ASTM C1561-03

Standard Guide for Determination of Plutonium and Neptunium in Uranium Hexafluoride by Alpha Spectrometry

SIGNIFICANCE AND USE
The method is applicable to the analysis of materials to demonstrate compliance with the specifications set forth in Specifications C 787 and C 996.
SCOPE
1.1 This method covers the determination of plutonium and neptunium isotopes in uranium hexafluoride by alpha spectroscopy. The method could also be applicable to any matrix that may be converted to a nitric acid system.
1.2 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 and health practices and determine the applicability of regulatory requirements prior to use.

General Information

• Status: Historical
• Publication Date: 09-Feb-2003
• ICS: 71.040.50 - Physicochemical methods of analysis
• Technical Committee: C26 - Nuclear Fuel Cycle
• Drafting Committee: C26.05 - Methods of Test

Relations

• Replaced By: ASTM C1561-10 - Standard Guide for Determination of Plutonium and Neptunium in Uranium Hexafluoride by Alpha Spectrometry
• Effective Date: 01-Oct-2010
• Referred By: ASTM C761-18 - Standard Test Methods for Chemical, Mass Spectrometric, Spectrochemical, Nuclear, and Radiochemical Analysis of Uranium Hexafluoride
• Effective Date: 10-Feb-2003
• Referred By: ASTM C799-19 - Standard Test Methods for Chemical, Mass Spectrometric, Spectrochemical, Nuclear, and Radiochemical Analysis of Nuclear-Grade Uranyl Nitrate Solutions
• Effective Date: 10-Feb-2003

