ASTM C1474-00(2006)e1
(Test Method)Standard Test Method for Analysis of Isotopic Composition of Uranium in Nuclear-Grade Fuel Material by Quadrupole Inductively Coupled Plasma-Mass Spectrometry
Standard Test Method for Analysis of Isotopic Composition of Uranium in Nuclear-Grade Fuel Material by Quadrupole Inductively Coupled Plasma-Mass Spectrometry
SIGNIFICANCE AND USE
Nuclear-grade reactor fuel material must meet certain criteria, such as those described in Specifications C 753, C 776, C 778, and C 833. Included in these criteria is the uranium isotopic composition. This test method is designed to demonstrate whether or not a given material meets an isotopic requirement and whether the effective fissile content is in compliance with the purchaser’specifications.
SCOPE
1.1 This test method is applicable to the determination of the isotopic composition of uranium (U) in nuclear-grade fuel material. The following isotopic weight percentages are determined using a quadrupole inductively coupled plasma-mass spectrometer (Q-ICP-MS): 233U, 234U, 235U, 236U, and 238U. The analysis can be performed on various material matrices after acid dissolution and sample dilution into water or dilute nitric (HNO3) acid. These materials include: fuel product, uranium oxide, uranium oxide alloys, uranyl nitrate (UNH) crystals, and solutions. The sample preparation discussed in this test method focuses on fuel product material but may be used for uranium oxide or a uranium oxide alloy. Other preparation techniques may be used and some references are given. Purification of the uranium by anion-exchange extraction is not required for this test method, as it is required by other test methods such as radiochemistry and thermal ionization mass spectroscopy (TIMS). This test method is also described in ASTM STP 1344.
1.2 The 233U isotope is primarily measured as a qualitative measure of its presence by comparing the 233U peak intensity to a background point since it is not normally found present in materials. The example data presented in this test method do not contain any 233U data. A 233U enriched standard is given in Section , and it may be used as a quantitative spike addition to the other standard materials listed.
1.3 A single standard calibration technique is used. Optimal accuracy (or a low bias) is achieved through the use of a single standard that is closely matched to the enrichment of the samples. The intensity or concentration is also adjusted to within a certain tolerance range to provide good statistical counting precision for the low-abundance isotopes while maintaining a low bias for the high-abundance isotopes, resulting from high-intensity dead time effects. No blank subtraction or background correction is utilized. Depending upon the standards chosen, enrichments between depleted and 97 % can be quantified. The calibration and measurements are made by measuring the intensity ratios of each low-abundance isotope to the intensity sum of 233U, 234U, 235U, 236U, and 238U. The high-abundance isotope is obtained by difference.
1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. The instrument is calibrated and the samples measured in units of isotopic weight percent (Wt %). For example, the 235U enrichment may be stated as Wt % 235U or as g 235U/100 g of U. Statements regarding dilutions, particularly for ug/g concentrations or lower, are given assuming a solution density of 1.0 since the uranium concentration of a solution is not important when making isotopic ratio measurements other than to maintain a reasonably consistent intensity within a tolerance range.
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 limitations prior to use. Specific precautionary statements are given in Section 9.
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
´1
Designation: C1474 – 00 (Reapproved 2006)
Standard Test Method for
Analysis of Isotopic Composition of Uranium in Nuclear-
Grade Fuel Material by Quadrupole Inductively Coupled
Plasma-Mass Spectrometry
This standard is issued under the fixed designation C1474; 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.
´ NOTE—Editorial changes were made in July 2006.
1. Scope within a certain tolerance range to provide good statistical
countingprecisionforthelow-abundanceisotopeswhilemain-
1.1 This test method is applicable to the determination of
taining a low bias for the high-abundance isotopes, resulting
the isotopic composition of uranium (U) in nuclear-grade fuel
from high-intensity dead time effects. No blank subtraction or
material. The following isotopic weight percentages are deter-
background correction is utilized. Depending upon the stan-
mined using a quadrupole inductively coupled plasma-mass
233 234 235 236 238
dards chosen, enrichments between depleted and 97% can be
spectrometer (Q-ICP-MS): U, U, U, U, and U.
