1、Designation: D 3865 09Standard Test Method forPlutonium in Water1This standard is issued under the fixed designation D 3865; 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 indicat
2、es the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of alpha-particle-emitting isotopes of plutonium concentrations over0.01 Bq/L (0.3 pCi/L) in water by means of chemical se
3、para-tions and alpha pulse-height analysis (alpha-particle spectrom-etry). Due to overlapping alpha-particle energies, this methodcannot distinguish239Pu from240Pu. Plutonium is chemicallyseparated from a 1-L water sample by coprecipitation withferric hydroxide, anion exchange and electrodeposition.
4、 Thetest method applies to soluble plutonium and to suspendedparticulate matter containing plutonium. In the latter situation,an acid dissolution step is required to assure that all of theplutonium dissolves.1.2 The values stated in SI units are to be regarded asstandard. No other units of measureme
5、nt are included in thisstandard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitati
6、ons prior to use. Specific hazards aregiven in Section 92. Referenced Documents2.1 ASTM Standards:2C 859 Terminology Relating to Nuclear MaterialsC 1163 Practice for Mounting Actinides for Alpha Spec-trometry Using Neodymium FluorideC 1284 Practice for Electrodeposition of the Actinides forAlpha Spe
7、ctrometryD 1129 Terminology Relating to WaterD 1193 Specification for Reagent WaterD 2777 Practice for Determination of Precision and Bias ofApplicable Test Methods of Committee D19 on WaterD 3084 Practice for Alpha-Particle Spectrometry of WaterD 3370 Practices for Sampling Water from Closed Condui
8、tsD 5847 Practice for Writing Quality Control Specificationsfor Standard Test Methods for Water Analysis3. Terminology3.1 Definitions:3.1.1 For definitions of terms used in this test method, referto Terminology D 1129 and Terminology C 859.4. Summary of Test Method4.1 The water sample is acidified a
9、nd a plutonium isotopictracer, for example236Pu or242Pu, is added as a tracer beforeany chemical separations are performed. Iron is added to thewater as iron (III), and the plutonium is coprecipitated with theiron as ferric hydroxide. After decantation and centrifugation,the ferric hydroxide precipi
10、tate containing the coprecipitatedplutonium is dissolved, and the solution is adjusted to 8 M inHNO3for anion exchange separation. When the sample fails todissolve because of the presence of insoluble residue, theresidue is treated by a rigorous acid dissolution using concen-trated nitric, hydrofluo
11、ric, and hydrochloric acids.4.2 After an anion exchange separation, the plutonium iselectrodeposited onto a stainless steel disk for counting byalpha pulse-height analysis using a silicon surface barrier orion-implanted detector. Table 1 shows the alpha energies of theisotopes of interest in this te
12、st method. The absolute activitiesof238Pu and239/240Pu are calculated independent of discretedetector efficiency and chemical yield corrections by directlycomparing the number of counts in each peak relative to countsobserved from a known activity of236Pu or242Pu tracer (seeEq 1).5. Significance and
13、 Use5.1 This test method was developed to measure plutoniumin environmental waters or waters released to the environmentand to determine whether or not the plutonium concentrationexceeds the maximum amount allowable by regulatory stat-utes.6. Interferences6.1 Thorium-228, when present in the origina
14、l water sampleat concentrations 100 times or greater than238Pu has beenfound to interfere with the determination of238Pu. Some228Thcomes through the chemical separation procedure and iselectrodeposited with the plutonium. If the disk is poorly plated1This test method is under the jurisdiction of AST
15、M Committee D19 on Waterand is the direct responsibility of Subcommittee D19.04 .Current edition approved Feb. 1, 2009. Published March 2009. Originallyapproved in 1980. Last previous edition approved in 2002 as D 3865 02.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontac
16、t ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.and if the resolution of
17、 peaks in the alpha spectrum is not betterthan 60 keV, the238Pu and the228Th may appear as one peak;the principal alpha energy of238Pu is 5.50 MeV while thatof228Th is 5.42 MeV. After a period of in-growth the presenceof228Th can be inferred from its decay progeny.6.2 Unless corrected, the presence
18、of the tracer isotope inthe original water sample will bias the yield of that tracer highand bias the results of the analyte plutonium isotopes low. Forexample, plutonium that originates from high burn-up pluto-nium may contain a small percentage of242Pu, in addition toother plutonium isotopes. The
