ML20237J128
| ML20237J128 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 08/10/1987 |
| From: | Williams N CYGNA ENERGY SERVICES |
| To: | Counsil W TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| References | |
| 84056.114, NUDOCS 8708170498 | |
| Download: ML20237J128 (212) | |
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- 2121 N. Cahfornia Blvd., Suite 390, Walnut Creek, CA 94596 415/934 57 August 10,1987 84056.114 Mr. W.G. Counsil Executive Vice President TU Electric Skyway Tower 400 North Olive Street, L.B. 81 Dallas, TX 75201
Subject:
Cable Tray Support Review Issues List (RIL) Comanche Peak Steam Electric Station Independent Assessment Program - All Phases Job No. 84056
References:
- 1. TU Electric " Generic Issues Report - Evaluation and Resolution of' Generic TechnicalIssues for Cable Tray Hangers", Revision 2
Dear Mr. Counsil:
Enclosed is Revision 14 of the Cable Tray Support Review issues List (RIL).' All significant changes are indicated by a revision bar in the right margin. is revision to the RIL is based on the information provided in Reference 1, transcripts u ,,ublic meetings, documents provided by TU Electric and the results of Cygna audits up through July 31, 1987. The communications reports' referenced in the Rlt will be issued by Cygna in two weeks. b San Francisco Boston Chicago Parsippany , 8708170498 870810
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% -j Very truly yours, i N.H. Williams3 P j Project Manager ; i i
NHW:jst - Attachments ' cc: ' Mr. Chris Grimes (USNRC)_w/ attachments ,[ ks. ALVietti-Cook (USNRC)M/attachrnEnt Mr. 3. Redding (TU Electric) w/ attachments Mrs. 3. Ellis (CASE), w/ attachments Mr. D. Pigott (Orrick, Herrington & Sutcliffe) w/ attachments Mr. L. Nace (TU Electric) w/ attachments Mr. R. Alexandru (Ebasco) w/ attachments Mr. B. Ramsey (Impell) w/ attachments 1 l Mr. E. Siskin (SWEC) w/ attachments l Mr. 3. Muffett (TU Electric) w/ attachments f i i s 1 ! i i __ _ _ _ _ _ . _ __ _ _ _ ____ ._ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . . . _ _ . _ _C
1 I
-l 07/31/87 Revision 14 Page i i
CABLE TRAY SUPPORTS Review Issues List < l l Table of Contents ; Issue ! No. Issue Title Page INTRODUCTION................................................. 1 ! l
- 1. Cont roll i ng Load Case ft. Desi gn. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 l l
- 2. Sei smi c Res ponse Combination Met hod. . . . . . . . . . . . . . . . . . . . . . . . . . 6 j
- 3. An c ho r B o l t D e s i gn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
- 4. D esi gn o f Compres sion Members. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 :
J
- 5. Vertical and Transverse Loading on Longitudinal ............. 38 ;
Type Supports ; l
- 6. Support Frame Dead and I nerti al Loads. . . . . . . . . . . . . . . . . . . . . . . . 40
- 7. Design of Angle Braces Neglecting Loading Eccentricity....... 44 l
- 8. Dynami c Ampl i fi cati on Factors (DAF) , Tri butary. . . . . . . . . . . . . . . 53 ,
Tray Support Reactions and Missing Mass Effects !
- 9. Reducti on i n C hannel Secti on P roperti es Due to . . . . . . . . . . . . . . 53 Clamp Bolt Holes
- 10. System Concept............................................... 61
- 11. V al i d i ty o f N AST RAN Mo d el s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
- 12. Worki ng Poi nt Devi ati on S tudy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
- 13. Reduced S pe ctral Accel era tions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
- 14. Non-Conformance wi th AISC Speci fi cati ons. . . . . . . . . . . . . . . . . . . . . 79 m_ __ TU Electric s
Comanche Peak Steam Electric Station
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07/31/87 Revision 14 l Page 11 l CABLE TRAY SUPPORTS i I Review Issues List l Issue i No. , Issue Title Page 1
- 15. M emb e r S u b s ti t u ti o n. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
- 16. Wel d Des i gn and Specifi cati ons . . . . . .. . . .. . . .... . .. . . . . . . . . . . . 88
- 17. E m b e d d e d P l a t e D e s i gn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101 i i
- 18. C a bl e T ray C 1 am ps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
- 19. FS A R L o a d C omb i n a t i o n s. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
- 20. Differences Between the i nL ;a11 ation and it.e ..... . . . . . . . . . . 116 Design / Construction Drawings without !
Appropriate Documentation i i l
- 21. D e s i gn C o n t ro1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . . . . . 13 3
- 22. Desi gn o f Su ppo rt N o. 3136, Detail "5 " , .. . . . . . . . . . . . . . . . . . . 154 Drawing 2323-S-0905 i J
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- 23. L oadi ng I n S tres s Model s. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156 i
- 24. D e si gn o f Fl e x u ral M emberc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 9 i
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- 25. C a bl e T ray Qual i fi ca ti on. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171
- 26. B a s e An gl e D e si g n. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 9 1
- 27. Su ppo rt Qual i fi ca ti on by Simil ari ty. . . . . . . . . . . . . . . . . . . . . . . . . 182
- 28. C ri ti cal Support Confi gurations and Loadings. .. . .. . . . . . . . . . . 186
- 29. Cumul ati ve E ffect of Revi ew I ssues. . . . . . . . . . . . . . . . . . . . . . . . . . 188
- 30. C a bl e T ra y D am pi n g V al u e s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191 pge- TU Electric
. . . . Comanche Peak Steam Electric Station
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' CABLE TRAY SUPPORTS Review Issues List Issue I No. Issue Title Pace
- 31. Mo dell i n g o f B oundary Condi ti o n s. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192 l 32. Condui ts Attached to Cabl e Trays or Supports. . . . . . . . . . . . . . . . . 193
- 33. A s-Buil t Wal kdown P ro ced ures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197
- 34. Sys tem Anal ysi s Met hodol o gi es . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203 l
l l I l TV Electric Comanche Peak Steam Electric Station N 3-IIA I Independent Assessment Program - All Phases 111111111lll111111!1111111ll11 Job No. 84055 PRJ:RIL ;
07/31/87 Revision 14. Page 1 CABLE TRAY SUPPORTS Review Issues List INTRODUCTION This document summarizes the major issues which have arisen from the review of i the design and installation of the Cable Tray Supports at Comanche Peak Steam ! ElectricStation(CPSES). This review was conducted as a part of the ! Independent Assessment Program (IAP) performed by Cygna Energy Services for TV Electric (formerly Texas Utilities Generating Company (TUGCO)). The various issues discussed here are the result of a review of the design documents (e.g. calculations, drawings and design changes) generated by Gibbs
& Hill, Inc. and TV Electric; installation documents (e.g., assembly drawings, fabrication procedures, quality assurance procedures, etc.) generated by TU Electric and Brown & Root, Inc; and a walkdown of the installed cable trays and supports located in CPSES, Unit 1. f i
The Cable Tray Support Review Issues List (RIL) is a tracking document which l provides a summary description of each issue, a list of relevant reference documents, a discussion of the methods used to resolve the issue and a brief , statement on the status of the resolution. During the course of the IAP, an effort was made by the Project (Gibbs & Hill, Inc., TV Electric and Brown & Root, Inc.) to resolve each issue through revisions to the existing design calculations, the generation of new calculations and the issuance of design change documents. In some cases, it l was not possible to resolve certain issues in that manner, while in other cases Cygna did not accept the resolution provided by the Project. In October,1984, TU Electric created the Comanche Peak Response Team (CPRT) to develop a unified approach for the resolution of all design and construction issues associated with the licensing of CPSES. A program plan was developed by the CPRT which is entitled the "CPRT Program Plan tnd l l Issue-Specific Action Plans", Revision 3. Appendix C of the Plan, " Civil / ! I Structural Discipline Specific Action Plan (DSAP VIII)", provides an outline ; of the approach followed by the Project to resolve the Cable Tray Support Review Issues identified by Cygna and others. TV Electric has contracted two consultants, Impell Corporation and Ebasco Services, Inc. to perform a 100% as-built evaluation of the cable tray support designs at CPSES in accordance with DSAP VIII. Impell is responsible for the cable tray systems located in the Unit 1 Safeguards and Reactor Buildings, TV Electric j Comanche Peak Steam Electric Station d8j6 s,d a f Independent Assessment Program - All Phases lillll;lllllililllilllllllllli Job No. 84056 PRJ:RIL l
l 07/3)/87 Revision 14 Page 2 L .q CABLE TRAY SUPPORTS ; Review Issues List l I while Ebasco is responsible for the cable tray systems in the balance of Unit f 1 and all of Unit 2. Both Impe11 and Ebasco developed a series of design J criteria, work instructions and generic calculations to guide the evaluation h effort and address each of the review issues. These documents are provided as j a part of the " Generic Issues Report for_ Evaluation and Resolution of Generic ! Technical Issues for Cable Tray Hangers", Revision 2 (GIR). Revision 14 of the Cable Tray Support RIL incorporates the responses provided in the GIR, in combination with the results of public meetings between Cygna and the CPSES Project and several audits of Impell and Ebasco's as-built evaluation program. This information has been used to update the status of - each issue and in some cases to regroup several interrelated issues. l i i
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l 07/31/87 i Revision 14 , Page 3 I CABLE TRAY SUPPORTS Review Issues List , l
- 1. Controlling Load Case for Design
References:
- 1. Gibbs & Hill Calculation Binder 2323-SCS-1010, Set 5 j Sheets 16-20, Revision 5 1
- 2. Communications Report between P. Huang, S. Chang (Gibbs j l & Hill) and J. Russ, W. Horstman (Cygna) dated November ]
13, 1984 j
- 3. Gibbs & Hill Calculation Binder 2323-SCS-1010, Set 5, Sheets 1-7, Revision 1
- 4. CPSES FSAR, Sections 3.8.3 and 3.8.4
- 5. Ebasco Procedures SAG.CP4, " Seismic Design Criteria for Cable Tray Hangers for CPSES, Unit 1", Revision 3 and l SAG.CP3, " Seismic Design Criteria for Cable Tray Hangers for CPSES, Unit 2", Revision 6
- 6. Ebasco Instruction, " General Instructions for Cable Tray Hanger Analysis for CPSES, Nos.1 and 2", Revision 4 l
- 7. Impell Instruction PI-02, " Dynamic Analyses of Cable Tray Systems", Revision 5 I
- 8. Impe11 Instruction PI-03, " Qualification of Cable Tray Supports", Revision 4, with Addendum
- 9. Impe11 Instruction PI-07, " Design Verification of Base Plates, Base Angles and Embedded Plates," Revision 3, ;
with Addendum
- 10. ASME, " Boiler and Pressure Vessel Code", Section III, Subsection NF,1983 edition
- 11. Communications Report between S. Harrison, J. Nandi (TV i Electric); G. Ashley, B. Ramsey (Impell); R. Alexandru, S.J. Chen, P. Harrison, F. Hettinger (Ebasco); and TU Electric
, . Comanche Peak Steam Electric Station
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07/31/87-Revision 14 Page 4 i l CAllLE TRAY SUPPORTS-Review Issues List N. Williams, W. Horstman, D. Leong, J. Russ, S. Tumminelli (Cygna) dated February 12,.1987'
- 12. AISC, "Spe:ifications for the Design, Fabrication and -
Erection of Structu, al Steel for Buildings", 7th edition
- 13. Impell report 0210-040/041. IM-P-004 Rev. O, dated 5/15/87, " Safety Margin Against Buckling using AISC l Factored Allowables".
l Sumary: Gibbs & Hill used the equivalent static method to design the cable tray supports. For all load cases, the equivalent static accelerations used in designing the supports for SSE events. are less than 160% of the corresponding accelerations l for 1/2 SSE (OllE) events. Based on this fact'and a review. l of Section 3.9.4 of the CPSES FSAR which allows a 60% increase in allowables for structural steel when designing for the SSE event, Gibbs & Hill determined that the design was governed by the OBE event (Reference 3). To validate this conclusion, the 60% increase in allowables l must be . liberally interpreted to be applicable to all support compcntnts rather than applicable only to structural steel as specified in the CPSES FSAR. Catalog items such as Richmond Inserts and Hilti Kwik-bolts do not have increased allowables for SSE events. By designing these . catalog components to the OBE event, the manufacturer's design factor of safety is not implicitly maintained for the SSE event. Furthermore, for the design of structural steel, the 60%. increase in allowables is acceptable for axial and strong-axis bending stresses in structural members. .The 60% increase cannot be applied to certain other allowable stresses. For example, the maximum increase in base plate stresses may only be 33%, at which point the material yield is reached. A limit on maximum allowable stress is not provided in the FSAR. ys - - TV Electric r . . _. N. Comanche Peak Stean Independent Assessn Electric StationM ert Program 2 Id
- All Phases 11111111111111111111ll11111111 Job No. 84056 FRJ.RIL
E l 07/31/87 l l Revision 14 i l Page 5 i- . '! CABLE TRAY' SUPPORTS j Review Issues List These limitations were not considered in the selection of j the governing seismic-load case. j Response: Impell and Ebasco will perform a 100% reanalysis for both ! the OBE and SSE loads assuming 4% and 7% critical damping, respectively, for the cable tray support systems. .(See , Issue No. 30.) Unfactored AISC (Reference 12) allowables for structural steel are used for the OBE load case. For the SSE load case, the AISC allowables are increased by 60%, [ with tensile and bending stresses limited to 0.9 Fy and compression stresses to 0.9 Fcr. Factors of safety for catalog components (i.e., Hilti expansion anchors and Richmond Inserts) are established for each load case. (See Issues'3.B and 3.E.) Factors of safety of 5.0 and 4.0 are used for Hilti Kwik-bolts and Super Kwik-bolts for the OBE and SSE load cases, res pecti vely. A factor of safety of 3.0 is used for Richmond Inserts for both load cases. Ebasco's implementation of this approach is discussed in Reference 5. Sections III.4 and IV. Sections 3.3.5 and 3.3.6 of Reference 7, Section 4.1.1 'of Reference 8 and Sections 4.1.3 and 5.1 of Reference 9 discusses Impell's impl ementation. Status: This issue is open relative to the allowable stresses for components governed by non-ductile failures (i.e., compres-sive stress allowables in the region governed by Euler buckling and bending stress allowables governed by lateral torsional buckling or local instability) under the SSE loading. Cygna believes that allowable stresses consisteit l with the ASME Code, Section III, Subsection NF. (Reference ( 10) may be more appropriate for these situations. (See [ Reference 11.) This issue is closed for all other allowable stresses, Hilti expansion anchors, and Richmond Inserts. A i joint position paper regarding the safety margins against buckling has been presented. (Reference 13.) Cygna is presently reviewing this document.
;,;;g TV Electric Comanche Peak Steam Electric Station NN L Id 3 Independent Assessment Program - All Phases -
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1. 07/31/87 ] Revision 14 l Page 6 i l CABLE TRAY SUPPORTS I l Review Issues List
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- 2. Seismic Response Combination Method
References:
- 1. CPSES FSAR Section 3.7B.2.7
- 2. Gibbs & Hill Calculation " Working Point Deviation Study" ,
I Binder No. 2323-SCS-215C, Sets 2-6
- 3. US NRC Regulatory Guide 1.92, Revision 1
- 4. N.H. Williams (Cygna) letter to J.B. George (TUGCO),
" Cable Tray Support Design Review Questions," 84056.031, .
dated August 31, 1984 l l
- 5. Gibbs & Hill Calculation in response to IAP Phase 2 l questions, Cygna Technical File 83090.11.2.1.50
] 4
- 6. Ebasco Procedures SAG.CP4, " Seismic Design Criteria for ]
Cable Tray Hangers for CPSES, Unit 1", Revision 3 and ] SAG.CP 3. " Seismic Design Criteria for Cable Tray l Hangers for CPSES, Unit 2", Revision 6 l
- 7. Ebasco Instruction, " General Instruction for Cable Tray Hanger Analyses for CPSES Nos. I and 2", Revision 4
- 8. Impe11 Instruction PI-02, " Dynamic Analysis of Cable Tray Systems", Revision 5
- 9. Communications Report between S. Harrison, J. Muffett (TV Electric); R. Wheaton, B. Ramsey (Impe11);
P. Harrison (Ebasco); and N. Williams, S. Tumminelli, D. Leong, J. Russ and W. Horstman (Cygna) dated March 6, 1987
- 10. Impe11 Calculation M-49, " Seismic Load Combination l Study", Rev. O. ,
- 11. Seismic Load Combinations, prepared by Impell 0210-040/041. IM-P-002, Revision 0, dated May 15, 1987.
=- TU Electric
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._ Comanche Peak Steam Electric Station L*!!LP.iifdl Independent Assessment Program - All Phases 1111ll1ll111111!!11111111111ll Job No. 84056 PRJ:RIL
1 07/31/87 Revision 14 Page 7 q CABLE TRAY SUPPORTS. i Review Issues List l I d
- 12. Communications Report between P. Harrison, J.
Christoudias, P. K. Hsueh (Ebasco); J. Russ,. K. Parikh, , W.'Horstman (Cygna); and S. Harrison (TV Electric) dated ] April 29,1987,10:15 a.m. ] i
- 13. Communications Report between G. Ashley (Impell); S.
Harrison (TV Electric); and W. Horstman, D. Leong, et al. (Cygna) dated May 14,1987, 2 :30 p.m. . l
- 14. Communications Report between G. Ashley and C. l Aboujaoude (Impell); and, W. Horstman, D. Leong and B. l Shakibnia (Cygna) dated May 15, 1987, 11:00 a.m.. l l
- 15. Communications Report between B. Chen, J. Christandias, P. Harrison, and J. Swanson (Ebasco); and W. Horstman 1 and B. Shakibnia (Cygna) dated June.23,'1987,10:00 a.m..
Summary: A. Closely Spsced Modes (10% Modal Combination) in Spectral ; Analysi s In the response spectra analyses performed for the Working Point Deviation Study (Reference 2), Cygna noted that modal responses were not combined considering closely spaced modes as required by References 1 and 3. , B. Inclusion of Dead Load in SRSS Combination In all Gibbs & Hill design calculations,'the acceleration due to deadweight is combined with the seismic accelerations using the SRSS method. A 1.0 g deadweight acceleration is first added to the vertical seismic acceleration. The sum is then combined with the two horizontal seismic components using the SRSS method. Response: A. Ebasco, in Section IV.3.C of Reference 6, and Impell, in Section 3.3.5 of Reference 8, indicate that the modal components of response from response spectrum analyses N- __ TV Electric
, . , Comanche Peak Steam Electric Station 6.51 L.9 (s I4_q Independent Assessment Program - All Phases lillllillllllllllllllllllill!! Job No. 84056 PRJ :RIL
i 1 07/31/87 . ) Revision 14 Page 8 l1 CABLE TRAY SUPPORTS Review Issues List ) will' be combined in accordance with US NRC Regulatory I Guide 1.92 (Reference 3). B. Ebasco, in Attachment F of Reference 7, and, Impell, in ] Sections 3.3.2, 3.3.5 and 3.3.6 of Reference 8, indicate i that the results of the dead weight analyses will be { combined with the SRSS of the three directional j components of the seismic analysis. The following ~ j combinations are used: DW + SEISMIC DW - SEISMIC Where: DW = dead weiglit forces / stresses (signed)' SEISMIC = seismic forces / stresses (unsigned) Cygna stated the combinations noted above may not 1 capture the critical loadings for the' support members or j the anchor bolts because the directional aspects of the j loading were not considered. Ebasco stated that the load combinations are performed at the stress level without consideration of sign or location of maximum bending stress. Anchor bolt loads are enveloped and applied to the base plate models by hand to analyze for l the critical loading case. (Reference 12.) Ebasco i stated that they would provide Cygna with a copy of J sample output and a description of the load combination method. (Reference 15'. ) Impell stated that they would provide an evaluation of the load combinations to demonstrate their appropriateness. After reviewing Reference 10, Cygna i noted that the comparison drawn between the time history analysis and the response spectrum analysis simply showed the conservatism inherent in the latter method with respect to the former method. (Reference 13.) Impell stated that they would provide further analysis l and also provided Reference 11. Impell stated.that the l spectra and time histories used in the load combination I TV Electric Comanche Peak Steam Electric Station Md2Id Independent Assessment Program - All Phases 11111111!!!l1111111111111111ll Job No. 84056 PRJ:RIL
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' CABLE TRAY SUPPORTS Review Issues List comparison were conservative with respect to the target Spectra and high member. interactions were chosen, i therefore, the comparison showed the conservatism of the -
load combination method. (Reference 14.) Status: A. Closed. 1 B. Open: Ebasco is to provide the responses indicated ~ l above to Cygna. Cygna _ has reviewed _Impell's' responses to the concerns noted in Reference 12. Impell. must provide an evaluation which shows the results of their j study are applicable to all systems within their i scope. Cygna notes that Ebasco has considered the directional application of loads and that Cygna will a consider this difference as part of their Cumulative Effects review. See Issue No. 29. l i i i , I l TV Electric >
- . . Comanche Peak Steam Electric Station {
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1 07/31/87 Revision 14 Page 10 CABLE TRAY SUPPORTS Review Issues List
- 3. Anchor Bolt Design i i
References:
- 1. Gibbs & Hill Calculations, " Evaluation of Detail 1, I Single-Bolt Connection," Cygna Technical File j 84056.11.1.259 !
)
- 2. Gibbs & Hill Calculation " Aux. Building Cable Tray Supports" Binder No. SCS-212C, Set 7. Sheet 4-11 Revision 0 i
- 3. Gibbs & Hill Calculations, " Justification of the Adequacy of 1" Richmond Inserts For the Effects of Prying Action," Cygna Technical File 84056.11.1.219
- 4. Brown & Root Procedure CEI-20, " Installation of i Hilti Drilled-In Bolts," Revision 9
- 5. Hilti, Inc., " Architects & Engineers Anchor and Fastener Design Manual" j
- 6. TUGC0 SDAR CP-80-12. " Reduced Allowable Loads for i Hil ti Kwi k-bol ts" l l 1
- 7. TUGC0 Instructions CP-EI-4.0-49, " Evaluation of i Thermo-Lag Fire Barrier Material on Class IE Electrical Raceways," Revision 1 l 8. US NRC Inspection Reports 50-445/81-14; 50-446/81-14, dated October 27, 1981.
- 9. Communication Report between R.M. Kissinger (TUGCO);
B.K. Bhujang et al. (Gibbs & Hill); and W.R. Horstman, et al (Cygna) dated 10/10/84 l
- 10. N.H. Wi'iliams (Cygna) letter to W.G. Counsil (TUGCO), " Cable Tray / Conduit Support Review Ques tions ," 84056.089, dated October 21, 1985
.__.___, TU Electric l r..- Comanche Peak Steam Electric Station d [d 2 f;d Independent Assessment Program - All Phases lillllllillllllllilill!!!!Illi Job No.- 84056 PRJ:RIL
l \, 07/31/87-Revision 14 Page 11.
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CABLE TRAY SUPPORTS 1 l Review Issues List ! l 1
- 11. US NRC Office of Inspection and Enforcement, IE j Bulletin No. 79-02 1
! 12. American Concrete Institute, " Code Requirements for ) l Nuclear Safety-Related Concrete Structures (ACI l l 349-76)" l l 13. Gibbs & Hill Interoffice Memo, T.D. Hawkins to M. j l Strange, dated July 25, 1984. { l l 14. Ebasco Procedures SAG.CP4, " Seismic Design Criteria for Cable Tray Hangers for CPSES Unit 1", Revision 3 . ! and SAG.CP3, " Seismic Design Criteria for Cable Tray Hangers for CPSES, Unit 2", Revision 6 jl l
- 15. Ebasco Instruction, " General Instructions for Cable l Tray Hanger Analysis for CPSES Nos. I and 2", i Revision 4 1 1
- 16. Ebasco Calculation, " Comanche Peak .SES Cable Tray Hanger Volume I", Book 3, " Prying Action Factors &
Formulas for Evaluating Anchor Bolts", Revision 1
- 17. Ebasco Calculation, " Comanche Peak SES Cable Tray ;
Hanger Volume I", Book 11, " Concrete Compressive I Stresses under CTH Anchorage Shims and Base Plates", ' Revision 0
- 18. Impell Instruction PI-07, " Design Verification of Base Plates, Base Angles and Embedded Plates",
Revision 3, September 16, 1986, with addendum dated January 7,1987 and January 19, 1987. '
- 19. Impe11 Instruction PI-02, " Dynamic Analysis of Cable Tray Systems", Revision 5
- 20. Impe11 Instruction PI-11. " Cable Tray System Analysis and Qualification Closecut", Revision 1 TV Electric n Comanche Peak Steam Electric Station NM 2 Id Independent Asses. ient Program - All Phases lilllllillllilllillllillllllll Job No. 84056 PRJ:RIL
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- Revision 14 Page 12 CABLE TRAY SUPPORTS Review Issues List
- i L 26. Impell Special. Study No. 5.2, " Diamond Cored ' Bolt I
- Holes", Preliminary Issue
- 27. Gibbs & Hill Specification 2323-SS-30 " Structural l Embedments", Revision 2 1
- 28. Communications Report between S. Harrison, R.
Hooten, J. Muffett, J. Redding (TV Electric);. R. j Alexandru, P. Harrison, E. Odar, M. Strehicw, 1 l (Ebasco); G. Ashley, R. Grubb, B. Ramsey (Impell); j and J. Russ, D. Leong, S. Tumminelli, W. Horstman, " i N. Williams (Cygna), dated February 13, 1987, 11:30 a.m. ; i
- 29. Transcripts of Cable Tray Hanger Design Verification j Meeting between TV Electric, Cygna Ebasco and Impell held at the CPSES site, January 26 and 27, 1987
- 30. Ebasco Calculation, " Comanche Peak SES Cable Tray i Hanger Volume 1", Book 12 "CTH Anchorage Base P. late Flexibility Study", Revision 0- l
- 31. Impell Calculation M-04, " Base Angle Stiffness",
i Revision 1
- 32. J. Metcalf (Hilti) 1etter to J. Russ (Cygna), " Data Sheets for Pullout Performance of Kwik-bolts", dated l February 3, 1987.
- 33. Transcripts of Cable Tray Hanger Design Verification meeting between TU Electric, Cygna,'Ebasco, Impell, JBA and SWEC held at the CPSES site May 19, 1987.
- 34. Impell/Ebasco Approach Towards Design Verification of Inaccessible Attributes IM-T-0210-040-238, dated May 15, 1987.
TV Electric
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- 35. Civil / structured Review Issues List, Rev. O, dated 07/21/87. )
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- 36. Communications Report between G. Ashley, et al. d (Impe11), S. Harrison (TV Electric) and W. Horstman et al (Cygna) dated May 14,1987,10:45 a.m. . f j
i
- 37. Impe11 Calculation #M-15 " Base Angle Interaction -
Diagram Development" Revision 0. y
- 38. Impe11. Calculation #M-25 " Prying Action Factors for .
Two-bolt Base Plate", Revision 3.
- 39. Communications Report between G. Ashley, (Impe11), i S. Harrison (TV Electric) and W. Horstman et al l (Cygna) dated May 14, 1987, 2:30 p.m..
- 40. Communications Report between S. Harrison (TV Electric); S. J. Chen, P. Harrison and F. Hettinger (Ebasco); and W. Horstman, D. Leong, et al (Cygna)
J dated May 1,1987, 2 :30 p.m. . ' Summary: A. Frame Connection Point and Anchor Bolt Pattern Centroid Eccentricity i In the design for the anchor bolts, Gibbs & Hill did not properly account for the eccentricity between the frame connection point to the base angle and the anchor bolt pattern centroid. The moment due to the q eccentricity may cause the base angle to rotate about its longitudinal axis, resulting in: (1)a compressive force along the toe of the angle section and (2) additional tension in the anchor bolt (s). 4 B. Safety Factor on Hilti Expansion Anchors at-SSE Level s , Gibbs & Hill's cable tray support designs employed a safety factor of 4.0 for Hilti expansion anchors for
- TV Electric .i
. . . .. .. Comanche Peak Steam Electric Station
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07/31/87 Revision 14 i Page 14 i CABLE TRAY SUPPORTS . Review Issues List 4 the 1/2 SSE load level. As discussed in Issue ! No.1, the 1/2' SSE event was assumed to govern the . support designs, without' consideration of the j reduced factor of safety on Hilti expansion' anchors j for the SSE event. The safety factor for the SSE j event will range from 2.5 to 3.0, depending on . " d building and floor elevation. i C. Inconsistent Application of ACI 349-76, Appendix B -] a Gibbs & Hill has' used the provisions of Reference 12 . to qualify several designs. Examples include the ! qualification of anchorages for Detail "11" (Gibbs & j Hill Drawing 2323-S-0905, Reference 2) and the use= < j of code provisions as justification for the factors j of safety used for Richmond Inserts. However, the ] designs do not comply with other sections of ACI 349-76, Appendix B. For example, Section B.7.3 ! states: A single expansion anchor used to anchor an j attachment shall be designed for one-half of l the design strength defined herein. For any of the cable tray support designs employing a single expansion anchor connection, this code provision would require a major reduction in the expansion anchor capacity. Cygna believes that the philosophy of the entire code appendix should be considered, rather than employing selected portions of the code. D. Factor of Safety on Richmond Inserts Gibbs & Hill's cable tray support designs employed a , l safety factor of 3.0 for Richmond Inserts for the 1/2 SSE load level. As discussed in Issue 1, the 1/2 SSE l event was assumed to govern the support designs, without TU Electric ! Comanche Peak Steam Electric Station h *IM I[. Independent Assessment Program - All Phases Il!!!!ll1111111111111111111111 Job No. 84056 PRJ:RIL m__i___ .
l f l 07/31/87 ! Revision 14 , l Page 15
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i Review Issues List l consideration of the reduced factor of safety on j l Richmond Inserts for the SSE event. The safety factor for the SSE event will range from 1.8 to 2.0, depending on the building and elevation. See Item C, above, for a discussion of ACI 349-76 as it has been applied to Richmond Inserts. , E. Richmond Insert Design
- 1. Prying action was not considered in the original design of Richmond Insert connections for cable tray j supports. To qualify those connections which use Richmond Inserts, Gibbs & Hill performed calculations which reference the results of the Richmond Insert testing program performed at the CPSES Site. (Reference 3.) These calculations showed that 1" diameter Richmond Inserts, originally designed with Ta = 10.1 kips and Va = 9.5 kips, were .
not the controlling anchorage type, but rather that the Hilti expansion anchors were the limiting case. Cygna has'the following comments regarding i these calculations: l The calculations do not account for the o instances where the allowable values for 1" diameter Richmond Inserts taken from Gibbs & i Hill Specification 2323-SS-30 (Ta = Va = 11.5 kips) may have been used without the prying factor. This situation could occur whenever a new design was performed after the issue of this specification or a CMC /DCA allowed a change which affected the Richmond Inserts i used in a support installation. Although Gibbs
& Hill has stated that their engineers were instructed to include the prying factor, Cygna could not locate any supporting documentation.
o Cygna has concerns on the use of the site testing of Richmond Inserts to justify higher
== TV Electric yL *i L.".i, 3t I.Comanche
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! CA.LE TRAY SUPPORTS l Review Issues List . l l' allowable loads than considered in the original design. See Pipe Support Review Issues List, Item 3, for additional detail.
- 2. The original design calculations for concrete connections using Richmond Inserts employed allowable values of tension (Ta = 10.1 k) and shear (Va = 9.5 kips). With the issuance of Gibbs & Hill Specification 2323-SS-30, restrictions were placed on certain Richmond Insert allowables.. Decreases in allowable tensions and shears were provided for .1 Richmond Inserts in cluster arrangements, Richmond Inserts embedded in the sides of concrete beams, and li Richmond Inserts used in spacings less than those originally considered in Gibbs & Hill designs.
Since these restrictions were imposed after the ! original design of the Richmond Insert connections l was completed, Cygna is concerned that cable tray - l supports installed using Richmond Insert clusters or l Richmond Inserts in the sides of concrete beams may not have been evaluated for the required reduction' in allowables. In discussions with TUGCO, Cygna was told that the Richmond Inserts in clusters were reserved for pipe whip restraints. Authorization to attach to these { clusters should have been obtained from the responsible TUGC0 group, and a' corresponding evaluation of the installation should have been performed. However, Cygna could not locate any TUGC0 Quality Control instructions or procedures regarding the use of these Richmond Insert clusters ; (Reference 10). ] 1 F. Connection Designs I
- 1. The cable tray support designs use angles or plates at base connections. The design drawings and' associated design change documents (i.e., CMC /DCAs) 1
- m. TV Electric
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I 07/31/87 Revision 14 Page 17 i CABLE TRAY SUPPORTS Review Issues List specify anchor bolt spacing and member placement tol erances. However, these tolerances may be outside the original design limits. ~ Gibbs'& Hill I has not fully evaluated the effects of all possible installation tolerances on the base member stresses or the ancho ages. Cygna's Phase 2 Observations CTS-00-05 and CTS-00-07 respectively addressed the design of base connections for Detail "E" supports with j three-directional loadii gs and Details "A-D" base plate designs (drawing number 2323-El-0601-01-S). .I These support connection designs must also be reviewed to assure that the above concerns are addressed. For several additional support types l considered in Cygna's Phase 4 review, the installation tolerances allowed by the design l drawings were not considered in the design cal cul ations.
