ANSI ANS 6.6.1-2015 Calculation and measurement of direct and scattered gamma radiation from LWR nuclear power plants.pdf

1、An American National StandardPublished by the American Nuclear Society 555 N. Kensington AveLa Grange Park, IL 60526ANSI/ANS these procedures are accredited by the American National Standards Institute, Inc., as meeting the criteria for American National Standards. The consensus committee that appro

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7、 taken to provide appropriate response in accordance with established procedures that ensure consensus.Comments on this standard are encouraged and should be sent to Society Headquarters.Published byAmerican Nuclear Society555 North Kensington AvenueLa Grange Park, Illinois 60526 USAThis document is

8、 copyright protected.Copyright 2015 by American Nuclear Society. Any part of this standard may be quoted. Credit lines, should read “Extracted from American National Standard ANSI/ANS-6.6.1-2015 with permission of the publisher, the American Nuclear Society.” Reproduction prohibited under copyright

9、convention unless written per mission is granted by the American Nuclear Society.Printed in the United States of AmericaAmerican National Standard ANSI/ANS-6.6.1-2015Inquiry RequestsInquiryFormatThe American Nuclear Society (ANS) Standards Committee will provide responses to inquiries about requirem

10、ents, recommendations, and/or permissive statements (i.e., “shall,” “should,” and “may,” respectively) in American National Standards that are developed and approved by ANS. Responses to inquiries will be provided according to the Policy Manual for the ANS Standards Committee. Nonrelevant inquiries

11、or those con-cerning unrelated subjects will be returned with appropriate explanation. ANS does not GHYHORSFDVHLQWHUSUHWDWLRQVRIUHTXLUHPHQWVLQDVWDQGDUGWKDWDUHDSSOLFDEOHWRDVSHFLFdesign, operation, facility, or other unique situation only and therefore is not intended for generic application.Responses

12、 to inquiries on standards are published in ANSs magazine, Nuclear News, and DUHDYDLODEOHSXEOLFORQWKH$16:HEVLWHRUEFRQWDFWLQJWKH$166FLHQWLF3XEOLFD-tions and Standards Department. Inquiry requests shall include the following:(1) the name, company name if applicable, mailing address, and telephone numb

13、er of the inquirer; UHIHUHQFHWRWKHDSSOLFDEOHVWDQGDUGHGLWLRQVHFWLRQSDUD JUDSKJXUHDQGRUWDEOH(3) the purpose(s) of the inquiry;(4) the inquiry stated in a clear, concise manner;(5) a proposed reply, if the inquirer is in a position to offer one.Inquiries should be addressed toAmerican Nuclear Society$7

14、716FLHQWLF3XEOLFDWLRQVDQG6WDQGDUGVHSDUWPHQW555 N. Kensington AvenueLa Grange Park, IL 60526or standardsans.orgAmerican National Standard ANSI/ANS-6.6.1-2015i(This foreword is not a part of American National Standard, “Calculation and Measure-ment of Direct and Scattered Gamma Radiation from LWR Nucl

15、ear Power Plants,” ANSI/ANS-6.6.1-2015.),QPLGDQHHGIRUDVWDQGDUGRQWKLVVXEMHFWZDVLGHQWLHGE.7UXEHFKDLU-man of ANS-6. The proposed standard had been listed among those having a high priority by the Atomic Energy Commission Directorate of Regulatory Standards. The project was assigned by the NTAB Executiv

16、e Committee in September 1973. Working Group ANS-ZDVIRUPHGDQG($:DUPDQZDVDSSRLQWHGFKDLUPDQLQ6HSWHPEHU7KHUVWmeeting of the working group was held in November 1973. Twelve subsequent meetings were held from February 1974 through June 1978. When preparing the initial version of this standard, the 1973 w

17、orking group provided a series of reference calculations with which a radiation analyst should compare results obtained by the method he/she elected to use in a given application. Comparison with the results of these reference calculations is intended to provide some assurance that the methods being

