1、Designation: C 996 04e1Standard Specification forUranium Hexafluoride Enriched to Less Than 5 %235U1This standard is issued under the fixed designation C 996; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revisio
2、n. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.e1NOTEThe table in Section 5.5 was corrected editorially in September 20041. Scope1.1 This specification covers nuclear grade uraniumhexafluo
3、ride (UF6) that either has been processed through anenrichment plant, or has been produced by the blending ofHighly Enriched Uranium with other uranium to obtain ura-nium of any235U concentration below 5 % and that is intendedfor fuel fabrication. The objectives of this specification aretwofold: (1)
4、 To define the impurity and uranium isotope limitsfor Enriched Commercial Grade UF6so that, with respect tofuel design and manufacture, it is essentially equivalent toenriched uranium made from natural UF6; and (2) To definelimits for Enriched Reprocessed UF6to be expected if Repro-cessed UF6is to b
5、e enriched without dilution with CommercialNatural UF6. For such UF6, special provisions, not definedherein, may be needed to ensure fuel performance and toprotect the work force, process equipment, and the environ-ment.1.2 This specification is intended to provide the nuclearindustry with a standar
6、d for enriched UF6that is to be used inthe production of sinterable UO2powder for fuel fabrication.In addition to this specification, the parties concerned mayagree to other appropriate conditions.1.3 The scope of this specification does not comprehen-sively cover all provisions for preventing criti
7、cality 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 applicable international, federal,state, and local regulations for processing, shipping, or in anyother way using UF6(see, for example
8、, TID-7016, DP-532, andDOE O474.1).1.4 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:2C 761 Test Methods for Chemical, Mass Spectrometric,Spectrochemical, Nuclear, and Radiochemical A
9、nalysis ofUranium HexafluorideC 787 Specification for Uranium Hexafluoride for Enrich-mentC 859 Terminology Relating to Nuclear MaterialsC 1052 Practice for Bulk Sampling of Liquid UraniumHexafluorideC 1295 Test Method for Gamma Energy Emission fromFission Products in Uranium HexafluorideC 1561 Guid
10、e for the Measurement of Plutonium and Nep-tunium in UF6E29 Practice for Using Significant Digits in Test Data toDetermine Conformance with Specifications2.2 ANSI Standards:3ANSI/ASME NQA-1 Quality Assurance Requirements forNuclear Facility ApplicationsANSI N14.1 Nuclear MaterialsUranium Hexafluorid
11、ePackaging for Transport2.3 U.S. Government Documents:Inspection, Weighing, and Sampling of Uranium Hexafluo-ride Cylinders, Procedure for Handling and Analysis ofUranium Hexafluoride, Vol. 1, DOE Report ORO-671-1,latest revision4Nuclear Safety Guide, U.S. NRC Report TID-7016, Rev. 2,1978Clarke, H.
12、K., Handbook of Nuclear Safety, DOE ReportDP-5324Code of Federal Regulations, Title 10, Part 50, (AppendixB)41This 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.Cur
13、rent edition approved June 1, 2004. Published July 2004. Originally approvedin 1983. Last previous edition approved in 1996 as C 996 96.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume in
14、formation, 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 10036.4Available from U.S. Government Printing Office Superintendent of Documents,732 N. Capitol St., NW, Mail Stop: SDE, Wa
15、shington, DC 20401.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.Control and Accountability of Nuclear Materials, DOEDirective 5633.3B42.4 Other Document:The UF6Manual: Good Handling Practices for UraniumHexafluoride, United States
16、 Enrichment Corporation Re-port USEC-651, latest revision53. Terminology3.1 Definitions of Terms Specific to This StandardTermsshall be defined in accordance with Terminology C 859 exceptfor the following:3.1.1 Commercial Natural UF6UF6from natural unirra-diated uranium (containing 0.711 6 0.004 g23
17、5U per 100 g U).3.1.1.1 DiscussionIt is recognized that some contamina-tion with reprocessed uranium may occur during routineprocessing. This is acceptable provided that the UF6meets therequirements for Commercial Natural UF6as specified inSpecification C 787.3.1.2 Reprocessed UF6any UF6made from ur
18、anium thathas been exposed in a neutron irradiation facility and subse-quently chemically separated from the fission products andtransuranic isotopes so generated.3.1.3 Highly Enriched Uraniumany form of uraniumhaving a235U content of 20 % or greater3.1.4 Enriched Commercial Grade UF6UF6enrichedfrom
