ASTM C1842-16

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation:C1842 −16
Standard Test Method for
The Analysis of Boron and Silicon in Uranium Hexfluoride
via Fourier-Transform Infrared (FTIR) Spectroscopy
This standard is issued under the fixed designation C1842; 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 2.2 Other Documents:
ANSI N14.1 Nuclear Materials – Uranium Hexfluo-
1.1 This test method is suitable for determining boron and
ride–Packaging for Transport
silicon impurities as BF and SiF in uranium hexafluoride.
3 4
ISO 7195 Nuclear Energy – Packaging of Uranium
This test method is an alternative to those described in Test
Hexafluoride (UF ) for Transport
Methods C761 and C1771.
3. Terminology
1.2 The values stated in SI units are to be regarded as
standard. No other units of measurement are included in this
3.1 Except as otherwise defined herein, definitions of terms
standard.
are as given in Terminology C859.
1.3 This standard does not purport to address all of the
3.2 Definitions of Terms Specific to This Standard:
safety concerns, if any, associated with its use. It is the
3.2.1 detection limit, n—based on the minimum absorbance
responsibility of the user of this standard to establish appro-
obtainable at a given pressure to yield a meaningful result. In
priate safety and health practices and determine the applica-
accordance with Terminology C859, a low concentration level
bility of regulatory limitations prior to use.
could be achieved with these methods.
3.2.2 FTIR, n—Fourier-transform infrared spectroscopy.
2. Referenced Documents
3.2.3 K, n—infrared absorbance constant in pressure units
2.1 ASTM Standards:
[1/Pa], K = OD/Pressure.
C761Test Methods for Chemical, Mass Spectrometric,
3.2.4 “1S” container, n—a nickel or Monel container as
Spectrochemical,Nuclear,andRadiochemicalAnalysisof
described in ANSI N14.1.
Uranium Hexafluoride
C787Specification for Uranium Hexafluoride for Enrich-
4. Summary of Test Method
ment
4.1 ToperformtheFourier-TransformInfrared(FTIR)spec-
C859Terminology Relating to Nuclear Materials
troscopic analysis of boron and silicon impurities in uranium
C996Specification for Uranium Hexafluoride Enriched to
235 hexafluoride,asamplemustbecollectedina“1S”containeror
Less Than 5% U
equivalent with the methods described in Practices C1052 or
C1052Practice for Bulk Sampling of Liquid Uranium
C1703.
Hexafluoride
C1703 Practice for Sampling of Gaseous Uranium 4.2 The bottle is kept at room temperature. The manifold
Hexafluoride andthesamplecellaremaintainedat50°C.Intheseconditions,
C1771Test Method for Determination of Boron, Silicon, UF ismainlyinsolidphaseinthebottleandboronandsilicon
and Technetium in Hydrolyzed Uranium Hexafluoride by are present in the gaseous phase of manifold. In this medium,
Inductively Coupled Plasma—Mass Spectrometer After
the boron and silicon chemical forms are respectively BF and
Removal of Uranium by Solid Phase Extraction SiF .
4.3 The test method is based on the analysis in the gas
phase. The gas phase is analyzed at 50°C by FTIR spectrom-
ThistestmethodisunderthejurisdictionofASTMCommitteeC26onNuclear
etry to determine the B and Si concentration in uranium
Fuel Cycle and is the direct responsibility of Subcommittee C26.05 on Methods of
hexafluoride.
Test.
Current edition approved June 1, 2016. Published July 2016. DOI: 10.1520/
C1842-16. Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
For referenced ASTM standards, visit the ASTM website, www.astm.org, or 4th Floor, New York, NY 10036, http://www.ansi.org.
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Available from International Organization for Standardization (ISO), ISO
Standards volume information, refer to the standard’s Document Summary page on Central Secretariat, BIBC II, Chemin de Blandonnet 8, CP 401, 1214 Vernier,
the ASTM website. Geneva, Switzerland, http://www.iso.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C1842−16
4.4 The manifold and sample cell are filled at the vapor 7.2 A Manifold System, built with materials of construction
pressure of UF at room temperature (near 12 kPa). inert to fluorine-bearing gases. The manifold system shall be
conditioned and passivated with an appropriate fluorinating
4.5 After a screening, if the spectrum is the UF spectrum,
agent.
thistestmethodcanbeusedtocheckthecomplianceofUF as
specified in Specifications C787 and C996.
7.3 A Sample Cell,windowsaremadeofmaterial(s)inertto
fluorine-bearing gases, for example, zinc selenide (ZnSe). A
4.6 The boron and silicon determinations are done on the
cell path length of more than 150 mm was found to be
gaseous phase. The concentration and the limits of detection
sufficient for the required LOD. The cell is heated at 50°C.
are in units of µg/g U.
7.4 A Pressure Gauge, which can be read to 1 Pa is
4.7 There are no spectral interferences from uranium
necessary.
hexafluoride’s infrared absorbences.
7.5 Absorbence Data, or OD optical density, can be deter-
5. Significance and Use
mined to 0.001 units.
5.1 This test method utilizes FTIR spectroscopy to deter-
mine the boron and silicon concentration in uranium hexafluo-
8. Calibration and Standardization
ride.
