1、An American National StandardPublished by the American Nuclear Society 555 N. Kensington AveLa Grange Park, IL 60526ANSI/ANS-5.1-2014 Decay Heat Powerin Light Water ReactorsANSI/ANS-5.1-2014ANSI/ANS-5.1-2014American National Standard Decay Heat Power in Light Water ReactorsSecretariatAmerican Nuclea
2、r SocietyPrepared by theAmerican Nuclear SocietyStandards CommitteeWorking Group ANS-5.1Published by theAmerican Nuclear Society555 North Kensington AvenueLa Grange Park, Illinois 60526 USAApproved November 4, 2014 by theAmerican National Standards Institute, Inc.Designation of this document as an A
3、merican National Standard attests that the principles of openness and due process have been followed in the approval procedure and that a consensus of those directly and materially affected by the standard has been achieved.This standard was developed under the procedures of the Standards Committee
4、of the American Nuclear Society; these procedures are accredited by the American National Standards Institute, Inc., as meeting the criteria for American National Standards. The consensus committee that approved the standard was balanced to ensure that competent, concerned, and varied interests have
5、 had an opportunity to participate.An American National Standard is intended to aid industry, consumers, governmental agencies, and general interest groups. Its use is entirely voluntary. The existence of an American National Standard, in and of itself, does not preclude anyone from manufacturing, m
6、arketing, purchasing, or using products, processes, or procedures not conforming to the standard.By publication of this standard, the American Nuclear Society does not insure anyone utilizing the standard against liability allegedly arising from or after its use. The content of this standard reflect
7、s acceptable practice at the time of its approval and publication. Changes, if any, occurring through developments in the state of the art may be considered at the time that the standard is subjected to periodic review. It may be reaffirmed, revised, or withdrawn at any time in accordance with estab
8、lished procedures. Users of this standard are cautioned to determine the validity of copies in their possession and to establish that they are of the latest issue.The American Nuclear Society accepts no responsibility for interpretations of this standard made by any individual or by any ad hoc group
9、 of individuals. Requests for interpretation should be sent to the Standards Department at Society Headquarters. Action will be taken to provide appropriate response in accordance with established procedures that ensure consensus on the interpretation.Comments on this standard are encouraged and sho
10、uld be sent to Society Headquarters.Published byAmerican Nuclear Society555 North Kensington AvenueLa Grange Park, Illinois 60526 USAThis document is copyright protected.Copyright 2014 by American Nuclear Society.Any part of this standard may be quoted. Credit lines should read “Extracted from Ameri
11、can National Standard ANSI/ANS-5.1-2014 with permission of the publisher, the American Nuclear Society.” Reproduction prohibited under copyright convention unless written permission is granted by the American Nuclear Society.Printed in the United States of AmericaAmerican National StandardAmerican N
12、ational Standard ANSI/ANS-5.1-2014The American Nuclear Society (ANS) Standards Committee will provide responses to inquiries about requirements, recommendations, and/or permissive statements (i.e., “shall,” “should,” and “may,” respectively) in American National Standards that are developed and appr
13、oved by ANS. Responses to inquiries will be provided according to the Policy Manual for the ANS Standards Committee. Nonrelevant inquiries or those concerning unrelated subjects will be returned with appropriate explanation. ANS does not develop case interpretations of requirements in a standard tha
14、t are applicable to a specific design, operation, facility, or other unique situation only and therefore is not intended for generic application.Responses to inquiries on standards are published in ANSs magazine, Nuclear News, and are available publicly on the ANS Web site or by contacting the ANS S
15、tandards Administrator.Inquiry requests shall include the following:(1) the name, company name if applicable, mailing address, and telephone number of the inquirer;(2) reference to the applicable standard edition, section, paragraph, figure, and/or table;(3) the purpose(s) of the inquiry;(4) the inq
16、uiry 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 SocietyATTN: Standards Administrator555 N. Kensington AvenueLa Grange Park, IL 60526or standardsans.orgInquiry RequestsInquiry FormatAmerican Na
17、tional Standard ANSI/ANS-5.1-2014American National Standard ANSI/ANS-5.1-2014-i-(This Foreword is not a part of American National Standard “Decay Heat Power in Light Water Reactors,” ANSI/ANS-5.1-2014.)This American National Standard provides values for the decay heat power from fission products and