- 2. For most support types, the design drawings allow l the use of either Hilti expansion anchors or l l Richmond Inserts for their anchorage to the l concrete. For support types A1 , A2, A i 2D , D '
i Detail "A" (Drawing 2323-El-0700-01-S)4, and Detail 11 (Drawing 2323-S-0905), the ' design calculations I evaluate the attachments for Hilti expansion anchors, but not for Richmond Inserts. G. Justification of Prying Factor In response to Reference 11, Gibbs & Hill support designers used a factor of 1.5 to account for the-effects of base angle / plate flexibility on anchor bolt tensile loads. The value of this factor is dependent on ' l the applied load, bolt pattern geometry, and angle thickness. Justification for the use of this factor has i not been provided. n==- TV Electric F. . - - - - Comanche Peak Steam Electric Station d @j 2 Id Independent Assessment Program - All Phases lillllililllllillllllilllillli Job No. 84056 PRJ:RIL
I 07/31/87 Revision 14 Page 18 i CABLE TRAY SUPPORTS I Review Issues List I H. Anchor Bolt Substitutions for Detail 1/1H and Details B, C and D I For Detail 1H (Gibbs & Hill Drawing 2323-S-0909),
" Hanger Connection Using Hilti Bolts for Regular Cable Tray Supports," a substitution of Richmond Inserts for Hilti expansion anchors is.. allowed by Note 14d (Gibbs &
Hill Drawing 2323-S-0901). j l Detail "1H" (Drawing 2323-S-0909) Any Hilti bolt may be substituted with existing 1" diameter or 1-1/2" Richmond Insert 'except for
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the 1-1/4" x 13-1/8" Super Kwik-bolt which may i be substituted only with 1-1/2 diameter ! Richmond Insert. J l Additional information on the allowable bolt - l substitutions are provided in DCA 2103, Revision 0: l Question: When only one Richmond Insert is 1 available for a two-bolt hanger connection, l may a combination of one Richmond Insert and l one Hilti bolt be used? If so, what is the I minimum and maximum distance between the bolts, and what is the allowable tolerance? ; 1 Answer: Yes, combinations of Richmond Inserts and Hilti Super Kwik-bolts may be used. Minimum and maximum spacing between bolts ; shall be the same as used for the "a" dimension shown in " Detail 1H, Two Bolt Hanger Connection," and the "a" and "b" dimensions shown in "Two Bolt Beam Connection." Tolerances shall be as shown in " Detail 1H," and in "Two Bolt Beam Connection." The DCA expands the scope of the substitution to include , the "Two Bolt Beam Connection" (Details B, C and D on Gibbs & Hill Drawing 2323-S-0903), and does not include TV Electric k 3 Comanche Peak Steam Electric Station A,N i I--d Independent Assessment Program - All Phases lilllillllilllllllllllll!!!Ill Job No. 84056 PRJ:RIL
07/31/87 Revision 14 i Page 19 i CABLE TRAY SUPPORTS l Review Issues List l l the restriction on the use of a 1-1/2" diameter Richmond i Insert as a substitute for the 1-1/4" x 13-1/8" Hilti l Super Kwi k-bol ts. - These substitutions are inconsistent with several aspects of the cable traj support design calculations. j The minimum bol t' spacings are 12",15" and 16" for 1" -i diameter Hilti Kwik-bolts,1-1/4" diameter Hilti Super ' Kwik-bolts, and 1" diameter Richmond Inserts, respecti vely. The tolerances specified for the connections employing only Hilti expansion anchors are different from the tolerances for the equivalent connection detail employing only Richmond Inserts. For j moment loads on the base' connections, the tensile-load J l in each anchor is calculated by dividing the applied moment by the minimum bolt spacing. The tensile load distribution due to direct pullout is calculated based on the allowed connection eccentricity. By substituting a Richmond Insert for a Hilti expansion anchor at the l Hilti spacing and eccentricity, the tensile load in the .l Richmond Insert may be greater than the previously cal cul ated 'l oad. The effect of this substitution on Richmond Insert tensile loads has not been considered in the cable tray support designs. In addition, since DCA 2103 does not limit the size of the Richmond Insert to be substituted for a 1-1/4" x 13-1/8" Hilti Super Kwik-bolt in the beam connection, a 1" Richmond Insert, which has a lower capacity than the indicated Kwik-bolt, could be used as a substitute, i Gibbs & Hill /TUGC0 was not able to provide the design verification documentation for DCA 2103 (Reference 13). , I. Base Angle Boundary Condition Assumptions For trapeze type supports, Gibbs & Hill has assumed that the hanger connections employing two-bolt base angles are free to rotate about the strong axis of the hanger. Since both the welds between the hanger and its TU Electric
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L : l 07/31/87 ' ! Revision 14 Page 20 l l CABLE TRAY SUPPORTS ! l Review Issues List l f j l base. angle and the base angle itself have significant flexural stiffness, this assumption requires.that the- , connection alla the calculated rotation without base I connection failure. Gibbs &-Hill has not justified such 1 connection behavior. (See Review Issue 26) l i Gibbs & Hill assumed that the generic transverse trapeze I frames were planar frames. The analytical models of the-frames, with the exception of the NASTRAN. system models, were also modeled as planar frames. By modeling the j supports as planar frames, rotations and translations ) out-of-plane were prevented. Therefore at the support reaction points, which were generally base angles, the only reactions that would be recovered were tension and shear on the base angle and anchor bolt (s). It must be - noted that the attachment point of the hanger members-was eccentric to the anchor bolt centerline, generally en the back of the outstanding leg of the base angle. When evaluating the base angles, Gibbs & Hill simply applied a tencion and shear to the base angle. The l distribution in tensile load to the anchor bolts due to l the location of the hanger along the_ length of the l anchor bolts was accounted for. However, the shear load I was simply divided by the number of bolts. Gibbs & Hill did not account for the eccentric application of the shear loads. Additionally, since Gibbs & Hill did not account for the out-of-plane loading of the support [ frames, they did not account for the forces acting perpendicular to the long direction of the base. angle. , Gibbs & Hill did not properly consider the case of a one-bolt base angle. These base angles were simply evaluated for the tensile and shear loads applied to them. Additional loads due to the eccentric application of reactions and out-of-plane ' loadings were not considered. Had Gibbs & Hill made such evaluations, a discrepancy in the modeling of the boundary condition would have been noted. Since the connection to the f m TU Electric Comanche Peak Steam Electric Station r*Ild iId L i Independent Assessment Program - All Phases PRJ:RIL
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i l 07/31/87 Revision 14 Page 21 l CABLE TRAY SUPPORTS Review Issues List concrete is via a single bolt, to resist the torsion due to the eccentric application of a shear reaction, friction between the concrete and the' base angle must be provided. Such considerations were not addressed. J. Installation of Expansion Anchors in Diamond Cored Holes Section 3.1.4.2.3 of Reference 4 discusses the reinstallation of an expansion bolt in.an empty but
" pre-used" hol e. Paragraph (a) of that section' states:
The bolt being replaced has' been removed from the concrete using a diamond core bit of the same nominal outside diameter as the replacement expansion bolt. The replacement i bolt shall be one diameter size larger than the bolt being removed. The Hilti " Architects and Engineers Design Manual" (Reference 5) addresses the bit type used in drilling holes for Hil ti Kwi k-bolts and Super Kwik-bol ts. On page C-4, Note 6a states: j All of the technical information pertaining to Kwik-bolts herein (e.g., pullout and shear ' l data) was accomplished using HILTI masonry carbide bits. Before installing the Kwik-bolt ! using another means of drilling (e.g.,- diamond l Core), contact your local HILTI Field Engineer for advice and proper procedures. On page C-1 (Reference 5) a footnote to the installation process description states: 1 To obtain maximum published holding values, use only HILTI carbide bits. In diFussions' with Hilti, Inc., Cygna learned that Hilti expansion anchors installed in diamond core-bored TU Electric
~~77 L'I F.i L IA L Comanche Peak Steam Electric Station Independent Assessment Program - All Phases Illlllllllllllilllllllllllilli Job No. 84056 PRJ:RIL
E 07/31/87 Revision 14 Page 22 J ! CABLE TRAY SUPPORTS Review Issues List > holes will provide ultimate strengths that are less than l those published.in the Hilti Design Manual. Primarily, , l the strength reduction is due to the diameter of the l core bore bit itsel f. It has been Hilti's experience that core bore bits are intentionally supplied at a ' larger diameter than the nominal size to account for the progressive reduction in bit' diameter over its life. l Thus, at the initial bit usage, the bit diameter will be. larger than that required for the bolt hole. . It is this t hole oversize which causes the reduction in expansion anchor capacity. In order to avoid any such strength reductions, careful , control on the bolt hole diameter must be established. J Control may be established by measuring the core bit i diameter or the Sole diameter. Cygna has not observed j l any QC procedures which impose such control. ] Additionally, Cygna did not observe any procedures which require craft or QC to document.which expansion bolts , were installed in diamond cored holes. l l K. Reduced Allowable Loads for 1" Diameter Hilti Kwik-bolts l Based on expansion anchor capacity tests performed by Hilti, Inc. in 1980, Hilti issued a letter giving ! reduced ultimate capacities for 1" diameter i Kwi k- bol ts. In response to this letter, TUGC0 issued a l Significant Deficiency Analysis Report (SDAR) (Reference 6) to evaluate the effect of the reduced I anchor bolt capacities for support installations at l CPSES. The resolution of this SDAR was to accept all i existing designs employing 1" diameter Kwik-bolts by. allowing a reduced safety factor of 3.41, and require that all future design efforts use the reduced ca paci ty. The US NRC accepted this resolution (Reference 8). TU Electric
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3 Revision 14 i Page 23 CABLE TRAY SUPPORTS .) ! Review Issues List , j I' l For the review of cable tray supports where the cable j tray load with Thermo-Lag exceeds the design load, .l Reference 7, section 3.2.2.1, paragraph'(b) states, j i All hangers shall then be evaluated for actual ) loads. During this evaluation, all pertinent design changes shall be taken into account. J Consideration shall be given to use of actual l tolerances, weld undercut-undersize,1" ) diameter Hilti' Kwik-bolt revised criteria and i actual field ' as-buil t' configuration However, Cygna's review of the subject Gibbs & Hill calculations and a discussion with TUGC0/Gibbs & Hill (Reference 9), verified that the original (unrevised) Hilti Kwik-bolt allowables had been used. TUGC0/Gibbs & Hill felt that the use of the original allowables was warranted, since the calculations reviewed an existing desi gn. This is not consistent with the requirements of Reference 7. , I Response: A. Impe11 and Ebasco have performed studies to determine i the magnitude of the effect of the eccentric loading on i ! base plates and base angles. These studies were per-formed using finite element models of typical anchorage l l configurations and accounted for both the' effects of eccentric loading and of plate flexbility (i.e. prying l a ction ) . The studies are contained in Reference 16 and ; summarized in Attachments G1 through G6 of Reference 15 l and Attachments A and F of Reference 18. l Ebasco also performed a study, Reference 17, to evaluate l the compressive stress in the concrete under the anchorage including the effects of shims under the anchorage. For support anchorage configurations not addressed by-the studies, Impell and Ebasco perform individual i 1 TV Electric
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'l analyses using finite element models' of the specific anchorage detail. 1 J
B. As discussed under Issue No'.1, the cable tray support l design verification evaluates each support for both OBE 'f and SSE loading. In accordance with Section IV.1.f.ti l of Reference 14 Section 3.3.6 of Reference 19 and I, Sections 4.1.3 and 5.1 of Reference 18,' safety factors ! of 5.0 and 4.0 are used for Hilti expansion anchors for the OBE and SSE load cases, respectively. C. See Reference 35, issue No.1. . - D. See Reference 35, issue No.1. E. All cable tray support anchorages, including these using. Richmond Inserts are individually design verified. As ! discussed under Issue No. 3.A. Ebasco and Impell have performed studies to determine the correct anchor bolt l loads, including the effect of prying action. Per Reference 33, Richmond Insert capacities are being verified by SWEC. For a discussion of Richmond Insert allowables, capacities of Richmond Inserts located in L beam sides, capacities of Richmond. Insert clusters, !, etc., see Reference 35, Review Issue No.1. l l F. The cable tray support design verification evaluates the anchorages for each individual support.. . The use of generic support anchorage details and the numerous- : l design changes is no longer a concern. See Section l l 111.2 of Reference 14 and Section 4.0 of Reference 18 I for the Project requirements. However, as discussed in Reference 29. Ebasco evaluates certain supports by , 4 l :
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L " grouping like supports and analyzing an ' enveloping support configuration. See Issue No. 27 for a discussion of the support grouping techniques. G. The finite element models used in the base plate and base angle studies discussed in Issue No. 3.A provided justifications for the prying factors now used by the P roject. H. In accordance with Section III.2 of Reference 14 and Section 4.0 of Reference 18, the design verification of I support anchorage will be based on the as-built support configurations. For supports which are fully accesible, anchor bolt substitution is .no longer of concern. For supports which have inaccessible attributes (e.g., anchor bolts that are covered with thermalog, inaccessibility due to congestion, etc.) the Project has issued a joint Impe11/Ebasco approach towards design verification of inaccessible attributes. (Reference 34.) Cygna is presently reviewing this document. I. Ebasco and Impe11 have performed finite element studies to develop the appropriate boundary conditions for use with the cable tray support modeling. .) Ebasco's study is documented in Reference 30 and summarized in Section III and Attachment G9 of Reference 15. All base plate / base angle configurations are assumed to be rigid for transnational' displacements and spring constants are developed for the three rotational displacements. The spring constants were developed for a larg:: number of standard anchorage configurations, and Reference 15 requires that spring : constants be developed individually for any support which does not confonn to one of the standard j configurations. l The Impe11 study is documented in Reference 31, and summarized in Section 3.2.5 of Reference 19. Impell TV Electric
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1 07/31/87 i Revision 14 Page 26 I l. CABLE TRAY SUPPORTS I Review Issues List assumes that the anchorage is rigid for transnational displacements and for rotations about the two geomethric axes of the base angle. Spring constants were developed for rotation about the longitudinal axis of the base ! angle only. The stiffness values are only a. function of the number of anchor bolts and thickness of the base { angl e. Unlike Ebasco, Impe11 does provide a large i number of stiffness values and does not require that spring constants be developed for non-standard anchorage j configurations. This is discussed in Reference 28. I { Cygna has discussed the eccentric application of post I reactions on one-bolt base angles with Impell (Reference )
- 36) and also noted during the audits that these reaction j were not considered by Ebasco in their base angle (
analyses. Impell stated that the primary effect of the i eccentricity would be torsional stresses in the post member. Impell also stated that they felt such increases would be negligible. Cygna also asked Impe11 about why they did not consider the eccentricity between , the axial post load and the back of the outstanding leg I of the base angle. This eccentricity was neglected in the determination; of the base angle stiffncsses and the support modeling for the systems analyses. Impell stated that they also felt that the effect of the eccentricity was negligible. (Reference 36.) i J. See Reference 35, issue No. 7. l K. The cable tray support design verifications effort will use the reduced capacities for 1 inch diameter Hilti Kwi k-bol ts. These values are specified in Appendix 2 of 1 Reference 14 and Attachment B of Reference 18. ) Status: A. Eccentricity between bolt pattern centroid and attach-ment point: Open: Cygna has reviewed the base plate studies and the methods used to analyze anchorage configurations which e -+ TV Electric __ Comanche Peak Steam Electric Station ! ENN 2 Id Independent Assessment Program - All Phases illllllllillllllilillllllillli Job No. 84056 PRJ:RIt i e.___----_-__.
07/31/87 i Revision 14 I Page 27 CABLE TRAY SUPPORTS 1 Review Issues List ; were not enveloped by the studies. Cygna had expressed concerns on the direction of the applied loading used ' 1 for the individual baseplate analyses (References 28 and -
- 29) but these were to be. addressed by Ebasco (Reference 40). Cygna has questioned the effect of shims on the results of the studies performed by Ebasco' and Impe11, i
and, as such Cygna is ' reviewing the grouting and 1 shimming procedures provided by TV Electric.-
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Richmond Insert allowables, prying action, cluster allowables and SS-30 restrictions:
'This issue is considered closed for cable trays:
See Reference 35, issue No. I for Richmond Insert allowables, cluster allowables and 5S-30 restrictions. Prying action is considered by Ebasco and Impe11 for the support design verification. Justification for Prying factor 1.5: Open: Impe11 and Ebasco have performed studies- to l' determine appropriate prying factors. Factors in some l cases are greater than originally _ used by Gibbs & Hill'. Cygna's review indicates that the prying factors ! used by Ebasco and Impe11 are identical. However, the configurations considered by Impell differ from those considered by Ebasco. Cygna is evaluating these differences as part of the cumulative effects review. See Issue 29. Base angle boundary conditions: Open: Impe11 and Ebasco have performed separate studies to determine appropriate boundary condition (trans-lational and rotational stiffnesses)' for use in support model s. The results are different for both cons ul tants. Cygna is currently evaluating the effects of the differences between the base boundary stiffness values as part of the cumulative effects review. Cygna TV Electric Comanche Peak Steam Electric Station d 'i! N t3IyA4 Independent Assessment Program - All Phases 1111lll1111!!I1111111111111111 Job No. 84056 PRJ:RIL l
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Revision 14 Page 28 CABLE TRAY SUPPORTS Review Issues List -l d I is also considering the neglect of the eccentricity ; between the post centerline and the' back of the base 1 angle's outstanding leg as. part of the same review- ) impell and Ebasco must address the: effects'of eccentric load application on one-bolt base angles. , B. Closed. C. Closed for cable trays. For status see Reference 35, issue No.1. D. Closed for cable trays. For status see Reference 35, j issue No.1. E. Open: See Issue No. 3.A for the status of the review of , the ' studies which determine prying action factors. See Reference 35,, Issue No.1. for the status.of the review of the Richmond Insert allowables. F. Open: Generic designs are no longer used. However, see Issue No. 27 for the status regarding Ebasco's support l grouping method which affects this issue. i t i G. See Issue No. 3.A for status. . j H. Closed for all supports which are accessible. See Issue No. 20 for the status regarding supports with inacces-sible attributes. l I. Open: See Issue No. 3.A for status. J. Closed for cable trays. For status see Reference 35, , issue No. 7. I l K. Closed. 4 TV Electric me - Comanche Peak Steam Electric Station ' t A NJL A. Independent Assessment Program - All Phases 11111ll1111111111ll1nllll1111 Job No. 84056 PRJ:RIL ;
07/31/87 Revision 14 Page 29 1 l CABLE TRAY SUPPORTS Review Issues List l
- 4. Design of Compression Members j I
References:
- 1. Gibbs & Hill Calculation Binder 2323-SCS-1010, Set 1
- 2. Gibbs & Hill Calculation Binder 2323-SCS-215C, Sets 2-6
(
- 3. N.H. Williams (Cygna) letter to J.B. George (TUGCO), l
" Cable Tray Support Review Questions," 84056.022, dated August 17, 1984, question 4
- 4. Timoshenko and Gere, " Theory of Elastic . Stability," 2nd Edition, pages 99 and 100
- 5. N.H. Williams (Cygna) letter to J.B. George (TUGC0),
" Cable Tray Support Review Questions," 84056.041, dated February 12, 1985
- 6. Ebasco Instruction, " General Instructions for Cable Tray Hanger Analyses for Comanche Peak SES Nos.1 and 2",
Revision 4 7 Ebasco Calculation, " Comanche Peak SES Cable Tray Hay,ger ! Volume I", Book 6. " Buckling Study", Revision 1 i
- 8. Impe11 Report No. 01-0210-1470, "E ffective-Length Factors or Buckling of Cable Tray Supports",' Revision 1
- 9. Impe11 Report No. 09-0210-0018, " Slenderness Ratio Limits for CPSES Cable Tray Supports", Revision' 0
- 10. Ebasco Procedure SAG.CP.09, " Instructions for Re-Evaluation of Cable Tray Hangers Affected by the Longitudinal Tie of Transverse Hangers to the Tray",
Revision 0
- 11. NCIG-01, " Visual Weld Acceptance Criteria", Revision 2 I
= "
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- 12. Ebasco Calculation, " Comanche Peak SES Cable Tray Hanger l Volume I", Book 16. "CTH Dimensional Tolerances",
Revision 1
- 13. Ebasco Procedures SAG.CP4, " Seismic Design Criteria for Cable Tray Hangers for CPSES Unit 1", Revision 3 and' 1 SAG.CP3, " Seismic Design Criteria for Cable Tray Hangers )
for CPSES Unit 2", Revision 6 j i
- 14. Impe11 Instruction PI-03, " Qualification of Cable Tray I Supports", Revision 4 )
- 15. Impe11 Instruction PI-02, " Dynamic Analysis' of Cable i Tray Systems", Revision 5 ,
- 16. Impe11 Report 09-0210-0017, "CPSES Cable Tray System Analysis / Test Correlations, Revision 0
- 17. Communications Report between S. Harrison, J. Muffett (TV Electric); P. Harrison (Ebasco); R. Wheaton, B.
Ramsey (Impell); and N. Williams, S. Tumminelli, D. Leong, J. Russ, W. Horstman (Cygna), dated March 6, .l 1987,11:30 a.m. l l
- 18. Transcripts of Cable Tray Hanger Design Verifications Meeting between TV Electric, Cygna, Ebasco and Impell held at the CPSE site, January 26 and 27,1987.
- 19. Transcripts of cable Tray Hanger Design Verification meeting between TV Electric, Cygna Ebasco, Impe11, JBA and SWEC held at the CPSES site, May 19, 1987.
- 20. Impe11 Calculation No: M-56 " Procedure for Refined ,
Effective Length Factor". ,
- 21. Communications Report between G. Ashley (Impe11) and W.
Horstman et al (Cygna) dated May 15, 1987, 12:30 p.m. I TV Electric rilmi Comanche Peak Steam Electric Station t'$i LPJ L IAT Independent Assessment Program - All Phases ll11!!!111111111111111111!!!!I Job No. 84056 PRJ:RIL
07/31/87 Revision 14 Page 31 CABLE TRAY SUPPORTS Review Issues List , i
- 22. Communications Report between S. Harrison (TV Electric);
~
G. Ashley and R. Kaczkowski (Impe11); D. Williams (QEST); and J. Russ (Cygna) dated July 10, 1987, 10:00 a.m.
- 23. Communications Report between P. Harrison and F.
Hettinger (Ebasco); S. Harrison and J. Nandi (TV Electric); and J. Russ and N. Williams (Cygna) dated July 13,1987, 7 :00 a.m. Summary: A. Compression Members with Slenderness Ratios'in I Excess of 200 In the design of compression members for trapeze type support frames, Gibbs & Hill did not consider.the entire unsupported length of the channels to calculate the slenderness ratios (Reference 1, Sheets 11 and 18 for support types A 4 and B4 , respectively). If the correct unsupported lengths and pinned end conditions are l assumed, the slenderness ratio of these members for ) l bending about their weak axis will exceed 200. AISC j l Specification Section 1.8.4. limits the slenderness l ratio for compression members to 200. 1 l B. Consideration of In-plane Sidesway In calculating the slenderness ratio of the compression , members for trapeze-type supports, Gibbs & Hill did not ' check the effectiveness of the in-plane sidesway restraint for the various support designs. This is discussed in Section 1.8 of the Commentary to the AISC Specifications. 4 C. Unsupported Lengths and Effective Length Factors for Cantilever Type Supports In the design of the compression member for cantilever type supports (e.g., SP-7, Detail s E, F, G, and H on Drawi ng 2323-El-0601-01-S , etc. ) Gibbs & Hill used the L-h_ k . . . __ _ TU ElectricPeak Steam Electric Station Comanche [*$Uj [Id Independent Assessment Program - All Phases
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07/31/87 Revision 14 Page.32 l CABr_E TRAY SUPPORTS Review Issues List distance from the face of the concrete to the centerline I of the cable tray as the cantilever length. The correct length should be from the concrete face to the clamp in the far side of the tray. i A value of k = 1.0 was used to calculate the minor axis i slenderness ratio, rather than the value of k = 2.0 for l cantilevers. A val ue of k = 1.0 i s ba sed on ' the ! assumption that the tray will provide lateral bracing at j the clamp location. ) I D. Effect of Weld Undercut in Regions of Maximum ) Compression { For the trapeze type supports, Gibbs & Hill has not considered the effect of weld undercut on the section properties of compression members at the point where in-plane braces are attached to the channel web. As shown in the Working Point Deviation Study (Reference 2), high stresses exist in the region of the brace attachment and may increase if the reduced section properties are considered. E. Effect of Out-of-Plumbness on Compression Members ) The design of compression members assened that the applied axial loat was parallel to the memWr his. Gibbs & Hill Installation Specifications 2323-SS-16b j allows an installation tolerance of 2 degrees from plumb for vertical members. Cygna was unable to locate calculations considering the effect of this tolerance. See Reference 5 fer a discussion of this issue. ' l F. Redaction in Unsupported Length of Compression Members l Due to Outstanding Leg of Base Angle For trapeze type supports in the Working Point Deviation Study (Reference 2), Gibbs & Hill reduced the unsupported length of the hangers by 5". This appears to be due to an assumption that the outstanding leg of n= E TV Electric
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CABLE TRAY SUPPORTS -1 Review Issues List . J l the' L5x5x3/4 base angle is rigid with respect to the l C6x8.2 hanger.- However, the minor axis moment of inertia for the C6x8.2 is-greater than the corresponding. moment of inertia for. the.L5x5x3/4; therefore, the buckling hinge would occur within the base angle rather than at a point in the hanger below the base angle, and the reduction in unsupported length.is unwarranted. G. Consideration of the Allowed Range of Brace Slopes i I For the design of braces in compression, the axial . force is a function of the brace slope. Gibbs' & Hill designs provide a range of allowable brace slopes. In some. cases, Gibbs & Hill calculations check the brace for the slope which results in the largest' axial load without considering other cases which have lower loads, but also i have reduced capacity due to a longer member length. Response: A. The design verification of compression members uses .the entire member length. This is in accordance with Ebasco criteria (Reference 6, Attachment E) and Impell criteria , (Reference 14). '! Studies were performed by Ebasco (Reference.7) and l Impe11 (Reference 8) to determine the appropriate effective length factors (k) for typical . cable tray support member configurations,. These k factors are used in conjunction with the unsupported member lengths to calculate the member slenderness. ratios. In the development of the k-factors Impell assumes that the cable trays provide bracing to the cable tray < support to prevent out-of-plane translation of the support due~ to friction between the cable tray and. the , support components. Impe11 feels that friction is justified based on the resultstof the cable tray system testing program. (Reference 16.) See Issue No.18 for a ! TU Electric f 3 Comanche Peak Steam Electric Station LNPJ i [43 Independent Assessment Program - All Phases lilllilllllililllillllllllilli ' Job No. 84056 PRJ:RIL
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'Page 34-CABLE TRAY SUPPORTS Review Issues List discussion of tray clamp behavior..
j In Ebasco's development of k-factors, no friction 4 i between the trays and clamps is assumed. The calculated ! k-factors are generally larger than those used by Impell . However, Reference 6 includes two sets of l k-factors, those based on Ebasco's studies without i friction and those based on Impell'_s studies with friction. The AISC has provided an interpretation clarifying the i definition of " compression members" and " tension mem-bers" as used in Section 1.8.4 of the AISC Specifi- ] cations. Members satisfying the definition of compres-sion members must satisfy a slenderness ratio of 200 and other limits on member. compressive stress levels. Tension member slenderness ratios are limited to 300. This is documented in Reference 9. B. The design verification of cable tray supports do not , consider the effects of in-plane sidesway in calculating ) the slenderness ratios for the compression members. Ebasco and Impell have indicated (Reference 18) that for the typical trapeze support, in-plane sidesway is associated with the major axis of the vertical channels ! while the out-of-plane buckling is associated with the ! l minor axis. Since the minor axis slenderness ratio l typically governs, there is no need to consider in-plane q sidesway. l l i Ebasco, in Reference 6, requires the use of k = 1.0 for l in-plane buckling of trapeze type support members and j k = 2.0 for cantilevered supports and both components of l L-shaped supports. Impell provides similar requirements in Section 4.1.3 of Reference 14. In References 21 and 22. Impell agreed to provide a study of k-factors for in-plane sidesway for those supports whose posts are rotated 900 . Ebasco has. also < agreed to provide a similar study. (Reference 23.) 4 TU Electric t -- N @)T[I[ Comanche Peak Steam Independent Assessment Electric Program Station
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C. In accordance with Reference 14, Section 4.1.3, Impe11 uses the distance from the face of the concrete to the j! outermost clamp location for the unsupported length. A value of k = 2.1 is used for' buckling perpendicular to the tray. For buckling parallel to the tray, bracing from the tray is assumed and the k-factors developed in Reference 8 are used. The assumed bracing provided by the tray is justified in Reference 16. Reference 6, Attachment E, provides Ebasco's criteria for the buckling of cantilever type supports. The calculation of the unsupported length is based on the type of tray clamps used. The unsupported length is ; equal to the distance from the face of the concrete to l the clamp which will transmit compressive axial load. A value of k = 2.0 is used for buckling about each axis. However, Paragraph 10 of Attachment E allows the consideration of coanectivity between the tray and the support in the tray axial direction and permits the use of the k-factors developed by Impell for minor axis i buckl ing. - l l l D. Since the supports will be individually evaluated based 1 l on the as-built support configuration, weld undercut 1 does not have to be considered on a generic basis. The project is performing weld inspections in accordance with Reference 11. If the welds satisfy the undercut ! limitations given in Reference 11, undercut will not be considered in the analyses, otherwise the weld will be repaired. Therefore, there is no need to consider weld undercut in the regions of maximum compression. E. Only members that are greater than two degrees out-of-plumb are to be individually evaluated. I f a member i s 4 less than or equal to two degrees out-of-plumb, any effects on the member are considered negligible. Thi s is based on a study performed by Ebasco (Reference 12) and the results of the cable tray system testing - TV Electric P Comanche Peak Steam Electric Station l L*i Fii3Id Independent Assessment Program - All Phases PRJ :RIl. 1111111111!!!!!11!I11111111111 Job No. 84056 (
07/31/87 Revision 14 Page 36 CABLE TRAY SUPPORTS Review Issues List y l (Reference 16). Ebasco's requirements are given in Attachment E of Reference 6 'and Impell's' requirements - are given in Reference 15. Section 3.2.1. F. The entire member length, measured from.the face of the concrete, will be used by both Ebasco and Impell. in l calculating the unsupported member length. Ebasco's procedure is contained in Reference 6,. Attachment E. Impell's procedure is noted in Reference 15, 1 Section 3.2, Reference 14, Section 4.0 and Referer.ce '8. l l G. This is no longer an issue. The design verifict. tion is , based on the as-built configurations of all supports. 1 Therefore, actual brace slopes are used without the need to consider the range of slopes allowed by the original j desi gn. Status: A. Open: Cygna is concerned about the application of the i results of the k-factor studies to support J configurations not addressed in the studies. Impell and i Ebasco must provide justification for use of the l existing values to these configurations. B. Open: Cygna is concerned about the use'of k = 1.0 for in-plane sidesway of longitudinal . trapeze type supports (e.g. L-Ai , L-A 4, etc) which have the vertical channels t oriented so that their minor axis is associated with in- ' plane sidesway. The use of k = 1.0 also affects the calculation of F'e used in AISC equation 1.6 - la to consider the moment magnification effect. ~ Impell and Ebasco have agreed to provide a study on k-factor for in-plane sidesway. { C. Closed: Cygna has reviewed Impell and Ebasco procedures and agrees with the lengths-used in. calculating the effective length. Additionally, Cygna has. reviewed the Impell PI-11 procedure for refined effective length.and agrees that it provides a conservative methodology. TV Electric [*hM [I[. Comanche IndependentPeak Steam Assessment Electric Program.- Station All Phases lillilillllllllllillllllilllli Job No. 84056 PRJ:RIl t
! j 07/31/87 l Revision 14 Page 37 j si CABLE TRAY SUPPORTS- l Review Issues List D. Open: See status for Issue 33. E. Open: Cygna will review References 12 and 16 for l acceptability. The effect of this must be considered in the cumulative effects evaluation. See Issue No. 29.- , F. Cl osed. G. Closed. 1 i l l l t
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- 5. Vertical and Transverse Loading on Longitudinal Type Supports
]
References:
- 1. Gibbs & Hill Calculation Binder 2323-SCS-101C, Set 2 1
- 2. .N.H. Williams (Cygna) letter to J.B. George (TUGCO),
" Cable Tray Support Review Questions," 84056.025, dated 1 August 21, 1984, questions 3 and 4 i
- 3. R.E. Ballard (Gibbs & Hill) letter to N.H. Williams I (Cygna), GTN-69437, dated September 10,1984, with -
attached calculations
~
- 4. Git.bs & Hill Calculation Binder 2323-SCS-1010, Set 5 i
j 5. Ebasco Instruction, " General Instructions for Cable Tray l Hanger Analysis for CPSES Nos. I and 2", Revision 4 ! 6. Ebasco Procedure SAG.CP11 " System Analysis for Cable Tray and Hanger Assembly for CPSES, Units 1 & 2", Revision 2
- 7. Impe11 Instructions PI-02, " Dynamic Analysis of Cable )
Tray Systems", Revision 5 Summary: Longitudinal trapeze type supports (e.g. , L-A1 , L-A4 , L-C4 , etc.) were assumed to act independently of the transverse supports (see Reference 4). Calculations for these ; longitudinal supports (Reference-1) only considered j longitudinal cable tray loads in the design of frame members i and anchor bolts. Since these supports are rigidly l connected to the cable trays with " heavy duty clamps," a tributary tray mass will be associated with these supports. Given this type of tray connection, Cygna has questioned whether these supports must be' additionally designed for vertical and possibly transverse seismic loads similar to i the transverse supports (References 2 and 3). Response: The Ebasco and Impe11 cable tray support evaluations will consider the effects of three dimensional loading on r TV Electric Comanche Peak Steam Electric Station F*$ Fj [ Id L Independent Assessment Program - All Phases illllilllllllllllllillllllilli Job No. 84056 PRJ :RIL
'i 07/31/87 'l Revision 14 ,j Page 39 CABLE TRAY SUPPORTS I Review Issues List {
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- longitudinal trapeze.- supports. This is implemented in i
! Reference 6 and Attachments 82, Y and Z of Reference 5 for i Ebasco's evaluations and Section 3.3.5 of Reference 2 for j Impell's evaluation. l Status: Closed, l-j l
- TV Electric
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- 6. Support Frame Dead and Inertial Loads
References:
- 1. Gibbs & Hill Calculation Binder 2323-SCS-101C, Set 5, I l
" Cable Tray Supports (Design Criteria and Reference)"
l
- 2. Ebasco Instruction, " General Instructions for Cable Tray I Hanger Analysis for CPSES Nos. I and 2", Revision 4 j i
- 3. Impell Instruction PI-02, " Dynamic Analysis of Cable. ]
Tray Systems", Revision 5 i I
- 4. Impell Report, 09-0210-0017, "CPSES Cable Tray System I Analysis / Test Correlation", Revision A I
- 5. Ebasco Procedure SAG.CP11. " System Analysis for Cable l Tray and Hanger Assembly for CPSES Units 1 & 2", j Revision 2 l
- 6. Transcripts of Cable Tray Hanger Design Verification meeting between TU Electric, Cygna, Ebasco, Impell, JBA ans SWEC held at the CPSES site, May 19, 1987.
l
- 7. Ebasco response EB-T-3029, attachment 5, dated I 05/15/87: " Nodal Point Spacing for Braces" l 8. Communications Report between P. Harrison et al (Ebasco) and W. Horstman, et al (Cygna), dated June 23, 1987, 10:00 a.m.
Sumary: A. Out-of-plane Inertial Loads Out-of-plane inertial loads (i.e. loads in the direction parallel to the cable tray) were not considered in the design of two-way cable tray supports. Such loads should, as a minimum, be considered in the design of base connections and anchorages. Assuming that tray clamps are able to transmit the loads from the two-way supports to the cable trays, out-of-plane inertial loads from the two-way supports must also be considered in the i I p TV Electric r,. Comanche Peak Steam Electric Station LS B ("j ( Id Independent Assessment Program - All Phases 111111lllll1111111111111111111 Job No. 84056 PRJ :RIL
07/31/87 Revision 14 Page 41-l CABLE TRAY SilPPORTS Review Issues List member and anchorage design of longitudinal supports. (See Review Issue 18.) B. Support Dead Weight Gibbs & Hill did not consistently consider support dead ! loads. The support design calculations considered support wet ght in one of the following ways: (a) The support weight was not considered. (b) The support weight was considered as a surcharge on the tray, in addition to the tray and cable weight. ! Usually, this value was given as 5 psf. :
)
(c) The support weight was calculated by considering the i actual weight of each of the support's frame members. I (d) A dead load equal to one half the support weight was : used as required by Reference 1, Sheet 3. I l l Method (b) also led to other problems in the support ! I desi gn. Initially, the tray unit weight was considered j as 35 psf. When the " effective" support weight of 5 psf was added to the cable tray unit weight the result was a total assumed tray design load of 40 psf. At a later point in time, when design changes were issued against the supports or a revised analysis was required, the designer reduced the design weight from 40 psf to 37.5 psf, or even 35 psf to remove some " conservatism" from the design loads in order to qualify the support. By doing so, the designer removed a portion of the support weight. Response: A. The dynamic testing of cable tray system models, as discussed in Reference 4, has demonstrated that friction type clamps will prevent relative displactnent between the supports and the cable trays in the tray axial TV Electric Comanche Peak Steam Electric Station NId t h,. Independent Assessment Program - All Phases lillilllillikillilillllllilli Job No. 84056 PRJ :RIL
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CABLE TRAY SUPPORTS Review Issues List I ( di rection. This effect could allow for the transfer of a portion of the out-of-plane inertial loads for a transverse support to a longitudinal support elsewhere i in the cable tray system. ! (See Issue No.18)' The two consultants have taken different approaches to the resolution of this issue. For the static and equivalent static analysis of transverse cable tray ]
)
supports, Ebasco does not assume connectivity between 1 the tray and the support for the transfer of j out-of-plane loads. This assumption is noted in J I Attachments B1, Y and 2 of Reference 2. - Thus, the out-of-plane inertial loads are resisted solely by the transverse support. For cases where the support 3 evaluation is performed using the response spectrum method, as discussed in Reference 5, connectivity l between the tray and any transverse support is not I l considered. However, a sufficient number of analyses assuming connectivity are to be run to show that.the assumption of no connectivity is conservative. I Impell performs the cable tray support evaluations using system models and response spectrum analyses. In accordance with Reference 3, seismic loading is applied , simultaneously in three orthogonal directions, thus I i accounting for the out-of-plane inertial loading. Impell's analyses consider connectivity between the transverse supports and the tray, hence, the out-of-plane inertial loads on the support are shared between the support under consideration and the l 1 longitudinal supports elsewhere in the cable tray . system. l When modelling the cable tray supports, Impell provides nodes at load application points, member connection I points, and at intermediate points within an individual l member's l ength. Ebasco provides nodes only at load ! application and member connection points. In support of such modeling practices, Ebasco provided Cygna with a y - TV Electric
, Comanche Peak Steam Electric Station psa.-Fj- 3iI -d Independent Assessment Program - All Phases i*h Illl!!Illllllilllllllillllllli Job No. 84056 PRJ:RIL 1
s i 07/31/87 i Revision 14' i Page 43 l l i CABLE TRAY SUPPORTS' L Review Issues lht ) l study. (Reference 7.) Cygna reviewed this study ' (Reference 8) and requested confirmation from Ebasco that both dead load and self weight excitation were q considered in calculating the additional contribution to j member interaction. Ebasco stated that the additional stresses in the study were from member deadweight and. jl inertial loads. ' B. The support member dead weight is included in the l support models, for both the equivalent static and 1 response spectrum analysis methods. This is specified I in Attachments B1, B2, Y and 2 of Reference 2 and Reference 5 for Ebasco and in Section 3.3.2 of Reference 3 for Impell - Status: A. Open: Ebasco's study has addressed Cygna's. concerns. i regarding the effects of member deadweight and inertial ! loads within the member's length. The response was in-the form of a sampling of member stresses for approximately 200 support members. Ebasco must provide assurance that study results envelop the remainder of l the affected plant population. l B. Open: See status for Item A above. I i . i l I
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CABLE TRAY SUPPORTS Review Issues List 3 l i
- 7. Design of Angle Braces Neglecting Loading Eccentricity l
References:
- 1. N.H. Williams (Cygna) 1 etter to J.B. George (TUGCO),
" Cable Tray Support Review Questions," 84056.025, dated August 21, 1984, questions 3 and 4 ,
- 2. N.H. Williams (Cygna) letter to.J.B. George (TUGCO),
" Cable Tray Support Review Questions," 84056.027, dated j August 27, 1984, . question 2 4
- 3. AISC, " Specifications. for the Design, Fabrication and-Erection of Structural Steel for Buildings", 7th ,
Edition, Sections 1.15.2 and 1.18.2.4
- 4. Gibbs & Hill Calculation " Cable Tray Support Type SP-7 With Brace. Brace Eccentricity Calculations." Cygna Technical File 84056.11-1.228
- 5. Gibbs & Hill Calculation " Verify the Adequacy of Brace L3x3x3/8 of the Governing Support Case 3C ." Gibbs &
Hill Calculation Binder 2323-SCS-1010, Set 1, Revision 1, dated 11/16/84
- 6. Gibbs & Hill Calculation " Justify the Use of Two i L3-1/2 x 3-1/2 x 3/8 Angles to Take the Appropriate Load l and Moment Individually in the Longitudinal Tray.
l Supports at the Lower Brace." Gibbs & Hill Calculation Binder 2323-SCS-101C, Set 2, Revision 6, dated 9/15/84 l 7. Ebasco Instruction, " General Instructions for Cable Tray Hanger Analysis for CPSES no.1 and 2", Revision 4
- 8. Impell calculations M-12, " Qualification Procedure for Cable Tray Support Evaluations", Revision 2
- 9. Impell Instruction PI-03, " Qualification of Cable Tray Support", Revision 4 TV Electric
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- 10. Impell Instruction PI-02, " Dynamic Analysis of Cable Tray Systems" Revision 5
- 11. Transcripts of Cable Tray Hanger Design Verification Meeting between TU Electric,_Cygna. Ebasco and Impell held at the CPSES site on Januar. 26 and 27, 1987-
- 12. Communications Report between S. Harrison, J. Muffett (TV Electric); P. Harrison (Ebasco); R. Wheaton, B.
Ramsey (Impell); and N. Williams, S. Tumminelli, D. Leong, J. Russ W. Horstman (Cygna), dated March 6, J 987,11:30 a.m.
- 13. Transcripts of Cable Tray Hanger Design Verification Meeting between TU Electric, Cygna Ebasco, .Impell, JBA and SWEC held at the CPSES site, May 19, 1987.
- 14. Impell Report. 05/15/87; Criteria for Single Angle Design IM-P-010 Revision 0, dated May 15, 1987.
- 15. Impe11 Calculation M-22, Revision 5.
- 16. Communications Report between G. Ashley (Impe11); S.
Harrison (TV Electric) and W. Horstman (Cygna); dated, , May 14 1987, 2:30 p.m..
- 17. Communications Report between G. Ashley (Impell); S.
l Harrison (TV Electric) and W. Horstman, et al (Cygna); dated, May 12, 1987, 3:00 p.m. ;
}
I 18. Communications Report between G. Ashley (Impe11) and W. Horstman (Cygna), dated, May 13,1987,10:00 a.m. . , 19. J. P. Padalino (Ebasco) letter to 0. W. Lowe (TV l Electric) " Design Criteria for Resolution of (Cygna) I Concerns". EB-T '3126, dated June 18. 1987.
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l a u - TV Electric Comanche Peak Steam Electric Station [ 82 (d.) L'Id Independent Assessment Program - All Phases l' lilllililllillllllllllllllilli Job No. 84056 PRJ :RIL 1 __________________a
f l_ 07/31/87 l Revision 14 Page 46 CABLE TRAY: SUPPORTS !. ' Review Issues List
- 20. Communications' Report between S. Harrison (TV Electric);-
G. Ashley. R. _Kaczkowski (Impell);' D. Williams (QEST); and J. Russ (Cygna), dated July. 10, 1987, 10 :00 a . m. . .
- 21. Communications Re' port between S. Harrison, J. Nandi (TV Electric); S. J. Chen, P. Harrison, F. Hettinger (Ebasco); and, J. Russ, N. Williams. (Cygna), dted July 13,1987, 7 :00 a.m. .
