ASTM E267-90(1995)
(Test Method)Standard Test Method for Uranium and Plutonium Concentrations and Isotopic Abundances
Standard Test Method for Uranium and Plutonium Concentrations and Isotopic Abundances
SCOPE
1.1 This test method is applicable to the determination of uranium (U) and plutonium (Pu) concentrations and their isotopic abundances (Note 1) in solutions which result from the dissolution of nuclear reactor fuels either before or after irradiation. A minimum sample size of 50 [mu]g of irradiated U will contain sufficient Pu for measurement and will minimize the effects of cross contamination by environment U. Note 1—The isotopic abundance of Pu can be determined by this test method; however, interference from U may be encountered. This interference may be due to (1) inadequate chemical separation of uranium and plutonium, (2) uranium contamination within the mass spectrometer, and (3) uranium contamination in the filament. One indication of uranium contamination is a changing 238/239 ratio during the mass spectrometer run, in which case, a meaningful Pu analysis cannot be obtained on that run. If inadequate separation is the problem, a second pass through the separation may remove the uranium. If contamination in the mass spectrometer or on the filaments is the problem, use of a larger sample, for example, 1 μg, on the filament may ease the problem. A recommended alternative method of determining Pu isotopic abundance without U interference is alpha spectroscopy using Practice D3084. The Pu abundance should be obtained by determining the ratio of alpha particle activity of Pu to the sum of the activities of Pu and Pu. (1) The contribution of Pu and Pu to the alpha activity differs from their isotopic abundances due to different specific activities.
1.2 The procedure is applicable to dissolver solutions of uranium fuels containing plutonium, aluminum, stainless steel, or zirconium. Interference from other alloying constituents has not been investigated and no provision has been made in the test method for fuels used in the Th U fuel cycle.
1.3 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.
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Designation: E 267 – 90 (Reapproved 1995)
Standard Test Method for
Uranium and Plutonium Concentrations and Isotopic
Abundances
This standard is issued under the fixed designation E 267; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope D 1193 Specification for Reagent Water
D 3084 Practice for Alpha-Particle Spectrometry of Water
1.1 This test method is applicable to the determination of
E 137 Practice for Evaluation of Mass Spectrometers for
uranium (U) and plutonium (Pu) concentrations and their
Quantitative Analysis from a Batch Inlet
isotopic abundances (Note 1) in solutions which result from the
E 219 Test Method for Atom Percent Fission in Uranium
dissolution of nuclear reactor fuels either before or after
Fuel (Radiochemical Method)
irradiation. A minimum sample size of 50 μg of irradiated U
E 244 Test Method for Atom Percent Fission in Uranium
will contain sufficient Pu for measurement and will minimize
and Plutonium Fuel (Mass Spectrometric Method)
the effects of cross contamination by environment U.
NOTE 1—The isotopic abundance of Pu can be determined by this 3. Summary of Test Method
test method; however, interference from U may be encountered. This
3.1 An aliquot of solution to be analyzed is spiked with
interference may be due to (1) inadequate chemical separation of uranium
233 242
known amounts of U and Pu (2–6). U and Pu are
and plutonium, (2) uranium contamination within the mass spectrometer,
separated by ion exchange and analyzed mass spectrometri-
and (3) uranium contamination in the filament. One indication of uranium
cally.
contamination is a changing 238/239 ratio during the mass spectrometer
run, in which case, a meaningful Pu analysis cannot be obtained on that
4. Significance and Use
run. If inadequate separation is the problem, a second pass through the
separation may remove the uranium. If contamination in the mass
4.1 This test method is specified for obtaining the atom
spectrometer or on the filaments is the problem, use of a larger sample, for
ratios and U atom percent abundances required by Test Method
example, 1 μg, on the filament may ease the problem. A recommended
238 238 E 244 and the U concentration required by Test Method E 219.
alternative method of determining Pu isotopic abundance without U
interference is alpha spectroscopy using Practice D 3084. The Pu
NOTE 2—The isotopic abundance of Pu normally is not required for
abundance should be obtained by determining the ratio of alpha particle
burnup analysis of conventional light-water reactor fuel.
