ML18018B668
| ML18018B668 | |
| Person / Time | |
|---|---|
| Site: | Harris  |
| Issue date: | 06/07/1984 |
| From: | Zimmerman S CAROLINA POWER & LIGHT CO. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| NLS-84-247, NUDOCS 8406140212 | |
| Download: ML18018B668 (56) | |
Text
I I.RFGULATORYiNFORMATION DISTRIBUTION BY%>EM (RIDSI F'ACCESSION NBR:8406140212 DOC DATE: 84/06/07-NOTARIZED:
NO DOCKET tt FACIL:50-400 Shearon Harris Nuclear Power Planti Unit 2<Carolina 05000400 AUTH,NAME AUTHOR AFF IlI ATION ZIMMERhlAN<S
~R~Carolina Power 8 Light Co~RECIP.NAME RECIPIENT AFFILIATION"DENTONgH~RE Office of Nuclear Reactor Regulationi Director i SUBJECT;Forwards addi info re functional capability of ASME Cl ss 1 pipingiin response to SER Open Item 3, DISTRIBUTION CODE: 8001S COPIES'ECEIVED;LTR
~Ee TITLE: Licensing Submittal:
PSAR/FSAR Amdts L elated C rrespondence NOTES;RECIPIENT ID CODE/NAME NRR/Dl/ADL NRR LB3 LA i INTERNAL: ELD/HDS1 IE/DEPER/EPB 36 IE/DQA SIP/QA821 NRR/DE/CEB 11 NRR/DE/EQB 13 NRR/DE/MEB 18 NRR/DE/SAB 24 NRR/DHFS/HFEB40 NRR/DHFS/PSRB NRR/DS I/AEB 26 NRR/DSI/CPB 10 NRR/DSI/ICSB 16 NRR/DSI'/PSB 19 NRR/DSI/RSB 23 RGN2 EXTERNAL: ACRS 41 DMB/DSS (AMDTS)LPDR 03 NSIC'5 COPIES LTTR ENCL 1 0 1 0 1 0 3 1 1 1 1 2 2 1 1 1 1 1 1 1 1'1 2 1 1 1 1 1 1 3" 6 6 1 1 1 1 1 1'ECIPIENT ID CODE/NAME NRR LB3 BC BUCKLEYrB Ol IE FILE IE/DEPER/IRB'35 NRR/DE/AEAB NRR/DE/EHEB NRR/DE/GB 28 NRR/DE/MTEB 17 NRR/DE/SGEB 25 NRR/DHFS/LQB 32 NRR/DL/SSPB NRR/DS I/ASB NRR/DS I/CSB 09 NRR/DS I/METB 12 S RAB 22 REG F IL 04 A I/MI8 BNL(AMOTS ONLY)FEMA REP OIV 39 NRC PDR 02 NTIS<<COPIES LTTR ENCL 1 0 1 1 1 1=1 1=1 0 1 1 2 2 1 1 1 1 1 1 1 0 1 1 1, 1~1 1 1 1 1'1 0 1 1 1 1 1 1 TOTAL NUMBER OF COPIES REQUIRED'TTR 53 ENCL 4 l b4 t N e II I II MCK Carolina Power&Light Company JUN 07 1984 SERIAL: NLS-84-247 Mr.Harold R.Denton, Director Office of Nuclear Reactor Regulation United States Nuclear Regulatory Commission Washington, DC 20555 SHEARON HARRIS NUCLEAR POWER PLANT UNIT NO~1-DOCKET NO+50-400 FUNCTIONAL CAPABILITY OF CLASS 1 PIPING
Dear Mr.Denton:
Carolina Power&Light Company (CP&L)hereby submits additional information concerning the Functional Capability of Class 1 Piping at the Shearon Harris Nuclear Power Plant.This information is in response to Safety Evaluation Report (SER)Open Item 3 from the Mechanical Engineering Branch.If you have further questions or require additional information;, please contact our.staff.Yours very truly, ESS/cfr (199NLU)Attachment S R.immerman anager Nuclear Licensing Section CC: Mr.B.C.Buckley (NRC)Mr.David Terao Mr.G.F.Maxwell (NRC-SHNPP)
Mr.J P O'Reilly (NRC-RII)Mr.Travis Payne (KUDZU)Mr.Daniel F.Read (CHANGE/ELP)
Chapel Hill Public Library Wake County Public Library Mr.Wells Eddleman Mr.John D.Runkle Dr.Richard D.Wilson Mr.G.0.Bright (ASLB)Dr.J.H.Carpenter (ASLB)Mr.J.L.Kelley (ASLB)8406i402i2 840607 PDR ADOCK 05000400 j E PDR 411 Fayettevilte Street~P.O.Box 1551~Raleigh, N.C.27602 CAROLINA POWER AND LIGHT COMPANY SHEARON HARRIS NUCLEAR POWER PLANT FUNCTIONAL CAPABILITY OF ASME CLASS 1 AUXILIARY PIPING, SYSTEMS RESPONSE TO SHNPP SER OPEN ITEM (3)
CAROLINA POWER AND LIGHT COMPANY*SHEARON HARRIS NUCLEAR POWER PLANT FUNCTIONAL CAPABILITY OF ASME CLASS 1 AUXILIARY PIPING SYSTEMS TABLE OF CONTENTS SECTION PAGE LIST OF FIGURES AND TABLES PREFACE 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 ABSTRACT INTRODUCTION SCOPE.NOMENCLATURE 6 DEFINITIONS METHODOLOGY DESCRIPTION OF FINITE ELEMENT MODEL RESULTS PIPING COMPONENTS OTHER THAN ELBOWS 10 12 16~;~9.0,.
10.0 CONCLUSION
S REFERENCES APPENDICES 20 21 TABLE F"1322.2.1
-Limits of Primary Load or Stress for S'ervice Loadings with Level D Service Limits,.ASME Code Section III, Division 1.
CAROLINA POWER AND LIGHT COMPANY SHEARON HARRIS NUCLEAR POWER PLANT~FUNCTIONAL CAPABILITY OF ASME CLASS 1 AUXILIARY PIPING SYSTEMS LIST OF FIGURES AND TABLES Fig.la Fig..lb Fib.lc Fig.2 Fig.3 Fig.4 Fig.5 Fig.6 Fig.7 Fig.8 Fig.9 Schematic Representation of the finite element modeled elbow.Plots of the elbow finite element model Plots of the elbow finite element model Stress strain curve of the modeled'lbow material (M"~)Finite Elements Results of the 1-1/2" elbow (M" 8'Finite Elements Results of the 3" elbow (M-6")Finite Elements Results of the 6" elbow (M-8'Finite Elements Results of the 12" elbow (M-8'Finite Elements Results of the 14" elbow Deformation shape of the modeled pipe under the applied moment ,,'ypical Progressive Deformation of the elbows cross section obtained from the finite elements results Fig.10 Progressive elasto-plastic stress distribution obtained from the finite elements results Fig..-.ll.
