1、Designation: C 998 05Standard Practice forSampling Surface Soil for Radionuclides1This standard is issued under the fixed designation C 998; 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 (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers the sampling of surface soil for thepurpose of obtaining a sample representative of a particulararea for subsequent chemical a
3、nalysis of selected radionu-clides. This practice describes one acceptable approach tocollect soil samples for radiochemical analysis.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 standard to esta
4、blish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 420 Guide to Site Characterization for Engineering, De-sign, and Construction PurposesD 1129 Terminology Relating to Water2.2 Other Refe
5、rences:MARLAP, Chapter 10IAEA-TECDOC-1415, Soil Sampling for EnvironmentalContaminants3. Terminology3.1 Definitions:3.1.1 samplingobtaining a representative portion of thematerial concerned (see Terminology D 1129).4. Summary of Practice4.1 Guidance is provided for the collection of soil samplesto a
6、 depth of 50 mm. Ten core samples are collected in aspecified pattern and composited to obtain sufficient sample soas to be representative of the area.5. Significance and Use5.1 Soil provides a source material for the determination ofselected radionuclides and serves as an integrator of thedepositio
7、n of airborne materials. Soil sampling should not beused as the primary measurement system to demonstratecompliance with applicable radionuclides in air standards. Thisshould be done by air sampling or by measuring emission rates.Soil sampling does serve as a secondary system, and in manycases, is t
8、he only available avenue if insufficient air samplingoccurred at the time of an incident. For many insolubleradionuclides, the primary exposure pathway to the generalpopulation is by inhalation. The resuspension of transuranicelements has received considerable attention (1, 2)3and theirmeasurement i
9、n soil is one means of establishing compliancewith the U.S. Environmental Protection Agency (EPA) guide-lines on exposure to transuranic elements. Soil sampling canprovide useful information for other purposes, such as plantuptake studies, total inventory of various radionuclides in soildue to atmos
10、pheric nuclear tests, and the accumulation ofradionuclides as a function of time. A soil sampling andanalysis program as part of a preoperational environmentalmonitoring program serves to establish baseline concentra-tions. Consideration was given to these criteria in preparingthis practice.5.2 Soil
11、 collected using this practice and subsequent analy-sis can be used to monitor radionuclide deposition of emissionsfrom nuclear facilities. The critical factors necessary to providethis information are sampling location, time of sampling,frequency of sampling, sample size, and maintenance of theinte
12、grity of the sample prior to analysis. Since the soil isconsidered to be a heterogeneous medium, multipoint samplingis necessary. The samples must represent the conditions exist-ing in the area for which data are desired.6. Apparatus6.1 Sampling Instrument4In order to standardize thesample collectio
13、n, it is suggested that the coring tool be thatinstrument used by golf courses to place the hole in the puttinggreen. This instrument is commercially available at reasonablecost, has approximately a 0.105-m diameter barrel, and cantake samples down to 300 mm. An illustration of the samplinginstrumen
14、t and its use is provided in Fig. 1.1This practice is under the jurisdiction of ASTM Committee C26 on NuclearFuel Cycle and is the direct responsibility of Subcommittee C26.05 on TestMethods.Current edition approved June 1, 2005. Published June 2005. Originallyapproved in 1983. Last previous edition
15、 approved in 2000 as C 998 90 (2000).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.3The boldface numbers in
16、 parentheses refer to the list of references at the end ofthis standard.4Model 28200 Scalloped Style of the Standard Manufacturing Company ofCedar Falls, IA, or its equivalent, has been found satisfactory for this purpose.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Consho
17、hocken, PA 19428-2959, United States.6.2 Sample Container, such as metal cans with lids, plasticbags, etc.6.3 Meter Stick.6.4 Small Scoop.7. Sampling7.1 Introduction The sampling depth for this practice isthe top 50 mm of soil. Experience has shown this depth is bestfor this purpose (3) and has been
18、 proven to provide samples forthe analysis of deposited radionuclides following a recentairborne release. The difference in concentration from previ-ously collected samples at the same locations would be ameasure of the contamination. If the purpose of the sampling isto measure the total amount of a
19、 radionuclide deposited ontothe soil, that is, from fallout of previous atmospheric nucleartests, then sampling must be conducted to a 300 mm depth. Itis recommended by the EPA (2) that soil sampling forplutonium be the top 10 mm of soil. Although this may be adesirable depth for resuspension studie
20、s in certain parts of thecountry that have powdery, dry, loose, sandy soils, in mostareas, the vegetative cover and root mat make this an unwork-able sampling depth. Because the data may be used in variousways, it is important to accurately record the sample location,the depth of the sample, and the
21、 sample weight. In order toobtain sufficient sample to be representative of the area, due tothe inherent heterogeneity of soil, it is recommended that atotal sampling area of greater than 0.05 m2be collected asdescribed in Section 8.7.2 Site Selection:7.2.1 As an idealized guideline, each site shoul
22、d be selectedon the basis that the soil appears, or was known to have been,undisturbed for a number of years. Open, level, grassy areasthat are mowed at reasonable intervals, such as public parks,are suitable choices. The site should have moderate to goodpermeability and there should be little or no
23、 runoff duringheavy rains. The site should not be near enough to buildings,trees, or other obstructions that it is sheltered or shielded. Highearthworm activity (as a result of direct observation of theremoved sample) or aeration of the root zone may result inuneven mixing of the surface soil and, t
