ML20210D075
| ML20210D075 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 03/13/1987 |
| From: | Alexandru R, Hettinger F, Schoppmann H EBASCO SERVICES, INC. |
| To: | |
| Shared Package | |
| ML20210C645 | List:
|
| References | |
| SAG-CP4, NUDOCS 8705060421 | |
| Download: ML20210D075 (12) | |
Text
-
4 SAG.CP4 --
O EBASCO SERVICES INCORPORATED Seismic Design Criteria For
' Cable Tray Hangers For Comanche Peak Steam Electric Station No. 1 i
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PREFARED l REVIEWED l
APPROVED 1.
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.PAGES l
4 lREVISIONl BY l
BY l
BY l DATE
-l AFFECTED l
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Document Number SAG.CP3, Rev 3 1 8/26/85 l
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'lR. Sullivan lR. Alexandru lG. Kanakaris 112/20/85 lp. i, 1 thru 6,.
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M -4" 1 l;
I l R2 lP. Harrison IF. Hettinger IR. Alexandru l 8/8/86 li, 2-5, 7-10 :
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l lH. Schoppaannl l
l l Appendices 1, 2 & 3 l
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l R3 lP. Harrison lF. Hettinger IR. Alexandru l~-1/15/87'lP. 1,~1 thru 10 1
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l l Appendix 1 cover
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'l land pages as noted, l
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land pages as noted',
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i l R4 l't [ScE6fp'mannlF. Hettinger lR. Alexandru l 3/13/87 lp. 2,6,7,9,10 revised - l l'
lp. 1,1,3-5,8 reprinted-l l
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l g-1 l-EBASCO SERVICES INCORPORATED 2 World Trade Center New York, NY 10048 COPYRIGHT @.1985
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TABLE OF CONTENTS-PAGE I.
Purpose 1
II.
Reference Documents 1
III.
Design Parameters for Cable Tray Hangers 2
4.
1.
Cable Tray Span Length 2
2.
Cable Tray Loading 2
3.
Material 3
1 4.
Design Loads 3
IV.
Seismic Design Approaches, Seismic Input Requirement and 4
Design Acceptance Criteria 1.
Static Analysis 5
~
2.
Equivalent Static Method 8
l 3.
Response Spectrum Method 9
V.
Recommendation of Successive Methods to be Used for Design of l
Cable Tray Hangers 10 Appendices 3
i 1.
Peak Acceleration Tables.
i 2.
" Structural Embedaents" Specification No. 2323-SS-30 'tevision 2, prepared by Gibbs & Hill, Inc. including all appendices as follows:
o SS-30 App. 1 Civil Engineering Instruction for the Installation of Hilti Drilled-In Bolts (CPSES Instruction Number CEI-20, Revision 9) o SS-30 App. 2 Design Criteria for Hilti Kwik and Super Kwik Bolts o SS-30 App. 3 Design Criteria for Screw Anchora o SS-30 App. 4 Design Criteria for Embedded Plate Strips j
o SS-30 App. 4W Design Criteria for Embedded Plate Strips (Alternate) 1 o SS-30 App. 5 Design Criteria for Embedded Large Steel Plates i
o SS-30 App. SW Design Criteria for Embedded Large Steel Plates (Alternate) i o SS-30 App. 6 Allowable Load Criteria for 1-1/2 Inch Diameter-A193 Grouted-In Anchor Bolts 3.
Deleted (Data Transferred to Appendix 2 above) 4.
Maximus Longitudinal Cable Tray Support Span.
1477a 1
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SEIS.41C DESIGN CRITERIA FOR SAG.CP4 CABLE TRAY HANGERS
]
I.
Purpose A cable tray hanger is classified as a seismic Category I structure, and therefore, it shall be adequately designed for the effect of the postulated seismic event combined with other applicable and concurrent i
loads. The design requirements for seismic Category I structures are delineated in Regulatory Guide 1.29.
This document provides the seismic design guideline for cable tray hangers of Comanche Paak Steam Electric Station Unit No.1.
These guidelines summarise the design parameters, applicable load combinations and. their associated acceptance criteria, i
the various design approaches and their corresponding seismic input criteria. The following sections describe in detail the guidelines for the seismic design of the cable tray hangers and lists the applicable reference documents.
In addition, cable trays shall be design. verified l
4 per Reference 13 and cable tray clamps shall be design verified per R3 3
Reference 14.
i j
II.