Summary: A. Double Angle Braces Longitudinal cable tray supports frequently use double angle sections as bracing to resist the longitudinal loads (e.g. , L-A4 , L-B4 , etc). For, the member. design, loads were assumed to produce only axial' stresses. The induced bending stresses due to the eccentric end connections were not conside' red. Neglecting these flexural stresses can result in members which are under-desi gned. The design of the double angles assume that the angles behave as a composite member. However, no intermittent filler plates are provided as required by the AISC Specification, Section 1.18.2.4. Thus, the double angles must be considered to act independently. , See Issue No.14.D. f l B. Single Angle Braces Transverse and longitudinal cable tray supports typically use angle sections as in-plane braces to resist transverse loads and provide bracing points on the vertical members (e.g. ,3A , 4A , 8 3
, B4 , L-A4 , etc) and for longitudinal bracing on some support types (e. g. , L-A. , SP-7_ with brace, etc. ). For the member design, loads were. assumed to produce only axial stresses. The induced. bending stresses due to eccentric end conditions were'not considered. Though .it is not explicitly stated in the AISC Specifications, it is standard practice (Reference 3, Sheet 3-59) to consider mm TV Electric -
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1 07/31/87 Revision 14 a Page 47 CABLE TRAY SUPPORTS Review Issues List l the bending stresses due to end connection eccentricity and check the interaction ratio considering the 1 principal axes section moduli. l C. Twist Buckling , i l Single angle longitudinal braces are typically connected l to the support frame by welding along the legs of the angl e. Some brace designs provide welding on only one angle leg at one end of the brace; while, at the other end of the brace, welding is provided on the opposite angle leg. Such end conditions may lead to failure by I twist buckling at load leve? s below the critical value I for Euler buckling. Twist buckling may also be a concern for angles which are supported by welding on the l l same leg at each end. Response: A. In Reference 7 Attachment E and Reference 10 l Section 3.2.3, it is required that filler plate spacing ! be checked in accordance with Section 1.18.2.4 of the- { AISC Specification. If these requirements are not ) satisfied, composite action will not be assumed. ' Further, Cygna's audit indicates that Impe11 conservatively includes only one of the two angles in i the support model when the requirements of Section 1.18.2.4 are not met for double angles. B. In accordance with Reference 7 Ebasco models all angle sections as pin ended (truss) members. The effect of the eccentric loading on the braces is considered by applying a bending moment to the end of the brace which is equal to the calculated axial load multiplied by the connection eccentricity. This is done us4g hand - calculations performed after the finite element analysis , has been completed. The bending moment is resolved into two components relative to the angle section's principal axes and bending stresses are calculated in accordance with Reference 3, sheet 3-59. g_ TU Electric Comanche Peak Steam Electric Station ; ri. $i* 8- ) isI, A Ir"jependent Assessment Program - All Phases ! lilllllillllllllilllllllllllli Job No. 84056 PRJ:RIL i
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07/31/87-Revision 14 Page 48 l CABLE TRAY SUPPORTS Review Issues List Ebasco calculates axial allowables for single angles t using the minor principal axis radius of gyration. .The bending stress allowable is 60% of the yield stress for the normal'1oad condition (0BE). Cygna had expressed concerns that the actual bending allowable was less than l that specified by Ebasco. Ebuco performed a. comparison l between the bending allowable specified in the ! Australian steel specifications and their bending 1 all owabl e. This comparison showed that the bending
- allowable was no greater than or'less than the bending I allowables specified in the Australian code for the range of brace lengths within Ebasco's scope.
l (Reference 19). l Impell models brace members using' beam elements and ignores the connection eccentricities. Impell perfonned a study (Reference 8, Appendix B) which showed that neglecting the connection eccentricities was more conservative in the calculation of axial forces in the brace. However, this study does not adress the impact of the end eccentricities on the bending moments in the brace. Additionally, the study concluded that proper end condition assumptions for the brace were important to obtain the proper member response. Impe11 concluded for the case where the brace member was welded to the back of the post member, the moments induced in the brace were significant. Similarly, the same would be true for braces connected to gusset plates. Impell considers moment fixity on all axes except that which would cause out-of-plane displacement of the brace. The gusset plate configuration was not addressed by the Impell study. Impe11's conclusion regarding the boundary conditions cf brace angle members only addresses the moment connectivity between the brace and,the post, i.e., braces modelled- as pin ended members will only have axial loads transferred to them from the structure that they are connected to while those members with TV Electric
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l l 07/31/87-l Revision 14 Page 49 CABLE TRAY SUPPORTS Review Issues List rotational connectivity.-at their ends will transfer momements. Given the studies above, Impell has not considered the moments due to eccentricities between the
- brace angle and post neutral axes.
1 Impell calculates axial allowables for sin 9 e1 ang1es using the minor principal ax's radius of gyration. Impel 1 Project Instruction, PI-11 currently allows the use of the geometric axis radius.of gyration to reduce the slenderness ratio of the brace members if they fail with the minimum principal axis radius of gyration. However, Cygna understands the PI-11 will be revised to specify only the use of the minimum principal ' axis radius of gyration. (Reference 16).. Impell's bending stress allowables are based on equation l 6.11 from the Structural Stability Research Council l guide on buckling. Cygna questioned Impell's. use of l these equations for angle sections. '(Reference 17). Impell performed a numerical comparison between the bending allowables specified in the Australian steel specifications and their bending allowable criteria. This comparison showed that the bending allowable was no greater than or less than the bending allowables specified in the Australian code for the range of brace lengths within Impell's scope. (Reference 14). Cygna , understands that Impell's comparison also included a consideration of the compactness criteria of the angle sections. All angle sections, but one, of those included in the SUPERPOST member database are. compact sections. Impell will also revise Project Instruction PI-03 to include the compactness criteria. ; In both the modelling and the bending stress' evaluation, Impell uses the brace member's geometric axes ~section properties. Cygna questioned the use of the geometric j axes section properties in the cable tray support model s. Impell provided information from the LaSalle docket and material based on work at Washington "W TV Electric . Comanche Peak Steam Electric Station E*IiN 2 M. Independent Assessment Program - All Phases lilllllllilillllillllillitilli Job No. 84056 PRJ :RIL
07/31/87 Revision 14 Page 50 CABLE TRAY SUPPORTS Review Issues List I University that states that the use of geometric axes was appropriate when predicting the response of the structure. Cygna notes that this is true only when the angle is attached along the same leg at each end of the member and the only flexure is about an axis that is perpendicular to the plane-of the attached leg. Cygna agress that the use of the geometric axes is acceptable in modelling the structures for the prediction of- the respoonse of the structure, but does- not agree that the use of these properties member stress evaluation is correct. Impell recognized this prior to Cygna comment and increases the flexural stresses in' the angle members by a factor of 1.2.- (Reference 8, Appendix F). C. Both Ebasco and Impe11 have provided evaluations for the twist buckling of angles. Ebasco's method for evaluation is contained in Attachment V of Rcference 7, while Impe11's is in Reference 8 and Section 4.1.3 of Reference 9. These methods are based on angle sections i which are uniformly loaded throughout their cross-section and with an effective length factor of 1.0. For angle sections with low slenderness ratios twist-buckling will govern the behavior while for those angle sections with high slenderness ratios Euler buckling will govern. Both Ebasco and Impe11 calculate the length corresponding to the slenderness ratio where twist-buckling behavior transitions into Euler bucl ing. For angle lengths less than this value, allowable axial stresses are based on the twist-buckling behavior transitions into Euler buckling. For angle ; lengths less than this value, allowable axial stresses are based on the twist-buckling failure mode. Ebasco : calculates the transition slenderness ratio by equating the twist-buckling allowable stress to the Euler , l buckling allowable stress. Impe11 calculates this ! slenderness ratio by equating the twist-buckling l allowable stress' to 95% of the Euler buckling allowable i stress. By using 95% of the Euler allowable stress,
. _i TV Electric g+-,
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1 l 07/31/87.. Revision 14 < Page 51' , CABLE TRAY SUPPORTS l Review Issues List Impe11 effectively decreases the maximum length at which twist-buckling governs. Therefore, Impell may check angles which would be governed by twist-buckling with q Euler buckling allowables. Additionally, Cygna has noted that the maximum lengths reported by Ebasco and Impe11 differ for various angle cross-sections. Cygna's review indicates that the-differences in length may not be solely attributable to ' l the use of 95% of the Euler length by Impell. Both Impell and Ebasco apply the limitation on length to angle sections which are restrained on the same leg at each end of the member. Neither of the consultants has 1 considered the configuration where different . legs are 2 restrained and loaded at opposite ends of the member. l l Status: A. Open: See Status for Issue No. 7.B. The response is ! satisfactory with respect to the use of filler plates. ! B. Open: Impe11 to address the acceptability of using geometric section properties for the stress evaluations of angle sections. Impe11 to incorporate compactness criteria for angles in Project Instruction PI-03. Impell to remove from Project Instruction PI-11 the use of geometric axes radius of gyration for the reduction i in effective length for angle sections. Impell and Ebasco are to address Cygna's concerns on the ; differences in assumed end conditions for_the modelling l l of angle braces which include concerns on end fixity.and eccentricities. C. Open: Impe11 to provide justification for the use of 95% of the Euler allowable in determining the critical lengths for twisting-buckling. This is required for Cygna to evaluate the differences noted between the TV Electric
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4 , 1 l CABLE TRAY SUPPORTS Review Issues List j I lengths reported by Ebasco and Impe11. j l Impell and Ebasco are to address twist-buckling for angle sections with restraint on the different. legs at i opposite ends of the member. ; 1 Cygna is presently evaluating the applicability of the Impell and Ebasco evaluations for twist-buckling of j angle sections with the same leg restrained at opposite ends of the member. l
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l l 07/31/87 l Revision 14 - .i Page 53 j CABLE TRAY SUPPORTS Review Issues List i
- 8. Dynamic Amplification Factors (DAF), Tributary Tray Support Reactions and Missing Mass Effects
References:
- 1. Gibbs & Hill Report, " Justification of the Equivalent Static Load Method Using a Factor of 1.0 Times Peck Spectrum Acceleration for the Design of Cable Tray Supports; Comanche Peak Units 1 and 2"
- 2. Communications Report between J. .Jan (Gibbs & Hill), and G. Bjorkman (Cygna) dated October 4, 1984, 4:00 p.m.
- 3. Communications Report between J. Jan, P. Huang, J. Pier (Gibbs & Hill); and N. Williams, G. Bjorkman (Cygna) dated September 13,1984, 3 :00 p.m. j i
- 4. Communications Report between J. Jan, J. Pier (Gibbs & l Hill); and G. Bjorkman (Cygna)' dated October 12, 1984, 10:00 a.m. I
- )
i 1
- 5. Communications Report between J. Jan (Gibbs & Hill); and !
G. Bjorkman (Cygna) dated October 18, 1984 l
)
- 6. Communications Report between J. Jan, et al. (Gibbs & j Hill); and H. Levin (TERA); R. Kissinger, et al. j (TUGCO); N. Williams, et al. (Cygna) dated October 31, 1984 i
- 7. CPSES, FSAR, Section 3.7B.3.5
- 8. Ebasco Procedures SAG.CP4, " Seismic Design Criteria for Cable Tray Hangers for CPSES, Unit 1", Revision 3 and l SAG.CP3, " Seismic Design Criteria for Cable Tray Hangers
! for CPSES, Unit 2", Revision 6
- 9. Ebasco Instruction, " General Instructions for Cable Tray Hanger Analysis for CPSES Nos. I and 2", Revision 4 l
=== TV Electric s n Comenche Peak Steam Electric Station u s ( d i It s Independent Assessment Program - All Phases lililllilllllillilllllllililli Job No. 84056 PRJ:RIL
i l 07/31/87 i Revision 14 ; Page 54 l CABLE. TRAY SUPPORTS Review Issues List. ; i l
- 10. Ebasco Calculation, "CPSES Cable Tray Hanger Volume 1".- 1 Books 9 & 10. "Multimode Response Multiplier Studies", I Revision 0 l q
- 11. Ebasco Calculation, "CPSES Cable Tray Hanger Volume 1",
Book 15. " Cable Tray Dynamic Load Redistribution Effects", Revision 1 l
- 12. Impe11 Instructions PI-02, " Dynamic Analysis of-Cable Tray Systems", Revision 5 ,
- 13. Transcripts of Cable Tray Hanger Desigt. Verification Meeting Between TU Electric, Cygna, Ebasco and Impell i held at the CPSES site on January 26 and 27,1987 )
- 14. Communications Report between B. Lashkari (JBA); J. Park (Impe11); J. Christoudias, D. Fong, P. Harrison, R.
Alexandru, S.J. Chen, F. Hettinger, J. Swanson (Ebasco); ] j and W. Horstman, D. Leong, J. Russ, S. Tumminelli (Cygna), dated February 10,1987, 8:30-5 :00 p.m. l ]
- 15. Communications Report between S. Harrison, J. Nandi (TV Electric); G. Ashley, B. Ramsey (Impe11); R. Alexandru, i P. Harrison, S.J. Chen, and F. Hettingor (Ebasco); and 1 N. Williams, W. Horstman, D. Leong, J. Russ, S. J Tumminelli (Cygna), dated February 12, 1987, 10:00 a.m. i l
- 16. Communications Report between S. Harrison (TV Electric);
l R. Alexandru, S. J. Chen, P. Harrison, F. Hettinger l (Ebasco); and, B. Atalya, D. Leong, J. Russ and S. , Tumminelli (Cygna) dated July 23,1987,1:45 p.m. . ] j L I ! Summary: A. Equivalent Static Analyses l Gibbs & Hill performed cable tray support designs using an " equivalent static analysis" to account for seismic l loads. The tray dead load on a support. was calculated i 1 r _ TV Electric i I .
,3 Comanche Peak Steam Electric Station d,FJtId Independent Assessment Program - All Phases i
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CABLE TRAY SUPPORTS Review Issues L.ist J by the tributary span method. The tray seismic load.was the product of the tray dead load and the peak spectral acceleration for the given buildings elevation. A dynamic amplification factor (DAF) was not included as required by Reference 7 (see also Issue 25.A). An additional factor to be considered is the ratio of the static reaction for a continuous beam to the reaction calculated by the tributary l span method. This ratio depends on the' relative stiffness between the trays and supports,- the relative stiffness between different support types and the number of continuous spans. B. Missing Mass Effects in Response Spectrum Analyses As discussed in Issue No.11. Gibbs & Hill perfomed several generic studies for cable tray support qualification using cable tray system models and the response spectrum. analyses method. In general, Gibbs & Hill did not check the analysis results for sufficient mass participation in the response spectrum analyses. < Response: A. Impell performs all cable tray support qualifications i using cable tray system models and the response spectrum analysis method. System models will accurately capture the support reactions for the continuously supported i tray. A dynamic amplification factor is not required I when performing response spectrum analyses. Impell's approach is discussed in Reference 12. l I l Ebasco performs support qualifications using static, l equivalent static, and response spectrum methods. The ! system models oualyzed using the response spectrum . i analysis method are similar to those used by Impell and l l do not need to consider this issue as indicated above. 1 i When performing support qualification by the static or ! equivalent static methods, Ebasco uses a multimode response multiplier (MRM) of 1.25. The MRM accounts for both the dynamic amplifications and the support 1 l Ew._ _ _ TU Electric , ! ,. . _ Comanche Peak Steam Electric Station - ! L*!! M, .i 2 l_d Independent Assessment Program - All Phases ! lililllllllillililllillllillil Job No. 84056 PRJ :RIL l
l I i 07/31/87 Revision 14 ; Page 56 j CABLE TRAY SUPPORTS Review Issues' List , reactions for the continuously supported tray. The 1 development of this factor is documented in ! References 10 and 11. j 1 B. For all response spectrum analyses performed for cable { tray support qualification, a missing mars correction will be incorporated. Ebasco uses the missing mass , option of P-Delta STRUDL and Impell uses the missing l mass correction in SUPERPIPE. See References 13 and 14. j Status: A. Open: Based on a review of Ebasco's MRM development study. Cygna provided several questions to Ebasco for 1 which responses are being prepared. See References 14, 15 and 16 for details. i l B. Closed: Missing mass effects are being accounted for. J j l l l l 1 1 i j l f 1 i _. _ TV Electric s .' Comanche Peak Steam Electric Station L-#g LP.; t I -Al. i Independent Assessment Program - All Phases 11111111111111111!Il!!I1111111 Job No. 84056 PRJ:RIL
e q i 07/31/87 l Revision 14 Page 57 q ! i l CABLE TRAY SUPPORTS l Review Issues List .
- 9. Reduction in Channel Section Properties Due to Clamp Bolt Holes i Referer.ces: 1. N.H. Williams (Cygna) letter to J.B. George (TUGCO),
" Cable Tray and Conduit Support Review Questions,"
84056.015, dated August 6,1984, Attachment B, question 2
- 2. Gibbs & Hill letter GTN-69371, dated 8/23/84, Calculation SCS-111C, Set 8, Sheets 34-39 i
! 3. AISC " Specification for the Design, Fabrication and Erection of Structural Steel for Buildings", 7th Edition
- 4. Ebasco Instruction, " General Instructions for Cable Tray Hanger Analysis of CPSES Nos. I and 2", Revision 4
- 5. Impell Instructions PI-11. " Cable Tray System Analysis j and Qualification Closeout", Revision 1, with addendum j dated January 19, 1987. ;
l 6. Impell Instructions PI-02, " Dynamic Analysis of Cable Tray Systems", Revision 5 l 1
- 7. Transcripts of Cable Tray Hanger Design Verification j Meeting Between TU Electric, Cygna, Ebasco and Impell held at the CPSES site, January 26 and 27,1987 ,
j
- 8. Transcripts of Cable Tray Hanger Design Verification Meeting between TV Electric, Cygna. Ebasco, Impell, and
'VEC held at the CPSES site, on April 21, 1987.
- 9. 2basco Book 25 Rev. O of Volume 1, " Reduction in Sectior. Properties due to Bolt Holes.
l 10. Impell Calc. M-65, " Reduction in Section Properties Due to Bolt Holes. l TV Electric N ! Comanche Peak Steam Electric Station i i.i [.P.! i Id Independent Assessment Program - All Phases 111111111111I1111!!111111111ll Job No. 84056 PRJ:RIL
07/31/87 Revision 14 Page 58 CABLE TRAY SUPPORTS Peview Issues List
- 11. Communications Report between P. Harrison, et al (Ebasco) and W. Horstman, et al (Cygna) dated June 23, 1987, 10:00 a.m.
- 12. Communication Report, between P. Harrison, et al (Ebasco); S. Harrison (TV Electric); and, W. Horstman et al (Cygna), dated April 29,1987,10:15 a.m. and 2:00
- p. m.
Summary: The AISC Specification (Reference 3), Section 1.10.1 states: Riveted and welded plate girders, cover-plated beams and rolled or welded beams shall in generai be proportioned by the moment of inertia of the gross section. No deduction shall be made for shop or field rivet or bolt holes in either flange, except that in cases where the reduction of the area of either flange by such holes, calculated in accordance with the provisions of . Section 1.14.3, exceeds 15 percent of the gross i flange area, the excess shall be deducted. j Cygna found instances where the areas of bolt holes, used for the tray clamp bolts, exceeded 15 perccnt of the gross flange area, and the required reduction in moment of inertia , i had not been considered in the design calculations. ! l An evaluation of this issue should consider the following items: > j o Cable trays may be placed anywhere in the beam span (for l example, see CMC 2646). ! j o The case for cantilevered supports where one tray is i close to the wall and other trays are located further . out from the wall. I ( l < P TV Electric Comanche Peak Steam Electric Station N. ML i
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i 07/31/87 Revision 14 Page 59 CABLE TRAY SUPPORTS ) l Review Issues List l i
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o The effect of DCA 17838, which provides bolt hole gage j tolerances, and allows the use of 3/4" diameter holes i for 5/8" diameter bolts. ] I o All unused flange holes are not required to be -l plug-welded and may be present in high moment regions. 1 (See Note 15 on Gibbs & Hill Drawing 2323-S-0901, ! Revision 4.) , t Response: The reduction in channel section properties due to bolt j holes will be considered in the design verification of cable i tray suoports. Impe11 considers the effect of a 3/4 inch diametcr bolt hole located at the tip of the channel flange or at the actual hole location, if available, per Used bolt holes will be
]
Section 2.3.2 of Reference 5. l identified on the as-built support drawings. Unused bolt ) holes are assumed to occur at any location in' the support.- l The unused bolt hole must be assumed to occur in the area 1
- where its presence will cause maximum stress. The effect of I l the section reduction will only be considered if the i interaction values exceed specified levels.
Ebasco follows a similar procedure to consider the effect of j bolt holes, as required by Attachment E. Item 11 of i Reference 4. j In Reference 7, Ebasco indicated that a sample of over 200 ; used bolt holes were reviewed to determine the maximum hole size present for the 5/8 inch diameter tray clamp bolts. This sample indicated that the largest hole used is 3/4' inch diameter. Ebasco and Impell make similar assumptions in deriving the ratios of ( A) net /( A) gross, for (Sxx) net /(Sxx) gross and (Syy) net /Syy gross which are used in calculating the section property reductions. oygna has noted differences in the values for several structural sections.
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-Page 60 CABLE TRAY SUPPORTS Review Issues 1.ist l'
Status: 1. Open: Cygna has reviewed the calculations and provided Ebasco with questions on the sampling of bolt hole ; di ameters. Ebasco is to provide a response to.these. l
- 2. Open: Cygna has reviewed Ebasco's calculation for reduction in section properties (Reference 9). and has found it acceptabl e. (Reference 11.) Cygna must review Impell's ;
calculation (Reference 10) and recompare the results to i Eba s co' s. d i l i l TU Electric
.. Comanche Peak Steam Electric Station
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- 10. System Concept
References:
- 1. N.H. Williams (Cygna) letter to J.B. George (TUGCO),
" Cable Tray Support Review Questions," 84056.031, dated I August 31, 1984, Attachment A, question 2 I
- 2. L.M. Popplewell (TUGCO) letter to N.H. Williams (Cygna),
dated September 28, 1984 with attached calculations
- 3. Ebasco Instruction " General Instructions for Cable Tray Hanger Analysis for CF'_S No. I and 2", Revision 4
- 4. Ebasco Procedure SAG.Ull, " System Analysis for Cable Tray and Hanger Assembly for CPSES Units 1 & 2",
Revision 2
- 5. Ebasco Calculation, " Comanche Peak SES Cable Tray Hanger Volume I", Book 2; " Computer Related Information",
Revision 3 l
- 6. Ebasco Calculation, " Comanche Peak SES Cable Tray Hanger Volume 1", Book 7: " Cable Tray Hanger Load Application Location Studies", Revision 1 !
- 7. Ebasco Procedures SAG.CP4, " Seismic Design Criteria for Cable Tray Hangers for CPSES Unit 1", Revision 3 and SAG.CP3, " Seismic Design Criteria for Cable Tray Hangers j for CPSES, Unit 2", Revision 6 l I
- 8. Impell Instruction PI-02, " Dynamic Analy. sis of Cable '
Tray Systems", Revision 5 l
- 9. Impell Calculation M-12, " Qualification Procedure for j Cable Tray Support Evaluations", Revision 2 -
- 10. Impell Report 01-0210-1470, " Effective-Length Factors ,
for Buckling of Cable Tray Supports", Revision 1 1
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- 11. Impe11 Instruction PI-07, " Design Verification of Base-Plates, Base Angles, and Embedded Plates", Revision 3 Summary: In order to justify certain design assumptions questioned by l
Cygna (Reference 1), documentation was' provided indicating that Gibbs & Hill had assumed that the cable tray and supports act as a system. (Reference 2.) As part of this
" systems" approach, the'following behavior was assumed:
A. Loading Eccentricities The moments introduced by the eccentricities between the load application points (i.e., tray centroid) and the member centroid were balanced by load couples between adjacent supports. More specifically, for longitudinal supports (e.g., SP-7 with brace, Detail 8, drawing i 2323-S-0903, etc.), the development of torsion in the ' beam due to longitudinal loading eccentricity is prevented due to the development of flexure in the cable tray. This tray moment is subsequently balanced by a vertical load coupled between adjacent supports. Similarly, the torsion in the beam and the weak axis bending in the hanger due to the vertical load placement eccentricities as well as the. bending moment in the beam due to the transverse load placement eccentricities are all balanced by either vertical or transverse load couples between adjacent supports. Such moment transfers as described above are only possible if full rotational and transnational compatibility exists between the cable. tray and support beam. The relative stiffness between the trays and their supports can also affect the percentage of the moment to be balanced by the load couples between supports. Gibbs & Hill assumes that the compatibility is provided by the heavy duty and friction types of tray cl amps. See Review Issue 18 for a discussion of Cygna's concerns regarding the clamp behavior. TU Electric I... Comanche Peak Steam Electric Station (*I, I tj [IU Independent Assessment Program - All Phases lilllilllllllillllillllllllill Job No. 84056 PRJ:RIL
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i 07/31/87 Revision 14 Page 63 CABLE TRAY SUPPORTS Review Issues List B. Bracing for Compresion Members In the design of trapeze support hanger members for compression loads, the trays provide lateral bracing at points along the length of the hanger. . Similarly, for cantilever type supports, the_ tray provides lateral bracing to the beam. (See issue No,' 4A.) j C. Independence of Transverse and Longitudinal Supports i l For trapeze type supports, the longitudinal and transverse support systems act independently. Therefore, the longitudinal supports are designed for . longitudinal loads only, i.e., no' transverse or vertical l load contribution is considered. (See Issue No. 5.) D. Base Angle Rotation l Additional tensile forces introduced by rotation of the base angles about the bolt pattern axis is minimized by ! the hanger attachment to the tray. (See Issue No. 3A.) E. Out-of-Plane Inertial Loads i For trapeze type supports, out-of-plane seismic inertial loads from two-way support frames (self-weight excitation) are resisted by the longitudinal supports. However, as discussed in Review Issue' 6, these inertial loads have not been considered in Gibbs & Hill's design ! of longitudinal supports. f F. Member Connection Eccentricities The cable tray supports use channel sections for the beam and hanger members. The typical connection between the beam and hanger is a lap joint, with the channels attached back-to-back. This type of connection will TV Electric r--- .
, n Comanche Peak Steam Electric Station t*$i MJa il Independent Assessment Program - All Phases l
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1 l 07/31/87 Revision 14 Page 64 , l CABLE TRAY SUPPORTS Review Issues List ' I introduce bending moments and torsion in the members due , to the eccentricity between the section neutral axes. (Reference 1. Question 2.2.) l 1 Gibbs & Hill addressed this issue in Reference 2, l indicating that a portion of the effect is resisted as ] additional loads in the cable tray, and the net effect i on the stress . level in the support is an increase of i less than.a three percent. j i Response: A. The design verification of cable tray hangers will f include the effects of most eccentricities between the cable tray and the support members. See Issue , Nos. 24.A. 24.B. 24.C, and 24.D. See Issue No.18 -] regarding clamp behavior. j i B. See Issue No. 4.A for a discussion pertaining to the l bracing for compression members, i l C. See Issue No. 5 for a discussion pertaining to the { l treatment of longitudinal and transverse supports. i D. See Issue No. 3.A for a discussion pertaining to the treatment of base angle rotation. r E. See Issue No. 6.A regarding' the treatment of out-of-plane inertial loads. i F. The effects or the eccentricities between members are considered in the desiga verification of the cable tray supports. In Reference 7 Section IV.1.a and Reference 3, Attachment E Ebasco specifies the methods to be used to account for connection eccentricities which are based on a study documented in Reference 6. For a typical back-to-back channel lap joint, the eccentricity is the distance between the center of gravity of one member and the shear center of the other. TU Electric 3- , Comanche Peak Steam Electric Station [*I!M L IA l Independent Assessment Program - All Phases 1111111111!?l111111111llI!!!!1 Job No. 84056 PRJ :RIL
07/31/87 Revision 14 Page 65 CABLE TRAY SUPPORTS Review Issues List Impell, in Reference 8. Section 3.2.3 and Reference 9, l specifies how the eccentricities will be considered. The method used by Impell in modelling lapped joints is ! consistent with Ebasco's approach. However, for other ; connection geometries, Impell's approach differs from 1 Ebasco's. j Status: A. See Issue Nos.18, 24.A, 24.B 24.C. and 24.0. B. See Issue No. 4.A and 18. I C. See Issue No. 5. j li D. See Issue No. 3.A. ' E. See Issue No. 6.A. l ! F. Open: Cygna has reviewed the eccentricities addressed by Impell's and Ebasco's procedures. Additionally, i Cygna has performed audits of both consultants to l determine what eccentricities are modelled for , j configurations not addressed by the procedures. Further ! review is required to evaluate the impact of any differences in the approaches used by the two ! consul tants. Cygna will evaluate the effect of individually insignificant eccentricities as a part of a review of the ANC0 test prograr, and the cumulative ;' effects review. See Issue No. 29. 4 l l l l l i I i p- TU Electric Comanche Peak Steam Electric Station b*Il (d 2 Id Independent Assessment Program - All Phases lillllililllllilillilitillllli Job No. 84056 PRJ :RIL i
07/31/87 Revision 14 Page 66 CABLE TRAY SUPPORTS Review Issues List
- 11. Validity of NASTRAN Model s
References:
- 1. Gibbs & Hill Calculation Bincer 2323-SCS-215C, Se'cs 2-6
- 2. Gibbs & Hill Calculation Binder 2323-SCS-101C, Set 3, -)
Sheets 234-243, Revision 9
]
- 3. Gibbs & Hill Calculation Binder DMI-13C, Set 1 _
l
- 4. Gibbs & Hill Report, " Justification of the Equivalent Static Load Method Using a Factor of 1.0 Times Peak Spectrum Acceleration for the Design of Cable Troy 1 Supports; Comanche Peak Units 1 and 2"
- 5. Ebasco Procedures SAG.CP4, " Seismic Design Criteria for ,
Cable Tray Hangers for CPSES, Unit 1", Revision 3 and
- SAG.CP3, " Seismic Design Criteria for Cable Tray Hangers l for CPSES, Unit 2", Revision 2
- 6. Impe11 Instructions PI-02, " Dynamic Analysis of Cable i Tray Systems", Revision 5 ;
Summary: Cygna has questioned the validity of the NASTRAN models used in the Gibbs & Hill generic studies, such as the Working Point Deviation Study (Reference 1), the qualification of Detail D1 (References 2 and 3) and the Dynamic Amplification Factor Study. (Reference 4.) The analysis models consist of l identical supports, separated by equal spans. Thi s modelling will influence the system frequencies and seismic response and may not be representative of an actual l installation, where a mixture of support types, non-uniform l spans and tees or elbows in the tray are used. ; Response: The design verification for cable tray supports is based on the as-built support configurations and cable tray routin g. This is specified in Reference 5, Section III.2 i f TV Electric
. .,-7Z Comanche Peak Steam Electric Station u'I LdjL Id Independent Assessment Program - All Phases 111111!!Ill111111ll11111ll1111 Job No. 84056 PRJ:RIL ..
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07/31/87 Revision 14 Page 67 CABLE TRAY SUPPORTS. j Review Issues List j l J for Ebasco and Reference 6, Section 3.2.1 for Impell. :The results of the Gibbs & Hill NASTRAN models will not be used. The dynamic amplification factor used 'by Ebasco is based on 1 a study performed using a series of' uniform supports at equal spacing. .This study is similar to the evaluation performed by Gibbs & Hill. See Issue No. 8 for a discussion 'j of this r' Jy. ! J Status: Closed for the original Gibbs & Hill NASTRAN models. See i Issue No. 8 for the status of the dynamic amplification I factor study performed by Ebasco.
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. I 1
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07/31/87 Revision 14 Page 68 CABLE TRAY SUPPORTS Review Issues List
- 12. Working Point Deviation Study i
References:
- 1. Gibbs & Hill Calculation Binder 2323-SCS-215C, Sets 2-6 l
i 2. Gibbs & Hill Calculation Binder 2323-SCS-216C, Sets 1-5
- 0. AISC, " Specification for the Design, Fabrication and erection of Structural Steel for Buildings", 7th edition
- 4. Gibbs & Hill Report, " Cable Tray Raceway System Dynamic Analysis Program," March 19, 1985
- 5. Connunications Report between M. Warner (B&R/TUGC0 QC) and W. Horstman, J. Russ (Cygna) dated November 16, 1985
- 6. Gibbs & Hill Drawing 2323-S-0903
- 7. Communications Report between B.K. Bhujang et al. (Gibbs
& Hill); R.M. Kissinger (TUGCO); and W. Horstman et al.
(Cygna) dated September 14, 1984
- 8. TV Electric, CPSES, " Generic Issues Report - Evaluation i
and Resolution of Generic Technical Issues for Cable Tray Hangers", Revision 1 I
- 9. Ebasco Instruction, " General Instructions for Cable Tray Hanger Analyses for CPSES Nos.1 and 2", Revision 4
- 10. Transcripts of the Cable Tray Hanger Design Verification and Meetino between 10 Electric, Cygna, Ebasco, and Impell held a the CPSES site, January 26 and 27,1987 Sunnary: Cable tray supports employ angle sections as braces in the following configurations: in-plane for trapeze type supports, out-of-plane for longitudinal trapeze supports, and in various other orientations for other support types.
The original designs for supports assumed that neutral axes . l of all members at a connection intersected at a common point, thus no connection eccentricities were considered.
-n TV Electric 3-. Comanche Peak Steam Electric Station t *$ ('i a IAl Independent Assessment Program - All Phases 11111111!!!ll111111111111111ll Job No. 84056 PRJ :RIL
07/31/87 Revision 14 Page 69 CABLE TRAY SUPPORTS Review Issues List The connection details shown on the design drawings (e.g., Details 4 and 5 on Reference 6) provided a brace working point location which was not consistent with the design assumptions. Based on a discussion with TUGC0 personnel (Reference 5), Cygna learned that the QC inspectors had difficulty in determining the design requirements for the working point locations, and Gibbs & Hill had been requested to provide clarification on the requirements and an allowable tolerance on the working point locations. DCA 20278 and DCA 20418 were issued in response, and the Working Point Deviation Study (References 1 and 2) was performed to consider the fact that the member neutral axes did not intersect at a common point and to provide the requested tolerances. T he following are comments on the analyses performed as a part i of this study. I A. Consideration of Design Change Documentation Gibbs & Hill's study (References 1 and 2) does not fully consider the effects of previously approved design change documentation. The analyses of the generic support types did not consider the effects of all generic design change documents which allow deviations from the original support designs. (Also see Review Issue 21.A.) Due to the overstress of certain components of several support types, a limiting spectral acceleration was calculated, and cut-off elevations were established using the individual floor response spectra. Frames below the cut-off elevations were not checked for compliance with the study parameters. Frames above the cut-off elevation were analyzed on a case-by-case basis, but the analyses did not consider the effects of design change documents associated with the individual support. TV Electric Comanche Peak Steam Electric Station [*$N i Id 3 Independent Assessment Program - All Phases ll11ll11ll1111111111ll1!!111ll Job No. 84056 PRJ:RIL
l 07/31/87 Revision 14 Page 70-- CABLE TRAY SUPPORTS 1 l Review Issues List ; B. Vertical and Transverse Loads on Longitudinal Supports ! l The effects of vertical and transverse loads on longitudinal support frames were not. considered in the Working Point Deviation Study. (See Issue Nos. 5 and10.) C. Assumptions Regarding Governing Components The portion of the study that evaluated longitudinal l trapeze supports only checked member stress interaction I as specified in Section 1.6.1 of Reference 3. No j evaluation was made to ensure that the connections, base j angles and anchor bolts are also adequate. j l l D. Modelling Assumptions l
- 1. Instead of modeling a longitudinal support in the i
tray run, one end of the tray was assumed to be fixed. The effect of this tray boundary condition l on the system response was not justified. Based upon the review of the NASTRAN models used in the
- Dynamic Analysis Program (Reference 4), Cygna learned that Gibbs & Hill's modelling of these fixed ends did not account for the response spectrum input at those points, but instead fixed them to an absolute rigid ground. If the same modelling technique was applied in the Working Point Deviation Study, the results of those response spectrum analyses may be incorrect.
- 2. The analysis assumed a single 24-inch tray per support level and did not assess the impact of more realistic multiple tray loadings or other tray 1 widths. j
- 3. Eccentricities were not properly modelled. (See Issue No.10).
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07/31/87 Revision 14 Page 71 CABLE TRAY SUPPORTS Review Issues List
- 4. The cable trays were modelled as translationally and rotationally fixed to the support beams. This assumption of tray attachment fixity was not justified. (See Issue No.18.)
- 5. The run configurations selected may not be representative of actual installations. Parameters j include systems of identical supports, uniform 8'-6" support spacing, and the assumed worst case frame dimensions. (See Issue Nos.11 and 28.)
1
- 6. The base angle modelling assumad a simply supported-beam for two bolt base connections. In reality, the concrete reactions (prying actions) provide flexural restraint to the base angle. (See Issue No. 26.)
- 7. Excitation in the longitudinal tray direction was not considered.
- 8. The out-of-plane transnational degrees of freedom were restrained on trapeze type supports, resulting in an unrealistically restrained system.
l E. Controlling Element of Supports Gibbs & Hill did not check all support components when determining the controlling support e'ement. For example, support type E4 was assumed to be limited by the load capacity of the Hilti expansion anchors. Cygna's review indicated that the actual governing component was the Richmond Inserts which were not checked by Gibbs & Hill. F. Working Point Location for Two-Bolt Brace Connections on Longitudinal Supports. The working point location shown on the design drawing ! does not coincide with the actual line of action of the brace load for two-bol t brace connections, e.g., Detail s _._= TV Electric 3
- Comanche Peak Steam Electric Station d F,.ii IAi Independent Assessment Program - All Phases ll1111111ll11111111111111111ll Job No. 84056 PRJ:R1L
07/31/87 Revision 14 Page 72 CABLE TRAY SUPPORTS Review Issues List "F" and "G" on Gibbs & Hill Drawing 2323-S-0903, and the l brace concrete attachments for support types L-Al through L-A4 , L-B1 , L-B 2, L-B 4, L-C ,1L-C2 and L-C4 on Gibbs & Hill Drawing 2323-S-0902. These offsets may induce larger tensile loads in the anchorages than originally considered in the designs. These connections- ,l were not evaluated as part of the Working Point l Deviation Study. j G. Arbitrary Allowed Working Point Deviations Several support types within Cygna's . review scope have specified allowable working point deviations without any supporting calculations.
- 1. Detail N (Gibbs & Hill Drawing 2323-El-0601-01-S)
Gibbs & Hill Calculation Binder 2323-SCS-216C, Set l 3, Sheet 5 indicates an allowable deviation of l 9" 3" for brace connection to beam. Calcul ations l are not included.
- 2. Detail V (Gibbs & Hill Drawing 2323-El-0601-01-S)
Gibbs & Hill Calculation Binder 2323-SCS-216C, Set 3, Sheet 5 states " Low Stress, Brace Working Point 4 Deviation of 6" is acceptable." Calculations to ) support this statement are not included. ) 1 H. Working Point Deviations by Similarity Several support types within Cygna's review scope have specified allowable working point deviations based on similarity to standard support types. >
- 1. Detail J (Gibbs & Hill Drawing 2323-El-0601-01-3) is qualified by similarity to Case B 3.
- 2. Detail 11 (Gibbs & Hill Drewing 2323-S-0905) is qualified by similarity to Detail 8 (Gibbs & Hill Drawing 2323-S-0903). ,
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i 07/31/87 Revision 14 Page 73 CABLE TRAY SUPPORTS Review Issues List l The calculations for case B3 and Detail 8 (Gibbs & Hill Calculation Binders 2323-SCS-215C. Sets 2 and 4) indicate that these support types will be overstressed for the allowed working point deviation.~ Cas e-by-case evaluations of Case B3 and Detail 8 supports were performed to determine if all as-designed supports were
- acce ptabl e. The support types which had been qualified l by similarity were not included in these case-by-case reviews; hence, there is no assurance that they are not overstressed also.