24、herefore, this type ofsite should be avoided. Care should be taken not to select a sitethat is fertilized or watered with sources that may addradioactive materials to the soil, that is, some fertilizers havehigh uranium concentrations. It is important to be able toaccurately describe the location at
25、 which the sample wascollected (the use of GPS is suggested) if it becomes necessaryto return and resample the location.7.2.2 The number of sites sampled is determined by thepurpose of the sampling and the information required from theparticular analysis. If the sampling is part of a preoperationals
26、urvey around a facility, one acceptable distribution is thatproposed in HASL-300 (4) and depicted in Fig. 2. Thisdistribution of 13 sampling sites extending up to 10 km in thedownwind direction from the facility should be adequate toprovide the background concentration of the nuclides ofinterest. Sa
27、mpling for other purposes may require other distri-bution of sites, while sampling to define the distribution of anuclide from a specific incident would require extensiveknowledge of meteorological and climatological factors. It isimportant that the purpose of the sampling dictate the sampledistribu
28、tion.8. Procedure8.1 Sampling Procedure:8.1.1 Select the sampling location based on Section 7.8.1.2 Measure out two 1-m2areas, about 3 m apart.8.1.3 Remove all vegetation to a height of 10 to 20 mmabove the soil and save if desired.8.1.4 Collect soil from the center and each corner of the two1-m2are
29、as.8.1.5 Insert the sampling tool to a depth of 50 mm below thesoil surface and remove the soil plug.8.1.6 Place the soil plug and residual vegetation and roots inan appropriate container.FIG. 1 Soil Sampling Instrument and UseFIG. 2 Soil Sampling PatternC9980528.1.7 Repeat the procedure until the t
30、en cores are collected.Composite the ten cores as one sample.8.1.8 Label the container with such information as location,time, date, collector, depth of core, and area sampled.8.1.9 Clean the sampling tools in water and detergent anddry before collecting the next sample.8.2 Sampling RationaleThe int
31、ent of the sampling proce-dure is to define the operational steps necessary to collect arepresentative sample from a desired location. The selection ofthe sampling tool should be dictated by local soil conditions asit is not the intent of this practice to identify one instrument tothe exclusion of a
32、ll others. However, two common procedures,or variations thereof, are most frequently used. These twoprocedures are the core procedure and the ring procedure.Because of the large variation in soil types, the core methoddescribed in HASL-300 (4) is recommended where applicable,and a ring method used b
33、y the Nevada Applied Ecology Group(NAEG) is offered as an option (5) for dry, sandy soils. Theconcepts and techniques in this practice are applicable to mostsituations requiring sampling surface soil for radionuclides.8.3 Core Procedure The collection of ten cores willsample about 0.086 m2of soil su
34、rface. Composite the ten coresto produce a single sample of about 4 to 5 kg. Most soilscontain sufficient moisture to be cohesive and the plug can beremoved intact. For some types of dry, loose soils, wetting theground by sprinkling prior to sampling may allow the plug tobe removed. Place the plugs
35、in a container, seal, and carefullylabel. Clean the sampling tools in water and detergent and drybefore proceeding to the next sample collection site.8.4 Ring ProcedureFor the dry, loose, sandy soil forwhich the core method is not applicable, press a ring, 100 mmin diameter and 50 mm deep, into the
36、soil. Remove the soilinside the ring with a small scoop to a depth of 50 mm andplace into a container. Repeat this until a total of ten cores arecollected, using the procedure outlined in Section 7 for samplelocation selection. Clean the sampling tools in water anddetergent and dry before proceeding
37、 to the next samplecollection site.9. Discussion9.1 Either method works well for fine-grained soils, butdifficulties occur with rocky soils. For samples in whichplutonium is the element of interest, the rocks may beconsidered voids in the sample and usually are discardedduring sample preparation. If
38、 this is the case, larger numbers ofcores, and therefore larger areas, should be sampled to ensurethat the sample is representative of the site. If it is necessary toremove large rocks, this should be noted in the sampling plan.9.2 The sampling techniques described in this practice willprovide suffi
39、cient information to allow the calculation ofresults in terms of deposition per unit area or concentration. Ifthe sampling is part of a routine monitoring program, it may benecessary to repeat the sampling at each location and compareresults to determine the effect of facility operation.10. Keywords
40、10.1 environmental; radionuclides; sampling; soilREFERENCES(1) “Proposed Guidance on Dose Limits for Persons Exposed to Transu-ranium Elements in the General Environment,” Environmental Protec-tion Agency 520/4-77-016, October 1977.(2) “Persons Exposed to Transuranium Elements in the Environment,”Fe
41、deral Register, Vol 42, No. 230, Nov. 30, 1977.(3) “Measurements of Radionuclides in the Environment: Sampling andAnalysis of Plutonium in Soil,” Atomic Energy Commission Regula-tory Guide 4.5, May 1974.(4) Harley, J. H., ed., “EML Procedures Manual,” D.O.E. Report HASL-300, August 1979.(5) Fowler,
42、F. B., Gilbert, R. O., and Essington, E. H., “Sampling of Soilsfor Radioactivity: Philosophy, Experience, and Results,”Atmospheric-Surface Exchange of Particulate and Gaseous Pollutants, ERDASymposium Series 38, 1974, pp. 706727.ASTM International takes no position respecting the validity of any pat
43、ent 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, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision
44、 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 revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comm
45、ents 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 you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighte
46、d 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).C998053
