ASTM E321-96
(Test Method)Standard Test Method for Atom Percent Fission in Uranium and Plutonium Fuel (Neodymium-148 Method)
Standard Test Method for Atom Percent Fission in Uranium and Plutonium Fuel (Neodymium-148 Method)
SCOPE
1.1 This test method covers the determination of stable fission product 148 Nd in irradiated uranium (U) fuel (with initial plutonium (Pu) content from 0 to 50%) as a measure of fuel burnup (1-3).
1.2 It is possible to obtain additional information about the uranium and plutonium concentrations and isotopic abundances on the same sample taken for burnup analysis. If this additional information is desired, it can be obtained by precisely measuring the spike and sample volumes and following the instructions in Test Method E267.
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:E321–96
Standard Test Method for
Atom Percent Fission in Uranium and Plutonium Fuel
(Neodymium-148 Method)
This standard is issued under the fixed designation E 321; 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 adjacent to Nd do not interfere. Interference from other rare
142 148
earths,suchasnaturalorfissionproduct Ceornatural Sm
1.1 This test method covers the determination of stable
and Sm is avoided by removing them in the chemical
fission product Nd in irradiated uranium (U) fuel (with
purification (4 and 5).
initial plutonium (Pu) content from 0 to 50 %) as a measure of
150 233 242
3.2 After addition of a blended Nd, U, and Pu spike
fuel burnup (1-3).
to the sample, the Nd, U, and Pu fractions are separated from
1.2 It is possible to obtain additional information about the
eachotherbyionexchange.Eachfractionisfurtherpurifiedfor
uranium and plutonium concentrations and isotopic abun-
mass analysis. Two alternative separation procedures are pro-
dances on the same sample taken for burnup analysis. If this
vided.
additional information is desired, it can be obtained by pre-
3.3 The gross alpha, beta, and gamma decontamination
cisely measuring the spike and sample volumes and following
factors are in excess of 10 and are normally limited to that
the instructions in Test Method E 267.
242 147 241
value by traces of Cm, Pm, and Am, respectively (and
1.3 This standard does not purport to address all of the
sometimes Ru),noneofwhichinterferesintheanalysis.The
safety concerns, if any, associated with its use. It is the
70 ng Nd minimum sample size recommended in the
responsibility of the user of this standard to establish appro-
procedure is large enough to exceed by 100-fold a typical
priate safety and health practices and determine the applica-
natural Nd blank of 0.7 6 0.7 ng Nd (for which a correction
bility of regulatory limitations prior to use.
is made) without exceeding radiation dose rates of 20 µ Sv/h
2. Referenced Documents (20 mR/h) at 1 m. Since a constant amount of fission products
is taken for each analysis, the radiation dose from each sample
2.1 ASTM Standards:
is similar for all burnup values and depends principally upon
D 1193 Specification for Reagent Water
cooling time. Gamma dose rates vary from 200 µ Sv/h (20
E 180 Practice for Determining the Precision of ASTM
mR/h) at 1 m for 60-day cooled fuel to 20 µ Sv/h (2 mR/h) at
Methods forAnalysis and Testing of Industrial Chemicals
1 m for 1-year cooled fuel. Beta dose rates are an order of
E 244 Test Method for Atom Percent Fission in Uranium
magnitude greater, but can be shielded out with a ⁄2-in.
and Plutonium Fuel (Mass Spectrometric Method)
(12.7-mm) thick plastic sheet. By use of such simple local
E 267 Test Method for Uranium and Plutonium Concentra-
shielding, dilute solutions of irradiated nuclear fuel dissolver
tions and Isotopic Abundances
solutions can be analyzed for burnup without an elaborate
3. Summary of Test Method
shielded analytical facility. The decontaminated Nd fraction is
mounted on a rhenium (Re) filament for mass analysis.
