1、Designation: C 1553 08Standard Guide forDrying Behavior of Spent Nuclear Fuel1This standard is issued under the fixed designation C 1553; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parent
2、heses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This guide is organized to discuss the three majorcomponents of significance in the drying behavior of spentnuclear fuel: evaluating the need for dryi
3、ng, drying spentnuclear fuel, and confirmation of adequate dryness.1.1.1 The guide addresses drying methods and their limita-tions in drying spent nuclear fuels that have been in storage atwater pools. The guide discusses sources and forms of waterthat remain in SNF, its container, or both, after th
4、e dryingprocess and discusses the importance and potential effects theymay have on fuel integrity, and container materials. The effectsof residual water are discussed mechanistically as a function ofthe container thermal and radiological environment to provideguidance on situations that may require
5、extraordinary dryingmethods, specialized handling, or other treatments.1.1.2 The basic issue in drying is to determine how dry theSNF must be in order to prevent issues with fuel retrievability,container pressurization, or container corrosion. Adequatedryness may be readily achieved for undamaged co
6、mmercialfuel but may become a complex issue for any SNF wherecladding damage has occurred during fuel irradiation, storage,or both, at the spent fuel pools. Dryness issues may also resultfrom the presence of sludge, crud, and other hydrated com-pounds connected to the SNF that hold water and resist
7、dryingefforts.1.2 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2
8、. 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 Geological Disposal of High-Level Radioactive WasteC 1562 Guide for Evaluation of Materials Used in ExtendedService of In
9、terim Spent Nuclear Fuel Dry Storage Sys-tems2.2 ANSI/ANS Standards:3ANSI/ANS 8.1-1998 Nuclear Criticality Safety in Opera-tions with Fissionable Materials Outside ReactorsANSI/ANS-8.7-1998 Nuclear Criticality Safety in the Stor-age of Fissile MaterialsANSI/ANS-57.9 American National Standard Design
10、 Cri-teria for Independent Spent Fuel Storage Installation (DryType)2.3 Government Documents:4Title 10 on Energy, Code of Federal Regulations, Part 60, 10CFR 60, U.S. Code of Federal Regulations, Disposal ofHigh Level radioactive Wastes in Geologic RepositoriesTitle 10 on Energy, Code of Federal Reg
11、ulations, Part 63, 10CFR 63, U.S. Code of Federal Regulations, Disposal ofHigh-Level Radioactive Wastes in Geologic Repository atYucca Mountain, NevadaTitle 10 on Energy, Code of Federal Regulations, Part 71, 10CFR 71, U.S. Code of Federal Regulations, Packagingand Transport of Radioactive Materials
12、Title 10 on Energy, Code of Federal Regulations, Part 72, 10CFR 72, U.S. Code of Federal Regulations, LicensingRequirements for the Independent Storage of SpentNuclear Fuel and High-Level Radioactive Waste3. Terminology3.1 DefinitionsTerms used in this guide are as defined inPractice C 1174 or, if n
13、ot defined therein as per their commonusage, except where defined specifically for this guide asdescribed as follows.3.2 Definitions of Terms Specific to This Standard:3.2.1 CRUD, nin nuclear waste management, deposits onfuel surfaces from corrosion products that circulate in the1This guide is under
14、 the jurisdiction of ASTM Committee C26 on Nuclear FuelCycle and is the direct responsibility of Subcommittee C26.13 on Spent Fuel andHigh Level Waste.Current edition approved Jan. 1, 2008. Published February 2008.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM C
15、ustomer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.4Available from U.S.