-,.,<Percentage of Ovalization versus bending moment~c~Ppp'-Fig.12 Representation of Decrease in Cross-Sectional area of an Elbow under applied Bending Moments.Fi@.13 Fig.14 TABLE I, Tee Section Under General Bending Moments Stress Patterns in Tees Under Limiting Bending Moment Case Summary of Class 1 Auxiliary Piping to be Evaluated for Functional Capability TABLE II, Summary of Material and Physical Properties of the Analyzed Pipe Sizes TABLE III, Ovalization and Percent Change in Area for Alternate Code Definitions of Component Limit Moments p pl 1 CAROLINA POWER AND LIGHT COMPANY SHEARON HARRIS NUCLEAR POWER PLANT FUNCTIONAL CAPABILITY OF ASME CLASS 1 AUXILIARY PIPING SYSTEMS PREFACE This report was prepared in response to SHNPP SER Open Item 8'(3)and presents the methodology and evaluation criteria which demonstrate the functional capability of Class 1 auxiliary piping as required by USNRC SRP 3.9.3 Appendix (~)A (NUREG-0800, July 1981).SHNPP SER Section 3.9.3.1 SER Open Item 8'(3)Functional Ca abilit of Class 1 Auxiliar Pi in S stems"For ASME Class 1 auxiliary piping systems, the applicant has used a stress limit of 3.0 Sm, as stated in Appendix F of the ASME Code,Section III, for use in equation (9)of Paragraph (1)NB-3652.The faulted limit used by the applicant is intended to ensure structural integrity and not the functional capability of the piping system.The applicant believes that these limits provide assurance that the piping will not collapse or experience gross distortion and, thus, will not cause a loss of capability to perform their safety function.The staff has not accepted the justification
(--'.p'rovided by the applicant and.4onsiders this item open."
CAROLINA POWER AND LIGHT COMPANY SHEARON HARRIS NUCLEAR POWER PLANT FUNCTIONAL CAPABILITY OF ASME CLASS 1 AUXILIARY PIPING SYSTEMS 1.0 ABSTRACT Functional capability of piping components is defined as the capability to deliver rated flow and retain dimensional stability when the design and'ervice loads, and their resulting stresses and strains, are at prescribed levels.This report presents the methodology, evaluation and acceptance criteria used in demonstrating the functional capability of Class 1 auxiliary piping systems.The scope of this report is limited to the evaluation of essential Class 1 auxiliar i in for the Shearon Harris Nuclear Power Plant.Generically, the issue of functional capability for piping was.not identified as an NRC concern until July 1981, when the NRC issued NUREG-0800 which included SRP 3.9.3 and its Appendix A, the (4)acceptance criteria adopted by the NRC for functional piping.Almost simultaneously,-the NRC approved NEDO-21985 as an acceptable (3)basis of demonstrating functional capability.
Prior to the NRC's adoption of these criteria, passive components in essential systems were considered operable if they met the pressure integrity considerations of the ASME code pursuant to Regulatory Guide 1.48.NEDO"21985 presents criteria for evaluation of functional (8)capability to be used in conjunction with elastic analysis of piping systems.It specifically recognizes that more sophisticated techniques such as elastic plastic analysis may be employed to reduce the conservatism resulting from NEDO-21985 criteria.The criteria presented herein make use of equations and definitions given in the ASME Code and are principally based upon inelastic analysis techniques.
A deformation ,limit in terms of an ultimate moment for different pipe sizes is established.
This limit was selected such that small reductions in the cross-sectional area are assured.The reduction in cross-sectional area is given in terms of ovalization which indicates the formation of an eliptical shape.Definitions and Nomenclature of underlined terms and phrases are presented in Section 4.0
~l I (i CAROLINA POWER AND LIGHT COMPANY SHEARON HARRIS NUCLEAR POWER PLANT FUNCTIONAL CAPABILITY OF ASME CLASS 1 AUXILIARY PIPING SYSTEMS
2.0 INTRODUCTION
Piping systems and components essential to plant safety should be capable of delivering rated flow and retain dimensional stability when the design and service loads, and their resulting stresses and strains, are at prescribed levels.The ability to do this is termed functional ca abilit.A piping system might lose its functional capability through the occurrence of a significantly reduced flow area.The ASME Boiler and Pressure Vessel Code Section III provides rules for piping design and analysis for Class l piping systems in Sub section NB.While Code rules provide levels of allowable stress limits to assure pressure retention capability, they may not assure the functional capability of certain system components under all designated loadinf()conditions.
I<In the past, the question of functional capability was addressed by I selecting conservative stress limits usually presented by multiples of the yield strength of materials.
In addition, elastic analysis W+4gs techniques are generally employed.The techniques employed in this report adopt inelastic methods of piping analyses and establish deformation limits such that small reductions in pipe cross-sectional area are assured.Finite element analyses of three dimensionally modeled elbows (shell elements), with elasto-plastic strain hardening material properties and with large deformation considerations are conducted.
The functional capability of essential piping is evaluated by computing the ovalization and resulting percentage change in flow area for different values of moments applied up to failure.
CAROLINA POWER AND LIGHT COMPANY SHEARON HARRIS NUCLEAR POWER PLANT FUNCTIONAL CAPABILITY OF ASME CLASS 1 AUXILIARY PIPING SYSTEMS 3.0 SCOPE The scope covered by'he methodology>
and evaluation criteria presented in this report is limited to Reactor Coolant Sytems (RCS), essential Class 1 auxiliary piping components.
The analytical approach is to perform an analysis for elbows and extend the results to other piping components by appropriate techniques.
U The piping of the RCS is required to maintain its functionability as well as structural integrity under all loading conditions including the Level D loadings.In essence, the piping is required to retain dimensional stability such that it will deliver its rated flow.Under Level D loading, the piping may undergo permanent plastic deformation as depicted from the ASME Code allowables being 3S or 0.7S and, m u therefore, plastic analyses are required to ascertain the piping deformation under the Level D loadings Table I presents a summary of the RCS Class 1 auxiliary piping to be evaluated for functional capability.
A total of five (5)Class 1 auxiliary pipe sizes ranging from l-l/2" to 14" in diameter were considered.
"4-CAROLINA POWER AND LIGHT COMPANY SHEARON HARRIS NUCLEAR POWER PLANT FUNCTIONAL CAPABILITY OF ASME CLASS 1 AUXILIARY PIPING SYSTEMS 4.0 NOMENCLATURE
&DEFINITIONS 4.1 Ovalization indicates the formation of an elipsoidal cross section as depicted below Ovalization 4 D, is the maximum decrease in the elbow diameter as it deforms into an elliptical shape.SECT.I-A 4.2 Percent cvalizattcn ci D x 100=Di-A x 100 nominal D 4.3 Percent chan e in Area, S A x 100~71 x A x B/4-('1V Di)/4 x 100 z A N (Di)/4 where, Di~inside diameter of the elbow cross section A Minimum inside diameter of the deformed shape B Maximum inside diameter of the deformed shape D~Nominal size of the pipe d-5" CAROLINA POWER AND LIGHT COMPANY SHEARON HARRIS NUCLEAR POWER PLANT FUNCTIONAL CAPABILITY OF ASME CLASS 1 AUXILIARY PIPING SYSTEMS 4.0 NOMENCLATURE
&DEFINITIONS (Cont'd)4.4 8 is the enforced rotation of the ends of the elbow 4.5 M is the moment resisted by the elbow 4.6 Instabilit moment, MI is the moment at which the moment resistance decreases for an increased rotation, i.e.the moment at which the tangent to the M-8 curve is horizontal.