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: C1561 – 03
Standard Guide for
Determination of Plutonium and Neptunium in Uranium
Hexafluoride by Alpha Spectrometry
This standard is issued under the fixed designation C1561; 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 4. Summary of Test Method
1.1 This method covers the determination of plutonium and 4.1 An aliquot of hydrolyzed uranium hexafluoride equiva-
neptunium isotopes in uranium hexafluoride by alpha spectros- lenttoapproximately0.5gofuraniumisconvertedtoanoxalic
copy. The method could also be applicable to any matrix that acid-nitric acid system and the uranium is selectively removed
may be converted to a nitric acid system. via solid phase extraction. Plutonium and neptunium are
1.2 This standard does not purport to address all of the further purified by additional solid phase extractions. The
safety concerns, if any, associated with its use. It is the plutonium and neptunium are then co-precipitated with neody-
responsibility of the user of this standard to establish appro- mium as the fluorides and counted by alpha spectrometry.
priate safety and health practices and determine the applica- 4.2 Tracer recoveries using this method are typically be-
bility of regulatory requirements prior to use. tween75and90 %.Theresolutionofthetraceristypicallyless
than 40 keV full-width at half-maximum.
2. Referenced Documents
4.3 The minimum detectable activity will vary with tracer
2.1 ASTM Standards:
recovery, sample size, instrument background, and counting
C787 Specification for Uranium Hexafluoride for Enrich- efficiency.
ment
5. Significance and Use
C996 Specification for Uranium Hexafluoride Enriched to
Less Than 5 % U 5.1 The method is applicable to the analysis of materials to
C1163 Practice for Mounting Actinides for Alpha Spec- demonstrate compliance with the specifications set forth in
trometry Using Neodymium Fluoride Specifications C787 and C996.
C1475 Guide for Determination of Neptunium-237 in Soil
6. Interferences
D1193 Specification for Reagent Water
D3084 Practice for Alpha-Particle Spectrometry of Water 6.1 Incomplete removal of U-234 from the neptunium
fraction could result in a false positive for the Np-237 analysis.
D3648 Practices for the Measurement of Radioactivity
The method has been shown to adequately remove uranium at
3. Terminology
enrichments up to 5 %. If the method is used for the analysis of
3.1 reagent blank—DI water processed the same as the materials at greater than 5 % enrichment, a blank consisting of
samples; used in the determination of the minimum detectable uranium at the same enrichment as the samples should be
activity. analyzed to show adequate removal of the U-234.
3.2 region-of-interest (ROI)—the channels, or region, in the 6.2 APu tracer is used to monitor the chemical recovery of
alpha spectra in which the counts due to a specific radioisotope the Np. Spiked analyses should be performed to confirm the
appear on a functioning calibrated alpha spectrometry system. appropriateness of this correction; fractionation of Np and Pu
during the separation could lead to incorrect test results.
7. Instrumentation
This guide is under the jurisdiction ofASTM Committee C26 on Nuclear Fuel
7.1 Alpha Spectrometry System—See Practices D3084 and
Cycle and is the direct responsibility of Subcommittee C26.05 on Methods of Test.
D3648 for a description of the apparatus.
Current edition approved Feb. 10, 2003. Published March 2003. DOI: 10.1520/
C1561-03.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
8. Apparatus
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
8.1 Ion Exchange Columns, able to hold a 10 mL resin bed
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. and 15 mL solution washes.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
C1561 – 03
8.2 Filter Paper, 0.1 µm pore size, 25-mm diameter, com- 9.20 Pu-236 or Pu-242 Tracer, traceable to a national or
patible with HF. international standard.
9.21 Sodium Nitrite (100 mg/mL)—Dissolve 500 mg
9. Reagents and Materials
NaNO in 5 mL water. Prepare fresh when using.
9.22 Extraction Chromatography Resin, containing
9.1 Purity of Reagents—Reagent grade chemicals shall be
octylphenyl-N,N-di-isobutyl carbamoylphosphine oxide
used in all tests. Unless otherwise indicated, it is intended that
(CMPO) dissolved in tri-n-butyl phosphate (TBP) as the
all reagents shall conform to the specifications of the Commit-
,
5 6
immobilized extractant.
tee onAnalytical Reagents of theAmerican Chemical Society,
9.23 Extraction Chromatography Resin, containing diamyl
where such specifications are available.
,
7 8
amylphosphonate (DAAP) as the immobilized extractant.
9.2 Purity of Water—Unless otherwise indicated, references
to water shall be understood to mean reagent water as defined
10. Calibration and Standardization
in Specification D1193.
10.1 The alpha spectrometry units should be calibrated for
9.3 Ammonium Oxalate (0.1M)—Dissolve 12.4 g ammo-
energy, resolution and efficiency according to the manufactur-
nium oxalate in approximately 500 mL of water and dilute to
ers instructions. The background counting rate for the instru-
1L.
ment should be measured at a frequency determined by the
9.4 Ascorbic Acid Solution (Saturated)—Add ascorbic acid
user. See Practices D3084 and D3648 for additional informa-
to 2M nitric acid while stirring until no more ascorbic acid will
tion.
dissolve. Prepare fresh when needed for use.
9.5 Ethanol, ethyl alcohol, absolute (200 proof), denatured.
11. Procedure
9.6 Hydrochloric Acid (HCl), specific gravity 1.19, concen-
11.1 Uranium Removal:
trated.
11.1.1 Pipette an aliquot of hydrolyzed UF sample equiva-
9.7 HydrochloricAcid, 9M—Add750mLconcentratedHCl
lent to 0.5 g uranium into a beaker. Add the Pu tracer to the
to 100 mL of water, dilute to a final volume of 1 L.
sample and evaporate to dryness. Add 10 mL concentrated
9.8 Hydrochloric Acid, 4M—Add 333 mL of concentrated
nitric acid and evaporate to dryness. Option: Neptunium-239
HCl to 500 mL of water; dilute to a final volume of 1 L.
can be added as an independent tracer for the Np-237; see
9.9 Hydrochloric Acid, 1.5M—Add 125 mLof concentrated
Guide C1475 for its use.
HCl to 500 mL of water; dilute to a final volume of 1 L.
11.1.2 Prepare 2 DAAP extraction columns per sample by
9.10 Hydrochloric Acid, 1M—Add 83 mL of concentrated
addingresinslurriedinwatertothecolumn.Allowthewaterto
HCl to 500 mL of water; dilute to a final volume of 1 L.
drain to obtain a 10 mLbed volume. Condition the columns by
9.11 Hydrofluoric Acid (HF), concentrated HF, minimum
adding 15 mL of the oxalic acid in 2M nitric acid solution.
assay 48 %.
Allow the solution to pass through the columns.
9.12 Iron (III) Nitrate (10 mg Fe/mL)—Dissolve 18.0 g of
11.1.3 Dissolve the sample residue in the beaker above by
Fe(NO ) ·9H O in 250 mL of water.
3 3 2
adding15mLoftheoxalicacidin2Mnitricacidsolution.Heat
9.13 Neodymium Chloride (10 mg Nd/mL)—Add 25 mL
gently to complete the dissolution. Add the sample to the first
concentrated HCl to 1.17 g neodymium oxide and heat at
of the extraction columns and collect the load solution in a
100°C until dissolved.Allow solution to cool and dilute to 100
clean beaker.Add an additional 15 mLof the oxalic acid in 2M
mL with water.
nitric acid solution to the column and collect the rinsate in the
9.14 Neodymium Chloride (100 µg Nd/mL)—Dilute1mLof
same beaker.
the 10 mg Nd/mL solution to 100 mL with water.
9.15 Nitric Acid (HNO ), concentrated nitric acid, specific
3 NOTE 1—The column retains the U; Pu and Np will pass through in the
gravity 1.42. load a
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