ASTM C1457-00(2005)
(Test Method)Standard Test Method for the Determination of Total Hydrogen Content of Uranium Oxide Powders and Pellets by Carrier Gas Extraction
Standard Test Method for the Determination of Total Hydrogen Content of Uranium Oxide Powders and Pellets by Carrier Gas Extraction
SIGNIFICANCE AND USE
Uranium dioxide is used as a nuclear-reactor fuel. Gadolinium oxide is used as an additive to uranium dioxide. In order to be suitable for this purpose, these materials must meet certain criteria for impurity content. This test method is designed to determine whether the hydrogen content meets Specifications C 753, C 776, C 888, and C 922.
SCOPE
1.1 This test method applies to the determination of hydrogen in nuclear-grade uranium oxide powders and pellets to determine compliance with specifications. Gadolinium oxide (Gd2O3) and gadolinium oxide-uranium oxide powders and pellets may also be analyzed using this test method.
1.2 This standard describes a procedure for measuring the total hydrogen content of uranium oxides. The total hydrogen content results from absorbed water, water of crystallization, hydro-carbides and other hydrogenated compounds which may exist as fuel's impurities.
1.3 This test method covers the determination of 0.05 to 200 g of residual hydrogen.
1.4 This test method describes an electrode furnace carrier gas combustion system equipped with a thermal conductivity detector.
1.5 The preferred system of units is micrograms hydrogen per gram of sample (g/g sample) or micrograms hydrogen per gram of uranium (g/g U).
1.6 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.
General Information
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information.
Designation:C1457–00 (Reapproved 2005)
Standard Test Method for
Determination of Total Hydrogen Content of Uranium Oxide
Powders and Pellets by Carrier Gas Extraction
This standard is issued under the fixed designation C1457; 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 C888 Specification for Nuclear-Grade Gadolinium Oxide
(Gd O ) Powder
1.1 This test method applies to the determination of hydro- 2 3
C922 Specification for Sintered Gadolinium Oxide-
gen in nuclear-grade uranium oxide powders and pellets to
Uranium Dioxide Pellets
determine compliance with specifications. Gadolinium oxide
(Gd O ) and gadolinium oxide-uranium oxide powders and
2 3
3. Summary of Test Method
pellets may also be analyzed using this test method.
3.1 The total hydrogen content is determined using a hy-
1.2 This standard describes a procedure for measuring the
drogen analyzer. The hydrogen analyzer is based on the carrier
total hydrogen content of uranium oxides. The total hydrogen
gas method using argon or nitrogen as carrier gas. The actual
content results from absorbed water, water of crystallization,
configuration of the system may vary with vendor and model.
hydro-carbides and other hydrogenated compounds which may
3.2 Thesamplestobeanalyzedaredroppedintoapreheated
exist as fuel’s impurities.
graphite crucible, and then, heated up to a temperature of more
1.3 Thistestmethodcoversthedeterminationof0.05to200
than 1700°C in a graphite crucible. At that temperature
µg of residual hydrogen.
hydrogen, oxygen, nitrogen, and carbon monoxide (oxygen is
1.4 This test method describes an electrode furnace carrier
converted to CO when it reacts with the crucible) are released.
gas combustion system equipped with a thermal conductivity
The release gas is purified in the carrier gas stream by
detector.
oxidation and absorption columns. The hydrogen is separated
1.5 The preferred system of units is micrograms hydrogen
by chromatographic means and analyzed in a thermal conduc-
per gram of sample (µg/g sample) or micrograms hydrogen per
tivity detector.
gram of uranium (µg/g U).
1.6 This standard does not purport to address all of the
4. Significance and Use
safety concerns, if any, associated with its use. It is the
4.1 Uranium dioxide is used as a nuclear-reactor fuel.
responsibility of the user of this standard to establish appro-
Gadolinium oxide is used as an additive to uranium dioxide. In
priate safety and health practices and determine the applica-
order to be suitable for this purpose, these materials must meet
bility of regulatory limitations prior to use.
