1、Designation: D 5928 96 (Reapproved 2003)Standard Test Method forScreening of Waste for Radioactivity1This standard is issued under the fixed designation D 5928; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revis
2、ion. A number in parentheses indicates 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 screening for a, b, and gradiation above ambient background levels or user-definedcriteria, or both
3、, in liquid, sludge, or solid waste materials.1.2 This test method is intended to be a gross screeningmethod for determining the presence or absence of radioactivematerials in liquid, sludge, or solid waste materials. It is notintended to replace more sophisticated quantitative analyticaltechniques,
4、 but to provide a method for rapidly screeningsamples for radioactivity above ambient background levels oruser-defined criteria, or both, for facilities prohibited fromhandling radioactive waste.1.3 This test method may not be suitable for applicationssuch as site assessments and remediation activit
5、ies.1.4 The values stated in SI units are to be regarded as thestandard.1.5 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 t
6、he applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C 859 Terminology Relating to Nuclear Materials3. Terminology3.1 For terminology related to radioactive materials, seeTerminology C 859.4. Summary of Test Method4.1 Asample is held within 6 mm of the
7、detector window ofa radiation survey meter, and the visible or audible reaction ofthe meter, or both, is noted. The user defines an application/project specific “negative” and “positive” result criteria. A“negative” test result indicates radiation levels are below theuser-established criteria; a “po
8、sitive” test result indicates theradiation levels are above the user-established criteria.5. Significance and Use5.1 Most facilities disposing or utilizing waste materials areprohibited from handling wastes that contain radioactive ma-terials. This test method provides the user a rapid method forscr
9、eening waste material samples in the field or laboratory forthe presence or absence of radioactivity at userestablishedcriteria. It is important to these facilities to be able to verifygenerator-supplied information that radioactive or mixedwastes have not been included in shipments of waste materia
10、ls.6. Interferences6.1 Needle deflections or audible clicks of the survey meter,or both, occur due to naturally occurring omni-directionalbackground radiation. This level of ambient background radia-tion should be periodically assessed. See Section 10.6.2 Possible sources of interference include pac
11、emakers,X-ray generating equipment, radium-based luminescent dials,polonium-based static eliminators, and smoke detectors con-taining a radioactive isotope sensing mechanism. Such inter-ferences can usually be traced to their source using the portableinstrument specified in this test method.6.3 A la
12、rge amount of potassium in the waste sample mayproduce a positive result due to the natural presence of theradioactive isotope, Potassium-40.6.4 The sensitivity of this test method to beta and gammaradiation may be dependent on sample volume.Asmall samplevolume with readings near background levels m
13、ay give a falsenegative result.6.5 Some radioactive isotopes, such as3H and14C, may notemit radiation of sufficient energy to be detected. If suspectedto be present in the waste, another procedure should be usedthat is appropriate to their determination.6.6 Liquid samples, as well as moisture in sol
14、id samples, aregood attenuators of radiation and will hinder detection of manyradionuclides unless they emit high-energy gamma radiation.The possible inability to detect alpha particles and low-level1This test method is under the jurisdiction of ASTM Committee D34 on WasteManagement and is the direc
15、t responsibility of Subcommittee D34.01.05 onScreening Methods.Current edition approved March 10, 2003. Published June 2003. Originallyapproved in 1996. Last previous edition approved in 1996 as D 5928 96.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer S
16、ervice 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.beta emissions that may be attenuated, in
17、 many cases, shouldnot be a serious shortcoming in this test method because theseemissions are often accompanied by higher energy gammaemissions.6.6.1 Moisture-laden Americium-241 bearing waste wouldbe a case where there is a high probability of non-detection dueto attenuation.6.7 Survey meter conta
18、mination can cause artificially low orhigh results when reading standard sources or ambient back-ground. If this occurs, the survey meter performance shall beconsidered unreliable and should be appropriately decontami-nated by qualified personnel, or disposed of in accordance withapplicable regulati
19、ons.6.8 The radiation monitor should be operated in accordancewith the manufacturers instructions.7. Apparatus7.1 Radiation Survey Meter, with a halogen-quenched un-compensated Geiger-Mueller tube with thin mica end-window.It is advisable to choose an instrument model that has aninternal counter (cp
20、m) or is capable of operating in a scalermode.NOTE 1The meter used in the development of this test method wasthe Monitor 4.3A number of other survey meters4are suitable for this testmethod. Through the end-window, this unit is capable of detecting andindicating alpha radiation (down to 2.5 MeV with
