1、ANSI/ANS-2.17-2010evaluation of subsurfaceradionuclide transport at commercialnuclear power plantsANSI/ANS-2.17-2010ANSI/ANS-2.17-2010American National StandardEvaluation of SubsurfaceRadionuclide Transport at CommercialNuclear Power PlantsSecretariatAmerican Nuclear SocietyPrepared by theAmerican N
2、uclear SocietyStandards CommitteeWorking Group ANS-2.17Published by theAmerican Nuclear Society555 North Kensington AvenueLa Grange Park, Illinois 60526 USAApproved December 23, 2010by theAmerican National Standards Institute, Inc.AmericanNationalStandardDesignation of this document as an American N
3、ational Standard attests thatthe principles of openness and due process have been followed in the approvalprocedure and that a consensus of those directly and materially affected bythe standard has been achieved.This standard was developed under procedures of the Standards Committee ofthe American N
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9、r interpretation should be sent to the Standards Department atSociety Headquarters. Action will be taken to provide appropriate response inaccordance with established procedures that ensure consensus on theinterpretation.Comments on this standard are encouraged and should be sent to SocietyHeadquart
10、ers.Published byAmerican Nuclear Society555 North Kensington AvenueLa Grange Park, Illinois 60526 USACopyright 2010 by American Nuclear Society. All rights reserved.Any part of this standard may be quoted. Credit lines should read “Extracted fromAmerican National Standard ANSI0ANS-2.17-2010 with per
11、mission of the publisher,the American Nuclear Society.” Reproduction prohibited under copyright conventionunless written permission is granted by the American Nuclear Society.Printed in the United States of AmericaForewordThis Foreword is not a part of American National Standard “Evaluation of Subsu
12、rfaceRadionuclide Transport at Commercial Nuclear Power Plants,” ANSI0ANS-2.17-2010.!This standard constitutes a major revision of the original standard, ANSI0ANS-2.17-1980, which was adopted on April 9, 1980, reaffirmed on October 3, 1989,and withdrawn on July 28, 2000. A new working group, Working
13、 Group ANS-2.17of ANS-25 Subcommittee Siting: Environmental surface occurrence and movement of radio-nuclides, except to the extent that surfaceradionuclide occurrence and movement mightaffect, or be affected by, on-site subsurfaceradionuclide occurrence and movemente.g.,a surface release that subse
14、quently infil-trates and affects groundwater, a subsur-face release that affects surface water,including exposure pathways across thegroundwatersurface-water transition zone!; corrective action, which might be requiredas the result of a subsurface radionucliderelease; dose calculations to demonstrat
15、e compli-ance with any regulatory requirement.2 Definitions2.1 Acronyms and initialismsALARA: as low as is reasonably achievableANS: American Nuclear SocietyANSI: American National Standards InstituteASTM: ASTM International, previously knownastheAmericanSocietyforTestingandMaterialsCFR: Code of Fed
16、eral RegulationsCRWMS: civilian radioactive waste manage-ment system management and operatingcontractorCSM: conceptual site modelDQO(s): data quality objectives!EIS: Environmental Impact StatementEPRI: Electric Power Research InstituteFEP(s): features!, events!, and processes!IAEA: International Ato
17、mic Energy AgencyNEI: Nuclear Energy InstituteNGWA: National Ground Water AssociationNRC: National Research CouncilREMP: Radiological Environmental Monitor-ing ProgramRETS: Radioactive Effluent TechnicalSpecificationsTEDE: total effective dose equivalentUSEPA: U.S. Environmental Protection AgencyUSN
18、RC: U.S. Nuclear Regulatory Commission2.2 Definition of termsabnormal radionuclide release: The un-planned or uncontrolled emission of an efflu-ent i.e., containing plant-related, licensedradioactive material!.aslowasisreasonablyachievable(ALARA):Every reasonable effort is made to maintain ex-posure
19、s to radiation as far below the dose lim-its as is practical consistent with the purposefor which the licensed activity is undertaken,taking into account the state of technology, theeconomics of improvements in relation to stateof technology, the economics of improvementsin relation to benefits to t
20、he public health and1safety, and other societal and socioeconomic con-siderations, and in relation to utilization of nu-clear energy and licensed materials in the publicinterest.ambient flow: Natural horizontal or verticalgroundwater movement through the subsur-face, or resulting from natural hydrau