quantified. The calibration and measurements are made by
The analysis can be performed on various material matrices
measuring the intensity ratios of each low-abundance isotope
after acid dissolution and sample dilution into water or dilute
233 234 235 236 238
to the intensity sum of U, U, U, U, and U. The
nitric (HNO ) acid. These materials include: fuel product,
high-abundance isotope is obtained by difference.
uranium oxide, uranium oxide alloys, uranyl nitrate (UNH)
1.4 The values stated in SI units are to be regarded as the
crystals, and solutions. The sample preparation discussed in
standard. The values given in parentheses are for information
this test method focuses on fuel product material but may be
only.Theinstrumentiscalibratedandthesamplesmeasuredin
used for uranium oxide or a uranium oxide alloy. Other
unitsofisotopicweightpercent(Wt%).Forexample,the U
preparation techniques may be used and some references are
235 235
enrichment may be stated as Wt% Uorasg U/100 g of
given. Purification of the uranium by anion-exchange extrac-
U. Statements regarding dilutions, particularly for ug/g con-
tion is not required for this test method, as it is required by
centrations or lower, are given assuming a solution density of
other test methods such as radiochemistry and thermal ioniza-
1.0 since the uranium concentration of a solution is not
tion mass spectroscopy (TIMS). This test method is also
2 importantwhenmakingisotopicratiomeasurementsotherthan
described in ASTM STP 1344 .
tomaintainareasonablyconsistentintensitywithinatolerance
1.2 The U isotope is primarily measured as a qualitative
range.
measure of its presence by comparing the U peak intensity
1.5 This standard does not purport to address all of the
to a background point since it is not normally found present in
safety concerns, if any, associated with its use. It is the
materials. The example data presented in this test method do
233 233
responsibility of the user of this standard to establish appro-
notcontainany Udata.A Uenrichedstandardisgivenin
priate safety and health practices and determine the applica-
Section 8, and it may be used as a quantitative spike addition
bility of regulatory limitations prior to use. Specific precau-
to the other standard materials listed.
tionary statements are given in Section 9.
1.3 Asingle standard calibration technique is used. Optimal
accuracy(oralowbias)isachievedthroughtheuseofasingle
2. Referenced Documents
standard that is closely matched to the enrichment of the
2.1 ASTM Standards:
samples. The intensity or concentration is also adjusted to
C753 Specification for Nuclear-Grade, Sinterable Uranium
Dioxide Powder
C776 Specification for Sintered Uranium Dioxide Pellets
ThistestmethodisunderthejurisdictionofASTMCommitteeC26onNuclear
C778 Specification for Standard Sand
Fuel Cycle and is the direct responsibility of Subcommittee C26.05 on Methods of
C833 Specification for Sintered (Uranium-Plutonium) Di-
Test.
Current edition approved July 1, 2006. Published September 2006. Originally
oxide Pellets
approved in 2000. Last previous edition approved in 2000 as C1474–00. DOI:
10.1520/C1474-00R06E01.
Policke,T.A.,Bolin,R.N.,andHarris,T.L.,“UraniumIsotopeMeasurements
by Quqdrupole ICP-MS for Process Monitoring of Enrichment,” Symposium on
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Applications of Inductively Coupled Plasma-Mass Spectrometry to Radionuclide
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Determinations: Second Volume, ASTM STP 1344, ASTM, 1998, p. 3.
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
´1
C1474 – 00 (2006)
C859 Terminology Relating to Nuclear Materials for all sample, standard, and control measurements.Acalibra-
C1347 Practice for Preparation and Dissolution of Uranium tion standard is run and all sample analyses are bracketed by
Materials for Analysis theanalysisofcontrols.Calculationsareperformedtomeasure
D1193 Specification for Reagent Water the intensity ratios of each low-abundance isotope to the
233 234 235 236 238
E135 Terminology Relating to Analytical Chemistry for intensity sum of U, U, U, U, and U. Mass bias
Metals, Ores, and Related Materials correction factors, which are established using the instrument
E456 Terminology Relating to Quality and Statistics software and the calibration standard data, are then applied to
E882 Guide for Accountability and Quality Control in the the sample and control data. The corrected ratio measurement
Chemical Analysis Laboratory for a low abundance isotope is equal to the abundance of that
isotope(forexamplethe Uintensity/Uisotopeintensitysum
3. Terminology
equals the U abundance). The high abundance isotope is
determined by subtracting the low-abundance isotopes from
3.1 Definitions:
100%.
