1、Designation: C 1431 99 (Reapproved 2005)Standard Guide forCorrosion Testing of Aluminum-Based Spent Nuclear Fuel inSupport of Repository Disposal1This standard is issued under the fixed designation C 1431; the number immediately following the designation indicates the year oforiginal adoption or, in
2、 the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This guide covers corrosion testing of aluminum-basedspent nuclear fuel in support
3、 of geologic repository disposal(per the requirements in 10 CFR 60 and 40CFR191). Thetesting described in this document is designed to provide datafor analysis of the chemical stability and radionuclide releasebehavior of aluminum-based waste forms produced fromaluminum-based spent nuclear fuels. Th
4、e data and analysesfrom the corrosion testing will support the technical basis forinclusion of aluminum-based spent nuclear fuels in the reposi-tory source term. Interim storage and transportation of thespent fuel will precede geologic disposal; therefore, referenceis also made to the requirements f
5、or interim storage (per 10CFR 72) and transportation (per 10 CFR 71). The analyses thatwill be based on the data developed are also necessary tosupport the safety analyses reports (SARs) and performanceassessments (PAs) for disposal systems.1.2 Spent nuclear fuel that is not reprocessed must be safe
6、lymanaged prior to transportation to, and disposal in, a geologicrepository. Placement is an interim storage facility may includedirect placement of the irradiated fuel or treatment of the fuelprior to placement, or both. The aluminum-based waste formsmay be required to be ready for geologic disposa
7、l, or roadready, prior to placement in extended interim storage. Interimstorage facilities, in the United States, handle fuel from civiliancommercial power reactors, defense nuclear materials produc-tion reactors, and research reactors. The research reactorsinclude both foreign and domestic reactors
8、. The aluminum-based fuels in the spent fuel inventory in the United States areprimarily from defense reactors and from foreign and domesticresearch reactors. The aluminum-based spent fuel inventoryincludes several different fuel forms and levels of235U enrich-ment. Highly enriched fuels (235U enric
9、hment levels 20 %)are part of this inventory.1.3 Knowledge of the corrosion behavior of aluminum-based spent nuclear fuels is required to ensure safety and tosupport licensing or other approval activities, or both, neces-sary for disposal in a geologic repository. The response of thealuminum-based s
10、pent nuclear fuel waste form(s) to disposalenvironments must be established for configuration-safetyanalyses, criticality analyses, PAs, and other analyses requiredto assess storage, treatment, transportation, and disposal ofspent nuclear fuels. This is particularly important for the highlyenriched,
11、 aluminum-based spent nuclear fuels. The test proto-cols described in this guide are designed to establish materialresponse under the repository relevant conditions.1.4 The majority of the aluminum-based spent nuclear fuelsare aluminum clad, aluminum-uranium alloys. The aluminum-uranium alloy typica
12、lly consists of uranium aluminide particlesdispersed in an aluminum matrix. Other aluminum-based fuelsinclude dispersions of uranium oxide, uranium silicide, oruranium carbide particles in an aluminum matrix. Theseparticles, including the aluminides, are generally cathodic tothe aluminum matrix. Sel
13、ective leaching of the aluminum inthe exposure environment may provide a mechanism forredistribution and relocation of the uranium-rich particles.Particle redistribution tendencies will depend on the nature ofthe aluminum corrosion processes and the size, shape, distri-bution and relative reactivity
14、 of the uranium-rich particles.Interpretation of test data will require an understanding of thematerial behavior. This understanding will enable evaluation ofthe design and configuration of the waste package to ensurethat unfilled regions in the waste package do not provide sitesfor the relocation o
15、f the uranium-rich particles into nuclearcritical configurations. Test samples must be evaluated, prior totesting, to ensure that the size and shape of the uranium-richparticles in the test samples are representative of the particlesin the waste form being evaluated.1.5 The use of the data obtained
16、by the testing described inthis guide will be optimized to the extent the samples mimicthe condition of the waste form during actual repositoryexposure. The use of Practice C 1174 is recommended forguidance. The selection of test samples, which may be unagedor artificially aged, should ensure that t
17、he test samples andconditions bound the waste form/repository conditions. Thetest procedures should carefully describe any artificial agingtreatment used in the test program and explain why thattreatment was selected.1This guide is under the jurisdiction of ASTM Committee C26 on Nuclear FuelCycle an