4.7 B2 is the stress index as per ASME Section III NB 3650 Equation 9, that accounts for the reduction of the moment carrying capacity of a fitting or weld.4.8~F yield strain~.002+~S E 4.9 t is the pipe thickness~dl'4>4.10 R is the pipe nominal radius clast'ic section modulus 4.12 Mult (Gerber)the ultimate moment calculated on the basis of the strain power law[Ref.2].4.13 Functional Ca abilit-Ability of a component, including its supports, to deliver rated flow andretain dimensional stability when the'esign and service loads, and their resulting stresses and strains, are at prescribed levels.
"6-CAROLINA POWER AND LIGHT COMPANY SHEARON HARRIS NUCLEAR POWER PLANT FUNCTIONAL CAPABILITY OF ASME CLASS 1 AUXILIARY PIPING SYSTEMS 4.0 NOMENCLATURE
&DEFINITIONS (Cont'd)'appropriate subsection of Section III, Division 1, of the ASME Code.selected as the basis for the design of a component.
4.16 Functional S stem-That configuration'f components which, irrespective of ASME Code Class designation or comb'ination of ASME Code Class designations, performs a particular function (i.e., each emergency core cooling system performs a single particular function and yet each may be comprised of some components which are ASME Class 1 and other components which are ASME Code Class 2).4.17 LOCA-Loss of Coolant Accidents" Defined in Appendix A of 10CFR Part 50 as"those postulated accidents that result from the loss of reactor coolant, at a rate in excess of the capability of the reactor coolant makeup system, from breaks in the reactor coolant pressure boundary, up to and including a break equivalent in size to the double-ended rupture of the largest pipe of the reactor coolant system." This condition includes the loads from the postulated pipe break, itself, and also any associated system transients or dynamic effects resulting from the postulated pipe break.4.18 MS/FWPB-Main Steam and Feedwater Pi e Breaks-Postulated breaks in the main steam and feedwater lines.
'l l 1 7)~Cg I
-7" CAROLINA POWER AND LIGHT COMPANY SHEARON HARRIS NUCLEAR POWER PLANT FUNCTIONAL CAPABILITY OF ASME CLASS 1 AUXILIARY PIPING SYSTEMS 4.0 NOMENCLATURE
&DEFINITIONS (Cont'd)4.19 Pi in Com onents-These items of a piping system such as tees, elbows, bends, pipe and tubing, and branch connections constructed in accordance with, the rules of Section III of the ASME Code.4.20 Postulated Desi n Basis Events" Those postulated natural phenomena (i.e., OBE, SSE), postulated site hazards, (i.e., nearby explosion), or postulated plant events (i.e., DBPB, LOCA, MS/FWPB)for which the plant is designed to survive without undue risk to the health and safety of the public.4.21 SSE" Safe Shutdown Earth uake-Defined in Section III(c)of Appendix A of 10CFR Part 100.4.22 Service Limits-The four limits for the service loading as provided in the appropriate subsection of Section III, Division 1, of the g~<,SME Code;Level A (Normal), Level B (Upset), Level C (Emergency), Level D (Faulted).
4.23 Service Loads-Those pressure, temperature, and mechanical loads provided in the Design Specification.
4.24 Essential Class 1 Auxiliar Pi in-Piping and piping components required to shutdown the reactor and mitigate the consequences of a postulated design basis accident by transporting a specified quantity of fluid from one point to another point, with a specified pressure drop between the two points.
"8" CAROLINA POWER AND LIGHT COMPANY SHEARON HARRIS NUCLEAR POWER PLANT FUNCTIONAL CAPABILITY OF ASME CLASS 1 AUXILIARY PIPING SYSTEMS 5.0 METHODOLOGY 5.1 Loading and Modeling Approach 5.1.1 Introductionc The application of shear and normal forces and out of plane and torsional moments on elbows do not result in any appreciable ovalization.
Therefore, for a certain level of stresses in the elbow the highest ovalization is attained when the stresses are attributable to in plane bending.Henceforth, in this study pure bending is applied on the ends of the elbow, and in order to assure the condition of pure bending the ends of the piping on each side of the elbow are unconstrained.
5.1.2 Loading
A pure bending moment is applied on each of the unrestrained ends of the elbow.The direction of moment is such that it produces tensile stresses on the concave side of the elbow, see Fig.(1).The.elbow is loaded via enforced rotation of its ends which is monotonically increased until failure takes place at the elbow.5.1.3 Model: A model of a 90 elbow of radius 1.5D with two straight pipe 0 segments of length 4 D on each end is considered in this study.The reason for using the straight segment of the pipe is twofold.First is to provide a suCLJ.cient zone for the plastic hinge to develop about the center (45 plane)of the elbow, and second is 0 to set the location of the loading point with its inherent assumptions (small linear displacement and elastic stress distribution) remote from the center of the plastic hinge.See Fig.(1).
CAROLINA POWER AND LIGHT COMPANY SHEARON HARRIS NUCLEAR POWER PLANT FUNCTIONAL CAPABILITY OF ASME CLASS 1 AUXILIARY.
PIPING SYSTEMS 5.0 METHODOLOGY (Cont'd)5.1 Loading and Modeling Approach (Cont'd)5.1.4 Finite Element Code: The MSC-NASTRAN
[Ref.7]Version 63 Code, Solution 66 is implemented to conduct the elasto-plastic large deformation analysis of the elbows.5.1.5 Boundary Conditions:
For the pure moment loading of the elbow in its plane of curvature, two planes of symmetry exist.2~45 plane of the elbow, normal to the centerline of the 0 piping, i.e.symmetry about the piping mid-length.
0 0-180 plane of the cross section containing the centerline of the piping, i.e.symmetry about the plane of curvature of the elbow.Therefore, both conditions of symmetry are utilized to reduce the model to 1/4 its original size.Free boundaries are provided for the end points at which the rotations are.applied. CAROLINA POWER AND LIGHT COMPANY SHEARON HARRIS NUCLEAR POWER PLANT FUNCTIONAL CAPABILITY OF ASME CLASS 1 AUXILIARY PIPING SYSTEMS
6.0 DESCRIPTION
OF THE FINITE ELEMENT MODEL Twelve (12)equal shell elements are used to describe the 180 segment 0 of the pipe cross section in the circumferential direction.
Along the length of the straight segment of the piping, 5 subdivisions are used, the first three from the free end are of length=D, the fourth and fifth are of length 2D/3 and D/3 respectively.
