ASTM C1703-18(2023)
(Practice)Standard Practice for Sampling of Gaseous Uranium Hexafluoride for Enrichment
Standard Practice for Sampling of Gaseous Uranium Hexafluoride for Enrichment
SIGNIFICANCE AND USE
5.1 Uranium hexafluoride is normally produced and handled in large (typically 1 to 14-ton) quantities and must, therefore, be characterized by reference to representative samples (see ISO 7195). The samples are used to determine compliance with the applicable commercial specification C787. The quantities involved, physical properties, chemical reactivity, and hazardous nature of UF6 are such that for representative sampling, specially designed equipment must be used and operated in accordance with the most carefully controlled and stringent procedures. This practice can be used by UF6 converters to review the effectiveness of existing procedures or as a guide to the design of equipment and procedures for future use.
5.2 The intention of this practice is to avoid liquid UF6 sampling once the cylinder has been filled. For safety reasons, manipulation of large quantities of liquid UF6 should be avoided when possible.
5.3 It is emphasized that this practice is not meant to address conventional or nuclear criticality safety issues.
SCOPE
1.1 This practice covers methods for withdrawing representative sample(s) of uranium hexafluoride (UF6) during a transfer occurring in the gas phase. Such transfer in the gas phase can take place during the filling of a cylinder during a continuous production process, for example the distillation column in a conversion facility. Such sample(s) may be used for determining compliance with the applicable commercial specification, for example Specification C787.
1.2 Since UF6 sampling is taken during the filling process, this practice does not address any special additional arrangements that may be agreed upon between the buyer and the seller when the sampled bulk material is being added to residues already present in a container (“heels recycle”). Such arrangements will be based on QA procedures such as traceability of cylinder origin (to prevent for example contamination with irradiated material).
1.3 If the receiving cylinder is purged after filling and sampling, special verifications must be performed by the user to verify the representativity of the sample(s). It is then expected that the results found on volatile impurities with gas phase sampling may be conservative.
1.4 This practice is only applicable when the transfer occurs in the gas phase. When the transfer is performed in the liquid phase, Practice C1052 should apply. This practice does not apply to gas sampling after the cylinder has been filled since the sample taken will not be representative of the cylinder.
1.5 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.6 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.
General Information
Relations
Standards Content (Sample)
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: C1703 −18 (Reapproved 2023)
Standard Practice for
Sampling of Gaseous Uranium Hexafluoride for Enrichment
This standard is issued under the fixed designation C1703; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
1.1 This practice covers methods for withdrawing represen-
tative sample(s) of uranium hexafluoride (UF ) during a
2. Referenced Documents
transfer occurring in the gas phase. Such transfer in the gas
2.1 ASTM Standards:
phase can take place during the filling of a cylinder during a
C761 Test Methods for Chemical, Mass Spectrometric,
continuous production process, for example the distillation
Spectrochemical, Nuclear, and RadiochemicalAnalysis of
column in a conversion facility. Such sample(s) may be used
Uranium Hexafluoride
for determining compliance with the applicable commercial
C787 Specification for Uranium Hexafluoride for Enrich-
specification, for example Specification C787.
ment
1.2 Since UF sampling is taken during the filling process,
C859 Terminology Relating to Nuclear Materials
this practice does not address any special additional arrange-
C1052 Practice for Bulk Sampling of Liquid Uranium
ments that may be agreed upon between the buyer and the
Hexafluoride
seller when the sampled bulk material is being added to
C1838 Practice for Cleaning for 1S and 2S Bottles
residues already present in a container (“heels recycle”). Such
2.2 Other Document:
arrangements will be based on QA procedures such as trace-
ISO 7195 Packaging of Uranium Hexafluoride (UF ) for
abilityofcylinderorigin(topreventforexamplecontamination
Transport
with irradiated material).
