ASTM_C_1562_-_10.pdf

Designation:C156210Standard Guide forEvaluation of Materials Used in Extended Service of InterimSpent Nuclear Fuel Dry Storage Systems1This standard is issued under the fixed designation C1562;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 parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 Part of the total inventory of commercial spent nuclearfuel(SNF)is stored in dry cask storage systems(DCSS)underlicenses granted by the U.S.Nuclear Regulatory Commission(NRC).The purpose of this guide is to provide information toassist in supporting the renewal of these licenses,safely andwithout removal of the SNF from its licensed confinement,forperiods beyond those governed by the term of the originallicense.This guide provides information on materials behaviorunder conditions that may be important to safety evaluationsfor the extended service of the renewal period.This guide iswritten for DCSS containing light water reactor(LWR)fuelthat is clad in zirconium alloy material and stored in accor-dance with the Code of Federal Regulations(CFR),at anindependent spent-fuel storage installation(ISFSI).2The com-ponents of an ISFSI,addressed in this document,include thecommercial SNF,canister,cask,and all parts of the storageinstallation including the ISFSI pad.The language of this guideis based,in part,on the requirements for a dry SNF storagelicense that is granted,by the U.S.Nuclear Regulatory Com-mission(NRC),for up to 20 years.Although governmentregulations may differ for various nations,the guidance onmaterials properties and behavior given here is expected tohave broad applicability.1.2 This guide addresses many of the factors affecting thetime-dependent behavior of materials under ISFSI service 10CFR Part 72.42.These factors are those regarded to beimportant to performance,in license extension,beyond thecurrently licensed 20-year period.Examples of these factorsare given in this guide and they include materials alterations orenvironmental conditions for components of an ISFSI systemthat,over time,could have significance related to safety.Forpurposes of this guide,a license period of an additional 20 to80 years is assumed.1.3 This guide addresses the determination of the conditionsof the spent fuel and storage cask materials at the end of theinitial 20-year license period as the result of normal events andconditions.However,the guide also addresses the analysis ofpotential spent fuel and cask materials degradation as the resultof off-normal,and accident-level events and conditions thatmay occur during any period.1.4 This guide provides information on materials behaviorto support continuing compliance with the safety criteria,which are part of the regulatory basis,for licensed storage ofSNF at an ISFSI.The safety functions addressed and discussedin this standard guide include thermal performance,radiologi-cal protection,confinement,sub-criticality,and retrievability.The regulatory basis includes 10 CFR Part 72 and supportingregulatory guides of the U.S.Nuclear Regulatory Commission.The requirements set forth in these documents indicate that thefollowing items were considered in the original licensingdecisions:properties of materials,design considerations fornormal and off-normal service,operational and natural events,and the bases for the original calculations.These items mayrequire reconsideration of the safety-related arguments thatdemonstrate how the systems continue to satisfy the regulatoryrequirements.Further,to ensure continued safe operation,theperformance of materials must be justified in relation to theeffects of time,temperature,radiation field,and environmentalconditions of normal and off-normal service.Arguments forlong-term performance must account for materials alterations(especially degradations)that are expected during the serviceperiods,which include the periods of the initial license and ofthe license renewal.This guide pertains only to structures,systems,and components important to safety during extendedstorage period and during retrieval functions,including trans-port and transfer operations.Materials information that per-tains to safety functions,including retrieval functions,ispertinent to current regulations and to license renewal process,and this information is the focus of the guide.This guide is notintended to supplant the existing regulatory process.1This guide is under 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.1,2010.Published March 2010.Originallyapproved in 2003.Last previous edition approved in 2003 as C1562 032.DOI:10.1520/C1562-10.2In general fuels of higher burnup(45 MWd/kgU)and MOX fuels are notincluded in this guide.Guidance for these fuels are expe