3.1 Fission product neodymium (Nd) is chemically sepa-
Samples from 20 ng to 20 µg run well in the mass spectrometer
rated from irradiated fuel and determined by isotopic dilution
+ +
with both NdO and Nd ion beams present. The metal ion is
mass spectrometry. Enriched Nd is selected as the Nd
enhanced by deposition of carbonaceous material on the
isotope diluent, and the mass-142 position is used to monitor
filament as oxygen getter. (Double and triple filament designs
for natural Nd contamination. The two rare earths immediately
do not require an oxygen getter.)
4. Significance and Use
ThistestmethodisunderthejurisdictionofASTMCommitteeC-26onNuclear
Fuel Cycle and is the direct responsibility of Subcommittee C26.05 on Methods of
4.1 The burnup of an irradiated nuclear fuel can be deter-
Test.
mined from the amount of a fission product formed during
Current edition approved Jan. 10, 1996. Published March 1996. Originally
published as E 321 – 67 T. Last previous edition E 321 – 79 (1990). irradiation. Among the fission products, Nd has the follow-
The boldface numbers in parentheses refer to the list of references appended to
ingpropertiestorecommenditasanidealburnupindicator:(1)
this test method.
It is not volatile, does not migrate in solid fuels below their
Annual Book of ASTM Standards, Vol 11.01.
recrystallization temperature, and has no volatile precursors.
Annual Book of ASTM Standards, Vol 15.05.
Annual Book of ASTM Standards, Vol 12.02.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
E321
(2) It is nonradioactive and requires no decay corrections. ( 3) 239Pu known solution (see 5.11) to a calibrated 1-litre volu-
It has a low destruction cross section and formation from metric flask. Rinse the micropipet into the flask three times
adjacent mass chains can be corrected for. (4) It has good with HNO (1 + 1). In a similar manner, add 0.500 mLof U
emission characteristics for mass analysis. (5) Its fission yield known solution (see 5.12) and 1.000 mL of Nd known
235 239
is nearly the same for U and Pu and is essentially solution (see 5.9).Add 10 drops of concentrated HF and dilute
independentofneutronenergy(6).(6)Ithasashieldedisotope, exactly to the 1-litre mark with HNO (1 + 1) and mix
142Nd, which can be used for correcting natural Nd contami- thoroughly.
nation. (7) It is not a normal constituent of unirradiated fuel. 5.3.1 From K (see 5.9), calculate the atoms of Nd/mL
4.2 The analysis of Nd in irradiated fuel does not depend of calibration standard, C , as follows:
on the availability of preirradiation sample data or irradiation
mL Nd known solution
history. Atom percent fission is directly proportional to the C 5 3 K (1)
148 148
1000 mL calibration standard
Nd-to-fuel ratio in irradiated fuel. However, the production
148 147 5.3.2 From K (see 5.12), calculate the atoms of U/mL
of Nd from Nd by neutron capture will introduce a
of calibration standard, C , as follows:
systematic error whose contribution must be corrected for. In
power reactor fuels, this correction is relatively small. In test
mL U known solution
C 5 3 K (2)
23 8 238
reactor irradiations where fluxes can be very high, this correc-
1000 mL calibration standard
tion can be substantial (see Table 1).
148 147 A
TABLE 1 K Factors to Correct Nd for Nd Thermal Neutron Capture
Total Neutron Exposure, fI (neutrons/cm )
Total Neutron Flux,
20 20 21 21 21
f (neutrons/cm /s)
1 3 10 3 3 10 1 3 10 2 3 10 3 3 10
3 3 10 0.9985 0.9985 0.9985 0.9985 0.9985
1 3 10 0.9956 0.9952 0.9950 0.9950 0.9950
3 3 10 0.9906 0.9870 0.9856 0.9853 0.9852
1 3 10 0.9858 0.9716 0.9598 0.9569 0.9559
3 3 10 0.9835 0.9592 0.9187 0.9008 0.8941
1 3 10 0.9826 0.9526 0.8816 0.8284 0.8006
A 147
Assuming continuous reactor operation and a 274 6 91 barn Nd effective neutron absorption cross section for a thermal neutron power reactor. This cross section
was obtained by adjusting the 440 6 150 barn Nd cross section (7) measured at 20°C to a Maxwellian spectrum at a neutron temperature of 300°C.
