ML20126E950
| ML20126E950 | |
| Person / Time | |
|---|---|
| Issue date: | 11/30/1992 |
| From: | Rodabaugh E, Terao D Office of Nuclear Reactor Regulation |
| To: | |
| References | |
| NUREG-1367, NUDOCS 9212300055 | |
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Text
,
e NUREG-1367 Functional Caaability o:?
Piping Systems U.S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation D. Terao, E. C. Rodabaugh pa arcog l
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AVAILABILITY NOTICE Availability of Reference Materials Cited in NRC Publications Most documents cited in NRC publications will be available from one of the following sources:
1.
The NRC Pubhc Document Room, 2120 L Street, NW., Lower Leve!, Washingten, DC 20555 2.
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NUREG-1367 i.
l Functional Capability of-l Piping Systems i
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Manuscript Completed: October 1992 Date Published: November 1992 l
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D. Terao, E. C. Rodabaugh i
Division of Engineering i
OlYice of Nuclear Reactor Regulation j
U.S. Nuclear Regulaton Commission Washington, DC 20555 b
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AllSTRACT A
General Design Criterion 1 of Appendix A to Part 50 of such an extent that the required flow through the pipe Title 10 of the Code of Federal Regulations requires, in would be restricted.
part, that structures, systems, and components important to safety be designed to withstand the effects of carth-The objective of this report is to examine the present quakes without a loss of capability to perform their safety rules in the American Society of Mechanical lingineers function. The function of a piping system is to convey lloiler and Pressure Vessel Code, Section 111, and poten-4 fluids from one hication to another.The functional capa-tial changes to these rules, to determine if they are ade-bility of a piping system might be lost if, for example, the quate for ensuring the functional capability of safety-cross-sectional flow area of the pipe were deformed to related piping systems in nuclear power plants.
i iii NUltfiG-1367
l CONTENTS Page ABSTRACF..........................................................................
iii NOMENCLATURE...
vii 1
I NTR O D U Crl O N................................................
I 2
B ACKG ROUN D..................
3 2.1 Prese n t Cod e R ul es.............................................................
3 2.2 Nuclear Regulatory Commission's Position on Piping Functionality........................
3 2.3 Nuclear Regulatory Commission Piping Review Committee Report 4
2.4 Relevance of Tests to Piping Functional Capability....................................
4 3
UEANEY DYNAMIC LOADING TESTS ON STRAIGHT PIPE..........................
5 3.1 Relationship Between Accelerations and Moments.............................
5 3.2 Comparisons with ' theoretical Limit Moments..........................................
5 3.3 Comparisons with Elastic Analysis.......
5 3.4 We igh t Stre%es.............................................................
6 3.5 Pressure Stresses...
7 4
ELECTRIC POWER RESEARCH INS 7TTUTE, NRC. AND GENERAL ELECTRIC COMPANY 'ITISTS OF PIPING COMPONENTS 9
4.1 Scope of Tests and Reported Results' 9
4.2 Comparisons with Theoretical Limit Moments....................
9 4.3 Comparisons with Elastic Analysis...............
10 4.4 Weight Stresses.............................
13 4.5 Pressure Stresses................
13 4.6 Tests 30 and 37.................
13 5
ELECFRIC POWER RESEARCH INSTrrUTE, NRC, AND GENERAL ELECTRIC COMPANY TESFS OF PIPING SYS'1TIMS..
15 5.1 Piping System Configurations and Materials 15 5.2 Loadings......
15 5.3 Comparisons with Theoretical Limit Moments..
15 5.4 Comparisons with Elastic Analysis..
16 5.5 Weight Stresses....................
17 5.6 Pressure Stresses..................
17 6
OTIIER PIPING SYSTEM TESTS.................
19 6.1 Hanford Engineering Development 12horatory Tests (Reference 14).............
19 6.2 References 15-20 Tests...................
20 6.3 Summary of Other Piping System Tests........
21 7
OTHER DYNAMIC LOADS.
23 7.1 Fluid Hammer..
23 7.2 Relief-Valve Actuation 23 7.3 Postulated Pressure Boundary Breaks 23 7.4 Vibrations...............
24 8
SUMMARY
AND LIMITATIONS 25 8.1 Reversing Dynamic loads..
25 8.2 Other Dynamic leads 27 v
9 CONCl USIONS.
29 9.1 1 unctional Capability Assurance, Present Code Requirements.
29 9.2 Functional Capability Assurance, I uture Code Requirements....................
29 10 RiiFERENCES...
31 FIGURES 1
Test Arrangement.
33 2
Response Versus input Acceleration 34 3
Strain at Pipe blidspan Versus input Acceleration 35 4
Deformed Shape and Permanent Strain After Tests 36 5
hican Strain Versus Input Acceleration......
37 6
Deformed Shape of Upper Surface of 103-mm Pipe, Test 16....
38 7
in-Plane Elbow Test Arrangements, Tests 1. 3-8, 13, 19, and 31.....................
39 8
4 NPS: Sch. 40 Stainless Steel Pipe, Test 15 40 9 6 NPS. Sch. 40 Carbon Steel Pipe, Test 34 41 10 6 NPS,9-in. llend Radius, Sch.10 Stainless Steel Elbow, Test 3.......
42 11 6 NPS. 6-in. Hend Radius, Sch. 40 Cartmn Steel Elbow, Test 13.........
43 12 Elbows: Static In-Plane Closing Moment Capacity and Dynamic In. Plane Moment Capacity Tests 44 13 Test 20 Configuration: 4 NPS Nozzle in 12 NPS Vessel...
45 14 Test Arrangement. Tests 30 and 37..
46 15 Pipir.g System l Configuration [ Material: Carbon Stect (A106-B)]..
47 16 Piping System 2 Configuration [ Material: Stainless Steel (l'ype 316)]...
48 17 load Measurement Device at Sleds 2 and 4 49 18 Piping System 1. Weight Stresses, SwT 50 19 Piping System 2, Weight Stresses. SwT 51 20 llanford Engir,ecting Development laboratory Piping System...
52 TABLES 1
Ileaney (Refs. 7,8,9, and 10) Straight Pipe Tests: Materials, Yield Strengths, Dimensions, Sinusoidal Input Test Frequencies, Pressures, and Test Planes....
53 2
Beaney (Refs. 7,8. 9, and 10) Straight Pipe Test Results Evaluated in Relation to Elastic Analysis. 2% or 5% Damping 54 3
Reference 11 Pipe Tests: Limit Moments and Measured Moments 56 4
Reference 11 Elbow (6 NPS,90") Tests: Limit Moments and Measured Moments...
57 5
Reference 3 Static and Dynamic In-Plane Moment Capacity Tests on Elix ws.......
58 6
Reference 11 Pipe Tests: Comparisons with 2Sy Limit 59 7
Reference 11 Elbow (6 NPS,90*) Tests: Comparisons with 2Sy Limit 60 8
Reference 11 Tests on Other Components: Comparisons with 2Sy Limit.
61 9
Reference 13 and Other Piping System Tests: Comparison with Elastic Analyses.
62 NUREG-1367 vi
i NOMENCLATURE Code allowable stress, Class 2 piping Code stress indices Sh B, B, B 6. B r i 2 2 2
Code allowable stress intensity, Class 1 piping pipe mean diameter Sm D
pipe outside diameter Sp Do
- t. tress due to mternal pressure pDo/2t resultant moment, used in Code Equation (9)
Afi stress due to weight Sw f
calculated limit moment Af.
maximum measured moment Afm waH tMcb.a r
internal pressure P
nominal section modulus of piping component Z
calculated wress based on clastic response S
spectrumanalysiswith + /-15% peakbroaden-ing and with either 2% or 5% damping Other symbols are defir M where used in text or tables i
l vii NUREG-1367
i 1
INTRODUCTION General Design Criterion 1 of Appendix A to Part 50 of The Code
- does not address the functional capability of Title 10 of the Code of Federal Regulations (10 CIH) piping systems; rather, it addresses pressure boundary i
requires that structures, systems, and components impor.
integrity. Accordingly, it does not necessarily follow that meetmg Code rules will ensure functional capability.
tant to safety be designed to withstand the effects of carthquakes without a loss of capability to perform their The objective of this report is to examine present C(xle safety function. The function of a piping system is to rules, and potential changes to these rules, to see if they convey fluids from one location to another. Sizing of the are sufficient to ensure maintenance of functional pipe usually involves a compromise as size increases capability, between increasing installed costs and decreasing pres-
'" Code" as used in this rebrt refers to the American Society of Me-sure drop. Functional capability of a piping system might chanicallingineers(AShi iloiler and Pressure Vessel Code (Ref.1).
be lost if, for example, displacements were large enough Portions of the Code are identified as they appear in the Code (e.g.,
NB-3652). For the purpme of this report, NL-3600 (Gass 2 piping) to " crimp,, a pipe cross section and thus reduce the flow and ND-3600 (Class 2 piping) are identical, hence, reference is to area.
NC-3600 for Cass 2 piping.
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1 NURl!G-1367
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2 HACKGROUND 2.1 Present Code Rules.
2.2 Nuclear Regulatory Commission's 1
Position on Piping Functionality i
Primary h> ads, such as internal pressure and weight, m.
combination with other loads such as those dua to earth-In the early 1970s, the stress limit of 3Sm was considered quakes are controlled' in the Code by Equation (9)in to be quite high, relative to prior stress limits used in i-NH-3652 (Class 1 piping) and Equations (8) and (9) in piping design. For example, the industrial piping code, l
NC-3652 and -3653.1 (Class 2 piping).'these Code equa-USAS B31.3-1967 (Ref. 2), permitted stresses of 1.2xSh j
tions are for loadings acting not more than 1% of the time. (Earth-l quake loadings ftt in this category.)'Ihe concerns of the BtPDo/2t+ B Afi/Z < lesser of XxSx or YxSy (1)
U.S. Nuclear Regulatory Commission (NRC) related to j
2 functional capability of piping with the 3Sm limit resulted The symbols are defined in the " Nomenclature" section in the preparation of NUREG/CR-0261 (Ref. 3).
j of this report.The values of X and Yare Reference 3 includes summaries of available data on static load capacities of straight pipe, elbows, branch con-Cla 11, ng-
,ss2 ng Condition nections, tees, and other piping components. In this refer-ence, several changes m B-indices were suggested:
i Design 1.5 1.5 -
Level A 1.8 1.5 (1) Restrict application of B indices to Do// < 50 (be-cause of the buckling of straight pipes with l
Level H 1.8 1.5 1.8 L5 Do/t > $0).
Level C 2.25 1.8 2.25 1.8 l
(2) Decrease B for elbows from 1.0 to 0.5; Level D 3.0 2.0 3.0 2.0 i
(3) Decrease B for elbows from 0.75xC to 0.67xC.
2 2
2 f
In Equation (1), Sr - Sm (allowable stress intensity) for (4) Decrease B3 or branch connections from 0.75xC3 t 0.50xC.
i Class I piping, and Sx - Sh (allowable stress) for Chss 2 3
i piping. Values of Sm are usually greater than those of Sh.-
However, the data in Reference 3 indicated that Equation -
l For example, for S A106 Grade H carbon steel at 500*F, (1),3Sm limit, as applied to straight pipe (B,
_0.5, B -
2 l
Sm - 18.9 ksi, while Sh - 15.0 ksi. Ilowever, for aus-1.0), was the least defensible from the standpoint of static l
tenitic stainless steels at elevated temperatures, Sm is load capacity. For straight pipe, limit load theory (con-l
-almost the same as Sh; for example, for SA312 Type 304 firmed by cited tests) gives the bending moment, Af, at t
i stainless steel at 650*F, Sm - 16.2 ksi, and Sh - 15.9 ksi.
zero pressure of The material yield strength, Sy, is 17.9 ksi; thus, Sm/Sy =
l Sh/Sy - 0.9.
Aft - (4/n) ZSy (2)
It should be emphasized that the resultant moment am-For austenitic stainless steels at elevated temperatures, plitude, Afi, includes both steady-state loads, such as Sm - 0.95y. Equation (1) with a 3Sm limit would permit l
weight, and dynamic loads, such as those caused by carth-application of a moment of 2.7/(4/w)a 2.1 times the
. quakes. In Level D applications, the dynamic k) ads have static bending limit moment, in Reference 3, it was sug--
i usually been the major contributor to Afi. However, in-gested that the Level D limit be made the lesser of 3Sm or i
creasing the Level D stress limits is being considered. This 2Sy.
possibility, along with the use of higher (e.g.,5%) damp-l-
ing in evaluating the response of piping systems to dy-From the standpoint of functional capability, the 2Sy limit -
namic loads, makes it.more important to recognize that _
is not defensible if Af, m Equation (1) comes from static Afi represents combinations of steady-state k> ads with loads such as weight or steady-state relief valve thrust.-
f dynamic loads.
Thus, Reference 3 indicated that even the 2Sy Level D limit was not clearly defensible for assurance of func-tional capability.
l NRC Standard Review Plan Section 3.9.3 (Ref. 4), Ap- -
l-pendix A, states:
- *In nib 3658 and NC-3658, rules are given for the analysis of flanged joints.Dese rules are based on the prevention of excessive leakage at 2.3 Functional Capability the joints. Ilecause kms of functional capabihty of a flanged joint (with-out kus of pressure boundary integrity)is deemed to be incredible, the The design of Class 1, 2, and 3 piping l
rules for flanged joints are not comidered any further in this report.
components shall include a functional capability -
3 NUREG-1367 u.
assurance program.This program shall demon-Functional capability of piping is discussed in Section strate that the piping components, as supported, 2.8.5 of Volume 2 of NUREG-1061. By 1984, sufficient can retain sufficient dimensional stability at serv.
carthquake-type-loading test data were available to indi-ice conditions so as not to impair the system's cate that earthquake loadings on piping systems, in the functional capability. The program may be based absence of high static loads, would not cause " collapse" on tests, analysis, or a combination of tests and (large plastic deformations) of piping systems. A staff analysis.
consultant suggested that functionality capability could be ensured by meeting Equation (1) with lxvel D limits The Mechanical Engineering Branch of NRC's Office of (lesser of 3Sm. 2Sy), provided at least one-half of the Nuclear Reactor Regulation prepared an interim techni-stress in Equation (1) came from earthquake-induced cal position on the functional capability of essential pining loadirgs.
systems
- to serve as a guide for applicants in preparing their functional capability assurance programs. In the
'the Piping Review Committee, at that time, was not interim technical position, the staff indicated that meet-ready to endorse the consultant's recommendation and ing Equation (1) with Ixvel C limits was sufficient assur-recommended the following:
ance of functional capability for components with Do/t < 50. 'lhe applicant was to provide additional dem-The functionality criterion for piping will be onstration for components using Irvel D limits and for maintained. Current ASME Code Class I or components with Do/t > 50.
Class 2 stress evaluation procedures, not to ex-ceed level C limits, will be used.1hese limits are During specific plant reviews, applicants submitted other similar to those now being used on a case-by-case methods of demonstrating functional capability to the tusis to satisfy the functionality criterion. It is NRC. Among these was " Functional Capability Criteria recommended that the upcoming EPRI[ Electric for Essential Mark 11 Piping" (Ref. 5), which included Power Research Institutel/NRC pipe tests be guidance for components with Do/t > 50.
evaluated to confirm that psition and to deter-mine whether it is appropriate to use the current It is apparent that functional capability assurance re.
higher Level D stress limits.
quires, in addition to the Code rules, another set of evalu-ations. An ideal solution to the problem would consist of
'I ne EPRl/NRC tests have now been completed; see Sec-evidence that meeting the Code rules for piping (with tions 4 and 5 of this report.The remainder of this report modifications discussed iater) would also ensure the func.
consists of evaluating the EPRI/NRC tests, along with tional capability of piping systems.
Other dynamic loading test data, to determine whether it is appropriate to use the current Level D stress limit for ensuring the functionality of piping systems.
2.3 Nuclear Regulatory Comm.ission Piping Review Committee Report 2.4 Relevance of Tests to Piping Starting in early 1983, the NRC Piping Review Commit-Functional Capability tee reviewed nuclear power plant piping in the context of current regulations, regulatory guides, standard review A significant aspect of the test data is that, with one plans, and other pertinent documents. 'lhe results of the exception discussed in Section 4.6, none of the lests re-review were published in late 1984 and early 1985 in sulted in loss of functional capability. Thus, the staff's NUREG-1061 (Ref. 6), which consists of five volumes.
evaluations are based on the premise that the test data provide lower bounds on combinations of steady-state (e.g., weight) and dynamic loadings that will not cause loss
- Faential piping systems are piping systems that are neecssary (1) for of functional capability. This lower bound premise may safe shutdown of the plant and for mamtaining the plant in a safe shut--
introduce conservatisms in the staff's recommendations.
down condition or (2) for reventing or mitigating the consequence of an acciden t that could resu in potential offsite exposures exceed mg the But, as will become apparent in the following discussions, guidelines of 10 CFR Part 100. Pipmg systems that are not essential do the premise leads to a sigmficant relaxation of Ihe present not require a funcuonality evaluation.
