ASTM C1457-00(2010)e1
(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 C753, C776, C888, and C922.
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 μg 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 (μg/g sample) or micrograms hydrogen per gram of uranium (μg/g U).
1.6 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.7 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: C1457 − 00 (Reapproved 2010)
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.
´ NOTE—Editorial corrections were made throughout in June 2010.
1. Scope 2. Referenced Documents
1.1 This test method applies to the determination of hydro- 2.1 ASTM Standards:
C753 Specification for Nuclear-Grade, Sinterable Uranium
gen in nuclear-grade uranium oxide powders and pellets to
determine compliance with specifications. Gadolinium oxide Dioxide Powder
C776 Specification for Sintered Uranium Dioxide Pellets
(Gd O ) and gadolinium oxide-uranium oxide powders and
2 3
pellets may also be analyzed using this test method. C888 Specification for Nuclear-Grade Gadolinium Oxide
(Gd O ) Powder
2 3
1.2 This standard describes a procedure for measuring the
C922 Specification for Sintered Gadolinium Oxide-Uranium
total hydrogen content of uranium oxides. The total hydrogen
Dioxide Pellets
content results from absorbed water, water of crystallization,
hydro-carbides and other hydrogenated compounds which may
3. Summary of Test Method
exist as fuel’s impurities.
3.1 The total hydrogen content is determined using a hy-
1.3 Thistestmethodcoversthedeterminationof0.05to200
drogen analyzer. The hydrogen analyzer is based on the carrier
µg of residual hydrogen. gas method using argon or nitrogen as carrier gas. The actual
configuration of the system may vary with vendor and model.
1.4 This test method describes an electrode furnace carrier
3.2 Thesamplestobeanalyzedaredroppedintoapreheated
gas combustion system equipped with a thermal conductivity
detector. graphite crucible, and then, heated up to a temperature of more
than 1700°C in a graphite crucible. At that temperature
1.5 The preferred system of units is micrograms hydrogen
hydrogen, oxygen, nitrogen, and carbon monoxide (oxygen is
per gram of sample (µg/g sample) or micrograms hydrogen per
converted to CO when it reacts with the crucible) are released.
gram of uranium (µg/g U).
The release gas is purified in the carrier gas stream by
1.6 The values stated in SI units are to be regarded as
oxidation and absorption columns. The hydrogen is separated
standard. No other units of measurement are included in this
by chromatographic means and analyzed in a thermal conduc-
standard.
tivity detector.
1.7 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
designed to determine whether the hydrogen content meets
Specifications C753, C776, C888, and C922.
This test method is under the jurisdiction ofASTM Committee C26 on Nuclear
Fuel Cycle and is the direct responsibility of Subcommittee C26.05 on Methods of
Test. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved June 1, 2010. Published June 2010. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 2000. Last previous edition approved in 2005 as C1457 – 00 (2005). Standards volume information, refer to the standard’s Document Summary page on
DOI: 10.1520/C1457-00R10E01. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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C1457 − 00 (2010)
5. Interferences 7.3 Carrier Gas Purifiers:
7.3.1 Copper Oxide, or rare earth copper oxide (converts H
5.1 Contamination of carrier gas, crucibles, or samples with
to H O), or
extraneous sources of hydrogen may cause a positive bias. A
7.3.2 Copper Turnings, or granules.
blankcorrectionwillhelptominimizethebiasfromcarriergas
and crucibles. Interference from adsorbed hydrogen on 7.4 Molecular Sieve-Sodium Hydroxide, on a fiber support
samples may be eliminated by keeping the sample in an inert (sodium hydroxide reacts with CO to yield water; the molecu-
atmosphere or vacuum. lar sieve separates N and H ).
2 2
5.2 The purification system typically associated with the 7.5 Schutze Reagent, iodine pentoxide over silica gel (con-
recommended combustion and detection equipment is de- verts CO to CO ).
signed to minimize other expected sources of interferences,
7.6 Magnesium Perchlorate—removes water.
suchassulfur,halogens,carbonmonoxide,carbondioxide,and
7.7 Silicone Vacuum Grease.
water.
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
becomes loaded with contaminants that prevent proper peak
7.11 Aluminum Oxide (Al O ), to check furnace tempera-
2 3
separation.
ture.
5.3 The temperature of >1700–1800°C must be reached. If
7.12 Hydrogen Standard Materials—Calibrate the instru-
not, the decomposition of the released water to hydrogen and
ment using either high purity (99.9999 %) certified hydrogen
carbon monoxide may not be complete. The temperature will
gas or NIST-traceable, or equivalent, metal standards. Steel
depend upon the instrument and type of graphite crucible used.
standards are the preferred metal standards because no flux is
Single wall crucibles will require a lower temperature (power)
used, and this best matches the conditions used to analyze
than double wall crucibles.
uranium oxide samples. Zr- or Ti-hydride standards may be
used, but require the use of a flux metal.
5.4 Incomplete fusion may result in partial or a late release
of hydrogen resulting in low results.
7.13 Sodium Tartrate or Sodium Tungstate may be used as
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 interference can be minimized by
or handling operations.
use of 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, crucible
hazards. Follow the manufacturer’s recommendations for safe
hot spots, or from misaligned electrodes may cause analysis
operation.
errors. Uranium samples should be evenly fused, fall out freely
8.3 This procedure uses hazardous chemicals. Use appro-
of the crucibles and contain very little uranium metal.
priate precautions for handling corrosives, oxidizers, and
gases.
6. Apparatus
6.1 Hydrogen Analyzer, consisting of an electrode furnace
9. Preparation of Apparatus
capable of operation at least up to 2200 to 2500°C, a thermal
9.1 Inspect and change instrument column packing and
conductivity detector for measuring, and auxiliary purification
reagents as recommended by manufacturer.
systems.
9.2 Che
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