1、Designation: C 833 01Standard Specification forSintered (Uranium-Plutonium) Dioxide Pellets1This standard is issued under the fixed designation C 833; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A num
2、ber in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.INTRODUCTIONThis specification is intended to provide the nuclear industry with a general standard foruranium-plutonium dioxide pellets for thermal r
3、eactor use. It recognizes the diversity of manufactur-ing methods by which uranium-plutonium dioxide pellets are produced and the many specialrequirements for chemical and physical characterization that may be imposed by the operatingconditions to which the pellets will be subjected in specific reac
4、tor systems. It does not recognize thepossible problems associated with the reprocessing of such pellets. It is, therefore, anticipated that thepurchaser may supplement this specification with additional requirements for specific applications.1. Scope1.1 This specification covers finished sintered a
5、nd ground(uranium-plutonium) dioxide pellets for use in thermal reac-tors. It applies to uranium-plutonium dioxide pellets containingplutonium additions up to 15 % weight. This specification maynot completely cover the requirements for pellets fabricatedfrom weapons-derived plutonium.1.2 This specif
6、ication does not include (1) provisions forpreventing criticality accidents or (2) requirements for healthand safety. Observance of this specification does not relieve theuser of the obligation to be aware of and conform to allapplicable international, federal, state, and local regulationspertaining
7、 to possessing, processing, shipping, or using sourceor special nuclear material. Examples of U.S. governmentdocuments are Code of Federal Regulations Title 10, Part50Domestic Licensing of Production and Utilization Facili-ties; Title 10, Part 71Packaging and Transportation of Radio-active Material;
8、 and Title 49, Part 173General Requirementsfor Shipments and Packaging.1.3 The following safety hazards caveat pertains only to thetechnical requirements portion, Section 4, of this specification:This standard does not purport to address all of the safetyconcerns, if any, associated with its use. It
9、 is the responsibilityof the user of this standard to establish appropriate safety andhealth practices and determine the applicability of regulatorylimitations prior to use.1.4 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.2.
10、 Referenced Documents2.1 ASTM Standards:C 698 Test Methods for Chemical, Mass Spectrometric, andSpectrochemical Analysis of Nuclear-Grade Mixed Oxides(U, Pu)O2)2C 753 Specification for Nuclear-Grade, Sinterable UraniumDioxide Powder2C 757 Specification for Nuclear-Grade Plutonium DioxidePowder, Sint
11、erable2C 859 Terminology Relating to Nuclear Materials2C 1165 Test Method for Determining Plutonium byControlled-Potential Coulometry in H2SO4At a PlatinumWorking Electrode2C 1204 Test Method for Uranium in the Presence of Pluto-nium by Iron(II) Reduction in Phosphoric Acid Followedby Chromium(VI) T
12、itration2C 1206 Test Method for Plutonium by Iron (II)/Chromium(VI) Amperometric Titration2C 1233 Practice for Determining Equivalent Boron Con-tents of Nuclear Material2E 105 Practice for Probability Sampling of Materials32.2 ANSI Standard:4ANSI/ASME NQA-1 Quality Assurance Requirements forNuclear
13、Facility Applications2.3 U.S. Government Documents:5USNRC Regulatory Guide 1.126 An Acceptable Model andRelated Statistical Methods for the Analysis of FuelDensification1This specification is under the jurisdiction of ASTM Committee C26 onNuclear Fuel Cycle and is the direct responsibility of Subcom
14、mittee C26.02 on Fueland Fertile Material Specifications.Current edition approved June 10, 2001. Published October 2001. Originallypublished as C 833 76. Last previous edition C 833 95a.2Annual Book of ASTM Standards, Vol 12.01.3Annual Book of ASTM Standards, Vol 14.02.4Available from American Natio
15、nal Standards Institute, 25 West 43rd St., 4thFloor, New York, NY 10036.5Available from Superintendent of Documents, U.S. Government PrintingOffice, Washington, DC 20402.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.Code of Federal
16、 Regulations Title 10, Part 50 DomesticLicensing of Production and Utilization FacilitiesCode of Federal Regulations Title 10, Part 71 Packagingand Transportation of Radioactive MaterialCode of Federal Regulations Title 49, Part 173 GeneralRequirements for Shipments and Packaging3. Terminology3.1 De
17、finitionsDefinitions shall be in accordance withTerminology C 8594. Technical Requirements4.1 Chemical RequirementsAll chemical analyses shall beperformed on portions of the representative sample prepared inaccordance with Section 6. Analytical chemistry methods shallbe as stated in Test Methods C 6