Along the elbow 9 closely 0 spaced subdivisions are used (5 each).Therefore, a total of 192 (12 x 14)shell elements, connecting a total of 195 grid points (15 x 13)are used to describe the 1/4 model,[figures lb and lc].A rigid body element is used to connect the grid points on the free end of the elbow such that when the moment is applied at the center of the cross section, a linear elestic stress distribution develops at the free pipe cross section.6.1 Material Properties:
A stress-strain curve of elasto-plastic strain hardening properties is used to describe the shell elements material properties,[Figure 2].The curve is digitized from the strain power law (S=S g)in the n 0 plastic region, whereas in the el'astic region the modulus of elasticity as per ASME Code is used.Stainless steel material A-376-304 and A-376-316 are used in this analysis, for which the following parameters are given:~Su si u~E(si)F u~Su(si)~Sm(si)Syy(si)A"376-304 785023 0.1865 25.5 x 10 A-376-316 89,014 0.2056 25.5 x 106 0.205 0.2283 58,058 16,200 20,'400 65,700 16,700 20,500 "11-CAROLINA POWER AND LIGHT COMPANY SHEARON HARRIS NUCLEAR POWER PLANT FUNCTIONAL CAPABILITY OF ASME CLASS 1 AUXILIARY PIPING SYSTEMS
6.0 DESCRIPTION
OF THE FINITE EL'EMENT MODEL (Cont'd)6.2 Yield Criterion:
The von-Misses yield criterion is used to represent the plane of stresses within each element, the equivalent stress of which is given by:$m equ 1/2[(S-S)+(S"S)+(S"S)]where S , S , S are the three principal stresses.Failure of the material is postulated when the equivalent stress as computed by von-Misses stress criteria exceeds the ultimate stress as defined in the stress"strain curve used.6.3 Large Deformationc A large deformation feature is.utilized in order to account for the effect of the ovalization of the pipe cross section on the moment carrying capacity of the elbow.The cross sectional ovalization reduces the pipe section modulus, i.e.reduces the value of Moment/max stress.The moment may still be increasing due to the plastic flow which allows greater portions of the cross section to be subjected to higher stresses.
-12" CAROLINA'POWER AND LIGHT COMPANY SHEARON HARRIS NUCLEAR POWER PLANT FUNCTIONAL CAPABILITY OF ASME CLASS 1 AUXILIARY PIPING SYSTEMS 7.0 RESULTS'he M-8 curves are obtained for all elbows of the pipe sizes listed in Table 1, and are given in Figs.3 through 7.Typical deformation shapes and stress distribution are given in Figs.8 through 10.On the M-8 curves, scales of%ovalization and%change in cross sectional area are provided in order to judge the functional capability at the different values of applied moments.Also scales of the maximum stresses and maximum strains which are encountered at the outer fibres of the convex side of the elbow are provided in order to indicate the'state of stress at the different values of applied moments.The M<<6 curves display the pipe softening as the applied rotation 8j increases past the instability point.The instability moment shown on the figures is defined on page 4 of this report.On each curve, the ultimate moment values due to Gerber[2]is provided for comparison purposes.The curve M(Gerber)/B2 is included.The M-6"~A." curve is consistently higher that M(Gerber)/B2, for all values of moment up to the instability moment.The ultimate moment due to Gerber is refered to herein as M 1 Ult In Table 3, a summary of the percentage ovalization and percentage change in area is computed for a number of limit moments of the analyzed pipe sizes.The selection of those momen.-s is inspired by the definitions of the ASME Code of the allowable design limits as per the rules of Appendix F for the design by analysis of piping components under Level D loading.Table F"1322.2-1 of the ASME Code is included in the Appendix to this report for convenience.
"13-CAROLINA POWER AND LIGHT COMPANY SHEARON HARRIS NUCLEAR POWER PLANT FUNCTIONAL CAPABILITY OF ASME CLASS 1 AUXILIARY PIPING SYSTEMS 7.0 RESULTS: (Cont'd)The allowable moments are described as follows: (1)M(3S.)/B2:
m M(3S)is the moment that corresponds to an elastic stress m distribution on the pipe cross section of a maximum value of 3S.This moment is then divided by B in order to account for m the reduction in moment carrying capacity of elbows due to ovalization and stress concentrations as per Equation (9)of Section NB 3652.(2)0.7 MI MI is the instabilit moment, as defined in Appendix F, and is the value at which the moment carrying capacity of the pipe reduces, or at which the deformation increases without bound, i.e.the value at which the tangent to the M-8 curve is horizontal.
The values of M are indicated in Figs.3 to 7 of this report.(3)0.9 M collapse M as defined in Appendix F, is the moment at which the collapse distortion is twice the value at.the calculated initial departure from linearity, i.e.M(2 Q);the moment pertinent to maximum strain of twice g.As per Appendix F, the latter may be based on a yield stress of 2.3S.g is obtained from m 2.3S S (g)".m o y The values of M 11 are directly extracted from the finite collapse elements results, for the calculated value of 2.0 C by using C y the strain scale of the M-9 curves.
"14-CAROLINA POWER AND LIGHT COMPANY SHEARON HARRIS NUCLEAR POWER PLANT FUNCTIONAL CAPABILITY OF ASME CLASS 1 AUXILIARY PIPING SYSTEMS'.0 RESULTS: (Cont'd)(4)0.7 M 1/B2: M 1 as previously defined is the ultimate moment due to testing ul.t[Gerber, Ref.2], which meets the Code definition as an instability moment, and hence the factor 0.7.The division by B2 is meant to transform the test results on straight pipes into applicable values for elbows and other components.
From Table 3, it.is evident that the employment of (0.7 M/B2)as a ul t'imit moment is conservative since its values are in general, lower than the other limits (with the exception of the l-l/2" diameter pipe, for which 0.7 M 1/B2 agrees with M(3S)/B2.Ult m The employment of (0.7 M/B2)as a functional capability criterion is ult in general, more appropriate than M(3S)since the former is obtained by plasti.c analyses which can better represent the plastic deformation
+'+i WiQ>g-i phenomenon of elbows ovalization.
However, for the specific pipe sizes considered, the highest ovalization pertaining to, M(3S)/B2 equals m 0.79%and the maximum area change for the same moment equals 0.09%, which are negligible.
Note that prior to failure of the pipes, ovalization up to 45%and decrease in area as high as 35%are recorded (Figs 3 to 9)but such moments are never approached if the requirements of ASME Codes are met.Typical percentage ovalization versus the bending moment in the elbow is shown in Fig ll.As can be seen, ovalization is negligible for moments as close as 80%of M , after which it increases exponentially.
Therefore, use of Level D stress limits is meaningful for these pipe sizes.
"15-CAROLINA POWER AND LIGHT COMPANY SHEARON HARRIS NUCLEAR POWER PLANT FUNCTIONAL CAPABILITY OF ASME CLASS 1 AUXILIARY PIPING SYSTEMS 7.0 RESULTS: (Cont'd)The relationship between the instability moment predicted by the finite element plastic analysis and t'e instability moment drawn from the test results (0.7M and 0.7M/B2)is demonstrated and is.particularly Glt accurate for the pipes of large t/R ratios.The differences at smaller values of,t/R (thinner pipes)is apparently due to the susceptability of thin pipes to local instability encountered in the tests due to the stress concentrations under t'e test loading apparatus rather than the instability moment collapse.The primary stresses attributable to the bending of the elbow are accompanied by local secondary stresses that change from tension to compression across'he thickness of the pipe wall and act in the circumferential direction of t'e pipe. CAROLINA POWER AND LIGHT COMPANY SHEARON HARRIS NUCLEAR POWER PLANT FUNCTIONAL CAPABILITY OF ASME CLASS 1 AUXILIARY PIPING SYSTEMS 8.0 PIPING COMPONENTS OTHER THAN ELBOWS;8.1 Functional Capability of Tee and Branch Connections.