NRC position on functionality.
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3 HEANEY DYNAMIC LOADING TESTS ON STRAIGliT PIPE i
3_
E. M. Beaneyof the llerkeley N uclear laboratories in the where D = pipe mean diameter,in.
United Kingdom has conducted a series of dynamic load-t = pipe wall thickness, in.
j-ing tests on straigk pipes, on straight pipes with stress concentrations, and on straight pipes with discrete corn.
Sy = yield strength of pipe material, psi l
ponents.The reports by Heaney of particular relevance to andgit,the responseaccelerationcorrespending;o Af,
t functional capability are References 7,8,9, and 10.
- 3 get = Af /(Af/gr)
(5) t 3.1 Relat,onsh,p Between i
i Accelerations and Moments For example, Equations (3), (4), and (5) as applied to Test 1 of Reference 8 give f
Figure 1 illustrates the test arrangement used by Heaney.
}
Table 1 is a summary of the material types, material yield get = 0.96422x(LO3583x43200/67.5 - 21.3.
l strengths, and pipe dimensions. A sinusoidal dynamic (g units) input was applied to the pipe ends as indicated in Figure
- 1. The tests of direct interest herein were run with the
}
sinsusoidal input frequency equal to the first mode natu.
3.2 Compar.isons with Theoret.ical j.
ral frequency of the pipe: that frequency is shown in Table Limit Moments i
- 1. Some tests were run with internal pressure in the pipes, i
as indicated in Table 1.
Figure 2 showsget for each of the five tests of Reference
- 8. It can be seen in this figure that, sincegit, corresponds 4
to Af, the limit moment is an approximate upper bound Figure 2 shows the test results from Reference 8. The t
input amplitude was increased to about 3g; the response to the moment that could be sustained in these dynamic j
acceleration.gr,at the midspan of the pipe (see Figure 1) loading tests. (rest 5 is anomolous in that the applied was measured. The relationship between mmnent and moment did not exceed about 65% of thelimit moment.)
response acceleration derived by Heaney is Equation (1), for zero ~ pressure, 2Sy limit, permits the i
Af = [386El/(4L2f2)kr (3) applicati n f a bending moment that is about 1.6 times the limit moment. Thus, the results shown in Figure 2 present a paradox: If applied moments in a piping system where Af = moment at midspan of pipe,in.-Ib are accurately calculated, then Equation (1), with a 2Sy i
E = modulus of clasticity, psi (3E+7 psi used limit, does not place any limit on input accelerations.
i herein)
Of course, to accurately calculate moments due to dy-I = momentofinertiaof pipecrosssection in.*
namic loads that are high enough to cause gross plastb L = length of pipe, in. (see Figure 1).
resp nse, an clastic-plastic analysis would be required.-
[.
f - frequency of input during testing, llz 3.3. Comparisons with Elastic Analysis gr = response acceleration An clastic-plastic analysis of piping systems is within tha For example, Equation (3) as applied to Test 1 of Refer-state-of-the-art, liowever, in the past and, the staff be.
I ence 8 gives lieves, foreseeable future, for pip;.ig system analysis, an clastic analysis has been and will continue to be used and, AI
.386x3E7x0.01263/(4x147.22x52) for carthquake loadings, an elastic response spectrum i
analysis with + /-15% peak broadening and not more
= 67.5 in. lb per unit g, than 5% damping. Thus, it is pertinent to evaluate Ucancy's test results in relation to clastic analysis, as l
Ifaving a relationship between Af and gr, the gr corre-l sponding to the theoretical limit moment, Af, can be Beancy's tests were run with an essentially constant fre-t l_
calculated as follows. The limit moment (in.-lb) for quency input. The input " response spectrum" is a single-stra_ight pipe is value acceleration at the test frequency; peak broadening is meaningless. Because the pipe response is similar to i
AfL = D2 Sy (4).
that of a single-degree-of-freedom dynamic structure, f
l 5
i gr = g/2(
(6)
(2% damping) or 4Sy (5% damping)only if the stress due to weight or other steady-state stress does not exceed
~
wheregt = acceleration at pipe midspan about 0.15Sy.
g - input acceleration 3A We,ght Stresses i
( = damping facter Table 1 includes a column headed " Test Flanc." A"V"in Figure 2 shows lines representing 1/2%,1%,2%, and 5%
this column indi ates that the dynamic loading is in a damping. It can be seen in this figure that, for low-level vertical plane as indicated by Figure 1. With this test input, the responses correspond to about 1% damping.
arrangement, the weight stress adds to the maximum flowever, for high-level input, the response is much less dynamic moment in the downward-displaced position. An than that indicated by an clastic analysis, even for 5%
"H"in this column indicates that the actuators were ro-damping. It is this aspect of an clastic analysis that makes lated 90' from the plane indicated by Figure 1. With this Code Equation (9)[ Equation (l) herein] highly conserva-test arrangement, the maximu_m weight stress is 90' from l
tive for reverring dynamic h> ads, the location of maximum dynamic moment.
Equation (1), for 7ero internal pressure, #
1.0 Figures 3 and 4, which show strain at pipe midspan and
=
2 (straight pipe), in omjunction with Equations (3) and (6),
deformed shape and permanent strain after tests, respec-can be written as tively, are from Reference 7. As indicated in Table 2 the weight stress at the pipe midspan was 0,1ISy. This weight Af/Z ~ S = (M/gek/22(
(7) stress was sufficient to induce biased strains (Figure 3) 1 and a post-test deformed shape (Figure 4). This magni-For example, Equation (7) as applied to Test I of Refer-tude of deformation is well below that which willimpair ence 8 for the highest test level of g ( = 3.6),2% damping, functional capability.
gwes i
Figure 5, which shows mean stram as a function of input acce na n,
Joyn uenc'e em mn n taw 2 S = 67.5x3.6/(2x0.02526x0.02) = 240,500 >si, I
headed Sw/Sy mdicates the weight stresses at pipe amplitude midspan. Other than Test 4, which showed the largest For companson with the Code I evel D limit, thc 2Sy limit Sw/Sy and the highest mean strain, there is no obvious (not 3Sm) will be used because Sy relates directly to limit mnd ton Mmn Sw/Sy and mean strain. In i est 4 high nwan stMns M aW l.9?ecate anysign6antlossof were developed; however, kiad theory.The ratio of S to 2Sy is thus a direct indication thse wue nd suQt to m of the test dynamic loadings to the dynamic h>adings per-mitted by the Code with a Level D stress allowable of 2Sy.
functional capability. hgures 3,4, and 5 serve as a warn-For example, for Test 1 of Reference 8, Sy = 43,200 psi:
ing th t weight and other steady-state stresses must be appropriately limited if Code Equation (9) with limits S/2Sy - 240500/(2x43200) = 2.78 such as 10Sy (2% damping) or 4Sy (5% damping)is to be clearly defensible.
Thus, for Test I of Reference 8, the maximum input of in Reference 9, Beaney mentions that "the pipe sags duc 3.6g is equivalent to 2.78 times the Code Level D allow-able.
to the one sided effect of gravity" but does not give quantitative data on the magnitude of the sagging.
Table 2 gives values of S/2Sy for all of References 7,8,9, Figu re 6, which shows deformed shape of upper surface of and 10 tests. Because collapse did not occur in any of pipe,is from Reference 10.The buckling indicated in this these tests, the S/2Sy values in Table 2 suggest that, for figure apparently occurred only in Test 16, during which a piping functional capability assurance, Equation (1) with pipe with Do/t = 103/1.5 - 69 was tested.The pipe was limits of about the following is appropriate, provided the filled with water, The combination of large Do/t, rela-moment used in Equation (1)is almost entirely a revers-ing dynamic moment.
tively high weight stress, and relatively low dynamic load input (1.9g) led to the incdient buckling as depicted in Figure 6.There is a bit of a mystery that Heaney noted but Analysis Damping, %
Stress Limit did not explain: Why did signs of buckling occur in Test 16 but not m rest 15?
2 10Sy 5
4Sy The onset of buckling could pose a challenge to mainte-nance of functional capability. Therefore, the staff rec-ommendations in this report will be " hedged" by limiting Specifically, the column in Table 2 headed "Sw/Sy" the applicability to Do/t < 50, the is, the same Do/t limit (weight stress / yield strength) supports the use of 10Sy imposed by the Code on the applicability of B-indices.
N UREG-1367 6
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1 3.5 Pressure Stresses wurse, uniform around the circumference of the pipe and, thus, do not bias the displacement direction, in con-4 Table 2, column headed "Sp/Sy," shows the ratios of cir-trast to weight stresses, which may bias the displacement cumferential stress due to internal pressure to the pipe direction.
4 material yield strength.
1 Although internal pressure is significant with respect to Code liquation (9) [liquation (1) herein] includes the
)
pressure boundary evaluation,lleancy's tests suggest that pressure term B,PDo/2t; its continued use is expected in internal pressure has little, if any, significance with re-any foreseeable Code rule changes for pressure boundary spect to functional capability. Pressure stresses are, of evaluations.
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1 4 ELECTRIC POWER RESEARCll INSTITUTE, NRC, AND GENERAL ELECTRIC COMPANY
- TESTS OF PIPING COMPONENTS 1
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?
4.1 Scope of Tesis and Reported Tests 33 and 34 were,in fact, tests on straight pipe. Ilow-1 ever, in the tests of tecs and reducers, the plasue response gUSUgIS was essentially in the pipes, not in either the tees or the reducers.
A total of 41 component tests were run. 'the types or j
components included cibows, tees, reducers, straight
.lhe co'.amn in Table 3 headed "Afm/Afi "indicat es that, as pipe, and fabocated branch connections. lhe tests are Y,,
Eg P;I g
y y;g described and the test results are given in Reference 11.
mo:nent is about as much moment as could be applied i
lieference 11 results were supplemented by data pro-when pipes are subjected to very high level, simulated vided in a letter from 11. Ilwang (General Electric Com-o pany) to 11. C. Rodabaugh &ded October 16,1991 (avail-earthquake-type dynamic loads.
j able in the author's personal file).
For Tests 15 and 34, Reference 11 gives data for several runs. Figures 8 and 9 are plots of Tests 15 and 34, The Figure 7 shows a representative tes_t arrangement with an calculated moment represents a measure of the magni-I elbow as the test component, Dynamic loadings were applied by motons applied to the sled. Numerous runs
,tude of the input, analogous to the g mput of Figure 2, lhe measured moment represents the response analo-were made in each test. The run of main interest to gous togr of lugure 2, convertible by means of Equation functional capab!' 'y is (in most tests) an earthquake time (3) to a response moment. As in Figure 2,11gures 8 and 9 history applied to the sted, scaled up to the highest magni-mdicate a rapid increase in response moment at low-tude used in the test.
magnitude mputs and a leveling off of response moment l
Reference 11 contains the results of measured moments at high inputs. Appendix A of Reference 11 includes a column headed "DYN MOMILIM MOM," where acting on the components. The measured moments were j
derived from strain gages placed on the inertia arm (see DYN MOM - maximum measured dynamic Figure 7), The inertia arm was sufficiently strong so that it moment l
responded clastically in all tests.'Ihus, comparisons can l
be made between measured moments and theoretical IJM MOM calculated static limit moment limit moments.
i lt might seem that DYN MOM /lJM MOM should be the Of the results given in Reference 11, the most significant same as Afm/ Aft in Table 3, This is approximately so, with respect to functionalcapability consists of the calcu-except for the tee tests. For the tee tests, IJM MOM was lated stress in the component at the highest magnitude of calculated in Reference 11 as sted input.These stresses were calculated using an clastic response spectrum analysis. The response spectrum was LIM MOM - D2Sy/g,,,
(g) f derived from the time-history input to the sled, using 2%
or 5% damping. The analysis is based on + /-15% peak wherc #2h is defined by the Code as 0.4(D/21)2'3 l
broadening of the so-derived response spectrum and l
gives the moment acting on the component. The calcu-The largest discrepancy exists for Test lit DYN MOM /
i lated stresses can be compared with the Code Equation LIM MOM = 2.4 compared with Afm/ Aft - 0.65.For-(9) stress limit of 2Sy. If the ratio of calculated stress to Test i1 D - 6.491 in.. t - 0.134 in., and Sy - 39.7 ksi.
l 2Sy is greater than unity, the test indicates that, for func-B23 - 3.35 and Equation (8) gives tional capability, an Equation (9) stress limit greater than 2Sy is defensible, llM MOM y 6.4912x0.134x39.7/3.35 - 67 in.-kip The DYN MOM used was that calculated at an imaginary 4.2 Comparisons with Theoretical location defined as the." tee center"t DYN MOM - 158
-Limit Moments in.-kip. Thus, in Appendix A of Reference 11, DYN MOM /IJM MOM - 158/67 - 2.36. In Test 11, essen-l 4.2.1 Tests on Straight Pipe tially all plastic response was confined to a narrow band of j;
the Schedule (Sch.) 10 branch pipe at its juncture with the Table 3 is a summary of Reference 11 results for what the tee,Thus,in the staff's view, the ratio of 2.4 shown in the staff deems to be essentially straight pipe tests. Only appendix is misleading. From a functional capability standpoint, however, the important aspect is that dis-placements were not sufficient to cause any loss of func-
- Subcontracted by tiPRI to entpMe test rewits
' tional Capability.
9 NURiiG-1367 l
n
.c-e m.
...m-.
-,,.r.-,.
--~m,_-%,,m,-em,.
m,oe-,,m_.-
~_ -
- ~--
I I
i 4
4.2.2 Tests on Elbows ness changes the calculated limit moment from 18910380 in.-kip. 'then, Af, daft - 400/380 - 1.05.
Table 4 is a summary of Reference 1i cibow tests. The limit moment was calculated as follows:
Thus, Test 13, evaluated using actual average wall thicki i
ness rather than nominal wall thickness, indicates that Aft - 0.84"D/tSy for P - 0 (9)
I!quation (9) is a good indicator of in-planc dynamic mo-i ment capacity for a carton steel cibow.
Aft = 0.96h" D}tSy for P > 0 1he average actual wall thickness of the Test 3 cibow was where h - cibow parameter - IR/r#
0.156 in. compared with the nominal wall thickness of elbow wall thickness 03 inEng h au mge wau tMness qnges the f
calculated limit moment from $2.3 to 67 in.-kip. 'then, R
climw bend radius Af, daft = 163/67 - 2.43. Obviously, the use of actual
=
cibow cross-section mean radius wall thickness does not explain the seeming paradox for r -
,i est 3.
'Ihe basis for l'quation (9), for P = 0, is discussed in i
Reference 3. It is based on an in plane bending limit flowever, evidence that the Af, daft ratio for Test 3 is moment, P = 0, theory developed by Spence and Findlay credible can be seen in Figure 12. This figure includes (Ref.12).The coefficient of 0.96 for P > 0 was suggested by the staff (used in Reference 11) to approximate the (1) static in plane closing moment capacity test data increase in moment capacity due to internal pressure, from Referenec 3; see Table 5 herein Insofar as the staff is aware, no closed-form theory exists (2) dynamic in-plane moment capacity test data from for an cibow limit moment with P > 0, or for an out-of-.
Reference 3; see 'Iable 5 herein plane or tor sional moment. Existing clastic-plastic, finite-(3) dynamic in-plane moment capacity test data from element computer programs might be used; however, to Reference 11: see Table 4 herein pick up the pressure effect and to distinguish between in-plane closing and in-plane opening, such programs Figure 12 shows that Test 3 results are on the high side of would have to include finite displacement effects. Static, static test data, but are consistent with prior dynamic test in-plane moment tests show that the moment capacity for data; thus, the Test 3 results are credible.
in-plane closing is much less than for in-plane opening.
At the other extreme of AI, daft in Table 4, for Test 37, For Tests 3 and 13, Reference 11 gives data for several Af, daft - 1.31. This is consistent with static test data for runs. Figures 10 and 11 are analogous to Figures 8 and 9, pipe elbows with zero internal pressure. Test 3 and Test which, in turn, are analogous to Figure 2.
37 elbows had the same nominal dimensions and were made of the same heat of stainless steel material.
Figure i1 shows responses that are similar to those of lleancy's straight pipe tests, that is, rapid rise in response Code Equation (9) [liquation (1) herein), for zero pres-at low magnitude input, followed by a leveling off of re-sure,2Sy limit, permits the application of a bending mo-sponse at high-magnitude input. However, the leveling ment of about 1.6 Aft.Thus, the results forTest 37 indi-off occurs at about two times Af., rather than in the cate that, if the' applied moments. are accurately f
vicinity of Af For dynamic equilibrium, the moment calculated, Code Equation (9) with a 2Sy limit does not t
capacity of the elbow cannot be exceeded in either the place nny limit on dynamic (e.g., carthquake-induced) closing direction or the opening direction. Thus, a para-
- loads, dox seems to exist.