18、98 (latest edition) or demon-strated equivalent as mutually agreed to between the buyer andthe seller.4.1.1 Uranium and Plutonium ContentUnless agreedupon by the buyer and seller, individual powders shall meet therequirements of Specifications C 753 and C 757, which alsoreference Test Methods C 1165
19、, C 1204, and C 1206. Theuranium and plutonium contents combined shall be a minimumof 87.7 % weight on a dry weight basis compensated for theAm-241 content. (Dry weight is defined as the sample weightminus the moisture content). The plutonium content shall bethat specified by the buyer, up to the li
20、mits covered in thisspecification (15%).4.1.2 Impurity ContentThe impurity content shall notexceed the individual element limit specified in Table 1 basedon the heavy metal content (uranium plus plutonium). Thesummation of the contribution of each of the impurity elementslisted in Table 1 shall not
21、exceed 1500 g/g (U + P). If anelement analysis is reported as “less than” a given concentra-tion, this “less than” value shall be used in the determination oftotal impurities.NOTE 1Higher impurity limits should be acceptable for restrictedburnups and linear power ratings if there is evidence to subs
22、tantiate therelaxation. Higher impurity levels of 450 ppm aluminum, 250 ppmcarbon, 250 ppm nitrogen, and 450 ppm silicon have been supported forburnups of less than 35 000 MWd/t. The extension of the burnup limitmay be determined by agreement between the buyer and seller assupporting data are accumu
23、lated.4.1.3 StoichiometryThe oxygen-to-heavy metal ratio ofsintered fuel pellets shall be within the range from 1.98 to 2.02.The nominal value and allowable tolerance shall be agreedupon between the buyer and seller.4.1.4 Moisture ContentThe moisture content limit is in-cluded in the total hydrogen
24、limit (see Table 1).4.1.5 Gas ContentThe gas content, exclusive of moisture,shall not exceed, at Standard Temperature and Pressure (0Cand one atmosphere), 0.05 L/kg of the heavy metal content.4.1.6 Americium-241 ContentThe americium-241 contentshall be measured by the seller and reported to the buye
25、r. Theamericium-241 content or activity is important in the handlingof UO2-PuO2pellets and will vary with time. The maximumacceptable americium-241 content on a given date along withthe date of analysis shall be agreed upon between the buyer andseller. The dates of separation of plutonium from this
26、isotopeand the analysis dates shall be considered; methods of report-ing shall be agreed upon between the buyer and seller.4.2 Nuclear Requirements:4.2.1 Isotopic ContentThe isotopic content of the ameri-cium, uranium, and plutonium in the (uranium-plutonium)dioxide pellets shall be determined and t
27、he date of thedetermination recorded. The234U,235U,236U, and238U contentof the uranium shall be reported as a mass percentage withrespect to total uranium, and the238Pu,239Pu,240Pu,241Pu, and242Pu content of the plutonium shall bereported on a Pu mass % or on (Pu + Am) mass % basis. Theequivalent pl
28、utonium content based on uranium and plutoniumisotopic concentrations shall be as agreed upon between thebuyer and seller.4.2.2 Plutonium Equivalent at a Given Date(uranium-plutonium) dioxide fuel shall be considered as defined by theplutonium content with adjustment (credit or debit) for theactual
29、isotopic composition of plutonium, americium, anduranium. The dates of isotopic analyses in support of thesedeterminations shall be recorded by the seller and reported tothe buyer. The allowable tolerances tolerances of the plutoniumequivalent content (either as uranium plus plutonium or as theindiv
30、idual elements) shall be as agreed upon between the buyerand seller.4.2.3 Equivalent Boron ContentFor thermal reactor use,the total equivalent boron content (EBC) shall not exceed 4.0g/g on a heavy metal basis. The method of performing thecalculation shall be as indicated in Practice C 1233. For the
31、purposes of EBC calculation, B, Gd, Eu, Dy, Sm, and Cd shallbe included.4.2.4 ReactivityAn integral test of reactivity may beperformed and correlated to total EBC by a method agreedupon between the buyer and the seller. If this is done, a totalEBC need not be determined.4.3 Physical Characteristics:
32、4.3.1 DimensionsThe dimensions and their tolerances ofthe pellet shall be specified by the buyer. These shall includediameter, length, perpendicularity, and, as required, othergeometric parameters including surface finish.4.3.2 Pellet DensityThe density and tolerance of sinteredpellets shall be as s
33、pecified by the buyer. The theoreticaldensity for UO2shall be considered to be 10.96 g/cm3. Thetheoretical density for PuO2shall be considered to be 11.46g/cm3. The theoretical density for the (U, Pu)O2pellets shall beTABLE 1 Impurity Elements and Maximum Concentration LimitsElementMaximum Concentra
34、tionLimit (g/g of U + Pu)Aluminum 250Carbon 100Calcium + magnesium 200Chlorine 25Chromium 250Cobalt 100Fluorine 25Hydrogen (total from allsources)1.3Iron 500Nickel 250Nitride/nitrogen 75Silicon 250C 8332calculated by linear interpolation between these values. Den-sity measurements shall be made by t
