ASTM C1871-18
(Test Method)Standard Test Method for Determination of Uranium Isotopic Composition by the Double Spike Method Using a Thermal Ionization Mass Spectrometer
Standard Test Method for Determination of Uranium Isotopic Composition by the Double Spike Method Using a Thermal Ionization Mass Spectrometer
SIGNIFICANCE AND USE
5.1 Uranium material is used as a fuel in certain types of nuclear reactors. To be suitable for use as nuclear fuel, the starting material shall meet certain specifications such as those described in Specifications C753, C776, C787, C833, C967, C996, and C1008, or as specified by the purchaser. The 235U/238U isotope amount ratios and the amount content of uranium material can be measured by mass spectrometry following this test method to ensure that they meet the specification.
5.2 The double spike method has been used for studies of uranium fractionation effects in isotope geochemistry and cosmochemistry, for uranium source attribution in nuclear forensics and for investigation of conversion or sampling processes in nuclear industry and nuclear safeguards (7-11). Most recently, the double spike method has been used for the validation of the Cristallini sampling method of UF6 (12 and 13). The double spike method can be used for a wide range of sample sizes even in samples containing as low as 50 μg of uranium. The concentration of the loading solution for the DS method has to be in the range of 1 to 6 mg/g to allow a sample loading of 4 to 6 μg of uranium. A minimum loading of 4 μg uranium per filament is recommended.
5.3 The measurement of 236U/238U ratios using this method is not possible due to the large isobaric interference from the 236U ion beam of the double spike onto the 236U ion beam from the sample (>50.000 times for close to natural material, for example, like IRMM-184).
5.4 The application of the double spike method for measurements of 235U/238U ratio is limited by the isobaric interference between the 236U from the double spike material and the 236U contained in the sample. As a consequence, the method is not suitable for samples which contain significant amounts of 236U due to prior neutron capture from 235U in the predecessor materials. For samples with 236U/238U ratios higher than about 10–6, the double spike method should be applied with...
SCOPE
1.1 This test method describes the determination of the isotope amount ratios of uranium material as nitrate solutions by the double spike (DS) method using a thermal ionization mass spectrometer (TIMS) instrument.
1.2 The analytical performance in the determination of the 235U/238U major isotope amount ratio by the DS method is five to ten times better in terms of the internal and external reproducibility compared to the (“classical”) total evaporation (TE) method as described in Test Method C1672 and the “modified total evaporation” (MTE) as described in Test Method C1832. This is due to the use of an internal rather than external mass fractionation correction by using a double spike material with a known or certified 233U/236U isotope ratio, which is mixed with the sample prior to the measurement, either during the sample preparation or directly on the TIMS filament.
1.3 The DS method cannot be applied for the determination of the 236U/238U minor isotope amount ratio, and is also not recommended for the determination of the 234U/238U minor isotope amount ratio.
1.4 In case the uranium amount concentration of the double spike is known or certified, the uranium amount concentration of the sample can be determined using the isotope dilution mass spectrometry (IDMS) method as described in Test Method C1672, by blending the sample gravimetrically with the double spike and performing a DS measurement.
1.5 An external mass fractionation correction by measurements of a certified reference material loaded on different filaments and measured in the same measurement sequence, as recommended for TE and required for MTE measurements, is not necessary for the DS method. However, for quality control (QC) purposes it is recommended to perform DS measurements of low enriched or natural uranium isotopic reference materials on a regular basis.
1.6 The DS method can only be applied to uranium samples with relative isotope ...
General Information
Relations
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: C1871 − 18
Standard Test Method for
Determination of Uranium Isotopic Composition by the
Double Spike Method Using a Thermal Ionization Mass
1
Spectrometer
This standard is issued under the fixed designation C1871; 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 ments of low enriched or natural uranium isotopic reference
materials on a regular basis.
1.1 This test method describes the determination of the
1.6 TheDSmethodcanonlybeappliedtouraniumsamples
isotope amount ratios of uranium material as nitrate solutions
233 236
with relative isotope abundances U/U and U/U below
by the double spike (DS) method using a thermal ionization
–5
mass spectrometer (TIMS) instrument. 10 , the DS method is therefore mainly used for low enriched
or close to natural uranium samples.
1.2 The analytical performance in the determination of the
235 238
1.7 Units—The values stated in SI units are to be regarded
U/ UmajorisotopeamountratiobytheDSmethodisfive
as the standard. When no SI units are provided, the values are
to ten times better in terms of the internal and external
for information only.
reproducibility compared to the (“classical”) total evaporation
(TE) method as described in Test Method C1672 and the
1.8 This standard does not purport to address all of the
“modified total evaporation” (MTE) as described in Test
safety concerns, if any, associated with its use. It is the
MethodC1832.Thisisduetotheuseofan internalratherthan
responsibility of the user of this standard to establish appro-
external mass fractionation correction by using a double spike
priate safety, health, and environmental practices and deter-
233 236
material with a known or certified U/ U isotope ratio,
mine the applicability of regulatory limitations prior to use.
which is mixed with the sample prior to the measurement,
1.9 This international standard was developed in accor-
either during the sample preparation or directly on the TIMS
dance with internationally recognized principles on standard-
filament.
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
1.3 The DS method cannot be applied for the determination
236 238
mendations issued by the World Trade Organization Technical
of the U/ U minor isotope amount ratio, and is also not
234 238
Barriers to Trade (TBT) Committee.
recommended for the determination of the U/ U minor
isotope amount ratio.
2. Referenced Documents
1.4 In case the uranium amount concentration of the double
2
2.1 ASTM Standards:
spike is known or certified, the uranium amount concentration
C753Specification for Nuclear-Grade, Sinterable Uranium
of the sample can be determined using the isotope dilution
Dioxide Powder
mass spectrometry (IDMS) method as described in Test
C776SpecificationforSinteredUraniumDioxidePelletsfor
Method C1672, by blending the sample gravimetrically with
Light Water Reactors
the double spike and performing a DS measurement.
C787Specification for Uranium Hexafluoride for Enrich-
1.5 An external mass fractionation correction by measure-
ment
ments of a certified reference material loaded on different
C833Specification for Sintered (Uranium-Plutonium) Diox-
filaments and measured in the same measurement sequence, as
ide Pellets for Light Water Reactors
recommended for TE and required for MTE measurements, is
C859Terminology Relating to Nuclear Materials
not necessary for the DS method. However, for quality control
C967Specification for Uranium Ore Concentrate
(QC) purposes it is recommended to perform DS measure-
C996Specification for Uranium Hexafluoride Enriched to
235
Less Than 5% U
1
ThistestmethodisunderthejurisdictionofASTMCommitteeC26onNuclear
2
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 Feb. 1, 2018. Published February 2018. DOI: 10.1520/ Standards volume information, refer to the standard’s Document Summary page on
C1871-18. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
---------------------- Page: 1 ----------------------
C1871 − 18
C1008 Specification for Sintered (Uranium-Plutonium) 3.3 Acronyms:
3
DioxidePellets—Fast Reactor Fuel (Withdrawn 2014) 3.3.1 CRM—certified reference material
C1068Guide for Qualification of Measurement Methods by
3.3.2 DS—double spike
a Laboratory Within the Nuclear Industry
3.3.3 DU—deplete
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.