ASTM D3865-2002 Standard Test Method for Plutonium in Water《水中钚的标准试验方法》.pdf

1、Designation: D 3865 02Standard 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 (e) 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 s

3、epara-tions and alpha pulse-height analysis (alpha-particle spectrom-etry). The isotopes,239Pu,240Pu, and238Pu, are chemicallyseparated from a 1-L water sample by coprecipitation withferric hydroxide, anion exchange and electrodeposition. Thetest method applies to soluble plutonium and to suspendedp

4、articulate matter containing plutonium. In the latter situation,an acid dissolution step is required to assure that all of theplutonium dissolves.1.2 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 stan

5、dard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. Specific hazards aregiven in Section 92. Referenced Documents2.1 ASTM Standards:C 859 Terminology Relating to Nuclear Materials2C 1192 Test Method for Mounting Actinide

6、s for AlphaSpectrometry Using Neodymium Fluoride3C 1284 Practice for Electrodeposition of the Actinides forAlpha Spectrometry2D 1129 Terminology Relating to Water4D 1193 Specification for Reagent Water4D 2777 Practice for Determination of Precision and Bias ofApplicable Methods of Committee D19 on W

7、ater4D 3084 Practice for Alpha Spectrometry of Water5D 3370 Practices for Sampling Water4D 3648 Practices for the Measurement of Radioactivity5D 3856 Guide for Good Laboratory Practices in Laborato-ries Engaged in Sampling and Analysis of Water4D 5847 Practice for Writing Quality Control Specificati

8、onsfor Standard Test Methods for Water Analysis53. 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 and242Pu is added as atracer before any chemical separati

9、ons are performed. Iron isadded to the water as iron (III), and the plutonium is copre-cipitated with the iron as ferric hydroxide. After decantationand centrifugation, the ferric hydroxide precipitate containingthe coprecipitated plutonium is dissolved, and the solution isadjusted to 8 M in HNO3for

10、 anion exchange separation. Whenthe sample fails to dissolve because of the presence ofinsoluble residue, the residue is treated by a rigorous aciddissolution using concentrated nitric, hydrofluoric, and hydro-chloric acids.4.2 After an anion exchange separation, the plutonium iselectrodeposited ont

11、o 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 test method. From the recovery ofthe242Pu tracer, the absolute activities of238Pu and239/240Pucan be calcu

12、lated.5. Significance and Use5.1 This test method was developed to measure plutoniumin environmental waters or waters released to the environment,and to determine whether or not the plutonium concentrationexceeds the maximum amount allowable by regulatory stat-utes.6. Interferences6.1228Th when pres

13、ent at concentrations 100 times orgreater than238Pu has been found to interfere with thedetermination of238Pu. Some228Th comes through thechemical separation procedure and is electrodeposited with the1This test method is under the jurisdiction of ASTM Committee D19 on Waterand is the direct responsi

14、bility of Subcommittee D19.04 .Current edition approved Feb. 10, 2002. Published May 2002. Originallypublished as D 3865 - 80. Last previous edition D 3865 - 97.2Annual Book of ASTM Standards, Vol 12.01.3Annual Book of ASTM Standards, Vol 15.02.4Annual Book of ASTM Standards, Vol 11.01.5Annual Book

15、of ASTM Standards, Vol 11.02.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.plutonium. If the disk is poorly plated and if the resolution ofthe sample as determined by the alpha spectrometer is notbetter than 60 keV, the238Pu and th

16、e228Th may appear as onepeak; the principal alpha energy of238Pu is 5.50 MeV whilethat of228Th is 5.42 MeV.7. Apparatus7.1 Alpha PulseHeight Analysis System, consisting of asilicon surface barrier, or ion-implanted detector, supportingelectronics, and pulse-height analyzer capable of giving aresolut

17、ion of 50 keV FWHM or better with a sample electrode-posited on a flat, mirror-finished stainless steel disk. Thecounting efficiency of the system should be greater than 15 %and the background in the energy region of each peak shouldbe less than ten counts in 60 000 s.7.2 Electrodeposition Apparatus

18、, consisting ofa0to12V,(0 to 2 A power supply (preferably constant current) and apreferably disposable) electrodeposition cell. The cathode is anapproximately 20-mm diameter stainless steel disk prepolishedto a mirror finish. The anode is an approximately 1-mmdiameter platinum wire with an approxima