18、 considered by this standards user produce results that are in reasonable agree ment with those of other methods. These reference calculations are intentionally simplistic to make this comparison effort easier to accomplish.7KHUVWZRUNLQJGUDIWZDVFRPSOHWHGLQ-XQH$UHYLVHGZRUNLQJGUDIWZDVGLV-WULEXWHGIRULQ

19、LWLDOUHYLHZE$16FKDLUVLQ-XQH7KHFRPSOHWHGUVWGUDIW UDIW1) was submitted to ANS-6 for ballot in September 1977. This draft was unanimously approved in subsequent balloting by ANS-6 subcommittee chairs, with the sole negative EDOORWEHLQJFKDQJHGWRDIUPDWLYHDIWHUUHVROXWLRQRIFRPPHQWV$UHRUJDQLHGZRUN-ing group

20、, ANS-6.6.1, was established in 2012 to reconsider the status of the standard. In June 2013, that working group recommended revisions of the standard to (a) correct HGLWRULDOHUURUV E XSGDWHWKHOLVWRIUHIHUHQFHGGRFXPHQWV F XSGDWHWKHGHQLWLRQVDQGunits of the dose terms, (d) update Figs. 6.3 through 6.8 t

21、o include dose rate results for the reference calculations computed based on a modern Monte Carlo (MCNP5) computer program, and (e) incorporate three new tables (Tables 6.3, 6.4, and 6.5) providing the MCNP5-computed dose rate results and their relative statistical uncertainty. 7KLVVWDQGDUGDGGUHVVHV

22、FRQWDLQHGVRXUFHVRIGLUHFWDQGVFDWWHUHGUDGLDWLRQDQGVSHFL-FDOOHFOXGHVHIXHQWUHOHDVHVDQGDFFLGHQWVRXUFHV0HDVXUHPHQWVDWVRPHRSHUDWLQJplants, which have no local shielding to reduce reactor cavity nozzle inspection port streaming, have indicated that localized streaming can be measurable outside the contain-m

23、ent. Such localized streaming effects are not addressed in this standard. Particular emphasis is placed on the direct and scattered radiation from 16N sources in ERLOLQJZDWHUUHDFWRUV %:5V 7KLVHPSKDVLVUHHFWVWKHIDFWWKDWDQDOVLVDQG16N mea-VXUHPHQWRIUDGLDWLRQDVVRFLDWHGZLWKVRXUFHVDW%:5VZDVLGHQWLHGDVDPDMRU

24、DUHDRIinterest in establishing priority for development of this standard. The three appendices to the standard are included as examples of the type of measurements and analyses that have been performed in connection with the 16N sources at BWRs. In Appendices A and B, the assumption is made that the

25、 observed dose rates are entirely the result of 16N activity. The QHWHIIHFWRIWKLVDVVXPSWLRQLVWRLQFUHDVHWKHDPRXQWRIFRQVHUYDWLVPLQWKHTXDQWLFD-tion of the source terms, in that other radiations are included in the measurements from which the 16N source terms are developed. This standard might reference

26、 documents and other standards that have been superseded or withdrawn at the time the standard is applied. A statement has been included in Sec. 8, References,” that provides guidance on the use of references.This standard does not incorporate the concepts of generating risk-informed insights, perfo

27、rmance-based requirements, or a graded approach to quality assurance. The user is advised that one or more of these techniques could enhance the application of this standard.ForewordAmerican National Standard ANSI/ANS-6.6.1-2015iiWorking Group ANS-6.6.1 of the ANS Standards Committee had the followi

28、ng membership: R. S. Amato (Chair), Bechtel Marine Propulsion Corp.J. Bevelacqua, Bevelacqua Resources Corp.P. Caracappa, Rensselaer Polytechnic InstituteJ. Chen, Westinghouse Electric Company, LLCB. Hinderliter, University of MinnesotaDuluthS. Wang, Westinghouse Electric Company, LLCThe membership

29、of the Radiation Protection and Shielding Subcommittee, at the time of the approval of this standard, was as follows: C. Sanders (Chair), UNLV/Sanders EngineeringA. Alpan, Westinghouse Electric CompanyR. S. Amato, Bechtel Marine Propulsion Corp.P. Bergstrom, National Institute of Standards the word