Reference Documents 4
The following lists the documents referenced or prepared by Gibbs & Hill 1
Inc. which will continue to be used for the design of seismic Category I j
cable tray hangers for Comanche Peak Steam Electric Station Unit No.1.
1.
APPLICABLE CODES AND REGULATORY GUIDES Regulatory Guide 1.29 - Seismic Design Classification, Rev. 3, o
September 1978.
Regulatory Guide 1.61 - Damping Values for Seismic Design of o
Nuclear Power Plants, October 1973.
Regulatory Guide 1.89 - Qualification of Class 1E Equipment for o
Nuclear' Power Plants, Rev.1 June 1984.
i Regulatory Guide 1.92 - Combining Modal Responses and Spatial o
Components in Seismic Response Analyses, Rev.1, February 1976.
4 i
NUREG 1.75 - Standard Review Plan Section 3.8.4, November 1975.
o AISC - Manual of Steel Construction, 7th Edition, including o
Supplements No.1, 2 & 3.
o AWS D1.1 Structural Welding Code.
i 2.
Cable tray specification No. 2323-ES-19. Revision 1, dated Nov. 22, 1976.
3.
CPSES/FSAR Section 3.8.4.3.3 " Load Combinations and Acceptance Criteria for Other Seismic Category.1 Steel Structures" i
4.
Design Criteria for Cable Tray Supports and Their Arrangement, Gibbs and Hill Calculation Book No. SCS - 113C 3/9-3/24 1477a e
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SEISMIC DESIGN CRIIERIA FOR SAG.CP4 CABLE TBAY HANGERS B
5.
Structural Embedmonts Specification No.- 2323-SS-30, Gibbs & Hill
-[
Revision 2, June 13,1986.
4 6.
Design procedures DP-1 Seismic Category I, Electrical Cable Tray Supports dated June 11, 1984.
]
'7.
Refined Response Spectra for Fuel Handling Building, ' dated Oct.
f 8.
Refined Response Spectra for Reactor Building' Internal Structure, j
dated Jan.1985 for SSE and Jan.1983 for OBE.
9.
Refined Response Spectra for Containment Building, dated Jan.1985 l
i
- 10. Refined Response Spectra for Auxiliary Building, dated Nov.1984 4
l
j i
13.
Ebasco Comanche Peak SES Cable Tray Hanger Volume I, Book 1 Part 1 lR4 (Rev. 3), Part 2 (Rev. 0) and Part 3 (Rev. 0).
l O
4
- 14. Ebasco document SAG.CP19, Design Criteria and Procedures for Design l
Verification of Cable Tray Clamps for CPSES Units 1 & 2, Rev.1, lR3 i
i 1/15/87.
I j
III. Design Parameters for Cable Tray Hangers j
The parameters considered in the design of cable tray hangers are as i
follows:
i j
1.
Cable tray span length i
j "As-built" span lengths shall be used in the hanger design I
verification.
2.
Cable tray loading i
2.1 The as-built tray and cable weight (reflecting the actual cable fill) and the as-built thermolag or thernoblanket configuration shall be used for design verification of the supports.
2.2 As an alternative to 2.1 if the as-built cable fill is not lR3 available, the maximum loadings listed below may be utilised for the support design verification. ~However, if by using these 1
lO maximum loadings the support fails to meet the seismic requirements l
, l 1477a
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SEISMIC DESIGN CRITERIA FOR SAG.CP4 CABLE TgAY HANGERS then the as-built cable fill shall be obtained and the design
()
verification _ completed in accordance with 2.1.
Tray Size Total Unit Weight (Lbs/ Foot) 6" 18 12" 35 18" 53 24" 70 30" 88 36" 105 Notes a.
The above data is applicable for both ladder and solid bottom types of trays.
b.
The above data is also applicable for various heights of tray side rails.
J c.
The above unit weight includes cable, tray, tray cover, j
and side rail extension.-
d.
The above unit weight does not include fire proofing material weight (Thermolag and Thernoblanket).
2.3 For trays which are fire proofed, the unit weight of fireproofing l
to be used is in the " General Instructions For Cable Trsy Hanger
{
Analysis". The Configuration (extent) of the fireproofing is shown on the as-built drawings.
i 2.4 All cable tray hangers shall be design verified based on "as-built" lR3 drawings (ie. hanger members, connection and anchorage details).
I j
2.5 All cable tray hanger components (members,. connections, base angles, base plates, embedded plates and anchor bolts) are design ve rified.
t 3.
Material a.
Support structure is ASTM A36 7
b.
Expansion anchors are Hilti Kwik and Super Kwik Drilled-in bolts c.
