ASTM C1431-99(2005)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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:C1431–99 (Reapproved 2005)
Standard Guide for
Corrosion Testing of Aluminum-Based Spent Nuclear Fuel in
Support of Repository Disposal
This standard is issued under the fixed designation C1431; 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 sary for disposal in a geologic repository. The response of the
aluminum-based spent nuclear fuel waste form(s) to disposal
1.1 This guide covers corrosion testing of aluminum-based
environments must be established for configuration-safety
spent nuclear fuel in support of geologic repository disposal
analyses, criticality analyses, PAs, and other analyses required
(per the requirements in 10 CFR 60 and 40CFR191). The
to assess storage, treatment, transportation, and disposal of
testing described in this document is designed to provide data
spentnuclearfuels.Thisisparticularlyimportantforthehighly
for analysis of the chemical stability and radionuclide release
enriched, aluminum-based spent nuclear fuels. The test proto-
behavior of aluminum-based waste forms produced from
cols described in this guide are designed to establish material
aluminum-based spent nuclear fuels. The data and analyses
response under the repository relevant conditions.
from the corrosion testing will support the technical basis for
1.4 The majority of the aluminum-based spent nuclear fuels
inclusion of aluminum-based spent nuclear fuels in the reposi-
are aluminum clad, aluminum-uranium alloys. The aluminum-
tory source term. Interim storage and transportation of the
uraniumalloytypicallyconsistsofuraniumaluminideparticles
spent fuel will precede geologic disposal; therefore, reference
dispersed in an aluminum matrix. Other aluminum-based fuels
is also made to the requirements for interim storage (per 10
include dispersions of uranium oxide, uranium silicide, or
CFR 72) and transportation (per 10 CFR 71).The analyses that
uranium carbide particles in an aluminum matrix. These
will be based on the data developed are also necessary to
particles, including the aluminides, are generally cathodic to
support the safety analyses reports (SARs) and performance
the aluminum matrix. Selective leaching of the aluminum in
assessments (PAs) for disposal systems.
the exposure environment may provide a mechanism for
1.2 Spent nuclear fuel that is not reprocessed must be safely
redistribution and relocation of the uranium-rich particles.
managed prior to transportation to, and disposal in, a geologic
Particle redistribution tendencies will depend on the nature of
repository.Placementisaninterimstoragefacilitymayinclude
the aluminum corrosion processes and the size, shape, distri-
direct placement of the irradiated fuel or treatment of the fuel
bution and relative reactivity of the uranium-rich particles.
prior to placement, or both. The aluminum-based waste forms
Interpretation of test data will require an understanding of the
may be required to be ready for geologic disposal, or road
materialbehavior.Thisunderstandingwillenableevaluationof
ready, prior to placement in extended interim storage. Interim
the design and configuration of the waste package to ensure
storagefacilities,intheUnitedStates,handlefuelfromcivilian
that unfilled regions in the waste package do not provide sites
commercial power reactors, defense nuclear materials produc-
for the relocation of the uranium-rich particles into nuclear
tion reactors, and research reactors. The research reactors
criticalconfigurations.Testsamplesmustbeevaluated,priorto
include both foreign and domestic reactors. The aluminum-
testing, to ensure that the size and shape of the uranium-rich
based fuels in the spent fuel inventory in the United States are
particles in the test samples are representative of the particles
primarily from defense reactors and from foreign and domestic
in the waste form being evaluated.
research reactors. The aluminum-based spent fuel inventory
1.5 The use of the data obtained by the testing described in
includes several different fuel forms and levels of U enrich-
this guide will be optimized to the extent the samples mimic
ment. Highly enriched fuels ( U enrichment levels > 20 %)
the condition of the waste form during actual repository
are part of this inventory.
exposure. The use of Practice C1174 is recommended for
1.3 Knowledge of the corrosion behavior of aluminum-
guidance. The selection of test samples, which may be unaged
based spent nuclear fuels is required to ensure safety and to
or artificially aged, should ensure that the test samples and
support licensing or other approval activities, or both, neces-
conditions bound the waste form/repository conditions. The
test procedures should carefully describe any artificial aging
This guide is under the jurisdiction ofASTM Committee C26 on Nuclear Fuel
treatment used in the test program and explain why that
Cycleandisthedirectresponsibilityof SubcommitteeC26.13 onRepositoryWaste.
treatment was selected.