I. Use of Enveloping Cases l The Working Point Deviation Study evaluates several support types by grouping them with an enveloping support of similar configuration. Reference 1, Set 2
- evaluates two groups. Group 1 includes Cases A 3
, B3 '
and C3 , considering Case C3 to envelope the other two. Group 2 includes Cases 4A , B4 , and C4 , considering case C4 to envelope the others. For each analysis, the ; enveloping case is found to be overstressed, and a j case-by-case as-designed review 'of supports of that type is conducted. The enveloped cases are not all included j in the case-by-case reviews, and a separate evaluation is not performed to show design adequacy of the other support types on a generic basis. J. Compressive Load Capacity of Members < As discussed in the status for Issue No. 4.A, Gibbs & Hill considered the effect of multiple discrete axial loads on the buckling capacity of the hangers in response to Cygna's concerns. The same effect was considered in the member evaluations for this study. Gibbs & Hill did not property apply the effect, since the factor is a function of the applied loading, and Gibbs & Hill did not calculate it for each load case. (Reference 7.) _ TU Electric Comanche Peak Steam Electric Station b.'$ . . FJi , 3 f A 5 Independent Assessment Program - All Phases lillllilllllllllilllllilllllli Job No. 84056 PRJ:RIL
g 1 07/31/87 , Revision 14 Page 74 l , CABLE TRAY SUPPORTS 'k l Review Issues List'
)
l Response: In accordance with Reference 8, Appendix A12, the cable tray support design verification effort will not rely upon the results of Gibbs & Hill's Working Point Deviation Study. , ! Cable tray supports will be evaluated on an individual basis - ) using as-built support configurations. I Reference 9, Attachment I provides details for the I consideration of the brace working point deviation in the ) i support finite element models. Both Ebasco and Impell use these guidelines. For braces attached directly to the back of a vertical channel a set of conditions are provided such d that if these conditions are satisfied, the working point deviation need not have to be modelled. During a discussion between Cygna and Ebasco (Reference 10), Ebasco indicated that the specified conditions are based on the requirement i that if the brace neutral axis passes through the panel zone l (defined by the intersection of the post and tier), the brace working point location will have no effect on the behavior- of the support. Status: Closed with respect to Gibb's & Hill's Working Point ! Deviation Study. This issue is not applicable to the I ! current design verification effort. Open: Ebasco must provide justification for the procedures specified in Attachment I, Reference 9. t l e----- - TV Electric 3 : Comanche Peak Steam Electric Station w* I (P) t '43 Independent Assessment Program - All Phases 111111ll11111111111lll11ll1111 Job No. 84056 PRJ:RIL i
i 07/31/87 Revision 14 Page 75 CABLE TRAY SUPPORTS Review Issues List
- 13. Reduced Spectral Accelerations l
References:
- 1. Gibbs & Hill Calculations, " Analysis of Alternate Detail 1"
- 2. Gibbs & Hill Calculation Binder SCS-101C, Set 3, Sheet 247, Revision 9
- 3. Gibbs & Hill Calculation Binder SCS-215C, Set 4
- 4. Gibbs & Hill Calculation Binder SCS-101C, Set 2, Sheets 131 & 132, Revision 5
- 5. Ebasco Procedures SAG.CP4, " Seismic Design Criteria for Cable Tray Hangers for CPSES Unit 1", Revision 3 and SAG.CP3, " Seismic Design Criteria for Cable Tray Hangers for CPSES Unit 2", Revision 6 i
- 6. Ebasco Instruction, " General Instruction for Cable Tray l Hanger Analysis for CPSES, Nos. I and 2",' Revision 4- )
)
- 7. Impell Instruction PI-02, " Dynamic Analysis of Cable Tray Systems", Revision 5
- 8. Communications Report between P. Harrison, et al (Ebasco); and W. Horstman, et al (Cygna); dated, June 23,1987,10:00 a.m.
I ) Sumary: For the qualification of the supports discussed below, Gibbs
& Hill used reduced spectral accelerations based on a calculated support-tray system frequency. These analyses assumed that all supports on a tray run are of the same type TU Electric '
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t , 1 ' 07/31/87 Revision 14 Page 76
\
l l CABLE TRAY SUPPORTS ! Review I-sues List l l and have equal spacings. (See Issue No.11.) These studies l are not representative of the cable tray installations at j I l CPSES. ! A. Transverse Supports I A reduced acceleration was used for the analysis of i l transverse supports, such as type A4, which was used in analysis of Alternate Detail 1. (Reference 1.) Thi s acceleration corresponds to a calculated frequency which l is higher than that corresponding to the spectral j peak. This frequency was calculated using a system~ model of identical supports equally spaced at 8 -6" and $ a tray weight of 35 psf. The results of this study may l not be valid for all installations as discussed in Issue i No. 11. B. Longitudinal Supports 4 For longitudinal supports (e.g., type SP-7 with brace l (Reference 3), L-Al (Reference 2), etc.), the frequency l calculations did not include the effect of the axial frequency of the tray and the eccentricities between the tray and support. C. Effects of Base Angle Flexibility I
- The flexural flexibility of the base angle supporting !
the brace of the longitudinal supports was not j l considered in frequency calculation. (References l 3,4.) Flexural defonnation of the base angle can i result in significant reduction in support frequency.
]
l Response: The current cable tray support design verification effort does not rely on the results of the Gibbs & Hill analyses ! discussed in this issue. Cable tray supports are design verified based on the as-built tray and support l configurations. TV Electric 8=[dt - 'I- U. Comanche Peak Steam Independent Assessment ProgramElectric Station
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A. In accordance with Reference 5, Sections III.1, III.2 and IV.2.c, Ebasco calculates cable tray system i frequencies based on the as-built support configurations ) and tray spans. The seismic input accelerations are i based on these frequencies.- In accordance with Reference 7, Impell . analyzes the cable tray supports using response spectrum analyses of system models based ! I on as-buil t geometry. The techniques used by Gibbs & l Hill are not employed. B. For equivalent static stress analyses of longitudinal l supports, Ebasco considers the axial stiffness of the ; l tray (Reference 5. Section IV.2.c) and the effect of-the ! eccentricities between the support and the tray. In the I calculation of the. support frequency in the longitudinal ') tray direction for equivalent static analyses, Ebasco 1 lumps the tray mass at the tier centerline neglecting ] the vertical eccentricity to the tray center of j
- gravi ty. This will overpredict the support-tray J l frequency. Ebasco stated that inclusion of the !
eccentricity would result in an unrealistically low l frequency since the tray provides rotational stiffness. (Reference 8.) For Ebasco's and Impe11's response spectrum systems analyses, tray stiffness and support , eccentricities are considered. I C. Ebasco and Impell have performed studies to determine ' the appropriate stiffness for base angle connections. i These stiffness values are included in Ebasco's support models (Reference 6, Attachment G9) and Impell's system l models (Reference 7, Sections 3.2.5). Status: A. Closed. B. Open: Ebasco to provide justification for neglecting the eccentricity as described above. See also Issue No. 24 for concerns regarding the modelling of the eccentricities between the tray and the support. ! TV Electric r , Comanche Peak Steam Electric Station L*$ F.} i Id Independent Assessment Program - All Phases ll111111111111111111lllll11111 Job No. 84056 PRJ:RIL i
[ 1 07/31/87 j Revision 14 Page 78-l f-1 i CABLE TRAY SUPPORTS i l Review Issues List ! l l C. See Issue No. 3.I for a discussion of the base angle stiffness studies. i l 3 ! 1 l i i i
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1 07/31/87 Revision 14 Page 79 CABLE TRAY SUPPORTS
- Review Issues List- !
- 14. Non-Conformance with AISC Specifications
References:
- 1. AISC, " Specifications for the Design, Fabrication and :
Erection of Structural Steel for. Buildings", 7th edition
- 2. CPSES, FSAR, Sections 3.8.3.2 and 3.8.4.2
- 3. Ebasco Procedures SAG.CP4. " Seismic Design Criteria'for Cable Tray Hangers for CPSES, Unit 1", Revision 3 and l SAG.CP3, " Seismic Design Criteria for Cable Tray Hangers j for CPSES, Unit 2", Revision 6
- 4. Transcripts of Cable Tray Hanger Design Verification Meeting between TU Electric, Cygna. Ebasco and Impell j held at the CPSES site on January 26 and 27,1987 l
- 5. Impell Instruction PI-03, " Qualifications of Cable Tray Supports", Revision 4
- 6. Communications Report between S. Harrison, J. Muffett (TV Electric); P. Harrison (Ebasco); R. Wheaton, B.
Ramsey (Impell); and N. Williams, S. Tumminelli, D. Leong, J. Russ, W. Horstman (Cygna), dated March 6, 1987, 11:30 a.m.
- 7. Ebasco Instruction, " General Instructions for Cable Tray Hanger Analysis for CPSES Nos.1 and 2", Revision 4
- 8. Impell Report, "CPSES Cable Tray System Analysis / Test ,
Correl ations", Report No. 09-0210-0017, Revision A (Preliminary Issue) l 9. ANCO Testing Laboratories, " Test Plan - Dynamic Testing of Typical Cable Tray Support Configurations', Document No. A-000150, Revision 1 l 10. Impell Special Study No. 5.9, " Oversize Bolt Holes", l Preliminary Issue j TV Electric
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07/31/87 i f Revision 14 l Page 80 1 1 CABLE TRAY SUPPORTS i Review Issues List ! 11 . Transcripts of cable-Tray Henger Design Verification Meeting between TU Electric, Cygna. Ebasco,. Impell, JBA j and SWEC held at the CPSES site, May 19, 1987. l
- 12. Ebasco response EB-T-3029, attachment 7, dated May 15, 1987, " Bolt Hole Oversize Statistical Study."
- 13. Ebasco Position Paper, Revision 2. June 19,1987:
Effects of Bolt Hole Oversize in CTH System Adequacy".
- 14. Ebasco Cable Tray Hanger Calculations, Volume 1, i i Book 22.
l
- 15. Communications P.eport between P. Harrison (Ebasco), B. (
Atalay, W. Horstman (Cygna), dated June 25, 1987, l 3:00 p.m. l
- 16. Communications Report between G. Ashley (Impe11); and S. i Tumminelli, W. Horstman (Cygna), dated May 13, 1987, 5 :30 p.m. .
l
- 17. Communications Report between G. Ashley (Impe11); S. l Harrison (TV Electric); and W. Horstman et al (Cygna) I dated May 14,' 1987, 2:30 p.m. .
- 18. Impe11 PI-11. " Cable Tray System Analysis and Qualification Closecut," Revision 2. ,
l
- 19. Communications Report betwen P. Harrison, et a1 !
(Ebasco); and, W. Horstman, B. Shakibnia (Cygna), dated June 23,1987,10:00 a.m.. q Summary: Reference 2 commits to designing the cable tray supports in ! accordance with Reference 1. Gibbs & Hill has not properly l 4 TU Electric
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I 07/31/87 Revision 14 Page 81 1 CABLE TRAY SUPPORTS Review Issuer List q 1 i considered the requirements of Reference 1, as discussed bel ow. A. Unbraced Length for Axial Buckling s [ ]t Section 1.8.4 (Reference 1) i*equires tha?. the f slenderness ratio, kl/r, be less thar. 200_ for 1 compression members. Depending on the. approach selected i for the resolution of Issue No. 4, this requirement may not be met. For example, if the friction type clamp cannot. provide adequate restraint in the longitudinal j direction, the k'value should be taken as 2.0 for I trapeze type ano ::entilever type supports. q Consequently, k1/r = 257 for a 5'-9" C6 x 8.2 hanger or l beam. g s B. Unbracdd Length for Lateral Torsional Buckling i s Section 1.5.1.4.6a (Reference 1) requires that Equxtion {
<> 1.5-7 be 'used to calculate the allowable bending stress a t, for channdis. In the denominator, "1" is the unbraced 1 ;
1ength of the compression flange. Cygna found the following instances where the AISC SpecificationAwere
'. not considered or were improperly applied: g t 4 g
d 1. Gibbs & Hill's Working Point Deviation Study"(Issue No.12) uses 22 ksi for the allowable flexural j t stress without checking Equation 1.5-7,. Since the d s frame heights are on the order oY144", an ' allowable i* flexural stress of 15 ksi is calculated,by Equation 4 1.5-7. N 2. ' Detail SP-7 and similar supports consihr "1" to be I the distance from the base attachment to the tray ! i centerline and not to the outside tray rail where 1
\; the load is applied. _ Use of the larger distance g
,will result in lower allowable bending stresses.
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+
! +.
i a
l 07/31/87 Revision 14 j Page 82 l CABLE TRAY SUPPORTS j Review Issues List. ] l C. Bolt Holes in Member Flanges ) 1 Reductions in the section properties of beams due to ] bolt holes in their flanges per Section 1.10.1 1 (Reference 1), were not considered. (See Issue No 9.) ) D. Lacing of Double Angles l Double angle braces are designed as composite members, without providing lacing per Section 1.18.2.4. l
^
(Reference 1.) (See Istve No. 7.) l E. Eccentric Connections l
- i Section 1.15.2 (Reference 1) discusses eccentric connections. This section requires that any axial members not meeting at a single working point be designed for the eccentricities. For example, this section of the specification applies to supports with I sir.gle angle braces (SP-7 with brace, L-Ay, etc). The gasset plates connected to these braces must also be designed for the eccentricities.
F. Oversize Bolt Holes Section 1.23.4 (Reference 1) specifies bolt holes to be 1/16" larger than the nominal bolt diameter. The bolt holes for anchor bolts in base plates / angles (per Gibbs
& Hill Drawing 2323-S-0903) and for. tray clamps. (per DCA 17838, Revision 8) are specified-as 1/8" larger than '
the nominal bolt diameter. Therefore, 'the bolt holes in Gibbs & Hill's designs should be considered oversized and should be treated as such in bearing connection cal cul ations. G. Use of the Allowable Compressive Stress For Secondary ; Members For the design of the longitudinal brace for support type SP-7 with brace, the brace was assumed to be a
**~ TU Electric NI Comanche Peak Steam Electric Station d @) i I A Independent Assessment Program - All Phases i lillfillllillilillllllilllilli Job No. 84056 PRJ:RIL '
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CABLE TRAY SUPPORTS Review Issues List l secondary member, and allowable compressive stresses were calculated per section 1.5.1.3.3 (Reference 1). 1 ! Since this is the sole member providing longitudinal load carrying capability, it should be considered a , primary member, and sections 1.5.1.3.1 and 1.5.1.3.2 are ! a ppli ca bl e. H. Member Length for Use in AISC Equation 1.6-la. I See the discussion for Item H in the Response section bel ow. Response: A. See Issue No. 4.A B. Ebasco, Reference 3, requires adherence to the AISC Specifications but does not specifically address the use of Eqn.1.5-7 or the calculation of the unsupported length. In Reference 4, Ebasco indicated that the total length of the tier members (horizontal channels) and the length of the post (vertical channels) between tiers is to be used as the unsupported length. Impell, Reference 5, Section 4.1.4, specifies that the full length of the tier shall be used as the unsupported length. The full length of a post may be used es the unsupported length. The trays are not assumed to provide bracing to the compression flanges of the channel s. In Reference 18. Impell allows a reduction in the unsupported length for posts in order to reduce the number of failures for any overstressed posts. Impe11 has also assumed that the tiers will provide bracing to the posts to inhibit lateral torsional buckling thus allowing the use of the distance between tiers for the unbraced length. Cygna, per Reference 15, was unable to locate any documentation to support this assumption and believes that the tiers may not be capable of providing bracing to the compression flanges.
. TV Electric
- . Comanche Peak Steam Electric Station L*$i F.. j2 - Id Independent Assessment Program - All Phases Illllllillllllllllllilillilill Job No. 84056 PRJ:RIL
i 07/31/87 Revision 14 i Page 84 l CABLE TRAY SUPPORTS i Review Issues List C. See Issue No. 9. D. See Issue No. 7.A. E. See Issue Nos. 7.A and 7.B for a discussion of the eccentricities associated with single and double angle i braces. The effect of eccentric loading on the gusset plates used at the ends of angle' braces is considered. In Reference 7, Section I.a. Ebasco specifies that gusset plates be evaluated for an eccentricity equal to i 1/2 of the gusset plate. thickness plus 1/2 of the leg thickness of the attached angle. Impell evaluates ) gusset plates in accordance with Attachment 7 of { Reference 5. The method of considering eccentric ' loading is not specified in Reference 7. F. In Reference 10, Impe11 addresses the oversized bolt i holes used for the anchor bolts and the tray clampt, ' This report indicates that the use of 1/8" oversized l holes is standard practice for anchor bolts and, ' therefore, their use is not an issue. For the clamp bolts, it is indicated that the additional relative displacement of the tray and support is'not significant. In fact, Impell asserts that the slipping will introduce additional damping. It is also indicated that, although the loading is not uniformally distributed among the bolts in a connection at working load levels, the ultimate capacity of the connection is not reduced. The cable tray suppurts used in the ANCO dynamic testing program (Reference 9) include installations with oversized bolt holes. The impact of the oversized holes is investigated in the correlations of the test results to those for finite element models. (Reference 8.) (Reference 14). Cygna's review of the ANCO test plan indicates that 1/8" oversized bolt holes are used in two test configurations. Ebasco has prepared a calculation involving a _ j TV Electric Comanche Peak Steam Electric Station E*!!d iId Independent Assessment Program - All Phases lilllillllillllllllilllilllill Job No. 84056 PRJ:RIL
V 07 /31 /87 RevisiO" 1 Page 85 l and TRAY SUPPORTS i t sizes igOO 7 hole e the pe of bolt CABLE Review Issues L s u sample wa s to determinable tray s 14 rt ppoO
/
/ of a / lysis calculationin thealso prepared aon CTH10 4o 0g statistical hole anaces. Thesize presentEbascoHole the results Oversize
'O O r i
edge distanm bolt ren ce 14). Bolt r nt itat ve i n i IQg components maximu which (Refe"Effect summa of port co izesand f offersOQf qua inst ence 13),is Ebas % position paper, Refer I , Adequa the adequacy y" (tistical analys of thesupCygna provided a conclusi c sta validity of / of the holes. justification lt for on the be evaluated with oversize tions bo will imary E ' a list of ques studies. bracing membersstresses for prAttachmen va rious g of the compre ssion in Ref erence 7, embers, includin wablerequired tion 4.1.3 and / All m the allo G. using is This Ref erence 5, Sec subjected the f or Impell . hose members. co and for Ebas 4 & 5 col ums e to be
, i .e. , tevaluated per ,
Attac hments beha am v ing as beloads, 1.6.2 ar1 and ofmmentary t to 6 flexural the Com bending momencompute H. Membersaxial to and "T he maximu of sections 1. .Onrs page S 132 of eve used to requirements : Ref erence 1ce 1, use it statesof inthose support, Formula membe as how well as to Refereneen points ss for treis of betw pplicableaxial a stresses the bending s mpressive ilitiesSTRUDL Formula 1.6 la checking capabfor Impell an experiencing coural the code stresses. members which code he an 1 j flex co usedms (SUPERPOST scan various Ebas Impell andanalysis prograalif In yperforming the rt. lect the tthese prog j their for Ebasco) to lqucable a, tray suppoboth use these ofand mom a d then individual For comprisefor Formula t's stresses1.6 / che ck r the quantity Howe enver, eachactual from a member. l of an a post individual elemenhighest a portion n is values fothe quantities innly member be in questio element may theo example, if f e t Progra Pea
(- 1 l 07/31/87 Revision 14 ) Page 86 l CABLE TRAY SUPPORTS
' Review Issues List-r trapeze support with two tiers, the programs would look at two individual post segments: between the uppermost f tier and the ceiling anchorage and between the two ti ers. However, Cygna believes that the entire member length, from the ceiling anchorage to the elevation of the lowermost tier is the correct length to scan over for the maximum moments to be used in Formul'a 1.6-la.
Impell stated the use.of a Cmvalue of 1.0 would account' for not scanning over the member length. (Reference 16). Ebasco stated that they believe that' the STRUDL code check module is correct in its interpretation. . (Reference 19). l Status: A. See Issue No. 4.A. B. Impell and Ebasco most provide an evaluation justifying the acceptability of using the tier-to-tier distance for use in .AISC equation 1.5-7. ! C. See Issue No. 9. D. See Issue No. 7.A. E. See Issue Nos. 7.A and 7.B for status of eccentric loading on angle braces. Additional review of gusset plate evaluation criteria is necessary. , F. Open: Additional review of the ANC0 test procedures, l the system test correlations study, and both Impell's and Ebasco's evaluations of the effects of oversize. bolt holes is required. Ebasco is to provide responses to Cygna concerns (Reference 15). G. Closed. l m TU Electric Comanche Peak Steam Electric Station nan i I d _ Independent Assessment Program - All Phases lilllllillllllllllllll!'llllli Job No. 84056' PRJ:RIL , _-____-_______________a
i 07/31/87 j Revision 14 i Page 87 j 1 1 CABLE' TRAY SUPPORTS '! Review Issues List i H. Impell and Ebasco must provide justification for using element lengths for selecting moment values for use in Formula 1.6-la. l
- .i
, l i j , I ( i 1 TV Electric
. .. .- Comanche Peak Steam Electric Station t m [F 'Ii1
# jt Independent Assessment Program - All Phases lilllillllilllllllililllilllli Job No. 84056 PRJ:RIL
07/31/87 Revision 14 Page 88 CABLE TRAY SUPPORTS Review Issues List
- 15. Member Substitution
References:
- 1. Communications. Reports between R.M. Kissinger (TUGCO)
( and J. Russ (Cygna), dated January 17,1985, 8 :15 a.m. and 3:45 p.m. l
- 2. CMC 69335, Revision 1, September 21, 1982.
- 3. Gibbs & Hill Drawing 2323-S-0901, Revision 4
- 4. Ebasco Procedures SAG.CP4, " Seismic Design Criteria for Cable Tray Hangers for CPSES Unit 1", Revision 3 and SAG.CP3, " Seismic Design Criteria for Cable Tray Hangers for CPSES, Unit 2", Revision 6 1
- 5. Ebasco Instruction, " General Instructions for Cable Tray Hanger Analysis for CPSES Nos.1 and 2", Revision 4
- 6. Impell Instruction PI-02, " Dynamic Analysis of Cable Tray Systems", Revision 5 l 1
- 7. Transcripts of Cable Tray Hanger Design Verification l Meeting between TV Electric, Cygna, Ebasco and Impell held at the CPSES site, January 26 and 27,1987
- 8. Impell Instructions PI-11, " Cable Tray System Analysis and Qualification Closeout". Revision 2.
- 9. Transcripts of Cable Tray Hanger Design Verification i Meetinn between TV Electric, Cygna Ebasco, Impell, JBA i and SWEC held at the CPSES site, May 19, 1987. ]
- 10. Impell IM-T-0210-040-238, dated May 15,1987, " Joint l Impell/Ebasco Approach Toward Design Verification of Inaccessible Attributes.
I _ TU Electric Comanche Peak Steam Electric Station L*I I G l Id Independent Assessment Program - Al'. Phases I!!lllllllllllllllilllllllilli Job No. 84056 PRJ :RIL , j
l 1 07/31/87 Revision 14 Page 89 CABLE TRAY SUPPORTS ' l Review Issues List Summary: Note 9 on 'Gibbs & Hill Drawing 2323-S-0901, Revision 4, , states: I Structural members shown on drawing numbers . 2323-S-900 series may be substituted by one step ] heavier shape of the same size. This note allows craft to substitute a member from one ] series with a member from another series, e.g., an American- 1 Standard Channel (C) for a Miscellaneous Channel (MC) or J vice versa, as long as the substituted shape .is. heavier j than, but of the 'same depth as the original member. Cygna j is concerned that this note allows the use of substitute ] sections which are heavier, but have lower section moduli. .i J At a later date, Reference 2 was issued, providing the following clarification: Structural members shown on drawing numbers 1 2323-S-900 series may be substituted by a member 1 of the same size and next heavier shape determined j by the material on site. The next step heavier l shape will be governed by sections as shown in l AISC Manual of Steel Construction. Examples are ,i shown on sheet 2 of 2. The examples shown on sheet 2 of Reference 2 include the substitution of a C4 x 7.25 for a C4 x 5.4, a C6 x 10.5 for a C6 x 8.2, etc. This clearly indicates that the j substitution should be of the same series as the specified ' member. Cygna's concern is what types of substitutions were performed by the craft and accepted by the QC inspectors during the time between the issuance of Reference 3 and Reference 2. Cygna was unable to locate any requirements for documenting member substitutions. i TU Electric Comanche Peak Steam Electric Station , 6. 8% L .! 6> ,N 3 Id Independent Assessment Program - All Phases 1 lilllillllllllilillllllllllll! Job No. 84056 PRJ :RIL
r 07/31/87 Revision 14 Page 90 CABLE TRAY SUPPORTS Review Issues List Within Cygna's walkdown scope, such a substitution was identified for support number 6654. (See Issue No. 20.) The design required an MC6 x 12, and the installed member ' ; was a C6 x 13, which has a smaller section modulus (S = 5.80 in3 for a C6 x 13 compared to S = 6.24 in3 for an MC6x12). For the other supports listed in Issue No. 20, the , required MC6x12's were substituted with C6 x 8.2's, a substitution not permitted by Reference 2. Response: The design verifications for cable tray supports will use the as-buil t support drawings. The analyses and stress evaluations will be based on the installed member sizes. l-This is required for Impell in Reference 6, Section 3.2 and for Ebasco in Reference 4, Section III.2. In cases where the installed member size cannot be l determined (inaccessible attributes) the ar designed member size will be used, considering the potential substitution of ( an American Standard channel ("C") of cne step heavier for a l miscellaneous channel ("MC") if the substitution will reruit in a reduction in member capacity. For Ebasco, this is specified in Reference 5, Attachment X, Section IV. Impell cites this procedure in Reference-8. See also Reference 10. l Status: Open: The Impell/Ebasco unified approach for inaccessible attributes has been provided to Cygna. See status for Issue N o. 16 a. TU Electric Comanche Peak Steam Electric Station Na N ,iI ti Independent Assessment Program - All Phases lilllllllllilllillfilllllillli Job No. 84056 PRJ :RIL ,
07/31/87 Revision 14 Page 91 CABLE TRAY SUPPORTS Review Issues List
- 16. Weld Design and Specifications
References:
- 1. N.H. Williams (Cygna) letter to V. Noonan (US NRC),
" Response to NRC Questions," 83090.023, dated March 8, 1985
- 2. Communications Report between S. Chang, P. Huang (Gibbs
& Hill) and W. Horstman, J. Russ, N. Williams (Cygna) dated October 27, 1984
- 3. Communications Report between S. Chang, P.' Huang (Gibbs
& Hill) and W. Horstman, J. Russ, N. Williams (Cygna) l dated November 13, 1984 1
l
- 4. Communications Report between S. Chang, P. Huang (Gibbs
& Hill) and J. Russ (Cygna) dated November 17, 1984
- 5. Communications Report between R. M. Kissinger (TUGCO) and J. Russ (Cygna), dated November 30, 1984
- 6. N.H. Williams (Cygna) letter to J.B. George (TUGCO),
" Cable Tray Support Reviev Questions," 84056.041, dated February 12, 1985
- 7. Ebasco Procedures SAG.CP4, " Seismic Design Criteria for Cable Tray Hangers for CPSES, Unit 1", Revision 3, and SAG.CP3, " Seismic Design Criteria for Cable Tray Hangers for CPSES, Unit 2", Revision 6
- 8. Ebasco Instruction, " General Instruction for Cable Tray Hanger Analysis for CPSES Nos.1- and.2", Revision 4
- 9. Impell Instruction PI-03, " Qualification of Cable Tray Supports", Revision 4
- 10. Transcripts of Cable Tray Hanger Design Verification Meeting between TU Electric, Cygna, Ebasco and Impell held at the CPSES site, January 26 and 27,1987 sm=-
, TV Electric Comanche Peak Steam Electric Station U*bN ) I ,l
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l Independent Assessment Program - All Phases lillllilillllllllilllllllllill Job No. 84056 PRJ:RIL ,
07/31/87 Revision 14 Page 92 CABLE TRAY SUPPORTS , Review Issues List l
- 11. Ebasco Cable Tray Hanger Calculations:-
CTH-1-102, Revision 0 i CTH-1-121, Revision 0 'l CTH-1-125, Revision 0 1
- 12. Communications Report between G. Ashley, et. al. 1 (Impell); J. Russ, et, al. (Cygna); R. Alexandru, et.- l al. (Ebasco); and S. Harrison, et. al. (TV Electric) dated February 13,1987,11:30 a.m. l l
- 13. AISC " Specifications for the Design, Fabrications and '
Eviction of Structural Steel for Buildings", 7th Edition d
- 14. AWS D1.1-79, " Structural Welding Code - Steel",1979
- 15. Communications Report between R. Kielbach, P. Harrison (Ebasco); and J. Russ (Cygna), dated March 16, 1987, 1:30 p.m. ,
! 16. Ebasco Report: " COMBS Computer Program - Calculation of ! Stresses in Composite Channels, Descriptions.and Verification of Computer Program", Revision 2. , i l 17. Communications Report between R. Wheaton, et a1 ! (Impell); J. Muffett, et al (TV Electric); and N. Williams, et al (Cygna), dated March 6,1987. l
- 18. Transcripts of Cable Tray Hanger Design Verification l Meeting between TV Electric, Cygna, Ebasco, Impell, JBA q and .SWEC held at the CPSES site, May 19, 1987. l l
l
- 19. Joint Impell/Ebasco Approach Toward Design Verification of Inaccessible Attributes, IM-T-0210-040-238, dated May 15, 1987.
- 20. Impell Report IM-P-003, Revision 0, dated May 15 - !
1987: Analysis of Welds Connecting Base Angles to Embedded Plates. l l . TV Electric
. Comanche Peak Steam Electric Station i L*t...N3L .ii M- Independent Assessment Program - All Phases llll111111111111111111ll111111 Job No. 84056 PRJ:RIL .
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7 l l 07/31/87 ' Revision 14 Page 93 CABLE TRAY SUPPORTS Review Issues List 1 21.- Impe11 Report IM-P-005, Revision 0, dated May 15, . l 1987: - Evaluation of Composite T-chtnnel Stitch Welds. for Torsional Stresses.
- 22. Ebasco Report EB-T-3029, Attachment 6, . dated May 15, .,
1987: Weld Base Metal Evaluation. l l
- 23. Communications Report. between P. Harrison, et al (Ebasco) and W. Horstman, et al -(Cygna), dated June 23 1987, 2:15 p.m.
s
- 24. Communications Report between G. Ashley (Impe11); S. I Harrison (TV Electric); W. Horstman et al (Cygna) dated .
May 13, 1987, 3:30 p.m.. ! 1
- 25. Communications Report betwen G. Ashley (Impell); S.
Harrison (TV Electric); W. Horstman et al (Cygna) dated j May 14,1987, 2:30 p.m.. I l
- 26. Communications Report between P, Harrison et al. i (Ebasco) and W. Horstman et al (Cygna) dated June 22, !
1987, 2:00 p.m..
- 27. Communications Report between P. Harrison and F.
I Hettinger (Ebasco); S. Harrison and J. Nandi (TV .{ Electric); and J. Russ and N. Williams (Cygna) dated 0 July 13.1987, 7 :00 a.m.. . i 28. Communications Report between P. Harrison et al (Ebasco); S. Harrison (TV Electric); and B. Shakibnia, ) et al (Cygna) dated July 14,1987,10:10 a.m. Summary: Cygna has noted the following. discrepancies in the weld designs for cable tray supports. q l A. Weld Details Not Shown on Design Drawings i The design drawings are missing the weld details for l I TV Electric Comanche Peak Steam' Electric Station dNi a Independent Assessment Program - All Phases t ll111ll111111111111lll!I111111 Job No. 84056 PRJ :RIL i l
07/31/87 Revision 14 Page 94 CABLE TRAY SUPPORTS Review Issues List several support types as described in Reference 1, . Attachment C. B. Weld Size Discrepancy between Design and Assembly Drawings l Per discussions with Gibbs & Hill /TUGC0 { References 2, ; 3, 4 and 5), Cygna has noted that the weld sizes shown on the assembly drawings differ from those.shown on the design drawings and those that were assumed in the Gibbs
& Hill -calculations.
C. Eccentricities in Welded Connections Eccentricities were not considered in the design of : welded connections. Some examples include: ' 1. Detail SP-7 with brace and similar connections i require a partial penetration groove weld at the ' gusset plate / beam connection. The design calculations did not consider the eccentric load transfer from the brace member. The eccentricity of the brace loads results in a weld stress in excess of the allowabl e.
- 2. Weld designs for the lap joints between channels and between the base angle and attached channel did not consider the eccentricity between the applied loads from the connecting members and the plane of the wel d.
D. Base Metal Thickness The weld designs did not consider the thickness of the connected parts. This issue was identified by DCA 2365, Revision 2, but was never considered in the design cal cul ations. Gibbs & Hill's weld designs assumed that the full weld throat would be developed without considering the thickness of the connected member. For TV Electric F' . , , 3 Comanche Peak Steam Electric Station L'$! f 9 a fd Independent Assessment Program - All Phases litillllillllllllllllllllllill Job No. 84056 PRJ:RIL-
1 07/31/87 l Revision 14 ) f Page 95 ) l i CABLE TRAY SUPPORTS Review Issues List l \ examp1e, the weld size for support designs empioying C6 x 8.2 channels with a fillet weld crossing the web of ( l the channel is limited to the 0.2 inch web thickness. l Gibbs & Hill designs specified a 5/16" fillet weld size I j I and did not reduce the throat to account for the minimum l material thickness. Cases where this may be a problem incl ude: Detail s E, F, G, H, J and K on Gibbs & Hill Drawing 2323-El-0601-01-S; SP-7 using an L6x4x3/4 base ; angle; and the Detail 2/2A on Gibbs & Hill Drawing ' 2323-S-0903 as modified per CMC 58338. I E. Minimum Weld Lengths j Gibbs & Hill assumed an incorrect minimum weld length for the beam / hanger base angle connection. Gibbs & Hill assumed a weld length of 1-k, where 1 = angle leg width l and k = distance from back of angle leg to end of ) fill et. However, because of the existence of the curve j at the angle toe with radius, r (approximately equal to one-half the leg thickness), the actual weld length is 1 - k- r. I F. Minimum Weld Size Requirements Table 1.17.5 of the AISC Specifications (Reference 13) specifies the minimum weld sizes to be used in con-nection designs. These weld sizes are based on the thickness of the thicker part joined. The weld size need not exceed the thickness of the thinner part joined except as required by a stress calculation. This table is based on AWS D1.1 (Reference 14) which is incorporated in the AISC Specifications by reference. AWS D1.1 requires the use of preheating the thicker part if the minimum weld size is not used. For material up to 3/4" in thickness, a preheat temperature of 70,F is requi red. For material greater than 3/4", It>Jt less than 1-1/2" thick, a preheat temperature of 150,F is requi red. g- _ TV Electric
, . . 3 I Comanche Peak Steam Electric Station Ji Lfj iI d Independent Assessment Program - All Phases ll1111111111111lll1!!1111111ll Job No. 84056 PRJ :RIL
07/31/87 Revision 14 Page 96 3 CABLE TRAY SUPPORTS Review Issues List Within Cygna's review scope, a minimum of eight supports do not meet the minimum weld size requirements of
.AISC.
G. Intermittent Fillet Welds Several cable tray support designs employ composite sections (e.g. SP-7 with brace, Detail 11 on draw lng 2323-S-0905, etc.) which are joined using intermittent fill et wel ds. An evaluation of these welds was not , provided by Gibbs & Hill in their design calculations. An evaluation of such welds should consider both the shear flow due to flexure of the- composite section and the shear associated with St. Venant and warping l' torsion. H. Base Angles Welded to Embedded Plates l Cable tray supports can be attached to embedded plates !' j by providing a fillet weld along the toe and heel of the base angle as a substitute for the required anchor bolts j (DCA 3423, Revision 1). The CVC for this DCA indicates i that calculations were not required in the design p verification of this DCA. i I. Partial Penetration Groove Weld Qualification. See Item I in Response section below. Response: A. The design verification is based on the as-built weld sizes and configurations per Reference 7 Section III.2 for Ebasco 'nd Reference 9. Sections 3.0 and 4.3 for q , Impell . The approach to be used for inaccessible welds l ! is described in Reference 19. I B. See response for Issue No.16.A. i TU Electric _. Comanche Peak Steam Electric Station U*bd 2 Id Independent Assessment Program - All Phases lill!lllllillllllllilllillilli Job No. 84056 PRJ :RIL l
07/31/87 Revision 14 Page 97 CABLE TRAY SUPPORTS , Review Issues List I C. -The project design criteria (References 8 and 9).do not consistently address the consideration of eccentric loadings on the welds. Based on a review of several Ebasco calculations, (Reference 11), Cygna determined that Ebasco evaluates welds by obtaining end forces for the member attached to. and weld and adding in the additional bending moments due to the eccentricity between the member center of gravity and the plane of the weld pattern. In Reference 12 Impell indicated that the welds are evaluated using the member end forces for the member attached to the weld without considering the additional bending moments due to eccentricities. In Reference 25 Impell stated that they would provide an evaluation of the effects of neglecting eccentricities. D. Shear stresses in the base material will be considered in the weld design verifications. Reference 8, Section IX, states that Ebasco will consider both the weld size and the base metal thickness in evaluating weld capacities. Reference 9 Section 4.3 states that Impell will check the base metal shear stresses when an allowable stress greater than 21 ksi is used for fillet wel ds. Cygna indicated that the instructions did not clearly indicate how base metal shear stresses will be considered or what will be done when the base metal is thinner than the weld throat. In Reference 10, Impell indicated that Reference 9 will be revised to require checking using the thickness of l the thinner part joined. Cygna audited Ebasco's report l pertaining to base metal stresses (Reference 22.) and stated that the beam-on-elastic foundation _ approach was not acceptable (Reference 23). Ebasco stated that a reevaluation will be performed to address Cygna's ' concerns. (References 23 and 27.)
=_ TV Electric Comanche Peak Steam Electric Station 6.Nd ,I-i d-Independent Assessment Program - All Phases lilillllifilllillittilllilllli Job No. 84056 PRJ :RIL
07/31/87 Revision 14 Page 98 CABLE TRAY SUPPORTS - Review Issues List E. See response for Issue No.16.A. .! F. In Reference 15, Ebasco stated that a review of the Brown & Root welding procedures indicated that low-hydrogen electrodes had been used for the cable tray , supports. These electrodes require a minimum preheat temperature of 50,F. A review of purchase orders showed that only these electrodes were used at the CPSES site. G. Both consultants will evaluate the adequacy of intermittent fillet. welds on the basis of the as-built weld patterns, q In Reference 9 Section 4.3 and Attachment 8 . Impell requires that intermittent fillet welds be evaluated, This evaluation is " based on the capacity necessary to j I resist slip or movement between the two channel sections." The stresses in the weld due to torsion are not considered. Impe11 evaluates the effects of
- stresses due to torsion in Reference 21. Cygna has l reviewed Reference 21.