19、tely 8-mm diameterloop at the end of the wire parallel to the cathode disk. Coolingof the cell during electrodeposition to at least 50C is recom-mended.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 r

20、eservoir, 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 Commit-tee onAnal

21、ytical Reagents of theAmerican Chemical Society.6Other 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 und

22、erstood to mean reagent water conformingto Specifications 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 (sp gr 0.90)Concentrated

23、am-monium hydroxide (NH4OH).8.5 Ammonium Hydroxide Solution (1+9)Mix 1 volumeof concentrated NH4OH (sp gr 0.90) with 9 volumes of water.8.6 Ammonium Hydroxide Solution (1+99)Mix 1 volumeof concentrated NH4OH (sp gr 0.90) with 99 volumes of water.8.7 Ammonium Iodide Solution (145 g/L)Dissolve 14.5 go

24、f NH4I 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.8.9 Boric Acid (H3BO3)Powdered or crystalline.8.10 Electrolyte, PreadjustedDissolve 132 g of amm

25、o-nium sulfate in water and dilute to 1 L. Add concentratedNH4OH or concentrated H2SO4while stirring to adjust the pHof the solution to 3.5. The solution is 1 M (NH4)2SO4.8.11 Ethyl Alcohol (C2H5OH)Make slightly basic with afew drops of concentrated NH4OH per 100 mL of alcohol.8.12 Ferric Chloride C

26、arrier Solution (50 mg Fe/mL)Dissolve 24 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 (sp gr 1.19)Concentrated hydro-chloric acid (HCl).8.14 Hydrochloric Acid Solution (3+1)Mix 3 volumes ofconcentrated HCL (sp gr 1.19)

27、 with 1 volume of water.8.15 Hydrofluoric Acid (sp gr 1.15)Concentrated hydrof-luoric acid (HF).8.16 Hydrogen Peroxide Solution (1+2)Standard 30 %.Commercially available reagent grade.8.17 Nitric Acid (sp gr 1.42)Concentrated nitric acid(HNO3).8.18 Nitric Acid Solution (1+1)Mix 1 volume of concen-tr

28、ated nitric acid (sp gr 1.42) with 1 volume of water.8.19 Nitric Acid Solution (1+8)Mix 1 volume of concen-trated nitric acid (sp gr 1.42) with 8 volumes of water.8.20242Pu Solutions, Standard (Approximately 0.2 Bq/mL).NOTE 1Standard242Pu solutions usually are available from theNational Institute of

29、 Standards and Technology; dilution to the requiredconcentration may be necessary.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 La

30、boratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary. U.S. Pharmaceutical Convention, Inc. (USPC).TABLE 1 Radioactive Decay Characteristics of Isotopes ofInterest in the Determination of Plutonium in WaterAIsotopeHalf LifeYearsPrincipal Alpha Ene

31、rgies 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 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)5.3

32、40 (26.6)ATable of Isotopes, Eighth Edition, Vol. 11, Richard B. Firestone, LawrenceBerkeley National Laboratory, University of California, 1996.BThese two isotopes are listed, especially in241Am, since they could interferein the determination of238Pu.D38650228.21 Sodium Hydrogen SulfateSulfuric Aci

33、d SolutionDissolve 10 g of sodium hydrogen sulfate in 100 mL of waterand then carefully add 100 mL of concentrated H2SO4(sp gr1.84) while stirring. This solution contains approximately 5 gof NaHSO4per 100 mL of 9 M H2SO4.8.22 Sodium Nitrite (NaNO2).8.23 Sulfuric Acid (sp gr 1.84)Concentrated sulfuri

34、c acid(H2SO4).8.24 Sulfuric Acid Solution (1+9)Carefully mix 1 volumeof concentrated sulfuric acid (sp gr 1.84) with 9 volumes ofwater.8.25 Thymol Blue Indicator SolutionDissolve 0.04 g ofsodium salt of thymol blue in 100 mL of water.9. HazardsNOTE 2Warning: Hydrofluoric acid is extremely hazardous.