30、“should” is used to denote a recommendation; and the word “may” is used to denote permission, neither a requirement nor a recommendation. HQLWLRQV7KHIROORZLQJVSHFLDOGHQLWLRQVZLOOEHXVHIXOLQXQGHUVWDQGLQJWKLVDQGFRPSDQLRQRUUHIHUHQFHVstandards. $QXPEHURIWHUPVDUHXVHGLQWKLVVWDQGDUGDVGHQHGLQWHWERRNVRQWKHVXE

31、MHFWRIUDGLDWLRQVKLHOGLQJDQGradiation detection. They are not used in any special sense in this standard. capacity factor:7KHFDSDFLWIDFWRULVGHQHGDVWKHHQHUJDFWXDOOVXSSOLHGEDSODQWLQDJLYHQWLPHinterval, divided by the product of the design power and the time interval. The capacity factor may be used in a

32、ssessing the annual absorbed dose, provided the principal sources are directly related to capacity.direct gamma rays: The term direct gamma rays is used to denote those gamma rays that do not undergo scattering interactions in transit from the source volume to the receptor location. It differs from

33、“uncollided JDPPDUDVLQWKDWVFDWWHULQJLQWHUQDOWRGLVWULEXWHGVRXUFHV VXFKDVDSLSHFRQWDLQLQJUDGLRDFWLYHXLG may be included in the direct category. dose rate and absorbed dose: The term dose is used herein to refer to either exposure (roent gens), absorbed dose (rad or gray), dose equivalent (rem or seiver

34、t), or ambient dose equivalent (rem or seivert). These lat-WHUWHUPVDUHVSHFLFDOOGHQHGLQ5HSRUWRIWKH,QWHUQDWLRQDO and, for 16N sources in BWRs, the heat balance for the steam cycle. For 16N sources, the transit time through piping and equipment and the relative quantities of liquid and steam inside com

35、-ponents during their normal equilibrium operation are the major processing data required. The 161VSHFLFactivity in BWR coolant is sensitive to water chemistry, and the process of direct hydrogen addition may lead to a several -fold increase in activity over that otherwise experienced.2),QWKHDEVHQFH

36、RIVSHFLFVRXUFHVWUHQJWKVWKDWPDEHHPSORHGIRUDVSHFLFSODQWWKHVRXUFHVWUHQJWKVreported in ANSI/ANS-18.1-1999 3 should be employed, to the extent that they are deemed to be appli-cable by the user of the standard. 7KHUHDUH861XFOHDU5HJXODWRU (b) alpha, beta, and gamma radiation from naturally occurring radio

37、nuclides in the terrestrial environment; (c) similar alpha, beta, and gamma radiation from widely distributed manmade radionuclides produced by weapons testing; G DOSKDEHWDDQGJDPPDUDGLDWLRQIURPUDGLRQXFOLGHVFRQWDLQHGLQWKHOLTXLGDQGJDVHRXVHIXHQWVIURPthe facility; and (e) the direct and scattered radiat

38、ion from contained on-site radionuclides. The quantitative evaluation of this last component requires its isolation from the others, all of which are time-varying. It is this fact that places the greatest constraints on the choice of direct and scattered radiation measurement techniques and methods

39、of data interpretation.Two important factors should be considered in the design of a radiation measurement program. First, its purpose(s) should be clearly understood, in terms of the data that are needed and the degree of accuracy GHVLUHG6HFRQGWKHGHVLJQZLOOEHQHWIURPDSULRUNQRZOHGJHRIWKHHSHFWHGVRXUFHVDQGRIWKHWSHVDQGUHODWLYHLQWHQVLWLHVRIUDGLDWLRQHOGVWKDWDUHOLNHOWREHSUHVHQW7KHVHFRQVLGHUDWLRQVDQGDQXQGHUVWDQG-ing of the necessity for discrimination of the radiation from contained on-site radionuclides from the other FRPSRQHQWVRI