19、tracer isotope,236Pu, is lesssubject to this problem given that it is not generated in reactorsburning plutonium or uranium. However, there is some poten-tial for tailing of the236Pu peak into analyte regions. Forsamples expected to be free of plutonium analyteisotopes242Pu may be the preferred trac
20、er isotope.7. Apparatus7.1 Alpha Spectrometry System, consisting of a siliconsurface barrier, or ion-implanted detector, supporting electron-ics, and multi-channel pulse-height analyzer capable of givinga resolution of 50 keV or better full-width at half-maximum(FWHM) with a sample electrodeposited
21、on a flat, mirror-finished stainless steel disk. The counting efficiency of thesystem should be greater than 15 % and the background in theenergy region of each analyte isotope should be less than tencounts in 60 000 s.7.2 Electrodeposition Apparatus, consisting ofa0to12V,0 to 2 A power supply (pref
22、erably constant current) and a(preferably disposable) electrodeposition cell. The cathode isan approximately 20-mm diameter stainless steel disk pre-polished to a mirror finish. The anode is an approximately1-mm diameter platinum wire with an approximately 8-mmdiameter loop at the end of the wire pa
23、rallel to the cathode disk.Cooling of the cell during electrodeposition to at least 50C isrecommended.7.3 Centrifuge, a 100-mL centrifuge bottle is convenient.7.4 Ion Exchange Column, approximately 13-mm insidediameter and 150 mm long with a 100-mL reservoir, and eithera fritted glass or borosilicat
24、e glass-wool plug at the bottom.8. Reagents and Materials8.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to the specifications of the Commit-tee onAnalytical Reagents of theAmerican Chemical Society.3O
25、ther grades may be used, provided it is first ascertained thatthe reagent is of sufficiently high purity to permit its usewithout reducing the accuracy of the determination.8.2 Purity of WaterUnless otherwise indicated, referenceto water shall be understood to mean reagent water conformingto Specifi
26、cations D 1193, Type III or better.8.3 Radioactive PurityRadioactive purity shall be suchthat the measured radioactivity of blank samples does notexceed the calculated probable error of the measurement.8.4 Ammonium Hydroxide (approximately 15 M, 28 %)Concentrated ammonium hydroxide (NH4OH). Store in
27、 well-sealed container to minimize absorption of carbon dioxide. Donot use if the solution is cloudy or if a precipitate is present.8.5 Ammonium Hydroxide Solution (1.5 M)Add 100 mLof 15 M NH4OH to 250 mL of water and dilute to 1 L withwater. Store in well-sealed container to minimize absorption ofc
28、arbon dioxide. Do not use if the solution is cloudy or if aprecipitate is present.8.6 Ammonium Hydroxide Solution (0.15 M)Add 10 mLof 15 M NH4OH to 250 mL of water and dilute to 1 L withwater. Do not use if the solution is cloudy or if a precipitate ispresent.8.7 Ammonium Iodide Solution (1 M)Dissol
29、ve 14.5 g ofNH4I in water and dilute to 100 mL. This solution must beprepared fresh weekly.8.8 Anion Exchange ResinStrongly basic, styrene, quater-nary ammonium salt, 4 % crosslinked, 100 to 200 mesh,chloride form. The 8 % crosslinked form may also be used. Thestudy which generated the precision and
30、 bias data referenced insection 15 was performed using only the 4 % crosslinked form.Those using 8 % crosslinked should validate that such asubstitution does not impact the performance of the method.8.9 Boric Acid (H3BO3)Powdered or crystalline.8.10 Electrolyte, PreadjustedThe solution is 1 M(NH4)2S
31、O4. Dissolve 132 g of ammonium sulfate in water anddilute to 1 L.Add concentrated NH4OH or concentrated H2SO4while stirring to adjust the pH of the solution to 3.5.8.11 Slightly Basic Ethyl Alcohol (C2H5OH) 95 %Makeslightly basic with a few drops of concentrated NH4OH per 100mL of alcohol.3Reagent C
32、hemicals, 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 LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand Nati
33、onal Formulary. U.S. Pharmaceutical Convention, Inc. (USPC).TABLE 1 Radioactive Decay Characteristics of Isotopes ofInterest in the Determination of Plutonium in WaterAIsotopeHalf LifeYearsPrincipal Alpha Energies in MeV(Abundance)236Pu 2.858 5.767 (69.14)5.730 (30.70)238Pu 87.7 5.499 (71.4)5.456 (2
34、8.6)239Pu 2.4110 3 1045.158 (73.3)5.144 (15.1)5.105 (11.5)240Pu 6563 5.168 (73.51)5.123 (26.39)242Pu 3.733 3 1054.902 (79)4.858 (21)241AmB432.2 5.544 (0.36)5.485 (85.1)5.442 (13.3)228ThB1.9131 5.423 (73.4)5.340 (26.6)ATable of Isotopes, Eighth Edition, Vol. 11, Richard B. Firestone, LawrenceBerkeley
