1、ANSI/ANS-6.4-2006nuclear analysis and designof concrete radiation shieldingfor nuclear power plantsANSI/ANS-6.4-2006ANSI/ANS-6.4-2006American National StandardNuclear Analysis and Design of ConcreteRadiation Shielding for Nuclear Power PlantsSecretariatAmerican Nuclear SocietyPrepared by theAmerican
2、 Nuclear SocietyStandards CommitteeWorking Group ANS-6.4Published by theAmerican Nuclear Society555 North Kensington AvenueLa Grange Park, Illinois 60526 USAApproved September 29, 2006by theAmerican National Standards Institute, Inc.AmericanNationalStandardDesignation of this document as an American
3、 National 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
4、 Nuclear Society; these procedures are accredited by the Amer-ican National Standards Institute, Inc., as meeting the criteria for AmericanNational Standards. The consensus committee that approved the standardwas balanced to ensure that competent, concerned, and varied interests havehad an opportuni
5、ty to participate.An American National Standard is intended to aid industry, consumers, gov-ernmental agencies, and general interest groups. Its use is entirely voluntary.The existence of an American National Standard, in and of itself, does notpreclude anyone from manufacturing, marketing, purchasi
6、ng, or using prod-ucts, processes, or procedures not conforming to the standard.By publication of this standard, the American Nuclear Society does not insureanyone utilizing the standard against liability allegedly arising from or afterits use. The content of this standard reflects acceptable practi
7、ce at the time ofits approval and publication. Changes, if any, occurring through developmentsin the state of the art, may be considered at the time that the standard issubjected to periodic review. It may be reaffirmed, revised, or withdrawn atany time in accordance with established procedures. Use
8、rs of this standardare cautioned to determine the validity of copies in their possession and toestablish that they are of the latest issue.The American Nuclear Society accepts no responsibility for interpretations ofthis standard made by any individual or by any ad hoc group of individuals.Requests
9、for 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 SocietyHeadqua
10、rters.Published byAmerican Nuclear Society555 North Kensington AvenueLa Grange Park, Illinois 60526 USACopyright 2006 by American Nuclear Society. All rights reserved.Any part of this standard may be quoted. Credit lines should read “Extracted fromAmerican National Standard ANSI0ANS-6.4-2006 with pe
11、rmission 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 “Nuclear Analysis a
12、ndDesign of Concrete Radiation Shielding for Nuclear Power Plants,” ANSI0ANS-6.4-2006.!The need for this standard was identified in mid-1972 by D. K. Trubey, thenchairman of SubcommitteeANS-6, Radiation Protection and Shielding. The then-existing standard, ANSI N101.6-1972, “Concrete Radiation Shiel
13、ds,” providedexcellent guidance on the construction of concrete radiation shielding structuresbut contained almost no information on shielding effectiveness or analysis. Thisstandard was first issued as ANSI0ANS-6.4-1977 N403!.After ANSI0ANS-6.4-1977 was issued, two significant events occurred that
14、led tothe decision to revise the standard: ANSI N101.6-1972 was withdrawn by ANSI,and theAmerican Concrete InstituteACI!issued its standardACI 349-80, “CodeRequirements for Nuclear Safety Related Concrete Structures,” as well as theCommentary ACI 349R-80, which provided updated requirements with reg
15、ard tothe construction aspects of concrete shielding structures. The withdrawal ofANSI N101.6-1972; the guidance provided by ACI 349-80; and advances in theevolution of shielding methods, data, and applications led to the revision,ANSI0ANS-6.4-1985.Since that revision effort, advances in buildup fac
16、tors prompted the revisionANSI0ANS-6.4-1997. Other advances, particularly with respect to transmissionand reflection of gamma rays and neutrons by concrete slabs, prompted thecurrent revision, ANSI0ANS-6.4-2006.This revised standard is meant to be a “guide to good practice” in the area ofconcrete sh
17、ielding analysis and design. Recommendations are given where pos-sible, but more often the choice of analytical methods must be left to the discre-tion of the shielding engineer as appropriate to the particular job, whether it bea conceptual design or final construction drawing.This standard was rev
18、ised by Working Group ANS-6.4 of the American NuclearSociety, which had the following members at the time it prepared and approvedthis standard:R. E. Faw Chair!, IndividualR. J. Donahue, Lawrence Berkeley National LaboratoryC. C. Graham, AmerenUE Callaway PlantS. J. Haynes, Sandia National Laborator
19、iesT. M. Lloyd, EnergySolutionsJ. D. Olson, Black the word “should” is used to denote arecommendation; and the word “may” is usedto denote permission, neither a requirementnor a recommendation. To conform with thisstandard, all concrete shield analyses and de-signs shall be performed in accordance w
20、ith itsrequirements, but not necessarily with itsrecommendations.2.2 Requirements2.2.1 Calculational methodsAny applicable method may be used by thedesigner in the analysis of shield effectiveness.The designer shall be aware, however, of anylimitations imposed by the method employed.Approximations s
