1、Designation: C1411 14Standard Practice forThe Ion Exchange Separation of Uranium and PlutoniumPrior to Isotopic Analysis1This standard is issued under the fixed designation C1411; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the
2、 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 This practice is for the ion exchange separation ofuranium and plutonium from each other and from otherimpuri
3、ties for subsequent isotopic analysis by thermal ioniza-tion mass spectrometry. Plutonium238 and uranium238, andplutonium241 and americium241, will appear as the samemass peak and must be chemically separated prior to analysis.Only high purity solutions can be analyzed reliably usingthermal ionizati
4、on mass spectrometry.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 This standard may involve hazardous material,operations, and equipment. This standard does not purport toaddress all of the safety concerns, if any, as
5、sociated with itsuse. It is the responsibility of the user of this standard toconsult and establish appropriate safety and health practicesand determine the applicability of regulatory limitations priorto use.2. Referenced Documents2.1 ASTM Standards:2C698 Test Methods for Chemical, Mass Spectrometr
6、ic, andSpectrochemical Analysis of Nuclear-Grade Mixed Ox-ides (U, Pu)O2)C833 Specification for Sintered (Uranium-Plutonium) Diox-ide PelletsC859 Terminology Relating to Nuclear MaterialsC1008 Specification for Sintered (Uranium-Plutonium) Di-oxide PelletsFast Reactor FuelC1168 Practice for Preparat
7、ion and Dissolution of PlutoniumMaterials for AnalysisC1347 Practice for Preparation and Dissolution of UraniumMaterials for AnalysisC1625 Test Method for Uranium and Plutonium Concentra-tions and Isotopic Abundances by Thermal IonizationMass SpectrometryD1193 Specification for Reagent Water3. Termi
8、nology3.1 Definitions: For definitions of terms used in thisstandard, refer to C859.4. Summary of Practice4.1 Solid samples are dissolved according to PracticesC1168, C1347, or other appropriate methods. The resultingsolution is processed by this practice to prepare separatesolutions of plutonium an
9、d uranium for mass spectrometricisotopic analysis using Method C698 or Method C1625.Appropriate aliquants are taken to provide up to 1 mg ofplutonium on the ion exchange column to be separated from 10mg or less of uranium. Valence adjustment is obtained by usingone of two procedures as described in
10、4.1.1 and 4.1.2 or by analternative method demonstrated by the user to perform theequivalent reduction/oxidation procedure.34.1.1 For any sample type, especially those containing largeamounts of impurities, ferrous sulfate may be used for reduc-tion. The aliquant is dissolved in 3 M HNO3. Ferrous su
11、lfate isadded to reduce all plutonium (VI) to plutonium (III), then 16M HNO3is added to oxidize plutonium (III) to plutonium (IV),and to adjust the final acid concentration to 8MHNO3.4.1.2 A hydrogen peroxide reduction may be used forrelatively pure samples which do not contain excessiveamounts of o
12、xidizing impurities. The aliquant is dissolved in 8M HNO3. Hydrogen peroxide is added to the aliquant prior tofuming to reduce plutonium (VI) to the lower oxidation states.The solution is warmed on a hot plate to destroy excesshydrogen peroxide and stabilize plutonium (IV) in solution.4,51This pract
13、ice is under the jurisdiction of ASTM Committee C26 on NuclearFuel Cycle and is the direct responsibility of Subcommittee C26.05 on Methods ofTest.Current edition approved Jan. 1, 2014. Published February 2014. Originallyapproved in 1990. Last previous edition approved in 2008 as C1411 08. DOI:10.15
14、20/C1411-14.2For 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 page onthe ASTM website.3Reduction of all higher plutonium oxidation stat
15、es to plutonium (III) by theaddition of hydroxylamine or NH2CLO4, followed by oxidation to plutonium (IV)by sodium nitrite and subsequent boiling to eliminate the nitrous fumes has beenfound to be acceptable. This method avoids the addition of Fe, which could interferewith electrodeposition of prior
16、 to mass spectrometry analysis samples.4I.V. Kressin and G.R. Waterbury, Anal. Chem. 34(12) , 1598 (1962).Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14.2 After valence adjustment, the resulting solution ispassed through an anion e
17、xchange column in the nitrate formwhich retains the plutonium; uranium and americium are notabsorbed. The adsorbed plutonium is washed with additional 8M nitric acid (HNO3) to remove impurities and then strippedfrom the column with 0.36 M hydrochloric acid (HCl) and 0.01M hydrofluoric acid (HF). The