Current edition approved June 1, 2005. Published December 2005. Originally
approved in 1999. Last previous edition approved in 1999 as C1431–99. DOI:
10.1520/C1431-99R05.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
C1431–99 (2005)
2. Referenced Documents fuel storage installation or a monitored retrievable storage
facility, as described in 10 CFR 72.
2.1 ASTM Standards:
3.2.9 melt-dilute process—a process to lower the fraction
C1174 Practice for Prediction of the Long-Term Behavior
of U in highly enriched, aluminum-based spent nuclear fuel
of Materials, Including Waste Forms, Used in Engineered
by melting and adding depleted uranium to the waste from.
Barrier Systems (EBS) for Geological Disposal of High-
3.2.10 performance assessment—an analysis that identifies
Level Radioactive Waste
the processes and events that might affect a disposal system,
2.2 Government Documents
examines the effects of those processes and events on the
10 CFR 60 US Code of Federal Regulations Title 10, Part
performance of the disposal system, and estimates the cumu-
60, Disposal of High Level Radioactive Wastes in Geo-
lative releases of radionuclides considering the associated
logic Repositories
uncertainties caused by all significant processes and events.
10 CFR 71 US Code of Federal Regulations Title 10, Part
3.2.11 safety analysis—an analysis to determine the risk to
71, Packaging and Transport of Radioactive Materials
the public health and safety associated with the storage,
10 CFR 72 US Code of Federal Regulations Title 10, Part
treatment, transportation, or disposal, or combination thereof,
72, Licensing Requirements for the Independent Storage
of aluminum-based spent nuclear fuel.
of Spent Nuclear and High-Level Radioactive Waste
3.2.12 service condition test—a test of a material conducted
under conditions in which the values of the independent
3. Terminology
variables characterizing the service environment are in the
3.1 Definitions:
range expected in actual service.
3.1.1 Terms used in this guide are defined in Practice
C1174, by common usage, by Webster’s New World Dictio-
4. Significance and Use
nary, or as described in 3.2, or combination thereof.
4.1 Disposition of aluminum-based spent nuclear fuel will
3.2 Definitions:
involve:
3.2.1 aluminum-based spent nuclear fuel—irradiated
4.1.1 Removal from the existing storage or transfer facility,
nuclear fuel or target elements or assemblies, or both, that are
4.1.2 Characterization or treatment, or both, of the fuel or
clad in aluminum or aluminum-rich alloys. The microstruc-
the resulting waste form, or both,
tures contain a continuous aluminum-rich matrix with
4.1.3 Placement of the waste form in a canister,
uranium-rich particles dispersed in this matrix.
4.1.4 Placement of the canister in a safe and environmen-
3.2.2 aluminum-based spent nuclear fuel form or waste
tally sound interim storage facility,
form—any metallic form produced from aluminum-based
4.1.5 Removal from the interim storage facility and trans-
spent nuclear fuel and having a microstructure containing a
port to the repository,
continuous aluminum-rich matrix with uranium-rich particles
4.1.6 placement in a waste container,
dispersed in this matrix. This term may include the fuel itself.
4.1.7 Emplacement in the repository, and
3.2.3 artificial aging—any short time treatment that is
4.1.8 Repository closure and geologic disposal. Actions in
designedtoduplicateorsimulatethematerial/propertychanges
each of these steps may significantly impact the success of any
that normally occur after prolonged exposure and radioactive
subsequent step.
decay.
4.2 Aluminum-based spent nuclear fuel and the aluminum-
3.2.4 attribute test—a test conducted to provide material
based waste forms display physical and chemical characteris-
properties that are required as input to behavior models, but
ticsthatdiffersignificantlyfromthecharacteristicsofcommer-
that are not themselves responses to the environment.
cial nuclear fuels and from high level radioactive waste
3.2.5 bounding—a test, sample condition or calculation
glasses. For example, some are highly enriched and most have
designed to provide an evaluation of the limits to material
heterogeneous microstructures that include very small,
behavior under relevant conditions.
uranium-rich particles.The impact of this difference on reposi-
3.2.6 characterization test—in high-level radioactive waste
tory performance must be evaluated and understood.
management, any test conducted principally to furnish infor-
4.3 The U.S. Nuclear Regulatory Commission has licensing
mation for a mechanistic understanding of alteration.