21、hall be chosen such that theattenuation afforded by the concrete shield isknown to be conservative with respect to thedesign objective. Conservatism may also be in-troduced by other means, such as the sourcestrength used or the radiation design dose rateoutside the shield; the concrete shield analys
22、isneed not necessarily be inherently conservative.2.2.2 DataSelection of material composition, density, crosssections, albedos, or other properties shall bemade such that calculational results are con-servative with respect to the design objectivesas measured by attenuation afforded by theshield.2.2
23、.3 Operational environmentNuclear heating shall be considered during thedetermination of the operating temperature andwater content of a concrete primary reactorshield and of any other concrete shields thatare exposed to an incident energy flux greaterthan 1010MeV0cm2s and that will operate at atemp
24、erature of 658C or greater.2.2.4 PenetrationsAll penetration configurations in concrete shieldwalls shall be shown to provide adequate at-tenuation. This requirement shall be satisfiedby one of the following:1! analysis that follows the guidance ofSec. 8.4 of this standard;2! determination that the
25、configuration issimilar to one that is functioning properlyunder comparable conditions in an operatingnuclear facility;13! determination that the configuration issimilar to one that has been evaluated exper-imentally and found to be effective for theradiation levels under consideration;4! determinat
26、ion that the configuration issimilar to one that has already been shownby analysis to be effective.2.2.5 ReflectionEach applicable reflection configuration shallbe reviewed to determine its effect on the de-sign radiation levels. See Sec. 8.5.3.!2.2.6 Quality assuranceThe quality assurance requireme
27、nts of Ameri-can National Standard “Quality Assurance Re-quirements for Nuclear Facility Applications,”ANSI0ASME NQA-1-2004 1#1!, Sections 3, 3S-1,and 3A-1, shall be followed. As a consequenceof these requirements, the shield designer shallreview the initial specification for concrete tobe used in s
28、hield walls and shall review anysubsequent changes to that specification. Theshield designer shall ensure the effectivenessof the shield wall based on the reviewed con-crete specification. In addition to the qualityassurance requirements of ANSI0ASME NQA-1-2004 1#, concrete shielding designed toprot
29、ect plant personnel should be tested inaccordance with American National Standard“Program for Testing Radiation Shields in LightWater Reactors LWR!,” ANSI0ANS-6.3.1-1987R1998!2#.2.3 Recommendations2.3.1 Calculational methodsThe following methods, listed in order of in-creasing complexity and sophist
30、ication, are suit-able for determining the effectiveness of aconcrete shield wall: the point-kernel method;the one-dimensional 1-D!, two-dimensional 2-D!, or three-dimensional 3-D! discrete ordi-nates methods; and the Monte Carlo method,as described in Sec. 6. The following methods,listed in order o
31、f increasing complexity, aresuitable for determining the effects of a pen-etration in a concrete shield wall: the albedomethod, the single scatter method, and theMonte Carlo method, as described in Sec. 8.4.The following methods, listed in order of in-creasing complexity, are suitable for evaluat-in
32、g the effects of reflection from a surface: thealbedo method, the single scatter method, andthe Monte Carlo method, as described inSecs. 8.4 and 8.5. The adequacy of the methodused should be demonstrated for typical shieldapplications rather than for each shield. Thisadequacy should be documented an
33、d may bebased on comparison with experiments, com-parison with field measurements, comparisonof varying levels of computational sophistica-tion, or other confirmatory comparisons.2.3.2 DataIn the analysis of a concrete primary reactorshield, a coupled neutrongamma-ray librarymay be employed, and the
34、 data library recom-mended in American National Standard “Neu-tron and Gamma-Ray Cross Sections for NuclearRadiation Protection Calculations for NuclearPower Plants,”ANSI0ANS-6.1.2-19993#, is sug-gested for use. The gamma-ray mass attenua-tion coefficients and buildup factors that aregiven inAmerica
35、n National Standard “Gamma-Ray Attenuation Coefficients and BuildupFactors for Engineering Materials,”ANSI0ANS-6.4-3-1991 withdrawn 2001!4#, should beused.2!If the actual concrete density and thechemical composition are known, based on con-crete mix specifications or measurements oftest samples, the
36、y should be used. If the chem-ical composition of an ordinary concrete is notknown, the composition of Type 04 concrete asspecified in Table 1 should be used.2.3.3 Other considerationsNeutron activation of trace elements should beconsidered. Rebar reinforcing steel! should beconsidered separately fr
37、om the concrete in or-der to allow determination of the sources ofsecondary gamma rays.2.3.4 DocumentationA document summarizing the shield designshould be prepared at a suitable time in thedesign evaluation. Chapter 12 of the Final Safety1!Numbers in brackets refer to corresponding numbers in Sec.