Ebasco evaluates the composite sections using an in-house computer program " COMBS", (Reference 16). Thi s l
- program includes an evaluation of the stresses in the ,
intermittent fillet welds which considers the shear due to flexure and the shear and normal stresses due to torsional loading. H. This type of connection does not occur frequently at CPSES and individual occurences are evaluated on a case-by-case basis. During Cygna's audit of Ebasco's cable tray hanger design verification effort .several supports which had l the base angle welded to an embedded plate were identified. The analysis of the base angles and welds for these supports were performed via finite element i models representing the base angle, welds and substrate. TV Electric
,. Comanche Peak Steam Electric Station Mt f d Independent Assessment Program - All Phases PRJ :RIL 111111111111ll11llllll11111lll Job No. 84056
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During the Impe11 audit Cygna noted.that such ) connections were evaluated via hand calculations. As l discussed in Reference 17, the load distribution assumed { in these calculations is based on a rigid plate assumption and does'not account for the stiffening effect of the outstanding leg of the base angle or the ! location of the applied load with respect to the 2 centroid of the weld pattern. Impe11 provided Reference 20 in response to Cygna's concerns. 1 I. Ebasco has performed an evaluation of the partial penetration groove welds used in the cable tray supports. The evaluation has considered the effective j throat to be used when calculating weld stress as well as the qualifica' tion of the actual weld joint. The j latter is accomplished via fabricating several joints-and testing them after the weld up. (Reference 26.) The qualification configuration is in the form of a tee-joint in which the stem has a prepared face which. butts the nther plate to form the tee. The edge of the stem > butting the other plate was beveled to 30 0 and 450 an gl es. This configuration was to cover the common joints of this type found in the plant and would include the connection between the gusset plate from a , longitudinal brace to the back of a tier web such as the j support types with Gibbs & Hill designation "SP-7 with brace. This support type allowed a range of brace slopes that are not fully covered by the Ebasco quali fication. Additionally, Cygna has identified instances where the allowed range was exceeded. (See , Issue 20.S) ! i Status: A. Open: Ebasco is to provide two references to the hidden attributes study. B. See Status for Issue No.16.A. TU Electric r.W? Comanche Peak Steam Electric Station L.#n 8)aI6 Independent Assessment Program - All Phases lililllilililllllllllkillllii Job No. 84056 PRJ:RIL
4
'07/31/87-Revision 14 Page 100 CABLE TRAY SUPPORTS Review Issues List -
C. Open: Impe11 is to provide their justification.for not including the eccentricity effects in weld evaluations (Reference 26). D. Open: Cygna will review the revised criteria in Reference 9 when available. Ebasco is to provide responses to Cygna's concerns as well . as calculation
- Vol ume I, Book 20, "CTH Weld Related Studies,"
Sections II to IV. (Reference 28). E. See status for Issue No.16.A. F. Cl osed. - G. Open: As discussed in Reference 17, Cygna will l review Impe11 Calculation M-59. Impe11 Cygna must l provide this document and other documents supporting .i Referenct 21 prior to review. H. Closed. I. Ebasco must provide justification that the partial penetration weld qualification addresses all such welds in the plant.
' - TV Electric 3 Comanche Peak Steam Electric Station r*$ ('d L fil L Independent Assessment Program - All Phases 11111!!1111111111111!!11111111 Job No. 84056 PRJ :RIL' Y
07/31/87 Revi sion .14 Page 101 l CABLE TRAY SUPPORTS Review Issues List
- 17. Embedded Plate Design
References:
l'. N.H. Williams (Cygna) letter to J.B. George (TUGCO),
"Cabl e Tray Support Review Questions," 84056.041, dated February 12,1985, . Attachment A, question 1
- 2. L.M. Popplewell (TUGCO) letter to N.H. Williams (Cygna) ,
dated April 19, 1984, page 11
- 3. Communications Report between N. Williams, J. Russ, W. .
Horstman (Cygna); R. Kissinger, T. Keiss (TUGCO); and B. l Bhujang, P. Huang, S. Chang (Gibbs & Hill) dated { September 15, 1984 j i
- 4. Communications Report between M. Warner (TUGCO) and N.
l Williams, J. Minichiello, J. Russ (Cygna) dated February-27, 1985 ) l 5. Gibbs & Hill Calculation Binder 2323-SCS-146C, Set 4 l S heet 3-9, 21
- 6. Gibbs & Hill Drawing 2323-S-0919. Revision 3 )
l
- 7. Brown & Root Installation Procedure CCP-45, " Permanent and Temporary Attachments to Weld Plates," Revision 1, August 18, 1980.
- 8. Gibbs & Hill Specification 2323-SS-30, Appendix 4,
" Design Criteria For Embedded Plate Strips," Revision 1
- 9. N.H. Williams (Cygna) letter to W.G. Counsil (TUGCO),
" Cable Tray / Conduit Support Review Questions,"
84056.089, dated October 21, 1985
- 10. Transcripts of the Cable Tray Hanger Design Verification Meeting between TV Electric, Cygna, Ebasco and Impe11 at the CPSES site, January 26 and 27,1987.
E_ TU Electric
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- 11. Transcripts of Cable Tray Hanger Design Verification Meeting between TU Electric, Cygna. Ebasco, Impell, JBA I and SWEC held at the CPSES site, May 19, 1987. l 1
- 12. Civil Structural Review Issue List, Revision 0, dated July 21,1987. .
Summary: A. Prying Action on Nelson Studs 1 Gibbs & Hill performed capacity calculations for cable tray support attachments to embedded strip plates. Cygna's review of these calculations indicates that the calculated capacities may not have considered the effect- ) of prying action on the tension in the Nelson Studs. j l l B. Stiffening Requirements for Moment Attachments j l \ l Questions from Cygna's pipe support reviewers and cable tray reviewers on the stiffening requirements for embedded plate moment connections elicited conflicting l responses from TUGC0 personnel. The pipe support i response indicated that attachments to embedded plates act as stiffeners for moment connections (Reference 2), while the cable tray support response indicated that any moment attachment must be stiffened or sufficiently' analyzed. (Reference 3. ) l C. Capacity Reduction for Attachment Locations Cygna has noted that calculations for cable tray supports attached to embedded plates did not consider the capacity reductions for attachment locations given in Gibbs & Hill Specification 2323-SS-30, " Structural Embedments". (Reference 1.) Cygna has requested any documents which address the corrective action associated with the issuance of Specification 2323-SS-30. ! (Reference 9.) TV Electric
- r. ..
Comanche Peak Steam Electric Station d W Jt3 IA Independent Assessment Program - All Phases 1111111111111llll111ll!!!!!111 Job No. 84056 PRJ :RIL
07/31/87 l Revision 14 Page 103 CABLE TRAY SUPPORTS Review Issues List D. Inspection Requirements for Attachment Spacing l A review of Brown.& Root Procedure CCP-45 (Reference 7) indicates that any.two adjacent attachments to an embedded strip plate must be separated by a minimum of 12". Based on a discussion between Cygna and TUGC0 (Reference 4), it was determined that, even though the installation procedure requires this separation, the inspection procedures for cable tray supports do not require an inspection of this attribute. Cygna walkdowns noted several instances where the l separation between attachments to embedded plates were less than 12". (See Pipe Support Issue No. 9.) Cygna is concerned that the 1ack of control of attachment l spacing may have an impact on the design adequacy of the attachments. < E. Installation of Details E, F, F, G, and H on Embedded r!ates Reference 5 is the design calculation for.the installation of Support Details E F,G, and H (Gibbs & Hill Drawing 2323-El-0601-01-S) on embedded strip pl ates. A maximum tributary tray span of 7'-6" is used in these calculations. Note 9 on Reference 6 states: The supports will have a location tolerance of l t 12" in the direction parallel to:the tray . and t 2" perpendicular to the tray. However, spacing between any two adjacent supports shall not exceed 9'-0" for Unit 1 and Common Areas...unless otherwise noted on the drawing. Supports installed in accordance with this ' drawing note may have to resist loads due to a 9'-0" tributary span, l l'-6" greater than the design tributary span.
= TV Electric sw _ h k Steam Electric Station L*I @j [ M_ Comanc e PeaIndependent Assessment Program - All Phases lillllllillllllllifillililllll Job No.- 84056 PRJ :RIL
07/31/87 Revision 14. Page 104' j l I CABLE TRAY SUPPORTS Review Issues List F. Spacing Requirements Between Embedded Plates and Concrete Anchors i Gibbs & Hill Specification 2323-SS-30-(Reference 8) { provides spacing requirements between embedded plates and Hilti expansion anchors. During Cygna's cable tray. support walkdowns, an instance was noted where an ; embedded plate was located near an opening in a concrete !
. wall . Several Hilti expansion anchors were installed within the opening, on the concrete surface perpendicular to the surface with the embedded plate, potentially violating the requirements of 2323-SS-30..
Cygna was unable to determine how the minimum spacing requirements would be applied to situations where the expansion anchor is installed in a surface perpendicular j to the embedded plate. l Response: A. See Reference 12, issue No. 4 l B. See Reference 12, issue No. 4 C. See Reference 12, issue No. 4 I D. See Reference 12, issue No. 2 E. Attachment loads from cable tray supports are calculated using as-built span data. These attachment loads are transmitted to SWEC for use in the embedded plate. eval uati ons. l F. See Reference 12, issue No. 2 Status: A. See Reference 12, issue No. 4 B. See Reference 12, issue No. 4 C. See Reference 12, issue No. 4
~ TV Electric ri Ld) 6 IA3 Comanche t Peak Steam Independent Assessment ProgramElectric Station
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CABLE TRAY SUPPORTS- i Review Issues List i i 1 D. See Reference 12, issue No. 2 E. See Reference 12, issue No. 4 F. See Reference 12, issue No. 2 l 1 I l l l l 1 t i 4 1 TV Electric
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- 18. Cable Tray Clamps
References:
- 1. Gibbs & Hill Drawing 2323-S-0902, Revision 5
- 2. TUGC0 Drawing TNE-SI-0902-02, Revision CP-2
- 3. Communication Report between T. Keiss (TUGCO) and W.
Horstman (Cygna) dated November 15, 1984
- 4. Ebasco Instruction " General Instructions for Cable Tray Hanger Analysis for Comanche Peak SES Nos. I and 2",
Revision 4 4
- 5. Ebasco Procedure SAG.CP11 " System Analysis for Cable Tray and Hanger Assembly for CPSES Units 1 and 2 l Revision 2
- 6. Impell CM culation M-10, " Clip Angle Stiffness",
Revision 2 I
- 7. Impell Calculation M-19. " Clip Stiffness Production Values", Revision 2
- 8. Impell Report 09-0210-0017, "CPSES Cable Tray System Analysis / Test Correlation", Revision A
- 9. Impell Instruction PI-02, " Dynamic Analysis of Cable-Tray Systems", Revision 5
- 10. Impell Calculation M-28, " Tray Clamp Behavior".
Revision 0 l
- 11. Impell Instruction PI-11, " Cable Tray, System Analysis and Qualification Closecut", Revision.1 i
- 12. Ebasco Calculation Vol.1, Book 21 "CTH Clamp :
Qualification, Methodology and Development", Revision 1. m== __ TU Electric
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- 13. Ebasco Report, SAG. CP-19, Rev. 3: " Design Criteria and Procedures for Design Verification of Cable Tray Clamps". j l
- 14. Communications Report between F. Hettinger, et a1 !
(Ebasco), S. Harrison (TU Electric) and B. Shakibnia, et I al (Cygna), dated July 14, 1987, 10:10 a.m.
- 15. CCL Test Report, Report No. A-717-86 dated June 27th 1986 and Report No. A-721-86 ' dated July 13, 1986. I,
- 16. A.S.M.E. Section III, Subsection NF. 3282.4. j i
- 17. Impe11 Instruction PI-06, " Design Verification of Cable Tray and Tray Clamps," Revision 0.
- 18. Communications Report between P. Harrison et al j
, (Ebasco); S. Harrison (TV Electric); and, W. Horstman et I al (Cygna) dated June 26, 1987, 1:00 p.m.. l Sumary: Two general categories of cable tray clamps are used at CPSES. " Friction" type clamps are installed on transverse type supports (e.g. , A1 , By , SP-7, etc. ). These clamps are assumed to provide vertical and horizontal transverse load transfer. " Heavy duty" clamps are installed on longitudinal I; trapeze supports (e'.g. , L-A1
, L-B , etc. ), three-way supports (e.g., SP-7 with brace, betail 8 on drawing 2323-S-0903, etc.), and transverse supports, where interferences (e.g., tray splice plates, fittings, etc.)
prevent the installation of friction type clamps. Heavy duty clamps are designed to transfer vertical, horizontal transv .rse, and longitudinal tray loads to the cable tray l support beam. References 1 and 2; DCA 3464, Revision 23; DCA 6299, Revision 7; and DCA 20331. Revision 0 provide ,! clamp configuration details. In addition to the indicated load transfers between trays i and supports, Gibbs & Hill has assumed other load transfer _ TV Electric Comanche Peak Steam Electric Station t r*i(9t
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07/31/87 Revision 14 Page 108 CABLE TRAY SUPPORTS Review Issues List mechanisms in order to justify behavioral assumptions mada in the support designs. A. Friction Type Clamps For " friction" type clamps, the following assumptions have been made in order to justify.the system concept. (See Issue No.10.) o The trays will provide out-of-plane; bracing to trapeze supports to reduce the buckling length of the vertical hanger members. (See Issue No. 4.) o The trays will provide lateral bracing to the compression flanges of the horizontal beams. (See Issue No. 24.) o The trays will provide out-of-plane' bracing to supports to prevent frame translation which would result in increased anchor bolt tensile loads. (See Issue No. 3.) o The cable trays will transfer out-of-plane inertial loads from transverse supports to longitudinal supports on the same tray run. (See Issue No. 6.) o The development of minor axis bending moment in the beams due to the-horizontal eccentricity between the l beam neutral axis and the clamp bolt is minimized by a bending moment in the cable tray. (See Issue No. I 24.) l o For vertical loading, the development of torsion in l the beam due to the eccentricity between the clamp location and the beam shear center is prevented by flexure of the cable tray. This assumes a full moment fixity between the tray and the support beam. (See Issue No. 24.)
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l V %\ C Revision 14 ' 5! , Page109 .I 2 3 y < i l CABLE TkhY SUPp0RTS'_ l L ,, , Revtw !ssues . List I y, ,, B. HeavyDutyIypeClamp$ ,'E: For heav[ duty clampsi ethd 2;he,above assumptions are alsa applicable. Additionally, the following assumption j l -
, was made by Gibbs & Will. -> !
% 3 s ', o The development of torsion due to longitudinal loads ;
, on three-way supports using composite . beam sections i (e.g., SP-?, with brace and Detail 8 on Drawing )
( 2323-S-0903, etc.) is prevented by flexure of the s
! cable tray. This assumes a full m.vnent' fixity' ')
( between the tray and the support beam. (SeeIssue j
\, N o.524. ) ,i l g i
%- t ' N,
' 4 The assumptions described above are valid only if the l l ,
clamps can provide sui, table displacement and rotational i compatibility between..the tray and the support beam. l Based on a discussion wjth TUGC0 (Reference 3), Cygna - i determined that installation tolerances (Reference 2; a
~
DCA 6299, Revision N DCA 20331 Revision 0; and , CMC 93450, Revidion 4)'have been adopted which allow gaps between the tray side rails, the support beam, and I the tray clamps. In order to provide the assumed compatibility, " friction" type clamps must be cinched sufficiently to develop friction at the tray / beam and tray / clamp interfaces. The existence of gaps will preclude the development of the normal contact force required for frictional resistance. C. Clamp Qualification Ebasco performed the clamp qualification in References
.12 and 13 which is based on Reference 15 Report. As indicated in Reference 14, an A.S.M.E. load rating i
procedure (Reference 16) was used by Ebasco to calculate
. safety factors against test load. In the following equations, a factor.of 1.0 is used for the OBE load rating, while for the SSE, a Factor of 1.5 is used.
! g,
, m TU Electric
..3 , Comanche Peak Steam Electric Station L'iii [d a 'AI Independent Assessment Program - All Phases lilillililllillfilllililllllli Ob No. 84356 PRJ:RIL
1 07/31/87 Revision 14 ' Page 110 j CABLE TRAY SUPPORTS Review Issues List j S i Load Rating = TLu x 1.0 x g- x 0.5 u. i l l Safety Factor = TLu (Test Load Utlimate) l Load Rating (Allowables) l Cygna asked the following questions' regarding "S" and "Su":
- 1. Why does Ebasco use the yield stress rather than the minimum tensile stress as required in Reference 167
- 2. Why does Ebasco use the allowable shear stress j instead of the bending allowable?
Response: A. The effects of the connectivity provided by friction type clamps between cable trays and transverse supports is considered in the design verification in two ways. 1 These assumptions on connectivity affect the issues regarding out-of-plane inertial loads, base angle ] rotation, effective length for compression members, etc. j In all analyses performed by. Impe11, the clamps are . assumed to provide full connectivity between-the cable trays and the supports. In References 6 and 7 Impell has developed clamp stiffness values associated with the six transnational and rotational degrees of freedom of the tray to support connections. These stiffnesses are summarized in Section 3.2.4 of Reference 9. The transmission of forces and moments between the cable tray and the cable tray support, in spite of the poten-tially significant gaps between the clamps and the tray, is justified based on the interpretation of the results i of a series of dynamic tests of futi scale models of cable tray systems. The test results are summarized in Reference 8. Analytical justification is provided in Reference 10. TV Electric d @j a 3-i Comenche Peak Steam Electric Station I t1 Independent Assessment Program - All Phases lillllilllllllllllllllllllllll Job No. 84056 PRJ:RIL
07/31/87' Revision 14 .l Page 111 CABLE TRAY SUPPORTS Review Issues List 1 In a large portion of. the analyses performed by Ebasc'o, 1 the friction type clamps are assumed to be incapable of 1 transmitting loads in the tray axial direction. The finite element models used, both for the individual supports analyzed by the equivalent static method (ESM) and the system models analyzed via the response spectrum method (RSM) assume no axial connectivity between the tray and the supports. References _4 and 5 provide Ebasco's modelling _ guidelines. In light of the connectivity assumption used by Impell, Ebasco will evaluate the impact of the differences between the assumptions used by the two consultants. In l i accordance with Attachment 2 of Reference 4. Ebasco will l reevaluate cable tray supports analyzed by the ESM to determine the impact of tray / support connectivity on the supports previously qualified assuming no connectivity. Similarly, for supports analyzed by RSM, Reference 5 specifies that a number of systems will be reanalyzed assuming tray / support connectivity to evaluate the impact of this assumption. Therefore, the current cable tray support design verification effort assumes connectivity between the tray and the support and thus, includes the same load ! transfer mechanisms employed by Gibbs & Hill. I B. For supports analyzed by the static or equivalent static l l methods, Ebasco assumes that the heavy duty clamps i l provide three directional force transfer without any I moment transfer. (Reference 4 Attachment B2.) Thus, l the heavy duty clamps do not reduce the torsion or j bending moments due to the eccentricities between the cable tray and the support. For cable tray supports included in response spectrum ] analyses (Ebasco's RSM models and Impe11's system 1 models), heavy duty clamps are assumed to' provide force and moment transfer between the tray and the support. l
=__Em TV Electric q Comanche Peak Steam Electric Station bvm-ML Independent Assessment Program - All Phases ]
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I 07/31/87 Revision 14 Page 112 , i CABLE TRAY SUPPORTS Review Issues List l The clamps are modelled as linear elastic spring elements having stiffness properties calculated in References 6 and 7. These values are documented in Reference 5 and Reference 9. Based on the results of' the. cable tray' system testing program, Impe11 has ' determined that higher clamp stiffness values than those documented in Reference 5 and 9 can be used. (References 8 and 11.) Justification for the differences in assumptions Ebasco has made for the static method and the response spectrum method has not been provided.
'C. Ebasco responded to Cygna questions (noted in the
" Summary" Section) as follows (Reference 14):
A majority of the longitudinal clamps fail in shear (i.e., the bolt fails in shear before the clamp fails in flexure), therefore, the shear yield stress is used in place of "Su" in the equation. For clamps with flexural failure modes (e.g., transverse clamps, where the clamp fails in flexure before the bolt fails in shear), the
~
bending allowables are used for the "S" tenn and the yield stress, "Sy", is used for the "Su" term. "Sy" is used because after the clamp deforms, or reaches yield, l it disengages from the tray. Ebasco also stated in' Reference 13 that the safety factor is calculated for SSE allowables only. Ebasco also stated that they would provide the latest revision of SAG.CP-19 and SAG.CP-18 (Reference 18). Impe11's tray c? amp qualification procedures are contained in Reference 17. Status: A. Open: Cygna must complete the review of the system test results for justifications of tray clamp behavior. B. Open: See Issue No.18.A for the status regarding the review of the system tests. Additional Cygna review of Ebasco clamp modelling procedure is required. TV Electric Comanche Peak Steam Electric Station dd [ fd Independent Assessment Program - All Phases lll11111111111111111111ll11111 Job No. 84056 PRJ:RTL
07/31/87 l Revision 14 ' l Page 113 CABLE TRAY SUPPORTS Review Issues List l C. Open: Ebasco to provide 1atest revision of SAG.CP-19 -) and SAG.CP-18. Cygna must review keference 17 and l associated documents. i I
- l i
l l l l 1 mm. TU Electric
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- 19. FSAR Load Combinations Refe.rences: 1. CPSES FSAR, Section 3.8.4.3 i l 2. Gibbs & Hill Calculation Binder SCS-103C, Set 1 l Sheets 14-19 !
- 3. Gibbs & Hill Calculation Binder SCS-103C, Set 2, Sheet 32 j
- 4. Transcripts of Cable Tray Hanger Design Verification meeting between TV Electric, Cygna, Ebasco and Impell ]
held at the CPSES site on January 26 and 27,1987
- 5. C.R. Levine (TUGCO) letter to K.C. Warapius (Impell) No. l TSG-19043 dated July 2,1986
- 6. Transcripts of Cable Tray Hanger Design Verification Meeting between TV Electric, Cygna Ebasco, Impell, JBA and SWEC held at the CPSES site, May 19, 1987. 'l l
- 7. Impe11 report 0210-040/41, IM-P-006 Revi sion 0, dated May 15, 1987: Effects of Thermal Loading on Cable Tray Systems.
- 8. Impe11 Calculation M-27 Revision 2. " Thermal Load Eval ua tion."
Summary: Reference 1 defines the loads and load combinations applicable to the design of cable tray supports. Cygna's review of the cable tray support designs indicates that only dead weight and seismic inertial loads are considered. For supports installed in the Reactor Buildings, the loads associated with a LOCA may be applicable, including pipe whip, jet impingement, and thermal loads. Two support types within Cygna's review were designed for installation in the Reactor Building, Detail A (Gibbs & Hill Drawing 2323-El-0500-04-5) and Detail C (Gibbs & Hill Drawing __ _ __- TV Electric Comanche Peak Steam Electric Station [*$N L Id Independent Assessment Program - All Phases 1111ll1111111111111111111lll11 Job No. 84056 'PRJ:RIL
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2323-El-0500-01-S.) The design calculations for these l supports, References 2 and 3, respectively, did not consider l these additional loads. Response: Information given in Reference 5 indicates that safe shutdown cable trays identified as pipe whip or jet d impingement targets have either been relocated or shielded from the potential k as. Therefore, there is no need to , evaluate the cable trays'or supports for these loads. In Reference 4, TU Electric indicated.that cable trays do J not need to be evaluated for the thermal effects associated with normal operating temperatures and had developed a position relating to the effects of thermal loads due to the 1 accident temperatures on support anchorages (Reference 7). 'l Reference 8 is listed as the basis for Reference 7. Status: Open: Impell must provide Cygna with revision 2 to j Calculation M-27. '
= :: TV Electric
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- 20. Differences Between the Installation and the Design / Construction Drawings l
[ without Appropriate Documentation
References:
- 1. Gibbs & Hill, Inc., Support Layout Drawing 2323-El-0713-01-S
- 2. Brown & Root, Inc., Fabrication Drawing FSE-00159 )
i
- 3. American Institute of Steel Construction, Inc., Manual )
I of Steel Construction, 7th Edition
- 4. Gibbs & Hill Support Layout Drawing 2323-El-0601-01-5 I
l
- 5. Gibbs & Hill Support Layout Drawing 2323-El-0700-01-S
- 6. Gibbs & Hill Cable Tray Support Design Drawings 2323-S-0900 series
- 7. N.H. Williams (Cygna) letter to J.B. George (TUGCO),
l " Cable Tray Support Walkdown Questions," 84056.026, l dated August 23, 1984
- 8. Communication Report between M. Warner, J. van Amerongen (TUGCO) and W. Horstman (Cygna) dated October 25, 1984 t 9. Communication Report between T. Webb, M. Hamburg (TUGC0) and W. Horstman (Cygna) dated f)ctober 18, 1984 1
- 10. Communication Report between M. Warner, C. Biggs (TUGCO) and W. Horstman (Cygna) dated October 10, 1984
- 11. Brown & Root Procedure No. CEI-20, Revision 9, j
" Installation of Hilti Drilled-In Bolts"
.i l
1-
- 12. L.M. Popplewell (TUGCO) letter to N.H. Williams (Cygna),
" Comanche Peak Steam Electric Station Cygna Review Questions," dated September 6,1984 l
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- 13. N.H. Williams (Cygna) letter to J.B. George (TUGCO),
" Cable Tray Support Walkdown Questions," 84056.021, dated. August 16, 1984 l
- 14. N.H. Williams (Cygna) letter to W.G. Counsil (TUGC0), l l " Cable Tray / Conduit Support Review Questions," j i 84056.089, dated October 21, 1985 l
- 15. Brown & Root Instruction QI-QAP-11.2-28, " Fabrication, Installation Inspections of ASME Component Supports, Classes 1, 2 and 3 " Revision 29 ,
- 16. Transcripts of Cable Tray Hanger Design Verification Meeting between TV Electric, Cygna, Ebasco and Impe11 -
held at the CPSES site on January 26 and 27,1987
- 17. TU Electric Procedures TNE-FVM-CS-001, " Field i Verification Method Unit 1 Cable Tray Hanger As-Buil. ting- i and Design Adequacy Verification Program" Rev. 5, July i 1,1986, and TNE-FVM-CS-003," Field Verification Method Unit 2 Cable Tray Hanger As-Builting and Design Adequacy i Verification Program", Revision 1, October 18, 1986.
Supplemental Procedure for Unit 2 Wal kdown, TNE-FVM-CS-019, " Selected Cable Tray Attributes Data Collection Unit 2", Revision 1, September 3,1986 I
- 18. TV Electric, CPSES, " Generic Issues Report Evaluation )
and Resolution of Generic Technical Issues for Cable Tray Hangers", Revision 2 l
- 19. Transcripts of Cable Tray Hanger Design Verification Meeting between TU Electric, Cygna. Ebasco, Impell, JBA and SWEC held at the CPSES site, May 19, 1987.
- 20. Impe11/Ebasco Approach Towards Design Verification of Inaccessible Attributes IM-T-0210-040-238, dated May 15, 1987.
=== TU Electric 1 l -
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- 21. Civil Structural Review Issues List Revision 0, dated
' July 21,1987.
- 22. Specification CPE-S-10.1, Revision 0, Summary: Cygna performed walkdown inspections on 49 of the 92
. supports within the review scope. Certain discrepancies between the as-built support configurations and the design requirements were as noted below.
A. Support No. 481, Longitudinal Type A4
- 1. Single angles were installed as braces in the longitudinal direction. A pair of angles is required' by the design drawing.
- 2. The slopes of the upper' longitudinal braces exceed ;
l the design limits. l l 1 l 3. The working point locations for-the lower longitudinal braces with respect to the beam elevation at the attachment to the hanger exceed the l design limit.
- 4. The working points for all longitudinal braces, with respect to the anchor bolts, exceed the design l imi ts.
- 5. The angle sections used for the longitudinal braces are inverted.
l 6. The length of several of the Hilti Super Kwik-bolts is insufficient to achieve the required embedment. B. Support No. 408, Type B4 l l ! TV Electric
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- 1. The lower corner of the frame is modified by -
CMC 9916, Revision 1, to avoid interference with the-CCW heat exchanger. This change document shows that 4" channel sections are to be used for the prescribed modification. A 6" channel section was 1' actually installed. The configuration of the notch, the weld pattern attaching the added members, the I elevation of the top beam, and the Richmond Insert locations do not match the requirements of i CMC 9916.
- 2. The bottom beam is a C4 x 5.4. A C4 x 7.25 is required.
l C. Support No. 649, Type A1 This installation uses concrete anchorage " Alternate Detail 1" (Gibbs' & Hill design Drawing 2323-S-0903), . j l which requires the use of an L6x6x3/4. An L5x5x3/4 was '1 i nstall ed. a 1 D. Support Nos. 722 and 2606, Detail "N", Drawing 2323-El-0601-01-S
- 1. The working point for the brace, with respect to the anchor bolts, exceeds the design limit.
- 2. For Support No. 2606, the length of the C6 x 8.2 beam is less than required. l
- 3. For Support No. 2606, the base angle is an L6x6x3/4, '
whereas the design requires an L5x5x3/4. E. Support Nos. 2992, 2994, 3005, 3017, 3021, 6654. Type A2 ; Reference 1 identified the above six supports as foll ows: "A2 (except all members shall be MC6 x 12)," where L = 8'-3" (frame width), h = 4'-2" (frame height). l TU Electric Comanche Peak Steam Electric Station ( d*IEd d Independent Assessment Program - All Phases
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- 1. The Cygna walkdown documented the installed hanger member sizes, as listed below in Table 1. Due to the presence of Thermo-Lag coating, which covers the entire bottom beam member and part of the hanger members, Cygna was unable to determine the installed beam member size.
TABLE 1 Cable Tray Support Hanger Member Sizes Dimensions
- Member Sizes Fl ange .
Support Depth Width No. (In) (In) Existing
- 2992 6 1-7/8 C6 x 8.2 2994 6 1-7/8 C6 x 8.2 -
l 3005 6 1-7/8 C6 x 8.2 3017 6 1-7/8 C6 x 8.2 ) l 3021 6 I-7/8 C6 x 8.2 i 6654 6 2-1/8 C6 x 13 l l
- Dimensions of the vertical channels (hangers) are based on measurements by Cygna. Member sizes are determined by selecting the channel type from Reference 3 which most closely ,
matches the measured depth and flange width.
- 2. The beam for Support No. 2992 was accessible and was found to be a C4 x 7.25 instead of the required MC6 x 12.
- 3. For the Detail I hanger connections for Support No. 2992, the distance from the anchor bolt to the end of the base angle exceeded the design limit, and the gauge dimension was less than required.
- 4. For Support No. 2992, a separation violation was noted between a Richmond Insert on the east hanger
_ - TV Electric
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07/31/87.. Revision 14 Page 121 CABLE TRAY SUPPORTS Review Issues List l l 4.. For Support No. 2992, a separation violation was noted between a Richmond Insert on the east hanger and a Hilti Kwik-bolt on an adjacent' pipe support. F. Support No. 455. Type SP-8
- 1. The brace connected to the wall on one side of the
- support is located outside of the bolt pattern on
[ the base angle. The Detail "B" (2323-S-0903) type connection requires the brace to be' located between the two bolts. l
- 2. The distance from the face of the concrete wall to t the support is less than that required on the design drawing.
- 3. Gaps of up to 1/4" between the base angles and the concrete, without grout' or shims, were' noted.
- 4. The distance between the top 1-1/4" Hilti Super Kwik-bolt on the north brace attachment and a 1/4" Hilti Kwik-bolt attaching the Thermo-Lag to the wall i is less than required. l l
G. Support Nos. 2998 and 13080, Special Type Supports l These supports were installed on floor slabs with 2" topping. The topping depth was not considered in selecting the length of the anchor bolts, and the required embedment length was not achieved. H. Hilti Super Kwik-bolts Without Stars Section 3.1.3.1 of Brown & Root Procedure CEI-20 (Reference 11) requires: Hilti Super Kwik-bolts shall be additionally marked with a " star" on the end which will > remain exposed upon installation. _ TV Electric pesii n.a m 4m Comanche Peak Steam Elect-ic Station L'$ [P.! [ It Independent Assessment Program - All Phases lilllillililllililllllllllllli Job No. 84056 PRJ:RIL
l l 1' 07/31/87 Revision .4 Page 122 l 1 CABLE TRAY SUPPORTS ') ! Review Issues List I Twenty-eight of the cable tray supports inspected by Cygna required the installation of Hilti Super Kwi k-bol ts. Of these, only:two supports had stars stamped on the bolts. The bolts on the remaining j supports were not : tamped. I. Contact Between the Component Cooling Water (CCW) Heat Exchanger and Cable Tray Support Nos. 332 and 408. See Issue No. 20.K. J. Support No. 2953, Detail "E" (Drawing 2323-El-0601-01-S) This support is attached near the end of an embedded strip plate. The distance from the end of the embedded-plate to a penetration through the concrete was less than the minimum distance required for the embedded , Nelson studs. I K. Proximity Violations Between Cable Tray Supports and Other Components i As a criteria for clearance between cable tray. supports and other non-attached components, Cygna used a minimum of 1-inch separation. This was based.on the inspection criteria for pipe supports (Reference 15), since no separation criteria was specified in the cable tray installation inspection instruction. The separation violations found are the following: Support No. Violation Description 202 1/2" clearance between beam and insulation on pipe passing through support
.____ TV Electric Comanche Peak Steam Electric Station
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l 07/31/87 Revision 14-Page 123 i I CABLE TRAY SUPPORTS L Review Issues List ) 299 Brace and hanger near: top of - . l support in contact with Thermo-Lag l on conduits f 1 332 0" clearance from CCW heat exchanger 408 1/2'? clearance between hanger and. i pipe passing through support. 0" 'l clearance from CCW heat exchanger l 1 605 1/8" clearance between end of beam j and an HVAC duct j 758 .1/8" clearance between brace and j pipe running parallel to support 1 frame l 765,766, 1" clearance between' braces and ) 767 pipe passing through support 2986 Hangers are in contact with. l Thermo-lag on en adjacent cable tray 3026 Thermo-lag on support beam is in contact with a pipe , 6654 West end of bottom beam is in contact with a pipe 3016 Bottom beam is in contact with insulation on a pipe 3022 5/8 inch clearance between bottom beam and insulation on a pipe 13131 Fire protection on the cable tray , is in contact with the rear
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l 07/31/87-Revision 14 Page 124 I CABLE TRAY SUPPORTS Review Issues List bracket- of the strut for a pipe support I L. Support No. 758, Detail "V" (Drawing 2323-El-0601-01-S)
- 1. The north base angle for this support is shared with support no. 759. This attachment was not documented -
on the CMC affecting support no. 758.
- 2. An anchor bolt spacing violation existed between one Hilti Super Kwik-bolt on the south. hanger and 'a rod hanger _ from a fire sprinkler line.
M. Support No.124. Type D2
- 1. The channel sections installed were C6 x 10.5 and C4 x 5.4 for the bottom and top beams, 'respectively.
The design requires C4 x 7.25 sections. I 2. The Richmond Insert pattern for the beam anchorage does not match that shown on CMC 1078, Revision 0. l N. Support No. 202. Type A4
- 1. The channel sections installed were 'C4 x 5.4 for the beams. The design requires use of C4 x 7.25 sections.
- 2. The anchor bolt length for the south hanger attachment is insufficient to achieve required embedment.
O. Support No. 479, Detail "C", Drawing 2323-El-0500-01-S The length of the overlap between the hanger and the base angle is less than required by design. l TV Electric Comanche Peak Steam Electric Station t'AIP)[ d Independent Assessment Program - All Phases lillllllllllllililllllllllilli Job No. 84056 PRJ:RIL l ,
1 l I 07/31/87. a Revision 14 1 Page 125 j CABLE TRAY SUPPORTS Review Issues 1.ist ! P. Support No. 589, Type A1 j
- 1. This support has an angle section added as a- !
stiffener to the east C6 x 8.2 hanger, per CMC 2646, Revision 5. The installed weld pattern attaching 3 the angle does not match that shown on the CMC.
- 2. Each hanger is attached to the concrete using a 'j single Hilti Super Kwik-bolt; however, the anchor bolts are not centered on the hanger as' required by the design.
l Q. Support No. 590, Type A1 j
- 1. This. support has an angle section added as a q stiffener to the east C6 x 8.2 hanger, per CMC 2646, {
Revision 5. The installed weld pattern attaching ] the angle does not match that shown on the CMC. l l
- 2. The depth of the notch provided to clear the tray rail exceeds the 3/4 inch limit given on CMC 2646.
R. Support No. 605, Detail "A", Drawing- 2323-El-0500-04-S The cable tray is attached to the this support using Type II friction clamps. The gage distances for the bolts attaching the elamps to the support beam are not within the design limit. , S. Support No. 638, Type SP-4 , 1. The slope of the brace member exceeds the design limit of 1.5:1.
- 2. The brace is attached to the frame using a gusset plate, which is not allowed by the design.
- 3. The working point of the brace with respect to the base angle is not within the design tolerance, l
TV Electric '
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T. Support No. 724, Detail "N", Drawing 2323-El-0601-01-S j i
- 1. The length of the C6 x 8.2 beam was less than the j required 6'-9" length. 1
- 2. The L3x3x3/8 brace was attached to the incorrect side of the gusset plate on the beam.
- 3. An L6x6x3/4 was used instead of the required L5x5x3/4 for the beam- base angle.
l l 4. The anchor bolt types and locations do not agree-with the requirements of CMC 155, Revision 0. j U. Support No. 763, Detail "K", Drawing 2323-El-0601-01-S
]
The installed base plates are 1-1/4" thick. The design l requires the use of 3/4" plates. l V. Support No. 764, Detail "K", Drawing 2323-El-0601-01-S
- 1. The installed base plates are 1-1/4" thick. The ;
design requires the use of 3/4" plates. ; 1
- 2. The tray attachment uses heavy-duty clamps with 1/2" l A307 bolts attaching the clamp to the tray. The distance from the end of the clamp to the bolt on one clamp is less than required by the design.
- 3. The channel used as a spacer between one tray and the support beam is not the required MC3 x 9 shape.
W. Support Nos. 765, 766, 767 Detail "J", Drawing 2323-El-0601-01-S
- 1. The in-plane braces for these supports are attached directly to the supports' south base angles. The c
TU Electric Comanche Peak Steam Electric Station L*I (d i fA3 Independent Assessment Program - All Phases lilllllillllill!!Illllillllll! Job No. 84056 PRJ:RIL
l l 07/31/87 ; Revision 14 'l Page 127 i , CABLE TRAY SUPPORTS l Review Issues List i design requires that the brace be attached to the hanger member, below the base angle. j j
- 2. For Support No. 766, there is a spacing violation between one of the Richmond Inserts on the south
! hanger attachment and an adjacent Hilti Kwik-bolt. )
- 3. For Support No.-767, there is a spacing violation:
between one of the Richmond Inserts on the south hanger attachment and a rod hanger.. X. Support .No. 2602, Detail "W", Drawing 2323-El-0601-01-S .
]
i Two non-seismic conduit supports were attached to this l l support at the east end of the W8 x 31 beam. The l l attachment of these conduits was not shown on applicable ' l CMCs affecting this support. ] I 1 Y. Support No. 2986, Type A4 This support installation has one Hilti Super Kwik-bolt for each hanger anchorage. The design drawing (2323-S-0909) requires that the bolt centerlines be coincident with the hanger centerlines, however the ' bolts are up to 1/4 inch off center.
- 2. Support No. 3026. Type SP-4 The north beam was a C4 x 5.4 section. The design requires the use of a C4 x 7.25 section. Since the other members were covered with Thermo-Lag, their sizes could not be determined.
AA. Support No. 3028, Type D1
- 1. The east hanger is composed of two separate pieces of channel, a C6 x 8.2 and a C6' x 10.5, butt-welded together approximately 11 inches above the cable trays.