Screw anchors are Richmond inserts d.
Embedded plates (strip and area plates) are ASTM A36 i
4.
Jesign loads The cable tray hangers shall be designed for the following loads and load combinationst
.!!O
' 1 1477a
SEISMIC DESIGN CRITERIA FOR SAG.CP4 CABLE TRAY HANGERS a.
Load definitions Normal loads, which are those loads encountered during normal plant operation and shutdown, includes J
D
- Dead loads and their related soments and forces.
4 L
- Live load equals sero.
lR3 To
- Thermal effects and loads during normal operating or shutdown conditions, based on the most critical transient or steady state condition.*
Severe environmental load includes:
F,qo - Loads generated by the operating basis earthquake lR3 including secondary wall displacement effects.
l l
Extreme environmental load includes a
F,q, - Loads generated by the safe shutdown earthquake lR3 including secondary wall displacement effects.
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- Except for anchorage components, accident temperatures (Ta) l are not considered in design verification per CPSES FSAR (Pg.
3.8-83 and 3.8-110). Accident thermal loads on anchorages are R3 considered generically by studies. Furthermore, per AISC Manual of Steel Construction (Ps. 6-9), no reductions in Fy are required for temperatures up to 700'F.
l b.
Load combinations The following load combinations shall be considered in design of cable tray hangers:
i.
D + L + F,q+o = S g
D + L + To F,
= 1.5S 11.
D + L + To + F,qoq, = 1.6S j
iii.
l where S is the required strength based on elastic design i
methods and the allowable stresses defined in Part 1 of the AISC " Specification for the Design, Fabrication, and Erection of Structural Steel for Buildings" (published in the Manual of Steel Construction, seventh edition). In no l
case shall allowable stress exceed 0.90 F for
- R3 for shear stresses. normal l
tensile stresses and 0.50F y I
2 IV.
Seismic Desian Approachee, Seismic Input Requirement, and Design Acceptance Criteria i
j There are several analytical methods available which will be used in design or design verification of cable tray hangers. Because the level 3
I 1477m
._~._.- - _- _ _.
1 SEISMIC DESIGN CRITgRIA FOR SAG.CP4 CARLE TRAY HANGERS.
i of sophistication is not the same for each method, the seismic input requirement must vary in order to compensate for whatever the method lacks in sophistication, and 'therefore the conservatism of results associated with each analysis method also varies.
4 j
For span layouts not in conformance with Appendiz 4 of this design i
criteria, design verification may be performed by the Response Spectrum l
Method (Section IV.3) or, if appropriate, by the squivalent Static Method (Section IV.2)'per Attachment Y of the General Instructions.
l The following procedures describe the three (3) most acceptable methods: static analysis, equivalent static method,.and response spectrum method. The seismic input criteria for each analysis method is also addressed.
IV.1 STATIC ANALYSIS 3
a.
Finite Element Model 4
)
A 3-D model shall be prepared to represent cable tray hangers. An i
offset or eccentricity /or transmission of loads shall be considered due to the assemblage of various types of
)
structural members and in the preparation of the computer model.
l l
Boundary conditions at auchorage points shall properly represent -
lR3 j
the actual anchorage condition.
I i
b.
Cable Tray Loadina
]
Tne total cable tray loading for each run shall be calculated based i
on Paragraph III.2 above and the actual tray span lengths which are j
shown on the Span Length Sketches obtained. from the site.
1 j
The cable tray loading shall be lumped as a nodal weight at the actual location on the tier and, if not known, at such a location on the tier that it will induce the worst member stress responses j
and the maximum anchorage reactions.
)!
c.
Seismic Input "a" Values l
For a static analysis the peak spectral "3" values f rom the 4%
i damping OBE curves and the 7% damping SSE curves which were generated at the sounting locations of cable tray hangers shall be used multiplied by a coefficient to account for multimode i
response. These peak spectral "3" values for various buildings and j
different floor elevations can be found in Appendix 1.
For the case where the hangers were supported off the wall, the envelope of the response spectrua curves for the floor lamediately'above and lR3 below the hanger location shall be used. The required seismic l
4 l
design "s" values in three (3) orthogonal directions are 1.25 (multimode response multiplier-MRM) times the peak spectral "g" i
values.
4 1 l 1477a 4
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E SEISMIC DESIGN CRITERIA FOR SAG.CP4 i,
CABLE TRAY HANGERS
- O d.
