1、Designation: C1431 99 (Reapproved 2010)1Standard Guide forCorrosion Testing of Aluminum-Based Spent Nuclear Fuel inSupport of Repository Disposal1This standard is issued under the fixed designation C1431; 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 () indicates an editorial change since the last revision or reapproval.1NOTEEditorial corrections were made throughout in June 2010.1. Scope1.1 This guide covers corro
3、sion testing of aluminum-basedspent nuclear fuel in support 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 wast
4、e forms produced fromaluminum-based spent nuclear fuels. The 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 dispo
5、sal; therefore, referenceis also made to the requirements for 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.
6、1.2 Spent nuclear fuel that is not reprocessed must be safelymanaged prior to transportation to, and disposal in, a geologicrepository. Placement in an interim storage facility may includedirect placement of the irradiated fuel or treatment of the fuelprior to placement, or both. The aluminum-based
7、waste formsmay be required to be ready for geologic disposal, 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
8、research reactorsinclude both foreign and domestic reactors. 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 l
9、evels of235U enrich-ment. Highly enriched fuels (235U enrichment 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
10、 a geologic repository. The response of thealuminum-based spent 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 fu
11、els. This is particularly important for the highlyenriched, 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,
12、 aluminum-uranium alloys. The aluminum-uranium alloy typically 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 al
13、uminides, are generally cathodic tothe aluminum matrix. Selective 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
14、 and the size, shape, distri-bution and relative reactivity 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
15、 the waste package do not provide sitesfor the relocation of 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 w
16、aste form being evaluated.1.5 The use of the data obtained by the testing described inthis guide will be optimized to the extent the samples mimicthe condition of the waste form during actual repository1This guide is under the jurisdiction of ASTM Committee C26 on Nuclear FuelCycle and is the direct
17、 responsibility of C26.13 on Spent Fuel and High LevelWaste.Current edition approved June 1, 2010. Published June 2010. Originallyapproved in 1999. Last previous edition approved in 2005 as C1431 99 (2005).DOI: 10.1520/C1431-99R10E01.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700,
18、 West Conshohocken, PA 19428-2959, United States.exposure. The use of Practice C1174 is recommended forguidance. The selection of test samples, which may be unagedor artificially aged, should ensure that the test samples andconditions bound the waste form/repository conditions. Thetest procedures sh
19、ould carefully describe any artificial agingtreatment used in the test program and explain why thattreatment was selected.2. Referenced Documents2.1 ASTM Standards:2C1174 Practice for Prediction of the Long-Term Behaviorof Materials, Including Waste Forms, Used in EngineeredBarrier Systems (EBS) for
20、 Geological Disposal of High-Level Radioactive Waste2.2 Government Documents10 CFR 60 US Code 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
21、Materials10 CFR 72 US Code of Federal Regulations Title 10, Part72, Licensing Requirements 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 PracticeC1174, by common usage, by Websters New World Dic
22、tio-nary, or as described in 3.2, or combination thereof.3.2 Definitions:3.2.1 aluminum-based 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 withurani
23、um-rich particles dispersed in this matrix.3.2.2 aluminum-based spent nuclear fuel form or 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
24、may include the fuel itself.3.2.3 artificial agingany short time treatment that isdesigned 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 i
25、nput to behavior models, butthat are not themselves responses to the environment.3.2.5 boundinga 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, an
26、y test conducted principally to furnish infor-mation for a mechanistic understanding of alteration.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 aque
27、ous corrosion, oxidation, reactionwith moist air, or other types of chemical interaction.3.2.8 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 mon
28、itored retrievable storagefacility, as described in 10 CFR 72.3.2.9 melt-dilute processa process to lower the fraction of235U in highly enriched, aluminum-based spent nuclear fuel bymelting and adding depleted uranium to the waste from.3.2.10 performance assessmentan analysis that identifiesthe proc
29、esses and events that might affect a disposal system,examines the effects of those processes 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 safe
30、ty analysisan analysis to determine the risk tothe public health and safety associated with 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
31、of the independentvariables characterizing the service environment are in therange expected 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 b
32、oth, of the fuel orthe resulting waste form, or both,4.1.3 Placement of the waste form in a 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 was
33、te container,4.1.7 Emplacement in the repository, and4.1.8 Repository closure and geologic 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 charact
34、eris-tics that differ significantly from the characteristics of commer-cial nuclear fuels and 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 re
35、posi-tory performance must be evaluated and understood.4.3 The U.S. Nuclear Regulatory Commission 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 requirementsestabli
36、shed by 10 CFR 60, 10 CFR 71, and 10 CFR 72. Theserequirements outline specific information needs that should bemet through test protocols, for example, those mentioned in2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Ann
37、ual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.C1431 99 (2010)12this guide. The information developed from the tests describedin this guide is not meant to be comprehensive. However, thetests discussed here will provide corrosion propert
38、y data tosupport the following information needs.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).4.3.2 A knowled
39、ge of the effects of radiolysis and tempera-ture on the oxidation, corrosion, and leaching 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 laborat
40、ory experiments or technicalanalyses, or both, about time dependence of the internalcondition 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 m
41、aterials on galvaniccorrosion (see 10 CFR 71.43) or the significance of electricalcontact between 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 retrieva
42、l of the waste forms (see10 CFR 72.3).4.3.7 Information on the physical and chemical condition 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 opera
43、tional safety problems withrespect to its removal from storage can be assessed, if suchremoval 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 Conditio
44、ns expected during each stage of the dispositionprocess must be addressed. Exposure conditions 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 r
45、epository storage while the aqueous environmentsarise after water intrusion into the repository 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 li
46、terature, or both,provide data pertinent to (a) corrosion or oxidation of wasteform constituents 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 produ
47、cts, or both and (e) selectiveleaching of waste form constituents. Selected tests shouldprovide 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 repositorydisposa
48、l,5.1.2 The temperature dependence of, and the effect ofradiolysis products on, waste form 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 o
49、f waste form micro-structure (the size, shape, distribution, and volume fraction ofthe uranium-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 r