21、a typical detectionefficiency of 80 % at 3.6 MeV), beta radiation (down to 150 KeV with atypical 75 % detection efficiency), gamma radiation and X-rays (down to10 KeV), with the survey meter set on its lowest energy range of 0.1 mr/h.8. Reagents and Materials8.1 The check sources used in the develop
22、ment of this testmethod were manufactured by Oxford Instruments, Inc.5Othersuitable check sources are available from a number of suppli-ers.6The check sources used in the development of this testmethod are federally exempt and do not require licensing.Sources other than the following (that is, Cesiu
23、m 137) areappropriate for this test method. The sources, levels of activity,and half-lives used in the development of this test method areas follows:Source Type Activity Half-Life (t12 )Polonium 210 alpha 0.1 Ci 138.4 daysStrontium 90 beta 0.1 Ci 28.6yearsCobalt 60 gamma 1.0 Ci 5.3years8.2 Check sou
24、rces should be replaced at least every threehalf-lives.9. Sample9.1 Because stratification of liquid samples is possible,thoroughly mix the sample by shaking or stirring prior totesting. Strongly multiphasic samples should have each layertested separately. Solid samples should be thoroughly mixed by
25、a method appropriate to their size and physical characteristics.10. Calibration and Standardization10.1 Check the battery power source of the survey meterprior to use. If the battery check indicates that the batterycharge is not in the optimal power range, it must be replacedprior to use.10.2 Check
26、the survey meters performance at least dailyusing the a, b, and g check sources. This is done by observingthe survey meter response when held within 6 mm of eachcheck standard. At a minimum, check sources should be 2times the ambient background. The check sources listed in 9.1far exceed this require
27、ment.10.3 The survey meter should be factory-calibrated at leastyearly.10.4 Assess the level of ambient background radiationperiodically. This may be prior to each test, daily, weekly, ormonthly depending on user requirements.10.4.1 Set the survey meter to its X1 or most sensitivesetting and enable
28、the audible alarm, if unit is so equipped.10.4.2 Record the number of audible meter clicks over aperiod of 60 s (counts per minute). Repeat this procedure twomore times, and take the average of the three repetitions usingthe following formula:Average ambient background radiation5Measurement No.11 Me
29、asurement No.21 Measurement No.3310.5 Unexpectedly high readings for ambient background orstandard sources infers that the survey meter is contaminated.See the section on Interferences.10.6 The user must clearly define the criteria to be used forreporting “negative” or “positive” test results. These
30、 criteriamay be project- or application-specific. A common definingpoint used is “two to three times the ambient backgroundlevel.”11. Procedure11.1 Perform the necessary steps presented in Section 10.11.2 Allow the survey meter to stabilize for 10 to 15 s at itsX1 or lowest appropriate setting.11.3
31、Place the end-window of the survey meter within 6 mmof the sample. Depending on the physical characteristics of thesample container (for example, the container is such that thesample is 6 mm from the opening), it may be necessary towithdraw a representative portion of the sample to an alternatesampl
32、e container, watch glass, or other appropriate vessel toallow the end-window to be placed within 6 mm of the sample.Do not allow the survey meter to come in direct contact withthe sample. This may contaminate the meter and may damagethe end-window.11.4 Record the counts per minute for a period of 60
33、 s(counts per minute).11.5 If the counts per minute are above the user-definedcriteria, then the sample may contain radioactive material.NOTE 2The user should recognize the potential interferences men-tioned in Section 6.3Manufactured by SE International, Inc., Summertown, TN.4For example, Five Leve
34、l Portable Meter, manufactured by Harshaw-Bicron,Inc., Solon, OH; Ludlum Measurements, Inc., Sweetwater, TX; and EberlineInstrument Corp., Santa Fe, NM.5Oxford Instruments, Inc., Oak Ridge, TN.6For example, The Source, Inc., Santa Fe, NM; Ludlum Measurements, Inc.,Sweetwater, TX; and Eberline Instru
35、ment Corp., Santa Fe, NM.D 5928 96 (2003)211.6 If radioactivity levels above the user-defined criteriaare observed, the background levels should be redetermined asdescribed in Section 10. The sample should then be retestedbeginning with 11.2.11.7 If radioactivity levels are confirmed to be above the
36、user-defined criteria, sample testing should be discontinued,and the appropriate health and safety professional or siteregulatory officer should be contacted for further instructions.11.8 If radioactivity levels are below the user-defined crite-ria, the test result may be recorded as not detected.12
37、. Precision and Bias12.1 PrecisionNo statement is made about the precisionbecause this screening test method produces only a positive ornegative test result.12.2 BiasNo statement is made about the bias becausethis screening test method produces only a positive or negativetest result.13. Keywords13.1
38、 radioactivity; screening method; waste materialsASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights
39、, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for re
40、vision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing yo
41、u shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).D 5928 96 (2003)3