Static Analysis 1
The seismic load effect on the cable tray hangers will be treated as a static load. The dynamic effect from both seismic event and response characteristics of support structure are conservatively 4
considered by using the 1.25 times the peak spectral."g".value as an input. However, for transverse type cantilever and trapese-cable tray hangers, the seismic load effect:due to.the hanger's lR4 self-weight in the longitudinal direction (direction parallel to i
tray run) shall be determined by multiplying the spectral "g" value i
corresponding to the CTH fundamental (lowest) longitudinal frequency by 1.25 regardless of whether that frequency is to the left or right of the peak response frequency.
1 If the cable tray hanger is attached to a steel structure, use 1.5 times the peak spectral "g" value and a fixed base boundary l
condition.
}
The static analysis shall be performed for the following load cases i
individually:
l i) Dead load f
- 11) Seismic load in vertical direction i
j 111) Seismic load in transverse direction I
i iv) Seismic load in longitudinal direction i
v) Thermal load if any j
Notes Seismic load includes both OBE and SSE events.
I e.
Analysis Results The following marious responses shall be obtained for each load I
combinations i
i i) Maximum member stresses (bending, axial and shear) and nodal lR3 displacements shall be obtained. The stresses and l
displacements resulting from the simultaneous effect of three earthquake components shall be obtained by using the SRSS i
}
method.
j
- 11) Maximum anchorage reactions shall also be obtained by using-SRSS method to account for the simultaneous effect of three earthquake components.
j f.
Seismic Design Acceptance of Cable Tray Hanners and their Anchoranes The cable tray hangers and their anchorages are considered to be acceptable when the structural member and connection stresses and 6-1477a e<-.,-,-.-
- - =
SEISMIC DESIGN CRITERIA FOR
' SAG.CP4-CABLE TRAY HANGERS the anchorage reactions, which are induced by the load combinations described in Sections.III.4.b, are within the allowable stress limits and allowable anchorage carrying capacity. The following i
describes the acceptance criteria for both support structure and.
i anchorages l-
- 1) Support Structure The structural member seismic design acceptance shall be-evaluated using AISC interaction formula with modification for various load combinations as follows:
fb.1 for load (Fa,fbx,
fa Pby) d 1.0 combination III.4.b.i Fbz fa fbs fby for load 1.0 (1.5 Fa + 1.5 Pbx + 1.5 Fby combination III.4.b.ii 114 fa fbs fby for load-g1.6 Fa,1.6 Fbx,1.6 Fby) 4 1.0 combination III.4.b'.iii lR4' f sG F for load combination III.4.b.i y
y j
f, slE 1.5F
!!EE 0.50 Fy for load combination III.4.b.ii lR3 y
i f sG 1.6 F flee 0.50 Fy for load y
y combination IV.4.b.iii.
lR3 1
j where fa = axial stress j
fy = shear stress j
fbi = bending stress Fa, Fbi and Fy = allowable stresses for axial, bending and shear stress, per AISC 7th Edition. In all cases
)
each individual denominator above lR4 i
for load combinations III.4.b.1, ii, l
iii shall be less than 0.9 Fy.
l I
ii) Anchorage (anch,rs) o Kwik-bolt and uper Kwik-bolt.
j.
The design criteria and allowable loads for above driven-in bolts are tabulated in Appendix 2.
o Screw Anchors.
I The design criteria and allowable loads for screw anchors i
are contained in Appendix 2.
When a redline. drawing does i
not identify the bolt / thread rod asterial in a Richmond Insert, A-36 material shall be assumed in the cable tray hanger design verification.
i Notes 1.
The allowable loads for Hilti expansion anchors for the load combination-involving OBE are the load I
capacities corresponding to a safety factor of 5, and I
~7-i
.1477m n
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SEISMIC DESIGN CRITERIA FOR-SAG.CP4-CABLE TRAY HANGERS for the load combination involving SSE are the load (q
, )
capacities corresponding to a safety factor of 4.
2.
h e safety factors for Richmond Anchors are 3.0 for lR3 j
both OBE and _SSE.
l 4
3.
Prying action on anchor bolt, if any, shall.be included.
The effects of the flexibility of the base plate on the anchor bolt shall be considered.
4.
For floor-sounted CTHs in building areas with concrete topping, the actual anchor bolt _ embedded i
length (as determined from the redline drawing) shall i
_ be reduced by two inches -(2") to account for the topping.
IV'2 EQUIVALENT STATIC METHOD s.
Finite Element Model See Section IV.1.a l
b.
Cable Tray Loading See Section IV.1.b c.