238 239 240
activity of Pu to the sum of the activities of Pu and Pu. (1) The
239 240
4.2 The separated heavy element fractions placed on mass
contribution of Pu and Pu to the alpha activity differs from their
spectrometric filaments must be very pure. The quantity
isotopic abundances due to different specific activities.
required depends upon the sensitivity of the instrument detec-
1.2 The procedure is applicable to dissolver solutions of
tion system. If a scintillator (7) or an electron multiplier
uranium fuels containing plutonium, aluminum, stainless steel,
detector is used, only a few nanograms are required. If a
or zirconium. Interference from other alloying constituents has
Faraday cup is used, a few micrograms are needed. Chemical
not been investigated and no provision has been made in the
232 233 purity of the sample becomes more important as the sample
test method for fuels used in the Th- U fuel cycle.
size decreases, because the ion emission of the sample is
1.3 This standard does not purport to address all of the
repressed by impurities.
safety concerns, if any, associated with its use. It is the
4.3 Operation at elevated temperature (for example, 50 to
responsibility of the user of this standard to establish appro-
60°C) (Note 3) will greatly improve the separation efficiency of
priate safety and health practices and determine the applica-
ion exchange columns. Such high-temperature operation yields
bility of regulatory limitations prior to use.
an iron-free U fraction and U-free Pu fraction, each of which
has desirable emission characteristics.
2. Referenced Documents
2.1 ASTM Standards:
NOTE 3—A simple glass tube column can be heated by an infrared lamp
until it is warm to the touch.
4.4 Extreme care must be taken to avoid contamination of
the sample by environmental U. The level of U contamination
This test method is under the jurisdiction of ASTM Committee C-26 on Nuclear
Fuel Cycle.
Current edition approved July 27, 1990. Published December 1990. Originally Annual Book of ASTM Standards, Vol 11.01.
e1 4
published as E 267 – 65 T. Last previous edition E 267 – 78(1985) . Annual Book of ASTM Standards, Vol 11.02.
2 5
The boldface numbers in parentheses refer to the list of references appended to Annual Book of ASTM Standards, Vol 05.03.
this test method. Annual Book of ASTM Standards, Vol 12.02.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
E 267
should be measured by analyzing an aliquot of 8 M nitric acid magnetic field or the accelerating voltage.
(HNO ) reagent as a blank and computing the amount of U it
6. Reagents and Materials
contains.
4.4.1 The U blank is normally 0.2 ng of total U. Blanks
6.1 Purity of Reagents—Reagent grade chemicals shall be
larger than 0.5 ng are undesirable, because as much as 5 ng of
used in all tests. Unless otherwise indicated, it is intended that
natural U contamination in a 50 μg sample of fully enriched U
all reagents shall conform to the specifications of the Commit-
235 238
will change its U-to- U ratio from 93.3-to-5.60 to 93.3-
tee on Analytical Reagents of the American Chemical Society,
to-5.61 (that is, 16.661 to 16.631) or 0.18 %.
where such specifications are available. Other grades may be
235 238
4.4.2 Where a 10 % decrease in U-to- U ratio from
used, provided it is first ascertained that the reagent is of
neutron irradiation of a fuel is being measured, such contami-
sufficiently high purity to permit its use without lessening the
nation introduces a 1.8 % error in the difference measurement.
accuracy of the determination.
It is clear that larger blanks or smaller samples cannot be
6.2 Purity of Water—Unless otherwise indicated, references
tolerated. In the analysis of small samples, environmental U
to water shall be understood to mean reagent water conforming
contamination can introduce the largest single source of error.
to Specification D 1193.