certain criteria for impurity content. This test method is
2. Referenced Documents designed to determine whether the hydrogen content meets
2 Specifications C753, C776, C888, and C922.
2.1 ASTM Standards:
C753 Specification for Nuclear-Grade, Sinterable Uranium
5. Interferences
Dioxide Powder
5.1 Contamination of carrier gas, crucibles, or samples with
C776 Specification for Sintered Uranium Dioxide Pellets
extraneous sources of hydrogen may cause a positive bias. A
blankcorrectionwillhelptominimizethebiasfromcarriergas
This test method is under the jurisdiction ofASTM Committee C26 on Nuclear
and crucibles. Interference from adsorbed hydrogen on
Fuel Cycle and is the direct responsibility of Subcommittee C26.05 on Methods of
samples may be eliminated by keeping the sample in an inert
Test.
atmosphere or vacuum.
Current edition approved June 1, 2005. Published December 2005. Originally
5.2 The purification system typically associated with the
approved in 2000. Last previous edition approved in 2000 as C1457–00. DOI:
10.1520/C1457-00R05.
recommended combustion and detection equipment is de-
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
signed to minimize other expected sources of interferences,
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
suchassulfur,halogens,carbonmonoxide,carbondioxide,and
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. water.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
C1457–00 (2005)
5.2.1 The nitrogen and hydrogen peaks are close together 7.8 Tin Flux, if Zr or Ti hydride standards are to be used.
and must be well-separated to prevent falsely high result from 7.9 Graphite Crucibles.
the nitrogen. The molecular sieve must be sufficiently long to 7.10 Tin Capsules.
separate the peaks and must be changed when the column 7.11 Aluminum Oxide (Al O ), to check furnace tempera-
2 3
becomes loaded with contaminants that prevent proper peak ture.
separation. 7.12 Hydrogen Standard Materials—Calibrate the instru-
5.3 The temperature of >1700–1800°C must be reached. If ment using either high purity (99.9999 %) certified hydrogen
not, the decomposition of the released water to hydrogen and gas or NIST-traceable, or equivalent, metal standards. Steel
carbon monoxide may not be complete. The temperature will standards are the preferred metal standards because no flux is
depend upon the instrument and type of graphite crucible used. used, and this best matches the conditions used to analyze
Single wall crucibles will require a lower temperature (power) uranium oxide samples. Zr- or Ti-hydride standards may be
than double wall crucibles. used, but require the use of a flux metal.
5.4 Incomplete fusion may result in partial or a late release 7.13 Sodium Tartrate or Sodium Tungstate may be used as
of hydrogen resulting in low results. check standards for uranium powder analyses.
5.5 At temperatures of more than 2200°C uranium metal
may be formed, and carbon dioxide released because of 8. Hazards and Precautions
reduction of UO by the graphite crucible.
8.1 Take proper safety precautions to prevent inhalation or
5.5.1 Carbon dioxide will interfere with the thermal con-
ingestion of uranium dioxide powders or dust during grinding
ductivity measurement. This is normally covered by use of
or handling operations.
chemical absorption, or a molecular sieve column, or both.
8.2 Operation of equipment presents electrical and thermal
5.5.2 Excess temperature, from too much power, or crucible
hazards. Follow the manufacturer’s recommendations for safe
hot spots, from misaligned electrodes may cause analysis
operation.
errors. Uranium samples should be evenly fused and should
8.3 This procedure uses hazardous chemicals. Use appro-
fall out freely of the crucibles and contain very little uranium
priate precautions for handling corrosives, oxidizers, and
metal.
gases.
6. Apparatus
9. Preparation of Apparatus
6.1 Hydrogen Analyzer, consisting of an electrode furnace
9.1 Inspect and change instrument column packing and
capable of operation at least up to 2200 to 2500°C, a thermal
reagents as recommended by manufacturer.
conductivity detector for measuring, and auxiliary purification
9.2 Check to ensure that the furnace heats properly on a
systems.
periodic basis. A quarterly check is recommended. A properly
6.2 Balance, with precision of 6 1 mg.
functioning furnace, set at normal operating parameters should
fuse Al O (approximately 2050°C melting point, depending
2 3
7. Reagents and Materials
upon form).
7.1 Purity of Reagents—Reagent grade chemicals shall be
9.3 Set the operating controls of the instrument system
used in all tests. Unless otherwise indicated, it is intended that
according to the operating instructions for the specific equip-
all reagents sh
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