ASTM C1076-97(2004)
(Specification)Standard Specification for Nuclear Grade Hafnium Oxide Pellets
Standard Specification for Nuclear Grade Hafnium Oxide Pellets
ABSTRACT
This specification covers the properties and requirements for pellets of stabilized cubic hafnium oxide used in nuclear reactors. Hafnium oxide should consist of a stabilizing agent, the recommended of which is yttrium oxide, though others such as calcium oxide and magnesium oxide may also be used as agreed upon by the buyer and seller. The material shall meet specified values of the following requirements: physical dimensions; density; mechanical properties; phase stabilization; impurity concentration limits; moisture concentration limit; visual appearance; end and circumferential chips; cracks; and fissures and other defects.
SCOPE
1.1 This specification applies to pellets of stabilized cubic hafnium oxide used in nuclear reactors.
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: C 1076 – 97 (Reapproved 2004)
Standard Specification for
Nuclear Grade Hafnium Oxide Pellets
This standard is issued under the fixed designation C 1076; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope 3.1.4 phase transformation—rearrangement of the atomic
ordering of a crystalline lattice as a material is cycled through
1.1 This specification applies to pellets of stabilized cubic
a critical transformation or inversion temperature. The change
hafnium oxide used in nuclear reactors.
from one crystalline phase to another may be accompanied by
1.2 The values stated in SI units are to be regarded as the
a volume change that could lead to cracks or defects in articles
standard. The values given in parentheses are for information
,
5 6
fabricated from such materials.
only.
3.1.5 powder lot—a specified quantity of hafnium oxide
2. Referenced Documents powder with stabilizing additive, blended together such that
samples taken in accordance with Section 7 can be considered
2.1 ASTM Standards:
as representative of the entire quantity.
C 559 Test Method for Bulk Density by Physical Measure-
3.1.6 seller—hafnium oxide pellet supplier.
ments of Manufactured Carbon and Graphite Articles
3.1.7 stabilizing additive—a material which, when present
C 859 Terminology Relating to Nuclear Materials
insufficientconcentrationinthesubjectmaterialexhibitingthe
C 1098 Specification for Nuclear Grade Hafnium Oxide
phase transformation, produces a stabilized crystalline phase
Powder
that does not undergo a transformation or inversion at any
E 105 Practice for Probability Sampling of Materials
temperature within the expected fabrication or usage regime of
2.2 ANSI Standard:
the manufactured pellet. The potentially deleterious volume
ANSI/ASME NQA-1 Quality Assurance Program Require-
change is therefore avoided.
ments for Nuclear Facility Applications
2.3 U.S. Government Document:
4. Chemical Composition
Code of Federal Regulations, Title 10, Part 50—Energy
4.1 The starting hafnium oxide powder shall be in accor-
(10CFR 50) Domestic Licensing of Production and Utili-
dance with Specification C 1098.
zation Facilities
4.2 Astabilizing additive shall be utilized with the hafnium
3. Terminology oxide. The recommended stabilizing additive is yttrium oxide
(Y O ). The typical concentration range is 7 to 10 weight %
3.1 Definitions—Terms shall be defined in accordance with 2 3
Y O in the finished product. References to other stabilizing
Terminology C 859 except for the following: 2 3
additives (such as calcium oxide (CaO) and magnesium oxide
3.1.1 buyer—organization issuing the purchase order.
(MgO)) may be found in the literature and these additives may
3.1.2 pellet—fabricated geometric shape of stabilized cubic
be used if agreed upon by the buyer and seller. It is cautioned,
hafnium oxide having a chemical composition as described in
however, that the buyer should be aware of potential destabi-
Section 4.
lization during thermal cycling when MgO or CaO is used.
3.1.3 pellet lot—the pellets produced from one hafnium
4.3 Use analytical chemistry methods as agreed upon be-
oxidepowderlotusingonesetofprocessparameters.Pelletlot
tween the buyer and the seller.
size shall be agreed upon between the seller and the buyer.
4.4 The hafnium concentration, in grams of hafnium per
unit volume or grams of hafnium per unit length, may be
This specification is under the jurisdiction of ASTM Committee C-26 on
specified by the buyer. In specifying the allowable range in
Nuclear Fuel Cycle and is the direct responsibility of Subcommittee C26.03 on
hafnium concentration, the buyer should consider the follow-
Neutron Absorber Materials Specifications.
Current edition approved May 10, 1997. Published May 1998. Originally
ing:
published as C 1076 – 87. Last previous edition C 1076 – 87.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Sevice at service@astm.org. For Annual Book of ASTM
Standardsvolume information, refer to the standard’s Document Summary page on Curtis, C. E., Doney, L. M., and Johnson, J. R., “Some Properties of
the ASTM website. Hafnium-Oxide, Hafnium-Silicate, Calcium-Hafnate, and Hafnium-Carbide,” Jour-
Available from American National Standards Institute, 11 W. 42nd St., 13th nal of American Ceramics Society, Vol 37, 1954, pp. 458–465.
Floor, New York, NY 10036. Brown, L. M., and Madiyasni, K. S., “Characterization of Alkoxy-Derived
Available from Superintendent of Documents, U.S. Government Printing Yttria-Stabilized Hafnia,” Journal ofAmerican Ceramics Society, Vol 53, 1970, pp.
Office, Washington, DC 20402. 590–594.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
C 1076 – 97 (2004)
4.4.1 Variations in chemical composition, satisfactory development of the cubic phace shall be mutually
4.4.2 Pellet bulk density, agreed upon between the buyer and the seller.
4.4.3 Type and concentration of stabilizing additive, and
5.5 Visual Appearance—Visual examination shall be con-
4.4.4 Pellet dimensions and dimensional tolerances. ducted on finished pellets in accordance with Section 7 on
4.5 The impurity concentration, excluding zirconia and the
Sampling. The seller and the buyer shall agree on visual
stabilizing additive, shall not exceed 0.5 weight %. Individual standards as representing the requirements of 5.5.1, 5.5.2, and
element limits are specified in Table 1. The buyer may specify
5.5.3.Thesestandardsshallbeusedasacceptancestandardsfor
additional limits for any other elements not listed in Table 1. the visual examination of the pellets. In the event of a dispute,
4.6 The zirconium concentration shall not exceed 4.5
the method of defect measurement shall be submitted by the
weight % on the basis of Zr/(Zr + Hf). seller for approval by the buyer. Maximum permissible defects
4.7 The moisture concentration limit is included in the total
are defined as follows:
hydrogen limit (see Table 1).
5.5.1 End Chips—Pellet-end surface shall not be chipped
beyond 10 % of the end-face surface area and no chip shall
5. Physical Requirements
exceed 1.02 mm (0.040 in.) in depth.
5.1 Physical Dimensions:
5.5.2 Circumferential Chips—Pellet circumferential sur-
5.1.1 Dimens
...
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