For Test 13 the paradox is resolved by considering the 4.3 Comparisons with Elastic Analysis actual wall thickness of the elbow that was tested, in a letter from H. Hwang (General lilectric Company) to E.
In Section 4.2, measured dynamic moments and limit C. Rodabaugh dated April 21,1989 (available in the moments were compared. The staff v/ill now compare author's file) regarding dimensional measurements of calculated stresses with a 2Sy stress limit, Calculated mo-Reference 11 test components, H. Hwang provided wall ments and/or stresses are given in Appendix B of Rcfer-thickness measurements of the elbows used in the compo-enee 11. These calculations are based on clastic response nent tests. Thc Test 13 cibow was nominally Sch. 40, spectrum analyses usmg either 2% or 5% damping and 0.250-in. nominal wall thickness. The measured thick-
+/-15% peak broadening. The response spectra used nesses ranged from 0.327 in. to 0.520 in. with an average were derived from the time-history inputs to the sled; see wall thickness of 0.425 in. Using the average wall thick.
Figure 7.
NUREG-1367 10
1 43.1 Tests on Straight Pipe using Level D - 2Sy, where Sy is the yield strength of the material used in the tested component. Ilecause in these Table 6 is a summary of the results of Reference 11 tests, tests 2Sy > 60ksi,thestaff sS/2Syratioisalwayslessthan which the staff deems to be equivalent to straight pipe X/D.
tests. The staff will use Test 9 as an example to illustrate i
the significance of Table 6-For example,in Test 34 (pipe test),X/D - 731/60 - 12.2, which aprecs with the "12" shown in Appendix A of Ref-j For Test 9,2% damping, the calculated stress amplitude crence 11. Ilut, for 2Tr. amping, S/2Sy = 731/(2x44.S) =
is 589 ksi. The material yield strength is 40.8 ksi. Thus, 8.2 as shown in Table 6.
j S/2Sy - 589/8L6 - 7.22. Ilypassing, untillater, the ques-4 tion of weight stress and pressure stress, Code Equation In addition, for those tests that involved tees, INIUr X (9) could be written as
- B,Af/2, where, for example in Test II, B ("Il,) "
2 d
3.34 was used to calculate the X/D - 16 shown in Appen-B PDo/2t +B,Af/Z < 14.44Sy dix A of Reference ll, Also,in calculatingX/D - 16, the i
That is, looking only at Test 9, the Code limit of 2Sy could calculated moment at the imaginary point at the center-be increased to 14.44Sy, and, since no loss of functional Ime intersections was used in its evaluations, since the capability occurred in Test 9, the increased stress limit pl stic response was confined to a narrow band of the would ensure functional capability, branch pipe at its intersection with the tee, the staff used
- - 1.0 for straight pipe with the calculated moment at 2
the branch pipe-to7 ec intersection weld. It thereby ob-t If the moments were to be calculated using 5% damping, I
Test 9 indicates the Code Equation (9) limit could be tamed S - 269 ksi and S/2Sy - 269/(2x39.7) - 3.4 as Shown m 'Iable 6.
increased to 8.0Sy, but not necessarily any higher.
A salient point is that the defensible stress limit for Code For all Table 6 tests, X/D and S/2Sy are as follows:
t Equation (9)is highly dependent on how the moments acting on the component are calculated. For Test 9:
Test No.
9 10 11 12 14 15 16 33 34 40 X/D 21 21 lee 27 18 13 30 -- 12 22 x
~
Defensible Code S/2Sy 7.2 7.43.49.06.5 11 20 - 8.2 18 Moments Calculated Equation (9) Limit It is apparent that the staff's evaluations of Table 6 tests Accurately, e.g., by clastic plastic are significantly more conservative (and, it believes, more analysis L3Sy realistic)than the X/D ratios in Appendix A of Reference lly clastic analysis,2% damping 14.4Sy
- 11. Even so, the staff s evaluations support a significant Ily clastic analysis,5% damping 8.0Sy increase in the present Code Equation (9) limit insofar as functional capability is concerned for example, the low-est S/2Sy of 3.4 suggests that tW Code Equathn (9) limit could be increased from 2Sy to 6.8Sy, provided the ap-Appendix A of Reference 11 includes a column headed plied moments are calculated using not more tinn 2%
" INPUT X/ LEVEL D "
damping.
where INPUT X -. calculated stress using linear 43.2 Tests on Elbows response spectrum analysis, 2%
damping, + /-15% peak broad-Table 7 is a summary of Ihe Reference 11 tests on cibows ening, and actual sted input, in the same format as that of Table 6.
Stress - B Af/Z.
2 L.EVELD - 3Sm - 60 ksi.
The stress was calculated using in the following, for brevity, this ratio is designated as S - B,Af/Z (W)
X/D.
where Af was calculated using clastic resp (mse spectrum in Table 6, the analogous ratio is S/2Sy,2% damping. In gnalyses,2% or 5% damping and + /-15% peak broaden-the context of a meaningful evaluation of the tests, the ing,and staff deems that use of Level D = 3Sm - 60 ksi is inappropriate. A more meaningful ratio is obtained by B2-1.3/h 2'3 (11) 11 MUREG-1367
Equation (lI)is from Nil-3683.7 of the Codet h is the elbm parameter as tabulated and defined in Table 4. The
.fest Comment B for each h involved in the tests is as follows:
2 21,22 Tests of lugs on pipe-relevant to pressure boundary integrity but not to functional h
0.41 0.25 0.17 0.11 23 Test of cibow with strut restraint-relevant B
237 3.27 4.29 5.51 to support hads but not directly to func-2 tional capability 24,32 Static limit moment tests of cibows-results The maximum elastic stress in an elbow (with h > 1.0) more or less consistent with Reference 3 depends on the moment direction:
static limit moment tests j
27 Midfrequency and sinesweep tests of a tec-results for this test not given in Appendix il Moment Direction Multiplier of (1/h)2/3 of Refewnee H 28,29 Water hammer tests -discussed in Section 7 In-plane 1.86 herein Out-of-plane 1.59 Torsion 1.00 43.3,1 American National Standards Institute (ANSI) 1116.9 Tees The B of 13/4 2'3 is intended to represent a conservative Tests 36,38, and 39 in Table 8 are tests of 6x6x6 ANSI 2
estimate of the moment capacity of an elbow subjected to 1116.9 tees, the same type of components included m an in. plane closing moment, it is conservative for both Table 6, Tests 9,10,11,12, and 14. Ilowever, the fable 8 out-of-plane and torsion moments. However, an impor-tests are significantly different from the Iable 6 tests, as tant aspect with respect to the staff's recommendations illustrated by the followmg sketch, for functional capability criteria is that they are based on the B-indices as prescribed in the present Code Any future Code revision that would decrease any of the O Test 12 gy B indices might invalidate the staff's recommendations.
M4 4
M The ratios in Appendix A of Reference 11, column headed "INPUr X/ LEVEL D," are higher than those in Table 7, S/2Sy,2% damping, because f.evel D - 3Sm -
m 77 60 ksi is less than 2Sy. Although the staff's evaluations are more conservative (and, it believes, more realistic) than Table 6 Table 8 Table 8 those m Reference 11, they still suggest that the present Tests 9,10,11,12, fests 38,39 Test 36 limit on Code Equation (9), for functional capability 34 evaluation, can be increased significantly. The lowest S/2Sy in Table 7,5% damping, is 5.2.This suggests that the 2Sy limit can be increased to 10.4Sy, even when using In Tests 36,38, and 39, plasticity and eventual fatigue 5% damping in calculating the applied moments.
failure occurred in the bodyof the tees.Thus,it is deemed appropriate to evaluate these tests using the B26 (fests 38 and 39) or Bar (fest 36) specified in the Code:
4.3.3 Tests on Other Components B23 - 0.4(R/T)2/3 - 2.02:B, - 0.5(R/7)2/3 - 2.52 2
where R = mean radius of attached pipe (3.1725 in.)
Table 8 is a summary of the Reference 11 tests on other 7 = nominal wall thickness of attached pipe components in the same format as that of Tables 6 and 7, (0.280 in.)
Reference 11 includes the results of 41 comp (ment tests.
433.2 Tests 18,and 20, l'abricated liranch Tables 6,7, and 8 contain the results of the staff's evalu-Connectmns ations of 33 of these tests.The eight tests not included in ne staff's evaluations of Tests 18 and 20 require a more Tables 6,7, and 8, and comments concerning them, are detailed explanation. The Code-specified B2b index for the following:
branch connections per Nil-3643 (see Nil-3683.8)is NURl!G-1367 12 A
i i
Ba = 1.5x3(R/T)2' (r/R)itr(t/T)(r/r,)
(12)
For Test 20. Hun 7 Appendix 11 of Reference 11 gives f
Af = 724 inekip,2% damping
]
where R = mean radius of run pipe Af = 410 in. kip,5% damping 1
T = nominal wall thickncss of run pipe These moments are used as Af3 in Equation (13) to give r = mean radius of branch pipe t = nominal wall thickness of branch pipe S = 3.4lbx724/3.21 - 770 ksi for 2% damping S - 3.416x410/3.21 - 436 ksi for 5% damping -
rp 7 radius to outside of noule i
For Test 20, B3 - 7.79 and 23 = 5.9 in.3 were used in For use in Code Equation (9),
Reference i1 without an explanation of their basis.They are obviously not in Eccordance witii the Cafe.
3(Af /Z )
(13)
S=B 3 3 X/D in Appendix A of Reference 11 and S/2Sy, ' /o damp-where Af3 moment applied to branch ing, in Table 8 are as follows:
=
23 section modulus of branch pipe Test No. 18 20 36 38 l,9
=
X/D 20 16 15 20 21 Test 18 S/2Sy 7.2 7.9 9.9 l '-
16 Test 18 of a pad. reinforced fabricated tee poses a prob.
As its evaluations in Tables 6 and 7. it is apparent that the lem because B-indices for pad-reinforced branch connec.
st ff's evaluations in Table 8 art more conservative than tions are not given in the Code, llowever, the staff be, those in Reference 11. Evce w, the staffs evaluations 3 for Test 18 can be bounded by using suggest that, for functiona' capability evaluations, the lieves that B Equation (12)with T = 0.322 in. (Sch. 40 run pipe)as an pyesent limit on Code Eqution (9) can be increased sig-upper bound and T = 0.322 + pad thickness = 0.644 in.
ntficantly. The lowr-S'.iSy m rable 8,5% damping, is as a lower bound. For T = 0.322 in., Equation (12) pives (3 mis suggests tL.ne 2Sylimit might be mercased to 2
8.6Sy, even when 5% damping is used in calculating the B3 = 1.5(4.1515/0.322)2'3(2.1315/4.1515),,
applied momenis.
(0.237/0.322)(2.1315/2.25) = 4.12 4.4 We. ht Stresses ig l
Changing only the T of 0.322 to U.644 in gives Tables 6,7, and 8, column headed "Sw/Sy," show weight B3 = 1.30. In its evaluation of Test 18, the staff used an stresses as ratios to yield st rength, Sy These ratios, except j
average B3 of 2.7.
for Tests 30 and 37 (elbows), are not more than 0.08.
Thus, they are of limited usefulness with respect to estab-l For Test 18, Run 6, Appendix B of Reference 11 gives lishing a reasonable bound on weight stresses combined i
with reversing dynamic stresses.
j-Af 915 in.-kip,2% damping
=
542 in.-kip, 5% damping Tests 30 and 37 are discussed in Section 4.6.
Af
=
- These moments are used for Af in Equation (13) to give 4.5 Pressure Stresses 3
I S = 2.7x915/3.21 - 770 ksi for 2% damping Tables 6, 7, and 8, column headed "Sp/Sy," show the nominal pressure stresses, PDo/2t, as ratios to yield S = 2.7x542/3.21 = 456 ksi for 5% damping strength, Sy, ForTest 18,B3 - 4.12 was used in Reference 11 without Although internal p essure is significant with respect to an explanation of its basis (perhaps coincidentally.
pressure boundary evaluation, the data do not suggest any B3 - 4.12 can be obtained from Equation (12) for an decrease in functional capability for Sp/Sy ratios up to unreinforced fabricated tee). In Reference 11 the Ca.le.
0.48. Indeed, as discu sed in Section 4.6, internal pressure prescribed 23 - 3.21 in.3 was used.
in elbows appears to increase their moment capacity.This
" inverse" pressure effect is also apparc~ in static tests on
~
Test 20 (see figure 13) cibows; see Reference 3.
As epplied to Test 20, Equation (12) gives M Tests 30 and 37 B3 = 1.5(6.1875/0.375)2/3(2.1315/6.1875)"8 Tests 30 and ~7 were in plane moment tests on nominally (0.237/0.375)(2.1315/2.25) = 3.416 -
identical cibows.'the test arrangement is shown in Figure 13 NUREG-1367
i l
l l
l
- 14. The assemblies were " tuned" (hethi of vertical arm, ellow cross section would have significantly decreased; magnitude and kication of weights, etc.) so that the first that is, functional capability would nave been lost.
1 mode response frequency was almut 1.4 Ilz.1hc time-history input was adjusted so that the peak of the _ input Although about 5% higher loadings were used in Test 37, I
(
response spectrum was at about 1.311t. The adjustment Run 5, than in Test 30, Run 4, the staff believes the major was made by expanding the time of the time-historyinput; difference is that Test 37 was nm at zero pressure, while a run for Tests 30 and 37 lasted about 110 sec, rather than Test 30 was run at 400-psi pressure. 'Ihe measured mo-the about 20 sec for other simulated carthquake inputs.
ments in Test 37, Run 5, and Test 30. Run 4, were 57 and i 12 in.-kip, respectively.'lhis rather directly indicates the The elbows were from the same heat of stainless steel increase in moment capacity due to an internal pressure material with Sy - 34 ksi. They were 6 nominal pipe sac of 400 psi with Sp/Sy - 0.24.
(NPS), Sch.10,9-in. bend radius.
Test 37 is a direct indication that a weight load (10.74 ksi The weight stress, at the mid-arc of the elbows, was 10.74 weight stress) that would not cause collapse by itself, in ksi for both elbows with Sw/Sy - 0.32.
combination with high reversing dynamic !oads (S. 2%
damping - 651 ksi), does cause collapse.
The only apparent testing ddierences were the followm.g:
llowever, Test 37 must be looked at in light of the follow-Test /Run Pressure S,2% Damping ing:
30/4 400 psi 620 kFi
- (1) 1 he test was meant to be an extreme evaluation of 37/5 0
6517si the concept that reversing dynamic loads do not cause collapse. 'i' pipe parameters selected for Test 30 was ended when a fatigue failure occurred. Some this extreme case included in plane moments (weak-permanent displacements occurred (not quantified in est direction), zero pressure _(worst case for pres-Referenc' 41)during the test runs, but it is beheved that sure), and thin-walled Sch.10 pipe, for which Do/t - 49 (high Do/t and pronounced cibow effects none of these deformations were sufficien: to reduce functional capability.
w th h = 0.11). The weight stress was such that Sw/Sy was 0.32 (significantly higher than the usual Test 37 consisted of low-level Runs 1 and 2 and then weight stresses in piping systems).The very low test frequency of about 1.3 Itz may have contributed to Run 3
4 5
the collapse in that 1.3 Hz gives the assembly more time to displace before reversal of dynamic load S,2% damping, ksi 79 324 651 occurs.
During Runs I through 4, displacements were relatively (2) The dynamic loads were very high; that is, S/2Sy,2%
small. During Run 5, after about 45 sec into the run, the damping, was 9.6i which is 9.6 times the present assembly began to ratchet-displace in the elbow closing Code I.evel D limit, direction. The test was terminated at about 72 see into Run (3) Test 37 was a component test. In a piping system, and m,5 because the displacements were becoming largeadditional plastic hinges would have to develop be-ereasing rapidly with time, fore large plastic displacements could occur.
AUM termination of Test 37, the upper end of the inertia Nevertheless, Test 37 constitutes a " red flag" to indicate ans bad displaced several feet and, if the test had been that appropriate control must be placed on steady-state continued for a few more seconds, t_he displacements loadings to avoid the possibility of loss of functional capa-would probably have increased to the extens that the -
bility during application of high reversing dynamic loads.
i i
- NUREG-1367 14 l-
5 ELECTRIC POWER RESEARCil INSTITUTE, NRC, AND GENERAL ELECTRIC COMPANY TESTS OF PIPING SYSTEMS Two piping systems, identified as System I and System 2, were tested. The system configurations, testing, and re-lief.13 Table System location suits are given in Iteference 13. Iteference 13 results are supplemented by additional data provided in a letter from 5-5 1
Node 72,6 NPS short-radius
- 11. Ilwang (General Electne Company) to E. C, cibow llodabaugh dated November 14,1991 (available in the 6-9 2
Node 6.12x4 NPS nonte, see author's file).