16、 Government Printing Office Superintendent of Documents,732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401, http:/www.access.gpo.gov.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.Copyright by ASTM Intl (all rights reserve
17、d); Thu Feb 19 02:08:37 EST 2009Downloaded/printed byGuo Dehua (CNIS) pursuant to License Agreement. No further reproductions authorized.reactor coolant. Compositions reflect materials exposed tocoolant and activation products formed during irradiation.Term was originally an acronym for “Chalk River
18、 UnidentifiedDeposits.”3.2.2 damaged fuel, nin nuclear waste management,nuclear fuel that has been geometrically altered in form/shapeto a degree that may affect retrievability from a (licensed)storage system or make it unsuitable for transport in a licensedcask.3.2.3 disposal, nin nuclear waste man
19、agement, the em-placement of radioactive wastes in a geologic repository withthe intent of leaving it there permanently. 10 CFR Part 63.23.2.4 failed fuel, nin drying of spent nuclear fuel, anybreach, such as hairline cracks or holes in a cladding thatpermits water into a fuel element.3.2.5 getter,
20、nin nuclear waste management, a material(typically a solid) used to chemically react with certain gases(for example, H2,O2,H2O vapor) to form a solid compound oflow vapor pressure.3.2.5.1 DiscussionA getter may also be used to absorbimpurities in chemical and metallurgical processes.3.2.6 independen
21、t spent fuel storage installation (ISFSI),na complex designed and constructed for the interim storageof spent nuclear fuel and other radioactive materials associatedwith spent fuel storage. 10 CFR Part 723.2.7 packaging, nin nuclear waste management,anas-sembly of components used to ensure complianc
22、e with therequirements of Title 10 of the Code of Federal Regulations,(CFR) Part 72 for independent storage of spent nuclear fuel andhigh-level radioactive waste or 10 CFR Part 71 for transpor-tation of radioactive materials.3.2.8 repository, geologic repository, nin nuclear wastemanagement, a dispo
23、sal site, a permanent location for radio-active wastes.3.2.9 spent nuclear fuel (SNF), nnuclear fuel that hasbeen irradiated in a nuclear reactor and contains fissionproducts, activation products, actinides, and un-reacted fission-able fuel. Normally spent fuel is contained in a metal claddingwhose
24、condition (undamaged, corroded, perforated, etc.) de-pends upon its original material properties as modified by theconditions during its service life including storage conditions.3.2.10 sludge, nin nuclear waste management, a slurry orsediment containing nuclear waste materials, a residue that hasus
25、ually been formed from processing operations, corrosion orwater basin storage.3.2.11 waste package, nin nuclear waste management,the waste form and any containers, shielding, packing andother absorbent materials immediately surrounding an indi-vidual waste container. 10 CFR Part 603.2.11.1 Discussio
26、nThe waste package is expected toconsist of an overpack (a container) into which commercialSNF, DOE SNF canisters and high level waste are to be placedfor disposal at a repository.3.2.12 water, nin drying of spent nuclear fuel,itisthetotal amount of moisture (specified by weight, volume, ornumber of
27、 moles) present (in a container) as a combination ofvapor, free or unbound liquid water, physisorbed water, chemi-sorbed water, and ice. The following specific terms for waterare used in this document:3.2.12.1 bound water, nbound water includes adsorbedsurface layers of water, and nearly all chemiso
28、rbed water.3.2.12.2 chemisorbed water, nwater that is bound to otherspecies by forces whose energy levels approximate those of achemical bond.3.2.12.3 physisorbed water (adsorbed water), nwater thatis physically bound (as an adsorbate, by weak forces) tointernal or external surfaces of solid materia
29、l.3.2.12.4 trapped water, nunbound water that is physicallytrapped or contained by surrounding matrix, blocked ventpores, cavities, or by the nearby formations of solids thatprevent or slow escape. Note: Traps may have varying degreesof reversibility and a trap may be for practical purposesirreversi
30、ble.3.2.12.5 unbound water, nwater, in the solid, liquid, orvapor state, that is not physically or chemically bound toanother species.4. Significance and Use4.1 This guide provides technical information for use bySNF owners to determine the forms of water usually associatedwith spent nuclear fuel du
31、e to corrosion damage of the fuel,cladding and storage materials during irradiation and in storagepools. Drying may be needed to prepare the SNF for sealed drystorage, transportation, and/or permanent disposal at a reposi-tory. This guide provides information for:4.1.1 Evaluating what drying system
32、should be used,4.1.2 Drying methods, and4.1.3 Methods to confirm that adequate dryness wasachieved.4.2 The guide can be used to determine:4.2.1 Drying technologies that are designed to remove mostof the unbound water but will not remove all forms of water.Water remaining on and in commercial and res
33、earch reactorspent nuclear fuels coming from water basin storage maybecome an issue when the fuel is sealed in a dry storage systemor transport cask. The movement to a dry storage environmenttypically results in an increase in fuel temperature due to thedecay heat. This temperature change could be s
