1、Designation: D3865 09 (Reapproved 2015)Standard Test Method forPlutonium in Water1This standard is issued under the fixed designation D3865; 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 par
2、entheses indicates 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 mean
3、s of chemical separa-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 el
4、ectrodeposition. 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 un
5、its of measurement 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 reg
6、ulatory limitations prior to use. Specific hazards aregiven in Section 9.2. Referenced Documents2.1 ASTM Standards:2C859 Terminology Relating to Nuclear MaterialsC1163 Practice for Mounting Actinides for Alpha Spectrom-etry Using Neodymium FluorideC1284 Practice for Electrodeposition of the Actinide
7、s forAlpha SpectrometryD1129 Terminology Relating to WaterD1193 Specification for Reagent WaterD2777 Practice for Determination of Precision and Bias ofApplicable Test Methods of Committee D19 on WaterD3084 Practice for Alpha-Particle Spectrometry of WaterD3370 Practices for Sampling Water from Clos
8、ed ConduitsD5847 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 D1129 and Terminology C859.4. Summary of Test Method4.1 The water sample is acidi
9、fied and 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 p
10、recipitate 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, hyd
11、rofluoric, 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 t
12、his test 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. Significan
13、ce and 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 o
14、riginal water sampleat concentrations 100 times or greater than238Pu has been1This test method is under the jurisdiction of ASTM Committee D19 on Waterand is the direct responsibility of Subcommittee D19.04 on Methods of Radiochemi-cal Analysis.Current edition approved Jan. 1, 2015. Published Januar
15、y 2015. Originallyapproved in 1980. Last previous edition approved in 2009 as D3865 09. DOI:10.1520/D3865-09R15.2For 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
16、standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1found to interfere with the determination of238Pu. Some228Thcomes through the chemical separation procedure and iselectrodeposited with
17、 the plutonium. If the disk is poorly platedand if the resolution of 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
18、 inferred from its decay progeny.6.2 Unless corrected, the presence 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 sm
19、all percentage of242Pu, in addition toother plutonium isotopes. The 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
20、 be free of plutonium analyte isotopes242Pu may be the preferred tracer isotope.7. Apparatus7.1 Alpha Spectrometry System, consisting of a siliconsurface barrier, or ion-implanted detector, supportingelectronics, and multi-channel pulse-height analyzer capable ofgiving a resolution of 50 keV or bett
21、er full-width at half-maximum (FWHM) with a sample electrodeposited on a flat,mirror-finished stainless steel disk. The counting efficiency ofthe system should be greater than 15 % and the background inthe energy region of each analyte isotope should be less thanten counts in 60 000 s.7.2 Electrodep
22、osition Apparatus, consisting ofa0to12V,0 to 2 A power supply (preferably 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 wir
23、e with an approximately 8-mmdiameter loop at the end of the wire parallel 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 lon
24、g with a 100-mL reservoir, and eithera fritted glass or borosilicate 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
25、Commit-tee onAnalytical Reagents of theAmerican Chemical Society.3Other 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 w
26、ater shall be understood to mean reagent water conformingto Specifications D1193, 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 (approxim
27、ately 15 M, 28 %)Concentrated ammonium hydroxide (NH4OH). Store in 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 wi
28、thwater. Store in well-sealed container to minimize absorption ofcarbon 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 i
29、f a precipitate ispresent.8.7 Ammonium Iodide Solution (1 M)Dissolve 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
30、 form may also be used. Thestudy which generated the precision and 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.3Reagent Chemicals, American Chemic
31、al 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 National Formulary. U.S. Phar
32、maceutical 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 (28.6)239Pu 2.4110 1045.158
33、 (73.3)5.144 (15.1)5.105 (11.5)240Pu 6563 5.168 (73.51)5.123 (26.39)242Pu 3.733 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 National Laboratory, Univers
34、ity of California, 1996.BThese two isotopes are listed, especially in241Am, since they could interfere inthe determination of238Pu.D3865 09 (2015)28.9 Boric Acid (H3BO3)Powdered or crystalline.8.10 Electrolyte, PreadjustedThe solution is 1 M(NH4)2SO4. Dissolve 132 g of ammonium sulfate in water andd
35、ilute 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.8.12 Ferric Chloride Carrier Solution (50 mg Fe/mL)Dissolve 24
36、 g of FeCl36H2O in a mixture of 4.4 mL ofconcentrated hydrochloric acid (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
37、 withwater.8.15 Hydrofluoric Acid ( 29 M, 49 %)Concentrated hy-drofluoric 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
38、water.8.19 Nitric Acid Solution (1.8 M)Add110mLof16Mnitric acid to 500 mL of water and dilute to 1 L with water.8.20236Pu or242Pu Solutions, Standard (Approximately0.2 Bq/mL)The study which generated the precision and biasdata referenced in section 15 was performed using only a242Putracer. Those usi
39、ng236Pu should validate that such a substitu-tion does not impact the 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 laborator
40、ies;dilution to the required concentration may be necessary.8.21 Sodium Hydrogen SulfateSulfuric Acid SolutionDissolve 10 g of sodium hydrogen sulfate in 100 mL of waterand then carefully add 100 mLof concentrated H2SO4( 18 M,95 %) while stirring. This solution contains approximately 5 gof NaHSO4per
41、 100 mL of 9 M H2SO4.8.22 Sodium Nitrite (NaNO2).8.23 Sulfuric Acid ( 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. (WarningAdd the acid slowly to water,with stirring,to prevent
42、 boiling and spattering.)8.25 Thymol Blue Indicator SolutionDissolve 0.04 g ofsodium salt of thymol blue in 100 mL of water.9. Hazards9.1 WarningHydrofluoric acid is extremely hazardous.Wear suitable protective gloves, safety glasses or goggles anda laboratory coat. Avoid breathing any HF fumes. Cle
43、an up allspills and wash thoroughly after using HF.10. Sampling10.1 Collect the sample in accordance with PracticesD3370. 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.1
44、1. Calibration and Standardization11.1 The236Pu or242Pu tracer used 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
45、 not replace the decay-corrected traceable value. If the verification 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
46、watersample. The volume should be approximately 1 litre. Docu-ment 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.
47、2 Bq of236Pu or242Pu. If the239Pu,240Pu, or238Pucontent of the sample 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 whi
48、le stirring to precipi-tate iron hydroxide. Add a slight excess of 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 thesupe
49、rnate, being careful not to remove any precipitate.Alternatively, the iron hydroxide precipitate may be filteredout.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