6.3 Anion Exchange Resin.
5. Apparatus
239 238
6.4 Blended Pu and U Calibration Standard—Prepare
5.1 Shielding—To work with highly irradiated fuel, shield-
a solution containing about 0.25 mg Pu/liter and 25 mg
ing is required for protection of personnel during preparation of
U/liter in 8 M HNO , as follows. With a new, calibrated,
the primary dilution of dissolver solution. The choice of
clean Kirk-type micropipet, add 0.500 mL of Pu known
shielding is dependent upon the type and level of the radioac-
solution (see 6.12) to a calibrated 1-L volumetric flask. Rinse
tivity of the samples being handled.
the micropipet into the flask three times with 8 M HNO .Ina
5.2 Glassware—To avoid cross contamination, use only
similar manner, add 0.100 mL of U known solution (see
new glassware (beakers, pipets, and columns) from which
6.14). Dilute exactly to the 1-L mark with 8 M HNO and mix
surface U has been removed by boiling in HNO (1 + 1) for 1
thoroughly. From the value K (see 6.12), calculate the atoms
to 2 h. Glassware is removed from the leaching solution, rinsed
of Pu/mL of calibration standard, C , as follows:
in redistilled water, oven-dried, and covered until used to avoid
C 5~mL Pu solution/1000 mL calibration standard!
recontamination with U from atmospheric dust. Wrapping
3 K (1)
clean glassware in aluminum foil or plastic film will protect it
From the value K (see 6.14), calculate the atoms of
against dust.
U/mL of calibration standard, C , as follows:
5.2.1 For accurate delivery of 500-μL volumes specified in 238
this procedure for spike and sample, a Kirk-type micropipet (8)
C 5~mL U solution/1000 mL calibration standard!
(also known as a “lambda” transfer pipet) is required. Such a
3 K (2)
pipet is calibrated to contain 500 μL with 60.2 % accuracy and
Flame-seal 3 to 5-mL portions in glass ampoules to prevent
is designed to be rinsed out with dilute acid to recover its
evaporation after preparation until time of use. For use, break
contents. Volumetric, measuring, and other type pipets are not
off the tip of an ampoule, pipet promptly the amount required,
sufficiently accurate for measuring spike and sample volumes.
and discard any unused solution. If more convenient, the
5.3 Mass Spectrometer—The suitability of mass spectrom-
calibration standard can be flame-sealed in premeasured por-
eters for use with this test method of analysis shall be evaluated
tions for quantitative transfer when needed.
by means of performance tests described in this test method
242 9 233
6.5 Blended Pu and U Spike Solution—Prepare a
and in Practice E 137. The mass spectrometer used should
solution containing about 0.25 mg Pu/liter and 5 mg
possess the following characteristics:
233 10
U/liter in 8 M HNO . Standardize the spike solution as
5.3.1 A thermal-ionization source with single or multiple
follows:
filaments of rhenium (Re),
6.5.1 In a 5-mL beaker, place about 0.1 mL of ferrous
5.3.2 An analyzer radius sufficient to resolve adjacent
solution, exactly 500 μL of calibration standard (see 6.4), and
masses in the mass-to-charge range being studied, that is,
exactly 500μ L of spike solution (see 6.5). In a second beaker,
+ +
m/e 5 233 to 238 for U or m/e 5 265 to 270 for UO ions.
place about 0.1 mL of ferrous solution and 1 mL of calibration
Resolution must be great enough to measure one part of U
in 250 parts of U,
5.3.3 A minimum of one stage of magnetic deflection. Since
“Reagent Chemicals, American Chemical Society Specifications,” Am. Chemi-
the resolution is not affected, the angle of deflection may vary
cal Soc., Washington, DC. For suggestions on the testing of reagents not listed by
with the instrument design,
the American Chemical Society, see “Reagent Chemicals and Standards,” by Joseph
Rosin, D. Van Nostrand Co., Inc., New York, NY and the “United States
5.3.4 A mechanism for changing samples,
Pharmacopeia.”
5.3.5 A direct-current, electron multiplier, scintillation or
Dowex-1-type resins (either AG 1-X2 or AG 1-X4, 200 to 400 mesh) obtained
semi-conductor detector (7) followed by a current-measuring
from Bio-Rad Laboratories 32nd St. and Griffin Ave., Richmond, CA, have been
device, such as a vibrating-reed electrometer or a fast counting
found satisfactory.
9 244 242
When Pu becomes available, it can be substituted for Pu with the
system for counting individual ions,
−7 advantage that it does not appear in the sample as a normal constituent.