19、 Commercial Natural UF6or Derived Enriched UF6thatmeets the specification limits for Enriched Commercial GradeUF6.3.1.5 Enriched Reprocessed UF6UF6enriched from Re-processed UF6, any mixture of Reprocessed UF6and Commer-cial Natural UF6or Derived Enriched UF6, exceeding theapplicable limits of Secti
20、ons 4 and 5 for Enriched CommercialGrade UF6. The wide range of irradiation levels, cooling times,reprocessing, conversion, and enrichment processes, and fuelcycle choices for combination with unirradiated UF6, togetherwith the varying acceptance limits of different fuel fabricationfacilities, make
21、it not practical to specify the exact radionuclidecomposition of Enriched Reprocessed UF6.3.1.6 Derived Enriched UF6any UF6obtained from theblending of Highly Enriched Uranium with any other uranium.3.2 For enriched UF6transactions, “buyer” usually repre-sents the electric power utility company or t
22、he fuel fabricator,and “seller” usually represents the isotopic enrichment facility.4. Safety, Health Physics, and Criticality Requirements4.1 The UF6concentration shall not be less than 99.5 g UF6per 100 g of sample in order to limit the potential hydrogencontent for nuclear criticality safety.4.2
23、The total absolute vapor pressure shall not exceed thevalues given below:380 kPa at 80C (55 psia at 176F), or517 kPa at 93C (75 psia at 200F), or862 kPa at 112C (125 psia at 235F)Additionally, if a measurement is taken over solid UF6, thevapor pressure shall not exceed the values given below:50 kPa
24、at 20C (7 psia at 68F), or69 kPa at 35C (10 psia at 95F)The purpose of the pressure check is to limit the hydrogenfluoride, air, or other volatile components that might causeoverpressure when heating the shipping container, such as toobtain a liquid sample or withdraw the contents.4.3 The total hydr
25、ocarbon, chlorocarbon, and partially sub-stituted halohydrocarbon content shall not exceed 0.01 mol %of the UF6. The reason for the exclusion of these materials isto prevent a vigorous reaction with UF6upon heating. It isessential that contamination of the UF6containers, such as byvacuum pump oil, b
26、e prevented since it is not practical toobtain a sample without heating the UF6. An alternative meansof demonstrating compliance with this requirement, other thanby direct measurement, may be agreed upon between theparties concerned.4.4 For Enriched Commercial Grade UF6meeting the re-quirements of S
27、ection 5,(1) the gamma activity from fissionproducts is expected to be below the detection limits of themeasurement methodology set forth in Test Method C 1295;and (2) the alpha activity from neptunium and plutonium isexpected to be below the detection limits of commonly usedmeasurement methodology
28、(Guide C 1561). Therefore unlessotherwise agreed upon between the buyer and seller, measure-ments are not required, except for Derived Enriched UF6resulting from blending with reprocessed uranium.4.5 For Enriched Reprocessed UF6, the gamma radiationfrom fission products shall not exceed 4.4 3 105MeV
29、Bq/kgU(4.4 3 105MeV/sec kgU). The measurements are to be madein accordance with Test Method C 1295, or equivalent.4.5.1 For Enriched Reprocessed UF6, the alpha activityfrom neptunium and plutonium shall be less than 3300 Bq/kgU(200 000 dpm/kgU). The measurements shall be made inaccordance with Guide
30、 C 1561, or equivalent.5. Chemical, Physical, and Isotopic Requirements5.1 Both Enriched Commercial Grade UF6and EnrichedReprocessed UF6must meet the specification criteria except asdifferentiated in 4.4, 4.5, 5.4, and 5.5. For certain isotopes,including artificially created radioactive species, two
31、 groups oflimits are set. Limits for Enriched Commercial Grade UF6areset so as to have no special impact on the use of this materialin existing facilities. For Enriched Reprocessed UF6, higherlimits are indicated to correspond with Specification C 787,and lower limits may be agreed upon by the buyer
32、 and selleraccording to the composition of the feed material presented forenrichment.5.2 The UF6content shall be reported as gUF6/100 gsample.5.3 The following impurity elements shall not exceed thesevalues:Element g/gUBoron 4Silicon 250For fully substituted chlorofluorocarbons a maximum limitmay be
33、 agreed upon between the parties concerned.5.4 Enriched Commercial Grade UF6shall comply with thelimits given in 5.5. For evaluating Enriched Commercial Grade5Available from United States Enrichment Corporation, 6903 Rockledge Drive,Bethesda, MD 20817.C99604e12UF6, the measured concentration of236U