3.1.1 For definitions of terms relating to analytical atomic
spectroscopy, refer to Terminology E135.
5. Significance and Use
3.1.2 For definitions of terms relating to statistics, refer to
5.1 Nuclear-grade reactor fuel material must meet certain
Terminology E456.
criteria, such as those described in Specifications C753, C776,
3.1.3 For definitions of terms relating to nuclear materials,
C778, and C833. Included in these criteria is the uranium
refer to Terminology C859.
isotopic composition. This test method is designed to demon-
3.1.4 For definitions of terms specifically related to
strate whether or not a given material meets an isotopic
Q-ICP-MS in addition to those found in 3.2, refer toAppendix
requirement and whether the effective fissile content is in
3 of Jarvis et al.
compliance with the purchaser’s specifications.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 dead time, n—the interval during which the detector
6. Interferences
and its associated counting electronics are unable to record
6.1 Adjacent Isotopic Peak Effects—Interferencescanoccur
another event or resolve successive pulses. The instrument
from adjacent isotopes of high concentration, such as an
signal response becomes nonlinear above a certain count rate
intense U peak interfering with the measurement of U
due to dead time effects.
and U. This is particularly the case for instruments that
3.2.2 mass bias or fractionation, n—the deviation of the
provide only nominal unit mass resolution at 10% of the peak
observed or measured isotope ratio from the true ratio as a
height. For this test method, the Q-ICP-MS peak resolution
function of the difference in mass between the two isotopes.
for U was set to within 0.70 6 0.15 daltons (Atomic Mass
Thisdeviationistheresultofseveraldifferentprocesses.Ithas
Units-AMU) full-width-tenth-maximum (FWTM) peak height
been suggested that the Q-ICP-MS ion transmission and
to reduce adjacent peak interference effects.
focusing device create a dense space charge effect, which can
6.2 Isobaric Molecular Ion Interferences— Ucouldinter-
cause a preferential loss of lighter isotopes. The result is an
236 +
fere with U determinations by forming a UH ion. Follow
under estimation of the lighter isotopes which can be signifi-
the instrument manufacturer’s instructions to minimize these
cant. “Rayleigh fractionation associated with sample evapo-
molecular ion formations, for example by optimizing the
rationinwhichlighterisotopesarecarriedawaypreferentially”
nebulizer gas flow rate. The use of a calibration standard that
is insignificant with solution nebulization, but with other
is similar in isotopic composition and intensity to the samples
methods of introduction such as electrothermal vaporization,
reducesthepotentialbiasfromthisinterferenceeffect.Thebias
can be more significant.
+
from the UH interference only becomes significant for the
integrated peak intensity of U when the sample intensity
4. Summary of Test Method
deviates from the calibration standard intensity and it is very
4.1 A sample of the nuclear-grade material (nominally 0.2
low, that is, near the background intensity contribution. A
g) is digested in HNO or a HNO /HF mixture and diluted in
3 3
naturally enriched standard, which contains no U, can be
series to a concentration of approximately 0.10 ug of uranium
used to test the significance of this interference.
per gram of solution (ug U/g solution or ppm of U). Other
6.3 Memory Interference Effects—Memory effects or
dissolution methods may be used.Astandard peristaltic pump
sample carryover can occur from previously run samples.
is used as the means of sample introduction into the plasma.
Theseeffectscanbedetectedinseveralways.Firstofall,ifthe
The uranium intensity (that is, concentration), as initially
bias factors from the calibration standard are outside of a
indicatedbyaratemeterreading,isadjustedtowithinacertain
normaltendedrange,itcanshowthattheglasswareanduptake
tolerance range to provide good precision and a reduced bias
system is contaminated with another enrichment. Secondly, it
can be detected by looking at the standard deviation of the
4 repeat trials from a sample analysis and whether the peak
Jarvis, K.E., Gray, A.L., and Houk, R.S., Handbook of Inductively Coupled
intensitymeasurementsarerandombetweentherepeattrialsor
Plasma Mass Spectrometry, Blackie and Son Ltd., Glasgow and London, or
Chapman and Hall, New York, 1992 .
whether they drift toward increasing or decreasing intensity.