18、d is the direct responsibility of Subcommittee C26.13 on Repository Waste.Current edition approved June 1, 2005. Published December 2005. Originallyapproved in 1999. Last previous edition approved in 1999 as C 143199.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocke
19、n, PA 19428-2959, United States.2. Referenced Documents2.1 ASTM Standards:2C 1174 Practice for Prediction of the Long-Term Behaviorof Materials, Including Waste Forms, Used in EngineeredBarrier Systems (EBS) for Geologic Disposal of High-Level Radioactive Waste2.2 Government Documents10 CFR 60 US Co
20、de of Federal Regulations Title 10, Part60, Disposal of High Level Radioactive Wastes in Geo-logic Repositories10 CFR 71 US Code of Federal Regulations Title 10, Part71, Packaging and Transport of Radioactive Materials10 CFR 72 US Code of Federal Regulations Title 10, Part72, Licensing Requirements
21、for the Independent Storageof Spent Nuclear and High-Level Radioactive Waste3. Terminology3.1 Definitions:3.1.1 Terms used in this guide are defined in PracticeC 1174, by common usage, by Websters New World Dictio-nary, or as described in 3.2, or combination thereof.3.2 Definitions:3.2.1 aluminum-ba
22、sed spent nuclear fuelirradiatednuclear fuel or target elements or assemblies, or both, that areclad in aluminum or aluminum-rich alloys. The microstruc-tures contain a continuous aluminum-rich matrix withuranium-rich particles dispersed in this matrix.3.2.2 aluminum-based spent nuclear fuel form or
23、 wasteformany metallic form produced from aluminum-basedspent nuclear fuel and having a microstructure containing acontinuous aluminum-rich matrix with uranium-rich particlesdispersed in this matrix. This term may include the fuel itself.3.2.3 artificial agingany short time treatment that isdesigned
24、 to duplicate or simulate the material/property changesthat normally occur after prolonged exposure and radioactivedecay.3.2.4 attribute testa test conducted to provide materialproperties that are required as input to behavior models, butthat are not themselves responses to the environment.3.2.5 bou
25、ndinga test, sample condition or calculationdesigned to provide an evaluation of the limits to materialbehavior under relevant conditions.3.2.6 characterization testin high-level radioactive wastemanagement, any test conducted principally to furnish infor-mation for a mechanistic understanding of al
26、teration.3.2.7 corrosion productan ion or compound formed dur-ing the interaction of the aluminum-based spent nuclear fuelwith its storage or disposal environment. The corrosion productmay be the result of aqueous corrosion, oxidation, reactionwith moist air, or other types of chemical interaction.3
27、.2.8 interim storage installationa facility designed tostore spent nuclear fuels for an extended period of time thatmeets the intent of the requirements of an independent spentfuel storage installation or a monitored retrievable storagefacility, as described in 10 CFR 72.3.2.9 melt-dilute processa p
28、rocess to lower the fractionof235U in highly enriched, aluminum-based spent nuclear fuelby melting and adding depleted uranium to the waste from.3.2.10 performance assessmentan analysis that identifiesthe processes and events that might affect a disposal system,examines the effects of those processe
29、s and events on theperformance of the disposal system, and estimates the cumu-lative releases of radionuclides considering the associateduncertainties caused by all significant processes and events.3.2.11 safety analysisan analysis to determine the risk tothe public health and safety associated with
30、 the storage,treatment, transportation, or disposal, or combination thereof,of aluminum-based spent nuclear fuel.3.2.12 service condition testa test of a material conductedunder conditions in which the values of the independentvariables characterizing the service environment are in therange expected
31、 in actual service.4. Significance and Use4.1 Disposition of aluminum-based spent nuclear fuel willinvolve:4.1.1 Removal from the existing storage or transfer facility,4.1.2 Characterization or treatment, or both, of the fuel orthe resulting waste form, or both,4.1.3 Placement of the waste form in a
32、 canister,4.1.4 Placement of the canister in a safe and environmen-tally sound interim storage facility,4.1.5 Removal from the interim storage facility and trans-port to the repository,4.1.6 placement in a waste container,4.1.7 Emplacement in the repository, and4.1.8 Repository closure and geologic
33、disposal. Actions ineach of these steps may significantly impact the success of anysubsequent step.4.2 Aluminum-based spent nuclear fuel and the aluminum-based waste forms display physical and chemical characteris-tics that differ significantly from the characteristics of commer-cial nuclear fuels a