18、 actinides following the shutdown of light water reactors operated with nuclear fuel consisting of uranium. The energy released in the fission process is divided into (1) prompt energy from the kinetic energy of fission fragments, neutrons, and gamma rays from prompt de-excitation of fission product
19、s and (2) delayed energy from beta particles and gamma rays emitted from the decay of fission products.The development of this standard was initiated due to the importance of energy release after reactor shutdown and the need for accurate data to evaluate fuel rod heating during a loss-of-coolant ac
20、cident. The ANS Standards Subcommittee first proposed the adoption of a new standard on decay heat power in October, 1971. Following minor revisions in 1973, it was submitted to the American National Standards Institute but remained as a draft standard. After significant technical developments based
21、 on data from new experimental programs, the draft standard was revised and approved and released as the 1979 standard. Since then, it was reaffirmed in 1985, revised in 1994, and revised again in 2005. The revisions since 1979 have been guided largely by recommendations made by Dickens, England, an
22、d Schenter on future improvements to the standard.1)A detailed technical summary of the development of the standard and revisions is provided as an Appendix to this standard.The standard prescribes methods that enable the calculation of fission product decay heat power and uncertainty with accuracie
23、s comparable to those of summation codes but without the need for complex calculations. Fission product decay heat values are provided for thermal neutron-induced fission of 235U, 239Pu, and 241Pu and fast fission of 238U. As revised, this standard provides better guidance on methods and implementat
24、ion, an improved representation of uncertainties in the fission product decay heat values, and an improved method for the neutron capture correction. Also included, for the first time, is a complete estimate of all actinide contributions to decay heat power. The changes in this revision do not alter
25、 the tabular data for standard fission product decay heat power and uncertainty values from the 1994 and 2005 standards, but they do include several recommendations for near-term improvements to the standard identified by Dickens, England, and Schenter. Relationship to Other StandardsANSI/ANS-19.3.4
26、-2002 (R2008), “Determination of Thermal Energy Deposition Rates in Nuclear Reactors” Proposed American National Standard ANS-19.8, “Fission-Product Yields for 235U, 238U, and 239Pu” (in draft form) ANSI/ANS 19.1-2002 (R2011), “Nuclear Data Sets for Reactor Design Calculations”This standard might re
27、ference documents and other standards that may have been superseded or withdrawn at the time this standard is applied. 1)J. K. Dickens, T. R. England, and R. E. Schenter, “Current Status and Proposed Improvements to the ANSI/ANS-5.1 American National Standard for Decay Heat Power in Light Water Reac
28、tors,” Nucl. Safety, 32, 209 (1991).ForewordAmerican National Standard ANSI/ANS-5.1-2014-ii-This standard does not incorporate the concepts of generating risk-informed insights, performance-based requirements, or a graded approach to quality assurance. The user is advised that one or more of these t
29、echniques could enhance the application of this standard.The working group acknowledges the substantial efforts of earlier working groups in establishing and maintaining this standard. The working group specifically acknowledges the significant contributions made to the standard by the late J. Kirk
30、Dickens and Robert Schenter, who passed away before this standard was issued. Both of these working group members played key roles in the development and advancement of the standard and provided a roadmap for future improvements of the standard that was used to guide this revision. Working Group ANS
31、-5.1 of the Standards Committee of the American Nuclear Society had the following membership at the time of its approval of this revision of the standard:I. C. Gauld (Chair), Oak Ridge National Laboratory M. C. Brady Raap (Past Chair for ANSI/ANS-5.1-2005), Pacific Northwest National LaboratoryW. B.
32、 Wilson (Past Chair for ANSI/ANS-5.1-1994), Los Alamos National LaboratoryM. Aissa, U.S. Nuclear Regulatory CommissionD. Carpenter, Bettis Atomic Power LaboratoryR.-T. Chiang, AREVA Inc.J. K. Dickens, IndividualA. H. Fero, Westinghouse Electric Company, LLCJ. Katakura, Nagaoka University of Technolo
33、gy J. Klingensmith, Westinghouse Electric Company, LLCE. R. Knuckles, IndividualR. Schenter, IndividualH. Trellue, Los Alamos National LaboratoryS. Wang, Westinghouse Electric Company, LLCT. Yoshida, Musashi Institute of TechnologyD. Ziabletsev, AREVA Inc.The membership of Subcommittee ANS-19 at the