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- 2. The hanger attachment to the concrete slab uses one Richmond Insert and one Hilti Kwik-bolt. The location of hanger with respect to the bolts does not meet the design requirements.
1 BB. Support No. 3134, Detail "11", Drawing 2323-S-0905-1
- 1. The beam length is 6 inches greater than that shown on CMC 8585, Revision 3. )
- 2. The longitudinal braces were L3x3x3/8 sections. The design requires the use of L3-1/2x3-1/2x3/8 sections.
- 3. Two conduits were supported by rod hangers attached to the base angle for the east' hanger, these conduits were not shown on any applicable change ,
documents. I CC. Support No. 5807. Type Longitudinal A1
- 1. The slope of the longitudinal braces are not with design tolerance.
- 2. The L3x3x3/8 sections for the braces are inverted. I
- 3. The weld between the west brace and the hanger does not provide the required minimum weld length.
- 4. The welds between the gusset plates and the base angles are not per design requirements.
- 5. The working points of the longitudinal braces with respect to the anchor bolts are not within the design tolerance.
- 6. The location of the TS6x6 from the attached pipe support does not correspond with the location shown on CMC 80294, Revision 0.
TU Electric
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- 7. Based on the indicated bolt length and the measured
! bolt projections, several of the Hilti Super Kwik-bolts do not provide sufficient embedment.. DD. Support No. 332, Detail "A", Drawing 2323-El-0700-01-S
- 1. The concrete edge distance for the Hilti expansion anchors exceeds the 10 inch limit required by DCA l 4897, Revision 0.
- 2. Separation violations between top anchor bolt and the anchor bolts for pipe support CC-2-01-003-A33R 1 are not documented.
EE. Support No. 629 Type SP-7 with brace J
- 1. The siope of the 1 longitudinal brace is not within the range. allowed by the design.
- 2. The gusset plate attaching the brace to the beam is located 2 inches from the end of the beam. The design requires the gusset plate to be flush'with the beam end.
FF. Support No. 631 Type SP-7 This support is attached to an embedded strip plate. A separation violation exists between the plate edge and a 1 inch diameter Hilti Super Kwik-bolt. GG. Support No. 720 Type SP-7 Separation violations between bottom Hilti Super Kwik-bolt and the anchor bolt on an adjacent support is not documented. I
- r;__ _ TV Electric Comanche Peak Steam Electric' Station NId Id Independent Assessment Program - All Phases lilllllllllillllllllillllillll Job No. 84056 PRJ:RIL
1 1 l 07/31/87 I Revision 14 ' j Page 130 CABLE TRAY SUPPORTS Review Issues List HH. Support No. 734, Detail "H", Drawing 2323-El-0601-01-S The top and bottom beams are not located within the design location tolerance. II. Support No. 790, Type SP-7 This support is located on the surface of an opening in j l a concrete wall. An embedded plate is located 8 inches I ( from the edge of the opening. The separation between the expansion anchors for the support and the embedded l plate does not meet the requirements of Gibbs & Hill specification 2323-SS-30. (See Issue No. '17.F. ) JJ. Support No. 2920. Type SP-7 with brace
- 1. This support uses a gusset plate to attach the l l
longitudinal brace to a horizontal base angle. Thi s ! ! connection is not allowed by the. design drawing.
- 2. The location of' the_ brace with respect to the anchor bolts does not meet the design requirements.
! KK. Support No. 3016, ' Detail "F", Drawing 2323-El-0601-01-S I
- 1. The bolt hole end distances on the base plate exceed the design limit of 3 inches.
- 2. The center anchor bolt is a 1 inch diameter expansion anchor. The design requires a minimum 1-1/4 inch diameter bolt.
LL. Support No. 3022, Detail "F", Drawing 2323-El-0601-01-S The locations of the Richmond Inserts do not agree with those shown on CMC 4534.
=> _. TU Electric
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07/31/87 Revision 14 Page 131 CABLE TRAY SUPPORTS Review Issues List MM. Potential Root Causes of Construction Discrep'encies. As summarized above, Cygna has noted a large number of construction discrepancies in the cable tray supports within the review scope. Cygna is concerned about the manner in which these discrepancies will be addressed in the current reevaluation program. Specifically, Cygna raised the following questions during the meeting documented in Reference 16:
- 1. After the as-built drawing development is completed, will an effort be made to compare these drawings with the original design drawings. to identify a 1 potential root cause of the construction ,
deficiencies?
- 2. Has an evaluation been performed to establish the.
root cause of the drawing quality problems?
- 3. What changes in project procedures have been made to ;
! prevent a reoccurrence of similar problems in future ] work at CPSES? j Response: The design verification of cable tray supports is based on the as-built configuration of the supports. (Reference 18). The as-built walkdown procedures are specified in Reference 17. All concerns associated with Issue Nos. 20.A through 20.J and 20.L through 20.LL 'are addressed through j the design verification of the as-built support i configurations. Issue No. 20.K. proximity violations between supports and other components, has been addressed. Per Reference 19, TV Electric has developed specifications (Reference 22) to address the separation / clearance requirements between the cable tray systems and other components. This issue has been transferred to Reference 21, Issue No.10. Cygna notes that spacing violations will al so be covered by SWEC. (Reference 19). Cygna understands that a 100% hardware / installation L TU Electric ' . . .. Comanche Peak Steam Electric Station d (Ejt d Independent Assessment Program - All Phases lillllllllllilllllllllllllllli Job No. 84056 PRJ:RIL
l 07/31/87 Revision 14 Page 132 CABLE TRAY SUPPORTS Review Issues List j reverification is being performed and, as such the generic implications of these discrepancies are no longer a concern with regard to cable trays. The root cause of these specific findings has been considered, but not formally addressed by the Project. (Reference 16.) I j Status: All issues regarding as-built discrepancies (A-J L-LL) are closed based on the current support as-built program. However, due to the state of the construction of CPSES, certain components on a number of supports are no longer j accessible for inspection (i.e., hidden or inaccessible i attributes). Reference 20 the is joint Impe11/Ebasco I approach towards design verification of inaccessible attributes. Ebasco must provide two reference documents for Reference 20. (See Issue No.16A). 1 l Based on a review of the as-built procedures (Reference 17) ! Cygna raised several concerns. These are discussed in Issue j No. 33. Issue No. 20.K: See Reference 21, issue 10. Issue No. 20.MM: Open. ___ TV Electric
.. Comanche Peak Steam Electric Station
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07/31/87 Revision 14 Page 133. CABLE TRAY SUPPORTS l Review Issies List L 21. Design Control i
References:
- 1. Gibbs & Hill Drawings 2323-El-0601-01-S, 2323-El-0700-01-S, 2323-El-0713-01-S 1
- 2. N.H. Williams '(Cygna) letter to J.B. George (TUGCO),
" Cable Tray Support Design Review Questions," 84056.022, dated August 17, 1984, questions 1, 2, and 6
- 3. N.H. Williams (Cygna) letter to J.B. George (TUGCO),
l " Cable Tray Support Design Review Questions," 84056.025, dated August 21, 1984, question 1
- 4. Gibbs & Hill Cable Tray Support Design Drawings 2323-S-0900 Series
- 5. Gibbs & Hill Calculations for Support Numbers 3025, 3028, 2861, Cygna Techtical File 84056.11.1.225
- 6. L.M. Popplewell (TUGC0) letter to N.H. Williams (Cygna),
" Responses to Cygna Review Questions," dated September 4,1984, with attached calculations
- 7. Gibbs & Hill Calculation Binder 2323-SCS-1010 Set 3, Sheets 206, Revision 6
- 8. L.M. Popplewell (TUGCO) letter to N.H. Williams (Cygna),
" Response to Cygna Design Review Questions," dated September 11, 1984, with attached calculations
- 9. Gibbs & Hill Calculation Binder 2323-SCS-1010, Set 5
- 10. Gibbs & Hill Drawing 2323-S-0901, Revision 4
- 11. N.H. Williams (Cygna) letter to J.B. George (TUGCO),
" Cable Tray Support and Electrical Review Questions,"
84056.019, dated August 10, 1984, questions 2.1 and 2.2 _ TU Electric Comanche Peak Steam Electric Station
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- 12. Gibbs & Hill Drawings 2323-El-0601-01-S ,
2323-El-0700-01-S, and 2323-El-0713-01-S l 13. Gibbs & Hill Specifications 2323-ES-19, Revision 1
" Cable Tray Specification" i l
- 14. Gibbs & Hill Calculation Binder 2323-SCS-111C, Set 8 I d
l 15. Communications Report between P. Huang (Gibbs & Hill) ! and J. Russ (Cygna) dated June 13, 1984 ! l l
- 16. L.M. Popplewell (TUGCO) letter to N. Williams (Cygna), j
" Comanche Peak Steam Electric Station Cygna Review j Questions," dated August 27, 1984 with attachments j
- 17. R.E. Ballard (Gibbs & Hill) letter to J.B. George (TUGCO), " Cable Tray Supports.Cygna Phase 4 Audit ,
I Activities," GTN-69377, dated August 24,1984, wi th attachments
- 18. L.M. Popplewell (TUGCO) letter to N. Williams (Cygna),
" Comanche Peak Steam Electric Station Cygna Review Questions," dated September 11, 1984, with attachments
- 19. Gibbs & Hill Calculations Binder 2323-SCS-111C, Set 7
- 20. TUGC0 Instruction CP-EI-4.0-49, Revision 1
- 21. Cable Tray Thenno-Lag Evaluation, Safeguards Building, Elevation 790'-6." Cygna Technical File 84056.11.1.1.315
- 22. N.H. Williams (Cygna) letter to J.B. George (TUGCO),
" Cable Tray Support Review Questions," 84056.041, dated February 12, 1985
- 23. Communications Report between 11. Warner (TUGCO) and N.
Williams et al. (Cygna), dated February 27, 1985 nr- ; TV Electric 3
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07/31/87 Revision 14 Page 135 CABLE TRAY SUPPORTS Review Issues List
- 24. N.H. Williams (Cygna) letter to V. Noonan (USNRC),
" Response to NRC Questions," 83090.023, dated March 8, 1985
, 25. Brown & Root Cable Tray Hanger Assembly Drawing FSE-00159
- 26. Gibbs & Hill Design Procedure DP-1, " Seismic Category I Electrical Cable Tray Supports,'? Revision 0, dated June 11, 1984.
- 27. N.H. Williams (Cygna) letter to W.G. Counsil (TUGCO),
" Cable Tray / Conduit Support Review Questions "
84056.089, dated October 21, 1985 ;
- 28. N.H. Williams (Cygna) letter to J.B. George (TUGCO), i
" Cable Tray Support Review Questions," 84056.027, dated August 27, 1984
- 29. Ebasco Procedures SAG.CP4, " Seismic Design Criteria for Cable Tray Hangers for CPSES Unit 1", Revision 3 and SAG.CP3, " Seismic Design Criteria for Cable Tray Hangers for CPSES Unit 2", Revision 6 ,
i
- 30. TV Electric Procedures TNE-FVM-CS-001, " Field Verification Method Unit 1 Cable Tray Hanger As-Builting and Design Adequacy Verification Program", Revision 5 July 1,.1986, and TNE-FVM-CS-003," Field Verification Method Unit 2 Cable Tray Hanger As-Suilting and Design Adequacy Verification Program", Revision 1, October 18 l 1986. Supplemental Procedure for Unit 2 Walkdown, l TNE-FVM-CS-019. " Selected Cable Tray Attributes Data Coll ection Unit 2", Revision 1, September. 3,1986. J
- 31. Ebasco Introduction, " General Instructions for Cable Tray Hanger Analysis for CPSES Nos. I and 2".-Revision 4
- 32. Impel'. Instruction P7-02, " Dynamic Analysis of Cable Tray Systems", Revision 5 i
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07/31/87 Revision 14 Page 136 CABLE TRAY SUPPORTS Review Issues Lir.t
- 33. Transcripts of the Cable Tray Hanger Design Verification Meeting between TU Electric, Cygna, Ebasco and Impell held at the CPSES site, January 26 and 27,1987
- 34. Impe11 Calculation M-39, " Side Rail Extension Study",
Revision 1
- 35. Transcripts of Cable Tray Hanger Design Verification Meeting between TV Electric, Cygna. Ebasco, Impe11, ~JBA and SWEC held at the CPSES site, May 19, 1987.
- 36. Impe11/Ebasco Approach Towards Design Verification of Inaccessible Attributes IM-T-0210-040-238,_ dated May 15, 1987.
Summary: A. Tracking and Consideration of Design Changes During the course of the design and construction of cable tray supports, a large number of design change documents (DCAs and CMCs) have been issued that affect the support designs. These design changes can be grouped into two categories. Generic design changes are issued against a Gibbs & Hill support design drawing (e.g., 2323-S-0901) and may affect all installations of one or more generic' support designs. Individual design changes are issued against a support layout plan (e.g., 2323-El-0601-01-S) and affect one or more individual support installations. Cygna's review has . identified several areas where oversights or errors may occur in the handling of these design changes. These may be due in part to the large numbers of design changes which have not been incorporated in the design drawings.
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- 1. Generic Evaluations In the process of. performing generic.. evaluations of support design adequacy (e.gt, the inclusion of base j plate flexibility in response to IE Bulletin 79-02, l the Working. Point Deviation Study, the evaluation 'of the effects of weld undercut / underrun, etc'.), Gibbs
& Hill based their calculations.on the original q support designs without considering the effects of J all applicable generic design changes.
1 (Reference 27.) .j
- 2. Case-by-Case Design Adequacy Reviews In some cases, as a result of the ~ generic studies ;
discussed above, the design limits for a support i type were made more restrictive than those of the original design. In order to qualify existing supports which had been specified based on the original design limits, a case-by-case design ! adequacy review was performed for all individual ! supports which exceeded the revised design limits. These reviews were based on the as-designed ! l configurations for the. individual supports, and did - not include the' effects of applicable individual design changes. (Reference 27.)
- 3. Tracking of Design Changes Affecting Individual Supports 'j The disign changes for individual . supports are tracked by the cable tray support plan' drawing number rather than by the support number. In order 1 to locate all design changes affecting a given sup port, one must manually search through all design changes affecting all supports on the applicable l support plan. Cygna has observed that some support plans have over' 200 design changes outstanding. In order to expedite .this effort, the-TUGC0 Field
~
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07/31/87 Revision 14 Page 138 i CASLE TRAY SUPPORTS Review Issues List Structural _ Engineering Group (FSEG) maintains a list of design changes sorted by individual support I number. This list is not a controlled document, and a Cygna's review noted several discrepancies between the design changes listed for individual supports and those located by Cygna through a search of design change documents at the Document Control , Center. It is Cygna's understanding, however, that ! this informal log is relied upon by the field l engineer to determine which design changes should be 3 considered in their evaluations of field change j requests. 1
- 4. Design Changes Used For Q.C. Inspectors A discussion with TUGC0 cable tray support ;
installation Q.C. personnel (Reference 23) indicated that the method of locating design changes for support inspection purposes was very cumbersome and placed an undue burden on the inspectors in assembling inspection packages. TUGC0 Q.C. indicated that the inspectors typically relied on the list of design changes included in the Brown &
- Root construction package as a basis for inspection without independently verifying the completeness of the package.
- 5. Adequacy of Design Review Cygna has noted instances where the design review for the verification of design changes may have been !
j inadequate. The design changes allowed deviations j l from the original design that invalidated certain i; assumptions on which the original design was ' based. However, the design review did not note this ! and did not assess the impact of the change on the , design basis. In other cases, the design review did l not assess the impact of the change on all l TU Electric
,Ei Comanche Peak Steam Electric Station 8m NJL [ Independent Assessment Program - All Phases Illlllilllilllllillllilllllill Job No. 84056 PRJ:RIL
I I I 07/31/87 l Revision 14 1 Page 139 f CABLE TRAY SUPPORTS l Review Issues List I components of a support that would be affected. Examples of this include: o Base angles are designed assuming a minimum distance of 3" from the bolt hole to the end of the angle. This distance is used in the 1 calculation of the resisting moment arm when a j bending moment is applied to the base angle. ] CMC 1970 reduced this distance to a minimum of i 1-1/4 " . The design review for this CMC did i not consider the impact of this reduction on the anchor bolt designs.
)
o Cable tray supports are designed for a frame I width based on a minimum distance of 3" from the outside tray rail to the inside of the . flange of the' hanger. (See Issue No. 28.A.) CMC 2646 allows the hanger to be notched so ] l i < that the tray rail actually overlaps the inside flange of the hanger. This can result in cable tray supports which do not meet the minimum width required by the Nign. The design review for this CMC only addressed the reduced section properties at the notch without considering the effect on the support wi dth, o Cable tray supports are designed to act as a system, with the cable tray acting as a link between supports. (See Issue No.10.) ' CMC 93450 allows gaps between the cable trays and the clamps attaching them to the supports. The frictional force between the clamps and , the trays, which is required to prevent relative axial displacement between the trays , and the supports, is eliminated by the gap. The design review for this CMC does not address the effect on the system behavior of the cable trays. (See Issue No.18.) TU Electric
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l 07/31/87 Revision 14 Page 140 I i J l CABLE TRAY SUPPORTS .] l Review Issues List j ! 1 o Cable trays are qualified for an 8'-0" maximum span. (See Issue No. 25.B.) DCA 1594 . provides an installation location tolerance l for the supports, resulting in a maximum spacing of 9'-0" between supports. The design review for this CMC does not consider the effect of the increased span on the cable tray qual ification. B. Criteria Violations in Individual Support Specifications on Support Plans 1 In the generic design of cable tray supports, support dimension and loading limitations are determined for each support type. These limitations are typically stated in the design calculations, but are not shown on the generic support design drawings. (Reference 4.) The dimensions for each support are specified in a descriptive block on the support plans (Reference 1), l and the loading is indicated by the supported tray width , shown. The tray supports listed below were identified as having loadings or support geometries which exceeded the design limitations. prior to the Cygna review, justifying documentation did not exist for the following individual support designs.
- 1. Support Nos. 3095, 3028, 2861, Type Di .
Drawing 2323-El-0713-01-S specifies these supports as Type Di (except beam to be MC6 x 16.3), L = 11'-9", h = 4'-2", and shows a tray width of 78". The design calculations for Type Dg supports limit L 8'-0" and tray width to 48".
- 2. Support No. 2607. Type A3 .
Drawing 2323-El-0601-01-5 specifies dimensions of L _____ TU Electric Comanche Peak Steam Electric Station rL *I (d L d Independent Assessment Program - All Phases lilllilllillilllilillilitulli Job No. 84056 PRJ:RIL
07/31/87 Revision 14'. j Page 141 I CABLE TRAY SUPPORTS ! Review Issues List
= 2'-9" and h = 4'-6" for this support. The design calculation for this support type limits h 2'-4".
- 3. Support No. 657. Type A1 .
Drawing 2323-El-0601-01 specifies this support as i Type A 1
, L = 7'-0", h = 2'-0". The design l
calculation for this support type limits L- 6'-0". 1
- 4. Support No. 734, Detail "H", Drawing 2323-El-0601-01-S. ,
This drawing specifies that one beam is to be an MC6 x 15.1, rotated 90, from its normal orientation. The support design requires the use of ,I C6 x 8.2 beam sections. The section modulus of l MC6 x 15.1 about its weak axis,1.75 in 3, is. smaller l than that of C6 x 8.2 about its strong axis, 4.38 l in 3. Therefore, this support should be reevaluated ! for vertical loads. I ! Rotating the MC6 x 15.190, from its normal orientation significantly increases the longitudinal stiffness of the support. This rotation, together ; with CMC 00164, which requires the use of a " heavy duty clamp," can introduce significant longitudinal loads to the support. The support design requires the addition of a longitudinal brace if longitudinal i loads are to be resisted.
- 5. Support No. 3011, Type SP-6. ,
Drawing 2323-El-0713-01-S specifies dimensions of L
= 8'-9" and h = 4'-6". The design calculation for '
this support type limits L 6'-0".
- 6. Support Nos. 2992, 2994, 3005, 3017, 3021, 3111, 6654, Type A2*
Drawing 2323-El-0713-01-$ specifies dimensions of L TV Electric Comanche Peak Steam Electric Station d(d 2 fd Independent Assessment Program - All Phases PRJ :RIL 1111111111!!!I1111111111llll11 Job No. 84056
R 1 07/31/87 Revision 14 Page 142 CABLE TRAY SUPPORTS Review Issues List
= 8'-3" and h = 4'-2", and shows a tray width of 78".. The design calculation for this support type limits L 6'-0".and the tray width to 48".
- 7. Support Nos. 95 and 112, Type SP.-7.
Drawing 2323-El-0700-01-S specifies these supports. as Type SP-7, L' =' 5'-1", and shows a tray width of 48". The design calculations for Type SP-71imits the tray width to 30".
- 8. Support No. 758, Detail "V", Drawing 2323-El-0601-S.
~
Drawing 2323-El-0601-01-S specifies this support as Detail "V", h1 = 8'-4", h2 = 7'-3", h3 = 4'-0", 1 1 = 5 '-9" , 1 2 '-3", a = 2'-6", and shows a tray width of 66". 2 T=he design for the support detail limits the tray width to 60".
- 9. Support Nos. 765, 766 and 767. Detail "J", Drawing 2323-El-0601-01-S.
Drawing 2323-El-0601-01-S specifies these supports as Detail "J", L = 8'-6", hi = 10'-10", h2 = 9'-6", h3 = 3'-6", and shows a tray width of 66". The design for the support detail limits the tray width to 48". Additionally, Gibbs & Hill was not consistent in establishing controlling criteria (i.e., support dimensions, tray width, etc.) in support designs. As an example, in several support designs, the support frame was designed for a particular height and width while the anchorages were designed using reactions from a frame with a different height and width. The lack of a single limiting configuration may affect the support dimensions as shown on the cable tray support plans. . Within h- TV Electric
. , s Comanche Peak Steam Electric Station L*t L 9 i A - Independent Assessment Program - All Phases lll111111111111111111111ll11ll - Job No. 84056 PRJ :RIL
y 07/31/87 Revision 14 1 l Page 143 i 1 CABLE TRAY SUPPORTS Review Issues List I { Cygna's scope, support types E 4, SP-6 and SP-8 are affected. 1 C. Consideration of As-Built Support Conditions in Generic Reviews Which Require a Case-by-Case Review
- 1. The SP-7 weld underrun analysis considered 5/16" 3 fillet welds which are specified on the design drawings. However, the FSE-00159 fabrication ]
drawings specify smaller weld sizes. In addition, ) the underrun analysis did not consider the effects of any design changes to the supports which were ] reported in CMCs and DCAs. (See Review; Issue 21.A.)
- 2. The Working Point Deviation Study did not include i the effects of all applicable design changes. (See Issue No.12.)
D. Inconsistencies in the Evaluation of Cable Tray Supports ! l For Thenno-lag Application l l
- 1. Tray cover weights were not included in the i development of the allowable span length tables (References 19 and 20) for fire-protected cable ]j trays.
- 2. Cygna believes that longitudinal supports are not evaluated for the added weight of fire protection. I Cygna noted evidence of the above in the fire l protection reviews for cable tray segment i T120SBD07. A longitudinal support (type L-A 1) was assumed to provide transverse restraint in the fire protection calculation. The calculated transverse j load was compared to an assumed design capacitf, but )
no longitudinal load was calculated. The original l design for this support type assumes that only. longitudinal restraint 15 provided. Note that the TU Electric
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R 07/31/87 Revision 14' Page 144 CABLE TRAY SUPPORTS Review Issues List calculations (Reference 21) reviewed by Cygna had not been design-reviewed at the time they were received from TUGCO.
- 3. Gibbs &' Hill performed calculations to deterinine the design capacity for supports to use as a comparison to the tray loads including fire protection.
(Reference 21.) A tributary span of 9'-0" was assumed. The actual design span was 8'-6";. therefore, the Reference 21 calculations overestimated the support design capacity.
- 4. For several cable tray segments within Cygna's review scope, the tray weight, including fire protection, exceeded the design limit of.35 psf by up to six percent, but engineering evaluations were not perfonned as required by Reference 20. See j j Reference 27, question 3, for a listing of the affected tray segments.
- 5. For tray segment no. T130SCA46, side rail extensions were installed, but a special evaluation was not j provided as required by Reference 20. '(See I l
Issue No. 25.C.I.) ) j Cygna has requested additional information on the fire l protection evaluation process in Reference 27. E. Tray Spans Between Supports Used In the Original Support Layout
- 1. Reference 13 indicates that cable trays are to be designed and qualified for 8'-0" transverse and vertical spans. Reference 10, Note 13, allows a i location tolerance for supports of
- 1/2 of the l
Richmond Insert spacing parallel to the tray, and limits the maximum spacing between supports to 9'-0." Gibbs & Hill cable tray support design '
' calculations assume a maximum tributary span of TV Electric '...-,-s-- Comanche Peak Steam Electric Station L4, L9 L I[
Independent Assessment Program - All Phases llllllll11111111lll1ll111lltll Job No. 84056 PRJ:RIL
I 07/31/87 Revision 14 Page 145 CABLE TRAY SUPPORTS Review Issues List l 8'-6," to account for a support spacing of 8'-0" on ( center and an erection tolerance of f 6." i Cygna reviewed the tray support plans for segments within the review scope ( Aeference 12) and noted 15 ; I locations where the as-c.esigned tray spans exceeded i l 8'-0". Cygna's walkdown of these tray segments t identified 5 locations where the as-built tray spans 3 exceeded 9'-0". (See Reference 11.) This indicates '! l l that the design and installation limitations for support spacings may not have been complied with in the preparation of support layout drawings and in q the fiel d. I l l , i l 2. Reference 13 indicates that cable trays are to be { designed and qualified for 40'-0" longitudinal I spans. Longitudinal support design calculations a assume a maximum longitudinal tributary span of I 40'-0". For several supports within Cygna's review, the support plan drawings (Reference 12) showed i these supports to have tributary spans greater than l 40'-0". (See Reference 11.) In addition, several ! horizontal tray segments were not provided with any l i longitudinal supports. (See P.eference 11.) Thi s ' indicates that the design limitations for the location of longitudinal supports may not have been complied with in the preparation of support layout 1 drawings. F. Lack of Calculations For Change Notices l I Cygna has noted several design reviews of change notices where the CVC was marked to indicate that new or revised I calculations were not required. Cygna considers some of i the design changes to be significant, such that l calculations should have been provided to justify their acceptability. In some cases, calculations marked "for i s l u_ TV Elcctric
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07/31/87 Revision 14 Page 146 CABLE TRAY SUPPORTS Review Issues List reference only" are attached to the CMC which the reviewer had accepted without new or revised cal cul ations. G. Design Calculation Retrievability and Completeness , During the course of the Phase 2 and 4 reviews, Cygna experienced difficulty in assembling complete support design calculation sets. Cygna noted that Gibbs &. Hill has similar difficulty. The following examples illustrate Cygna's concerns.
- 1. In Phase 2 of Cygna's IAP, Cygna requested an evaluation of the effect of torsion in the C4x7.25 beams on the support design adequacy. Gibbs & Hill provided calculations (Reference 14, Sheets 28-33) which evaluate torsion in the beams. These calculations were performed in 1982, but were not included in the indicated calculation binder (the-cover sheet for Reference 14 indicated that the total number of sheets was 6). Subsequent to Cygna's review of these calculations, they were added to form Revision 1 of Reference' 14.
- 2. Cygna requested a list of all calculations relevant to several generic support designs. (Reference 15.) Gibbs & Hill provided a list of calculation binder and sheet numbers for each support type. T he review of these calculations by Cygna indicated that there were additional calculations relevant to the support designs which had not been included on the l list. For example, the Working Point Deviation i Study involved several supports listed in Reference 15, but was not referenced in Gibbs & Hill's response.
The difficulties in identifying and locating all-calculations pertinent to a support design may be in part attributable to Gibbs & Hill's methods of TU Electric Comanche Peak Steam Electric Station II,.d L,Id Independent Assessment Program - All Phases 11111111111111111111ll1111lll1 Job No. 84056 PRJ :RIL
1 07/31/87 " Revision 14 Page 147 CABLE TRAY SUPPORTS j Review Issues List ] l controlling structural design calculations. Cygna observed that, as a general rule, Gibbs & Hill did not . revise or' supersede older calculations. I n ' performing R generic studies (e.g., Working Point Deviation Study, I weld undersite/ undercut, evaluation of torsional stresses in members, etc.) or performing design reviews for. generic design changes, the new calculations evaluate only the effects of'the changes. These new calculations may reference. the previous calculations as a source of data, but the previous calculations are not g superseded by the new calculations, nor are' they revised-to reflect the results of the design change or generic study. Hence, it is extremely difficult, from reviewing - an original design calculation, to determine if it is still applicable to the support design. It is also 1 difficult to identify and locate generic study or design l change review calculations that are applicable to the l support design. l H. Lack of Controlled Design Criteria l At the initiation of this review, the cable tray support ) l design criteria used by Gibbs & Hill consisted of a ! calculation set in a structural calculation binder.- (Reference 9.) Cygna's review of this document indicated that insufficient detail was given to assure that cable tray support designs were performed in a consistent manner and that the designs satisfied the requirements of the CPSES .FSAR. . Examples of the impact of an incomplete design criteria include: .4
- 1. Cygna has noted instances where the field design '
review group did not utilize the proper criteria to evaluate support adequacy. The evaluations for fire protection compared the as-built support load to a ' design load consisting of the allowable distributed load over a 9'-0" tributary tray span. . Since the maximum tributary span assumed in the current design TV Electric Comanche Peak Steam Electric Station i*i! N t 4 Independent Assessment Program - All Phases lilllllllllllillllililllllllli Job No. 84056 PRJ :RIL i
.07/31/87
, Revision 14 L Page 148 I i CABLE TRH SUPPORTS l I Review Issues List calculation is 8'-6", the use of .a 9'-0" span f overestimates the allowable load. 1
- 2. Cygna has asked what supplements to the 7th Edition ,
of -AISC ' Specifications were ' committed to in.the 1 FS AR. No evidence was found to indicate that proper direction was given to design engineers tu utilize j the requirements of any supplements to which CPSES I was committed. l I. Differences Between Design Drawings and Assembly Drawings Cygna performed a review of the cable tray support ! assembly drawings (Reference 25), khich are used for l construction purposes, and evaluated the accuracy of these drawings via a comparison with the applicable design drawings. (References 1 and 4.) Numerous drawing discrepancies were noted, which included: o Incorrect weld sizes specified for fillet welds. (See Review Issue 16.A) o Incorrect weld patterns o Incorrect member sizes specified in the " Bill of Material" o Incorrect anchor bolt connection details j o Incorrect support dimensioas i l o Members that are not required by the design J For a detailed listing of the individual discrepancies, see Reference 24. t Response: A. The design verification of cable tray supports is based I on the as-built support configuration, as specified in TU Electric
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1 07/31/87 i Revision 14 Page 149 1 i CABLE TRAY SUPPORTS 'l l Review Issues List I Section III.2 of Reference 29 and Reference 30. Since all supports have been as-built there is no need for the previously issued design change.. documents except for those supports with hidden attributes. Desi gn verification for supports with hidden attributes is discussed in Reference 36. , l B. This is no longer an issue since all of the supports are j now individually design verified. J { C. This is no longer an issue since the results of the j Gibbs & Hill generic studies are no longer used. j l l D. All cable tray supports will be individually evaluated, considering the weight of Thermo-lag, if applicable.
- 1. Per Section III of Reference 29, Ebasco considers l the as-built weight of the cable tray, including tray covers. The cable tray weights used by Impell, Reference 32, Section 3.2.2, include the weight of i tha covers.
)
- 2. The design verification of cable tray supports i include all support types (transverse, longitudinal and multi-directional). Thern-lag weights are included as applicable.
- 3. The original Gibbs & Hill calculations for cable tray supports considering Thermo-lag are no longer used.
- 4. The cable tray system evaluation is based on the as- ;
built tray and cable weights. However, Reference 29 and 32 indicate that if the as-built weight of the tray is unavailable, a nonnal weight of 35 psf should be used. This raises several questions:
- a. In what cases are the as-built cable fill weights unavailable? Are there any
~-
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07/31/87 Revision 14 Page 150 CABLE TRAY SUPPORTS Review Issues List i !' outstanding issues relative to the ~ accuracy or completeness of the cable and raceway schedul e?
- b. Since Cygna has found instances where the i
actual tray weight exceeded 35 psf, what is the justification for using 35 psf? In Reference 35, the response to these questions was l given as follows: In Unit 1 the Ebasco and Impe11 design verification is based on as-built data, and the El-1700 Report 30 to determine the cable tray analysis weights and fills. .TU Electric will use the CARDS module of the INDMS program for the long term maintenance of cable tray weights. The program inputs are as follows: o The weight of tray, siderails and side Covers. o Cable tray hanger number to corresponding cable tray nodes, o The analysis weights used in the Impell and Ebasco calculations. The program outputs will be: o Actual cable tray weights .and reports that give cases where actual tray weights exceed analysis. tray weights. TU Electric will only accept CTH. calculations af ter the - design and actual tray weights are reconcil ed. TV. Electric is developing a - program to address future cable TU Electric 3 Comanche Peak Steam Electric Station b*$Id L Al Independent Assessment Program - All Phases tilllilllilillllilillilllillli Job No. 84056 PRJ:RIL
q i 07/31/87 f Revision 14 1 Page 151 j I CABLE TRAY SUPPORTS Review Issues List I addi tions. The weight effects of the cable ] additions will be checked by the j civil / structural group.
- 5. Ebasco includes the weight of the cable tray siderail extension in calculating the tray weight. )
l (Reference 29.) Impe11 provided an evaluation j (Reference 34) indicating that the impact of 1 siderail extensions in the cable tray system I l l evaluations is not significant. Cygna believes that l the weight of the extensions should be considered. ) See TU Electric response in issue 21D.4.b. l l E. Cable tray supports are evaluated based on the as-built tray spans. Span length violations in the original ! support layout are, therefore, no longer .an issue. For a l discussion of the evaluation of the acceptability of the cable trays, see Issue No. 25. See also Issue 33.C for i i a discussion on cable tray span walkdowns. I F. Since 100% of the cable tray supports are being' design verified. calculations associated with the review of l previously issued design changes are no longer used. TV Electric is developing a procedure to control the review of any design changes that may be generated in the future (Reference 33). G. The original Gibbs & Hill and TUGC0 design calculations are superceded by the current cable tray support design verification effort. H. Both Ebasco and Impell have developed sets of design criteria, project instructions and procedures to 9 sure consistency and compliance with the CPSES FSAR foNell calculations associated with the cable tray support design verification program. TV Electric
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07/31/87 Revision 14 Page 152 CABLE TRAY SUPPORTS Review Issues List I. The cable tray support design verification program is based on the as-built support drawings. No reliance is placed on the original Brown & Root assembly drawings. Status: A. Open: See Issue No.16.A. l B. Closed: Since all of the supports are being individually design verified. C. Clo ed. D. 1. Cl osed.
- 2. Closed.
- 3. Closed.
- 4. Open. Cygna to review procedures when available.
, 5. Open: Cygna has concerns regarding Impell's method of justification for not including the weight of the siderail extensions. See the Status for Issue No. 21.H regarding differences in the assumptions used by each consultant. See also issue No. 21.0.4. E. Closed for the evaluation of the cable tray supports. See Issue No. 25 for the evaluation of the cable trays and Issue No. 33 for cable tray span walkdowns. F. Open: As part of the review of design control issues, Cygna will be reviewing key aspects relating to design control procedures. G. Closed. H. Open: Cygna's review of the design criteria and work instructions used for the cable tray support design verifications has noted differences in the anslysis methods and assumptions used by the two consultants. TV Electric 3 Comanche Peak Steam Electric Station 7*$ L (#I a IAl Independent Assessment Program - All Phases lll1!Il1111ll111111111111llll! Job No. 84056 PRJ :RIL
t 07/31/87 Revision 14 Page 153 CABLE TRAY SUPPORTS Review Issues List Such differences are noted in the applicable locations within the Review Issues List. Cygna is also reviewing the criteria and analysis methods used individually by each consultant to assure consistency.with the approach taken within their , individual work scope. Cygna must review the programs i' described in " Response" Section of Issue No. 21.D.4 when a vaila bl e. I. Closed. TU Electric Comanche Peak Steam Electric Station N.,d[II [ A Independent Assessment Program - All Phases lillllitillllllitillllitilliti Job No. 84056 PRJ:RIL
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CABLE TRAY SUPPORTS Review Issues List-
- 22. Design of Support No. 3136 Detail "5",' Drawing 2323-S-0905
References:
- 1. Gibbs & Hill Calculation Binder SAB-1341, Set 3 Revision 0
- 2. . Communication Report between B.K. Bhujang (Gibbs & Hill)
.and N. Williams, et al. (Cygna) dated October 20, 1984
- 3. Gibbs & Hill Calculation Binder SAB-1341, Set 3, Revision 1
- 4. N.H. Williams (Cygna) letter to W.G. Counsil (TUGCO),
" Cable Tray / Conduit Support Review Questions", ;
84056.089, dated October 21, 1985 ; 1 l 5. Transcripts of the Cable Tray Hanger Design Verification Meeting between TU Electric, Cygna. Ebasco and Impell at l the CPSES site, January 26 and 27,1987
- 6. Transcripts of Cable Tray Hanger Design Verification
- Meeting between TV Electric, Cygna. Ebasco, Impell, JBA
]
l and SWEC held at the CPSES. site, April ' 21,1987.
- 7. Civil / Structural Review Issue list Revision 0, dated July 21,1987. j Summary: Support No. 3136, located at elevation 790'-6" at the Auxiliary Building / Safeguards Building boundary, is embedded in a fire wall. In reviewing the design calculations for this support (Reference 1), Cygna noted several concerns. A- i list of Cygna's questions was provided (Reference 2 Attachment A) to Gibbs & Hill for their review. These concerns included:
o Justification for not considering tornado depressurization loads was not provided. o The original cable tray support is Seismic Category I, while the fire wall is Seismic Category II. TV Electric 3 Comanche Peak Steam Electric Station d$d i A . Independent Assessment Program - All Phases lilllillilililillitilllillllli Job No. 84056 PRJ:RIL
a l 1 07/31/87-Revision 14 Page 155 i i CABLE TRAY SUPPORTS I Review Issues List Justification for this conflict'in design classification was not provided. l l , o Several errors were found in the finite element model l l and in the calculations. 1 l Response: During the discussions in Reference 6, Ebasco provide the l following response: Isolated cases of cable tray hangers supported from Category 1 II structure are identified and evaluated on a case-by-case ! I basis. Seismic Category II walls affected by Category I l attachments will be qualified by the SWEC Civil Structural Corrective Action Program. Status: This issue is closed here, and is transferred to Reference 7, I ssue No. 9. l 1 1 l i l l \ l l l i TV Electric Comanche Peak Steam Electric Station < [*IiN) [ Igl Independent Assessment Program - All Phases 111111111ll1111!!111111!!!1111 Job No. 84056 PRJ :RIL l t -_ _ _ _ _ _ ____ _
-07/31/87 Revision 14 Page 156 CABLE TRAY SUPPORTS Review Issues List
- 23. Loading In STRESS Model s-
References:
- 1. .Gibbs & Hill Computer Output Binder 2323-DMI-5P
- 2. Gibbs & Hill Calculation Binder 2323-SCS-2150, Set 2
- 3. Gibbs & Hill Drawing 2323-S-0901, Revision 4
- 4. Cygna Energy Services, " Independent Assessment Program Final Report - Volume 1, for Texas Utilities Services Inc., Comanche Peak Steam Electric Station," Report No. TR-83090, Revision 0
- 5. Ebasco Instruction, " General Instructions for Cable Tray Hanger Analysis for Comanche Peak SES No. I and 2",
Review 5.