Figure 13 6-11 2
Node 52,6 NPS, Sch. 40 pipe l
5.1 Piping System Configurations and Materials Table 5-5 Table 6-9 Table 6-11 Aim Alc Alm Aic Alm Ale Figures 15 and 16 show the configurations of Systems 1 66.1 92.5 39 53 110 150 and 2, respectively.
330 634.7 78 96 255-293 725 3228.4 119 334 576 915 System I was made of carbon steel (A106-II), it is charac-717 4994.1 156 572 681 1551 terized in Iteference 13 as follows: "[ System 1) was rela-235 1091 837 2658 l
tively balanced with regard to dynamic strain such that several different locations had cyclic plastic strains of where Afm - measured moment, inAp about the same magnitude.a calculated moment, in.-kip, using 2%
Afc System 2 was made of stamless steel (Type 316). It is damping, + /-15% peak broadening characterized in lleference 13 as follows:"[ System 2] had unbalanced stresses with a single high-stress location The data were sufficient so that plots of Alm versus Afe, where failure was predicted to tour while the remainder analogous to Figures 8 through 11, could be made. How-of the piping system was at a relatively lower stress."
ever, such plots are of little value because of the major uncertainties discussed below.
5.2 Loadings Iteference 13 does not describe how the moments were Both Systems I and 2 were test:d with an internal pres-measur:d. II.owever, in a letter from i1. Hwang (General sure of 1000 psi.
Electric Company) to E. C. llodabaugh dated November 14,1991 (available in the author's file), Hwang stated that Iteference 13 describes the various time-history inputs the measurement devices shown in Figure 17 were used in used in the system tests. From the standpoint of func-both Systems 1 and 2.To the extent that applied moments uonal capability, the highest input is of primary signifi-do not exceed the yield moment of the 6 NPS, Sch.160 cance for both systems; the highest input was associated pipe on which strain gages were mounted, the strair with " Time History B," with all sleds acting in unison, measurements can be used to calculate measured mo-ments (e.g., at Node 72 in Systein 1).
l 5.3 Comparisons witli Theoretical The yield strength of the Sch.160 pipe used in System 2, I
~ Limit Moments according to Table 6-1 of iteference 13, is 31.3 ksi. The
- yield moment of the load measurement device (Figure 17)
L
'In princi;-le, dynamic moments at any kication la a piping is then system ctmnot exceed the moment capacity at that loca-p tion. This aspect of dynamic loading tests is discussed in Afy = SyZ d 31.3x17.81 - 557 in.-kip Sections 3.2 and 4.2. Comparisons of test measured mo-ments with calculated moments are shown in Figures 1 Thus, the values of Aim from Table 6-11 greater than 557 and 8 through !I and Tables 3. 4, and 5.
in.-kip may reflect yiciding of the measurement device and not be an accurate indication of the measured mo-2 Ileference 13 gives measured and calculated moments at '
ment. It is this uncertainty that makes comparison with three hx.atics as shown below:
the limit moment of straight pipe questionable.
i 15 NUlt!!G-1367 l
i
'Ihe moments cited from Reference 13, according to the Ref.13 Sy, 2,
2% Damping 5% Damping letter from 11. Ilwang to E. C. Rodabaugh dated Novem.
Table ksi ins 5, ksi S/2Sy 5,ksi S/2Sy ber 14,1991, are resultant moments; that is, 5-5 43.8 4.29 8.50 2520 29 (16) 6-9 35.7 3.42 3.21 1162 16 826 12 Af - (Afx? + Afy? + Afz2)"2 e
6-11 35 0 1m 8.50 313 4.5 219
- 3..I
'the moment capacity of climws (Table 5-5) and nozzles (Tabic 6-9)are significantly dependent on the orientation -
l'or Table 5-5, a significant uncertainty existed concern-of the applied moments. It is this uncertainty that makes ing the actual wall thicknen of the short-radius elbow.
j i
comparisons with limit moments of cibows or nozzles This uncertainty goes back to the measured wall thick-J questionable.
nesses that were available for Component Test 13, which 1
indicated that the average actual wall thickness was 0.425 in, rather than the nominal wall thickness of 0.280 in.
Accordingly, no meaningful comparisons can be made flowever, in a actter from W. P. Chen (Energy Technol-i between Reference 13 measured moments and either ogy Engineering Center) to E. C. Rodabaugh dated limit load theory or tests or the component tests of Refer-December 19,1991 (available in the author's file), Chen ence 11 discussed herein in Section 4.
provided the measured wall thicknesses of cibows in Sys-tems 1 and 2. l'or the short-radius elbow at Node 72, the average wall thickness is 0.310 in., which is only 11 % more 5.4 Comparisons with Elastic Analysis than the nominal wall thickness.
Reference 13 gives the following calculated moments:
Table 5-5 of Reference 13 does not give a calculated moment for 5% damping. liowever, Table 2-1 in.the Executive Summary of Reference 13 gives INPUT X/
LEVEL D - 24.0 for 5% damping. The S/2Sy, shown h Aic, in.-ki 1
Ref.13 Sy, for Damp' p'of p rentheses, was obained using S/2Sy - 24x60/(2x43.8)
Table System Location ksi 2%
5
- 16.4.
1 5-5 1
Node 72, 43.8 4994 Table 6-9 of Reference 13 pertains to the evaluation of a 4
6 NPS short.
nozzle that, according to II. IIwang (General Electric radius elbow Company)in a letter to E. C. Rodabaugh dated Novem-ber 14,1991 (available in the author's file), was dimen-1 6-9 2
Node 6,12x4 35.7 1091 775 synally the same as that used for Component Test 20; see NPS nozzle I1gure 13 herem The calculation of B2 - 3.42,is dis-cussed herem m Section 4.3.3.2.
6-11 2
Node 52, 35.0 2658 1860 Table 6-11 of Reference 13 pertains to the evaluation of 6 NPS Sch.
straight pipe, with no complications. Staff ratios of S/2Sy l
40 p pc and Reference 13 ratios of S/3Sm are as follows:
Ref.13 S/2Sy S/35m Table 2%
5%
- 2%
5%
where Afc is the moment calculated by an clastic response spectrum analysis,15% peak broadening, damping of 2%
5~5
'9 16 4'
'4 or 5% as indicated. These values are taken from the indicated Reference 13 tables under the columns " Full 6-9 16 12 21 15 Sled-4 ARS" for System 1 and " FULL UNIF" for System 6-11 4.5 3.1 5.2 3.7
- 2. Sy i< the material yield wenyth according to Reference 13, Tables 5-1 and 6-1. For the 12x4 nozzle, Sy is for the 12 NPS pipe.
As its evaluations in Tables 6,7, and 8, it is apparent that the staff's evaluations are more conservative than those in Reference 13,largely because the staff incorporated the The staff evaluated these calculated moments in a man-material property, Sy, rather than using Sm - 20 ksi, ner analogous to that for Tables 2,6,7, and 8, that is, Even so, the staff's evaluations indicate that, for func-develop ratios of S/2Sy, where S - B Af/2 and Sy - yield tional capability, the present Code Equation (9) limit of 2
strength of the material.The results are summarized as 2Sy could be increased to 9Sy for 2% damping or to 6Sy 4
follows:
for 5% damping.
NUREG-1367 16
s 5.5 Weight Stresses swr, sr.
i 4
System Fig. Node Component Bg, ksi ksi s W r/sy Figures 18 and 19 show weight stresses, Swr, for Systems 1 and 2. Reference 13 gives no further information on 1
18 8
Vesselet 3 48 8.5 45.4 0.19 weight stresses. Ilowever, in a letter from 11. liwang 2
19 6
Nonle 3 61 10 35.7 0 28 (General Electric Company) to E. C, Rodabaugh dated November 14,1991 (available in the author's file), liwang provided the following information:
Thus, the staff concludes from the two piping system tests that weight stresses of up to about 0.25Sy in combination swr = B Afw/Z, or Bzi, Afwb/2, or B, Afar /Z with the high reversing dynamic loads such as those ap-(1) 2 2
plied in the tests will not impair the functional capability 2
f piping systems.
where B, B,, B r are Code indices 2 2f 2
resultant moment due to weight at 5.6 Pres, cure Stresses Afw
=
e elbows Systems 1 and 2 were tested with an internal pressure of i
Afwb = resultant moment due to weight on 1000 psi /The pressure stresses, PDo/2t. of particular rele-branch of tees and at Node 8, Sys.
vance are the following:
tem 1,and Node 6. System 2 System /
Sy.
Sp, moment due to weight on runs of Node ksi Dimensions ksi Sp/Sy Afar tees 1/72 43.8 6 NPS,0.280-in. wall 11.3 0.26 pipe section modulus 2/52 35.0 6 NPS,0.280-in. wall 11.3 0.32 l
Z
=
2/6 35.7 4 NPS,0.237-in. wall 8.99 0.25 (2) Afw, Afwb and Afwr were calculated by analyses of the piping systems with weight loading, including the weight of water in the systems-From the standpoint of pressure boundary integrity, using an internal pressure of 1000 psi was appropriate, al-though using a higher internal pressure would have been (3) Swr is in unus of ksi.
even more appropriate liowever, from the standpoint of functional capabihty, using zero internal pressure might have been more bounding; that is, the elbows in the sys-For the highest weight stress in each system:
tems would have had lesser moment capacity.
17 NUREG-1367
6 OTilER PlPING SYSTEM TESTS Piping systems, other than the two systems discusssed in Section 5, were tested using dynamic loadings. Table 9 direction. Plastic hinges developed at points 11 and C, but (Refs.14-20) identifies the tests the staff reviewed for there was no significant reduction in cross-sectional flow this report.
area.
Directional changes in the piping system were made by The major purpose of reviewing other piping system tests was to see if any of those tests might invalidate conclu.
cold-bending the pipe to a bend radius of 3 in. The B sions drawn from the evaluations in Sections 3,4, and 5.
index for the bends is 1.3h 2/3 = 1.3/1.1422/3 = 1.19.The 2
ratio of the in plane, closing, limit moment, using Equa.
The llanford Engineering Development laboratory tion (9). to the straight pipe limit moment with the same (llEDL) tests (Ref.14) are the most significant because large displacements occurred to the extent that functional Sy, using Equation (2), is 1.17. Thus, even ignoring the capability was threatened. The llEDL tests are described cold-bending effect on yield strength, the bends had only in Section 6.1. Except for the IIEDL tests, the other a little less moment capacity than the straight pipe. Cold-piping system tests, like the two system tests discussed in bending significantly increases the yield strength of an l
Section 5, did not result in any threat to functional capa-austenitic stainless steel material. Thus, the bends would be expected to be stronger than the straight pipe and, bility and, like most tests in Sections 3,4, and 5, provideindeed, the hinge at point 11 formed in the straight pipe.
lower bounds on combinations of steady-state (weight)
The significance of this lies in generalization of the "no and dynamic loadings that will not cause loss of functional significant loss in flow area " If, for examplc, ANSI 1116.9 capability, elt ows with a bend radius of 1.5 in. had been used in the For direct comparison with the tests discussed in SectionsllEDL system, and if the elbow material yield strength 3,4, and 5, it would be ideal to have clastic responsewere not greater than that of the pipe, the hinge at point spectrum analyses using 2% or 5% dampingand + /- 15%
11 might form in the elbow with incipient loss of flow area.
peak broadenmg. If the yield strength of the material at Reference 14 gives the results of an clastic response spec-the highest stress location were available, calculation of trum analysis using 10% damping, no peak broadening.
S/2Sy in direct analogy to those calculc ted in Sections 3,4, The response spectrum used is shown in Figure 5-1 of and 5 would be possible. Of the cited references (Refs.
Reference 14, that 14-20), none provide exactly what would be needed.
is, a response spectrum for a flowever, each of the references does proside clastic sinusoidalinput at 2112. Ihc highest stress in the system analvses, which are sufficient for the major purpose of was calculated to occur at the bend at point 11 in Figure
. At an input of 0.36g, thc highest stre.s was calculated dete'rmining if any of these tests invalidate conclusions to be 60 ksi. The yield strength of the pipe material is drawn from the eval"ations in Sections 3,4, and 5.
stated to be 40 ksi. For a maximum input of 2.8g, S/2Sy - 60x2.8/(0.36x2x40) = 5.83 10% damping 6.1 Hanford Engineering Development Laboratory Tests (Referenee 14)
An estimate of S/2Sy for 5% damping is needed. There are indications in Reference 14 that the system essentially The llEDL piping system has undergone namerous tests,responded as a single-degree-of freedom system to the starting in 1979 with design verification tests and continu-2-Hz sinsusoidal input. Then, the calculated st ress for 5%
ing to 1985 (see Table 1-1 of Reference 14). The tests ofdamping would be two times that for 10% damping, lead-ing to primary interest in this report are identified in Reference 14 as " modified four-support configuration" tests and are S/2Sy = 5.83x2 - 11.7 5% damping discussed below.
This S/2Sy, rounded off to 12, is shown in Table 9. Using
,The configuration is shown m. Figure 20a. The system was the hypothesis of single-degree.of freedom response, subjected to sinusoidal input at a frequency of 2112, with peak broadening is meaningless and the S/2Sy ratios for step increases of maximum acceleration levels up to 2.8g.
the first three entries in Table 9 are deemed to be reason-The 2-Hz input frequency coincides with the measured ably comparable.
first mode natural frequency of 2 IIz. The calculated first mode frequency is 2.14 Hz. The system was not pressur-Reference 14, Figure 5-2, indicates weight stresses did ized.
not exceed about 10 ksi. Sw/Sy < 0.25.Thus, the HEDL tests cannot be used to defend high reversing dynamic Figure 20b shows the displacement of point A as a func-loads in combination with steady-state stresses higher tion of input acceleration. At the end of the 2.8g test, than 0.25Sy. Ilowever, the IIEDL t ests obviously support point A was permanently displaced 18 in. in the positive Za 4Sy limit on Code Equation (9). Indeed, from only these tests, a limit of about 20Sy is defensible.
'9 suREo-1367
~~
S/2Sy - 21xbO!(2x45) = 14 5% damping,3 NPS 6.2 References 15-20 Tests system
'lhe piping system tests in References 15 through 20 did The yield strength of the A106-il material for the 6 NPS not result in any threat to functional capability. In the system, accordmg to Table 6-2 of Reference 17,is 54 ksi.
following sections the staff briefly describes how the
- Thus, S/2Sy ratios shown in Table 9 were de rived from the cited 5% damp ng,6 NPS i
references and what information on weight stresses can S/2Sy - 15x60l(2x54) - 8.3 be gleaned from the references.
system Reference 17 ind: cates the weight stresses are not more 6.2.1 Iteference 15 than 10 ksi; Sw/Sy was less than about 0.2.
I igure 4 of Reference 15 is a response spectrum for 2%
damping. It indicates that the maximum test input was 6.2,4 Iteference 18 about four times that required to produce a maximum Reference 18 gives the results of an clastic response spec-calculated stress of 2.4Sh. l'or the A106-il material,Sh -
Wm ana@ udng 2Wampng, + N gaha&n-15 ksi 2.4Sh = 36 ksi.The yield strength,Sy. of the pipe ing. 'the max, mum calculated S/3Sm was 2.5: 3Sm = 60 i
materialis not given. Using a typical Sy of 45 ksileads to ksi.The yield strength, Sy, of the austenitic stainless steel piping material is not given. Using a typical Sy of 35 ksi S/2Sy - 4x36/(2x45) = 1.6 2% damping leads to The effect of peak broadening is not discussed in Refer.
S/2Sy - 2.5x60!(2x35) = 2.1 2% damping' ence 15. W eight stresses are not given, but Sw/Sy was probably less than 0.1.
Weight stresses are not gis en, but Sw/Sy was probably less than 0.2.
6.2.2 Iteference 16 6.2.5 Iteference 19 Reference 16 states that the piping system without Reference 19 gives the results of clastic response spec-branhes withstood seismic inputs that were approxi-trum analyses using (probably) 3% damping, no peak mately four times the input required to produce a calcu.
broadening. Calculated stresses are summarized in Table lated stress equal to the i evel D stress limit f or Class 2 7 of Reference 19.The highest calculated stressis 25.5 ksi piping. It appears that the calculated stresses are from an at location "Q A100" for Test T41.21.2.This test is for the clastic resp (mse spectrum analysis using 3% damping "KWU support configuration" at an input excitation of and, probably, no peak broadening. Although Reference "300%SSl!." The maximum input was 800%SSil; thus, 16 does not give important details, it appears that this S(nom) - 25.5x8/3 - 68 ksi. Stresses in Reference 19 would translate to an S/2Sy between 2 and 4; a value of 3 is were calculated using M/Z, not B M/Z. location 2
shown in Table 9.This S/2Sy is very approximate.
"Q A100" is at an 8 NPS,0.535-in wall,12-in. bend radius elbow for which B = 2.42. Thus, S = B M/Z = 2.42x 2
2 Reference 16 does not give analogous information for the 6S - 165 ksi at 800%SSE input.The yield strength, Sy.of piping system with branches. Weight stresses are not the austemtic stainless steel pipe material is not given.
given, but Sw/Sy was probably lese than 0.1.