21、lic gra-dients in an open borehole, well, or piezometer.aquifer: A geologic formation, group of forma-tions, or part of a formation that contains suf-ficient saturated permeable material to yieldsignificant quantities of water to springs, seeps,and wells.aquifer, confined: An aquifer bounded aboveby
22、 an aquitard.aquifer, unconfined: An aquifer whose uppersurface is a water table.aquitard: A geologic formation that restricts,but does not prevent, groundwater movementinto or between aquifers.baselineconcentration,local:The concentra-tion or activity of a substance that is indicativeof local site
23、conditions prior to the operation ofthe nuclear power plant.baseline concentration, regional: The con-centration or activity of a substance that isindicative of regional conditions prior to theoperation of the nuclear power plant.biogeochemical processes: The chemical in-teractions that exist among
24、the atmosphere,hydrosphere, lithosphere, and biosphere.capillary zone: The region above the watertable where pores are saturated but where thewater gauge pressure is negative; also calledthe tension-saturated mercial nuclear power plant: A commer-cial electrical generating facility using a nu-clear
25、reactor as its heat source to provide steamto a turbine generator.conceptual site model (CSM): An abstract,qualitative representation of the relevant flowand transport FEPs that affect subsurface ra-dionuclide transport at the site. The CSM is bestpresented as a set of two-dimensional graphicsplan a
26、nd profile!or a three-dimensional graphicisometric!, which qualitatively present the in-terrelationshipsamongtheFEPs,alongwithsup-porting text.confining layer: A geologic unit within thesaturated or unsaturated zones that has a dis-tinctly lower hydraulic conductivity than theunderlying and overlyin
27、g geologic units; alsocalled an aquitard when in the saturated zone.contamination: Occurrence of material in alocation where it is not considered indigenousto its surroundings.corrective action: Activities undertaken tomanage or remediate the occurrence or move-ment of subsurface radionuclides.criti
28、cal outcome: A long-term, strategic goal,stated in terms of the expected results, thatcaptures the essence of the desired end state tobe achieved.data quality objective(s) DQO(s): Qualita-tive and quantitative statements derived fromthe DQO process that clarify the study objec-tives, define the most
29、 appropriate type of datato collect, determine the most appropriate con-ditions from which to collect the data, and spec-ify tolerable limits on decision error rates.Because DQOs will be used to establish thequality and quantity of data needed to supportdecisions, they should encompass the total un-
30、certainty resulting from all data collection ac-tivities, including analytical and samplingactivities.data quality objective process: A system-atic, strategic-planning tool based on the sci-entific method that identifies and defines thetype, quality, and quantity of data needed tosatisfy a specified
31、 use. DQOs are the qualita-tive and quantitative outputs from the DQOprocess.dual porosity model: A flow and transportmodel applied to a porous medium composed oftwo porosity fractions or domains. One fractionstores and transmits solute mobile flow do-main!, while the second fraction only storessolu
32、te immobile domain!. Fluid and solute ex-change between the mobile and immobile do-mains occur as functions of the hydraulic headand concentration gradient between the two,respectively.effluent concentration limit: The concentra-tion valuesgiven in columns 1 and 2 of Table 2American National Standar
33、d ANSI0ANS-2.17-20102in 10 CFR 20, Appendix B 1#,1! equivalent tothe radionuclide concentrations that, if inhaledor ingested continuously over the course of ayear, would produce a total effective dose equiv-alent of 0.05 rem 50 millirem or 0.5 mSv!.effluent discharge (radioactive): The emis-sion of
34、an effluent i.e., containing plant-related, licensed radioactive material! into theunrestricted area.engineered barrier: A man-made cover, wall,or device used to prevent fluid flow or contam-inant migration.exposure pathway: A mechanism by whichradioactive material is transferred from thelo-cal! env
35、ironment to humans. There are threecommonly recognized exposure pathways: inha-lation, ingestion, and direct radiation. For ex-ample, ingestion is an exposure pathway, andit might include dose contributions from one ormore routes of exposure. One route of exposurethat might contribute to the ingesti