4.3 The test method can be applied directly to U fuel 5.3.3 From K (see 5.11), calculate the atoms of Pu/mL
containing less than 0.5 % initial Pu with 1 to 100 GW of calibration standard, C , as follows:
23 9
days/metric ton burnup. For fuel containing 5 to 50 % initial
mL Pu known solution
Pu, increase the Pu content by a factor of 10 to 100, C 5 3 K (3)
239 239
1000 mL calibration standard
respectively in both reagents 5.3 and 5.4.
5.3.4 Flame seal 3 to 5-mL portions in glass ampoules to
preventevaporationafterpreparationuntiltimeofuse.Foruse,
5. Reagents and Materials
break off the tip of an ampoule, pipet promptly the amount
5.1 Purity of Reagents—Reagent grade chemicals shall be
required, and discard any unused solution. If more convenient,
used in all tests. Unless otherwise indicated, it is intended that
calibration solution can be flame-sealed in pre-measured
all reagents shall conform to the specifications of the Commit-
1000-µL portions for quantitative transfer when needed.
tee onAnalytical Reagents of theAmerican Chemical Society,
150 233 242
5.4 Blended Nd, U, and Pu Spike Solution—
where such specifications are available. Other grades may be
Prepare a solution containing about 0.4 mg Nd/litre, 50 mg
used, provided it is first ascertained that the reagent is of
233U/litre, and 2.5 mg Pu/litre in HNO (1 + 1) with 0.01 M
sufficiently high purity to permit its use without lessening the
HF. These isotopes are obtained in greater than 95, 99, and
accuracy of the determination.
99 % isotopic purity, respectively, from the Isotopes Sales
5.2 Purity of Water— Unless otherwise indicated, refer-
DepartmentofOakRidgeNationalLaboratory.Standardizethe
ences to water shall be understood to mean reagent water as
spike solution as follows:
defined in Specification D 1193.
5.4.1 In a 5-mL beaker, place about 0.1 mL of ferrous
148 239 238
5.3 Blended Nd, Pu, and U Calibration Standard—
solution, exactly 500 µL of calibration standard (see 5.3) and
Prepare a solution containing about 0.0400 mg Nd/litre, 50
exactly 500 µL of spike solution (see 5.4). In a second beaker,
238 239
mg U/litre, and 2.5 mg Pu/litre, in nitric acid (HNO ,
place about 0.1 mLof ferrous solution and 1 mLof calibration
1 + 1) with 0.01 M hydrofluoric acid (HF) as follows. With a
standard without any spike. In a third beaker, place about 0.1
new calibrated, clean, Kirk-type micropipet, add 0.500 mL of
mL of ferrous solution and 1 mL of spike solution without
standard. Mix well and allow to stand for 5 min to reduce Pu
(VI) to Pu (III) or Pu (IV).
“Reagent Chemicals,American Chemical Society Specifications,”Am. Chemi-
5.4.2 Follow the procedure described in 7.2.4-7.5.8 or
cal Soc., Washington, DC. For suggestions on the testing of reagents not listed by
7.6.2-7.7.11. Measure the Pu, U, and Nd isotopes by surface
theAmerican Chemical Society, see “Reagent Chemicals and Standards,” by Joseph
ionization mass spectrometry following the procedure de-
Rosin, D. Van Nostrand Co., Inc., New York, NY, and the “United States
Pharmacopeia.” scribed in 7.8.1-7.8.3.2 . On the Pu fractions, record the atom
E321
242 239
ratios of Pu to Pu in the calibration standard, C ; in the invert a 50-mL beaker over the top and let it stand for at least
2/9
spike solution, S ; and in the standard-plus-spike mixture, 8 days to allow any gaseous oxidation products to escape.