34、will be used as anindicator for contamination with reprocessed uranium, on theassumption that there is no opportunity for contamination withirradiated uranium that has not been processed to remove themajority of fission products. Uranium isotopic concentrationsshall be determined and reported for234
35、U,235U, and236U.5.5 RadionuclidesThe following values represent limitsobtainable from the enrichment of UF6feed materials at thecorresponding limits of Specification C 787. For purposes ofdetermining conformance with these limits, the observedvalues shall be rounded to the nearest significant digit
36、indicatedin accordance with the rounding method of Practice E29. Forexample, for234U in Enriched Commercial Grade UF6theobserved value would be rounded to the nearest 0.1 3103g234U/g235U.Enriched Commercial Grade UF6Enriched Reprocessed UF6232U 0.0001 g/gU, see 5.5.1, 5.5.2, and 5.5.3 0.050 g/gU, se
37、e Note 1234U11.03 103g/g235U, see Note 2 2000 g/gU, see Note 1236U 250 g/gU, see 5.5.3 see Note 199Tc 0.01 g/gU, see 5.5.4 5 g/gU, see Note 15.5.1 If the236U measurement result is less than 125 g/gU,then measurement of232U is not required unless agreed uponbetween the buyer and seller.5.5.2 If the23
38、6U measurement result is greater than 125 butless than 250 g/gU, then measurement and reporting of232Uare required for routine acceptance of the UF6.5.5.3 The buyer may consider acceptance of the lot above250 g/gU on the basis of the total significance of all themeasured levels of radionuclides to d
39、etermine the suitabilityfor intended use in the fuel fabrication and irradiation. Ifthe236U measurement result is greater than 250 but less than500 g/gU, then measurement of232U and notification ofresults before shipment are required.5.5.4 The buyer and seller may agree to waive the require-ment to
40、measure99Tc, provided that (1) the236U content is lessthan 125 g/gU; and (2) adequate capability to meet the99Tclimit for Commercial Natural UF6can be demonstrated throughquality assurance records. Such records shall include theresults of the sellers periodic measurements of99Tc in theUF6.NOTE 1Enri
41、chment of Reprocessed UF6feed material at the limit ofSpecification C 787 could be expected to reach these limits. Defining theselimits does not imply that any fuel fabrication plant designed for EnrichedCommercial Grade UF6could handle Enriched Reprocessed UF6withoutdilution with Enriched Commercia
42、l Grade UF6and other special precau-tions. With respect to the variability of Reprocessed UF6from various fuelhistories and the demands that would be placed on the fuel fabricators andusers, it could be necessary for the seller and buyer to agree on lowerlimits after enrichment than implied by Speci
43、fication C 787 feed limits.NOTE 2A234U content greater than 10.0 3 103g/g235U shall requireagreement in advance between the parties (for example, supplier, receiver)to accept the material. It is recognized that some applications may notallow for the limit in the table due to licensing, regulatory, o
44、r contractuallimitations.6. Sampling6.1 A representative sample of sufficient size to performtests prescribed shall be taken while the material is liquid andhomogeneous. Relevant sample procedures are given in Prac-tice C 1052, USEC Report USEC-651, and DOE ReportORO-671-1.6.2 All samples shall be c
45、learly identified including thesellers lot number.6.3 All containers used for a lot shall be positively identifiedas containing material from a particular homogeneous lot.7. Test Methods for Chemical and Isotopic Analysis7.1 Chemical and isotopic analysis shall conform to TestMethods C 761, or demon
46、strated equivalent, as mutuallyagreed upon between the buyer and seller.8. Packaging, Handling, and Shipping8.1 Procedures for packaging, handling, and shipping UF6are given in ANSI N14.1, USEC Report USEC-651, and DOEReport ORO-671-1 or appropriate national or internationalprocedures.8.2 Cylinders
47、used for transport of Reprocessed UF6shallnot be used for Enriched Commercial Grade UF6unlessdecontaminated internally before filling with Enriched Com-mercial Grade UF6.9. Quality Assurance9.1 Quality assurance requirements shall be agreed uponbetween the buyer and the seller when specified in the
48、purchaseorder. Code of Federal Regulations, Title 10, Part 50 (Appen-dix B) and ANSI/ASME NQA-1 are referenced as guides.10. Keywords10.1 low enriched uranium; nuclear fuel; uranium enrich-ment; uranium hexafluorideASTM International takes no position respecting the validity of any patent rights ass
49、erted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM I