Using a typical Sy of 35 ksileads to It appears that for both systems, Reference 16 tests were S/2Sy = 165/(2x35) = 2.4 3% damIiinbi low-level tests relative to 1(cferences 13,14, and 17 tests.
Weight stresses are not given, but Sw/Sy was probably less than 0.2.
6.2.3 Ileference 17 Reference 17 gives the results of clastic response spec-6.2,6 Ileference 20 trum analyses using 5% damping, no peak broadening.
Reference 20 gives the results of a hnear ciastic time Table 2-1 of Reference 17 shows the followine history analysis using (probably) damping equivalent to
~
about 1% in a response spectrum analysis.
S/3Sm - 30/l.4 - 21 for 3 NPS system S/3Sm = 30/2.0 = 15 for 6 NPS system The calculated results are summarized in Reference 20 as uhere 3Sm = 60 ksi Mammum test input 1895 gal (l.93g)
Theyield strength.Sy, for the A106-11 pipe material is not given for the 3 NPS system. Using a typical Sy of 45 ksi Maximum allowable input for Code liquation (9) = 60 ksi 240 gal (0.24g) leads to NU Rl!G-1367 20
Figures 6 through 10 of Reference 24 indicate that the other weight stresses are given, but Sw/Sy probably did yield strength of the pipe material was atmut 25 kg/mm -
not exceed 0.2 at any location.
36 ksi. Thus, S/2Sy - (Is95/240)60/(2x36) - 6.6 6.3 Summary of Other Piping System Tests The S/2Sy of 6.6 in Table 9 is shown in parentheses be-cause a response spectrum analysis was not available, it Results of the other piping system tests do not invalidate may be that, on the basis of a response spectrum analysi,
the conclusions drawn from the evaluations in Sections 3, s
Reference 20 tests were low-level tests relative to Refer-4, and 5 of this report. In particular, the HliDL tests (Ref.
ences 13,14, and 17 tests.
- 14) support a limit of 4Sy on Code Equation (9). None of the other piping system tests provide a defense of steady-Reference 20 cites a weight stress of 0.1 kg/mm = 0.14 state stresses greater than about 0.25Sy when combined hsi, presumably at the location at which S is maximum. No with reversing dynamic stresses of 4Sy.
21 NUREG-1367
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7 OTHER DYNAMIC LOADS Dynamic loads applied in the tests discussed in Sections 3 The conclusions quoted from Reference 13 are the fol-through 6 were rapidly reversing in nature. The " rapidly" lowing:
is quantified as dominant reponses of 2 Ilz or more. Pro-7.3.4 Water llammer Test Conclusions vided the dominant response is not less than about 2 Ilz, these tests support, in regard to asssurance of functional in general solid water wave load, because of capability, an increase in the Code Equation (9) Level D quick load reversal, daes not cause pipe collapse, limit from 2Sy to 4Sy, with steady-state stresses up to even when the calculated moment exceeds the about 0.25Sy.
limit moment.
Strut failure due to water hammer can occur, but Other dynamic loads are the result of the following:
in the test the failure load exceeded 10 times of its rated load.
i o
fluid hammer Slug type loading of long duration (simulating static loads) can cause pipe " collapse."
- fluid pressure waves
- slug flow A fluid (e.g., steam or water) pressure wave load could be caused by closing of a valve or slamming of a check valve, o
relief-valve actuation Time-history analyses are used to evaluate such loads, and damping is not very significant. The staff agrees with
- steady-state forces the conclusion in Reference 13 that pressure wave loads are appropriately included with other rapidly reversing
- short-time effects dynamic loads.
o postulated pressure boundary breaks As indicated by the third conclusion in Reference 13, slug flow may produce collapse and thus constitutes a threat to vibrations (e.g., piping connected to a reciprocating functional capability. No increase in Code Equation (9) e pump) can be defended.
The question discussed in the following sections is: Can Slug flow is, of course, difficult to anticipate in the design the Code Equation (9) 1.evel D limit be increascJ when stage. Designs should include drains and vents, and oper-other dynamic loads are applied to piping systems, either ating procedures should be implemented so that the pos.
I alone or in combination with rapidly reversing dynamic sibility of slug flow is mmimued.
l loads?
7.2 Relief-Valve Actuation 7.1 Fluid Hanuner The steady-state thrust (e.g., acting for one or more sec.
onds)should be evaluated as equivalent to a weight stress.
A part of the EPRI, NRC, and General Electric Company pt ogram consisted of water-hammer tests.These tests are The time-variable effects would depend on whether there desenbed m Section 7, " Pipe System Water Hammer is any slug flow. Ilowever, whether there is slug flow or rests, of Reference 13.
not, the information is insufficient to defend any increase in Code Equation (9) level D limits for those portions of Five piping systems were tested; the tests were identified as Test 28, Test 29, MS-1, MS-2 Runs 1-5, and MX-2 in boiling-water reactors, relief-valve actuation may Runs 6 and 7. Water-hammer tests consisted of cause building vibration. The effect of this building-filtered vibration on piping systems is appropriately in.
cluded with other rapidly reversing dynamic loads, (1) piping systems filled with water, sudden pressure increase at one end of system:" solid water-hammer load
~
7.3 Postulated Pressure Boundary Breaks (2) piping systems partially filled with water, sudden pressure increase at one end of system: " slug-type A concern is whether the postulated pressure boundary loading" break might cause loss of functional capability of piping 23 N U REG-1367
i systems other than the system in which the break is postu-7,4 yjbrationS lated.
llecause the break effects will be "filtere :" at other pip.
Vibrations, such as those induced by attached equipment ing systems, the staff believes that the effects of postu.
or fluid flow, are difficult to anticipate in the design stage, lated breaks can be considered to be rapidly reversing for
'the staff believes that such vibrations are best evaluated the purpose of evaluating piping systems other than the during preoperational testing.
system in which a break is postulated.
NURIIG-1367 24
i 1
8
SUMMARY
AND LIMITATIONS The objective of this report is to examine present Code use 2% and up to 5% damping. 'lhus, the stafI s evalu.
rules and potential changes in Code rules to see if theyare ations are focused on 2% or 5% damping.
sufficient to ensure maintenance of functional capainlity.
Ilowever, it is within the state of the. art to more accu-Str esses calculated by using Code IIquation (9)lliquation ratcly eidculate the dynamic portion of Afi using an (l' Mrcin] are limited as indicated in Section 2.1 of this clastic plastic analysis. 'the approach used by the staff in rr t.
Sections 3.2,4.2, and 5.3, " Comparisons with' theoretical 1.imit Moments," was to look at Code liquation (9) with As indicated in Section 2.2 of this report, the staff believes the thought that Afi might be inore accurately calculated.
that for static loadings, meeting Code !!quation (9) with "Ihe staff concludes that, if Afi is accurately c:deulated.
l lxvel D limits does not adequately demonstrate func.
Code !!quation (9), with a 2Sy limit, is not conservative.
tional capability, llowever, as discussed in the previous sections of this report, the results of many dynamic tests If clastic plastic analyses of piping systems in nuc! car show that the functionality of piping Systems has been power plants become routine, the staff believes that, for maintained at equivalent stress levels significantly higher ensuring pipmg functionality, a revised set of guidelines than Ixvel D limits. 'the following sections summarize might be needed for NitC's acceptance of such analyses.
the findings and the limitations for ensuring piping func.
'lhus, its recommendations discussed herein apply only to tionality.
clastic response spectrum analyses.
8.1 ReVer$lilg DyllilllllC lAll(IS S/2Sy lleversing dynamic loads are those due to carthquakes and building. filtered loads such as those due to vibration 2% 1)amping 5% Damping Sw/Sy of buildings caused by relief valve actuation in boiling-Table Min. Max Avg.
M m.
M ax.
Avg.
Max.
water reactors.
2 0 62 5.5 3.5 0 25 2.2 1.4 0.15 The test data esaluated in Sections 3,4,5, and 6 of this 6
3.4 20 10 2.2 10 56 0 06 report are relevant to this type of dynamic loading.
7 9.1 24 13 5.2 15 7.4 0 32 i
H 7.2 16 11 4.3 84 64 Out A significant aspect of the test data is that, with one N/A' 4.5 29 16 31 12 7.6 0 211 exception discussed in Section 4.6, none of the tests re-sulted in loss of functional capability. 'thus, the staff's in the staff's judgment, the averages of S/2Sy are reason-evaluations are based on the premise that the test data able indicators of lower bounds on functional capability, provide lower bounds on combinations of steady state since functional capability was not lost in any tests other (e.g., weight) and dynamic hiadings that will not cause loss than Test 37 of iteference 11. Also, in Table 2 the values of functional capability, this lower bound premise may of S/25- < 1 do not mean that the pipe could not with-miroduce conservatisms in the staff's recommendations.
stand h ;er dynamic loads; rather, no attempt was made Ilut, as will become apparent in the following discussions' to apply higher dynamic loads.
l this premise leads to a significant relaxation of the pre-sent NitC position on functionality; that is, present Code
'lhus, the staff finds that the dynamic test results clearly l evel D limits ensure pipmg functionality,covided demonstrate that with certain Emitations discussed in steady. state stresses do not exceed 0.25Sy and the dy.
Sections 8.1.3, 8.1.5, and 8.1.7. Code IIquation (9) with a narme loadings are similar to t hose induced by earthquake stress limit of 2Sy, using 5% damping, provides assurance internal loadmgs.
that piping lunctional capability will be maintained.
8.1.1 Method of Calculating Mi in Code 8,1.3 Steady State Stresses Equation (9)
Weight stresses should be considered as design condi-
'lhe moment, Afi, ren vents both steady-state (c.p.,
tions. 'Ihe Code limit on liquation (9) for design veeight) loads and d)% ue loads. Values of Afi are ob-conditions is 1.5Sx, where St - Sm for Class 1 piping, tained by a'wlyses of rrping systems. In the past, the Sr - Sh for Class 2 piping. In the Imunding case in which l
dynamic p con of Ah has been obtained 1y an clastic
/* - 0, Sm - Sh - OSSy (austenitic steel at 650*lt), the response sp.ctrum analysis with 4 /-15% peak broaden-
.NrA. not apptwable; resuus were obtained trom scciion 5 of ms ing and as loir as 0.5% dampmg. The present trend is to report.
i 25 NUlti!G-1367 t
allowable moment due to weight using Equation (9), for Code Equation (9)lxtel D limits also ensures functional 1.5St - 1.35Sy, and for straight pipe (11, - 1.0), is capability.
Af = 1.35 ZSv
'Ihc staff's recommended limit on steady state stresses of O.25Sy is not dectned to be onerous if the steady. state Equation (2) gives stresses are due to weight. Typically, weight stresses do not exceed about 3 ksi. Some examples of the 0.25Sy limit are Aft - (4/n)2Sy - 1.27 ZSy 1hus,in this bounding case, the moment due to weight is Material Temp.,*l Sy, Lsi 0.25Sy, LSi about equal to the theoreticallimit moment.
A106-Il 100 35 8.75 At Ixvel D, the stress due to combinations of weight plus A106-Il 650 25.4 6.35 dynamic loads is limited to 2Sy. 'lhus, at 1.evel D, there is
'lype 304 100 30 7.5 a spectrum of allowable combinations ranging from
'lype 304 650 17.9 4.48-Sw - U.SJ = 2.USy, toSw - 1.35Sy, SJ - 0.65Sy, where Sw - weight stress Sd - dynamic stress.
However, if the steady-state stress is due to the steady.
I mit of 0.255[y might be restrictive.
sta t o a dekah Marge, Men tk naTs k The test evaluations clearly indicate that the combination of Sw - 0. Sd - 2.0Sy maintains functional capability.
8.1.4 Pressure Stresses Unfortunately, no tests are available that show that the combination of Sw - 1.35Sy, SJ - 0.65Sy maintains Code Equation (9) includes the term (see Equation (1) functional capabihty. That is, if a straight pipe were herein} /l l'Do/2i. Far most components P > 0, this term i
loaded to its limit load by weight and then subjected to a reduces the allowable combinations of Sw and Sd, dynamic stress of + /-Oh5Sy, would functional capability be maintained?
'the staff's test data evaluations did not indicate any ad-verse ef fect of P > 0 on functional capability, indeeJ, for in the absence of relevant test data, the stalf recommends elbows, P > 0 tenced to increase the moment capacity.
that steady state stresses be limited to 0.25Sy. Its judg-This aspect is partially recognited in the Code by ment is based mainly on Reference 11 Tests 30 and 37, in these tests, the combinations were 131 - -0.14 0.4h but not < 0 nor > 0.5 Thus,for elbows withh < 1/4, the pressure term becomes Test 30 S/2Sy - 5.2 (5% damping), Sw/Sy - 0.32, zero.Ilut forothercomponents,andcibowswithh > 1/4, no collapse the pressure term, P > 0, tends to add to the matgin for Test 37/4 S/2Sy - 2.8 (5% damping), Sw/Sy - 0.32, amance of fum tional capany.
no collapse llowever, there is a potential for external pressure to Test 37/5 5/2Sy - 5.5 (5% damping), Sw/Sy - 0.32, jeopardire functional capability. An external pressute collapse imght anse for pipmg inside the contamment when the containment is pressuriicd under accident conditions.
Ma s o/t limit (see Section 8.1.5) partially ad-Using Code Equation (9)I evel D limit of 2Sy.
dresses this concern. Ilowever, the staff's recommenda.
S/2Sy - (2-0.32)/2 - 0.84 tions include a restriction that external pressure must not exceed internal pressure, as a remm, der that this special condition might need to be considered.
Comparing th,s value with the corresponding value from i
- fest 37. Run 4, indicates that permitting Sw/Sy up to 0.25 8.1.5 Do/t Limit is adequate to ensure maintenance of functional capabil.
ity, The value of 0.25 was deliberately chosen to be a bit The available test data are mostly for components with less than that in Test 37-Do/r < 50, for example, 6 NpS, Sch.10, Do/t =
6.625/0.134 = 49.4.Three ficancy tests (Ref.10)were on A conceptually more direct method of controlling steady-straight pipe with Do/t - 103/1,5 - 69, but incipient state stresses might be t, introduce an Equation (9a),
buckling occurred in one of these three tests, which would directly, and independently of Code Equa.
tion (9), limit steady state stresses to 0.25Sy Ilowever.
Thus, the staff deems it prudent to limit its recommenda-the staff's present goal is to be able to say that meeting tions for functional capability evaluation to companents NUREG-1367 26
with Do/t < $0.'ihe Code also applies this limit to appli.
Using the Code !!quation (9)I cvel D limit of 4Sy, cability of B indices.
~
~
8.1.6 Future Changes in Il Indices
'lhe staff's recommendations are based on B-indices as Cornparing this allowable value (1.84) with Test 37, Itun given in the present Code (itef.1). Code committees
- 4. S/2Sy - 2.8, no collapse, indicates that permitting constantly review newly developed data relevant to stress Sw/Sy up to 0.25 is adequate to ensure maintenance of indices and, sometimes, tha,e reviews lead to reducing functional capability, even if the 1.evel D limit on Code the magnitude of stress indices. Ilowever, the Code com.
IIquation (9) is increased to 4Sy, mittees are interested in pressure txiundary integrity, not n ecessarily functional capability. 'l h us, it becomes incum-bent on the NitC staff to review any future Code changes
!Iowever, the boundary between static loading and dy-in B. indices from the standpoint of their effect on func.
namic loading is not well defined. Use of a Code liqua.
tional capability.
tion (9) limit of 4Sy can only be defended by the available test dats for rapidly reversing dynamic loads.1 or Compo.
8.1.7 Future Changes to Code Equation (9) nent Test 37, d:scussed in section 4.6, and the t il!DI. test, Stress Lirnits discussed in section 6.1, the dominant response frequen-cies were atx)ut 2 lle, lloth of these tests resulted in an Code committees have been reviewing from the stand.
incipient threat to functional capability,'thus, the staff point of pressure boundary integrity the same sets of test believes that it is prudent to restrict a Code liquation (9) data reviewed in this report from the standpoint of func*
limit of 4Sy to piping systerns for which the clastic re.
tional capability. It is possible that the Code liquation (9) spinse spectrum analysis indicates thal the resp mse f.evel D limit of 2Sy might be mercased to 4Sy.
stress contribution at 2 Ili and less is not more than Sy.
It would be highly desirable that,if the i.evel D limit were increased to 4Sy, it could be demonstrated that meeting the Code would also ensure functional capability.
8,2 Ollier Dytiattiic leads As stated in Section 8.1.3, Section 7 contains a brief discussion of other dynamic Test 30 S/2Sy - 5.2 (5% damping), Sw/Sy - 0.32, loads.The staff concludes that it is appropriate to include no collapse fluid hammer pressure wave h> ads in the category of re.