34、nd from high level radioactive wasteglasses. For example, some are highly enriched and most haveheterogeneous microstructures that include very small,uranium-rich particles. The impact of this difference on reposi-tory performance must be evaluated and understood.4.3 The U.S. Nuclear Regulatory Comm
35、ission has licensingauthority over public domain transportation and repositorydisposal (and most of the interim dry storage) of spent nuclearfuels and high-level radioactive waste under the requirementsestablished by 10 CFR 60, 10 CFR 71, and 10 CFR 72. Theserequirements outline specific information
36、 needs that should bemet through test protocols, for example, those mentioned inthis guide. The information developed from the tests describedin this guide is not meant to be comprehensive. However, thetests discussed here will provide corrosion property data tosupport the following information need
37、s.4.3.1 A knowledge of the solubility, leaching, oxidation/reduction reactions, and corrosion of the waste form constitu-ents in/by the repository environment (dry air, moist air, andrepository relevant water) (see 10 CFR 60.112 and 135).2For referenced ASTM standards, visit the ASTM website, www.as
38、tm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.C 1431 99 (2005)24.3.2 A knowledge of the effects of radiolysis and tempera-ture on the oxidation, corrosion, and leaching
39、behavior (see 10CFR 60.135).4.3.3 A knowledge of the temperature dependence of thesolubility of waste form constituents plus oxidation and corro-sion products (see 10 CFR 60.135).4.3.4 Information from laboratory experiments or technicalanalyses, or both, about time dependence of the internalconditi
40、on of the waste package (see 10 CFR 60.143 and 10CFR 72.76).4.3.5 Laboratory demonstrations of the effects of the elec-trochemical differences between the aluminum-based wasteform and the candidate packaging materials on galvaniccorrosion (see 10 CFR 71.43) or the significance of electricalcontact b
41、etween the waste form and the packaging materials onitems outlined in 4.3.1-4.3.4 (see 10 CFR 60.135), or both.4.3.6 Information on the risk involved in the receipt, han-dling, packaging, storage, and retrieval of the waste forms (see10 CFR 72.3).4.3.7 Information on the physical and chemical condit
42、ion ofthe waste form upon repository placement so that itemsoutlined in 4.3.1-4.3.4 can be evaluated (see 10 CFR 60.135).4.3.8 Knowledge of the degradation of the waste formduring interim storage so that operational safety problems withrespect to its removal from storage can be assessed, if suchremo
43、val is necessary (see 10 CFR 72.123).4.3.9 Knowledge of the condition of the waste form prior torepository placement so that items outlined in 4.3.1-4.3.4 areproperly addressed (see 10 CFR 60.135).4.4 Conditions expected during each stage of the dispositionprocess must be addressed. Exposure conditi
44、ons anticipatedover the interim storage through geologic disposition periodsinclude dry and moist air, and aqueous environments. The airenvironments are associated with interim storage and the earlystages of repository storage while the aqueous environmentsarise after water intrusion into the reposi
45、tory has causedcorrosion-induced failure of the waste package.5. Information Relevant to Geologic Disposal5.1 Tests of the aluminum-based waste forms should, alongwith applicable and qualified data from the literature, or both,provide data pertinent to (a) corrosion or oxidation of wasteform constit
46、uents in vapor environments, or both, (b) corrosionor oxidation of waste form constituents in liquid environments,or both, (c) dissolution of waste form constituents, (d) oxida-tion products or corrosion products, or both and (e) selectiveleaching of waste form constituents. Selected tests shouldpro
47、vide data concerning:5.1.1 The effective release rates (as solute or colloidalspecies) and dissolution rates of waste form constituents andcorrosion products in water compositions relevant to repositorydisposal,5.1.2 The temperature dependence of, and the effect ofradiolysis products on, waste form
48、constituent solubility inrepository relevant water compositions,5.1.3 The corrosion rate or relative corrosion rates of thevarious constituents in the waste form, or both,5.1.4 An understanding of the effect of waste form micro-structure (the size, shape, distribution, and volume fraction ofthe uran
49、ium-rich particles, for example), corrosion products,and their formation sequence on corrosion and oxidationbehavior, and5.1.5 An understanding of the release of uranium-richcolloids or particles, or both, during storage and disposition.5.2 Tests conducted to supply the data needs described in5.1 would ideally provide sufficient information to help estab-lish mechanistic models, or, in any case, empirical correlations,for:5.2.1 Corrosion rates under the bounding or potential rangeof repository conditions,5.2.2 The effective solubility of waste form constituents,including