8.1.1 Introduction Presented here is a simplified engineering explanation aim'ed at proving that the functional capability of the tees and branch connections is well assured when the structural integrity Code requirements are satisfied.
The explanation provided is an analogy between branch connections and elbows so that the conclusions obtained from the plastic analysis of elbows can be utilized.It consequently follows that the discussion on functional capability is applicable only to tees and branch connections of the pipe sizes and thickness to radius ratios covered in the elbow analysis.8.1.2 Tees versus Elbows For an elbow, the decrease in cross sectional area under an applied bending moment is attributed to the ovalization of the circular section under the influence of the radially inward resultants of the tensile and compressive membrane forces in the concave and convex sides of the elbow.This fact is schematically shown in Fig.12.For a tee connection, while the decrease in cross sectional area is attributed to the same phenomenon, it is much more difficult to visualize and assess.This is due to three reasons:
'-17-CAROLINA POWER AND LIGHT COMPANY SHEARON HARRIS NUCLEAR POWER PLANT FUNCTIONAL CAPABILITY OF ASME CLASS 1 AUXILIARY PIPING SYSTEMS 8.0 PIPING COMPONENTS OTHER THAN ELBOWS: (Cont'd)8.1 (Cont'd)8.1.2 Tees versus Elbows (Cont'd)First, the tee has three legs and as such, it could be sub)ected to three bending moments, the interaction of which is not immediately obvious.Second, unlike the elbow where stability can be achieved only if the bending moments at each leg are equal, for the tee there are infinite combinations of balanced bending moments acting on the three legs.Third, the distribution of stress and internal forces is more complicated in tees than in elbows.The above three items must be addressed for any sound comparison of functional capability between tee's and elbows.8.1.3 Bending Moments on Tee Legs (the limiting case),.AVj'Apt'kW'c ('l It will be shown here that as far as functional capability is concerned, all possible bending moment combinations on the three legs of the tees are bounded by a limiting case.This is the case where the tee is loaded by two equal bending moments on two perpendicular legs, (much as an elbow is loaded).To show that this is the limiting case, reference is made to Figure 13a which shows a tee loaded by a bending moment at each leg.The behavior of this tee can be thought of as resulting from the super-position of two loading conditions; one attempting to close the flow area, and other counteracting the first, attempting to open the flow area.This is schematically shown in figure 13b.It is evident that the absence of the counteracting moment would result in the greatest area reduction.
~3~"18" CAROLINA POWER AND LIGHT COMPANY SHEARON HARRIS NUCLEAR POWER PLANT FUNCTIONAL CAPABILITY OF ASME CLASS 1 AUXILIARY PIPING SYSTEMS 8.0 PIPING COMPONENTS OTHER THAN ELBOWS: (Cont'd)8.1 (Cont'd)8.1.4 Stress patterns in the Tee For the limiting loading case, viz, that where the tee is loaded similar to the elbow, the stress patterns are schematically represented in Figure 14.As can be seen from the stress distribution at section AB and section DC, the resultant forces acting at points B and D are similar to their counterparts (concave and convex sides)on the elbow.This will tend to close the diagonal cross section BD which does not represent a flow cross sectional area.The cross sections AB, CB, DC however, will not be sub)ect to ovalization.
It is these latter sections that deliver the rated flow.Figure 14 shows how section DB may be ovalized while the perpendicular section (AB, BC 6 DC)shift more or less rigidly.It can thus be concluded that the flow sections of tees and branch connections will ovalize less than elbows of the same properties.
Since it was documented by elasto-plastic analysis that elbows undergo negligible area reduction under bending moments meeting Code requirements for structural integrity, the same holds true for tees and branch connections. CAROLINA POWER AND LIGHT COMPANY SHEARON HARRIS NUCLEAR POWER PLANT FUNCTIONAL CAPABILITY OF ASME CLASS 1 AUXILIARY PIPING SYSTEMS 8.0 PIPING COMPONENTS OTHER THAN ELBOWS: (Cont'd)8.2 Functional Capability of Straight Pipe and Reducers For the specific pipe sizes and schedules considered in this study, it was concluded that for elbows 0.7M exceeds 3S/B2.u m Recognizing that M was developed from elastic-plastic analysis u and that straight pipes are more stable (less prone to ovalization and subsequent collapse)than elbows, it can be conservatively concluded that functional capability will always be assured for straight pipe if Level D limits are met.Recognizing that reducers are ,gradual transitions in straight il piping, and that B2 has been~demonstrated to be a meaningful parameter for functional capability, it is concluded that reducers are stable relative to elbows and not prone to gross deformations if Level D limits are met. .CAROLINA POWER AND LIGHT COMPANY SHEARON HARRIS NUCLEAR POWER PLANT FUNCTIONAL CAPABILITY OF ASME CLASS 1 AUXILIARY PIPING SYSTEMS
9.0 CONCLUSION
S It has been demonstrated by finite element elastic-plastic analysis on elbows that meaningful functional capability limits can be derived based on the ultimate moment as defined by Gerber modified by the B stress index for the piping component.
Small deformations are assured if stresses less than 70%of the modified limit are maintained in the piping system.This criterion should be valid for any pipe size.For the specific cases of relatively thick piping found'n the Class 1 portions of pressurized water reactors and for Shearon Harris Nuclear Power Plant in particular, it is demonstrated that the small deformation limit defined above is bounded by a stress of 3.0S calculated by an m elastic analysis.Therefore, for these specific cases, the ASME III Level D limits do in fact represent acceptable functional capability limits.
<s 4~-21-CAROLINA POWER AND LIGHT COMPANY SHEARON HARRIS NUCLEAR POWER PLANT FUNCTIONAL CAPABILITY OF ASME CLASS 1 AUXILIARY PIPING SYSTEMS
10.0 REFERENCES
l.ASME Boiler and Pressure Vessel Code,Section III, Division 1, Pressure Vessels, 1977 Edition with Addenda up to and including Summer 1978'SMEy New York, NY.2~Gerber, T.L.,"Plastic Deformation of Piping Due To Pipe Whip Loading", ASME Paper No.74-NE-l, ASME PVP, Nuclear Materials Division, June 1974.3~Rodabaugh, E.C.,"Functional Capability Criteria for Essential Mark II Piping", Nuclear Energy Engineering Division, General Electric Company, San Jose, California, NED0-21985, September 1978.4.USNRC Standard Review Plan, 3.9.3 Rev.1, ASME Code Class 1, 2 and 3 Components, Component Supports, and Core Support Structures, Section 3.9.3.1, Loading Combinations, Design Transients and Stress Limits.5.Rodabaugh, E.C., and Moore, S.E.,"Evaluation of the Plastic Characteristics of Piping Products in Relation to ASME Code Criteria", US Nuclear Regulatory Commission, NUREG/CR-0261, July 1978.6.Liu, T.H., Johnson, E.R., and Chang K.C.;"Functional Capability of ASME Class 2/3 Stainless Steel Bends and Elbows", Nuclear Technology Division, Westinghouse Electric Corporation, Pennsylvania, ASME 83-PVP-66.