34、 time of the review and approval of this standard was as follows:D. M. Cokinos (Chair), Brookhaven National LaboratoryC. T. Rombough (Secretary), CTR Technical Services A. Attard, IndividualS. Baker, TranswareW. H. Bell, South Carolina Electric s). : Infinite irradiation time (T 1013s for computatio
35、nal purposes).fi(t) : Decay heat power t seconds after a fission pulse from fissionable nuclide i (MeV/s)/fission. fi(t) : One standard deviation in fi(t) (MeV/s)/fission.32American National Standard ANSI/ANS-5.1-2014Fi(t,T) : Decay heat power t seconds after an operating period of T seconds at cons
36、tant fission rate of nuclide i in the absence of neutron capture in fission products (MeV/s)/(fission/s). Fi(t,T) : One standard deviation in Fi(t,T) (MeV/s)/(fission/s).Qi: Total recoverable energy2)associated with one fission of nuclide i (MeV/fission).Qi: One standard deviation in Qi(MeV/fission)
37、.Pi: Average power from the fissioning of nuclide i during operation period T(MeV/s). Pi: One standard deviation in Pi(MeV/s). : An index specifying an operating period at constant power.Pd(t,T) : Total fission product decay heat power at t seconds after shutdown from an operating history of T secon
38、ds duration (MeV/s).uniF0A2uniF028 uniF029PtTd,: Total fission product decay heat power corresponding to Pd(t,T): but uncorrected for neutron capture in fission products (MeV/s).uniF0A2uniF028 uniF029PtTdi, : Fission product decay heat power contribution to uniF0A2uniF028 uniF029PtTd,by the ith fiss
39、ionable nu-clide, uncorrected for neutron capture in fission products (MeV/s).PdHE(t,T) : The contribution of actinide decay heat power contributed by 239U and 239Np (MeV/s).PdA(t,T) : The contribution of actinide decay heat power contributed by heavy elements excluding 239U and 239Np (MeV/s).PdC(t,
40、T) : The contribution of decay heat power from neutron capture in all fission products (MeV/s).PdCs(t,T) : The contribution of 134Cs to the decay heat power (MeV/s).PdE(t,T) : The contribution to the decay heat power from neutron capture in fission products ex-cluding 134Cs (MeV/s).G(t) : The factor
41、 that accounts for neutron capture in fission products for t 104s.H(t) : The factor that accounts for neutron capture in fission products for t 104s, excluding the contribution from 134Cs.A(t) : The factor that accounts for the contribution from actinides excluding 239U and 239Np. y : Fissions per i
42、nitial fissile atom (dimensionless).4 Fission product decay heat power4.1 GeneralThe data on fission product decay heat power from the fission of nuclide i is represented by fi(t), the decay heat power per fission following an instantaneous fission pulse of a significant number of fission events. Th
43、e method for applying these data for the calculation of fission product decay heat power for an irradiation interval of time T followed by a shutdown time t is presented in two ways in this standard. The first method of presentation is represented in terms of Fi(t,T), the decay heat power from fissi
44、on products produced at a constant rate over an operating interval T. The second method of presentation is Fi(t,), the decay heat power from fission products produced at a constant rate over an infinitely long operating interval T. Both Fi(t,T) and Fi(t,) exclude the contribution to fission product
45、decay heat power from neutron absorption in the fission products.2)Includes fission fragment and neutron kinetic energy, prompt energy, and radiation from complete decay of fission products, and and radiation from capture reactions in all fuel, coolant, and structural materials.54American National S
46、tandard ANSI/ANS-5.1-20144.2 Determining decay heat power and uncertainty from Fi(t,T)The average fission product decay heat power per fission following an instantaneous fission pulse is represented as fi(t). The data representing fi(t) and its assigned one sigma uncertainty, fi(t) for the thermal f
47、ission of 235U and 239Pu are shown in Tables 1 and 2, respectively; the data for fast fission of 238U and thermal fission of 241Pu are given in Tables 3 and 4, respectively.Table 1 Tabular data for standard decay heat power for pulse thermal fission of 235UTime after shutdown, t(s)Decay heat power f
48、 (t) (MeV/s)/fissionOne sigma uncertainty f (t) (MeV/s)/fissionOne sigma uncertainty (percent)1.0E+00 8.219E-011)1.282E-01 15.61.5E+00 6.677E-01 0.661E-01 9.92.0E+00 5.600E-01 0.386E-01 6.94.0E+00 3.413E-01 0.147E-01 4.36.0E+00 2.447E-01 0.086E-01 3.58.0E+00 1.882E-01 0.058E-01 3.11.0E+01 1.513E-01
49、0.048E-01 3.21.5E+01 9.956E-02 0.259E-02 2.62.0E+01 7.341E-02 0.176E-02 2.44.0E+01 3.544E-02 0.071E-02 2.06.0E+01 2.322E-02 0.044E-02 1.98.0E+01 1.685E-02 0.032E-02 1.91.0E+02 1.295E-02 0.023E-02 1.81.5E+02 7.866E-03 0.149E-03 1.92.0E+02 5.480E-03 0.104E-03 1.94.0E+02 2.383E-03 0.045E-03 1.96.0E+02 1.581E-03 0.028E-03 1.88.0E+02 1.195E-03 0.023E-03 1.91.0E+03 9.587E-04 0.173E-04 1.81.5E+03 6.345E-04 0.114E-04 1.82.0E+03 4.648E-04 0.084E-04 1.84.0E+03 1.977E-04 0.038E-04 1.96.0E+03 1.152E-04 0.021E-04 1.88.0E+03 7.891E-05 0.142E-05 1.81.0E+04 5.897