1.3 If the receiving cylinder is purged after filling and
3. Terminology
sampling, special verifications must be performed by the user
3.1 Definitions of Terms Specific to This Standard:
to verify the representativity of the sample(s). It is then
3.1.1 container—a vessel either holding or receiving by
expected that the results found on volatile impurities with gas
transfer, the UF to be sampled; it may consist of, for example,
phase sampling may be conservative.
a fixed vessel in a UF handling plant or a cylinder to be used
1.4 This practice is only applicable when the transfer occurs
for the transport of UF .
in the gas phase. When the transfer is performed in the liquid
3.1.2 sample vessel—the small vessel into which the sample
phase, Practice C1052 should apply. This practice does not
of UF is withdrawn for analysis in the laboratory for charac-
apply to gas sampling after the cylinder has been filled since
terization. It can be a 1S or 2S bottle or a PCTFE
the sample taken will not be representative of the cylinder.
(polychlorotrifluoroethylene)/PTFE (polytetrafluoroethylene)
1.5 This standard does not purport to address all of the
pot or tube or any other type of cylinder compatible with UF .
safety concerns, if any, associated with its use. It is the
3.2 For definitions of terms used in this test method but not
responsibility of the user of this standard to establish appro-
defined herein, refer to Terminology C859.
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
4. Summary of Practices
1.6 This international standard was developed in accor-
4.1 A common method of withdrawing gas UF for sam-
dance with internationally recognized principles on standard- 6
pling utilizes a continuous withdrawal using for example a
ization established in the Decision on Principles for the
capillary to produce one sample. Depending on the pressure
Development of International Standards, Guides and Recom-
1 2
This practice is under the jurisdiction of ASTM Committee C26 on Nuclear For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Fuel Cycle and is the direct responsibility of Subcommittee C26.02 on Fuel and contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Fertile Material Specifications. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Jan. 1, 2023. Published January 2023. Originally the ASTM website.
approved in 2008. Last previous edition approved in 2018 as C1703 – 18. DOI: Available from American National Standards Institute (ANSI), 25 W. 43rd St.,
10.1520/C1703-18R23. 4th Floor, New York, NY 10036, http://www.ansi.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C1703 − 18 (2023)
and temperature conditions during the transfer, the sampled 7.2 Uranium hexafluoride is very reactive and corrosive. It
UF is either liquefied or solidified in the sample vessel. reacts readily with water, atmospheric moisture, certain metals,
and many organic materials. For reasons of safety and to avoid
4.2 An example of this is the sampling of UF coming from
contamination, precautions must be taken to avoid contact with
a distillation column. In such case, the sampled gas UF can be
such materials.The sampling equipment is therefore fabricated
condensed in the liquid phase in the sampling vessel. The
to appropriate high standards of vacuum and high temperature
representative sample is then homogenized before analysis at
integrity, and components in direct contact with UF are made
the laboratory. It is assumed that the flow rate from the
from nickel, high-nickel alloys, or materials having equivalent
distillation is either constant (for example using a mass flow
resistance to UF corrosion. The formation of an inert fluoride
controller) or that the capillary will take its variation in
layer is often an important feature of UF corrosion resistance,
account.
and hence, internal surfaces are generally conditioned with a
4.3 During sampling, the presence of residues may have
suitable fluorinating agent, sometimes UF itself.
significant implications for the quality of the UF . For safety
7.3 Cross-contamination may occur between subsequent
and quality reasons, cylinders and bottles shall be clean, dry,
samples taken using the same equipment, and appropriate
and empty before filling.
precautions must be taken to prevent this. It is therefore
recommended that, before taking definitive samples, the equip-
5. Significance and Use
ment is flushed through with an aliquot of the material to be
5.1 Uraniumhexafluorideisnormallyproducedandhandled
sampled. This is normally accomplished by taking an initial
in large (typically 1 to 14-ton) quantities and must, therefore,
volume which is then rejected and not used for definitive
be characterized by reference to representative samples (see
analysis. Alternative procedures to prevent cross-
ISO7195).Thesamplesareusedtodeterminecompliancewith
contamination are possible and should be validated individu-
the applicable commercial specification C787. The quantities
ally.
involved, physical properties, chemical reactivity, and hazard-
ous nature of UF are such that for representative sampling,
8. Procedure for Continuous Sampling During Filling of
specially designed equipment must be used and operated in
a Transport Cylinder
accordance with the most carefully controlled and stringent
8.1 Sample Preparation:
procedures. This practice
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.