- 6. Transcripts of Cable Tray Hanger Design Verification Meeting between TV Electric, Cygna, Ebasco, Impell, JBA and SWEC held at the CPSES site, May 19, 1987.
- 7. Communications Report between P. Harrison, et al (Ebasco) and J. Russ, et al (Cygna) dated May 1,1987, 11:20 a.m.
Summary: For the design of standard support Cases Aj , Bj , Cj and Dj , where i = 1 to 4, finite element analyses were performed (Reference 1) using the program STRESS. Single beam elements were used to model the horizontal members (beams). The analytical results may be inaccurate due to the following concerns: l A. Tray Load Application Point l l Tray loads were applied at the beam / hanger intersection, rather than within the span of the beam where the tray is physically located. Modelling thb load placements in this fashion eliminates the effects of bending and torsion due to vertical loads on the beams, and for l TU Electric 3 .. -. Comanche Peak Steam Electric Station k*$,[ s"j L Id Independent Assessment Program - All Phases litilllllllllilllilllllillllli Job No. 84056 PRJ :RIL
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Cases D j , will totally. remove the load applied at the wall connection from the support. (See Cygna's Phase 2 !
.0bservation CT-00-03 in Reference 4.) l B. Tributary Load Calculations The applied loads are calculated based on an 8'-0" i tributary tray. span. The actual design span is 8'-6" if ;
installation tolerances are considered. : C. Modelling of Support Frame Height , The support design drawings'(Reference 3) specify the support frame heights as the distance from the bottom of ( the concrete to the top of the C4x7.25 beam. The models I considered this distance to be from the concrete to the centerline of the beam, thus underestimating the support l height by two inches. This error is also found in the ; related design calculations for the trapeze supports. l l Response: A. For response spectrum analyses of cable tray supports, i both Impell and Ebasco generate cable tray system models ] which have the tray loads applied to the support at the 4 tray centerline location. For the static and equivalent static analyses of cable tray supports, per Reference 5 Attachments B1 and B2, Ebasco applies the vertical and longitudinal loads from the tray to the support at the cable tray clamp 4 locations. liowever, the horizontal transverse load from l the tray is applied to the support at the beam to hanger intersection point. This may result in an underestimation of the axial load in the beam. In l Reference 7, Ebasco provided a study which addresses the j effects of the modelling assumption. - B. The current cable tray support design verification l effort does not use the results of Gibbs & H111's' i TV Electric ; Comanche Peak Steam Electric Station (*h (d [ Id Independent Assessment Program - All Phases lililllllllillllllillllllillli Job No. 84056 PRJ:RIL
07/31/87 Revision 14 ' Page 158 CABLE TRAY SUPPORTS Review Issues . List ! support analyses. Therefore, this is no longer an issue. 1 I' C. See response for Issue No. 23.B. l Status: A. Open: Further discussion with Ebasco is required.
- 8. Closed.
C. Cl osed. 1 l l
,1 l
l
\
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07/31/87 Revision-14 Page 159 CABLE TRAY SUPPORTS Review Issues List
- 24. Design of Flexural Members
References:
- 1. N.H. Williams (Cygna) letter to J.B. George (TUGCO),
" Cable Tray Support Review Questions," 84056.031. ' .ed August 31, 1984
- 2. L.M. Popplewell (TUGCO) letter to N.H. Williams (Cygna)
" Comanche Peak Steam Electric Station Cygna Review Questions," dated September 28, 1984
!. 3. Communication Report between E. Bezkor et al. . (Gibbs & i Hill) and M. Engleman et al. (Cygna) dated-April 11,1985 l
- 4. Gibbs & Hill Drawing 2323-S-0903
- 5. Ebasco Instruction, " General Instructions for Cable Tray Hanger Analysis for CPSES Nos. I and 2", Revision 4
- 6. Ebasco Calculation, " Comanche Peak SES Cable Tray Hanger Volume I", Book 2, " Computer Related Information",
Revision 3
- 7. Ebasco Calculation, " Comanche Peak SES Cable Tray Hanger Volume I", Book 7. " Cable Tray Hanger Load Application Location Study", Revision 1
- 8. Ebasco Procedures SAG.CP4, " Seismic Design Criteria for Cable Tray Hangers for CPSES Unit 1", Revision 3 and SAG.CP3, " Seismic Design Criteria for Cable Tray Hangers for CPSES Unit 2", Revision 6
- 9. Impell Instruction PI-02, " Dynamic Analysis of Cable Tray Systems", Revision 5
- 10. Impe11 Calculation M-12. " Qualification Procedures for Cable Tray Support Evaluations" Revision 2 TV Electric Comanche Peak Steam Electric Station L*ii Ld l I ,i t Independent Assessment Program - All Phases Illllllllilllllllillllllllllll Job No. 84056 PRJ:RIL
07/31/87 Revision 14 Page 160 CABLE TRAY SUPPORTS 4 Review Issues List i
- 11. Impe11 Instruction PI-11. " Cable Tray System Analysis I and Qualification Closecut", Revision 1 l
- 12. Impell' Instruction PI-03, " Qualification of Cable Tray l i
Supports", Revision 4 l 13. Ebasco Procedure SAG.CP11. " System Analysis for Cable Tray and Hanger Assembly for CPSES Units 1 & 2", j Revision 2
- 14. Transcripts of the Cable Tray Hanger Design Verification )
Meeting between TV Electric, Cygna. Ebasco and Impe11 { held at the CPSES site, January 26 and 27,1987-
- 15. Communication Report between R. Ramsey, et al (Impell); ;
< S. Harrison (TV Electric); R. Alexandru, et al (Ebasco); and J. Russ, et al (Cygna), dated February 2,1987. t
- 16. NCIG-01, " Visual Weld Acceptance Criteria", Revision 2 l
- 17. Ebasco response EB-T-3029, dated May 15, 1987, Attachment 3, " Effective Section at Anchorage for Composite Members".
- 18. Ebasco response EB-T-3029, dated May 15, 1987, Attachment 4, " Enhancement of COMBS Computer Program Verification Manual".
- 19. Impe11 report IM-P-005, Revision 0, dated May 15 1987, "Evaluatioin of Composite T-channel Stitch Welds for Torsional Stresses".
- 20. Ebasco response EB-T-3029, dated May 15, 1987, Attachment 2. " Major Axis Bending Due to Transverse Loadi ng" .
' 21. Communications Report between P. Harrison, et al (Ebasco); and W. Horstman, et al (Cygna),' dated June 25 1987,11:40 a.m.
. TV Electric 7* .. s Comanche Peak Steam Electric Station o $s Fj i M Independent Assessment Program - All 'hases 11lllllilllilllllllllllillllli Job No. 84056 PRJ:RIL i . I
07/31/87 Revision 14 ! Page 161 ( CAP 11 MAY SifPPORTS l l Review Hssues 1.ist
- 22. Ebasco Calcuhliion so. 3306.El% Revision 0, Dept. No. -
558.
- 23. Communications Report betwetm P., Harrison, et al (Ebasco) anIl St. ilbrstman et aCl l(Iygna) dated June 23, 1987,10:00 a.m.
- 24. Communications Report betwetm L Ashley (Impell) and W.
Horstman, et #1 (Cygna), detadi'May 15 1987, 12:30 p.m.
- 25. Communicat.ims Erport between E IAshley (Impell); S.
Harrison (TE Eikectric), and E Marstman, et al (Cygna), ] dated May 14, 1987. I i
- 26. Impel.1 Ia'lculathm 'M-59, " Tee Channel Stitch Welds and Web Crippliim.g".
- 27. Communications hiport betwasu !P. ; Harrison (Ebasco); S.
Harrison (TU Hectric), ant '.W. Hbmstman, et al (Cygna), dated April 29. IL987,10:15 a mt. amd 2 p.m.
- 28. Communications 'Re; port "setween 5 J. .Chen, J.
Christoudias,, IP.. Harrison, 2 'Swanson (Ebasco) and W. Horstman, J. Enss (Cygna), distal April 30, 1987, 9:00 !
- p. m. !
i l 29. Communications .Pagert between 3. flarrison (TV Electric); G. Ashley, R. Kac2kowski (I npe%),; D. Williams (QEST); and John Russ f(tygna.), de.ted July .10,1987,10:00 a.m. l 30. Communications Report beteen P. Harrison (Ebasco) and W. Horstman (Cy,gna.), June 23, ILtlR7. 6:00 p.m.
- 31. Communications Report betwast 5 . Harrison (TV Electric);
- P. Harrison, et aM (Ebasco); ant! .W. Horstman, et al (Cygna), dated Mlay 1.,1987,, .2.GD ;p m. -
i
- TV Electric Comanche Peak Steam E7
- ectrir 3tation
@m (d ) fil Independent Assessmeid;irrrcitjram - A'l'1 IHrases lililllilillllillllllillllilli Job No. 8405E P&:TE.
l
l i 07/31/87 Revision 14 i Page 162 CABLE TRAY SUPPORTS . Review Issues List ) l Summary: In the design of cable tray support flexural members (i.e., i beams and hangers, now generally referred to as tiers and posts, respectively), Gibbs & Hill did not consider several important items as discussed below. j A. Major Axis Bending Due to Transverse Loading l Additional major axis bending stresses due to transverse q loads are introduced by the vertical eccentricity J between the cable tray centerlines and the beam neutral ; axis. (Reference 1.) Gibbs & Hill provided i calculations (Reference 2) indicating that the increase t in bending stress did not exceed 2.5% of the allowable stress level. However, the analysis incorrectly assumed that the beam was a fixed-fixed member, effectively isolating it from the remainder of the support structure. In addition, the load transfer mechanism that was assumed to be provided by the tray clamps may not be applicable to all clamp configurations. 1 l B. Minor Axis Bending Due to Transverse Loading Minor axis bending of the beams due to transverse , loading is introduced by the horizontal eccentricity j between the beam neutral axis and the location of the l tray clamp bolt holes in the beam's top flange. (Reference 1.) Gibbs & Hill's response-(Reference 2) l l did not consider the allowed tolerance in bolt hole gage i per DCA 17838, Revision 8. A load-transfer mechanism was assumed to be provided by the clamp, allowing the l trays and supports to act as a system. This assumption results in increased transverse loads on adjacent [ supports and no minor axis flexure in the beams. j t I l C. Torsion Due to Vertical Loading Vertical loading introduces torsion into the' beams due to the horizontal offset between the tray clamp location and the shear center of the beam. In Gibbs & Hill's , TV Electric
.. . ---- Comanche Peak Steam Electric Station
- t. *$LdL'I l l Independent Assessment Program - All Phases ll1111ll1111lll111111111111111 Job No. 84056 PRJ:RIL L__________-_______-_-____--_.
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.Page 163 i 1
CABLE TRAY SUPPORTS Review Issues List response (Reference 2), the torsional moment was completely eliminated, based on an assumed moment resistance provided by'the tray clamps and the tray / support system concept. (See Issue No.10 for the acceptability of the system concept.) D. Torsion Due'to Longitudinal Loading Torsion is introduced into the beam by longitudinal loading due to: I
- 1. The vertical offset between the tray centerline and the beam shear center (for longitudinal trapeze type i supports , e. g. , L-Ay , L-P1) .
- 2. The vertical offset between the tray centerline and ,
the shear center of the composite beam (for i longitudinal supports similar to SP-7 with brace, i Detail 8, drawing 2323-S-0903, etc.). l l l l Gibbs & Hill's evaluation of the torsional effects are included in Reference 2. The evaluation of torsion due to loading type 1 only considers the eccentricity l between the shear center and .the top of the tray rungs i for ladder type trays or the tray bottom for trough type ! trays. The centroid of the tray fill is a'more appropriate location from which to calculate the l eccentri ci ty. For loading type 2, the longitudine1 load is applied at the bottom of the tray side rails, rather than the centroid of the tray fill. The tray clamps are assumed to provie rotational restraint to the top flange of the composite beam, and all torsional moments are assumed to be resisted by a couple fonned between adjacent vertical supports through flexure of the cable tray. All these assumptions must be justified per Issue Nos. 10 and 18. l l E. Reduction in Section Properties Due to Bolt Holes and l Weld Undercut l 2 TU Electric , Comanche Peak Steam Electric Station l' NId )Id Independent Assessment Program - All Phases 1111111ll11111111111ll11111111 ' Job No. 84056. PRJ:RIL
1 J l i 07/31/87 Revision 14 Page 164 CABLE TRAY SUPPORTS j Review, Issues List ; i Gibbs & Hill has not consistently considered the ! reduction in the beam section properties due to bolt j holes through the' flanges (see Issue No. 9) 'and weld undercut effects. Based on CMC 58338, Revision 0, the welded connection between the beam and hanger can i include vertical fillet welds crossing the web of the beam, thus weld undercut would affect the beam capacity-l at this critical location. Weld undercut could also i affect the beam capacity at beam-to-base angle / plate connection for the cantilever type of supports.. 1 In addition, based on the tray installation tolerances , provided in Gibbs & Hill Specification-2323-ES-100, Section 2.28, and the effect of CMC 2646, Revision 5, j the tray clamp can be located such that the bolt hole is in the same cross-sectional plane as the effect of weld .] undercut. Thus, it is possible that both' reductions may occur simul taneously. l l F. Evaluation of Shear Stresses i , Gibbs & Hill has not evaluated the effects' of shear ) stresses on beam acceptability. Shear stresses will be ! introduced by two loadings: ') I
- 1. Direct shear stresses due to the applied forces
- 2. St. Venant shear stresses associated with torsional !
loads. (See Items C and D above.) Cygna's review indicates that direct shear stresses are l minor and generally do not govern the design of flexural ; members. When these stresses are considered in ! combination with the potentially large St. Venant shear ; stresses, the effect can be a significant factor in the l
- member design. (Reference 3.)
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.. v07/31/87 l> .. 1 Revision 14
; Papl165 CABLE TRAY SUPPORTS $ . .7 1 l
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7
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G. Unbraced Length for Lateral Torsional Bucklir!g g 1 (; j 1
.i i f M 3 1 < Gibbs & HilP generally Nkumes an allc$$ble major axis. 'l'
-{
'\ 7 bending stress of' 22 psi 'for member designs. Thd, capacity reduction. based on the unsupported lere/.N of 3 k ) {
the beam's compression flange (AISC Equatic,n 1.5@Hp , q' either not considered at all or r.ot ' properly coni,fdered. 4 (See Issue No.' I4.) Justification is provided, 6gdd on , 1 i' the assumption that the tray and tray clamp will' provide
! later 1 bracirji ot the beam's;comprcpion flange. This >
, l assumption'is ibpendent on the tray Lamp's ability to ;
- i. provide bracing'(see Issue No.18) add neglects /.
+ ;
s, , j ampression of the bottom f1ange due to support frame ; sidesway and seismic uplift. For cantilever type. 4
]
suppor$s, the "1" value in Equation 1.5-7 is improperly 1
.-' selecN.( as discussed in Issue No.14.B. ,
f
. >, l H. Increase Factor for Warping Normal Stresses 's
^
See discussion in Response Section bel.ow; , a ,e j Response: A. For system models, Impell, per Referedce 9, 4 1~ s , i
'i Section 3.2.4, and Ebasco, per Reference 13, include an ; j
, eccentricity equal to the distance from the tray center ;
of gravity to the beam center of gravity. I The effect of the vertical eccentricity is considered .in
- ) > ' the analysis of the' cable tray supports. - For equivalent i static analyses, Ebasco, per Reference 5, Attat.hments B1 4
and B2, applies a major axis bending moment to the support which is equal to the applied transverse load l times the distance from the beam center of gravity to the bottom Vf the tray. This approach is based on Study No. 7b'. (Reference 6.) In Reference 15, Ebasco iy indicated that the load was assumed to act at the tray
,t bottom rather than at the tray center of gravity. Cygna did not agree with this and requested additional justification.
Man om ggggg TV Electric rd Comantbe Peak Steam Electric Station
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07/31/87 Revision 14 Page 166 CABLE TRAY SUPP0F,TS Review Issues List Ebasco provided the requested justification. The response was based on a comparison of tier stress interaction ratios from models which differed solely as to the point of transverse load application for three ; sample supports. One model applied the moment based on I the eccentricity required by Ebasco design criteria, the other model applied a moment based on the eccentricity between .the tier center-of-gravity and the tray center-l of-gravity (Reference 20). The increase in overall stresses was less than 3% and Ebasco concluded that this i increase was negligible. Cygna reviewed Reference 22 and questioned if the three selected ~ supports l represented the supports with the highest interaction l ratios for tiers. Ebasco stated the chosen samples were
- representative supports, but not necessarily those with ,
highest interaction ratios. Ebasco agreed to verify the representativeness of the supports with the highest interaction ratios and also to check if there was any means to determine which support tier had the highest interaction ratio. Cygna also asked how Attachment Z (Reference 5) 4 connectivity was considered. Ebasco stated the calculation was performed prior to inclusion of attachment Z loads that and that all calculations would be revisited to account for effect of connectivity. Ebasco felt that the inclusion of connectivity will not increase the 3% difference in combined stresses, but may actually decrease it. B. The minor axis bending moment due to this eccentricity : is considered explicitly by Ebasco in Attachments B1'and B2 of Reference 5 in individual support models used for equivalent static analyses. The eccentricity used is equal to the distance between the beam center of gravity and the clamp bolt location. For system models, Ebasco, per Reference 13, includes a horizontal eccentricity (equal to the distance between the beam shear center and the web centerline) to account for torsion due to h- TU Electric b.._. Comanche Peak Steam Electric Station A (tj 2 h Independent Assessment Program - All Phases-lilllllllillllllilllilllllllli Job No. 84056 PRJ :RIL q
f 07/31/87~ Revision 14 l Page 167 l I l CABLE TRAY SUPPORTS Review Issues List I applied vertical loads. (See Issue No. 24.C.) The l magnitude of the eccentricity is approximately equal to i or greater than the distance between the clamp bolt hole j centerline and the minor neutral axis. (Reference 15.) Impe11, in Reference 10, indicates that the effect of j this eccentricity is not significant and will not be { consi dered. In this study, a moment equal to the j horizontal transverse load multiplied by the ; eccentricity is. applied to a finite element model of a single tier and one tray. The model distributes the load between the tier and the tray and shows that the majority of the load is resisted by the cable tray. This study assumes that the clamps are able to transmit this moment in the form of a torque about the longitudinal axis of the bolt used to attach the tray clamp to the beam. This assumption is not justified. l During an Impell audit Cygna demonstrated.that the tier l may experience additional stress if minor axis bending l was considered (Reference 24). If the tier is highly ! stressed due to other loadings, then the additional ) l stress due to minor axis bending may result in j r interaction ratios greater than unity. Impell stated j l that they would provide a white paper addressing this I issue (Reference 24). C. For equivalent static analyses, Reference 5, Attachments B1 and B2, and for system models, Reference 13. Ebasco considers an eccentricity equal to ! the distance from the shear center to the centerline of the tier web. This is based on a study in Reference 7 which indicates that the vertical load from the tray is transferred at the location of the web centerline. Thi s is reasonable for downwards loading from the tray, but ; may be unconservative for upwards loading, which would be applied at the clamp bolt location. In Reference 14, Ebasco deferred discussion. p ._ _ TV Electric 5 s. - Comanche' Peak Steam Electric Station [*li L9 i id Independent Assessment Program - All Phases lilllllillllllllilillllillllli Job No. 84056 PRJ:RIL l
07/31/87 l Revision 14 Page 168 3 CABLE TRAY SUPPORTS $ Review Issues List l l Impell, per Reference 9 Section 3.2.4, includes an ,I eccentricity equal to the distance between the beam's ! shear center and center of gravity. This is included in the model by providing a spring (to model clamp stiffness) capable of ~esisting only vertical tray loads at the end of a rigid link with a length equal to the eccentri ci ty. However, Impe11 models a rotational spring coupling torsion in the beam to minor axis bending of the cable tray. This may result in a large portion of the torsional load being absorbed by the cable tray. D. For system models Ebasco in Reference 44, and Impe11 in Reference 9, Section 3.2.4, model an eccentricity equal to the distance between the center of gravities of the cable tray and the beam. l l For equivalent static models, Ebasco, in Reference 5, l Attachments B1 and B2, considers an eccentricity that depends on the number of bolts between the cable tray and the clamp. For clamps with a single bolt, the l eccentricity used is the distance between the centerline I of the tray clamp bolt and the neutral axis of the beam. For clamps with two or more bolts, the distance , from the center of gravity to the top flange of the beam is used as the eccentricity. In Reference 14. Ebasco indicated that this is done based on the assumption that a portion of the torsion will be resisted as minor axis i bending of the cable tray since the two bolts will . j develop a couple. The cable trays are not evaluated for j the effect of this moment. Ebasco provided further information on April 30, 1987 (Reference 28). I E. The evaluation of the effect of bolt holes through the channel flange is addressed in Issue No. 9. l Since the supports will be individually evaluated based on the as-built support configuration, weld undercut does not have to be considered on a generic basis. The s i t TV Electric Comanche Peak Steam Electric Station d LP.T-ii id Independent Assessment Program - All Phases 1111!!!!111111!!111lli11111111 Job No. 84056 PRJ:RIL-
I ! 07/31/87 i Revi sion ~ 14 Page 169 j I CABLE TRAY SUPPORTS I Review Issues List .I
)
I project is performing weld inspections in accordance l with Reference 16. If the welds satisfy the undercut j limitations given in Reference 16, undercut will not be ; considered in the analyses. If the undercat exceeds the I allowable, the inspection report for the support is marked unsatisfactory and "dispositioned". l F. Composi te Section: j
- 1. The evaluation of cable tray support members ]
includes consideration of the effects-of direct i shear and St. Venant shear stresses. This is i specified in Section VI and Attachment M of { Reference 5 and Attachments 4 and 5 of Reference 12. j In addition to the shear stresses associated with ! torsional . loads, the warping normal stresses due to ! l torsion are included in the member evaluations. Impell ar.d Ebasco consider the entire cross-section of composite T-channels to be effective in resisting , torsional moments. Cygna is concerned that this t l assumption is not correct as the boundary l connections of such members may not allow participation of the full composite cross-section. Ebasco made additional verifications to address this issue in Reference 17 which was reviewed by Cygna. j Ebasco in Reference 17 concluded that the composite ! channel section welded to the base angle will participate in resisting torsion and that the weld was more critical than the shear in the composite section. Cygna questioned the degree of participation of the connection in resisting torsion (i.e., semi-fixed or fully fixed). Also it was not clear how the criticality of the weld vs. shear stress in member was justified (Reference 23). Impell also stated that they would provide an
- evaluation of the ability of the connection to l
_ TU Electric Z Comanche Peak Steam Electric Station i 6.*i!E Id Independent Assessment Program - All Phases l l 1111111ll1!111111lllll!!!!ll11 Job No. 84056 PRJ:RIL I
07/31/87 Revision 14 Page 170 CABLE' TRAY SUPPORTS Review Issues List provide the required baundary conditions (Reference 29).
- 2. Cygna requested that the " COMBS" computer program l verification manual be enhanced to include all the
! boundary conditions. Ebasco in Reference 18 has j included all the boundary conditions and incorporated in " COMBS" program.-
- 3. Cygna asked Ebasco how composite cable tray members with multiple bracing or connection points were eval uated. Ebasco provided Cygna with several sample calculations which demonstrated their use of l the COMBS program for this purpose (Reference 27).
l
- 4. Cygna asked Ebasco to confirm which section-properties are used for composite tee-channels.
Ebasco replied that they would provide Cygna with this information (Reference 30). l G. See Response for Issue No.14.B.- H. Cygna noted that Ebasco uses an increase factor of 1.30 to account for the underprediction.of we.rping normal stresses by STRUDL. Cygna understands that this factor is used by all engineers when performing RSM analyses, yet this practice is not specified in the project work instructions (Reference 31). Status: A. Open: Ebasco must provide assurance of the plant-wide applicability of the conclusions on the vertical eccentricity of transverse tray loads. B. Open: Impe11 is to provide a white paper on the effects. of minor-axis bending. l l N
~
TU Electric N ~ Comanche Peak Steam Electric Station 3 E*IN L d Independent Assessment Program - All Phases 11111111111111ll1!I111111!!111 Job No. 84056 PRJ:RIL
07/31/87 Revision 14 Page 171 CABLE TRAY SUPPORTS Review Issues List C. Open: Cygna is considering the differences. in eccentric vertical load application as part of the Cumulative Effects review. See Issue No. 29. D. Open: Ebasco must provide justification for the assumed I eccentricities as discussed above. E. See Issue No. 9 for the status of the evaluation of bolt ! holes in members. Cygna must review Reference 16 regarding the effects of weld undercut and obtain additional information on the disposition methods. I l F. Composite Section: 1 J
- 1. Open: Ebasco to provide response to Cygna's comments as discussed above. Impe11 is to address the boundary conditions for composite sections.
-)
l l 2. Cl os ed. . l
- 3. Open: Impell and Ebasco are to provide the j methodologies.for the qualification of composite i sections with multiple bracing or attachment points. I l
- 4. Open: Ebasco is to provide Cygna with the section properties used for ccmposite members.
G. See status for Issue No.14.B. H. Ebasco must provide appropriate guidance for use of the warping normal increase factor. TU Electric 7 Comanche Peak Steam Electric Station d [ Pj2 f[I Independent Assessment Program - All Phases lilillllillllllilllilllllllill Job No. 84056 PRJ:RIL
07/31/87 Revision 14 Page 172 CABLE TRAY SUPPORTS ) Review Issues List i
- 25. Cable Tray Qualification
References:
- 1. Gibbs & Hill Specification 2323-ES-19, Revision 1
- 2. Gibbs & Hill Calculation Binder 2323-SCS-111C, Set 7, Revision 1 i
i
- 3. T.J. Cope, Test Report and Calculations for the j Qualification of Cable Trays i
- 4. CPSES FSAR, Section 3.10B.3, Amendment 44 ,
i
- 5. Gibbs & Hill Specification 2323-ES-100, Revision 2 l
- 6. IEEE " Recommended Practices for Seismic Qualification of Class IE Equipment for Nuclear Power Generating l Stations," STD 344-1975 l 1
- 7. CPSES FSAR Section 3.7B.3.5 l 8. Gibbs & Hill Drawing 2323-S-0901, Revision 4 j
- 9. L.M. Popplewell (TUGC0) 1etter to N.H. Williams (Cygna), I'
" Response to Cygna Review Question 2.1 of Letter 84056.019," dated August 27, 1984-with attached cal cul ati ons 1
- 10. Cable Tray Thermo-Lag Evaluation Safeguards Building, Elevation 790'-6," Cygna Technical File 84056.11.1.1.315
- 11. TUGC0 Instruction CP-EI-4.0-49, Revision 1
- 12. N.H. Williams (Cygna) letter to W.G. Counsil (TUGCO),
"Cavie Tray / Conduit Support Review Questions "
84056.089, dated October 21, 1985 ,
- 13. Ebasco Calculation, " Comanche Peak SES Cable Tray Hanger Volume I", Book 1, " General Input Data", Revision 3 g TV Electric Comanche Peak Steam Electric Station b'I N IAI Independent Assessment Program - All Phases lilllilllillllllililllilllllll Job No. 84056 PRJ:RIL l
07/31/87 Revision 14 Page 173 CABLE TRAY SUPPORTS Review Issues List j
- 14. Impell Instruction PI-02 " Dynamic Analysis of Cable Tray Systems", Revision 5
- 15. Impell Instruction PI-06, " Tray and Clip Qualification", ')
Revision 0 I
- 16. CCL Test Plan: " Static Tests of Cable Trays and ] '
Fittings", Procedure No. 1903.20-1, Revision 1
- 17. . Ebasco Instruction, " General Instructions for Cable Tray l
Hanger Analysis for CPSES, Nos.1 and 2", Revision 4
- 18. Transcripts of the Cable Tray Hanger Design Verification ,
Meeting between TV Electric, Cygna, Ebasco and Impell l held at the CPSES site, January 26 and 27,1987 l
- 19. Impe11 Calculation M-03, " Cable Tray Properties", j l Revision 4 .i
- 1
- 20. Communications Report between P. Harrison, et al (Ebasco) and J. Russ, et al (Cygna) dated May 1,1987, j 11:20 a.m.
)
- 21. Communications Report between P. Harrison (Ebasco) W.
and W. Horstman, et al (Cygna), dated, June-23,1987, j 4:00 p.m.. I
- 22. Communications Report between P. Harrison, et al (Ebasco); S. Harrison (TV Electric) and B. Shakibnia, et al (Cygna), dated, July 14,1987,10:10 a.m. .
, Summary: The qualification requirements for cable trays are outlined in References 1 and 4. In reviewing related specifications, calculations, and installations of cable trays, Cygna has ; I noted several areas of concern. TV Electric
. . . . Comanche Peak Steam Electric Sta'. ion 8, m ["j 2 I i A Independent Assessment Program All Phases lilll!lllillllllllilllilllllll Job No. 84056 PRJ:RIL
[-
.l l
l 07/31/87 Revision 14 Page 174 l- l l CABLE TRAY SUPPORTS . Review Issues List A. Dynamic Amplification Factor Qualification of cable trays is performed through static load testing and calculation of loading interactions for -l dead load plus three components of seismic load. (Reference 1. Section 3.9 and Reference 3.). Seismic loads are calculated by.the equivalent static load , method, using total tray dead weight times the peak l spectral acceleration. No apparent dynamic amplification factor (DAF) is used. Reference 6, Section 5.3, and Reference 7, recommend the use of a - DAF = 1.5 unless justification is provided. (See j Issue No. 8.) B. Cable Tray Stress Interaction 1 The interaction equation specified .for checking cable tray capacity (Reference 1. Section 3.9.4) is limited in ] j its application and may have been used incorrectly. ] The testing and qualification of cable trays is based on i an 8'-0" simply supported tray span (References ~ 1 and l 3); yet Reference 8, Note 13, allows a support installation tolerance resulting in a maximum tray span of 9'-0" for Unit 1. The capacity values derived in the tray testing are total loads (1bs) uniformly distributed over an 8'-0" section of cable tray. (Reference 3.) These values, F , F n t and F), as used with the interaction _ equation. ) are only applicable to tray sections with 8'-0" spans. However, for the fire protection evaluation calculations (Reference 2) and tray span violation calculations (Reference 9), total loads for various tray spans were calculated as f6 = (w)x(1), where w is the tray unit weight and 1 is the tray span. This load was compared with the rated tray capacity using the interaction equation. TU Electric Comanche Peak Steam Electric Station 82 (.b; Al Independent Assessment Program - All Phases 111111111111ll11ll111111!!Illl Job No. 84056 PRJ:RIL L_____________--_-----_----- _ _ - - _
07/31/87 Revision 14 Page 175 CABLE TRAY SUPPORTS Review Issues List For evaluation of trays with spans other than 8'-0", a capacity comparison must be made in tenns of tray bending moment which is proportional to _ (w) x. (1 ), rather than the total load _ on the tray section. For example, if an 8'-0" tray span will support a total distributed load of 1600 lbs (200 lb/ft), by increasing the span to 10'-0", a uniform load of 128 lb/ft (1280 lbs) would result in the same bending moment at mid span. Therefore, the capacity for the 10'-0" span would be 1280 lbs and not the 1600 lbs assumed. C. Modifications to Cable Tray Hardware and Siderail , Extensions i Cygna has noted several instances of modifications to cable tray hardware without adequate justification or documentation.
- 1. Tray Segment No. T130SCA46 is assumed to be a 24"x6" ladder-type tray in the fire protection evaluation calculations for Safeguards Building Elevation 790'-6". (Reference 10.) _ Cygna's wal kdown indicates that this tray is actually a 24"x4" ladder-type tray with 6" side rail extensions added to increase the tray depth. The tray qualification test report (Reference 3) does not provide qualification for trays using side rail extensions. The procedure governing fire protection evaluations (Reference 11 Section 3.2.2.2) states:
Evaluation process described in 3.2.2 is not applicable to the cable trays (and their supports) where additional siderails are added. ' For such cases, actual as-butit configuration of the tray system with actual cable' weight , shall be taken into account and I proper engineering evaluation I TV Electric Comanche Peak Steam Electric Station UNd f[ Independent Assessment Program - All Phases 1111lll1111111111111111!!!!I11 Job No. 84056 PRJ:RIL
I 3 l 07/31/87 Revision 14 Page 176 CABLE TRAY SUPPORTS Review Issues List j j
~d performed. No standard j methodology is recommended, but i shall be based on acceptable engineering practice.
The referenced calculations do not perform an. I evaluation of this tray segment. These calculations (Reference 10) were obtained from TUGC0 prior to their design review; therefore, this possible omission may be corrected through the design review process. l l 2. Tray Segment T120SBC35 is joined to a tray reducer t I with side rail splice connector plates. These plates have been modified by removing portions of their bottom flanges such that only the web. area remai ns. This connector will not satisfy the requirements of Reference 1, Section 3.7, l Paragraph f, which states that connectors "shall
- have moment and shear strengths at least equal to l those of the continuous uncut side rail." Cygna was i
unable to locate documentation justifying this . modification of vendor-supplied hardware. l 1 D. Cable Tray Section Properties Cable tray section properties are calculated using the static test results. (Reference 3.) .The moment of inertia is calculated based on the flexural displacement formula for a simply supported beam. For horizontal transverse loading (i.e., in the plane of the rungs) . ladder-type cable trays show a truss-like behavior, and I the deflection will be due to both flexure and shear I deformations. This will affect the calculated moment of inertia-as used in any Gibbs & Hill analyses which consider the tray properties for frequency or displacement cal cul ations. i' __.___ TU Electric 3- Comanche Peak Steam Electric Station ' 8m 8)i IAi Independent Assessment Program - All Phases lilllilllii!!Illllllllilllllll Job No. 84056 PRJ :RIL
07/31/87 Revision 14 j Page 177- J CABLE TRAY SUPPORTS 1 Review Issues List 4 1 Response: A. Ebasco performs cable tray qualification in accordance with Reference 13. A multi-mode response multiplier i (MRM) of 1.25 is used for the static and equivalent l j static qualifications. j Impe11 performs response spectrum analyses of the cable tray systems in accordance with Reference 14. The forces and moments in the cable tray are calculated as part of this analysis. B. Cable trays are evaluated based on the individual as-l built span lengths. In Reference 13, Ebasco has developed tables of allowable tray spans for specific buildings and elevations. These tables provide a l maximum tray span of 8'-0", which is consistent with the l original tray testing program. For tray spans greater than 8'-0", the trays are qualified by calculations. l Impe11 follows a similar approach in tray evaluation in
- Reference 15.
A series of tray capacity tests and' tests of fittings have been perfonned by CCL. (Reference 16.) Cygna has initiated a review of the test results for Ebasco. Cygna understands that Ebasco has developed a tray qualification procedure SAG. CP-18 which-incorporates ' the test results and Reference 13. Cygna has requested f a copy of this procedure. (References 21 and 22.) ) C. For the design verification, Ebasco, in Attachment C of Reference 17, includes the weight of siderail extensions in calculating the dead weight of the t:ay but does not-consider their contribution to tray stiffness. Impe11 does not consider the mass or stiffness contributions of the siderail extensions since they assume that the allowance for future cable routing accounts for the ) wei ght. See Issue No. 21.D.
~
TV Electric I AN2 Comanche Peak Steam Electric StationM Independent Assessment Program - ' ll1!I1llll11111!!!11ll11111111 Job No. 84056 PRJ:RIL
L i , 1 07/31/87 l l- Revision 14 1 Page 178 j l CABLE TRAY SUPPORTS !! Review Issues List 'I In Reference 18, it was. indicated that the Project has identified modified splice plates as a potential probl em. TU Electric has issued a Significant ' l Deficiency Analysis Report (SDAR 86-52) to address this f f problem. ] D. Cable tray section properties are calculated based on < test data (References 13,19 and 21) assuming load-deflection behavior predominated by flexure. A j correction factor. is applied to the capacities for short j span segments to account for shear behavior. ) i i Status: A. Open for Ebasco; see Issue No. 8. Closed for Impell. B. Open: Cygna is presently reviewing Ebasco's tray j qualification procedure. Ebasco must- provide the latest d revi sion of SAG.CP-18. Cygna must review the Impell tray qualification effort. C. See Issue No. 21.0 for the status with respect to weight consideration of siderail extensions. Open for modified splice plates Cygna's receipt of data on the evaluation l of SDAR 86-52. i l l D. Open: Cygna must receive and review the latest revision-l of Ebasco procedure SAG CP-18 and must review Impell's l tray qualification. J TV Electric Tomanche Peak Steam Electric Station
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07/31/87 Revision 14 Page 179 CABLE TRAY SUPPORTS Review Issues List
- 26. Base Angle Design
References:
- 1. Gibbs & Hill Calculation Binder 2323-SCS-2150, Sets 2 l through 6
- 2. Gibbs & Hill Calculation Binder 2323-SCS-101C, Set 1
- 3. Transcripts of the Cable Tray Design Verification Meeting between TV Electric, Cygna. Ebasco and Impell q held at the CPSES site, January 26 and 27,1987.
- 4. Ebasco Instructions, " General Instructions for Cable
! Tray Hanger Analysis for CPSES Nos. I and 2", Revision 4 , 5. Impell Instruction PI-07, " Design Verification of Base l Plates, Base Angles and Embedded Plates", Revision 3
- 6. Communications Report between G. Ashley, et al (Impell),
S. Harrison (TV Electric) and W. Horstman, et al (Cygna) I dated May 14,1987,10:45 a.m. . i- 7. Impell Calculation M-15. " Base Angle Interaction Diagram Development," Revision 0.
- 8. Communications Report between G. Ashley (Impell); S.
Harrison (TV Electric); and W. Horstman, et al (Cygna) dated May 14, 1987, 2:30 p.m.. I Summary: A. Base Angles Modelled as Simply Supported Beams In References 1 and 2, the base angles were modelled as simply supported beams. This modelling technique does not include the stiffening effects of concrete bearing at the angle ends. b_ _ TU Electric 7 . . _. ,3 = Comanche Peak Steam Electric Station i.*h (9 6 d Independent Assessment Program - All Phases 111lll1111111111111111111111ll Job No. 84056 PRJ:RIL
07/31/87 Revision 14 Page 180 CABLE TRAY SUPPORTS Review Issues List i l B. Principal Axes The principal axes were not considered in the analyses of the base angles subjected to the various loadings. I C. Maximum Base Angle Lengths Not Considered 1 The base angle lengths due.to the maximum spacing of the Richmond' Inserts were not considered in the Working l Point Deviation Study. 1 l J D. Lack of Design Calculations for Base Angles For support types Di , D2 , L-A 1, L-A , SP-4, SP-6, SP-8,. and Detail 11 (Drawing 2323-S-0905)4the design ; calculations do not include an evaluation of the base l
' angles. !