Pittsburgh, 7.McNeal Schwendler NASTRAN, Version 63 released August 12, 1983.8.USNRC Regulatory Guide 1.48,"Design Limits and Loading Combinations for Seismic Category I Fluid System Components".
CAROLINA POHER AND LIGHT COMPANY SHEARON HARRIS NUCLEAR POHER PLANT
SUMMARY
OF CLASS 1 AUXILIARY PIPING TO BE EVALUATED FOR FUNCTIONAL CAPABILITY TABLE I S stem/Class 1 Line Reactor Coolant S stem DESIGN BASIS EVENT SURGE LINE RHR LINE(HL ACCUM LINE(CL MAIN STEAM FEEDWATER SAFE SHUTDOWN REACTOR COOIART PIPE BREAK PIPE BREAK PIPE BREAK PIPE BREAK PIPE BREAK PIPE BREAK EARTILIACAKE Line Attached Line Attached to Line Attached to An Loo 14" Surge Line 4" Pressuriser Spray RCL Drain RTD RPV Vent RPV Bottom Incore.6" Pressurizer PORV Inlet 6" Pressuriser SRV Inlet SI SI/N (1)N N N SI SI SI SI SI SI SI SI'SI SI SI SI SI SI SI SI SI SI SI SI SI SI SI SI SI SI SI SI SI SI SI SI SI.SI SI SI SI SI SI SI E SI SI SI SI SI SI ,E SI SI SI SI SI SI Chemical 6 Volume Control S stem 3" Charging 3" Letdown 1-1/2" RCP Seal Hater In)3/4u RCP Bypass 2" Boron In)(C/L)Residual Heat Removal S stem 12" RHR Suction Safet In ection S stem 12" Accumulator Inj 6" SIS to Cold Leg 6" SIS to Hot Leg SI/<<(I)N N N SI SI SI SI SI SI'SI SI SI E SI SI SI SI SI E SI SI.SI SI SI E E E E SI SI SI SI E SI E E E SI SI SI SI E SI SI E SI SI SI SI SI E SI SI SI SI SI SI SI SI E SI E E E TABLE" I NOTES AND DEFINITIONS Essential line-required to function and maintain its pressure boundary.non-essential line (structural integrity line)-required to maintain its pressure boundary only.not required to function or maintain its pressure boundary.SI-for hot leg break N" for cold leg and crossover leg break CAROLINA POWER AND LIGHT COMPANY SHEARON HARRIS NUCLEAR POWER PLANT FUNCTIONAL CAPABILITY OF ASME CLASS 1 AUXILIARY PIPING SYSTEMS TABLE II PROPERTIES OF ANALYZED PIPE SIZES NOMINAL PIPE SIZE (IN.)PIPE SCHEDULE OUTSIDE DIAM.(IN.)INSIDE DIAM.(IN.)WALL THICKNESS (IN.)INSIDE AREA (IN.2)MOMENT OF SECTION t/R INTERTIA MODULUS THICKNESS SHAPE (IN.)(IN.)NOM.RAD.B2 FACTOR 1"1/2 160 1.90 1.338 0.281 1.406 0.483 0.508 0.3471 1.4978 1.46510 160 3.50 2.626 0.437 5.42 5.03 2.876 0.2809 1.6416 1.4355 160 6.625 5.189 0.718 21.15 59.0 17.81 0.2434 1.7864 1.4141 12 140 12.75 10.50 1.125 86.6 701.109.9 0.193 2.0573 1.3878 14 160 14.0 11.188 1.406 98.3 1017.159.6 0.2233 1.7802 1.40377 CAROLINA POWER AND LIGHT COMPANY SHEARON HARRIS NUCLEAR POWER PLANT FUNCTIONAL CAPABILITY OF ASME CLASS 1 AUXILIARY PIPING SYSTEMS TABLE III OVALIZATION AND PERCENT CHANGE IN AREA FOR ALTERNATE CODE DEFINITIONS OF COMPONENT LIMIT MOMENTS APPROACH ELASTIC PLASTIC (FINITE ELEMENT)MODIFIED TEST RESULTS LINE SIZE&ELBOW PARAMETERS collapse COMPARISON M(3Sm)/B2 0.7MI (Su~2.3Sm)PARAMETERS 106 in-lb 106 in-lb 106 in-lb 0.7 Mult/B2 106 in"lb 1-1/2" Moment 0.0165 0.017 0.019 0.0169 B2 1.4978 Ovalization 0.75%0.87%t/R 0.3471 Area Change 0.09%'.1%2.98%0.08/0.87%0.1%3 I I B2 1.6416 t/R=0.2809 Moment Ovalization Area Change 0.0851 0.66%0.08%0.095 1.05 0.137%0.106 4.15%0.91%0.0833 0.925/0.12%Moment 0.485 B2~1.7864 Ovalization 0.388%t/R 0.2434 Area Change 0.03%0.541 0.73%0.06%0.623 4.91%0.99/0.454 0.613/o 0.051%12ll Moment 2.676 2.99 3.47 2.49 B2 2.0573 t/R 0.193 Ovalization Area Change 0.788%0.031'/o 0.84/0.04/o 6.54%l.24%0.698/0.032%]4ll B2=1.7802 t/R~0.2233 Moment Ovalization Area Change 4.357 0.411%0'28%5.18'.525%0.039%5.94 5.26%1.14%3.997 0.405%0.030%
FIG.1-A SCHEMATIC REPRESENTATION OF THE FINITE ELEMENT MODELED ELBOW 0 z"111 e-0 2 111 Y111 r3 r2 Xp 4D e-1ap SECTION A-A.A-:<<~"111 2111 OUT OF THE PAGE 20 Yo D R~D/2 2111 111 14 Cy 0+~0 90 R 1.5D A~Y111 IN THE PAGE OSSS (X,Y,Z)("111~Y111 (r,e, Z)~BASIC COORDINATES SYSTEM CARTESIAN COORDINATES AT THE FREE END~CYLINDRICAL COORDINATES AT 8~5 OF THE ELBOW (r~, g~, 2)~CYLINDRICAL COORDINATES AT 8 (5)DEGREES OF THE ELBOW 1 FIGURE 1b PLOT OF THE ELBOW FINITE'LEMENT MODEL 6" Q ELBOW CP&L SHEARON HARRIS FIGURE 1c PLOT OF THE ELBOW FINITE ELEMENT MODEL 6" P ELBOW CP&L-SHEARON HARRIS l.~f FIGURE 2 STRESS STRAIN CURVE OF THE MODELED ELBOW MATERIAL 90 70 A37 YPE 3 A376 TYPE (TEMP.~6500)30 20 10 0'0.025:0.05;:0.075'10'.125 i0 15'0.175 0.20 0.225'STRAIN (IN/IN)'P&L SHEARON HARRIS FIG.3 (M-8)flNlTE ELEMENTS RESULTS OF THE 1N" ELBOW I I I~I!ili I!I l.i!i I li!I RUN NAME B1PAG96, 1.6" EI.BOW SHED 160 MATERIAL A376 TYPE 304 epee I~DATE 4/7/84 s I I~~I i}I sl 0.61.2 1.25 14.0 17.9 8.7 21.0 0 I:.23.5 14.2 I I 25.5 14.9 26.0 16.3 Il'll I'I 26.O~15.3 1!i'I)i.:'!I i"'.ll::.:.!'.