2/9
233 238
M .OntheUfractionsrecordthecorresponding U-to- U Dilute to the mark with HNO (1 + 1) and mix thoroughly. By
2/9 3
ratios, C , S , and M . On the Nd fractions, record the using the individual weight of Pu in grams, the purity, and the
3/8 3/8 3/8
corresponding Nd-to- Nd ratios, C , S , and M . molecular weight of the Pu given on the NIST certificate, with
50/48 50/48 50/48
Correct all average measured ratios for mass discrimination the atom fraction, A , determined as in 8.8, calculate the atoms
239 239
bias (see 6.2). of Pu/mL of Pu known solution, K , as follows:
5.4.3 Calculate the number of atoms of Nd/mL of Spike,
K 5 @~mg Pu/100 mL solution!3 % purity/100!
A , as follows:
3~6.025 3 10 atoms/Pu molecular weight!3 A # (8)
A 5 C M 2 C !/ 1 2 M /S ! (4) 238
@~ ~ #
50 148 50/48 50/48 50/48 50/48
5.12 U Known Solution—Heat U O from the National
3 8
Institute of Standards and Technology Natural Uranium Oxide
5.4.4 Calculate the number of atoms of U/mL of spike,
A , as follows: Standard Sample 950 in an open crucible at 900°C for1hand
cool in a dessicator in accordance with the certificate accom-
A 5 C @~M 2 C !/~1 2 M /S !# (5)
33 238 3/8 3/8 3/8 3/8
panying the standard sample. Weigh about 12.0 g of U O
3 8
5.4.5 Calculatethenumberofatomsof Pu/mLspike, A ,
accurately to 0.1 mg and place it in a calibrated 100-mL
as follows:
volumetric flask. Dissolve the oxide in HNO (1 + 1). Dilute to
A 5 C @~M 2 C !/~1 2 M /S !# (6) the 100-mL mark with HNO (1 + 1) and mix thoroughly. By
42 239 2/9 2/9 2/9 2/9
using the measured weight of U O in grams, the purity given
3 8
5.4.6 Store in the same manner as the calibration standard
on the NIST certificate, and the atom fraction U, A ,
(see 5.3), that is, flame seal 3 to 5-mL portions in glass
238 238
determined as in 8.5, calculate the atoms U/mL of U
ampoules. For use, break off the tip of an ampoule, pipet
solution, K , as follows:
promptly the amount required, and discard any unused solu-
tion. If more convenient, spike solution can be flame sealed in K 5 @~ g U O /100 mL solution! 3 ~% purity/100
238 3 8
3 848.0 mg U/1 g U O 3 6.025
! ~
a premeasured 1000-µL portions for quantitative transfer to 3 8
3 10 atoms/238.03 molecular weight! 3 A (9)
individual samples. #
5.5 Ferrous Solution (0.001 M)—Add 40 mg of reagent
5.13 Reagents and Materials for Procedure A:
grade ferrous ammonium sulfate (Fe(NH ) (SO ) ·6H O) and
4 2 4 2 2 5.13.1 Dowex AGMP-1 Resin—Convert Dowex AGMP-1
1 drop of concentrated H SO to 5 mL of redistilled water.
2 4 (200 to 400 mesh) chloride form resin to nitrate form by
Dilute to 100 mL with water and mix. This solution does not
washing 200 mL of resin in a suitable column (for example, a
keep well. Prepare fresh daily.
250-mL buret) with HNO (1 + 1) until a drop of effluent
5.6 Filament Mounting Solution—Dissolve 70 mg of su-
falling into an AgNO solution remains clear. Finally, rinse
crose in 100 mL of water (single filament only).
with water, and dry overnight in a vacuum dessicator. Store the
5.7 Hydrofluoric Acid—Reagent grade concentrated HF (28
resin in an airtight container. Since the elution characteristics
M).
of ion exchange resins depend upon their actual percentage
5.8 Methanol, absolute.
cross linkage and particle size (surface-to-volume ratio), which
5.9 Nd Known Solution—Heat natural Nd O (>99.9 %
may vary from one lot to the next, it is most convenient to set
2 3
pure) in an open crucible at 900°C for1hto destroy any
aside a bottle of resin to be used solely for this procedure.
carbonates present and cool in a dessicator. Weigh 0.4071 g of
Before use on actual samples, a small amount of tracer Nd
Nd O and place it in a calibrated 500-mL volumetric flask.
should be taken thro
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