35、he method stated inSpecification C 753 (for the geometric method) by an immer-sion density technique, or by demonstrated equivalent methodas mutually agreed upon between the buyer and the seller.4.3.3 Grain Size and Pore MorphologyBecause there isno unique structure for ensuring satisfactory perform
36、ance, thepellet grain size and pore morphology shall be mutually agreedupon between the buyer and the seller.4.3.4 Plutonium-Oxide Homogeneity and Size:4.3.4.1 Plutonium Homogeneity Within a Pellet LotHomogeneity of the Pu content shall be demonstrated throughanalyses of multiple pellets. Each sampl
37、e for analysis shouldbe one pellet or a fragment thereof. The range of the equivalentPu content shall not exceed 6 5.0% relative or 6 0.2%absolute, whichever is less restrictive. Alternative methods andcriteria that may be agreed upon between the buyer and theseller are possible for evaluation of pl
38、utonium homogeneitywithin a lot.4.3.4.2 Plutonium-Oxide Particle Size and DistributionWithin a PelletThe maximum equivalent diameter of Pu-richparticles shall be less than 400 m. The distribution of Pu-richparticles shall satisfy either of the following requirements: (a)No more than 5% of the nomina
39、l PuO2shall be present inPu-rich particles with equivalent diameters of 200 m orgreater, or (b) No more than 5% of the Pu-rich particles shallbe greater than 100 m in diameter and the average diameter ofPu-rich particles will be less than 50 m. The method fordetermining the Pu homogeneity and what c
40、onstitutes a Pu-richparticle shall be agreed upon between the buyer and seller. Thearea percentage and the volume percentage shall be regarded asequivalent provided the homogeneity requirements of 4.3.4.1are satisfied.NOTE 2These limits are based on PuO2that has a nominal 65% fissleplutonium content
41、. Smaller particle size may be required for greater fissleplutonium content.4.3.5 Pellet IntegrityPellets shall be inspected accordingto criteria which maintain adequate fuel performance andensure that excessive breakage will not occur during fuel rodloading. Acceptable test methods include a visual
42、 (1X) com-parison with pellet standards or other methods, for example,loadability tests, approved by both the buyer and the seller.4.3.5.1 Surface CracksThe limits for surface cracks are asfollows:(1) Axial Cracks, including those leading to pellet ends12the pellet length.(2) Circumferential Cracks1
43、23 of the pellet circumfer-ence.4.3.5.2 ChipsThe limits for chips (missing material) areas follows:(1) Cylindrical Surface Chips(a) Cylindrical Surface Areathe total area of allchips shall be less than 5 % of the pellet cylindrical surfacearea.(b) Maximum Linear Dimension30 % of the pelletlength.(2)
44、 Pellet Ends1/3 of the pellet end surfaces (may beinspected as 1/3 of the missing circumference at the pellet end).4.3.6 Cleanliness and WorkmanshipThe surfaces of fin-ished pellets shall be visually (1X) free of loose chips, oil,macroscopic inclusions, and foreign materials.4.4 IdentificationIt sha
45、ll be possible to identify pellets asto total fissile and total plutonium content by, for example,marking or coding or other administrative controls. Otheridentification can be used (for example, total plutonium and“reference date”).4.5 Irradiation Stability (Densification)An estimate of thefuel pel
46、let irradiation stability shall be obtained unless ad-equate allowance for such effects are factored into the fuel roddesign. The estimate of the stability shall consist of either (a)conformance to the thermal stability test as specified in theapplicable Regulatory Guide 1.126, or (b) by adequate co
47、rre-lation of manufacturing process or microstructure to in-reactorbehavior, or both.5. Lot Requirements5.1 A (UO2-PuO2) powder lot is defined as a quantity of(UO2-PuO2) powder that is manufactured to produce uniformisotopic, chemical, physical, and sinterability characteristics.5.2 A pellet lot is
48、defined as a group of pellets made from asingle (UO2-PuO2) powder lot using one set of blending andpelletizing process parameters.5.3 The identity of a pellet lot shall be retained throughoutprocessing without mixing with other established pellet lots.5.4 Conformance to this specification shall be e
49、stablishedfor each pellet lot.6. Sampling6.1 Sampling, weighing of the sample, and handling thesample shall be done under conditions that ensure that thesample is representative of the pellet or powder lot. Inparticular, (Uranium-plutonium) dioxide pellets may be hygro-scopic and retain sufficient water after exposure to a moistatmosphere to cause detectable errors. Sampling plans shall bemutually agreed upon between the buyer and the seller.Practice E 105 is recommended as a guide.6.2 The buyer or his representative shall have the option tot