35、 Wearrubber gloves, safety glasses or goggles and a laboratory coat. Avoidbreathing any HF fumes. Clean up all spills and wash thoroughly afterusing HF.10. Sampling10.1 Collect the sample in accordance with PracticesD 3370. Preserve the sample by adjusting the acidity to pH 1with HNO3(1+8) if the sa

36、mple is not to be analyzed within 24h. Record the volume of the sample and the volume of acidadded.11. Calibration and Standardization11.1 The236Pu or242Pu tracer used in this method shall betraceable to the National Institute for Standards and Technol-ogy. While the laboratory is advised to verify

37、the activity of thereceived and diluted tracer solution, the results of theseverification measurements shall not replace the decay-corrected traceable value. If the verification measurements failto verify the traceable activity of the as-received236Pu or242Pu tracer solution the laboratory will reso

38、lve this with thesupplier.12. Procedure12.1 Coprecipitation:12.1.1 Measure a known volume approximately 1 L of thewater sample to be analyzed plus the volume of acid added, ifany.12.1.2 If the sample has not been acidified, add 150 mL ofconcentrated HNO3per litre of sample.12.1.3 Mix the sample comp

39、letely, and add an accuratelyknown amount of the236Pu or242Pu standard solution to giveabout 0.2 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

40、1 mL of ferric chloride carrier solution and stirabout 10 min.12.1.6 Add concentrated NH4OH while stirring to precipi-tate the iron. Add a slight excess of the concentrated NH4OHto 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 t

41、he precipitate to settle.12.1.8 After the sample has settled sufficiently, decant thesupernate, being careful not to remove any precipitate. (If theanalyst wishes to continue immediately, the iron hydroxidemay be filtered out at this time.)12.1.9 Slurry the precipitate and remaining supernate andtra

42、nsfer 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. If organic matter is believed to be present,transfer to a TFEfluorocarbon beaker, 250 mL being aconvenient size; add 2 mL 30

43、 % H2O2, 2 mL concentratedHNO3and heat to mean dryness. Repeat as necessary. Thenadd 2 mL concentrated HNO3and proceed.12.1.12 If the precipitate dissolves completely, add a vol-ume of concentrated HNO3equal to the volume of the samplesolution, dilute to 100 to 150 mL with 8 M HNO3, and thenproceed

44、to 12.3. If the precipitate does not dissolve in HNO3,proceed to 12.2.12.2 Acid Dissolution of Insoluble Residue:12.2.1 If the precipitate fails to dissolve in HNO3, add moreconcentrated HNO3to a total volume of about 75 mL, transferthe entire sample to a TFE-fluorocarbon beaker, and add 75 mLof con

45、centrated HF. (WarningSee Section 9.)12.2.2 Stir and heat on a magnetic stirrer hot plate for about4 h at a temperature near boiling. Add equal amounts ofconcentrated HNO3and concentrated HF to keep the volume atabout 150 mL.12.2.3 Allow the mixture to cool, and decant the solutioninto another TFE-f

46、luorocarbon beaker.12.2.4 Evaporate this solution to dryness.12.2.5 While this solution is drying, add 75 mL of concen-trated HCl and2gofH3BO3to the undissolved residue. Stirand let stand until the solution from the previous step hasevaporated to dryness.12.2.6 Transfer the HCl-H3BO3mixture from the

47、 last step tothe dried sample, leaving any residue behind. Rinse the residueonce with water and transfer this water to the sample.12.2.7 Evaporate the sample in the TFE-fluorocarbon bea-ker to about 10 mL.12.2.8 Add 100 mL of concentrated HNO3and boil toremove the HCl.12.2.9 Evaporate the sample to

48、a volume of about 50 mL.12.2.10 Remove from the hot plate, and add a volume ofwater equal to the volume of the sample.12.2.11 Add HNO3(1+1) to a volume of 150 mL, add1gofH3BO3, and allow the solution to cool.12.2.12 Filter the solution through a glass fiber filter andwash the filter a few times with

49、 HNO3(1+1). Discard anyresidue in the filter paper and proceed with the analysis of thefiltrate in accordance with 12.3.1.12.3 Column Preparation:12.3.1 Slurry about 10 mL of the anion exchange resin withwater.12.3.2 Pour it into a column of about 13-mm inside diam-eter to a resin depth of about 80 mm. Use more resin whenanalyzing samples which were treated for suspended matter.D386502312.3.3 Wash the resin with 10 column volumes ofHNO3(1+1) to convert the resin to the nitrate form.12.4 Anion Exchange Separation:12.4.1 To the solution from the coprecipitat