38、9, “References.”2!Other data contained in this standard, including the data in the Appendices, may be used by the shielddesigner.American National Standard ANSI0ANS-6.4-20062Table1Typicalconcreteproperties5ConcretetypeOrdinary6#Ordinary7#MagnetiteBariteMagnetiteandsteelpunchingsLimoniteandsteelpunch
39、ingsSerpentine6#Designation0304MBAMS2LSSCompositionofmixlb0yd3!Water330370340347373Cement875550940980525AggregateSandandgravel!Sandandgravel!4900magnetiteore!4980BaSO4ore!1900magnetiteore!4800punchings!1820limoniteore!4680punchings!2030serpentine!956sand!Densityofcuredconcretetheoretical!Ing0cm32.39
40、2.353.53a3.35a4.64a4.54a2.1aInlb0ft3151b148b220a212a290a283132aElementalcompositionofcuredconcreteg0cm3!Hinmix!0.020.0130.011a0.012a0.011a0.014a0.035aHinore!0.017Oinmix!0.1590.1030.087a0.097a0.090a0.091a1.126Oinoreandcement!0.9801.0681.0810.9460.5480.617Si0.3420.7420.0910.0350.0730.0670.460Ca0.5820.
41、1940.2510.1680.2580.2610.150C0.1180.002Na0.0400.009Mg0.0570.0060.0330.0040.0170.0070.297Al0.0850.1070.0830.0140.0480.0290.042S0.0070.0030.0050.361K0.0040.0450.0040.009Fe0.0030.0291.6760.1593.5123.420.068OtherNi:0.026,P:0.007Ti:0.192,V:0.011,Mn:0.007,Cr:0.006Ba:1.551Ti:0.074,V:0.003V:0.004Cr:0.002aCo
42、ncreteinwhich50%ofthewateraddedtotheoriginalmixisretained.bMinimumacceptabledensity140lb0ft3.American National Standard ANSI0ANS-6.4-20063Analysis Report FSAR! may serve in lieu of aseparate document. However, if a separate doc-ument is prepared, the guidelines of Sec. 3 ofthis standard should be fo
43、llowed.3 Standards of documentationDocumentation that summarizes the shield de-sign, and all related calculations, shall be pre-pared at a suitable time in the evolution of theshield design for quality control purposes andfor future reference. This documentation shouldinclude sections listed in Secs
44、. 3.1 through 3.6of this standard.3.1 Shield design approachThis section should describe the approach usedin the design of the shielding, including appro-priate discussions of those portions of the shielddesign that are based on earlier designs oroperating experience.3.2 Shield design descriptionThi
45、s section should contain a detailed descrip-tion of the shield design, including major equip-ment locations and shielding arrangements, typeof concrete used, shielding thicknesses, majorsources of radiation to be shielded, and radia-tion zone designations throughout the plant.The results of analyses
46、 of radiation levels, withthe shielding as described, should also be pre-sented either in this section or in a separatesection as described in Sec. 3.4. A discussionshould also be included that indicates the de-sign phase e.g., conceptual phase, preliminaryphase, etc.!upon which the present shield a
47、naly-ses are based.3.3 Methods of analysisThe methods of analysis used in design ofthe shielding should be described in generalterms with appropriate discussions of com-puter programs employed. Sufficient detailshould be included to provide for a basic un-derstanding of the theory involved and thesp
48、ecific applications. Examples drawings orsketches! should be included to depict howspecific configurations were modeled for com-puter representations. These examples shoulddepict boundary and region designations andconvey the general level of complexity in-volved in the analysis.3.4 Description of a
49、nalysesThis section may be presented separately or incombination with Sec. 3.2. The material to beincluded should be subdivided by portions ofthe plante.g., Reactor Building,Auxiliary Build-ing, etc.!.This section may contain dose levels and othershielding criteria used in the design, a descrip-tion of the sources of radiation to be shielded,the location and extent of shielding, sufficientdescription of the models employed and simpli-fying assumptions to allow a specialist in thefield to evaluate independently the adequacy ofthe model and assu