18、 effluent containing the uraniumand americium is converted to a HCl medium, and this solutionis passed through an anion exchange column in the chlorideform which retains the uranium. The adsorbed uranium iswashed with additional 9 M HCl to remove the impurities andthen stripped from the column with
19、0.1 M HCl.5. Significance and Use5.1 Uranium and plutonium are used in nuclear reactor fueland must be analyzed to insure that they meet certain criteriafor isotopic composition as described in Specification C833and Specification C1008. This standard practice is used tochemically separate the same m
20、ass peak interferences fromuranium and plutonium and from other impurities prior toisotopic abundance determination by thermal ionization massspectrometry.5.2 In those facilities where perchloric acid use is tolerated,the separation in Test Method C698 may be used prior toisotopic abundance determin
21、ation. Uranium and plutoniumconcentrations as well as isotopic abundances using thermalionization mass spectrometry can be determined using thisseparation and following Test Method C1625.6. Interferences6.1 The separated heavy element fractions placed on massspectrometric filaments must be very pure
22、. The quantityrequired depends upon the sensitivity of the instrument detec-tion system. Chemical purity of the sample becomes moreimportant as the sample size decreases, because the ionemission of the sample is repressed by impurities.6.2 Organics from ion exchange resin degradation products,if pre
23、sent, could affect the response of the mass spectrometerduring the plutonium and uranium isotopic abundance mea-surements. Evaporation of the samples with concentrated nitricacid after the ion exchange separation has been found todestroy any resin degradation products. Organics from extrac-tion resi
24、ns may not be destroyed by this process, and willrequire a perchloric acid treatment, heating in a furnace at500C, or both.6.3 The use of hydrogen peroxide for valence adjustment,when possible, avoids the addition of iron, an element which isnot cleanly removed from uranium by HCl ion exchange.6.4 E
25、lemental impurities, especially alkali elements, tend toproduce unstable ion emission and alter observed ratios in anunpredictable manner.6.5 Isobaric impurities or contaminants will alter the ob-served isotopic ratios; most notable of these for plutonium areamericium-241 and uranium-238; the most n
26、otable isobaricimpurity for uranium is plutonium-238.6.6 Extreme care must be taken to avoid contamination ofthe sample by environmental uranium. The level of uraniumcontamination should be measured by analyzing an aliquant of8MHNO3reagent as a blank taken through the same chemicalprocessing as the
27、sample and computing the amount ofuranium it contains.7. Apparatus7.1 Ion Exchange ColumnsDisposable, 0.9 cm id3cmwith a 15 mL reservoir.7.2 Beakers or Alternate Acceptable Containerspretreated, 20-30 mL, borosilicate glass. To avoid crosscontamination, use only new borosilicate glass containerspret
28、reated by heating in 4 M HNO3to leach uranium, rinsed indeionized water, and air or oven dried prior to use.7.3 Infrared Heating Lamps or Hot Plate with adjustablelow and high heat settings.7.4 Transfer PipetsDisposable.8. Reagents8.1 Reagent grade or better chemicals should be used.Unless otherwise
29、 indicated, it is intended that all reagentsconform to the specifications of the Committee on AnalyticalReagents of the American Chemical Society6where suchspecifications are available. Other grades of reagents may beused, provided it is first ascertained that the reagent is ofsufficiently high puri
30、ty to permit its use without lessening theaccuracy of measurements made on the prepared materials.Store solutions in appropriate polyethylene or glass bottlesexcept as noted.8.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean laboratory accepteddemineralized
31、 or deionized water conforming to SpecificationD1193.8.3 Nitric Acid (sp gr 1.42), 16 Mconcentrated nitric acid(HNO3).8.4 Nitric Acid, 8 M Add 500 mL of HNO3(sp gr 1.42) toabout 400 mL of water and dilute to 1 L.8.5 Nitric Acid, 4 M Add 250 mL of HNO3(sp gr 1.42) toabout 700 mL of water and dilute t
32、o 1 L with water.8.6 Nitric Acid, 3 M Add 187 mL of HNO3(sp gr 1.42) toabout 750 mL of water and dilute to 1 L with water.8.7 Hydrochloric Acid (sp gr 1.19), 12 Mconcentratedhydrochloric acid (HCl).8.8 Hydrochloric Acid, 9MAdd 750 ml of HCl (sp. gr.1.19) to about 250 ml of water and dilute to 1 L.5C
33、.E. Pietri, B.P. Freeman, and J.R. Weiss, DOE/NBL-298 , September 1981.6Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChe
34、micals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.C1411 1428.9 Hydrofluoric Acid (sp gr 1.18), 29 Mconcentratedhydrofluoric acid (HF).8.10 Hydrochloric Acid, 0.1 MAdd 8 mL of HCl (sp gr1.19) to ab