Test 37/4 S/2Sy - 2.8 ($% damping). Sw/Sy = 0.32, versing dynamic loads 'lhose dynamic huds that are not no collapse cleady in the category of reversing dynam e loads, and combmations of reversing with nonteversmg dynamic Test 37/5 S/2Sy - 5.5 (5% damping). Sw/Sy - 0.32, leads, will require special consideration. Some sugges.
collapse tions are included in Section 7.
27 NUltliG-1367 l
i 1
1 i
1 9 CONCI,USIONS l
9.1 Functional Capability Assurance, 9.2 Functional Capability Assurance, l
Present Cmle Requirements Future Code Requircinents
'lhe staff concludes that piping functional capability is Until such time as Code changes are made, the staff can i
ensured by meeting the present Code (Ref.1) require.
make no specific conclusions concerning such changes.
1 ments, provided If the Code !!quation (9) l. cycl D limit is increased to, for example,4Sy, the staff concludes that in addition to re-I (1) Dynamic hiads are reversing 'this includes loads due strictions (1) through (5)in the previous section, nn addi-to carthquakes, building filtered loads such as those tional restriction would be needed; that is, the clastic i
due to vibration of buildings caused by relief valve response spectrum analysis must show that the response i
actuation in boiling water reactorr., and pressure stress contribution at 2 llz and less is not more than Sy.
l wave loads (not slug ilow fluid hammer).
(See Section 8.1.7.)
l (2) Dynamic moments are calculated using an clastic l
response spectrum analysts with + /-15% peak Any changes in B indices.in the present Code should be i
broadening and with not more than 5% damping.
reviewed to determine whether such changes would ad.
versely affect the assurance of functional capability.
l (3) Steady + tate (e.g., weight) stresses do not exceed J
0.25$y.
With the use of a limit greater than 2Sy, increased vigi-lance would be needed to provide assurance that such (4) Do/I does not exceed 50.
components as piping supports, anchors, restraints, (5) !!xternal pressure does not exceed internal pressure.
guides, and anchors have sufficient load capacity.
y 4
29 NUREG-1367 -
10 ItEFEltENCES 1.
Amenean Society of hicchanical lingineers, lloiter llerkeley, Gloucestershire, Un ted Kingdom. April and Pressure Vessel Code, Section 111, Division 1, 1988.
" Nuclear Power Plant Com;mnents," New York, 11 General lilectric Company, Nuclear linergy lingi-1959 lidation.
necting Division,"Pipmg and I. ting Dynamic itch-u 2.
United States of America Standard 113 1.1-1 % 7, abihty Program," Volume 2 " Component Test ite-
" USA Standard Code for Pressure Power Piping" port," liPiti Contract 11P 1543-15 Draf t, San Jose.
American Society of hicchanical lingineers, New Cahfornia December 1989.
Y"'
- 12. J. Spence and G.11. Findlay,"1.imit inads for Pipe 3.
U.S. Nuclear llegulatory Commission, NUlll!G/
llends Under in. Plane llendmg," Paper No.1-28, Cibt)261,"livaluation of the Plastic Characteristics l'incedings of the 2nd hdcrnational Conferrnre on of Piping Productsin Itelation to AShill Code Crite-l'rcssure l'essel Technology, American Society of hic-ria " Itodabaugh and hioore, J uly 1978.
chanical I!ngineers, New York, October 1973.
4.
, NUltliG-OS00. " Standard Iteview Plan for the
- 13. General lilectric Company, Nuclear I!nergy lingi lleview of Safety Analysis lleports for Nuclear neering Division," Piping and Pittmg Dynamic 1(eli-Power Plants," Section 3.9.3,"AShili Code Class 1, ability Program " Volume 3," System Test lleport,"
2, and 3 Components. Component Suplurts, and Draft, San Jose, California, February 1990.
Core Support Structures," llev.1, July 1981.
- 14. llanford lingineering Development laboratory, 5.
General filectric Company, Nuclear linergy lingi, "lligh.txvelDynamie;l'estingand AnalyticalCorre-neering Division, " Functional Capability Criteria lations for a One-Inch Diameter Piping System,"
for Iksential hiark 11 Piping," N!!DO-21985. San ht, it 1 indquist, hi J. Anderson, L K. Severud, and Jose, Cahfornia, September 1978, ii. G. Weine r, lil!DI.-Thill 85-24, Itichland, Wash-ington, i ebruary 1986.
6.
U.
h..
Nuclear llegulatory Commission, 15.
G. li, lloward,11. A. Johnson, W.11. Walton,11. T.
Null!!G-1061,"Iteport of the U.S. Nuclear llegu.
latory Commission Piping lleview Committee" (5 Tang, and Y K. Tang, " Piping thtreme Dynamic Volumes). Volume 2, "livaluation of Seismic De.
llesponse Studies /' Proctrdmg5 of the 7th Structuru/
Afechanics in Reactor Trr hnology Con /ctrncc. Vol. F, signs-A lleview of Seisuiic Design llequirements for Nuclear Power Plant Piping," April 1985.
August 1983.
16.
U. S. Nuclear llegulatory Commission, NUlti!G/
7, ii. ht. lleaney,"Itesponse of Tubes to Seismic l oad.
Cib3843, "I ahoratory Studies: Dynamic itesponse ing " TPitD/il/0605/N85, Central lilectricity Gen.
of Prototypical Piping Systems," ANCO !!ngineers, crating floard, lierkeley Nuclear Iahoratories, lierkeley, Gloucestershire, United Kin;; dom, Janu.
Inc., August 1984.
ary 1985.
17.
, NUltliG/Cib5023 "lligh-l evel Seismic lle-8.
-, Itesponse of Pipes to Seismic lixeitation-lif.
Sponse and 1 ailure Prediction hiethods for Pipmg,"
Westinghouse llanford Co., January 1988, fect of Pipe Diameter / Wall 'lhickness llatio and hiaterial Propeities," TPilD/ll/0637/N85, Central
- 18. 11. Charalambus,11. llaas, and 11. hiihatsch, "Com-lilectricity Generating floard, llerkeley Nuclear parisons of Dynamic Test Data with llesults of Vari-laboratories, llerkeley, Gloucestershire, United ous Analytical hiethods," Nucicar Engmecting and Kingdom, J uly 1985.
Design, Vol. 96, pp. 447-462,1986.
9
, Itesponse of Pressurized StraigLt Pipe to Seis-19 U. S. Nuclear llegulatory Commission, NUlti:G/
mie lixeitation," TPitD/ll/0826/it86 Central lilee-Cib5757," Verification of Piping itesponse Calcu-tricity Ge nerating lloard, llerkeley Nuclear I ahora-lation of Sh1 ACS Code with Data from SeismicTest-tories, llerkeley, Gloucestershire, United Kingdom, ingof an in Plant PipingSystem," Argonne National February 1986.
I aboratory, September 1991.
"ltesponse of Stainless Steel Pipes to Seismic 20.
, NUltliG/ Cit-5585,"The liigh I evel Vibration 10.
l ixeita t ion," TPlt D/ll / 1051/ It 85, Cen t ral lilect rici ty
'lest Program," linmkhaven National laboratory, Generating thiard, llerkeley Nuclear I ahoratories, hiay 1991.
31 N U11IiG-1367
i i
Load Y/////A t////f/1-Frome l
Displacement
~
Transducer o
o Servo
~Volve
~
3 L 2 Actuator
=
~~~
Actuator
~~~
w Straight Pipe Piston h
w 50-mm l
Pivot M oj L?] 1 Travel Pivoted Strain i
Link
/
Gouge f
,0
/
1 u synyrrrrr f
/vrrrrnmnru 4
i
/
4
/
A l
'/
Pivot Test Pipe Accelerometer Light Spring c
L r
Figure 1 Test arrangement Source: References 7, 8, 9. and 10.
2C 3
d
.LM u
i t
i 1/2% 1%
2%
5%
I b
97 1
}
22 f
/
i
. 20
{
I 4
-A ja 4
4 1
i h
1 16 3
h O
.-]
14 g.."*.......".....*c*......
,.r 2
a p'..**
....'O.........
. O * * * * '",,,
y L-9'5 i
12 9.._
~93 =j
,e.s*~'.*
l 4
10
,I I
/
r l
/
I 8 4
/
4
/'
Pipo Symbol i
gt 7
i 6-I I
1
+
21.3 (f
2
- +O-15.6 I
4 3
l I
16.9
^
4
.-.e.-.
11.5
(' l
,p 5
18.8 2
[- damping factor J
I I
'I 0
0 1
2 3
input Acceleraton, p Figure 2 Response versus input acceleration Source: Reference 8.
NUlWG-1367 34
4 4
I l
2
'I
~
Input Acceleration, p f
1
.\\,'
I i
a 0
i
-.i 1
,s a
2 f-a s,'" g=
Most Positive Strain l
..t s
\\
6 -+
'*N N*N
-e N
Negative Strain
-e "N
"N Figure 3 Strain at pipe midspan versus input acceleration Source: Reference 7.
35 NUREG-1367
. -. -. ~ _ _ -.. - -.. -..
-.=_
l l
l E
E E
30 12 Deformed $hore 10 20 x=- Straln Gage
-6 Result 10 4
Strain
'3 i-4 0
$00 400 300 700 100 0
100
.200 300 400 klo Distance from Center une of Tube, mm Figure 4 Deformed shape and permanent strain after tests Source: Reference 7, NURiiG-1367 36
. ~.....
Input Acceleration 0
1 2
3
- ( q
D.,
-=-vg q. - - -v- - - -7 5 z
N
\\
'~'%3 x'-
- g _.
-02
'+\\
\\g
- k.,
-1
.\\-
- 0. t
....,(\\
4
'C OI
-06
\\\\'""'"*..........,,,,,.............,2
-10
.{ - 1 2 3
\\
Central Offset Pipe Gage Gage Sw/Sy
-16 0.076
.\\
1
- o ---
\\'\\
2 x-0.11
-18 3
-o-
-A-0.11
\\,4 4
- + - -
0.15
(
5
- -.w - -
0.13 4 0 l
0 Figure 5 Mean strain versus input acceleration Source: Reference 8.
1 l
37 NUlWG-1367
1 i
i i
i l
1
.i
-s w
2..
.g i
-o 150 125 too n
so as o
as so 75 300 its iso
[ Distance from Center of Span Figure 6 Deformed shape of upper surface of 103-mm pipe, Test 16 Source: Reference 10.
l l
l l
- NUREG-1367' 38 m u e
--+-e m rmr e--
s~.s
,we r
,,,r-~~.,
wry-
+
-e
-y r w,
.,i--y,..ywe,w,.w.,vmve-,we,,w.y-e.p,--,e-e.c+--
--,v,.v--.r-
,4-w
,--am.
y. v 9
y er.
.. ~. -.. - - _.. - - -..... -..
1 1
l l
jWeight o
D l
-o
-f-o-
\\
h 3N Inertia Arm
- 48in, i
l
[
i 2.1 m
i f l
1 I
I v
v Test Specimen Elbow o o o Test 4
D'-~
Fixture N U
l- -
o o
h 8
i l o
o 11 % in, g j.
o o o 21 % in.
7
, 9 10 in.
NRC Sled \\
"i"
^.~f,4 i [,. i i,^.^, f
.I f m I" I t
^r
^
..:l.
4 in.
h 9 in.
Direction 1*t:b *c2 E
I-b__
a
.A-A.
H of Motlon A
Clamp Figure 7 in-plane elbow test arrangements, Tests 1, 3-8,13,19, and 31 Source: Reference 11, 39 NUREG-1367
250 200 e 10
'II
- 9 d 150 f
e0 b2 Mt - 148 in. kip y
$100 N
O 2
All Data Points:
50 Simulated Earthquake input; Run Numbers Are Shown.
I I
I i
i 1
O 0
500 1000 1500 2000 2500 3000 Calculated Moment, in. kip,2% Damping Figure 8 4 NPS, Sch. 40 stainless steel pipe, Test 15 Source: Reference 11.
t NUREG-1367 40
. =
l e 12 600 -
o7
)
e 11 500 i
e 10
- g Mt - 490 in. kip 400
.94
.E
$j 300 p
O Sinesweep input e Simulated Earthquako input E2 Run Numbers Are Shown.
200 -O 5 e8 100 I
I I
I I
1 0
1000 2000 3000 4000 5000 6000 Calculated Moment, in. kip,2% Dampin0 Figure 9 6 NPS, Sch. 40 carbon steel pipe, Test 34 Source: Reference 11, 41 NUl(I!G-1367
pg All Data Points:
Simulated Earthquake input; Run Numbers Are Shown.
11 e
5 150 e 10 E
e0 e8 7
$ 100 e7 E2 e6 ML = 523 in kip 50
/
o5 0
i i
i 1
0 250 500 750 1000 Calculated Momont, In.-kip,2% Damping Figure 10 6 NPS, 9-in. bend radius, Sch.10 stainless steel cibow, Test 3 Source: Reference 11.
NUltliG-1367 42
Mt = 380 in. kip Average Wall Thickness 400
[
e8 e9
.o
?
.d 300 M = 109 in. kip t
u Nominal Wall Thickness S 200 e5 g
2 100 All Data Points:
Simulated Earthquake input; Run Numbers Are Shown.
Ui -
I I
I I
I O
500 1000 1600 2000 2500 Calculated Moment, in, kip,2% Damping Note:
This elbow had a measured average wall thickness of 1.52 times nominal wall thickness.
Ca?0ulated moments are based on nominal wall thickness.
Figure 11 6 NPS, 6-in, bond radius, Sch. 40 carbon steel elbow, Test 13 Source: Reference 11, i
43 NURiiG-1367
1.0 0 95 3
Ts o
05
-o
,3 0.00 19,35 41) a
,,v 0.05 6
6
[
p*
amo e 11 I = 0425 0.50 A 6 0AS O 6 M = 08h00 p2' Sy. P = 0 0.40 3
&g 0.35 O
O 0.30 -li 37 Reference 3 Static Tests
[
(see Table 5) 0 25 6 P=0 o P>0 0.20 Reference 3 Dynamic Tests (see Table 5)
Q 24 (4) and 24 (5), P>0 Reference 11 Dynamic Tests 0.15 (see Table 4)
W P=0 o
P>0 P = internal pressure l
0.10 l
l I
l l
l l
l l
l l
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 2
h = tR/r Note: Number next to symbolis test number, Figure 12 Elbows: Static in-plano closing moment capacity and dynamic in-plane moment capacity tests Source: References 3 and 11.
NUltlIG-1367 44
1 I
Cap a
Detail A W
/
/<*
C 8
M 1
12 NPS 4
a Detail A Nominal Dimensions
- -0.375-in. Wall 4
4 in.
=
12.75 in.
Outer Diameter Probablo 0.531 in.
F I
/ lh Failure Location y
I
/,
, y m
l
{-/
n a
w r-(" X e
0.237 in.
4 15' 4.5in.
Outer Diameter Figure 13 Test 20 configuration: 4 NPS nozzle in 12 NPS vessel Source: Reference 11.
45 NUltliG-1367
.__m...
a I
J l
o D+ o -
l
-o x
n A
l Inertia Arm %
48in.
1 9
I J
^
n If
,~
I j
W W
inertia Arm %
ExtenMon 36in.
i g
q n
n ip I
1 I
I I
n W
W Test Specimen i
- 27In, 8
o o
q o
o h
8 o
o i l 11 % in. ig +h...
0o o g
n 21 % in. -
i i
i yi g
NRC Sled
.L e r,, -.
im n
N y. n.t, r _
.. r...,,,i r
4 tri, 6 9 in.
Direction 4
1,5
..- T o
e, uotion=
u G4af o
Clamp Figure 14 Test arrangement, Tests 30 and 37 Source: Reference 11.
NURl!G-1367 46
Hangoc Fq.co 6266 Sin 6 s4 Grreen or EquiveWc Sied 3 D
Support to Top of 5,
g.
Pipe or tMttom of Prpe s*
.O 6 an I d406% \\
Y#e 56
\\sl EL= 1823 ft 41/2 m gy p 62 gS
\\ 58 26' 5,
~6m6x3 3
g g
6 in_
s,N p.4 ife L
28 6x6=6 r24 8"
18 in.
5 sC 4
34
/
6 in.
EL-1817 ft 7-1/2 n 663*64 9 I 3h PIPE 8^
30 18 x 6 Vesselet 88 6
(50 lbs g*
ggy g, 32 6m6 N
22 Y
g i18 N
Q r(150lbl (
74
~
1200 m) i i
3 i
72 76 Sled 4 3
45 n (18 1 m h 30 D
78 6n g g
12,16 80 6n%
g'30 en 82 14' 8.,
36 Ja n M h 160
- 38) [,4o; 2m m g
4 I'B in,
\\
2 1150 lba 6n (50lbl 46 9*-
- 2.O'6 y
Y 44
,(
48 Sled 2 50 27 h
\\
eN 2
Sin. Sch. 40
[
2 h 12 n g gg z/Nx y
'/
18 n s
f g
e Sted 1 x
j/
(
6-in. Sch. 40 input Note: Valves 18,38, and 66 ere simulated,by lump weight.
valve 86 is a motorwerated valve.