5.3.6 A pumping system to attain a vacuum of 2 or 3 3 10
These isotopes in greater than 99 % isotopic purity are obtained through the
torr in the source, the analyzer, and the detector regions, and
Division of Research of the Atomic Energy Commission from the Isotopes
5.3.7 A mechanism to scan masses of interest by varying the Distribution Office of Oak Ridge National Laboratory.
E 267
standard without any spike. In a third beaker, place 0.1 mL of the 100-mm mark five times.
ferrous solution and 1 mL of spike without standard. Mix well 6.10 Nitric Acid (sp gr 1.42)—Distill to obtain a 16 M
and allow to stand for 5 min to reduce Pu to Pu (III) or Pu (IV) reagent low in U and dissolved solids. Dilute further with
to promote Pu isotopic exchange. redistilled water to 8 M,3 M, 0.5 M, and 0.05 M concentra-
6.5.2 Follow the procedure described in 8.5.2-8.8.6. On the tions.
242 239
Pu fraction, record the isotopic ratios of Pu to Pu in the 6.11 Nitrite Solution (0.1 M)—Add 0.69 g of sodium nitrite
calibration standard, C ; in the spike solution, S ; and in the (NaNO ) and 0.2 g of NaOH to 50 mL of redistilled water,
2/9 2/9 2
standard-plus-spike mixture, M . On the U fraction, record dilute to 100 mL with redistilled water, and mix.
2/9
233 238 239
the corresponding U-to- U ratios, C , S , and M . 6.12 Pu Known Solution—Add 10 mL of 6 M HCL to a
3/8 3/8 3/8
Correct all ratios for mass discrimination bias (see Section 7). clean calibrated 1-L flask. Cool the flask in an ice water bath.
6.5.3 Calculate the number of atoms of Pu/mL of spike, Allow time for the acid to reach approximately 0°C and place
S , as follows: in a glove box. Displace the air in the flask with inert gas (A,
He, or N ). Within the glove box, open the U.S. New
S 5 C $~M 2 C !/@1 2 ~M /S !#% (3)
2 239 2/9 2/9 2/9 2/9
Brunswick Laboratory Plutonium Metal Standard Sample 126,
6.5.4 Calculate the number of atoms of U/mL of spike,
containing about 0.5 g Pu (actual weight individually certified)
S , as follows:
and add the metal to the cooled HCl. After dissolution of the
S 5 C M 2 C / 1 2 M /S (4)
$~ ! @ ~ !#% metal is complete, add 10 drops of concentrated HF and 400
3 238 3/8 3/8 3/8 3/8
242 233
mL of 8 M HNO and swirl. Place the flask in a stainless-steel
6.5.5 Calculate the ratio of Pu atoms to U atoms in the 3
beaker for protection and invert a 50-mL beaker over the top
spike, S , as follows:
2/3
and let it stand for at least 8 days to allow any gaseous
S 5 S /S (5)
2/3 2 3
oxidation products to escape. Dilute to the mark with 8 M
6.5.6 Store in the same manner as the calibration standard
HNO and mix thoroughly. By using the individual weight of
(see 6.4), that is, flame-seal 3 to 5-mL portions in glass
Pu in grams, the purity, and the molecular weight of the Pu
ampoules. For use, break off the tip of an ampoule, pipet
given on the NBL certificate, with atom fraction Pu, A ,
promptly the amount required, and discard any unused solu-
determined as in Eq 14, (see 9.2), calculate the atoms of
239 239
tion. If more convenient, spike solution can be flame-sealed in
Pu/mL of Pu known solution, K , as follows:
premeasured portions for quantitative transfer to individual
K 5~g Pu/1000 mL solution!3~percent purity/100!
samples.
3~6.022 3 10 atoms!/~Pu molecular weight!3 A
6.6 Ferrous Solution (0.001 M)—Add 40 mg of reagent
(6)
grade ferrous ammonium sulfate [Fe(NH ) (SO ) ·6H O] and
4 2 4 2 2
6.13 Sucrose Solutio
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