Seisalc Input "g" Value i) Tne fundamental (lowest) frequency of cable tray hanger (f )
h I
shall be determined in each of three '(3) orthogonal directions -
separately.
- 11) Determine the frequency of cable tray itself corresponding to 4
the actual span length (fe) in each of three (3) orthogonal t
directions separately.
iii) Determine the system frequency using the following conservative formula:
1 1
1 2 " 7 + "I""7 f
fsys c
h 1
l.
When f or fh are 33 Hg or larger this tern's c
contribution to the system frequency may be disregarded.
1 he above system frequency will be calculated for each of three 1
(3) orthogonal directions separately.
iv)
Obtain the spectral "g" value corresponding to the system i
frequency (fsys) for each direction' separately when fsys is on the right side of the peak response frequency. If fsys is at lO 1
1477m
SEISMIC DESIGN CRITERIA FOR-SAG.CP4 CABLE TRAY HANGERS the lef t side of the peak frequency, the peak spectral "g"
4 value shall be used (except as noted in Section IV.1.c & d).
v) Determine the required seismic design "g" values for the cable tray hanger by multiplying 1.25 to th'e above "g" value (obtained in Step iv) to account for multimode response (except as noted in Section IV.1.c & d).
d.
Equivalent Static Method The stress analysis for the cable tray hangers shall be performed on the 3-D finite element model using the "g" value obtained in Step c.
The load cases which shall be considered are the same as those listed in Section IV.1.d.
4 I
e.
Analysis Results-See Section IV.1.e.
f.
Seismic Design Acceptance of Cable Tray Hangers and their Anchorages See Section IV.1.f.
i IV.3 RESPONSE SPECTRUM METHOD l
a.
3-D Model of Cable Tray and Tray Hangers j
construct a 3-D model of tray systems which include and therefore simulate the dynamic behavior of cable tray itself and cable tray j
hangers.
J In order to adequately simulate the seismic response of the cable.
1 tray system, a minimum of 4 cable tray spans shall be included in the model, with two spans on each side of the hanger under consideration.
The cable tray will be represented by-a beam type finite element in the 3-D model, with properties obtained from tray Vendor's static load test report.
l The stiffness of longitudinal supports shall also be considered and l
l simulated by a spring constant attached to the ends of 3-D model.
b.
Frequency Analysis Perform a f requency analysis on the above 3-D model which includes lR3 all modes up to 33 Hz, or up to the highest cutoff frequency of the IR4 input spectra.
l i
i i
9-f 1477m w
SEISMIC DESIGN CAITERIA FOR
-SAG.CP4 CABLE TRAY HANGERS c.
Spectral Analysis Perform seismic response analysis for the above 3-D model using the appropriate floor response spectrum as an input. NRC Reg. Guide 1.92 shall be followed in calculating the modal response. Missing l'
mass correction shall be applied to account for rigid mode effects I R4 -
for modal frequencies higher than 33 Hs or the input spectra cutoff' frequency.
The 4% damping of OBE curves and 7% damping of SSE curves shall be used as an input for each direction separately. Seismic responses are obtained directly f rom these analyses using modal superposition per NRC Reg. Guide 1.92.
i d.
Response Spectra Analysis l
1he stress analysis for cable tray hangers shall be performed on R3 the 3-D finite element model using the "3" value obtained in l
Step c.
The load cases which shall be considered are the same as l
those listed in Section IV.1.d.
l 1
e.
Analysis Results See Section IV.1.e f.
Seismic Design Acceptance of Cable Tray Hanners and their Anchoranes 4
See Section IV.1.f.
V.
Recommendation of Successive Methods to be Used for Desian of Cable Tray 4
Hangers The cable tray hangers may be designed or design verified by a static analysis method first (1V.1). If the cable tray hangers fail to meet t
the seismic requirement under this most conservative method, a refined analysis method of equivalent static method (IV.2) shall be used.
If the cable tray hangers still fail to meet the design criteria, then the response spectrum method (IV.3), may be used.
The response spectrum
{
method approach simulates better the dynamic behavior of the cable tray system under the effect of the postulated seismic event and thus may produce seismic responses of the structural systes closer'to reality.
l 1herefore, by response spectrum method, the conservatism associated with
.I the seismic response obtained from static analysis and equivalent static method can be reduced to a minimum.
In conclusion, if the cable tray hangers still fail to pass the acceptance criteria by a spectral response analysis, a much more refined analysis such as a time history analysis method can be used. A procedure for such analyses will be given, should the need arise.
1 LO I
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