34、ignificant tocause the release of water remaining in a sealed dry packagethat may result in container pressurization, fuel retrievabilityissues, and container corrosion.4.2.2 A methodology for evaluating drying processes thatmay not readily remove all forms of water that may be retainedin pores in f
35、uel cladding, capillaries, sludge, crud, and thinwetted surface films. Drying techniques are even less success-ful in removing bound water. Removal of bound water willonly occur when the specific threshold energy is applied tobreak the bonds involved and release the water. For spentnuclear fuel this
36、 threshold energy may come from the combi-nation of thermal input and ionizing radiation.4.2.3 How the residual water retained with the SNF, CRUDand sludge inside a sealed package may become available toreact with the internal environment, the fuel, and the packagematerials as a result of extended t
37、ime at equilibrium dry storagetemperatures, or as the direct result of radiolytic decomposi-tion.C1553082Copyright by ASTM Intl (all rights reserved); Thu Feb 19 02:08:37 EST 2009Downloaded/printed byGuo Dehua (CNIS) pursuant to License Agreement. No further reproductions authorized.5. Evaluating th
38、e Drying Approach5.1 Some forms of fuel degradationsuch as claddingpinholes or cracksmay form before or during the dry storageperiod without violating design or licensing requirements.However, damage such as small cladding cracks or pinholesformed during the dry storage period could cause the fuel t
39、o bere-classified as failed fuel for repository disposal consider-ations. The objective in drying commercial LWR SNF contain-ers is to eliminate enough water to preclude “gross” damage tocommercial fuel or its cladding during dry storage and trans-port. The drying process itself must not damage the
40、fuel. Forexample, the thermal cycling during the drying process forcommercial LWR SNF may affect the hydride re-orientationprocess in the zircaloy cladding.5.2 DOE research and production reactor SNF that is nottreated or reprocessed, will eventually be stored in sealedcanisters within dry storage s
41、ystems that may or may not beregulated by the NRC. DOE dry storage canisters are expectedto contain the SNF through interim storage, transport, andrepository packaging. The objectives of drying processes usedon this fuel are to:5.2.1 Preclude geometric reconfiguration of the packagedfuel,5.2.2 Preve
42、nt internal damage to the canister from over-pressurization or corrosion, and5.2.3 Minimize hydrogen generation or materials corrosionthat could be a problem during transport or repository handlingoperations.5.3 The decision to select the drying methodology fortreating fuel for interim dry storage f
43、acility or disposition in ageologic repository could be based on the following factors:5.3.1 Nature and degree of fuel damage including its storagehistory,5.3.2 Form of water in the packaged SNF container,5.3.3 Thermal and radiological environments involved,5.3.4 Degree of self heating contribution
44、to the dryingprocess,5.3.5 Potential for corrosion and radiolytic degradation ofthe fuel and container material,5.3.6 Mechanisms of water interaction with the fuel andcontainer components,5.3.7 Interactions that need to be considered to set thebounds for residual water, and5.3.8 Maximum allowable wa
45、ter based on items 5.3.5through 5.3.7.5.4 Categorization of SNF and Defects for DryingEvaluationWater in SNF storage and transport containerscan be a potential cause, result, or both, of fuel claddingdamage or “failed fuel.” However, there is not a single,universal definition of failure. The NRC ISG
46、-1 Rev 2 definesdamaged fuel as “spent nuclear fuel with known or suspectedcladding defects greater than a hairline crack or a pinhole leakthat have potential for release of significant amount of fuelparticles.” For the purposes of SNF transport per 10 CFR71.55, fuel is essentially regarded as “fail
47、ed” only when thegeometric form of the fuel has been “substantially altered.” Forthe purposes of dry cask storage per 10 CFR 72.22, the SNFcladding is required to: “be protected against degradation andgross rupture.” Gross rupture is defined as that which couldresult in the release of significant qu
48、antities of fuel materialsand fission products to the storage environment. For thepurposes of receipt of SNF containers at a geologic repository,10 CFR 961 defines three categories of commercial LWR“failed fuel:”Class F-1 failed fuel has visually observable failure or damageClass F-2 failed fuel has
49、 “radioactive leakage”Class F-3 failed fuel is badly damaged and requires “encapsulation”Each of these damaged or failed fuels could potentiallyrequire different handling/treatment than those used for non-failed fuel. It is, therefore, important when addressing thepotential for fuel damage or failure due to moisture in the SNFcontainers to be clear about the kind and extent of claddingdamage. It is particularly important to note that SNF could beregarded as intact or non-failed for the purposes of storage ortransport performance but “failed” for the purposes o