2c Figure 15 Piping System 1 configuration [ material carbon steel (A106-B)]
E Source: Reference 13.
?c.
~ _ - _
't 8
i Y
h z
x I
W8x15 (or 1
i 6.625-in. Sch.100 Pipe, or W8x21) 36 160 lb
- p 400 lb 34 4
38 3
46 31 48Y
'I 42in.
O N
5 21 LED 3 o
- 6 6.376 n ED 4 6.
6-in. PIPE 8*
4 2
Sch. 40 Q
0 go 22 e ti"J'
/
SLtD 1 1'
2Bf ED 2 Residual Heat Removal Near Containment Note: Valves 42 and 14 are simulated by weight.
Figure 16 Piping System 2 configuration (material: stainless steel (Type 316))
Source: Reference 13.
NUR110-1367 48
Attach to Sled 6-in. Sch.100 Outer Diameter of Hub 6-in. 900 Class Shpon Flange G in. Sch. 40 6 in, t
^
0.718 in. h 0.260 SG1,2,3 Q SG13,14,15 y
p (SG1 in Axlal) (SG13 in Axial) 3 h
i 1:3 Slope h
SG4 SG16 L
SG6 SG18 SGS SG17
)
~
Detail A Y
j Connection to Sled Designed by Others I, Rosette I
. Uniaxial i
SG1 Through SG6 SG13 Through SG18 (6 Channels Each Place)
AA Typical for Two Places Note: SG - strain gauge Figure 17 Load measurement device at Sleds 2 and 4 Source: Reference 13.
49 NUREO-1367
-..._. _..- - _.. ~
-__..--__-..--.~._..m_-m.-..
_.m. m
..-_~_.___._m.
5 l
Z Swr = 3 8 h
S
= M6 r Ox = 52 b
f Dy = 8.8 i
Q Swy = 3.4 8
- 'S Sb- = 1.33 Dy = 8 4 4 l
3 l
7 54 8
= 22 SWT
- 3 T C
S
= 125 J
.b R
= 21
[
?
L I
62 58-2 SWT
- I 7 4
SWT
- 21 S
= 243 3
= 2?3 Swr *2.7 a
- 4o 1
Sb 60 g
= 3s s
- 244 b
26 4l 94 R
= 41 SWt = 2.4 S
= 153 3
M
" 26 SWT * ' '
il S
= 108 24 i
3 SWT=3.3 g
,,g 2
g S
= 104 30 1i b
i R
= t.8 SWT = 3 6
)
32 S
286
=
3 t80 g
4.g l
1 1I
. S w y = 2.3 87 34 g,
f(
4 S
= 395 m
b SWT
- 8 5 R. e 6,5 gg pg 3
D b
Swy = 1.3 gg A
3 50
=
4 S
= 108 b
R
=ts
{
SLED 4 34 2
Swr = 2.5 9
{
S
= t12 3
R
=20 tt i
8 hi-b ti h y SLED 1 f
l~
Syg = vveight stress Sb = bending stress due to g ARS (plastic, assumed sled capacity)
,l R = SWm z
3 I
Indicates the High-Stress Locations 1 i 6
t.
d 44 Swy = 3 4 1
S
= 276 2
l l
3 n
=46 SLED 2 l
j' Figure 18 Piping System 1, weight stresses, Sg Source: Reference 13.
i f
l l.
j i
(1) Input 25 times safe shutdown earthquake TH-B 35% ARS unbroadened Swy=25 g.
S
= 710 49 h y (2) High-weight stress system b
U (3) fn = 4.1(x1, 5.3(zi, 6.OlY), 6.T(Z), 8.31 )
2 X
SWT = 5 6 32 S
- I '%
O b
s
~"
R
= 21 9
b R
=04 D, = 2 = 2 6 38 WT
=120016 D = 2 = 2.8 OYN =5310lb g Swy = 6 8 y
6 in, g.g = i e D. = 2 3 r S
= T22 3
b
}
30 b
.0 j Sw = 2 9 g
y
=
S
" 148 b
n 82 = 2 02
' 50 R
= 2.5 han - 6 5 48 o
S
" I38 2
I 24 b
R
=23 2
6 m.
SWT = 5 6 SWT " O S
= 34 b
M = 1350 (en Ap)
S
= 757 26 b
.g = 0 8 l
y = 1o90,
303
[
"M b
te f-gg
=6 SWT = 3.3
/Al7 A" = 4 6 "D
b l
S w y = 1.3
- : "'S
{
Sur = =
Sb = Bending stress. B M/Z, at ETEC sled capacity 2
20 b
m D", = 2 1.5 S 'T = weight stress R
=
W n_p = 2 1.4 R = S /3Sm g2 " 3 42 b
D, = 2 4.9 6-in. SCH 40 elbow MUM = 232 in.-kip 8
C2 = 6 84 4-in. SCH 40 elbow MUM = 102 in.-kip g
5o 4-in. x 6-in. tee MUM = 96 in.-kip N
I Swr = 0.3
[
$6. f, gyr g1 /$m.-M T
- 724 (N
/
mg R
= 2.s z
E Figure 19 Piping System 2, weight stresses, SWT Source: Reference 13.
.L w
i i
i i
j 1
i i
s.
)
,24 "
j Rigid Strut i
O Snubber W
i p
18" 1.315" 0.0., 0.133" Wall y
Stainless Steel Pipe 3
A T1ni -
0'
,33" 43"
)
2" I
40" \\
[
d jim h
(
24"
'h 2
BY h
la) 1 in.-Diameter Pipe loop, Modified Four Support Configuration 4
i 20 l
i I
I I
+
i i
I A
,,C N
1 e 15 5.
j p
a i
10-6 5
i 0
l-1 I
I l
.5 1.0
.1.5
- 2.0 2.5 3.0 -
Sinusoidal Strongback Input Acceleration (G) (ACCEL E1M1)-
i HEDL 8511441.3 t
g,
.(b) High-Level'Sinusoidal Test, Permanent Displacement at Upper Elbow n
i -
Figure 20 Hanford Engineering Development Laboratory piping system Source: Reference 14.
NUREG-1367 52
_-. a, _2.
c.....,_._.
..u
.. a.-...
~. -. _. _ _
l l
Table I fleaney (Refs. 7 H,9, and 10) Straight Pipe Tests: Materials, Yield Strengths, I
Dimensions, Sinusoidal input Test l'requencies, Pressures, and Test Planes Pipe b
Sy, Do, t,
I, f,
P, Test Ref.
Test Mil.
MN/m2 mm mm mm 11 MN/m2 Plane (a)
(b)
(c)
(d)
(e)
(f)
(g)
(h)
(i) 1 7
(j)
CS 209 25.4 2.64 3530 5
0.(X)
V 1
8 1
CS 298 25.4 0.91 3739 5
0.00 V
2 CS 219 25.4 2.64 3617 5
0.00 V
i 3
CS 248 25.4 6.35 3386 5
0.00 V
4 CS 161 34.1 4.06 4165 5
0.00 V
5 CS 223 51.8 4.47 5664 5
0.00 V
9 1
CS 162 34.14 4.06 4166 5
29.2 V
2 CS 162 34.14 4.06 4166 5
29.2 V
j 3
CS 162 34.14 4.06 4166 5
29.2 V
4 CS
-298 25.4 0.91 3734 5
14.3 V
i 5
CS 162 34.14 4.06 2946 9
29.2 V
6 CS 298 25.4 0.91 2642 9
14.3 V
7 CS 298 25.4 0.91 2642 9
14.3 V
8 CS 162 34.14 4.06 2946 9
29.2 V
i 10 1
CS 162 34.1 4.06 2946 9.7 0.00 11 2
CS 162 34.1 4.06 2946 9.4 29.5 11 3
CS 162 34.1 4.06 4166 4.8 0.00 1I 4
CS 162 34.1 4.06 4166 4.7 29.5 Ii 5
CS 195 25.4 2.64 3556 4.8 0.00 11 i
6 CS 195 25.4 2.64 3556 4.6 31.0 li 1
7 SS 247 25.4 2.64 3556 4.7 0.00 11 j
8 SS 247 25.4 2.64 3556 4.6 38.2 11 9
SS 247 25.4 2.64 2891 6.7 38.2 11 10 SS 247 25.4 2.64 2946 6.5 57.4 11 11 SS 261 78 1.5 6121 5.2 0.00 11 a
12 SS 261 78 1.5 3988 7.5 0.00 11 13 SS 261 78 1.5 3988 7.5 10.3 11 3
14 SS 335 103 1.5 6039 7.3 0.00 V
15 SS 335 103 1.5 5490 5.1 0.00 V
16 SS 335 103 1.5 5490 5.0 7.2 V
(a) Test identification according to references.
(b) CS = carbon steel; SS = Type 316 stainless steel.
.(c) Sy = yield strength of pipe material (from references).
(d) Do pipe outside diameter.
4 (c) t - pipe wall thickness.
(f)
L = pipe span length.
(g) / = sinusoidalinput test frequency.
4 (h) P = internal pressure in pipe while being tested.
(i)
V = dynamic loading in vertical plane;11 = dynamic huding in horizontal plane.
(j)
Straight pipe test of Reference 7.
4 53
' NUlWG-1367
. - - - -. ~ - _ -. - - -
_. - _ ~~..-..-.- - -.
4-i i
j i
Table 2 licancy (Refs. 7, H,9, and 10) Stralght Pipe Test Results Ev luated in Relation to Elastic Analpis,2%. or 5% Damping S/2Sy a
f.
Sr GI C = 0.02
( = 0.05 Sr/Sy Sp/Sy i
Ref.
Test II M/gr gm/
j (a)
(b)
(c)
(d)
(e)
(0 (0
(g)
(h) 7 (i) 5 178.4 4.2 30.3 5.19 2.08 0.11 0.00 i
i 8
1 5
67.5 3.6 43.2 2.78 1.11 0.076 0.00-2 5
170.0 3.5 31.8 3.93 1.57 0.11 0.00 3
5 299.9 3.0 36.0 3.40 1.36 0.11 0.00
)
4 5
455.4 2.7 23.4 4.18 1.67 0.15 0.00 j
5 1057 2.7 32.3 2.48 0.99 0.13 0.00 J
9 1
5 456.9 1.8 23.5 2.77 1.11 0.15 0.67 l
2 5
456.9 (j) 23.5 0.15 0.67 3
5 456.9 3.6 23.5 5.$4 2.22 0,15 0.67 1
4 5-67.7 0.8 43.2 0.62 0.25 0.076 0.65 j
9 282.0 5.0 -
23.5 4.75 1.90 0.076 0.67 6
9 41.7 2.1 43.2 1.00 0.40 0.038 0.65 4
)
7 9
41.7 2.6 43.2 1.24 0.50 0.038
- 0.65 8
9 282.0 4.8 23.5 4.56 1.82 0.076 0.67 4
10 1
, 9.7 241.8 5.7 23.5 4.66 1.86 0.076 0.00 2
9.4 257.5 5.3 23.5 4.61 1.84 0.076 0.67 3
4.8 493.9 2.8 23.5 4.67 1.87 0.153 0.00 4
4.7 515.1 2.6 23.5 4.52 1.81 0.153 0.67 4
5 4.8 190.8 3.3 28.3 4.67 1.87 0.121 0.00 6
4.6 207.7 2.7 28.3 4.16 1.67 0.121 0.69 7
4.7 199.0 2.8 35.8 3.27-1.31 0.095 0.00 i
8 4.6 207.7 14 35.8 1.70 0.68 0.095 0.67 9
6.7 14 8.2 4.4 35.8 3.82 1.53 0.063 0.67 i
10 6.5
. 151.6 5.5 35.8 4.89 1.95 0.065 1.00 i
11 5.2 1168 3.7 37.9 3.46 1.38 0.073 0.00 i
12 7.5 1323 3.6 37.9 3.81 1.52 0.080(k) 0.00 i
13 7.5 1323 2.3 37.9 2.43 0.97 0.080(k) 1.01 14 7.3 1422 5.3 48.6 2.66 1.06 0.042 0.00 l-15 5.1 3526 2.3 48.6 2.86 1.14 0.107(k) 0.00 16 5.0 3669 1.9 48.6 2.46 0.98 0.107(k) 0.73 i
4 4
1 i
I NUREG-1367 54
Table 2 (Continued)
Tule Notes:
(a) Test identification according to references.
(b) / - sinusoidalinput test frequency.
(c) M/gr = 386 Ell (4f2 Lt) where M = moment at center of pipe span, in.-lb gr = response acceleration E = modulus of elasticity,30,000 ksi used I = section modulus of pipe cross section, in, f = sinusoidalinput test frequency,117.
L = pipe span length,in, t
(d) gmi - maximum input acceleration during each test (from figures in the references).
l (c) Sy = yield strength of pipe material (from references).
(f)
S = (MI r)Kmi (2CZ) l g
where ( = damping factor. 0.02 or 0.05 2 = section modulus of pipe cross section, in.
(g) Sw = stress nt center of pipe span due to weight.
(h) Sp = stress due to internal pressure = PD/(21) where P = internal pressure D = pipe mean diameter - Do - t t = pipe wall thickness (See Table 1 for values of P,- Do, and t.)
(i)
Straight pipe test of iteference 7.
(j)
No sms given in Iteference 9 for Test 2.
(k) In 1(cference 10. Tests 12,13,15, and 16, the pipe was filled with water.
L l
L
}
55
- NUlti!G-1367 iiw-q y' v
>-T" TMwePw"wr'-XW'W+Ms?-'
-TF*'"ef'*--"'1*
FP""W'V 4""'k' T-
- M'W-1-'-**.W-1**T'-"1
' ' -WP- * " "'
F
'T' Y'9*-'
.. - ~
3 -
i t
1 j
Table 3 Reference 11 Pipe Tests: 1Jmit Moments and Measured Moments i
Pipe Test Run Sy, PD, No.
No.
Type NPS Sch.
Mil.
ksi 2sSy -
Aft Afm Af /Afm t
_ f)
-(a)
(b)
(c)
(d)
(e) -
(
9 6
T 6
40 SS 40.8 0.472 420 540-1.29 l
10 7
T 6
4p SS 40.8 0.278 446 491 1.10 e
i 11 6
T 6
10 SS 39.7-0.244 219.
143 -
0.65 i
j 12 6
-T 6
-40 SS 40.8 0.472 420 492 1.17 l
14 6
T 6
40 CS 41.5 0.464 429 564 1.32 l.27 15 10 R
4 40 SS 37.0 0.413 148 189-16 6
R 4
40 CS 49.5 0.309 205 260 1.27 33 P
6 40 CS 44.5 0.255 490 532 1.09 '
]
34 12 P
6 40 CS
- 44.5 0.255 490:
605 1.23 1
40 R
4 40_
SS -
37.0
'O.000 159 202' 1.27 (a) T - 6x6x6 ANSI B16.9 tee, fixed at both run ends, branch loaded.
j R - 4 NPS pipe between 8x4 and 6x4 ANSI B16.9 reducers.
P = straight pipe.
l Maximum loads are due to earthquake. type dynamic input, except for Test 33, during which sinesweep dynamic input was used.
l (b) SS - stainless steel, SA312 Type 316; CS - carixm steel, SA106-II.
(c) Sy - yield strength of material, ksi(from Appendix D of Reference 11).
For tees (no data for pipe), tee data were used.
l For reducers, pipe data were used.
For pipe, Sch. 40 pipe data were used.
(d)
P_ = internal pressure; D = mean diameter of pipe; t - nominal wall thickness of pipe.
l (e) AIt = calculated limit moment, in,-kip, - DatSy[1-0.75(PD/2tSy)2]ur -
l (f)
Afm - maximum measured dynamic moment, in.-kip (from Appendix 11 of Reference 11).
i ForTests 12 and 14, Afm was adjusted by dividing the Reference 11 measured moment by 1.09 to obtain-estimate of measured moment at the failure location.
i c.
l l
t I-l, h'
l.
t l
l
_ NUREG-1367 56 4
Table 4 Reference 11 Elbow (6 NI'S,90*) Tests: 1..imit Moments and Measured Moments Elbow Test!
Sy, Test PDo/
Af /Afm Run Sch.
Mil.
h ksi Plane 2tSy Aft Afm L
(a)
(b)
(c)
(d)
(e)
(f) 1/8 80 CS 0.41 40.0 in 0.269 424 569 1.34 2/8 80 CS 0.41 40.0 Out 0.269
?