35、 National Laboratory, University of California, 1996.BThese two isotopes are listed, especially in241Am, since they could interferein the determination of238Pu.D38650928.12 Ferric Chloride Carrier Solution (50 mg Fe/mL)Dissolve 24 g of FeCl36H2O in a mixture of 4.4 mL ofconcentrated hydrochloric aci
36、d (sp gr 1.19) and 95.6 mL ofwater.8.13 Hydrochloric Acid (approximately 12 M, 36 %)Concentrated hydrochloric acid (HCl).8.14 Hydrochloric Acid Solution (9 M)Add 750 mL of 12M hydrochloric acid to 150 mL of water and dilute to 1 L withwater.8.15 Hydrofluoric Acid ( 29 M, 49 %)Concentrated hy-drofluo
37、ric acid (HF).8.16 Hydrogen Peroxide Solution (H2O2)Standard 30 %.8.17 Nitric Acid ( 16 M, 69 %)Concentrated nitric acid(HNO3).8.18 Nitric Acid Solution (8 M)Add 500 mL of 16 Mnitric acid to 250 mL of water and dilute to 1 L with water.8.19 Nitric Acid Solution (1.8 M)Add110mLof16Mnitric acid to 500
38、 mL of water and dilute to 1 L with water.8.20236Pu or242Pu Solutions, Standard (Approximately 0.2Bq/mL)The study which generated the precision and biasdata referenced in section 15 was performed using only a242Putracer. Those using236Pu should validate that such a substitu-tion does not impact the
39、performance of the method.NOTE 1Standard236Pu and242Pu tracer solutions usually are avail-able from the National Institute of Standards and Technology (NIST),vendors with traceability to NIST, or other national standards laboratories;dilution to the required concentration may be necessary.8.21 Sodiu
40、m Hydrogen SulfateSulfuric Acid SolutionDissolve 10 g of sodium hydrogen sulfate in 100 mL of waterand then carefully add 100 mL of concentrated H2SO4( 18 M,95 %) while stirring. This solution contains approximately 5 gof NaHSO4per 100 mL of 9 M H2SO4.8.22 Sodium Nitrite (NaNO2).8.23 Sulfuric Acid (
41、 18 M, 95%)Concentrated sulfuricacid (H2SO4).8.24 Sulfuric Acid Solution (1.8 M)Carefully add 100 mLof 18 M sulfuric acid to 750 mL of water and dilute to 1 L withwater. Warning: Add the acid slowly to water,with stirring, toprevent boiling and spattering.8.25 Thymol Blue Indicator SolutionDissolve
42、0.04 g ofsodium salt of thymol blue in 100 mL of water.9. Hazards9.1 Warning: Hydrofluoric acid is extremely hazardous.Wear suitable protective gloves, safety glasses or goggles anda laboratory coat. Avoid breathing any HF fumes. Clean up allspills and wash thoroughly after using HF.10. Sampling10.1
43、 Collect the sample in accordance with PracticesD 3370. Preserve the sample by adjusting the acidity to pH 1with HNO3(1.8 M) if the sample is not to be analyzed within24 h. Record the volume of the sample and the volume of acidadded.11. Calibration and Standardization11.1 The236Pu or242Pu tracer use
44、d in this method shall betraceable to NIST or another national standards laboratory.While the laboratory is advised to verify the activity of thereceived and diluted tracer solution, the results of theseverification measurements shall not replace the decay-corrected traceable value. If the verificat
45、ion measurements failto verify the traceable activity of the as-received236Pu or242Putracer solution the laboratory will resolve this with the supplier.12. Procedure12.1 Coprecipitation:12.1.1 Accurately measure a known volume of the watersample. The volume should be approximately 1 litre. Docu-ment
46、 the known volume.12.1.2 If the sample has not been acidified, add 150 mL ofconcentrated HNO3per litre of sample.12.1.3 Mix the sample completely, and add an accuratelyknown amount of the236Pu or242Pu standard solution to giveabout 0.2 Bq of236Pu or242Pu. If the239Pu,240Pu, or238Pucontent of the sam
47、ple is known to be high236Pu tracer isrecommended.12.1.4 Heat the sample to about 60C and stir at thistemperature for about 1 h.12.1.5 Add 1 mL of ferric chloride carrier solution and stirabout 10 min.12.1.6 Add concentrated NH4OH while stirring to precipi-tate iron hydroxide. Add a slight excess of
48、 the concentratedNH4OH to raise the pH to 9 to 10 as indicated with pH paper.12.1.7 Continue to stir the sample for about 30 min beforeallowing the precipitate to settle.12.1.8 After the sample has settled sufficiently, decant thesupernate, being careful not to remove any precipitate. Alter-natively
49、, the iron hydroxide precipitate may be filtered out.12.1.9 Slurry the precipitate and remaining supernate andtransfer to a 100 mL centrifuge bottle.12.1.10 Centrifuge the sample and pour off the remainingsupernate.12.1.11 Dissolve the ferric hydroxide with a minimum ofconcentrated HNO3. Transfer to a beaker, add 2 mL 30 %H2O2, 2 mL concentrated HNO3and heat to near dryness.Repeat twice if necessary to achieve dissolution. Then add anadditional 2 mL concentrated HNO3and proceed.12.1.12 If the precipitate dissolves completely, add a vol-ume of concentr
