in a solution (saturated potassium chloride solution for the
calomel electrode) for overnight storage.
plutonium ratios and amounts titrated at that facility. If any
modificationismadetotheprocedureinRef (4)forapplication
7. Reagents
at the facility to uranium, plutonium mixed oxides, confirma-
tion that the modification does not degrade the analysis
7.1 Purity of Reagents—Reagent grade chemicals shall be
technique as stated should be demonstrated prior to its use. used in all tests. Unless otherwise indicated, it is intended that
all reagents conform to the specifications of the Committee on
4. Significance and Use
Analytical Reagents of theAmerican Chemical Society where
4.1 Factors governing selection of a method for the deter-
such specifications are available. Other grades of reagents
mination of uranium include available quantity of sample,
may be used, provided it is first ascertained that the reagent is
sample purity, desired level of reliability, and equipment
of sufficiently high purity to permit its use without lessening
availability.
the accuracy of the determination.
4.2 This test method is suitable for samples between 20mg
7.2 Purity of Water—Unless otherwise indicated, references
to 300 mg of uranium, is applicable to fast breeder reactor
to water shall be understood to mean laboratory accepted
(FBR)-mixed oxides having a uranium to plutonium ratio of
demineralized or deionized water.
2.5 and greater, is tolerant towards most metallic impurity
7.3 Ferrous Sulfate (1.0 M)—Add 100 mL of sulfuric acid
elements usually specified for FBR-mixed oxide fuel, and uses
(H SO , sp gr 1.84) to 750 mL of water as the solution is
2 4
no special equipment.
stirred. Add 280 g of ferrous sulfate heptahydrate
4.3 The ruggedness of the titration method has been studied
(FeSO ·7H O), and dilute the solution to 1 L with water.
4 2
for both the volumetric (6) and the weight (7) titration of
Prepare ferrous sulfate reagent fresh on a weekly basis. See
uranium with dichromate.
Note 6 on combination of this reagent.
7.4 Nitric Acid (HNO ),8M—Add 500 mLof HNO (sp gr
5. Interferences
3 3
1.42) to less than 500 mL of water and dilute to 1 L.
5.1 Interfering elements are not generally present in signifi-
7.5 Nitric Acid (8 M)-Sulfamic Acid (0.15 M)-Ammonium
cant quantities in mixed uranium, plutonium oxide product
Molybdate (0.4%)—Dissolve4gof ammonium molybdate
material. However, elements that cause bias when present in
[(NH ) Mo O ·4H O]in400mLofwater,andadd500mLof
milligram quantities are silver (Ag), vanadium (V), plutonium
4 6 7 24 2
nitric acid (HNO , sp gr 1.42). Mix and add 100 mL of 1.5 M
(Pt),ruthenium(Ru),osmium(Os),andiodine(I).Interference
sulfamic acid solution (see 7.9) and mix.
fromtin(Sn),arsenic(As),antimony(Sb),molybdenum(Mo),
manganese (Mn), fluorine (F), chlorine (Cl), and bromine (Br)
7.6 Orthophosphoric Acid (H PO ), 85 %—Test and treat
3 4
are eliminated when the preparation procedure is followed as
for reducing substances prior to use (see Annex A2).
given (4, 8, 9, 10, 11, 12) in this titrimetric method. Of the
7.7 Potassium Dichromate Solution (2 %)—Dissolve 2 g of
metallic impurity elements usually included in specifications
K Cr O in water, and dilute to 100 g with water.
2 2 7
for FBR-mixed oxide fuel, silver, manganese, lead (Pb), and
vanadium interfere. 7.8 Potassium Dichromate Titrant (0.0045 M and 0.045
M)—Dissolve 2.65 g of reagent grade or purer grade K Cr O
2 2 7
5.2 Other interfering metallic elements are gold (Au), mer-
inwater;transferthissolutiontoapre-weighed,2Lvolumetric
cury (Hg), iridium (Ir), and palladium (Pd). Elimination of
flaskanddilutetovolume;thissolutionisforuseintitrationof
their interference requires their separation from uranium by
20 to less than 100 mg uranium aliquants. Dissolve 26.5 g of
such techniques as ion exchange and solvent extraction (13,
reagent grade or purer grade K Cr O in water; transfer this
2 2 7
14).
solution to a pre-weighed, 2L flask and dilute to volume; this
5.3 An initial fuming with sulfuric acid removes such
solution is for use in titration of 100mg to 300 mg uranium
impurityelementsasthehalidesandvolatilemetallicelements.
aliquants.