36、on exposurepathway is often referred to as grass-cow-milk-infant-thyroid route of exposure.feature(s),event(s),andprocess(es)FEP(s):Anassessmentoftherelevanta!features,whichare identified physical characteristics of thetotal system, and how they behave over time;b! events, which are occurrences of a
37、bnormalradionuclide releases; and c! processes, whichinclude physical, chemical, and biological pro-cesses that govern radionuclide transport.flux: The volumetric or mass discharge perunit cross-sectional area of mediumsolids pluspores!; called the Darcian flux when applied towater movement.groundwa
38、ter: All water contained in pores,fractures, or voids at or below the water tablealso called the phreatic surface!; also identi-fies water in the phreatic zone.2!groundwater recharge: The process involvedin the addition of water to the phreatic zone;also the amount of water added to the satu-rated z
39、one.hydraulic gradient: The change in hydraulichead with distance.hydraulic head: One of several measures ofthe energy content of water in this case, en-ergy per unit weight!, expressed as a height offreshwater above a datum. In fresh ground-water, the hydraulic head is commonly foundusing the water
40、 surface elevation in an openborehole, well, or piezometer.hydrostratigraphy: A conceptual frameworkthat classifies geologic materials of consider-able lateral extent into reasonably distinct hy-drologic systems.infiltration: The movement of water from abovethe ground surface into the vadose zone.in
41、termediate point of compliance: A loca-tion used as a reference point for the purposeof protecting the groundwater resource, wherethere are no immediate existing receptors butwhere contamination is regarded as undesirable.mathematical model: A quantitative repre-sentation of the relevant flow and tr
42、ansportFEPs that affect subsurface radionuclide trans-port at the site. The mathematical model canbe an algebraic equation for simple, homo-geneous systems, or it can be a computer modelin more complicated systems.normal radionuclide release: The emissionof an effluent containing plant-related, lice
43、nsedradioactivematerial.Theknown,planned,orcon-trolled release of radionuclides to the environ-ment, including controlled releases of low-levelradioactivematerials.Theeffluentdischargeper-formed in accordance with RETS.perched water: Subsurface water collectingon low-permeability geologic materials
44、that areseparated from an underlying main body ofgroundwater by an unsaturated zone. Waterlocated above the water table whose water gaugepressure is greater than zero.performance assessment: A systematic analy-sis that addresses the types and likelihood ofabnormal radionuclide releases, their result
45、ingimpacts, and how these impacts compare toregulatory standards.1!Numbers in brackets refer to corresponding numbers in Sec. 8, “References.”2!Regulatory agencies and industry might consider groundwater to include all subsurface water, so that allcontaminants in the subsurface are evaluated, not on
46、ly those in the phreatic zone.American National Standard ANSI0ANS-2.17-20103performance-based regulation: Regulationsthat are outcome oriented rather than proce-dure oriented. An approach to regulatory prac-tice that establishes performance and resultsas the primary basis for decision making.Perform
47、ance-based regulations have the follow-ing attributes: a! measurable, calculable, orobjectively observable parameters exist or canbe developed to monitor performance; b! objec-tive criteria exist or can be developed to assessperformance; c! licensees have flexibility todetermine how to meet the esta
48、blished perfor-mance criteria in ways that will encourage andreward improved outcomes; and d! a frame-work exists or can be developed in which thefailure to meet a performance criterion, whileundesirable, will not in and of itself constituteor result in an immediate safety concern.performance indica
49、tor: An observable hydro-logice.g., water content, water flux, water qual-ity parameter! or radiologic e.g., tritium!parameter, the value or change in value! ofwhich is used to determine whether a perfor-mance objective is achieved.performance objective: A targeted outcomeor goal desired to achieve a successful end re-sult e.g., a goal to meet a defined level ofenvironmental quality!.performance threshold: A quantitative crite-rion for each performance indicator that de-fines when performance objectives are, or arenot, being met.phreatic zone:
