1、Designation:C78715Standard Specification forUranium Hexafluoride for Enrichment1This standard is issued under the fixed designation C787;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 parenthese
2、s indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This specification covers uranium hexafluoride(UF6)intended for feeding to an enrichment plant.Included arespecifications for UF6derived from unirradiated natu
3、ral ura-nium and UF6derived from irradiated uranium that has beenreprocessed and converted to UF6for enrichment and subse-quent reuse.The objectives of this specification are twofold:(1)To define the impurity and uranium isotope limits forCommercial Natural UF6feedstock;and(2)To define addi-tional l
4、imits for Reprocessed UF6(or any mixture of Repro-cessed UF6and Commercial Natural UF6).For such UF6,special provisions may be needed to ensure that no extra hazardarises to the work force,process equipment,or the environ-ment.1.2 The scope of this specification does not comprehen-sively cover all p
5、rovisions for preventing criticality accidentsor requirements for health and safety or for shipping.Obser-vance of this specification does not relieve the user of theobligation to conform to all international,federal,state,andlocal regulations for processing,shipping,or in any other wayusing UF6(see
6、,for example,TID-7016,DP-532,ORNL-NUREG-CSD-6,and DOE O 474.1).1.3 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.2.Referenced Documents2.1 ASTM Standards:2C761 Test Methods for Chemical,Mass Spectrometric,Spectrochemical,Nucle
7、ar,and Radiochemical Analysis ofUranium HexafluorideC859 Terminology Relating to Nuclear MaterialsC996 Specification for Uranium Hexafluoride Enriched toLess Than 5%235UC1052 Practice for Bulk Sampling of Liquid UraniumHexafluorideC1295 Test Method for Gamma Energy Emission fromFission and Decay Pro
8、ducts in Uranium Hexafluoride andUranyl Nitrate SolutionC1703 PracticeforSamplingofGaseousUraniumHexafluoride2.2 ANSI Standard:N14.1 Packaging of Uranium Hexafluoride for Transport32.3 U.S.Government Documents:Inspection,Weighing,and Sampling of Uranium Hexafluo-ride Cylinders,Procedures for Handlin
9、g and Analysis ofUranium Hexafluoride,Vol.1,Department of EnergyReport ORO-671-1,latest revision4The UF6Manual:Good Handling Practices for UraniumHexafluoride,United States Enrichment Corporation Re-port USEC-651,latest revision5Nuclear Safety Guide,U.S.Nuclear Regulatory CommissionReport TID-7016,R
10、ev.2,1978,and ORNL-NUREG-CSD-64Clarke,H.K.,Handbook of Nuclear Safety,Department ofEnergy Report DP-5324Control and Accountability of Nuclear Materials,DOEDirective O 474.143.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 Terms shall be defined in accordance with Terminol-ogy C8
11、59,except for the following:3.1.2 Commercial Natural UF6UF6from natural unirra-diated uranium(containing 0.711 6 0.004 g235U per 100 g U).3.1.2.1 DiscussionIt is recognized that some contamina-tion with reprocessed uranium may occur during routineprocessing.This is acceptable provided that the UF6me
12、ets therequirements for Commercial Natural UF6.1This specification is under the jurisdiction of ASTM Committee C26 onNuclear Fuel Cycle and is the direct responsibility of Subcommittee C26.02 on Fueland Fertile Material Specifications.Current edition approved July 1,2015.Published July 2015.Original
13、ly approvedin 1976.Last previous edition approved in 2011 as C787 11.DOI:10.1520/C0787-15.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary
14、page onthe ASTM website.3Available from American National Standards Institute,11 W.42nd St.,13thFloor,New York,NY 10036.4Available from Superintendent of Documents,U.S.Government PrintingOffice,Washington,DC 20402.5Available from United States Enrichment Corporation,6903 Rockledge Drive,Bethesda,MD
15、20817.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.1.3 Reprocessed UF6any UF6made from uranium thathas been exposed in a neutron irradiation facility and subse-quently chemically separated from the fission products andtransuranic iso
16、topes so generated.3.1.3.1 DiscussionThe requirements for Reprocessed UF6given in this specification are intended to be typical ofreprocessed spent fuel that has achieved burnup levels of up to50 000 Megawatt days per tonne of uranium in light waterreactors and has been cooled for ten years after discharge.It isrecognized that different limits would be necessary to accom-modate different fuel histories.4.Safety,Health Physics,and Criticality Requirements4.1 The UF6concentration shall be not less