5.4 The effects of impurities and their removal are listed in
TableA1.1 of AnnexA1, and the details are given in Refs (4,
8, 9, 10, 11, 12, 13, 14, 15). ACS Reagent Chemicals, Specifications and Procedures for Reagents and
Standard-Grade Reference Materials, American Chemical Society, Washington,
6. Apparatus DC. For suggestions on the testing of reagents not listed by theAmerican Chemical
Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset,
6.1 Buret—Polyethylenebottle(preparationinstructionscan
U.K., and the United States Pharmacopeia and National Formulary, U.S. Pharma-
be found in Appendix X1), glass weight, or volumetric. copeial Convention, Inc. (USPC), Rockville, MD.
C1204 − 14 (2023)
7.8.1 If potassium dichromate traceable to a national stan- sulfate dihydrate (VOSO ·2H O) crystals, mix the solid with
4 2
dards laboratory (for example the National Institute of Stan- the temperature equilibrated sulfuric acid, and dilute the
dards Technology (NIST) in the U.S. or the Federal Institute solution to 2 L. The vanadyl sulfate concentration should
for Materials Research and Testing (BAM) in Germany) was provide 75mg to 125 mg VOSO ·2H O per titration, but the
4 2
used, proceed as in 7.8.1.1 and 7.8.1.2 before going to 7.8.3; concentration is not critical (see Refs (6) and (7)).
otherwise go to 7.8.2. 7.13.1 The vanadyl sulfate solution is not stable (16);
7.8.1.1 Allow the solution to equilibrate to room H SO stabilizes the vanadium(IV) oxidation state, but the
2 4
temperature, weigh the solution, and compute the uranium H SO concentrationisnotcritical.TheVOSO ·2H Osolution
2 4 4 2
equivalenttitrationfactoraftercorrectingtheweightofdichro- should be prepared at suitable intervals to prevent vanadi-
mate for buoyancy (see 11.1.1) and for oxidizing power (see um(V) interference (24-h intervals for preparation are sug-
11.1.2). gested).
7.8.1.2 Verifythepreparationaccuracyofthedichromateor 7.13.2 Alternatively, crystalline vanadyl sulfate dihydrate
ceric titrant solution by titration with a standard uranium (75mg to 125 mg per titration) may be used with a water
solution (see 7.12) within laboratory accepted error limits. diluent in place of the solution (see 10.13).
7.8.2 Ifareagentgradedichromateorcerictitrantwasused,
8. Hazards
allow the solution to equilibrate to room temperature and
8.1 Since plutonium- and uranium-bearing materials are
standardizethedichromatesolutionagainstCRMuranium(see
radioactive and toxic, adequate laboratory facilities, gloved
7.12).
boxes, fume hoods, etc., along with safe techniques, must be
7.8.3 Store the dichromate solution in one or more borosili-
usedinhandlingsamplescontainingthesematerials.Adetailed
cate glass bottles with poly-seal tops, or equivalent containers,
discussion of all precautions necessary is beyond the scope of
to prevent concentration changes due to evaporation.
this test method. However, personnel who handle radioactive
7.9 Sulfamic Acid (1.5 M)—Dissolve 146 g of sulfamic acid
materials should be familiar with such safe handling practices
(NH SO H) in water, filter the solution, and dilute to 1 L.
2 3
as are given in Guide C852 and Refs (17) and (18).
7.10 Sulfuric Acid (1 M)—Add56mLofH SO (spgr1.84)
2 4
8.2 Committee C-26 Safeguards Statement:
to water, while stirring, and dilute to 1 L with water.
8.2.1 The materials (nuclear grade mixed oxides (U, Pu)O
7.11 Sulfuric Acid (0.05 M)—Add 2.8 mL of H SO (sp gr powders and pellets) to which this test method applies are
2 4
1.84) to water, while stirring, and dilute to 1 L with water. subject to nuclear safeguard regulations governing their pos-
session and use. The analytical method in this test method
7.12 Uranium Reference Solution—Guide C1128, Section
meets U.S. Department of Energy guidelines for acceptability
X3.4 may be used to prepare working reference solutions, or
of a measurement method for generation of safeguards ac-
solutions may be prepared with appropriate in-house proce-
countability measurement data.
dures from certified uranium metal.
8.2.2 When used in conjunction with the appropriate stan-
7.12.1 Clean the surface of the uranium metal, New Bruns-
dard or certified reference materials (SRMs or CRMs), this
...
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