ASTM C1052-20

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: C1052 − 14 C1052 − 20
Standard Practice for
Bulk Sampling of Liquid Uranium Hexafluoride
This standard is issued under the fixed designation C1052; 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
1.1 This practice covers methods for withdrawing representative samples of liquid uranium hexafluoride (UF ) from bulk
quantities of the material. Such samples are then prepared for further analytical testing in accordance with Practices C1689 and
C1346. Multiple different methods are used for determining compliance with the applicable commercial specification, for example
SpecificationSpecifications C787 and Specification C996. Methods used for compliance to each of these standards can be found
in the Referenced Documents section of each respective specification.
1.2 It is assumed that the bulk liquid UF being sampled comprises a single quality and quantity of material. This practice does
not address any special additional arrangements that might be required for taking proportional or composite samples. When the
sampled bulk material is being added to UF residues already in a container (“heels recycle”) additional arrangements are required
to avoid cross contamination of the bulk UF , these are addressed in the appropriate section (8.2) of Specifications C787 and C996.
1.3 The number of samples to be taken, their nominal sample weight, and their disposition shall be agreed upon between the
parties.
1.4 The scope of this practice does not include provisions for preventing criticality incidents.
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 safety, health, and healthenvironmental 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.
2. Referenced Documents
2.1 ASTM Standards:
C787 Specification for Uranium Hexafluoride for Enrichment
C859 Terminology Relating to Nuclear Materials
C996 Specification for Uranium Hexafluoride Enriched to Less Than 5 % U
C1346 Practice for Dissolution of UF from P-10 Tubes
C1689 Practice for Subsampling of Uranium Hexafluoride
2.2 Other Documents:
USEC-651 Uranium Hexafluoride: A Manual of Good Handling Practices
ANSI N14.1 Uranium Hexafluoride: Packaging for Transport
3,4
ISO/DIS 7195 Packaging of Uranium Hexafluoride (UF ) for Transport
USEC-651 Uranium Hexafluoride: A Manual of Good Handling Practices
This practice is under the jurisdiction of ASTM Committee C26 on Nuclear Fuel Cycle and is the direct responsibility of Subcommittee C26.02 on Fuel and Fertile
Material Specifications.
Current edition approved Jan. 15, 2014July 1, 2020. Published February 2014August 2020. Originally approved in 1985. Last previous edition approved in 20072014 as
C1052 – 01 (2007).C1052 – 14. DOI: 10.1520/C1052-14.10.1520/C1052-20.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Available from United States Enrichment Corp., 6903 Rockledge Dr., Bethesda, MD 20817.
Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.
Available from International Organization for Standardization (ISO), ISO Central Secretariat, BIBC II, Chemin de Blandonnet 8, CP 401, 1214 Vernier, Geneva,
Switzerland, http://www.iso.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C1052 − 20
3. Terminology
3.1 Definitions:
3.1.1 For definitions of terms used in this practice but not defined herein, refer to Terminology C859.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 container—container, n—the bulk vessel either holding or receiving by transfer, the UF to be sampled; it may consist of,
for example, a fixed vessel in a UF handling plant or a cylinder to be used for the transport of UF .
6 6
3.2.2 sample bottle—bottle, n—the small vessel into which the sample of UF is withdrawn for transfer to the laboratory for
characterization.
4. Summary of Practice
4.1 Two methods of withdrawing a sample are described, namely: (1) direct withdrawal from a filled container, and (2)
withdrawal from the inlet-line during the filling of a container by liquid transfer. The first method involves tilting or turning the
container in such a way that its valve is below the surface of the liquefied UF , and dependent on the equipment, this requires that
the container holds more than a specified minimum quantity of UF . Liquid UF is withdrawn into a graduated volume and then
6 6
transferred to the respective sample bottle(s). In the second method, a small proportion of the UF flowing from one container to
another is withdrawn into a graduated volume and then transferred to the respective sample bottle(s).
4.2 For both methods of sampling, the presence of residues may have significant implications for the quality of the UF . For
safety and quality reasons, containers and bottles shall be clean, dry, and empty before filling.
4.3 Various types of sample bottles are in use and are described in detail in the applicable national and international standards,
for example, ANSI N14.1 and ISO/DIS 7195. For a given type of sample bottle, the detailed configuration, for example, valve
orientation, terminal fittings, and the like, may vary. Hence, the type and configuration of bottles to be used for the withdrawal of
samples shall be agreed upon between the parties.
5. Significance and Use
5.1 Uranium hexafluoride is normally produced and handled in large (typically 1- to 20-ton) quantities and must, therefore, be
characterized by reference to representative samples. The quantities involved, physical properties, chemical reactivity, and
hazardous nature of UF 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 indicates appropriate principles, equipment,
and procedures currently in use for bulk sampling of liquid UF . It is used by UF converters, enrichers, and fuel fabricators to
6 6
review the effectiveness of existing procedures or as a guide to the design of equipment and procedures for future use.
5.2 It is emphasized that this practice is not meant to address conventional or nuclear criticality safety issues.
6. Hazards
6.1 Because of its chemical, radiochemical, and toxic properties, UF is a hazardous material. UF is very reactive and
6 6
corrosive. It reacts readily with water, atmospheric moisture, certain metals, and many organic materials. For reasons of safety and
to avoid contamination, precautions must be taken to avoid contact with such materials. Suitable handling procedures are described
in USEC-651.
7. Principles
7.1 The essential purpose of the sample is to be representative of the bulk material for the purpose of determining compliance
with the applicable material specification. To ensure that the sample is representative for this purpose, certain principles, as
described below, must be observed.
7.2 Special attention must be given to ensuring that the bulk material from which the sample is withdrawn is homogeneous,
particularly in those circumstances when it has been prepared by the blending together of materials having different compositions.
In practice, the low viscosity, and hence easy mobility, of liquid UF facilitates the process of homogenization by the action of
convection currents within the bulk upon heating. It is necessary to determine and establish for each set of sampling equipment
the physical conditions, normally a combination of the minimum time and temperature for which liquefied uranium hexafluoride
is held, which guarantee homogeneity of the bulk UF .
7.3 The sampling equipment is fabricated to appropriate high standards of vacuum integrity, and components in direct contact
with UF are made from nickel, high-nickel alloys, or materials having equivalent resistance to UF corrosion. The formation of
6 6
an inert fluoride layer is often an important feature of UF corrosion resistance, and hence, internal surfaces are generally
conditioned with a suitable fluorinating agent, sometimes UF itself.
7.4 Cross-contamination may occur between subsequent samples taken using the same equipment, and appropriate precautions
must be taken to prevent this. It is therefore recommended that, before taking definitive samples, the equipment is flushed through
------------------
...