Date,A.R.,andGray,A.L., Applications of Inductively Coupled Plasma Mass
Also, the percent standard deviation (% SD) of the intensity
Spectrometry, Blackie and Son Ltd., Glasgow and London, or Chapman and Hall,
ratios should be less than or on the same order of the % SD of
New York, 1989.
the peak intensities. If the peak intensity measurements are
´1
C1474 – 00 (2006)
intensity versus concentration range, and is therefore also instrument
higher, then it may be an indication of a memory effect from a
dependent. Intensity levels above this range can become nonlinear as a
sample of a different enrichment level. It could also be
function of concentration due to dead time effects.
indicative of general instrument instability or problems with
8.6 Isotopic Enrichment Standard Primary Stock Solutions,
sample uptake and delivery to the plasma.
5000 ug of U O per g of solution (4235 ug of U per g of
3 8
7. Apparatus solution)—0.250 g of the appropriate NBL U O isotopic
3 8
standard heated to dissolve with 5 mL of water and 10 mL of
7.1 Balance, with precision of 0.00001 g.
concentrated HNO , then diluted to 50.0 g of water in a
7.2 Polytetrafluoroethylene (PTFE) Oak Ridge Tubes,30
125-mL polypropylene sample bottle.
mL, or equivalent.
8.7 Isotopic Enrichment Standard Secondary Stock Solu-
7.3 Drying Oven, controlled at 108 6 5°C.
tions, 84.7 ug of U per g of solution—Add 2.0 mL of the
7.4 Polypropylene Sample Bottle, 125 mL, or equivalent.
appropriate isotopic enrichment standard primary stock solu-
7.5 Disposable Polypropylene Tubes With Snap-on Caps ,
tion (see 8.6) to a 125-mLpolypropylene sample bottle, add 5
14 mL, or equivalent.
mL of concentrated HNO , then dilute to 100.0 g with water.
7.6 Q-ICP-MS Instrument, controlled by computer and
fitted with the associated software and peripherals.
NOTE 2—The isotopic calibration standard and analysis control mate-
rials should be within 1.0 Wt % of the U enrichment to be analyzed in
7.7 Peristaltic Pump.
unknown sample materials. Likewise, the low-abundance isotopes ( U
and U) should be in close agreement between standards and samples. It
8. Reagents and Materials
is recommended that separate primary and secondary stock solutions be
8.1 Purity of Reagents—Reagent grade chemicals shall be
made from a separate and preferably an independent source of isotopic
used in all tests. Unless otherwise indicated, it is intended that
enrichment standard (to serve as standard and control stock solutions) if
all reagents conform to the specifications of the Committee on
such a source can be found. However, given the limited availability of
such standards, the primary and secondary stock solutions may be made
Analytical Reagents of theAmerican Chemical Society where
from the same enrichment CRM, with separate dissolutions and bottles
such specifications are available. Other grades may be used
being designated as standard and control stock solutions.
provided it is first ascertained that the reagent is of sufficiently
8.8 Isotopic Enrichment U O Standards—New Brunswick
high purity to permit its use without lessening the accuracy of
3 8
Laboratory (NBL) Certified Reference Materials (CRMs),
the determination.
dependingontheenrichmentleveltobeanalyzed:forexample,
8.2 Purity of Water—Unlessotherwiseindicated,references
CRM U-010, CRM U-030, CRM U-030A, CRM U-050, CRM
to water shall be understood to mean reagent water, as defined
U-200, CRM U-350, CRM U-500, CRM U-750, CRM U-850,
by Type I of Specification D1193.
8.3 HydrofluoricAcid (sp gr 1.18)—49%w/wconcentrated CRM U-900, CRM U-930, and CRM U-970.
8.9 Nitric Acid (sp gr 1.42)—70% w/w concentrated nitric
hydrofluoric acid (HF).
acid (HNO ).
8.4 Isotopic Calibration Standard, 0.10 ug of U per g of
8.10 U Isotopic Enrichment Spike Standard—NewBrun-
solution—Add 100 uL of the appropriate isotopic calibration
swick Laboratory (NBL) CRM 111A, used as a spi
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.