8.1 Calibration:
5.2 These detection limits are low and very effective to
8.1.1 BF and SiF are calibrated between 15 and 150 Pa.
3 4
check the compliance of UF with Specifications C787 and
Thecelltemperatureismaintainedat50°C.Differentpressures
C996.
of pure BF or pure SiF are introduced between 15 and 150
3 4
Pa. The maximum of absorbance and the scans are recorded.
6. Hazards
The response of absorbance as a function of pressure is linear.
6.1 Uranium hexafluoride is a hazardous material. It is a
TheslopeofthislineisK.Theslopeisconstantfromnearzero
highly reactive and toxic substance in addition to its radioac-
absorbance to about 0.8 absorbance units.
tive properties. It must be handled as a gas in containers and
-1
8.1.2 The K value are measured at 1441 cm for BF and
manifolds using materials of construction that are inert to
-1
1029 cm for SiF (see Fig. 1 and Fig. 2).
fluorine-bearing gases, such as nickel, Monel™, copper, or
8.1.3 The operating experience of each laboratory for pre-
aluminum.
cision calculations of impurities are critical to the success of
the method. Each laboratory shall determine the “K” values
7. Apparatus
specific to its instrumentation: K = Σ OD/Σ Pressure.
7.1 Fourier-Transform Infrared Spectrophotometer, with a
-1
resolution of 60.5 cm or better. The scanning range depends 8.2 Calibration of Pressure Gauge and FTIR Instrument—
on the equipment being used, but at minimum shall be 600 to Pressure gauges and the FTIR instruments are very stable over
-1
time. Annual calibration is recommended.
1550 cm .
FIG. 1BF Spectrum in Pure Medium
C1842−16
FIG. 2SiF Spectrum in Pure Medium
8.3 Calibration Checks—The calibration of the gauge 9.1.4 Evacuate manifold system until readout on gauge
should be checked before analyzing a UF standard. After the displays a value of less than 10 Pa.
check of the gauge calibration, 10 kPa of UF standard are
9.1.5 Verify the digital manometer for zero and full scale
-1
introduced and the maximum of absorbance at 625 cm is
readings.
recorded. These calibration checks should be performed each
9.1.6 Obtain an infrared background spectrum on the FTIR
day that the instrument is used. If the difference on the OD is
to check that the manifold is clean.
above 1%, the pressure gauge should be recalibrated. If the
9.1.7 Connect the sample 1S bottle on the manifold and
-1
wavelengthdifferenceisgreatherthan0.5cm ,thentheFTIR
control the tightness.
instrument should be recalibrated
9.1.8 Open the bottle valve on the manifold. Wait until the
pressure is stabilized and close the valve. Record the sample
9. Procedure
pressure (P).
9.1 Acquire a Sample Scan:
9.1.9 Obtaintheinfraredspectrum.Thespectrumwillbethe
9.1.1 Weigh the empty bottle (M1).
result of ten scans.
9.1.2 Withdraw a sample in a 1S bottle with the process
9.2 Interpret Spectrum:
defined in Practices C1052 or C1703.
9.1.3 Weigh the bottle to determine the UF mass in the 9.2.1 Record the absorbance maxima (OD BF and OD
6 3
bottle (M2). SiF ) and the infrared spectrum (see Fig. 3).
FIG. 3SiF Spectrum in UF Medium
4 6
C1842−16
9.3 Representativity of the Sample: 10.2.1 CalculatethepartialpressureofBF (PBF )andSiF
3 3 4
9.3.1 The representativity of the sample is validated by the (PSiF ).
following process. Control the concentration of UF in the gas
PBF 5ODBF ⁄KBF ;PSiF 5ODSiF ⁄KSiF
3 3 3 4 4 4
phase. If the UF concentration is above 80%, the sample is
10.2.2 Calculate the mass of UF (MUF6) by the difference
validated and the boron and silicon concentration could be
of bottle mass empty (M1) and after the sampling (M2).
determined. If the UF concentration is under 80%, a resam-
pling is necessary.
MUF6 5M2 2M1
9.3.2 To determine the concentration of UF in the gas
10.2.3 Multiply the mass of UF by 0.6761 to calculate the
phase,performaUF calibrationintroducingapressureofpure
mass of uranium (MU).
UF (PUF ) and record the UF absorbance (ODUF)to
6 6 6 6
MU 5MUF 30.6761
calculate KUF (KUF = ODUF / PUF ). Record the UF
6 6 6 6 6
absorbance on the infrared spectrum of the sample and
10.2.4 Divide the mass of UF by the volumetric mass of
calculate the UF pressure with the K value. To calculate the
UF to obtain the volume of UF (VUF ).
6 6 6
concentration of UF in the gas phase, divide the UF pressure
6 6
VUF 5MUF 35.09
6 6
by the sample pressure (%UF = PUF / Psample).
6 6
10.2.5 Subtract the UF volume from the volume bottle
9.4 Evacuation of the Manifold System: 6
(VB) to calculate the free volume (VFB).
9.4.1 Open the cold trap.
9.4.2 Continue the total evacuation until the pressure gauge
VFB 5VB 2VUF6
reads below 10 Pa.
10.2.6 Add the free volume of the bottle, the manifold
NOTE 1—The manifold system must be passiva
...