J Response: A. Base angle behavior has been studied in great detail in ) a number of finite element models by Ebasco and Impell . The stiffening effect of the concrete was included in these models. From these models a set of l boundary stiffnesses were developed for.-use in the l support models. The development of these values are discussed under Issue No. 3. j Per Reference 3, no action is required for the evaluation of stresses in the base angles.- By ignoring the stiffening effect of the bearing on the concrete, the calculated stress level should be conservative. 1 B. Ebasco has indicated that the principal axes section l properties will be used in the calculation of bending stresses for the base angles. This is documented in Attachment E of Reference 4. Attachment F of Reference 5 indicates that Impell utilizes geometric properties for base angles. However, Impell multiplies the stress interaction ration by a , factor of "1.2" to account for the conversion to i principal axes. Cygna,upon review of Reference 7,
== , TU Electric i
- - Comanche Peak Steam Electric Station ds 7" L9 2 Id Independent Assessment Program - All Phases PRJ:RIL 1111ll1llll111111111111111111i Job No. 84056
i 07/31/87 , Revision 14 l Page 181 I CABLE TRAY SUPPORTS Review Issues List questioned why the stressessat one point on the base l angle, due to Mx,. are combined using an SRSS rather than i absolutely (Reference 6). An absolute combination will 1 increase the correction factors for bending stresses. l Impell agreed to review the combination method's effects 1 and respond to Cygna's concerns (Reference 8). ) { C. This is ne longer an issue. Per Reference 3, the design verification of cable tray supports will use the as-built lengths of base angles and spacing between anchor bolts. D. This is no longer an issue. Per Reference 3, the design j! verification of base. angles is done individually for q each support.
]
Status: A. See Issue No. 3.A. for status ' B. Open: Impell is to review the the use of an SRSS combination method for computing total stresses in a-
- base angle and the usage'of. the 1.2 factor. Impe11 must provide Cygna with a response.
C. Closed. I I D. Cl osed. l l l TU Electric
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- 27. Support Qualification by similarity
References:
- 1. Gibbs & Hill Calculation Binder 2323-SCS-104C, Set 1 l
l 2. Gibbs & Hill Calculation Binder 2323-SCS-104C, Set 5
- 3. R.E. Ballard (Gibbs & Hill)-letter to J.B. George.
j (TUGCO), GTN-69361, dated August 21,1984, with i attachments i l 0 1 4. R.E. Ballard (Gibbs & Hill) letter to J.B. George I ! (TUGCO), GTN-69377, dated August 29,1984, with j i attachments. ]
- 5. Transcripts of the Cable Tray Hanger Design Verification Meeting between TV Electric, Cygna, Ebasco and Impell held at the CPSES site, January 26 and 27,1987. j l l
- 6. Ebasco Calculation, " Comanche Peak SES Cable Tray Hanger (
Volume I", Books 4 & 8, " Cable Tray Hanger Geometry l Grouping", Revision 1 [ I
- 7. Communications Report between B. Lushkari (JBA); J. Park j (Impell); J. Christoudias, D. Fong, P. Harrison, R. !
Alexandru, S. Chen, F. Hettinger, J. Swanson (Ebasco); l W. Horstman, D. Leong, J. Russ, S. Tumminelli (Cygna), dated February 10,1987, 8 :30 a.m.- 5 :00 p.m. j
- 8. Communications Report between S. Harrison (TV Electric),
W. Horstman et al (Cygna) and P. . Harrison (Ebasco) dated May 1,1987, 2 :30 p.m..
- 9. Communications Report between G. Ashley (Impell); P. l Harrisoon (Ebasco); S. Harrison (TV Electric); and, W.
Horstman, et al (Cygna) dated May 13,1987, 3 :30 p.m. . l l
= -- TU Electric 3-- Comanche Peak Steam Electric Station d Fj i Id Independent Assessment Program - All Phases lilllilllililllililllllilillli Job No. 84056' PRJ:RIL
07/31/87 Revision 14 Page-183 I CABLE TRAY SUPPORTS Review Issues List Sumary: A. Qualification by Similarity in Original Design Calculations In the Gibbs & Hill design calculations, several ' support types were qualified by similarity to another support type without showing similarity. Cygna's review of the geometry, loading, connection details, etc. indicated that the designs were not obviously similar, and that calculations should have been provided. Supports in this category are:
- 1. Detail A, Drawing 2323-El-0700-01-S.
Reference 2 states that Detail A is similar to .!' Ca;e SP-7. Cygna noted that the cantilever length l for Detail A is greater than for SP-7 and that the anchor bolt attachment is unlike the attachment for SP-7.
- 2. Detail N , Drawi ng 2323-El-0601-01-S. l Reference 1 states that Detail N is similar to Detail s V and R on the same drawing. Cygna noted that the frame geometry and tray locations for Detail N was unlike either of the cited details.
- 3. Detail J. Drawing 2323-El-0601-01-S.
Reference 1 states that Detail J is similar to case B. 3 Cygna noted that the member sizes used are different than those for Case B3 , and the frame dimensians exceed the design limits for Case B3-
- 4. Detail V, Drawing 2323-El-0601-01-S.
Reference 1 states that Detail V is similar to Detail B, drawing 2323-El-0713-01-S. Cygna noted that Detail B is a three bay frame with braces in all bays and was designed as a pinned truss. Detail V does not' have braces in all bays, and if the'same . m TV Electric
, Comanche Peak Steam Electric Station r*$Idt il
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07/31/87 Revision 14 Page 184 CABLE TRAY SUPPORTS Review Issues 1.ist design technique is applied, the frame would be statically unstable. t B. Qualification by Similarity in the Working Point l Deviation Study Allowed working point deviations for individually designed supports were established based on similarity to standard support types without justification. See Issue No.12.H for a discussion of this topic. Response: A. Impell does not use similarity in the support design verification. Each support is evaluated individually based on the as-built configuration. Per Reference 5, Ebasco does not use similarity in the same manner previously used by Gibbs & Hill. However, they do perform " grouping" of supports as defined in. Reference 6. The grouping technique was discussed in References 5, 7 and 8. Supports are grouped. based on , geometry, dimensions and tray loading. One enveloping , support in the group is analyzed in order to qualify the ! structural members of all supports in the. group. Other . components of the supports (e.g. , anchor bol ts, base angles, welds, etc.) are evaluated individually for each support within the group. During discussions with Ebasco (Reference 9), Cygna i asked how Attachment Z of the Ebasco General j Instructions was implemented with respect to grouped ' supports. Ebasco stated that the Attachment Z instructions were not complete at that time. l B. See Response for Issue No. 27.A. I Status: A. Open: Cygna has completed the audit of Ebasco's support _; grouping procedures and has raised several' questions ; TU Electric
. . .. ,_ Comanche Peak Steam Electric Station j d (d 2 Id Independent Assessment Program - All Phases !
lilllllilitilllllllllllilllill Job No. 84056 PRJ :RIL i
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07/31/87 ) Revision 14 i Page 185 ! 4 CABLE TRAY SUPPORTS l Review Issues List j l i regarding the content of the data base used to develop the support groups. Per discussions with Ebasco (Reference 8), Cygna understands that Ebasco does'not f use the database for the grouping supports. Ebasco must provide assurances that the database will not be used in any fashion which will affect 'the support
. qqualification. Additionally, Ebasco must provide the Attachment Z instructions when completed.
1 1 I; l n i j i i' l l
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l l 07/31/87 i Revision 14 l Page 186 CABLE TRAY SUPPORTS , Review Issues List I
- 28. Critical Support Configurations and Loadings l
References:
- 1. Gibbs & Hill Calculation Binder 2323-SCS-1010, Set I r
- 2. Gibbs & Hill Calculation Binder 2323-DMI-5P l 3. Gibbs & Hill Calculation Binder 2323-SCS-2150, Sets 2-5 l
l 4. Gibbs & Hill Specification 2323-ES-19 " Cable Trays," Revision 1
- 5. N.H. Williams (Cygna) letter to W.G. Counsil (TUGCO)
" Cable Tray / Conduit Support Review Questions,"
84056.089, dated October 28, 1985
- 6. Transcripts of the Cable Tray Hanger Design Verification Meeting between TU Electric, Cygna, Ebasco and Impell held at the CPSES site, January 26 and 27,1987 )
Sumary: A. Critical Aspect Ratios Gibbs & Hill design calculations (References 1, 2 and 3) for trapeze type supports considered only a limited number of support aspect ratios. Justification was not provided to show that the chosen aspect ratios would i provide the critical configuration to evaluate all components of the support design. The determination of aspect ratios was based on an assumed frame width based on supported tray width and the maximum frame height. The frame ridth determination assumed that: (a) trays were installed with a minimum 6" horizontal spacing, (b) the distance between the side rail of a tray and the vertical hanger flange was a minimum of 3", and (c) all trays on a support were 30" or less in width. Cygna's support walkdown noted that trays were installed with spacings as small as 1" between adjacent trays, and 0" between tray siderails and the hanger flange.
~~
- TU Electric
_ _ Comanche Peak Steam Electric Station dN2M Independent Assessment Program - All Phases lililllllilillitilllililllllli Job No. 84056 PRJ:RIL
i 07/31/87 Revision 14 Page 187 i l CABLE TRAY SUPPORTS j Review Issues List l j Reference 4 indicates that cable tray installations at l CPSES allow a maximum tray width of 36". l B. Tray Location on Support In the design of the frame members for trapeze supports, I Gibbs & Hill typically applied the loadings to.the frame in a symmetric pattern. In reviewing the support layout j ! plans, Cygna has noted that the cable trays are often- ! j located in an asymmetric fashion on the supports. T hi s j l could result in higher stresses in the support members ] l and higher loads on the anchorages than considered in ] l the design. Response: A. The choice of critical aspect ratios for the design of l generic support types is no longer an issue since all ! l cable tray supports are design verified based on their \ as-built configuration. This was discussed in ! Reference 6 as it relates to the support grouping used i by Ebasco for certain groups of similar supports. See ') Issue No. 27 for additional details.
]
B. Per Reference 6, the design, verification of cable tray l supports is. based on the as-built support - l confi gurations. Therefore, this is no longer an issue. Status: A. Closed. 1 1 l B. Closed, l TU Electric Comanche Peak Steam Electric Station l [*IN i i 3 l j . Independent Assessment Program - All Phases PRJ:RIL lll111111111111111111111111111 Job No. 84056 j
i l l 07/31/87 , Revision 14 Page 188 t CABLE TRAY SUPPORTS Review Issues List
- 29. Cumulative Effect of Review Issues l
References:
- 1. TU Electric, CPSES, " Generic Issues Report (GIR): l Evaluation and Resolution of Generic Technical Issues for Cable Tray Hangers", Revision 2 l
I Summary: In this Review Issues List, a number of the cited issues may { lead to small unconservatisms when occurring singly in a i support design. .Such unconservatisms may usually be negl ected. However, since several of these issues pertain I l to all cable tray support designs on a generic basis, their l effect can be cumulative, such that the sum of many small unconservatisms may be significant. Therefore, any ; reevaluation of support designs should consider the l cumulative effect of all pertinent Review Issues. l l Response: TV Electric provided the following response in Reference 1. This issue is inherently addressed by the comprehensive engineering approach to the design verification of the electrical cable tray raceways and by the implementation of extensive "as-built" analysis qualification, and test j acti vi ti es. As discussed in the introduction (of Reference 1), all the generic technical cable tray issues fall into four categori es: deviations between the "as-designed" and "as-built" raceway systems, control of design documents, analysis assumptions and methods, and design assumptions and methods. The "as-built" vs "as-designed" issues are addressed cumulatively via the comprehensive "as-built" program. 100 percent of all accessible cable tray system components have been "as-buil t". Inaccessi bl e components critical to the design verification effort have or will be rendered 6ccessible or have been classified as " hidden attributes". Hidden attributes n_ TV Electric
. . - - .. - Comanche Peak Steam Electric Station p*$
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L 07/31/87 ; Revision 14 Page 189 (. CABLE TRAY SUPPORTS i l Review Issues List ! have been conservatively qualified via statistical studies and evaluated for worst effect in design , veri fi cation. In addition, this program has resolved i instances of improper installation and poor construction l quali ty. j The issues related to control of design documents have been cumulatively addressed by virtue of the design ) verification program which will generate "as-built" ] design documentation, support drawings, and j qualification calculations on 100 percent of the cable I tray supports. - l l All analytical issues (analysis assumptions and methods) ! and design issues (design criteria and assumptions) have ! been simultaneously addressed by the development of procedures and instructions, supported by studies, which-have systematically considered each issue. By virtue of the overall approach which has been implemented, the cumulative effect of these issues have been addressed ; di rectly. Additionally, an extensive test program which has i included component tests and full scale system dynamic l tests has provided additional data to validate the overall design verification approach as. well as demonstrate the substantial conservatism in the l met hods. Thus the actual margins of safety of the cable tray systems have been demonstrated to be much larger than the margins calculated in design verification. 1 In summary, the overall design verification approach has fully addressed and resolved each of the generic technical issues both individually and collectively, provided 100% "as-built" documentation of the cable tray system designs including resolution of improper installation or construction, and confirmed the conservatism of the approach through extensive l t _ TV Electric Comanche Peak Steam Electric Station A f D 2 Id Independent Assessment Program - All Phases 111!!!!l111111111111llll1111ll Job No. 84056 PRJ:RIL l 1
07/31/87 i Revision 14 Page 190 i CABLE TRAY SUPPORTS l Review Issues List l testing. This ensures that the margin of safety in the cable tray systems is acceptable. l Status: This issue will remain open until such a time .as all other 1 issues have been satisfactorily resolved. Cygna'will } I I perform a review of the approach used to assess " hidden attributes" and audit the results of the various test- ) pro grams. Cygna will review the ANC0 systems tests as a j basis for assessing the cumulative effects of any i potentially unconservative analytical assumptions. At this I time, Cygna is still evaluating the applicability of the I systems tests to certain member behavioral questions. Specifically, issues associated with non-ductile failure modes (Issue No.1), allowable flexural stresses for angle i sections (Issue 7.B), and the unsupported lengths for sections susceptible to lateral torsional buckling (Issue 14.B) are still open and require further discussion as to code interpretations. 1 l I L l l _ TV Electric
.. - ;- Comanche Peak Steam Electric Station L *$ FJ L T A Independent Assessment Program - All Phases 1111111111 1111111!!!11111111l Job No. 84056 PRJ :RIL t
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07/31/87 i Revision 14 Page 191 CABLE TRAY SUPPORTS : Review Issues 1.ist
- 30. Cable Tray Damping Values
References:
- 1. CASE /NRC Hearing Transcripts, 13196, 13303-13307, 13318, 13321, and 13454-13461
- 2. USAEC ." Damping Values for Seismic Design of Nuclear Power Plants", Regulatory Guide 1.61, October 1973
- 3. Ebasco Procedure SAG.CP.05, " Dynamic Cable Tray System Test Specification", Revision 3'
- 4. ANC0 Testing Laboratories, " Test Plan - Dynamic Testing i of Typical Cable Tray Support Configurations". Document No. A-00150, Revi sion 1
- 5. Impe11 Report 09-0210-0017 "CPSES Cable Tray System Analysis / Test Correlation", Revision 0 Summary: Damping values of 4% and 7% have been used for the ,
evaluation of OBE and SSE seismic inertia loads, respectively, in the design verification of the CPSES cable i tray systems. These damping values correspond.to those , l recommended by Reference 2 for bolted steel structures. ; CASE, in Reference 1, has questioned the acceptability of ) these values for the cable tray systems. I Response: Cable tray system dynamic testing has been performed in j l accordance with References 3 and 4. The results of these l l tests, as discussed in Reference 5, validate the selected j damping values. l Status: Open: Cygna is presently reviewing the results of the i system tests. i l- TV Electric ! . . . Comanche Peak Steam Electric Station L [*$ (9 [I t Independent Assessment Program - All Phases 2 lilllllllllililllllllllilllitt Job No. 84056 PRJ:RIL i
_ _ _ _ - . - = _ _ _ _ _ - _ - _ - _ _ _ l 1 07/31/87 l Revision 14 Page 192 I CABLE TRAY SUPPORTS I Review Issues List- ;
\
- 31. Modelling of Boundary Conditions
References:
- 1. CASE /NRC Hearing Transcripts 13707 and 13776
]
> 2. ANC0 Testing Laboratory, " Test Plan - Dynamic Testing of , ! Typical Cable Tray Support Configurations", Document No. A-000150, Revision 1 .
- 3. Impe11 Report 09-0210-0017, "CPSES Cable Tray System Analysis / Test Correlations", Revision 0 !
l
- 4. Impe11 Special Study No. 5.9, " Oversized Bolt Holes", j Preliminary Issue
- 5. Gibbs & Hill, Drawing 2323-S-0903, Revision 3 Summary: Gibbs & Hill's cable tray support designs .for CPSES employ Hilti' Kwik-bolts and Richmond Inserts for anchorage to the concrete s.tructures. The design drawings'(Reference 5) ;
specify that the holes in the base plates or base angles are I. to be 1/8 inch larger in diameter than the nominal diameter of the anchor bolt. l During testimony, Reference 1, CASE has questioned the behavior of those bolted connections due to the hole size i and the modelling techniques used to represent the l essociated boundary conditions. i Response: See~ Response for Issue No.14.F. Status: See Status for Issue No.14.F.
- TU Electric 3
Comanche Peak. Steam Electric Station U*k ('$ a IAI Independent Assessment Program - All Phases lillllllllllililllllilllllllli Job No. 84056 PRJ:RIL l l
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- [i jg 07/31/87 r s Revision 14
# Page 193 g j, , y Ji,' .
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CABLE IRAY SUPPORTS ReviedIssues List
- 1
. /
- 32. Conduits Attarthd to Cable Trays or Supports i
,p Referekes::
- 1. TranscHpts of the Cable Tray Hanger Design Verification
,Meetingbetween JU Electric, Cygna. Ebasco and 'Impell held W the CPSE site on January 26 and 27,1987.
- 2. Ebasco Instruction, 'Gpneral Inst dtions for Cable Tray Hancer Analysis for CPSES Nos l'5and 2", Revision 4
.. Ys
~, 3. ImptM Instruction PI-GA, " Dynamic Analysis of Cable
< TrayGystems", Revi$1on. h l 1 -
' f
's' '
4
- 4. f atscruti of Cable Tray Hanger Design Verification Me<,Mng b'eEween TV Electric, Cygna, Ebasco, Impell, JBA E !
3yi and ShEC held at the CPSES site, May 19, 1987. y / , e e f, V - "
- 5. \ Ebasco response EB-T-3029, attachment 1, dated 05/15/87: " Determination of Doripant Frequency at Point
< of Conduit Attachment to e Cable ' fray Hanger".
' ,1 , s
, 4
, {[ 6. Communicate .*)s Report au%ke(F. Hettinger, et al il " a (Ebasco) and 3. Tumminelli/ et al (Cygna) dcted June 26 1987 p 10:45 a.m.
.p
.V g s
- 7. Comniun-ications Report between S. Harrison (TU Electric);
G. Ashley, R. Kaczkowski (Impell); D. Williams (QESTk and J. Russ (Cygna) datec: July 10, 1987, 10:00 a.m..,
- 8. Communications Report between S. Harrison (TV Electfic); .)
P. Harrison, S. J. Chen et al (Ebasco); and, B. Atalya, D. Leoag et al (Cygna) dated July 23, 1987, 10:30 a.m.. Sumary: In several instances within Cygna's cable tray support review scope, conduits were attached to a cable tray support or directly to the cable tray (e.g., conduit support type CS D-16) .
;;- TV Electric
. ms;; Comanche Peak Steam Electric Station
[*$ [d i Id Independent Assessment Program - All Phases 11111111111111!!11ll111111llll Job No. 84056 PRJ :RIL i
07/31/87 Revision 14 Page 194 CABLE TRAY SUPPORTS Review Issues 1.ist 1 A. How were the loads from the attached conduit being considered in the cable tray support design verifications? B. How were the loads from a conduit attached to a cable tray considered in the cable tray design verifications? ; C. Attachment U of Reference 2 indicates thtt cable tray supports with conduits attached must be checked to determine the support fundamental frequency at the conduit attachment location. The frequency is calculated by performing a kinenatic condensation of the support model to the degree of freedom associatad with the conduit attachment loce. tion. Cygna is concerned about the accuracy of a frequency analysis based on the condensation of the entire mass and stiffness matrices I to a single degree of freedom. Response: A. The lumped weight of the attached conduits were calculated based on the tributary conduit span on either side of the cable tray support. Conduit clamps were assumed to transmit three directional loads to the cable tray supports. , For cable tray supports analyzed via the equivalent I static method, Ebasco considered attachment of conduits in accordance with Attachment U of Reference 2. T he loads from the conduit were calculated using the peak I acceleration from the appropriate amplified response spectra (2% damping OBE, 3% damping SSE) and a dynamic amplification factor of 1.5. For the system models analyzed by the response spectrum method, Impell, in Reference 3, included the conduit lumped weights as a part of the model. Seismic loads were develtped as part of the responso spectrum analysis, using 4% damping 0BE and 7% damping SSE
- amplified response spectra. This approach assumed that the conduit had the same damping as the cable trays p .
TU Electric Comanche Peak Steam Electric Station [*$N [ I[i Independent Assi.ssment Program - All Phases ll11111!!!!!!lll11111111111111 Job No. 84056 PRJ:RIL l l
i j 07/31/87 ! Revision 14 I Page 195 i CABLE TRAY SUPPORTS Review Issues List l rather than the lower damping values used by Ebasco and that the conduits were rigid (i.e. by modelling these as lumped weights the dynamic effects associated with the flexibility of the conduit spans was neglected). B. According to discussions with the TV Electric (Reference 7), the cable trays are being walked down and all attachments to the tray are being identified. The analysis of any attached conduit and the connection will be performed by the conduit group. The tray evaluation will be by the cognizant cable tray contractor. C. Ebasco, in Reference 5 prepared an evaluation of the condensation method used in determining support frequency at the conduit attachment location. i l As indicated in Reference 6, Cygna reviewed Ebasco's Reference 5 paper and disagrees with the application of the Guyan kinematic condensation technique to determine the frequency at a point. The reasons being: A Guyan reduction is not a filtering technique (i.e., it l does not allow an accurate reduction of the frequency at l a specified mass point. The accuracy of the procedure depends on the mass and stiffness distribution in the ; system to which the condensation is applied. The j technique is especially susceptible to inaccuracies if .j the mass distribution in the system is somewhat uniform l , or if, at the point of condensation, the mass is low or the point is not well supported. Ebasco responded by stating that the condensation was used as a screening technique to determine if the frequency was less than or larger than a value of 14.5 , Hz. l Cygna met with Ebasco to discuss the status of the review of kinematic condensation (Reference 8). Cygna presented an evaluation which showed that a Guyan-reduction, as used by Ebasco could overpredict the _ _. TV Electric Comanche Pean Steam Electric Station A l d iId Independent Assessment Program - All Phases lillllllllillllilllllllllillli Job No. 84056 PRJ:RIL
07/31/87 l Revision 14 l Page 196 CABLE TRAY SUPPORTS Review Issues List frequency of the conduit / cable tray support system. ) Ebasco agreed and stated that they would use the first i frequency of the combined system which had greater than l 10% of the system masc participating. Cygna stated that this was a reasonable value. Status: A. Open: Justification for the modelling of conduits as , lumped weights in the Impell system models is required. ( j B. Open: Cygna must be provided with the applicable j procedures for the walkdown, recording and analytical disposition of conduits attached to cable trays prior to review. C. Open: Cygna must review the procedures for Ebasco's present approach, as described above, for kinematic condensation. 4 i l 1 l I , 1 l l
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- 33. As-buil t Wal kdown Procedttr_e_ss
References:
- 1. TU Electric Procedures TNE-FVM-CS-001, " Field Verification Method Unit 1 Cable Tray Hanger As-Builting and Design Adequacy Verification Program", Rev. 5, July 1,1986, and TNE-FVM-CS-003," Field Verification Method Unit 2 Cable Tray Hanger As-Builting and Design Adequacy Verification Program", Revision 1, October 18, 1986..
Supplemental Procedure for Unit 2 Walkdown, TNE-FVM-CS-019, " Selected Cable Tray Attributes Data Collection Unit 2", Revision 1. September 3,1986 [
- 2. Transcripts of Cable Tray Hanger Design Verification Meeting between TV Electric, Cygna, Ebasco and Impe11 held at the CPSES site, January 26 and 27,1987 l
- 3. NCIG-01 " Visual Weld Acceptance Criteria", Revision 2
- 4. TUGC0 Instruction QI-QP-11.10-9, " Modification, Rework and "As-built- Inspection / Verification of Cable Tray Hangers in Unit I", Revision 6
- 5. Transcripts of cable Tray Hanger Design Verification meeting between TU Electric, Cygna, Ebasco, Impell, JBA l and SWEC held at the CPSES site, May 19, 1987
- 6. Impe11 report "Effect of Measurement Tolerances used for Collection of As-built Data " IM-P-009. Revision 0, May 15, 1987.
- 7. Joint Impe11/Ebasco Approach Towards Design Verification of Inaccessible Attributes IM-T-0210-040-238, dated May 15, 1987.
- 8. Impe11 calculation M-69, " Cable Tray As-built-Measurement Tc,lerances," Revision 0.
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- 9. Transcripts of Cable Tray Hanger Design Verification Meeting between TU Electric, Cygna. Ebasco, Impell and SWEC held at the CPSES site, April 21, 1987.
- 10. Communications Report between P. Harrison, et al (Ebasco), S. Harrison (TV Electric) and W. Horstman, et al (Cyg'na), dated, May 1,1987, 2 :30 p.m.
- 11. Communications Report between P. harrison, R. Keilbach (Ebasco); W. Horstman, B. Shakibnia (Cygna), dated June >
22, 1987, 2:00 p.m.. i Sumary: As a part of the cable tray hanger design verification i program as-built drawings are being developed for a.. cabl e tray supports. These as-built drawings will be based on engineering walkdowns performed in accordance with Reference
- 1. Based on a review of the procedure, Cygna raised several questions during the meeting documented in Reference 2.
l A. As-built Tolerances for Dimensional Measurer.ents Table 5 of Reference 1 provides a number of measurement tolerances for member lengths, anchor bolt spacing, etc. i
- 1. What is the basis of the given tolerances?
- 2. How are these tolerances considered in the support eval uations?
( B. Cable Tray Support Walkdown Procedures / Instructions With respect to the walkdown/ inspection procedures and l the product on of as-built drawings, Cygna has' the i following coi cerns:
- 1. What is the basis for the acceptance of VWAC as the weld inspection criteria? How have these criteria been reconciled with the analysis assumptions?
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- 2. Where are the dimensions for the locations of the )
ends of brace members taken to? Are the dimensions 'l used in calculating whether or not to consider the i working point offset from the beam / hanger intersection taken directly in the walkdown? (See Issue No.12. ) {
- 3. In Section 3.2.2B.2.a.2.b of Reference 1, what is the basis for assuming that the effective throat of {
full and partial penetration welds is one half of l the beveled members thickness? How will this ) effective throat be used in the design' verification j of the support? l i
- 4. Expansion anchor types and embedment lengths are to d be as-buil t. How are Hilti Super Kwik-bolts being identified if the " star" stump is not present or obscured by paint? How is the embedment depth 4 determined if the length mark is obscured by paint? l
- 5. Section 3.2.2.B.7 of Reference 1 requires that the attachments of other items to the cable tray s.ipport must be recorded. Does the walkdown show the method
, of attachment (e.g., wel ds, bol ts, etc. ) of other ! items to the cable tray support? Is the extent on any Thermo-lag on the attachment recorded? If the attachment is a conduit, is the extent and configuration of Thermo-lag on the conduit span recorded? i l C. Cable Tray Span Walkdowns ! In Section 3.9 of Reference 1, the procedure for the walkdown of cable tray spans is provided.
- 1. The use of tray covers to allow the reduction in minimum spacing requirements at the discretion of craft, implies that their existence and location is r_ =E TV Electric M=NF Comanche Peak Steam Electric Station L*$ [d 2 Id Independent Assessment Program - All Phases 111!!llll1111ll111111111111lll J0b No. 84056 'PRJ :RIL
1 l I 07/31/87 I Revision 14 j Page 200 1 j CABLE TRAY SUPPORTS Review Issues List > I 1 not fully documented. Section 3.9 dces not address I identifying and locating tray covers. What is the 1 basis for not considering tray covers, in the I development of the cable tray span sketches? How
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I will any noted tray spacing violations be reconciled ! with other discipline requirements, e.g., i el ectrical, damage study, etc.? 'l
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- 2. Modified tray connection plates have been i i denti fi ed. Will such connections be located? If' I not, why? I
- 3. Will tray siderail extensions be located? If not,
]
why? q j
- 4. Will the locations and types of other components, e.g., conduits, light fixtures, etc., attached to l the cable trays be identified and recorded? If not, I why? 1 Response: A. Cygna understands that Reference 6 is the governing i document for the acceptability of the measurement -
tolerances to be used during as-built walkdowns. The j acceptability of these tolerances is based on a comparison l of the walkdown tolerances for CPSES work to other 1 l industrial facilities as well as PVRC recommendations. . Cygna has reviewed References 6 and 8 and has concerns on ; the conclusions relating to acceptability for all tol erances. B. 1. In Reference 2, TU Electric indicated that they have received NRC approval for the use of VWAC at CPSES. i According to VWAC, if a weld satisfies the inspection requirements (e.g., weld length, size, undercut limits, etc.) there is no need to consider any. impact . on the weld or member design. l
- 2. In Reference 2, Ebasco provided a s&mple of several support as-built drawings showing the measurement ,
A - TV Electric
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Page 201 i CABLE TRAY SUPPORTS l Review Issues List ] locations. The wal kdown dimensions are used to calculate the working-point offset for the modelling. j
- 3. In Reference 2' Ebasco indicated that it is not -
possible to visually determine the weld penetration depth. - Therefore, one half of the member thickness is used for conservatism. This value is used in 1 calculating the weld stresses. Discussions with i Ebasco on the weld thickness are recorded in l Reference 11. I
- 4. In Reference 2 Ebasco indicated' that Ultra-sonic Testing (UT) will be used to identify.the expansion anchor type if no " star" is visible. Embedment can also be checked by LTT. If UT cannot be performed or is nonconclusive, the anchor bolt is treated as an inaccessible attribute which is discussed in 1 Reference 7.
I
- 5. The type of attachment including its connection .is identified. Procedurally, the extent of Thermo-Lag is not required. Conduits are noted as well as their 1 span lengths. (Reference 2.) Additional procedures are to describe load trans'er; requirements between di sci plines.
C. Cable Tray Span Walkdowns
- 1. Per discussions between Impe11,.Ebasco and Cygna, the location and extent of tray covers will be identified -
in cable tray span wal kdowns. This'is a part of post raceway QC inspection and separation inspection as per QI-QP-11.40 .and QI-QP-11.3-29. Tray spacing ; violations are also noted and reconciled'as per .the ; above procedures. (Reference 9).
- 2. Modified splice connections are identified. See Issue No. 25.C.
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- 3. The location and extent of siderail' extensions will be recorded along with the location of tray covers.
(Reference 9).
- 4. The location of other components attached to cable trays will be performed under Memo-?CP/C-1530. This i memo will revise the walkdown procedure ECE-FVM-CS-001 (Reference 9).
Status: A. 1. Open: Ebasco to provide a response to Cygna's ., l concerns on measurement tolerances (Reference 10). . l
- 2. Further discussion with Impe11 is required.
B. 1. Open: Cygna to review the NRC acceptance of VWAC and the applicability of the criteria to cable tray l supports at CPSES. 1 i
- 2. Cl osed.
! 3. Open: See status for Issue No.16.I.
- 4. Open: Pending review of the inaccessible attributes study. S ee I ssue No.- '16.A.
- 5. Open: Review of the load transfer procedures is requi red, i C. Open: Review of procedures is required.
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- 34. System Analysis Methodologies
References:
- 1. Communications Report between S. Harrison, J. Muffet (TV Electric); P. Harrison (Ebasco), R. Wheaton, B.
Ramsey (Impell); and N. Williams et al (Cygna) dated March 3,1987,11:30 a.m..
- 2. . Communications Report betneen 3. Harrison (TV Electric); G. Ashley, J. Ramuta (Impell); D. L eong et ,
al (Cygna) dated May 14,1987,10 :45 a.m. . l
- 3. Communications Report between G. Ashley, C.
Aboujaoude (Impell); B. Shakibnia et al (Cygna) dated May 15,1987,11:00 a.m..
- 4. Impell Calculation M-13, Revision 1, May 30,1986, y
" Development of Seismic Overlap Procedures". I
- 5. Impell White Paper IM-P-001, Revision 0, May 15, ;
1987, " Impact of SUPERPIPE Error SP-004 on Evaluation j 176-063-02". i i Summary: In the process of reviewinc the Impell systems analyses, two concerns were raised regarding the methods used to l simplify the cable tray sytems models. Both concerns were presented in Reference 1. The first issue involves corrective action for a SUPERPIPE error. The second involves overlap criteria used to break large cable tray systems into smaller analysis problems. See the response i section-for discussion of these concerns. i- Response: A. SUPERPIPE Error SP-004 SUPERPIPE Error Sp-004 involves the incorrect assignment of directional masses for static load cases. For the gravity load case, the x-direction mass is used instead of-the Y-direction (vertical) mass. The only' points affected by this error are those lumped weights used to model omitted trays. TV Electric Comanche Peak Steam Electric' Station , rL *fs 8- ) iiI[ Independent Assessment Program - All Phases ' 111lllll11111111111lll11111111 Job No. 84056 PRJ :RIL '
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07/31/87 , Revision 14 1 Page 204 l CABLE TRAY SUPPORTS I Review Issues List A correction for the error is specified in Impe11 Project Instruction PI-02. Upward and downward forces are j specified to correct for the misapplied loads. . However,. 1 PI-02 fails to specify'which versions of SUPERPIPE this correction is to be applied to. In Cygna's review of system analysis 176-063-02(Reference j 1), partial application of'the PI-02 correction was made; however, the error had been corrected in the SUPERPIPE i version being used for.the analysis. Cygna is. concerned .f that, because PI-02 does not limit the use of the { correction to affected SUPERPIPE ver'sions, the gravity. ] analyses for some problems may not be correct. j ( In Reference 5 Impe11 states that the added gravity load.
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in analysis 176-063-02 is conservative. Cygna agrees that i this would be the case if gravity plus downward seismic ' were the controlling load combination. However, if upward - seismic load controls the design, the added gravity load would tend to decrease its impact. Reference 5 is written to address the specific case of analysis 176-063-02 but does not address possible errors in other analyses. B. Overlap Criteria In the review of systems analyses 176-063-02 and 176-063- l 01 (Reference 1), Cygna noted that there was a gang support shared by the two systems. The support loads ~ for ' the same support from the two analyses differed by a factor of 2. To verify that the support loads calculated for the two analyses were appropriate, Cygna reviewed the overlap criteria development calculation M-13 (Reference 4). Several concerns were discussed in Reference 2. I Several simple systems model s' were used in M-13. T he - results of partial models with overlap regions were compared to the .results of full models. Response spectrum analysis methods were used for all- analyses; however, the TV Electric _ Comanche Peak Steam Electric Station M4i 2 Id Independent Assessment Program - All Phases lillllllllllllillllllillllllli Job No. 84056 PRJ :RIL L______________________
07/31/87 Revision 14 Page 205 CABLE TRAY SUPPORTS r Review Issues List , 1 I partial models used the Reg Guide 1.92 modal combination technique, while the full models used the Completc Quadratic Combination (CQC) technique. Cygna is concerned with Impell's use of the CQC " I methodology, as the'CPSES FSAR specifies that Reg Guide 1.92 methods be used. While Impell-stated that the CQC 3 method gave a more accurate prediction of the actual j response of the system, Cygna stressed that their concern was more in regards'to the CPSES licensing commitments than to the technical aspects of CQC. Impell agreed to provide additional- justification for using CQC. The study used tray clamp. loads and anchor reactions as the basis for comparison of responses of the systems. Cygna asked why these were used instead of other response i quantities such as member stresses or bending moments in -] the trays. Impell stated that they chose tray clamp loads ! and anchor reactions because they represented the input ) and output quantitites to the tray supports. Cygna feels -{ that those quantities are adequate for the study. j In the review of M-13 (Reference 4), Cygna could not locate the development of the 1.10 factor used to increase support loads in the overlap region. . Impell stated in References 2 and 3 that the 1.10 factor was not developed 1 in M-13 but was' recommended in a NUREG which contained results of a Brookhaven. National Laboratory study on l oterlap criteria in piping. The Brookhaven study l ' indicated that the 1.10 factor was only necessary in the l overlap regions. Although the results of Impell's studies were not always consistent with the Brookhaven results, they decided to adopt the Brookhaven recommendations. Impell pointed out that the results of the study presented in the histogram in M-13 show that there is a high ! confidence that the support loads are'not underpredicted i by the overlap process. Cygna stated that the overlap study and the subject-histrogram was based on results of all supports in the system, and not just those in the TV Electric
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p 07/31/87 i Revision 14 Page 206 CABLE TRAY SUPPORTS Review Issues List overlap regions. Therefore, there are a significant ! portion of supports inside and outside the overlap region j which will see lower loads with the overlap model than the full model (12% according to the histogram). Cygna also . noted that there were a significant number of cases where the support loads were overestimated with the overlap model. Impell agreed to address both the overprediction and underprediction of loads in the models. Cygna noted that, .in the overlap study, each support load component.was evaluated separately. That is, .for a two-way support, if either partial model gave higher results for each load direction, the overlap criteria was adequate. However, in Model 6 of M-13, it was shown that neither partial model alone (considering both loading. directions) was adequate to envelop the results of the i full model . In Reference 3 Impell stated that thev feel ! that it is adequate to use the results of the partial models to evaluate the supports and that the ae is no need to envelop the results of the two analyses. , 1 In Reference 3, Cygna presented concerns regarding the j applicability of the overlap study to all applications in -l the pl ant. For exampl e, system analysis 176-063-02 contained three supports in a row with three common trays. Only one tray was modeled in the analysis. T he other trays were represented by lumped masses. The i overlap study only considers one gang support. Impell agreed to addres's this concern; however, they stated that j the tray flexibility would not provide significant coupling effects. Similarly, Cygna noted a lack of restriction in applying the overlap criteria to areas where the next longitudinal support may be distant from the break point. The present > overlap analysis considers 24 feet of tray as a-tributary-load on the longitudinal support closet to the break point, which corresponds to a longitudinal span of about ! 50 feet. Impell feels that this span is adequate. Cygna
; TV Electric '
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1 07/31/87 Revision 14 1 Page 207 CABLE TRAY SUPPORTS Review Issues List noted that there are instances where longitudinal supports are up to 90 feet apart. Therefore, in some instances, l the overlap analysis may underpredict-longitudinal loads on supports near the breakpoint. Impell agreed to respond to this concern. 1 Status: A. SUPERPIPE Error SP-004
~l Impell is to address the generic impact of the !
implementation. of the PI-02 correction in SUPERPIPE { versions in which Error SP-004 was corrected. Impell is to address the impact of overprediction of gravity laods with rspect to upward seismic loads. 3 B. Overlap Criteria ! Impell is to justify the use of CQC in the overlap study. Impell is to respond to Cygna's cancerns regarding i overprediction and underprediction of support loads with the partici models. They are to address the underprediction of loads outside of the overlap region, where the 1.10 factor is not applied. Impell is to address the applicability of the overlap study models to ) other configurations in the plant. Impell also should ! provide justification for evaluating overlap supports with the results of each partial model separately.
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