III!ill!;ii.'.5" ELBOW-%OF OVALIZATION I"I s 0 45.0 0.0 0.095 65.0 0.15 58 058.1 0.209'0.24: 58.156 0.253 936.6 jl', I"0.253 IIIIIIIIIIII!'{IIIIIL!IIllllllllllilllllllill!
I!!il,':iiill!',"",:, PJII%lglll!II)IJ[q!
j)t)fjg[$)i.'{1:..EFFECTIVE PLASTIC STRAIN ii s~e see 0.05 I~I:il!I.II'~I's{CI o CCI R I z III O 0.04 0.03~}r".il I I s!II.s I I I~s~~{~~~0.02/82 RB GE ER FINITE I!li'e/BZf!i NT LEME~~I~I~!{i ii'!fi Ills AN ALYS IS-1 I ls e', E LBOW 0.01~~elli s I.ll Ie l!s.':lll'.I!+It 111 Is~~~".'I t I CPS{L 0.1 BI SHEARON HARRIS 0.2 0.3 0.4 0.5 1 0.6 0 (Rao!AN)0.7',i i I~~I!0.8 ii'!';101 9: 'l:Ill:I I i1.0 j s'Is FIG.4 (M-0)FINITE ELEMENTS RESULTS OF THE 3" ELBOW a~I a'I oL I I'I ll:~I\':.I!i I a a.:-'5.57-I.a.~...a:111~~ii.7'7)I II~4116 I I!I 19.13 a 24.57 III I j 3" ELBOW-%OF OVALIZAT)ON ELBOW-%AREA CHANGE~~I, ,I 144.7 51.1: 53.3 55.5, 57.9 ELBOW-MAX EQUIV.STRE SS IKSI)I.'la alai 26 a 1'4!i!):~~~~I 048: a~al a I 101'128 160 199 OW-PLA IC STRA a I'I:II I z O:..I~j~~~j~a~~al"Fl jl)i li, LI NIT IIji LE N ANA YS)BOW 10:::.'.09:::..06 oaf li li.l lail ERB 2 3 G/62 02 0 la II a:iI'~I Ia'iLII II all!I j aa al I,:I:Ia ill!all Ial: 1111 F 11 Ia:jl a I I I~li" a~~~~~~~~a'I'i a I: la I!Ii~~Ii i a 0.1i CP)IIL: SHEARON HARRIS 0.2: a i[o.sj I 0.4 O.5)!10.6]i"I O.7'1)RUN NAME BO3AG85 4/06/84 (3)GERBER/B2 t)RAOIAN!2)RUN NAME 803AGF 3/26/84 lp 9i I i o,lj g.l 3 a I 1.5 FIG.5 (M-0)FINlTEELEMENTS RESULTS Ol.THE 6" ELBOW:is:j'I.I~;ll a I~IO O 0~il j, I'I'l l: I ILI'I I~I I'..11~~I~."'!L!I'I'~ii I~I I'I: I I:~I I I I.I':ELASTRO PLASTIC LARGE DEFORMATION ANALYSIS'6" ELBOW-SCHEDULE 160.MATERIAL A376-TYPE 304 I!I J I 6" ELBOW-%OF OVALIZATION j ij 6" ELBOW-%CHANGE IN AREA..1.6.~jj!III'C4 II 6"'LBOW-EQUIVALENT STRES KSI z I-z III 0!ij!j j'jj j!:ill I!I~~j.:ll I~I I FINI LEMEN TA'6"'LBOW-PLASTIC STRAIN LBOW i!jj!i~;I jl!jj'll-.i 1,1 l"'.4'ERBER/B2
.7 GERBER/B2':.'l I~~I'I I!II ll::~->>2.';:: Il.l'i I'I I i:: P'&L...j I II.'HEARON HAR R IS.2 I I 3j.6!j 1.0 1.2 1.3.1.5'UM BOBAG87, 4 104!4
~'IG.6 (M-8)FINITE ELEMENTS RESULTS OF THE 12" ELBOW I:::>>:'.it: I I>>::I I~CÃ'~.I~I I!I I~~>>'I I j k>>I>>I!~~I!>>In!I.~'..F I';I, i l il 12" ELBOW-%OF OVALIZATION 12>>I ELBOW-%CHANGE IN AREA>>>>>>ENT STRES S~12 ELBOW-EQUIVAL iKSI I>>':in.ti~>>t: i,j>>t>>i o.I C>>!'" E LBOW-PLASTIC STRAIN i!i j Iij!Iil i i::12.0.~~!jilt t'!i!Iii':;:10.0 Ii'i I'!I qi>>I..ij!!I i%FL%C I ij'I!TTE A AN I'N I fi G 12 ELBOW.ELASTRO.PLASTIC LARGE DEFORMATION ANALYSIS 12" PIPE-SCHEDULE 14OMATERIAL A376-TYPE 316: Ill ,I I gati tpl I!II:.il!'8.0 iiil i!i lit!I I.i>>\I I I I'I'"!III!::I~I~ljf>>: f>>G/2 ij FINI GERBER LEMEN H ANA I 1 LY I S i IS-12" iE BO~I>>I ill.I!.: ".16(CPSIL.".'I>0 I1>>E I 24 40 48 64 80 88 I 0 44 RUN NAME E12 AG 83, 44I-84 SOZAGFV 3404t4 FIG.7 (M-8)FINITE.":.ELEMENTS RESULTS OF THE 14" ELBOW 6.0 14.0'17:2:4 01.03 41.47.03\0.1 322 47.64 19.32 9.78 52.95 23!I 25.77:15.96 Il~27 i20.91 56.75 e il I!I:.32.86:,j lj 57AO 35.67 27.44 57.88'197[I i!'i ii,'-14" ELBOW-%OF OV I I:.L 4!-': 'LI2ATION:
Ni)l Ii'I"'IIII I14" ELBOW-%CHANGE IN AREA 14" ELBOW-PLASTIC STRAIN i'"')ll'ii{I!14" ELBOW-EQUIVALENT STRESS SI)~~1~I~.12.0 EL AS 14ee TIC L DUL ROP LAS SCHE PIPE-E1 E DEFOR MATER I I I!ALYSIS PE 304 ATI L ON AN A376.TY IA~!I:I I ii!!~~e I: I:~~IO O ttt R I-z III 0 0.0 6.0 FIN TE E LE T ANA 14" 0~e GE I R BE I I~I:~{!'I llii li:::I:I~I~~I e~I)~I:I e!I'I 4.0 7G B2~I el I!2.0 I~e II I'ett{Ii!I~~~~1 e~~I~le~II'll e~e~~0 I II~CPSIL SHEARON HARRIS 0.2 0.3 0.4 I I~0.5 j I Itii i j'i'll I!~li e!!II I.'I'I.I I.)ROTATION RAD!~I'I: '.,tO~I'I I I.e.'0.8: l0.9-:1.0"...:
lil'.:I: I1)RUN NAME B14AG37 4/11/84 l2)RUN NAME I ,~~t~
FIGURE 8 DEFORMATION SHAPE OF THE MODELED PIPE UNDER THE APPLIED MOMENT I 6" ELBOW SCH 160 SUBCASE 4, S 100 1707 tt 1807 1607 7 1107 1007 1907 07 10 107 00 0~SCALE'lt6 IS USED FOR BOTH PIPE LENGTH AND ITS DEFORMATIONS.