574 7
3/11 10 SS 0.11 34.0 In 0.285 52.3 163 3.12 4/7 40 CS 0.25 47.8 In 0.237 246 396 1.61 5/8 40 CS 0.25 47.8 In 0.403 246 478 1.94 6/8 40 SS 0.25 54.2 in 0.355 279 457 1.64 7/8 40 SS 0.25 54.2 in 0.209 279 426 1,53 8/8 40 SS 0.25 54.2 In 0.000 232 342 1,47 13/10 40 CS 0.17 47.0 in 0.241 189 400 2.12 17/?
40 CS 0.17 47.0 Tor 0.241
?
19/8 40 SS 0.25 64 0 In 0325 278 450 1.52 23/4 40 CS 0.25 42.3 in 0.268 217 470 2,16(g) 25/14 10 SS 0.11 34.0 in 0.570 52.3 3807 7.31(h) 26/7 40 CS 0.25 42.3 la 0.455 -
217 30/4 10 SS 0.11 34.0 In 0.285 52.3 112 2,14 31/7 10 SS 0.11 38.6 in 0.251 59.4 150 2.53 35/7 40 CS 0.25 42.3 In 0.455 217 394 1.82 37/5 10 SS 0.11 34.0 in 0.000 43.6 57 1.31 41/?
40 CS 0.25 44.0 In 0.438 226 398 1.76 (a) All except Tests 13 and 17,9-in. bend radius; Tests 13 and 17,6 in. bend radius.
Maximum loads are due to earthquake-type dynamic input, except for Test 25, during which dynamic input in the middle-range frequency was used, and Test 26. during which sinesweep dynamic input was used.
(b). CS = carbon steel, SA106-Il; SS = stainless steel, SA312 Type 316.
(c) h - elbow parameter - tR/r2 where t - elbow nominal wall thickness R = elbow bend radius r - mean cibow cross-section radius -
(d) Sy = material yield strength (from Appendix D of Reference 11).
Af - limit moment calculated using liquation (9), in.-kip; conceptually, in-plane, closing limit moment.
(c) t (f)
Afm - maximum measured moment, in.-kip (from Appendix 11 of Reference 11).
(g) Assembly restrained with a strut. Significance of the measured moment is not clear.
(h) Reference 11 Appendix 11, states: Mid-freq. moment measuring mr.thod is still in study, results will be changed."
57 NURIIG-1367
Table 5 Reference 3 Static and Dynamle In-Plane Moment Capacity Tests on Elbows (See Figure 12 for plot of these data.)
Test Sy, l'th /2t, A1,
- IFtSy, Iden.
Mil.
ksi ksi in.-kip in.-kip Af/IFtSy h
(a)
(b)
(c)
(d)
(e)
(f) 22(2)
CS 50.0 0
261 +
563.6 0.46 +
0.25 22(5)
CS 50.0 17.0 347 +
563.6 0.61+
0.25 22(8)
CS 37.8 0
450 +.
626.3 0.72 +
0.41 22(11)
CS 39.6 0
202 +
446.4 0.45 +
0.17
[
22(15)
SS 37,7 0
206 +
425.0 0.48 +
0.25 j
22(16)
SS 37.7 0
202 +
425.0 0.48+
0.25 22(17)
SS 35.6 0
200 +
401.3 0.50 +
0.17 22(18)
SS 35.4-0 381 586.5 0.65 0.41 22(19)
CS 46.0 0
202 518.5 0.39 0.17 22(20)
CS 34.6 0
369 573.3 0.64 0.27 l
23(1)
SS 36.3 0
3300 6515 0.51 0.15 13(1)
CS (45) 15.0 269 +
488.1 0.55+
0.26 13(5)-
SS (35) 0 166 +
379.6 0.44 +
0.26 13(6)
SS (35) 18.6 313 379.6 0.82 0.26 13(7)
SS (35) 0 122 274.3 0.44 0.18 13(8)
SS (35) 0 79 221.4 0.36 0.14 13(9)
SS (35) 0 78 +
106.4 0.73 +
0.40 24(4)
SS (35) 16.5
+ /-43.8(g) 47.5 0.92 0.18 24($,
SS (35) 17.3
+ /-45.0(g) 47.5 0.95 0.18 (a)
Identification according to Table 4 cf Reference 3.
(b) CS = cartmn steel; SS - stainless steel.
(c)
Sy - yield strength as listed in Reference 3. For References 13 and 24 in Reference 3, yield strengths were not given. 'lypical values of 45 ksi for carlen steel and 35 ksi for stainless steel were used.
1 (d) P = internal pressure; D - mean diameter of elbow;t - nominal wall thickness of elbow.
(e)
From Table 4 of Reference 3, column headed "Afm". A "+ " indicates that the moment capacity was not reached in the static loading test.
(f) h - elbow parameter - tR/r2
~
where t - elbow wall thickness R - cIbow bend radius r - cibow mean cross-section radius (g) These values were derived from sinusoidal dynamic loading tests.
NUREG-1367 58
l Table 6 Reference 11 Pipe Tests: Comparisons with 2Sy 1.imit Pipe 2% Damping 5% Damping Test /
Sy, S,
S, Run Type NPS Sch.
Mil.
Lsi ksi S/2Sy ksi S/2Sy Sw/Sy Sp/Sy (a)
(b)
(c)
(d)
(e)
(0 (g) 9/6 T
6 40 SS 40.8 589 7.2 330 4.0 0.02 0.47 10/7 T
6 40 SS 40.8 600 7.4 335 4.1 0.02 0.28 11/6 T
6 10 SS 39.7 269 3.4 178 2.2 0.04 0.24 l
12/6 T
6 40 SS 40.8 737 9.0 401 4.9 0.02
- 0.47 14!6 T
6 40 CS 41.5 542 6.5 304 3.7 0.02 0.46 4
15/9 R
4 40 SS 37.0 787 11 428 5.8 0.06 0.41-5 16/6 R
4 40 CS 49.5 1979 20 1011 10 0.04 0.31 33/?
P 6
40 CS 44.5 0.00 0.25 34/12 P 6
40 CS 44.5 731 8.2 419 4.7 0.01 0.25 40/5 R
4 40 SS 37.0 1345 18 786 11 0.06 0.00 (a) T - 6x6x6 ANSI B16.9 tee, fixed at both run ends, branch loaded..
R - 4 NPS pipe between 8x4 and 6x4 ANSI H16.9 reducers.
P - straight pipe.
Maximum loads are due to earthquake-type dynamic input, except for Test 33, during which sinesweep dynamic input was used.
(b) SS = stainless steel, SA312 Type 316; CS = carbon steel, SA106-II.
(c) Sy - material yield strength (from Appendix D of Reference 11).
For tecs (no data for pipe), tee data were used.
For reducers, pipe data were used.
For pipe, Sch. 40 pipe data were used.
(d) From Appendix B of Reference 11, Case 2, B Af/Z with B _= 1.00. Appendix B states: " Case 2 Actual tested 2
2 time history used 2% damping amplified response spectrum + /-15% broadening response spectrum analysis."
(e) From Appendix H of Reference 11. Case 3, B Af/Z with Bz - 1.00. Appendix H states: " Case 3 Same as 2
I Case 2 except using 5% damping."
(f)
Sw - stress due to weight - Af,/Z where Af, - moment due to weight.
(g) Sp - stress due to internal pressure - PD/2t where P = internal pressure D = pipe mean diameter t -
pipe nominal wall thickness l
l l
59 NURiiG-1367 l
=.
. - =
t 4
Table 7 Reference 11 Elbow (6 NPS,90*) Tests: Comparisons with 2Sy Limil Elbow 2% Damping 5% Damping 2
Test /
Sy, Test S,
S, Run Sch.
Mll.
ksi Plane ksi S/2Sy ksi S/2Sy Sw/Sy Sp/Sy (a)
(b)
(c)
(d)
(e)
(f)
(g) 1/8 80 CS 40.0 In 890 11 547 6.8 0.01 0.27 2/8 80 CS 40.0 Out 897 11 501 6.3 0.01 0.27 3/10 10 SS 34.0 in 1276 19 752 11 0.04 0.28 4/?
40 CS 47.8 in 1057 11 648 6.8 0.01 0.24 5/8 40 CS 47.8 In 1238 13 674 7.0 0.01 0.49 1
6/8 40 SS 54.2 In 1158 11 634 5.8 0.01 0.36 7/8 40 SS 54.2 in 1392 13 756 7.0 0.01 0.21 8/8 40 SS 54.2 In 1442 13 7,'6 7.2 0.01 0.00 13/10 40 CS 47.0 In 1255 13 679 7.2 0.02 0.24 17/7 40 CS 47.0 Tor 0.02 0.24 19/8 40 SS 54.0 In 1331 12 707 6.5 0.01 0.L 25/15 10 SS 34.0 In 1628 24 990 15 0.04 0.57 26/?
40 CS 4?. 3 In 0.01 0.46 30/4 10 SS 34.0 -
In
-620 9.1 356 5.2 0.32 0.28 31/11 10 SS 38.6 in 1391 18 738 9.6 c ')4 0.25 35/7 40 CS 42.3 In 0.08 0.46 37/5 10 SS 34.0 in 651 9.6 375 5.5 0.32 0.00 41/7 40 CS 44.0 in 0.01 0.44 4
l (a)
All except Tests 13 and 17,9-in. bend radius: Tests 13 and 17,6-in bend radius.
Maximum loads are due to carthquake-type dynamic input, except for Test 25, during which dynamic input in the middle. range frequency was used, and Test 26, during which sinesweep dynamic input was used.
(b) Elbow material: CS = carbon steel, SA106-B; SS = stainless steel, SA312 Type 316.
(c) Sy = materialyield strength (from Appendix D of Reference 11),
i (d) From Appendix B of Reference 11.
i Response spectrum analysis based on 2% damping, + /-15% peak broadening.
l (c) Same as (d), except 5% damping was used.
(f)
Sw = stress due to weight - B Afw/Z where Af = moment due to weight at mid-arc of cibow.
2 (g) Sp = stress due to internal pressure = PD/2 where P = internal pressure D = cibow mean diameter t = cibow nominal wall thickness l
I I
r l
l l
i NUREG-1367 60 i
I
Table 8 Reference 11 Tests on Other Components: Comparisons with 2Sy Limit Pipe
' 2% Damping 5% Damping Test /
Sy, S,
S, Run Type Site Sch.
Mll.
ksi ksi S/2Sy ksi S/2Sy Sw/Sy Sp/Sy (a)
(b)
(c)
(d).
(e)
(f)
(g) 10/6 RFT (a)
(a)
CS 53.4 770 7.2 456 4.3 0.08 0.24 20/7 NZ (a)
(a)
SS 48.7 770 7,9 436 4.5 0.05 0.34 36/8 TR 6
40 CS 45 5 902 9.9 610 6.7 0.05 0.42 38/6 Til 6
40 SS 40.1 1185 15 654 8.2 0.05 0.48 39/4 TB 6
40 SS 40.1 1248 16 674 8.4 0.04 0.00 (a)
RIT - reinforced (with pad) fabricated tee; 4 NPS, Sch. 40 branch; 8 NPS, Sch. 40 run: pad thickness =
0.322 in.
NZ - nozzle (see Figure 13)
TR - 6x6x6 ANSI B16.9 tee, loaded through run.
l TB - 6x6x6 ANSI B16.9 tee, fixed at one run end, branch loaded.
(b) Pipe material: CS - carbon steel, SA106-B; SS - stainless steel, SA312 Type 316.
l (c) Sy - materialyield strength (from Appendix D of Reference 11). For Tests 18 and 20, run pipe material yield strengths.
(d) Moments from Appendix B of Reference 11.
Response spectrum analysis based on 2% damping, + /-15% peak broadening.
See text for conversion of moments to stresses.
(e) Same as (d), except 5% damping was used.
Sw - stress due to weight = B Afw/Z where Af, - moment due to weight.
(f) 2 (g) Sp - stress due to internal pressure - PD/21 where P - internal pressure D - run pipe mean diameter t - run pipe nominal wall thickness 61 NUREG-1367
p e
Table 9 Reference 13 and Other Piping System Tests: Comparison with Elastic Analyses Test
- Damping, Ref, Location
System Description
. Mtl.
S/2Sy (a)
(b)
(c)
(c) 13 IIIT:C System 1. 6 NPS and 3 NPS, Sch. 40 CS 16 5
See Figure 15 and Section 5 13 III'EC System 2,6 NPS and 4 NPS, Sch. 40 SS 12 5
See Figure 16 and Section 5 14 HEDL 1 NPS, Sch. 40 SS 12 5
See Figure 20 15 ANCO-Z bend,4 NPS, Sch. 40 CS 1.6 2
16 ANCO 8 NPS and 6 NPS, Sch. 40 CS 3
3 No branches 16 ANCO 8 NPS and 6 NPS, Sch. 40 CS Two 3 NPS, Sch. 40 branches 17 ETEC 3 NPS, Sch. 40 CS 14 5
One 3 NPS, Sch. 40 branch 17 ETEC 6 NPS, Sch. 40 CS 8.3 5
One 3 NPS, Sch 40 branch 18 KWU 4.5-in. outer diameter. 0.165-in. wall thickness SS 2.1 2
(Germany) 2.38-in, outer diameter,0.l l4-in, wall branch 19 HDR 18-in - to 4.5-in.-outer-diameter pipes SS 2.4 3
(Germany)
D/t = about 15 20 Tadotsu -
1/2.5 scale model of one loop of-SS (6.6)
(d)
(Japan)
PWR primary coolant system D/t - about 12 (a) L'TEC - Energy Technology Engineering Center, Canoga Park, California HEDL - llanford Engineering Development Laboratory, Richland, Washington ANCO - ANCO Engineers, Culver City, California KWU = Kraftwerk Union, Aktiengesellschaft, Federal Republic of Germany HDR - Heissdampfreaktor, Kahl/ Main, Federal Republic of Germany Tadotsu - Tadotsu Engineering Laboratory, Tadotsu.cho, Kagawa Prefecture, Japan (b) CS - carbon steel pipe material (e.g., A106-B)-
SS - austenitic stainless steel pipe material (e.g., A312 Type 304)
(c) S ' - calculated stress usir; response spectrum analysis with indicated damping, except for Reference 20.
S for Reference 20 is from a time history analysis.
Sy yield strength of piping material.
(d) Time history analysis NUREG-1367 62
NRC FORM M5 U.S. NUCLEAR REGULATORY COMMIS$ ION
- 1. REPORT NUMBER
(?-C9)
( Assigned by NRC. Add Voi,,
NRCM 1102.
Supp.. Rev., and Addendum Num.
3m, 3202 BIBLIOGRAPHIC DATA SHEET
- " " * "v l (see Instructions on tne reverse)
NUREG-1367 2 TITLE AND SUOil1LE
- 3. DATE HEPOHi PUBLISHED Functional Capability of Piping Systems l
uoNTN YrAR November 1992
- 6. AUTrtOHt b)
- 6. T YPE OF HEPORT Technical D. Terao, E. C. Rodabaugh
- 7. PERIOD COVERED (inclusive Dates)
- 8. PEHFOHMING ORGAN!ZA TION - NAML AND ADDRESS (if NRC, provios Division. Office or Region. U.S. Nuclear Hegulatory Commission, and mamna azress: it contractor, provide nam. and m mna addressa Division of Engineering a
Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, DC 20555
- 9. SPONSOHING OHGANIZATION - NAME AND ADDRESS (rf NRC, type 'Same as above"; it contractor, provide NRC Division. Office or Region, U,S. Nuclear Regulatory Commission, and maliang address,)
Same as above
- 10. SUPPLEMENT ARY NOTES
- 11. Al3STRACT (200 worcs or less)
General Design Criterion 1 of Appendix A to Part f0 of Title 10 of the Code of Federal Regulations requires, in part, that structures, systems, and components important to safety be designed to withstand the effects of earthquakes with.
out a loss of capability to perform their safety function. The function of a piping system is to convey fluids from one location to another. De functional capability of a piping system might be lost if, for example, the cross-sectional flow area of the pipe were deformed to such an extent that the required flow through the pipe would be restricted.
The objective of this report is to examine the present rules in the American Society of Mechanical Engineers Boiler and Pressure Vessel Code,Section III, and potential changes to these rules, to determine if they are adequate for en-suring the functional capability of safety-related piping systems in nuclear power plants.
i
- 12. KEY WORDS/DESCRIPTORS (List words or phrases that will assist researchers in locating the report.)
- 13. AVAILABILITY ST ATEMENT Unlimited
- 14. SECURITY CLASSIFICATION piping -
operability limits functional capability Unclassified
~
stress limit (Th" P )
Unclassified
- 15. NUMOER OF PAGES
- 16. PRICL
[
NRC FORM 335 (2-89) 1
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NURECr1367 FUNCTIONAL CAPAlllLITY OF PIPING SYSTEMS NOVEMBER 1992 UNITED STATES FIRST CLASF MAIL NUCLEAR REGULATORY COMMISSION POSTAGE AND FEES PAID i
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PERMIT NO. G 67
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OFFICIAL BUSINESS PENALTY FOR PRIVATE USE. $300
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