35、out 900 mL of water and dilute to 1 L with water.8.11 Stripping solution (0.36 M HCl, 0.01 M HF)Add 30mL of HCl (sp gr 1.19) and 0.4 mL HF (sp gr 1.18) to about900 mL of water and dilute to 1 L with water.8.12 Anion exchange resin, 50-100 mesh, wet, chlorideform for uranium separation.8.13 Anion exc
36、hange resin, nitrate form, 50-100 mesh, wet,for plutonium separation.8.13.1 WarningThe dry and wet mesh size of the resinsdiffer; for the chloride form of the resin, a 100-200 mesh, dryresin is purchased to provide 50-100 mesh, wet resin. The100-200 mesh dry chloride resin may be used to prepare the
37、50-100 mesh, wet nitrate form of resin.NOTE 1The exchange capacity of the resin should be between 0.6and 0.7 milliequivalents/gram of dry resin for optimum separation. Astrong base anion exchange resin (quarternary amine functional groups onstyrene divinyl benzene polymeric beads.) is most often use
38、d, with DVBcross linkages of 8%. The resin is available in the chloride form. Othersmay be used but the volume of resin may need to be adjusted to providethe desired degree of separation.8.14 Sulfuric Acid (sp gr 1.84), 18 Mconcentrated sulfuricacid (H2SO4).8.15 Ferrous Sulfate Solution (0.1 M)add 1
39、.5 g of ferroussulfate heptahydrate (FeSO47H2O) to approximately 40 mLof water; add 0.3 mL (7 drops) concentrated sulfuric acid anddilute to 50 mL with water.8.16 Hydrogen Peroxide (H2O2, 30 %), stabilized.9. Precautions9.1 Strong acids are used during this analysis. Safety glassesand gloves must be
40、 worn when handling these solutions.Extreme care should be exercised in using hydrofluoric acidand other hot concentrated acids.Acid solutions are evaporatedduring this analysis. These operations must be conducted in afume hood.9.2 Hydrofluoric acid is a highly corrosive and toxic acidthat can sever
41、ely burn skin, eyes, and mucous membranes.Hydrofluoric acid differs from other acids because the fluorideion readily penetrates the skin, causing destruction of deeptissue layers. Unlike other acids that are rapidly neutralized,hydrofluoric acid reactions with tissue may continue for days ifleft unt
42、reated. Familiarization and compliance with the MSDSis essential.10. Procedure10.1 Plutonium Anion Exchange Separation:10.1.1 Sample Preparation:10.1.1.1 Dissolve solid samples according to PracticeC1168, C1347, or other appropriate methods. Aliquants of thesolution containing the approximate desire
43、d quantity of ele-ment are taken; the desired quantity of element will dependupon whether or not the solution is diluted prior to filamentloading. (WarningNo initial aliquant should contain morethan 10 mg of uranium to prevent inadequate rinsing of the ionexchange resin by the volumes given, and hen
44、ce, inadequateseparation of uranium and plutonium.)NOTE 2If uranium or plutonium concentration is desired, tracersshould be added and equilibrated with the sample during dissolution;concentration may then be determined by isotope dilution TIMS. Ifconcentration is to be determined by other means, tot
45、al dissolution of thesample and quantitative transfers of the sample is essential. Theseprecautions may not be necessary if the only measurement to be made isthe isotope ratios of the uranium or plutonium, or both, in the sample.10.1.1.2 An aliquant containing up to 1 mg of plutonium istransferred t
46、o a new, acid leached 20-30 mL container for ionexchange preparation.NOTE 3From this separation, a maximum of 200 ng of plutonium or2 g of uranium will be loaded on a filament for thermal ionization massspectrometric isotopic abundance determination.10.1.1.3 Fume the aliquant just to dryness on a ho
47、t plate orunder an infrared heat lamp. If the sample contains halides, add8MHNO3and dry two more times. (WarningOverheatingmay cause polymerization of plutonium and difficulty insubsequent dissolution.)For most samples, proceed with 10.1.2 for ferrous sulfatereduction. For relatively pure samples, f
48、ree of transitionelements, proceed with 10.1.3 for hydrogen peroxide reduc-tion. (See 4.1 for a further discussion of the valence adjust-ment.)10.1.2 Ferrous Sulfate Valence Adjustment:10.1.2.1 Dissolve the residue from 10.1.1.3 in8mLof3MHNO3.10.1.2.2 Add 1 drop of 0.1 M FeSO4solution, prepared thed
49、ay of the ion exchange, from a disposable pipet. Swirl to mixwell. This will reduce all plutonium in higher oxidation statesto plutonium (III).10.1.2.3 Add 5 mL of 16 M HNO3. Swirl to mix well. Thiswill oxidize plutonium (III) to plutonium (IV) and adjust thesolution concentration to 8MHNO3.10.1.2.4 Proceed to 10.1.4.10.1.3 Hydrogen Peroxide Valence Adjustment:10.1.3.1 Dissolve the residue from 10.1.1.3 in5mLof8MHNO3.10.1.3.2 Add 4 drops of 30 % H2O2from a disposable pipet.Place the beaker on a hot plate at low heat (80 C) for aminimum of 1.5 h while