authority over public domain transportation and repository
3.2.7 corrosion product—an ion or compound formed dur-
disposal (and most of the interim dry storage) of spent nuclear
ing the interaction of the aluminum-based spent nuclear fuel
fuels and high-level radioactive waste under the requirements
withitsstorageordisposalenvironment.Thecorrosionproduct
established by 10 CFR 60, 10 CFR 71, and 10 CFR 72. These
may be the result of aqueous corrosion, oxidation, reaction
requirements outline specific information needs that should be
with moist air, or other types of chemical interaction.
met through test protocols, for example, those mentioned in
3.2.8 interim storage installation—a facility designed to
this guide. The information developed from the tests described
store spent nuclear fuels for an extended period of time that
in this guide is not meant to be comprehensive. However, the
meets the intent of the requirements of an independent spent
tests discussed here will provide corrosion property data to
support the following information needs.
4.3.1 A knowledge of the solubility, leaching, oxidation/
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
reduction reactions, and corrosion of the waste form constitu-
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
ents in/by the repository environment (dry air, moist air, and
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. repository relevant water) (see 10 CFR 60.112 and 135).
C1431–99 (2005)
4.3.2 Aknowledge of the effects of radiolysis and tempera- the uranium-rich particles, for example), corrosion products,
ture on the oxidation, corrosion, and leaching behavior (see 10 and their formation sequence on corrosion and oxidation
CFR 60.135). behavior, and
4.3.3 A knowledge of the temperature dependence of the 5.1.5 An understanding of the release of uranium-rich
solubility of waste form constituents plus oxidation and corro- colloids or particles, or both, during storage and disposition.
sion products (see 10 CFR 60.135). 5.2 Tests conducted to supply the data needs described in
4.3.4 Information from laboratory experiments or technical 5.1 would ideally provide sufficient information to help estab-
analyses, or both, about time dependence of the internal lishmechanisticmodels,or,inanycase,empiricalcorrelations,
condition of the waste package (see 10 CFR 60.143 and 10 for:
CFR 72.76). 5.2.1 Corrosion rates under the bounding or potential range
4.3.5 Laboratory demonstrations of the effects of the elec- of repository conditions,
trochemical differences between the aluminum-based waste 5.2.2 The effective solubility of waste form constituents,
form and the candidate packaging materials on galvanic including corrosion products, as a function of the temperature
corrosion (see 10 CFR 71.43) or the significance of electrical and chemistry of the water that may surround the waste form
contactbetweenthewasteformandthepackagingmaterialson after a canister breach in the repository, and
items outlined in 4.3.1-4.3.4 (see 10 CFR 60.135), or both. 5.2.3 The selective leaching of the aluminum matrix from
4.3.6 Information on the risk involved in the receipt, han- the uranium-rich particles with anticipated waste package/
dling, packaging, storage, and retrieval of the waste forms (see repository environments.
10 CFR 72.3). 5.3 Theinformationneedsdescribedin5.1andcorrelations/
4.3.7 Information on the physical and chemical condition of models described in 5.2 should enable the calculation of the
the waste form upon repository placement so that items rateofreleaseofradionuclidesfromthealuminum-basedwaste
outlined in 4.3.1-4.3.4 can be evaluated (see 10 CFR 60.135). forms stored in the repository.
4.3.8 Knowledge of the degradation of the waste form 5.4 The information needs described in 5.1 should provide
during interim storage so that operational safety problems with the necessary particle size and leach rate information for an
respect to its removal from storage can be assessed, if such analysttomodelthepotentialforacriticalityresultingfromthe
removal is necessary (see 10 CFR 72.123). redistribution of uranium-rich particles.
4.3.9 Knowledge of the condition of the waste form prior to
6. Relationship of Aluminum-Based Waste Forms to
repository placement so that items outlined in 4.3.1-4.3.4 are
Other Waste Forms
properly addressed (see 10 CFR 60.135).
6.1 The aluminum-based waste forms differ from commer-
4.4 Conditionsexpectedduringeachstageofthedisposition
cialspentfuelsandhighlevelwasteglassesinseveralrespects,
process must be addressed. Exposure conditions anticipated
including homogeneity, reactivity, and the tendency toward
over the interim storage through geologic disposition periods
galvan
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