CPSL SHEARON HARR IS 210'50'60'00'BOW FIGURE 9 TYPi~L PROGRESSIVE DEFORMATION 0 HE ELBOW'S CROSS SECTION OBTAINED BY THE FINITE ELEMENT METHOD 200'190'703 160'170'80'90'50'10' I~I 220'40'30'30'40'20'
'I~~I I I I I 3 I l 7 IV 3 C.g~3I//~X X r 3I A/'40'20'30'30'20'40'50'10'I
~3 33 110'50'60'00'00'60'70'0'0'70'80'0'0'80'90'0'913 70'90'00'0'0'00'10'0'
~~~RUN: E12AG83, 4.6 84 A-SUBCASE 2,09, 833.08 RAD DISPLACEMENT B-SUBCASE 4,01, 8.308 RAD DISPLACEMENT C-SUBCASE 4,30, 8~.888 RAD DISPLACEMENT
,'L*50'10'20'0'0'203 330'0'340'0'50'0'o 10'50'0'40'PSL SHEARON HARRIS 30'30' FIGURE 1D PROGRESSIVE ELASTO-PLASTIC STRESS DISTRIBUTION OBTAINED FROM THE FINITE ELEMENTS RESULTS li I:!~~e:I II:: eI'~~eg I I~I~II e~~itic b 1 e jFll ji)j~IIII!I~II.I e~~I: j Ie lile I'I ,'l4" P PIPE ELBOW: SCH 160 MATERIAL A376 TYPE 304 Y}I le l Ii)!i I e I ille~~I~e li e'I jl I e.I EID: 101 I 0 I O KSI 28.6 KSI: I~~9.9 3 KS 62.2 KSI O~'V I i I-I I~L 11.3)I ISUBC ASE 1 3te4 BC A U E2 10 4I.O'3 SUBCAS e(e II j I 0 3.6 U I C SE 4.10 A I~t'I e CP8IL SHEARON HARRIS FIGURE 11 PERCENTAGE FLATTENING VERSUS BENDING MOMENT ELASTO MLASTIC LARGE DEFORMATION ANALYSIS C~iII'~ll l e C 4~~ELEBOW 35 le 1-;:ii iBI 14" P ELBOW~4444I~25'Vii 5M lI 6" p 4 ELBOW ELBOW~~20"y ELBOW m'lK 15'IO e 0 0 0.2 0.4 0.6 0.8 1.0ee 1.2 1.4 1.8 M/MI (MI=INSTABILITY MOMENT)CP&L SHEARON HARRIS IN FIGURE 12 REPRESENTATION OF DECREASE IN CROSS SECTIONAL AREA OF AN ELBOW UNDER APPLIED BENDING MOMENTS 4 g4 FIGURE 13 TEE SECTION UNDER GENERAL BENDING MOMENTS 13-A M)+M2 13-B M1 M2 Mq+M2 FIGURE$4 STRESS PATTERNS IN TEES UNDER LIMITING BENDING MOMENT CASE A'l CROSS-SECTION C-D B'ROSS-SECTION A-B.FREE END I I C'C Clp, (t B'l l l l A'B I!~+.~/I/I I I I l\\\'l l r C'ROSS-SECTION B-C Hi+i i Tab)e i-l322.2-1 SECTION III, DIVISION I-.APPENDICES TABLE F-1322.2-1 LIMITS OF PRIMARY LOAD OR STRESS FOR SERVICE LOADINGS WITH LEVEL D SERVICE LIMITS Method of Analysis System F-l322.1 Component F.13222 Load or Stress (Note (6))Covicionents
[Nous 0)/6))Component Supports (Note (3))Elasuc Elastic Stress H8-3221, H 8.3230 F-1323.1 245~>>0.75>>for materiah Table l-l-2 I 0.75 for matc>>lab Tabk l.l.l I Alternative Limits:~Valves (F-1350), in preparation Piping (p-1360), pressure s2 x Design Pnssure 3.05w (Ea.(9), HB.3652)1.SS~I'2$r I bvt not>075>>(Note il))Inelastic Collapse load HB 3213.22 Stress rado F-1321.2i a)Elastic Collapse load Stress ratio Piastic imtabiiity F.1321.1(e)
Strain limit load Ine iastic Load P F.1323.2 (Note (7))Load Pstress 5>>F-1321.2(c)
F 1323.3 Stress F-1324.1 Load P F 1324.2 Load Pr, stress Scc F-1324.3 Load P F-)324.4 Load P F-1321.1(I)
F-)324.$Stress F 1324.6 0.9Pc based onSr 2.3$or on Pc derived from F.)321.ltd) or F-1321.3I a)[Notes (2), (7))~>>far iOaaS P,[Hate (4))0.7S5 t5 5)/3 I[Note (1))0.9P, based onS,~2DSw or on Pc de'ved from F 1321 1(d)or F-1321.3iai 0.75)for loads Pr (Note Ia))0.7P, or loads PsP, vvhere P~~Sv+IS(-5,)/3 (Note ISI)0.7P, or ioaas PsP, where P<~Sr+IS i Sc)/3, but not>P, (Note ta))0.75>>5+{5 5)/3 i (Note I1))1.55~)>>1.2$>>j but not>0.75(Note (1))Sane as components,'~0.7S>>5,'iS-S,/I[N'"'")but not>0.75>>r Same as components Same as components Same as componerns Same as components Use greater of limits specified.
Use lesser of limits specified.
NOTES: (1)Svalue at temperature shall be specified and justified in Design ReporL (2)P, denotes the collapse load based on lower bound theorem of limit analyses or as defined in F-1321.1(d).
(3)The Design t.lmits selected from this Table shall be used in conjuncUon with F-1323 and F-1324, as applicable, in order to determine the limits for P, Pi, and Po., (4)Higher limits for S~may be used as specified in A-9000, where the type of stress field is taken into account.(5)Si is the true effective stress associated with plastic instability (F-1324.4).
(6)For coinpressive loads or stresses, the stability requirements of F-1325 shall be met.(7)This method is not permitted if deformation limits are stated in Design Specifications.
(8)P, denotes the load associated with the strain limit placed on the component[F-1321.1(f)I.
oe r1 I